Browsing by Author "Bensah, Y.D."
Now showing 1 - 11 of 11
Results Per Page
Sort Options
Item Application of clay ceramics and nanotechnology in water treatment: A review(Cogent Engineering, 2018-07) Annan, E.; Agyei-Tuffour, B.; Bensah, Y.D.; Konadu, D.S.; Yaya, A.; Onwona-Agyeman, B.; Nyankson, E.The increasing demand to provide clean water for drinking has brought to the fore the importance of seeking other materials with the ability or combined effect with other materials to purify water. Clay ceramics are known to be natural and also easily engineered porous-structured materials. Review papers on water filtration over the last decade have been on specific mechanisms or technologies. This review paper presents a single platform which provides information encapsulating all these technologies. This paper highlights water contaminants, and their various treatment technologies. The effectiveness of these technologies are evaluated via scholarly documented peer-reviewed papers. Moreover, the discussions are interspersed with the World Health Organization’s (WHO) standard for various contaminants along with the exploration of the efficiency of clay minerals as potent water filtration material. Finally, current trends in application of nanotechnology in water purification systems are also highlighted. These technologies include adsorption, microbial disinfection, and photocatalysis.Item The effect of natural fibre reinforcement on polyurethane composite foams –A review(Scientific African, 2021) Kuranchie, C.; Yaya, A.; Bensah, Y.D.The use of natural fibre reinforced polyurethane composite foams is becoming increasingly popular in the cellular foam industry. This demand is due to the increase in the use of ecofriendly, biodegradable, and sustainable materials to produce polyurethane composite materials for such applications. In this regard, natural fibres from agro-waste are being preferred to their synthetic counterparts due to readily availability, strength, lightweight, biodegradability, and cost-effectiveness. In addition to their renewable nature, the use of natural fibre in polyurethane foams produces composite foams with better properties than the neat polyurethane foams. This review explores the preparation, and properties of nat- ural fibre reinforced polyurethane composite foams and discusses the effect of chemical modification of these fibres on the interfacial adhesion of the fibre-polymer matrix sys- tem. It also assesses the trends and future potential of the global market of natural fibres and the polyurethane composite foams.Item Evolution of cellular morphology in pure materials(Journal of Materials Science, 2020-05-28) Bensah, Y.D.The evolution of cellular morphology during interfacial instability for liquid–solid transition for pure unary material systems is studied using the maximum entropy production (generation) rate principle (MEPR) for steady-state directional solidification. This approach is dependent on a quantity called maximum entropy production rate density which inherently contains key solidification parameters that governs cellular evolution for liquid–solid transformation. The maximum entropy production rate density is computationally measured from the solid–liquid interface in diffuse form and considers steady-state solidification at low velocities for both near and far from equilibrium conditions. The results are presented in mathematical expressions for morphological instability that corresponding to the evolution of a cellular morphology which emanates from the solid–liquid interface. The model is formulated to evaluate the solid–liquid interface thickness, the solidification velocity, grain boundary energy, and the size of the cellular morphological at instability. The results are tested with a number of pure single element materials at different temperature gradients which compare well with available experimental data.Item Morphological growth criterion for faceted to non-faceted transition in pure materials(Results in Physics, 2023) Bensah, Y.D.A criterion to explain the morphological growth transition from faceted to non-faceted (f-nf) morphology in the case of directional solidification is presented for pure materials. The criterion is based on the number of atomic layers at the solid–liquid interface and allows a foreknowledge of the solidification growth velocity at which f-nf transition becomes significant. The basis for the transition criterion hinges on the Cahn theory of interface structure and the theory of liquid–solid transition by the maximum entropy production