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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Antecedents and consequences of emotional dissonance: Understanding the relationships among personality, emotional dissonance, job satisfaction, intention to quit and job performance

Diamond, Laurie K 01 June 2005 (has links)
The primary goal of this research was to explore the antecedents and consequences of emotional dissonance for debt collectors. The antecedents were personality factors (extraversion, anger, conscientiousness and agreeableness) and pro-social factors. The consequences of emotional dissonance were job satisfaction, intention to quit and job performance. A path model was developed to explain the relations among the studys measures in a sample of 188 full-time debt collectors. The path analysis results failed to show strong relations between personality and emotional dissonance. However, strong relations were found between emotional dissonance, job satisfaction, intention to quit, and performance. Job satisfaction acted as a mediator between emotional dissonance and intention to quit as well as emotional dissonance and performance.
162

Λειτουργική και αισθητική ένταξη συστημάτων αξιοποίησης της ηλιακής ενέργειας στα κτίρια / Building integration of solar energy systems regarding practical and aesthetacal aspects

Σιαμπέκου, Χριστιάνα 28 June 2007 (has links)
Στην παρούσα εργασία μελετήθηκαν βιβλιογραφικά οι ενεργειακές και αισθητικές παράμετροι που συμβάλλουν στην εξοικονόμηση ενέργειας στον κτιριακό τομέα. Παράλληλα έγινε πειραματική μελέτη μιας καινοτόμου προτεινόμενης διάταξης με φακούς Fresnel για τον έλεγχο του φωτισμού και της θερμοκρασίας των εσωτερικών χώρων των κτιρίων, καθώς και τριών πειραματικών διατάξεων θερμικών ηλιακών συλλεκτών με σκοπό την εκτίμηση της απόδοσης των συλλεκτών με πολύχρωμη απορροφητική επιφάνεια σε σχέση με αυτή των μαύρων συλλέκτων και σε σχέση με το πλεονέκτημα της αισθητικής ενσωμάτωσής τους στα κτίρια. / The abstract is not available.
163

A high-flux solar concentrating system.

Mouzouris, Michael. January 2011 (has links)
This research investigates the collection of concentrating solar energy and its transmission through optical fibres for use in high temperature applications such as lunar in-situ resource utilisation (ISRU) programmes, solar power generation and solar surgery. A prototype collector, known as the Fibre Optic Concentrating Utilisation System (FOCUS), has been developed and is capable of delivering high energy fluxes to a remote target. Salient performance results include flux concentrations approaching 1000 suns with an overall optical efficiency of 13%, measured from the inlet of the collector to the fibre outlet. The system comprises a novel solar concentrator designed to inject solar energy into a four metre long fibre optic cable for the transmission of light to the target. A nonimaging reflective lens in the form of a 600 mm diameter ring array concentrator was chosen for the collection of solar energy. Advantageous characteristics over the more common parabolic dish are its rearward focusing capacity and single stage reflection. The ring array comprises a nested set of paraboloidal elements constructed using composite material techniques to demonstrate a low-cost, effective fabrication process. At concentrator focus, a fibre optic cable of numerical aperture 0.37 is positioned to transport the highly concentrated energy away from the collector. The cable is treated to withstand UV exposure and high solar energy flux, and allows flexibility for target positioning. A computational analysis of the optical system was performed using ray tracing software, from which a predictive model of concentrator performance was developed to compare with experimental results. Performance testing of FOCUS was conducted using energy balance principles in conjunction with a flat plate calorimeter. Temperatures approaching 1500°C and flux levels in the region of 1800 suns were achieved before injection to the cable, demonstrating the optical system's suitability for use in high flux applications. During testing, peak temperatures exceeding 900°C were achieved at the remote target with a measured flux of 104 W/cm2 at the cable outlet. The predicted optical efficiency was 22%, indicating that further refinements to the ray trace model are necessary, specifically with regard to losses at the inlet to the cable. FOCUS was able to demonstrate its usefulness as a test bed for lunar in-situ resource utilisation technologies by successfully melting a lunar soil simulant. The system permits further terrestrial-based ISRU research, such as oxygen production from regolith and the fabrication of structural elements from lunar soil. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.
164

