Estimulação transcraniana por corrente contínua e a flutuação de força em idosas durante exercício isométrico

The fluctuacion force has been increasingly used in studies with elderly as a good predictor of performance and functionality of the motor. However, most analyzes the fluctuation of force in one session. Thus, identifying the minimum amount of sessions needed for familiarization with the fluctuation strength in isometric exercise become relevant. Furthermore, to investigate the effects of applying transcranial direct current stimulation (tDCS) associated with regular exercise on rates fluctuation task force is extremely important. In the first experiment, volunteers were subjected to a protocol marked by a familiarization session to establish the parameters of VCM and eight sessions with intensity of 30% MVC in office. It was observed that two familiarization sessions are required so there is a fluctuation stabilizing force. In experiment II, subjects performed an isometric contraction before and after applying tDCS (cathode, anode and sham) applied to M1. ETCC anodic effectively contributed to reducing the fluctuation of force during isometric exercise in the elderly, while the cathodic caused the increased levels of strength fluctuation. It was concluded that there is a need to implement a familiarization protocol with at least two sessions to avoid possible misunderstandings of measurements in tests of fluctuacion force. Besides that tDCS interfered with the behavior of the oscillations of force, with cathodic promoting increased fluctuation strength and anodic contributed to greater stability, demonstrating the potential of this technique neuromodulation associated with exercise as rehabilitation tools

A influência da estimulação transcrâniana por corrente contínua nos parâmetros de dano muscular induzido pelo exercício

A estimulação transcraniana por corrente contínua (ETCC) é uma técnica não invasiva que apresenta características anti-fadigante e analgésica. Com o objetivo de testar seus efeitos sobre a diminuição da força e do aparecimento da dor muscular de início tardio (DMIT), apresentados após um evento de dano muscular induzido pelo exercício (DMIE), foi utilizado um estudo clínico de caráter experimental, controlado, randomizado e duplo-cego. A amostra foi composta por 24 jovens do sexo masculino, aparentemente saudáveis (19,7±1,8 anos; 23,6±3,65 IMC), os quais foram alocada, de forma aleatória e estratificada, nos seguintes grupos: G1: grupo controle; G2: grupo de estimulação após o dano e G3: grupo com estimulação antes e após o dano muscular. Os dados foram submetidos à estatística descritiva e análise de variância ANOVA, adotando-se um nível de significância de 5%. O aumento nos níveis séricos de CK (56.18%) e LDH (24,15%) comprovou a ocorrência do DMIE. Em contrapartida, após a análise de variância para comparação dos tratamentos aplicados, pode-se observar que não houve diferenças significativas nos níveis de CK (p= 0,3514) e força muscular (p= 0,9702). A DMIT transcorreu como esperado, mas sem diferença significativa entre os grupos (p= 0,4861). Estes dados demonstraram que a ETCC não foi capaz de modular a DMIT e a diminuição da força muscular após o DMIE em jovens aparentemente saudáveis

Efeito da estimulação transcraniana por corrente contínua anódica sobre o controle do movimento em para-halterofilistas

Introduction: The sport practiced by people with disabilities has been growing in recent years. Consequently, advances in assessment and training methods have emerged. However, the paralympic sport keeps in tow these advances, with few specific studies that consider disability as intervening factor. The transcranial direct current stimulation (tDCS) is a technique that has proven to be capable of modulating brain function. Studies show beneficial effects of tDCS on muscle strength, power and fatigue during exercise. Objective: Investigate de the effect of tDCS on movement control in para-powerlifters. Methods: Eight subjects underwent two sessions of motion capture, which previously applied the anodic tDCS or sham sessions in the cerebellum. Three movements were performed with increasing load between 90-95% of 1MR. The movements were recorded by an 10 infrared cameras system which reconstructed the 3D trajectory of markers placed on the bar. Results: There have been changes between the anodic and sham conditions over bar level (initial, final, maximum during the eccentric and concentric phase) and in the difference between the final and initial bar level. Moreover, there was difference in bar level (final and during the eccentric phase) comparing athletes amputees and les autres. Conclusion: The findings of this study suggest that tDCS applied prior to the exercise over the cerebellum in para-powerlifters acts differently according to disability

