Abstract

---

This research investigates the design principle for metal organic frameworks (MOF) deposited composite membranes for nanofiltration using functionalized/modified UiO-66 (UiO stands for University of Oslo) nanoparticles for the purpose of exploring the importance of functional groups around the nanopores. The nanoparticles were synthesized using water as modulator and characterized by XRD, FTIR, TEM, BET and TGA. The XRD major (sharp) peaks indicated the crystallin ity of the nanoparticles whilst the minor peaks at 2θ = 6° originated from reo-nanoregions. The intensity of the reo peak was correlated with the concentration of missing clusters/linkers, cluster defects in the samples and become prominent as small amount of modulator was added. The particle sizes were found to be in the range of 150‐60 nm, 160-60 nm for UiO 66-NH2, UiO-66-CH3 frameworks respectively. The dependence of the particle size on the amount of water demonstrated its role to accelerate the formation of crystal nuclei. The BET surface area and pore volume were found to be in the range of 800-1000 m2/g and 0.37-0.44 m3/g without clear tendency on the framework type. The pore size distribution was sharp ly concentrated in the range of 0.7-0.8 nm whilst the weight loss due to ligand decomposition was found to have changed by the water addition irrespective of the ligand functionalization. The functionalized UiO-66 formed polycrystalline, de fective nanoparticles and gave high flux compared to non-functionalized type and was found to be superior for leakage tolerance irrespective of the frameworks. However, the tendency to leakage was found to be greater for smaller particle size. Its polycrystalline nature played an important role whilst the modification affects the chemoselectivity and permea tion. The pore engineering geared towards changing the chemical environment played significant effects and unlock infor mation for proper understanding of the role of chemical environment in UiO-66-CH3 and UiO-66-NH2 nanocomposite membranes.

Abstract

---

Nigeria is the largest producer of cassava in the world and the peel accounts for between 5 -15% of the tuber. Cassava peel is often left unattended in the country, making it a source of methane gas which is one of the culprits of global warming. Agricultural residues are good sources of renewable energy. This study investigated the potential of electricity and heat generation from cassava peels. The dried peel was ground and used for proximate analysis according to ASTM D 5142-04 procedure, from where moisture, ash, Volatile Matter (VM) and the Fixed Carbon (FC) contents were determined. The Higher Heating Value (HHV) of cassava was calculated using the FC. Performance of four plants tagged A, B, C and D were simulated using thermodynamics equations. Plant A was simulated as a boiler-steam turbine combination, Plant B, gasifier-boiler steam turbine, Plant C, gasifier-gas turbine and Plant D, gasifier-internal combustion engine combination. Parameters investigated were power output, heat output, annual electrical energy generation per peel mass. Results gave the moisture, ash, VM and FC contents as 6.53, 3.78, 89.57 and 6.65 % respectively while the HHV was determined to be 15.422 MJ/kg. Estimated power output was 2.51 x 105, 1.78 x 105, 1.39 x 106 and 1.26b x 106 kW for Plants A, B, C and D respectively. In a like manner, the heat output is1.02 x 107, 7.24 x 106, 8.84 x 106 and 1.06 x 107 MJ/h. Annual electrical energy output was determined to be 9.03 x 108, 6.42 x 108, 5.00 x 109 and 4.52 x 109 kWh and the electrical energy gener ation per cassava peel consumption was 0.202, 0.144, 1.121 and 1.009 kWh/kg for Plants A, B, C and D respectively. Cas sava peel possesses good potential for heat and electrical energy co-generation in Nigeria.

Abstract

---

In this study, a Potentiostat was developed for teaching and research purposes because Potentiostats are expensive equip ment and are of high importance in corrosion monitoring due to its various applications. The fabrication of this potenti ostat entailed the use of electronic devices and components, including operational amplifiers in the control circuit. A mi crocontroller was used to send data from the circuit to the computer system, and the results obtained were visualized in real-time on a software application, made with Python programming language and Tkinter (a library for desktop applica tion development) installed on the computer system. The software application uses linear regression (an algorithm in ma chine learning) to calculate the slope of the anodic and cathodic curve, which are used to obtain the corrosion rate. This study proffers solution to some of the shortcomings of locally-made potentiostats, which are unable to plot corrosion data in real-time and determine anodic and cathodic slopes needed to obtain the corrosion rate, while still being affordable for teaching and research purposes.

Abstract

---

This study presents the formulation and development of silicon nano-composite based conductive ink for possible screen printing of selected electronic devices. An XRD technique was employed to characterize and the result analysis showed that the particles were nano- sized Silicon nano-composite based conductive inks were formulated and developed from milled silicon nano-particle which served as the dispersed phase or filler materials and dispersed in styrene acrylic and distilled water. A modified screen-printing method was adopted for the deposition of formulated inks on ceramic substrates. Current-voltage characteristics of the printed electronic devices were obtained and employed to determine the nature of interface, behavioural responses upon voltage application, resistivity, effect mass of charge carrier, and barrier height of the con ductive inks. The study revealed that the mass fraction of silicon nano-particle and styrene acrylic in ink formulation E meets the needs of additive manufacturing technology of selected electronic devices.

Abstract

---

Increasing environmental pressures are forcing tanneries to reduce the level of nitrogenous compounds in generated effluents, due to strict regulations on effluent quality from various unit processes which bating plays a vital role. Bating imparts smoothness and stretchy effect to the resultant leather with the addition of proteolytic enzymes which are expensive, hence the need for alternative sources. This research investigated the bating potential of dried Musa acuminata peel in the production of leather. The functional groups present in both conventional bate and dried sieved M acuminata peels were analyzed using Fourier Transform Infrared instrument. Bating trials were varied based on the weight of the three goat skins with reference to the percentages offered as: 1%, 2 % and 3 % of M. acuminata at 310 K for 30, 45, 50, 60 and 120 min respectively. Absorptive frequencies of the powdered bate, M. acuminata and raw pelt (treated raw skins) shows that there were –C=O functional groups in M. acuminata and raw pelt but absent in the conventional bate before applications on the pelts. Absorptive frequencies for conventional bate and M. acuminata on Pelts after application on the pelts shows that carbonyl group were absent in Conventional bate; 2 % M. acuminata and 3 % M. acuminata on the pelt which shows that carboxylic acid ionizes to effect bating of the collagen but was not observed in sample 2 % M. acuminata (1543.1 cm-1 ). Temperature of 310 K at which bating was carried out with respect to the time taken (35, 80, 60 and 50 was used for comparison between Sample of 3 % M. acuminata (50 min of mechanical agitation, at 310 K activity environment) when compared with the conventional bate of 1 % offered (35 min of mechanical agitation, at 310 K activity environment) accounts for 15 min difference for the M. acuminata peel to achieve the needed porosity via the ionization of the carboxylic group before and after bating. Shrinkage temperature for samples of Conventional bate (1 %) M. acuminata (1 %) M. acuminata (2 %) and M. acuminata (3 %) range from 369 – 371 K with respect to chrome tanning. Ball burst analysis for samples. M. acuminata (1 %), M. acuminata (2 %) and M. acuminata (3 %) indicated that the force at load crack (N) for the control sample was higher than those of samples M. acuminata (2 %) and M. acuminata (3 %). The retention at burst in maximum value for all the other samples was higher than that of the control while in displacement the control sample (Conventional bate) gave the highest value on Load at crack.

Abstract

---

From its humble beginnings as Alessandro Volta’s “voltaic pile”, electrochemical power (EP) has been power ing paradigm shifts in technology for the past 150 years. From the life-support systems in manned space explo ration of the 1960s, to the electric vehicles of the last 20 years, EP has been the unsung hero. EP is enjoying renewed focus and a flurry of R&D activities in today’s resource-constrained and environment-conscious world that is urgently looking for a “silver-bullet” for its global warming and pollution problems. This paper discusses the impetus for the renewed interest in EP, with emphasis on its storied high operating efficiencies and green credentials, compared with traditional power production systems. It highlights the impact of cumula tive years of EP R&D, the basic electrochemistry of mature EP systems, the global energy conundrum and the steady permeation of EP into the global energy mix. Recent re-imagination trends of EP into applications hith erto the preserve of traditional power technologies and novel applications outside of its native scope of porta ble and reserve power were also discussed. In view of the inevitable global shift towards EP as a veritable fu ture energy source, the urgent need for a strategic local R&D focus on EP in Nigeria was emphasised. In view of this, the research efforts and direction of our team at the Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife are presented and put in context.

Abstract

---

Air pollution has been a vital subject attracting experts' attention towards the search for ways in which the pollution can better be controlled and minimized to avert the ongoing global warming and climatic changes experienced globally due to the release of poisonous gas regularly release to our environment. The bulk of the discharged gases are traced to the use of fossil fuel and the burning of biomass, which pollutes our environment by the emission of carbon monoxide (CO) to the atmosphere, which has been said to be a dangerous air pollutant with adverse effects on man and its environment. As a way for devising a solution for the better management of air pollution, this study computationally screened and evaluated the CO adsorption potential of different selected metallic oxides, MgO, SiO2, Al2O3, and Y2O3 which could be used as an active agent for CO capture and sensation as an adsorbent with the aid of a molecular modeling application called Spartan. The Lewis acidity of the cluster’s adsorption sites was equally evaluated using ammonia as a basic molecular probe. Find ings from the study reveal that the site acidity has a direct relation to adsorption strength. The study indicates that the met al site of the various clusters was generally more acidic compared to oxygen sites. Moreover, the MgO was of higher acid ity, lesser stability, and better adsorption potential for CO than the other metal oxides. Thus, MgO would be more promis ing for CO adsorption based on the findings from this study.

Abstract

---

This study determined the clay content, chemical composition, grain fineness number, distribution and shape of some selected silica sand deposits in south west Nigeria. This is with a view to document the silica sand deposits in Nigeria for sand moulding in the foundry industry. The silica sand deposits were collected from four river bed de posits in Igbokoda (Ondo State), Ote (Ogun State), Opa (Osun State), and Osooro (Oyo State), respectively. The clay content off sand samples from these deposits were determined using washing off method; grain fineness num ber and distribution were evaluated using sieve analysis; grain shapes were observed using magnifying lens; chemi cal compositions were characterized by x-ray fluorescence; and the phases were characterized by x-ray diffractome ter. The results showed that the clay content for samples taken from Igbokoda, Ote, Opa, Osooro are 2.18%, 2.40%, 3.44%, 6.96% respectively. The average grain fineness number of 48.23, 53.74, 61.82, and 68.48 were obtained for samples taken from Igbokoda, Ote, Opa and Osooro respectively. All the silica sands from the study area have a mixture of angular and sub-angular grain shapes. X-ray diffraction and fluorescence result showed quartz as the most prominent mineral in the selected sand deposits with silica contents of 83.14%, 80.56%, 86.46% and 82.71% for Igbokoda, Ote, Opa, and Osooro respectively. From the outcome of this study, it was concluded that all the sili ca sand deposit in the study area are grade D.

Abstract

---

This study reports abrasion, biocompatibility and degradation behavior of Polypropylene (PP)/Sugarcane Ba gasse Ash Particulate (SBAP) composites for possible application as dental implant materials. PP composites were prepared with varying weight per cent of SBAP ranging from 10 – 50 wt% at regular interval of 10. Hard ness test and wear analysis were conducted. Degradation test was performed using different media, namely artifi cial human saliva (AHS), artificial human saliva with sodium floride (ASSF) and Hank’s balanced salt solution (HBSS). Biocompatibility test was conducted using different sex of rats by varying dose injected into their mouth. Results reveal an increase in hardness values and wear resistance with the filler loading. Additionally, the degradation rate of the composites decreases averagely with the filler addition. It was deduced from the results that the composites are biocompatible and non-toxic. Therefore, PP/SBAP composites would be compatible to human body. Hence, the composites could be recommended to be used as dental restorative materials.

Abstract

---

This study examined the effects of inner-gate (ingate) types on some mechanical properties of cast aluminium 6063 (Al-Mg-Si) alloy. In this work, rods of aluminium 6063 alloy were cast using top gating, bottom gating and parting line gating designs. Ingot of 6063 aluminium alloy was melted using crucible furnace and poured into already pre pared sand moulds. The casting from each gating system design was machined and tested for tensile, hardness and impact energy. The results from the tensile test revealed strength of 133.29, 122. 46 and 101.26 MPa for bottom gating, parting line gating and top gating respectively. Also, the results from the hardness test gave 61.25, 43.25 and 36.25 BHN for bottom gating, parting line gating and top gating respectively while impact test revealed that castings from top gating, parting line gating and bottom gating systems gave impact energy of 38.800, 36.108 and 34.476 Joules respectively. The study showed that the bottom gating system design produces casting of high tensile and hardness strength but least impact strength, followed by castings from parting line gating system while castings from top gating system produced castings of low tensile and hardness strength but high impact energy. Therefore, bottom gating design is recommended for use in applications that require high values of tensile strength and hardness while top gating design is recommended for use in applications that require high impact energy

Abstract

---

Aluminium Matrix Composites (AMC) are combinations of aluminium alloy and other components usually non metal and commonly ceramic such as silicon carbide (SiC) and aluminium oxides (Al2O3) in order to improve the engineering properties of the aluminium alloy. This research work examined the mechanical and microstructural properties of Al-SiC auto brake disc rotor composite. Aluminium ingots were first heated in the furnace at a tem perature of 720oC to molten state and SiC particles having average size of 25 µm preheated to 840oC for about two hours were added as reinforcement (5%, 10%, 15%, and 20% of SiC). The mixture was then stirred for 10 minutes at 850 rpm to ensure homogenous distribution of Composite Metal Particles (CMP) prior to pouring into the preheated metallic mould at 940oC. A control sample without SiC additions was also produced. The produced samples were shaped into standard samples for the purpose of hardness, impact, tensile, compression properties determination and wear. The morphology examination and elemental composition analysis of phases present in the produced composite samples were carried out using scanning electron microscope, with the attached energy dispersive X-ray spectroscopy. Auto brake disc rotor was produced with standard dimension. The mechanical properties showed improvement in terms of hardness, impact toughness, compressive stress, decrease in yield stress and wear rate, it was observed that there is an increase in the Charpy impact strength of the reinforced AMC when compared with unreinforced Al. The highest impact strength was recorded at 15 wt. % reinforcement. This obviously translate that, with the presence of SiC the impact strength of the composite was improved. The Scan ning Electron Microscope (SEM) results revealed the phases present in the composite while the Energy Dispersive X-ray indicated the elemental composition of the composite.

Abstract

---

The study identified and acquired relevant data for pipeline monitoring model, formulated a mathematical model, simulat ed the model and evaluated it. This is with a view to developing an intelligent information gathering for pipeline monitor ing and security. Data was acquired by taking different aerial images of vandalisation tools and probable vandals using Unmanned Aerial Vehicle (UAV). Surfer 10 application was used to digitize the Nigerian pipeline grid and distribution network to obtain the pipeline coordinates. The itinerary of the UAV for monitoring pipeline was formulated while Sobel edge detection algorithm was engaged with template matching algorithm for vandal detection. Stored image templates of digging equipment around the vicinity of the pipeline were used in a template matching model to detect the presence or absence of digging activities. The different template matching algorithms method such as sum of absolute difference (SAD), sum of squared differences (SDD) and maximum absolute differences (MAD) were used on random images, where best fit results which produced optimal correlation and peak signal to noise ratio (PSNR) values were adopted for object detection and classification. The designed model was simulated using Simulink in MATLAB and evaluation was done by comparing the efficiency of the model. The simulation results showed SSD technique as having the best accuracy with an average value of 5.7065 x E+04 while SAD and MAD techniques have average values of 4.1835 x E+04 and 1.635 x E+04, respectively

Abstract

---

In this study, a new bis-arylidene derived benzoxazine: 2,6-bis((3-(2-hydroxyethyl)-3,4-dihydro-2H-benzo[e] [1,3]oxazin-6-yl)methylene)cyclohexanone (HEB) was synthesized from its precursor: 2,6-bis(4 hydroxybenzylidene)cyclohexanone (BCH). The BCH was obtained as an aldocondensation product of cyclo hexanone and 4-hydroxybenzaldehyde, in an acid catalysed organic medium. Both HEB and BCH were charac terised using Fourier Transform Infrared (FTIR), and Nuclear Magnetic Resonance (NMR) spectroscopic tech niques to ascertain the structural features of the targeted products. Different weight ratios of HEB (0,10, 20, 30, and 40%) were added into an epoxy resin to form the modified epoxy materials; ME-0%, ME-10%, ME-20%, ME-30%, and ME-40%, respectively. The thermal behaviour of the modified epoxy resins was investigated us ing thermal gravimetric analysis (TGA). The result obtained showed enhanced thermal properties of the modi fied epoxy materials over the native epoxy resin. The outcome further showed better performance with higher content of the modifier

