Browsing Research articles (Dept of Chemistry) by Issue Date
Now showing items 41-60 of 85
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Photochromism, anomalous multi-banded fluorescence and laser properties of some amino- and tosyl-amino derivative of oxadiazole
(Elsevier Ltd. www.elsevier.com/locate/saa, 2006)The multi-banded fluorescence and laser properties of 11 new amino- and tosylamino derivatives of 2,5-di(phenyl)-1,3,4-oxadiazole and oxadiazole in various solvents at 293 K are reported. All the compounds investigated ... -
Evaluation of methods for the isolation, detection and quantification of cyanobacterial hepatotoxins
(Elsevier Ltd. www.elsevier.com/locate/aquatox, 2006)Cyanobacterial hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They are extremely stable in water due ... -
Investigation of sustainability of rain-fed agriculture through soil moisture modeling in the Pandamatenga Plains of Botswana
(Elsevier Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/413/description#description, 2006)The agricultural economic sector of Botswana is limited mainly to range resources-based livestock and pockets of arable farming based on rainfall and limited irrigated agriculture at several places. In this study agricultural ... -
Work in Thermodynamics
(Chemic Publishing Co., http://www.asianjournalofchemistry.com/, 2006)The expression for mechanical work obtained in the expansion of a gas commonly used in physical chemistry textbooks is critically examined. The mathematical form of the first law of thermodynamics is arrived at by a procedure ... -
Volumetric Properties of (Difurylmethane + Alkan-1-ol) Binary Mixtures at 298.15 K
(Journal of Solution Chemistry., 2006)Densities (ρ) of the binary systems of {difurylmethane+(ethanol or propan-1- ol or butan-1-ol or pentan-1-ol or hexan-1-ol)} have been measured with an Anton Paar DMA 4500 vibrating-tube densimeter over the entire ... -
Evaluation of methods for the isolation, detection and quantification of cyanobacterial hepatotoxins
(Elsevier Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/505509/description#description, 2006)Cyanobacterial hepatotoxins such as microcystins and nodularins have been responsible for the poisoning of both animals and humans who ingest or come into contact with toxic blooms. They are extremely stable in water due ... -
Kinetic studies on the reactions of some tetrakis(arylisocyanide)cobalt(II) complexes with pyridine in 2,2,2-trifluoroethanol
(Springer, http://www.springer.com/chemistry/journal/11243, 2006)The interaction of pyridine with four tetraki(arylisocyanide)cobalt(II) complexes, [Co(CNR)4(ClO4)2] R = 2,6- Me2C6H3 (A), 2,4,6-Me3C6H2 (B), 2,6-Et2C6H3 (C) and 2,6-iPr2C6H3 (D), have been studied in 2,2,2-trifluoroeth ... -
Photochromism, anomalous multi-banded fluorescence and laser properties of some amino- and tosyl-amino derivatives of oxadiazole
(Elsevier Science Ltd. www.elsevier.com/locate/saa, 2006)The multi-banded fluorescence and laser properties of 11 new amino- and tosylamino derivatives of 2,5-di(phenyl)-1,3,4-oxadiazole and oxadiazole in various solvents at 293K are reported. All the compounds investigated ... -
Deltamethrin in sediment samples of the Okavango Delta, Botswana
(Water SA Pretoria; Water Research Commission; http://www.wrc.org.za/, 2006-10)Deltamethrin concentrations were determined in 35 sediment samples collected from three different habitats: channel, lagoon and pool sites from Xakanaxa in the Okavango Delta, NW Botswana. The samples were Soxhlet-extracted ... -
Antimicrobial activity of the methanolic extracts and compounds from Treculia obovoidea (Moraceae)
(Elsevier Ireland Ltd. www.elsevier.com/locate/jethpharm, 2007)The crude extract from Treculia obovoidea was subjected to purification by repeated chromatography. Eight compounds were isolated from Treculia obovoidea and identified as Psoralen (1), Bergapten (2), 7-methoxycoumarin ... -
Fire and its influence on microbial community structure and soil biochemical properties in the Okavango Delta, Botswana
(Academic Journals. http://www.academicjournals.org/SRE, 2007)The influence of wild fires on microbial community structure, soil organic matter, sulphur oxidising and nitrifying microbial populations in the floodplains of the Okavango Delta of Botswana was assessed. Microbial ... -
Rotenoid derivatives and other constituents of the twigs of Millettia duchesnei
(Elsevier Ltd. www.elsevier.com/locate/phytochem, 2007)Three prenylated rotenoids, elliptol, 12-deoxo-12a-methoxyelliptone and 6-methoxy-6a,12a-dehydrodeguelin were isolated from the twigs of Millettia duchesnei, together with the known compounds, 6a,12a-dehydrodeguelin, ... -
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 ... -
Viscosity, molecular weight and concentration relationships at 298K of low molecular weight cis-polyisoprene in a good solvent
(Elsevier B.V. www.elsevier.com/locate/colsurfa, 2007)Aseries of six well characterised homopolymers of cis-polyisoprene (PIP) ranging from 1180 to 115,000 molecular weight were utilised to explore viscosity and the scaling relationship between viscosity and concentration ... -
Chemical constituents of Treculia acuminata and Treculia africana (Moraceae)
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2007)Three species of the genus Treculia namely, Treculia acuminata Baill., Treculia africana Decne ex. Treà ´cul and Treculia obovoidea N.E.Br. grow in the humid rain forest of southwest Cameroon. They are also widely ... -
Antimicrobial activity of the extract from the twigs of Dorstenia Elliptica (Moraceae)
(Pharmacologyonline. http://www.pharmacologyonline.org/, 2007)The crude extract from the twigs of Dorstenia elliptica (DET) as well one of the five compounds isolated from this extract namely O-[3-(2, 2-dimethyl-3-oxo-2H-furan-5-yl)-3- hydroxybutyl]bergaptol (5) were tested for ... -
A fluorescence spectroscopic study of a coagulating protein extracted from Moringa oleifera seeds
(Elsevier B.V. www.elsevier.com/locate/colsurfb, 2007)The fluorescence studies of coagulating protein extracted from Moringa oleifera seeds have been studied using steady-state intrinsic fluorescence. The fluorescence spectra are dominated by tryptophan emission and the ... -
Antimicrobial activity of the methanolic extracts and compounds from Treculia africana and Treculia acuminata (Moraceae)
(Elsevier Ltd. www.elsevier.com/locate/sajb, 2007)The crude methanolic extracts from Treculia africana and Treculia acuminata, three compounds isolated from T. africana and identified as, Phyllocoumarin (1), Catechin (2) and 6, 9-dihydroxy-megastigmane-3-one (3), four ... -
Two new anthraquinones from Gladiolus psittascinus
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2007)Gladiolus psittascinus HOOK, an herbaceous plant, is propagated by its bulb. This onion-looking plant occurs in rocky places in western province of Cameroon. The bulbs are used to treat asthma, gonorrhoea, diabetes and ... -
Lanneanol: A new cytotoxic dihydroalkylcyclohexenol and phenolic compounds from Lannea nigritana (Sc. Ell.) Keay
(Elsevier Ltd. www.elsevier.com/locate/biochemsyseco, 2007)The genus Lannea belongs to the family Anacardiaceae and consists of 40 species. Lannea nigritana (Sc. Elliot) Keay is a small tree of 3e6 m of height found in the tropical rain forest (Berhaut, 1971; Letouzey, 1972). It ...