Arranjo de antenas de microfita com substrato anisotrópico com patch supercondutor e aplicações em nanotecnologia

The main objective in this work is the analysis of resonance frequency microstrip structures with glass fiber and electromagnetic band gap (EBG/PBG) substrate and analysis of microstrip antennas with rectangular patch of superconductor of high critical temperature (HTS). In this work was used the superconductors YBCO (critical temperature of 90K), SnBaCaCuOy (critical temperature of 160K), and Sn5InCa2Ba4Cu10Oy (critical temperature of 212K) with results in Gigahertz and Terahertz. Was used microstrip antennas arrays planar and linear phase and linear phase planar with patch with superconductor. It presents a study of the major theories that explain superconductivity. In phase arrays were obtained the factors arrays for such configurations, and the criteria of phase and spacing between the elements compound in the array, which were examined in order to get a main lobe with high directivity and high gain. In the analysis we used the method of Transverse Transmission Line (TTL) used in domain of the Fourier Transform (FTD). The LTT is a full wave method, which obtains the electromagnetic field in terms of the components transverse of the structure. The addition of superconductive patch is made using the boundary condition resistive complex. Results are obtained resonance frequency as a function of the parameters of the antenna, radiation patterns of the E and H Planes, for the phase antenna arrays in linear and planar configurations, for different values of the phase and the spacing between elements

Aplicações de arranjos de antenas de microfita com patch supercondutor

This work has as main objective the study of arrays of microstrip antennas with superconductor rectangular patch. The phases and the radiation patterns are analyzed. A study of the main theories is presented that explain the microscopic and macroscopic phenomena of superconductivity. The BCS, London equations and the Two Fluid Model, are theories used in the applications of superconductors, at the microstrip antennas and antennas arrays. Phase Arrangements will be analyzed in linear and planar configurations. The arrangement factors of these configurations are obtained, and the phase criteria and the spacing between the elements, are examined in order to minimize losses in the superconductor, compared with normal conductors. The new rectangular patch antenna, consist of a superconducting material, with the critical temperature of 233 K, whose formula is Tl5Ba4Ca2Cu9Oy, is analyzed by the method of the Transverse nTransmission Line (TTL), developed by H. C. C. Fernandes, applied in the Fourier Transform Domain (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of the transverse components of the structure. The inclusion of superconducting patch is made using the complex resistive boundary condition, using the impedance of the superconductor in the Dyadic Green function, in the structure. Results are obtained from the resonance frequency depending on the parameters of the antenna using superconducting material, radiation patterns in E-Plane and H -Plane, the phased antennas array in linear and planar configurations, for different values of phase angles and different spacing between the elements

Identificação de uma planta de corrente de um motor de indução utilizando redes de base radial

The present work describes the use of a mathematical tool to solve problems arising from control theory, including the identification, analysis of the phase portrait and stability, as well as the temporal evolution of the plant s current induction motor. The system identification is an area of mathematical modeling that has as its objective the study of techniques which can determine a dynamic model in representing a real system. The tool used in the identification and analysis of nonlinear dynamical system is the Radial Basis Function (RBF). The process or plant that is used has a mathematical model unknown, but belongs to a particular class that contains an internal dynamics that can be modeled.Will be presented as contributions to the analysis of asymptotic stability of the RBF. The identification using radial basis function is demonstrated through computer simulations from a real data set obtained from the plant

Antenas de microfita com patch supercondutor a 212 K

This work has as main objective to study the application of microstrip antennas with patch and use of superconducting arrays of planar and linear phase. Was presented a study of the main theories that explain clearly the superconductivity. The BCS theory, Equations of London and the Two Fluid Model are theories that supported the implementation of the superconducting microstrip antennas. Arrangements phase was analyzed in linear and planar configuration of its antennas are reported factors such arrays to settings and criteria of phase and the spacing between the elements that make the arrayst was reviewed in order to minimize losses due to secondary lobes. The antenna used has a rectangular patch Sn5InCa2Ba4Cu10Oy the superconducting material was analyzed by the method of Transverse Transmission Line (TTL) applied in the field of Fourier transform (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of cross-cutting components of the structure. The inclusion of superconducting patch is made using the boundary condition, complex resistive. Are obtained when the resonant frequency depending on the parameters of the antenna, radiation pattern of E-Plan and H-Plan for the M-phase arrangements of antennas in the linear and planar configurations for different values of phase and spacing between the elements.

