Faculty of Science: Recent submissions
Now showing items 321-340 of 381
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Examination of Blepharis aspera as a possible Cu–Ni indicator plant
(South African Journal of Science, 2007)BLEPHARIS ASPERA WAS COLLECTED FROM A copper–nickel mineralized area in Botswana and examined as a possible Cu–Ni indicator plant for biogeochemical prospecting. Different plant parts and the host soils were analysed using ... -
Contact charging of solution-cast polymers by metals
(Elsevier Science Ltd. www.elsevier.com/locate/elstat, 2005)The charge transfer between metals and some solution-cast polymers has been investigated by employing intermittent soft contact under a controlled condition. The result of our measurements reveals that the measured charge ... -
Gravity anomaly patterns in the south-central Zimbabwe Archaean craton and their geological interpretation
(Elsevier Science Ltd. www.elsevier.com/locate/jafrearsci, 2008)The granite-greenstone terrain of south-central Zimbabwe, encompassing the Belingwe (Mberengwa) greenstone belt and sections of the Great Dyke, provides important constraints on models for the evolution of the Zimbabwe ... -
Phenylpropanoid glycosides of Gnidia polycephala
(Elsevier Ltd. www.elsevier.com/locate/phytochem, 2003)Two phenylpropanoid glucosides, 2-O-b-d-glucosyloxy-4-methoxybenzenepropanoic acid and its methyl ester, together with syringin and adicardin were isolated from the stem of Gnidia polycephala and characterized by physical ... -
Pn arrivals and lateral variations of Moho geometry beneath the Kaapvaal craton
(Elsevier Science Ltd. www.elsevier.com/locate/lithos, 2003)Pn arrivals from mining-induced earthquakes on the edge of the Witwatersrand basin show that the P wavespeeds in the uppermost mantle are almost constant throughout most of the Kaapvaal craton. The presence of only small ... -
South African seismicity, April 1997 to April 1999, and regional variations in the crust and uppermost mantle of the Kaapvaal craton
(Elsevier Science Ltd. www.elsevier.com/locate/lithos, 2003)Events induced by deep gold-mining activity on the edge of the Witwatersrand basin dominate the seismicity of South Africa. The deployment of 54 broad-band seismic stations at 84 separate locations across southern Africa ... -
The role of human factors in the degradation of natural resources in and around the Okavango Delta, Botswana
(Taylor & Francis, http://www.tandf.co.uk/journals/titles/00207233.asp, 2007)This paper draws on archival information, anecdotal evidence from local communities, in situ observations during field investigation and multi-date remotely sensed satellite imagery. The authors investigated the role of ... -
Phase segregation in Pb:GeSbTe chalcogenide system
(EDP Sciences. http://www.epjap.org/, 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, ... -
Isoflavonoids from Seeds of Millettia griffoniana (Bail), 15
(Verlag der Zeitschrift fu¨r Naturforschung, Tu¨bingen · http://znaturforsch.com, 2005)Three new isoflavonoids, griffonianone F, G and H were isolated from the seeds of Millettia griffoniana, along with the known prebarbigerone, pseudobaptigenin, pseudobaptigenin methyl ether, tephrosin, dipterixine, ... -
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 B.V. 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 ... -
The Okwa basement complex, western Botswana: U–Pb zircon geochronology and implications for Eburnean processes in southern Africa
(Elsevier Ltd. www.elsevier.com/locate/jafrearsci, 2006)The Okwa Basement Complex crops out at the northwestern edge of the Kaapvaal craton within the Okwa Inlier, an isolated exposure of Precambrian basement in the Kalahari Desert. New U–Pb zircon dating was performed on all ... -
Fluorescence and laser properties of D2-, C2- and D3 symmetry series oligophenylenes
(Elsevier Science Ltd. www.elsevier.com/locate/saa, 2003) -
Plant alkali content and radio wave communication efficiency in high intensity savanna wildfires
(Elsevier Science Ltd. www.elsevier.com/locate/jastp, 2007)The flames of wildfires are weakly ionized gas. The ionization is mainly due to omnipresent alkali and alkaline earth metal species that are emitted from thermally decomposing plant structure into the flame during a ... -
Effective atomic numbers for W/Cu alloy for total photon attenuation
(Elsevier Science Ltd. www.elsevier.com/locate/radphyschem, 2004)The study of interaction of photons with matter finds wide application in areas such as industry, medical radiation dosimetry and radiation shielding. A careful review of these measurements indicates that the studies ... -
Photon interaction cross sections in the low energy region in Mg and V
(Elsevier Science Ltd. www.elsevier.com/locate/radphyschem, 2004)The interaction of photons with matter has been extensively studied over the past several decades in view of its importance in basic radiation physics research, medical, industrial and other applied fields. Large amounts ... -
Comprehensive study of solar conditions in Mozambique: the effect of trade winds on solar components
(Elsevier Science Ltd. www.elsevier.com/locate/renene, 2003)A new algorithm to simulate all solar components and optimum slopes, Bopt, based on new models for direct normal beam and diffuse radiation and an analytical model to predict Bopt, developed at the University of Botswana ... -
Mantle structure and composition to 800-km depth beneath southern Africa and surrounding oceans from broadband body waves
(Elsevier Science Ltd. www.elsevier.com/locate/lithos, 2003)Average one-dimensional P and S wavespeed models from the surface to depths of 800 km were derived for the southern African region using travel times and waveforms from earthquakes recorded at stations of the Kaapvaal and ... -
Reaction of a bulky phosphite with [Ru3(CO)12]: the molecular structure of one of the decomposition products
(Elsevier B.V. www.elsevier.com/locate/ica, 2008)Mono- and bis-substituted phosphite complexes [Ru3(CO)12 x Lx] (L = tris(2,4-di-tert-butylphenyl) phosphite; x = 1, 2) were synthesized by simple substitution reactions, and were characterized by spectroscopic methods. ... -
Dinklagins A, B and C: three prenylated flavonoids and other constituents from the twigs of Dorstenia dinklagei
(Elsevier Science Ltd. www.elsevier.com/locate/phytochem, 2002)Three prenylated flavonoids, dinklagins A, B and C identified, respectively, as ( )-6-(3,3-dimethylallyl)-7-hydroxy-6000, 6000-dimethylchromeno-( 40,30,2000,3000)-flavanone, (+)-5,40,500x-trihydroxy-600,600-dimethylchro ... -
Antioxidant activity of prenylated flavonoids from the West African medicinal plant Dorstenia mannii
(Elsevier Science Ireland Ltd. www.elsevier.com/locate/jethpharm, 2003)The antioxidant activities of three prenylated flavonoids from Dorstenia mannii (6,8-diprenyleriodictyol, dorsmanin C and dorsmanin F) were compared to the common, non-prenylated flavonoid, quercetin. The prenylated ...