900 resultados para marca-passo artificial
IIRSA: outro passo na pilhagem, exploração e (des) integração dos povos e territórios sul-americanos
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La llamada Iniciativa para la Integración de Infraestructura Regional Suramericana (IIRSA) es un acuerdo multinacional celebrado entre los 12 países de América del Sur desde el año 2000, materializado a través de 10 ejes de comercialización orientados a la construcción de varios proyectos de infraestructura, que incluye la construcción de una enorme red de energía, de comunicación y transporte. Estos proyectos han sido financiados principalmente por los organismos multilaterales (BID, CAF, FONPLATA) profundizando la dependencia económica y política de los países involucrados, en especial mediante el aumento de la deuda externa, las empresas transnacionales garantizarán la infraestructura necesaria para la explotación más acentuada de nuestros recursos naturales y de la mano de obra barata, asegurando el abastecimiento de sus mercados. En este sentido, el discurso de crecimiento económico regional creará los mecanismos necesarios para la reproducción ampliada del sistema capitalista, mediante la promoción de la liberalización de los mercados internacionales, tales como intenta los Estados Unidos a través del Área de Libre Comercio de las Américas. En realidad, es un Desarrollo Regional de los países del Norte, un plan estratégico de ordenamiento territorial construido por transnacionales y dictado por el imperialismo de Norteamérica. Bajo la dirección del gobierno de Brasil ha sido implementado sigilosamente, para que los jefes de Estado, sin nombrarlo, ejecuten sus planes de desarrollo como parte de esta tan evidente estrategia de saqueo, entusiasmados y convencidos de que serán generosamente recompensados. Proclaman e inauguran proyectos de infraestructura que las empresas multinacionales y transnacionales consideran indispensables para el saqueo de los recursos naturales que aún quedan, después de cinco siglos de explotación continua de América Latina. En este sentido, nuestra investigación se volvió hacia el análisis de lo sector energético de lo Eje Perú-Brasil-Bolivia, por considerarlo de suma importancia para el mantenimiento de la explotación y consolidación hegemónica de las corporaciones multinacionales en América Latina
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Background: In bovines, more efficient management practices are important for maximizing profitability. In order to increase the pregnancy rates in artificial insemination (AI) programs, several hormonal protocols were developed to synchronize the follicular wave and the moment of ovulation in beef and dairy cattle. In dairy cattle, detection of estrus can be difficult due to a number of factors including the incidence of silent estrus. Hormonal treatments designed to control both luteal and follicular function has permitting efficient synchronizations of time of ovulation. Thus, the AI can be performed in a large number of animals on a fixed schedule without the need for detection of estrus. Using these management techniques, the fixed-time artificial insemination (TAI) can overcome the problem of accurate estrus detection and help in reducing the incidence of repeat breeding. In addition, with TAI in cattle operations, it is possible to facilitate management practices and commercialization, and to reduce the time and semen wasting with animals inseminated at incorrect times. The investigation of practical and efficient TAI protocols is important for reducing the labor and animal handling of TAI in dairy cattle, as well as for increasing the profitability of the cattle management system. This study was carried out in order to investigate the effectiveness of