8 resultados para Leilão duplo contínuo

em Universidade Federal do Rio Grande do Norte(UFRN)


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Conselho Nacional de Desenvolvimento Científico e Tecnológico

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PURPOSE: To evaluate the capacity of clofazimine (CFZ) to control cutaneous activity of systemic lupus erythematosus (SLE), compared with chloroquine diphosphate (CDP). METHODS: A prospective, randomized, controlled, double blind clinical trial was carried out in thirty-three patients with SLE and cutaneous lesions (malar rash and/or discoid lupus and/or subacute cutaneous lupus), after approval by the respective Ethics Committee. Sixteen patients received clofazimine - 100mg/day (CFZ group) and 17 received chloroquine diphosphate - 250mg/day (CDP group), during six months. Both groups applied broad-spectrum sunscreens twice a day. The dose of prednisone was kept stable during the study. Cutaneous lesions were evaluated by 2 blinded observers and photographed at baseline and at months 1, 2, 4 and 6. RESULTS: Thirty-three patients began and 27 completed the 6 months of treatment. The groups were homogeneous and comparable in terms of demographic and clinical characteristics. Five CFZ-patients and one CDP-patients dropped out due to severe flare of disease requiring other treatment. At the end of the study, 12 CFZ-patients (75%) and 14 CDP-patients (82,4%) presented complete or near-complete remission of skin lesions; intention-to-treat analysis showed no significant difference in the response rates between groups. Side effects in both groups were frequent, but patients didn t have to discontinue the drugs. CONCLUSIONS: Clofazimine and chloroquine were effective in controlling cutaneous lesions in SLE patients

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This work presents a theoretical analysis and numerical and experimental results of the scattering characteristics of frequency selective surfaces, using elements of type patch perfectly conductor. The structures are composed of two frequency selective surfaces on isotropic dielectric substrates cascaded, separated by a layer of air. The analysis is performed using the method of equivalent transmission line in combination with the Galerkin method, to determine the transmission and reflection characteristics of the structures analyzed. Specifically, the analysis uses the impedance method, which models the structure by an equivalent circuit, and applies the theory of transmission lines to determine the dyadic Green's function for the cascade structure. This function relates the incident field and surface current densities. These fields are determined algebraically by means of potential incidents and the imposition of the continuity of the fields in the dielectric interfaces. The Galerkin method is applied to the numerical determination of the unknown weight coefficients and hence the unknown densities of surface currents, which are expanded in terms of known basis functions multiplied by these weight coefficients. From the determination of these functions, it becomes possible to obtain numerical scattered fields at the top and bottom of the structures and characteristics of transmission and reflection of these structures. At work, we present numerical and experimental results for the characteristics of transmission and reflection. Comparisons were made with other results presented in literature, and it was observed a good agreement in the cases presented suggestions continuity of the work are presented

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Amongst the results of the AutPoc Project - Automation of Wells, established between UFRN and Petrobras with the support of the CNPq, FINEP, CTPETRO, FUNPEC, was developed a simulator for equipped wells of oil with the method of rise for continuous gas-lift. The gas-lift is a method of rise sufficiently used in production offshore (sea production), and its basic concept is to inject gas in the deep one of the producing well of oil transform it less dense in order to facilitate its displacement since the reservoir until the surface. Based in the use of tables and equations that condense the biggest number of information on characteristics of the reservoir, the well and the valves of gas injection, it is allowed, through successive interpolations, to simulate representative curves of the physical behavior of the existing characteristic variable. With a simulator that approaches a computer of real the physical conditions of an oil well is possible to analyze peculiar behaviors with very bigger speeds, since the constants of time of the system in question well are raised e, moreover, to optimize costs with assays in field. The simulator presents great versatility, with prominance the analysis of the influence of parameters, as the static pressure, relation gas-liquid, pressure in the head of the well, BSW (Relation Basic Sediments and Water) in curves of request in deep of the well and the attainment of the curve of performance of the well where it can be simulated rules of control and otimization. In moving the rules of control, the simulator allows the use in two ways of simulation: the application of the control saw software simulated enclosed in the proper simulator, as well as the use of external controllers. This implies that the simulator can be used as tool of validation of control algorithms. Through the potentialities above cited, of course one another powerful application for the simulator appears: the didactic use of the tool. It will be possible to use it in formation courses and recycling of engineers

