Dissertations / Theses on the topic 'Economic aspects of Heating plants'

Small hydropower offers many advantages as a source of energy and it has been successfully developed by the private sector in the U.S. and in Ontario. Although there is considerable interest in developing British Columbia's vast small hydro resource, there has been very little progress to date. The reasons for this are related more to economic and political factors than to technical issues. In this thesis I review the situation in B.C. and propose a policy framework for energy purchase price, one of the main issues involved in small hydro development. The price offered small hydro producers for their electricity is clearly less than B.C. Hydro's avoided cost, but there is little evidence to support the amount offered. I suggest that, in the absence of an established, competitve market, energy purchase rates should be based on the utility's avoided costs, and that avoided costs be determined by amortizing the capital costs of the next scheduled project over a 20 year period, rather than basing them on the average levelized costs of all future projects. Furthermore, small hydro development should take a two-stage approach, similar to Ontario's, whereby energy is initially purchased at the utility's full avoided cost and later, when the small hydro industry has had a chance to develop, energy would be purchased at market value or through a competitive bidding process.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

This study investigates the economic impact of the ARC PPRI Weeds Research Division. The Division researches appropriate methods of biological control for invasive alien plants (IAPs). These plants pose an increasing threat to environmental integrity and ecosystem service provision impacting on economic potential. Since the work of the Division is considered a public good, a predominantly descriptive approach has been adopted for the valuation process. A combination of quantitative cost analysis and a qualitative study of the impacts of research and invasive alien plants is used to deal with the challenges associated with non-market valuation. The study found that investment into the Weeds Division is a valuable activity that supports the long-term growth potential of the South African economy. The role of a well-functioning environment is highlighted as an essential base for the creation of sustained growth opportunities in any society. It was determined that investment into the Division should be increased into the future to support efficient spending of scarce state funds. Biological control research was found to provide strategic future growth potential, creating opportunities for the development of a competitive advantage in the biotechnology and environmental management sectors. The study adds to the increasing move towards a more holistic view of economic valuation, taking factors other than pure finance and econometrics into consideration. This is an important shift in prevailing economic thought, as a realisation is reached that a single, or even triple, bottom line is an outdated and insufficient decision making basis.

Oilseed is the third most important export item in Ethiopian foreign trade. It has registered a high export growth rate over recent years both in terms of volume and value. Besides its growing share in export, it is widely used for the extraction of edible oil and oilcake that is supplied to the domestic market. Although farmers are the primary producers of oilseeds, they are not able to benefit from the growing market share of the product due to the fact that they find themselves at the end of an extended market chain. As a result they only receive a very small proportion of what the final buyers are paying for the oilseed products. In addition, there is not much experience on the part of the farmers to process oilseeds, change it to edible oil and oilcake and retain the value addition in the local economy. This thesis used the value chain approach to investigate the possibilities for the primary producers to increase their income share from the selling of their products either by directly selling to exporters or by processing oilseeds, producing edible oil and oilcake, and retaining the value addition in the local economy.

The study was conducted to investigate the ecological effectiveness and economicefficiency of four wastewater treatment plants in East Central Indiana (Muncie, Anderson, Alexandria, and Paws). Data were collected from the four plants, then analyzed descriptively and statistically, and compared in terms of ecological effectiveness and economic efficiency. The Muncie, Anderson, and Paws wastewater treatment facilities were not significantly different from one another in terms of biochemical oxygen demand (BOD5) reductions, but each reduced BOD5 more than the Alexandria facility over the three- year period (1996, 1997, and 1998). Plants were not statistically different regarding suspended solids (SS) reductions. The Muncie, Anderson, and Paws wastewater treatment plants were also not significantly different from one another on ammonia reduction, but each plant reduced ammonia significantly more than Alexandria. Muncie and Anderson were not different from each other on dissolved oxygen (DO) levels, but each had a statistically higher level of DO in the final effluent than Alexandria and Paws. The study showed a statistically significant difference in fecal coliform bacteria abatement between Anderson and Alexandria, Anderson and Paws, and Muncie and Alexandria. Furthermore, Muncie, Anderson and Alexandria were different in terms of cost per 1000 gallons of wastewater treated. Muncie has been treating wastewater at a lower cost than the other treatment plants, whereas Anderson had a higher cost over the three-year period.
Department of Natural Resources and Environmental Management

The demand for fossil fuels by Ontario's conventional steam power generation sector is examined. It is hypothesised that the enactment of a carbon fee policy will induce a change in the relative prices of the three fuels used in this sector (coal, natural gas and heavy fuel oil). This would lead to substantial interfuel substitution and greenhouse gas abatement. The demand share equations for the three fuels are derived from the translog functional form and set in a simulation model to estimate the value of a carbon fee necessary, to reduce carbon dioxide emissions in compliance with the Kyoto Protocol. Results suggest that a fuel specific carbon fee policy would be successful in achieving the desired emissions reduction at a negligible net cost to society.

Alineant-se amb l'ambiciós paquet de mesures de la UE per 2030 que pretén reduir les emissions de gasos d'efecte hivernacle i reemplaçar les fonts de calor convencionals amb fonts renovables dins de nuclis urbans, les plantes centralitzades de calefacció solar amb emmagatzemament estacional (CSHPSS) es troben entre les tecnologies més prometedores per estalviar energia en els sectors industrial i residencial-comercial. Aquest treball presenta una avaluació exhaustiva de la possibilitat d'integrar CSHPSS al sector residencial de diversos estats membres de la UE a través d'un enfocament sistemàtic d'optimització d'aquests sistemes tenint en compte els criteris econòmics i ambientals. Aquest enfocament incorpora simultàniament les anàlisis de cicle de vida econòmic i mediambiental al mateix temps que procura satisfer tècnicament tant la demanda de calefacció com els serveis domèstics d'aigua calenta. La metodologia s'aplica a una comunitat residencial de 1120 habitatges en diverses zones de la UE, amb Barcelona, Madrid, Atenes, Berlín i Hèlsinki com a exemples de diferents tipus climàtics europeus. L'avaluació ambiental mostra una millora significativa comparant la CSHPSS amb un sistema de calefacció de gas natural, arribant en alguns casos fins a un 87% de reduccions. D'altra banda, una àmplia millora econòmica és especialment limitada a la zona climàtica mediterrània (Atenes) a causa de les baixes demandes de calefacció i els preus dels recursos no renovables, el cost econòmic total de la CSHPSS pot superar fins a un 50.8% un sistema de calefacció de gas natural. No obstant això, tenint en compte l'actual tendència creixent en els preus del gas natural a tota la UE, l'estudi dels costos futurs de la planta confirma la seva viabilitat econòmica a llarg termini. En general, la nostra eina pot guiar els enginyers i arquitectes en la transició cap a un sector residencial més sostenible.
Alineándose con el ambicioso paquete de medidas de la UE para 2030 que pretende reducir las emisiones de gases de efecto invernadero y reemplazar las fuentes de calor convencionales con fuentes renovables dentro de núcleos urbanos, las plantas centralizadas de calefacción solar con almacenamiento estacional (CSHPSS) se encuentran entre las tecnologías más prometedoras para ahorrar energía en los sectores industrial y residencial-comercial. Este trabajo presenta una evaluación exhaustiva de la posibilidad de integrar CSHPSS en el sector residencial de varios estados miembros de la UE a través de un enfoque sistemático de optimización de estos sistemas teniendo en cuenta los criterios económicos y ambientales. Este enfoque incorpora simultáneamente los análisis de ciclo de vida económico y medioambiental al mismo tiempo que procura satisfacer técnicamente tanto la demanda de calefacción como los servicios domésticos de agua caliente. La metodología se aplica a una comunidad residencial de 1120 viviendas en diversas zonas de la UE, con Barcelona, Madrid, Atenas, Berlín y Helsinki como ejemplos de diferentes tipos climáticos europeos. La evaluación ambiental muestra una mejora significativa comparando la CSHPSS con un sistema de calefacción de gas natural, llegando en algunos casos hasta un 87% de reducciones. Por otro lado, una amplia mejora económica es especialmente limitada en la zona climática mediterránea (Atenas) debido a las bajas demandas de calefacción y los precios de los recursos no renovables, el costo económico total de la CSHPSS puede superar hasta un 50.8% un sistema de calefacción de gas natural. Sin embargo, teniendo en cuenta la actual tendencia creciente en los precios del gas natural en toda la UE, el estudio de los costos futuros de la planta confirma su viabilidad económica a largo plazo. En general, nuestra herramienta puede guiar a los ingenieros y arquitectos en la transición hacia un sector residencial más sostenible.
Aligning with the ambitious EU 2030 climate and energy package for cutting the greenhouse emissions and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, central solar heating plants coupled with seasonal storage (CSHPSS) are among the most promising technologies to save energy in the industrial and residential-commercial building sectors. This work presents a comprehensive evaluation for the possibility of integrating CSHPSS in the residential sector in various EU member states through the introduction of a systematic approach to optimize these systems according to economic and environmental criteria. This approach comprises simultaneously the life cycle cost analysis for the economic evaluation and the life cycle assessment for the environmental impact estimation while technically satisfying both the space heating demand and the domestic hot water services. The methodology framework is applied to a residential neighborhood community of 1120 dwellings in various EU zones with Barcelona, Madrid, Athens, Berlin, and Helsinki acting as proxy for different European climate types. The environmental assessment shows a significant improvement when using the CSHPSS in comparison to a natural gas heating system, arriving in some cases up to 87% reductions. On the other hand, an extensive economic improvement is especially limited in the Mediterranean climate zone (Athens) due to low heating demands and the prices of the non-renewable resources, there the total economic cost of the CSHPSS can increase up to 50.8% compared to a natural gas heating system. However, considering the incremental tendency in natural gas prices all over EU nowadays, the study of future plant costs confirms its favorable long term economic feasibility. Overall, our tool can guide engineers and architects in the transition towards a more sustainable residential sector.

