Navegando por Data de Publicação, começando com "2015-02-11"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 7 de 7

Efeitos da hibridização e do campo magnético externo na supercondutividade de modelos multibandas
(Universidade Federal de São Carlos, 2015-02-11) Silva, Márcio Gomes da; Padilha, Igor Tavares; https://lattes.cnpq.br/4605895860650284; Sousa, José Ricardo de; https://lattes.cnpq.br/3871066069541626; https://lattes.cnpq.br/2363782297790054
Superconductivity one of the most intriguing physical phenomena has been extensively studied due to their potential for technological applications. Despite advances in research in physics there is still no complete theory to explain the phenomenon. We study the behavior of a superconducting system described by a multiband model. We consider the interband interaction, i.e., the interaction is between the fermions with dierent masses at dierent bands, under the inuence hybridization. Also, we study the intraband interaction with hybridization and external magnetic eld. Using the method of Green's functions of Zubarev, we calculate the superconducting order parameters with intra-and interbanda interaction at zero temperature, ie, T = 0, and for dierent temperatures of zero. Interband interaction obtained in the superconducting order parameter as a function of temperature and hybridization V. The phase diagram T versus V was also obtained. The superconducting properties, such as free energy, entropy and specic heat, were also determined in the intraband interaction. Initially, we calculate the superconducting properties in zero eld, ie, for H = 0, then we consider the presence of external magnetic eld H nonzero. obtained an implicit equation that relates the magnetic field, temperature and hybridization, which allowed us to obtain the phase diagram T versus T and T versus V . Our results show that both the hybridization V , as the external magnetic field H acts at the expense of superconductivity by suppressing it. We noticed also, and conrmed by other studies, that the intraband interaction, we have only second order transition, since the interaction interbanda, we obtained a superconducting tricritico point where we encounter a line first with a second order. Based on these results, we conclude that left a signicant contribution to research in superconductivity.
Propriedades ópticas da alumina anódica porosa e o efeito do guia de onda
(Universidade Federal de São Carlos, 2015-02-11) Carossi, Lory Cantelli; Trivinho-Strixino, Francisco; https://lattes.cnpq.br/9740223649776400; https://lattes.cnpq.br/8708083193756979
Nanoporous anodic alumina films (NAA) may present different behavior to reflectance and photoluminescence techniques, with Fabry-Pérot interferences and waveguide properties. This phenomenon makes possible the use of NAA as transducer signal in optical sensors. In this work, we investigated how the pre-treatment, the number of steps of anodizing, the anodizing electrolyte mode and temperature affect electrochemical characteristics, morphological and optical mainly NAA. As a result, it was noticeable that the realization of electropolishing is necessary for both the NAA with good regularity as to make it possible to obtain a spectrum with the Fabry-Pérot interference. If the fabrication of NAA is done in two steps, it is possible to obtain reflectance spectra and luminescence fringed with better amplitudes, areas and heights. Regarding the anodizing mode, both the NAA anodized in galvanostatic how potentiostatic showed similar morphologies and spectra with fringes, but the interferences were better defined when the galvanostatic mode was performed. Regarding the temperature, it was noticeable that the change of this parameter leads influences the porous oxide thickness. The spectrum of the luminescence and reflectance increasing the electrolyte temperature caused an increase in interference. However, the range and resolution of interference decreased with increasing temperature. The oxide thicknesses were estimated by energy variation (?E), graph slope between order and 1/? and fast Fourier transform (FFT) techniques. The ratio of film thickness and pore diameter (L/dp) was performed to validate the NAA films with better waveguides property. Moreover, the surface composition analysis of NAA films anodized in phosphoric acid, oxalic acid and mixtures thereof by backscattering spectroscopy Rutherford (RBS) was performed. From simulations it was possible to note that the amount of carbon in the porous oxide structure is practically zero, which may indicate that the origin of the luminescence is related to the presence of more centers F.
Investigação empírica sobre o relacionamento entre Seis Sigma e prioridades competitivas
(Universidade Federal de São Carlos, 2015-02-11) Silva, Brena Bezerra; Mergulhão, Ricardo Coser; https://lattes.cnpq.br/0598720328915137; https://lattes.cnpq.br/6895269832274542; Caten, Carla Schwengber Ten; http://lattes.cnpq.br/2048340677678671; Martins, Roberto Antonio; http://lattes.cnpq.br/3518820028045730; Carvalho, Marly Monteiro de; http://lattes.cnpq.br/1386670520349091
Six Sigma is an improvement program adopted by many companies to improve their business performance. However, some studies indicate that the relationship between Six Sigma and competitive advantage is not that clear. In this context, the main objective of this dissertation is to identify the relationship between the implementation factors of Six Sigma and competitive priorities in companies that operating in Brazil. As steps, this research conducted bibliometric analysis, content analysis, descriptive analysis and factor analysis. The research investigated 45 companies, through a survey, to find the relationship between Six Sigma implementation factors with competitive priorities in Brazil. Implantation factors identified were: "collect and availability of data", "previous infrastructure", "performance indicators", "goal setting", "capacity for change", "top management involvement" and "statistical thinking" . The results indicate the implementation factors that have relationship with competitive priorities are "collection and availability of data," "previous infrastructure" and "capacity for change". In addition to this result, it was found that the dimensions of competitive priorities that have relationship with implementation factors are "reliability" and "flexibility".