Abstract

---

Bismuth and cobalt co-doped perovskite-type nanomaterials with the composition Nd0.5Bi0.2(Co0.3Mn0.1)FeO3-δ were syn thesized by using the citric acid sol-gel route and annealed at annealing temperatures (TA) of 400, 750 and 900°C to pro duce powders labelled NdCo400, NdCo750 and NdCo900 respectively. The powders obtained were characterized using Powder X-ray diffraction (PXRD) analysis, transmission electron microscopy (TEM), Fourier transform infrared spectros copy (FTIR), Braunuer-Emmet-Teller (BET) Method, vibrating sample magnetometer, (VSM) and photoluminescence spectroscopy (PL). The powder X-ray diffraction (PXRD) analysis of the powders showed that they contain highly crystal line orthorhombic perovskite-type nanoparticles whose crystallinity increased with higher annealing temperature. The lat tice parameters, after refinement for NdCo900, showed that the parameters a, b and c have values 5.939, 5.488 and 7.740 Å respectively. The TEM results showed cubic crystallites with average crystalline size within the range of 17-30 nm for both NdCo750 and NdCo900 respectively. The BET specific surface areas obtained was 12.46 and 5.92 m2 g-1 for NdCo750 and NdCo900. Room temperature VSM analysis showed TA dependent properties for the powders NdCo400 (11.09 emu g-1, 402 Oe), NdCo750 (9.00 emu g-1, 2181 Oe) and NdCo900 (9.44 emu g-1, 683.16 Oe) for saturation mag netization MS and coercive field HC values respectively. Photoluminescence spectroscopy showed that the powders were all active in the visible region and could be useful for visible light photodegradation of organic dyes. NdCo900 was the most effective for the decolourization of RhB dye with kobs = 1.6 × 10-2 min‑1 and percent efficiency E % = 99.1 %. A 73 % mineralization of the dye was also achieved after 3 h

Abstract

---

High demand for motorcycle and its spare parts in the country necessitate production of some of its parts locally to conserve foreign exchange and create jobs. Brake shoes are one of the frequently replaceable parts in the motorcycle, and hence, need for domestication to reduce pressure on importation. In this paper, aluminum scraps were obtained from two local aluminum companies and were characterized via chemical analysis with positive material identifica tion machine, tensile test with Instron 300DX, hardness test with Wolpert Wilson instrument MLIE/TL/003, and fatigue test with Mitsubishi A200. The results were compared with the composition and properties of aluminum 360, 380, 383, and B390 standards selected from previous research to be suitable for motorcycle brake shoe production. Appropriate master alloy was selected based on the chemical composition of the target metal obtained from litera ture, chemical composition of the scraps and oxidation of elements during the process of melting. Appropriate quan tities of charge required was calculated analytically. The results obtained shows that the scraps conformed to the 6xxx series of aluminum alloy with hardness of 44-69% less, yield strength of 57-75% less, ultimate tensile strength of 78-80% less, percentage elongation of 57-79% less, and fatigue strength of 6-43% higher when compared with aluminum 360, 380, 383, and B390 standards. It was observed that the local scraps were not suitable to produce motorcycle brake shoe. Therefore, some quantities of Al - Si 50 and Al – Cu 33 should be incorporated into the scrap to meet up with aluminum 360, 380, 383 and B390 standard.

Abstract

---

Bamboo fibres of 1 to 3 mm sizes were milled to particle size of approximately 100μm using a hammer mill. The bamboo sawdust (BS) was chemical treated using NaOH of concentration 6 % wt/v for 72 h at room temperature. Dried bamboo sawdust was mixed with polyester at different weight ranging from 0 % to 24 % wt. %. The com posites were tested for the tensile properties. Theoretical mechanical equations were used to predict the proper ties. Polyester curve showed linear deformation behaviour with the stress rising to a maximum value with signs of yielding before fracture. The tensile strength of polyester was 49.38 MPa, increasing to a maximum of 76.47 MPa at 24 % wt. of BS. At zero wt. % of BS the modulus was 1381 MPa, and increased to 2587.08 MPa at 24 % wt. The strain decreased from 5.5 % at pure polyester to 3.32 % at 24 % wt. of BS. A maximum percentage decrease of ≈ 40 % for the strain was recorded, an indication of the brittleness of the composites. Prediction of mechanical properties using published theories of mechanical equations (tensile strength and Young’ modulus) with experi mental results of bamboo sawdust reinforced polyester composites was investigated. The models used were rule of mixture (Parallel and Series), Hirsch’s and Halpin-Tsai models. Irrespective of the equation used tensile strength increased with increase in the volume fraction of BS. The best correlation between theoretical and exper imental tensile strength was predicted using the Halpin-Tsai model, followed by Hirsch, Parallel and Series re spectively. Depending on the volume or weight fraction the percentage prediction was between 79 and 88 % for Parallel and Series models and between 97 and 99 % for Halpin-Tsai and Hirsch models

Abstract

---

In this investigation, hybrid laser-arc welding was performed on 6-mm thick ultrahigh-strength quenched and tempered steel plates. Laser-arc welds were characterized for hardness and metallurgical properties in three defined cooling cycles. Destructive tests of the joints revealed that the joints were characterized by tensile strength similar to that of the base material. Microstructural characterization was made by optical microscopy, scanning electron microscopy and X-ray diffraction. It was revealed that the weld beads consist of lath martensitic structure with small percentage of retained austenite. Quantitative analysis of mixed mi crostructures of the heat affected zone (HAZ) revealed 0%, 38% and 62% of the upper bainite for the cooling cycles- cycles A, B and C respectively. In addition, the hardness profile of the cross-section of the weld was characterized by Vicker’s microhard ness test. The hardness fluctuation values within the HAZ for the cycles A, B and C are 450-510, 370-425 and 320-375 HV respectively, thus increasing as the upper bainite percentage increases with each cycle.

Abstract

---

Tin oxide nanoparticles has been synthesized via green route using SnCl .2H O and Euphorbia trigona (African 2 2 cactus) plant extract as precursors. In this green route process parameters such as, solution pH, precursor concentration and synthesis temperature were optimized to produce nanoparticles with smaller size. The degree of sensitivity of the process parameters vis-a-viz towards optimization were carried out by applying the Box-Behnken Design from Response Surface Methodology (RSM). The Box-Behnken Design was designated as a statistical prediction technique with the goal of decreasing the number of possible experimental outcomes, which would invariably reduced time and quantity of reagents, by this means plummeting the general cost of the production process. The particle size of the nanoparticles was chosen as the response factor for the green synthesis. The optimal predicted conditions obtained tetragonal cassiterite phase of SnO were at a solution pH of 10, precursor concentration of 0.40 M and synthesis 2 ο temperature of 57.5 C. From the optimized experimental conditions, the particle size was found to be 6.71 nm which , was also found to be in accordance with predicted value of 6.73 nm from the developed model. These results were 2 substantiated by the comparatively high correlation coefficients of SnO NPs (R = 99.96, R = 99.87, R =99.28) 2 2 adj obtained from the statistical prediction after the Analysis of Variance (ANOVA).

Abstract

---

Copper doped tin oxide thin film was synthesised by electrodeposition technique. Film growth was maintained at cathodic potential of 1.60 V at a varied deposition time. Surface morphological studies of the deposited films were achieved by field emission scanning electron microscopy (FE-SEM). The scanning electron microscopy image revealed evenly distributed films, across the substrate with rice-like or dome-like particles, depending on the deposition time. Post-annealing enhanced films crystallinity and particles agglomeration. Energy disperse X-ray spectra revealed the elemental constituents present in the film. The results obtained from electrical characterisation of the samples showed the ohmic properties of the deposited sample. X-ray diffraction results indicated that samples are polycrystalline in nature with tetragonal rutile structure. The average interplanar spacing and crystallite size of the samples were estimated as 2.93 Å and 202.5 Å respectively. Optical characterisation of the samples showed that absorption and transmittance across the ultraviolet-visible spectrum range depend on deposition time. The estimated energy band gaps of 3.06 eV suggested the films as good candidates for transparent contact electrodes in optoelectronic applications.

Abstract

---

TiO was synthesized by Sol-gel method and doped by Impregnation of Nitrogen from Ammonium Chloride to obtain 5% 2 N-TiO . The undoped TiO and N-doped TiO photocatalysts were characterized by Fourier Transform Infrared (FTIR) 2 2 Spectroscopy, X-Ray Diffraction (XRD) Crystallography and Scanning Electron Microscopy (SEM). Investigation of the activities of the photocatalysts for degradation of Indigo carmine dye in aqueous solution was carried out at different operating conditions of pH, temperature, catalyst concentration and dye concentration under aeration and UV- irradiation using a 20 Watt UV lamp in a specially constructed reactor made up of four compartments. The dye degradation reaction was monitored on a N4S UV-Spectrophotometer at 290 nm. The FTIR results attested the presence of N-H, Ti-O-Ti, Ti O, H-O-H, O-H functional groups in the catalysts. The XRD Crystallography results show that 5% N- TiO catalyst 2 contains a mixture of anatase and rutile phase compared to undoped TiO which contains pure anatase phase. The SEM 2 results show decrease in particle size when TiO was doped with Nitrogen. The degradation rate was found to comply 2 2 o with first order kinetics and optimum degradation was attained at the same pH and temperature of 3 and 40 C respectively for both photocatalysts. However, the dye and catalyst concentrations where optimum degradation was observed for 5 % N-TiO and undoped TiO were found to be 20 ppm, 0.025 g/l and 12.5 ppm, 0.05 g/l respectively. Percent degradation in 2 the presence of both UV- Irradiation and catalyst was calculated to be 28.5 % and 34.14% for TiO and 5% N- TiO 2 2 respectively. The percent degradation result shows a higher efficiency on 5% N- TiO than undoped TiO

Abstract

---

The properties of surfaces in contact are known to have significant influence on the tribological behavior of any tribosystem in different contact situations. In the present work, the effect of using different ball counterface material on the tribological behavior of AISI 340L stainless steel under marginally lubricated contact was studied. The frictional behavior was evaluated using a ball-on-flat configuration in reciprocating sliding under marginally lubricated contact condition. 440C stainless steel, Al (2017) alloy and bronze were used as the ball counterface while base-stock synthetic polyalfaolefin oil (PAO10) without additives was used as lubricant. After the friction test, flats and balls surfaces were examined by optical profilometer and optical microscope in order to assess the wear dimension and mechanism. In all the sliding pairs tested at different loads, an initial rapid increase in friction coefficient and a period of transition to a lower steady state friction coefficient were observed. In SS304L-440C pair, wear proportional to applied load occurred in the AISI 340L stainless steel flat by a combination of gross plasticity and abrasion. For both SS304L-Al (2017) and SS304L bronze pairs, severe wear proportional to applied load, which occurred predominantly by abrasive mechanism was observed in the different ball counterface. The study concluded that the types of materials in contact have significant influence on the tribological property of any tribosystem.

Abstract

---

The study investigated the physicochemical properties and heavy metal contents of water samples from three major sources; river (sample A), borehole (sample B), and well (sample C), in Usen using standard procedures. The heavy metal content was analyzed using Atomic Absorption Spectrometer. The results obtained were compared to permissible limits based on WHO standard. The pH of the water samples ranged from 6.80 to 7.00. The nitrate content varied from 2.30 to 2.40 mg/L, which was lower than the maximum limit of 10 mg/L. The conductivity was from 36.52 to 64.61 us/cm. Copper was not detected in all the water sources investigated. There was significant difference in the contents of other metals investigated. The concentration of other metals ranged from 1.84 – 9.12, 0.002 – 0.035, 0.001 – 0.061, 0.074 – 0.263, and 0.055 – 0.243 mg/kg for iron, cadmium, lead, zinc and manganese respectively. The metal contents were in the order: Fe> Zn> Mn> Pb > Cd > Cu. The results of this study also revealed that the water samples under study are contaminated by heavy metals and therefore unfit for human consumption. Thus, it becomes very important to treat these waters to make it safe for the populace.

Abstract

---

Nanocrystalline BaTiO (BT) powder was synthesized by a combination of the solid-state and mechanochemical method. X-ray diffraction, field emission scanning electron microscopy, and impedance spectroscopy utilised appropriately to characterize the BT sample (ceramic). The X-ray diffraction confirmed a single-phase perovskite compound of cubic symmetry with space group Pm-3m. The crystallite size and crystal cell volumes were found to be 3 25.7 nm and 64.250 Å respectively. The average grain size estimated from FE-SEM was found to be 144.5 nm by using intercept technique. Electrical parameters like impedance, modulus, and electrical conductivity of the ceramic were obtained from AC complex impedance spectroscopy technique in the frequency and temperature range of 40Hz – o 1MHz and 30 to 150 C, respectively. Both impedance and modulus plots showed the negative temperature coefficient of o resistance (NTCR) character in the sample at 70, 110, 130, and 150 C with are similar to a semiconductor. This can be used for the fabrication of highly sensitive thermistors. The Cole-Cole (Nyquist) plot represents the grain and grain boundary conduction which indicates the ideal non-Debye type dielectric relaxation. The modulus analysis suggested the temperature-dependent relaxation process in the BT ceramic. A positive temperature coefficient of resistance o (PTCR) character was observed at 90, 50, and 30 C. The activation energy values are found to be 1.12 eV and 1.07 eV for Z″, and M” while it's 0.46 eV and 0.12 eV for t and t respectively. g , gb A possible suggestion is due to hopping conduction. The AC and DC conductivity spectra were found to rise with increasing temperature and frequency obey the Jonscher's power law. The conduction process was observed to be thermally activated and followed by Arrhenius law. that the carrier transport

Abstract

---

Current anaerobic digestion technologies are geared towards maximizing biogas yield and the subsequent use of the anaerobic slurries as soil amendments. However, only few studies have established the agronomic risk associated with the utilisation of anaerobic slurries. Therefore, this study evaluates the effect of agronomic use of anaerobic slurry on lycopersicum esculentum seedlings. L. esculentum is one of the most important vegetables worldwide. In this study, Palm esculentum Oil Mill Effluent (POME) collected from the Nigeria Institute for Oil Palm Research (NIFOR) was anaerobically digested at 1:1 effluent (E) to inoculum (I) ratio using the mesophilic technique. The physicochemical of the POME such as pH, Chemical Oxygen Demand (COD), lead, chromium, zinc, calcium, magnesium, phosphate, etc., were determined before and after anaerobic digestion. The anaerobic slurry was evaluated for their bio-fertility potential by using them as soil amendments at different doses: 0, 200, 400 and 600 ml/3 kg soil in a completely randomized design in triplicate followed by screenhouse trial. The physicochemical properties of the soil were determined using standard methods before and after the screenhouse experiment. The results showed that anaerobic digestion of the effluent was a successful biological treatment system with high COD removal efficiency (over 60 % reductions), while water properties such as total solids, nitrate, phosphate etc., were not considerably affected by the treatments. Result from the pre-plant soils revealed that the soil organic carbon, nitrogen, phosphorus, magnesium and calcium increased with increasing anaerobic slurry applications while the soil pH remained in the acidic region and the soil exchangeable acidity reduced. The plant height, number of leaves, leaf length, stem girth and total biomass yield by the plant significantly (p<0.05) increased with increasing anaerobic slurry treatments. Soil amendments with the anaerobic slurry improved soil fertility, plant nutrient and heavy metals uptake increased. Therefore, this should be applied with caution to avoid bio-accumulation of heavy metals in plants. Among the selected heavy metals evaluated, zinc in the 200 ml treatment had the highest uptake (195.50 mg/kg) while cadmium in the control and 200 ml treatment had the lowest (0.00 mg/kg).

Abstract

---

Metal nanoparticles are known to possess outstanding mechanical properties, relative to their bulk materials. However, due to large surface energy, nanoparticles tend to coalesce to each other, forming bulk particles and eventually deteriorate in quality. It is therefore, essential to immobilize nanoparticles on a support to help particles stay away from each other. This paper reports the effects of weight fraction on the average crystallite size of ZnO supported groundnut shell based activated carbon composites. Preparation of activated carbon from groundnut shell was carried out by chemical activation process, using ZnCl as activating agent at 2 activation temperature, activation time and impregnation ratio of 600°C, 1.32 hrs and 3 respectively. Surface characterization was carried out on the prepared activated carbon to determine the surface morphology and proximate analysis of the sample. ZnO was synthesized using the sol-gel method with zinc acetate as precur sor salt. The surface morphology and average particle size of synthesized ZnO were determined using scanning electron microscopy (SEM) and transmission electron microscope (TEM) respectively. Groundnut shell activated carbon (GSAC) and ZnO were mixed at different weight percentages (75:25, 50:50 and 25:75) to produce GSAC/ZnO composites. The composites developed were then characterized using X-ray diffrac tion (XRD). Relying on lattice parameters such as diffraction peaks and full width at half maximum (FWHM) obtained from the X-ray powder diffraction, the effects of weight fraction on the average crystallite size of ZnO supported GSAC composites were determined using Scherrer equation. The result obtained showed increase in average crystallite size with decrease in the amount of GSAC present in the GSAC/ZnO compos ite. The GSAC/ZnO composite with 75:25 weight fraction was found to have the smallest average crystallite size of 38.42 nm while GSAC/ZnO composite with 25:75 weight fraction was found to have the largest average crystallite size of 74.42 nm. The results suggest that the stabilization influence of groundnut shell activated carbon on ZnO reduced with increase in the amount of ZnO in the composites.