Thesis (MComm (Economics)--Nelson Mandela Metropolitan University, 2011.
ENGLISH ABSTRACT: Renewable energy technology has received much attention over recent years. The depletion of known fossil fuel reserves and the volatility of international fuel prices require that society looks beyond the current coal-dominated electricity generation methods. Wind energy is an internationally well-established technology with large markets in major countries around the world, such as the USA and Germany. South Africa has the potential to generate large amounts of electricity from the wind because of the strength of the country’s wind resource. The long coast line and open areas are ideal for the exploitation of wind energy.
Sponsored by the Centre for Renewable and Sustainable Energy Studies

The main purpose of this thesis is to empirically calculate the welfare changes which might be expected to result from potato yield reductions caused by ambient ozone loadings in the Lower Mainland of British Columbia. The objectives of the research are: (1) to review the scientific literature pertaining to the effects of ozone loadings on agricultural crops; (2) to review the methodologies employed in previous regional economic assessments of ozone damages; and (3) to apply an economically defensible technique to the analysis of welfare losses due to ozone. Ozone in the Lower Mainland may be pictured as being restricted laterally by the mountain ranges surrounding Vancouver, and vertically by stagnant high pressure systems. Land/sea breezes aid in transporting ozone and its precursors from Vancouver up the Fraser Valley towards important crop growing regions. The highest levels of ozone occur during spring and summer coinciding with the most active season for many crops. Seasonal ambient ozone dose, measured as hours-ppm>0.10ppm was found to be high in rural areas, especially Abbotsford, during the late 1970's and early 1980's, dropping to low levels in more recent years. Potatoes are one of the economically important crops in the Lower Mainland known to be sensitive to ozone. Potato tuber weight reductions are estimated to have reached 16.5 percent in the Abbotsford region in 1981 at seasonal ambient ozone loadings. An aggregate supply/demand model is set up for potato production in B.C. based upon prior estimates of supply and demand elasticities. This model assumes the price in the B.C. market is set exogeneously by U.S. imports. Thus, all policy relevent welfare changes affect producers' quasi-rent alone. Sensitivity of the model to import price, and the price elasticity of supply is tested. A range of welfare estimates is reported for a variety of ambient ozone loadings. The total damages to potato producers, assuming all regions of B.C. are affected by the same seasonal dose as Abbotsford, are calculated to be around one million dollars at ambient ozone loadings in four out of eight years. A peak occurred in 1981 at 2.4-2.9 million dollars total damages. Damages may be overestimated because 20-30 percent of potato production takes place outside the Lower Mainland, Abbotsford often appears to receive higher ambient ozone loadings than other regions, and not all potato cultivars grown in the Lower Mainland are as sensitive to ozone as that employed here. However, there are also reasons to be cautious over discounting these estimates as too large. Potato response to ozone is restricted to tuber weight reductions while other important effects may include increased plant stress and damage to crop quality. In addition, missing air quality information for some years and stations, suggests that actual ozone dose could be higher than calculated.
Science, Faculty of
Resources, Environment and Sustainability (IRES), Institute for
Graduate

The aim of this thesis was to explore the socio-economic factors that impact on the sustainable harvesting of buchu in the Western Cape of South Africa. Some of the factors that were explored include poverty, natural resource tenure, legislation, and local practices with regard to the harvesting of buchu.

The purpose of this study was to investigate the economic feasibility of alternative crop rotations and to determine the economic implications of including forages and livestock during the transition to organic agriculture in Nova Scotia. The rotation systems were distinguished by: (i) frequency of forage in the rotation, (ii) source of nutrient supply, and (iii) type of farming operation. The economic analysis was divided in two parts. The first part analysed data from a four-year crop rotation experiment, using enterprise budgeting and statistical methods to compare differences among rotations under different treatments. The second part involved the development of a multi-period linear programming (LP) model to simulate a commercial operation.
The results from the statistical analysis suggest that crop enterprise net returns tended to be higher in forage-based rotations and in the livestock systems compared to cash crop rotations and the stockless system. Results from the LP model suggest that including forages and beef cattle during the transition to organic agriculture can provide considerable economic benefits, especially when crops were grown under ruminant compost.