Análise de antenas de microfita com patches circulares sobre substratos anisotrópicos usando o método dos potenciais de Hertz

This work consists on the theoretical and numerical analysis of some properties of circular microstrip patch antennas on isotropic and uniaxial anisotropic substrates. For this purpose, a full wave analysis is performed, using Hertz Vector Potentials method in the Hankel Transform domain. In the numerical analysis, the moment method is also used in order to determine some characteristics of the antenna, such as: resonant frequency and radiation pattern. The definition of Hertz potentials in the Hankel domain is used in association with Maxwell´s equations and the boundary conditions of the structures to obtain the Green´s functions, relating the components of the current density on the patch and the tangential electric field components. Then, the Galerkin method is used to generate a matrix equation whose nontrivial solution is the complex resonant frequency of the structure. In the analysis, a microstrip antenna with only one isotropic dielectric layer is initially considered. For this structure, the effect of using superconductor patches is also analyzed. An analysis of a circular microstrip antenna on an uniaxial anisotropic dielectric layer is performed, using the Hertz vector potentials oriented along the optical axis of the material, that is perpendicular to the microstrip ground plane. Afterwards, the circular microstrip antenna using two uniaxial anisotropic dielectric layers is investigated, considering the particular case in which the inferior layer is filled by air. In this study, numerical results for resonant frequency and radiation pattern for circular microstrip antennas on isotropic and uniaxial anisotropic substrates are presented and compared with measured and calculated results found in the literature

Influência da corrente de pulso, do tempo de pulso e diâmetro de gota sobre a estabilidade da transferência metálica no processo MIG-P

To obtain a process stability and a quality weld bead it is necessary an adequate parameters set: base current and time, pulse current and pulse time, because these influence the mode of metal transfer and the weld quality in the MIG-P, sometimes requiring special sources with synergistic modes with external control for this stability. This work aims to analyze and compare the effects of pulse parameters and droplet size in arc stability in MIG-P, four packets of pulse parameters were analysed: Ip = 160 A, tp = 5.7 ms; Ip = 300 A and tp = 2 ms, Ip = 350 A, tp = 1.2 ms and Ip = 350 A, tp = 0.8 ms. Each was analyzed with three different drop diameters: drop with the same diameter of the wire electrode; droplet diameter larger drop smaller than the diameter of the wire electrode. For purposes of comparison the same was determined relation between the average current and welding speed was determined generating a constant (Im / Vs = K) for all parameters. Welding in flat plate by simple deposition for the MIG-P with a distance beak contact number (DBCP) constant was perfomed subsequently making up welding in flat plate by simple deposition with an inclination of 10 degrees to vary the DBCP, where by assessment on how the MIG-P behaved in such a situation was possible, in addition to evaluating the MIG-P with adaptive control, in order to maintain a constant arc stability. Also high speed recording synchronized with acquiring current x voltage (oscillogram) was executed for better interpretation of the transfer mechanism and better evaluation in regard to the study of the stability of the process. It is concluded that parameters 3 and 4 exhibited greater versatility; diameters drop equal to or slightly less than the diameter of the wire exhibited better stability due to their higher frequency of detachment, and the detachment of the drop base does not harm the maintenance the height of the arc

Uso de metamaterial em antenas de microfita com supercondutor

Metamaterials have attracted great attention in recent decades, due to their electromagnetic properties which are not found in nature. Since metamaterials are now synthesized by the insertion of artificially manufactured inclusions in a specified homogeneous medium, it became possible for the researcher to work with a wide collection of independent parameters, for example, the electromagnetic properties of the material. An investigation of the properties of ring resonators was performed as well as those of metamaterials. A study of the major theories that clearly explain superconductivity was presented. The BCS theory, London Equations and the Two-Fluid Model are theories that support the application of superconducting microstrip antennas. Therefore, this thesis presents theoretical, numerical and experimental-computational analysis using full-wave formalism, through the application of the Transverse Transmission Line – LTT method applied in the Fourier Transform Domain (FTD). The LTT is a full wave method, which, as a rule, obtains the electromagnetic fields in terms of the transverse components of the structure. The inclusion of the superconducting patch is performed using the complex resistive boundary condition. Results of resonant frequency as a function of antenna parameters are obtained. To validate the analysis, computer programs were developed using Fortran, simulations were created using the commercial software, with curves being drawn using commercial software and MATLAB, in addition to comparing the conventional patch with the superconductor as well as comparing a metamaterial substrate with a conventional one, joining the substrate with the patch, observing what improves on both cas

