Browsing Faculty of Natural Sciences by Title
Now showing items 1588-1607 of 2571
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The new 6th edition of the WHO laboratory manual for the examination and processing of human semen: Is it a step toward better standard operating procedure?
(Shanghai Institute Materia Medica, 2021)Semen analysis (SA) remains the cornerstone of male infertility evaluation and should ideally be performed by an accredited andrology laboratory or in vitro fertilization (IVF) clinics based on the standards defined ... -
A new auroral phenomenon, the anti-black aurora
(Nature, 2021)Black auroras are small-scale features embedded in the diffuse background aurora, typically occurring post-substorm after magnetic midnight and with an eastward drift imposed. Black auroras show a significant reduction in ... -
New constraints on primordial features from the galaxy two-point correlation function
(Physical Review, 2023)Features in the primordial power spectrum represent the imprinted signal in the density perturbations of the physics and evolution of the early Universe. A measurement of such signals will represents the need to go beyond ... -
New formulas for the (−2) moment of the photoabsorption cross section, σ−2
(American Physical Society, 2015)Two new formulas for the (−2) moment of the photoabsorption cross section, σ−2, have been determined, respectively, from the 1988 photoneutron evaluation of Dietrich and Berman and a mass-dependent symmetry energy ... -
New imino-pyridyl nickel (II) complexes: synthesis, molecular structures and application as Heck coupling catalysts
(Elsevier, 2012)Reactions of imino-pyridyl ligands, (2-pyridyl-2-thiophenemethyl)imine (L1) and (2-pyridyl-2-thiopheneethyl)imine (L2) with NiBr2(DME) gave the corresponding complexes [Ni(L1)Br2] (1) and [Ni(L2)Br2] (2) in good yields. ... -
New insights in the evaluation of reserves of selected wells of the Pletmos Basin offshore South Africa
(One Petro, 2016)The area evaluated has similar structural styles and settings as the producing neighboring fields of F-A and E-M in the adjacent Bredasdorp basin Offshore South Africa. The main objective of this study is to create a ... -
A new macromedusa from the coast of Mozambique: Aurelia mozambica sp. nov. (Scyphozoa: Ulmaridae)
(Magnolia Press, 2021)A new species of the cosmopolitan jellyfish genus Aurelia is described from the coastal waters of Mozambique using a combination of morphological, meristic and genetic information (COI and 18S). The species can be separated ... -
A New Model For Including Galactic Winds in Simulations of Galaxy Formation II: Implementation of PhEW in Cosmological Simulations
(Monthly Notices of the Royal Astronomical Society, 2021)Although galactic winds play a critical role in regulating galaxy formation, hydrodynamic cosmological simulations do not resolve the scales that govern the interaction between winds and the ambient circumgalactic medium ... -
A new model for including galactic winds in simulations of galaxy formation – I. Introducing the Physically Evolved Winds (PhEW) model
(Oxford University Press, 2020-07-08)The propagation and evolution of cold galactic winds in galactic haloes is crucial to galaxy formation models. However, modelling of this process in hydrodynamic simulations of galaxy formation is oversimplified owing to ... -
A new modified spatial approach for monitoring non-perennial river water availability using remote sensing in the Tankwa Karoo, Western Cape, South Africa
(AJOL, 2021)Non-perennial rivers (N-PRs) make up two thirds of all rivers in South Africa, yet many are ungauged. Traditionally, it has been assumed that when a flow is recorded, there is water throughout that river. These assumptions ... -
New observations on the diel vertical distribution of Hydromedusae in the southern Benguela ecosystem
(NISC (Pty) Ltd and Taylor& Francis, 2003)Diel vertical migration (DVM) of six common species of hydromedusae was investigated during two drogue studies conducted in St Helena Bay on the west coast of South Africa in February 1995. Clytia spp., Obelia spp. and ... -
New palladium (II) complexes from halogen substituted Schiff base ligands: Synthesis, spectroscopic, biological activity, density functional theory, and molecular docking investigations
(Inorganica Chimica Acta, 2023)Two novel palladium (II) complexes Pd(L1)2 and Pd(L2)2 derived from ON donor bidentate ligands: 2-(((2-bromo-4-chlorophenyl)imino)methyl)phenol (HL1) and 2-(((-bromo-4-methylphenyl)imino)methyl)phenol (HL2) are reported. ... -
New palladium(II) and platinum(II) complexes based on pyrrole Schiff bases: synthesis, characterization, X-ray structure, and anticancer activity
(American Chemical Society, 2020)New palladium (Pd)II and platinum (Pt)II complexes (C1−C5) from the Schiff base ligands, R-(phenyl)methanamine (L1), R-(pyridin-2-yl)methanamine (L2), and R-(furan2-yl)methanamine (L3) (R-(E)-N-((1H-pyrrol-2-yl) methylene)) ... -
New parameter-uniform discretisations of singularly perturbed Volterra integro-differential equations
(Natural Sciences Publishing, 2018)We design and analyse two numerical methods namely a fitted mesh and a fitted operator finite difference methods for solving singularly perturbed Volterra integro-differential equations. The fitted mesh method we propose ... -
A new parameter-uniform discretization of semilinear singularly perturbed problems
(MDPI, 2022)In this paper, we present a numerical approach to solving singularly perturbed semilinear convection-diffusion problems. The nonlinear part of the problem is linearized via the quasilinearization technique. We then design ... -
New phenylene bridged binuclear bis (imino-quinolyl) palladium(II) complexes: synthesis, characterization and Heck reactions
(Elsevier, 2012)Two new phenylene bridged binuclear bis(imino-quinolyl) palladium (II) complexes were prepared from the reaction of the ligand 1,4-bis(imino-quinolyl)benzene, L1 with either Pd(cod)Cl2 or Pd(cod)ClMe. The molecular structure ... -
New protocols for the synthesis of 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate esters using an efficient additive
(TUBITAK, 2020)This work introduces a new additive named 4,4’-trimethylenedipiperidine for the practical and ecofriendly preparation of ethyl 5-amino-7-(4-phenyl)-4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylate derivatives. ... -
A new sample of southern radio galaxies: Host-galaxy masses and star-formation rates
(Oxford University Press, 2019)In this study we define a new sample of distant powerful radio galaxies in order to study their host galaxy properties and provide targets for future observations of H I absorption with new radio telescopes and to understand ... -
A new species of Magelona (Polychaeta: Magelonidae) from southern Namibia
(Iziko Museums of Cape Town, 2010)A new species of Magelonidae, Magelona debeerei sp. nov., is described and illustrated from grab-samples collected at <100moff the southwest coast of Africa. Magelona debeerei sp. nov. has previously been identified from ... -
A new technique to isolate kinematically anomalous gas in HI data cubes
(Oxford University Press, 2023)H I line observations of nearby galaxies often reveal the presence of extraplanar and/or kinematically anomalous gas that deviates from the general circular flow. In this work, we study the dependence of kinematically ...