15,644 research outputs found

    Thermodynamics of (2+1)-flavor QCD: Confronting Models with Lattice Studies

    Full text link
    The Polyakov-quark-meson (PQM) model, which combines chiral as well as deconfinement aspects of strongly interacting matter is introduced for three light quark flavors. An analysis of the chiral and deconfinement phase transition of the model and its thermodynamics at finite temperatures is given. Three different forms of the effective Polyakov loop potential are considered. The findings of the (2+1)-flavor model investigations are confronted to corresponding recent QCD lattice simulations of the RBC-Bielefeld, HotQCD and Wuppertal-Budapest collaborations. The influence of the heavier quark masses, which are used in the lattice calculations, is taken into account. In the transition region the bulk thermodynamics of the PQM model agrees well with the lattice data.Comment: 13 pages, 7 figures, 3 tables; minor changes, final version to appear in Phys. Rev.

    Recent climate change in Japan – spatial and temporal characteristics of trends of temperature

    Get PDF
    In this paper temperature series of Japan were statistically analysed in order to answer the question whether recent climate change can be proved for Japan; the results were compared and discussed with the global trends. The observations in Japan started for some stations in the 1870s, 59 stations are available since 1901, 136 stations since 1959. Modern statistical methods were applied, such as: Gaussian binominal low-pass filter (30 yr), trend analysis (linear regression model) including the trend-to-noise-ratio as measure of significance and the non-parametric, non-linear trend test according to MANN (MANN's Q). According to the results of the analyses, climate change in Japan is clearly shown for temperature over the 100 yr (1901–2000): Annual mean temperatures increased at all stations from 0.35 (Hakodate) to 2.95°C (Tokyo). The magnitude of climate change is illustrated to increase over the recent period 1976–2000. Seasonally, the strongest warming trends were observed for winter temperatures and also increasing temperature trends prevailed in summer, with the exception of slightly decreasing trends at only four stations

    Recent climate change affecting rainstorm occurrences: a case study in East China

    Get PDF
    The paper aims to investigate the occurrences of rainstorms and their relationship with the climate change scenario. The study period under investigation refers to the period of greatest recent warming between 1976–2000 whereas the study area covers China east of 105 E longitude. This region is commonly considered to be controlled by the monsoon type of climate over East Asia. <br><br> Positive (increasing) trends of rainstorm occurrences, both in annual and summer respects, have been shown for subtropical China whereas a non-uniform picture is associated with temperate China. The increase of rainstorms in subtropical China corresponds with an increasing trend of precipitation. At the same time, subtropical China experiences a mostly decreasing recent temperature change. No clear evidence could, however, be proved for a direct linkage between increasing temperatures and greater rainstorm occurrences. Within the climate change scenario a great risk of rainstorm occurrences must be regarded as part of the increasing risk of extreme weather events. <br><br> Rainstorm occurrences are of a great practical importance as they increase the risk for environmental hazards such as landslides, landslips and floods. Landuse planners must therefore pay a great attention to an increasing number of rainstorms and their adverse risk impact on the environment. <br><br> Such practical aspects need particular attention in subtropical China as the region of largest increase of rainstorm occurrences and where, at the same time, the mountains and hilly landscapes are particularly hazard-prone to landslides and floods

    Modeling the momentum distributions of annihilating electron-positron pairs in solids

    Get PDF
    Measuring the Doppler broadening of the positron annihilation radiation or the angular correlation between the two annihilation gamma quanta reflects the momentum distribution of electrons seen by positrons in the material.Vacancy-type defects in solids localize positrons and the measured spectra are sensitive to the detailed chemical and geometric environments of the defects. However, the measured information is indirect and when using it in defect identification comparisons with theoretically predicted spectra is indispensable. In this article we present a computational scheme for calculating momentum distributions of electron-positron pairs annihilating in solids. Valence electron states and their interaction with ion cores are described using the all-electron projector augmented-wave method, and atomic orbitals are used to describe the core states. We apply our numerical scheme to selected systems and compare three different enhancement (electron-positron correlation) schemes previously used in the calculation of momentum distributions of annihilating electron-positron pairs within the density-functional theory. We show that the use of a state-dependent enhancement scheme leads to better results than a position-dependent enhancement factor in the case of ratios of Doppler spectra between different systems. Further, we demonstrate the applicability of our scheme for studying vacancy-type defects in metals and semiconductors. Especially we study the effect of forces due to a positron localized at a vacancy-type defect on the ionic relaxations.Comment: Submitted to Physical Review B on September 1 2005. Revised manuscript submitted on November 14 200

