75 resultados para Loggers


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The collection of wind speed time series by means of digital data loggers occurs in many domains, including civil engineering, environmental sciences and wind turbine technology. Since averaging intervals are often significantly larger than typical system time scales, the information lost has to be recovered in order to reconstruct the true dynamics of the system. In the present work we present a simple algorithm capable of generating a real-time wind speed time series from data logger records containing the average, maximum, and minimum values of the wind speed in a fixed interval, as well as the standard deviation. The signal is generated from a generalized random Fourier series. The spectrum can be matched to any desired theoretical or measured frequency distribution. Extreme values are specified through a postprocessing step based on the concept of constrained simulation. Applications of the algorithm to 10-min wind speed records logged at a test site at 60 m height above the ground show that the recorded 10-min values can be reproduced by the simulated time series to a high degree of accuracy.

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Hybrid Photovoltaic Thermal (PVT) collectors are an emerging technology that combines PV and solar thermal systems in a single solar collector producing heat and electricity simultaneously. The focus of this thesis work is to evaluate the performance of unglazed open loop PVT air system integrated on a garage roof in Borlänge. As it is thought to have a significant potential for preheating ventilation of the building and improving the PV modules electrical efficiency. The performance evaluation is important to optimize the cooling strategy of the collector in order to enhance its electrical efficiency and maximize the production of thermal energy. The evaluation process involves monitoring the electrical and thermal energies for a certain period of time and investigating the cooling effect on the performance through controlling the air mass flow provided by a variable speed fan connected to the collector by an air distribution duct. The distribution duct transfers the heated outlet air from the collector to inside the building. The PVT air collector consists of 34 Solibro CIGS type PV modules (115 Wp for each module) which are roof integrated and have replaced the traditional roof material. The collector is oriented toward the south-west with a tilt of 29 ᵒ. The collector consists of 17 parallel air ducts formed between the PV modules and the insulated roof surface. Each air duct has a depth of 0.05 m, length of 2.38 m and width of 2.38 m. The air ducts are connected to each other through holes. The monitoring system is based on using T-type thermocouples to measure the relevant temperatures, air sensor to measure the air mass flow. These parameters are needed to calculate the thermal energy. The monitoring system contains also voltage dividers to measure the PV modules voltage and shunt resistance to measure the PV current, and AC energy meters which are needed to calculate the produced electrical energy. All signals recorded from the thermocouples, voltage dividers and shunt resistances are connected to data loggers. The strategy of cooling in this work was based on switching the fan on, only when the difference between the air duct temperature (under the middle of top of PV column) and the room temperature becomes higher than 5 °C. This strategy was effective in term of avoiding high electrical consumption by the fan, and it is recommended for further development. The temperature difference of 5 °C is the minimum value to compensate the heat losses in the collecting duct and distribution duct. The PVT air collector has an area of (Ac=32 m2), and air mass flow of 0.002 kg/s m2. The nominal output power of the collector is 4 kWppv (34 CIGS modules with 115 Wppvfor each module). The collector produces thermal output energy of 6.88 kWth/day (0.21 kWth/m2 day) and an electrical output energy of 13.46 kWhel/day (0.42 kWhel/m2 day) with cooling case. The PVT air collector has a daily thermal energy yield of 1.72 kWhth/kWppv, and a daily PV electrical energy yield of 3.36 kWhel /kWppv. The fan energy requirement in this case was 0.18 kWh/day which is very small compared to the electrical energy generated by the PV collector. The obtained thermal efficiency was 8 % which is small compared to the results reported in literature for PVT air collectors. The small thermal efficiency was due to small operating air mass flow. Therefore, the study suggests increasing the air mass flow by a factor of 25. The electrical efficiency was fluctuating around 14 %, which is higher than the theoretical efficiency of the PV modules, and this discrepancy was due to the poor method of recording the solar irradiance in the location. Due to shading effect, it was better to use more than one pyranometer.

