5,181 research outputs found

    Part 1 of the McMaster University Laboratory Test Program on Brick Veneer/Steel Stud Wall Systems

    Get PDF
    The behaviour of steel stud backup wall panels subjected to lateral loads was investigated experimentally and analytically. In addition, various steel stud to track connections were investigated experimentally. The experimental work consisted of the fabrication and testing of 109 steel stud to track connections. Thirty-two full size steel stud backup wall panels were also tested. Some of the panels were braced with various types of commonly used steel bridging while others were braced with gypsum board sheathing or Styrofoam SM insulation. Twelve beam tests were also performed in order to establish the flexural bending capacity of the steel studs tested. The analytical study consisted of an evaluation of the results of the test program. A one-dimensional elastic Finite Element program was developed to investigate the distribution of torsional stresses in steel studs as part of the analysis. The model had the limitation of ignoring the effects of web perforations. Based on analysis of the test and analytical results, several recommendations were made for design and construction of steel stud backup walls

    WISDOM: A Grid-Enabled Drug Discovery Initiative Against Malaria

    Get PDF
    The goal of this chapter is to present the WISDOM initiative, which is one of the main accomplishments in the use of grids for biomedical sciences achieved on grid infrastructures in Europe. Researchers in life sciences are among the most active scientifi c communities on the EGEE infrastructure. As a consequence, the biomedical virtual organization stands fourth in terms of resources consumed in 2007, with an average of 7000 jobs submitted every day to the grid and more than 4 million hours of CPU consumed in the last 12 months. Only three experiments on the CERN Large Hadron Collider have used more resources. Compared to particle physics, the use of resources is much less centralized as about 40 different scientifi c applications are now currently deployed on EGEE. Each of them requires an amount of CPU which ranges from a few to a few hundred CPU years. Thanks to the 20,000 processors available to the users of the biomedical virtual organization, crunching factors in the hundreds are witnessed routinely. Such performances were already achieved on supercomputers but at the cost of reservation and long delays in the access to resources. On the contrary, grid infrastructures are constantly open to the user communities. Such changes in the scale of the computing resources made continuously available to the researchers in biomedical sciences open opportunities for exploring new fi elds or changing the approach to existing challenges. In this chapter, we would like to show the potential impact of grids in the fi eld of drug discovery through the example of the WISDOM initiative

    Euclidean Preferences, Option Sets and Strategy Proofness

    Get PDF
    In this note, we use the technique of option sets to sort out the implications of coalitional strategyproofness in the spatial setting. We also discuss related issues and open problems

    The Copeland measure of Condorcet choice functions

    Get PDF
    AbstractWe propose a measure to compare an arbitrary choice function with the Copeland choice function. We compute this measure for the familiar Condorcet choice functions

    Validation of the GATE Monte Carlo simulation platform for modelling a CsI(Tl) scintillation camera dedicated to small animal imaging

    Get PDF
    Monte Carlo simulations are increasingly used in scintigraphic imaging to model imaging systems and to develop and assess tomographic reconstruction algorithms and correction methods for improved image quantitation. GATE (GEANT 4 Application for Tomographic Emission) is a new Monte Carlo simulation platform based on GEANT4 dedicated to nuclear imaging applications. This paper describes the GATE simulation of a prototype of scintillation camera dedicated to small animal imaging and consisting of a CsI(Tl) crystal array coupled to a position sensitive photomultiplier tube. The relevance of GATE to model the camera prototype was assessed by comparing simulated 99mTc point spread functions, energy spectra, sensitivities, scatter fractions and image of a capillary phantom with the corresponding experimental measurements. Results showed an excellent agreement between simulated and experimental data: experimental spatial resolutions were predicted with an error less than 100 mu m. The difference between experimental and simulated system sensitivities for different source-to-collimator distances was within 2%. Simulated and experimental scatter fractions in a [98-182 keV] energy window differed by less than 2% for sources located in water. Simulated and experimental energy spectra agreed very well between 40 and 180 keV. These results demonstrate the ability and flexibility of GATE for simulating original detector designs. The main weakness of GATE concerns the long computation time it requires: this issue is currently under investigation by the GEANT4 and the GATE collaboration

    Palaeoecology of the Cenomanian amber forest of Sarthe (western France)

    Get PDF
    Cretaceous ambers have been discovered in France since the beginning of the 18th century. The best known are those from south-western France which are Late Albian-Early Cenomanian in age, but there are other important amber deposits in other regions. Here, we summarise the data on one of these other Cretaceous amber regions, the Sarthe Department. These deposits have been mentioned in the literature since the end of the 18th century, but they have remained relatively unknown. The material, that has been studied during the 1970's and 1980's, yielded a well-diversified arthropod fauna (72 arthropod specimens, including arachnids, cockroaches, bugs, beetles, flies, wasps...) dated to late Early-Middle Cenomanian. In the last decade, 4 types of bacteria, a possible testate amoeba and fungal remains were also found. A re-examination of the historical collections of the Sarthe amber, housed in the "Musée Vert" (Le Mans, France), allows to estimate the geographical extent of the amber deposits in the Sarthe Department. The study of the microfossils of these samples provides new data on their palaeoenvironment

    Stress response function of a two-dimensional ordered packing of frictional beads

    Full text link
    We study the stress profile of an ordered two-dimensional packing of beads in response to the application of a vertical overload localized at its top surface. Disorder is introduced through the Coulombic friction between the grains which gives some indeterminacy and allows the choice of one constrained random number per grain in the calculation of the contact forces. The so-called `multi-agent' technique we use, lets us deal with systems as large as 1000×10001000\times1000 grains. We show that the average response profile has a double peaked structure. At large depth zz, the position of these peaks grows with czcz, while their widths scales like Dz\sqrt{Dz}. cc and DD are analogous to `propagation' and `diffusion' coefficients. Their values depend on that of the friction coefficient μ\mu. At small μ\mu, we get c0cμc_0-c \propto \mu and DμβD \propto \mu^\beta, with β2.5\beta \sim 2.5, which means that the peaks get closer and wider as the disorder gets larger. This behavior is qualitatively what was predicted in a model where a stochastic relation between the stress components is assumed.Comment: 7 pages, 7 figures, accepted version to Europhys. Let

    Ariane Utilization for Secondary Payloads

    Get PDF
    In preparing for the future, the European Space Agency (ESA) has identified a growing shortage of flight opportunities for secondary payloads. This was most directly felt in the execution of the In-Orbit Technology Demonstration Programme (TOP), which is aimed at the demonstration of new technologies in orbit, before their application in projects, thereby reducing the overall risk. The TOP took a lead in investigating the possibility of using the European heavy lift launcher Ariane-IV as a low cost secondary payload carrier, not only for technological, but also for scientific and educational experiments. The secondary payloads were in the form of attached platforms, and small satellites. This paper gives a detailed account of the efforts, which resulted in firm plans to establish a secondary payload capability on the Ariane-IV. Also, an overview of the technical implementation is given
    corecore