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Sample records for shock spherical cows

  1. Spherical shock waves in general relativity

    International Nuclear Information System (INIS)

    Nutku, Y.

    1991-01-01

    We present the metric appropriate to a spherical shock wave in the framework of general relativity. This is a Petrov type-N vacuum solution of the Einstein field equations where the metric is continuous across the shock and the Riemann tensor suffers a step-function discontinuity. Spherical gravitational waves are described by type-N Robinson-Trautman metrics. However, for shock waves the Robinson-Trautman solutions are unacceptable because the metric becomes discontinuous in the Robinson-Trautman coordinate system. Other coordinate systems that have so far been introduced for describing Robinson-Trautman solutions also suffer from the same defect. We shall present the C 0 -form of the metric appropriate to spherical shock waves using Penrose's approach of identification with warp. Further extensions of Penrose's method yield accelerating, as well as coupled electromagnetic-gravitational shock-wave solutions

  2. Shock-driven Turbulent Mixing in Spherically Confined Geometries

    Science.gov (United States)

    Boureima, Ismael; Ramaprabhu, Praveen

    2017-11-01

    We report results from detailed numerical simulations of turbulent mixing generated by shock passage through a material interface separating two gases in a spherical configuration. The problem definition is similar to the spherical implosion defined by. In this configuration, a spherical shock converges on a perturbed interface between gases with differing properties. During the implosion, perturbations at the interface are subjected to growth due to the RM instability, the RT instability, as well as Bell-Plesset effects. We report on several quantities of interest to the turbulence modeling community, including the turbulent kinetic energy, the anisotropy tensor, density self-correlation, atomic mixing etc. The simulations were performed using the FLASH code, at a resolution of 3072 x 1024 x 1024 in the radial, azimuthal and polar directions. We also report preliminary results from a study in which the convergence ratio of the implosion is varied by modifying the adiabatic index of the inner material.

  3. Electron-ion thermal equilibration after spherical shock collapse

    Energy Technology Data Exchange (ETDEWEB)

    Rygg, J R; Frenje, J A; Li, C K; Seguin, F H; Petrasso, R D; Meyerhofer, D D; Stoeckl, C

    2009-08-14

    A comprehensive set of dual nuclear product observations provides a snapshot of imploding inertial confinement fusion capsules at the time of shock collapse, shortly before the final stages of compression. The collapse of strong convergent shocks at the center of spherical capsules filled with D{sub 2} and {sup 3}He gas induces D-D and D-{sup 3}He nuclear production. Temporal and spectral diagnostics of products from both reactions are used to measure shock timing, temperature, and capsule areal density. The density and temperature inferred from these measurements are used to estimate the electron-ion thermal coupling, and demonstrate a lower electron-ion relaxation rate for capsules with lower initial gas density.

  4. Shock waves from non-spherically collapsing cavitation bubbles

    Science.gov (United States)

    Supponen, Outi; Obreschkow, Danail; Farhat, Mohamed

    2017-11-01

    Combining simultaneous high-speed imaging and hydrophone measurements, we uncover details of the multiple shock wave emission from laser-induced cavitation bubbles collapsing in a non-spherical way. For strongly deformed bubbles collapsing near a free surface, we identify the distinct shock waves caused by the jet impact onto the opposite bubble wall and by the individual collapses of the remaining bubble segments. The energy carried by each of these shocks depends on the level of bubble deformation, quantified by the anisotropy parameter ζ, the dimensionless equivalent of the Kelvin impulse. For jetting bubbles, at ζ hammer pressure is found to be the most energetic shock. Through statistical analysis of the experimental data and theoretical derivations, and by comparing bubbles deformed by different sources (variable gravity achieved on parabolic flights, and neighboring free and rigid surfaces), we find that the shock peak pressure may be approximated as the jet impact-induced water hammer as ph = 0.45 (ρc2 Δp) 1 / 2ζ-1 .

  5. Strong Shock Propagating Over A Random Bed of Spherical Particles

    Science.gov (United States)

    Mehta, Yash; Salari, Kambiz; Jackson, Thomas L.; Balachandar, S.; Thakur, Siddharth

    2017-11-01

    The study of shock interaction with particles has been largely motivated because of its wide-ranging applications. The complex interaction between the compressible flow features, such as shock wave and expansion fan, and the dispersed phase makes this multi-phase flow very difficult to predict and control. In this talk we will be presenting results on fully resolved inviscid simulations of shock interaction with random bed of particles. One of the fascinating observations from these simulations are the flow field fluctuations due to the presence of randomly distributed particles. Rigorous averaging (Favre averaging) of the governing equations results in Reynolds stress like term, which can be classified as pseudo turbulence in this case. We have computed this ``Reynolds stress'' term along with individual fluctuations and the turbulent kinetic energy. Average pressure was also computed to characterize the strength of the transmitted and the reflected waves. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program.

