ABSTRACT Plant species in the genus Helichrysum, are widely used in Southern African traditional medicine. Antibacterial and antifungal activities were reported for most of the Helichrysum species including H. argyrosphaerum. As a starting point to elucidate the structures of the compounds that may be responsible for these properties, phytochemical screening was performed to qualitatively identify the classes of compounds present. The results showed that the plant is rich in polyphenols and ...
Abstract The High Energy Stereoscopic System (H.E.S.S.) is an array of imaging atmospheric Cherenkov telescopes located in the Khomas highlands of Namibia. Their primary purpose is to detect Cherenkov light (CL) produced by particles in extensive air showers which are produced by incident high energy particles (gamma rays or cosmic rays) on the Earth’s atmosphere. The array consists of four 107 m2 optical telescopes and a larger 614 m2 collective surface area telescope in the centre of th...
ABSTRACT In 1991, Michael Grätzel and co-workers developed a new photovoltaic cell known as Dye Sensitized solar cells (DSSCs); these photovoltaic semiconductor devices convert solar radiation directly into electricity [1]. Metal-free sensitizers such as organic dyes and natural dyes have received attention as alternative DSSC applications and have been extensively developed [2]. Two metal free dyes were reported. These dyes were prepared through Schiff base synthetic methods, which a...
Abstract In Namibia seawater is employed by marine fish factories during processing. Previous studies indicated that chlorine and Ultra Violet (UV) light are ineffective in keeping seawater free from bacteria throughout the distribution system. However, laboratory studies showed that hydrogen peroxide eliminates both sessile and attached bacteria from seawater. Secondly it is not known whether Vibrio alginolyticus bacteria isolated from the Namibian marine waters and from hake fis...
Abstract The United Nation predicted that by 2025, 1.8 billion people will be living in countries with absolute water scarcity and two-thirds of the world population could be under stress condition. In semi-arid regions, most communities depend on groundwater as the source of drinking water and thus with changes in global climatic conditions and increase in population, groundwater resources are facing challenges of both over-exploitation and contamination. Therefore, there is an urgent ne...
ABSTRACT Six samples were generated by mixing the flours (AYB+ maize composite) with graded levels of defatted coconut flour (100:0, 90:10, 80:20, 70:30, 60:40, 50:50), sugar, salt, sorghum malt extract and water. Breakfast cereals were produced by roasting (280°C) -a dry heat treatment process to gelatinize and semi-dextrinize the starch in order to generate dry ready to eat products from blends of African yam bean (Sphenostylis stenocarpa), maize (Zea mays) and defatted coconut (Cocos nuci...
ABSTRACT Echinoids are recognized as important components of temperate kelp forests because of the impact that they have by grazing. The provision of shelter by some echinoid species for both juvenile conspecifics and for other species of echinoids has been widely documented. The behaviour is thought to be important in the survival of these species. The role of echinoids as protective "nurseries" for several types of marine animals has also been suggested. Adult echinoids are supported 1 - 2 ...
ABSTRACT Five years hav~ passed since the Two Oceans Aquarium, Cape Town, opened it doors for the first time in November, 1995. Since then, a seaweed community has established itself in the Kelp tank. The seaweeds were brought in as either epiphytes on mature macro algae or as epiphytes on boulders that were placed on the floor of the tank. Thus, the community in the tank can be assumed to have established itself naturally. This study looked at the extent of the species diversity, zonation pa...
ABSTRACT We find new exact solutions to Einstein-Maxwell's field equation for charged anisotropic stellar objects. We use the linear equations of the state consistent with quark matter and metric function. In our model, we choose a new measure of anisotropy. Through the transformation of Einstein-Maxwell field equations, new solutions for charged anisotropic matter are obtained. The models generated enable us to regain previous isotropic and anisotropic results as a specific case. We regain ...
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Abstract As an initial step towards characterisation of the molecular processes that define the phenotype of the mycobacterial stationary phase, the effect of growth phase of Mycobacterium smegmatis on total protein synthesis and on the heat shock response was investigated. De novo protein synthesis was monitored by labelling with 35 [S]methionine and the protein expression profiles analysed using one- and/two-dimensional polyacrylamide gel electrophoresis , autoradiography , and/or immunoblo...
Abstract: In this paper, acceptance sampling plans are developed for the odds exponential log logistic distribution (OELLD) introduced by Rosaiah et al. [1] based on lifetime percentiles when the life test is truncated at a predetermined time. The minimum sample size necessary to ensure the specified lifetime percentile is obtained under a given customer’s risk. The operating characteristic values of the sampling plans as well as the producer’s risk are presented. One example with real d...
ABSTRACT The blue amphibole asbestos, crocidolite, which occurs as interbedded seams in banded ironstones of the Lower Griquatown stage of the Transvaal System in the Northern Cape Province, is the finely fibrous form of the soda-amphibole riebeckite. Despite the widespread occurrence of the Precambrian type of banded ironstones, crocidolite is a mineral of rare occurrence and is only developed to a relatively minor extent in South Afric.a, Western Australia and Central China. The com...
ABSTRACT A significant part of Inventory Management is inventory monitoring. In recent years, many inventory management systems have been created. These frameworks allow stocks of products and items put away in amasses be taken up. It is important to track the inventory and that is where control systems for inventory come in. The stock data the board frameworks and stock observing frameworks are coordinated and sent together at a fixed point at store locations in some of the current inventory...