436 resultados para Suborbital Flights


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Argumenta-se na contemporaneidade que o trabalho adquiriu a possibilidade de ser realizado “a qualquer hora e em qualquer lugar” e que, particularmente, pode ser realizado em movimento, enquanto a pessoa que trabalha desloca-se de um lugar a outro. Este estudo investiga esse último, o trabalho móvel; em especial, aquele que envolve o uso de tecnologias de informação e comunicação e realizado enquanto a pessoa que trabalha desloca-se por meio do sistema de transporte aéreo. Este projeto explora, especificamente, o desempenho de espaço-tempos de trabalho em terminais de aeroportos e em aviões. Para tanto, adota a abordagem teórico-metodológica Teoria Ator-Rede que considera o social um movimento de associações entre elementos heterogêneos e os espaço-tempos, incluindo aqueles de trabalho, efeitos de modos como humanos e não humanos relacionam-se entre si. A estratégia metodológica envolveu uma combinação de observação de campo, auto-observação e entrevistas com pessoas que vivem a experiência do trabalho móvel. A coleta de dados compreendeu: (a) horas de observação de pessoas e situações, em alguns terminais de aeroportos no Brasil e em voos entre a cidade de São Paulo e outras capitais do país, e (b) entrevistas semiestruturadas com pessoas que, com certa frequência, deslocam-se para trabalhar por meio do sistema de transporte aéreo. Como resultado, este estudo contribui para as análises sobre o fenômeno do trabalho móvel, realizado em aeroportos e aviões, e destaca: os atores envolvidos, bem como os agentes que levam esses atores a agir; a quantidade de objetos ativos na manifestação do fenômeno; e as controvérsias envolvidas com o tema. Além disso, aponta elementos empíricos (i) que revelam lugares em que os fenômenos de trabalho móvel se manifestam esporadicamente, de modo disperso, como “bolhas”, e (ii) que se contrapõem à ideia que é possível trabalhar “a qualquer hora e em qualquer lugar”. As contribuições deste estudo ecoam resultados de pesquisas desenvolvidas sobre trabalho móvel, assim como apresentam particularidades, como a metáfora da bolha, amplificações de aspectos pouco presentes nos textos sobre o tema e elementos peculiares do trabalho móvel investigado no espaço-tempo da pesquisa

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Spacecraft move with high speeds and suffer abrupt changes in acceleration. So, an onboard GPS receiver could calculate navigation solutions if the Doppler effect is taken into consideration during the satellite signals acquisition and tracking. Thus, for the receiver subject to such dynamic cope these shifts in the frequency signal, resulting from this effect, it is imperative to adjust its acquisition bandwidth and increase its tracking loop to a higher order. This paper presents the changes in the GPS Orion s software, an open architecture receiver produced by GEC Plessey Semiconductors, nowadays Zarlink, in order to make it able to generate navigation fix for vehicle under high dynamics, especially Low Earth Orbit satellites. GPS Architect development system, sold by the same company, supported the modifications. Furthermore, it presents GPS Monitor Aerospace s characteristics, a computational tool developed for monitoring navigation fix calculated by the GPS receiver, through graphics. Although it was not possible to simulate the software modifications implemented in the receiver in high dynamics, it was observed that the receiver worked in stationary tests, verified also in the new interface. This work also presents the results of GPS Receiver for Aerospace Applications experiment, achieved with the receiver s participation in a suborbital mission, Operation Maracati 2, in December 2010, using a digital second order carrier tracking loop. Despite an incident moments before the launch have hindered the effective navigation of the receiver, it was observed that the experiment worked properly, acquiring new satellites and tracking them during the VSB-30 rocket flight.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Sleep-deprived rats exhibit defensive fighting as well as explosive flights very similar to the wild-running of audiogenic seizures. In order to determine why sleep deprivation is a common factor that facilitates both panic and convulsive manifestations, the present study was undertaken to investigate whether rats that display sleep deprivation-induced fighting (SDIF) are the same as those that are susceptible to audiogenic wild-running (WR). Twenty-eight male adult Wistar rats were divided into two groups assigned to two e-sleep deprivation for 5 days and had their SDIF evaluated in social experimental schemes. In the first, 18 subjects were submitted to REM grouping. After 1 week for recovery, their susceptibility to WR was tested in an acoustic stimulation trial ( 104 dB, 200 Hz, 60 S). Rats that did not present WR received a lactate infusion and were tested again by acoustic stimulation 40 min later. In the second experimental scheme, 10 subjects were initially evaluated for WR susceptibility and the number of SDIF was recorded in social grouping after I week. Three categories of WR-susceptibility were determined: WR-sensitive rats, intermediate WR-sensitive rats and WR-insensitive rats. T'he number of SDIF in each category was significantly different and there was a high positive correlation (r=0.89; Spearman test) between the number of SDIF and the level of WR-susceptibility. We conclude that the reasons why sleep deprivation exerts facilitatory effects on both panic and convulsive manifestations are due to overlappings of neural pathways responsible for both behavioral patterns and for the property of sleep deprivation to increase neuronal excitability. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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This work focuses the geological and geomorphological characterization of the inner shelf in the West Coast of the Rio Grande do Norte state, particularly the reef coral barrier offshore of Maracajaú (Maxaranguape district). If developed without the necessary concerns, tourism and entertainment activities that have been widely increased during the last five years can lead to irreversible environmental damages to the biotic and abiotic ecosystems of the region. Regarding these aspects, it is crucial the realization of a detailed study to envisage the achievement of a self-sustainable development, especially with respect to the possibilities of a rational usage of the region. This is the aim of this manuscript, which consisted of an initial stage of digital modeling of the terrain with basis on digitalization and vectorization of the Nautical map number 803 (Naval Service of Brazil, 1971). Information obtained in this phase was improved with the digital processing of small format aerial photos acquired from six flights, which were integrated to form a photomosaic of the area. The refined maps produced with the data from Nautical and aerial photo-interpretations aided to locate 9 bathymetric profiles, which provided information about the sea floor relief of the whole area. This later aided in the choosing of areas to bottom sampling that, in its turn, helped to characterize sediments present in floor of the inner shelf. Sixty-four samples collected during this work were studied by granulometrical and chemical analysis; with the later one developed in order to measure carbonate and organic matter contents. Forty-two of these samples showed carbonate content higher than 80% and organic matter in the range of 0.58% to 24.06%. With respect to grain size, these samples are in the interval between fine- to mid-grained sands. Sands with grain sizes higher than this one are also composed by carbonate carapaces such as pale yellow to red rhodolites with ellipsoidal and spheroidal shapes. During determination of the submerse features, the small format aerial photos demonstrated to be a useful methodology to aid the delineation of the sea floor topography through shallow deep waters. The bathymetry, for its turn, revealed several features at the bottom of the platform, in which the most conspicuous are undulations and morphological details of the São Roque Channel. Examination of bottom, aside from sand, yielded the identification of bivalves, ostracods, fragments of bryozoans, spikes of sponges, spines of echinoderms, operculum of gastropods and foraminifers. From the above it is concluded that the multi-methodological approach developed in this study worked efficiently, permitting the geomorphological and environmental characterization of the inner shelf of the North Maracajaú