  6. Discrete Element Simulation of Elastoplastic Shock Wave Propagation in Spherical Particles

    Directory of Open Access Journals (Sweden)

    M. Shoaib

    2011-01-01

    Full Text Available Elastoplastic shock wave propagation in a one-dimensional assembly of spherical metal particles is presented by extending well-established quasistatic compaction models. The compaction process is modeled by a discrete element method while using elastic and plastic loading, elastic unloading, and adhesion at contacts with typical dynamic loading parameters. Of particular interest is to study the development of the elastoplastic shock wave, its propagation, and reflection during entire loading process. Simulation results yield information on contact behavior, velocity, and deformation of particles during dynamic loading. Effects of shock wave propagation on loading parameters are also discussed. The elastoplastic shock propagation in granular material has many practical applications including the high-velocity compaction of particulate material.

  7. Phisical and chemical transformation of rocks and ores in spherical shock waves

    Science.gov (United States)

    Kozlov, E. A.; Anfilogov, V. N.; Zugin, Y. N.; Belogub, E. V.; Brichko, S. N.

    2003-04-01

    The method of creation of the spherical converging waves in shut system is worked out. A spheric sample of rock is placed into a steel container. The shock wave is produced by layer explosive, which is placed on the surface of a steel container. The experiments are realized in the shut condition and the result of the shock action is preserved in the sample. Graphitic qurartzite, graphic granit and sulfide ore were exposed of the shock wave action. The pressure and temperature in the spheric sample is the function of radius. We have following results of the shock wave action from periphery to center. The graphitic quartzite: 24 - 11 mm - big fractures in quartz grains; 11- 8 mm - planar fractures in quartz grains (P = 7.5 Gpa); 8 - 7 mm (P = 14 - 22 Gpa) amorphous areas in quartz, little crystals of coesite; 7 -5.8 mm-diaplectic and partial meltihg zone; 5.8 - 1.4 mm - isotropic glass. There is no transformation of graphite to diamond. The graphic granit: 24- 13 mm - unchanged granit; 13 - 10 mm - quartz has block structure; 10-8 mm - grains of fielspar become isotropic, quartz has planar separate forms; 8 -4.5 mm - clean transparent rose diaplectic glass; 4,5 - 0 mm clean granulated glass. The sample of the sulphide ore consists of pyrite, chalcopyrite and quartz. The results of the shock action on sulphilde ore: 24 -12 mm - big fractures in the sulphide ore; 12 -8 mm - relicts of the primary sulphides with rims and veinlets of the new sulphides (mainly chalcopyrite), which were crystalizated from melt; 8 -0 mm- porous material consists of bornite, chalcopyrite, pyrrotite, pyrite and little quantity of silicate glass.

  8. The interaction of laser driven shock waves with a spherical density perturbation

    International Nuclear Information System (INIS)

    Bach, D.R; Budil, K.S.; Klein, R.I.; Perry, T.S.

    1999-01-01

    Strong shock waves produced by illumination of a CH target by laser produced x-rays were driven through a copper sphere. The motion and deformation of the sphere were measured using radiographs generated by backlighting the sphere with a large area backlighter. The sphere became non-spherical after the passage of the shock, having a complicated down-stream structure. This was an instability-induced structure that was predicted by calculations. The experiment is a convenient laboratory model of the complicated interactions occurring in much larger systems such as in astrophysics in the interaction of shocks formed in the interstellar medium with various types of clouds. In particular, the experiment is a useful tool for checking the computational ability of the new generation ASCI computers, as it requires three-dimensional modeling. This experiment has shown that three dimensional calculations seem to be necessary to describe major features observed in the experiment. Any attempt to explain hydrodynamic behavior with similar instabilities must take into account these three dimensional effects

  9. Heat shock protein 70, oxidative stress, and antioxidant status in periparturient crossbred cows supplemented with α-tocopherol acetate.

    Science.gov (United States)

    Aggarwal, Anjali; Ashutosh; Chandra, Gulab; Singh, Anil Kumar

    2013-01-01

    The study was conducted to investigating the effect of α-tocopherol acetate on heat shock protein 70 (Hsp70), oxidative stress, and antioxidant status during periparturient period in medium body condition score crossbred cows. Twenty crossbred Karan Fries cows with confirmed pregnancy were selected 2 months before expected date of calving. The cows were randomly distributed in to two groups: 10 cows were kept as control and 10 were supplemented with α-tocopherol acetate during dry period for 2 months. Blood samples were collected at -20, -10, -5, 0, 5, 10, and 20 days in relation to the expected date of calving. Superoxide dismutase, catalase, and total immunoglobulin were significantly higher (P stress, heat shock protein Hsp70 levels, improved antioxidant, and improved immunity status indicating beneficial effect of α-tocopherol acetate treatment.

  10. Numerical procedure for the calculation of nonsteady spherical shock fronts with radiation

    International Nuclear Information System (INIS)

    Winkler, K.H.

