Faculty of Science: Recent submissions
Now showing items 201-220 of 381
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Heterogeneous crystallization and composition dependence of optical parameters in Sn–Sb–Bi–Se chalcogenides
(Springer, 2010)Bulk samples of Sn10Sb20-xBixSe70 (0 B x B 8) chalcogenide alloys were prepared by the conventional melt quenching technique. Thin films were prepared on wellcleaned glass substrates by thermal evaporation technique. ... -
A ca. 200Ma hiatus between the Lower and Upper Transvaal Groups of southern Africa: SHRIMP U–Pb detrital zircon evidence from the Segwagwa Group, Botswana: Implications for Palaeoproterozoic glaciations
(Elsevier www.elsevier.com/locate/epsl, 2006)The Segwagwa Group of southeastern Botswana, a correlate of the Pretoria Group of the Transvaal Supergroup of South Africa, consists of a major sequence of siliciclastic sedimentary rocks, minor carbonates and basaltic to ... -
Thermal analysis and annealing temperature dependence of electrical properties in Sn10Sb20Se70 glassy semiconductor
(Springer Netherlands, 2008)The melt-quenched Sn10Sb20Se70 sample in the bulk form was used to prepare films on well-cleaned glass substrates by thermal evaporation method. The activation energy for glass transition (apparent) and crystallization has ... -
Effect of annealing on the structural, optical and electrical properties of ITO films by RF sputtering under low vacuum level
(Elsevier Ltd, 2008)Indium tin oxide (ITO) thin films were prepared by RF sputtering of ceramic ITO target in pure argon atmosphere at a high base pressure of 3 10 4mbar without substrate heating and oxygen admittance. The use of pure argon ... -
Screen integrable lightlike hypersurfacesof indefinite sasakian manifolds
(Birkhäuser Basel. http://www.springerlink.com/content/110963/?p=c42ba01ff0bd482b81a3ebdf3b649c9a&pi=0, 2009)We investigate lightlike hypersurfaces of indefinite Sasakian manifolds, tangent to the structure vector field and whose screen distribution is integrable. We prove some results on parallel vector fields and on a leaf ... -
Mineralogical appraisal of sediments of duricrust suites and pans around Jwaneng area, Botswana
(Bioline http://www.bioline.org, 2007)A mineralogical investigation of duricrust suites in Letlhakeng valley, and five pans around Jwaneng in Botswana was undertaken in order to know the mineral assemblages and infer on their landscape formation. In Letlhakeng, ... -
Characterization of agriculture-related land degradation in eastern and western parts of Botswana
(University of Botswana, http://www.ub.bw, 2005-04)A study was carried out during 1998-2001 with the objective of, firstly, assessing the impact of cultivation on soil quality, and secondly, evaluating the effects of human and animal activities on soil erosion and range ... -
Effect of annealing on the structural, optical and electrical properties of ITO films by RF sputtering under low vacuum level
(Elsevier Science Ltd. http://www.elsevier.com/locate/mejo, 2008)Indium tin oxide (ITO) thin films were prepared by RF sputtering of ceramic ITO target in pure argon atmosphere at a high base pressure of 3×10−4 mbar without substrate heating and oxygen admittance. The use of pure argon ... -
Voluntary counseling and testing among post-partum women in Botswana
(Elsevier www.elsevier.com/locate/pateducou, 2007)Objective: To determine uptake and socio-demographics predictors of acceptance of voluntary counseling and testing (VCT) among postpartum women in Botswana. Methods: Women attending maternal and child health clinics for ... -
Nitrogen cycling in the soil–plant system along a precipitation gradient in the Kalahari sands
(Blackwell Publishing, 2004-01-01)Nitrogen (N) cycling was analyzed in the Kalahari region of southern Africa, where a strong precipitation gradient (from 978 to 230mm mean annual precipitation) is the main variable affecting vegetation. The region is ... -
Origins of strandline duricrusts around the Makgadikgadi Pans (Botswana Kalahari) as deduced from their chemical and isotope composition
(Elsevier www.elsevier.com/locate/sedgeo, 2009)Trace elements togetherwith some O and C isotope analysiswere undertaken on duricrust strandline deposits in the palaeo-Makgadikgadi sub-basin (PMSB) to provide insight into palaeo-climatic conditions through the interpretation ... -
Optical properties of amorphous Sb2Se3:Sn films
(Taylor & Francis, 2010)The measurements and analysis of optical transmission and far-infrared (IR) reflectivity spectra of thermally evaporated Sb2Se3:Sn films are reported. The refractive index and film thickness have been determined from ... -
Effect of composition on optical constants of Pb: GeSbTechalcogenide thin films
(2008)Optical properties of Pb doped ternary Ge-Sb-Te chalcognide films prepared by thermal evaporation have been studied in the visible and near-infrared spectral regions. The straightforward analysis proposed by Swanepoel has ... -
Environmental chemistry and mineralogy of particulate air matter around Selebi Phikwe nickel–copper plant, Botswana
(Elsevier www.elsevier.com/locate/mineng, 2004)This study aimed at chemically and mineralogically characterizing whole particulate air matter (PAM) occurring at the Selebi Phikwe nickel–copper (Ni–Cu) area in Botswana, and postulating its possible environmental ... -
Vulnerability of traditional beef sector to drought and the challenges of climate change: the case of Kgatleng District, Botswana
(Academic journals http://hdl/handle.net/10289/973, 2008)Cattle’s rearing in Botswana is undertaken in two sectors: the communal and commercial. The communal sector is exclusively free range and therefore depends on biomass production. This makes the systems highly susceptible ... -
On semi-parallel lightlike hypersurfaces of indefinite Kenmotsu manifolds
(Birkhäuser Basel. http://www.springerlink.com/content/107580/?p=1930c3cc1de944feae211b785b3b42a4&pi=0, 2009)We study semi-parallel lightlike hypersurfaces of an indefinite Kenmotsu manifold, tangent to the structure vector field. Some Theorems on parallel and semi-parallel vector field, geodesibility of lightlike hypersurfaces ... -
Nanoindentation measurements of the mechanical properties of polycrystalline Au and Ag thin films on silicon substrates: Effects of grain size and film thickness
(Elsevier, 2006)This paper presents the results of nanoindentation experimental studies of the contact-induced deformation in Au and Ag thin films. The paper examines the effects of film thickness and substrate deformation restraint on ... -
Thermal annealing dependence of some physical propertiesof Bi-substituted Sn–Sb–Se glassy thin films
(EDP Sciences, 2009)Bulk glasses of the Sn10Sb20−xBixSe70 (0 x 8) system were prepared by the conventional melt quenching technique. Thin films were prepared by the thermal evaporation technique on glass substrates. Appearance of some ... -
Phase segregation in Pb:GeSbTe chalcogenide system
(EDP Sciences, 2008)Effect of Pb substitution on the amorphous-crystalline transformation temperature, optical band gap and crystalline structure of Ge2Sb2Te5 has been studied. In Pb:GeSbTe chalcogenide films prepared by thermal evaporation, ... -
Identification of Cu and Ni indicator plants from mineralised locations in Botswana
(Elsevier www.elsevier.com/locate/jgeoexp, 2005)Plant species that accumulate high levels of metals in proportion to the metal content in the soil are of considerable interest in biogeochemical and biogeobotanical prospecting. This study was aimed at investigating ...