The geometry of the receiver and recuperator in a small-scale open and direct recuperative solar thermal Brayton cycle can be optimised in such a way that the system produces maximum net power output. The purpose of this work was to apply the second law of thermodynamics and entropy generation minimisation to optimise these geometries using an optimisation method. The dynamic trajectory optimisation method was used and off-the-shelf micro-turbines and a range of parabolic dish concentrator diameters were considered. A modified cavity receiver was used in the analysis with an assumed cavity wall construction method of either a circular tube or a rectangular channel. A maximum temperature constraint of 1 200 K was set for the receiver surface temperature. A counterflow plate-type recuperator was considered and the recuperator length was constrained to the length of the radius of the concentrator. Systems producing a steady-state net power output of 2 – 100 kW were analysed. The effect of various conditions, such as wind, receiver inclination and concentrator rim angle on the maximum net power output, and optimum geometry of the system were investigated. Forty-five different micro-turbines and seven concentrator diameters between 6 and 18 metres were considered. Results show the optimum geometries, optimum operating conditions and minimum entropy generation as a function of the system mass flow rate. The optimum receiver tube diameter was relatively large when compared with the receiver size. The optimum counterflow plate-type recuperator channel aspect ratio is a linear function of the optimum system mass flow rate for a constant recuperator height. The optimum recuperator length and optimum NTU are small at small system mass flow rates but increase as the system mass flow rate increases until the length constraint is reached. For the optimised systems with maximum net power output, the solar receiver is the main contributor to the total rate of minimum entropy generation. The contributions from the recuperator, compressor and turbine are next in line. Results show that the irreversibilities were spread throughout the system in such a way that the minimum internal irreversibility rate was almost three times the minimum external irreversibility rate for all optimum system geometries and for different concentrator diameters. For a specific environment and parameters, there exists an optimum receiver and recuperator geometry so that the system can produce maximum net power output. / Dissertation (MEng)--University of Pretoria, 2011. / Mechanical and Aeronautical Engineering / unrestricted

This paper is divided into four distinct sections. 1. An explanation of the meaning of input/output analysis, especially the derivation and significance of the table of direct and indirect requirements. 2. An outline of the decisions taken in constructing the West Malaysian 1960 transactions table from a set of National Accounts - especially the treatment and valuation of imports and exports; producer versus purchaser price valuation of transactions; and problems of inconsistent and incomplete double entry records. 3. An explanation of the method of forecasting from input/ output tables. This includes discussion of: a. A method of estimating aggregate demand for Malaya for 1970. b. A method of projection of value added for each sector, 1970. c. The likely stability of the input coefficients over time. 4. Results; a. Differences between the 1960 and 1965 table projections due to changes in Leontief inverses and value added coefficients over time, as the economy undergoes change. b. Comparison of the table projections with the First Malaysia Plan projections: i. Are the Plan projections likely to be reached in 1970? ii. Why are some of the table projections so inaccurate? The paper concludes that 1. The projections from the 1965 input/ output table are generally superior to those from the 1960 table. 2. Under conditions of structural change, even 5 years is too far ahead to expect input/output analysis to yield accurate projections for most sectors. / Arts, Faculty of / Vancouver School of Economics / Graduate

The dissertation deals with the interplay of fiscal and monetary policy in face of uncertainty about the estimation of the true output gap. Theoretical framework of the dissertation set this interplay of monetary and fiscal policy into the realm of game theory, in particularly non-cooperative games of the Nash and Stackelberg equilibrium, respectively. The theoretical framework continued with a description of various methods used for estimation of potential output and output gap, with a special emphasis on methods used in both the Czech National Bank and Czech Ministry of Finance. In the applied part of the dissertation, I studied the interplay of monetary and fiscal policy in the case of Czech economy facing an uncertainty about the estimation of the true output gap. I studied the impact of this interplay on major macroeconomic variables and I tried to determine, which of these two policies plays the role of a leader and which plays the role of a follower in the case of Czech economic environment.