    The basis of the numerical method is an implicit difference scheme with time backward differences to a freely moving coordinate system. The coordinate system itself is determined simultaneously with the iterative solution of the physical equations as a function of the physical variables. Shock fronts, even nonsteady ones, are calculated as discontinuities according to the Rankine--Hugoniot equations. The radiation field is obtained from the two-dimensional, static, spherically symmetric transport equation in conjunction with the time-dependent one-dimensional moment equations. No artificial viscosity of any type is ever used. The applicability of the method developed is demonstrated by an example involving the calculation of protostar collapse. 11 figures

  11. Numerical investigation of interactions of multiple spherical shock waves between themselves and with the underlying surface

    Science.gov (United States)

    Andrushchenko, V. A.; Murashkin, I. V.; Shevelev, Yu. D.

    2016-06-01

    Within the investigation of various aspects of asteroid and comet danger and, in particular, the explosion of several fragments of meteoroids in the atmosphere above the Earth surface, the toy problem about four point explosions in the case of their special arrangement above the underlying surface is numerically solved. Complex interactions of primary and secondary shock waves between themselves, with the hard surface, and with tangential discontinuities are examined. The structure of flow inside gas regions disturbed by the explosions—the occurrence of eddy structures in them and the influence of reflected shocks waves on them—are investigated. The tendency of the external wave fronts of each explosion to form a unified front and the tendency of their internal hot domains to merge into a joined configuration (where the second process proceeds a little later than the first one) is revealed. This unified front and joined configuration are qualitatively identical to the external internal structure for the solitary explosion. The specially arranged explosions are chosen because the effects of multiple diffraction, interference, and, the main thing, cumulation of spherical waves are manifested more clearly in this caseTwo variants with different altitude of the explosions above the surface are calculated.

  12. Evaporation effects in a shock-driven multiphase instability with a spherical interface

    Science.gov (United States)

    Paudel, Manoj; Dahal, Jeevan; McFarland, Jacob

    2017-11-01

    This talk presents results from 3D numerical simulations of a shock driven instability of a gas-particle system with a spherical interface. Two cases, one with an evaporating particle cloud and another with a gas only approximation of this particle cloud, were run in the hydrodynamics code FLASH, developed at University of Chicago. It is shown that the gas only approximation, a classical Richtmyer Meshkov instability, cannot replicate effects from particles like, lag, clustering, and evaporation. Instead, both gas hydrodynamics and particle properties influence one another and are coupled. Results are presented to highlight the coupling of interface evolution and particle evaporation. Qualitative and quantitative differences in the RMI and SDMI are presented by studying the change in gas properties like density and vorticity within the interface. Similarly, the effect of gas hydrodynamics on particles distribution and evaporation is studied. Particle evaporation rates are compared with 1D models and show poor agreement. The variation in evaporation rates for similar sized particles and the role of gas hydrodynamics in these variation is explored.

  13. Propagation of a strong spherical shock wave in a gravitating or non-gravitating dusty gas with exponentially varying density

    Science.gov (United States)

    Nath, G.; Vishwakarma, J. P.

    2016-06-01

    The propagation of a strong spherical shock wave in a dusty gas with or without self-gravitational effects is investigated in the case of isothermal and adiabatic flows. The dusty gas is assumed to be a mixture of small solid particles and perfect gas. The equilibrium flow conditions are assumed to be maintained, and the density of the mixture is assumed to be varying and obeying an exponential law. Non-similarity solutions are obtained and the effects of variations of the mass concentration of solid particles in the mixture and the ratio of the density of solid particles to the initial density of the gas, and the presence of self-gravitational field on the flow variables are investigated at given times. Our analysis reveals that after inclusion of gravitational field effects surprisingly the shock strength increases and remarkable differences are found in the distribution of flow variables. An increase in time also, increases the shock strength. Further, it is investigated that the consideration of isothermal flow increases the shock strength, and removes the singularity in the density distribution. Also, the presence of gravitational field increases the compressibility of the medium, due to which it is compressed and therefore the distance between the inner contact surface and the shock surface is reduced. The shock waves in self-gravitating dusty gas can be important for description of shocks in supernova explosions, in the study of central part of star burst galaxies, star formation and shocks in stellar explosion, nuclear explosion, in industry, rupture of a pressurized vessel and explosion in the ionosphere. Other potential applications of this study include analysis of data from exploding wire experiments and cylindrically symmetric hypersonic flow problems associated with meteors or re-entry of vehicles etc. A comparison is made between the solutions in the cases of the gravitating and the non-gravitating media. The obtained solutions are applicable for

  14. Magnetogasdynamic spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes

    Science.gov (United States)

    Nath, G.; Vishwakarma, J. P.

