The transport critical current density (J(_c)) of a 37 filament Bi-2223/Ag tape has been measured as a function of field and temperature from 4.2 K up to 90 K. Data have been obtained over a large current range from 10 mA up to 100 A and in fields up to 23 T with the tape in 3 orientations with respect to field. These comprehensive data have been used to test the predictions of the flux creep and weak link models used to explain J(_c) in Bi-2223 tapes. The J(_c)(B,T) dependence of optimised Bi-2223 tapes has been calculated using a curved film model. The model assumes perfect grain connectivity and that the local superconducting properties are equivalent to those in the best reported thin films. A comparison between the calculations and measured J(_c)(B,T) dependencies suggest that in high fields at 20 K, J(_c) in presently available industrially processed tapes is only a factor of 8 below the performance of ideal fully optimised tapes. Transport measurements have been made on Bi-2223 single filaments extracted from an alloy sheathed multifilamentary tape in liquid nitrogen at 77 K in fields up to 300 mT with the field aligned parallel and perpendicular to the a-b planes. Further Jc(B,T) data have been taken in a variable temperature insert at temperatures between 60 to 90 K in fields up to 15 T. In a study of the electric field-current density {E-J) characteristics of the c-axis orientated data at 77 K, negative curvature is observed in traces below 280 mT. However, the 280 mT trace exhibits both positive and negative curvature in different current regimes in contrast to the predictions of standard theory. A laboratory scale Bi-2223 superconducting magnet producing a maximum field of 1.29 T at 4.2 K has been designed and fabricated. The magnet comprises 6 resin impregnated double wound pancakes with a 40 mm bore fabricated via the react and wind route. Critical current density measurements have been made as a function of magnetic field, angle and strain at 4.2 K and 77 K on short samples of the constituent tape. The E-J characteristics of all component coils have been measured and a comparison with short sample data shows that minimal additional damage occurred beyond that produced by the bending strain on the tape and the long length variation in J(_c). Sufficient detail is provided for the non-specialist to assess the potential use of brittle superconducting tapes for magnet technology and construct a laboratory scale magnet.

Esta tese aborda a relação entre a gestão de custos inter-organizacional (GCI), custos de transação (CT), e gestão de riscos em alianças (GRA) em empresas que operam no Brasil. O método de pesquisa foi o survey, com aplicação de um questionário. Os níveis de GCI, CT e GRA foram medidos tendo como base a percepção dos gestores de compras e suprimentos das empresas selecionadas. A amostra teve 85 respostas válidas, de 5 setores da indústria de manufatura (automotivo, bens de consumo, eletrônica, química e metalurgia). Os resultados demonstram uma associação significativa entre GCI e GRA, isto é, empresas que adotam a abordagem de gestão de custos inter-organizacional com maior intensidade possuem maior ênfase nas práticas de gestão de riscos. Além disso, verificou-se que a abordagem de GCI e GRA não afetam a percepção dos gestores sobre os CT, ou seja, a adoção de gestão de custos inter-organizacional não aumenta a percepção de custos de transação quando esta abordagem é adotada juntamente com práticas de gestão de riscos em alianças. Além disso, verificou-se que as empresas do setor de eletroeletrônicos apresentaram maiores níveis de GCI, enquanto as empresas da indústria automotiva tiveram os menores, demonstrando que empresas desse setor possuem menor propensão a compartir recursos, informações e tecnologia com seus fornecedores. Com relação à percepção de custos de transação e práticas de gestão de riscos, a análise demonstrou que não há diferenças significativas entre os setores estudados. Adicionalmente, os resultados demonstram que as empresas que utilizam ferramentas de gestão de custos, tais como custeio baseado em atividades (ABC) ou custeio alvo, possuem maiores níveis de GCI, o número de fornecedores e o tamanho desses parceiros também influencia na intensidade com que as empresas adotam a abordagem de GCI. Em relação à percepção de custos de transação, os resultados revelam que a experiência dos gestores e do tamanho da companhia influenciam na visão sobre os custos de transação. Já em relação às práticas de gestão de riscos em alianças, os resultados demonstram que as empresas que possuem acordos de ganhos compartilhados com fornecedores tendem a adotar mais intensamente as práticas GRA, além disso, o tamanho do fornecedor e setor de atuação da empresa também influenciam na intensidade com que tais práticas são adotadas. As principais contribuições deste trabalho foram o desenvolvimento de instrumentos para mensuração do nível de adoção de práticas de GCI e GRA, bem como a investigação empíricas sobre a relação entre percepção de GCI, CT e GRA. / This PhD dissertation addresses the relationship between inter-organizational cost management (IOCM), transaction costs (TC), and alliance risk management (ARM) in companies operating in Brazil. The research method consists in applying a survey questionnaire. The scores of IOCM, TC, and ARM were measured having the perception of purchase and supply managers of selected firms as a basis. The sample has 85 valid answers, from 5 sectors of the manufacturing industry (automotive, consumer goods, electronics, chemical, and metallurgy). The results demonstrate a significant association between IOCM and ARM, that is, companies adopting an inter-organizational cost management approach have more emphasis on practices of alliance risk management. Besides, it was found that IOCM and ARM approach do not affect the manager\'s perception about TC, thus, adoption of inter-organizational cost management approach does not increases perception of transaction cost since this approach is combined with practices of alliance risk management. Moreover, it was found that firms from the electronics industry have the highest level of IOCM, while automotive industry firms have the lowest, showing that automotive firms has less likelihoods to share resources, information and technology with suppliers. Regarding perception of transaction cost and alliance risk management, there is no significant difference between the industries studied. Additionally, the research demonstrates that companies using a cost management tool, such as activity-based costing (ABC) or target costing, have a higher level of IOCM, number of suppliers and the size of partners also influences the intensity as firms adopting IOCM approach. Regarding the perception of transaction costs, the results reveal that both manager\'s experience and company size influence the perception of transaction cost. Concerning the practices of alliance risk management, the results demonstrate that the firms having earnings-sharing agreements with suppliers apply more ARM practices, also, the size of suppliers and the industry of the firms influences the intensity as firms adopt practices of alliance risk management. The main contribution of this study was the development of an instrument to measure the level of IOCM and ARM, as well as an empirical investigation of the relationship between perceived level of IOCM, TC and ARM.