The Akosombo Dam on the Volta River in Ghana was built in 1963 to provide cheap energy to fuel industry and to accelerate the economic growth of the country. It provides hydroelectric power, enhanced fishing and water transportation upstream, and improved opportunities for irrigated farming, especially in the lower reaches, and their attendant economic multiplier effects. A few years after the construction of this major dam, a rapid expansion of industrialization took place in Ghana. This brought about an exponential increase in demand for more electrical power. This led to the construction of a smaller dam at Akuse, downstream of the Akosomho Dam in 1981 and the formation of a headpond at Kpong. The impoundment of the river at the two sites (Akosombo and Kpong) caused an alteration in the existing ecological and biophysical processes in the river basin, including a slowing of the flow of the river, upstream and downstream. Changes in the natural processes, such as a reduction in the flow of the river and an increase in nutrient status of the water, resulted in an invasion of aquatic weeds, increasing the density of aquatic snails (intermediate hosts of schistosomiasis), silting and closure of the estuary, as well as other more subtle effects. The invasion of the river's main course and the dams by aquatic plants led to a corresponding reduction of navigable water both upstream and downstream. The aim of this thesis was to quantify the impact and control of waterweeds, especially water hyacinth, Eichhornia crassipes (Mart) Solms-Laubach (Pontederiaceae), in Ghana. A floral survey on the Kpong Headpond recorded 49 emergent, 12 free floating and I submerged aquatic plant species, many of which were indigenous, but the exotic or introduced water hyacinth was recorded at most of the sampling sites, and was the most abundant and had the biggest impact on the utilization of the water resource. Mats of water hyacinth served as substrates for other, indigenous species to grow out into the main channel of the headpond, including the intake point of the Kpong head works of the Ghana Water Company Limited (GWCL) and landing sites for boats. These mats resulted in a reduction of the fish (fin and shell) harvest, reducing the annual production to far below demand. Water hyacinth was also shown to have severe health implications. A survey of the Ministry of Health records showed that the prevalence of both urinary and intestinal schistosomiasis had risen significantly over time as the abundance of waterweeds, most notably water hyacinth, increased, and ranged between 70% and 75% but up to 100% in some lakeside communities. Based on the work done by an NGO on board the medical boat ("Onipa Nua "), losses in terms of money due to the effect on health of the aquatic weed infestations on the Volta River in 2006 amounted to US$ 620,000. Economic losses due to invasive alien aquatic weeds were also calculated on the Oti River Arm of Lake Volta. It was estimated that about US$2.3 million per annum would be lost to the Volta Lake Transport Company and individual boat transport operators if this section of the river were 100% covered by aquatic weeds (water hyacinth and Salvinia molesta D.S. Mitchell (Salviniaceae)). It was also estimated that US$327,038 was spent annually in monitoring and managing the weeds in the Oti River. Control interventions for aquatic weeds have been implemented in river systems in Ghana. The biological control agents Neochetina bruchi Hustache (Coleoptera, Curculionidae) and Neochetina eichhorniae Warner (Coleoptera, Curculionidae) have been used on water hyacinth infestations in the Oti River Arm of Lake Volta, the Tano River and the Lagoon complex in the south-western part of the country. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) has been used to control salvinia, and Neohydronomous affinis Hustache (Coleoptera: Curculionidae) to control water lettuce, Pistia stratiotes Lilmaeus (Araceae) in the Tano River and Lagoon complex. Although these projects have been regarded as successful, they have relied on research from elsewhere in the world and no postrelease quantification has been conducted. In evaluating the impact of the biological control agents Neochetina bruchi and Neochetina eichhorniae weevils on water hyacinth infestations in the Tano River, fresh adult feeding scars were recorded as well as the numbers of adult weevils on each water hyacinth plant sampled at six sites. Despite being released in 1994, weevil numbers and resultant damage to plants in the Tano Lagoon was low in comparison to other regions of the world where these agents have been used. The main reason for this is that this lagoon floods seasonally, washing weevil-infested plants out to sea. Water hyacinth then re-infests the lagoon from seed and the weevil populations are low. To resolve this situation, two courses of action are proposed. The first is to mass rear the weevils along the shore of the lagoon and release them when the first seedlings recruit. The second proposal is that additional agents that have shorter lifecycies and are more mobile than the weevils should be released. To this end, the water hyacinth mirid, Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae) was imported from South Africa and released onto the Tano Lagoon in 2009. Retrospective laboratory host specificity trials were conducted on Neachetina eichharniae and Neachetina bruchi weevils 15 years after their release into Ghana to see if any variation in their host ranges had occurred. Considerable damage was inflicted on the E. crassipes leaves by the Neachetina weevils, while little feeding damage was recorded on both Heteranthera callifalia Kunth. (Pontederiaceae) and Eichharnia natans (P.Beauv.) Solms (Pontederiaceae). All the weevils introduced on H callifalia and E. natans died after the first week. This study served to confirm the host specificity and thereby the safety of these agents. Invasive alien aquatic macrophytes have negative impacts on the environment and economy of Ghana. The control of these weeds is essential to socioeconomic development and improved human health standards in riparian communities. Biological control offers a safe and sustainable control option, but requires diligent implementation. However, aquatic weed invasion is more typically a result of the anthropogenically induced eutrophication of water bodies, and this is the main issue that has to be addressed.

Renewable energy has become an important feature of most modern economies with clean and non-exhaustible sources of power being given a greater significance. Wind energy is one of the favoured renewable, as it is (2013) generally the cheapest and most mature technology available for commercial use. The South African government, as outlined by the Department of Energy's Integrated Resource Plan (IRP), aims to install 5 GW (Gigawatts) of wind energy by 2020. However, South Africa has had little experience in the wind energy industry which is limited to two projects, Klipheuwel (2002) and Darling (2008). Much effort has been dedicated to calculating balance sheet costs, which carries uncertainty due to the high reliance on country specific and site specific variables. An aspect which deserves more attention, and is often ignored, is the public‟s attitudes towards local wind farm developments, which have been known to "make or break" a project during the planning stages. Public backlashes have mostly been concerned with the visual "intrusiveness" of wind farms in the landscape. Detrimental effects on scenery, while seemingly innocuous, are acknowledged as being the single largest barrier to successful wind farm development. Individuals within an area become sentimentally attached to their surroundings, where significant rapid changes in the landscape are viewed as "damage". Economics recognises such declines in scenic resources as market failures, where an externalised cost is passed on to the public and is often not accounted for by private parties responsible for the liability. The primary objective therefore was to measure the magnitude of the visual impact, caused by the Waainek Wind Farm, on the Grahamstown community. Conventional NIMBY¹ (not in my back yard) reasoning, which seeks to explain local wind farm resistance, has attracted criticism with regard to its simplistic approach to wind farm problem identification. Contemporary arguments propose that NIMBY is a poor explanation for the trouble experienced on the local level because it groups problems into one all-encompassing term, leaving much of the discontent unexplained. Instead, the NIMBY explanation is really a broad set of unattended problems, largely resulting from the unsound practices present in the public participation process. Insufficient community involvement and disparities in the negotiation power structures have become the recent focus in wind farm literature. Essentially, these disparities force opposition groups to select factors which may seem more serious to developers, leading to ineffective remedial measures because the core underlying problems are not being remedied. Thus these considerations formed an additional area of investigation. No NIMBY effect was found for the Grahamstown community, as support for both the local and general level was roughly 80%. The public participation process on the other hand revealed that while many found the practices of the developer to be unfair, attitudes towards the wind farm were not adversely affected, especially for the lower income Grahamstown East areas. While the public participation process in this instance did not have any effect on people’s attitudes, careful inspection of the circumstances need to be given. Wind farms are new to South Africa, where the novelty and benefits are the focus of enthusiasm. Job opportunities as well as clean energy are positive drivers for attitudes; however given time, once the anticipation for wind farms dulls, real problems may be revealed. Thus it is crucial to implement good practice procedures during the public participation process, especially when national adoption rates of wind energy are low. Early implementation of an effective public participation process system will ensure that when major problems do arise in future projects, experience and institutional processes would have had ample opportunity to evolve appropriately over a period of time. The double bounded Contingent Valuation Method was used to value the impact of the wind farm on the Waainek scenery through a hypothetical scenario based procedure which presented pictures of the landscape before and after the wind farm had been installed. Based on the perceived impact of the wind farm, respondents were asked their Willingness to Pay to relocate the development, based solely on visual impacts. Learning design Contingent Valuation (Bateman et al., 2008) is a novel technique employed to familiarize respondents with the hypothetical market institution as well as the scenic goods being valued. Average Willingness to Pay was found to be R67 per month, with a final total monthly negative visual impact of R104,000 to R121,000 per month for the entire Grahamstown community. Grahamstown Central (middle-high income) residents were more likely to pay than Grahamstown East (low-middle income) East residents because of socio-economic differences present in each area. A ranking exercise determined that while negative visual impacts are present, the overall benefits derived from the wind farm are potentially much higher. Additionally, positive scenic improvements were found, but were not measured due to time constraints, and would have worked to reduce the net visual impact of the Waainek Wind Farm. ¹Problem where individuals support the general concept of wind power, but when it comes to local implementation, opposition to the development arises within the same group.