During the course of the last decade successive governments in the UK have placed young people’s aspirations at the core of their attempts to address poor outcomes within the education system and the labour market. An area-based approach to policy has come to the fore which links ‘low aspirations’ with particular community- and neighbourhood-level factors, in particular area-level deprivation. This area-based focus on the determinants of aspirations has faced intensifying critique from the academic research base. Responding to this policy and research debate, this thesis examines whether, and how, young people’s occupational aspirations are shaped by the areas they live in. The thesis is based on a mixed methods research design and has two sections: an extensive phase and an intensive phase. The extensive phase of the research consists of logistic regression analysis of data from the Understanding Society Youth Questionnaire, and considers whether the types of occupations young people aspire to vary between different types of area. The intensive phase of the research consists of phenomenographic analysis of semi-structured interviews conducted with young people in a deprived, outer-urban neighbourhood in Manchester, and considers how young people’s subjective orientations towards the area they live in produce different forms of aspiration. The thesis finds compelling evidence that young people’s occupational aspirations are shaped by the areas they live in, but does not corroborate the claim at the core of current government policy, that aspirations are lower in more deprived areas. The extensive phase of the research instead identifies area type, rather than deprivation, as the primary area-level factor shaping young people’s aspirations, with young people from particular inner city area types almost five times as likely as their peers from deprived outer-urban areas to aspire to ‘higher’ professional, managerial and technical occupations. Meanwhile, the intensive phase of the research finds evidence that experiences of neighbourhood and family life in an area of concentrated deprivation can lead young people to adopt particular forms of aspiration that require lower levels of skill and further training, but on closer examination of the motivations for these forms of aspiration, finds little evidence that these aspirations are straightforwardly ‘low’. Above all, the research demonstrates that young people produce multiple different senses of place, and myriad forms of aspiration, from within the same deprived spatial context: they do not simply reproduce what they see around them when imagining their futures. While there is compelling evidence that young people’s occupational aspirations are shaped by the areas they live in, these area effects demand more nuanced research alongside policy approaches that are more receptive to young people’s constructions of place.

Circadian rhythms exist in almost all of living species, and they occupy an important role in daily biological activities of these species. This thesis deals with reduction of measurements in circadian models, and recovery of circadian phases. Two mathematical models of circadian rhythms are considered, with a 3rd order model for Neurospora, and a 7th order model for Mammals. The reduction of measurements of circadian models is shown by the proposals of observer designs to the two mathematical models of circadian rhythms. Both mathematical models contain strong nonlinearities, which make the observer design challenging. Two observer designs, reduced-order and one-sided Lipschitz, are applied to the circadian models to tackle the nonlinearities. Reduced-order observer design is based on a state transformation to make certain nonlinearities have no impact on the observer errors, and the design of one-sided Lipschitz observer is based on systems with one-sided Lipschitz nonlinearities. Both observer designs are based on the existing methods in literature. The existing method of reduced-order observer has been applied to a class of multi-output nonlinear systems. A new reduced-order observer design which extends the existing one in literature is presented in this thesis. In this new reduced-order observer method, the observer error dynamics can be designed by choosing the observer gain, unlike the existing one, of which the observer error dynamics depend on the invariant zeros under certain input-output map. The recovery of circadian phases is carried out to provide a solution to phase shifts occurred in circadian disorders. The restoration of circadian phases is performed by the synchronizations of trajectories of a controlled model with trajectories of a reference model. The reference model and the controlled model have phase differences, and both these models are based on a given 3rd order model of Neurospora circadian rhythms. The phase differences are reflected by different initial conditions, and by parameter uncertainty. The synchronizations of the two models are performed by using back-stepping method for the case of different initial conditions, and by using adaptive back-stepping method for the remaining case. Several simulation studies of the proposed observer designs and the proposed schemes of synchronizations are carried out with the results shown in this thesis.

The goal of this thesis is to estimate potential output of the economy of the Czech Republic from 1999 to 2011. In the first chapter I focus on description of the overall product of the economy, introduction and definition, mostly NAIRU approach, of the potential output and several approaches to estimate potential output. Production function is analysed in the following chapter from econometric as well as economic perspective. The most important properties of the production functions are also described in this chapter. In the end of the second chapter I deal with three most common types of production function. Estimated values of the variables in the production function including the value of the potential output of the Czech economy and relevant interpretations are presented in the last chapter of this thesis.