TAI in dairy heifers treated with a practical progesterone-based protocol.Materials, Methods & Results: This experiment was conducted at the university farm located in southwestern Brazil, during May 2009. Thirty-nine cycling crossbred dairy heifers were employed in this study. All animals received a single intramuscular injection of estradiol benzoate and intravaginal progesterone releasing device in a random stage of the estrous cycle (Day 0). on day 7 the animals were treated with PGF2a analogue and on day 9 the device was removed. Forty-eight hours after the device removal (day 11) a synthetic analogue of GnRH was administered and the animals were fixed-time artificially inseminated at the time of GnRH injection. The inseminations were performed using four different batches from the same Holstein bull. Among the heifers that were synchronized (87.2%), 30.8% ovulated until 24 h after TAI and 56.4% ovulated between 24 and 32 h after TAI. The conception rate was 61.5%. No effects of ovulation time in conception rates were detected. The conception rate from heifers that ovulated until 24 h after TAI was 58.3% and from heifers that ovulated between 24 and 32 h after TAI was 77.3%. The mean of ovulatory follicle in heifers that ovulated until 24 h was 14.3 mm and in heifers that ovulated between 24 and 32 h was 11.9 mm.Discussion: Taking together, the findings of the present study, along with those of others, emphasize the concept that development of practical methods for TAI offers significant advantages to dairy producers if conception rates are close or greater to those obtained after breeding at detected estrus. Thus, the results of the present study reinforce the possibility of making dairy cattle production more cost-effective using TAI. In conclusion, with the progesterone-based TAI protocol of the present experiment all synchronized animals ovulated up to 32 h after GnRH+TAI and no effects of ovulation time related to conception rate was detected. The exogenous control of luteal and follicular development facilitated the reproductive management and animal handling. Also, inseminating the heifers at the moment of GnRH injection in a progesterone-based TAI protocol is a practical strategy and provided satisfactory results regarding ovulation and conception rates in dairy heifers.
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O cultivo associado é uma alternativa para culturas de ciclo longo e propriedades com limitação de área. Todavia, para o estabelecimento de associações, há necessidade de conhecer a tolerância das espécies ao sombreamento. O trabalho objetivou avaliar o crescimento de parte aérea, partição de fotoassimilados e produção de rizomas em plantas de taro 'Japonês' cultivadas sob intensidades e períodos de sombreamento artificial. Utilizou-se o delineamento de blocos ao acaso, com 13 tratamentos e quatro repetições. Os tratamentos foram constituídos de quatro intensidades de sombreamento (controle = pleno sol; 18; 30 e 50% de sombra, mantidos durante o ciclo todo), além da implementação das intensidades de sombra de 18; 30 e 50%, em três períodos (inicial = 0 a 3; intermediário = 3 a 6 e final = 6 a 9 meses). Aos 60; 90; 120; 150; 180; 210; 240 e 270 dias após o plantio (dat), avaliou-se crescimento de planta e partição de massa entre órgãos e aos 270 dat a produção de rizomas. Plantas sob sombreamento, sobretudo nas maiores intensidades e durante o ciclo todo, apresentaram maior produção de biomassa de parte aérea e de rizomas-mãe e filhos pequenos, em detrimento de rizomas-filho grandes, médios e comerciáveis. A intensidade de 18% de sombra, durante todo o ciclo ou nos períodos inicial e intermediário, foi a que menos afetou o desenvolvimento das plantas e produção de biomassa de rizomas-filho comerciáveis.
