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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.
441

Rock : uma análise na perspectiva da crítica religiosa-cristã

Schaffer, Vandir Rudolfo January 1992 (has links)
Trata-se de uma análise da literatura de inspiração religiosa-cristã sobre o movimento rock, identificando no seu discurso os preceitos éticos-religiosos que fundamentam uma estética condenatória da música rock. A revisão da literatura sobre o rock aponta dois grupos bem distintos quanto ao seu posicionamento estético-ideológico. De um lado, os estudiosos em geral, que aceitam o rock como um movimento capaz de representar a cultura jovem, uma música associada a uma manifestação social normal e no campo oposto estão os religiosos - pastores, conselheiros e professores - que consideram o rock como uma música perigosa e com influência destruidora sobre a juventude. Esta dupla conotação ligada ao rock gerou a idéia deste estudo, tendo em vista os seguintes objetivos: 1) Apresentar uma revisão crítica da bibliografia de inspiração religiosa-cristã sobre o rock; e 2) Tentar encontrar respostas aos questionamentos quanto aos efeitos negativos desta música através da análise da relação música rock/ouvinte. A dissertação compõe-se de três partes que correspondem aos três capítulos do trabalho. O primeiro, aborda o rock sob a visão da literatura religiosa, que é a que condena a prática dessa música, e considera o porquê dessa condenação. O segundo capítulo, por sua vez, analisa o tema na concepção da literatura não-religiosa com uma avaliação comparativa com os tópicos do capítulo anterior. Por fim, o terceiro capítulo, apresenta os resultados da pesquisa de campo, realizada no ROCK IN RIO II - Rio de Janeiro no período de 22 a 24 de janeiro de 1991 - onde se contextualiza, na prática musical do rock, opiniões, conceitos e fatos apresentados nos capítulos anteriores. Conclui-se que o discurso condenatório ao rock representa uma disputa de poder pela qual os religiosos querem assegurar a lealdade dos membros da comunidade cristã a seus princípios. Neste sentido, o rock representa uma ameaça porque a sua missão, segundo a sua literatura e filosofia, é não copiar o mundo em seu estilo de vida e preferência musical. No entanto, através do estudo da literatura não-religiosa e da pesquisa de campo observou-se que esta música é um reflexo da sociedade e cultura atual e que, a maioria dos problemas apontados pela crítica religiosa-cristã no rock, são resultado de fatores extra-musicais. / This thesis deals with an analysis of religious-christian literature concerning the rock movement which identifies religious ethical norms that condemn rock music. This literature points to two different groups regarding their ideological position. One group accepts rock as just a cultural movement associated with young people. The other, mainly religious and clergymen, consider rock music to be dangerous with a destructive influence on the youth. These two stands generated the basic idea of this research along with the following objectives: 1) To present a critical analysis of the bibliography related to the religious-christian viewpoint dealing with rock; 2) To discuss the negative critique to this music by means of an analysis of the relation rock music/listeners. The thesis is divided into three chapters: the first indicates very strong condemnation of this music by much of the religious literature and why so. The second one is a comparative of the topics presented in the first chapter by using non-religious literature. Finally, the third chapter shows the results of field work done at the "Rock in Rio II Festival" in Rio de Janeiro, 1991. Much of what was presented in the previous chapters is discussed vis a vis data gathered at that event. It can be concluded that the discussion dealing with the condemnation of rock represents a dispute of power by which those of a religious background desire to maintain the loyalty of the christian community to its principles. In this way, rock appears to be a threat to them because their mission, acording to their literature and philosophy, is not to copy the world in its life style and its musical preference. However, research dealing with non-religous literature revealed that this music is a reflection of the society and its current culture. Also, this literature leads to conclude that many of the problems pointed out by the religious critics concerning rock music are effected by non-musical factors.
442

