Topology Optimization Method Research on Hollow Wide-chord Fan Blade of a High-bypass Turbofan Engine

AbstractIn order to realize lightweight design of a high-bypass turbofan engine, topology optimization of vacuum structure on a wide-chord fan blade was carried out regarding mixed loading conditions as static strength, vibration and bird-strike. Without changing the leaf shape, relationship of performance indices on vacuum structure was analyzed with simplified mechanical model of loading conditions. Topology optimization designs were carried out according to the highly sensitive conditions. Vacuum structure layout of fan blade was constructed integrating the major load transfer paths in each design proposal. Performance indices of different fan blade structures were compared. Result shown that optimized fan blade can realize lightweight as well as meeting the strength design requirement

Experimental feasibility of measuring the gravitational redshift of light using dispersion in optical fibers

This paper describes a new class of experiments that use dispersion in optical fibers to convert the gravitational frequency shift of light into a measurable phase shift or time delay. Two conceptual models are explored. In the first model, long counter-propagating pulses are used in a vertical fiber optic Sagnac interferometer. The second model uses optical solitons in vertically separated fiber optic storage rings. We discuss the feasibility of using such an instrument to make a high precision measurement of the gravitational frequency shift of light.Comment: 11 pages, 12 figure

Renormalization Group Flow of Quantum Gravity in the Einstein-Hilbert Truncation

The exact renormalization group equation for pure quantum gravity is used to derive the non-perturbative \Fbeta-functions for the dimensionless Newton constant and cosmological constant on the theory space spanned by the Einstein-Hilbert truncation. The resulting coupled differential equations are evaluated for a sharp cutoff function. The features of these flow equations are compared to those found when using a smooth cutoff. The system of equations with sharp cutoff is then solved numerically, deriving the complete renormalization group flow of the Einstein-Hilbert truncation in $d=4$. The resulting renormalization group trajectories are classified and their physical relevance is discussed. The non-trivial fixed point which, if present in the exact theory, might render Quantum Einstein Gravity nonperturbatively renormalizable is investigated for various spacetime dimensionalities.Comment: 58 pages, latex, 24 figure

Short-term exposure to air pollution and incidence of stroke in the Women's Health Initiative

Background: Evidence of the association between daily variation in air pollution and risk of stroke is inconsistent, potentially due to the heterogeneity in stroke etiology. Objectives: To estimate the associations between daily variation in ambient air pollution and risk of stroke and its subtypes among participants of the Women's Health Initiative, a large prospective cohort study in the United States. Methods: We used national-scale, log-normal ordinary kriging models to estimate daily concentrations of fine particulate matter (PM2.5), respirable particulate matter (PM10), nitrogen dioxide (NO2), nitrogen oxides (NOx), sulphur dioxide, and ozone at participant addresses. Stroke was adjudicated by trained neurologists and classified as ischemic or hemorrhagic. Ischemic strokes were further classified according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification. We used a time-stratified case-crossover approach to estimate the odds ratio (OR) of the risk of stroke associated with an interquartile range (IQR) increase in concentrations of each air pollutant. We performed stratified analysis to examine whether associations varied across subgroups defined by age at stroke onset, US census region, smoking status, body mass index, and prior history of diabetes mellitus, hypertension, heart or circulation problems, or arterial fibrillation at enrollment. Results: Among 5417 confirmed strokes between 1993 and 2012, 4300 (79.4%) were classified as ischemic and 924 (17.1%) as hemorrhagic. No association was observed between day-to-day variation in any pollutant and risk of total stroke, ischemic stroke, or specific etiologies of ischemic stroke. We observed a positive association between risk of hemorrhagic stroke and NO2 and NOx in the 3 days prior to stroke with OR of 1.24 (95% CI: 1.01, 1.52) and 1.18 (95% CI: 1.03, 1.34) per IQR increase, respectively. The observed associations with hemorrhagic stroke were more pronounced among non-obese participants. Conclusions: In this large cohort of post-menopausal US women, daily NO2 and NOx were associated with higher risk of hemorrhagic stroke, but ambient levels of four other air pollutants were not associated with higher risk of total stroke, ischemic stroke, or ischemic stroke subtypes