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Artificial Intelligence techniques are applied to improve performance of a simulated oil distillation system. The chosen system was a debutanizer column. At this process, the feed, which comes to the column, is segmented by heating. The lightest components become steams, by forming the LPG (Liquefied Petroleum Gas). The others components, C5+, continue liquid. In the composition of the LPG, ideally, we have only propane and butanes, but, in practice, there are contaminants, for example, pentanes. The objective of this work is to control pentane amount in LPG, by means of intelligent set points (SP s) determination for PID controllers that are present in original instrumentation (regulatory control) of the column. A fuzzy system will be responsible for adjusting the SP's, driven by the comparison between the molar fraction of the pentane present in the output of the plant (LPG) and the desired amount. However, the molar fraction of pentane is difficult to measure on-line, due to constraints such as: long intervals of measurement, high reliability and low cost. Therefore, an inference system was used, based on a multilayer neural network, to infer the pentane molar fraction through secondary variables of the column. Finally, the results shown that the proposed control system were able to control the value of pentane molar fraction under different operational situations
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The Electrical Submersible Pump (ESP) has been one of the most appropriate solutions for lifting method in onshore and offshore applications. The typical features for this application are adverse temperature, viscosity fluids and gas environments. The difficulties in equipments maintenance and setup contributing to increasing costs of oil production in deep water, therefore, the optimization through automation can be a excellent approach for decrease costs and failures in subsurface equipment. This work describe a computer simulation related with the artificial lifting method ESP. This tool support the dynamic behavior of ESP approach, considering the source and electric energy transmission model for the motor, the electric motor model (including the thermal calculation), flow tubbing simulation, centrifugal pump behavior simulation with liquid nature effects and reservoir requirements. In addition, there are tri-dimensional animation for each ESP subsytem (transformer, motor, pump, seal, gas separator, command unit). This computer simulation propose a improvement for monitoring oil wells for maximization of well production. Currenty, the proprietaries simulators are based on specific equipments manufactures. Therefore, it is not possible simulation equipments of another manufactures. In the propose approach there are support for diverse kinds of manufactures equipments
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This study shows the implementation and the embedding of an Artificial Neural Network (ANN) in hardware, or in a programmable device, as a field programmable gate array (FPGA). This work allowed the exploration of different implementations, described in VHDL, of multilayer perceptrons ANN. Due to the parallelism inherent to ANNs, there are disadvantages in software implementations due to the sequential nature of the Von Neumann architectures. As an alternative to this problem, there is a hardware implementation that allows to exploit all the parallelism implicit in this model. Currently, there is an increase in use of FPGAs as a platform to implement neural networks in hardware, exploiting the high processing power, low cost, ease of programming and ability to reconfigure the circuit, allowing the network to adapt to different applications. Given this context, the aim is to develop arrays of neural networks in hardware, a flexible architecture, in which it is possible to add or remove neurons, and mainly, modify the network topology, in order to enable a modular network of fixed-point arithmetic in a FPGA. Five synthesis of VHDL descriptions were produced: two for the neuron with one or two entrances, and three different architectures of ANN. The descriptions of the used architectures became very modular, easily allowing the increase or decrease of the number of neurons. As a result, some complete neural networks were implemented in FPGA, in fixed-point arithmetic, with a high-capacity parallel processing
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The using of supervision systems has become more and more essential in accessing, managing and obtaining data of industrial processes, because of constant and frequent developments in industrial automation. These supervisory systems (SCADA) have been widely used in many industrial environments to store process data and to control the processes in accordance with some adopted strategy. The SCADA s control hardware is the set of equipments that execute this work. The SCADA s supervision software accesses process data through the control hardware and shows them to the users. Currently, many industrial systems adopt supervision softwares developed by the same manufacturer of the control hardware. Usually, these softwares cannot be used with other equipments made by distinct manufacturers. This work proposes an approach for developing supervisory systems able to access process information through different control hardwares. An architecture for supervisory systems is first defined, in order to guarantee efficiency in communication and data exchange. Then, the architecture is applied in a supervisory system to monitor oil wells that use distinct control hardwares. The implementation was modeled and verified by using the formal method of the Petri networks. Finally, experimental results are presented to demonstrate the applicability of the proposed solution