Thesis (MScMedSc)--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: Introduction: Athrixia phylicoides is an aromatic, indigenous shrub with high antioxidant content and numerous indigenous medicinal properties inferred by ingestion of an herbal brew of the plant. Commercialization of “bush tea” (derived from A. phylicoides) holds economic and developmental potential for indigenous communities provided the safety and efficacy of the herbal tea is established. Recently A. phylicoides has been shown by McGaw et al. (2007) to have similar antioxidant activity to Rooibos tea, and a unique, new flavonol (i.e. a polyphenolic antioxidant plant metabolite) 5-hydroxy-6,7,8,3′,4′,5′-hexamethoxyflavon-3-ol, unique to A. phylicoides, was isolated by Mashimbye et al. in 2006. With changes in the socio-economic climate and a new trend in merging Western lifestyle with traditional practices, new interest has been shown in herbal/natural remedies. Study Aim: The aim of this study was to firstly, determine the in vitro effect of A. phylicoides aqueous extract on glucose metabolism in cell lines that mimic the three key organs implicated in glucose homeostasis. Secondly, the study aimed to determine the potential ex vivo antioxidant and anti-inflammatory effect of the extract in pancreatic β-cells and peripheral mononuclear cells respectively. Methods: Leaves and fine twigs of A. phylicoides were processed into an aqueous extract. C2C12, Chang and 3T3-L1 cells were cultured under standard conditions and acutely exposed to increasing concentrations of extract and water vehicle, as well as 1 μM insulin and metformin as positive controls. Glucose uptake from 8 mM glucose culture media was determined using a fluorimetric oxidase method. Radioactive 14C-glucose oxidation to 14CO2 and determination of glycogen content of cells were used to assess the fate of intracellular glucose. RT-PCR was used to assess the extract effect on insulin-signalling gene expression. The antioxidative effect of A. phylicoides extract in pancreatic β-cells isolated from Wistar rats was determined by measuring nitric oxide (NO) production in response to hyperglycemic conditions. NO was labelled with diaminofluorocein diacetate and fluorescence was measured using flow cytometry. Insulin secretion of pancreatic β- cells was measured using radio-immuno assay. The anti-oxidative effect of the extract in lipopolysaccharide-stimulated peripheral mononuclear cells isolated from Wistar rats was determined by measuring the production of TNF-α using an ELISA kit. Results: C2C12 myocytes showed maximal increased glucose uptake at the 0.05 μg/μl extract concentration (228.3% ± 66.2, p<0.001). In Chang cells, A. phylicoides extract maximally increased the amount of glucose taken up at the 0.05 μg/μl concentration (134.5% ± 2.5, p<0.05). In 3T3-L1 cells, the extract maximally increased the amount of glucose taken up at the 0.025 μg/μl concentration (143.5% ± 10.3, p<0.001). An extract-induced increase in insulin receptor and glucose transporter four expression was seen in C2C12 myocytes. The oxidation of 14C-glucose to 14CO2 by C2C12 myocytes was maximally increased following acute exposure to the extract at 0.1 μg/μl (2919.3 fmol/1x10^6 cells ± 428, p<0.01). The oxidation of 14C-glucose to 14CO2 by Chang cells was maximally increased following acute exposure to extract at 0.1 μg/μl (4476.7 fmol/1x10^6 cells ± 1620, p<0.05); as seen in the C2C12 cells. A. phylicoides extract increased glycogen storage at all three concentrations tested in Chang cells, but maximally at the 0.025 μg/μl concentration (13.6 μg/1x10^6 cells ± 0.7, p<0.05). A. phylicoides extract did not have any measurable effect on the oxidative status of β-cells or the anti-inflammatory status of peripheral mononuclear cells. The extract did show an increase in first phase insulin secretion of β-cells in hyperglycemic conditions, although it was not significant. Conclusion: Athrixia phylicoides aqueous extract stimulates in vitro glucose uptake and metabolism in an insulin-mimetic manner, suggesting that this extract could potentially be beneficial to type two diabetics as an adjunct therapy.
AFRIKAANSE OPSOMMING: Inleiding: Athrixia phylicoides is 'n aromatiese, inheemse struik met 'n hoë antioksidant inhoud. Vele tradisionele medisinale eienskappe is gekoppel aan die ingestie van 'n kruie brousel van die plant, wat ook bekend as “bostee” is. Kommersialisering van “bostee” hou ekonomiese en ontwikkelings potensiaal in vir inheemse gemeenskappe mits die veiligheid en effektiwiteit van die kruietee bevestig kan word. McGaw et al. (2007) het onlangs bevind dat A. phylicoides se antioksidant aktiwiteit vergelykbaar is met die van rooibostee. 'n Unieke nuwe flavonol ('n polifenoliese antioksidant plant metaboliet) 5-hydroksie-6,7,8,3′,4′,5′-hexamethoksieflavon-3-ol, eie aan A. phylicoides, is deur Mashimbye et al. in 2006 geïsoleer. Met veranderings in die sosio-ekonomiese klimaat en 'n nuwe tendens om die westerse lewenstyl met tradisionele gebruike aan te vul word nuwe belangstelling in kruie/natuurlike rate ondervind. Studie Doelwitte: Die doelwitte van hierdie studie was eerstens om die in vitro effek van A. phylicoides waterekstrak op die glukosemetabolisme van drie sellyne wat die sleutel organe naboots wat glukosehomeostase beheer, te bepaal. Tweedens, is die potensiële ex vivo antioksidant en anti-inflammatoriese effek van die ekstrak op pankreatiese β-selle en perifere mononuklêere-selle onderskeidelik ondersoek. Metodes: n Waterige ekstrak is van die blare en fyn takkies van A. phylicoides berei. C2C12, Chang and 3T3-L1 selle is gekultuur onder standaard kondisies en akuut blootgestel aan stygende ekstrakkonsentrasies. Water het as kontrole gedien, met 1 μM insulien en metformien as positiewe kontroles. Glukose opname vanuit 8 mM glukose kultuurmedia is bepaal deur 'n fluorimetriese oksidase metode. Radioaktiewe 14C-glukose-oksidasie na 14CO2 en die bepaling van die glukogeen inhoud van selle is gebruik om die lot van intrasellulêre glukose te bepaal. RT-PKR is gebruik om die effek van die ekstrak op die insulien-seinpad geen-uitdrukking te ondersoek. Die antioksidant effek van A. phylicoides ekstrak in pankreatiese β-selle geïsoleer van Wistar rotte, is bepaal deur stikstofoksied (NO) produksie na aanleiding van hiperglukemiese kondisies. NO is met diaminofluorosien diasetaat gemerk en die fluoresensie gemeet deur vloeisitometrie. Insulien afskeiding deur die pankreatiese β-selle is deur radio-immuno metode bepaal. Die anti-oksidatiewe effek van die ekstrak op lipopolisakkaried-gestimuleerde perifere mononuklêere-selle afkomstig van Wistar rotte is bepaal deur die meting van TNF-α produksie met 'n ELISA kit. Resultate: C2C12 miosiete het 'n maksimale toename in glukoseopname by 'n 0.05 μg/μl ekstrakkonsentrasie (228.3% ± 66.2, p<0.001) gehad. Dieselfde ekstrakkonsentrasie het maksimale toename in glukoseopname in Chang selle (134.5% ± 2.5, p<0.05 getoon. In 3T3-L1 selle is maksimale toename in die glukoseopname by 'n konsentrasie van 0.025 μg/μl (143.5% ± 10.3, p<0.001) bereik. 'n Ekstrak-geinduseerde verhoging in die insulienreseptor en glukosetransporter vier ekspressie is in C2C12 miosiete waargeneem. Die oksidasie van 14C-glukose na 14CO2 deur C2C12 miosiete is maksimaal verhoog deur akute blootstelling aan die ekstrak by 'n konsentrasie van 0.1 μg/μl (2919.3 fmol/1x10^6 cells ± 428, p<0.01). Die oksidasie van 14C-glukose na 14CO2 deur Chang selle was maksimaal verhoog deur akute blootstelling aan die ekstrak by 'n konsentrasie van 0.1 μg/μl (4476.7 fmol/1x10^6 cells ± 1620, p<0.05) soos gevind in die C2C12 selle. Die ekstrak het glukogeenstoring verhoog teen al drie die konsentrasies waarteen getoets is in Chang selle, maar 'n maksimale effek is gevind by 'n konsentrasie van 0.025 (13.6 μg/1x10^6 cells ± 0.7, p<0.05). A. phylicoides ekstrak het nie 'n meetbare effek op die oksidatiewe status van β-selle of die anti-inflammatoriese status van perifere mononuklêere-selle gehad nie. Die ekstrak het wel 'n verhoging in die eerstefase insuliensekresie van β-selle in hyperglukemiese kondisies gehad, alhoewel die verhoging nie statisties betekenisvol was nie. Afleiding: Athrixia phylicoides waterekstrak stimuleer in vitro glukoseopname en metabolisme in 'n insulin-mimetiese manier, wat beteken dat die ekstrak potensiëel voordele vir tipe twee diabete kan inhou as aanvullingsterapie.

