900 resultados para Thermal Performance Regulation


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The increasing demand for electrical energy and the difficulties involved in installing new transmission lines presents a global challenge. Transmission line cables need to conduct more current, which creates the problem of excessive cable sag and limits the distance between towers. Therefore, it is necessary to develop new cables that have low thermal expansion coefficients, low densities, and high resistance to mechanical stress and corrosion. Continuous fiber-reinforced polymers are now widely used in many industries, including electrical utilities, and provide properties that are superior to those of traditional ACSR (aluminum conductor steel reinforced) cables. Although composite core cables show good performance in terms of corrosion, the contact of carbon fibers with aluminum promotes galvanic corrosion, which compromises mechanical performance. In this work, three different fiber coatings were tested (phenol formaldehyde resin, epoxy-based resin, and epoxy resin with polyester braiding), with measurements of the galvanic current. The use of epoxy resin combined with polyester braiding provided the best inhibition of galvanic corrosion. Investigation of thermal stability revealed that use of phenol formaldehyde resin resulted in a higher glass transition temperature. On the other hand, a post-cure process applied to epoxy-based resin enabled it to achieve glass transition temperatures of up to 200 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Work on Pt-Sn-C catalysts for ethanol oxidation showed that a thermal treatment at moderate temperatures leads to a significant increase in activity. The best activity was observed for Pt3Sn1 thermally treated at 200 degrees C and ascribed to a Pt3Sn1 phase plus a cleaning effect. However, electronic effects may be very important and these were not evaluated in the Pt3Sn1 phase. Therefore, in this work we investigated the effect of the degree of alloy on the electronic structure of Pt3Sn1 electrocatalysts by performing electrochemical in situ X-ray absorption (XAS) experiments in the Pt L-III XANES region. Overall, the results show that although the occupancy of the Pt 5d band depends on the degree of alloy other factors, such as the presence of tin oxides/hydroxides in the materials, have to be considered to understand the performance of the DEFC.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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In tropical climates the heat is one of the major constraints to production of broilers and is responsible for inducing a high mortality, especially in the finishing phase. Thus, the objective of this study was to compare the thermal conditioning early (TC) and feed formulation using dietary electrolytes (DE). Therefore, the electrolyte balance of K+Na-Cl was set at 350 mEq/kg and electrolyte ratio (K+Cl)/Na) in the 3:1 program PPFR (http://www.fmva.unesp.br/ppfr). A total of 300 Cobb 500 1-dold male broiler chicks was randomly allocated to 24 floor pens with six replicates per treatment in a 2x2 factorial arrangement (with and without TC and with and without DE). Dietary treatments consisted: (T1) a traditional diet without TC; (T2) traditional diet with TC; (T3) with the application of dietary electrolyte and without TC and (T4) application of dietary electrolyte with TC. The thermal conditioning was conducted at 5 d of age (36°C for 24 h), only half of the batch (150 birds). After this period, all birds were transferred to boxes of 1.5 x3m (12 birds / box), with wood shavings reused as litter. Chicks were exposed to acute stress (36°C) for 8 h at the age 36, in all treatments, being electronically monitored the temperature and humidity of the microclimate of the birds. Feed and water were provided ad libitum, even during periods of stress. Were measured performance data (weight gain, feed intake and feed conversion) and mortality rate. The early thermal conditioning (T2) and effect of dietary electrolytes (T3) were effective to minimize the mortality of broilers subjected to acute heat stress with a significant difference (P<0.05), without prejudice on broiler performance. The results also showed that there was a more favorable effect when applied dietary electrolytes and thermal conditioning simultaneously (treatment T4). However, for the treatment none of these strategies has been applied (T1), the mortality rate was 83% over that in which they were applied (T4). It was concluded from this study that both techniques: the thermal conditioning early as the dietary electrolytes are efficacious in minimize the damaging effects caused by heat broiler.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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There are many mango cultivars available in different regions. It is about time we analysed their productive behavior in these areas, as well as their phenological performance. This study aimed to evaluate: phenological cycles, thermal time and growth curves of mango fruit cultivars in subtropical conditions. For this study we used the following cultivars: Espada Vermelha, Keitt and Palmer. All the experiments were done at UNESP experimental farm in Sao Manuel (SP), during the agricultural cycle from 2012 to 2013. It was selected 15 branches in each plant, which provided 150 per cultivar. It was determined the number of days of phenological cycles of flowering to fruit ripening, as well as the total number of days to flowering and harvesting. The thermal time was evaluated to each phenological cycle and expressed in accumulation of degree-days. The measurement of the longitudinal diameters (LD) and transverse diameters (TD) of the fruitwere performed in a 12 day’s intervals, from the tenth day after the flowers anthesis, to evaluate the growth curve. Based on the data, it was found that Keitt cultivar requires more days for the fruit to reach physiological maturity and greater accumulation of degree-days to complete its production cycle. The growth curves of the three varieties of fruits have a simple sigmoidal model in function of the days after anthesis.