    2016-11-01

    Similarity solutions are obtained for the flow behind a spherical shock wave in a non-ideal gas under gravitational field with conductive and radiative heat fluxes, in the presence of a spatially decreasing azimuthal magnetic field. The shock wave is driven by a piston moving with time according to power law. The radiation is considered to be of the diffusion type for an optically thick grey gas model and the heat conduction is expressed in terms of Fourier's law for heat conduction. Similarity solutions exist only when the surrounding medium is of constant density. The gas is assumed to have infinite electrical conductivity and to obey a simplified van der Waals equation of state. It is shown that an increase of the gravitational parameter or the Alfven-Mach number or the parameter of the non-idealness of the gas decreases the compressibility of the gas in the flow-field behind the shock, and hence there is a decrease in the shock strength. The pressure and density vanish at the inner surface (piston) and hence a vacuum is formed at the center of symmetry. The shock waves in conducting non-ideal gas under gravitational field with conductive and radiative heat fluxes can be important for description of shocks in supernova explosions, in the study of a flare produced shock in the solar wind, central part of star burst galaxies, nuclear explosion etc. The solutions obtained can be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

  15. Propagation of a Strong Shock Over a Random Bed of Spherical Particles

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Y. [Univ. of Florida, Gainesville, FL (United States); Neal, C. [Univ. of Florida, Gainesville, FL (United States); Salari, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jackson, T. L. [Univ. of Florida, Gainesville, FL (United States); Balachandar, S. [Univ. of Florida, Gainesville, FL (United States); Thakur, S. [Univ. of Florida, Gainesville, FL (United States)

    2017-04-11

    Propagation of a strong shock through a bed of particles results in complex wave dynamics such as a reflected shock, a transmitted shock, and highly unsteady flow inside the particle bed. In this paper we present three-dimensional numerical simulations of shock propagation in air over a random bed of particles. We assume the flow is inviscid and governed by the Euler equations of gas dynamics. Simulations are carried out by varying the volume fraction of the particle bed at a fixed shock Mach number. We compute the unsteady inviscid streamwise and transverse drag coefficients as a function of time for each particle in the random bed as a function of volume fraction. We show that (i) there are significant variations in the peak drag for the particles in the bed, (ii) the mean peak drag as a function of streamwise distance through the bed decreases with a slope that increases as the volume fraction increases, and (iii) the deviation from the mean peak drag does not correlate with local volume fraction. We also present the local Mach number and pressure contours for the different volume fractions to explain the various observed complex physical mechanisms occurring during the shock-particle interactions. Since the shock interaction with the random bed of particles leads to transmitted and reflected waves, we compute the average flow properties to characterize the strength of the transmitted and reflected shock waves and quantify the energy dissipation inside the particle bed. Finally, to better understand the complex wave dynamics in a random bed, we consider a simpler approximation of a planar shock propagating in a duct with a sudden area change. We obtain Riemann solutions to this problem, which are used to compare with fully resolved numerical simulations.

  16. Bright emissive core-shell spherical microparticles for shock compression spectroscopy

    International Nuclear Information System (INIS)

    Christensen, James M.; Banishev, Alexandr A.; Dlott, Dana D.

    2014-01-01

    Experiments were performed to study the response to shock compression of rhodamine 6G (R6G) dye encapsulated in 1.25 μm diameter silica microspheres. When R6G was encapsulated in microspheres, the emission intensity under steady-state irradiation (the brightness) was 3.4 times greater than the same dye in solution (the free dye). At least part of the brightness improvement was caused by an enhanced radiative rate. When the microspheres were embedded in poly-methylmethacrylate subjected to planar shocks in the 3–8.4 GPa range by laser-driven flyer plates, the dye emission redshifted and lost intensity. The dye emission redshift represents an instantaneous response to changes in the local density. In free dye samples, the shock-induced intensity loss had considerably slower rise times and fall times than the redshift. When dye was encapsulated in microspheres, the time dependence of the intensity loss matched the redshift almost exactly over a range of shock pressures and durations. The faster response to shock of dye in silica microspheres was explained by dye photophysics. The microsphere environment decreased the singlet state lifetime, which decreased the rise time, and it also decreased the triplet state lifetime, which decreased the fall time. Since it is much easier and more convenient to make measurements of intensity rather than spectral shift, these microspheres represent a substantial improvement in optical sensors to monitor shock compression of microstructured materials.

  17. Effects of heat stress on serum insulin, adipokines, AMP-activated protein kinase, and heat shock signal molecules in dairy cows.

    Science.gov (United States)

    Min, Li; Cheng, Jian-bo; Shi, Bao-lu; Yang, Hong-jian; Zheng, Nan; Wang, Jia-qi

    2015-06-01

    Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperature-humidity index (THI) is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines (leptin and adiponectin), AMP-activated protein kinase (AMPK), and heat shock signal molecules (heat shock transcription factor (HSF) and heat shock proteins (HSP)) in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment: eighteen lactating Holstein dairy cows were used. The treatments were: heat stress (HS, THI average=81.7, n=9) and cooling (CL, THI average=53.4, n=9). Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment: HS treatment cows (n=9) from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90 (Pstressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future.