This study examines the relationship between atomic energy production and community identity in Richland, Washington. Over the past fifty years, the identity of southeastern Washington has been intimately tied to production and industry at the Hanford Site. Today, however, environmental restoration and waste management programs have replaced plutonium production. The decline of the nuclear industry has influenced reinterpretations of local history and community identity through public display, commodity goods, and the re-scripting of historical texts.
Department of Anthropology

The growth and accumulation of macroalgae in estuaries are a common sight throughout the world (Boyer and Fong, 2005). Because macroalgae establish such complex but important links with other components within an estuary, it is essential to know which variables control and regulate their occurrences. The type of algae that will occur in an estuary depends however, on the physical and chemical features of the particular estuary (Lobban and Harrison, 1994). The focus of this study was to document and provide a listing of algae from estuaries around the Eastern Cape coast of South Africa and describe the communities which form within each estuarine habitat. The questions posed were: Do algae assemblages differ in estuaries with different environmental conditions? Are different plant communities inhabited by different algae communities? Also, are algae diverse in estuaries that are in a pristine condition? The estuaries were Mngazana, Ngqusi/Nxaxo, Mtati, Mpekweni, East Kleinemonde, West Kleinemonde, Kariega, Bushmans, Kowie and the Sundays estuary. Percentage cover surveys were conducted and environmental parameters recorded to determine community structure of algae and their environmental tolerances. A total of 49 different macroalgal species were identified from 11 estuaries, which were dominated by Chlorophytes (23 species) and Rhodophytes (17 species). The Ochrophytes consisted of 10 species. The highest number of species recorded was 29 at the Bushmans estuary (March 2009), while the lowest number (4 species) was recorded at Mtati (October 2008). Common Chlorophytes found included Ulva prolifera, Chaetomorpha linum and Codium tenue. In the Division Ochrophyta, species from the Genus Ectocarpus were the most common. Of the red algae filamentous reds, Polysiphonia incompta and Polysiphonia kowiensis were the common algae found at estuaries. Salinity (p= 0.029861; n= 49) and temperature (p= 0.037641; n= 49) were the driving environmental parameters of estuaries and significantly influenced richness of species. In ordination analyses, patterns of biogeographic distribution were noticeable and were described by salinity. Four gradients caused by salinity were therefore found – which is inversely correlated to water clarity. Moreover, a clear split between temporarily open/closed and the permanently open estuaries was observed. Samples grouped into four communities presumably based on the similarity in conditions of estuaries. Within each estuarine community and major type of estuary there was a range of environmental conditions. However, the macroalgae within each community may not have been colonists of or found in greatest abundances in the estuaries of these communities per se, but may have grouped together in this manner based on the optimum growing conditions for them. Also, specific algal groups were not directly determined by the type of estuary they were found in; they were driven by environmental ranges rather. The results therefore support hypothesis one which states species distribution and diversity differ and are influenced by environmental gradients of the estuary. Although close species and habitat relationships were apparent from the ordination analyses, providing support for hypothesis two which states “Different plant communities in estuaries will be inhabited by different macroalgae communities”, the evidence was not substantial enough to provide sufficient support for the hypothesis. Lastly, the hypothesis “Macroalgae are diverse in estuaries that are in a pristine condition” was not accepted as highest species numbers were found in estuaries of greatest anthropogenic disturbance (e.g. Bushmans estuary) and not in estuaries which where ecologically more natural (e.g. Mtati estuary). By doing monthly macroalgal sampling over a period of one year for example one would obtain greater information of biodiversity, and patterns of macroalgal seasonality may be uncovered as well. This is an area of reasearch which needs to be investigated in the future as it would greatly add to the understanding of the role macroalge have in an estuarine environment.

Thesis (M. Tech. (Mech. Eng.)) -- Central University of Technology, Free state, 2010
The purpose of this research is to minimize the use of active systems in providing thermal comfort in single-family detached, middle to high income residential buildings in Bloemfontein. The typical case study house was selected according to the criteria as reviewed by Mathews et al., (1999). Measurements were taken for seven days (18 – 24 May 2009). The measurements were carried out in the winter period for Bloemfontein, South Africa. Ecolog TH1, humidity and temperature data logger was used in doing the measurements. These measurements included indoor temperatures and indoor relative humidity. Temperature swings of 8.43 ºC and thermal lag of 1 hour were observed. For the period of seven days (168 hours), the house was thermally comfortable for 84 hours. Thermal analysis for the base case house was done using Ecotect™ (building analysis software) and the simulated results were compared with the measured results. A mean bias error (MBE) of between 10.3% ≤≤11.5% was obtained on the initial calibration. The final calibration of the model yielded error between0.364% ≤≤0.365%. The final calibration model which presented a small error was adopted as the base case. Passive strategies were incorporated to the Ecotect™ model (final calibrated model) singly and in combination; then both thermal and space load simulations were obtained and compared to simulations from the original situation (base case) for assessing improvements in terms of thermal comfort and heating, ventilation and air conditioning (HVAC) energy consumption. Annual HVAC electricity savings of up to 55.2 % were obtained from incorporating passive strategies in combination. Incorporating passive strategies resulted in small improvements in thermal comfort.

According to the United States Department of Energy, fossil-fueled power plants account for 78% of stationary source CO2 emission in the United States and Canada. This has led electric utilities across the globe to research different alternatives for energy. Carbon sequestration has been identified as a bridge between fossil fuels and clean energy. This thesis will present research results regarding the transportation costs of CO2 and the suitability of geology in the Florida Pan-Handle for sequestration infrastructure. The thesis will utilize various evaluation tools including GIS, numerical models, and optimization models. Analysis performed for this thesis and review of published literature produced estimated carbon storage capacities for two areas in and near the Florida Pan-Handle. These areas were labeled Disposal Area 1 and Disposal Area 3. Disposal Area 1 was estimated to contain capacity for the storage of 5.58 gigatonnes of CO2. Disposal Area 3 was estimated to contain capacity for the storage of 2.02 gigatonnes of CO2. Transportation scenarios were analyzed over a 25 year period and the capacities above are sufficient to store the CO2 emissions from the Pan-Handle network of power plants for the study period. Four transportation routing scenarios were investigated using transportation costs from the Poiencot and Brown CO2 pipeline capital cost model. The scenarios (models) consisted of the Right-Of-Way, Solo-Funded, Piece-Wise, and Authority models. Each presents a different method for the overall funding of the Florida Pan-Handle CO2 network and produced different total levelized and mean unit costs. The cheapest network on a mean unit cost basis was the network for Disposal Area 1 in the Authority Model, producing a mean unit cost of $0.64 per tonne of CO2.