Estudo da densidade de corrente crítica para reversão da magnetização de nanoelementos ferromagnéticos

The discovery that a spin-polarized current is capable of exerting a torque in a ferromagnetic material, through spin transfer, might provide the development of new technological devices that store information via the direction of magnetization. The reduction of current density to revert the magnetization is a primary issue to potential applications on non volatile random access memories (MRAM). We report a theorical study of the dipolar and shape effects on the critical current density for reversal of magnetization, via spin transfer torque (STT), on ferromagnetic nanoelements. The nanostructured system consists on a reference layer, in which the current will be spin-polarized, and a free layer of magnetization reversal. We observed considerable changes on the critical current density as a function of the element’s reversion layer thickness (t = 1.0 nm, 1.5 nm, 2.0 nm e 2.5 nm) and geometry (circular and elliptical), the material kind of the system free layer (Iron and Permalloy) and according to the orientation of the magnetization and the spin polarization with the major axis. We show that the critical current density may be reduced about 50% by reducing the Fe free layer thickness and around 75% when we change the saturation magnetization of circular nanoelements with 2.5 nm of thickness. We still observed a reduction as much as 90% on the current density of reversion for thin nanoelements magnetized along the minor axis direction, using in-plane spin polarization parallel to the magnetization.

Estimulação transcraniana por corrente contínua (ETCC) sobre o córtex motor na modulação autonômica em pessoas com lesão medular com diferentes graus e níveis de lesão

Introduction: Transcranial Direct Current Stimulation (tDCS) has been used in studies for the treatment of chronic pain, but their effects on the autonomic nervous system (ANS) are non-existent. Therefore, the need for studies is of fundamental importance, as these individuals have autonomic imbalance and the intensity of this is dependent on the degree and level of injury. Objective: We investigated the effect of tDCS on the ANS in people with spinal cord injury (SCI) with different degrees and levels of injury. Methods: Randomized, placebo-controlled, double-blind, applied anodal tDCS or sham on the primary motor cortex (M1), bilaterally. The subjects (lower incomplete injury, n = 7; lower complete injury, n = 9; and high complete thoracic injury, n = 3) visited the laboratory three times and received active or sham tDCS for 13min. The heart rate variability (HRV) was measured before, during and after stimulation and analyzed the variables LF, HF and LF / HF. Results: The tDCS modulated the ANS in different ways among the groups. In individuals with SCI high complete thoracic the tDCS did not change the HRV. However, for individuals with SCI low incomplete, tDCS changed the HRV in order to increase sympathetic (LF, p = 0.046) and reduced parasympathetic (HF, p = 0.046). For individuals SCI low complete to tDCS changed the HRV reduction sympathetic (LF, p = 0.017) and increased parasympathetic (HF, p = 0.017). Conclusions: The present study suggests that anodal tDCS applied on the motor cortex bilaterally could modulate the ANS balance in people with spinal cord injury and that this effect is dependent on the degree and level of injury.