  18. Inorganic zinc supplementation modulates heat shock and immune response in heat stressed peripheral blood mononuclear cells of periparturient dairy cows.

    Science.gov (United States)

    Sheikh, Aasif Ahmad; Aggarwal, Anjali; B, Indu; Aarif, Ovais

    2017-06-01

    Thermal stress in India is one of the major constraints affecting dairy cattle productivity. Every attempt should be made to ameliorate the heat and calving related stress in high producing dairy cows for higher economic returns. In the current study, inorganic zinc was tried to alleviate the adverse effects of thermal stress in periparturient cows. Twelve cows, six each of Sahiwal and Karan Fries (KF) in their second parity with confirmed pregnancy were chosen for the experiment. The blood samples were collected periparturiently on three occasions viz. -21, 0 and +21 days relative to calving. The in vitro study was conducted after isolating peripheral blood mononuclear cells (PBMC) from whole blood. The cultured PBMC were subjected to three different levels of exposures viz. 37°C as control, 42°C to induce thermal stress and 42°C + zinc to ameliorate the adverse effects of high temperature. Heat shock lead to a significant (PZinc treatment to thermally stressed PBMC caused a fall in the HSP concentration in both the breeds during periparturient period. Moreover, heat stress increased significantly (Pzinc supplementation to PBMC. IL-6 levels decreased periparturiently. Heat and calving related stress caused a fall in the IL-12 levels which increased significantly (Pzinc supplementation. These findings suggest that zinc supplementation attenuates the HSP response and augments immunity in PBMC of periparturient dairy cows. The study could help to alleviate the heat stress and potentiate immunity by providing mineral supplements in periparturient dairy cattle habituating tropics. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A functional integral approach to shock wave solutions of Euler equations with spherical symmetry

    Science.gov (United States)

    Yang, Tong

    1995-08-01

    For n×n systems of conservation laws in one dimension without source terms, the existence of global weak solutions was proved by Glimm [1]. Glimm constructed approximate solutions using a difference scheme by solving a class of Riemann problems. In this paper, we consider the Cauchy problem for the Euler equations in the spherically symmetric case when the initial data are small perturbations of the trivial solution, i.e., u≡0 and ρ≡ constant, where u is velocity and ρ is density. We show that this Cauchy problem can be reduced to an ideal nonlinear problem approximately. If we assume all the waves move at constant speeds in the ideal problem, by using Glimm's scheme and an integral approach to sum the contributions of the reflected waves that correspond to each path through the solution, we get uniform bounds on the L ∞ norm and total variational norm of the solutions for all time. The geometric effects of spherical symmetry leads to a non-integrable source term in the Euler equations. Correspondingly, we consider an infinite reflection problem and solve it by considering the cancellations between reflections of different orders in our ideal problem. Thus we view this as an analysis of the interaction effects at the quadratic level in a nonlinear model problem for the Euler equations. Although it is far more difficult to obtain estimates in the exact solutions of the Euler equations due to the problem of controlling the time at which the cancellations occur, we believe that this analysis of the wave behaviour will be the first step in solving the problem of existence of global weak solutions for the spherically symmetric Euler equations outside of fixed ball.

  20. Non-spherical voids and lattice reorientation patterning in a shock-loaded Al single crystal

    DEFF Research Database (Denmark)

    Hong, Chuanshi; Fæster, Søren; Hansen, Niels

    2017-01-01

    An Al single crystal shock loaded in the direction and captured at incipient spallation was examined by combining X-ray tomography, electron backscatter diffraction on a scanning electron microscope, and transmission electron microscopy (TEM). Octahedral voids with {1 1 1} faces were...... of the observed reorientation patterns based on active slip systems rationalizes the key features observed and suggests that the systematic reorientation patterns result from the dominance of a single slip system in each individual zone. Microstructures revealed by TEM in the spall region show formation...

  1. Transient Interaction of a Spherical Shell with an Underwater Explosion Shock Wave and Subsequent Pulsating Bubble

    Directory of Open Access Journals (Sweden)

    H. Huang

    1995-01-01

    Full Text Available The nonlinear interaction problem is analyzed by simultaneously solving the mass, momentum, and energy conservation equations together .with appropriate material constitutive equations governing the fluid dynamics of the explosion gaseous product and the water and the structural dynamics of the compliant shell. A finite difference technique in a coupled Eulerian–Lagrangian scheme is used. The computer program PISCES 2DELK is employed to carry out the numerical computations. The results demonstrate that to rigorously analyze the response of a submerged structure to a nearby explosion, the interactions among the explosion shock wave, the structure, its surrounding media, and the explosion bubble need to be considered.

  2. Self-similar flow behind a spherical shock wave in a non-ideal dusty gas under a gravitational field: Isothermal flow

    Science.gov (United States)

    Nath, G.

