Browsing Journals: Department of Physical Sciences by Title
Now showing items 25-44 of 59
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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 ... -
Heavy metal concentrations in soil and vegetables irrigated with sewage effluent: A case study of Embu sewage treatment plant, Kenya
(Elsevier, 2020-02)As a result of the increasing constraint in the availability of fresh water for irrigation, wastewater especially sewage effluent is being used for irrigation of agriculture fields, par- ticularly in urban and peri–urban ... -
In vitro anti-cancer efficacy and phyto-chemical screening of solvent extracts of Kigelia africana (Lam.) Benth
(Heliyon, 2020)Background and objectives: Kigelia africana is a medicinal plant growing naturally in many parts of Africa. In Kenya, a water concoction of the plant is used to treat breast and prostate cancers. Laboratory data on its ... -
Influence of alkaline earth metal cations; Ca2+, Sr2+ and Ba2+ on the structural and optical properties of MAl2O4: Eu2+, Nd3+ phosphors.
(2014)Eu2+ doped and Nd3+ co-doped MAl2O4:Eu2+, Nd3+ (M = Ca, Sr, and Ba) phosphors were prepared by a solution-combustion method. The obtained powders were investigated in terms of their phase composition, particle morphology ... -
Influence of Lysinibacillus sphaericus on compressive strength and water sorptivity in microbial cement mortar
(Elsevier, 2019-11)Cement structures are subject to degradation either by aggressive media or development of micro/macro cracks which create external substance ingress pathways. Microbiocementation can be employed as a self-intelligent solution ... -
Influence of Lysinibacillus sphaericus on compressive strength and water sorptivity in microbial cement mortar
(Elsevier, 2019-11)Cement structures are subject to degradation either by aggressive media or development of micro/macro cracks which create external substance ingress pathways. Microbiocementation can be employed as a self-intelligent solution ... -
Influence of Starkeya novella on Mechanical and Microstructural Properties of Cement Mortars
(Hindawi, 2020-04)Cement-based materials are subject to degradation during their service life. Most of the structural failures have been associated with corrosion of the rebar due to chloride ingress, alkali aggregate reaction, and/or sulfate ... -
Investigating a Prototype Heat Exchanger for Steam Storage
(2014-07)A coiled tube single pass counter flow heat exchanger was designed and fabricated using locally available materials and its capacity to transmit heat to water to make steam was tested. The heat exchanger was part of ... -
Magnetic Concentration of Iron in Lateritic Soils from Kamahuha, Murang’a County, in Kenya using Carbon Monoxide Generated In-Situ
(IJSET, 2014-08)Chemical and Mineral Analyses of laterites from selected sites in Kamahuha area of Murang’a County, in the Republic of Kenya, have been carried out with particular interest in the levels of iron and the type of minerals ... -
Malaria vector control strategies. What is appropriate towards sustainable global eradication?
(ELSEVIER, 2020-10)Malaria a mosquito-borne disease caused by Plasmodium remains to be a main global burden despite concerted efforts to eliminate it. While diverse control strategies have been put in place for mosquito-borne diseases, vector ... -
Performance of Potential Pozzolanic Cement in Chloride media
(2014-04)The paper presents finding of the pozzolanic activity of calcined clays from selected regions of Embu County – Kenya. The results are also presented for the compressive strength development and Chloride ingress resistance ... -
Phenolic and Monoterpenoid Mosquito Repellent Constituents of Headspace Vapors of Conyza newii
(2013-01)The plant Conyza newii has been reported to posses, mosquito repellent and fumigant toxicity properties. In this study headspace vapors emitted by the plant were obtained by adsorption on porapak Q® through headspace ... -
Physicochemical Performance of Portland-Rice Husk Ash-Calcined Clay-Dried Acetylene Lime Sludge Cement in Sulphate and Chloride Media
(Hindawi, 2019-03)This paper reports leach and/or intake of SO42−, Cl−, Ca2+, Na+, and K+ from and/or into cement mortar cubes made from a novel cementious material in naturally encountered environmental simulated media. The paper also ... -
A preliminary study of Thermoluminescence of beta-irradiated SrAl2O4:Eu2+, Dy3+ phosphors
(2015)Eu2+ doped and Dy3+ co-doped strontium aluminate (SrAl2O4:Eu2+,Dy3+) phosphors were synthesized by the solution - combustion technique at 500 oC using urea as a reducer, a widely known method for preparing nano sized ... -
Properties of activated blended cement containing high content of calcined clay
(Elsevier, 2018-08)This paper presents findings of an experimental investigation on sodium sulphate (Na2SO4) activated calcined clay e Portland cement blends in sulphuric acid media. Calcined clays were blended with Ordinary Portland Cement ...