Rock : uma análise na perspectiva da crítica religiosa-cristã

Schaffer, Vandir Rudolfo January 1992 (has links)
Trata-se de uma análise da literatura de inspiração religiosa-cristã sobre o movimento rock, identificando no seu discurso os preceitos éticos-religiosos que fundamentam uma estética condenatória da música rock. A revisão da literatura sobre o rock aponta dois grupos bem distintos quanto ao seu posicionamento estético-ideológico. De um lado, os estudiosos em geral, que aceitam o rock como um movimento capaz de representar a cultura jovem, uma música associada a uma manifestação social normal e no campo oposto estão os religiosos - pastores, conselheiros e professores - que consideram o rock como uma música perigosa e com influência destruidora sobre a juventude. Esta dupla conotação ligada ao rock gerou a idéia deste estudo, tendo em vista os seguintes objetivos: 1) Apresentar uma revisão crítica da bibliografia de inspiração religiosa-cristã sobre o rock; e 2) Tentar encontrar respostas aos questionamentos quanto aos efeitos negativos desta música através da análise da relação música rock/ouvinte. A dissertação compõe-se de três partes que correspondem aos três capítulos do trabalho. O primeiro, aborda o rock sob a visão da literatura religiosa, que é a que condena a prática dessa música, e considera o porquê dessa condenação. O segundo capítulo, por sua vez, analisa o tema na concepção da literatura não-religiosa com uma avaliação comparativa com os tópicos do capítulo anterior. Por fim, o terceiro capítulo, apresenta os resultados da pesquisa de campo, realizada no ROCK IN RIO II - Rio de Janeiro no período de 22 a 24 de janeiro de 1991 - onde se contextualiza, na prática musical do rock, opiniões, conceitos e fatos apresentados nos capítulos anteriores. Conclui-se que o discurso condenatório ao rock representa uma disputa de poder pela qual os religiosos querem assegurar a lealdade dos membros da comunidade cristã a seus princípios. Neste sentido, o rock representa uma ameaça porque a sua missão, segundo a sua literatura e filosofia, é não copiar o mundo em seu estilo de vida e preferência musical. No entanto, através do estudo da literatura não-religiosa e da pesquisa de campo observou-se que esta música é um reflexo da sociedade e cultura atual e que, a maioria dos problemas apontados pela crítica religiosa-cristã no rock, são resultado de fatores extra-musicais. / This thesis deals with an analysis of religious-christian literature concerning the rock movement which identifies religious ethical norms that condemn rock music. This literature points to two different groups regarding their ideological position. One group accepts rock as just a cultural movement associated with young people. The other, mainly religious and clergymen, consider rock music to be dangerous with a destructive influence on the youth. These two stands generated the basic idea of this research along with the following objectives: 1) To present a critical analysis of the bibliography related to the religious-christian viewpoint dealing with rock; 2) To discuss the negative critique to this music by means of an analysis of the relation rock music/listeners. The thesis is divided into three chapters: the first indicates very strong condemnation of this music by much of the religious literature and why so. The second one is a comparative of the topics presented in the first chapter by using non-religious literature. Finally, the third chapter shows the results of field work done at the "Rock in Rio II Festival" in Rio de Janeiro, 1991. Much of what was presented in the previous chapters is discussed vis a vis data gathered at that event. It can be concluded that the discussion dealing with the condemnation of rock represents a dispute of power by which those of a religious background desire to maintain the loyalty of the christian community to its principles. In this way, rock appears to be a threat to them because their mission, acording to their literature and philosophy, is not to copy the world in its life style and its musical preference. However, research dealing with non-religous literature revealed that this music is a reflection of the society and its current culture. Also, this literature leads to conclude that many of the problems pointed out by the religious critics concerning rock music are effected by non-musical factors.
443

Cirurgia radioguiada com 99mTc-sestamibi intravenoso e ressonancia nuclear magnetica no cancer de mama / Radioguided surgery with 99mTc-sestamibi intravenous and magnetic resonance imaging for breast cancer

