RESUMO
In February 1992, the Ulysses spacecraft flew through the giant magnetosphere of Jupiter. The primary objective of the encounter was to use the gravity field of Jupiter to redirect the spacecraft to the sun's polar regions, which will now be traversed in 1994 and 1995. However, the Ulysses scientific investigations were well suited to observations of the Jovian magnetosphere, and the encounter has resulted in a major contribution to our understanding of this complex and dynamic plasma environment. Among the more exciting results are (i) possible entry into the polar cap, (ii) the identification of magnetospheric ions originating from Jupiter's ionosphere, lo, and the solar wind, (iii) observation of longitudinal asymmetries in density and discrete wave-emitting regions of the lo plasma torus, (iv) the presence of counter-streaming ions and electrons, field-aligned currents, and energetic electron and radio bursts in the dusk sector on high-latitude magnetic field lines, and (v) the identification of the direction of the magnetic field in the dusk sector, which is indicative of tailward convection. This overview serves as an introduction to the accompanying reports that present the preliminary scientific findings. Aspects of the encounter that are common to all of the investigations, such as spacecraft capabilities, the flight path past Jupiter, and unique aspects of the encounter, are presented herein.
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During the encounter with comet Giacobini-Zinner, the energetic particle anisotropy spectrometer on the International Cometary Explorer spacecraft observed large fluxes of energetic ions, believed to result principally from ionization of the cometary atmosphere followed by pickup and acceleration by the ambient flow of the solar wind. These heavy cometary ions were observed from approximately 1 day before closest approach to about 2(1/2) days afterward. Three regimes of differing ion characteristics have been identified. An outer region with a scale of approximately 10(6) kilometers contains variable fluxes of antisolar-streaming pick-up ions in the undisturbed solar wind. In the middle region, of approximately 10(5) kilometers, fluxes have less large-scale variability and broader angular and energy distributions. This region is separated from the outer zone by a sharp transition. The inner region has a scale of approximately 10(4) kilometers and is characterized by reduced fluxes and complex angular distributions.
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The Ulysses spacecraft made the first exploration of the region of Jupiter's magnetosphere at high Jovigraphic latitudes ( approximately 37 degrees south) on the dusk side and reached higher magnetic latitudes ( approximately 49 degrees north) on the day side than any previous mission to Jupiter. The cosmic and solar particle investigations (COSPIN) instrumentation achieved a remarkably well integrated set of observations of energetic charged particles in the energy ranges of approximately 1 to 170 megaelectron volts for electrons and 0.3 to 20 megaelectron volts for protons and heavier nuclei. The new findings include (i) an apparent polar cap region in the northern hemisphere in which energetic charged particles following Jovian magnetic field lines may have direct access to the interplanetary medium, (ii) high-energy electron bursts (rise times = 1 minute and energies extending to > approximately 17 megaelectron volts) on the dusk side that are apparently associated with field-aligned currents and radio burst emissions, (iii) persistence of the global 10-hour relativistic electron "clock" phenomenon throughout Jupiter's magnetosphere, (iv) on the basis of charged-particle measurements, apparent dragging of magnetic field lines at large radii in the dusk sector toward the tail, and (v) consistent outflow of megaelectron volt electrons and large-scale departures from corotation for nucleons.
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Observations of galactic cosmic radiation and anomalous component nuclei with charged particle sensors on the Ulysses spacecraft showed that heliospheric magnetic field structure over the south solar pole does not permit substantially more direct access to the local interstellar cosmic ray spectrum than is possible in the equatorial zone. Fluxes of galactic cosmic rays and the anomalous component increased as a result of latitude gradients by less than 50% from the equator to -80 degrees . Thus, the modulated cosmic ray nucleon, electron, and anomalous component fluxes are nearly spherically symmetric in the inner solar system. The cosmic rays and the anomalous nuclear component underwent a continuous, -26 day recurrent modulation to -80.2 degrees , whereas all recurring magnetic field compressions and recurring streams in the solar wind disappeared above approximately 55 degrees S latitude.
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Proton fluxes obtained by two instruments carried on the ESA/NASA Ulysses spacecraft are reported for the period from launch in October 1990 till Jupiter encounter in February 1992. Proton energy ranges are 24-59, 71-99, 130-320, 320-2100 and > 2100 MeV. The Sun was very active during this period, the events of March 1991 being some of the largest of the solar cycle. The relationship between events on the Sun and the observed proton flux is discussed.
Assuntos
Elétrons , Prótons , Monitoramento de Radiação/instrumentação , Atividade Solar , Voo Espacial , Astronave/instrumentação , Meio Ambiente Extraterreno , Júpiter , Espalhamento de Radiação , Sistema SolarRESUMO
The ultra heavy cosmic ray experiment (UHCRE) on the Long Duration Exposure Facility (LDEF) collected approximately 3000 cosmic ray nuclei with Z > 65 in the energy region E > 1.5 GeV/n. Almost 40% of the sample has been analysed to date. Details of the overall charge abundance pattern is outlined with estimates of the actinide abundance.
