50 research outputs found

    Climate Change Mitigation Potential in South Africa: A National to Sectoral Analysis

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    This paper discusses some of the impacts attributed to climate change that are likely to hit Southern Africa as a result of increasing global greenhouse gas emissions into the atmosphere. As South Africa is a significant contributor to greenhouse gas emissions and currently ranked first in Africa, the paper assesses the country.s greenhouse gas emissions profile and possible future projections of emissions and their implications. It then discusses the strategic interventions proposed by South Africa in reducing the gap in emissions between what is required by science and what would happen if development continues at current rates without abating greenhouse gas emissions. Given that the majority of emissions are a result of energy consumption, the paper provides practical solutions to themes such as energy efficiency mostly for the industrial and commercial sectors. With international treaties on the reduction of greenhouse gas emissions (e.g. Kyoto protocol), there are business opportunities in the area of climate change mitigation. Thus, the paper finally discusses the Clean Development Mechanism (CDM) scenario in South Africa and how the country can benefit from other emission trading schemes being practiced in different regions of the world.

    A Survey on Modeling Line Commutated Converter HVDC Transmission Systems

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    This paper review about the dynamic phasor model of a line-commutated converter (LCC) high-voltage direct current (HVDC) transmission system. The mathematical definition and properties of dynamic phasors are utilized to model both the dc-side and the ac-side of a LCC-HVDC transmission system as well as 6-pulse Graetz Bridge, which is the building block of such a system. The developed model includes low-frequency dynamics of the systems, i.e., fundamental frequency component (50 Hz) at the ac-side and dc component at the dc-side, and removes high-frequency transients. The developed model, however, is capable of accommodating higher harmonics if necessary. The model is also able to simulate the system during abnormal modes of operations such as unbalanced operation and commutation failure. In order to develop the dynamic phasor model of a line-commutated converter, the concept of switching functions is utilized. The developed model is capable of capturing large-signal transients of the system as well as steady state operating conditions. The model can be used in order to decrease the computational intensity of LCC-HVDC simulations

    A study on the limitations of evolutionary computation and other bio-inspired approaches for integer factorization

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    Integer Factorization is a vital number theoretic problem frequently finding application in public-key cryptography like RSA encryption systems, and other areas like Fourier transform algorithm. The problem is computationally intractable because it is a one-way mathematical function. Due to its computational infeasibility, it is extremely hard to find the prime factors of a semi prime number generated from two randomly chosen similar sized prime numbers. There has been a recently growing interest in the community with regards to evolutionary computation and other alternative approaches to solving this problem as an optimization task. However, the results still seem to be very rudimentary in nature and there\u27s much work to be done. This paper emphasizes on such approaches and presents a critic study in details. The paper puts forth criticism and ideas in this aspect

    Inter-Relationship between Economic Growth, Savings and Inflation in Asia

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    The present study examines the inter- relationship between economic growth, saving rate and inflation for south-east and south Asia in a simultaneous equation framework using two stage least squares with panel data. The relationship between saving rate and growth has been found to be bi-directional and positive. Inflation has a highly significant negative effect on growth but positive effect on saving rate. Inflation is not affected by growth but is largely determined by its past values, and saving rate is not affected by interest rate. These findings for countries in Asia with widely divergent values of aggregates are very relevant for development policies and strategies

    ENVIRONMENTAL CHEMISTRY: MONITORING AND REMEDIATION OF POLLUTANTS IN AIR, WATER, AND SOIL

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    The purpose of this study is to determine pollutants present in air, water, and soil. Highlighting the impacts of these pollutants and ways to monitor and control these pollutants are other objectives of this research. Further, air pollution, water pollution, and soil pollution are illustrated as a part of environmental pollutio

    Beneficial Effect of Oryzanol on Transient Middle Artery Occlusion Induced Ischemic Stroke in Atherosclerotic Rats. Improvement in Behavioural and Biochemical Parameters

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    The present study was designed to determine the beneficial effect of oryzanol treatment in the ischemic stroke in atherosclerotic rats. Atherosclerosis was induced in rats using high fat diet (containing 20% ground nut oil, 0.5% cholesterol, 1% cholic acid) for 32 days. Ischemic stroke was induced in the atherosclerotic rat (AT rats) on 33rd day using tMCAO model. In the oryzanol treatment group, oryzanol (100 mg/kg, po) was administered on the very first day (day rats were fed with high fat diet), ischemic stroke was induced on 33rd day and oryzanol treatment was continued after the induction of ischemia from 34th day to 40th day. The neurological score was determined for 7days with gap of 24 hrs between the testing procedure. Rats were sacrificed followed by the blood collection and excision of whole brain for the determination of various parameters including brain damage (infarct volume, brain hemisphere weight difference, and Na+-K+-ATPase activity) and oxidative stress parameter (SOD activity, reduced GSH level, MDA level, nitrite level and LDH level). It was observed that ischemia-reperfusion (IR rats) in atherosclerotic rats increased the neurological score, increase in infarct volume, brain hemisphere weight difference and reduced activity of Na+-K+-ATPase. Further IR rats showed the decreased activity of SOD activity and GSH, whereas the level of MDA, nitrite and LDH activity was found to be increased in the atherosclerotic-IR rats. Further it was observed that the oryzanol treatment in the atherosclerotic counteracted the high fat induced rise in the TG, LDL, and VLDL level and increased the level of HDL in the treated animals. Further the administration of oryzanol improved the neurological score, reduce the infarct volume, brain hemisphere weight difference and improve the activity of Na+-K+-ATPase. Oryzanol treatment further improved the SOD activity, increased the level of GSH, reduced the level of MDA, nitrite and LDH activity in atherosclerotic-IR rat

    Impact of wild prey availability on livestock predation by snow leopards

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    The fieldwork was supported by Fondation Segré-Whitley Fund for Nature, Conservation Leadership Programme and National Geographic Young Explorer fund. These grants supported K.R.S., Y.V.B. and C.M. Laboratory analysis was supported by the Department of Science and Technology, Government of India. This grant supported U.R., V.C., Y.V.B., K.R.S. and C.M. Data Dryad Repository. (http://dx.doi.org/10.5061/dryad.8p689)An increasing proportion of the world’s poor is rearing livestock today, and the global livestock population is growing. Livestock predation by large carnivores and their retaliatory killing is becoming an economic and conservation concern. A common recommendation for carnivore conservation and for reducing predation on livestock is to increase wild prey populations based on the assumption that the carnivores will consume this alternative food. Livestock predation, however, could either reduce or intensify with increases in wild prey depending on prey choice and trends in carnivore abundance. We show that the extent of livestock predation by the endangered snow leopard Panthera uncia intensifies with increases in the density of wild ungulate prey, and subsequently stabilizes. We found that snow leopard density, estimated at seven sites, was a positive linear function of the density of wild ungulates—the preferred prey—and showed no discernible relationship with livestock density. We also found that modelled livestock predation increased with livestock density. Our results suggest that snow leopard conservation would benefit from an increase in wild ungulates, but that would intensify the problem of livestock predation for pastoralists. The potential benefits of increased wild prey abundance in reducing livestock predation can be overwhelmed by a resultant increase in snow leopard populations. Snow leopard conservation efforts aimed at facilitating increases in wild prey must be accompanied by greater assistance for better livestock protection and offsetting the economic damage caused by carnivores.Publisher PDFPeer reviewe
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