530 research outputs found

    A Stochastic Finite Element Method with a Deviatoric-volumetric Split for the Stochastic Linear Isotropic Elasticity Tensor

    Get PDF
    This paper presents a numerical method for solution of a stochastic partial differential equation (SPDE) for a linear elastic body with stochastic coefficients (random variables and/or random fields). To this end the stochastic finite element method (SFEM) is employed, which uses WIENER’S polynomial chaos expansion in order to decompose the coefficients into deterministic and stochastic parts. As a special case, we consider isotropic material behavior with two fluctuating parameters. Computational approaches involving GALERKIN projection are applied to reduce the SPDE into a system of deterministic PDEs. Furthermore, we consider normally distributed random variables, which are assumed to be stochastically independent, and which establish the number of stochastic dimensions. Subsequently, the resulting finite element equation is solved iteratively. Finally, in a representative example for a plate with a ring hole we study the influence of different variances for material parameters on the variances for the finite element results

    Thermoviscoplastic modelling of asymmetric effects for polymers at large strains

    Get PDF
    AbstractGlassy polymers such as polycarbonate exhibit different behaviours in different loading scenarios, such as tension and compression. To this end a flow rule is postulated within a thermodynamic consistent framework in a mixed variant formulation and decomposed into a sum of weighted stress mode related quantities. The different stress modes are chosen such that they are accessible to individual examination in the laboratory, where tension and compression are typical examples. The characterisation of the stress modes is obtained in the octahedral plane of the deviatoric stress space in terms of the Lode angle, such that stress mode dependent scalar weighting functions can be constructed. Furthermore the numerical implementation of the constitutive equations into a finite element program is briefly described. In a numerical example, the model is used to simulate the laser transmission welding process

    Electronic structure of intermetallics based on a rare earth element and a transition or noble metal

    Get PDF
    The results of ab initio study of resonant surface states genesis in the vicinity of Γ point for GdRh[2]Si[2] are presented in this work. Our electronic band structure calculations have shown that the resonant surface states are already formed in three atomic layer slab Si-Rh-Si. The states localization within three layer slab causes its resonant nature and presence of these states on Si- and Gd- termination surfaces

    Investigation of fluorescent properties of plasma exosomes in diagnosis and prognosis of colorectal cancer

    Get PDF
    Exosomes of blood plasma were studied using multiphoton tomography (two-photon microscopy). Exosomes were isolated in patients with colorectal cancer and in healthy donors. Images of fluorescence of exosomes were obtained at a wavelength of 760 nm and second harmonic generation at a wavelength of 380 nm. As a result of the analysis of the obtained data, qualitative differences were found between samples from patients with colorectal cancer and healthy donors

    Extension Education Drives Economic Stimulus Through Trade Adjustment Assistance for Farmers

    Get PDF
    Trade Adjustment Assistance for Farmers (TAAF) is a national multifaceted USDA program that provided technical and financial assistance to farmers and fishermen adversely affected by import competition. This article describes how Extension was successfully mobilized to deliver the TAAF program to 10,983 producers across the nation using innovative education technologies to achieve program objectives and improve the economic well-being of participating farmers and fisherman. The innovative technologies included online curricula and business planning, the use of personal business planning consultants, and linking Extension education outcomes to financial assistance payments that producers used primarily to invest in their business

    Unique Multiorganizational Collaborative Proves Effective in Delivering 2014 Farm Bill Education

    Get PDF
    The Agricultural Act of 2014 is critical to the economic safety net for U.S. producers. This act represented a major change in philosophy, requiring producers to make key decisions about their options on the basis of risk management. To add to the complexity of the issue, the time period for delivering applicable education to landowners before sign-up deadlines was relatively short. This article highlights a unique multiorganizational statewide approach to delivering the applicable education. It involved University of Minnesota Extension, the Center for Farm Financial Management, the U.S. Department of Agriculture, and banks and resulted in substantive evaluative outcomes

    The Demands of a Women\u27s College Soccer Season

    Get PDF
    The purpose of this study was to use GPS, accelerometers, and session rating of perceived exertion (sRPE) to examine the demands of a Division II women’s soccer team. Data was collected on 25 collegiate Division II women’s soccer players over an entire regular season (17 matches and 24 practices). ZephyrTM BioHarnesses (BHs) were used to collect tri-axial acceleration information and GPS derived variables for all matches and practices. Acceleration data was used to calculate Impulse Load, a measure of mechanical load that includes only locomotor related accelerations. GPS was used to quantify total distance and distance in six speed zones. Internal Training Loads were assessed via sRPE. Mean Impulse Load, total distance, and sRPE during match play was 20,120 ± 8609 N·s, 5.48 ± 2.35 km, and 892.50 ± 358.50, respectively. Mean Impulse Load, total distance, and sRPE during practice was 12,410 ± 4067 N·s, 2.95 ± 0.95 km, and 143.30 ± 123.50, respectively. Several very large to nearly perfect correlations were found between Impulse Load and total distance (r = 0.95; p < 0.001), Impulse Load and sRPE (r = 0.84; p < 0.001), and total distance and sRPE (r = 0.82; p < 0.001). This study details the mechanical demands of Division II women’s soccer match play. This study also demonstrates that Impulse Load is a good indicator of total distance
    corecore