Browsing Research articles (Dept of Physics) by Title
Now showing items 41-60 of 85
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Magnetic hysteresis properties of interacting and noninteracting micron-sized magnetite produced by electron beam lithography
(AGU and the Geochemical Society. http://www.agu.org/journals/gc/index.shtml, 2006)The magnetic hysteresis properties for well-defined micron-sized magnetite samples produced by electron beam lithography (EBL) are presented. In addition to measuring standard hysteresis parameters, first-order reversal ... -
Magnetic measurements as a proxy for car pollution in Gaborone
(BOSHASTED, 2000)Emissions of vehicles represent a significant contribution to environmental pollution along roads. Pollutants from cars include gases such as (NOx, CO, CO2), solid components such as sort particles from exhaust system, ... -
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 ... -
Mantle structure beneath the incipient Okavango rift zone in southern Africa
(The Geological Society of America, https://pubs.geoscienceworld.org/, 2107-02-01)Numerous investigations of the mature segments of the East African rift system (EARS) have significantly improved our understanding of the structure and processes associated with well-developed continental rifts. In contrast, ... -
Measurement of breakdown electric field strength for vegetation and hydrocarbon flames
(Scientific Research Publishing Inc., https://www.scirp.org/, 2018)A significant number of fire-induced power disruptions are observed in several countries every year. The faults are normally phase-to-phase short circuiting or conductor-to-ground discharges at mid-span region of the ... -
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 ... -
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 ... -
Natural radioactivity in the soil samples of Botswana
(Elsevier, www.elsevier.com/locate/radmeas, 2008)Studies on concentrations of primordial radionuclides in soil samples of Botswana were carried out. Measurements were made by gamma spectrometry employing a 41% relative efficiency HPGe detector. The activity of 226Ra ... -
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 ... -
Nondestructive measurement of momentum transfer collision frequency for low temperature combustion plasma
(Hindawi Publishing Corporation, https://www.hindawi.com/journals/ijap/, 2014)Accurately measured momentum transfer collision frequency and electron density for fire plasma enable correct simulation of electromagnetic wave propagation in the medium. The simulation is essential for designing ... -
Observations on the effect of proximity to rhyolitic intrusions on Kübler index
(Mineralogical Society of Poland, http://www.degruyter.com/view/j/mipo, 2010)The Upper Ordovician sedimentary succession of southeast Ireland is riddled with almost synsedimentary igneous intrusions. A study was required to determine any effects of these intrusions on Kübler Index (KI) so that ... -
Optical Characterization of TiO2-bound (CuFeMnO4) Absorber Paint for Solar Thermal Applications
(Science and Education Publishing, http://www.sciepub.com/journal/AJER, 2016)A composite thin film consisting of TiO2 (binder), uniformly mixed CuFeMnO4 paint (solar absorber) was coated on textured aluminum sheets by dip coating. The film’s elemental analysis was done using energy dispersive x-ray ... -
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 ... -
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. ... -
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 ... -
Origin and palaeo-environments of calcareous sediments' in the Moshaweng dry valley, Southeast Botswana
(John Wiley & Sons, Ltd. http://www3.interscience.wiley.com/journal/117935722/grouphome/home.html, 2002)Quaternary sedimentation in the Moshaweng dry valley of southeastern Botswana is evaluated on the basis of geomorphological evolution and sedimentological analyses. Stratigraphic evidence reveals an 'upper surface (1095 ... -
The P wavespeed structure below and around the Kaapvaal craton to depths of 800 km, from traveltimes and waveforms of local and regional earthquakes and mining-induced tremors
(Oxford University Press, https://academic.oup.com/gji, 2002-10-01)An average P-wavespeed model from the surface to depths of 800 km was derived for southern Africa using traveltimes and waveforms from earthquakes recorded at stations of the Kaapvaal and South African National networks. ... -
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, ... -
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, ... -
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 ...