Faculty of Science: Recent submissions
Now showing items 141-160 of 381
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Structural, optical and fluorescence properties of wet chemically synthesized ZnO:Pd2+ nanocrystals
(SpringerOpen, http://www.inl-journal.com/, 2013)This paper presents the structural, optical and photoluminescence properties of wet chemically synthesized ZnO: Pd2+ colloidal nanocrystals characterised by X-ray diffraction, scanning electron microscopy/energy-dispersive ... -
Simulation of solar radiation conditions in coastal and continental areas by using a new algorithm
(David Publishing Company, http://www.davidpublishing.com/journals_info.asp?jId=1000, 2011)An algorithm developed at the University of Botswana is used to study solar radiation conditions in Namibia, South Africa, Mozambique and Botswana. The synoptic stations chosen for the study differ by meteorological ... -
Multivariate analysis of Harpagophytum DC. ex Meisn (Pedaliaceae) based on fruit characters
(Academic Journals; http://www.academicjournals.org/ijbc, 2011)Harpagophytum is bitypic and native to Southern Africa. Its two species are Harpagophytum procumbens and H. zeyheri. H. procumbens is medicinal. A reliable method of identifying the species is through its fruit. However, ... -
Piezoelectric energy harvesting devices: an alternative energy source for wireless sensors
(Hindawi Publishing Corporation, http://www.hindawi.com/journals/smr/, 2012)The recent advances in ultralow power device integration, communication electronics, and microelectromechanical systems (MEMS) technology have fuelled the emerging technology of wireless sensor networks (WSNs). The spatial ... -
Finite element modeling of a piezoelectric composite beam and comparative performance study of piezoelectric materials for voltage generation
(International Scholarly Research Network, http://www.hindawi.com/isrn/materials.science/, 2012)A comparative study of the traditional PZT ceramics and new single crystals is critical in selecting the best material and optimization of transducer design for applications such as conversion of ambient vibrations into ... -
Assessing acceptance of adaptive educational hypermedia systems: prior knowledge vs. cognitive styles
(International Journal of Computer Science Issues, http://www.ijcsi.org/index.php, 2012)Perceived usefulness and ease of use have proved to be key determinants of the acceptance and usage of e-learning systems. On the contrary, little is known about students' perceptions in Adaptive Educational Hypermedia ... -
Reactions of salicylaldehyde and enolates or their equivalents: versatile synthetic routes to chromane derivatives
(Beilstein-Institut, https://www.beilstein-journals.org/bjoc/home/home.htm, 2012)The reported methodologies for the synthesis of chromane derivatives through the reaction of salicylaldehyde and enolates are discussed. The enolates and their equivalents involved in the reactions discussed in this article ... -
Antioxidant and antibacterial constituents from Morus nigra
(Academic Journals, http://www.academicjournals.org/ajpp, 2011-06)The objective of this study was to isolate and characterize the constituents of the local Morus nigra L. (Black mulberry), to compare its constituents with other studied Mulberries and to evaluate its antioxidative and ... -
Global environmental change and food systems in Southern Africa: The dynamic challenges facing regional policy
(Academic Journals, http://www.academicjournals.org/JGRP, 2011-04)There is a growing concern that Global environmental change (GEC) will exacerbate the stress on Southern African food systems leading to increasing food insecurity, which is signified by rising levels of chronic and ... -
Land tenure and management reforms in East and Southern Africa - the case of Botswana
(Elsevier Science Ltd. http://www.elsevier.com/locate/landusepol, 2000)Since attainment of independence, almost every country in East and Southern Africa has introduced some kind of land reform aimed at reconciling indigenous land tenure practices and those introduced by colonial regimes. ... -
Minerals that host metals at Dorowa Rock Phosphate Mine, Zimbabwe
(Bentham Open, http://www.benthamscience.com/open/tomj/index.htm, 2011)This study set out to establish the major minerals at Dorowa and determine which of those are likely to host metals that may leach into surface and groundwater. This study comes after a preliminary assessment of the water ... -
Comparative analysis of heavy metal concentration in secondary treated wastewater irrigated soils cultivated by different crops
(Springer, http://link.springer.com/, 2010-03)The use of treated urban wastewater for irrigation is a relatively recent innovation in Botswana and knowledge is still limited on its impact on soil heavy metal levels. The aim of this study is to analyze and compare ... -
Analysis of the effects of kraal manure accumulation on soil nutrient status through time
(Academic Journals, 2010-11)This study investigated the influence of the accumulation of animal wastes on the soils of active kraal sites through time. This investigation involved the sampling and analysis of the soils of kraals that had been in use ... -
Analyzing the load balance of term-based partitioning
(The Science and Information Organization Inc., http://ijacsa.thesai.org/, 2011)In parallel (IR) systems, where a large-scale collection is indexed and searched, the query response time is limited by the time of the slowest node in the system. Thus distributing the load equally across the nodes is ... -
Using merkle tree to mitigate cooperative black-hole attack in Wireless Mesh Networks
(The Science and Information Organization Inc., www.ijacsa.thesai.org, 2011)Security is always a major concern and a topic of hot discussion to users of Wireless Mesh Networks (WMNs). The open architecture of WMNs makes it very easy for malicious attackers to exploit the loopholes in the routing ... -
A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane
(Elsevier Science Ltd, www.elsevier.com/locate/aca, 2012)Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems ... -
Intermediate and ion-pair formation in the outer-sphere reactions between azido-pentacyanocobaltate(III) and iron(II) polypyridyl complexes in aqueous medium
(Springer Science+Business Media B.V., http://www.springer.com/chemistry/journal/11243, 2009)The kinetics of the reactions between azidopentacyanocobaltate(III), Co(CN)5N3 3-, and iron(II) polypyridyl complexes, Fe(LL)3 2? (LL = bipy, phen), have been studied in both neutral and acidic aqueous solutions at I ... -
Cyclic voltammetric studies of tris(alkylisocyanide)-bis(triarylphosphine)cobalt(II) and tris-(alkylisocyanide)bis(triarylphosphine)cobalt(I) complexes exhibiting synthetic interconvertability
(NRC Research Press, http://www.nrcresearchpress.com/loi/cjc, 2003)Nine pairs of corresponding [CoI(CNR)3(PR3 ′ )2]X, [CoII(CNR)3(PR3 ′ )2]X2 complexes — where X = ClO4, BF4; CNR = CNCMe3, CNCHMe2, CNC6H11, CNCH2Ph; PR3′ = PPh3, P(C6H4Me-p)3, P(C6H4OMe-p)3 — have been studied using cyclic ... -
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 ... -
Bis(pyrazolyl) palladium(II), platinum(II) and gold(III) complexes: Syntheses, molecular structures and substitution reactions with L-cysteine
(Elsevier Science Ltd, www.elsevier.com/locate/ica, 2009)A series of pyrazolyl palladium(II), platinum(II) and gold(III) complexes, [PdCl2(3,5-R2bpza)] {R = H (1), R = Me (2), bpza = bis-pyrazolyl acetic acid}, [PtCl2(3,5-R2bpza)] {R = H (3a), R = Me (4)}, [AuCl2(3,5- R2bpza)]Cl ...