Browsing Faculty of Natural Sciences by Title
Now showing items 2101-2120 of 2571
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The search for the ideal biocatalyst
(Nature Publishing Group, 2002)While the use of enzymes as biocatalysts to assist in the industrial manufacture of fine chemicals and pharmaceuticals has enormous potential, application is frequently limited by evolution-led catalyst traits. The advent ... -
A search for variable subdwarf B stars in TESS Full Frame Images III. An update on variable targets in both ecliptic hemispheres – contamination analysis and new sdB pulsators
(Oxford University Press, 2023)We present an update on the variable star survey performed on the TESS 30 min Full Frame Image (FFI) data reported by our first two papers in this series. This update includes a contamination analysis in order to identify ... -
Seasonal variation of citrinin in traditionally brewed African beer
(Academic Journals, 2013)A seasonal study on citrinin concentrations in traditional beer was conducted using a standardised enzyme-linked immunosorbent assay. Representative samples of indigenous South African beer were collected during the hot, ... -
Seaweed diversity associated with a Brazilian tropical rhodolith bed
(Universidad Autónoma de Baja California, 2010)This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espírito Santo State (Brazil). Qualitative and quantitative sampling ... -
Seaweeds in two oceans: beta-diversity
(Frontiers Media, 2017)Several species assembly mechanisms have been proposed to structure ecological communities. We assess the biogeography of seaweeds along 2,900 km of South Africa’s coastline in relation to a thermal gradient produced by ... -
Secure contactless smart card transactions on mobile devices
(Telkom, 2009)This paper presents work in progress to explore the utility of Near Field Communication technology to secure mobile financial services. The objective is to evaluate the potential of this approach as an upcoming technology ... -
Security of a Mesh Potato Network in Ad Hoc Mode
(Telkom, 2013)Wireless Mesh Networks can provide low cost and reliable community-owned connectivity in developing rural areas. A rural community can use mesh networks to access a wide range of modern information and communication ... -
Seed germination and early seedling growth responses to drought stress in annual Medicago L. And Trifolium L. Forages
(MDPI, 2022)Climate change in the Mediterranean-like regions of South Africa has resulted in increased rainfall variability, a delayed start to the wet winter season, and increased occurrences of out-ofseason summer rainfall events. ... -
Seed germination and seedling establishment in pistacia atlantica desf. and pistacia lentiscus l. under drought
(Russian Journal of Plant Physiology, 2023)The rehabilitation of degraded Mediterranean areas requires reintroduction of key-stone woody species. However, seed germination and seedling establishment for native species are poor. Germination behavior of Pistacia ... -
Seed priming with MeJa prevents salt-induced growth inhibition and oxidative damage in sorghum bicolor by inducing the expression of jasmonic acid biosynthesis genes
(Multidisciplinary Digital Publishing Institute (MDPI), 2023)Salinity is one of the major detrimental abiotic stresses at the forefront of deterring crop productivity globally. Although the exogenous application of phytohormones has formerly proven efficacious to plants, their effect ... -
An SEIR model with infected immigrants and recovered emigrants
(Springer Science and Business Media Deutschland GmbH, 2021)We present a deterministic SEIR model of the said form. The population in point can be considered as consisting of a local population together with a migrant subpopulation. The migrants come into the local population for ... -
An SEIRS epidemic model with stochastic transmission
(Springer, 2017)For an SEIRS epidemic model with stochastic perturbations on transmission from the susceptible class to the latent and infectious classes, we prove the existence of global positive solutions. For sufficiently small values ... -
Selecting an appropriate method for expressing S locus F-box-S2 recombinant protein
(Elsevier, 2017)A single locus (S locus) including at least two linked genes (female and male determinants) genetically controls the gametophytic self-incompatibility (GSI) in apple, which has evolved to avoid self-fertilization. There ... -
Selection analysis identifies clusters of unusual mutational changes in omicron lineage ba.1 that likely impact spike function
(Oxford University Press, 2022)Among the 30 nonsynonymous nucleotide substitutions in the Omicron S-gene are 13 that have only rarely been seen in other SARS-CoV-2 sequences. These mutations cluster within three functionally important regions of the ... -
Selection of Clostridium spp. in biological sand filters neutralizing synthetic acid mine drainage
(Wiley, 2013)In this study, three biological sand filter (BSF) were contaminated with a synthetic iron- [1500 mg L-1 Fe(II), 500 mg L-1 Fe(III)] and sulphate-rich (6000 mg L-1 SO2/4-) acid mine drainage (AMD) (pH = 2), for 24 days, to ... -
Selection of diazotrophic bacterial communities in biological sand filter mesocosms used for the treatment of phenolic-laden wastewater
(Springer Verlag, 2013)Agri effluents such as winery or olive mill waste-waters are characterized by high phenolic concentrations. These compounds are highly toxic and generally refractory to biodegradation. Biological sand filters (BSFs) represent ... -
Selectivity of oxygen evolution reaction on carbon cloth-supported δ-mno2 nanosheets in electrolysis of real seawater
(Molecules, 2023)Electrolysis of seawater using solar and wind energy is a promising technology for hydrogen production which is not affected by the shortage of freshwater resources. However, the competition of chlorine evolution reactions ... -
Selenium functionalized carbon for high dispersion of platinumeruthenium nanoparticles and its effect on the electrocatalytic oxidation of methanol
(Elsevier, 2013)Using selenium functionalized carbon as supports, platinumeruthenium nanoparticles were highly dispersed on the carbon surface, and showed improved electrochemical properties for methanol electrooxidation. The method ... -
Selenium-functionalized carbon as a support for platinum nanoparticles with improved electrochemical properties for the oxygen reduction reaction and CO tolerance
(Electrochemical Society, 2013)Using selenium-functionalized carbon as supports, platinum nanoparticles were uniformly dispersed on the carbon surface, and showed improved electrochemical properties for the oxygen reduction reaction. At the same time ... -
Self-catalytic growth of tin oxide nanowires by chemical vapor deposition process
(Hindawi, 2013)We report on the synthesis of tin oxide (SnO2) nanowires by a chemical vapor deposition (CVD) process. Commercially bought SnO nanopowders were vaporized at 1050∘C for 30 minutes with argon gas continuously passing through ...