Alien invasive vegetation threatens the functioning of natural ecosystems as well as their services, which sustain human welfare, both directly and indirectly. The proliferation of this vegetation in South Africa has been attributed to the ignorance of the social implications affiliated to their existence. Investment decisions are predominantly based on the marginal private costs of an activity, since individuals have not been made accountable for costs imposed on society in the past. Consequently, their marginal private costs always fall well short of the marginal social costs. In order to promote sustainable development as well as curtail widespread invasion by alien plants in South Africa, it is essential to close the gap between these costs and support research aimed at ascertaining monetary values for non-market goods, such as biodiversity. This study scrutinizes the economic viability of alien plant eradication in the Mhlatuze Catchment by comparing the costs and benefits associated with this eradication process. A series of formal in-depth interviews with major stakeholders residing in the upper reaches of the catchment were conducted in an attempt to evoke individuals' perceptions concerning alien vegetation together with the actual costs incurred in extirpating this vegetation. The contingent valuation method (CVM), which relies on surveys to elicit the maximum amount respondents would be willing to pay to obtain or retain some nonmarket good, was employed to glean monetary values for benefits such as biodiversity and augmented streamflow. The findings suggest that there is a positive net effect associated with alien vegetation extirpation in the Mhlatuze Catchment, since the social benefits outweigh the costs. Given the temporal and financial constraints that prevailed, it was only possible to examine some of the benefits affiliated to this process, such as increased timber harvesting, streamflow, biodiversity and reduced fire hazard. Consequently, this analysis represents a minimum estimate of the benefits, further enhancing the argument in favour of extirpation. The results lend support to calls for greater policy emphasis on, as well as funds for, the eradication of alien invasive plants.
Thesis (M.A.)-University of Natal, Pietermaritzburg, 2001.

Please read the abstract in the section, 00front, of this document
Dissertation (MSc (Agric))--University of Pretoria, 2006.
Agricultural Economics, Extension and Rural Development
unrestricted

Nuclear power plants across the United States are reaching the end of their current operating licenses, forcing decision makers to think about the way forward. As they consider the best alternatives for dealing with aging nuclear plants, it is becoming increasingly important to have an accurate method for calculating the long-term costs of nuclear power plants. This report begins by investigating the methodologies currently used in these calculations. They focus on the uncertainty associated with deregulated electricity markets and can be broken down into two main categories: discounted cash flow and real options analysis. Next the report discusses the limitations of the current methodologies, focusing specifically on those aspects of evaluation that are currently eclipsed by electricity market uncertainty. Finally the report offers recommendations for addressing these limitations and creating a stronger analytical framework for calculating the lifetime cost of nuclear power plants.
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Text in English
The introduction of the New Growth Path (NGP) and the New Industrial Policy Framework (NIPF) have created an opportunity for the industrialisation of indigenous medicinal and aromatic plants (MAPs Amarula (Sclerocarya birrea), Buchu (Agathosma betulina), and Pelargonium (Pelargonium sidoides) for job creation and economic development in South Africa. The aim is to create a locally sustainable industry which creates jobs as well as improvement of the balance of payments. The National Growth Plan highlights some of the opportunities for industrialization as well as creation of decent jobs. There is increasing pressure on the harvesting of wild indigenous medicinal and aromatic plants (MAPS). The establishment of a local pharmaceutical and nutraceutical industry for processing MAPS remains a challenge in South Africa and many low income countries. The objective of this study was to assess the challenges and their impact looking at particular species, Amarula, Buchu and Pelargonium by using structured focus group interviews with users in communities and businesses in KwaZulu Natal Province, Eastern Cape and the Western Cape. More data/information was also collected from key stakeholder companies including desk-top reviews. Data/information was analysed using the SPSS computer programme and the Atlas software to summarize data and the results. Graphs and tables were used where necessary. The qualitative research reported on some qualitative assessments and challenges facing the establishment of medicinal and aromatic plants in South Africa. Comparative findings from BRICS were also reported. The results of the study indicated that there is continuous exploitation of several medicinal plant species, for plant trade, from the wild and substantial loss of their habitat. The research identifies a number of challenges such as: poor standards for raw materials, lack of research and development linking industry driven revenues, demand exceeding supply, regulatory risk, community risk, lack of understanding of judicious agronomic practices, ethical challenges, liquidity risk as well as political instability fail to attract foreign direct investments. The research concludes that for the establishment of a viable local pharmaceutical industry, iii beverage industry and nutraceutical industry with sustainable harvesting, there are serious hegemonic challenges which will require multi-stakeholder analysis. However, for the South African (SA) industry to be competitive, detailed feasibility studies need to be done comparing SA with other BRICS countries. There is also a need for the Research and Development to be strengthened. It must also be linked into industrial development in the industry. Furthermore there is a need to initiate the incentivizing of the pharmaceutical manufacturing to lower the cost of setting up the businesses in the industry and lessen the need to harvest from South African forests. Furthermore there is a need for programmes of production so that key species are given opportunity for cultivation and the attention they deserve to preserve these depleting resources.
Agriculture and  Animal Health
M.Sc. (Agriculture)

The dissertation analyses the economic and ecological aspects of Darvill Waste Water Works (WWW) through key indicators from Sustainable Development Records (SDR). The SDR study identifies disturbances caused by large concentrations of soap, oil and grease (SaG), therefore a framework of proposed solutions to dealing with these problems has also been investigated. The first component of the study highlights the importance of adequate indicators. Key indicators provide important information that is useful to management and policy makers. The SDR used to analyse the DarvillWWW in Pietermaritzburg provides relevant information for the management of Darvill WWW and Umgeni Water (UW), the City Council and the Department of Water Affairs and Forestry (DWAF). According to the SDR model the Works is identified as a service providing social institution. The operation of this institution affects the community of Pietermaritzburg as well as the surrounding natural environment. SDR uses the key indicators of effectiveness, Thrift and Margin to analyse the economic and ecological impacts of the service provided.The study incorporates relevant data for Darvill WWW during 1993- 1996. Effectiveness measures the degree of compliance with national water quality standards as set out by the DWAF. Compliance of the following variables, E.coli, Chlorine, Soluble Reactive Phosphate (SRP), Total Suspended Solids (TSS), Conductivity, Chemical Oxygen Demand (COD) and Ammonia were investigated. These variables produce varying trends. Increasing compliance is linked to improved plant efficiency while decreasing compliance is linked to the poor quality of industrial effluent. Industrial effluent containing large concentrations of SOG is a particular problem. Thrift measures the costs of operating the Works in terms of energy, chemicals, labour and capital. Overall financial, energy and labour thrift declined while chemical thrift increased. Increasing chemical thrift is due to the reduced consumption of chemicals as a result of a greater reliance on the process of biological phosphate removal. Decreasing thrift is related to increased costs of capital, energy and labour due to the deteriorating quality of vegetable oil effluent. Margin measures the deviation of non-complying samples from water quality standards. Analysis of the data produced varying trends. The following variables were analysed, E.coli, Chlorine, SRP, TSS, Conductivity, COD and Ammonia. Marginal difference is studied in an attempt to analyse those samples which do not comply with national standards. Deteriorating quality of industrial effiuent seems to be the reason for deviation from the standards. Chemical margin was also studied for the period between 1993-1996. Chemical margin is a comparison between the value of sludge produced and the cost of chemicals used to produce the sludge. The SDR study highlights deteriorating quality of industrial effluent as a cause for concern to Darvill WWW. Proposed management options are investigated to provide a workable solution. The second part of the study investigates alternate options for handling wet industrial effluent from the vegetable oil industries. These industries were identified as the source of large concentrations of SOG that were entering the Works which impacts negatively on the operational capacity, thereby increasing operating costs and decreasing the quality of the service provided. Vegetable oil industries were found guilty of discharging industrial effluent that did not meet the City standards into the sewers, they were also charged with illegal dumping into rivers. The study identified the interested and affected parties and alternate solutions were proposed to the problems. Interested and affected parties include UW, Pietermaritzburg City Council, DWAF. Some of the aspects that were investigated include the local industrial tariff, the drainage By-laws, national legislation, the "polluter pays" principle and the principle of pollution prevention. Economic incentives using economic instruments were reviewed. These include ecotaxes such as marketable/tradable permits and pollution charges. These instruments may allow for more equitable charges thereby promoting the "polluter pays" principle. The use of these instruments may be able to achieve a workable solution but further investigations are necessary. SDR analysis indicates that Darvill WWW seems to be effectively treating wastewater but operating costs are increasing in order to achieve compliance. These costs are being unfairly borne by the City ratepayers and UW and a more equitable situation is necessary.
Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 1997.