Duarte, Giuliano Mendes 31 October 2007 (has links)
Orientador: Cesar Cabello dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T08:45:28Z (GMT). No. of bitstreams: 1 Duarte_GiulianoMendes_D.pdf: 5275602 bytes, checksum: 5180518eed1c8045749e430f93e8b706 (MD5) Previous issue date: 2007 / Resumo: Objetivos: Estudar a utilização de cirurgia radioguiada com 99mTc-sestamibi associada à ressonância nuclear magnética (RNM) no câncer de mama. Para isso, foram desenvolvidas duas novas técnicas: uma intitulada Avaliação Intra-peratória Radioguiada das Margens (Radioguided Intraoperative Margins Evaluation -RIME) que usa um radiofármaco intravenoso para auxiliar, através de uma sonda detectora de radiação (probe), a ressecção tumoral; a outra intitulada Fusão da Ressonância Nuclear Magnética e Cintilografia Mamária (Magnetic Resonance Imaging/ Scintimammography fusion ¿ MRI/SM) que procura determinar a extensão tumoral. Dessa forma, esta tese visa avaliar a factibilidade das técnicas, o valor da RIME em obter margens livres e o valor da MRI/SM em determinar o tamanho real do tumor comparando com outros exames. Sujeitos e métodos: Foi realizado um estudo experimental descritivo em 23 mulheres com carcinoma ductal invasivo de mama estádios IIA a IIIA, agendadas para mastectomia. Dois a dez dias antes da cirurgia, as pacientes foram submetidas à cintilografia mamária com 99mTc-sestamibi, na qual foi localizado o tumor e estimado o tempo ideal para iniciar a cirurgia radioguiada através de uma curva de contagem de radiação por tempo. No mesmo dia, 20 pacientes realizaram uma ressonância nuclear agnética com gadolíneo. No momento da cirurgia, a mesma dose de 99mTc-sestamibi foi injetada intravenosamente. Esperou-se o tempo ideal estimado previamente e então foi realizada uma segmentectomia com auxílio do probe, que determinou as margens de ressecção. A ressonância foi usada para avaliar comprometimento da pele, fáscia profunda a outros focos de tumor que foram incluídos na segmentectomia. Isso caracterizou a RIME. Após, todas as pacientes foram submetidas à mastectomia. A egmentectomia e a mama residual foram examinadas histologicamente. Paralelamente, foi desenvolvido um programa de computador em linguagem visual que realizou, de forma semi-automática, a fusão das imagens de ressonância e cintilografia em 20 pacientes (MRI/SM). Foi determinado como tumor na MRI/SM a área de intersecção das imagens, o tumor foi medido e comparado com a medida no exame histológico, ressonância nuclear magnética, mamografia e exame clínico. Para análise estatística foram utilizados os testes exato de Fisher, t de Student, Wilcoxon e regressão linear. Resultados: Em todas as pacientes foi possível realizar as técnicas de RIME e MRI/SM (factibilidade de 100%). A RIME permitiu a ressecção do tumor com margens livres em 19 pacientes, com média de margem de 4,8mm. Em 11 casos não havia doença residual na mama após a segmentectomia. A média do tamanho da doença residual na mama foi 3,6mm e geralmente estava localizado próximo ao leito tumoral (<1,5cm em 10 pacientes). Não houve associação entre presença de doença residual e o tamanho do tumor ou estado das margens. A medida do tumor na MRI/SM teve uma correlação com o exame histológico melhor que a ressonância, a mamografia e exame clínico em todos os diâmetros estudados. Conclusões: As técnicas de RIME e MRI/SM são factíveis. A RIME permitiu auxiliar a ressecção tumoral com margens livres na maioria das vezes. A MRI/SM parece ser melhor que ressonância, mamografia e exame clínico para determinar a extensão tumoral / Abstract: Aims: To study the use of radioguided surgery with 99mTc-sestamibi, associated with magnetic resonance imaging (MRI), for breast cancer evaluation. For this, we developed two techniques: the first was dominated Radioguided Intraoperative Margins Evaluation (RIME), a technique that uses a radiopharmaceutical agent to distinguish normal and cancer tissue with a probe; the second was termed Magnetic Resonance Imaging and Scintimammography fusion (MRI/SM) to determine the extension of cancer. Thus, this study aims to assess the feasibility of techniques, the ability of RIME to obtain free margins and the ability of MRI/SM to determine the real tumor extension, in comparison to other examinations. Subjects and methods: A descriptive experimental study was carried out on 23 women with invasive ductal breast carcinoma, stages IIA to IIIA, programmed for mastectomy. Two to 10 days before the surgery, the patients were submitted to a scintimammography with 99mTc-sestamibi to localize the tumor and to estimate the optimal time to begin radioguided surgery, through a curve of radiation count per time. On the same day, 20 patients realized a MRI with gadolinium. At the moment of the surgery, the same dose of 99mTc-sestamibi was injected intravenously, after a previously-estimated optimal time a segmentectomy was performed with a probe that determined the resection margins. MRI was used to evaluate the compromising of the skin, deep fascia and the other tumor foci that were included in the segmentectomy, characterizing the RIME. All the patients were then submitted to mastectomy. The segmentectomy and residual breast were histopathologically examined. In parallel, software was developed in visual language to perform the MRI/SM fusion in 20 patients. The intersection area between the MRI and scintimammography was determined as tumor in MRI/SM and the tumor was measured and compared with the measurement in the pathological, MRI, mammography and clinical examination. The Fisher¿s exact test, Student¿s t-test, Wilcoxon¿s test and linear regression were used for statistical analysis. Results: The RIME and MRI/SM techniques were successfully performed in all patients (feasibility of 100%). The principal tumor was removed by RIME and provided histologically-free margins in 19 patients (mean margins, 4.8mm). Additionally, 11 patients were without residual disease after segmentectomy. The mean size of residual carcinoma was 3.6mm and generally located near the tumor bed (< 1.5cm in 10 patients). There was no significant association between presence of residual disease and tumor size or margin status. The MRI/SM cancer measurements correlated better with pathology than MRI, mammography and clinical examination in all diameters analyzed. Conclusions: The RIME and MRI/SM techniques are feasible. In general, RIME aids in tumor resection with free margins. MRI/SM seems to be better than MRI, mammography and clinical examination to determine the tumoral extension / Doutorado / Tocoginecologia / Doutor em Tocoginecologia
444