Abstract

---

Magnetite nanoparticles have been produced by green synthesis method. Aqueous extract of Mangifera indica leaves was used as reducing agent for co-precipitation of magnetite from iron (II) and iron (III) salts 3 in 1:2 molar ratio. Optimisation of the process was carried out using 2 factorial design of experiments taking into consideration stirring time of reaction medium, temperature and volume of extracts with 2 hdrodynamic particle size as response. A 2 factorial design was afterwards conducted with temperature of reaction medium and volumetric ratio of plant extracts to iron precursor as factors and hydrodynamic particle size as response. Characterisation of the nanoparticles was done using UV-visible spectrometer, Dynamic Light Scattering (DLS) method for hydrodynamic particle size measurement, X-ray diffraction (XRD) and High Resolution Transmission Electron Microscopy (HRTEM). Results obtained reveals that the best parameter for the synthesis of magnetite nanoparticles is a volume of precursor to plant extract ratio o of 1:15 at a temperature of 70 C. Measurement of particle size of the magnetite nanoparticles using DLS method gave an average hydrodynamic particle size of 143.9 nm; the particles size measurement using Scherer's equation from the XRD spectra gave 52.04 nm, while the High Resolution Transmission Electron Microscopy result indicated that the nanoparticles are spherical in nature, with a mean particle size of approximately 9 nm. It can be inferred from the analyses that, ratio of iron precursors to plant extract, temperature, and stirring time, played important roles in size of particles.

Abstract

---

A low cost Fused Filament Fabrication (FFF) 3D printer was designed and fabricated, using in part local materials. The printer was based on the open source Replicating Rapid Prototyping (RepRap) design. The Arduino (Integrated Development Environment) IDE board was used for the implementation, and it uses the Repetier-Host software for the slicing and the printing operations. The print volume of the printer is 95 mm x 90 mm x 80 mm, and the printer uses the Polylactic Acid (PLA) filament. The optimum conditions to print the PLA material were achieved at a print temperature of 210 ºC; for a print speed of 55 mm/s and a layer height of 0.2 mm. At these conditions, the dimensional deviation of the printed object from the CAD model was an average of 0.05 mm. Further developmental activities, with the use of more locally sourced materials, may help boost the local economy, in accordance with the Nigerian local content act

Abstract

---

There is evidence that appropriate footwear plays pivoted role in the management of diabetic foot problems and inappropriate footwear causes foot ulceration. Therefore, this work was aimed at investigating how footwear could be used to prevent or reduce diabetic foot problem. Structured questionnaires were designed and used to gather information from diabetic patients. The study was carried out at different hospitals in Kaduna State. The results obtained from the survey showed that up to 75% of the diabetic subjects have not received information about the type of footwear they should wear most often. The outcome of this research further showed very poor choice of footwear by people suffering with diabetes in Kaduna State, Nigeria. It was discovered that up to 53% female and 37% male of the patients were wearing slippers most often. Only 17% male and 13% female respondents wear shoes. Up to 29% male and 19% female were using sanders. The results also showed that 14% male and 15% female were wearing half-shoe. Only 2% and 1% male participants were using sneakers and boots respectively. None of the patients used custom-moulded footwear. The paper also highlights key areas that would require further research

Abstract

---

The need for new renewable energy resources and its utilization as sustainable solution for transport fuel, respiratory health and environmental problems drives this study. This study involved chemical profiling of African Mahogany (AM) methyl esters fatty acid (ME-FA) produced at multiple of two times, three times and four times seed oil to methanol molar ratios (MR). The key factors kept constant were 1% NaOH catalyst concentration at o 60C processed in 1 hour. The oil yield from African mahogany seed kernel was 44.88% by weight. The percent free fatty acid was reduced serially from 34.78 mg (KOH)/g (of the oil) by H SO acid esterification to 0.46 mg 2 4 (KOH)/g (of the oil). This was followed by the 1% NaOH transesterification at different multiples of oil to methanol molar portions. The chemical profiles of the biodiesel yields were characterised using the gas chromatograph and mass spectrometer (GCMS) system. The results indicated increasing yields of ME-FA at 71.73% for AM at MR – 1:6, 85.96% for AM at MR – 1:9 and 84.37% for AM at MR – 1:12. Similarly, the essential component of Octadecenoic acid methyl ester increased from 16.55% in crude AM oil to produce biodiesels at 40.25%, 40.80% and 43.21% for the biodiesel samples. Thus, a mathematical model y = 10.505x + 47.048 (MR = 1 < x < 5) was established.

Abstract

---

This study is focus on producing polyurethane foams that would have same or better properties compared to the conventional and still be able to undergo biodegradation upon disposal. Microfibers were isolated sequentially using nitric acid, sodium hydroxide and hypochlorite bleaching under different extraction conditions. The cellulose microfibers extracted were characterized for their composition, structure, and properties using prescribed procedures. Polyurethane foams were made from the biopolyol containing as much as 25 ml liquid cellulose. Samples of the foams were characterized based on morphology, density, modulus and compression test using standard methods. The biodegradation integrity of the foams was assessed in this study using short-term accelerated laboratory experiments including microbial analysis, and soil burial experiments. The results were compared with the conventional polyurethane foams. The results showed that the cellulose based polyurethane foam sample with 10-15 ml liquid Fibers have about 75 ± 0.50% cellulose for the acid treated and 79 ± 1.05% for the alkaline treated. The results revealed that the optimum conditions to remove most of non-cellulosic materials from the sugar bagasse were 1M HNO , 7M o 3 NaOH, 3 h and 100 C for both the alkaline and the acid procedure, and 10 ml/L NaClO, 45 minutes and 95 oC for bleaching treatment. The results showed that the studied foams biodegraded under anaerobic conditions. Differences in the properties of the foams produced in comparison with the conventional foams were not significant. However, significant difference was observed in the biodegradation of the foams produced with the conventional foams.

Abstract

---

The lack of chemical plants for the manufacture of simple chemicals such as NaOH, KOH and KCOin most part of 2 3 sub-Saharan African countries leads to high cost of importing these chemicals which make them less readily available for many industrial purposes. An investigation was carried out using waste plantain peels to produce potassium carbonate for industrial purposes such as paper making, glass making, soap making etc. The elemental composition analysis result of ashed plantain peel shows K(42.16%), Al(1.773%), P (0.758%), Ca (0.162%) and some other Trace elements (52.817%). The thermal decomposition of the product was investigated using Thermo gravimetric Analysis (TGA) which indicates the stability and decomposition status of produced. The purity morphology of the synthesized product shows major peaks attributed to potassium carbonate which assign JCPDS file number {98-1435} and minor silica {14-1303}. Finally, FTIR analysis was carried out which shows the band ranges of compounds present in the produced silica which includes: OH (2500- 3500Cm), K - O (624 Cm ), Si-O -1-1 (427 Cm). The application of the synthesized product was recommended as a potential candidate in soap making -1 industries.

Abstract

---

The present study examines the physicochemical parameters and heavy metal contents of soil from Okpella Mining Area in Edo State. Top soil samples and control samples from about 200m from the mining area were analyzed for their heavy metals content using Atomic Absorption Spectrometer (AAS) techniques. The pH, electrical conductivity and organic matter were determined using standard procedures. The soil pH ranged from 6.8 to 7.9 which show slightly acidic to alkaline conditions. The concentrations of the metals in mg/kg were as follows: Cu (23.03 to 170.83), Pb (3.50 to 10.59), Cd (0.70 to 1.93), Cr (0.75 to 8.74), Ni (5.0 to 34.52), Zn (3.29 to 25.46), Mn (3.49 to 22.50), Fe (22.03 to105.67), Co (9.99 to 64.43) and As (0.35 to 1.20). Inter elemental correlation showed that most of the metals investigated were of common origin. The mean concentrations of the metals were in the general order: Cu>Fe> Co> Ni> Zn>Mn>Pb>Cr>Cd>As. The concentrations of the metals at mining area were generally higher than control. With the exception of Cd, the concentration of other metals analyzed were within safe limit based on WHO standard. Results from pollution index assessment also show that Cd has higher degree of contamination. There is therefore need to monitor agricultural activities going on in this area so as to guard the safety of man and organisms in the area

Abstract

---

The Selective Laser Melting (SLM) is one of the Additive Manufacturing (AM) processes and it is more favoured over Selective Laser Sintering (SLS) because it can consolidate metal powders to a near full density (with relative density of more than 99%) and it can achieve a surface roughness of less than 20µm. However, the SLM process involves the use of high density energy laser to operate, by melting and re-solidification at very fast rates, which makes it very prone to defects and failures, like cracking, balling, delamination. Residual stresses are also caused by the high thermal gradient between the melt pool and the powder solid. A three-dimensional Finite Element Model (FEM) of selective laser melting was developed by using ANSYS software (workbench module 16.2) to predict the unsteady temperature evolution and distribution between the melt pool and the powder solid. The model incorporated a coupled thermal and mechanical simulation with convection. Temperature dependent material properties were also incorporated into the model. The moving heat source was described as a Gaussian distribution. It was observed that the heat accumulated during the previous scan tracks affected the next scan track and that the heat distribution to the surrounding powder bed was due to the fact that the heated-up material has greater conductivity than the untreated powder in front of the laser. This insight may be useful in the production of as fabricated parts by the SLM process.

Abstract

---

The Nigerian Steel (NST) 37-2 has vast applications as a substitute for foreign steels in Nigeria, but, its reliability, the effects of induced residual stress in the material, optimum cutting parameters, efficient process planning, chip formation process and surface roughness of the machined products are some of the challenges faced in the industry. In this study, the finite element modelling and simulation of orthogonal cutting of NST 37-2 steel was carried out, and the effect of cutting speed was investigated to address informed predictability on the material. The finite element simulations were conducted by using the ABAQUS software. The Johnson-Cook plastic and damage models were employed together with arbitrary Lagrangian-Eulerian (ALE) formulations. The results showed mainly continuous chip formation for all simulations. It was observed that the cutting and the thrust forces decreased with increase in cutting speed. Also, the temperature of the shear zone region increased with increase in cutting speed

Abstract

---

Rapid Prototyping, which can also be referred to as Solid Freeform Fabrication, Additive Manufacturing, Layered Manufacturing, or 3D Printing is a process of making a three-dimensional solid object of virtually any shape from a digital computer model. This paper reviews the advances in this printing technology with a view to popularizing its use for STEM and non-technical education among other uses. Illustrations were done using models of Mathematical objects including Hypercube and Icosidodecahedron; Engineering Objects including Automatic Transmission Gearing System, Brake Caliper and Suspension Bridge. Some of the other objects shown to have been 3D printed include: Building, Drone, Human Skull, Humanoid Robot, Human Teeth and Archeological Objects. The paper aims to enthuse and attract a large number of academics to embrace this technology that is already redefining a wide variety of systems and processes and also encourage materials scientists and engineers to expand the frontiers on range of feedstock materials that can be explored and used for 3D printing

Abstract

---

A series of nickel/molybdenum bimetallic nanocatalysts were prepared by wet impregnation method on USY zeolite and alumina as support. The catalysts were characterized by nitrogen-sorption (for Brauneur-Emmet-Teller, BET surface area determination), X-ray diffractometry (XRD), Scanning Electron Microscopy (SEM), Scanning Electron Microscopy-Electron Dispersive X-ray Spectroscopy (SEM-EDX) , Transmission Electron Microscopy (TEM) and Temperature Programmed Reduction (TPR). The results of nitrogen sorption reveal a reduction of BET surface area of about 40% for nanocatalyst on alumina and zeolite. With the increase of zeolite content of our catalyst, the micropore volume and surface area increased while the average pore size decreased. Hence, as the micropores increased the mesopores and macropores decreased. The SEM surface morphologies of the catalysts confirmed that deposition of metals occurs in the pores and on the surface of the catalysts which have contributed to reduction in the surface area as indicated in the BET result. The EDX revealed the deposition of metals onto the surfaces. The presence of Al and Si in the support and Ni and Mo as active metals was confirmed. The TEM displayed a homogeneous dispersion of metals on the supports. The micrograph showed a worm-like motif with a random channel system which matches the plate-like particles assembled in parallel identified by the N-2 adsorption-desorption isotherm. However, the catalysts had darker coloration as the percentage of the zeolite was increased on the support due to the coating of pores with the metals which had better interactions as corroborated by the TPR profiles. The results of TPR showed that the weaker interaction between the Mo and Ni species and the support leads to better reducibility of the metal oxides on zeolite than on alumina. As the zeolite content of the mixed support was increased, the peak mainly due to the reduction of Mo became weaker, hence the reducibility of metal precursor on the support varies with different zeolite content.

Abstract

---

The quantity of carbon-enriched stabilised austenite (γHC) in austempered ductile iron (ADI) with various casting thicknesses was evaluated in this study. Ductile iron grade that conforms to ASTM A536 65-45-12 was cast, specimens of section thickness in the range of 5 to 25 mm were machined, isothermally treated to 820°C austenitising temperature, and austempered at austempering temperature (T ) of 300 and 375°C. The resulting phase distributions A of treated specimens were characterised using X-Ray Diffraction (XRD) method. The patterns of XRD were found to consist of ferrite (α) and austenite (γ) phases. The percentage volume of carbon-enriched stabilised austenite in the ADI decreased as section thickness increased. It was concluded that the carbon-enriched stabilised austenite in ADI depends on the casting section thickness and austempering temperature

Abstract

---

With continuous industrial demands and as the market potential of purified copper in Nigeria and around the world is on the increase, the development of cheap and eco-friendly methods for the processing of mixed and lower grade copper ores become paramount. Consequently, this study examines the effect of ammonia-ammonium chloride concentration, temperature and particle size on the extent of covellite ore dissolution for predicting optimal copper extraction conditions. The results of the dissolution rates were found to be influenced by ammonium ion concentration, reaction temperature and particle size. At optimal leaching conditions, 82.9% of the initial 10 g/L covellite ore reacted within 120 minutes. The un-leached products (~17%) examined by X-ray diffraction was found to contain siliceous impurities that could be processed further to serve as a by-product for some defined industries. In all, the dissolution data was accordingly analysed and found to follow the shrinking core model for the diffusion controlled reaction. The calculated activation energy of 31.16 kJ/mol supported the proposed mechanism, assumed to be first order relation.

Abstract

---

One of the most power consuming applications in the process and petroleum industry is the turbulent means of transporting fluid over long distances through pipelines. High pumping energy is required to overcome the occurring frictional pressure drop. An economical approach has been reported where addition of small amount in parts per million (ppm) of high molecular weight polymeric solution can lead to large decrease in pressure drop. Synthetic polymers are more effective in reducing pressure drop (drag reduction, DR), but cannot be degraded easily by biological means. There is the need to combine them with natural polymers to improve DR and reduce their environmental effect. In this study, an experimental flow facility which consists of liquid storage tanks, pumps and unplasticised polyvinylchloride (uPVC) horizontal pipe system with 20 mm ID has been constructed. DR in single phase water flow was investigated using partially hydrolyzed polyacrylamide (HPAM; magnafloc 1011), polyethylene oxide (PEO) and Aloe Vera mucilage (AVM) separately, as well as mixtures of HPAM-AVM and PEO AVM at Reynolds number from 12,916 to 48,871. The master solutions of 2000 ppm and 20000 ppm for HPAM, PEO and AVM respectively and their respective mixtures were used at different concentrations. The pressure drop was measured using mercury U-tube manometer. Drag reduction of 75.2, 78, 82.5 and 83% was obtained by the polymer mixtures, which was higher than the DR of individual polymer alone at all mixing proportions and Reynolds numbers at the same concentration. The observed synergism in DR may be attributed to the increase in the dimension of the macromolecular coil of the polymer mixture solutions due to the presence and rigidity of other polymer molecules.