The phase diagram of complex oxides is very diverse due to the strong interaction between electrons in the electronic structure. It is possible to probe those interactions by changing electrostatically the carrier density, the main concept behind the Field-Effect Transistors (FET) which is the building blocks of nanoelectronics devices. In the case of high-TC superconductor copper oxides, it is possible to use this concept to switch between superconducting and insulator phases, for example using an adjacent liquid electrolyte layer to inject charges in a superconducting film. With that in mind, the objective of this work was to establish protocols to grow superconductor and ferroelectric films for future fabrication of superconducting FET devices. We optimized the deposition conditions for the growth of a single layer of superconductor YBa2Cu3O7–x and the ferroelectric barium titanate on SrTiO3 substrates by pulsed laser deposition (PLD). Several techniques were employed to study the properties of the thin films, such as X-ray diffraction, atomic force microscope, X-ray photoelectron spectroscopy, resistance vs temperature and ferroelectric hysteresis. Regarding the superconductors thin films, we observed several relations between the superconducting features and the growth parameters. For instance, lower growth temperatures contribute to the nucleation of a-axis oriented grains meanwhile higher growth temperature tends to be c-axis oriented. Regarding the frequency of the laser (proportional to the growth rate), it seems that lower frequency is related to higher surface roughness and the presence of non-superconducting contributions. As it increases, the roughness decrease and the sample presents a sharper superconducting transition. Finally, we also did the first steps towards the field effect device by growing a heterostructure thin film consisting of a superconductor and ferroelectric material. The sample grew c-axis oriented on strontium titanate substrate, though with a high value of surface roughness. / O diagrama de fase dos óxidos complexos é muito diverso devido à forte interação entre os elétrons na estrutura eletrônica. É possível sondar essas interações alterando eletrostaticamente a densidade da portadores, o principal conceito por trás dos transistores de efeito de campo (FET), que é o elemento fundamental dos dispositivos nanoeletrônicos. No caso de supercondutores de alta temperatura a base de óxidos de cobre, é possível usar este conceito para alternar entre fases supercondutoras e isolantes, por exemplo utilizando uma camada adjacente de eletrólito líquido para injetar cargas no filme supercondutor. Com isso em mente, o objetivo desse trabalho foi estabelecer protocolos para crescer filmes supercondutores e ferroelétricos para fabricações futuras de dipositivos FET supercodutores. Nós optimizamos as condições de deposição para o crescimento de uma única camada do supercondutor YBa2Cu3O7–x e do ferroeléctrico titanato de bário em substratos SrTiO3 por deposição de laser pulsado (PLD). Diversas técnicas foram empregadas para estudar as propriedades dos filmes finos, como difração de raios-X, microscopia de força atômica, espectroscopia de fotoelétrons de raios-X, resistência vs temperatura e histerese ferroelétrica. Em relação aos filmes finos supercondutores, observamos várias relações das propriedades supercondutoras com os parâmetros de crescimento. Por exemplo, temperaturas de crescimento mais baixas contribuem para a nucleação de grãos orientados no eixo a, enquanto a temperatura de crescimento mais alta tende a ser orientada para o eixo c. Em relação à frequência do laser (proporcional à taxa de crescimento), há um indício que valores menores de frequência está relacionada à maior rugosidade superficial e à presença de contribuições não supercondutoras. À medida que aumenta a frequência, a rugosidade diminui e a amostra apresenta uma transição supercondutora mais nítida. Por fim, também fizemos os primeiros passos em direção ao dispositivo de efeito de campo, desenvolvendo um filme fino de heteroestrutura com um material supercondutor e ferroelétrico. A amostra cresceu orientada no eixo c em substrato de titanato de estrôncio com alto valor de rugosidade superficial.