The Kunstkammer object in seventeenth-century Salzburg : a case study, early modern collections, transformation and materiality

Mitchell, Sarah January 2005 (has links)
The phenomenon of princely and scientific collections that proliferated in Europe during the sixteenth and seventeenth centuries has become an important focus for modern historical analysis. These collections provide a microcosm of contemporary political, economic and philosophical ideas, often characterized by geographical and cultural differences. The mid-seventeenth century Kunst- and Wunderkammer studied here, instituted by the archbishops of Salzburg, brings forward themes sometimes neglected in the literature. The archbishops' collection was part of broader efforts to reinvent the city of Salzburg as a representation of both sacred and secular authority. Strategies for significant display were derived from religious and imperial ritual, drawing on the potential of objects as signifiers. In this context, I also examine some of the debates within the literature on princely and scientific collections, where the study of wonder and science begins to merge in cross-disciplinary scholarship. Finally, I highlight the role of transformation and materiality in these collections to argue that the act of collecting objects and the act of making were imbricated in the process of self-definition. Within themes of technology and process, I investigate the pursuit of creating Kunstkammer objects, as well as the business of their display and use in diplomacy.
165

Library of Charles Areskine (1680-1763) : Scottish lawyers and book collecting, 1700-1760

Baston, Karen Grudzien January 2012 (has links)
The thesis uses the study of an individual’s book collection to examine wider themes in eighteenth century Scottish legal, social, political, and intellectual history. Charles Areskine’s library was made up of the books he needed as an advocate and judge, the texts he wanted to use to better understand the law and its history, and the books he used to enhance his ability to participate in the intellectual milieu of early eighteenth century Britain. Charles Areskine of Alva, Lord Tinwald (1680-1763) was an important Scottish lawyer and judge. Following a legal education in the Netherlands, he became an advocate and was called to the Bar in 1711. Areskine’s legal career was very successful and he attained high positions in the Scottish legal establishment becoming Lord Advocate (1737-1742) and Lord Justice Clerk (1748-1763). He was appointed to the bench as Lord Tinwald in1744. He served in parliament and developed his country estates at Tinwald in Dumfriesshire and at Alva in Clackmannanshire. Areskine is an interesting figure in the early Scottish Enlightenment not least because he began his career not in legal but in academic circles. He was a regent at the University of Edinburgh when he was barely out of his teens and from 1707 to 1734 he was the first Professor of the Law of Nature and Nations at Edinburgh. Areskine was also a traveller, a client of the earl of Ilay, a friend to philosophers, a patron of the arts, and a book collector. A manuscript which lists of the contents of Areskine’s library survives in the National Library of Scotland as NLS MS 3283. ‘Catalogŭs Librorŭm D. Dni. Caroli Areskine de Barjarg, Regiarŭm Causarum Procŭratoris. 1731’ lists 1290 titles divided into books on legal topics, which are not given any specific headings, and ‘Libri Miscellanei’. Although it is clearly dated as 1731, the manuscript was continuously added to and acted as a library catalogue throughout Areskine’s life. The list provides important evidence about Areskine’s participation in the legal, intellectual, and cultural concerns of the early Scottish Enlightenment. Areskine’s law books provide evidence for his scholarly interest in the history of law while showing the types of books lawyers turned to in order to fashion their arguments in the courts. His ‘miscellaneous’ books demonstrate his engagement with the wider cultural concerns of the first half of the eighteenth century. The books that eighteenth century Scottish lawyers owned provide evidence for their interests and influence. Areskine was not unique: his book collecting was part of a wider tradition among Scottish lawyers. Areskine’s legally educated patron, Archibald Campbell, had one of the largest private libraries in Britain and his colleagues on the Bench, Lord Arniston and Lord Hailes, created collections which they stored in specially built rooms in their houses. Because so many of them survive in the Alva Collections of the Advocates Library and the National Library of Scotland, it has been possible to examine Areskine’s books for clues about who owned them before he did and what happened to them after his death. Several inscriptions and bookplates survive in the Alva books which give evidence for a lively book market which was centred on the Scottish legal community. Advocates bought and sold many of their books at auctions. This study shows that books on topics of interest to Scottish lawyers changed hands and stayed in use for decades.
166

