70 research outputs found

    Nonlinear Free Vibration Analysis of Laminated Carbon/Epoxy Curved Panels

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    Nonlinear frequency responses of the laminated carbon/epoxy composite curved shell panels have been investigated numerically and validated with in-house experimentation. The nonlinear responses have been computed numerically via customised computer code developed in MATLAB environment with the help of current mathematical model in conjunction with the direct iterative method. The mathematical model of the layered composite structure derived using various shear deformable kinematic models (two higher-order theories) in association with Green-Lagrange nonlinear strains. The current model includes all the nonlinear higher-order strain terms in the formulation to achieve generality. Further, the modal test has been conducted experimentally to evaluate the desired frequency values and are extracted via the transformed signals using fast Fourier transform technique. In addition, the results are computed using the simulation model developed in commercial finite element package (ANSYS) via batch input technique. Finally, numerical examples are solved for different geometrical configurations and discussed the effects of other design parameters (thickness ratio, curvature ratio and constraint condition) on the fundamental linear and nonlinear frequency responses in details

    Single Spin Asymmetry ANA_N in Polarized Proton-Proton Elastic Scattering at s=200\sqrt{s}=200 GeV

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    We report a high precision measurement of the transverse single spin asymmetry ANA_N at the center of mass energy s=200\sqrt{s}=200 GeV in elastic proton-proton scattering by the STAR experiment at RHIC. The ANA_N was measured in the four-momentum transfer squared tt range 0.003t0.0350.003 \leqslant |t| \leqslant 0.035 \GeVcSq, the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of ANA_N and its tt-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the single spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated by the Pomeron amplitude at this s\sqrt{s}, we conclude that this measurement addresses the question about the presence of a hadronic spin flip due to the Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure

    Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV

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    We report a measurement of the longitudinal double-spin asymmetry A_LL and the differential cross section for inclusive Pi0 production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of Pi0's in their parent jets was found to be around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC

    High pTp_{T} non-photonic electron production in pp+pp collisions at s\sqrt{s} = 200 GeV

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    We present the measurement of non-photonic electron production at high transverse momentum (pT>p_T > 2.5 GeV/cc) in pp + pp collisions at s\sqrt{s} = 200 GeV using data recorded during 2005 and 2008 by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The measured cross-sections from the two runs are consistent with each other despite a large difference in photonic background levels due to different detector configurations. We compare the measured non-photonic electron cross-sections with previously published RHIC data and pQCD calculations. Using the relative contributions of B and D mesons to non-photonic electrons, we determine the integrated cross sections of electrons (e++e2\frac{e^++e^-}{2}) at 3 GeV/c<pT< c < p_T <~10 GeV/cc from bottom and charm meson decays to be dσ(Be)+(BDe)dyeye=0{d\sigma_{(B\to e)+(B\to D \to e)} \over dy_e}|_{y_e=0} = 4.0±0.5\pm0.5({\rm stat.})±1.1\pm1.1({\rm syst.}) nb and dσDedyeye=0{d\sigma_{D\to e} \over dy_e}|_{y_e=0} = 6.2±0.7\pm0.7({\rm stat.})±1.5\pm1.5({\rm syst.}) nb, respectively.Comment: 17 pages, 17 figure

    Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

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    We present first measurements of the evolution of the differential transverse momentum correlation function, {\it C}, with collision centrality in Au+Au interactions at sNN=200\sqrt{s_{NN}} = 200 GeV. {\it C} exhibits a strong dependence on collision centrality that is qualitatively similar to that of number correlations previously reported. We use the observed longitudinal broadening of the near-side peak of {\it C} with increasing centrality to estimate the ratio of the shear viscosity to entropy density, η/s\eta/s, of the matter formed in central Au+Au interactions. We obtain an upper limit estimate of η/s\eta/s that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.

    Longitudinal scaling property of the charge balance function in Au + Au collisions at 200 GeV

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    We present measurements of the charge balance function, from the charged particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au collisions at 200 GeV using the STAR detector at RHIC. We observe that the balance function is boost-invariant within the pseudorapidity coverage [-1.3, 1.3]. The balance function properly scaled by the width of the observed pseudorapidity window does not depend on the position or size of the pseudorapidity window. This scaling property also holds for particles in different transverse momentum ranges. In addition, we find that the width of the balance function decreases monotonically with increasing transverse momentum for all centrality classes.Comment: 6 pages, 3 figure

    Measurement of the Bottom contribution to non-photonic electron production in p+pp+p collisions at s\sqrt{s} =200 GeV

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    The contribution of BB meson decays to non-photonic electrons, which are mainly produced by the semi-leptonic decays of heavy flavor mesons, in p+pp+p collisions at s=\sqrt{s} = 200 GeV has been measured using azimuthal correlations between non-photonic electrons and hadrons. The extracted BB decay contribution is approximately 50% at a transverse momentum of pT5p_{T} \geq 5 GeV/cc. These measurements constrain the nuclear modification factor for electrons from BB and DD meson decays. The result indicates that BB meson production in heavy ion collisions is also suppressed at high pTp_{T}.Comment: 6 pages, 4 figures, accepted by PR

