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As the transition from the use of fossil fuels torenewable sources takes place, consumption of electricity willgreatly increase. The shift in energy sources will have a deepimpact on how financial decisions in the grid will be made. Toensure that the necessary investments are made to meet the newneeds, many network administrators have used different typesof markets for capacity. This project reviews how the networkadministrator PJM in the US uses capacity markets to secure thesupply of electricity and stability in the grid. A literature studywas conducted together with a market simulation and the resultsfrom the simulation shows that the use of a separate capacitymarket is a successful concept for securing future electricitysupply and stability in the grid. / I takt med att övergången från användningen av fossila bränslen till förnybara källor sker, kommer elförbrukningen att öka kraftigt. Skiftet av energikällorkommer att ha en stor påverkan på hur finansiella beslut inom elnätet kommer att tas. För att se till att nödvändiga investeringar görs för att klara de nya behoven har många nätverksadministratörer använt sig av olika slags marknader för kapacitet. I detta projekt undersöks hur nätverksadministratören PJM i USA använder sig av kapacitetsmarknader för att säkra elproduktionen och stabiliteten i nätet. En litteraturstudie genomfördes tillsammans med en marknadssimulering och resultatet från undersökningen visar på att användningen av en separat kapacitetsmarknad är ett framgångsrikt koncept för att säkra framtida elförsörjning och stabilitet i nätet. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

Det här examensarbetet inriktar sig på att med ett simuleringsprogram försöka utröna om det skulle gå att använda feedback control av löphju-let på en kaplanturbin för att reglera frekvensen ut på elnätet. Detta görs idag med hjälp av att öka eller minska magnetiseringen av generatorn. Det blir också en jämförelse för att se om det blir någon skillnad på resultatet mellan PID/PI. Resultatet mellan PID och PI är väldigt snar-lika och på frågan om det skulle gå att frekvens styra med löphjulet är svaret antagligen, det beror på hur mycket turbinens svängmassa på-verkar varvtalsändringen. Det skulle däremot ge ökat underhåll och större förslitning på lager och packningar. / This degree project focuses on using a simulation program to try to find out if it would be possible to use feedback control of the impeller on a Kaplan turbine to regulate the frequency on the power grid. This is done today by increasing or decreasing the magnetization of the genera-tor. There will also be a comparison to see if there is any difference in the result between PID/PI. The result between PID and PI is very close, and to the question of whether it would be possible to control the fre-quency with the impeller, the answer is probably, it depends on how much the turbine's swing mass affects the speed change. However, this would result in increased maintenance and greater wear and tear on bearings and seals.

South Africa’s growing elephant populations are concentrated in relatively small enclosed protected areas resulting in the over utilisation of the available food sources. Elephants and other herbivores as well as other natural disturbances such as fires and droughts play an important role in maintaining savannah environments. When these disturbances become too concentrated in a particular area the vegetation composition may be negatively affected. Excessive damage to the vegetation would result from exceeding the capacity of a protected area to provide food resources. The effect of the 120 elephants on the vegetation of Welgevonden Private Game Reserve, is not known. The rugged terrain of this reserve makes it a difficult, time consuming and labour intensive exercise to conduct ground studies. Satellite images can be used as a monitoring tool for vegetation change and improve the quantity and quality of environmental data to be collected significantly, allowing more informed management decision-making. This study evaluated the use of satellite imagery for monitoring elephant induced vegetation change on Welgevonden Private Game Reserve. The LANDSAT Thematic Mapper multispectral images, acquired at two yearly intervals from 1993 until 2007 were used. However, no suitable images were available for the years 1997, 2001 and 2003. A series of vegetation change maps was produced and the distribution of water sources and fire occurrences mapped. The areas of change were then correlated with the spatial distribution of water points and fire occurances, with uncorrelated areas of change. This was analysed using large animal population trends, weather data and management practices. On the visual comparison of the vegetation maps, it was seen that over this time period there was some decrease and thinning of woodland, but the most notable change was the increase of open woodland and decrease in grasslands. Using only the digital change detection for the period 1993 to 2007, a general increase in vegetation cover is seen. But this generalisation is misleading, since comparing the digital change detection to the vegetation maps indicates that while vegetation cover may have increased, significant changes occurred in the vegetation types. Most of the areas of significant change that were identified showed a strong positive correlation with burnt areas. The distribution of the water sources could not be directly linked to the vegetation change although rainfall fluctuations seemed to have accelerated vegetation changes. Years with high game counts, such as 1999, also coincide with very low rainfall making it difficult to differentiate between the effects of heavy utilisation of vegetation and low rainfall. Furthermore, many of the initial vegetation changes could be the result of land use changes due to the introduction of browsers, selective grazers and elephants that allow for more natural utilisation of the vegetation. Remote sensing makes it possible to successfully track changes in vegetation and identify areas of potential elephant induced vegetation change. Vegetation changes caused by disturbances, such as fire and anthropogenic activities, can be accounted for but it is not possible to conclude with a high level of certainty that the further changes seen are solely a result of elephant damage. Further work is required to reliably isolate elephant induced vegetation changes, as well as to establish the effects these changes have on the ecosystem as a whole. / Environmental Sciences / (M. Sc. (Environmetal Sciences))