Avaliação da limitação ventilatória e dos índices da potência circulatória e ventilatória de pacientes com doença arterial coronariana
(Universidade Federal de São Carlos, 2015-02-11) Castello-Simões, Viviane; Catai, Aparecida Maria; https://lattes.cnpq.br/5801652590531684; https://lattes.cnpq.br/8573168804662842
This thesis consisted of two studies described below. The Study 1 aimed to investigate if expiratory flow limitation (EFL) present at moderate intensity exercise in subjects following myocardial infarction (MI) (as shown in a previous study conducted in our laboratory) already manifests in those with stable coronary artery disease (CAD). Forty-one men aged 40-65 years were allocated into four different groups: 1) stable coronary artery disease (SCADG) (n=9), 2) recent myocardial infarction (RMIG) (n=8), 3) late myocardial infarction group (LMIG) (n=12), and 4) health control group (CG) (n=12). Two cardiopulmonary exercise testing (CPX) at constant workload (moderate and high intensity) were applied and EFL was evaluated by exercise flow-volume loops. We observed that during moderate intensity exercise the RMIG and LMIG presented with a significantly higher number of subjects with EFL compared to the CG, while no significant difference was observed among groups at high intensity exercise. Regarding the degree of expiratory flow limitation, the RMIG and LMIG showed significantly higher values at moderate intensity exercise when compared to the CG. At high intensity exercise, significantly higher values for the degree of expiratory flow limitation were observed only in the LMIG compared to the CG. We concluded that an EFL was only present in MI groups (recent and late) during moderate intensity exercise; whereas at high intensity exercise all groups presented EFL. Thus, EFL observed at moderate intensity exercise in both MI groups may be linked to the consequences of event and not to CAD. Following, the Study II aimed to investigate the indexes of circulatory (CP) and ventilatory power (VP) in CAD patients. Eighty-seven men were studied aged 40-65 years, being 42 subjects in the CAD group and 45 in the CG. CPX was performed on a treadmill and the following measures were obtained: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic BP x peak HR), 5) peak oxygen pulse = (peak VO2/peak HR), 6) the oxygen uptake efficiency (OUES), 7) the carbon dioxide production efficiency (VE/VCO2 slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/VE/VCO2 slope). The CAD group had significantly lower values for peak VO2, peak HR, peak systolic BP, peak rate-pressure product, peak oxygen pulse, the OUES, CP and VP and significantly higher values for peak diastolic BP and the VE/VCO2 slope compared to the CG. Furthermore, a stepwise regression analysis showed that CP was influenced by the group and VP was influenced both by group and by number of vessels with stenosis after treatment. Given the findings, we concluded that the indices of CP and VP were lower in men with CAD compared to CG. Thus, both studies brought important findings related to the responses of the cardiovascular, pulmonary and musculoskeletal systems of patients with CAD during physical exercise, bringing many contributions to clinical practice and assisting in the prescription of exercise training.
Diretrizes para práticas de qualidade nas diferentes etapas do processo de produção de lajes alveolares de concreto protendido
(Universidade Federal de São Carlos, 2015-02-11) Direitinho, Romão Manuel Leitão Carrapato; Ferreira, Marcelo de Araújo; https://lattes.cnpq.br/4199122391532470; https://lattes.cnpq.br/7860027005969838
Industrialization in the Brazilian construction industry is a growing trend, while the need to fulfill tight deadlines increases as well as labor costs, being mandatory to keep quality standards and the competitiveness of enterprises. In this sense, the precast concrete is an increasingly valid solution.Among him, the floor in hollow core slabs of prestressed concrete, as part of a constructive system of open cycle. This kind of floor can be applied in various sectors and to the most varied typologies. The ABNT NBR 14861: 2011 is still quite new, and includes a set of quality control care for the implementation of hollow core slabs in prestressed concrete, although it is felt that the respective degree of detail could be improved.On the other hand, the standard has just focusing on such care specially concerning project and product approaches, and not so much with a process approach. There is also some difficulty in the flow of information and knowledge between the academy and industry in general. The dissertation provides a detailed analysis of production of hollow core slabs in prestressed concrete, according to the respective processes, since the inputs enter factories, until the structural cover is performed on site. The macro-production process is divided into several stages of lower complexity, and contains a detailed listing of quality control procedures required, in a simple and practical manner. Thus, can be established a kind of a guide to good quality control practices for the production of LACP, which is then systematized through a set of checklists. The establishment of guidelines for good quality control practices in the various LACP production stages is the main goal of this research. In order to accomplish this goal have been made extensive literature reviews on Quality and hollow core slabs, using theses, dissertations, monographs, papers, magazines and electronic sites. Were also made visits to a factory which produces equipment for production of hollow core slabs, and to a plant producing LACP, in the interior of the state of São Paulo, during which were made unstructured interviews with their maximum management responsables. Finally it was made an essentially qualitative comparative analysis of the data collected and the quality control procedures of the ABNT NBR 14861: 2011. It is intended, with the checklists contained in the dissertation, to ensure production, transportation to site, installation of LACP and execution of the respective structural wrapper, with the highest quality consistency that is possible, thereby minimizing to minimum the existence of possible non-compliances.
