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