Wavy stripes and squares in zero P number convection

A simple model to explain numerically observed behaviour of chaotically varying stripes and square patterns in zero Prandtl number convection in Boussinesq fluid is presented. The nonlinear interaction of mutually perpendicular sets of wavy rolls, via higher mode, may lead to a competition between the two sets of wavy rolls. The appearance of square patterns is due to the secondary forward Hopf bifurcation of a set of wavy rolls.Comment: 8 pages and 3 figures, late

Quasiperiodic waves at the onset of zero Prandtl number convection with rotation

We show the possibility of quasiperiodic waves at the onset of thermal convection in a thin horizontal layer of slowly rotating zero-Prandtl number Boussinesq fluid confined between stress-free conducting boundaries. Two independent frequencies emerge due to an interaction between a stationary instability and a self-tuned wavy instability in presence of coriolis force, if Taylor number is raised above a critical value. Constructing a dynamical system for the hydrodynamical problem, the competition between the interacting instabilities is analyzed. The forward bifurcation from the conductive state is self-tuned.Comment: 9 pages of text (LaTex), 5 figures (Jpeg format

Isospin Asymmetry in Nuclei and Neutron Stars

The roles of isospin asymmetry in nuclei and neutron stars are investigated using a range of potential and field-theoretical models of nucleonic matter. The parameters of these models are fixed by fitting the properties of homogeneous bulk matter and closed-shell nuclei. We discuss and unravel the causes of correlations among the neutron skin thickness in heavy nuclei, the pressure of beta-equilibrated matter at a density of 0.1 fm$^{-3}$, the derivative of the nuclear symmetry energy at the same density and the radii of moderate mass neutron stars. Constraints on the symmetry properties of nuclear matter from the binding energies of nuclei are examined. The extent to which forthcoming neutron skin measurements will further delimit the symmetry properties is investigated. The impact of symmetry energy constraints for the mass and moment of inertia contained within neutron star crusts and the threshold density for the nucleon direct Urca process, all of which are potentially measurable, is explored. We also comment on the minimum neutron star radius, assuming that only nucleonic matter exists within the star.Comment: 49 pages, 17 figures, Phys. Rep. (in press); made improvements to "RAPR" and corrected transition densitie

Efficient model for modular multi-level converter simulation

Detailed models of modular multi-level converters (MMCs) are cumbersome for electromagnetic transient simulation programs because of their high number of components which involve large simulation times. In this work, the modeling of an MMC is addressed with the objective of reducing the simulation time. First, the MMC structure is presented, including the modulation technique, the voltage balancing algorithm and the circulating current control used to validate the model. Next, an efficient simplified model is proposed. This is formed by just one variable voltage source, one variable capacitor and one variable resistor per arm, regardless of the number of submodules. This simplified model allows the simulation time to be reduced while keeping the dynamics of the MMC. The comparison through several PSCAD simulations with a detailed 5-level MMC model proves its validity during both steady-state and transient conditions (ac and dc short-circuits).The authors acknowledge the financial support of the Spanish Ministry of Economy and EU FEDER Funds under Grant DPI2014-53245-R and the Universitat Jaume I under Grants P1.1B2013-51 and E-2014-24.Vidal-Albalate, R.; Belenguer, E.; Beltrán, H.; Blasco Gimenez, R. (2015). Efficient model for modular multi-level converter simulation. Mathematics and Computers in Simulation. 99(1):1-15. https://doi.org/10.1016/j.matcom.2015.10.001S11599

Nuclear collision in strong magnetic field

We studied nucleus-nucleus collision in strong magnetic field based on a transport model. It is found that neutrons and protons can be separated from a nucleus by strong magnetic field and neutron-rich high density nuclear matter and low density proton collectivity matter can be formed during nucleus-nucleus collision. The electric field produced by proton collectivity can accelerate proton and charged meson up to very high energies. Besides the studies of isospin physics such as symmetry energy, these results may help us to understand the acceleration mechanisms of high energy charged particles in the cosmic raysComment: 8 pages, 4 fig

Prevalence of clinically significant liver disease within the general population, as defined by non-invasive markers of liver fibrosis: a systematic review