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Objectives: This text presents an anatomical study of the normal bony orbital structure of a sample of different bird species belonging to the order Psittaciformes.Procedures: the bony anatomy of Psittaciformes' skulls was examined and described using cadavers of birds that were presented already dead to the Federal University of Parana, Brazil or had been euthanized for humane reasons. Dissections of the orbital cavity were performed under 2-4 x magnification, and descriptions of the orbital bones were made from observations of macerated skulls that had been boiled and cleaned. The present paper discusses the main features of the bony orbit of psittaciform birds, describing known anatomical information but also bringing new information, mainly concerning species differences that might help not only veterinary anatomists but also zoologists, clinicians, researchers, and students of veterinary ophthalmology to better comprehend this order of birds.Results and conclusions: Variations in the anatomic conformation of the bony elements of the orbit were observed in different species of Psittaciformes. Based on these differences, Psittaciformes were classified into two different groups. The first group of Psittaciformes shows an enclosed (complete) bony orbit formed by the junction of the orbital with the postorbital processes, creating a suborbital arch. The second group of Psittaciformes essentially lacked a suborbital arch, presenting an open (incomplete) bony orbit, typical of most modern birds. In the latter group, orbital and postorbital processes are present.

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Power-law distributions have been observed in various economical and physical systems. Levy flights have infinite variance which discourage a physical approach. We introduce a class of stochastic processes, the gradually truncated Levy flight in which large steps of a Levy flight are gradually eliminated. It has finite variance and the system can be analyzed in a closed form. We applied the present method to explain the distribution of a particular economical index. The present method can be applied to describe time series in a variety of fields, i.e. turbulent flow, anomalous diffusion, polymers, etc. (C) 1999 Elsevier B.V. B.V. All rights reserved.

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The information on the project being developed in Brazil for a flight to binary or triple near-Earth asteroid is presented. The project plans to launch a spacecraft into an orbit around the asteroid and to study the asteroid and its satellite within six months. Main attention is concentrated on the analysis of trajectories of flight to asteroids with both impulsive and low thrust in the period 2013-2020. For comparison, the characteristics of flights to the (45) Eugenia triple asteroid of the Main Belt are also given.

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Air accidents represent a small proportion of the flights registered worldwide. Airplane collisions in the air are rare. In September of 2006, a Boeing 737-800 collided in midair with a Legacy Jet. It was the largest accident registered in the history of Brazilian aviation until that time. The present study explores aspects of press coverage of the accident. Data and information reported in the media about the accident from September 2006 to August 2007 were collected and discussed. Media coverage called attention to two unusual aspects: politicisation of the discussion, culminating in the opening of congressional inquiries, and equally the concomitance of police investigations interfering in the work of agencies responsible for the official accident investigation. Emphasis on assigning guilt and establishing penalties may close the windows of opportunity an accident had opened for discussions on the improvement of air safety. In Brazil, political imperatives and organizational pressures have interfered and the possibilities of organizational learning from the accident have been drastically curtailed.

