897 research outputs found

    The Common Fundamental Plane of X-ray Emissions from Pulsars and Magnetars in Quiescence

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    Magnetars are a unique class of neutron stars characterized by their incredibly strong magnetic fields. Unlike normal pulsars whose X-ray emission was driven by rotational energy loss, magnetars exhibit distinct X-ray emissions thought to be driven by their strong magnetic fields. Here we present the results of magnetar X-ray spectra analysis in their quiescent state. Most of the spectra of magnetars can be fitted with a model consisting of a power-law and a black body component. We found that the luminosity of the power-law component can be described by a function of black body temperature and its emission radius. The same relation was seen in pulsars whose X-ray emission mechanism is thought to be different. The fact that magnetars and pulsars share a common fundamental plane in the space spanned by non-thermal X-ray luminosity, surface temperature, and the radius of the thermally emitting region indicates that further fundamental information is necessary to gain a complete comprehension of the magnetospheric emissions from these two classes of neutron stars.Comment: 7 pages, 1 figure. Submitted to Nature Astronom

    Statistical Modelling of Extreme Rainfall in Taiwan

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    In this paper, the annual maximum daily rainfall data from 1961 to 2010 are modelled for 18 stations in Taiwan. We fit the rainfall data with stationary and non-stationary generalized extreme value distributions (GEV), and estimate their future behaviour based on the best fitting model. The non-stationary model means that the parameter of location of the GEV distribution is formulated as linear and quadratic functions of time to detect temporal trends in the maximum rainfall. Future behavior refers to the return level and the return period of the extreme rainfall. The 10, 20, 50 and 100-years return levels and their 95% confidence intervals of the return levels stationary models are provided. The return period is calculated based on the record-high (ranked 1st) extreme rainfall brought by the top 10 typhoons for each station in Taiwan. The estimates show that non-stationary model with increasing trend is suitable for the Kaohsiung, Hengchun, Taitung and Dawu stations. The Kaohsing and Hengchun stations have greater trends than the other two stations, showing that the positive trend extreme rainfall in the southern region is greater than in the eastern region of Taiwan. In addition, the Keelung, Anbu, Zhuzihu, Tamsui, Yilan, Taipei, Hsinchu, Taichung, Alishan, Yushan and Tainan stations are fitted well with the Gumbel distribution, while the Sun Moon Lake, Hualien and Chenggong stations are fitted well with the GEV distribution

    Research Methods in Occupational Health Psychology

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    http://www.springerpub.com/occupational-health-psychology.html Occupational Health Psychology (OHP) is a rapidly expanding interdisciplinary field that focuses on the science and practice of psychology in promoting and developing workplace health- and safety-related initiatives. This comprehensive text for undergraduate and graduate survey courses is the first to encompass a wide range of key issues in OHP. It draws from the domains of psychology, public health, preventive medicine,nursing, industrial engineering, law, and epidemiology to focus on the theory and practice of protecting and promoting the health, well-being, and safety of individuals in the workplace and improving the quality of work life. The text addresses key psychosocial work issues that are often related to mental and physical health problems, including psychological distress, burnout,depression, accidental injury, obesity, and cardiovascular disease. It examines leadership styles as they impact organizational culture and provides specific recommendations for reducing employee-related stress through improved leader practices. Also addressed is the relationship between adverse psychosocial working conditions and harmful health behaviors, along with interventions aimed at improving the work environment and maximizing effectiveness. Additionally, the book discusses how scientists and practitioners in OHP conduct research and other important concerns such as workplace violence, work/family balance, and safety

    Observational connection of non-thermal X-ray emission from pulsars with their timing properties and thermal emission

