1,002 research outputs found
A Stellar-mass Black Hole in the Ultra-luminous X-ray Source M82 X-1?
We have analyzed the archival XMM-Newton data of the bright Ultra-Luminous
X-ray Source (ULX) M82 X-1 with an 105 ksec exposure when the source was in the
steady state. Thanks to the high photon statistics from the large effective
area and long exposure, we were able to discriminate different X-ray continuum
spectral models. Neither the standard accretion disk model (where the radial
dependency of the disk effective temperature is T(r) \propto r^-3/4) nor a
power-law model gives a satisfactory fit. In fact, observed curvature of the
M82 X-1 spectrum was just between those of the two models. When the exponent of
the radial dependence (p in T(r) \propto r^-p) of the disk temperature is
allowed to be free, we obtained p =0.61^+0.03_-0.02. Such a reduction of p from
the standard value 3/4 under extremely high mass accretion rates is predicted
from the accretion disk theory as a consequence of the radial energy advection.
Thus, the accretion disk in M82 X-1 is considered to be in the Slim disk state,
where an optically thick Advection Dominant Accretion Flow (ADAF) is taking
place. We have applied a theoretical slim disk spectral model to M82 X-1, and
estimated the black hole mass ~ 19-32 M_odot. We propose that M82 X-1 is a
relatively massive stellar black hole which has been produced through evolution
of an extremely massive star, shining at a super-Eddington luminosity by
several times the Eddington limit.Comment: 12 pages, 2 figures, Accepted for ApJ
Finite element analysis of tube drawing process with diameter expansion
This paper presents a tube drawing process with diameter expansion for producing a thin-walled tube effectively. In this proposed process, the tube was flared by a plug pushing into the tube, and then the tube was expanded by drawing the plug in the tube axial direction with chucking the flared tube edge. Optimum plug shape, such as the plug half angle and the corner radius, was investigated by a series of analyses using the finite element method (FEM) for improving the forming limit and the dimension accuracy. At first, a friction coefficient was determined to 0.3 by a comparison of the flaring limit between the analysis and the experiment of the tube flaring. As a result of the analyses in the drawing with the diameter expansion, the forming limit was high when the plug half angle was set to 18~30°. The thickness reduction ratio increased with an increase in the expansion ratio and the plug half angle. In addition, the overshoot, which is a difference between the plug diameter and the tube inner diameter after the drawing, was prevented by using the plug with the corner radius of 20 mm
Zero-shot domain adaptation of anomalous samples for semi-supervised anomaly detection
Semi-supervised anomaly detection~(SSAD) is a task where normal data and a
limited number of anomalous data are available for training. In practical
situations, SSAD methods suffer adapting to domain shifts, since anomalous data
are unlikely to be available for the target domain in the training phase. To
solve this problem, we propose a domain adaptation method for SSAD where no
anomalous data are available for the target domain. First, we introduce a
domain-adversarial network to a variational auto-encoder-based SSAD model to
obtain domain-invariant latent variables. Since the decoder cannot reconstruct
the original data solely from domain-invariant latent variables, we conditioned
the decoder on the domain label. To compensate for the missing anomalous data
of the target domain, we introduce an importance sampling-based weighted loss
function that approximates the ideal loss function. Experimental results
indicate that the proposed method helps adapt SSAD models to the target domain
when no anomalous data are available for the target domain
Attitude Control Flight Experience: Coping with Solar Radiation and Ion Engines Leak Thrust in Hayabusa (MUSES-C)
The paper presents the attitude reorientation taking the advantage of solar radiation pressure without use of any fuel aboard. The strategy had been adopted to make Hayabusa spacecraft keep pointed toward the Sun for several months, while spinning. The paper adds the above mentioned results reported in Sedona this February showing another challenge of combining ion engines propulsion tactically balanced with the solar radiation torque with no spin motion. The operation has been performed since this March for a half year successfully. The flight results are presented with the estimated solar array panel diffusion coefficient and the ion engine's swirl torque