Abstract

---

This work reports on hydrogen bond energy of sulphated cellulose nanocrystals (CNC) obtained from rubber wood (RW) cellulose for effective steric stabilization of magnetite nanoparticles obtained via the modified Massart's method. The particles morphology, structure and crystallite properties were investigated by using microscopic techniques. The magnetic properties of Fe O nanoparticles were investigated by using physical 3 4 property measurement system. The average width of CNC was ≈20 nm with length of between 190 nm-300 nm. Changes in the hydrogen bond energy of the RW cellulose, during acid hydrolysis, were investigated by using the FT-IR hydrogen bonding energy calculation. The CNCs capped Fe O particles synthesized, were 3 4 monodispersed and oval in shape (with average particle diameter of ≈4 nm). The Fe O nanoparticles obtained, 3 4 exhibited superparamagnetic behaviour and saturation magnetization (Ms) of ≈67.5 amu/g

Abstract

---

Talc by its intrinsic properties is an important material with diverse industrial applications. In the present work, the evaluation of a Nigeria sourced talc ore for industrial utilization by sulphuric acid leaching was studied and accordingly characterized. During the experiments, it was found that the increase in acid concentration, reaction temperature and decreased particle size increase the extent of the ore dissolution. At optimal conditions (2.0 mol/L H2SO4, 75°C, -90+75µm), 71.2% of the ore reacted within 120 minutes with moderate stirring. The unleached product was analysed to contain silica. The estimated activation energy of 28.72 kJ/mol supported the proposed diffusion-controlled reaction kinetics. The leached product is hydrophilic having specific surface area increased from 0.15 m2 /g to 3.76 m2 /g with total cumulative pore volume of 0.010986 ml/g. Finally, a decrease in the ore’s iron content from 3.75% to 0.16% yielded 95.73% product purity

Abstract

---

We have demonstrated that activated carbon could be produced via microwave-assisted activation at a much shorter time (ranging from 2-5 min) and reduced cost compared to the conventional activation method embraced by most researchers in the production of activated carbon. The research work is not only limited to surface chemistry and adsorption studies but also includes structural, microstructural and electrochemical studies/investigations of the produced Nickel Oxide Filled Activated Carbon (NOFAC). Its uniqueness is tied to cost effectiveness and the use of agricultural waste product. Activated carbon filled with nickel oxide was prepared via microwave-assisted chemical activation using coconut shell, palm kernel shell and their mixture with potassium hydroxide as activating agent. The effect of the incorporation of NiO on the structure and surface chemistry of the raw materials after activation was studied employing Fourier Transform Infra-Red (FTIR) Spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) analysis. The electrochemical characteristics were investigated employing Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD) analysis and Electrochemical Impedance Spectroscopy (EIS). The FTIR spectroscopy confirmed the existence of strong interfacial interaction between NiO and the host matrices showing creation and annihilation of absorption bands in the IR spectra with significant absorptions observed below 500cm-1 for nickel oxide. The TEM results showed that the microstructural evolution of host matrices is as a result of incorporation of NiO and activation using microwave power respectively. A follow-up with XRD confirmed the presence of anomalous graphite structure surrounded by traces of impurities resulting from the activating agent. Finally, the scan rate studies revealed activated palm kernel shell as the best candidate with better current response, higher value of specific capacitance and better electrochemical behaviour.

Abstract

---

Landolphia owariensis belongs to the family Apocynaceae and its roots are commonly used as medicinal plant for the treatment of malaria and as purgative. The leaves extract is antimicrobial and the stem extract is used as a vermifuge. The phytochemical analysis of L. owariensis indicated secondary plant metabolites such as tannins, and flavonoids. The presence of tannins and flavonoids makes it imperative to conduct a formal study of its tanning potentials. This paper is reporting the application of phytochemical and classical methods of tannin analysis, and the use of the extracts for tanning purpose. The result of the phytochemical analysis showed the presence of tannins, saponins, fat and oils; while the classical analysis showed that the extract contains tans, non-tans, total soluble and moisture. The tanning extracts were used to tanned goat skins and the resultant leather shows favorable standard value for shrinkage temperature, tensile strength, and ball burst

Abstract

---

The leather industry is ranked first in foreign exchange earnings from non-oil export products in Nigeria. Unfortunately, 5-10% of fatliquor applied to the resultant leather articles are imported with attendant negative effects on value addition and job creation. It is imperative to look inward into plants that can give good yield of oil that can be converted into fatliquor. Based on this, oil from Cucurbita maxima (kabewa) seed was extracted and characterised and results presented as follows: Saponification value 198.18mgKOH/g, iodine value 68.56, acid value 6.95mgKOH/g, pH 5.5 and 50% oil yield. Heavy metal contents were analysed using AAS indicated Fe2+0.4357ppm, Ni2+ 0.0424ppm and Pb2+ 0.0021ppm. FT-IR analysis revealed –OH, -CH≡CH-, and –C=O as the functional groups present in the oil. GC-MS determination showed that the dominant fatty acids present in the oil include: palmitic acid (C16H32O2), oleic acid (C18H32O2), stearic acid (C18H36O2), palmitoleic acid (C16H30O2) and myristic acid (C14H28O2). The yield of the oil was good and can be used alone or in combination with other fatliquors after subjecting it to sulphation

Abstract

---

Metal-Organic Frameworks (MOFs) [Cu(INA)2] were prepared by a solvent free method and were used for the adsorption of anthracene from solution. The [Cu(INA)2] MOFs were found to be good adsorption materials having good adsorption capacity. The maximum adsorption capacity for the [Cu(INA)2] MOFs was observed to be 22.73 mg/g for anthracene. The adsorption process favoured the pseudo-secondorder kinetics and the Langmuir isotherm was found to be most appropriate model for the adsorption data. [Cu(INA)2 ] MOFs, therefore, can be used as environmentally friendly adsorbents in the treatment of wastewater

Abstract

---

The possibility of using solid tannery waste in HDPE was studied by examination of the mechanical properties, morphology and thermal properties of the composites produced. Composite was manufactured by compression moulding technique for varying fibre contents from 10% to 60%. Mechanical and physical tests were conducted on composite specimens in accordance to ASTM D638. A partial replacement of 10-40 wt% of HDPE (petroleum-derived plastics) was successful with tensile value of 118.868, 100.971 MPa at 10 wt% for composite of HDPE filled chrome waste and HDPE filled vegetable re-tanned waste, while HDPE (control sample) at 10 wt% gave 25.338 MPa only, The optimal value for tensile strength, and elastic modulus was obtained at filler loads of 10wt%. The morphology and thermal properties of the matrix and composites were studied by scanning electron microscopy, thermogravimetric analysis, thermal differential analysis and differential scanning calorimetry. The TGA and DTA results of composites were more thermally stable with additives than the control or it’s composite without additives. The thermal differential analysis of composites without additives displays two steps weight losses while composites with additives display a single step weight loss. In conclusion, the additives does improve the mechanical properties of HDPE/Leather solid waste, it greatly helps to stabilize the composite against thermal and photo degradation. HDPE90/Vegetable waste10 were shown to have better properties than those of Chrome tanned and Hide un-tanned waste

Abstract

---

Biomass fibres obtained from agricultural wastes have found application in the production of structural reinforcement for bio-composites used for manufacturing engineering components because of their low cost, biodegradable and eco-friendly advantages. The effects of hybridization on the mechanical properties of bagasse/sisal/coir reinforced epoxy hybrid composites have been studied. Bagasse has gained applications in paper making and as a biofuel in industries especially in Egypt, India and Cuba. However, its potentials have not been fully utilized as engineering materials due to its moderate strength. This work is therefore aimed at tailoring its properties through hybridization with other supporting natural fibres for better performance and applications. Hybridization was found to increase both the tensile strength and flexural modulus of the composites in the order: Bagasse/Epoxy < Bagasse/Coir/Epoxy < Bagasse/Sisal/Epoxy < Bagasse/Sisal/Coir/Epoxy. The tensile strength of the three-fibre/matrix hybrid system of Bagasse/Sisal/Coir reinforced epoxy composites was 53.25 MPa, showing an improvement of 70.1 % over the pure Bagasse/Epoxy composite. However, when blended with sisal and coir, the tensile strength value was raised to 43.6 MPa with the composition of 60%B/40%S having an improvement of 39.3% over the pure Bagasse/Epoxy composite while that of 60%B/40%C registered a strength value of 40.6 MPa. On the other hand, the hardness of the composites decreased with the hybridization of the fibres. The hardness strength value for the hybrid composites showed that as the sisal component increased from 40 % to 60 %, the composition with 50 %B/50 %C showed the highest numerical strength of 8.87 RHF followed by 60 %B/40 %C having 8.63 RHF. As fibre loading increases, the rate of water absorption increases and the rate of water absorption is higher for the hybridized composite than for the unhybridized composite system. The specific water absorption value of the hybrid composite is as follows 60 wt%B40%S < 40 %B60 %C <60 %B/10 %S/30 %C having absorption rate of 6.5 %, 7 % and 10.8 % respectively

Abstract

---

Seed oil has been proposed as alternative base fluid for drilling mud but its stability to oxidation is still an issue to deal with. This paper reports the influence of stabilizing neem oil through chemical modification on its flow and electric conduction properties. Ester derivatives were produced from laboratory purified neem oil. The purified neem oil (PNO) was epoxidized to convert the double bonds to epoxy rings in order to eliminate the weak pi-bonds that are susceptible to oxidation. The derived products from these controlled reactions were verified using Fourier Transform Infrared (FTIR) spectroscopy. The viscosity of the epoxy neem was found to have increased. Glycerol was then removed from the epoxy oil to produce alkyl ester of epoxy neem oil. This reduced the viscosity of the epoxy oil. The mid frequency dielectric response of the PNO and its derivatives are related to ionic conduction. PNO has an electrical conductivity of 1.26 × 10-9 S·m-1 at 20ºC; this is about 100 times higher than the conductivity of diesel oil used as base oil for drilling fluid. The bulk conductivity is thermally activated (activation energy = 0.31 eV) and influenced by the liquid viscosity. A higher conductivity was observed for the ester derivatives compared to that for PNO and this may be attributed to polarization of suspended nanoimpurities. The obtained results support the proposition that suspension of conducting nano-particles in the neem oil derivatives will pave way for the production of a suitable base liquid that will provide lubrication and electric current path for a sustainable oil-based drilling fluid for offshore drilling

Abstract

---

The physico-chemical properties of biodiesel are its specifications that define a set of quality standards. These properties include specific gravity, acid number, viscosity, cetane number, flashpoint, pour point, cloud point, cold filter flogging point, sulphated ash, carbon residue, sulphur content, copper strip corrosion and free fatty acid among others. This research presents the results of specific gravity, acid number, sulphur content, colour index and copper strip corrosion of biodiesel from Cotton, Jatropha, Neem and their binary blends and multi-blends with diesel. The properties were tested in accordance with the ASTM standards and it was observed that, all the fuels conform to the ASTM standards for all the properties except the pure Neem biodiesel B100N whose colour is slightly above the standard and the acid values that are slightly below the minimum standards which depict no harm. This implies that all the fuel samples can be used in Compression Ignition engines with the anticipation of improved quality of atomization, combustion, fuel droplets, air-fuel mixing and without fear of damages on either fuel pumps and filters or climate condition due to sulphur content of the fuel.

Abstract

---

Dutsen Bakura hill amethyst mineralization is located within a sheared granitic gneiss in the PanAfrican basement complex of northcentral Nigeria. The zone of mineralization is within a shear zone that trend NE-SW consistent with Pan-African structural trend. Mineralization consists of bands of milky quartz and amethyst, apparently formed from two stage sequence of silicification. Major, trace and rare earth element (REE) distribution patterns are used to distinguished host rock and mineralization characteristic. SiO2 content ranges generally between 76.77 – 79.25 wt % ; Al2O3 content ranges between 11.61 – 11.85 wt %; Fe2O3(T) content ranges between 1.49 – 2.26 wt %; Na2O content ranges between 2.91 - 4.99 wt % in the granite gneiss. The sheared granite gneiss has SiO2 content ranging between 82.09 w % - 99.21 wt %; Al2O3 content ranging between 7.42 - 10.34 wt % which is slightly lower than that of the granite gneiss; Fe2O3 (T) content ranges between 0.67 – 3.90 wt %; Na2O content ranges between 0.01 - 0.02 wt %. Major element content distribution within the mineralised zone is as follows: The SiO2 content in the amethyst ranges from 98.95 - 100 wt %; Al2O3 ranges between 0.06 – 0.18 wt %; Fe2O3 (T) ranges between 0.63 – 0.67 wt %; Na2O content ranges between 0.01 -0.02. However, SiO2 in the milky quartz ranges from 97.43 to 99.22 wt%; Al2O3 content ranges between 0.05 – 0.22 wt %; Fe2O3 (T) content ranges between 0.56 – 0.66 wt %; Na2O content ranges between 0.01 -0.02 wt %. This paper reports the geological and chemical characteristics of amethyst mineralization of Dutsen Bakura hill with the general view of chemically characterizing Nigerian amethyst.Dutsen Bakura hill amethyst mineralization is located within a sheared granitic gneiss in the PanAfrican basement complex of northcentral Nigeria. The zone of mineralization is within a shear zone that trend NE-SW consistent with Pan-African structural trend. Mineralization consists of bands of milky quartz and amethyst, apparently formed from two stage sequence of silicification. Major, trace and rare earth element (REE) distribution patterns are used to distinguished host rock and mineralization characteristic. SiO2 content ranges generally between 76.77 – 79.25 wt % ; Al2O3 content ranges between 11.61 – 11.85 wt %; Fe2O3(T) content ranges between 1.49 – 2.26 wt %; Na2O content ranges between 2.91 - 4.99 wt % in the granite gneiss. The sheared granite gneiss has SiO2 content ranging between 82.09 w % - 99.21 wt %; Al2O3 content ranging between 7.42 - 10.34 wt % which is slightly lower than that of the granite gneiss; Fe2O3 (T) content ranges between 0.67 – 3.90 wt %; Na2O content ranges between 0.01 - 0.02 wt %. Major element content distribution within the mineralised zone is as follows: The SiO2 content in the amethyst ranges from 98.95 - 100 wt %; Al2O3 ranges between 0.06 – 0.18 wt %; Fe2O3 (T) ranges between 0.63 – 0.67 wt %; Na2O content ranges between 0.01 -0.02. However, SiO2 in the milky quartz ranges from 97.43 to 99.22 wt%; Al2O3 content ranges between 0.05 – 0.22 wt %; Fe2O3 (T) content ranges between 0.56 – 0.66 wt %; Na2O content ranges between 0.01 -0.02 wt %. This paper reports the geological and chemical characteristics of amethyst mineralization of Dutsen Bakura hill with the general view of chemically characterizing Nigerian amethyst.

Abstract

---

The pressure upon many nations of the world especially in the developing economies is the attainment of the Sustainable Development goals, one of which is Environmental Sustainability. A shift from fossil fuel to renewable alternative energy such as biogas has been identified as a key strategy for attaining this. The production of biogas from various substrates via anaerobic digestion has been extensively explored. The influence of variability in ambient and digester temperatures on biogas production from cow dung and chicken droppings was explored in this study. Anaerobic digestion of Cow dung and Chicken droppings for the production of high quality biogas was carried out at average ambient temperatures of 20.45±4 oC and 37.00±3 oC. The total biogas production for Cow dung and Chicken droppings were respectively 0.035444 m3 and 0.210984 m3 for the first temperature range and 0.183471 m3 and 0.321066 m3 for the second temperature range. The results of the daily and cumulative biogas production where subjected to the Modified Gompertz model. The total biogas yield for Cow dung and Chicken droppings based on the Modified Gompertz equation were respectively 0.0374 m3 and 0.217 m3 for the first temperature range and 0.181 m3 and 0.322 m3 for the second temperature range. This study demonstrated that there is a clear variation in the volume of biogas produced at lower and higher temperatures within the mesophilic range.

Abstract

---

Zippers are textile fastening devices which are flexible and operate by moving a slider along two rows of inter-lockable elements. In Nigeria, the polyester and nylon coil type of zippers are the most commonly used and patronized by makers of female garments and dresses. Previous study on the strength of zippers in a region similar to Nigeria showed zipper failures were as a result of wrong application of zipper to garment fits. In this study, the effect of laundering activity on the crosswise strength and slider lock strength of the nylon coil zipper in Nigeria was investigated. Two (2) sets of #3 nylon coil zippers were separated into groups and subjected to a number of wash cycles. The crosswise strength and slider lock strength tests were performed and the results were compared to a group of control-samples. The average slider lock strength for the Gyro Washed samples were 54.28 N, 43.31 N and 44.27 N for the first, second and third Wash cycles respectively; while the control samples recorded an average strength of 47.28 N. The average crosswise strength recorded were 679 N, 667 N and 680 N for the first ,second and third Wash cycles respectively; while the control samples recorded an average strength of 486.04 N. The Average slider Lock strength recorded from the Motorised Tensometer for the hand washed samples were 45.0 N, 50.0 N and 48.3 N for the for the first ,second and third Wash cycles respectively, while the control samples recorded an average strength of 33.3 N. The results showed that laundry/wash activity has an effect on the slider lock and cross wise strength of the zippers which can also hinder the smooth operation/movement of sliders along the zipper elements/chain.

Abstract

---

The studies investigate the physicochemical properties and concentration of radioactive elements present in the geophagious ‘Nzu clay’ samples obtained from Azonogogo, Delta State and Uzella River, Owan West LGA, Edo State. The mineral composition of the clay samples were investigated using XRD while the radioactive elements were determined by using Hiper Pure Gammanium detector with Resolution (FWHM): 2.3 Kev, 60Co at 1.33Mev. The result of the physicochemical properties shows that water absorption and swelling power of processed/finished ‘Nzu clay’ obtained from Uzella River have the highest values of 2.230±0.000 and 2.070±0.000 respectively. The pH of the raw and processed/finished ‘Nzu clay’ is 5.150±0.494 and 4.500±0.141 respectively, showing increased acidity in the clay. The levels of radioactive elements in ‘Nzu Clay’ indicated that the average specific activities of 40K, 238U and 232Th ranged from 54.45±32.45 to 127.60±14.7, 21.35±6.28 to 38.75±4.67 and 26.83±13.94 to 44.51±1.16 respectively. The mean absorbed dose rate and annual Gonadal Equivalent Dose (AGED) of the ‘Nzu Clay’ was calculated to be 48.86 nGy/h and 207.1Sv/y, respectively. The XRD analysis reveals that the ‘Nzu clay’ is dominantly composed of the mineral Kaolinite and Quartz. The presence of these radioactive elements, though not beyond the permissible limits put the habitual consumer at health risk on the long run.