    2013-10-01

    Similarity solutions are obtained for one-dimensional unsteady isothermal flow of a dusty gas behind a spherical shock wave with time dependent energy input. The dusty gas is assumed to be a mixture of non-ideal (or perfect) gas and small solid particles, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-conditions are maintained, and the viscous stress and heat conduction of the mixture are negligible. The medium is taken to be under the influence of the gravitational field due to a heavy nucleus at the origin (Roche model). The total energy of the flow-field behind the shock is increasing. The effects of an increase in the mass concentration of solid particles, the ratio of the density of the solid particles to the initial density of the gas, the gravitational parameter (or shock Mach number), and the parameter of non-idealness of the gas in the mixture, are investigated. It is shown that due to presence of gravitational field the isothermal compressibility of the medium and the flow-variables increases and the shock strength decreases. A comparison has also been made between the medium with and without gravitational field. The shock waves in dusty medium can be important for description of star formation, shocks in supernova explosions, etc.

  3. Propagation of a spherical shock wave in mixture of non-ideal gas and small solid particles under gravitational field with conductive and radiative heat fluxes

    Science.gov (United States)

    Nath, Gorakh

    Self-similar solutions are obtained for one-dimensional unsteady adiabatic flow behind a spherical shock wave propagating in a dusty gas with conductive and radiative heat fluxes under a gravitational field. The shock is assumed to be driven out by a moving piston and the dusty gas to be a mixture of non-ideal (or perfect) gas and small solid particles, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-conditions are maintained and variable energy input is continuously supplied by the piston. The heat conduction is express in terms of Fourier’s law and the radiation is considered to be of the diffusion type for an optically thick grey gas model. The thermal conductivity and the absorption coefficient are assumed to vary with temperature and density. The medium is assumed to be under a gravitational field due to heavy nucleus at the origin (Roche Model). The unsteady model of Roche consists of a dusty gas distributed with spherical symmetry around a nucleus having large mass It is assumed that the gravitational effect of the mixture itself can be neglected compared with the attraction of the heavy nucleus. The density of the ambient medium is taken to be constant. Our analysis reveals that after inclusion of gravitational field effect surprisingly the shock strength increases and remarkable difference can be found in the distribution of flow variables. The effects of the variation of the heat transfer parameters, the gravitational parameter and non-idealness of the gas in the mixture are investigated. Also, the effects of an increase in (i) the mass concentration of solid particles in the mixture and (ii) the ratio of the density of solid particles to the initial density of the gas on the flow variables are investigated. It is found that the shock strength is increased with an increase in the value of gravitational parameter. Further, it is investigated that the presence of gravitational field increases the

  4. Propagation of a spherical shock wave in mixture of non-ideal gas and small solid particles under the influence of gravitational field with conductive and radiative heat fluxes

    Science.gov (United States)

    Nath, G.

    2016-01-01

    Self-similar solutions are obtained for one-dimensional unsteady adiabatic flow behind a spherical shock wave propagating in a dusty gas with conductive and radiative heat fluxes under the influence of a gravitational field. The shock is assumed to be driven out by a moving piston and the dusty gas to be a mixture of non-ideal gas and small solid particles, in which solid particles are uniformly distributed. It is assumed that the equilibrium flow-conditions are maintained and variable energy input is continuously supplied by the piston. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be of the diffusion type for an optically thick grey gas model. The thermal conductivity K and the absorption coefficient αR are assumed to vary with temperature and density. The medium is assumed to be under the influence of a gravitational field due to central mass ( bar{m} ) at the origin (Roche Model). It is assumed that the gravitational effect of the mixture itself can be neglected compared with the attraction of the central mass. The initial density of the ambient medium is taken to be always constant. The effects of the variation of the gravitational parameter and nonidealness of the gas in the mixture are investigated. Also, the effects of an increase in (i) the mass concentration of solid particles in the mixture and (ii) the ratio of the density of solid particles to the initial density of the gas on the flow variables are investigated. It is shown that due to an increase in the gravitational parameter the compressibility of the medium at any point in the flow-field behind the shock decreases and all other flow variables and the shock strength are increased. Further, it is found that the presence of gravitational field increases the compressibility of the medium, due to which it is compressed and therefore the distance between the piston and the shock surface is reduced. The shock waves in dusty gas under the influence of a

  5. Reproductive Performance of Holstein Dairy Cows Grazing in Dry-summer Subtropical Climatic Conditions: Effect of Heat Stress and Heat Shock on Meiotic Competence and Fertilization

    Directory of Open Access Journals (Sweden)