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The purpose of this study was to investigate the effectiveness of implementing the Self-Regulated Strategy Development (SRSD) model of instruction (Graham & Harris, 2005; Harris & Graham, 1996) on the writing skills and writing self-regulation, attitudes, self-efficacy, and knowledge of 6 first grade students. A multiple-baseline design across participants with multiple probes (Kazdin, 2010) was used to test the effectiveness of the SRSD instructional intervention. Each participant was taught an SRSD story writing strategy as well as self-regulation strategies. All students wrote stories in response to picture prompts during the baseline, instruction, independent performance, and maintenance phases. Stories were assessed for essential story components, length, and overall quality. All participants also completed a writing attitude scale, a writing self-efficacy scale, and participated in brief interviews during the baseline and independent performance phases. Results indicated that SRSD can be beneficial for average first grade writers. Participants wrote stories that contained more essential components, were longer, and of better quality after SRSD instruction. Participants also showed some improvement in writing self-efficacy from pre- to post-instruction. All of the students maintained positive writing attitudes throughout the study.

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This paper describes a CMOS implementation of a linear voltage regulator (LVR) used to power up implanted physiological signal systems, as it is the case of a wireless blood pressure biosensor. The topology is based on a classical structure of a linear low-dropout regulator. The circuit is powered up from an RF link, thus characterizing a passive radio frequency identification (RFID) tag. The LVR was designed to meet important features such as low power consumption and small silicon area, without the need for any external discrete components. The low power operation represents an essential condition to avoid a high-energy RF link, thus minimizing the transmitted power and therefore minimizing the thermal effects on the patient's tissues. The project was implemented in a 0.35-mu m CMOS process, and the prototypes were tested to validate the overall performance. The LVR output is regulated at 1 V and supplies a maximum load current of 0.5 mA at 37 degrees C. The load regulation is 13 mV/mA, and the line regulation is 39 mV/V. The LVR total power consumption is 1.2 mW.

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A wealth of evidence indicates that the dorsal raphe nucleus (DR) is not a homogenous structure, but an aggregate of distinctive populations of neurons that may differ anatomically, neurochemically and functionally. Other findings suggest that serotonergic neurons within the mid-caudal and caudal part of the DR are involved in anxiety processing while those within the lateral wings (IwDR) and ventrolateral periaqueductal gray (vIPAG) are responsive to panic-evoking stimuli/situations. However, no study to date has directly compared the activity of 5-HT and non-5HT neurons within different subnuclei of the DR following the expression of anxiety- and panic-related defensive responses. In the present investigation, the number of doubly immunostained cells for Fos protein and tryptophan hydroxylase, a marker of serotonergic neurons, was assessed within the rat DR, median raphe nucleus (MRN) and PAG following inhibitory avoidance and escape performance in the elevated T-maze, behaviors associated with anxiety and panic, respectively. Inhibitory avoidance, but not escape, significantly increased the number of Fos-expressing serotonergic neurons within the mid-caudal part of the dorsal subnucleus, caudal and interfascicular subnuclei of the DR and in the MRN. Escape, on the other hand, caused a marked increase in the activity of non-5HT cells within the IwDR, vIPAG, dorsolateral and dorsomedial columns of the PAG. These results strongly corroborate the view that different subsets of neurons in the DR are activated by anxiety- and panic-relevant stimuli/situations, with important implications for the understanding of the pathophysiology of generalized anxiety and panic disorders. (C) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