    Characteristics of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) rRNA genes of Apis mellifera (Insecta: Hymenoptera): structure, organization, and retrotransposable elements

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    As an accompanying manuscript to the release of the honey bee genome, we report the entire sequence of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) ribosomal RNA (rRNA)-encoding gene sequences (rDNA) and related internally and externally transcribed spacer regions of Apis mellifera (Insecta: Hymenoptera: Apocrita). Additionally, we predict secondary structures for the mature rRNA molecules based on comparative sequence analyses with other arthropod taxa and reference to recently published crystal structures of the ribosome. In general, the structures of honey bee rRNAs are in agreement with previously predicted rRNA models from other arthropods in core regions of the rRNA, with little additional expansion in non-conserved regions. Our multiple sequence alignments are made available on several public databases and provide a preliminary establishment of a global structural model of all rRNAs from the insects. Additionally, we provide conserved stretches of sequences flanking the rDNA cistrons that comprise the externally transcribed spacer regions (ETS) and part of the intergenic spacer region (IGS), including several repetitive motifs. Finally, we report the occurrence of retrotransposition in the nuclear large subunit rDNA, as R2 elements are present in the usual insertion points found in other arthropods. Interestingly, functional R1 elements usually present in the genomes of insects were not detected in the honey bee rRNA genes. The reverse transcriptase products of the R2 elements are deduced from their putative open reading frames and structurally aligned with those from another hymenopteran insect, the jewel wasp Nasonia (Pteromalidae). Stretches of conserved amino acids shared between Apis and Nasonia are illustrated and serve as potential sites for primer design, as target amplicons within these R2 elements may serve as novel phylogenetic markers for Hymenoptera. Given the impending completion of the sequencing of the Nasonia genome, we expect our report eventually to shed light on the evolution of the hymenopteran genome within higher insects, particularly regarding the relative maintenance of conserved rDNA genes, related variable spacer regions and retrotransposable elements

    Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

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    7191/Mar294

    Event-plane-dependent Dihadron Correlations With Harmonic Vn Subtraction In Au + Au Collisions At S Nn =200 Gev