Plant efficiency and profitability are becoming increasingly important and operating at the most optimal point is a necessity. The definition of proper operational bounds on output variables such as product quality, production rates etc., is critical for plant optimisation. The use of operational bounds that do not lie within the region of the output operational space of the plant can result in the control system attempting to operate the plant in a non attainable region. The use of operational bounds that lie within the bounds of the output operational space of the plant and if the output operational space is non convex can also result in the control system attempting to operate the plant in a non attainable region. This results in non feasible optimisation. A numerical intersection algorithm has been developed that identifies the feasible region of operation known as the desired operational space. This is accomplished by finding the intersection of the required operational space and the achievable output operational space. The algorithm was simulated and evaluated on a case study under various scenarios. These scenarios included specifying operational bounds that lie partially within the bounds of the achievable operational space and also specifying operational bounds that lie within the bounds of the operational space which was non convex. The results yielded a desired operational space with bounds that were guaranteed to lie within an attainable region on the output operational space. The desired operational space bounds were also simplified into a rectangle with high and low limits that can be readily used in control systems. / Dissertation (MEng)--University of Pretoria, 2012. / Chemical Engineering / unrestricted

Syftet med denna studie var att vidga kunskapen om hur mellanstadielärare bedriver och anpassar sin undervisning i läsförståelse av skönlitteratur. Syftet var dessutom att undersöka vilka resurser och vilket stöd som är gynnsamt för elever med svenska som andraspråk. Studien riktar sig mot mellanstadielärare som inte innehar en vidareutbildning inom svenska som andraspråk. Undersökningen utgår från semistrukturerade kvalitativa intervjuer med 6 stycken verksamma lärare i årskurs 4–6. Resultatet visar att mycket fokus ligger på ordförståelse och arbeten med skönlitterära texter. Utfallet pekar också på att i 5 av 6 klasser har modersmålet inte en tydlig plats i undervisningen samt att outputen inte är prioriterad. Vokabuläret nämns av hälften som viktigt men olika representationsformer för ordläran inkluderas enbart i viss utsträckning. Vidare visar resultatet även att resurser och stöd för elever med svenska som andraspråk är essentiellt för vidare kunskapsinhämtning.  För att skapa en språklig variation i arbetet kommer elever med svenska som andraspråk även refereras till sva-elever.

This paper investigates the vulnerability of South Africa to the shocks that originate from its major trading partners over time using a structural vector autoregressive framework. We examine the impact of shocks emanating from the EU, the US, China, Japan, India and Brazil on South Africa’s output growth through both direct and indirect trade linkages, by considering the changing trade patterns from 1996 to 2017. The results suggest that the South African economy has become more integrated with emerging economies. Furthermore, China has increased its impact on the output growth of the other sample economies through trade linkages, which implies that developments in China are of increasing importance to other economies. The US and the EU are still dominated in propagating shocks despite their declining impact on the output growth of other economies in this sample.

Scholarly communication has changed with the growth in technology, particularly the internet and the social web. The changes include a broader definition of the scholarly communication format, and the role of social media in the research process, amongst others. This study sought to record the body of work that PLAAS had produced over a 20-year period (1995 to 2015) and to measure its visibility and impact through bibliometrics and altmetrics. It was the first time that such a study had been done. The Web of Science Citation Index and Scopus are two commercial databases that have recently been joined by Google Scholar, the first open database of scholarly items with citation counts based on the entire contents of the World Wide Web. Scopus and Google Scholar were used in this study. Methods used in the study included the compilation of a full bibliographic record of the outputs during that period. Citation analysis and publication counts were conducted, per author, within Scopus and Google Scholar. Altmetric analysis was achieved with the Altmetric Explorer database, and by studying three PLAAS grey literature outputs in more depth for altmetric indicators. The last method used was a small survey based on an online multiple-choice questionnaire of researchers at PLAAS to investigate their attitudes to a selection of the social media platforms commonly used by scholars. The full list of outputs, once compiled, showed a composition of 54% grey literature published by PLAAS and 46% journal articles and monographs. The results showed that bibliometrics, as a purely quantitative indicator, can be useful in measuring the impact of a body of work on the scholarly domain and in this study indicated high publication and citation rates. The authors of the highest number of PLAAS outputs and with the highest citation counts and h-indices, were found to be the same throughout the study. These authors are closely associated with the Institute and have contributed to the good academic reputation of its research. The study was inconclusive with regard to the impact on social media platforms as none of the grey literature from PLAAS had a unique identifier which made it difficult to track; in addition, the use of social media by the Institute and its researchers was intermittent and uneven in covering all the PLAAS-published outputs that were produced. Key recommendations for PLAAS to improve the visibility and impact of their outputs in scholarly and social contexts were to use unique identifiers, to track their social media activity and to keep author profiles up to date. Further use and application of the research design in other research units and departments at UWC will generate results that are useful to research management at UWC.