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To study the production and propagation of fast secondaries particles in the atmosphere, data collected during eleven quiet-time balloon flights are analysed. Comparisons of these data with those obtained in different geomagnetic rigidity regions permit to estimate the contributions of the proton and electron components in the measured intensities. Derivations of this last component in the «upward» and «downward» moving electrons fluxes indicate that in the anomaly region a fraction of these particles, produced by the primary protons, are leaving the atmosphere and will not return to the Earth. © 1991 Società Italiana di Fisica.

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Power-law distributions, i.e. Levy flights have been observed in various economical, biological, and physical systems in high-frequency regime. These distributions can be successfully explained via gradually truncated Levy flight (GTLF). In general, these systems converge to a Gaussian distribution in the low-frequency regime. In the present work, we develop a model for the physical basis for the cut-off length in GTLF and its variation with respect to the time interval between successive observations. We observe that GTLF automatically approach a Gaussian distribution in the low-frequency regime. We applied the present method to analyze time series in some physical and financial systems. The agreement between the experimental results and theoretical curves is excellent. The present method can be applied to analyze time series in a variety of fields, which in turn provide a basis for the development of further microscopic models for the system. © 2000 Elsevier Science B.V. All rights reserved.

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The breeding biology of the only Scarlet Ibis Eudocimus ruber colony in southeastern Brazil was studied during the 1996-97 breeding season. The ibises began to visit their colony site by mid-September. Nest building and egg laying took place in early November and was synchronous, making the first nesting pulse. Mean clutch size in this pulse was 2.45 eggs/nest, and 0.67 young/nest reached age three weeks, when they were able to walk about the nest tree and environs. Predation was the main cause of nest failures (74% of all losses), followed by nest collapses (19%). A second nesting pulse, also synchronous, started in late December, when the young from the first nests were already able to wander about the colony and make short flights. Mean clutch size of this pulse was 2.05 eggs/nest and productivity was 0.34 young/nest. Nest collapses during storms accounted for 58% of the losses, and predation for a further 27%. A third pulse, with only a few nests, started when the second pulse young were in their third week, but no nest was successful. The incubation time was 21-24 days, and the young were able to fly well when 40 days old, deserting the colony by age 75 days. Nesting early in the breeding season yielded greater success. Nests were built close to each other (a sphere with a 1.8 m radius and centered on an average nest would include the four nearest neighbors) and there was always more than one nest per tree. Most nests were built on the upper third of the nest-tree and had some cover from overhanging branches. There was a trend for the ibises building their nests in even closer proximity during the second pulse, perhaps as a strategy to lessen individual predation risks. Received 30 August 2000, accepted 4 October 2000.

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Studies related with the flight activity of aphids captured with traps can be useful to predict the appearance of alate forms in the field. It is also useful to understand the population dynamics of those insects. This work was carried out at the Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, State of São Paulo, during the period from July 1997 to December 1999, aiming to determine the population curve of alate Brevicoryne brassicae (L.) in the region of Jaboticabal and the influence meteorological factors plays on it. The population survey was carried out in four places, and the alate aphids were sampled by yellow water traps. The influence of air temperature, relative humidity, rainfall and sunshine brightness was verified using stepwise regression. The first captures of alate B. brassicae in the traps began at the end of June. In the region of Jaboticabal, the population curve of alate B. brassicae showed the highest frequency of flights during September. The appearance of alate forms in kale fields at initial stage of development was favored by maximum and minimum temperatures of 26.4°C and 13.5°C, respectively; relative humidity of 75.1%, and reduced rainfall.

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Objective: To determine the accuracy of the variables related to the fixed-height stair-climbing test (SCT) using maximal oxygen uptake (V̇O 2 max) as the gold standard. Methods: The SCT was performed on a staircase consisting of 6 flights (72 steps; 12.16 m total height), with verbal encouragement, in 51 patients. Stair-climbing time was measured, the variables 'work' and 'power' also being calculated. The V̇O2 max was measured using ergospirometry according to the Balke protocol. We calculated the Pearson linear correlation (r), as well as the values of p, between the SCT variables and V̇O2 max. To determine accuracy, the V̇O 2 max cut-off point was set at 25 mL/kg/min, and individuals were classified as normal or altered. The cut-off points for the SCT variables were determined using the receiver operating characteristic curve. The Kappa statistic (k) was used in order to assess concordance. Results: The following values were obtained for the variable 'time': cut-off point = 40 s; mean = 41 ± 15.5 s; r = -0.707; p < 0.005; specificity = 89%; sensibility = 83%; accuracy = 86%; and k = 0.724. For 'power', the values obtained were as follows: cut-off point = 200 w; mean = 222.3 ± 95.2 w; r = 0.515; p < 0.005; specificity = 67%; sensibility= 75%; accuracy = 71%; and k = 0.414. Since the correlation between the variable 'work' and V̇O2 max was not significant, that variable was discarded. Conclusion: Of the SCT variables tested, using V̇O2 max as the gold standard, the variable 'time' was the most accurate.