Práticas colaborativas: investigação da relação entre abordagem de gestão de custos inter-organizacional, custo de transação e gestão de riscos em alianças / Collaborative practices: an investigation of relationship among inter-organizational cost management approach, transaction costs and alliance risk management

Rodrigo Paiva Souza 03 November 2015 (has links)
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.
445

Avaliação da permeabilidade epitelial pulmonar em pacientes submetidos a esquemas de quimioterapia contendo bleomicina através da taxa de depuração pulmonar do 99M TC-DTPA

Azambuja, Evandro de January 2002 (has links)
Resumo não disponível.
446

The effect of the update of the European standard EN 50128 : - The management of the safety of the software applications for railway applications

Nordström, Åsa January 2017 (has links)
The European standard EN 50128 "Railway applications - Communication, signalling and processing systems - Software for railway control and protection systems" is one of the European standards for European Railway systems. It is intended for software aspects, specifying procedures and technical requirements for the development of programmable Electronic systems, which are used in railway control and protection applications. Since 2017- 04-25 the original version EN 50128:2001 has been replaced by the updated new version EN 50128:2011. The update is quite extensive and will effect many parts of the existing Railway systems. The aim of this study is to investigate the effect of the EN 50128 update. The work for this study includes literature study, document research and interview with the relevant supplies and experts. Qualitative and quantitative methods have been used in the study to reach the possible best results. The effects due to the EN 50128 update have been extensively investigated. The following issues have been addressed: - How can the update of the standard EN 50128 be done smoothly by the companies? - How much money have they spent to update their process to follow the 2011 version? - What parts of the process have been the most extensive and expensive to change due to the standard update? The results of the work are useful for an organized and professional assessor to help and support the companies dealing with this complex software, in order for them to be prepared for the upcoming standard update as well as possible. If the affected companies have been proactive in their own development of their methods/techniques, the 2011 version of the standard will not be a major work to follow for their process. A standard is a guideline and a support in the way to a safer system.
447

