Faculty of Science: Recent submissions
Now showing items 1-20 of 381
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Photoionization cross-section in a GaAs spherical quantum shell: the effect of parabolic confining electric potentials
(Springer Nature, https://www.springer.com/, 2021-06-22)Theoretical study on binding energies due to a centred charged impurity and the associated photoionization cross-section (PCS) in a spherical shell are presented. This was achieved by solving the Schrödinger equation within ... -
Optical properties of GaAs nanowires with an electric potential that varies inversely with the square of the radial distance
(Hindawi, https://www.hindawi.com/, 2019-07-10)A theoretical investigation of optical properties of a cylindrical quantum wire (CQW) is presented. The properties studied were optical absorption coefficient (AC) and change in refractive index (CRI) of the quantum wire. ... -
Effect of an inverse parabolic confining electric potential on third harmonic generation in cylindrical quantum wires
(EnPress Publisher, LLC, https://systems.enpress-publisher.com, 2019)A theoretical investigation of the effect of an inverse parabolic potential on third harmonic generation in cylindrical quantum wires is presented. The wave functions are obtained as solutions to Schrödinger equation solved ... -
Probing semiconductor quantum well qubits and associated Shannon entropy using semi‑relativistic quantum mechanics
(Springer Nature, https://www.springer.com/, 2023-08-07)Electron states in GaAs, GaN and AlN quantum wells are studied by solving a semi-relativistic wave equation within the effective mass approximation. The quantum states are in turn used to probe the properties of two-level ... -
Diamagnetic susceptibility and optical properties of a spherical quantum dot: effects of the parabolic and the shifted parabolic potentials
(Springer Science+Business Media, LLC, part of Springer Nature, https://www.springer.com/journal/11082, 2019-06-22)Centred charge donor related diamagnetic susceptibility and optical properties of a spherical GaAs quantum dot are presented. In particular, effects of intrinsic parabolic and shifted parabolic potentials on these quantities ... -
The effects of cup-like and hill-like parabolic confining potentials on photoionization cross section of a donor in a spherical quantum dot
(EDP Sciences, Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, https://www.springer.com/journal/10051, 2016-08-08)A theoretical investigation of the effects of hill-like and cup-like parabolic confining electric potentials on photoionization cross section (PCS) in a spherical quantum dot is presented. The hill-like and the cup-like ... -
Electron-LO-phonon intrasubband scattering rates in a hollow cylinder under the influence of a uniform axial applied magnetic field
(Springer Science+Business Media, LLC, part of Springer Nature, https://www.springer.com/journal/11082, 2021-11-06)Scattering rates arising from the interactions of electrons with bulk longitudinal optical (LO) phonon modes in a hollow cylinder are calculated as functions of the inner radius and the uniform axial applied magnetic field. ... -
Optical transition rates in a cylindrical quantum wire with an inverse parabolic potential
(Opast Group LLC, https://www.opastpublishers.com/journal/advances-in-theoretical-computational-physics, 2019-05-25)Electron transition rates due to interaction with circularly polarized light incident along the axis of a free-standing solid cylindrical nanowire are evaluated in the dipole approximation. In this case, the allowed optical ... -
Wildfires in Botswana and their frequency of occurrence
(Scientific Research Publishing Inc., https://www.scirp.org/journal/journalarticles.aspx?journalid=492, 2021-09-13)Fires play an essential part in the maintenance of the environment, but amplified fire activity often leads to adverse effects in the environment such as destruction of property and loss of life. Botswana has experienced ... -
Natural pigments as photosensitizers for dye-sensitized solar cells with TiO2 thin films
(Gazi University, https://www.ijrer.org/ijrer/index.php/ijrer, 2015)Dye-sensitized solar cells (DSSCs) were fabricated using four natural dyes extracted from the leaves of lemon (Citrus limon) and morula (Sclerocarya birrea) and flowers of bougainvillea (Bougainvillea glabra). Optical ... -
Electrophilicity of oxalic acid monomer is enhanced in the dimer by intermolecular proton transfer
(Royal Society of Chemistry, https://pubs.rsc.org/en/journals/journalissues/cp#!recentarticles&adv, 2017)We have analyzed the effect of excess electron attachment on the network of hydrogen bonds in the oxalic acid dimer (OA)2. The most stable anionic structures may be viewed as complexes of a neutral hydrogenated moiety HOA˙ ... -
Seismicity Study of Botswana from 1966 to 2012
(Scientific Research Publishing Inc., https://www.scirp.org/journal/ijg/, 2018-12-29)The history of Botswana’s major seismic events has been initiated by two earthquakes that occurred on the 11th of September and 11th of October 1952 with ML Richter magnitudes of 6.1 and 6.7, respectively, in the Okavango ... -
Coupling NCA dimensionality reduction with machine learning in multispectral rock classification problems
(MDPI, https://www.mdpi.com/, 2021-08-05)Though multitudes of industries depend on the mining industry for resources, this industry has taken hits in terms of declining mineral ore grades and its current use of traditional, time consuming and computationally ... -
Contaminant binding and bioaccessibility in the dust from the Ni-Cu mining/smelting District of Selebi-Phikwe (Botswana)
(Wiley Periodicals LLC, https://www.wiley.com/, 2022-08-22)We studied the dust fractions of the smelting slag, mine tailings, and soil from the former Ni-Cu mining and processing district in Selebi-Phikwe (eastern Botswana). Multi-method chemical and mineralogical investigations ... -
Biosurfactant production by halophilic yeasts isolated from extreme environments in Botswana
(Oxford University Press, https://academic.oup.com/femsle, 2021)Nine morphologically distinct halophilic yeasts were isolated from Makgadikgadi and Sua pans, as pristine and extreme environments in Botswana. Screening for biosurfactant production showed that Rhodotorula mucilaginosa ... -
Advances in the use of biocontrol applications in preharvest and postharvest environments: a food safety milestone
(John Wiley & Sons, Inc., https://onlinelibrary.wiley.com/journal/17454565, 2022-04)Increasing concerns toward food safety and public health have rendered the use of synthetic chemicals in agricultural environments unacceptable. A shift toward biologically safe approaches has been considered a preferred ... -
Spectral angle mapping and AI methods applied in automatic identification of placer deposit magnetite using multispectral camera mounted on UAV
(https://www.mdpi.com, 2022-02-20)The use of drones in mining environments is one way in which data pertaining to the state of a site in various industries can be remotely collected. This paper proposes a combined system that employs a 6-bands multispectral ... -
Prevalence of Cryptosporidium parvum, Giardia intestinalis and molecular characterization of group A rotavirus associated with diarrhea in children below five years old in Gaborone, Botswana
(Pan African Medical Journal, https://www.panafrican-med-journal.com/, 2020-10-14)Introduction Cryptosporidium, Giardia and rotaviruses are amongst the leading causes of acute gastroenteritis in children ≤5 years worldwide. The purpose of this study was to determine the occurrence of Cryptosporidium ... -
Technological advances in phytopathogen detection and metagenome profiling techniques
(Springer Science+Business Media, LLC, part of Springer Nature 2020, https://www.springer.com/journal/284, 2020)The use of advanced molecular methods in plant pathology and applied microbiology has necessitated for more accurate, rapid detection and identification of plant pathogens. This is particularly significant given accelerated ... -
A new method of quantifying aerosol concentrations in atmosphere
(Springer Nature Switzerland AG. Part of Springer Nature, https://www.springer.com/journal/703, 2014-04)Africa is one of the sources of biomass burning emissions. It is estimated that about 6 million tons of fuel per day is consumed in the southern hemisphere. Biomass burning has an important contribution on aerosol particle ...