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    STAR measurements of dihadron azimuthal correlations (Δφ) are reported in midcentral (20-60%) Au+Au collisions at sNN=200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, φs=|φt-ψEP|. The elliptic (v2), triangular (v3), and quadratic (v4) flow harmonic backgrounds are subtracted using the zero yield at minimum (ZYAM) method. The results are compared to minimum-bias d+Au collisions. It is found that a finite near-side (|Δφ|π/2) correlation shows a modification from d+Au data, varying with φs. The modification may be a consequence of path-length-dependent jet quenching and may lead to a better understanding of high-density QCD. © 2014 American Physical Society.894DOE; U.S. Department of EnergyArsene, I., (2005) Nucl. Phys. A, 757, p. 1. , (BRAHMS Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.02. 130;Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , (PHOBOS Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03. 084;Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , (STAR Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03. 085;Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , (PHENIX Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.086Heinz, U., Kolb, P.F., (2002) Nucl. Phys. A, 702, p. 269. , NUPABL 0375-9474 10.1016/S0375-9474(02)00714-5Wang, X.-N., Gyulassy, M., (1992) Phys. Rev. Lett., 68, p. 1480. , PRLTAO 0031-9007 10.1103/PhysRevLett.68.1480Adler, S., (2003) Phys. Rev. Lett., 91, p. 072301. , (PHENIX Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.91. 072301;Adams, J., (2003) Phys. Rev. Lett., 91, p. 072304. , (STAR Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.91.072304;Adler, C., (2003) Phys. Rev. Lett., 90, p. 082302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.90.082302Adams, J., (2005) Phys. Rev. Lett., 95, p. 152301. , (STAR Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.95.152301;Aggarwal, M.M., (2010) Phys. Rev. C, 82, p. 024912. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.82.024912Adams, J., (2004) Phys. Rev. Lett., 93, p. 252301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.93.252301Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813 10.1103/PhysRevC.58.1671Alver, B., (2008) Phys. Rev. C, 77, p. 014906. , PRVCAN 0556-2813 10.1103/PhysRevC.77.014906Feng, A., (2008), Ph.D. thesis, Institute of Particle Physics, CCNU, (unpublished);Konzer, J., (2013), Ph.D. thesis, Purdue University, (unpublished)Agakishiev, H., (STAR Collaboration), arXiv:1010.0690Ackermann, K.H., (2003) Nucl. Instrum. Meth., A499, p. 624. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01960-5Ackermann, K.H., (1999) Nucl. Phys. A, 661, p. 681. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/S0375-9474(99)85117-3Adams, J., (2004) Phys. Rev. Lett., 92, p. 112301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.92.112301Borghini, N., Dinh, P.M., Ollitrault, J.Y., (2000) Phys. Rev. C, 62, p. 034902. , PRVCAN 0556-2813 10.1103/PhysRevC.62.034902Adams, J., (2005) Phys. Rev. C, 72, p. 014904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.72.014904Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.79.034909Bielcikova, J., (2004) Phys. Rev C, 69, p. 021901. , (R) () PRVCAN 0556-2813 10.1103/PhysRevC.69.021901;Konzer, J., Wang, F., (2009) Nucl. Instrum. Meth., A606, p. 713. , NIMAER 0168-9002 10.1016/j.nima.2009.05.011Mishra, A.P., (2008) Phys. Rev. C, 77, p. 064902. , PRVCAN 0556-2813 10.1103/PhysRevC.77.064902;Alver, B., Roland, G., (2010) Phys. Rev. C, 81, p. 054905. , PRVCAN 0556-2813 10.1103/PhysRevC.81.054905Alver, B., Roland, G., (2010) Phys. Rev. C, 82, p. 039903. , 0556-2813 10.1103/PhysRevC.82.039903Xu, J., Ko, C.M., (2011) Phys. Rev. C, 84, p. 014903. , PRVCAN 0556-2813 10.1103/PhysRevC.84.014903Petersen, H., (2010) Phys. Rev. C, 82, p. 041901. , PRVCAN 0556-2813 10.1103/PhysRevC.82.041901Takahashi, J., (2009) Phys. Rev. Lett., 103, p. 242301. , PRLTAO 0031-9007 10.1103/PhysRevLett.103.242301;Andrade, R.P.G., (2012) Phys. Lett. B, 712, p. 226. , PYLBAJ 0370-2693 10.1016/j.physletb.2012.04.044;Qian, W.L., (2013) Phys. Rev. C, 87, p. 014904. , PRVCAN 0556-2813 10.1103/PhysRevC.87.014904Schenke, B., Jeon, S., Gale, C., (2011) Phys. Rev. Lett., 106, p. 042301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.042301;Qiu, Z., Heinz, U.W., (2011) Phys. Rev. C, 84, p. 024911. , PRVCAN 0556-2813 10.1103/PhysRevC.84.024911;Song, H., (2011) Phys. Rev. Lett., 106, p. 192301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.192301;Schenke, B., Jeon, S., Gale, C., (2012) Phys. Rev. C, 85, p. 024901. , PRVCAN 0556-2813 10.1103/PhysRevC.85.024901;Schenke, B., Tribedy, P., Venugopalan, R., (2012) Phys. Rev. Lett., 108, p. 252301. , PRLTAO 0031-9007 10.1103/PhysRevLett.108.252301Adare, A., (2011) Phys. Rev. Lett., 107, p. 252301. , (PHENIX Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.107.252301Adamczyk, L., (2013) Phys. Rev. C, 88, p. 014904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.88.014904Abelev, B.I., (2008) Phys. Rev. Lett., 101, p. 252301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.101.252301Teaney, D., Yan, L., (2011) Phys. Rev. C, 83, p. 064904. , PRVCAN 0556-2813 10.1103/PhysRevC.83.064904Pandit, Y., (2013) J. Phys. Conf. Ser., 446, p. 012012. , (STAR Collaboration),. 1742-6596 10.1088/1742-6596/446/1/012012Ajitanand, N.N., (2005) Phys. Rev. C, 72, p. 011902. , PRVCAN 0556-2813 10.1103/PhysRevC.72.011902Agakishiev, G., (2012) Phys. Rev. C, 86, p. 064902. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.86.064902Adler, C., (2002) Phys. Rev. C, 66, p. 034904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.66.034904Abelev, B.I., (2009) Phys. Rev. C, 80, p. 064912. , (STAR Collaboration), () PRVCAN 0556-2813 10.1103/PhysRevC.80.064912;Abelev, B.I., (2010) Phys. Rev. Lett., 105, p. 022301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.022301Adler, S.S., (2006) Phys. Rev. Lett., 97, p. 052301. , (PHENIX Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.97. 052301;Adare, A., (2008) Phys. Rev. C, 78, p. 014901. , (PHENIX Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.78.014901Stoecker, H., (2005) Nucl. Phys. A, 750, p. 121. , NUPABL 0375-9474 10.1016/j.nuclphysa.2004.12.074;Casalderrey-Solana, J., Shuryak, E.V., Teaney, D., (2005) J. Phys. Conf. Ser., 27, p. 22. , 1742-6588 10.1088/1742-6596/27/1/003;Ruppert, J., Müller, B., (2005) Phys. Lett. B, 618, p. 123. , PYLBAJ 0370-2693 10.1016/j.physletb.2005.04.075Betz, B., (2010) Phys. Rev. Lett., 105, p. 222301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.222301;Ma, G.L., Wang, X.N., (2011) Phys. Rev. Lett., 106, p. 162301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.162301Abelev, B.I., (2009) Phys. Rev. Lett., 102, p. 052302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.102.052302Adamczyk, L., (2014) Phys. Rev. Lett., 112, p. 122301. , (STAR Collaboration),. 10.1103/PhysRevLett.112.12230
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