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As condições de ambiente térmico e aéreo, no interior de instalações para animais, alteram-se durante o dia, devido à influência do ambiente externo. Para que análises estatísticas e geoestatísticas sejam representativas, uma grande quantidade de pontos distribuídos espacialmente na área da instalação deve ser monitorada. Este trabalho propõe que a variação no tempo das variáveis ambientais de interesse para a produção animal, monitoradas no interior de instalações para animais, pode ser modelada com precisão a partir de registros discretos no tempo. O objetivo deste trabalho foi desenvolver um método numérico para corrigir as variações temporais dessas variáveis ambientais, transformando os dados para que tais observações independam do tempo gasto durante a aferição. O método proposto aproximou os valores registrados com retardos de tempo aos esperados no exato momento de interesse, caso os dados fossem medidos simultaneamente neste momento em todos os pontos distribuídos espacialmente. O modelo de correção numérica para variáveis ambientais foi validado para o parâmetro ambiental temperatura do ar, sendo que os valores corrigidos pelo método não diferiram pelo teste Tukey, a 5% de probabilidade dos valores reais registrados por meio de dataloggers.

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

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Non-audio signals have been recorded in the flash ROM memory of a portable MP3 player, in WAV format file, to examine the possibility of using these cheap and small instruments as general-purpose portable data loggers. A 1200-Hz FM carrier modulated by the non-audio signal has replaced the microphone signal, while using the REC operating mode of the MP3 player, which triggers the voice recording function. The signal recovery was carried out by a PLL-based FM demodulator whose input is the FM signal captured in the coil leads of the MP3 player's earphone. Sinusoidal and electrocardiogram signals have been used in the system evaluation. Although the quality of low frequency signals needs improvement, overall the results indicate the viability of the proposal. Suggestions are made for improvements and extensions of the work.

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The Locus coeruleus (LC) has been suggested as a CO2 chemoreceptor site in mammals. In the present study, we assessed the role of LC noradrenergic neurons in the cardiorespiratory and thermal responses to hypercapnia. To selectively destroy LC noradrenergic neurons, we administered 6-hydroxydopamine (6-OHDA) bilaterally into the LC of male Wistar rats. Control animals had vehicle (ascorbic acid) injected (sham group) into the LC. Pulmonary ventilation (plethysmograph), mean arterial pressure (MAP), heart rate (HR), and body core temperature (T-c, data loggers) were measured followed by 60 min of hypercapnic exposure (7% CO2 in air). To verify the correct placement and effectiveness of the chemical lesions, tyrosine hydroxylase immunoreactivity was performed. Hypercapnia caused an increase in pulmonary ventilation in all groups, which resulted from increases in respiratory frequency and tidal volume (V-T) in sham-operated and 6-OHDA-lesioned groups. The hypercapnic ventilatory response was significantly decreased in 6-OHDA-lesioned rats compared with sham group. This difference was due to a decreased V-T in 6-OHDA rats. LC chemical lesion or hypercapnia did not affect MAP, HR, and T-c. Thus, we conclude that LC noradrenergic neurons modulate hypercapnic ventilatory response but play no role in cardiovascular and thermal regulation under resting conditions.

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Objetivou-se, com este trabalho, avaliar a influência das variáveis ambientais nos níveis de ruídos emitidos por suínos e quantificar as faixas em dB comparativamente às condições de conforto térmico estabelecidas pela literatura. O experimento foi conduzido em câmara climática, onde foram alojados cinco leitões em fase de creche, submetidos à variação na temperatura ambiente de 20°C a 38°C e umidade relativa de 50% a 80%. Decibelímetros foram instalados para o registro dos níveis de ruídos e sensores dataloggers para os dados de temperatura e umidade relativa. O nível de atividade foi utilizado para quantificar a movimentação dos animais por intermédio de análise de imagens. Análises de correlação e regressão foram aplicadas nos dados para análise estatística. As variáveis ambientais influenciam na emissão de ruídos pelos leitões quando expostos a diferentes condições térmicas. Os níveis de ruídos foram estabelecidos em faixas de acordo com a condição térmica a que animais foram submetidos. Para a condição de conforto (20 a 23°C), níveis de ruídos na faixa de 70 a 75dB; condição de alerta (23 a 30°C), níveis de ruídos na faixa de 60 a 70dB e para condição de estresse térmico (acima de 30°C), na faixa de 55 a 60dB.

