1000 resultados para Electrical behaviors


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Thermal behavior of polyaniline(PAn) doped with kinds of inorganic or organic acids under desired atmosphere were studied by TG,DSC and in-situ electrical conductivity measurements. The reason for the thermal stability of electrical conductivity of doped PAn was discussed.

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The microwave and electrical applications of some important conducting polymers are analyzed in this investigation.One of the major drawbacks of conducting polymers is their poor processability,and a solution to overcome this is sought in this investigation.Conducting polymer thermoplastic composites were prepared by the insitu polymerization method to improve the extent of miscibility probably to a semi IPN level.The attractive features of the conducting composite developed are excellent processability,good microwave and electrical conductivity,good microwave absorption,load sensitivity and satisfactory mechanical properties.The composite shows typical frequency selective microwave absorption and refelection behaviors.

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Ein Drittel des weltweiten gesamten Energiebedarfs wird durch Gebäude verbraucht. Um diesen Energiebedarf teilweise zu decken, den erheblichen Energieverbrauch zu reduzieren und weiterhin andere Gebäudefunktionen beizubehalten, ist Gebäudeintegrierte Photovoltaik (BIPV) eine der am besten geeigneten Lösungen für die Gebäudenanwendung. Im Bezug auf eine Vielzahl von Gestalltungsmöglichkeiten, sind die Randbedingungen der BIPV-Anwendungen eindeutig anders im Vergleich zu Standard-PV-Anwendungen, insbesondere bezüglich der Betriebstemperatur. Bisher gab es nicht viele Informationen zu den relevanten thermischen Auswirkungen auf die entsprechenden elektrischen Eigenschaften zusammen mit thermischen und mechanischen relevanten Gebäudenfunktionen. Die meisten Hersteller übernehmen diese Eigenschaften von entsprechenden PV-Modulen und konventionellen Bauprodukten Normen, die zur ungenauen System- und Gebäudeplanungen führen. Deshalb ist die Untersuchung des thermischen Einflusses auf elektrische, thermische sowie mechanische Eigenschaften das Hauptziel der vorliegenden Arbeit. Zunächst wird das Temperatur-Model mit dem Power-Balance-Konzept erstellt. Unter Berücksichtigung der variablen Installationsmöglichkeiten und Konfigurationen des Moduls wird das Model auf Basis dynamischer und stationär Eigenschaften entwickelt. Im Hinblick auf die dynamische Simulation können der Energieertrag und Leistung zusammen mit der thermischen Gebäudesimulation in Echtzeit simuliert werden. Für stationäre Simulationen können die relevanten Gebäudefunktionen von BIPV-Modulen sowohl im Sommer als auch im Winter simuliert werden. Basierend auf unterschiedlichen thermischen und mechanischen Last-Szenarien wurde darüber hinaus das mechanische Model zusammen mit Variationen von Belastungsdauer, Montagesystem und Verkapselungsmaterialien entwickelt. Um die Temperatur- und Mechanik-Modelle zu validieren, wurden die verschiedenen Prüfeinrichtungen zusammen mit neuen Testmethoden entwickelt. Bei Verwendung der Prüfanlage „PV variable mounting system“ und „mechanical testing equipment“ werden zudem die verschiedenen Szenarien von Montagesystemen, Modul-Konfigurationen und mechanischen Belastungen emuliert. Mit der neuen Testmethode „back-bias current concept“ können zum einen die solare Einstrahlung und bestimmte Betriebstemperaturen eingestellt werden. Darüber hinaus wurden mit den eingangs erwähnten validierten Modellen das jeweilige elektrische, thermische und mechanische Verhalten auf andere Konfigurationen bewertet. Zum Abschluss wird die Anwendung von Software-Tools bei PV-Herstellern im Hinblick auf die entsprechenden Modellentwicklungen thematisiert.

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Objective To measure cutaneous electrical nociceptive thresholds in relation to known thermal and mechanical stimulation for nociceptive threshold detection in cats.Study design Prospective, blinded, randomized cross-over study with 1-week washout interval.Animals Eight adult cats [bodyweight 5.1 +/- 1.8 kg (mean + SD)].Methods Mechanical nociceptive thresholds were tested using a step-wise manual inflation of a modified blood pressure bladder attached to the cat's thoracic limb. Thermal nociceptive thresholds were measured by increasing the temperature of a probe placed on the thorax. The electrical nociceptive threshold was tested using an escalating current from a constant current generator passed between electrodes placed on the thoracic region. A positive response (threshold) was recorded when cats displayed any or all of the following behaviors: leg shake, head turn, avoidance, or vocalization. Four baseline readings were performed before intramuscular injection of meperidine (5 mg kg(-1)) or an equal volume of saline. Threshold recordings with each modality were made at 15, 30, 45, 60, 90, and 120 minutes post-injection. Data were analyzed using ANOVA and paired t-tests (significance at p < 0.05).Results There were no significant changes in thermal, mechanical, or electrical thresholds after saline. Thermal thresholds increased at 15-60 minutes (p < 0.01) and mechanical threshold increased at 30 and 45 minutes after meperidine (p < 0.05). Maximum thermal threshold was +4.1 +/- 0.3 degrees C above baseline at 15 minutes while maximum mechanical threshold was 296 +/- 265 mmHg above baseline at 30 minutes after meperidine. Electrical thresholds following meperidine were not significantly different than baseline (p > 0.05). Thermal and electrical thresholds after meperidine were significantly higher than saline at 30 and 45 minutes (p < 0.05), and at 120 minutes (p < 0.05), respectively. Mechanical thresholds were significantly higher than saline treatment at 30 minutes (p <= 0.05).Conclusion and clinical relevance Electrical stimulation did not detect meperidine analgesia whereas both thermal and mechanical thresholds changed after meperidine administration in cats.