Diagnosis of orthopaedic prosthesis infections with radionuclide techniques; clinical application of various imaging methods

Larikka, M. (Martti) 23 January 2004 (has links)
Abstract A variety of radiopharmaceuticals and imaging techniques are currently available for scintigraphic imaging of infections. However, comparisons on the clinical value of such techniques have been limited, especially in prosthesis infections. This series included 138 cases with suspected prosthesis infections – 94 in hip and 44 in knee prostheses of patients whose final diagnoses were based on clinical, operative and microbiological findings, and who underwent three-phase bone, 99mTc -leukocyte and 99mTc-ciprofloxacin imaging in the Department of Clinical Chemistry, Oulu University Hospital and in the Laboratory, L?nsi-Pohja Central Hospital, during the years from 1993 to 2001. The normal arterial and soft-tissue phase images of three-phase bone imaging practically excluded infection in hip prostheses, whereas these techniques frequently yielded false positive findings in patients with knee prostheses, resulting in specificity of 23% or less. In combined 99mTc-leukocyte/bone imaging, diagnostic accuracy was 80–86% at two- to four-hour images and 87–98% at 24-hour images. The 99mTc-ciprofloxacin images showed unspecific accumulation of tracer in the one-hour and four-hour images, which disappeared in the 24-hour images in most hip and knee prostheses. 99mTc-ciprofloxacin imaging yielded almost as good diagnostic accuracy as combined 99mTc-leukocyte/bone imaging. In conclusion, in suspected hip prosthesis infections, normal findings in three-phase bone imaging exclude infection, whereas abnormal results in the arterial and soft-tissue phases should be confirmed with 99mTc-leukocyte imaging using 24-hour images. Contrary-wise, in suspected knee prosthesis infections, 99mTc-leukocyte imaging with 24-hour images is the first-line examination, and abnormal results in 24-hour images should be confirmed by using 99mTc-bone-metabolic imaging. 99mTc-ciprofloxacin yielded almost equally good results as 99mTc-leukocyte/bone-metabolic imaging, but unfortunately, the tracer is not commercially available, although it has been patented.
448

Un modèle de liaisons fortes tridimensionnel pour les cuprates supraconducteurs monocouches à base de lanthane. / A three-dimensional tight-binding model for single-layer La-based cuprate superconductors

