46,796 research outputs found

    Asymptotic behavior of the least common multiple of consecutive arithmetic progression terms

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    Let ll and mm be two integers with l>m0l>m\ge 0, and let aa and bb be integers with a1a\ge 1 and a+b1a+b\ge 1. In this paper, we prove that loglcmmn<iln{ai+b}=An+o(n)\log {\rm lcm}_{mn<i\le ln}\{ai+b\} =An+o(n), where AA is a constant depending on l,ml, m and aa.Comment: 8 pages. To appear in Archiv der Mathemati

    Synthesis and structural characterization of 2Dioxane.2H2O.CuCl2: metal-organic compound with Heisenberg antiferromagnetic S=1/2 chains

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    A novel organometallic compound 2Dioxane.CuCl2.2H2O has been synthesized and structurally characterized by X-ray crystallography. Magnetic susceptibility and zero-field inelastic neutron scattering have also been used to study its magnetic properties. It turns out that this material is a weakly coupled one-dimensional S=1/2 Heisenberg antiferromagnetic chain system with chain direction along the crystallographic c axis and the nearest-neighbor intra-chain exchange constant J=0.85(4) meV. The next-nearest-neighbor inter-chain exchange constant J' is also estimated to be 0.05 meV. The observed magnetic excitation spectrum from inelastic neutron scattering is in excellent agreement with numerical calculations based on the Muller ansatz.Comment: 4 pages; 5 figure

    The least common multiple of a sequence of products of linear polynomials

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    Let f(x)f(x) be the product of several linear polynomials with integer coefficients. In this paper, we obtain the estimate: loglcm(f(1),...,f(n))An\log {\rm lcm}(f(1), ..., f(n))\sim An as nn\rightarrow\infty , where AA is a constant depending on ff.Comment: To appear in Acta Mathematica Hungaric

    Develop, demonstrate, and verify large area composite structural bonding with polyimide adhesives

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    The technology required to produce graphite-polyimide structural components with operational capability at 598 K (600 F) is considered. A series of polyimide adhesives was screened for mechanical and physical properties and processibility in fabricating large midplane bonded panels and honeycomb sandwich panels in an effort to fabricate a structural test component of the space shuttle aft body flap. From 41 formulations, LaRC-13, FM34B-18, and a modified LaRC-13 adhesive were selected for further evaluation. The LaRC-13 adhesive was rated as the best of the three adhesives in terms of availability, cost, processibility, properties, and ability to produce void fee large area (12" x 12") midplane bonds. Surface treatments and primers for the adhesives were evaluated and processes were developed for the fabrication of honeycomb sandwich panels of very good quality which was evidenced by rupture in the honeycomb core rather than in the facesheet bands on flatwise tensile strength testing. The fabrication of the adhesively bonded honeycomb sandwich cover panels, ribs, and leading edge covers of Celion graphite/LARC-160 polyimide laminates is described

    Assessing somatization in urologic chronic pelvic pain syndrome

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    BACKGROUND: This study examined the prevalence of somatization disorder in Urological Chronic Pelvic Pain Syndrome (UCPPS) and the utility of two self-report symptom screening tools for assessment of somatization in patients with UCPPS. METHODS: The study sample included 65 patients with UCPPS who enrolled in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Study at Washington University. Patients completed the PolySymptomatic PolySyndromic Questionnaire (PSPS-Q) (n = 64) and the Patient Health Questionnaire-15 Somatic Symptom Severity Scale (PHQ-15) (n = 50). Review of patient medical records found that only 47% (n = 30) contained sufficient documentation to assess Perley-Guze criteria for somatization disorder. RESULTS: Few (only 6.5%) of the UCPPS sample met Perley-Guze criteria for definite somatization disorder. Perley-Guze somatization disorder was predicted by definite PSPS-Q somatization with at least 75% sensitivity and specificity. Perley-Guze somatization disorder was predicted by severe (\u3e 15) PHQ-15 threshold that had \u3e 90% sensitivity and specificity but was met by only 16% of patients. The moderate (\u3e 10) PHQ-15 threshold had higher sensitivity (100%) but lower specificity (52%) and was met by 52% of the sample. CONCLUSIONS: The PHQ-15 is brief, but it measures symptoms constituting only one dimension of somatization. The PSPS-Q uniquely captures two conceptual dimensions inherent in the definition of somatization disorder, both number of symptoms and symptom distribution across multiple organ systems, with relevance for UCPPS as a syndrome that is not just a collection of urological symptoms but a broader syndrome with symptoms extending beyond the urological system

    Sensitivity of Global Modeling Initiative chemistry and transport model simulations of radon-222 and lead-210 to input meteorological data