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The medullary raphé is an important component of the central respiratory network, playing a key role in CO2 central chemoreception. However, its participation in hypoxic ventilatory responses is less understood. In the present study, we assessed the role of nucleus raphé obscurus (ROb), and specifically 5-HT neurons confined in the ROb, on ventilatory and thermoregulatory responses to hypoxia. Chemical lesions of the ROb were performed using either ibotenic acid (non-specific lesion; control animals received PBS) or anti-SERT-SAP (5-HT specific lesion; control animals received IgG-SAP). Ventilation (VE; whole body plethysmograph) and body temperature (Tb; data loggers) were measured during normoxia (21% O2, N2 balance) and hypoxia exposure (7% O2, N2 balance, 1h) in conscious adult rats. Ibotenic acid or anti-SERT-SAP-induced lesions did not affect baseline values of VE and Tb. Similarly, both lesion procedures did not alter the ventilatory or thermoregulatory responses to hypoxia. Although evidence in the literature suggests a role of the rostral medullary raphé in hypoxic ventilatory responses, under the present experimental conditions our data indicate that caudal medullary raphé (ROb) and its 5-HT neurons neither participate in the tonic maintenance of breathing nor in the ventilatory and thermal responses to hypoxia. © 2013 Elsevier B.V.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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O trabalho analisa o efeito do inoculante bacteriano em silagens de capim Elefante (Pennisetum purpureum cv. Roxo) em concentrações crescentes de inclusão. O experimento realizado no Departamento de Zootecnia da Universidade Federal Rural da Amazônia (UFRA) consistiu em cinco tratamentos e quatro repetições (Controle, LP/PC4, LP/PC5, LP/PC55, LP/PC6) que se encontravam em baldes plásticos com tampa e vedada com fita plástica, onde foram pesadas semanalmente ate o final do experimento. Foram realizadas análises químicas e bromatológicas da forragem e das silagens onde foi retirada amostras no momento da abertura (Dia 0) e no ultimo dia de aerobiose (Dia 10), alem da contagem de fungos e leveduras nas silagens para avaliar a qualidade do material ensilado. No período de aerobiose foi inseridos data loggers nos silos para a observar a temperatura na pós fermentação. Não houve diferença significativa na composição química das silagens e na contagem de fungos, recuperação de matéria seca, mas houve diferença na contagem de leveduras no momento de abertura. O tratamento de maior dosagem do inoculante ajudou teve maior tempo para a quebra da estabilidade aeróbia, quando comparado com o tratamento Controle. A utilização do inoculante bacteriano Lactobacillus plantarum e Pediococcus acidilactici pode ser recomendável, pois melhorou a estabilidade, mas em termos de perfil fermentativo e composição bromatológica, seus efeitos foram mínimos.

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Esta tese analisa a prática violenta da pistolagem no Estado do Pará e discute a seletividade da justiça penal paraense em face de tais conflitos que culminam sempre com a eliminação física das vítimas ou resultam na vida em suspenso dos “jurados para morrer”, pessoas envolvidas com a questão da terra no Pará (agentes de pastorais, esposas e filhos de lideranças rurais assassinadas, entre outros) e que sofrem constantes ameaças de morte por parte de fazendeiros, grileiros, madeireiros e pistoleiros. Desenvolve-se a partir de duas grandes “frentes de trabalho”: a primeira lança luzes sobre a violência embutida na pistolagem, para daí compreender de que modo as relações sociais entre pistoleiros, mandantes, intermediários e vítimas dão vida à prática dos crimes de mando; a segunda, por seu turno, consiste em discutir a seletividade das agências de poder envolvidas no processo de criminalização dos estratos sociais mais débeis, de um lado, e imunização das ações delituosas dos segmentos mais poderosos da sociedade, de outro. Essa segunda frente de trabalho procura explicar a impunidade nos assassinatos sob encomenda promovida pelo sistema penal paraense, aqui entendido como um conjunto de agências de poder, tais como a Polícia Civil, o Ministério Público e o Poder Judiciário.

