Browsing Faculty of Natural and Agricultural Sciences by Title
Now showing items 65-84 of 4825
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The ablation of gas clouds by blazar jets
(EDP Sciences, 2020)Context. Flaring activity in blazars can last for vastly different timescales, and it may be the result of density enhancements in the jet flow that result from the intrusion of an interstellar cloud into the jet. Aims. ... -
Abnormal tricarboxylic acid cycle metabolites in isovaleric acidaemia
(Springer, 2009)Background Although a number of abnormal diagnostic metabolites have previously been described in the urine of patients with isovaleric acidaemia (IVA), they do not fully explain the clinical symptoms associated with this ... -
Above-cloud aerosol optical depth from airborne observations in the southeast Atlantic
(EGU, 2020)The southeast Atlantic (SEA) region is host to a climatologically significant biomass burning aerosol layer overlying marine stratocumulus. We present the first results of the directly measured above-cloud aerosol optical ... -
The absence of diffusion in the South African short rate
(SASA, 2019)In the field of Financial Mathematics, stochastic differential equations are used to describe the dynamics of interest rates. An example is a model for the short rate, which is a mathematically defined rate not directly ... -
Absolute reflectance of a concave mirror used for astro-particle physics experiments
(Elsevier, 2019)The absolute reflectance of a reflector and its point spread function are the key parameters of a telescope for measuring light flux. Typically, one is using low-cost technologies for producing mirrors for the needs of ... -
Abundance and diversity of plant-parasitic nematodes associated with watermelon in Nigeria, with focus on Meloidogyne spp.
(Brill, 2020)Little information is available for nematode pests associated with watermelon in sub-Saharan Africa (SSA). This study recorded the abundance and prevalence of plant-parasitic nematodes from 25 localities across south-west ... -
Abundance ratios and IMF slopes in the dwarf elliptical galaxy NGC 1396 with MUSE
(Oxford Univ Press, 2016)Deep observations of the dwarf elliptical (dE) galaxy NGC 1396 (MV = −16.60, Mass ∼4 × 108 M⊙), located in the Fornax cluster, have been performed with the Very Large Telescope/Multi Unit Spectroscopic Explorer spectrograph ... -
Abundance ratios in dwarf elliptical galaxies
(Oxford Univ Press, 2018)We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range −19.0 < Mr < −16.0. We analyse ... -
Abundant interaction solutions of the KP equation
(SpringerSpringer, 2017)Based on the Hirota bilinear form of the KP equation, five classes of interaction solutions between lumps and line solitons are generated via Maple symbolic computations. Analyticity is automatically guaranteed for the ... -
Academic publishing in disaster risk reduction: past, present, and future
(Wiley, 2020)Nowadays there are approximately 80 Anglophone journals that deal primarily with disaster risk reduction (DRR) and allied fields. This large array signals a sustained, if uneven, growth in DRR scholarship but also competition ... -
Accelerating high-energy pulsar radiation codes
(IOP Publishing, 2010)Curvature radiation (CR) is believed to be a dominant mechanism for creating gamma-ray emission from pulsars and is emitted by relativistic particles that are constrained to move along curved magnetic field lines. Additionally, ... -
Acceleration of galactic electrons at the solar wind termination shock and Voyager 1 observations
(PoS, 2017)Diffusive shock acceleration (DSA) , as an acceleration process for G alactic electrons at the solar wind termination shock (TS) , is investigated with a comprehensive numerical model which ... -
Acceleration of petaelectronvolt protons in the Galactic Centre
(Nature Publishing Group, 2016)Galactic cosmic rays reach energies of at least a few petaelectronvolts1 (of the order of 1015 electronvolts). This implies that our Galaxy contains petaelectronvolt accelerators (‘PeVatrons’), but all proposed models of ... -
Acceleration of solar wind particles by traveling interplanetary shocks
(IOP Publishing, 2019)The acceleration of thermal solar wind (SW) protons at spherical interplanetary shocks driven by coronal mass ejections is investigated. The SW velocity distribution is represented using κ-functions, which are transformed ... -
Acceptance of ICT: applicability of the Unified Theory of Acceptance and Use of Technology (UTAUT) to South African students
(Kennesaw State University, 2018)We are told that university students are Digital Natives and the diffusion of digital technologies into education holds prospective advantages. However, will students in Africa be prepared to engage with and accept the ... -
Access to risk mitigating weather forecasts and changes in farming operations in East and West Africa: evidence from a Baseline Survey
(MDPI, 2015)Unfavorable weather currently ranks among the major challenges facing agricultural development in many African countries. Impact mitigation through access to reliable and timely weather forecasts and other adaptive ... -
Access to safe drinking water, sanitation, and under 5 diarrhea morbidity in South Africa
(Medknow Publications, 2017)Background: Universal access to safe drinking water and improved sanitation are paramount sustainable development goals. This is critical for overcoming several health challenges in developing countries. This study analyzed ... -
The Accounting concept of measurement and the thin line between representational measurement theory and the classical theory of measurement.
(Clute Institute [for academic research], 2011)The purpose of this study is to discuss a possible way forward in accounting measurement. It also highlights the importance of understanding the lack of appreciation given by the accounting researchers to the distinction ... -
Accumulation of heavy metals and metalloid in foodstuffs from agricultural soils around Tarkwa area in Ghana, and associated human health risks
(MDPI, 2015)This study was carried out to assess the extent of heavy metals and metalloid accumulation from agricultural soils to foodstuffs (viz, M. esculenta (cassava) and Musa paradisiaca (plantain)) around thirteen neighboring ... -
Accumulation of persistent organic pollutants in consumers of eel from polluted rivers compared to marketable eel
(Elsevier, 2016)Globally, many river sediments are seriously contaminated with persistent organic pollutants (POPs) known to accumulate in aquatic food. In the Netherlands, toxicological risks of human exposure to dioxins and dioxin-like ...