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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.
491

Sistema digital para manobra sincronizada de disjuntores - estudo e especificação funcional. / Digital system for synchronized switching of circuit breakers.

Garbelotti, Marcus Vinicius 24 April 2006 (has links)
Nesta dissertação, discorre-se sobre manobra sincronizada de disjuntores. Entre as atividades desenvolvidas para a sua elaboração estão a análise de transitórios causados por manobras em capacitores, reatores e linhas de transmissão, estudos de sobretensão e estudos para a determinação de instantes favoráveis às manobras, sob o ponto de vista de diminuição de sobretensões. Completa a dissertação a especificação de equipamento de sincronismo que, a partir de medições em tempo real de variáveis elétricas - que interferem nas sobretensões - e de variáveis climáticas - que interferem no tempo de acionamento dos contatos dos disjuntores - calculam o tempo de atraso necessário para o fechamento elétrico em instantes mais convenientes. / The scope of this dissertation is the study of synchronized switching of circuit breakers. The transients caused by capacitor, reactor and transmission line switching are analyzed, for overvoltage evaluation and to determined the favorable time in the wave that leads to smallest overvoltages. Finally the specification of an equipment is produced. The equipment acquire, in real time, the values of electrical variables (current and voltages) the ambient temperature and oil pressure in the circuit breaker operating mechanism, voltage in the auxiliary system and assign a delay in the breaker switching time in order to control overvoltages.
492

Modulation des propriétés macroscopiques des fibres de pin maritime par polymérisation radicalaire contrôlée amorcée depuis la surface : élaboration de bio-hybrides fonctionnels. / Modulation of macroscopic properties of Maritime Pine fibers by Surface Initiated Controlled Radical Polymerization : development of functional bio-hybrids

Tastet, Damien 06 December 2011 (has links)
Ce travail s’inscrit au sein du projet régional de recherche BEMA (Bois Eco Matériaux Aquitaine) qui allie partenaires universitaires et industriels afin de valoriser, à travers la filière panneaux de particules, des ressources abondantes en Aquitaine : le maïs et le Pin Maritime. L’objectif de cette thèse est de greffer de manière covalente des chaînes de polymère à la surface de fibres de bois afin de modifier leur état de surface et de favoriser leur comptabilisation avec un liant naturel et/ou synthétique. Pour atteindre cet objectif, nous avons choisi d’utiliser une technique de polymérisation particulière, la polymérisation radicalaire contrôlée. Le contexte scientifique international du début de la thèse montre la faisabilité du projet de par la réalisation de plusieurs études sur de la cellulose modèle de type papier filtre. Le défi de cette thèse consiste à transposer ce mécanisme sur des fibres de bois brutes afin de leur conférer de nouvelles propriétés (résistance à l’eau, caractère fongicide, meilleure comptabilisation…). Afin d’atteindre l’objectif énoncé ci-dessus, nous avons développé plusieurs aspects de la chimie des polymères en mettant en oeuvre différentes techniques de synthèse (RAFT, NMP) mais aussi de caractérisation adaptées à la présence de fibres de bois brutes (Mesure d’angle de contact, TGA, XPS). Enfin, nous avons valorisé la présence de polymères fonctionnels en insérant à la surface des fibres de bois des nanoparticules d’oxyde de silice ou de métaux de manière contrôlée. / This work is part of the regional research project BEMA (Bois Eco Matériaux Aquitaine) which combines academic and industrial partners to develop, through the wood pannel industry, abundant resources in Aquitaine: corn and Maritime Pine. The objective of this thesis is to covalently graft polymer chains on the surface of wood fibers in order to modify their surface properties and to facilitate their compatibilization with natural and/or synthetic binders. To achieve this goal, we chose to use a special polymerization technique, the controlled radical polymerization. The international scientific context of the beginning of the thesis shows the feasibility of the project through several studies carried out on model cellulose, such as filter paper. The challenge of this thesis is to implement this mechanism on raw wood fibers to give them new properties (water resistance, fungicidal character, best compatibilization ...). To achieve the objective stated above, we investigated several polymer synthetic pathways (RAFT, NMP) but also characterization techniques (Contact angle measurements, TGA, XPS) suitable with the presence of raw wood fibers. What’s more, we have valued the presence of functional polymers by inserting at the wood fibers surface oxide nanoparticles of silica or metal in a controlled manner.
493

Liberdade na escolha das respostas e variabilidade de resposta no processo adaptativo em aprendizagem motora / Freedom in response choice and response variability on adaptive process in motor learning

