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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Multi-wavelength observations of X-ray binaries

Unger, Sarah January 1993 (has links)
No description available.
2

Multi-wavelength studies of the high mass X-ray binaries X persei (4U0352+309) and OAO1657-415

Roche, Paul January 1993 (has links)
No description available.
3

Patents, pills, poverty and pandemic: the ethical issues

Brown, Walter January 2003 (has links) (PDF)
This thesis argues that corporations qua corporations are moral agents sui generis and hence capable of being held morally responsible. I argue that corporations qua corporations are responsible for the actual and foreseen consequences of their actions. I analyse normative theories and the different proscriptive responsibilities they place on moral agents and hence corporations. I examine Kantianism, utilitarianism and virtue ethics. I argue for a unique normative ethical theory that incorporates reasoning from all three of the normative theories. I argue for a broad range of reasons to factor into deciding whether an act is ethical or not. One of the claims of this thesis is that ethical theories must incorporate an agent’s motivation, intention and character traits as relevant to deciding on whether an action is ethical or not. My thesis argues for an indispensable role for the virtues while at the same time incorporating impartial beneficence and universal rationality from utilitarianism and Kantianism. This position I, following the literature, refer to as moderate virtue theory. Having established corporate qua corporate responsibility I question the pharmaceutical corporation’s practice of patenting life saving medication during a state of pandemic in poor countries. The moderate virtue theory position prioritises contexts and the actual human condition and criticises normative theories that attempt to give universal, abstracted answers to ethical problems. It is for this reason and the current (2003) HIV/AIDS pandemic that I focus on a particular context. I examine the practice of patenting life saving medication within South Africa and argue, applying moderate virtue theory, that this act cannot be justified. I argue that a pharmaceutical corporation that patents life saving medication in South Africa cannot justify that action and thus is morally responsible for that action. I also argue that corporations patenting HIV/AIDS medication in South Africa have unethical motivations and intentions.
4

The effects of buffer molarity, agitation rate and mesh size on verapamil release from modified release mini-tablets using USP Apparatus 3

Khamanga, S.M.M., Walker, R.B. 05 1900 (has links) (PDF)
The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
5

A contribution to cabbage pest management by subsistence and small-scale farmers in the Eastern Cape, South Africa

Mkize, N. January 2004 (has links) (PDF)
The interaction between farmers, agricultural scientists and extension workers is sometimes overlooked in agricultural entomology. In an attempt to respond to this reality this study examines some foundation of this interaction in relation to the pest management practices of subsistence and small-scale farmers and also highlights the problems that might arise in the implementation of IPM. Problems involving pests occurrence; language barriers; beliefs, knowledge and perception about insects, and visual literacy are examined. The thesis has a two-fold focus, firstly the study of pests on cabbages of subsistence farmers in Grahamstown and secondly a broader focus on other aspects such as cultural entomology, perception of insects and visual literacy specifically in relation to Xhosa speaking people in the Eastern Cape. The most important crop for emergent farmers in the Eastern Cape are cabbages, which have a variety of pests of which diamondback moths and are the most important. Traditional pest management practices tend to influence the development of IPM programmes adopted by these farmers. Eastern Cape farmers apply periodic cropping systems, which had an effect on the population densities of diamondback moth (DBM), other lepidopteran pests and their parasitoids. Considering the maximum population densities of DBM, which were 0.2 - 2.9 larvae/plant, there were no major pest problems. The availability of parasitoids, even in highly disturbed and patchy environments, showed good potential for biological control. Since some extension officers cannot speak the local farmers’ language, a dictionary of insect names was formulated in their language (isiXhosa) to assist communication. Response-frequency distribution analysis showed that the dictionary is essentially complete. The literal translations of some names show that isiXhosa speakers often relate insects to people, or to their habitat or classify them according to their behaviour. Farmers from eight sites in the Eastern Cape were interviewed regarding their knowledge and perception of insect pests and their control there of. To some extent, farmers still rely on cultural control and have beliefs about insects that reflected both reality and superstition. There is no difference between the Ciskei and Transkei regions regarding insect-related beliefs. Farmers generally lack an understanding of insect ecology. There is a need for farmers to be taught about insects to assist with the implementation of IPM. Leftover pesticides from commercial farms or detergents are sometimes used to manage the pests. When training illiterate or semi-literate farmers, it is important to understand their media literacy so as to design useful graphic and object training media. Generally farmers showed that they either understand graphic or object media depending on the features of the insects being looked at. These findings are discussed with regard to the potential development of IPM training material for subsistence and small-scale farmers in a community.
6

