Eisen-Gallium-Legierungen sind aufgrund ihrer hohen Magnetostriktion und ihrer hervorragenden mechanischen Eigenschaften sehr interessant für Anwendungen sowohl in Form von Sensoren als auch Aktoren. Die fortschreitende Miniaturisierung erfordert die Herstellung von Bauteilen in eindimensionaler Struktur und komplexen Geometrien. Beide Herausforderungen sind mit templatbasierter elektrochemischer Abscheidung zugänglich. Es konnte gezeigt werden, dass dünne Fe-Ga-Schichten schon aus einfachen wässrigen Elektrolyten abgeschieden werden können. Gallium kann nur in Anwesenheit von Fe induziert reduziert werden. Gleichzeitig konnte nachgewiesen werden, dass durch die Hydrolyseneigung der Ga-Ionen immer Hydroxide gebildet und in das Deposit eingebunden werden. Durch die Einführung einer alternierenden potentiostatischen Abscheidung mit einem Reduktions- und einem Relaxationsschritt können dennoch dichte und homogene Fe80Ga20-Schichten mit wenigen Defekten und einem vernachlässigbar kleinen Sauerstoffgehalt hergestellt werden. Die Übertragung der so gefundenen Abscheideparameter zur templatbasierten Nanodrahtherstellung ist nur bis zu einem Porendurchmesser von 100nm möglich. Wird der Durchmesser der Porenkanäle weiter verringert, führt aufgrund eingeschränkter Diffusionsvorgänge die Abscheidung zu segmentierten und sauerstoffreichen Depositen. Die Modifizierung des Elektrolyten durch Komplexierung der Metallionen verhindert die Bildung und Einbindung der Hydroxide. Damit können auch für Porendurchmesser kleiner 100nm Drähte in AAO-Template abgeschieden werden. Diese sind dicht, defektfrei und weisen keinen Zusammensetzungsgradienten entlang der Wachstumsrichtung auf. Detaillierte TEM-Untersuchungen konnten zeigen, dass die Herstellung durch ein einfacheres potentiostatisches Abscheideregime zu weniger verspannten und dennoch homogenen und defektfreien Drähten führt. Für die Herstellung von magnetisch aktiven Drähten sollte daher die potentiostatische der gepulsten Abscheidung vorgezogen werden.

No description available.

Quaternary GalnAsN containing a small amount of nitrogen (<2%) is a potentially promising material for realizing long-wavelength emission lasers for applications in optical communication systems. Such devices should have better high-temperature characteristics than conventional InGaAsP lasers due to an increase of the conduction band offset. In this thesis, the GS-MBE growth of quaternary GalnAsN and ternary GaAsN was carried out. Active N was produced by passing high purity nitrogen gas into either an RF or an ECR plasma source. The RF plasma source was found to produce better quality nitrides. Characterization techniques such as photoluminescence, X-ray diffraction, TEM, SIMS, and Hall effect measurements were used to characterize thick layers (e.g. 1 pm) and quantum wells of these nitride materials. The concentration of N incorporated into GalnAs and GaAs is very dependent on growth conditions and plasma conditions. The incorporation of a small amount of N into compressively strained InGaAs reduces the strain and produces a red-shift of photoluminescence peak. However, compared to N-free InGaAs materials, the optical quality is dramatically degraded yielding reduced photoluminescence intensity and a broadened FWHM of the PL peak. Hall effect measurements on un-doped, Si-doped, Bedoped thick GalnAsN layers indicate the presence of a high concentration of electron and hole traps. The results of SIMS suggest that impurity H might be responsible for the deep level defects formed. However, the nature of the defects is currently unknown. From TEM observations and comparison to samples grown with a He-plasma instead of a Nplasma, spinodal decomposition and ion-induced damage in GalnAsN may produce the reduced quality of materials, but these are not the major reasons responsible for the dramatic degradation of optical quality. Thermal annealing was found to be an effective method for significantly improving the optical quality of GalnAsN with a low N concentration. Optimum annealing conditions were obtained. Hall effect measurements on annealed samples indicate that electron and hole traps are reduced but still present after anneal. / Thesis / Master of Engineering (ME)

The focus of the study was an exploration of the perceptions of secondary schools’ principals about the effectiveness of school governing bodies in Ga-Rankuwa, Tshwane West District. The main research question was formulated as follows: What are the secondary schools’ principals’ perceptions about the effectiveness of school governing bodies in school governance? The main aims were to determine how the findings of the study could add to new knowledge about the effectiveness of school governing bodies in Ga-Rankuwa and to ascertain if the perceptions of secondary schools’ principals play a role in the effective functioning of school governing bodies. A review literature worked a synthesis of perspectives on functions and roles of school governing bodies. The study examined the roles, functions of school governing bodies in selected developed, and developing countries and discussed in detail school governing bodies in the South African education system after 1994. Informed by the literature review, an empirical inquiry using a mixed method; combination of qualitative and quantitative methods to explore the perceptions of secondary schools’ principals about the effectiveness of school governing bodies in Ga-Rankuwa, Tshwane West District. Sampling of respondents was purposeful. Qualitative and quantitative methods of data gathering were used in order to produce reliable and valid results. The study involved seven (n=7) secondary schools principals who responded to a researcher-designed, pen-and-paper questionnaire and participated in semi-structured interviews. Ethical requirements were met and the identity and privacy of participants were protected. Data presented were mainly derived from documentary sources, the questionnaire and interviews. Data were analyzed, the findings presented, interpreted and the significance noted. Findings indicated that little had been documented in relation to the exploration of perceptions of secondary schools` principals about the effectiveness of school governing bodies in Ga-Rankuwa. Overall, the principals were positive about the role played by the school governing bodies; although they identified several areas in which both school governing body members and principals required ongoing training. Based on the findings of the literature and the empirical study, the researcher recommended the establishment of a special unit for the training and induction of secondary principals and newly elected members of school governing bodies to ensure effective school governance. The constraints of the study were financial. The findings of this small-scale study cannot be generalised; however, several areas for future research were identified. / Educational Leadership and Management / D. Ed. (Education Management)