Photopoulos, Raphaël 27 September 2019 (has links)
Dans cette thèse, nous construisons un modèle de liaisons fortes tridimensionnel minimal pour les cuprates supraconducteurs monocouches à base de lanthane. Celui-ci prend en compte huit orbitales, dont deux d'entre elles impliquent les ions oxygène apicaux. L'optimisation des paramètres microscopiques permet de reproduire presque parfaitement la bande de conduction tridimensionnelle telle qu'elle a été obtenue à partir des calculs DFT. Nous discutons la façon dont chacun des paramètres entrant en jeu dans ce modèle multi-bandes influence la bande de conduction, et nous montrons que la forme particulière de sa dispersion contraint les valeurs des paramètres. Nous mettons alors en évidence que la détermination standard d'un modèle effectif à une bande au travers d'un traitement perturbatif converge lentement en raison de la valeur relativement faible du gap de transfert de charges. A ce stade, cela nous permet, en revanche, de lever le voile sur l'origine microscopique des amplitudes de saut des électrons au sein des plans et en-dehors des plans. Une approche alternative au calcul des paramètres microscopiques de saut du modèle effectif de liaisons fortes est présentée et mise à contribution. Il en résulte que l'accord avec la DFT est préservé à condition que les amplitudes de saut de plus longue portée soient conservées. Une comparaison avec les modèles existants est également effectuée. La surface de Fermi, mettant en exergue des domaines décalés qui alternent en taille et en forme, est comparée à l'expérience. De plus, la densité d'états du modèle est aussi calculée. Une analyse plus approfondie du modèle est réalisée au travers d'une étude en couplage faible des instabilités magnétiques. Les calculs sont effectués sur de grandes cellules et nous avons trouvé une compétition parmi plusieurs instabilités magnétiques tridimensionnelles dans la région d’intérêt du dopage en trous accessible expérimentalement. Bien qu'à notre connaissance cela ne semble pas avoir été évoqué expérimentalement, nous montrons à l'issue de notre étude, que la tendance du modèle à former des ondes de densité de spin incommensurables tridimensionnelles est la plus forte à proximité du dopage 1/8. / In this thesis, we construct a minimal three-dimensional tight-binding model for single-layer La-based cuprate superconductors. It entails eight orbitals, two of them involving apical oxygen ions. Parameter optimization allows to almost perfectly reproduce the three-dimensional conduction band as obtained from DFT. We discuss how each parameter entering this multiband model influences it, and show that the peculiar form of its dispersion severely constraints the parameter values. We then evidence that standard perturbative derivation of an effective one-band model is poorly converging because of the comparatively small value of the charge transfer gap. Yet, this allows us to unravel the microscopical origin of the in-plane and out-of-plane hopping amplitudes. An alternative approach to the computation of the tight-binding parameters of the effective model is presented and worked out. It results that the agreement with DFT is preserved provided longer-ranged hopping amplitudes are retained. A comparison with existing models is performed, too. The Fermi surface, showing staggered pieces alternating in size and shape, is compared to experiment. The density of states is calculated as well. The model is further analyzed through a weak coupling study of magnetic instabilities. It is performed on large clusters and competition between several three-dimensional magnetic instabilities in the hole-doping region of experimental interest is found. We show that the tendency to form a three-dimensional incommensurate spin density wave is strongest in the vicinity of 1/8 doping.
449

Structures of technetium and rhenium complexes

Leibnitz, P., Reck, G., Pietzsch, H.-J., Spies, H. January 2001 (has links)
Investigations in the 99mTc chemistry are stimulated by the search for new radiopharmaceuticals for nuclear medical applications. To understand the coordination mode of Tc with various complexing agents, macroscopic studies of technetium coordination chemistry are often performed using the low energy ß-emitting radionuclide 99Tc, which has a much longer half life (t1/2 = 2.12 x 105 years) than 99mTc, in the mg level. Investigations of Re coordination chemistry are done in conjunction with Tc studies because Re possesses chemical properties similar to those of Tc. For some chemical tasks, Re provides a non-radioactive alternative to work with Tc radioisotopes. In addition, 186Re and 188Re are of great interest to nuclear medicine as they possess nuclear properties favorable for use in therapeutic radiopharmaceuticals. Our investigations of Tc and Re coordination chemistry are toward this goal. A large series of technetium and rhenium complexes resulted from this studies have been characterized by X-ray crystal structure determinations. This survey covers the structural investigations performed by P.Leibnitz and G.Reck (BAM) from 1992 till now. It summarizes results obtained in the Rossendorf technetium group and is not intended to compete with the well-written reviews published so far.
450

Design of a telepresence interfacefor direct teleoperation of robots : The synergy between Virtual Reality and FreeLook Control

Pérez Mejías, Carlos January 2016 (has links)
In direct teleoperation the interface is vital to control a robot. Often it is reduced to a simple controller and the feedback provided by a camera stream in a monitor which leads to poor results. A telepresence system combined with a Free Look Control is proposed to increase the result in terms of situational awareness, usability and comfort. The telepresence system provides the sense of depth to the operatorin several manners. Free Look Control replaces Tank Control as control mode, in which the robot can be driven in any direction and the operator takes the control of the camera. A synergy is found when both features are implemented together as their advantages are increased. In addition a multi-camera setup is created, in order to build the 3D environment shown to the operator, which is calibrated in an automatic way. The two different control modes are tested and compared by several people. The outcome shows how the inclusion of these characteristics improve the result of the teleoperation in a visible way.

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