383 research outputs found
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Biological oxidants and antioxidants
No full textBook ReviewThe generation of reactive oxygen species, such as the
supcroxideanionradical and hydroxyl radical, is known
to lead to a variety of pathological conditions. Antioxidants
such as vitamins A, C, Eand antioxidant enzymes
are known to prevent the deleterious elfects of these
toxic radicals. THe role of free radicals in disease may
be most familiar to readers of the literature on postischacmic
organ reperfusion injury. However, recent
studies have shown that these radicals may also play a
role in the ageing process, artherosclerosis,
carcinogenesisa and even Diabetes mellitu
Innovative Research and Development capacity at academic institutions not fully utilized by industry.
No full textPublished in The Chronicle Newspaper of 2013 on the productivity column.The global information age has brought about swift changes in all aspects of life. Great
developments in information and communication technologies have simplified a lot of
things to the general public. On the other hand, it has complicated or even intensified the
need for competition. As such in order to stay ahead, there is need to invest in Innovation,
Research and Development. Failure to do this will create a leading role for those that are
innovative and those that engage in massive research
Being a World Class Manufacturing (WCM) Company: An aspiration for many organizations.
No full textPublished in The Chronicle Newspaper of 14 february 2013 on the productivity columnManufacturing is defined as basically the transformation of materials from one form to another
and in most instances it will be from raw materials to more valuable products. Many
organizations in Zimbabwe and the world over are engaged in this transformation but doing it at
different levels of efficiency. It however is important to note that all those organizations in
manufacturing are in business so at to make money. The major question is whether there any
organizations that do not want to make money. This coupled with the globalization challenge,
calls for organizations to be competitive
Application of goal programming on a marketing decision for a promotional strategy
No full textA Monthly Double-Blind Peer Reviewed Refereed Open Access International e-Journal - Included in the International Serial Directories.Promotions have become an essential tool to financial performance of retail organisations. The actuation of this study was to map a way to survive in a stiff competition market environment by focusing efforts on products that are best financial performers in a grocery retail shop. In doing so, Pareto analysis was used to classify the products according to their sales frequency contribution. The products that exhibit the largest frequency were chosen as the vital few products and 14 out of 46 were identified. In addition to the sales frequency goal were 3 more priority goals that had to be considered because high sales do not necessarily mean high profits. That is where goal programming approach came in to strike a balance amongst the prioritised goals. Finally the number of products reduced to 10 for the optimal promotional product mix and they constituted approximately 20% of the total number of products under study. This complies with 80:20 PARETO principle. A survey in the consumer market confirmed the products and thus, validating the goal programming outcome. The study, therefore, concludes that a mathematical programming approach is effectively applicable to a marketing decision problem where a promotional marketing strategy is needed
Potential Use of Superoxide Dismutase As A Biomarker of Metal Pollution In Two Species of Freshwater Snails Lymnaea Natalensis And Helisoma Duryi.
No full textPresented at the Southern African Society of Aquatic Scientists Conference in 2004.Toxic metals such as lead and cadmium are widely found in our environment. Humans and animals are exposed to these metals from numerous sources through contaminated air, water, soil and food. Exposure to these metals has been shown to cause an increase in the production of reactive oxygen species (ROS) such as hydroxyl radical COIr), superoxide anion radical C02-) or hydrogen peroxide (H202). These ROS are toxic to the cell and usually cause apoptosis. A number of enzymes are responsible for the removal of these ROS and include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and quinone oxidoreductase (QOR). At times exposure to metals results in the induction, repression or inhibition of these enzymes. We have prevsiously reported on the effect of metals on CAT, GPX and QOR. However, it has been shown that SOD can be induced as a result of exposure to metals. This study was therefore conducted to assess the possibility of using metal exposure related induction of SOD as a potential biomarker of water pollution. The study was performed using two species of aquatic snails found in Southern Africa, namely Lymnaea natalensis and Helisoma duryi. Adult snails reared in outdoor cement aquaria were exposed daily for three days to three concentrations (0.01 ppm, 0.1 ppm and 1.0 ppm) of copper (Cu), cadmium (Cd), lead (Ph) or zinc (Zn) individually. SOD activity was measured in post-mitochondrial fractions. Although not statistically significant, our data indicates a trend in hoth species of snails where Cu, Cd and Pb caused dose related increases in SO..p activity. However, Pb caused a dose related change only in L natalensis and not in H. ~ryi. The activity was increased several fold at 1 ppm while the lower concentrations seemed to have little or no effect. These results suggest that metal exposure results in an increased SOD activity in aquatic invertebrates. Furthermore, induction of SOD activity as a result of exposure to metal is a potential biomarker of water pollution. However, further studies are required using other metals and a wider concentration range in order to test the reliability of this enzyme as a biomarker.Department of Water Affairs and Forestry Water Research Commission
Designing of an Intelligent Fuzzy Logic System for Accretion Prevention in Sponge Iron SL/RN Rotary Kiln Based 100tpd DRI Process.