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

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Several pharmacological targets have been proposed as modulators of panic-like reactions. However, interest should be given to other potential therapeutic neurochemical agents. Recent attention has been given to the potential anxiolytic properties of cannabidiol, because of its complex actions on the endocannabinoid system together with its effects on other neurotransmitter systems. The aim of this study was to investigate the effects of cannabidiol on innate fear-related behaviors evoked by a prey vs predator paradigm. Male Swiss mice were submitted to habituation in an arena containing a burrow and subsequently pre-treated with intraperitoneal administrations of vehicle or cannabidiol. A constrictor snake was placed inside the arena, and defensive and non-defensive behaviors were recorded. Cannabidiol caused a clear anti-aversive effect, decreasing explosive escape and defensive immobility behaviors outside and inside the burrow. These results show that cannabidiol modulates defensive behaviors evoked by the presence of threatening stimuli, even in a potentially safe environment following a fear response, suggesting a panicolytic effect. Neuropsychopharmacology (2012) 37, 412-421; doi:10.1038/npp.2011.188; published online 14 September 2011

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Solar Decathlon Europe (SDE) is an international multidisciplinary competition in which 20 universityteams build and operate energy-efficient solar-powered houses. The aim of SDE is not only scientificbut also educational and divulgative, making visitors to understand the problems presented by realengineering applications and architecture. From a research perspective, the energy data gathered dur-ing the competition constitutes a very promising information for the analysis and understanding of thephotovoltaic systems, grid structures, energy balances and energy efficiency of the set of houses. Thisarticle focuses on the electrical energy components of SDE competition, the energy performance of thehouses and the strategies and behaviors followed by the teams. The rules evaluate the houses? electricalenergy self-sufficiency by looking at the electricity autonomy in terms of aggregated electrical energybalance; the temporary generation-consumption profile pattern correlation; and the use of electricityper measurable area. Although the houses are evaluated under the same climatological and consump-tion conditions, production results are very different due to the specific engineering solutions (differentelectrical topologies, presence or absence of batteries, diverse photovoltaic module solutions, etc.)

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With the growing body of research on traumatic brain injury and spinal cord injury, computational neuroscience has recently focused its modeling efforts on neuronal functional deficits following mechanical loading. However, in most of these efforts, cell damage is generally only characterized by purely mechanistic criteria, function of quantities such as stress, strain or their corresponding rates. The modeling of functional deficits in neurites as a consequence of macroscopic mechanical insults has been rarely explored. In particular, a quantitative mechanically based model of electrophysiological impairment in neuronal cells has only very recently been proposed (Jerusalem et al., 2013). In this paper, we present the implementation details of Neurite: the finite difference parallel program used in this reference. Following the application of a macroscopic strain at a given strain rate produced by a mechanical insult, Neurite is able to simulate the resulting neuronal electrical signal propagation, and thus the corresponding functional deficits. The simulation of the coupled mechanical and electrophysiological behaviors requires computational expensive calculations that increase in complexity as the network of the simulated cells grows. The solvers implemented in Neurite-explicit and implicit-were therefore parallelized using graphics processing units in order to reduce the burden of the simulation costs of large scale scenarios. Cable Theory and Hodgkin-Huxley models were implemented to account for the electrophysiological passive and active regions of a neurite, respectively, whereas a coupled mechanical model accounting for the neurite mechanical behavior within its surrounding medium was adopted as a link between lectrophysiology and mechanics (Jerusalem et al., 2013). This paper provides the details of the parallel implementation of Neurite, along with three different application examples: a long myelinated axon, a segmented dendritic tree, and a damaged axon. The capabilities of the program to deal with large scale scenarios, segmented neuronal structures, and functional deficits under mechanical loading are specifically highlighted.

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There is increasing interest in the role the environment plays in shaping the dietary behavior of youth, particularly in the context of obesity prevention. An overview of environmental factors associated with obesity-related dietary behaviors among youth is needed to inform the development of interventions. A systematic review of observational studies on environmental correlates of energy, fat, fruit/ vegetable, snack/fast food and soft drink intakes in children (4–12 years) and adolescents (13–18 years) was conducted. The results were summarized using the analysis grid for environments linked to obesity. The 58 papers reviewed mostly focused on sociocultural and economical–environmental factors at the household level. The most consistent associations were found between parental intake and children’s fat, fruit/vegetable intakes, parent and sibling intake with adolescent’s energy and fat intakes and parental education with adolescent’s fruit/ vegetable intake. A less consistent but positive association was found for availability and accessibility on children’s fruit/vegetable intake. Environmental factors are predominantly studied at the household level and focus on sociocultural and economic aspects. Most consistent associations were found for parental influences (parental intake and education).More studies examining environmental factors using longitudinal study designs and validated measures are needed for solid evidence to inform interventions.