COLLECTORS FOR ENABLING FLOTATION OF OXIDIZED COAL

Dube, Raghav M. 01 January 2012 (has links)
The coalburg seam coal is an example of difficult to float bituminous coal. Laboratory tests conducted on coalburg flotation feed sample revealed recovery values around 28% with 15% product ash when using fuel oil as collector under natural pH conditions. A detailed study showed that increasing pH from natural value of 5.6 to 7.5 provided a significant improvement in recovery of approximately 32 absolute percentage points. The improvement is believed to be result of the release of humic acids from the surface and the dispersion of clay particles thereby leaving a more hydrophobic surface. Based on the tests conducted with various commercially available collectors, oleic acid was selected as a model collector for oxidized coals. Conventional flotation tests found an increase in combustible recovery of 10 absolute percentage points above the pH improvement using 4:1 blend of fuel oil and oleic acid. The problem of higher ash in conventional cell product due to entrainment was minimized by the use of wash water in a flotation column. A flotation concentrate containing less than 7.5% ash was produced while recovering around 75% of the combustible material. Further testing using fatty acids-fuel oil blend also showed evidence of a near 200% increase in flotation rate.
167

Statistical ray-tracing analysis of the linear Fresnel mirror solar concentrator

Ying, Xiaomin January 1993 (has links)
The Monte Carlo-type statistical ray-tracing method was used to investigate the performance of the line-focusing Fresnel mirror solar concentrator. An optical model of the line-focusing Fresnel mirror concentrator using the statistical ray-tracing approach was developed. Many rays of sunlight from the solar disk were selected at random and traced through the concentrator in this model. This optical model permits calculation of the local and geometric concentration ratios. The latter requires an energyloss analysis. Small sun-tracking errors of the diurnal or transverse type were included in the model.Based on the optical model and the Monte Carlo-type statistical ray-tracing method, a computer program was written implementing the model and computations using Pascal. To facilitate performance comparisons, a baseline concentrator design was adopted. To study the effects of imperfect tracking, performance data were generated for small tracking errors up to approximately two and one-half degrees. The selected mirror configuration permitted comparisons between the statistical approach and previous applications of the "extreme ray" analysis for an imperfectly tracking mirror concentrator.Simulation results demonstrated that the concentration characteristics are highly sensitive to the tracking error. The geometric concentration ratio dramatically decreases when the tracking error increases, which is the same as the "extreme ray" analysis. Results of some typical numerical calculations are presented graphically and discussed. / Department of Physics and Astronomy
168

Analysis of tracking error effects for the Fresnel mirror solar concentrator

Zhan, Yong January 1989 (has links)
The solar concentration performance of a tracking, flat-base, line-focusing Fresnel mirror was investigated in this study. The Fresnel mirror consists of flat mirror strips situated on a base and oriented at appropriate angles to focus incident light to a desired line. Simple optical ray tracing and energy conservation were used to develop a mathematical model of the concentrator assuming small or zero diurnal tracking errors. The model analyzed the concentrator design and provided detailed expressions for the geometric evaluation of the concentrated sunlight rays in the focal plane above the mirror. The local concentration ratio and the geometric concentration ratio were introduced to describe the intensity profile in the focal plane and the average concentration of sunlight on a target absorber. Included in the model were losses of incident sunlight due to imperfect reflection, nonreflecting portions of the base, and blockage by adjacent mirror strips when imperfect tracking occurs.Based on the analytical model and using the Ada high level language, a computer program was written to simulate the concentrator. To facilitate performance comparisons, a baseline concentrator design was adopted. To study the effects of imperfect tracking, performance data were generated for small tracking errors up to approximately two and one-half degrees. The effects of design variations were studied by varying the concentrator focal length, strip width, and base width.Simulation results demonstrated that the concentration characteristics were highly sensitive to tracking error. Intensity profile shifts relative to the target caused the highest losses in intercepted sunlight.Design decisions were found to dramatically affect the concentration character- istics. For the baseline concentrator under perfect tracking conditions, an optimum focal length was identified. Except for the disadvantage of added costs, decreased strip widths was found to be a way to increase both the maximum and average concentration ratio for the absorber. Using smaller strip widths might, however, critically affect the energy intercepted by the target under imperfect tracking. Increasing the concentrator base width increased the total amount of power in the focal plane, with a higher maximum concentration ratio and additional tailing of the intensity profile. / Department of Physics and Astronomy
169

Effective methods of TfD practice: understanding the conditions that provide autonomy and empowerment for marginalized communities.