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This work proposes a computer simulator for sucker rod pumped vertical wells. The simulator is able to represent the dynamic behavior of the systems and the computation of several important parameters, allowing the easy visualization of several pertinent phenomena. The use of the simulator allows the execution of several tests at lower costs and shorter times, than real wells experiments. The simulation uses a model based on the dynamic behavior of the rod string. This dynamic model is represented by a second order partial differencial equation. Through this model, several common field situations can be verified. Moreover, the simulation includes 3D animations, facilitating the physical understanding of the process, due to a better visual interpretation of the phenomena. Another important characteristic is the emulation of the main sensors used in sucker rod pumping automation. The emulation of the sensors is implemented through a microcontrolled interface between the simulator and the industrial controllers. By means of this interface, the controllers interpret the simulator as a real well. A "fault module" was included in the simulator. This module incorporates the six more important faults found in sucker rod pumping. Therefore, the analysis and verification of these problems through the simulator, allows the user to identify such situations that otherwise could be observed only in the field. The simulation of these faults receives a different treatment due to the different boundary conditions imposed to the numeric solution of the problem. Possible applications of the simulator are: the design and analysis of wells, training of technicians and engineers, execution of tests in controllers and supervisory systems, and validation of control algorithms
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Este estudo teve como objetivos determinar e comparar o efeito de três dietas: Psidium guajava, Eucalyptus grandis e dieta artificial no comportamento de chamamento e no padrão temporal do comportamento de chamamento de fêmeas virgens de Thyrinteina arnobia (Stoll). Foram analisados os parâmetros: tempo médio para o início do chamamento, número médio de chamamento, tempo médio de cada chamamento e tempo médio total de chamamento. Os bioensaios relacionados ao comportamento de chamamento de fêmeas virgens foram realizados durante seis escotofases consecutivas e as observações tomadas a cada 5 min., a 22 ± 1ºC, 70 ± 5% de UR e 10h de escotofase. As fêmeas, independente da dieta analisada, apresentaram duas posições diferentes de chamamento. A maioria das fêmeas virgens iniciou o chamamento na 1ª hora da 1ª escotofase. O padrão de chamamento da fêmea individualizada foi característico de um padrão contínuo. O tipo de dieta oferecida na fase larval influenciou o início do comportamento de chamamento (pré-chamamento) e o tempo médio total de chamamento. O tipo de dieta também alterou a coloração da glândula de feromônio.
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This study aimed to achieve a better understanding about the foraging behavior of leaf-cutter ant (Atta sexdens rubropilosa Forel) workers with respect to defoliation sites in plants. To accomplish that, artificial plants 70 cm in height were prepared and divided into four levels (heights), having natural plant leaves attached to them. Evaluations during the bioassays included the number of leaves dropped by the ants, as well as the percentage of plant mass removed. In all replicates, it became evident that the most exploited plant site is the apical region, which significantly differed from other plant levels.
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The present work makes some comments on the scattered productions of Gilberto Freyre and Luís da Câmara Cascudo, in the period which includes the early years of their intellectual performance, the second decade of the twentieth century. The corpus of the research is delimited on the texts published by Gilberto Freyre, from 1918 to 1926, which were gathered in the book Tempo de aprendiz (1979), and from the ones published by Câmara Cascudo in Natal local newpapers, such as A Imprensa and A República, in 1924, 1927, 1928 and 1929. Concerning Câmara Cascudo s texts, the delimitations of these years is due to they had a relevant importance for the literary and cultural history of Rio Grande do Norte. The included discussions in these writers texts mainly happen around the