Cette habilitation propose une revue de l'effet d'impuretés non magnétiques ou magnétiques dans des systèmes de fermions fortement corrélés de basse dimension. Dans une première partie, on montre l'effet des ces impuretés sur les propriétés magnétiques de chaînes ou échelles de spin. Dans une seconde partie, on montre comment cet effet se transforme dans le cas des supraconducteurs à haute température critique, tant dans leur état normal que supraconducteur. Il est démontré que l'impureté peut servir d'outil efficace et original pour sonder les propriétés magnétiques locales de ces systèmes, en particulier en utilisant conjointement la Résonance Magnétique Nucléaire. Au passage, une revue est proposée des propriétés physiques des chaînes, echelles, et surtout des supraconducteurs à haute Tc.

Uno de los objetivos principales que se plantea en cualquier campo, tanto en investigación como en la clínica, consiste en lograr la estandarización de estudios para así poder obtener conclusiones generales, poder determinar parámetros y patrones de normalidad y, consecuentemente, determinar con precisión la patología valorando la desviación de estos índices.En los estudios renográficos, una función que posibilita esta estandarización es la función de retención renal que representa la fracción de trazador que es retenida en el riñón, a través del tiempo, como respuesta a una entrada instantánea en forma de bolo radiactivo si el trazador se hubiese introducido directamente en la arteria renal.Puesto que en un estudio real, la inyección se realiza en una vena periférica, la función de retención renal se ha de obtener mediante la deconvolución de la curva actividad/tiempo del área renal con la curva correspondiente a un área vascular representativa de la actividad sanguínea.El objetivo fundamental de este trabajo fue obtener un método de cálculo de la función de retención renal que incluyese una optimización en el grado de filtrado. Mediante simulación numérica de un estudio gammagráfico renal, se simularon estudios con 131I-Hippuran y 99mTc-MAG3.Mediante simulación numérica se ha demostrado la existencia de un valor mínimo en el error cuadrático medio entre las funciones de retención renal teóricas y las obtenidas mediante deconvolución. La presencia de este valor mínimo se manifiesta para los tres filtros considerados (filtro de tres puntos, filtros de Butterworth y filtro "data bounding") y para los dos trazadores, 131I-Hippuran y 99mTc-MAG3, estudiados en este trabajo.La ordenación de los tres filtros en base al valor mínimo del error cuadrático medio es: filtro de Butterworth, filtro de tres puntos y filtro "data bounding", éste con valores mucho más altos del error que los dos filtros lineales. Esta ordenación es la misma para los dos trazadores, siendo los valores del error correspondiente a 99mTc-MAG3 aproximadamente la mitad que los de 131I-Hippuran.El valor del factor de suavizado que hace mínimo el error, depende del tiempo de tránsito y de la relación señal/ruido. Se ha comprobado que para 99mTc-MAG3 el valor del suavizado que hace mínimo el error es menor que para 131I-Hippuran, lo que está de acuerdo con su mayor relación señal/ruido. Asimismo para cada trazador, se ha demostrado que la dependencia respecto al tiempo de tránsito es mayor que respecto a la relación señal/ruido. Este hecho, que se repite para los tres filtros, ha permitido obtener valores de los factores de suavizado óptimos para cada trazador como funciones del tiempo de tránsito exclusivamente. Se ha analizado el comportamiento de los tres filtros en la determinación de los parámetros de interés funcional derivados de la función de retención renal. Para ello, se modelizó la función de retención renal mediante una función de cuatro parámetros: h(t) = (A-D) / (1+t/C)**B) + D donde A corresponde a la altura de la función de retención renal par aun tiempo igual a cero, B se relaciona con la dispersión de tiempos de tránsito, C es el tiempo medio de tránsito intrarrenal y D es el valor de estabilización relacionado con una posible retención de trazador en el riñón. De este estudio se ha concluído: La estima del parámetro A es mejor para los métodos de filtrado lineales que para el no lineal, ya que proporciona información no sesgada y presenta valores del error relativo menores que para el filtro no lineal. De los filtros lineales, el algoritmo que incluye un filtro de Butterworth optimizado presenta los mejores resultados.Los resultados hallados para el parámetro B, indican que el filtro de Butterworth es el que determina mejor este parámetro, lo que se refleja en un valor medio próximo