104,234 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

    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

    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

    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

    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

    Mercury in Florida Bay fish: spatial distribution of elevated concentrations and possible linkages to Everglades restoration

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    Health advisories are now posted in northern Florida Bay, adjacent to the Everglades, warning of high mercury concentrations in some species of gamefish. Highest concentrations of mercury in both forage fish and gamefish have been measured in the northeastern corner of Florida Bay, adjacent to the dominant freshwater inflows from the Everglades. Thirty percent of spotted seatrout (Cynoscion nebulosus Cuvier, 1830) analyzed exceeded Florida’s no consumption level of 1.5 μg g−1 mercury in this area. We hypothesized that freshwater draining the Everglades served as the major source of methylmercury entering the food web supporting gamefish. A lack of correlation between mercury concentrations and salinity did not support this hypothesis, although enhanced bioavailability of methylmercury is possible as freshwater is diluted with estuarine water. Stable isotopes of carbon, nitrogen, and sulfur were measured in fish to elucidate the shared pathways of methylmercury and nutrient elements through the food web. These data support a benthic source of both methylmercury and nutrient elements to gamefish within the eastern bay, as opposed to a dominant watershed source. Ecological characteristics of the eastern bay, including active redox cycling in near-surface sediments without excessive sulfide production are hypothesized to promote methylmercury formation and bioaccumulation in the benthos. Methylmercury may then accumulate in gamefish through a food web supported by benthic microalgae, detritus, pink shrimp (Farfantepenaeus duorarum Burkenroad, 1939), and other epibenthic feeders. Uncertainty remains as to the relative importance of watershed imports of methylmercury from the Everglades and in situ production in the bay, an uncertainty that needs resolution if the effects of Everglades restoration on mercury levels in fish are to be modeled and managed

    Collective Efficacy and Firearms Violence in Anchorage, Alaska: Preliminary Findings

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    Paper also presented at the 2007 annual meeting of the Western Society of Criminology, Scottsdale, Arizona.This paper seeks to advance the discussion of the utility of collective efficacy, as captured by Sampson, Raudenbush and Earls, in understanding community levels of crime by exploring the relation between community structure, collective efficacy, and in this case firearms violence, in Anchorage, Alaska. The specific aims of this paper are to report the results of a test of the collective efficacy thesis, modeled loosely after the test presented in the 1997 Science paper by Sampson, Raudenbush and Earls, as an explanation of neighborhood rates of firearms violence in Anchorage.Measures Replication and Data / Collective Efficacy and Violence in Anchorage / Discussion and Conclusions / References / Table
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