Abstract

---

Vinylsulphone disperse reactive dyes were synthesized by diazotizing 2-methoxy-5-methyl-4- (sulfatoethylsulfonyl) aniline and coupling with substituted pyridone derivatives. The synthesized dyes were applied successfully on polyester without dispersing agent and the dyeing showed good leveling and build up with desired colour yield. The dyeing was dependent on the pH and the optimum pH was found to be 5, similar to that employed in conventional polyester dyeing. The fastness properties obtained are excellent and comparable with the conventional disperse dyes

Abstract

---

A new copper deposit associated with the marginal granite porphyry of Banke Younger Granite Complex was discovered at Zarara hill, Kano State Nigeria. Preliminary study was undertaken with the main objectives of mineralogical and chemical characterization of the deposit. Twelve samples were obtained polished thin sections were prepared and studied using backscattered images and electron microprobe techniques. The results indicate that the ore mineralogical assemblage comprises of primary chalcopyrite, galena, sphalerite, arsenopyrite and pyrite, while secondary minerals formed from the alteration of the primary ore minerals are malachite, azurite, chalcocite and goethite. The gangue mineral assemblage include quartz, feldspar and hematite. Hence, chemical characterization of the deposit revealed that the economic metals include Cu, Pb, Zn, and S with trace concentrations of Cd, Co, Se, Ni, Mo etc. Therefore, adequate mineralogical and chemical characterization of mineral deposits is essential as a prerequisite for deposit’s evaluation because other elements with possible economic and environmental significance might be present within the ore minerals as solid solutions.

Abstract

---

Novel perovskite-type nanomaterials with the composition La1-x(Bix)FeO3-δ (where x = 0.5 and 0.2) were synthesized by using a modified citric acid sol-gel route and annealed at 900 °C in (1) in air (LB0.5FO-air and LB0.2FO-air), and (2) in Argon atmosphere (LB0.5FO-Ar and LB0.2FO-Ar). Scanning electron microscopy and powder X-ray diffraction analysis of the powders showed that they contain crystalline perovskite-type nanoparticles with crystallite sizes 37-41 nm. The lattice parameters, after refinement, showed that the particles crystallized in an orthorhombic structure. The BET specific surface areas (SSA) ranged between 1.76-4.37 m2 g -1 with powders synthesized under argon having the higher SSAs. Vibrating sample magnetometer analysis of the hysteresis loop showed a slightly higher magnetization value for the samples synthesized in air. Photoluminescence spectroscopy showed that the powders were all active in the visible region and could be useful for visible light photodegradation of organic dyes. The powders were all screened for photocatalytic activity against an organic dye (Rhodamine B) in the visible region of the solar spectrum and the photocatalytic activities were good for powders synthesized in argon, In addition, a mineralization of up to 80% was achieved after 3 hrs of photodegradation for these powders as well. The materials therefore, show good potential for the photocatalytic degradation of organic pollutants and photocatalyst recovery after photodegradation

Abstract

---

The present work evaluates the potentials of using indigenous microbial strains isolated from wastewaters of an effluent treatment plant of a Textile Industry and the feasibility of employing nanofiltration (NF) membrane and reverse osmosis (RO) systems as an alternative treatment method of textile wastewater discharged from textile industry. Experiments were performed in a laboratory - scale set up using four potential candidates’ microbial strains, in which the bacterial strains (Pseudomonas monteilii and Aeromonas hydrophila) and the fungal strains (Phanerochaete chrysosporium and Aspergillus oryzae) were selected based on their ability to decolorize and degrade dyes effluent into non-toxic form. Decolorization efficiencies of the microbial strains were measured as a function of the operational parameters (aeration, dye concentration, pH, temperature, total viable count and optical density) and the microbial isolates showed increase in cell number as the concentration, absorbance and pH decreases. The effects of dye concentration, pH of solution, feed temperature, dissolved salts and operating pressure on permeate flux and dye rejection were studied using the membrane technologies. Results at operating conditions of dye concentration of 60 mg/L, feed temperature of 38 °C and pressure at 8.5 bar showed the final dye removal with NF membrane as 97.3 %, 99.1 % and 98.9 % for organic dyes, Congo red and Direct blue 80, respectively. While with RO membrane, the final dye removals were 97.5 %, 97.7 %, and 98.6 % for organic dyes, Congo red and Direct blue 80 dyes, respectively. Higher color removal was achieved due to the existence of NaCl salt in the solution. It was later confirmed that pH of solution also had a positive impact on dye removal. A comparison was made between the results of dye decolorization in microbial and membrane methods and it was found that the use of membrane technologies in dye removal from the effluent of textiles industry was highly effective and promising

Abstract

---

Sodium silicate in powdered form was successfully synthesized from both rice husk ash and Kankara kaolinite clay. The impure nature of both monomer and NaOH used does not seems to hinder the depolymerization reaction viz-a-viz product formation. The crystallinity of sodium silicate produced tends to increase with reaction time, temperature, and Na2O/SiO2 ratio. About 93% crystallinity for assynthesized sodium silicate was obtained using Na2O/SiO2 molar ratio of 0.9, reaction time and temperature of 75mins and 100°C, respectively. The starting material and product formed were characterized using XRF, XRD and SEM analysis. The result proved that the sodium silicate produced can serve as an excellent replacement to its commercial counterpartSodium silicate in powdered form was successfully synthesized from both rice husk ash and Kankara kaolinite clay. The impure nature of both monomer and NaOH used does not seems to hinder the depolymerization reaction viz-a-viz product formation. The crystallinity of sodium silicate produced tends to increase with reaction time, temperature, and Na2O/SiO2 ratio. About 93% crystallinity for assynthesized sodium silicate was obtained using Na2O/SiO2 molar ratio of 0.9, reaction time and temperature of 75mins and 100°C, respectively. The starting material and product formed were characterized using XRF, XRD and SEM analysis. The result proved that the sodium silicate produced can serve as an excellent replacement to its commercial counterpart

Abstract

---

The present study determined the effect of sodium hydroxide (NaOH) treatment on the properties of baobab pod/sisal fibres reinforced low-density polyethylene (LDPE) hybrid composites. Used to treatment the fibres, were different concentrations of NaOH 2 -10 wt% at 2 wt% interval. The hybrid composites were compounded using two roll mills machine and compressed in a mold using hydraulic press at a pressure of 10 kN and temperature of 120 oC. The fibre content of the hybrid composites was 10 wt% with baobab and sisal fibre ratio of 1:1. Tensile, impact, hardness, water absorption and morphological analysis were conducted on the produced hybrid composites. The mechanical properties of the hybrid composite increased with increase NaOH concentration up to 6 wt%, while the water absorption decreased with increase in concentration of NaOH solution. The morphology revealed that surface cracks and voids were more in hybrid composites produced with untreated and fibres treated at higher concentrations of NaOH.

Abstract

---

A series of azo dyes was synthesised by coupling reaction of napththalen-2-ol with diazotized 4- sodiumphenolate, 4-Nitrophenylazo and 4-Chlorophenylazo respectively, as diazo components. The characterization of the dyes was carried out by GC/MS analysis. The solubility of dyes in the visible absorption spectra was also determined. The dyeing performances of the three dyes were assessed on cotton, wool and nylon fabrics, also determined are the molar absorbtivity, dyebath exhaustion (%E) and dye fixation (%F). The dyed fabrics show very good washing fastness properties for wool and nylon and moderate for the cotton fabric. These dyes were found to give bright yellow to purple colour shades with very good depth and levelness on the fabrics. The dyebath exhaustion and fixation on the various fabrics were also found to be very good

Abstract

---

In recent years, nanocomposite materials have received much interest in nanotechnology. This new trend in nanotechnology is aimed at producing materials of unique properties. In view of this, zeolite goethite nanocomposite was synthesized to reinforce zeolite properties. Zeolite was synthesized hydrothermally from sodium aluminate, sodium silicate and sodium hydroxide at 100 oC for 24 h. The composite was synthesized using in-situ method by adding aqueous solution of the synthesized zeolite during the synthesis of goethite. The structure, morphology and surface area of the zeolite and the composite were investigated using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Brunnauer Emmet Teller (BET) surface area analyzer respectively. The FTIR spectra and SEM micrographs confirmed the formation of zeolite–goethite composite with the surface area increase from 163.491 m2/g for zeolite to 304.839 m2/g for zeolite goethite nanocomposite. It is evident that properties of zeolite can be improved upon by compositing with other materials like goethite. It can also be employed as an adsorbent for different environmental applications as revealed by the surface area.

Abstract

---

Zeolite Y was synthesized using commercial sodium hydroxide and Kankara kaolin as starting material in the presence of sodium silicate formed from kaolinite clay. Synthesis was done at 90°C, 95°C and 100°C for crystallization time of 12, 18, 24 and 36 hours. Results showed that commercial sodium hydroxide could be used to successfully produce zeolite Y from Kankara kaolin when gelling ratios of =30, =0.8 = 0.7 are used. Zeolite Y with the best crystallinity was produced at 90°C for 18 hours. Crystallisation of zeolite materials from kaolin and low grade NaOH is quite different from commercial zeolite because the sources of Si and Al are relatively less reactive due to the presence of competitive cation ions, like K+, Mg2+, present in the monomer. Additionally, the sodium silicate, selectivity induces the formation of zeolite NaY and eliminate the processes of induction and nucleation. Cost analysis per unit catalyst, showed an overwhelming $185.524 difference between imported high grade chemicals and local chemicals in favour of locally obtained chemicals. The as-synthesized zeolite was characterized using XRF, XRD and SEM analyses. The resulting NaY zeolite can find application in refining process, as shown by the XRD results

Abstract

---

Bagasse ash results from burning bagasse, a matted cellulose fiber residue from sugarcane that has been processed in sugar mills. In this paper, Bagasse ash has been chemically characterized in order to evaluate the possibility of its use in glass manufacture. The result of X-ray fluorescence (XRF) showed the ash to contain SiO2 - 31.67%, K2O - 31.41%, P2O5 - 8.14%, MgO - 4.89%, CaO - 3.92%, Na2O - 3.17%, Fe2O3 - 1.23% the ash was normalized as no LOI was carried out. Qualitative and quantitative X-ray diffractometry (XRD) for determination of composition and presence of crystalline material, showed the presence of silica in free and various combined states and potassium magnesium carbonate. Scanning electron microscopy (SEM/EDS) at 100µm and 300µm showed clusters of spherical and rod like microstructure at different spectra

Abstract

---

The study explored solid modelling for possible optimization of conventional laboratory heat exchangers. 240mm, 360mm, 480mm, 600mm and 720mm lengths conventional and unconventional Allihn, Graham, Liebig and Zigzag condensing models were designed and fabricated. An automated coolant system for test running the condensing models was sketched, constructed and used for test running the models using tap water as purification liquid in distillation flasks and coolant from the automated system for condensing vapour. Distillation temperatures range between 93-110oC; while differences between inlet and outlet temperatures were between 6-10oC. Optimal designs for 240mm, 360mm, 480mm, 600mm and 720mm based on distillation rates were Model Nos. 43=BZBZBWB (TA) with distillation rate (WDR) of 477mLs/hr, 38=SBSBS (TB) WDR of 458mLs/hr, 18=BSB (TB) WDR of 438mLs/hr, 18=BSB (TB) WDR of 422mLs/hr and 38= SBSBS (TB) WDR of 428mLs/hr respectively. The models could potentially be used for separation, purification, extraction and teaching aids in science and engineering laboratories and tertiary institutions of higher learning.

Abstract

---

A comparative analysis was carried out for essential quality parameters of five different bed sheets fabrics; Two foreign and three locally produced flat bedsheet fabrics. These fabrics were compared on parameters such as fabric thickness, air permeability, water absorption, fabric flammability, abrasion resistance, tensile strength, crease recovery, fabric shrinkage, stain removal, fabric handle, fabric sett, fabric drape, yarn count and yarn crimp using the appropriate techniques and apparatus. The results obtained show that the locally produced fabric exhibited comparably better end-use performance characteristic in terms of air permeability, water absorption, flammability, and drape. The foreign flat bed sheets are better in terms of crease recovery, handle, tensile strength, yarn crimp and shrinkage. These fabrics are therefore valued for their end-use performance.

Abstract

---

The concentrations of some selected heavy metals were assessed by atomic absorption spectrophotometry in noodles sold in the study area. Total of eight different brands of noodles were investigated. The results of heavy metals in samples in mg/kg were in the order: Fe (13.15 – 144.75); Pb (0.00 – 0.55); Cd (0.00 – 0.01); As (0.00 – 0.14); Ni (0.01 – 0.09); Cu (0.02 – 0.33); Zn (1.45 – 8.05) and Cr (0.06 – 0.25). Estimates of daily intakes of metals and health risk index for noodles revealed that the local consumers were safe but were at risk of potential bioaccumulation arising from dietary of Ni, Cd, Cu, Zn in some samples.

Abstract

---

The kinetics of the removal of manganese cadmium and lead in aqueous solution using cocoa shell as an adsorbent was investigated. The effect of contact time, kinetic of sorption mechanism and the adsorbate concentrations on sorption of Mn2+, Cd2+ and Pb2+ ions were examined. The kinetic of the sorption mechanism of Mn2+, Cd2+ and Pb2+ was evaluated using pseudo-first order (Lagergren) rate and the pseudo-second (Ho-model) rate model. The rate limiting sorption step was physisorption and results indicate that pseudo-second order model provides a more appropriate description of the adsorption rate for the metals ions sorption in cocoa shell. The maximum adsorption capacities per unit gram of the adsorbent at equilibrium time, neutral pH, 200 r p m, and temperature of 25 0C are 9.02 to 40.04 mg kg-1 for Mn2+, 7.02 to 25.89 mg kg-1 for Cd2+ and 5.25 to 11.01 for Pb2+ under 10 to 50 mg kg-1 initial metal concentration. Sorption equilibrium isotherm was determined and correlated with Langmuir and Freundlich model. It was found that the Freudlich adsorption model best fitted the isotherm data. It is concluded that cocoa shell can be use as an effective adsorbent for removal of heavy metals from aqueous solution.

Abstract

---

This paper reports the findings of an investigation into the admixture potential of bone ash (BA) with a focus on the setting time of ordinary Portland cement (OPC). Cow bones are agricultural waste and constitute a sizeable proportion of solid waste in many cities of the world. Heaps of cow bones constitute aesthetic problem to the environment, unnecessary occupation of space and exude unpleasant odour that pollutes the environment. Cow bones need to be properly disposed to check the nuisance they constitute to the society. In the ever increasing endeavours to convert waste to wealth, investigation into the potentials of converting cow bones to beneficial applications in concrete becomes relevant. Bone vis-à-vis cow bone is mainly composed of compounds of calcium. The presence of calcium compounds in bone as well as in cement warrants effects of bone ash on cement to be envisaged. Cow bones were air-dried and incinerated to ash. The resulting ash was sieved through 75µm sieve. Based on weight of cement, 0%, 0.1%, 0.15%, 0.25%, 0.5, 1.0, 1.5%, 2.0%, and 2.5% of the ash were separately mixed with OPC to produce cement-bone ash (CBA). The required quantity of water determined from consistency test was added to the CBA mixture and mixed thoroughly to obtain CBA paste. The CBA paste was tested for setting time. Results show that BA decreases the setting time of OPC; the higher the content of BA, the faster is the reduction in the setting time of OPC. Reaction mechanisms are articulated and developed to explain reasons for the decrease in the setting time of OPC due to the addition of BA. It is concluded that BA is an accelerator; hence BA is recommended for use as an accelerator in concrete.

Abstract

---

In this research, factorial design have been employed to study the influence of four important factors; pH, catalyst dosage, irradiation time and dye concentration in the treatment of C.I. Direct Yellow 96 dyestuff using UV/TiO2 and UV/H2O2 photo-degradation processes. The results indicate that the adsorbent dosage and irradiation time exhibit a significant positive effect on the efficiency of decolourization, whereas the initial dye concentration and pH of dye solution show a significant negative effect in UV/TiO2 for the dye. Under UV/TiO2, maximum degradation of 73% was obtained at dye concentration of 5mg/l, pH 4, reaction time of 90min and catalyst dose of 2g/l. Under UV/H2O2 the irradiation time and initial dye concentration exhibit a significant positive effect on the efficiency of decolourization, whereas the pH of dye solution and adsorbent dosage show a significant negative effect for the dye. However, the UV/H2O2 gave a maximum degradation of 58% at dye concentration of 5mg/l, pH 4, reaction time of 90min and H2O2 catalyst dose of 25mM. Hence, both methods can be adopted as a preliminary treatment process for dye wastewaters

Abstract

---

This work has investigated gold cyanidation and characterization of Itagunmodi gold deposit using cyanide from cassava. The gold ore was subjected to selective removal of associated minerals, treated to varied concentrations of cyanide extracted from cassava and precipitation of the gold. The precipitated gold was characterized using optical microscope, SEM - EDX, EDXRF and XRFS. The result showed that after 24 hours of cyanidation using analar grade sodium cyanide of 60 mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.096 g (96 mg) gold. Also, under the same condition, using cassava based cyanide concentration of 60 mg/l, 10 g Itagunmodi gold ore concentrate yielded 0.08 g (80 mg) gold. This work has shown that sourcing cyanide from cassava waste for gold leaching is the appropriate alternative to the conventional cyanidation.