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    International audienceWe have used the Global Modeling Initiative chemistry and transport model to simulate the radionuclides radon-222 and lead-210 using three different sets of input meteorological information: 1. Output from the Goddard Space Flight Center Global Modeling and Assimilation Office GEOS-STRAT assimilation; 2. Output from the Goddard Institute for Space Studies GISS II' general circulation model; and 3. Output from the National Center for Atmospheric Research MACCM3 general circulation model. We intercompare these simulations with observations to determine the variability resulting from the different meteorological data used to drive the model, and to assess the agreement of the simulations with observations at the surface and in the upper troposphere/lower stratosphere region. The observational datasets we use are primarily climatologies developed from multiple years of observations. In the upper troposphere/lower stratosphere region, climatological distributions of lead-210 were constructed from ~25 years of aircraft and balloon observations compiled into the US Environmental Measurements Laboratory RANDAB database. Taken as a whole, no simulation stands out as superior to the others. However, the simulation driven by the NCAR MACCM3 meteorological data compares better with lead-210 observations in the upper troposphere/lower stratosphere region. Comparisons of simulations made with and without convection show that the role played by convective transport and scavenging in the three simulations differs substantially. These differences may have implications for evaluation of the importance of very short-lived halogen-containing species on stratospheric halogen budgets

    Temperature-dependent Fermi surface evolution in heavy fermion CeIrIn5

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    In Cerium-based heavy electron materials, the 4f electron's magnetic moments bind to the itinerant quasiparticles to form composite heavy quasiparticles at low temperature. The volume of the Fermi surfacein the Brillouin zone incorporates the moments to produce a "large FS" due to the Luttinger theorem. When the 4f electrons are localized free moments, a "small FS" is induced since it contains only broad bands of conduction spd electrons. We have addressed theoretically the evolution of the heavy fermion FS as a function of temperature, using a first principles dynamical mean-field theory (DMFT) approach combined with density functional theory (DFT+DMFT). We focus on the archetypical heavy electrons in CeIrIn5, which is believed to be near a quantum critical point. Upon cooling, both the quantum oscillation frequencies and cyclotron masses show logarithmic scaling behavior (~ ln(T_0/T)) with different characteristic temperatures T_0 = 130 and 50 K, respectively. The resistivity coherence peak observed at T ~ 50 K is the result of the competition between the binding of incoherent 4f electrons to the spd conduction electrons at Fermi level and the formation of coherent 4f electrons.Comment: 5 pages main article,3 figures for the main article, 2 page Supplementary information, 2 figures for the Supplementary information. Supplementary movie 1 and 2 are provided on the webpage(http://www-ph.postech.ac.kr/~win/supple.html

    BIOMECHANICAL ANALYSIS OF THE LUNGE TECHNIQUE IN THE ELITE FEMALE FENCERS

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    The objective of this study is to profile the lunge technique of four female elite epee fencers. The motion was filmed with a video camera (50Hz) during a trial competition against Jiang Su Team. Data were collected and analysed using a Peak Performance System. The lunge in attacking technique was analysed. The kinematic parameters included stride length of lunge, reaction time, horizontal velocity of the centre of gravity and time to reach the target were determined. The centre of gravly and the Made of all four athletes were found to move simultaneously. The findings contradicted the belief of the athletes that the blade leads the movement of the body

    Dressed Polyakov loop and flavor dependent phase transitions

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    The chiral condensate and dressed Polyakov loop at finite temperature and density have been investigated in the framework of Nf = 2+1 Nambu-Jona-Lasinio (NJL) model with two degenerate u, d quarks and one strange quark. In the case of explicit chiral symmetry breaking with physical quark masses, it is found that the phase transitions for light u, d quarks and s quark are sequentially happened, and the separation between the transition lines for different flavors becomes wider and wider with the increase of baryon density. For each flavor, the pseudo-critical temperatures for chiral condensate and dressed Polyakov loop differ in a narrow transition range in the lower baryon density region, and the two transitions coincide in the higher baryon density region.Comment: 9 pages, 9 figures; Version accepted in Phys. Rev.

    Domain walls and the conductivity of mesoscopic ferromagnets

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    Quantum interference phenomena in the conductivity of mesoscopic ferromagnets are considered, particularly with regard to the effects of geometric phases acquired by electrons propagating through regions of spatially varying magnetization (due, e.g., to magnetic domain walls). Weak localization and electron-electron interaction quantum corrections to the conductivity and universal conductance fluctuations are discussed. Experiments are proposed for multiply-connected geometries that should reveal conductance oscillations with variations of the profile of the magnetization.Comment: 4 pages, 1 fugure, RevTEX, Submitted to Phys. Rev. Let
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