    Krishna Pavani

    2015-03-01

    Full Text Available The present study was designed to evaluate how environmental factors in a dry-summer subtropical climate in Terceira-Azores (situated in the North Atlantic Ocean: 38° 43′ N 27° 12′ W can affect dairy cow (Holstein fertility, as well as seasonal influence on in vitro oocytes maturation and embryos development. Impact of heat shock (HS effects on in vitro oocyte’s maturation and further embryo development after in vitro fertilization (IVF was also evaluated. For such purpose the result of the first artificial insemination (AI performed 60 to 90 days after calving of 6,300 cows were recorded for one year. In parallel, climatic data was obtained at different elevation points (n = 5 from 0 to 1,000 m and grazing points from 0 to 500 m, in Terceira island, and the temperature humidity index (THI was calculated. For in vitro experiments, oocytes (n = 706 were collected weekly during all year, for meiotic maturation and IVF. Further, to evaluate HS effect, 891 oocytes were collected in the cold moths (December, January, February and March and divided in three groups treated to HS for 24 h during in vitro maturation at: C (Control = 38.5°C, HS1 (39.5°C and HS2 (40.5°C. Oocytes from each group were used for meiotic assessment and IVF. Cleavage, morula and blastocyst development were evaluated respectively on day 2, 6, and 9 after IVF. A negative correlation between cow’s conception rate (CR and THI in grazing points (−91.3%; p<0.001 was observed. Mean THI in warmer months (June, July, August and September was 71.7±0.7 and the CR (40.2±1.5% while in cold months THI was 62.8±0.2 and CR was 63.8±0.4%. A similar impact was obtained with in vitro results in which nuclear maturation rate (NMR ranged from 78.4% (±8.0 to 44.3% (±8.1, while embryos development ranged from 53.8% (±5.8 to 36.3% (±3.3 in cold and warmer months respectively. In vitro HS results showed a significant decline (p<0.05 on NMR of oocytes for every 1°C rising

  6. Spherical models

    CERN Document Server

    Wenninger, Magnus J

    2012-01-01

    Well-illustrated, practical approach to creating star-faced spherical forms that can serve as basic structures for geodesic domes. Complete instructions for making models from circular bands of paper with just a ruler and compass. Discusses tessellation, or tiling, and how to make spherical models of the semiregular solids and concludes with a discussion of the relationship of polyhedra to geodesic domes and directions for building models of domes. "". . . very pleasant reading."" - Science. 1979 edition.

  7. Spherical CNNs

    OpenAIRE

    Cohen, Taco S.; Geiger, Mario; Koehler, Jonas; Welling, Max

    2018-01-01

    Convolutional Neural Networks (CNNs) have become the method of choice for learning problems involving 2D planar images. However, a number of problems of recent interest have created a demand for models that can analyze spherical images. Examples include omnidirectional vision for drones, robots, and autonomous cars, molecular regression problems, and global weather and climate modelling. A naive application of convolutional networks to a planar projection of the spherical signal is destined t...

  8. [Allergy to cow's milk].

    Science.gov (United States)

    Fourrier, E

    1997-04-01

    After recalling the medical reluctance as well as the risks that there are in complete elimination of milk in infants, the author presents several clinical pictures and then a classification of the immunological types: Allergic shock of neonates, digestive and extra-digestive (skin and respiratory airways) symptoms finally the rare chronic gastro-enteritis to cow milk. Non-reaginic food allergies: Acute gastro-enteropathy to cow milk, with villous atrophy and Heiner's syndrome, delayed hypersensitivities are studied, of difficult diagnosis that may cover almost all pathologies. They may be found in the digestive system, respiratory, the kidneys and even in the organs of behaviour. Migraine of food origin must be remembered. Development in regressive rules is a function of the type of allergy and the suddenness of the symptoms. Diagnosis is above all by questioning and confirmation or not by skin and in vitro tests. Certainty can only be shown by tests of elimination and re-introduction. The diet, at the same time of both diagnostic and therapeutic value, is based on the replacement of cow milk by foods that contain the same amount of proteins. It is essential, especially in the very small, to have perfect match of food so as to avoid any risk of a dramatic hypoprotinemia, which may happen if the child does not like the suggested diet, or if the parents cannot buy the substitution products. In such conditions great care must be taken to avoid provoking a crisis. Care must be taken to decide: If the elimination of cow milk is always justified each time. If it is, always check that the substituted protein is properly made, the family may change the diet mistakenly.

  9. Mach Stem Modeling with Spherical Shock Waves

    Science.gov (United States)

    1985-03-01

    Maryland, September 1962. AD-414630 51. Potocki , M. L. Evaluations of Five Nuclear Effects Programs Developed by Horizons Technology. Thesis, Air...Major, USAF 513-255-5533 AFIT/ENG DO FORM 1473, 83 APR EDITION OF I JAN 13 IS OBSOLETE. SECURITY CLASSIFICATION OF THIS PACE *r I "I .t P

  10. Cow's milk and children

    Science.gov (United States)

    Milk and children; Cow's milk allergy - children; Lactose intolerance - children ... You may have heard that cow's milk should not be given to babies younger than 1 year old. This is because cow's milk doesn't provide enough of ...

  11. An approximate solution for spherical and cylindrical piston problem

    Indian Academy of Sciences (India)

    the growth and decay of shock strengths for spherical and cylindrical pistons starting from a non-zero ... conditions at an appropriate level, a new theory of shock dynamics (NTSD) has been proposed (Ravindran and ..... sive, its packing density etc. which are not included in our mathematical formulation, it may explain the ...