Abstract

---

This study investigated the heavy metal status of soils around waste dumpsites in Ughell, metropolis, Delta State, Nigeria. Two different dumpsites were used for this study. For the metal analysis, soil samples were collected at 0-15cm depth. The soil samples were air dried for five days and sieved. 2.0g of the soil sample was digested with HNO3/HClO4 mixture and analysed for heavy metals (Fe, Pb, Cd, Zn, Cu and Mn) concentration using Atomic Absorption Spectrophotometer (AAS) Buck 200A model. The result obtained ranged from18.23-32.31mg/kg for Fe; 1.28-1.36mg/kg for Pb; 4.72-6.23mg/kg for Cd; 13.6-17.62mg/kg for Zn; 1.32-1.35mg/kg for Cu and 26.36-29.82mg/kg for Mn. The mean concentration of all the metals in the two sampling stations is in the order: Mn>Fe>Zn>Cd>Cu>Pb. The results when compared with the control site were quite higher indicating the metal enrichment of soil from the waste in the dumpsites. The results were within DPR target value except cadmium. The level of Cadmium in the present study calls for concern, considering the location of the sites and toxicity of cadmium. All hands must therefore be on deck to check the effect of these metals now and in the future in order to promote a healthy environment for sustainable development

Abstract

---

This study was aimed at the evaluation of the stabilization potential of sawdust ash (SDA) on black cotton soil. Soil samples were treated with up to 10 % SDA content by dry weight of soil compacted with reduced British Standard light (RBSL) energy. Index properties of the natural soil showed that the soil belongs to A-7-5 (36) in American Association of State Highway Transportation Officials (AASHTO) classification system and CH in Unified Soil Classification System (USCS) classification system. The natural soil has liquid limit, plasticity index and free swell values of 60.0, 32.4 and 50.0 %, respectively. These properties suggest a soil that cannot be used for engineering purpose in its natural state and requires improvement. The liquid limit, plastic limit and linear shrinkage decreased to minimum values of 54 %, 24.4 %, and 14.2 %, respectively, while plasticity index increased to 14.2 % at 10 % SDA content. Also optimum moisture content (OMC) increased to a maximum value of 30 % while maximum dry density decreased to a minimum value of 0.86Mg/m3 at 10 % SDA content. Peak unsoaked California bearing ratio (CBR) value of 4 % was recorded at 2% SDA content. On the other hand peak 7 days unconfined compressive strength (UCS) value of 90kN/m2 was recorded at 8 % SDA content. This value fell of specification requirement of the CBR value to be used as sub-base or base material. The durability of samples determined by immersion in water recorded peak resistance to loss in strength of 48.24 % (i.e., loss in strength of 51.76 %) at 8 % SDA content. The results recorded indicate that black cotton soil compacted with RBSL energy cannot be used as a road pavement material, but for low load bearing structures such as road shoulders and pedestrian walkways. However, SDA can be beneficially used as an admixture in road construction when a higher compactive effort is used.

Abstract

---

The high demand for citric acid by many industries cannot be over emphasized. Presently, 70 % of the total citric acid produced globally is consumed by food industries, 12 % by pharmaceutical industries and the remaining 18 % by other industries. Moreover, rapid increase in food/beverage industries in Nigeria with no known company producing citric acid in Nigeria makes its scarcity severe. Cassava peels from cassava processing industries and lemon peels are abundant. Surface fermentation method was employed in production of citric acid at varying pH from 3.0 to 4.5. Physico-chemical properties and Fourier Transform Infra Red spectroscopic analysis were conducted using standard methods. The kinetics of the production process was also determined. The yields and physico-chemical properties of the citric acid obtained from both substrates were comparable to that of commercial citric acid. The yields obtained from cassava peels are lower when compared to those from lemon peels when the same quantities were used. The optimum yield obtained from lemon and cassava peels after 192 h of fermentation at optimum pH 4 were found to be 34.4 g/kg and 32.7 g/kg respectively. The infra red spectra of citric acid produced from cassava and lemon peels showed bands at 3497, 3290 and 3288 cm-1 depicting hydroxyl group bonded to carboxyl. The 1750 cm-1 carbonyl band was observed for both peels. There was increase in percentage yields of citric acid over 48 – 192 h fermentation periods for pH range of 3.0 – 4.5. The kinetics of the production process was observed to follow a pseudo-second order as it gave best fit compared to other models used. The range of pseudo – second rate constant fell within 1.045 x 10-3 – 2.411 x 10-3 kg/g.hr for pH range of pH 3.0 – 4.5 for lemon peels while that of cassava peel ranged from 1.071 x 10-3 to 98.91 x 10-3 kg/g.hr for pH 3.0 – 4.5 range. The possibility of production of citric acid in Nigeria from lemon and cassava waste peels could reduce importation of this product by industries and thus save enough revenue for the country.

Abstract

---

The leather industries in Nigeria depend largely on imported fatliquors at exorbitant rates and that has affected the leather value chain, to avert this, there is the need to look into our indigenous plants to make this product available. In this light African star apple (Chrysophyllum Albidum) seed was considered for its affordability and availability. The seed was collected and some physico-chemical parameters analysed and presented as follows: Moisture content (18.3%); Saponification value (222.05mgKOH/g); Acid value (3.8mgKOH/g); Free Fatty Acid value (2.54mgKOH/g); Peroxide value (5.5mgKOH/g); Specific gravity (0.90g/cm3); Refractive index (1.3573); Ester value (218.25); Iodine value (28mg/100g of sample); Percentage yield of oil (13%).Some heavy metals of interest such as: Iron, lead and nickel were analysed to ascertain their concentrations in the sample using Atomic Absorption Spectrophotometer (AAS). Functional groups present were analysed using Fourier Transform Infrared Spectroscopy (FTIR) as follows: -OH; Alkyl group –C-H; -CHO from aldehyde and amide –N-H, alkanes –C=C stretch. Furthermore GC-MS was employed to validate the degree of saturation and unsaturation of fatty acids and alcohols. The GC-MS key results include: Palmitic acid (21.22%), stearic acid (8.08%),tridecanoic (9.94%),tridecenal (2.25%),docosanoic (0.92%); oleic (12%), linoleic (11.91%) and fatty alcohol (palmitoleic 40.40%). Palmitic and stearic acid play important role in the production of fatliquor though surface active agents are needed to lower its viscosity.ChrysophyllumAlbidum can be used in combination with groundnut or castor seed oils because of its low yield (13%) for fatliquor production in the leather industry

Abstract

---

Use of appropriate footwear among people suffering with diabetic foot complications has been well documented to play a vital role in the prevention and treatment of established foot diseases. The incidence and prevalence rates of diabetes in Africa are increasing and foot complications are rising parallel. However, there is a paucity of literature on the role of people suffering with diabetics in ensuring the use of appropriate footwear in the management of diabetic foot complications. This paper explores current practice in the use of appropriate footwear among patients with diabetes mellitus in Kaduna State, Nigeria. The study was carried out at different hospitals in Kaduna State. A self administered structured questionnaire was developed. The questionnaire was divided into two sections: Demographic and footwear questionnaire. The footwear questionnaire focused on three themes: Diabetic foot problems, type of footwear worn by diabetic patients frequently and the role of proper footwear fastening mechanism in the prevention of diabetic foot complications. The findings indicate that up to 77% females and 62% males’ respondents used footwear that do not have any form of fastening or are slip-on footwear. Lace-up shoes were used by 28% of the male participants and only 12% of female patients used a similar type of footwear. Footwear with fastening mechanism were the least popular type of footwear used by the research subjects. This study shows that the use of appropriate footwear in the management of diabetic foot complications in this part of the World is suboptimal.

Abstract

---

This study investigates the characterization of River Niger Silica sand at Itobe with Iyoloko clay as additives for its possible uses in sand casting in the foundries. A measure of 5-25 %wt Iyoloko clay was added to the sand mixture in ratio 3:1. The chemical, physical and mechanical properties measured includes: chemical analysis of the Iyoloko clay, particle size, density, permeability, compatibility, mouldability, moisture content, green compression and shear strength, dry compression and shear strength. The results revealed that, addition of Iyoloko clay to River Niger Silica sand at Itobe, increased the mouldability, grain fineness number (G.F.N), both green and dry strength, slightly decreased the density, permeability and moisture content. These results shows that better properties of foundry sand are achievable by addition of Iyoloko clay to River Niger Silica sand and can be used to enhance the mould properties of foundry sand.

Abstract

---

This study presents a relationship between developed physical and mechanical properties of Nigerian grown Ebony ((Kanyan) Diospyros mespiliformi) timber. This is in order to determine the full potential for its utilization. Wood specimens for the test were prepared and determined in accordance with EN 13183-1 (2002) and EN 408 (2003). The mechanical properties were determined using three point bending test in accordance with ASTM D193 (2000). The mean moisture content, oven dry density, bulk density, bending strength, and modulus of elasticity were found to be 30.52% (MC), 768.56 Kg/m3 (DD), 1060.89 Kg/m3 (BD), 72.55 N/mm2 (BS) and 11722.78 N/mm2 (MOE) respectively. A relationship between the properties was determined using regression equation. The best relationship was between DD and MOE (R2 =0.893) and DD and BS (R2 = 0.894) followed by BS and MOE (R2 =0.813) then

Abstract

---

The solid waste from palm oil mill industry in Nigeria has been on the increase annually. This study thus investigates the utilization of Palm kernel shells (PKS) bio-agricultural wastes as a filler material for epoxy composite fabrication in which the filler was treated in an alkali solution. The composites were fabricated by employing filler particle size of 150μm and loadings of 5%, 10%, 20%, 30% and 40% using hand mixing technique. The composites were tested following appropriate ASTM standards for tensile, impact, hardness, morphological and water absorption properties. Fabricated composites showed good mechanical properties with 5-10% filler loadings attaining maximum values which improved on alkali treatment. The water absorption properties of the composites were not encouraging as saturation point was reached just after three days of immersion but, treatment with alkali reduced water absorption rate. SEM analysis of the fractured tensile specimens further highlighted the reason for the improved mechanical properties recorded by the alkali washed palm kernel shell composites due to the removal of natural impurities hence, providing larger surface area for mechanical interlocking. PKS composites therefore, have adequate properties for applications in the automotive industry as vehicle door and as partition panels and particle board products in building construction.

Abstract

---

This study is aimed at modeling of lead adsorption on Eucalyptus tereticornis (locally known as Turare) leaves from laboratory simulated wastewater through the application of response surface methodology (RSM). Batch studies were performed to evaluate the different parameters considered: contact time and adsorbent dosage. Central Composite Design (CCD) in Response Surface Methodology was employed which gave a total of 13 experimental runs that lead to a quadratic model relating the response (adsorption capacity) and the variables. Analysis of variance (ANOVA) indicated that the model was significant as indicated in model P-value of 0.0001. Significant model terms were (contact time) and (adsorbent dosage). Experimental results showed that at constant pH 5, the adsorption capacity has reached a maximum of 0.8147 mg/g with a contact time of 70 min. Optimization of the model indicated adsorbent dosage of 1 g/L and 120 min adsorption time as optimum conditions for the process. The actual and predicted values of the response agreed closely as evidenced from the model R2-Value of 0.9651.

Abstract

---

The dyeing of nanocrystalline (NCC) cellulose powder extracted from corn cob (Saleh, 2015) was carried out using Reactive (Procion Violet H-3R), Disperse (Foron YellowS.E 2GL) and Direct (Solophenyl Yellow) dyes. The percentage exhaustion in each case was calculated to determine which of the dyes exhausted best. The fastness of the dyed NCC powder to washing, chlorination and light were also investigated to determine which of the dyes has the best fastness properties and which of the dyes is suitable for application in a particular area. Based on the exhaustion and fastness results, the disperse dye with overall excellent properties was chosen as the best dye for nanocrystalline cellulose dyeing. Fabrics were dyed alongside to serve as a control.

Abstract

---

Diospyros mespiliformis is ubiquitously found plant in northern Nigerian farms and forests. Previously, various parts of this plant were reported for treatment of different types of diseases and there was neither a report of collection of the plant’s fruit pulp and seed from Dutsin-Ma nor on GC Ms analysis. Preliminary phytochemical screenings of n-hexane and methanol extracts were carried out according to standard procedures. Various bioactive compounds’ characterization of the extracts was done by GC-MS technique. The phytochemical analysis of the crude extracts of the n-hexane and methanol on the seed plant revealed the presence of alkaloids, flavonoids, phlobatanins, saponins, steroidal nucleus, tannins, cardiac glycosides, anthraquinones, cardenolides, and terpenoids. The GC MS analysis of pulp showed 26 peaks of different phytoconstituents of which major components are: octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, octadecanoic acid, 6-octadecenoic acid and eicosanoic acid; while the GC-MS analysis of seed showed 22 peaks of different phytoconstituents of which major components are: hexadecanoic acid, n-hexadecanoic acid, 9 octadecenoic acid and 9, 12-octadecadienoic acid. In conclusion, both the presence of phytochemicals detected from the phytochemical screening and the high unsaturated fatty acid content analyzed from GC-MS confirm the reports of the applications of Diospyros mespiliformis for the treatment of various diseases.

Abstract

---

Uniformly disperse single-walled carbon nanotube (SWCNT)/High density polyethylene (HDPE) nanocomposite has been produced using the developed nanofeeder injection mould machine. The dispersion state of SWCNTs in the HDPE matrix was evaluated by transmission electron microscope and Atomic force microscope images and confirmed with conductivity test. It was found that the dispersion state of SWCNTs was better in the samples produced with the nanofeeder injection moulding machine for all concentrations of SWCNTs. This nanofeeder injection moulding machine developed can be adopted in the mass production of uniformly dispersed nanocomposite which is relevant in the area such as optical displays, catalysis, photovoltaics, gas sensors, electrical devices, mechanics, photo-conductors and superconductor devices.

Abstract

---

Active methylene azo disperse dyes were synthesized and characterized. A good percentage yield of each of the dyes were obtained in the range of 58-82 %. The dyes have well defined melting points in the range of 270 – 404 C. The visible absorption spectra of the dyes showed that the dyes absorbed maximally within the visible region of the electromagnetic spectrum. The results of halochromism of the dyes showed that the dyes exhibited both negative and positive halochromism. The molar extinction coefficient of the dyes was generally high indicating high hue strength. On application of the dyes on fabric, a high percentage exhaustion of 73 and 69 percent was obtained on polyester and nylon 6.6 fabrics respectively. The assessment of fastness properties of the dyes showed that the dyes have ratings of 4-5 for wash fastness, fastness to pressing and perspiration on both fabrics.

Abstract

---

The rapid turnover in technology in developed and developing countries like Nigeria, has created a new environmental problem in electronic waste (e-waste) management due to high obsolesce rate of consumption. Households are one of the major consumers of electronic equipment and consequently the major sources of electronic wastes (e-waste). In this study, an assessment of the sources, types, lifespan, and the end-of-life management options of electronic equipment acquired by households in three cities in Nigeria (Lagos metropolis, Kaduna metropolis and FCT Abuja) have been studied and compared. Also, a census of the number of out-of-use electronics currently in the households was carried out. The results of the study revealed that both new and used (secondhand) electronic equipments are acquired in households in the study areas. The study also showed that the average lifespan of desktop computers, laptop computers, printers, mobile phones is 2.5-3.5 years, while televisions have lifespan of 3.5-5.5 years. Mobile phones and televisions had the highest average penetration rates of 4.88 and 1.96 respectively while printers had the least penetration rate of 0.6. The most preferred end-of-life options for e-wastes in the study areas were storage and sales, which indicates that users still value their equipment at its end-of-life. The study recommended appropriate e-waste management strategies such as establishment of e-waste collection centers and awareness creation in the households on the need for proper e-wastes disposal.

Abstract

---

On a global scale, sustainable environment and noise pollution are of serious concern in most developing countries, and Nigeria is no exception. Notable scholars have studied many materials - natural and synthetic - for noise control in buildings. Sustainable environment evolves from the production, application and use of sustainable products. A product is considered sustainable if the materials used for its production could be readily available for future generations and create no negative environmental impact such as waste generation and pollution, without compromising the health of its inhabitants. However, few studies have been developed on a comparative analysis of the eco-acoustical properties of conventional synthetic materials, agricultural and environmental wastes products. The aim of this article therefore is to evaluate the sustainability of agricultural and environmental waste products for noise control in buildings from the view of past scholars. Critical literature reviews and content analysis of the recent studies alongside the collected secondary data from the Life Cycle Assessment, Eco-invent, and Eco-profiles of the natural and sustainable environmental waste materials would be presented in the literature. The paper concludes that sustainable acoustical materials (agricultural or environmental wastes) are a valid alternative to traditional synthetic materials; most importantly is the reuse of environmental waste materials which could substantially reduce environmental pollution and also serve as a source of wealth creation for the unemployed Nigerian.