Walter, Cinthya 16 June 2014 (has links)
O objetivo desse estudo foi investigar os efeitos da liberdade na escolha das respostas, da variabilidade de resposta resultante dessa liberdade e da variabilidade externamente determinada no processo adaptativo em aprendizagem motora. Foram realizados oito experimentos, compostos por duas fases: estabilização, contendo 100 tentativas com conhecimento de resultados (CR), e adaptação, com 24 tentativas em uma mesma condição para todos os grupos, sem CR. Participaram do estudo 96 adultos de ambos os sexos, sem experiência prévia na tarefa utilizada. Como tarefa foi utilizada uma habilidade motora sequencial e de precisão temporal que consistiu em movimentar um cursor, usando o mouse, direcionando-o a seis alvos numa sequência, de forma que os \"toques\" nos alvos fossem realizados em coincidência com estímulos auditivos. A ordem dos toques na sequência foi livre nos grupos com liberdade na escolha das respostas e determinada nos grupos yokeds. Na fase de adaptação foi realizada uma modificação perceptivo-efetora na tarefa. O experimento 1 foi realizado para investigar o efeito da liberdade na escolha das respostas no processo adaptativo em aprendizagem motora. Os resultados evidenciaram que a liberdade na escolha da resposta, durante a fase de estabilização, beneficiou o processo adaptativo. O experimento 2 foi realizado para investigar o efeito da meta de aprendizagem nas escolhas dos aprendizes e no processo adaptativo em aprendizagem motora. Os resultados indicaram que a meta de aprendizagem teve efeito nas escolhas dos aprendizes, mas essas escolhas não ocasionaram superioridade nas medidas de desempenho na fase de adaptação. Houve menor tempo de planejamento da ação no primeiro bloco da fase de adaptação, indicando melhor preparação para uma nova situação nessa condição. Os experimentos 3 e 4 foram realizados para investigar o efeito da variabilidade de resposta resultante da condição de liberdade na escolha das respostas com meta de aprendizagem no processo adaptativo em aprendizagem motora. Os resultados desses dois experimentos apontaram que na presença da meta de aprendizagem, quando a liberdade na escolha das respostas é explorada ativa e efetivamente, o desempenho na fase de adaptação é favorecido, com indicativos de superioridade da condição com maior quantidade de variações na sequência quando comparada à condição com maior número de sequências utilizadas na fase de estabilização. Os experimentos 5 a 8 foram conduzidos para comparar o efeito da variabilidade resultante da liberdade na escolha das respostas com meta de aprendizagem com o da variabilidade externamente determinada no processo adaptativo em aprendizagem motora. Os resultados desses experimentos indicaram que a condição de liberdade na escolha das respostas com meta de aprendizagem não é suficiente para beneficiar o processo adaptativo. Quando a variabilidade de resposta resultante foi menor os benefícios da liberdade na escolha das respostas foram anulados, mas quando a variabilidade de resposta resultante foi maior os benefícios da liberdade na escolha das respostas foram igualados aos da variabilidade de resposta externamente determinada / The purpose of this study was to investigate the effects of freedom in response choice, variability resulting from this freedom, and externally determined variability on the adaptive process in motor learning. Eight experiments were carried out, each of them comprising two phases: stabilization, which consisted of 100 trials with knowledge of results (KR), and adaptation, with 24 trials in a same condition for all groups, without KR. Ninety-six adults of both sexes with no previous experience with the task took part in this study. The task consisted of a spatiotemporal sequential motor skill of moving a cursor, using the computer mouse, to six targets in sequence, so that the \"touches\" in the targets were performed in coincidence with auditory stimuli. The order of touches in the sequence was free for the groups with freedom in response choice and determined for the yoked groups. A perceptual-motor change in the task was introduced in the adaptation phase. The experiment 1 was conducted to investigate the effect of freedom in response choice on the adaptive process in motor learning. Results showed that freedom in response choice during the stabilization phase benefited adaptive process. The experiment 2 was conducted to investigate the effect of learning goal both on the learner\'s choice and on the adaptive process in motor learning. Results indicated that learning goal had an effect on learners\' choices, but these choices did not lead to superiority in performance measures during the adaptive phase. The results also showed less time for planning the action in the first block of adaptive phase, suggesting better preparation for a new situation in the learning goal condition. Experiments 3 and 4 were conduced to investigate the effect of response variability resulting from freedom in response choice with learning goal on the adaptive process in motor learning. Results of both experiments revealed that, with learning goal, when freedom in response choice is actively and effectively explored, performance in the adaptation phase is favored, with indicative of superiority of higher sequence variations condition over the higher number of sequences used condition in the stabilization phase. Experiments 5 to 8 were conduced to compare the effect of variability resulting from freedom in response choice, with learning goal, to the effect of externally determined variability on the adaptive process in motor learning. The results of these experiments indicated that freedom in response choice is not enough to benefit adaptive process. When response variability resulting from freedom was lower, the benefits were absent, but when it was higher, the benefits were matched to those of the externally determined response variability
494