This paper examines U.K financial metric data to determine whether or not the founding of the Federal Reserve had real economic effects on the U.K financial markets. To measure for real effects I use a composite stock price index collected from a variety of industries. I develop the theory using empirical conclusions from past studies on the Federal Reserve and its impact on U.S financial markets to direct my examination of the U.K markets. Although the U.K data shows that the founding of the Federal Reserve influenced short-term interest rates, the analysis does not find real effects on U.K stock prices and long-term interest rates.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The conservation of resources which fall under communal tenure has been a major dilemma for the past 60 years. In South Africa communal lands support more than a quarter of the country’s citizens, mostly the poorest members of society whose livelihoods rely heavily on natural resources. Wildlife enterprise is an alternative land use strategy for implementing community based resource management on communal lands. Additionally, safari hunting has been recognised as an efficient means of initiating wildlife based land use practises. In the 1980’s a community owned game reserve, which utilised safari hunting as an income source, was established on one of South Africa’s black homelands, the Ciskei. Since then, the reserve has been disbanded but little is known about how it operated, the reason it was formed or why it failed. The aim of this study was twofold: firstly, to document and understand the happenings of a failed community owned hunting reserve in South Africa’s Eastern Cape Province and secondly, to determine what level of support there would be amongst the local residents if the reserve was to be re-established. Semi structured, qualitative interviews were conducted to gather information about the reserve from key informants. Structured, randomly selected household surveys were used to gauge local residents support on the idea of having the reserve re-established. Additionally, in doing so it was possible to view, though indirectly, the thoughts and attitudes of the residents to the notion of safari hunting as a land use option. In review of the reserve history it was found that complexities that make up the social settings of communal lands in South Africa were ignored and dealt with through the age-old approach of top-down management regimes. Once the power of the initial authorities was lost the entire project was doomed to failure as local residents felt no need to keep the project alive. Results showed that 73.7% of the respondents would support the redevelopment of the Ntabethemba Reserve while 19.5% would not. The remaining 6.8% could not say whether they would or would not. The majority of the respondents (73%) believed that the area should be marketed for safari hunters, whilst 13% were against it, 9% were neutral and 5% were unsure. The Ntabethemba Reserve can be viewed as a ‘joint-management’ project where management responsibilities were adopted by a non-community party. If a future project is to be undertaken it needs to be aware of the complex socio-ecological setting of the area and account for this in ways that are beyond those advocated in the traditional approach to protected area conservation. The highly skewed distribution of livestock ownership needs to be taken into consideration in that those few individuals who own the most livestock would lose the most from any development that reduces grazing