Abstract

---

This study examines the influence of compactive efforts on the geotechnical properties of compacted black cotton soil treated with metakaolin (MTK) to assess its suitability for use as a barrier material in waste containment application. Black cotton soil treated with up to 10% MTK (obtained from calcinations of kaolin) by dry weight of soil was used. The natural soil classifies as A-7-6(22) and Clay with high Plasticity CH according to American Association of State Highway and Transportation Officials AASHTO and Unified Soil Classification System USCS respectively. The laboratory result obtained showed that there was a significant improvement in some of the geotechnical properties of the soil. The liquid limit and plastic limit decreased from 50 and 27.38% for the natural soil to 47.1 and 16.7 % when treated with 10 % metakaolin while the plasticity index increased from 22.59 % for the natural soil to 30.93% when treated with 10 % metakaolin content The hydraulic conductivity value decreased from 1.91 x 10-8 , 1.81 x 10-8 and 1.72 x 10-8 to 0.38 x 10-8 , 0.66 x 10-8 and 0.66 x 10-8 cm/sec for the three compactive efforts of British Standard Light (BSL), West Africa Standard (WAS) and British Standard Heavy (BSH) respectively. It was recommended that MTK treated black cotton soil could be used as a liner or cover material in waste containment facilities.

Abstract

---

Health-care services in rural or urban settings inevitably generate wastes that may be hazardous to health or have harmful environmental effects. This paper therefore assesses the generation, characterization and disposal of hospital waste of some selected hospitals within Kaduna metropolis. Nine hospitals were selected for the study. The weight of waste generated in these facilities is measured after which the wastes were segregated into various classes. 927 kg per day was generated out of which 84% is non-hazardous and 16% hazardous. Waste generation rate in these facilities range from 1.14 to 2.32 Kg/bed/day and 0.13 to 0.50 Kg/out-patient/day. The composition of waste across these facilities include; non-hazardous, infectious, sharps, and pharmaceutical wastes. Out of the facilities surveyed, two have locally built incinerator for waste pretreatment, three employ the use of open burning method, and four facilities do not have any form of waste pretreatment. The paper recommends pretreating of hazardous hospital waste before disposal.

Abstract

---

The work was aimed at the production of biodegradable grease from Atili (Blackdate) Oil that will be environmentally friendly. The grease was produced by mixing and blending of the base oil (Atili oil) with a mixture of calcium hydroxide and the stearic acid at 90oC which was then slowly heated to 190oC for about three hours to obtain the desired product. Three sets of the grease were produced by varying the amount of thickener, the base oil, the stearic acid and the temperature of the reaction. The grease produced was then milled (pound) to obtain a smooth-textured product at room temperature. The tests carried out to analyze the grease produced were dropping point test, unworked and worked penetration test; and most importantly, the test for biodegradability known as BOD5 test. Dropping point test was carried out to determine the temperature at which the grease sample began to drip. The consistency of the grease was measured using the worked and unworked penetration test. Finally, the Biochemical Oxygen Demand test or BOD5 was carried out by measuring the amount of oxygen dissolved in a grease sample initially and after five days. The results showed that dropping point was 70oC, 68oC and 71oC for sets 1, 2, and 3 samples respectively. The consistency values were 0.4 mm, 0.8 mm, and 0.3mm for sets 1, 2, and 3 samples respectively. The BOD was found to be 18.0 ppm, 16.8 ppm, and 18.0ppm for sets 1, 2, and 3 respectively. The grease produced was found to be more biodegradable than those made of mineral oil like Oando and Texaco grease which were 4.8ppm and 6.0ppm respectively. The consistency and dropping point of the grease was found to be dependent on the nature and amount of thickener used and also the viscosity of the base oil

Abstract

---

Nanomedicine can be succinctly defined as the application of nanotechnologies in a healthcare setting. Nanomedicine ascends from the integration of different sciences; physics, chemistry, biology, materials science, engineering, using the nanometer scale. This leads to scientists with different backgrounds, and diversified technical and intellectual skills, trying to address medical problems using nanotechnology. The task of nanomedicine is to integrate the knowledge of physicists, chemists and biologists to reach an ideal answer. Presently, nanomedicines are being explored for the management of various disease conditions which includes fungal infections, asthma and emphysema, ovarian and breast cancer, menopausal symptoms, chronic pain, kidney disease, multiple sclerosis. Nanotechnology is creating an insurrection, a paradigm shift in the manner we diagnose and treat disease. This treatise and current research concentrates on specific fields such as Nanodiagnostics, Molecular imaging, Dental Care, Orthopedics, Cardiac therapy and newly targeted drug-delivery systems. Nanomedicine offers hope for treatment of spinal cord injuries, diabetes, heart disease, Parkinson’s disease and cancer.

Abstract

---

The use and effectiveness of granular and powdered activated carbon made from Borassus aethiopum shells in adsorption studies were investigated. The source material was carbonized at 5000C and for a residence time of three hour in a muffle furnace, while 0.5M each of H3PO4 and ZnCl2 were used for chemical activation at 7500C and for 60m residence time. The adsorption of lead from aqueous solution by ZnCl2 and H3PO4 activated carbons was evaluated for the possibility of using the source material for the removal of heavy metals from aqueous solution. The effect of varying the concentration of the solution and the type of activating agents on the adsorption capacity were assessed. The results indicated that ZnCl2 activated carbons exhibited better adsorption capacity than H3PO4 activated carbons. This provides low cost method of producing activated carbons locally in developing country like Nigeria for use in water treatment.

Abstract

---

Samples of hematite (α-Fe2O3) nanoparticles (HTW) have been synthesized through a modified sol-gel method in Tween 20 (a polysorbate surfactant), separate portions of the powders were annealed at three different temperatures (400, 500 and 600 °C). The samples were characterized by X-ray diffraction (XRD), high-resolution electron microscopy (HRTEM), Mössbauer spectroscopy and by means of a vibrating sample magnetometer (VSM). In addition, all the characterization techniques used showed the formation of phases of hematite nanoparticles with improved purity and crystallinity after higher temperature annealing. The nanoparticle size range was between 16 and 27 nm indicating good size control for Tween 20. The BET specific surface area ranged between 17 and 37 m2 g -1 which is also good for synthesis via solution route. The saturation magnetization and and mӧssbauer analysis both support the presence in the sample at lower annealing temperature of the presence of impurities of maghemite (γ-Fe2O3). Of particular note was the ability of Tween 20 to control the growth of the particles so that grain sizes well below 15 nm were obtained. Thus, Tween 20, when used as a surfactant in the sol-gel route, can serve to improve the physical properties of synthesized hematite nanoparticles.

Abstract

---

Novel bacterial strains capable of decolorizing textile dyes were isolated from dye contaminated soil obtained from the vicinity of African Textiles Industry Challawa, Kano - Nigeria. The Carcinogenic azo dye Congo red used widely in various industrial processes poses terrific environmental concern, causing major health problems to human beings. In the present study, decolourization of Congo red by newly isolated antibiotics sensitive novel bacterial strains from dyes contaminated soil of a treatment plant capable of decolorizing organic dyes were investigated and identified as Rhodococcus rhodochrous and Pseudomonas aeruginosa strains by 16S rDNA gene sequence analysis. Decolorization of Congo red dye using these bacterial strains was assayed by screening and optimizing various parameters to determine the optimal conditions required for maximum decolourization. Rhodococcus rhodochrous and Pseudomonas aeruginosa showed maximum decolourization upon incubation for 24 hrs at 37 °C and pH 7. Enhanced decolourization was achieved by amendment with glucose and peptone as well as carbon and nitrogen sources in the culture medium. The bacterial strains showed great potential in the decolourization of Congo red dye up to 96.1 % for Rhodococcus rhodocchrous and 91.1 % for Pseudomonas aeruginosa in the aqueous environment at optimal conditions. High performance liquid chromatography (HPLC) analysis confirmed that dye decolourization occurred due to the breakdown of dye molecules into colourless end products. The less toxic nature of the dye degraded products was observed by microbial toxicity assay of agricultural significant bacteria and this can be exploited for the bioremediation of different classes of textile dyes and their derivatives containing waste

Abstract

---

The effects of kolaviron , an active component of Garcinia kola seeds were investigated on sodium arsenite-induced hepatotoxicity in rats. Administration of a single dose of sodium arsenite (10mg/kg body weight) orally, increased the activities of serum marker enzymes-Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT). This also led to increase in lipid peroxidation and reduction in the activities of antioxidant enzymes such as superoxide dismutase(SOD) and catalase(CAT). Treatment with 100mg/kg body weight of kolaviron for thirteen days before and after induction of arsenite toxicity reduced the serum activities of ALT and AST significantly (p<0.05). Levels of endogenous antioxidant (SOD, CAT, GST (glutathione-s-transferase) and GSH (reduced glutathione) were also elevated significantly in rats treated with kolaviron. This study revealed that kolaviron possess antioxidant and hepatoprotective property against hepatotoxicity caused by arsenite.

Abstract

---

Nzu clay’ is a geophagious clay consumed in Africa for some medicinal purposes. This study reports the level of accumulated metals in mice that ingested ‘Nzu clay’ for 14 days. Eight female mice (10 ± 2 g) were each fed 0.02 g of ‘Nzu’ mixed with Bendel Plc Feed per day. The ‘Nzu clay’ contained 2.900 mg/kg Pb and 2.143 mg/kg Cd, while the experimental mice accumulated 0.893 mg/kg of Pb and 2.750 mg/kg Cd, but the control accumulated 0.714 mg/kg Pb and 2.250 mg/kg Cd. By extrapolation for 65 kg human weight, 0.014 mg/kg of Cd is anticipated to be accumulated at the end of two weeks. This is 13-fold the WHO tolerable weekly intake of 0.007 mg/kg body weight of human; and 10-fold increase in Pb compared to the WHO tolerable weekly intake. Neutron activation analysis indicated that the clay contained As, Cd and Pb at levels above WHO limits in foods. The accumulated concentration of Al in the mice was four-fold the 120.24 mg/kg in the control, while the accumulated Al concentration was 230-fold the tolerable intake. The accumulated concentration of manganese was 2.05 mg/kg compared to 0.07 mg/kg in the control. ‘Nzu clay’ is rich in K (96.0 mg/kg) and the mice also accumulated 11.5 mg/kg K; the National Academy of Sciences maximum level of daily dietary intake of K is approximately 72 mg/kg. The concentration of As in the clay was 51 mg/kg, which is of health concern. The level of Cr in the experimental mice was significantly elevated (Students’ t-test, P < 0.05) compared to the control. The accumulated level of Cr in the experimental mice was about 36-fold higher than the tolerable intake. The accumulated Fe and Mg in the mice was about 33-fold and 2-fold respectively. This implies that consumption of ‘Nzu clay’ result to bio-accumulation of essential and non-essential metals. Accumulation of heavy metals of health concern at long-term ingestion of the clay call for continuous ban on its consumption.

Abstract

---

The work reports the physicochemical properties of gum exudates from two Combretaceae tree species (Terminalia avicennioides (TA) and Anogeissus latifolia (AL)) determined by standard methods. The gum exudates exhibited differences in physicochemical qualities. The physicochemical properties of the gum were in the following ranges: moisture (11.3 - 11.5%); swelling capacity at 30oC (11 - 13%); pH (4.34 - 5.24); melting temperature (218- 242oC); total ash (3.30- 3.54%); nitrogen (0.70 - 0.71%); protein (4.38 - 4.46%) and ash content (0.53 - 0.60). The two gum samples did not contain tannin and fibre. The gum samples had high proportion of Ca and contained Ni, Pb and Cd at levels below the maximum permissible limits. The physicochemical parameters obtained for TA and AL compare well with those reported in previous studies on other gums. This signals the need for exploitation of the exudates for potential industrial applications

Abstract

---

An extracted vanillin from Foster Clark vanilla flavour for the chemical substitution of toxic carriers used in aqueous dyeing of polyester fabrics was assessed. The extracted vanillin was used to compare the dyeing of a woven polyester fabric with two commercial dyes C.I Disperse Yellow 56, and C.I. Disperse Yellow 50. The vanillin carrier is used for dyeing at 3 % shade at boil, the dye uptakes increased for both C,I Disperse Yellow 56 and C.I Foron Yellow 50 , while higher at 0.15 g of vanillin at pH 4 gave 70.4 % exhaustion on C.I Foron Yellow 50 and least on C.I Disperse Yellow 56 gave 0.66 % at pH 11. The wash, heat pressing and light fastness was determined, an excellent wash fastness was observed at both ISO 2 and ISO 3 wash fastness respectively, given an excellent rating at 4-5. More so, the light fastness test gives a high fastness rating at an average of 6-7 for both the two commercial dyes at different pH and concentration used. The study confirms that vanillin can be used as a chemical substitute to conventional carriers using the aforementioned dyes and gave good wash and light fastness properties

Abstract

---

Crushed particles of canarium schweinfurthii (Blackdate) seed shells were used to reinforce general purpose unsaturated polyester and the properties were studied in this work. Particles of sizes 0.6mm, 1.18mm and 2.36mm with each particle size having a composition weight of 100g, 150g, 180g 200g and 220g respectively were used as reinforcement. The results showed that the composite produced from particles of sizes 0.60mm and composition weight of 100g absorbed the least amount of water with percentage water absorption of 0.89%. The composite from particle size of 1.18mm had the best tensile strength and modulus of rupture of 69.95MN/m2 and 29.39MN/m2 at composition weight of 180g and 100g respectively

Abstract

---

High energy requirement of vapour compression refrigeration systems necessitate the increasing need for more reliable, flexible and cost efficient cooling systems alternatives. Energy saving potential, Carbon emission reduction and waste heat utilization of adsorption refrigeration system could be exploited in this regard. Some of the setbacks that hinder adsorption refrigeration systems from real mass production and commercialization can be address by the development of relatively low cost, available and suitable adsorbent materials. This research work seeks to locally produce date-seed activated carbon and test its adsorptive properties for possible application in adsorption refrigeration system. Physico-chemical analysis was carried out using standard established procedures. The average pH-level, porosity, bulk density and iodine number were found to be 9.43, 62.25%, 0.41g/cm3 and 1075mg/g respectively. The Date-seed activated carbon was found to have relatively good adsorptive characteristic in addition to its availability and relative low cost and therefore could be used as adsorbent in refrigeration system

Abstract

---

Zinc sulphide (ZnS) thin films were deposited from inorganic reagents (solution electrolytes) using a two electrodes electrochemical cell. The film’s thickness and particle distribution were determined by Surface profiler. The film’s particles are continuous but not uniformly distributed across the substrate and the thickness was determined to be 70 nm. X-ray diffraction (XRD) study indicated that the film possesses Zinc blend cubic structure. Crystal size and inter-planar spacing were estimated as 0.36 nm and 0.29 nm respectively. Optical characterization showed that the film has poor absorbance in the visible light region while transmittance is enhanced as wavelength increases. Energy band gap of 3.49 eV was estimated for the film. I-V characteristic of ITO/ZnS/Ag is linear indicating possibility of an ohmic contact between ITO substrate and ZnS film and also between ZnS and Ag. Thus, this study demonstrates that ZnS thin film can be a good recipe for window layer of tin film solar cells.

Abstract

---

Using the Pearson Correlation technique, this paper established significant linear relationship among pairs of analysed physic-chemical parameters with the determined regulated (regTHMsDBPs) and emerging (emergTHMsDBPs) Tri-halomethanes Disinfection By-Products in the drinking water produced by the Ahmadu Bello University water treatment plant. Using standard methods including the USEPA Method 551.1, selected physico-chemical parameters and the levels of the regulated and emerging tri-halomethanes were determined. These were subsequently subjected to statistical correlation analyses. Statistical correlation of pairs of the some of the chemical parameters with total mean tri-halomethanes, show that total mean regulated tri-halomethanes DBPs (TregTHMs) values significantly correlated positively with temperature, total dissolved solids (TDS), total organic carbon (TOC) and residual chlorine values, while significantly correlating negatively with pH. On the other hand, total mean emerging tri-halomethane DBPs (TemergTHMs) significantly correlated with nitrates concentration levels (F=0.62578*) while being highly significantly correlating with residual chlorine (F=5.2670**), total organic carbon (F=13.3882**), total dissolved solids (F=6.2695**) and pH (F=2.7783**) and total mean regulated THMs (TregTHMs) with F=25.4016**. Similarly, the resulting grand total THM (GTTHMs) concentration levels (comprising of the regulated and the emerging THMs) showed highly significant correlation with the total regulated THMs (TregTHMs) (F=54.9578**) and with total emerging THMs (TemergTHM2)(F=289.2349**) but with pH (F=3.3757**) as the only physico-chemical parameter. These signify that the concentrations of both emerging and regulated THMs are both significantly affected by the proportions of the total dissolved solids, nitrates, total organic carbon and residual chlorine. The generation of these models has established additional frontier to manipulate the concentrations of DBPs in treated drinking water by controlling independent physic-chemical variables in the drinking water treatment process. These predictive models could be safely used to predict the levels of these DBPs even though additional testing and analyses can enhance the confidence in such recommendation and extrapolation.