Kandil, Yasmine 30 April 2012 (has links)
This research began as a quest to better understand the relationships between marginalized communities, facilitators, and not-for-profit organizations, or NGO’s, in a specific Theatre for Development (TfD) process. When a TfD project that engaged and positively impacted the lives of Egyptian young garbage pickers was discontinued by the funding NGO, the researcher, who was the group’s theatre facilitator, set out to find solutions to this disempowering process. Initially, this research was created to explore how to pass on the skills of practicing theatre to marginalized communities, as a means for them to claim the process, practicing it independently of NGOs and facilitators. This initial inquiry then evolved to encompass exploring effective methods of TfD practice, where the question then became: What are the conditions that provide empowerment and autonomy for marginalized communities in the TfD context? Using Narrative Inquiry the researcher recalls her experience working with the garbage pickers in one of the biggest slums in the world, Mokkatam City, in Cairo. The narrative is used to question the choices made by both the facilitators and NGOs which ultimately compromised an otherwise life changing experience for the young community. The researcher then employs Action Research to outline a community-based participatory project carried out with a group of immigrant and refugee youth in Victoria, Canada. The study traced the progression of the three action research stages carried out to find ways of using TfD to empower this vulnerable community. The documentation of this project was completed using Reflective Practitioner Case Study which enabled the researcher to reflect on her practice with the aim of improving her approach through critical analysis. The findings of this research do not support the researcher’s initial hypothesis that the development of theatre skills will enable the community to function independently of outside support. Instead, through the careful examination of the experiences of the young participants in the slums of Cairo, and the immigrant and refugee communities in Canada, this research points to the importance of TfD integrating the celebration of life and the development of relationships as part of its process of enriching the experience of marginalized communities. This finding, together with an examination of the notion of sustainability redefines the place of the exit strategy through the ways in which the immigrant participants of the latter phases of the study, chose to integrate the benefits of TfD practice into their lives. / Graduate
170

Far away is close at hand : an ethnographic investigation of social conduct in mixed reality museum visits

Galani, Areti January 2005 (has links)
This thesis investigates how museum companions organise their conduct regarding their engagement with the exhibition and their social interaction with each other in the course of a visit. The main objectives of the thesis are the empirical investigation of social conduct in casual group museum visits and the exploration and understanding of social conduct in real-time distributed museum visits through mobile mixed reality technology. A third area of interest is the application of qualitative methodology, based on ethnomethodology and ethnographic methods, for the fulfilment of the above objectives. In particular this thesis presents and discusses fieldwork of collocated casual group visits alongside video recording and interviews collected in distributed museum visits during trial sessions in the Mack Room mixed reality museum environment. Drawing on vignettes of activity among collocated and distributed participants, the thesis develops discussion around three themes: the collaborative exploration of museum artefacts, aspects of the collaborative management of shared museum visits and the constitution of the visiting ‘order’ in and through social conduct. Among others, issues of collaborative alignment, awareness, indication of engagement and disengagement and conflicting accountabilities are discussed. The contribution of this thesis in current research in museum studies, CSCW and social science is explored. Findings reported in this thesis extend current visitor studies research to include the study of social conduct in the management of collocated visits and the constitution of visiting order. They also suggest that studies of sociality among distributed visitors may open opportunities for museums to support mutually complementing local and distributed experiences. With regard to understanding asymmetries in mobile mixed reality environments, the thesis points out that asymmetries could be better understood with reference to the activity in context rather than the technological features themselves. This thesis also makes a contribution to social studies research with regard to exploring the changing character of talk in distributed collaborative settings. Future research with respect to mixed reality applications for museum visits is also outlined.

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