Influencia dos antiinflamatorios, indometacina, deflazacort, e meloxicam sobre a secreção gastrica de ratos
Orientador: Maria Cecilia Ferraz de Arruda VeigaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: Muitos estudos têm relacionado os antiinflamatórios com alterações gástricas. Com o objetivo de apresentar alguma contribuição nesta área de pesquisa é que nos propusemos a investigar a influencia de antiinflamatórios sobre a secreção gástrica de ratos. Foram utilizados neste experimento, quarenta ratos (Wistar), machos com 120 dias de idade, pesando em média 350 gramas, os quais foram submetidos a jejum de 72 horas, e a seguir anestesiados com éter, e submetidos à ligação do piloro. Após 4 horas foi coletada a secreção gástrica para análise. O soro fisiológico e as drogas forma administradas por sonda gástrica, num volume de 0,5 ml, após a ligadura do piloro, de acordo com as seguinte distribuição:GRUPO I - Soro Fisiológico; GRUPO TI - Indometacina; GRUPO li Detlazacort; GRUPO N - Meloxicam. Após o experimento, o suco gástrico foi coletado para a avaliação do pH, volume, acidez livre, acidez total e atividade péptica.Resultados: Volume (ml) e pH : G-I ( 5,80 e 1,72 ); G-TI ( 9,72 e 1,18 ); G-li ( 8,79 e 2,11 ); G-N ( 6,63 e 2,13 ) Acidez livre e total (llEq/4h): G-I - ( 438,08 e 572,70 ); G-TI - ( 878,02 e 989,00); G-li - ( 462,97 e 600,97); G-N - (375,37 e 460,36 ) Atividade Péptica ( UE/4h ): G-I- ( 6,25 ); G-TI - ( 4,17 ); G-li - ( 5,87 ); G-N - ( 4,76 ). A I I indometacina aumentou o volume do suco gástrico reduziu o pH e aumentou a acidez livre e acidez total, sinalizando claramente, para uma indução a secreção clorídrica pelas células parietais , e reduziu significativamente a atividade péptica. O meloxicam não aumentou o volume de suco gástrico e não alterou a atividade péptica e aumentou significativamente o pH, o que pode indicar uma redução na secreção gástrica ácida. O deflazacort aumentou o volume de suco gástrico e o pH e não apresentou diferença significativa em relação aos controles no que se refere a acidez livre e total. Da mesma forma que o meloxicam, o deflazacort não alterou a atividade péptica. Desta forma, no que se refere ao principal efeito adverso dos antiinflamatório, que é a agressividade a mucosa gástrica, dos antiinflamatórios testados neste trabalho, o meloxicam mostrou-se o menos efetivo em induzir alterações nos parâmetros da secreção gástrica analisadosAbstract: Many studies have established a relationship between anti-inflammatory medications and gastric reactions. Our objective is to contribute to this research area by investigating the influence ofanti-inflammatory medications on the gastric secretion of rats. Forty 120-day-old male Wistar rats were used. They weighed 350 grams and were submitted to a 72-hour fasting. Then, they were anesthetized with ether and had their pylorus ligated. After 4 hours, the gastric secretion was collected and taken to analysis. The physiological sodium chloride solution and the drugs were given via gastric probe after the pylorus ligature at a 0.5-ml-volume leveI, according to the following distribution: GROUP I - physiological sodium chloride solution; GROUP II - Indomethacin; GROUP li - Deflazacort; GROUP IV - Meloxicam. After the experiment, the gastric juice was collected and its pH, free acidity, total acidity and peptic acidity were evaluated. The results were: volume (ml) and pH: G-I (5,80 and 1,72), G-II (9,72 and 1,18), G-li (8,79 and 2,11), G-IV (6,63 and 2,13); free acidity and total acidity (lillq/4h): G-I - (438,08 and 572,70), G-II - (878,02 and 989,00), G-li - (462,97 and 600,97), G-IV - (375,37 and 460,36), peptic activity (UE/4h): G-I (6,25), G-II (4,17), G-ill (5,87), G-IV (4,76). Indomethacin made the gastric juice volume increase and the pH decrease and it also increased the free and total acidity evidencing a chlorinous secretion induction by the parietal cells and a peptic activity reduction. Meloxicam did not make the gastric juice volume increase or the peptic activity change, but it increased the pH significantly, what may indicate a reduction gastric secretion. Deflazacort increased the gastric juice volume and the pH, but the ftee and total acidity were not changed significantly in comparison to the controls. As Meloxicam, Deflazacort did not chage the peptic activity. Thus, regarding the main adverse reactions of the use of anti-inflammatory medications, which is aggression to the gastric mucus, among the medications tested in this work, Meloxicam presented the less changes in the gastric secretion parameters analyzed.MestradoFisiologia OralMestre em Odontologi
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