  12. Cow's milk - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002448.htm Cow's milk - infants To use the sharing features on this ... year old, you should not feed your baby cow's milk, according to the American Academy of Pediatrics (AAP). ...

  13. Selective dry cow treatment in dairy cows

    NARCIS (Netherlands)

    Scherpenzeel, C.G.M.

    2017-01-01

    In the dairy industry, udder health is associated with mastitis management, of which blanket dry cow treatment has been an important part for decades. To prevent the udder from new intramammary infections during the dry period, the use of blanket dry cow treatment has been advocated for more than 50

  14. Spherical neutron generator

    Science.gov (United States)

    Leung, Ka-Ngo

    2006-11-21

    A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.

  15. Theoretical Study of a Spherical Plasma Focus

    Science.gov (United States)

    Ay, Yasar

    A theoretical model is developed for two concentric electrodes spherical plasma focus device in order to investigate the plasma sheath dynamics, radiative emission, and the ion properties. The work focuses on the model development of the plasma sheath dynamics and its validation, followed by studying of the radiation effects and the beam-ion properties in such unique geometry as a pulsed source for neutrons, soft and hard x-rays, and electron and ion beams. Chapter 1 is an introduction on fusion systems including plasma focus. Chapter 2 is an extensive literature survey on plasma focus modeling and experiments including the various radiations and their mechanism. Chapter 3 details modeling and validation of the plasma sheath dynamics model with comparison between hydrogen, deuterium, tritium and deuterium-tritium mixture for the production of pulsed neutrons. Chapter 4 is a study of the radiative phase, in which neutron yield is investigated, as well as the predicted beam-ion properties. Chapter 5 summarizes and discusses the results. Chapter 6 provides concluding remarks and proposed future works. The phases of the developed model are the rundown phase I, rundown phase II, the reflected phase and a radiative phase. The rundown phase I starts immediately after the completion of the gas breakdown and ends when the current sheath reaches the equator point of the spherical shape. Then immediately followed by rundown phase II to start and it ends when the shock front hits the axis, which is the beginning of the reflected shock phase. Reflected shock front moves towards the incoming current sheath and meets it which is both the end of the reflected shock phase and the beginning of the radiative phase. After the reflected shock front and the current sheath meet, the current sheath continues to move radially inward by compressing the produced plasma column until it reaches the axis. Since the discharge current contains important information about the plasma dynamic

  16. Acceleration mechanisms flares, magnetic reconnection and shock waves

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1979-01-01

    Several mechanisms are briefly discussed for the acceleration of particles in the astrophysical environment. Included are hydrodynamic acceleration, spherically convergent shocks, shock and a density gradient, coherent electromagnetic acceleration, the flux tube origin, symmetries and instabilities, reconnection, galactic flares, intergalactic acceleration, stochastic acceleration, and astrophysical shocks. It is noted that the supernova shock wave models still depend critically on the presupernova star structure and the assumption of highly compact presupernova models for type I supernovae. 37 references

  17. Dissecting the COW

    International Nuclear Information System (INIS)

    Linstadt, E.

    1985-04-01

    The COW, or Console On Wheels, is the primary operator interface to the SLC accelerator control system. A hardware and software description of the COW, a microcomputer based system with a color graphics display output and touch-panel and knob inputs, is given. The ease of development and expandability, due to both the modular nature of the hardware and the multitasking, interrupt driven software running in the COW, are described. Integration of the COW into the SLCNET communications network and SLC Control system is detailed

  18. Spherically Actuated Motor

    Science.gov (United States)

    Peeples, Steven

    2015-01-01

    A three degree of freedom (DOF) spherical actuator is proposed that will replace functions requiring three single DOF actuators in robotic manipulators providing space and weight savings while reducing the overall failure rate. Exploration satellites, Space Station payload manipulators, and rovers requiring pan, tilt, and rotate movements need an actuator for each function. Not only does each actuator introduce additional failure modes and require bulky mechanical gimbals, each contains many moving parts, decreasing mean time to failure. A conventional robotic manipulator is shown in figure 1. Spherical motors perform all three actuation functions, i.e., three DOF, with only one moving part. Given a standard three actuator system whose actuators have a given failure rate compared to a spherical motor with an equal failure rate, the three actuator system is three times as likely to fail over the latter. The Jet Propulsion Laboratory reliability studies of NASA robotic spacecraft have shown that mechanical hardware/mechanism failures are more frequent and more likely to significantly affect mission success than are electronic failures. Unfortunately, previously designed spherical motors have been unable to provide the performance needed by space missions. This inadequacy is also why they are unavailable commercially. An improved patentable spherically actuated motor (SAM) is proposed to provide the performance and versatility required by NASA missions.

  19. Spherical geodesic mesh generation

    Energy Technology Data Exchange (ETDEWEB)

    Fung, