Browsing Faculty of Natural Sciences by Title
Now showing items 854-873 of 2567
-
Figure rotation of dark haloes in cold dark matter simulations
(Oxford University Press, 2007)We investigate the figure rotation of dark matter haloes identified in cold dark matter (CDM) simulations.We find that when strict criteria are used to select suitable haloes for study, five of the 222 haloes identified ... -
Finding universal relations in Subhalo properties with artificial intelligence
(The Astrophysical Journal, 2022)We use a generic formalism designed to search for relations in high-dimensional spaces to determine if the total mass of a subhalo can be predicted from other internal properties such as velocity dispersion, radius, or ... -
Fine structure of the isovector giant dipole resonance in 142-150Nd and 152Sm
(American Physical Society, 2020)Background: Inelastic proton scattering at energies of a few hundred MeV and very-forward scattering angles including 0 ∘ has been established as a tool for the study of electric-dipole strength distributions in nuclei. ... -
Fine-scale characterization of irrigated and rainfed croplands at national scale using multi-source data, random forest, and deep learning algorithms
(Elsevier [Commercial Publisher], 2023)Knowledge of the extent and distribution of irrigated and rainfed croplands is critical in providing the necessary baseline data for enhancing agricultural efficiency and making informed policy decisions. Accurately ... -
Fine-scale multi-temporal and spatial analysis of agricultural drought in agro-ecological regions of Zimbabwe
(Taylor & Francis, 2022)This study utilised multi-temporal satellite data to characterize droughts across the five Agro-ecological zones (AEZ) of Zimbabwe at monthly, seasonal, sub-seasonal and annual scales (2000 to 2018) using a combination of ... -
First ground-based observations of sprites over southern Africa
(Academy of Science of South Africa, 2018)Sprites are the optical signatures of electrical discharges in the mesosphere triggered by large lightning strikes associated with thunderstorms. Since their discovery in the late 1980s, sprites have been observed ... -
First HETDEX Spectroscopic Determinations of Lyα and UV Luminosity Functions at z=2–3: Bridging a Gap between Faint AGNs and Bright Galaxies
(The Astrophysical Journal, 2021)We present Lyα and ultraviolet (UV)-continuum luminosity functions (LFs) of galaxies and active galactic nuclei (AGNs) at z = 2.0–3.5 determined by the untargeted optical spectroscopic survey of the Hobby–Eberly Telescope ... -
First observation of the coexistence of multiple chiral doublet bands and pseudospin doublet bands in the A ≈ 80 mass region
(Elsevier, 2022)Two nearly degenerate positive-parity bands with the π g2 9/2 ⊗ ν g−1 9/2 configuration and three nearly degenerate negative-parity bands with the π g9/2(p3/2, f5/2) ⊗ ν g−1 9/2 configuration have been identified in ... -
First Observations of E-Region Near Range Echoes Partially Modulated by F-Region Traveling Ionospheric Disturbances Observed by the Same SuperDARN HF Radar
(Journal of Geophysical Research: Space Physics, 2022)We present the first observations from SuperDARN HF radar data of E-region Near Range Echoes (NREs) whose amplitudes are partially modulated by Medium-Scale Traveling Ionospheric Disturbances (MSTIDs) propagating in the ... -
First Observations of E‐Region Near Range Echoes Partially Modulated by F‐Region Traveling Ionospheric Disturbances Observed by the Same SuperDARN HF Radar
(American Geophysical Union, 2022)We present the first observations from SuperDARN HF radar data of E‐region Near Range Echoes (NREs) whose amplitudes are partially modulated by Medium‐Scale Traveling Ionospheric Disturbances (MSTIDs) propagating in the ... -
First record of epizootic ulcerative syndrome from the Upper Congo catchment: an outbreak in the Bangweulu swamps, Zambia
(Wiley, 2017)We report on the first outbreak of epizootic ulcerative syndrome (EUS) amongst wild fish populations in the Bangweulu swamps, an inland delta, in the north of Zambia during 2014. The area supports a large and diverse ... -
First record of the water mold achlya bisexualis (saprolegniaceae) isolated from ornamental fish in south africa
(American fisheries society, 2019)The order Saprolegniales (Class Oomycota) is a group of fungus-like eukaryotic microorganisms that have been associated with infections in fish and fish eggs. Infections with microorganisms from this order are clearly ... -
First report of Sporolithon ptychoides (Sporolithales, Corallinophycidae, Rhodophyta) for the Atlantic Ocean
(Wiley-Blackwell, 2011)Samples corresponding to Sporolithon ptychoides Heydrich were collected in the mesophotic zone (50 m depth) south of Espírito Santo State, Brazil. The collected material presented features characteristic of the species ... -
First report of the melobesioid alga (Corallinales, Rhodophyta) Mesophyllum incisum (Foslie) Adey in South Africa
(Elsevier, 1997)Mesophyllum incisum is reported and studied for the first time in South Africa. It has a th all us surface (SEM) with Leptophyturn-type epithallial cells. TetraJbisporangial conceptacles are mound-like and lack a peripheral ... -
First-principles investigation of W[sbnd]V and W[sbnd]Mo alloys as potential plasma facing materials (PFMs) for nuclear application
(Elsevier, 2021)Density-functional theory (DFT) based first-principles calculations were used to investigate the crystal structure, binding energy, phase stability and elastic properties of body-centered cubic (BCC) W-based binary solid ... -
A fitted numerical method for a model arising in HIV-related cancer-immune system dynamics
(Tianjin Polytechnic University, 2019)The effect of diseases such as cancer and HIV among our societies is evident. Thus, from the mathematical point of view many models has been developed with the aim to contribute towards understanding the dynamics of ... -
A fitted numerical method for parabolic turning point singularly perturbed problems with an interior layer
(Wiley, 2019)The objective of this paper is to construct and analyzea fitted operator finite difference method (FOFDM) forthe family of time-dependent singularly perturbed parabolicconvection–diffusion problems. The solution to the ... -
A fitted numerical method for singularly perturbed parabolic reaction-diffusion problems
(Spring Verlag, 2013)This paper treats a time-dependent singularly perturbed reaction-diffusion problem. We semidiscretize the problem in time by means of the classical backward Euler method. We develop a fitted operator finite difference ... -
A fitted operator method for a model arising in vascular tumor dynamics
(Tianjin Polytechnic University, 2020)In this paper, we consider a model for the population kinetics of human tumor cells in vitro, differentiated by phases of the cell division cycle and length of time within each phase. Since it is not easy to isolate ... -
A fitted operator method for tumor cells dynamics in their micro-environment
(Tianjin Polytechnic University, 2019)In this paper, we consider a quasi non-linear reaction-diffusion model designed to mimic tumor cells’ proliferation and migration under the influence of their micro-environment in vitro. Since the model can be used to ...