    Health 4.0: How Digitisation Drives Innovation in the Healthcare Sector

    Get PDF
    Driven by networked Electronic Health Record systems, Artificial Intelligence, real-time data from wearable devices with an overlay of invisible user interfaces and improved analytics, a revolution is afoot in the healthcare industry. Over the next few years, it is likely to fundamentally change how healthcare is delivered and how the outcomes are measured. The focus on collaboration, coherence, and convergence will make healthcare more predictive and personalised. This revolution is called Health 4.0. Data portability allows patients and their physicians to access it anytime anywhere and enhanced analytics allows for differential diagnosis and medical responses that can be predictive, timely, and innovative. Health 4.0 allows the value of data more consistently and effectively. It can pinpoint areas of improvement and enable decisions that are more informed. What it also does is help move the entire healthcare industry from a system that is reactive and focused on fee-for-service to a system that is value-based, which measures outcomes and ensures proactive prevention (Thuemmler, Bai, 2017). In this paper, the authors discuss how digitisation is paving the way for data-driven innovation in the healthcare systems. They elaborate on the opportunities and challenges for all stakeholders involved and discuss how emerging technologies can help overcome the inherent rigidity of today’s healthcare ecosystem. Following on from this, the authors explain the importance of research on the actual design of smart healthcare products and product service systems of the future and the challenges faced from the viewpoint of design practice

    On the Applicability of Weak-Coupling Results in High Density QCD

    Get PDF
    Quark matter at asymptotically high baryon chemical potential is in a color superconducting state characterized by a gap Delta. We demonstrate that although present weak-coupling calculations of Delta are formally correct for mu -> Infinity, the contributions which have to this point been neglected are large enough that present results can only be trusted for mu >> mu_c ~ 10^8 MeV. We make this argument by using the gauge dependence of the present calculation as a diagnostic tool. It is known that the present calculation yields a gauge invariant result for mu -> Infinity; we show, however, that the gauge dependence of this result only begins to decrease for mu > mu_c, and conclude that the result can certainly not be trusted for mu < mu_c. In an appendix, we set up the calculation of the influence of the Meissner effect on the magnitude of the gap. This contribution to Delta is, however, much smaller than the neglected contributions whose absence we detect via the resulting gauge dependence.Comment: 21 pages, 3 figures, uses LaTeX2e and ReVTeX, updated figures, made minor text change

    Near-infrared studies of the 2010 outburst of the recurrent nova U Scorpii

    Get PDF
    We present near-infrared (near-IR) observations of the 2010 outburst of U Sco. JHK photometry is presented on 10 consecutive days starting from 0.59 d after outburst. Such photometry can gainfully be integrated into a larger data base of other multiwavelength data which aim to comprehensively study the evolution of U Sco. Early near-IR spectra, starting from 0.56 d after outburst, are presented and their general characteristics discussed. Early in the eruption, we see very broad wings in several spectral lines, with tails extending up to ∼10 000 km s−1 along the line of sight; it is unexpected to have a nova with ejection velocities equal to those usually thought to be exclusive to supernovae. From recombination analysis, we estimate an upper limit of [inline image] for the ejected mass

    Engage D3.5 Opportunities for innovative ATM research (interim report)

    Get PDF
    This document reports on the topics and academic disciplines of past Exploratory Research projects, notably SESAR Workpackage E (long-term and innovative research) and SESAR Exploratory Research (ER) with a view of tracing the evolution of research as well as opportunities for future research. This analysis is complemented with relevant activities in Engage, such as the Engage thematic challenges

    Abstract delta modelling

    Get PDF
    Article / Letter to editorLeiden Inst Advanced Computer Science
    • …
    corecore