South Africa has over 19 500 different indigenous plant species. Most of these are of ethnobotanical significance and are still used by local rural communities as medicine, food and for making beverages. The relatively little research that has been conducted on indigenous plant species has focused mainly on their medicinal potential. However, in view of the rapidly growing size of the global and local beverage industry and their constant search for new products, beverage-making indigenous plant species may have commercial development potential. To date, no detailed studies have been conducted on these plants, especially in the species-rich Limpopo province. The aim of this study was, therefore to evaluate the potential of indigenous plants for commercial beverage production. In order to achieve this, a survey was conducted in the Limpopo province to identify beverage-making plants and to document beverage preparation methods. Selected beverages were analysed and evaluated for their nutrient and sensory characteristics and a market product acceptability survey was conducted to identify those beverages with the greatest potential for development. Sixty three different beverage-plant species were identified in three study areas within the Limpopo province. These were used for the preparation of teas, fruit juices and alcoholic beverages. Plants that received further research attention were selected on the basis of their status as indigenous plants, frequency of use, nature of harvesting methods and availability. Some of the selected beverages were found to be rich in nutrients, especially with respect to vitamin C and mineral content. Furthermore, sensory analyses and market surveys indicated that four species, namely, Doyvalis caffra, Garcinia livingstonei, Grewia flavescens and Englerophytum magalismontanum have potential for further development for the beverage industry while Athrixia phylicoides has commercialisation potential as a herbal tea. However, further research is required to improve and refine preparation methods and to ensure compliance with quality standards. The availability of sufficient plant material for the industry must also be ensured. This research has indicated that South African indigenous plants have untapped market potential for the beverage industry which, if developed sustainably, could contribute to economic growth of the rural parts of South Africa.
Environmental Sciences
D. Ed. (Environmental Management)

The production of forage in British Columbia plays and integral role in sustaining livestock herds within the province. Forage is an important component in the daily feed requirements of horses, sheep, and cattle. Fluctuations in the availability of forage due to drought or bad weather conditions can impose considerable costs on farmers who raise livestock. Wide—spread drought conditions can significantly limit the availability of forage crops within certain regions, causing prices within those regions to become inflated. Under standard insurance in British Columbia, farmers are only insured against shortfalls in production; there is no compensation provided against increases in the price of forage. For those purchasing forage, a Wide—Spread Drought (WSD) insurance scheme would provide insurance against the price—risk associated with drastic weather conditions. However, since forage prices are required to operate such a policy and are non—observable, a mechanism is needed in order to estimate them. A regional spatial price—equilibrium model which relates regional prices to regional production is developed in this thesis. The model will eventually be used to predict prices and hence determine whether a particular region is eligible for a payout under the WSD insurance scheme. A key assumption behind the model is that according to the ‘Law of One Price’; prices are perfectly arbitraged. In a competitive setting, in which agents maximize individual welfare, total welfare is maximized and prices between regions will not differ by more than the transportation costs. This spatial price—equilibrium model is applied to British Columbia forage production. The regions incorporated in the study include the Peace River, Central Interior, Cariboo—Chilcotin, Thompson—Okanagan, and Kootenay Regions. The Lower Mainland/Fraser Valley and Vancouver Island are excluded as they do not typically fall under the forage crop insurance plan in British Columbia.

Healthcare in South Africa is polarised between western and traditional African systems of therapy. The latter is consulted by the majority of the population and therefore plays an integral role in the delivery of healthcare to South Africans. Traditional medicines are primarily plant products with long storage lives, among which the dominance of bark is typical of southern African traditional healthcare systems. Expansion of the traditional healthcare sector during the twentieth century, in response to rising consumer demands, stimulated a lucrative trade in medicinal plants that is centred in KwaZulu-Natal. Since herbal medicines are sourced almost exclusively from indigenous vegetation, harvesting pressures exerted on the indigenous flora to meet demands for traditional medicines have rendered such resources non-sustainable. Although trees comprise a small fraction of South African medicinal plant species, bark from them constitutes a substantial proportion of the plant products used medicinally. Trees are among the most threatened medicinal plants in South African due to their limited abundance, the ecological sensitivity of the vegetation in which they occur, and destructive methods of commercial bark harvesting that frequently take place within protected areas. In KwaZulu-Natal, bark is harvested primarily from forests that occupy an extent of only 0.1 % in the province. Conservation of economically valuable tree species is particularly problematic since data necessary for the establishment of sustainable usage systems are absent or inaccessible. Alternatives to in situ conservation for renewable bark resources include propagation, multi-use timber systems and reintroduction of locally extinct species. To facilitate appropriate management of bark resources, there is a need for specialist publications and consolidated data with which sustainable usage levels may be determined. The importance of bark in South African traditional healthcare is poorly reflected by the ethno botanical literature. In this study, 180 bark species used in traditional healthcare in KwaZulu-Natal were inventoried from thorough literature surveys, but this number is anticipated to be a conservative reflection of actual statistics. Where trade data were recorded in the literature, they indicated intensive exploitation of bark resources in KwaZulu-Natal and throughout South Africa, but conservation and management data were lacking for 72 % of the species inventoried. A number of problems were encountered in the literature, of which vague information and the documentation of local vernacular nomenclature were the most troublesome. Despite the importance of traditional medicine, the country's political history led to the prevailing situation, where the traditional healthcare sector is largely unregulated. Coupled with increasingly limited availability of medicinal plants, the quality and appropriate use of traditional medicines is negatively affected by growing numbers of inadequately trained practitioners, herbalist retailers and plant gatherers. Possibilities of misidentification or purposeful adulteration of medicinal bark products therefore lead to concerns for patient safety, since dried bark is difficult or impossible to identify. Whilst bark characters are useful for field identifications, many useful diagnostic characters are lost through desiccation, and anatomy and morphology of bark are variable. Additionally, medicinal bark products used in KwaZulu-Natal, and their identification, are largely undocumented. This study focussed on eight bark species used medicinally in the province, elected by an esteemed traditional medical practitioner as having problematic identity. Monograph-type characterisation profiles were drawn up for reference specimens collected from various localities, and their medicinal bark products traded under vernacular names recorded in the literature. In the absence of standardised traditional medicines, there is a need for reliable and affordable methods for their authentication. Phytochemical bark characters identified by Thin Layer Chromatography (TLC) have proved useful in chemotaxonomic studies, and the technique is widely used for herbal drug authentication. TLC was tested here for authentication of medicinal bark products from the aforementioned study species. Three reference samples of each species were collected, and TLC-generated fingerprints compared. At the intraspecific level, TLC was useful in confirming the relationship of ethanol and hexane bark extracts, but was less meaningful in distinguishing between fingerprints of different species. Three medicinal bark products of each study species were purchased and fingerprints compared to a reference. The technique proved useful in confirming the identity of several medicinal bark products. Authentication of medicinal bark products may be useful in toxicology cases and in the accurate documentation of their trade. This research identified a complexity of issues surrounding the use of bark in traditional healthcare in KwaZulu-Natal, and indeed South Africa. A multi-faceted approach is required to secure their sustainability. Critical, however, to factors such as effective conservation and regulation of the traditional healthcare sector, is recognition of the importance, and documentation, of traditional bark medicines. The integrity of traditional healthcare, and the future of the South African flora, hinge upon the sustainable use of medicinal products such as bark.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

A new peat replacement product is being manufactured in South Africa. This product which is marketed under the brand name Fibregro is made from spent wattle bark originating from the tanning extract manufacturing process. Fibregro is currently being used in South Africa to dilute and in some instances replace local peat in mushroom and horticultural applications. In addition to its role as a peat replacement, Fibregro is in a position where it could also qualify to cany a Forest Stewardship Council (FSC) label. Once in full production it is estimated that the company will be able to produce more products than can be sold locally. As a result export opportunities need to be pursued. The United Kingdom (UK) was identified as a potential export destination on account of developments in this country in respect of the certification of forest products (especially FSC certification) and moves to reduce peat mining. A mail survey was undertaken amongst growing media producers in the UK to address two key issues relating to Fibregro, namely: • Whether Fibregro's peat free status could be exploited in the UK growing media and mushroom casing markets. • Whether enough advantages existed in the UK market to justify the extra effort and cost associated with qualifying Fibrego to carry an FSC label. Key findings arising from this survey indicate that a niche is developing in the UK growing media market for a good peat substitute. The addition of an FSC label will render the product unique in the growing media market in this country. A number of recommendations arise from this work. These are: • In order to penetrate the UK growing media market Fibrgro must be positioned as an effective peat reducing agent which is capable of extending the peat reduction levels beyond that of composts. • Fibregro distributors should be identified from amongst the larger growing media producers in the UK. • Potential use of Fibregro as a mushroom casing in the UK appears to be limited. • A combination of peat free and FSC labelling while capable of rendering Fibregro unique in the UK growing media market needs to be carefully considered on account of chain-of-custody requirements along the supply chain.
Thesis (M.B.A.) University of KwaZulu-Natal, Pietermaritzburg 2004.