al teórico.La estima del parámetro C es mejor para los métodos de filtrado lineal que para el no lineal. En ambos, el error relativo es menor y no existe sesgo, siendo el filtro de Butterworth el que presenta los mejores resultados.Respecto al parámetro D, los valores hallados en todos los casos están muy próximos al valor teórico que es cero.En consecuencia, el método de deconvolución propuesto es el algoritmo matricial y un filtro de Butterworth optimizado en función del tiempo de tránsito.Se ha valorado la aplicabilidad del algoritmo de deconvolución en estudios reales con 131I-Hippuran. Además del filtro de Butterworth, se utilizó el filtro de tres puntos por ser el más empleado en Medicina Nuclear. De este estudio se ha concluído que los dos métodos de filtrado lineal determinan los parámetros derivados de la función de retención renal de forma equivalente. Se ha estudiado la relación existente entre las estimas del tiempo de tránsito renal y de la función renal relativa efectuadas sobre la función de retención renal, y sobre el renograma. Los resultados obtenidos al aplicar el algoritmo de deconvolución propuesto permiten concluir: El tiempo en el instante de máxima actividad en el renograma sobreestima el tiempo de tránsito renal, hecho que se comprobó que también sucedía en los estudios simulados. Se ha comprobado que esta sobrevaloración, que se acentúa para valores de tiempo en el máximo elevados, es debida fundamentalmente al valor de la constante de tiempo de la primera exponencial de la curva de aclaramiento plasmático y al grado de dispersión del tiempo de tránsito.La estima de la función renal relativa realizada sobre el renograma corregido de actividad extrarrenal da valores comparables a los obtenidos sobre la función de retención renal, no existiendo diferencias significativas.Se aplicó al algoritmo de deconvolución propuesto a estudios reales con 99mTc-MAG3. Al ser la relación señal/ruido unas tres veces mayor que la del Hippuran permitió obtener la función de retención con menor filtrado. De este estudio se ha concluído:La estima del tiempo de tránsito renal efectuada sobre el renograma como tiempo en el máximo sobrevalora el tiempo de tránsito intrarrenal en relación a la estima efectuada sobre la función de retención renal. Esta sobrevaloración es mayor para tiempos de tránsito largos.La estima de la función renal relativa realizada sobre el renograma presenta, en general, valores inferiores a los obtenidos a partir de la función de retención renal. Esto es debido a la presencia de la actividad de tipo vascular no eliminada totalmente al efectuar la corrección de la actividad extrarrenal. / The main aim of the study was to obtain a calculation method of the renal retention function which includes an optimization of the degree of filtering. Studies with (131)I-Hippuran and 99m Tc-Mag 3 were simulated by means of the numerical simulation of a renal gammagraphic study. The existence of an optimum filtering was demonstrated. This minimum value is present for the three filterings considered (smoothing, Butterworth and data bounding) and for the two tracers. Consequently the functions of the corresponding filterings were obtained. The renal retention functions were obtained and the derived parameters were calculated: relative renal function and the mean transit time. The algorithm of the deconvolution proposed consist of a matrix algorithm to perform the deconvolution and a Butterworth filtering optimized in function of renal transit time. The algorithm of deconvolution was subsequently applied to one group of renal studies with (131)I-Hippuran and to another with (99m)Tc-Mag(3) in order to assess its applicability in real cases. Likewise, we evaluated the degree of correlation between the values of the two parameters calculated on the renogram (which is normally performed in clinical practice) and those obtained from the renal retention function. For both tracers it was demonstrated the value of the transit time estimated on the renogram overestimated the value of the transit time especially in all the cases presenting renal obstruction. In the cases of (131)I-Hippuran the estimate of the relative renal function performed on the corrected renogram of the extrarrenal background gives values comparable to those obtained from the renal retention function. For the (99m)Tc-Mag(3) , the estimate carried out on the renogram yields, in general, values that are lower than those obtained from the renal retention function. This is due to the presence of the vascular background which was not wholly eliminated when correcting the renogram.