lands. Both the benefits and the costs need to be distributed in such a way that a situation is avoided where only a few are benefiting at the expense of others. / AFRIKAANSE OPSOMMING: Die bewaring van hulpbronne in gebiede met kommunale grondregte is reeds vir die afgelope 60 jaar uiters problematies. In Suid-Afrika is meer as ‘n kwart van alle landsburgers afhanklik van kommunale grondgebiede vir hulle lewensonderhoud. Dit is hoofsaaklik die armste lede van die gemeenskap wat op die natuurlike hulpbronne in hierdie gebiede staatmaak. Natuurlewe-ondernemings bied ‘n alternatiewe strategie vir grondverbruik, wat die implementasie van gemeenskapsaangedrewe hulpbronbestuur op kommunale grond moontlik maak. Daarmee gepaard, is safari-jag ‘n erkende en effektiewe metode om praktyke rondom natuurlewe-gesentreerde grondverbruik te inisieer. Gedurende die 1980’s is ‘n natuurreservaat met gemeenskapsregte in een van Suid-Afrika se swart tuislande, naamlik die Ciskei, gevestig. Safari-jag is as inkomstebron in hierdie reservaat benut. Die reservaat is sedertdien ontbind. Daar is egter min inligting oor hoe die reservaat bedryf is, oor die redes waarom dit geskep is, of waarom dit misluk het. Hierdie studie was tweedoelig: eerstens om die gebeure rondom ‘n mislukte jagreservaat met gemeenskapsregte in die Oos-Kaapprovinsie te dokumenteer en te begryp, and tweedens, om te bepaal of, en in hoe ‘n mate, die plaaslike inworners die hervestiging van die reservaat sou ondersteun. Half-gestruktureerde, kwalitatiewe onderhoude is gevoer om inligting oor die reservaat van sleutelinformante in te win. Gestruktureerde, ewekansig geselekteerde huishoudelike steekproewe is gedoen om die steun vir die moontlike hervestiging van die reservaat te peil. Op indirekte wyse was dit verder moontlik om inwoners se houdings en benaderings tot safari-jag as grondverbruikerskeuse te evalueer. Toe die geskiedenis van die reservaat in oorsig geneem is, is bevind dat die ingewikkelde sosiale agtergrond van gemeenkappe met kommunale grondregte in Suid-Afrika verontagsaam is, en dat die afgeleefde bestuursbenadering “van-bo-af-ondertoe” ook hier gebruik is. Toe die eermalige owerhede al hulle uitvoerende magte verloor het was die projek tot mislukking bestem, omdat die plaaslike inwoners geen rede gesien het om dit aan die lewe te hou nie. Die resultate het getoon dat 73.7% van die respondente die herontwikkeling van die Ntabethemba Reservaat sou ondersteun, terwyl 19.5% dit nie sou doen nie. Die oorblywende 6.8% kon nie sȇ of hulle ten gunste daarvan was of nie. Die meerderheid van die respondente (73%) is van mening dat die gebied as safarijaggebbied bemark moet word, terwyl 13% daarteen was, 9% neutraal en 5% onseker was. Die Ntabethemba-reservaat kan eerder as ‘n projek van “gesamentlike-bestuur” beskou word, as ‘n inisiatief wat uiteraard op “kommunaal-gebaseerde natuurlike hulpbronbestuur” (CBNRM) gegrond is. As ‘n projek in die toekoms weer geloots word, moet sorgvuldig ag geslaan word op die ingewikkelde sosio-ekologiese agtergrond van die gebied. Dit mag nie, soos in die verlede, bloot volgens die tradisionele benadering tot die bewaring van beskermde gebiede van stapel gestuur word nie. Die erg skewe verspreiding van veebesit is uiters belangrik in hierdie konteks, aangesien die paar individue wat die meeste vee besit, die grootste verliese sal moet dra as ‘n ontwikkeling plaasvind wat weidingsverliese behels. Beide voordele en verliese moet opgeweeg en eweredig versprei word, sodat ‘n paar mense nie ten koste van ander begunstig word nie.