No full textPresented as part of SAIIE25 Proceedings, 9th ? 11th of July 2013, Stellenbosch, South Africa ? 2013 SAIIE.Sponge iron is an intermediate product of steel formed during direct reduction of iron ore with aid of regulated temperatures and pressures within a rotary kiln. The greatest
challenge is the direct measurement of kiln shell temperatures due to the catastrophic
accumulation of sintered particles of solid bed which form rings at places along the length of the kiln thus hindering material flow. The accretion reduces productivity, damage kiln lining and reduces the production period as well as reduction in product quality. This process
requires a controller which will be able to control with imprecise and partial data input; and be able to achieve the desired product quality under dynamic process conditions thus a Fuzzy Controller was used for the proposed design. The main goal of the research was to predict the rate of accretion build up within the kiln and minimize it with aid of a Fuzzy Control System cascaded to an already existing Programmable Logic Controller. A 16.2%
build up rate was achieved as compared to the most appreciated 27% thus nearly a 10%
decrease, a result which can improve the campaign period by approximately 48 hours which will be a 200 tons of sponge iron
Academic staff development strategies in engineering fields of study: case study of Zimbabwe.
No full textPresented as part of the Proceedings of the 2nd Biennial Conference of the South African Society for Engineering Education, Cape Town.
11-12 June, 2013: Full Paper.Higher education is the basic instrument of economic growth and technological advancement in any society. The economic meltdown in Zimbabwe which climaxed 2008 with an inflation level
of 231million % exacerbated the brain drain. After the economic meltdown, Zimbabwe is in the process of rebuilding the quality of staff and the staffing levels in its higher education
institutions. The challenge has been the decision on the mode of study: whether to go via taught masters or masters by research; where to allow the faculty members to study: in the region, or
beyond; on a fulltime or on a part-time basis or on a split-site basis. These challenges have been
due to the need to have a quick but quality programme of staff development, while maximising on the resources available for staff development. A survey was undertaken of the engineering related departments in Zimbabwe universities focusing on the existing staffing levels, their qualifications, current numbers undergoing study and their levels. The challenges faced by each
institution from the administrative side and from the staff side are summarised.
Recommendations on staff development strategies are given in conclusion
Problem solving and its impact on Productivity.
No full textPublished in The Chronicle Newspaper of 4 July 2013 on the productivity column.Our lives are full of problems which many optimists would want to call challenges. Some very optimistic
people have called them temporary setbacks. This stands to show that problems do exist and they
hinder progress in one way or the other. Trying to attain improved productivity in an organization comes
with its own challenges as well. What then distinguishes success and failure is how one handles or tries
to overcome any such problems. Adopting proper problem solving techniques has a definite positive
impact on productivity or on any other problems that may arise in one?s life
SME Lending: Do Lending Technologies Matter? Sample Evidence from Zimbabwe
No full textThis is an article published in the journal of World Review of Business Research. The article examines the lending technologies used by Zimbabwean banks to lend money to SMEs. This is examined within the context of Black empowerment and indigenisation policy of Zimbabwe.This paper examines and tests the claim that bank lending technologies are
responsible for the low volume of lending to SMEs in Zimbabwe. Based on a
survey of directors of SMEs and bank lending officers, tests are conducted to
determine if there is any evidence of discrimination against SMEs based on age,
management, size, and information attributes. The study reveals that application
of uniform lending criteria to SMEs and large corporates does not result in
discrimination against SMEs based on age, size, management, or information
attributes. Based on this evidence, the study submits that differences in SME
lending between foreign and indigenous banks are due to factors other than their
lending technologies. The study further provides rationale for collateral-based
lending in the SMEs sector in Zimbabwe. The study however questions the static
nature of lending technologies used by banks in Zimbabwe, in the wake of high
nonperforming loans
Are the Terms and Conditions Offered by Cloud-Servers Safe for Personal Health Record-Keeping?
No full textPresented at the 8th Health Informatics in Africa Conference (HELINA 2013).
Peer-reviewed and selected under the responsibility of the Scientific Programme Committee.This exploratory paper investigates the terms and conditions offered by cloud service providers,
questioning whether these are a safe environment for personal health record-keeping with regards to
privacy, security and intellectual property control among other factors. We focus on evaluating the extent
to which the privacy of sensitive information is protected in these systems as well as the extent to which
terms provided comply with relevant regulations. Whilst many people may be excited about the
introduction of cloud solutions to managing their personal health information, there are questions that we
urge the public to ask before entrusting their sensitive health records to any cloud-service system