122,675 research outputs found

    Production and Spectroscopy of Heavy Hadrons at the LHC

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    Measurements of heavy flavor production and decay have featured prominently in the early results from the four large LHC experiments: ALICE, ATLAS, CMS, and LHCb. These results provide tests of QCD models in a new energy region and point the way toward future measurements of CP violation and searches for new physics. An overview of open heavy flavor studies is presented here, focusing on how the new measurements extend our knowledge of this area of physics. Heavy quarkonia states at the LHC are summarized in other proceedings of this conference. I also discuss briefly how heavy flavor measurements are likely to evolve as LHC luminosities increase.Comment: proceedings for the XIV International Conference on Hadron Spectroscopy (Hadron 2011), 13 pages, 9 figure

    Strain sensor for high temperatures Patent

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    Water cooled gage for strain measurements in high temperature environment

    The Third Person of the Trinity: How the Holy Spirit Facilitates Man\u27s Walk with God

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    Much of the modern church knows the Father and the Son very well as part of its common worship, practice, and conversation. However, the Holy Spirit is given little more than recognition in many circles. He is referenced, talked about, and mentioned in songs and sermons, but there is often a resistance to letting Him lead the believer and the church. It is vital that the church opens its eyes to the indwelling, personal, and powerful Spirit which the Lord has sent to them. Through a study of the role of the Holy Spirit within the Scriptures, as well as a substantial consideration of the views of the Early Church Fathers, this paper seeks to kindle a renewed appreciation for, and a reliance upon the third person of the Trinity. The overarching theme revealed through this research is the marvelous reality that the God of the universe resides within the believer. The final section delves into this reality in search of the process that results in learning to truly walk with the Holy Spirit

    The multiplicity of massive stars

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    Binaries are excellent astrophysical laboratories that provide us with direct measurements of fundamental stellar parameters. Compared to single isolated star, multiplicity induces new processes, offering the opportunity to confront our understanding of a broad range of physics under the extreme conditions found in, and close to, astrophysical objects. In this contribution, we will discuss the parameter space occupied by massive binaries, and the observational means to investigate it. We will review the multiplicity fraction of OB stars within each regime, and in different astrophysical environments. In particular we will compare the O star spectroscopic binary fraction in nearby open clusters and we will show that the current data are adequately described by an homogeneous fraction of f~0.44. We will also summarize our current understanding of the observed parameter distributions of O+OB spectroscopic binaries. We will show that the period distribution is overabundant in short period binaries and that it can be described by a bi-modal Oepik law with a break point around P~10d. The distribution of the mass-ratios shows no indication for a twin population of equal mass binaries and seems rather uniform in the range 0.2< q=M_2/M_1<1.0.Comment: 12 pages, 4 figures, IAU272: Active OB stars: structure, evolution, mass los

    Adaptive high-order finite element solution of transient elastohydrodynamic lubrication problems

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    This article presents a new numerical method to solve transient line contact elastohydrodynamic lubrication (EHL) problems. A high-order discontinuous Galerkin (DG) finite element method is used for the spatial discretization, and the standard Crank-Nicolson method is employed to approximate the time derivative. An h-adaptivity method is used for grid adaptation with the time-stepping, and the penalty method is employed to handle the cavitation condition. The roughness model employed here is a simple indentation, which is located on the upper surface. Numerical results are presented comparing the DG method to standard finite difference (FD) techniques. It is shown that micro-EHL features are captured with far fewer degrees of freedom than when using low-order FD methods

    Lensing Properties of Cored Galaxy Models

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    A method is developed to evaluate the magnifications of the images of galaxies with lensing potentials stratified on similar concentric ellipses. A simple contour integral is provided which enables the sums of the magnifications of even parity or odd parity or the central image to be easily calculated. The sums for pairs of images vary considerably with source position, while the signed sums can be remarkably uniform inside the tangential caustic in the absence of naked cusps. For a family of models in which the potential is a power-law of the elliptic radius, the number of visible images is found as a function of flattening, external shear and core radius. The magnification of the central image depends on the core radius and the slope of the potential. For typical source and lens redshifts, the missing central image leads to strong constraints; the mass distribution in the lensing galaxy must be nearly cusped, and the cusp must be isothermal or stronger. This is in accord with the cuspy cores seen in high resolution photometry of nearby, massive, early-type galaxies, which typically have the surface density falling like distance^{-1.3} outside a break radius of a few hundred parsecs. Cuspy cores by themselves can provide an explanation of the missing central images. Dark matter at large radii may alter the slope of the projected density; provided the slope remains isothermal or steeper and the break radius remains small, then the central image remains unobservable. The sensitivity of the radio maps must be increased fifty-fold to find the central images in abundance.Comment: 42 pages, 11 figures, ApJ in pres

    DSN Ground Communications Facility

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    A functional description of the Ground Communications Facility (GCF) and its relationships with other elements of the Deep Space Network and the NASA Communications Network is presented together with development objectives and goals and comments on implementation activities in support of flight projects. The voice, teletype, high speed data, wideband data, monitor and control, data records, network log processor, and network communications equipment subsystems are individually examined

    In-flight friction and wear mechanism

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    A unique mechanism developed for conducting friction and wear experiments in orbit is described. The device is capable of testing twelve material samples simultaneously. Parameters considered critical include: power, weight, volume, mounting, cleanliness, and thermal designs. The device performed flawlessly in orbit over an eighteen month period and demonstrated the usefulness of this design for future unmanned spacecraft or shuttle applications

    Optimal Measurements for Tests of EPR-Steering with No Detection Loophole using Two-Qubit Werner States

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    It has been shown in earlier works that the vertices of Platonic solids are good measurement choices for tests of EPR-steering using isotropically entangled pairs of qubits. Such measurements are regularly spaced, and measurement diversity is a good feature for making EPR-steering inequalities easier to violate in the presence of experimental imperfections. However, such measurements are provably suboptimal. Here, we develop a method for devising optimal strategies for tests of EPR-steering, in the sense of being most robust to mixture and inefficiency (while still closing the detection loophole of course), for a given number nn of measurement settings. We allow for arbitrary measurement directions, and arbitrary weightings of the outcomes in the EPR-steering inequality. This is a difficult optimization problem for large nn, so we also consider more practical ways of constructing near-optimal EPR-steering inequalities in this limit.Comment: 15 pages, 11 Figure
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