Browsing School of Pure and Applied Sciences by Title
Now showing items 104-123 of 170
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Phylogenetic studies uncover a predominantly African lineage in a widely distributed lichen-forming fungal species
(MycoKeys, 2016)A number of lichen-forming fungal species are widely distributed. Here, we investigate biogeographic patterns in a widely distributed isidiate taxon –Parmelinella wallichiana – using molecular sequence data. Our results ... -
Physico-Chemical Properties of Kenyan made Calcined Clay-Limestone Cement (LC3).
(Elsevier, 2020)In Kenya fired clay bricks are mainly used as construction materials. However, vast quantities of these Fired Rejected Clay Bricks (FRCB) generated are rejected annually as a result of improper calcination or demolition ... -
Physicochemical Performance of Portland-Rice Husk Ash-Calcined Clay-Dried Acetylene Lime Sludge Cement in Sulphate and Chloride Media
(ResearchGate GmbH, 2019)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 ... -
Physicochemical Properties of Hydrated Portland Cement Blended with Rice Husk Ash
(Hindawi, 2020)In the presence of significant quantities of carbon dioxide (CO2) and elevated temperatures in the atmosphere due to climate change, cement-based materials are susceptible to carbonation. Blended cements are more prone to ... -
Poisson Incorporated Credibility Regression Modelling of Systematic Mortality Risk for Populations with Finite Data
(Hindawi, 2021-12-21)This study considered the modeling of systematic mortality risk for populations with finite data using the Poisson incorporated Credibility regression model. For novelty, we have included the credibility regression approach ... -
Polyphyly of the genus Canoparmelia—uncovering incongruences between phenotype-based classification and molecular phylogeny within lichenized Ascomycota (Parmeliaceae)
(PHYTOTAXA, 2016)Many phenotypical features traditionally used to classify genera in Parmeliaceae and in lichens in general have evolved several times independently, potentially limiting their taxonomic utility. Here, we aim to elucidate ... -
The Possibility of Angle Trisection (A Compass-Straightedge Construction)
(Journal of Mathematics and System Science, 2017)The objective of this paper is to provide a provable solution of the ancient Greek problem of trisecting an arbitrary angle employing only compass and straightedge (ruler).(Pierre Laurent Wantzel, 1837) obscurely presented ... -
Potential for Selected Kenyan Clay in Production of Limestone Calcined Clay Cement
(Springer, 2020)The potential for calcined clay, and in particular Limestone Calcined Clay Cement (LC3), to be used in concrete in Kenya was examined in this study. Locations of clay sources and existing mining infrastructure were examined ... -
Prediction of Compressive Strength of Calcined Clay Based Cement Mortars Using Support Vector Machine and Artificial Neural Network Techniques
(Research Gate, 2020)Prediction of strength in cement based materials is vital in construction industry as it forms the basis upon which important tasks can be performed such as the time for mortar form removal, project scheduling and quality ... -
Prediction of the likelihood of Households Food Security in the Lake Victoria Region of Kenya
(Pakistan Journal of Statistics and Operation Research, 2011)This paper considers the modeling and prediction of households food security status using a sample of households in the Lake Victoria region of Kenya. A priori expected food security factors and their measurements are ... -
Preparation and Chemical/Microstructural Characterization of Azacrown Ether-Crosslinked Chitosan Films
(Multidisciplinary Digital Publishing Institute, 2017)Chemically stable porous azacrown ether-crosslinked chitosan films were prepared by reacting varying molar amounts of N,N-diallyl-7,16-diaza-1,4,10,13-tetraoxa-dibenzo-18-crown-6 (molar equivalents ranging from 0, 0.125, ... -
Preparation of tervalent molybdenum complexes and a study of their reduction by zinc under low pressure of carbon monoxide
(Kenyatta University, 2011)Previously, molybdenum hexacarbonyl, MO(CO)6 has been prepared by reduction of highoxidation state molybdenum compounds such as MoCls under high pressure (60-100atm.) and temperature (20-1000C), carbonylation of metal oxide ... -
Pricing of European call options using generalized Wishart processes
(Mathematics and Systems Science, 2023)This study explores a multiple-security, high-risk pricing model where the implied volatility has been portrayed through Generalized Wishart affine processes. The presence of dual dependency matrices distinctively characterizes ... -
Pyroprocessing and the Optimum Mix Ratio of Rice Husks, Broken Bricks and Spent Bleaching Earth to Make Pozzolanic Cement
(Elsevier, 2019)This paper presents the findings of an experimental investigation on optimizing pozzolanic activity of a blend of Rice Husks (RH), Spent Bleaching Earth (SBE) and Broken Bricks (BB) to form pozzolana that would have ... -
Regioselective reactions of electrophilic iron dicarbonyl cations, [(η5-C5R5)(CO)2Fe]+ (R = H, CH3) with heterofunctional amine ligands
(Elsevier, 2012)The reactions of the ether salts [(η5-C5R5)(CO)2Fe(E)]BF4, (R = H, E = Et2O; R = CH3, E = THF) with various ligands possessing two different coordination sites have been investigated. It was established that [(Cp(CO)2Fe(OEt2)]BF4 ... -
Relativistic Dynamics in a Matter-Dominated Friedmann Universe
(Springer India, 2017)The energy density of the universe is estimated to be composed of 68% dark energy. Dark energy is associated with the accelerated expansion of the universe. In this work, we consider the evolution of the number density ... -
Resilience of soils and vegetation subjected to different grazing intensities in a semi-arid rangeland of Kenya
(Taylor & Francis, 1997)The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a ... -
Review of Carbonation Resistance in Hydrated Cement Based Materials
(Elsevier, 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 ... -
Review of Clay-Based Nanocomposites as Adsorbents for the Removal of Heavy Metals
(Hindawi, 2022-06-22)Due to rapid industrialization, urbanization, and surge in modern human activities, water contamination is a major threat to humanity globally. Contaminants ranging from organic compounds, dyes, to inorganic heavy metals ... -
A Review on Pyroprocessing Techniques for Selected Wastes Used for Blended Cement Production Applications
(Elsevier, 2020)Pyroprocessing is an important stage in cement manufacturing. In this process, materials are subjected to high temperatures so asto cause a chemical or physical change. Its control improves efficiency in energy utilization ...