rate (MEPR) principle. The criterion is tested with a number of pure materials and compared with experimental measurements for salol. The criterion fits quite well with available experimental data.Item Morphological instability at the solid–liquid interface by the maximum entropy production rate principle(Canadian Journal of Physics, 2018-04) Bensah, Y.D.We examine the morphological instability from planar to non-planar cellular morphology with the maximum entropy production rate (MEPR) principle. An expression that quantifies the MEPR density at the solid–liquid interface (SLI) during direction solidification is presented, which leads to an instability criterion for dilute binary alloys. The instability criterion also affords to theoretically calculate the instability solidification growth velocity. The model considers steady state solidification at close-to and far-from equilibrium conditions.Item The nature and effect of sulphur compounds on co2 and air reactivity of petrol coke(Journal of Engineering and Applied Sciences, 2010-06) Bensah, Y.D.; Foosnaes, T.Three different single-source coke types (SSA, SSB and SSC) were studied for their air and CO2 reactivities using the Hydro method and the observed correlation with reactivity determinant parameter such as elemental composition was noted. The reaction temperatures were 525 °C and 960 °C for air and CO2 reactivities, respectively. Coke sample SSA recorded the highest CO2 reactivity value of 166 mg/g h while coke sample SSB recorded the lowest value of 25 mg/g h. The coke CO2 reactivity showed a moderately strong correlation with the combined effect of Na, Fe and Ca concentrations. The inhibitory effect of sulphur as a catalytic poison on Na was observed with significant downward trend in CO2 reactivity of the investigated cokes. Coke air reactivities showed the expected strong correlation with V. Air reactivity was highest in sample SSC (262 mg/g h) at V concentration of 378 ppm and lowest in sample SSB (39.6 mg/g h) at V concentration of 68 ppm. Sample SSA recorded reactivity value of 129.6 mg/g h at V concentration of 147 ppm. The compound 1-butanethiol was identified by 1-D 1H NMR and 13C NMR, and by 2-D COSY, HSQC and HMBC NMR spectroscopic techniques. It is proposed that 1-butanethiol is one of the possible organosulphur compounds responsible for the reaction with Na forming a stable non-mobile complex partially inhibiting the catalytic effect of Na. © 2006-2010 Asian Research Publishing Network (ARPN). All rights reserved.Item Preparation and Characterization of Rubber Blends for Industrial Tire Tread Fabrication(International Journal of Polymer Science, 2018-09) Mensah, B.; Agyei-Tuffour, B.; Nyankson, E.; Bensah, Y.D.; Dodoo-Arhin, D.; Bediako, J.K.; Onwona-Agyeman, B.; Yaya, A.The physico-mechanical properties of variable rubber blends including epoxide natural rubber (ENR), polybutadiene rubber (BR), and solution polymerized styrene-butadiene rubber (SBR) filled with silanized silica and carbon black mixtures were explored. The tensile, hardness, resilience, abrasion, and fatigue behavior were investigated. An optimized composition involving 30 phr of ENR and 70 phr SBR filled with mixtures of carbon blacks and silanized silica was proposed to be a suitable composition for the future development of green passenger truck tires, with low rolling resistance (fuel saving ability), high wear resistance, and desired fatigue failure properties.Item Processing of waste polyethylene into polymer-ceramic composite through lipid assisted melt compounding(ARPN Journal of Engineering and Applied Sciences, 2012-06) Bensah, Y.D.; Agyei-Tuffour, B.; Damoah, L.N.W.; Efavi, J.K.In this work, a modified approach to melt compounding has been successfully developed to study the dispersion of kaolin particles in polyethylene and properties of polyethylene-kaolin clay composites. The process involved the use of melt compounding technique with vegetable lipid acting as a melting medium with the capability to enhance miscibility of the polyethylene with the kaolin which is necessary for strength improvement of the polyethylene-kaolin composite. Eight different compositional batches were formulated and cast at 245 °C. In all the thermal and mechanical properties as well the microstructure of the composites were studied. Comparisons of the composites with pristine polyethylene-lipid have shown an improved glass transition temperature (Tg) and the thermal decomposition temperatures as a result of changes in the chemical structure. Proportional kaolin additions did not