Quantitative magnetic resonance imaging studies of extended drug release systems

Chen, Chen January 2014 (has links)
No description available.
495

Adaptive supervisory control scheme for voltage controlled demand response in power systems

Abraham, Etimbuk January 2018 (has links)
Radical changes to present day power systems will lead to power systems with a significant penetration of renewable energy sources and smartness, expressed in an extensive utilization of novel sensors and cyber secure Information and Communication Technology. Although these renewable energy sources prove to contribute to the reduction of CO2 emissions into the environment, its high penetration affects power system dynamic performance as a result of reduced power system inertia as well as less flexibility with regards to dispatching generation to balance future demand. These pose a threat both to the security and stability of future power systems. It is therefore very important to develop new methods through which power system security and stability can be maintained. This research investigated the development of methods through which the contributions of on-load tap changing transformers/transformer clusters could be assessed with the intent of developing real time adaptive voltage controlled demand response schemes for power systems. The development of such a scheme enables more active system components to be involved in the provision of frequency control as an ancillary service and deploys a new frequency control service with low infrastructural investment, bearing in mind that OLTC transformers are already very prevalent in power systems. In this thesis, a novel online adaptive supervisory controller for ensuring optimal dispatch of voltage-controlled demand response resources is developed. This novel controller is designed using the assessment results of OLTC transformer impacts on steady-state frequency and was tested for a variety of scenarios. To achieve the effective performance of the adaptive supervisory controller, the extensive use of statistical techniques for assessing OLTC transformer contributions to voltage controlled demand response is presented. This thesis also includes the use of unsupervised machine learning techniques for power system partitioning and the further use of statistical methods for assessing the contributions of OLTC transformer aggregates.
496

Considerações sobre analgesia controlada pelo paciente (PCA) em hospital universitário

Barros, Guilherme Antonio Moreira de [UNESP] January 2001 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2001Bitstream added on 2014-06-13T20:28:37Z : No. of bitstreams: 1 barros_gam_me_botfm.pdf: 228323 bytes, checksum: 6466d10f0d4eb9a3ff79e8f785fea941 (MD5) / Com o rápido avanço que foi observado nos últimos anos nas técnicas cirúrgicas e anestésicas, os procedimentos se tornaram cada vez mais invasivos. Como houve progressivo envelhecimento da população, o período mais delicado de recuperação, ou seja, o pós-operatório, passou a receber maior atenção. O surgimento de novas técnicas de analgesia, como a Analgesia Controlada pelo Paciente (PCA), vem preencher as necessidades da comunidade médica, cada vez mais atenta à qualidade dos serviços prestados. O Hospital de Clínicas da Faculdade de Medicina da UNESP, Botucatu, atento a essa nova realidade constituiu o Serviço de Dor Aguda (SEDA) para que esta lacuna fosse também preenchida em nosso meio. No intuito de identificar a atuação do SEDA, realizou-se levantamento, de fevereiro de 1995 a dezembro de 1997, com a pesquisa das evoluções de 679 pacientes seguidos pelo SEDA e que fizeram uso do método PCA de analgesia. Observou-se que os resultados obtidos pelo Serviço estavam acima da média relatada pela literatura internacional, com excelentes níveis de analgesia atingidos, baixa ocorrência de efeitos colaterais, e nenhuma complicação fatal no período do estudo. / In the past years a fast developing has been observed in the surgery and anesthetic technique, with more invasive procedures being performed. As the general population has becoming older, the critical recovery period, it means the post surgery period, became focus of attention. The developing of new analgesia techniques, such as Patient Controlled Analgesia (PCA), has the intention of fulfill the needs of the medical community, day by day more aware about the quality of the services. The Hospital of the Sao Paulo State Medical School, Botucatu, aware of this new reality had decided to form the Acute Pain Management Service (SEDA). With the goal of identify the way the SEDA acts this research was realized in period between February, 1995, to December, 1997. Data of 679 patients who used the PCA device were evaluated. The results in this study were as good as the international literature shows, with high quality analgesia, low side effects and no fatal complications on the period observed.
497

