Abstract

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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

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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

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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

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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

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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

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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

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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.