At present, there is no evidence based pathway to stratify risk of chronic liver disease in a general population setting. Non-invasive tests of liver fibrosis may provide a mechanism for earlier diagnosis. These tests have been extensively validated in the hospital setting but their performance in a general population setting is unclear. We performed a systematic review of non-invasive tests used to stratify patients at risk of clinically significant liver disease in a general population setting and report the prevalence of chronic liver disease as defined by these tests. We systematically searched EMBASE, MEDLINE, Web of Science, reference lists from the original studies and recent conference proceedings. All study designs were considered. Nineteen studies were identified, utilising eleven non-invasive tests. Only transient elastography and Fibrotest were compared against histological end-points. The prevalence of liver fibrosis varied between 0.7% and 25.7%. More focussed stratification for advanced liver fibrosis (0.9%-2%) or cirrhosis (0.1%-1.7%) narrowed estimates of prevalence. Studies targeting patients with liver disease risk factors such as hazardous alcohol use or type 2 diabetes reported higher prevalence of advanced liver fibrosis (0%-27.9%) and cirrhosis (2.4%-4%). Validated non-invasive tests of liver fibrosis consistently detected otherwise unrecognised liver disease in the general population. Studies targeting risk factors found cirrhosis in 2.4 to 4 % of their target populations. Reliance on abnormal liver function tests will miss the majority of patients with significant liver injury. New pathways to stratify chronic liver, using non-invasive markers of liver fibrosis, are needed in the general population setting

How 'dynasty' became a modern global concept : intellectual histories of sovereignty and property

The modern concept of ‘dynasty’ is a politically-motivated modern intellectual invention. For many advocates of a strong sovereign nation-state across the nineteenth and early twentieth century, in France, Germany, and Japan, the concept helped in visualizing the nation-state as a primordial entity sealed by the continuity of birth and blood, indeed by the perpetuity of sovereignty. Hegel’s references to ‘dynasty’, read with Marx’s critique, further show how ‘dynasty’ encoded the intersection of sovereignty and big property, indeed the coming into self-consciousness of their mutual identification-in-difference in the age of capitalism. Imaginaries about ‘dynasty’ also connected national sovereignty with patriarchal authority. European colonialism helped globalize the concept in the non-European world; British India offers an exemplar of ensuing debates. The globalization of the abstraction of ‘dynasty’ was ultimately bound to the globalization of capitalist-colonial infrastructures of production, circulation, violence, and exploitation. Simultaneously, colonized actors, like Indian peasant/‘tribal’ populations, brought to play alternate precolonial Indian-origin concepts of collective regality, expressed through terms like ‘rajavamshi’ and ‘Kshatriya’. These concepts nourished new forms of democracy in modern India. Global intellectual histories can thus expand political thought today by provincializing and deconstructing Eurocentric political vocabularies and by recuperating subaltern models of collective and polyarchic power.PostprintPeer reviewe

Observation of a J^PC = 1-+ exotic resonance in diffractive dissociation of 190 GeV/c pi- into pi- pi- pi+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the pi- pi- pi+ final state using a 190 GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1 GeV^2/c^2. The well-known resonances a1(1260), a2(1320), and pi2(1670) are clearly observed. In addition, the data show a significant natural parity exchange production of a resonance with spin-exotic quantum numbers J^PC = 1-+ at 1.66 GeV/c^2 decaying to rho pi. The resonant nature of this wave is evident from the mass-dependent phase differences to the J^PC = 2-+ and 1++ waves. From a mass-dependent fit a resonance mass of 1660 +- 10+0-64 MeV/c^2 and a width of 269+-21+42-64 MeV/c^2 is deduced.Comment: 7 page, 3 figures; version 2 gives some more details, data unchanged; version 3 updated authors, text shortened, data unchange

Transverse spin effects in hadron-pair production from semi-inclusive deep inelastic scattering

First measurements of azimuthal asymmetries in hadron-pair production in deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron) and NH_3 (proton) targets are presented. The data were taken in the years 2002-2004 and 2007 with the COMPASS spectrometer using a muon beam of 160 GeV/c at the CERN SPS. The asymmetries provide access to the transversity distribution functions, without involving the Collins effect as in single hadron production. The sizeable asymmetries measured on the NH_ target indicate non-vanishing u-quark transversity and two-hadron interference fragmentation functions. The small asymmetries measured on the ^6LiD target can be interpreted as indication for a cancellation of u- and d-quark transversities.Comment: 13 pages, 4 figures, updated to the published versio