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    The origin and radiation mechanisms of high energy emissions from pulsars have remained mysterious since their discovery. Here we report, based on a sample of 68 pulsars, observational connection of non-thermal X-ray emissions from pulsars with their timing properties and thermal emissions, which may provide some constraints on theoretical modeling. Besides strong correlations with the spin-down power E˙\dot{E} and the magnetic field strength at the light cylinder BlcB_{\rm lc}, the non-thermal X-ray luminosity in 0.5 - 8 keV, LpL_{\rm p}, represented by the power-law component in the spectral model, is found to be strongly correlated with the highest possible electric field strength in the polar gap, EpcE_{\rm pc}, of the pulsar. The spectral power index Γp\Gamma_{\rm p} of that power-law component is also found, for the first time in the literature, to strongly correlate with E˙\dot{E}, BlcB_{\rm lc} and EpcE_{\rm pc}, thanks to the large sample. In addition, we found that LpL_{\rm p} can be well described by LpT5.96±0.64R2.24±0.18L_{\rm p}\propto T^{5.96\pm 0.64}R^{2.24\pm 0.18}, where TT and RR are the surface temperature and the emitting-region radius of the surface thermal emission, represented by the black-body component in the spectral model. Γp\Gamma_{\rm p}, on the other hand, can be well described only when timing variables are included, and the relation is Γp=log(T5.8±1.93R2.29±0.85P1.19±0.88P˙0.94±0.44)\Gamma_{\rm p} = \log(T^{-5.8\pm 1.93}R^{-2.29\pm 0.85}P^{-1.19\pm 0.88}\dot{P}^{0.94\pm 0.44}) plus a constant. These relations strongly suggest the existence of connections between surface thermal emission and electron-positron pair production in pulsar magnetospheres.Comment: 13 pages, 11 figures, accepted by MNRA

    Differentiation of Foot-and-Mouth Disease-Infected pigs from Vaccinated Pigs Using Antibody-Detecting Sandwich ELISA

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    The presence of serum antibodies for nonstructural proteins of the foot-and-mouth disease virus (FMDV) can differentiate FMDV-infected animals from vaccinated animals. In this study, a sandwich ELISA was developed for rapid detection of the foot-and-mouth disease (FMD) antibodies; it was based on an Escherichia coli-expressed, highly conserved region of the 3ABC nonstructural protein of the FMDV O/TW/99 strain and a monoclonal antibody derived from the expressed protein. The diagnostic sensitivity of the assay was 98.4%, and the diagnostic specificity was 100% for naïve and vaccinated pigs; the detection ability of the assay was comparable those of the PrioCHECK and UBI kits. There was 97.5, 93.4 and 66.6% agreement between the results obtained from our ELISA and those obtained from the PrioCHECK, UBI and CHEKIT kits, respectively. The kappa statistics were 0.95, 0.87 and 0.37, respectively. Moreover, antibodies for nonstructural proteins of the serotypes A, C, Asia 1, SAT 1, SAT 2 and SAT 3 were also detected in bovine sera. Furthermore, the absence of cross-reactions generated by different antibody titers against the swine vesicular disease virus and vesicular stomatitis virus (VSV) was also highlighted in this assay's specificit

    Application of Advanced Framework Technology in Smart Cities to Improve Resource Utilization

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    Nowadays, the application technology and demand are growth; there have been millions of solutions for user communication in smart cities. However, the quality of the autonomy of handheld devices and the information exchange of applications are functions of requesting services or participating in communications. Therefore, it is very difficult and tedious to implement resource management and control in such an environment. This study here proposes distributed cyber-physical systems (CPS) for agent-based middleware framework (AMF) using to achieve technology, thereby improving the reliability of environmental communication in smart cities. The technical solution has the characteristics of avoiding the problem of data source interruption because of the proxy technology of the linear calculation model. The aforementioned agents are independent and autonomous of each other in terms of providing seamless resource sharing and response scheduling, and have nothing to do with communication time and request queries. In this study, the architecture mainly uses the best linear calculation model to classify overlapping agents, and then allocates non-overlapping resources, and finally analyzes the overall architecture operation performance by responding to processed queries, storage utilization and resource usage, pause time and response

    Effect of Catalyst Morphology on the Quality of CVD Grown Graphene

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    The strong interest in graphene has motivated large effort in the scalable production of high-quality material. The potential of chemical vapor deposition on Cu foil to produce such graphene is impeded by lacking understanding of the relation between catalyst properties and graphene performance. We here present a systematic analysis of the catalyst morphology and its effect on electrical properties of graphene. We find that nanometer sized particles increase the density of bilayer regions but have no significant effect on carrier transport. Long wavelength roughness (waviness), on the other hand, generates defective graphitic regions that deteriorate carrier mobility. These findings shed light on the graphene formation process on Cu substrates and open a route to improve graphene quality for electronics applications
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