Abstract

---

This study was carried out to examine the catalytic effects of Single Super Phosphate (SSP) with Wood ash on the production of biogas from Cow Dung. The study was carried out in four identical reactors to enable variation of the catalyst combination (100gSSP/50gWoodash, 150gSSP/75gWoodash and 200gSSP/100gWoodash). The research showed that SSP and Wood ash could reduce the lag phase in anaerobic digestion of cow dung. The control which was Cow dung digested without any catalyst had the longest lag phase of 7.5 days as compared to 5.9 days for those digested with catalyst. At the end of 32 days digestion period, total volume of biogas produced across the digesters were 0.0906m3 (no catalyst), 0.0973m3 , 0.0937m3 , and 0.1141m3 (200gSSP/100gWood ash), which indicated an increment with increase in catalyst. The Modified Gompertz equation was applied to describe the cumulative biogas generation. The Biogas production Kinetic Constants estimated by the linear regression method using the solver function in Microsoft Excel as well as other characteristics obtained for the four digesters were 0.0037m3 /day 0.0036m3 /day 0.0045m3 /day and 0.0056m3 /day for Biogas Production Rate and 0.0893m3 , 0.0841m3 , 0.0977m3 and 0.1188m3 for Biogas Production Potential. The average temperatures of the digesters recorded were 35.20 oC, 35.30 oC, 35.17 oC, and 35.18 oC respectively while the average ambient temperature observed during the study was 36 0C which were within the mesophilic range.

Abstract

---

Low aspect ratio pristine Multi-walled carbon nanotubes prepared by carbon vapour deposition (CVD) were dispersed in Miranol, Cetyl pyridinium chloride and a 50:50 ratio mixture of them. They were each applied on 100% PET fabric using classical polyester dyeing techniques (exhaust dyeing) as well as cold padding by 3, 5-minute dip-dry techniques under controlled conditions. Exhaust dyeing yielded poor, uneven uptake; cold padding gave good, level uptake. The chroma characteristics of the dyed fabrics conformed to the Kubelka-Munk equation for determining additive reflectance functions. The polyester fabric became electrically conductive at a percolation threshold between 1-2.5% shade (owf). The electrical conductivity increased with the concentration of carbon nanotubes, up to 5.0x10-3 S/m at 5 % shade concentration. From the percolation threshold onwards, the conductivity was able to power light-emitting diodes (LEDs).

Abstract

---

Due to the depletion of world petroleum reserves and increased environmental concerns, recent interest in alternative source for petroleum-based fuels has been developed. Biodiesel arose as the potential candidate for a diesel substitute due to the similarities it has with petroleum-based diesel. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feedstock like vegetable oils and animal fats. It is produced largely by transesterification in which oil or fat is reacted with a monohydric alcohol in the presence of a catalyst. In this research, biodiesel was produced from groundnut oil and shea butter oil using homogeneous catalyst under varying operating conditions such as temperature, concentration of NaOH(s) and time of reaction, and the conditions which gave the optimum biodiesel yield were obtained. The best operating temperature and catalyst concentration for the transesterification of both oils were found to be 70℃ and 1% catalyst (NaOH) respectively. While the optimum reaction time was found to be 75 and 60 min for shea butter and groundnut oils respectively. The study showed that both sh

Abstract

---

The synthesis and characterisation of Zn-Al hydrotalcite-like compounds intercalated with sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) have been investigated in details. The synthesis has been carried out following calcination-regeneration method. The organic modification was intended to derive hydrotalcite-like compounds appropriate for various applications such as polymer-HTlcs nanocomposite, and as scavengers of organic pollutants. The inorganic organic hybrid materials were characterised by a range of techniques such as XRD, XRF, FT-IR, TG DTA, and SEM. Characterisation data showed that pure phase of the series of hydrotalcites has been synthesised and cation molar ratios conform well to the expected ratios of Zn/Al cations in the different samples. Varying the ratios of the Zn2+/Al3+ results in distinguishing properties e.g. charge density, crystallinity, amount and orientation of anions in the interlayers and morphology. TGA showed differences in the temperature at which transitions were completed

Abstract

---

Caesalpinia coriaria has been screened for their Phytochemicals and antimicrobial activity against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus spp. and Salmonella spp. The tannins extracted using water, acetone and methanol exhibited antimicrobial activity against Staphylococcus aureus, Bacillus subtillis, Escherichia Coli, Proteus vulgaris, Shigella dysenteriae and Candida albicans. The results showed that methanol extracts have more inhibitory effect than the other extracts. However, in this study the focus is on water extract which is the solvent used traditionally. The highest zone of inhibition of the water extract was found to be 22 mm of Bacillus subtillis compared with a standard Sparfloxacin 10µg/disc which gave 23 mm of Bacillus subtillis. Phytochemicals screening including alkaloids, tannins, saponin, steroid, terpenoids, flavonoid, carbohydrates, and glycosides were present. The proximate analysis of the extracts - moisture content, total soluble, pH, and total solid and total insoluble gave 4.00%, 50.88%, 5.59, 96.00% and 45.12% respectively. . It may be concluded that Caesalpinia coriaria pods contain bioactive compounds of potentially therapeutic and prophylactic significance and thus could be a promissory candidate for drug development.

Abstract

---

Zinc oxide ceramic varistors were realized by doping ZnO with small quantities of MnO2 and PbO. The preparation technique of Direct Mixing of Constituent Phases (DMCP) was used. The samples were pelletized at a pressure of 1.24 X 103 N/cm2 and sintered in ambient atmosphere at a temperature of 850°C for a period of 36hours. They were characterized by measuring the current-voltage response to evaluate the non-ohmic behaviour. Breakdown threshold voltages of 2.02 X 103 V/m and 4.80 X 103 V/cm were recorded at currents 1.05 A/cm2 and 1.20A/cm2 respectively. Microstructural analyses were carried out using x-ray diffraction and scanning electron microscopy techniques. The XRD spectra re vealed the formation of structures and polymorphs of the additives in the sample while the SEM mi crographs revealed the sizes, types and distribution of grains in the matrix. The grain sizes for the re spective sample types were obtained as 1.621 µm and 1.020 µm. The microstructural analysis gave good correlation with the electrical response of the varistor samples.

Abstract

---

The physical properties of clay deposits located in Mailolo in Hadejia Local Government Area, Gwaram in Ringim Local Government Area and Firimo in Birnin Kudu Local Government Area of Jigawa State were assessed for use as refractory materials. Jigawa State is blessed with abundant deposits of clay, which is mostly used for the production of potteries, mud houses and structures. Samples of clays were collected from the deposits and test specimens were prepared for evaluating their physical properties to determine whether they will be suitable for refractory applications. The results of the assessment showed that Firimo, Mailolo and Gwaram possesses cold crushing strength values of 44.6 kg/cm2, 281.13 kg/cm2 and 223.6 kg/cm2 ; bulk strength values of 1.93 g/cm3, 1.73 g/cm3 and 1.41 g/cm3; moisture content values of 2.20% , 3.70% and 4.30%; percentage clay content values of 32.83%, 64.66% and 83.12% ; water absorption values of 3.00% ,4.00% and 5.00% and refractoriness values of 12500C, 12000C and 12000C respectively. Due to their low refractoriness, thermal shock resistance and apparent porosity the clays will only be suitable for low temperature refractory applications such as insulation, bakery oven lining, patching materials, slag pot and ladles lining etc.

Abstract

---

A frequently referenced component in the prevention of diabetic foot problems is the use of therapeutic footwear. Thus, footwear should be designed to relieve pressure areas, reduce shock and shear forces and be able to accommodate foot deformities by supporting and stabilizing them. There is however lack of adequate knowledge about the role of footwear and multidisciplinary approach in the management of foot related problems among diabetic patients and health care providers. This study is the first of its kind to be done in Nigeria with an aim to develop a design framework that would help to identify appropriate footwear designs for people suffering with diabetes. The proposed design framework was developed based on information gathered through questionnaires and interview surveys of diabetic patients and medical doctors in Nigeria respectively. The design framework shows three step-by-step procedures for provision of appropriate footwear to people suffering with diabetes. Product Design Specification was also formulated to determine key elements that could be considered in the design and selection of appropriate materials for diabetic footwear manufacture. Three functional prototypes (footwear) were made and used to test various usability aspects of the product with the prospective users. It was concluded that the high rate of amputation reported amongst diabetic patients could be drastically reduced through effective use of the proposed design frame work. Finally, limitations of this work and areas that would require further research were also outlined.

Abstract

---

The flow patterns during oil-water flows were investigated in two acrylic pipes that had different diameters, 38 mm ID and 14 mm ID respectively. Water (ρ = 1000 kgm-3, μ = 0.001 kgm-1s-1) and Exxsol D140 oil (ρ = 830 kgm-3, μ = 0.0055 kgm-1s-1) were used as test fluids, while the patterns were recorded with a high speed camera. Dispersed and rivulet flows were seen in the small pipe but not in the large one at the conditions studied. The dual continuous pattern appeared in both pipes but, with different characteristics. Larger drop sizes and smoother interface were seen in the smaller pipe. Double-wire conductance probes were used to collect time-series records of the oil-water interface variation during stratified flow in the pipes. Data was collected at 256 Hz (or 512 Hz) for up to 4 min. Following de-trending and normalisation, the signal was found to be stationary and normal. Power spectra were computed via the auto-correlation function. Low-frequency contributions (due partly to the pumps) were seen in both pipes. In the large pipe, contributions were in the range 20 – 50 Hz and their normalised power increased with the mixture velocity. These higher frequencies were attributed to the fluctuations and roughness of the interface, notorious in the large-diameter pipe during stratified flow. In contrast, the interface in the small pipe was smooth.

Abstract

---

In this research, Atili (blackdate) oil (Canarium Schweinfurthii) was extracted from the pulp using aqueous biphasic system (ABS) prepared from fixed concentration (40%) of polyethylene glycol (PEG) and varying concentrations of salt (di-sodium hydrogen phosphate (Na2HPO4)) at 10%, 20%, 30%, 40% and 50% respectively. The partitioning of the atili oil to the PEG-rich phase for the various combinations of the salt concentration with the fixed PEG concentration were compared and the extracted atili oil characterized. The extraction process was carried out by preparing the aqueous biphasic systems with the varying salt concentrations and placing the enclosed pulp of atili fruit inside the ABS prepared until the oil partitions to the PEG-rich phase. The ABS prepared from the salt concentration at 20% was found to give the best system for extracting atili oil with a yield of 43.50 mls of atili oil /100g of atili pulp. Lastly, the acid value , saponification value, free fatty acid and ester values were found to be 0.22, 116.13, 0.11 and 115.92 respectively.

Abstract

---

Atili (blackdate) oil was bleached in this research using three different adsorbents; acidic fuller’s earth, activated carbon, and the mixture of fuller’s earth and activated carbon. The adsorbents were compared to give the most suitable of the three. The bleaching process was carried out by agitation of varying amounts of the different adsorbents at 80oC and a contact time of 45mins. The bleaching data were fitted to Langmuir and Freundlich isotherms; bleaching with fuller’s earth gave good fits to both. Fuller’s earth was observed to be most suitable for bleaching of Atili (blackdate) oil, giving a colour removal of 88.25%, which was followed by activated carbon with a colour removal of 85.95% and lastly the mixture, with colour removal of 85.34% all with 2g of adsorbent. Finally, photometric colour was determined as the average absorbance between 420 and 800 nm

Abstract

---

Subgrade materials from Master Test Section (MTS) 1 were tested to obtain their physical properties. Three samples each from the MTSs making a total eighteen (18) samples were obtained and subjected to laboratory test to determine their basic physical properties. Testing include particle size distribution, Atterberg limits and specific gravity tests. The samples were classified according to American Association of State Highway and Transportation Officials (AASHTO) and the Unified Soil Classification System (USCS). The AASHTO soil classification shows that the subgrade soil samples obtained from the MTS 1 were either clayey soil (A-6 and A-7-6) or silty soils (A-4, A-5 and A-2-4). The AASHTO soil classification generally showed that the subgrade samples were “Fair to Poor” in subgrade properties for use as construction materials. The USCS soil classification indicated that most of the samples were lean clay soil with gravel (CL) except few that were either clayey gravel (GC) or clayey sand (SC). This showed that the subgrade samples were mostly clay soil.

Abstract

---

The aim of the work presented in this paper is to evaluate and develop a framework for reliability analysis of distribution system modeling and simulation using Petri-Nets. The problem of detecting, isolating and restoring fault events in dynamic systems modeled is considered. As the complexity of power system increases, fault diagnosis become very difficult task therefore necessitate the development of PN to anchor onto power system in order to tackle and overcome these situation. A sample power system network which has 2 sources, 4 buses, 10 over current relays, 5 circuit breakers and 2 distribution lines connected loads is used as test network. The modeled network is then simulated with five fault cases. Results of these simulations are given in order of the PN firing sequence as follows: M1 = (1; 0; 0; 0; 0; 0; 0); M2 = (0; 1; 0; 0; 0; 0; 0); M3 = (0; 0; 1; 1; 0; 0; 0); M4 = (0; 0; 1; 0; 1; 1; 0); M5 = (0; 0; 1; 0; 1; 0; 1) and M6 = (1; 0; 0; 0; 0; 0; 0).It is shown from five cases that the faulted power system elements are diagnosed accurately by using the Petri nets based fault diagnosis models analytical and simulation.

Abstract

---

Alkyl ester derivatives of palm kernel oil have been prepared for use as bio-dielectrics in oil filled High Voltage (HV) electric equipment. Electrical conduction and loss characteristics of the ester derivatives were studied to understand the behaviour of the material under applied electric field. Frequency response analyzer was used to study electrical conduction within the fluids since dielectric loss occurring at low frequencies under AC condition is dominated by mobile charge carriers. This is particularly important since power dissipation at power frequency, 50 Hz, may lead to dielectric heating. The dielectric response analyses of the samples within the range 10-3 - 104 Hz showed a constant real relative permittivity at high frequency region. When the frequency dropped below 101 Hz, interfacial polarization was observed at the electrode-liquid interface and this resulted in a significant dielectric increment in the real part of the relative permittivity at low frequencies with a negative slope greater than 1 and a frequency independent conductance (εʹ slope = -1). This is an indication of Maxwell-Wagner interfacial effect where electric double layer (EDL) is formed. The real part acquired a slope of about -1 around frequency of 10-3 Hz. This suggests that the establishment of the EDL may be tending towards steady state. This change in the low frequency dispersion could be due to the ionic species undergoing interfacial electrochemical processes, or ions of lower mobility may have contributed to the EDL formation within the frequency region. This may have limited the effect of the strongly divergent processes at the interface.

Abstract

---

The paper presents the results of a laboratory study on the effect of groundnut shell ash on the particle size distribution and plasticity characteristics of black cotton soil. Black cotton soil was treated with a maximum 10 % groundnut shell ash by weight of dry soil. The results show that there was a substantial reduction in the amount of fines content with higher doses of groundnut shell ash. The percentage of silt fraction in the natural soil was 91 % and on treatment with maximum 10 % groundnut shell ash content (by weight of dry soil) at optimum moisture content (OMC), the silt fraction was reduced to 1.3 %. The plasticity index increased from 38 to 75 % when treated with 10 % groundnut shell ash content by weight of dry soil. The results obtained place the soil below the Highway Research Board of America (1943) requirements of plasticity index of less than 50 %. The plasticity modulus (PM), plasticity product (PP) and the shrinkage modulus (SM) increased while the grading modulus (GM) decreased with higher doses of groundnut shell ash. However, the treated soil can be admixed with more potent stabilizer since its workability was improved by addition of 10% groundnut shell ash content by dry weight of soil.

Abstract

---

Biodegradable polymers can either be natural or synthetic and they have been greatly applied across fields especially in medicals due to their bioabsorbability, biocompatibility and biodegradability. A lot had been achieved through the efforts of polymer scientist in using synthetic materials in human body and this is due to the versatility and biodiversity of the materials. Synthetic biodegradable polymers in general are of greater advantage over natural materials in that they can be tailored to give a wider range of properties and have more predictable lot-to-lot uniformity than materials from natural sources. Lately, there is a large increase in the use of these polymer materials in ecological applications, packaging, and pharmaceutics and even in agriculture. Hence, researchers have also intensified efforts to make these polymer based materials eco-friendly so as to reduce the pollution problems such as blockage of drainages and littering of the environment by these polymeric materials. In this review however, we will focus on synthetic biodegradable with emphasis on their mode of degradation, applications and processing conditions.

Abstract

---

Chitin was isolated from locust using a standard procedure as described in literature with slight modifications. Chitosan was then synthesized from the isolated chitin by treatment with 50% concentration of NaOH, the degree of the deacetylation obtained was 64.4% using Potentiometer Titration method. Both chitin and chitosan ash content and moisture content were then analyzed. They were then characterized using FTIR, TGA, DSC and XRD and the results compared with chitin and chitosan obtained from other sources and they thus show similar physicochemical and chemical structure. Thus locust is a promising alternative source for both chitin and chitosan.