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The purpose of this study was to assess the effect of training load regulation, using the CMJ at the beginning of the session, on the total plyometric training load and the vertical jump performance. 44 males were divided into 4 groups: No Regulation Group (nRG), Regulation Group (RG), Yoked Group (YG) and Control Group (CG). The nRG received 6 weeks of plyometric training, with no adjustment in training load. The RG underwent the same training; however, the training load was adjusted according to the CMJ performance at the beginning of each session. The adjustment made in RG was replicated for the volunteers from the corresponding quartile in the YG, with no consideration given to the YG participant's condition at the beginning of its session. At the end of the training, the CMJ and SJ performance of all of the participants was reassessed. The total training load was significantly lower (p=0.036; ES=0.82) in the RG and the YG (1905 +/- 37 jumps) compared to the nRG (1926 +/- 0 jumps). The enhancement in vertical jump performance was significant for the groups that underwent the training (p<0.001). Vertical jump performance, performed at the beginning of the session, as a tool to regulate the training load resulted in a decrease of the total training load, without decreasing the long-term effects on vertical jump performance.

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Soybean (Glycine max (Merrill) L) contains high content of aglycone isoflavones, as well as glucoside and malonylconjugates. In this work, the content of isoflavones in defatted soy flour was determined by reversed-phase high-performance liquid chromatography (RPHPLC) after alcoholic extraction in methanol/water mixture in the ratio 80:20 (v/v). It was observed that the heating treatment transformed the malonylglucosides into glucoside isoflavones. After heat treatment at 121 degrees C for 30 min, nearly all malonylisoflavones were converted into glucoside, but acetylisoflavones were not detected via RPHPLC analysis. Electrospray ionization mass spectrometry confirmed the presence of malonylisoflavones in heat-treated defatted soy flour by direct infusion analysis. (c) 2012 Elsevier Ltd. All rights reserved.

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The biological characteristics of Telenomus remus Nixon, 1937 (Hymenoptera: Platygastridae) on eggs of Spodoptera albula (Walker, 1857); S. cosmioides Walker 1858, S. eridania (Cramer, 1782); and S. frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) were evaluated under different temperatures (19, 22, 25, 28, 31, and 34 degrees C +/- 1 degrees C). The duration of the T remus egg-to-adult period on eggs of all four Spodoptera species and the longevity of adults of T. remus were both inversely proportional to the increase in temperature. Parasitoid emergence was higher than 80% at temperatures from 19 to 28 degrees C when the parasitoid was reared on eggs of S. eridania and S. frugiperda. Differently, when the parasitoid was reared on eggs of S. albula and S. cosmioides, T. remus emergence at rates of 80% or higher just occurred from 22 to 25 degrees C and at 22 degrees C, respectively. At 34 degrees C, this parameter was lower than 30% for T reams reared in all hosts. The sex ratio was 64-86% females, except for T. remus in S. cosmioides eggs at 34 C, in which temperature it was 39%. The estimated thermal requirements of T. remus, for the thermal constant (K) and the base temperature (T(base)), were: 125.39 DD and 15.139 degrees C; 125.56 DD and 14.912 degrees C; 142.98 DD and 14.197 degrees C; and 149.16 DD and 13.846 degrees C, for S. cosmioides, S. frugiperda, S. albula, and S. eridania, respectively. In general, T. remus showed good parasitism potential on all the hosts, although eggs of S. frugiperda, S. eridania, and S. albula proved to be the most suitable for mass rearing of T reams in the laboratory. Eggs of S. cosmioides are less suitable because of the lower parasitoid emergence observed at most of the temperatures with exception of 22 degrees C.