ABSTRACT This paper presents the effect of polymer concentration on the release of fungicidal antimicrobial (AM) agent to prolonging the shelf life of packaged food. This project aimed to produce and test AM films with varying polymer ratio to control the release of fungicidal AM agent. The effects of potassium sorbate (PS) released on peanut and fresh breads was tested for nineteen days to determine the effect of AM agent to inhibit the growth of Aspergillus niger (A. niger). The microbe wa...
Abstract This research work presents the results of analytical studies of effects of pressure and adhesion energy on the interfacial properties of cold welded and laminated surfaces in organic and Hybrid Organic/Inorganic electronic structures. The analytical modeling is based on the physics of elastic behaviour of a cantilever beam. The energy balance approach was employed to model the surface contacts in Hybrid Organic/Inorganic structures, HOISOLs, and Organic Light Emitting Diodes, OLEDs...
ABSTRACT The increasing rate of cancer patients worldwide, and especially Africa has led to numerous efforts to battle it. One approach to this has been localized drug delivery to reduce the quantity of drugs needed for therapeutic effect. Poly-di-methyl-siloxane (PDMS) is an elastomer with much focus on it as a microfluidic device. PDMS is one polymer of choice for localized drug delivery due to its biocompatibility, transparency, and ease of fabrication. However, its highly hydrophobic nat...
Abstract This work presents the results of experimental and theoretical studies of the biodegradation of polyethylene, recycling of polyethylene into strong and tough earth-based composite building materials and the statistical distribution and particle size analysis of the polyethylene composites. Serratia marcescens subsp. marcescens and its supernatants are able to biodegrade linear low density polyethylene (LLDPE). The results show that the cell-free extracts degrade LLDPE faster than th...
Abstract Bioinspired design involves the use of concepts observed in natural biological materials in engineering design. The hope is that the leveraging of biological materials in the engineering domain can lead to many technological innovations and novel products. This work presents the initial material characterization of kinixys erosa tortoise shell using a combination of xray diffraction, optical/scanning electron microscopy and micro-mechanical testing. The results were used in the anal...
ABSTRACT The use of local clays for the production of porcelain pin insulators was investigated. Clays from Awo-omama, Ibere and Nsu were used for the study. Test samples were made by varying the compositions of feldspar and quartz needed to form a mouldable plastic body with each clay. The following properties were determined: electrical resistivity, apparent porosity, water absorption, bulk density, linear shrinkage as well as crystalline phases produced after firing. This characterizat...
ABSTRACT Organolead trihalide perovskite solar cells have shown success as light absorbers in photovoltaic cells due to their efficiency increasing from 3.5% to over 20% within only five years. However, pinhole formation and incomplete coverage of solution-processed perovskite film results in increased current leakage, reducing efficiency. Hence the surface morphology of perovskite film is important for high performance of perovskite solar cells. Here the morphology is carefully controlled b...
ABSTRACT The effect of cooling rate and modification on the microstructure and tensile properties of Al-Si-Mg alloys was carried out. Castings were produced using a stepped pattern that has different section thicknesses. Sand casting technique was used. A thermocouple inserted into the mould cavity recorded the cooling rates for the different sections. The Al5.43%Si3.83%Mg which was melted in the crucible furnace was modified with sodium (Na) and strontium (Sr) in separate cases. T...
BACKGROUND The numerous limitations of inorganic solar cells has led to keen interest and exploitation of organic solar cells in recent times. They offer several advantages such as lightness, mechanical flexibility, low production cost, ease of processing and have a high potential for large area solar conversion1 . The properties, performance and lifespan of these solar cells depend on the properties of the active layer and interface between the components1 . Thus far research efforts have b...
ABSTRACT Drilling fluids play sophisticated roles in the drilling process which include, keeping formation fluids at bay, stabilizing the wellbore without damaging the formation, lubricating the bit and drill-string and clearing cuttings from the bit face. Weighting agents are compounds that are dissolved or suspended in drilling fluid to increase its density. The effect of density also contributes to the stability of the borehole by increasing the pressure exerted by the wellbore fluid onto...
ABSTRACT The theoretical study of methylammonium bismuth halide, (CH3NH3)3Bi2I9, was simulated using SCAPS 1D software package. The effect of the bismuth perovskite absorber layer thickness on the solar cell performance was investigated using three different materials (organic and inorganic) materials such as Cu2O, CuI, and spiro-OMeTAD as hole transporting layer (HTL), and four different materials (organic and inorganic) materials such as ZnO, TiO2, PCBM, and P3HT as electron transporting l...
ABSTRACT This thesis is focused on fabrication of biodegradable implantable devices for extended localized drug release. Paclitaxel (PT) was used as cancer drug in the study. Poly lactic –co- glycolic acid (PLGA) is a polymer used for drug elution. In this work, the role of enzymes on the degradation of PLGA, Effect of different pH on the degradation of PLGA and the kinetics of drug release was elucidated. PLGA ratios of 75:25 and 85:15 were used. The enzyme used in the study is lipase enz...
ABSTRACT The growing global understanding of ecological footprints and environmental pollution invented by humans is gainfully affecting our material design practice, pushing the search for more sustainable alternatives, and development of natural biocomposites. In this research, the natural ability of saprophytic fungi to digest and bind lingo-cellulose is utilized to develop natural biocomposite materials for novel applications in design and architecture. This study aims to provide an insi...
ABSTRACT When a well is drilled, the equilibrium in-situ stress is changed. In order to support the stress relief induced by the drilling and to prevent hydrocarbon influx into the cavity, the borehole is filled with a fluid. These operations create new stress configurations. The main point in wellbore projects is the definition of the drilling fluid density to keep the wellbore stable. The lower bound to the fluid density is the collapse stress that is the limit to shearing. The upper bound...
ABSTRACT Like any industry, the economic success of the oil and gas industry can be no swifter than its success in corrosion control/prevention. Some oil and gas industries operate in hostile offshore environment that harbors significantly quite substantially different corrosive agents including ions of chloride, Cl- , bicarbonate (HCO3 - ), hydrogen sulfide (HS- ), sulfide (S- ), etc., coupled with gases such as oxygen (O2), carbon dioxide (CO2), just to name a few. Oil and gas structural m...