A research report submitted to the Faculty of Mining Engineering. University of Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering
Hlstorically South Africa has enjoyed a privileged position with its vast natural resource base in that it has.not needed to generate wealth but has merely explored this base, The only true way to create wealth, is to add value to a commodity by means of beneficiation, South Africa is the world's largest producer of vanadium accounting for approximately 70% of the western world's requirements. Unfortunately the South African producers of vanadium mainly export vanadium in the form of slag and pentoxide, instead or ferrovanadium and other prime alloys. ( Abbreviation abstract)
AC 2018

Oregon's nursery and greenhouse industry has ranked the first in the State's agricultural for 18 years. The majority of nursery sales from the Pacific Northwest come from Oregon. Due to data limitations, empirical study of the Oregon nursery industry is rare. The present dissertation consists of three essays that analyze the demand and supply of inputs and outputs and the relationship between producers and retailers in the Oregon nursery industry. Chapter 2 identifies the major factors affecting farm labor supply and demand and evaluates their relative importance in the Oregon nursery industry from 1991 to 2008. Empirical results show that border control effort doesn't have an influential role in labor supply, while the Oregon and Mexican minimum wage do. It is because of the substantial gap between the U.S. and Mexican economies, reflected for an example in the minimum wage gap, which attracts a continual flow of immigrants. Risk of border apprehension is not great enough to prevent the flow. Increases in Oregon minimum wage is more effective than border apprehension policies in boosting the average wage and in reducing the number of hours that illegal immigrants work in the nursery sector. Chapter 3 investigates producers' and retailers' choices of, and reactions to, various contract types in the Oregon nursery industry from 2005 to 2010. As new and fast-growing retailers in the industry, big-box stores are less likely than independent retailers to make pre-order contracts with the producer. However, once a pre-order contract is chosen, big-box stores demand more days of pre-order interval than independent retailers do. Transactions with independent retailers exhibit – on average over the sample range – scale economies and scope diseconomies. Boosting per-transaction revenue scale and the number of species sold to big-box stores enhances transaction efficiency. Chapter 4 examines the interaction between supply and demand in Oregon nursery products. The result indicates that the production and transaction costs are major drivers on the supply side, while transportation costs and consumer demand for nursery products play important roles on the demand side. At the genus level, the supply elasticities of coniferous plants are larger than those of deciduous plants, which in turn are higher than those of flowering plants. The demand elasticities are the lowest in coniferous trees followed by deciduous plants, then flowering plants. Price discounts on plants with high demand elasticities would significantly boost sales and enlarge the market, while those on plants with low demand elasticities would have less sales impact. Empirically, patenting seems to bring no direct signs of greater profitability. The wholesale nursery may wish to reconsider the pricing and marketing policies of its patented plants to differentiate them more effectively from its non-patented plants.
Graduation date: 2013

This ethnographic research examines socioeconomic vulnerabilities to resettlement from a large hydropower dam and agricultural commodification in a Tibetan village in Yunnan Province, Southwest China. After providing an initial background on the dynamics of the research region and hydrodevelopment on its rivers, the research framework of examining vulnerability through a lens of political ecology and local knowledge is outlined. Utilizing this framework, the socioeconomic strategies surrounding agriculture and commodified forest products within the study village are initially outlined through the use of oral histories, previous literature, and quantitative household survey data. After providing a detailed background on these income strategies, vulnerabilities to resettlement are examined through qualitative analysis of individual household interviews. This analysis shows that village households are highly reliant on the village's specific location in order to collect the resources and pursue the agriculture that they do; making them vulnerable to future resettlement. The analysis also shows that in the opinions of villagers, a good standard of living is significantly defined by their ability to pursue specific economic strategies. Next, interview results are analyzed to show how agricultural commodification and a very high reliance on one government sponsored company to purchase crops has also made the village highly vulnerable economically. The thesis concludes with reflections on future hydrodevelopment and resettlement scenarios within the village, and provides recommendations to improve local level resilience and promote better capacity to adapt to change.
Graduation date: 2013

Maize (Zea mays L.) streak virus disease (MSD) is the most important virus disease in Africa but farmers are unaware of its status. A project was initiated to assess the current status of MSD and to breed for its resistance. Four populations comprised of two BC1F1 and two F2 progenies developed by backcrossing and selfing the F1 progenies of two crosses between a donor line (CMl 202) and two susceptible lines (CMl 321 and CMl 384) were developed. Conventional and molecular marker assisted selection (MAS) methods were used to screen for resistance to MSD in each of the four populations. To facilitate unbiased comparison, separate screening nurseries were established for MAS and conventional screening. The objectives of the study were five-fold; 1) to assess the status of MSD in Uganda and understand farmers' preferences and varietal selection criteria for maize using a participatory rural appraisal (PRA), 2) to screen for MSD resistance in early generations of segregating maize populations using conventional method, 3) to screen for resistance to MSD using SSR marker assisted selection , 4) to compare the effectiveness of marker assisted selection and conventional methods for selection for resistance to MSD, and 5) to compare costs associated with MAS and conventional selection methods. Results of PRA showed that unreliable rainfall and insect pests were the dominant constraints to maize productivity in Uganda. Diseases were ranked fifth among the production constraints . Maize streak virus disease was considered the most important disease constraint. Farmers showed common preference for high yielding and early maturing cultivars. However, farmers had other special preferences which were diverse and included large, white and high test density kernels for marketing, and sweet taste, particularly for home consumption. Farmers' research priorities included tolerance to drought, resistance to insect pests and diseases, sweetness, prolificacy, resistance to lodging, and drooping leaves because theyt cover the soil fast and prevent weed growth. Conventional screening for resistance to MSD showed that backcross and selfing populations segregated in 1:1 and 3:1 Mendelian ratios confirming the presence of one major gene with simple inheritance . Severity and incidence of disease were positively correlated suggesting a non-reference by the insects. In the selfing populations, the presence of complete esistance against MSD was suggested because frequency distribution patterns were highly skewed in favour of resistance. There was a decrease in disease severities with selection from BC1F1 to BC2F1 and from F2 to F3 generations indicating that high response to selection was achieved. On the other hand, one marker, umc1917, consistently polymorphic and eo-dominant was selected and used in MAS protocol. Results showed that the observed outcomes fitted the expected ratio of 1:2:1 for a F2 population and 1:1 for a BC1F1 population (X2 not significant). Evaluation of F3 and BC2F1 progeny selected using markers showed low disease severity suggesting that marker assisted selection was effective. However, the study showed that the presence of the O'Tl, was not consistent with symptom expression in the field. Evaluation of lines in three-way crosses identified ten potential lines that were high yielding, highly resistant to MSD and stable across three locations. Both MAS and conventional selection were equally effective in identifying high yielding lines although resistance was higher under MAS. Costs of MAS and conventional method varied depending on the units for comparison. The total costs of conventional method were higher than that of MAS in both first and second selection cycles. Comparing costs per row for conventional and costs per plant or data point for MAS showed that conventional selection was 2.4 times more expensive than costs per sample for MAS. However, costs per plant for MAS were 6.6 times higher than for conventional selection.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2006