Browsing Articles: Department of Physical Sciences by Title
Now showing items 11-30 of 59
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Chemical composition and mosquito repellency of essential oil of Conyza newii propagated in different geographical locations of Kenya
(John Wiley & Sons, 2014)Previously, essential oil of Conyza newii (Asterale: Asteracea, Oliv. & Hiern) growing in the northern part of West Pokot (35◦E, 1◦N) of Kenya was shown to be highly repellent [RD50 =8.9×10−5 mg/cm2, 95% confidence interval ... -
Combustion synthesis, characterization and luminescence properties of barium aluminate phosphor
(Elsevier, 2014-09)The blue-green emitting Eu2+ and Nd3+ doped polycrystalline barium aluminate (BaAl2O4:Eu2+,Nd3+) phosphor, was prepared by a solution-combustion method at 500 °C without a post-annealing process. The characteristic variation ... -
Concentration of Laterites Using Biomass
(Kenya Industrial Property Institute, 2015-06-11)A method of concentrating iron in laterites to make the iron extraction process economical is disclosed. Concentration using biomass yields higher levels of iron by using appropriate ratio of biomass: laterites. The ... -
Copper extraction by wet chemical method
(Elsevier, 2018-07)In many countries large deposits of copper with no locally established copper based industries occur because known methods for extraction are prohibitively expensive and unaffordable. This study reports on an affordable and ... -
Copper extraction by wet chemical method
(Elsevier, 2018-07)In many countries large deposits of copper with no locally established copper based industries occur because known methods for extraction are prohibitively expensive and unaffordable. This study reports on an affordable and ... -
Crop residues used as lignocellulose materials for particleboards formulation
(Heliyon, 2020-09)Efforts to reduce pressure on use of wood in particleboard formulation have included the use of non-wood materials such as crop residues. Physical and mechanical properties are determined by the number of the hydroxyl (-OH) ... -
Determination of Potassium Levels in Intensive Subsistence Agricultural Soils in Nyamira County, Kenya
(2013)Assessment of potassium levels in agricultural soils of Nyamira County, Kenya was necessitated by the observed progressive drops in maize acreage yields over the years despite use of phosphorus and nitrogenous fertilizers. ... -
Diffusivity of Chloride Ion in Mortar Cubes Made Using Ordinary Portland and Portland Pozzolana Cements
(2014)Cement is subject to degradation by aggressive media. This study investigated chloride diffusivity in mortar made from Kenyan cements which included three brands of Ordinary Portland Cements (OPC) and three brands of ... -
Diffusivity of Sulphate Ion in Selected Ordinary Portland and Portland Pozzolana Cements Mortar
(Kenya Chemical Society, 2014)Cement is subject to degradation by aggressive media. This study investigated sulphate diffusivity in mortar made from selected Kenyan cements which included three brands of Ordinary Portland Cements (OPC) and three ... -
Effect of Bacillus cohnii on Some Physicomechanical and Microstructural Properties of Ordinary Portland Cement
(Hindawi, 2020-09)Cement-made materials face durability and sustainability challenges. (is is majorly caused by the presence of cracks. Cracking affects the mechanical strength of cement-based materials. Microbiologically induced calcite ... -
Effect of Ga3+ and Gd3+ ions substitution on the structural and optical properties of Ce3+-doped yttrium aluminium garnet phosphor nanopowders
(John Wiley & Sons, 2016-03)ABSTRACT: The structural and optical properties of commercially obtained Y3Al5O12:Ce3+ phosphor were investigated by replacing Al3+ with Ga3+ and Y3+ with Gd3+ in the Y3Al5O12:Ce3+ structure to form Y3(Al,Ga)5O12:Ce3+ and ... -
Effect of Ga3+ and Gd3+ ions substitution on the structural and optical properties of Ce3+-doped yttrium aluminium garnet phosphor nanopowders
(John Wiley & Sons, 2016-01)ABSTRACT: The structural and optical properties of commercially obtained Y3Al5O12:Ce3+ phosphor were investigated by replacing Al3+ with Ga3+ and Y3+ with Gd3+ in the Y3Al5O12:Ce3+ structure to form Y3(Al,Ga)5O12:Ce3+ and ... -
Effects of biocementation on some properties of cement-based materials incorporating Bacillus Species bacteria – a review
(Taylor and Francis, 2019-11)There is a growing need in the construction industry to improve transfer and durability aspects of Portland pozzolana cement. Ureolytic bacteria have recently emerged as potential micro-organisms well known for precipitation ... -
Effects of biocementation on some properties of cement-based materials incorporating Bacillus Species bacteria – a review
(Taylor and Francis, 2019-11)There is a growing need in the construction industry to improve transfer and durability aspects of Portland pozzolana cement. Ureolytic bacteria have recently emerged as potential micro-organisms well known for precipitation ... -
Effects of Chlorides on Corrosion of Simulated Reinforced Blended Cement Mortars
(Hindawi, 2019-03)Cementitious materials are subject to degradation when subjected to corrosive chloride media. This paper reports the experimental results on corrosion studies conducted on a potential cementitious material, PCDC, made ... -
Effects of Temperature on Ilmenite During Concentration of Iron in Laterites Using Charcoal and Separation using Magnetic Separation
(IJSET, 2014-06)Effect of temperature on ilmenite minerals found in laterites has been investigated. It was found that during reduction of iron minerals in laterites to magnetite using charcoal at temperatures of about 500-700oC, ... -
Effects of Zeolites X and Y on the Degradation of Malathion in Water
(2013)The inclusion of both zeolites X and zeolite Y significantly affected the dissipation of malathion in water. In the fresh water, malathion degradation followed a pseudo-first order kinetics with concomitant half-life ... -
Energy recovery from biomethanation of vinasse and its potential application in ozonation post-treatment for removal of biorecalcitrant organic compounds
(ELSEVIER, 2020-10)Vinasse is characterized by a high chemical oxygen demand (COD) and dark brown colour, which requires abatement before disposal to prevent the pollution of receiving streams. Anaerobic digestion (AD) usually applied for ... -
Equilibrium Studies for Adsorption of Zn2+ on to Acid Treated Kikuyu Grass Pennisetum Clandestinum Biomass
(2016-04)The feasibility of using Pennisetum clandestinum biomass as low-cost adsorbent for the removal of Zn2+ was investigated in batch studies. The Freundlich, Langmuir,Dubinin Raduskevich and Temkin adsorption isotherms were ...