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This experiment evaluated temperament, vaginal temperature, and plasma cortisol in beef cows from wolf-naive and wolf-experienced origins that were subjected to a simulated wolf encounter. Multiparous, pregnant, nonlactating Angus-crossbreed cows from the Eastern Oregon Agricultural Research Center located near Burns, OR (CON; n = 50), and from a commercial operation near Council, ID (WLF; n = 50), were used. To date, grey wolves are not present around Burns, OR, and thus CON were naive to wolves. Conversely, wolves are present around Council, ID, and WLF cows were selected from a herd that had experienced multiple confirmed wolf-predation episodes from 2008 to 2012. Following a 50-d commingling and adaptation period, CON and WLF cows were ranked by temperament, BW, and BCS and allocated to 5 groups (d 0; 10 CON and 10 WLF cows/group). Groups were individually subjected to the experimental procedures on d 2 (n = 3) and d 3 (n = 2). Before the simulated wolf encounter, cow temperament was assessed and blood samples and vaginal temperatures (using intravaginal data loggers) were collected (presimulation assessments). Cows were then sorted by origin, moved to 2 adjacent drylot pens (10 WLF and 10 CON cows/pen), and subjected to a simulated wolf encounter event for 20 min, which consisted of 1) cotton plugs saturated with wolf urine attached to the drylot fence, 2) continuous reproduction of wolf howls, and 3) 3 leashed dogs that were walked along the fence perimeter. Thereafter, WLF and CON cows were commingled and returned to the handling facility for postsimulation assessments, which were conducted immediately after exposure to wolf-urine-saturated cotton plugs, wolf howl reproduction, and 20-s exposure to the 3 dogs while being restrained in a squeeze chute. Chute score, temperament score, and plasma cortisol concentration increased (P <= 0.01) from pre- to postsimulation assessment in WLF but did not change in CON cows (P >= 0.19). Exit velocity decreased (P = 0.01) from pre-to postsimulation assessment in CON but did not change (P = 0.79) in WLF cows. In addition, WLF cows had a greater (P = 0.03) increase in temperature from pre-to postsimulation assessments compared with CON cows. In conclusion, the simulated wolf encounter increased excitability and fear-related physiological stress responses in cows that originated from a wolf-experienced herd but not in cows that originated from a wolf-naive herd.

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Individuals of the species Turdus leucomelas are adapted to live in environments already modified by humans, thus obtaining reproductive success in their nesting in vegetation, as well as built their nests in human buildings. Nests found in buildings are often less camouflaged, making them more exposed to predators compared to nests built in vegetation; however the nests built buildings are common, indicating a possible advantage associated with these nests. By means of this idea if was assumed that a possible advantage to this construction in buildings is linked to a change in variation in the internal temperature of the nest during incubation and development of pups until they leave their nests. Accordingly, with the aid of iButtons and TidBits (temperature data loggers), the present study aimed to analyze the influence of the nesting site on how the temperature is kept, and how it changes in the microenvironment in which the nest is inserted, indicating potential benefits associated with that choice. In the samples found with the vegetation, temperature data showed a pattern of temperature of the microenvironment of the nests is not very stable, varying with ambient temperature, whereas in the samples found with the human constructions, the temperature data showed a pattern of temperature microenvironment nests more stable for a long time. When comparing the two environments which they settled nests, as well as the different times of day (daytime and nighttime), how the temperature was kept and pattern of change within the nest was significantly different (F=43.85, p<0.001), with higher and more constant internal temperatures in nests installed in construction, compared to vegetation. When observing periods of the day, it was found that in both environments the temperature inside the nest reached higher values and higher than the environment at night, coinciding with the rest of the female at night. Data may suggest changes in the...

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)