Randomized controlled trial to evaluate the successfulness of the retractable sham acupuncture needle in blinding patients. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Conclusions. The retractable non-invasive needle seems to have reasonably good capability of blinding patients and is more successful in acupuncture-naive subjects than in experienced ones. The failure to produce similar sensation of stimulation in the sham acupuncture group may be the major reason for incomplete blinding. (Abstract shortened by UMI.) / Design, participants and outcomes. We conducted a randomized controlled trial of 398 acupuncture-naive subjects and 197 acupuncture-experienced subjects who were recruited from the outpatients clinic of a university hospital in China. Acupuncture-naive and experienced subjects were randomized separately to receive the real acupuncture treatment or the placebo acupuncture at acupoint Hegu on the left hand. After the intervention, the percentage of patients who thought they had received real acupuncture was compared between the real and sham acupuncture groups. We defined the degree of blinding as 100% minus the difference in the percentage between the two groups. The score of pain, soreness, numbness, heaviness and distension during the treatment was also compared between the two groups. / Introduction. The newly designed retractable needle which can be used to produce non-invasive placebo or (sham) acupuncture seems promising and has been used in clinical trials. Several studies investigated the credibility of the retractable needle in blinding patients. These studies are generally small and mostly in acupuncture-naive patients and mainly focused on the difference in acupuncture-related sensations rather than the successfulness of blinding. / Objectives. To quantify the degree of blinding of the retractable non-invasive placebo needle in blinding both acupuncture-naive and experienced subjects in clinical trials and to explore possible reasons for incomplete blinding of the sham needle. / Results. In acupuncture-naive subjects, the percentage of those who thought they had received real acupuncture was 70.4% and 42.7% respectively in the real and sham acupuncture groups. The degree of blinding was 72.3% (95% CI: 62.9%, 81.7%). In acupuncture-experienced subjects, the degree of blinding was 58.9 (95% CI: 46.2%, 71.6%). The difference in degree of blinding between acupuncture-naive and experienced subjects was statistically significant (P<0.05). The score of pain, soreness, numbness, heaviness and distension in the real acupuncture group was all statistically significantly higher than that in the sham acupuncture group in both acupuncture-naive and experienced subjects (P<0.001). / Zhang Hongwei. / "February 2005." / Adviser: Jin Ling Tang. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0161. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 93-102). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
498

Avaliação da alteração de valores laboratoriais em pacientes submetidos à cirurgia ortognática sob hipotensão /

Ribeiro Neto, Carlos Alberto. January 2016 (has links)
Orientador: Marcelo Silva Monnazzi / Resumo: A cirurgia ortognática sob hipotensão induzida vem sendo realizada já há um certo tempo. Os benefícios vão desde a melhora no campo cirúrgico até a menor perda sanguínea. Sendo assim, esta pesquisa nasceu de um desejo tanto da equipe de anestesia quanto dos cirurgiões envolvidos de se avaliar em números, se este procedimento sob hipotensão pode gerar algum malefício ao paciente, devido a baixa pressão em que o mesmo é mantido durante a cirurgia. Foi realizado um estudo retrospectivo no prontuário de 50 pacientes tratados com cirurgia ortognática, os quais foram anestesiados com técnica de hipotensão induzida, cujos prontuários contemplavam todas os registros de exames necessários para o estudo. Os registros desses pacientes foram então analisados em dois momentos, o pré-operatório e o pós-operatório. Com base nos resultados constatou-se que não há diferença estatisticamente significante em grande parte dos valores laboratoriais avaliados, com exceção do ETCO2. No entanto, algumas alterações encontradas em comparação com os valores tidos como normais, podem sugerir que a cirurgia ortognática sob hipotensão induzida altere a função renal. Portanto, estudos com outras metodologias e maior amostragem são necessários para confirmar esses dados. / Abstract: The hypotensive anaesthesia during orthognathic surgery is routinely used in many maxillofacial services around the world. The benefits of this technique are widely described in the scientific literature, benefits such as significant decrease of blood loss, improved surgical field and reduction in operation time. The possible detriments of this technique is not well defined and few literatures addresses these issues. Therefore, this study was born in conjunction with the surgeons and anesthesiologists desire in to verify the possible hematologic changes suffered by the patients undergoing this kind of surgery and anesthesia. A prospective evaluation of some laboratory parameters in 50 patients was done, during 50 consecutive orthognathic surgeries. The results demonstrate that the majority of the evaluated parameters did not change during or after the surgery. The base excess did not change during the surgery; however, it was different from the normality average, and the renal clearance collected after two hours of surgery revealed bigger than the normal parameters; so it is possible to suggest that the orthognathic surgery under hypotension causes some negative effect in the renal function of the patients, although light. More studies with a bigger sample and different evaluations are necessary to clarify these possible effects. / Mestre
499