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The continuous gas lift method is the main artificial lifting method used in the oil industry for submarine wells, due to its robustness and the large range of flow rate that the well might operate. Nowadays, there is a huge amount of wells producing under this mechanism. This method of elevation has a slow dynamics due to the transients and a correlation between the injected gas rate and the of produced oil rate. Electronics controllers have been used to adjust many parameters of the oil wells and also to improve the efficiency of the gas lift injection system. This paper presents a intelligent control system applied to continuous gas injection in wells, based in production s rules, that has the target of keeping the wells producing during the maximum period of time, in its best operational condition, and doing automatically all necessary adjustments when occurs some disturbance in the system. The author also describes the application of the intelligent control system as a tool to control the flow pressure in the botton of the well (Pwf). In this case, the control system actuates in the surface control valve

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This study offers an analytical approach in order to provide a determination of the temperature field developed during the DC TIG welding of a thin plate of aluminum. The non-linear characteristics of the phenomenon, such as the dependence of the thermophysical and mechanical properties with temperature were considered in this study. In addition to the conductive heat exchange process, were taken into account the exchange by natural convection and radiation. A transient analysis is performed in order to obtain the temperature field as a function of time. It is also discussed a three-dimensional modeling of the heat source. The results obtained from the analytical model were be compared with the experimental ones and those available in the literature. The analytical results show a good correlation with the experimental ones available in the literature, thus proving the feasibility and efficiency of the analytical method for the simulation of the heat cycle for this welding process.

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The high-intensity interval exercise has been described as an option for increasing physical activity and its use also being suggested in the therapeutic management of many conditions such as diabetes mellitus and heart failure. However, the knowledge of its physiological effects and parameters that can assure greater safety for interval exercise prescription; especially its effect on short- and medium-term (24 hours after exercise) exercise recovery, need to be clarified. This study objective was to evaluate the effect of continuous and interval aerobic exercise on the cardiac autonomic control immediate and medium term (24 hours), by assessing heart rate variability (HRV). The present study is a randomized crossover clinical trial in which healthy young individuals with low level of physical activity had the VFC 24 hours measured by a heart rate sensor and portable accelerometer (3D eMotion HRV, Kuopio, Finland) before and after continuous aerobic exercise (60-70% HR max, 21 min.) and interval exercise (cycle 1 min. 80-90% HR max, 2 min. at 50-60% HR max, duration 21 min.). HRV was measured in the time and frequency domain and the sympathovagal balance determined by the ratio LF / HF. Nonlinear evaluation was calculated by Shannon entropy. The data demonstrated delayed heart rate recovery immediate after exercise and lower HR after 24 hours compared to pre intervention values, especially in the interval exercise group. There was a tendency to higher predominance and representatives index values of sympathetic stimulation during the day in interval exercise group; however, without statistical significance. The study results help to clarify the effects of interval exercise on the 24 hours following interval exercise, setting parameters for prescription and for further evaluation of groups with metabolic and cardiovascular diseases.

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Background: Cardiac Rehabilitation (CR) has effect on mortality in patients with heart failure (HF) chronic, and the exercise of the treatment of this patient. The most common exercise is ongoing training. Recently we have been studying the effects of interval training, but there is no consensus on the optimal dose of exercise. Objective: To evaluate the effects of interval aerobic training are superior to continuous aerobic training in patients with chronic HF. Methods: The clinical trial evaluated patients through cardiopulmonary test (CPX) and quality of life before and after the RC (3 times / 12 weeks). Patients were randomized into Group Interval Training (GTI - 85% of heart rate reserve - FCR), Continuous Training Group (GTC - 60% of HRR) and control group (CG) who received guidelines. Results: 18 patients were evaluated (mean age 44.7 ± 13.2 years and 35.2 ± 8.9% of left ventricular ejection fraction [LVEF]). Both groups were efficient to increase the peak VO2 and 15.1% (P = 0.02) in GTI and 16.1% (P = 0.01) GTC. As for the quality of life the GTI GTC showed improvement compared to the control group (P = 0.006). Hemodynamic mismatch events during the CPX were reduced after training in more GTC (patients 1 to 4) than in the GTI (5 to 3). Cardiac risk also decreased in the GTC (3 patients left the severe risk to take after training). Conclusion: Continuous training becomes more appropriate for improving fitness with little chance of developing cardiac event patients with chronic HF.