Recuperação avançada de óleos pesados em poços fraturados utilizando aquecimento eletromagnético indutivo

The success achieved by thermal methods of recovery, in heavy oils, prompted the emergence of studies on the use of electromagnetic waves as heat generating sources in oil reservoirs. Thus, this generation is achieved by three types of different processes according to the frequency range used. They are: the electromagnetic induction heating, the resistive and the dielectric, also known as radiation. This study was based on computer simulations in oil reservoirs with characteristics similar to those found in the sedimentary basins of the Brazilian Northeast. All cases studied were simulated using the software STARS, CMG (Computer Group, version 2012.10 Modeling). Some simulations took into account the inclusion of electrically sensitive particles in certain sectors of the reservoir model studied by fracturing. The purpose of this work is the use of the electromagnetic induction heating as a recovery method of heavy oil, to check the influence of these aforementioned particles on the reservoir model used. Comparative analyses were made involving electromagnetic induction heating, the operation of hydraulic fracturing and the injection of water to the different situations of the reservoir model studied. It was found that fracturing the injection well in order that the electromagnetic heating occurs in the same well where there is water injection, there was a considerable increase in the recovery factor and in the cumulative oil production in relation to the models in which hydraulic fracturing occurred in the production well and water injection in the injection well. This is due to the generation of steam in situ in the reservoir.

A Geração de inovação na carcinicultura do RN: Uma análise a partir da imersão social

This dissertation examines the organizational innovation as a nonlinear process, which occurs in a social and political context and, therefore, socially immersed. Examines the case of shrimp in the state of RN, starting from the following problem: although the norteriograndense shrimp occupies the largest producer of farmed shrimp from Brazil, has a series of bottlenecks concerning the generation of industry innovation, concerning the social relationships and policies between the various actors in the network, whether private or public, and its consequences in terms of opportunity and limits generated for the innovative dynamics. The objective of the research is to understand how the social embeddedness of political actors affects norteriograndense shrimp within the context of structural relations, the industry generation of innovation, throughout its technological trajectory . The approach of social embeddedness balances atomised perspectives, undersocialized and oversocialized, of economic action, considering both the human capacity to act as sources of constraint, whose mechanisms are analyzed the structural and political. In methodological terms this is a case study, analyzed from the research literature, documentary and experimental. Primary data were collected through semi-structured interviews and analyzed in depth by the technique of content analysis. Was adopted a longitudinal approach, seeking to understand the phenomenon from the perspective of the subjects, describing it in an inductive process of investigation. After characterizing the sector and defining their technological trajectory, the analysis of the results followed its four stages: (1) Introduction of Technology: 1973-1980, (2) Intensification of Research: 1981-1991, (3) Technological Adaptation, 1992 -2003, (4) Technological Crisis: 2004-2009. A cross-sectional analysis along the evolutionary trajectory revealed the character of structural changes and policies over time, and implications on the generating process of innovation. Note that, the technological limit to which the sector reached requires changes in technology standards, but is more likely that the potiguar shrimp is entering a new phase of his career in technology rather than a new technological paradigm

Aqui o nativo é o caboclo... : O processo de construção da identidade cabocla em Mirandas/RN

Ce travaille de dissertation (Master) est le résultat de trois ans de travaille auprès de Mirandas, endroit situé à 22 kilomètres de la ville de Caraúbas, région ouest de l Etat du Rio Grande do Norte. Pendant cette période, on a compris que les habitants de Mirandas se identifient et sont identifiés pour les autres comme des caboclos , catégorie de classification que dans le discours courant, soit à Mirandas ou dans la siège de la municipalité, a des rapports avec la vision que les tous premiers habitants de Mirandas sont venus de la ville du Cabo , dans l Etat de Pernambuco. Et pourtant ; l usage qu a été fait de cette version a fini pour cacher des éléments qui ont défini l identité de Mirandas, tel comme la probable descendance indigène que parfois est actionnée dans les narratives qui montrent des rapports entre les portugais et des femmes indiens qu ont été pris à casco de cavalo (cheval) . (MACÊDO, 2010; CAVIGNAC, 2003). Donc, cette ethnographie porte à la lumière des éléments que sont utilisés pour les mirandenses pour définir leur identité. Cette identité peut être bien visualisé a partir des éléments que les caboclos font des signes diacritiques (BARTH, 1998; OLIVEIRA, 1976), bien comme des rapports établis entre les habitants de Mirandas et ces de Caraúbas. Des rapports qui ont rendu possible les manifestations d affinité et de conflits et que, donc, nous aide à entendre comme cette identité se réactualise dans ces rapports d union et opposition que les mirandenses construisent avec les caraubenses. Cela arrive dans les rapports territoriaux, économiques et de façon plus marquante, dans les rapports religieux.