Systèmes injectables à libération prolongée de principe actif à partir de matériaux biocompatibles / Injectable systems for the controlled release of drug from biodegradable materials

Duffau, Emilie 17 December 2015 (has links)
Les systèmes à libération prolongée de principe actif constituent un enjeu thérapeutique dans le domaine pharmaceutique et vétérinaire. Ces systèmes présentent différents avantages comme une réduction de la fréquence d’administration permettant une meilleure observance du traitement ainsi qu’un apport optimisé de la dose thérapeutique. Des systèmes à base de principe actif hydrophobe, de polymère et de composé hydrosoluble, ont été élaborés selon différents procédés et ont été caractérisés. Les relations structure/fonctionnalité des différents systèmes ont été mises en évidences grâce à différentes techniques comme la spectroscopie Raman. Les structures, les mécanismes et le temps de libération de l’actif diffèrent selon la nature du polymère, la formulation et la technique de mise en forme. Ce travail fournit des éléments de compréhension et des outils méthodologiques utiles pour le développement de nouvelles formes galéniques à base de polymères biocompatibles, modulables en termes de taille, de temps de libération et de cible thérapeutique. / Controlled release systems are a therapeutic challenge in the pharmaceutical and veterinary. These systems give advantages such as reduced frequency of administration for better observance and an optimized intake of the therapeutic dose. Systems based on hydrophobic active ingredient, polymer and water soluble compound, have been developed by various methods and have been characterized. The structure / functionality have been put into evidence through various techniques such as Raman spectroscopy. The structures, mechanisms and the release time depending on the type of polymer, formulation and shaping technique. This work provides elements of understanding and useful methodological tools for the development of new formulations based on polymeric matrix system, flexible in terms of size, time of liberation and therapeutic target.
500

A feasibility trial of group cognitive analytic music therapy in secure hospital settings

Compton Dickinson, Stella J. January 2014 (has links)
There are no large-scale outcome studies of music therapy in secure hospital settings for people who have committed serious offences. These patients have a right to expect evidence-based multi-disciplinary treatment (Duggan et al. 2006); NICE (2010). Music therapy therefore should take a form which can be integrated into the treatment pathway. A single site implementation of a mixed-methods patient preference randomised controlled trial investigated the clinical effectiveness of a manualised music therapy model called Group Cognitive Analytic Music Therapy (G-CAMT). This context-specific, time limited intervention incorporates theories from Group Analysis (Foulkes 1964) and Cognitive Analytic Therapy (Ryle and Kerr 2003). The central research question was ‘Is G-CAMT feasible and effective for offenders in a secure multi-disciplinary treatment setting?’ The research process followed the Medical Research Council framework for developing and evaluating complex interventions (Campbell et al. 2000, 2007). Twenty patients were recruited; those expressing no preference were randomised to treatment or control arms. The two music therapists and the principal investigator were masked to their allocation status. Those in the treatment arm were allocated to one of two treatment groups of five, each run individually by one of the music therapists. Each group had sixteen ninety minute weekly sessions with followup at eight weeks. Treatment and control groups received standard care. The primary measure was the Person’s Relating to Others Questionnaire (Birtchnell and Evans 2004) Secondary measures were the Basic Empathy Scale (Jolliffe and Farrington 2006a), The Multi-Scale Dissociation Inventory (Briere, 2002) and an observational measure, the Chart of Interpersonal Reactions in Closed Living Environments (Blackburn and Glasgow, 1993). Quantitative data from these measures were examined for associations with qualitative data from semi-structured interviews administered to the music therapists and analyzed using Interpretative Phenomenological Analysis (Smith et.al. 2009) Findings from the results of the primary measure demonstrated statistically significant (Mann Whitney U: p<.05) reductions in favour of the treatment group compared to the control, in intrusive, restrictive and possessive behaviors and helpless or self-denigrating behaviours. There were improvements over time within the treatment group in the domains of sociability and hostility (Friedman Test :p<.04). The use of a manual was shown to help the music therapists manage the risk of violence without constraining their creativity. Two years after the end of the treatment 78% of treatment participants had moved to conditions of lower security over a mean period of 19 months compared with 66% of control subjects over a mean period of 25.5 months. The thesis concludes by situating G-CAMT amongst contemporary music therapy models.

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