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Radiação Cósmica , Monitoramento de Radiação/instrumentação , Voo Espacial/instrumentação , Elementos da Série Actinoide , Radiometria , AstronaveRESUMO
The DIAS-ESTEC Ultra Heavy Cosmic Ray Experiment (UHCRE) on the Long Duration Exposure Facility, collected approximately 3000 cosmic ray nuclei with Z > 65 in the energy region E > 1.5 GeV nucleon-1 during a six year exposure in Earth orbit. The entire accessible collecting area of the solid state nuclear track detector (SSNTD) array has been scanned for actinides, yielding a sample of 30 from an exposure of approximately 150 m2 sr yr. The UHCRE experimental setup is described and the observed charge spectrum presented. The current best value for the cosmic ray actinide relative abundance, (Z > 88)/(74 < or = Z < or = 87), is reported.
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Elementos da Série Actinoide/análise , Radiação Cósmica , Monitoramento de Radiação/instrumentação , Voo Espacial/instrumentação , Astronave/instrumentação , Calibragem , Meio Ambiente Extraterreno , Polímeros , RadiometriaRESUMO
The European Space Agency's Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote( )imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.
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In five full-time and part-time specialists for internal medicine, respectively, of the district outpatient department the quality of the documentation of the ambulatory care has been tested. The documentations proved to be sufficient. Obviously this or that specialist sometimes keeps away from establishing a tentative diagnosis in the primary consultation. But the making of a preliminary diagnosis involves to do with a limited but sufficient examination programme.
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Prontuários Médicos/normas , Assistência Ambulatorial , Alemanha Oriental , Humanos , Encaminhamento e ConsultaRESUMO
Vessels implants as possible vessel connections for chronic haemodialysis have to meet certain requirements concerning resistance to cutting and kinking and ability to be sewn under tolerable intraoperative damage risk. Preservation in peroxyethanic acid significant reduces the mechanical resistance of the biological primary material; by contrast, preservation in methanal clearly raises the mechanical stability of the preparations.
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Artérias/transplante , Diálise Renal/métodos , Preservação de Tecido/métodos , Veias/transplante , Formaldeído/farmacologia , Humanos , Ácido Peracético/farmacologiaRESUMO
The substitutes could be decontaminated by means of six to eight times soaking into sterile sodium chloride solution (154 mmol/l = 9 g/l) in each case half an hour if a short preparation time for the implantation of protein cross-linked and methanal storaged bioprotheses is existent. This procedure must be carried out under strict aseptic conditions. A microbial recontamination of the preparations threats moreover.
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Bioprótese , Prótese Vascular , Formaldeído , Animais , Valva Aórtica , Manejo de Espécimes , SuínosRESUMO
Methanal (formaldehyde) preserved and ethane acid peroxide finally sterilised aortic segments showed in vitro and in vivo a significant decrease of the material characteristics in case of watering for 180 days. Intraperitoneal incorporation in a xenogeneous animal species during 60 days reduced the mechanical stability of the substitutes without long-term watering and also with long-term watering, but with an additionally greater negative effect.
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Bioprótese , Prótese Vascular , Formaldeído/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Soluções , SuínosRESUMO
After exposure of contaminated xenogenous aortic valve grafts to 0.5 g% Cialit solution for 30 minutes, to 0.1 g% solution for 24 hours, or to 0.02 g% solution for 288 hours, growth of germs on the graft had stopped. Cialit has bacteriostatic and fungistatic effectiveness and fair stability of solubility; nevertheless it ought to be used with reservation. No safe destruction of microbes- spores and viruses in particular- can be guaranteed at acceptable Cialit concentrations of 0.1 g% and below.
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Valva Aórtica/transplante , Bactérias/efeitos dos fármacos , Cialit/farmacologia , Compostos de Etilmercúrio/farmacologia , Preservação de Tecido/métodos , Transplante Heterólogo , Animais , Esterilização , SuínosRESUMO
The determination of the concentration in acetate puffered methanol solutions (formaldehyde solutions) with pH = 5.60 during 14 months disproved the opinion of the limited durability of these solutions. Neither a significant decrease of the methanal mass concentration nor a noticeable change of the pH value could be proved during the period of the examination under different influences of light and temperature. Methanal solutions can be applied farther in the practice of the preservation.
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Acetatos , Formaldeído , Soluções Tampão , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Soluções , Temperatura , Fatores de TempoRESUMO
Biologic cardiac valve substitutes were sterilized at room temperature using beta-propiolactone with a 0.5 vol.% solution within 120 minutes, with a 1.0 vol.% solution within 90 minutes, and with a 1.5 resp. 2.0 vol.% solution within 60 minutes. The physico-chemic properties of the graft can be influenced by appropriately chosen concentration and sterilizing period. Enlarged procedures for decontamination are not necessary because of the rapid dissolution of aqueous beta-propiolactone solutions.
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Bioprótese , Próteses Valvulares Cardíacas , Lactonas/farmacologia , Propiolactona/farmacologia , Esterilização/métodos , Animais , Valva Aórtica/transplante , Bactérias/efeitos dos fármacos , Temperatura , Fatores de TempoRESUMO
Allogenic and xenogenic tissues can be preserved with acetate buffered formaldehyde solution 1,332 mol/l and pH 5,60. The permeation of methanol molecules through the tissue was analysed with a double chamber research arrangement with a rotating set-up. The coefficient of diffusion of the formaldehyde (methanal) through the wall of the aorta descendens of pigs was calculated by means of the first Fick principle from the obtained measured particulars.