This three part dissertation begins by "Examining the Origin of Federal Reserve Independence." This paper explores early Fed history with a particular emphasis on the period between 1947 and 1953 in order to provide a complete political account of Fed Independence. / Government

This report reviews the 2007 financial crisis and the actions of the Federal Reserve. The Full Employment Act of 1946 and the "Humphrey-Hawkins" Act guides the Fed's actions. These two laws outline the long-term goals of the monetary policy framework the Fed uses; however, the framework lacks principles for achieving the mandated long term goals such as reliable, complete data. This report looks at the use of model-based forecasting and gives recommendations for principles which will strengthen the preexisting monetary framework. / text

Glutamate is the main excitatory neurotransmitter in the CNS and at the neuromuscular junctions (NMJs) of invertebrate. The characteristic similarities to CNS glutamatergic synapses in vertebrate and the anatomical simplicity of invertebrate NMJs favor the investigation of glutamatergic synaptic functions in this system. This dissertation mainly aimed to physiologically separate two functional vesicle groups, the reserve pool (RP) and readily releasable pool (RRP) within presynaptic nerve terminals of Procambarus Clarkii and Drosophila melanogaster. This was addressed in part by blocking the vesicular glutamate transporter (VGlut) with bafilomycin A1. Various frequencies of motor nerve stimulation, exposure time, and concentration of bafilomycin A1 were examined. The low-output tonic opener NMJs in crayfish exposed to 4μM bafilomycin A1 and 20Hz continuous stimulation decreased the EPSP amplitude to 50% in ∼30min with controls lasting 3h. After activity and bafilomycin A1-induced synaptic depression, the EPSPs were rapidly revitalized by serotonin (5-HT, 1μM) in the crayfish preparations. The 5-HT action can be blocked almost completely with a PLC inhibitor, but partially with a cAMP activator. The higher output synapses of the larval Drosophila NMJ when stimulated at 1Hz or 5Hz and exposed to 4μM of bafilomycin A1 showed a depression rate of 50% within ∼10min with controls lasting ∼40min. After low frequency depression and/or exposure to bafilomycin A1 a burst of higher frequency (10Hz) can recruit vesicles from the RP to the RRP. Physiological differences in low- (tonic like) and high-output (phasic like) synapses match many of the expected anatomical features of these terminals, part of this dissertation highlights physiological differences and differential modulation and/or extent of the vesicles in a RP for maintaining synaptic output during evoked depression of the RRP in crayfish abdomen extensor preparation. With the use of bafilomycin A1, the tonic terminal is fatigue resistant due to a large RRP, whereas the phasic depresses rapidly upon continuous stimulation. Upon depression of the tonic terminal, 5-HT has a large RP to act on to recruit vesicles to the RRP; whereas, the phasic terminal, 5-HT can recruit RP vesicles to the RRP prior to synaptic depression but not after depression.

The focus of this study is the effect of environmental conditions on the social relationships among females in a free-ranging troop of chacma baboons (Papio cynocephalus ursinus), in a southern woodland habitat. The female dominance hierarchy, rank related differential costs and benefits to individuals, and the nature of special relationships between females, were followed. The study was conducted for a total of 18 months during three years, at Mkuzi Game Reserve, Zululand, South-Africa. The study troop occupy a rich woodland habitat with abundant food resources. Visibility under these conditions is poor and the baboons are subjected to leopard predation. Intra-troop competition for food among female primates and its effect on lifetime reproductive success, has been widely stressed to be a major cost for low ranking females. No evidence of competition for food was found among females at Mkuzi. It is suggested that the main cause for mortality may be predation by leopards, and that females compete mainly over a safe spatial position. The following characteristics of female sociality at Mkuzi may support this suggestion: 1. While no indication of rank related feeding behaviour, reproductive success, or 'attractiveness' to others was found, the higher ranking females had more access to central, and thus better protected, spatial positions in the troop. 2. The importance of social associations among females at Mkuzi seems to lie in mutual grooming and protection from predation by the vicinity to each other, and not in coalitionary support. Female associates were thus not necessarily adjacent ranking and probably not kin. 3. Although female dominance hierarchy was usually stable, the lowest ranking adult female has promoted her rank independently, following the disappearance of her only female associate and during her pregnancy, when she was probably subjected to high risk of predation. 4. Following troop fission, most females chose to improve their own rank position by adopting the AYS strategy (Abandon Your immediate Superior in rank), rather than joining associates. It is suggested that the resident males were responsible for the initiation of troop fission, in order to decrease the high cost of sexual competition to them, by reducing the number of males in each daughter troop. High intensity of competition between males was the result of the high female reproductive success. Risk of predation, and therefore the cost to individual females, increased after fission. This study may present an additional accumulating behavioural evidence on adaptations environmental conditions. the of flexibility primates example to of social and to various environmental conditions. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.