Browsing Articles: Department of Physical Sciences by Title
Now showing items 30-49 of 59
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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 ... -
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 ... -
Properties of blue emitting CaAl2O4:Eu2+, Nd3+ phosphor by optimizing the amount of flux and fuel
(Elsevier, 2014-04)Long afterglow CaAl2O4:0.03Eu2+, 0.03Nd3+ phosphor was prepared by solution-combustion synthesis. The active role of boric acid (H3BO3) as a flux in enhancing the Eu2+ photoluminescence and the effect of a varied amount ... -
A prototype parabolic trough solar concentrators for steam production
(Jomo Kenyatta University of Agriculture and Technology, 2012)In this work, the potential for a solar-thermal concentrator to produce steam has been studied. Three parabolic trough solar concentrators (PTSCs) of dimensions: - aperture width of 1.2 m, Collector length of 5.8 m and ... -
A Prototype Steam Storage System for Power Production
(2014-08-01)Use of solar energy on a large scale is mainly limited to the sun duration hours, weather conditions and adequate solar thermal storage technology. A means of addressing this problem using local materials is provided. ... -
Review of Carbonation Resistance in Hydrated Cement Based Materials
(Hindawi, 2019)Blended cements are preferred to Ordinary Portland Cement (OPC) in construction industry due to costs and technological and environmental benefits associated with them. Prevalence of significant quantities of carbon dioxide ...