modernist and regionalist ideas that happened restrictively in the Northeast region of Brazil, and are based on the relationships between literature and culture. Thus, the set of collaborations of both writers is useful as a sample of the intellectual thinking of the mentioned region. Besides, it is representative in the way the cultural debate got along in the country, which in turn, demanded the inclusion of the local realities in order to follow the renewing process of the worldwide thinking, and as matter of fact, arrange a new process in the Brazilian literary tradition. In this way, the study goals to set the positions taken by the two writers faced to the new challenges that the Brazilian reality of that moment was imposed on. The theoretical basis of this work is focused on the accumulated studies about the Brazilians modernism, regionalism and literature, pointing out the Candido s texts, (2006, 2004, 2002, 1995, 1993 and 1989), Schwarz s (1999, 1997a and 1997b), Perrone- Moysés s (2007), Pallares-Burque s (2005), Azevedo s(1996), D Andrea s (1992), Araújo s (2006, 1998, 1997 and 1995), among other authors. Therefore, It is relevant the participation of both writers in that moment which highlights the renewing of the national thinking and the formation of the Brazilian cultural modernity, even the positions taken by them reveal, at times, different views concerning literature and tradition without being disagreeing, however
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Die Beziehung zwischen Literatur und Gesellschaft wurden, im Laufe der Jahrhunderte, aus unterschiedlichen Perspektiven analysiert. Die Wissenschaftler analysieren manchmal die Aspekten der sozialen Realität, sie betonen manchmal die Natur der literarischen Werk. Wir glauben, dass Antonio Candido einen Gleichgewichtszustand erreicht, als er das Konzept der strukturellen Reduktion oder Formalisierung entwickelt. Nämlich, der Prozess, bei dem die menschliche und soziale Leben zu einem Bestandteil der literarischen Struktur wird. Der Autor tritt eine Einbahnstraße und er kann Daten aus der sozialen Ordnung aufholen, ohne dabei die Materialität des Textes den Augen verlieren. Und das sind die theoretische Annahmen, die die Entwicklung dieser Arbeit leiten. Wir wollen zu zeigen, dass die Struktur der mamediana Lyrik aufdeckt, signifikante Daten der Gesellschaft, in der der Autore eingefügt wurde enthüllt. Folglich, wir analysieren soziale Thema, das sein Werk durchzieht. Zuerst, wir untersuchen, wie Zila Mamede den Alltag der Gesellschaft vertreten. Von der strukturellen Organisation der Gedichte, wir erkennen, das die Episode aus kleiner Städte ein Akt des Widerstands gegen die fragmentierte Profil der kapitalistischen Gesellschaf sind. Das ist, warum sie doch eng mit der Idee der Tradition erscheinen. Die dichotome Beziehung zwischen den regionalen Daten und der Element der Modernisierung etabliert, sie wird durch die Organisation des Raumes verstärkt. Während die Stadt bei konkrete gesellschaftliche Ordnung Spitzenbeträge verweist, hat die Landschaft eine harmonische und warme Form. Allgemeinen, die moderne Stadt von Zila Mamede geformt, ist eine Abbild der Industriegesellschaft. Die Bilder die Landschaft sind ein Gegenmittel gegen die Feindseligkeiten Merkmale der neuen urbanen Zustand. So, die Landschaft hat die Funktion von Umstrukturierung der Persönlichkeit des Einzelnen durch die Erfahrung der großen Städte betroffen verdinglichenden. Der Konflikt, der durch das lyrische mamediana läuft, sind Reflexionen des Prozesses der Modernisierung der Stadt Natal, ihres eigenen Landes die politische Instabilität, sie durch verschiedene staatliche Programme ging, während Der Autor seine literarische Tätigkeit verfolgt
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The aim of this study was the evaluation of the effectiveness of photodynamic therapy on the decontamination of artificially induced carious bovine dentin, using Photoge(R) as the photosensitizer agent and an LED device as a light source. Dentin samples obtained from bovine incisors were immersed in sterile broth supplemented by Lactobacillus acidophillus 10(8) colony formation units (CFU) and Streptococcus mutans 10 8 CFU. Different concentrations of photosensitizer, PA = 1 mg/ml, PB = 2 mg/ml, and PC = 3 mg/ml, and two fluences, D = 24 J/cm(2) and D = 48 J/cm(2), were investigated. After CFU counting per milligram of carious dentin and statistical analysis, we observed that the photodynamic therapy (PDT) parameters used were effective for bacterial reduction in the in vitro model under study. The best result was achieved with the application of Photoge(R) at 2 mg/ml and photoactivated under 24 J/cm(2) showing a survival factor of 0.14. At higher photosensitizer concentrations, a higher dark toxicity was observed. We propose a simple mathematical expression for the determination of PDT parameters of photosensitizer concentration and light fluence for different survival factor values. Since LED devices are simpler and cheaper compared to laser systems, it would be interesting to verify their efficacy as a light source in photodynamic therapy for the decontamination of carious dentin.