In this study, available coastal models are briefly discussed and under wind waves and a numerical shoreline change model for longshore sediment transport based on &ldquo / one-line&rdquo / theory is developed. In numerical model, wave diffraction phenomenon in one-dimensional modeling is extensively discussed and to represent the irregular wave diffraction in the sheltered zones of coastal structures a simpler approach based on the methodology introduced by Kamphuis (2000) is proposed. Furthermore, the numerical model results are compared with analytical solutions of accretion and erosion at a single groin. An application to a case study of a groin field constructed to the east side of Kizilirmak river mouth, at Bafra alluvial plain, is carried out by the numerical model. The results of comparisons show that the numerical model is in good agreement with the analytical solutions of shoreline changes at a groin. Similarly, numerical model results are compared with field data of Bafra and it is shown that they are in good agreement qualitatively. Therefore, the numerical model is accepted to be capable of representing of shoreline evolution qualitatively even for complex coastal regions.

Climate change and anticipated impacts of sea level rise such as increased coastal erosion, inundation, flooding due to storm surges and salt water intrusion to freshwater resources will affect all the countries but mostly small island countries of oceans and low-lying lands along coastlines. Turkey having 8333 km of coastline including physically, ecologically and socio-economically important low-lying deltas should also prepare for the impacts of sea level rise as well as other impacts of climate change while participating in mitigation efforts. Thus, a coastal vulnerability assessment of Turkey to sea level rise is needed both as a part of coastal zone management policies for sustainable development and as a guideline for resource allocation for preparation of adaptation options for upcoming problems due to sea level rise. In this study, a coastal vulnerability matrix and a corresponding coastal vulnerability index &ndash / CVI (SLR) of a region to sea level rise using indicators of impacts of sea level rise which use commonly available data are developed. The results of the matrix and the index enable decision makers to compare and rank different regions according to their vulnerabilities to sea level rise, to prioritize impacts of sea level rise on the region according to the vulnerability of the region to each impact and to determine the most vulnerable parameters for planning of adaptation measures to sea level rise. The developed coastal vulnerability assessment model is used to determine the vulnerability of G&ouml / ksu Delta (Specially Protected Area), Mersin that has unique geological, ecological and socio-economical properties which are protected and recognized by both national and international communities.

In this study, a numerical model &ldquo / Modified Coast-Structure Interaction Numerical Model&rdquo / (CSIM) is developed with an implicit approach to determine the shoreline changes due to wind wave induced longshore sediment transport under the presence of groins, T-groins and offshore breakwaters by making modifications on the explicit numerical model &ldquo / Coast-Structure Interaction Numerical Model&rdquo / (CSI). Using representative wave data transformed to a chosen reference depth from deep water, numerical model (CSIM) simulates the shoreline changes considering structure interference. Breaking and diffraction within the sheltered zones of coastal structures defined for offshore breakwaters by using vectorial summation of the diffraction coefficients and as for T-groins shore-perpendicular part forms a boundary to define the shoreline changes seperately at two sides of the structure. Numerical model, CSIM is tested with a case study by applying in Bafra Delta, Kizilirmak river mouth at Black sea coast of Turkey. Numerical model simulations show that model results are in good agreement qualitatively with field measurements.

In this study, new design approaches are introduced for the seismic design of block type quay walls after reviewing the conventional methodologies. Within the development of the new design approaches an inverse triangular dynamic pressures distributions are applied to define both seismic earth pressures and seismic surcharge pressures. Differently from the conventional design methodology, the hydrodynamic forces are taken into consideration while dynamic forces are specified and equivalent unit weight concept is used during the both static and dynamic calculations Compatibility of this new design approaches are tested by case studies for the site and it is seen that the numerical results are in good agreement qualitatively with field measurements.

Turkey has very different geomorphologic, hydrologic and climatic conditions, so the runoff coefficient should be different from one basin to another. But only one constant value, which is 0.37, is being used for all the basins in Turkey. In this thesis, monthly, seasonal and annual runoff coefficients of 48 sub-basins in western and southern part of Anatolia are determined by using synchronous and average rainfall, runoff data of 26 year record period. Their temporal and spatial distributions are investigated. The relationship between the basin parameters and the runoff coefficient are also examined. Some of the basins have unrealistic large runoff coefficients, therefore excluded from the analyses. The basin boundaries and parameters are determined by using Geograhic Information System (GIS), and areal average precipitations are found by a program written in visual basic language that uses ArcObjects. The Box-Cox transformed data are used in regression analysis. There are a number of dams in the region, which affect the natural flow. Such streams are found and their sub-basins are not used in the analyses. The results revealed that there is not a strong the relationship between the basin parameters and annual and seasonal runoff coefficients for the whole region, but there are significant relations between them for some basins.