Short-term Air Pollution Levels and Blood Pressure in Older Women

Background: Evidence of associations between daily variation in air pollution and blood pressure (BP) is varied and few prior longitudinal studies adjusted for calendar time. Methods: We studied 143,658 postmenopausal women 50 to 79 years of age from the Women's Health Initiative (1993-2005). We estimated daily atmospheric particulate matter (PM) (in three size fractions: PM2.5, PM2.5-10, and PM10) and nitrogen dioxide (NO2) concentrations at participants' residential addresses using validated lognormal kriging models. We used linear mixed-effects models to estimate the association between air pollution concentrations and repeated measures of systolic and diastolic BP (SBP, DBP) adjusting for confounders and calendar time. Results: Short-term PM2.5and NO2were each positively associated with DBP {0.10 mmHg [95% confidence interval (CI): 0.04, 0.15]; 0.13 mmHg (95% CI: 0.09, 0.18), respectively} for interquartile range changes in lag 3-5 day PM2.5and NO2. Short-term NO2was negatively associated with SBP [-0.21 mmHg (95%CI: -0.30, -0.13)]. In two-pollutant models, the NO2-DBP association was slightly stronger, but for PM2.5was attenuated to null, compared with single-pollutant models. Associations between short-term NO2and DBP were more pronounced among those with higher body mass index, lower neighborhood socioeconomic position, and diabetes. When long-term (annual) and lag 3-5 day PM2.5were in the same model, associations with long-term PM2.5were stronger than for lag 3-5 day. Conclusions: We observed that short-term PM2.5and NO2levels were associated with increased DBP, although two-pollutant model results suggest NO2was more likely responsible for observed associations. Long-term PM2.5effects were larger than short-term

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Non-Equilibrium Bose-Einstein Condensates, Dynamical Scaling and Symmetric Evolution in large N Phi^4 theory

We analyze the non-equilibrium dynamics of the O(N) Phi^4 model in the large N limit and for states of large energy density. The dynamics is dramatically different when the energy density is above the top of the tree level potential V_0 than when it is below it.When the energy density is below V_0, we find that non-perturbative particle production through spinodal instabilities provides a dynamical mechanism for the Maxwell construction. The asymptotic values of the order parameter only depend on the initial energy density and all values between the minima of the tree level potential are available, the asymptotic dynamical `effective potential' is flat between the minima. When the energy density is larger than V_0, the evolution samples ergodically the broken symmetry states, as a consequence of non-perturbative particle production via parametric amplification. Furthermore, we examine the quantum dynamics of phase ordering into the broken symmetry phase and find novel scaling behavior of the correlation function. There is a crossover in the dynamical correlation length at a time scale t_s \sim \ln(1/lambda). For t < t_s the dynamical correlation length \xi(t) \propto \sqrt{t} and the evolution is dominated by spinodal instabilities, whereas for t>t_s the evolution is non-linear and dominated by the onset of non-equilibrium Bose-Einstein condensation of long-wavelength Goldstone bosons.In this regime a true scaling solution emerges with a non- perturbative anomalous scaling length dimension z=1/2 and a dynamical correlation length \xi(t) \propto (t-t_s). The equal time correlation function in this scaling regime vanishes for r>2(t-t_s) by causality. For t > t_s the equal time correlation function falls of as 1/r. A semiclassical but stochastic description emerges for time scales t > t_s.Comment: Minor improvements, to appear in Phys. Rev. D. Latex file, 48 pages, 12 .ps figure

Genome-wide association study and meta-analysis identify loci associated with ventricular and supraventricular ectopy

The genetic basis of supraventricular and ventricular ectopy (SVE, VE) remains largely uncharacterized, despite established genetic mechanisms of arrhythmogenesis. To identify novel genetic variants associated with SVE/VE in ancestrally diverse human populations, we conducted a genome-wide association study of electrocardiographically identified SVE and VE in five cohorts including approximately 43,000 participants of African, European and Hispanic/Latino ancestry. In thirteen ancestry-stratified subgroups, we tested multivariable-adjusted associations of SVE and VE with single nucleotide polymorphism (SNP) dosage. We combined subgroup-specific association estimates in inverse variance-weighted, fixed-effects and Bayesian meta-analyses. We also combined fixed-effects meta-analytic t-test statistics for SVE and VE in multi-trait SNP association analyses. No loci reached genome-wide significance in trans-ethnic meta-analyses. However, we found genome-wide significant SNPs intronic to an apoptosis-enhancing gene previously associated with QRS interval duration (FAF1; lead SNP rs7545860; effect allele frequency = 0.02; P = 2.0 × 10-8) in multi-trait analysis among European ancestry participants and near a locus encoding calcium-dependent glycoproteins (DSC3; lead SNP rs8086068; effect allele frequency = 0.17) in meta-analysis of SVE (P = 4.0 × 10-8) and multi-trait analysis (P = 2.9 × 10-9) among African ancestry participants. The novel findings suggest several mechanisms by which genetic variation may predispose to ectopy in humans and highlight the potential value of leveraging pleiotropy in future studies of ectopy-related phenotypes

Constitutive behavior of an AA4032 piston alloy with Cu and Er additions upon high temperature compressive deformation

The Research and Researchers for Industry (RRi); King Mongkut’s University of Technology Thonbur