change the crystallization temperature (Tc) of the blends as compared to the pristine polyethylene-lipid blend. Incorporation of 60% kaolin by weight in the polyethylene-lipid matrix significantly improved the mechanical properties of the composites to its peak and an increased compressive strength of 2.0 to 8.7 MPa has been measured. Scanning electron microscopic (SEM) analyses shows the formation of a web-like entanglement caused by the dispersion of the kaolin particles in the matrix. © 2006-2012 Asian Research Publishing Network (ARPN).Item Solidification Morphology and Bifurcation Predictions with the Maximum Entropy Production Rate Model(entropy, 2019-12-26) Bensah, Y.D.; Sekhar, J.A.The use of the principle of maximum entropy generation per unit volume is a new approach in materials science that has implications for understanding the morphological evolution during solid–liquid interface growth, including bifurcations with or without di useness. A review based on a pre-publication arXiv preprint is first presented. A detailed comparison with experimental observations indicates that the Maximum Entropy Production Rate-density model (MEPR) can correctly predict bifurcations for dilute alloys during solidification. The model predicts a critical di useness of the interface at which a plane-front or any other form of di use interface will become unstable. A further confidence test for the model is o ered in this article by comparing the predicted liquid di usion coe cients to those obtained experimentally. A comparison of the experimentally determined solute di usion constant in dilute binary Pb–Sn alloys with those predicted by the various solidification instability models (1953–2011) is additionally discussed. A good predictability is noted for the MEPR model when the interface di useness is small. In comparison, the more traditional interface break-down models have low predictiveness.Item Structure and diffuseness model of solid-liquid interface for binary alloys(Results in Physics, 2023) Bensah, Y.D.Using the morphological instability at the solid–liquid interface as a basis by the maximum entropy production rate principle (MEPR), a model is presented on the morphological structure and diffuseness of the interface during directional solidification of binary alloys. It is shown that, the independent diffuseness theory of Cahn and the Jackson roughness criterion can be unified at a limiting condition under this new MEPR solidification model. The model under the principle of MEPR is applied to describe the evolution of atomistically smooth and rough interfaces through the evaluation of the size of the solid–liquid interface and the of number atomic layers. The model is tested with data for binary alloys of aluminium, lead, and tin at varying solute concentrations. The results showed strong agreement with available data from experimental measurements.Item Synthesis and characterization of zinc and copper oxide nanoparticles and their antibacteria activity(Results in Materials, 2020) Asamoah, R.B.; Yaya, A.; Mensah, B.; Nbalayim, P.; Apalangya, V.; Bensah, Y.D.; Damoah, L.N.W.; Agyei-Tuffour, B.; Dodoo-Arhin, D.; Annan, E.Inorganic nano-metal oxides can be effective alternatives to drug resistant organic antibiotics due to their broad spectrum antimicrobial activity against pathogenic and mutagenic gram-negative and positive bacteria. In this study, zinc and copper oxides (ZnO and CuO) were synthesised using a wet chemical reduction method. The oxide nanoparticles were characterized using X-ray diffraction (XRD), UV–Vis spectrometer, Fourier Transformed Infrared spectrometer and Transmission electron microscopy (TEM). The antibacterial activities of the nanoparticles were investigated against e. coli and s. aureus using disk diffusion and microdilution tests. The TEM micrographs showed that copper oxide nanoparticles assumed a nanorod shape of average length of 100 nm whiles zinc oxide nanoparticles were spherical of average diameter of 15 nm. The FTIR results showed that the nanoparticles were free of impurities and organic surfactants, which was confirmed by XRD. For the antibacteria tests, the minimum inhibition concentration (MIC) of CuO against e. coli and s. aureus were 1 mg/ml and 0.25 mg/ml respectively whiles it was 0.1 mg/ml for ZnO against s. aureus with ZnO producing no inhibition against e. coli. With the microdilution test, both nanoparticles exhibited activity against both bacterias at all varying concentrations. The results concluded that CuO had higher antibacteria activity compared to ZnO.