Televisão e formação na era digital: um exame crítico das pretensões formativas do programa Salto para o futuro
(Universidade Federal de São Carlos, 2015-02-11) Bet, David Silva; Zuin, Antônio Álvaro Soares; https://lattes.cnpq.br/5543562307373287; https://lattes.cnpq.br/2205364981301004
The sea of real-time images, the instant access to latest news and the contemporary demand that praises and requires the so-called positive social values pass by the exhausting and brutalized affirmation process of this established culture. Television, in this regard, can become a powerful vehicle of ideology exchange, due to its global reach. However, television could be an education tool, provided that its content and form are properly prepared to this end. Following these discussions, and guided by readings of texts by Theodor W. Adorno and Herbert Marcuse, we propose the analysis of the content of educational television program, transmitted by television and Internet, Salto para o Futuro (Leap into the Future, in Portuguese), on TV Escola (Ministry of Education), as well as the observation of technical changes, in other words, the way the information are structured and transmitted by this mean of communication, born as a result of the digital technology emergence. Analysis has demonstrated that there is Form predominance over Content since the analyzed episode articulates its messages via TV newscast format, which beforehand tends to ensure spectators adhesion by its serious aspect. Another important aspect comes from the presence of a discursive pattern in the messages: the hero specialist teacher cliché who in the future, by magically jumping over the historical and material contradictions in the present days, will save education by using technology. Finally, we conclude that the general format of the Salto Para o Futuro TV show (Leap into the Future, in Portuguese) does not allow the offer for explanatory information. However, through the radical change of its dynamics - disruption of the formal hierarchy by dialectic relation tension of the Formation concept - the program could envision an educational horizon: an aid to reveal the mechanisms that prevent the refusal and resistance of what is presented as if it were real.
Síndrome da fragilidade e complexidade do controle postural baseado na análise de entropia
(Universidade Federal de São Carlos, 2015-02-11) Carmelo, Verena de Vassimon Barroso; Takahashi, Anielle Cristhine de Medeiros; https://lattes.cnpq.br/8336705133403404; https://lattes.cnpq.br/7496298739077529
Frailty Syndrome represents a clinical state of vulnerability, resulting from decline of resilience and physiological reserves and it is associated with adverse outcomes such as falls. Thus, the aim of this study was to evaluate the complexity of oscillations of center of pressure (CoP)in the frailty syndrome before and after a functional task. CoP oscillations in the anteroposterior (AP) and mediolateral (ML) direction was obtained by a force platform in a quite-standing position, 30 seconds before and after standing from a chair. Additionally, it was performed the timed up and Go test (TUGT). The complexity of CoP oscillations was analyzed by entropies: corrected approximate (CApEn), sample (SampEn) and conditional (CI), as well as their normalized versions (NCApEn, NSampEn and NCI). Linear data of CoP oscillations were obtained by amplitude, RMS and the total average speed (TAS). Repeated measures two way analysis of variance was carried out to evaluate the effects of groups, time (pre and post-functional task) and the interaction between them for complexity variables. Forty-two elderly were evaluated, divided into groups: nonfrail (n = 15; 75.6± 4.2 years), prefrail (n = 15; 78.9± 6.8 years) and frail (n = 12; 73.0±19.2 years). In the AP direction, only nonfrail and pre-frail elderly subjects showed significant reduction after functional task in CApEn, NCApEn, SampEn, NSampEn and NCI and significant increase in RMS. In the ML direction, only nonfrail showed significant reduction in complexity after functional activity in CApEn, NCApEn, SampEn and NSampEn. All groups showed significant increase in the RMS after the functional activity in the ML direction. A significant correlation was observed between the performance on the TUGT and the complexity indices (CApEn and NCApEn) in post- functional task only for nonfrail subjects in the AP direction. Then, after a voluntary disturbance on balance, frail elderly subjects show no variation in CoP oscillations entropy indexes suggesting a deficit in the postural control, possibly because the basal values are already reduced.