M. Tech. Business Administration / The aim of this study was to determine the most important factors that influence the adoption of fashion clothing amongst the Generation-Y consumers living in Ga-Rankuwa and how that influences broader societal trends in the retail market. The purpose of this study is to assist marketers and retailers to sustain their businesses by examining the relationship between fashion involvement, fashion innovativeness, fashion opinion leadership and fashion adoption, based on this group’s perception.

Working with two small group of domain experts I evaluate human-centered approaches to application development which are applicable to geovisualization, following an ISO13407 taxonomy that covers context of use, eliciting requirements, and design. These approaches include field studies and contextual analysis of subjects' context; establishing requirements using a template, via a lecture to communicate geovisualization to subjects and by communicating subjects' context to geovisualization experts with a scenario; autoethnography to understand the geovisualization design process; wireframe, paper and digital interactive prototyping with alternative protocols; and a decision making process for prioritising application improvement. I find that the acquisition and use of real user data is key; that a template approach and teaching subjects about visualization tools and interactions both fail to elicit useful requirements for a visualization application. Consulting geovisualization experts with a scenario of user context and samples of user data does yield suggestions for tools and interactions of use to a visualization designer. The complex and composite natures of both visualization and human-centered domains, incorporating learning from both domains, with user context, makes design challenging. Wireframe, paper and digital interactive prototypes mediate between the user and visualization domains successfully, eliciting exploratory behaviour and suggestions to improve prototypes. Paper prototypes are particularly successful at eliciting suggestions and especially novel visualization improvements. Decision-making techniques prove useful for prioritising different possible improvements, although domain subjects select data-related features over more novel alternative and rank these more inconsistently. The research concludes that understanding subject context of use and data is important and occurs throughout the process of engagement with domain experts, and that standard requirements elicitation techniques are unsuccessful for geovisualization. Engagement with subjects at an early stage with simple prototypes incorporating real subject data and moving to successively more complex prototypes holds the best promise for creating successful geovisualization applications.

"A field work placement in the social service department of the Veterans Administration Hospital, Augusta, Georgia, provided motivation and a source of data for this study. In reviewing the literature and conferring with social service administrators, it was pointed out that a basic criterion was needed in order to determine the positive effects of social service activities with neuropsychiatric tubercular patients. As the complexity of multiple interacting factors made a study of direct effect impossible, it was decided to compare social service activities and other factors to rapid and non-rapid movement of patients from Ward 14. This determined the association of other factors, in addition to social service activities, associated with movement and provided some basis on which further study of the effects of social service could be undertaken. An attempt was also made to show the association of specific characteristics of social service contacts with movement"--Introduction. / Typescript. / "June, 1959." / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Social Work." / Advisor: Howard Borsuk, Professor Directing Study. / Includes bibliographical references.

"The purpose of the study was to ascertain whether there were any marked differences when the study sample of fifty-seven patients (dichotomized by level of education attained) were distributed by each of the possible recommendations made by the Committee. The data for the study were collected from the hospital records of fifty-seven male patients to determine if there were marked differences on eleven social and medical descriptive items between twenty-four patients who had no high school education, and thirty-three patients who completed high school. Knowledge of marked differences not due to chance in the various social and medical descriptive items studied might be of help to the Committee in arriving at recommendations for patient care. The frequency distribution on sixteen possible Committee recommendations for patient care between the two sub-samples are given; to what extent the recommendations were followed also is indicated. If the data revealed differentiating items between the patients who completed high school and those who did not complete high school the Committee might show whether it would be feasible to make more recommendations for the patient population"--Introduction. / Typescript. / "June, 1960." / "Submitted to the Graduate School of Florida State University in partial fulfillment of the requirements for the degree of Master of Social Work." / Advisor: John T. Greene, Professor Directing Study. / Includes bibliographical references.

No description available.

Over one hundred and seventy maps and plans are preserved from the ancient Near East, drawn on clay tablets or inscribed in stone, though a full study of all the available cartographic material from Mesopotamia has never before been undertaken. This thesis offers a critical analysis of these maps and plans, with particular focus on their graphic conventions, typology and function in Near Eastern society. The text on many of these maps is also undeciphered and a number of examples are translated here for the first time, including an unpublished map of an irrigation network in the Schøyen Collection. By examining all this material in a single study, it becomes clear that there was a coherent documentary genre in Mesopotamia which was cartographic in nature, and which served a variety of administrative and planning purposes. The Near Eastern cartographic corpus is also contextualised within the wider history of cartography, so that its place in the global development of graphic mapping can be better understood.