Open Source in South African Schools: Two Case Studies

Halse, Guy Antony, Terzoli, Alfredo 08 1900 (has links) (PDF)
One of the major problems facing schools in South Africa is the difficulty in obtaining modern, up-to-date computer facilities. This paper looks at the use of open source solutions in two government schools in South Africa to demonstrate that it is possible for schools to utilise almost any existing computer to provide effective network solutions.
7

Neural network-based ionospheric modelling over the South African region

McKinnell, L.-A., Poole, A.W.V. 11 1900 (has links) (PDF)
During the past decade, South African scientists have pioneered research in the field of ionospheric modelling using the technique of neural networks (NNs). Global ionospheric models have always been insufficient for the South African region owing to an historical paucity of available data. Within the past 10 years, however, three new ionospheric sounders have been installed locally and are operating continuously. These sounders are located at Grahamstown (33.3°S, 26.5°E), Louisvale (28.5°S, 21.2°E) and Madimbo (22.4°S, 30.9°E). The addition of a modern sounder at Grahamstown enlarged the ionospheric database for this station to 30 years, making this archive a considerable asset for ionospheric research. Quality control and online availability of the data has also added to its attraction. An important requirement for empirical modelling, but especially for employing NNs, is a large database describing the history of the relationship between the ionosphere and the geophysical parameters that define its behaviour. This review describes the path of South African ionospheric modelling over the past 10 years, the role of NNs in this development, the international collaborations that have arisen from this, and the future of ionospheric modelling in South Africa.
8

Sobriety of crisp and fuzzy topological spaces

Jacot-Guillarmod, Paul Frederic January 2004 (has links) (PDF)
The objective of this thesis is a survey of crisp and fuzzy sober topological spaces. We begin by examining sobriety of crisp topological spaces. We then extend this to the L-topological case and obtain analogous results and characterizations to those of the crisp case. We then briefly examine semi-sobriety of (L; M)-topological spaces.
9

100 years of chemistry at Rhodes University

Brown, M.E., Eve, D.J., Kaye, P.T., Rivett, D.E.A., Watkins, G.M. 11 1900 (has links) (PDF)
The history of Grahamstown is well documented and two books deal with the history of Rhodes University. Although the Chemistry Department was one of the founding departments, coverage in the official histories is minimal and sometimes inaccurate or misleading. The Rhodes University Centenary is an appropriate time to look back on some of the achievements of the department and some of its graduates over the past 100 years.
10

Evidence for Archaean lamprophyre from the Kaapvaal Craton, South Africa

Prevec, Stephen A., Anhaeusser, Carl R., Poujol, Marc 11 1900 (has links) (PDF)
A suite of mafic dykes occurs as a late component in a wellcharacterized trondhjemite–tonalite–diorite–granodiorite assemblage in the Johannesburg Dome of the central Kaapvaal Craton, southern Africa. The dykes have been subdivided into two sets, based on their orientation, and major and trace element geochemistry. Set 1 dykes are characterized by elevated SiO2, Al2O3 and TiO2, and particularly by enriched LILE and HSFE (e.g. Zr > 200 ppm, Nb > 20 ppm, Ba > 300 ppm), higher than in any of the accompanying felsic rocks. REE and trace element values for Set 1 dykes are similar to those for calc-alkaline lamprophyres. The Set 2 dykes have similar trace element distributions, but are significantly less enriched in general, and are broadly tholeiitic in composition, with enriched MgO (>11 wt.%) indicative of an olivine–phyric tholeiitic basaltic protolith. Field relationships and available U–Pb zircon geochronology indicate that the dykes are contemporaneous with components of the trondhjemitic host rocks, and with late granodiorites. The geochemical, geochronological and field petrological setting indicates partial melting of basaltic and eclogitic lithosphere at c. 3120 Myr ago in the basal Kaapvaal Craton, and subsequent emplacement into pre-existing c. 3430 Myr tonalitic to dioritic crust.

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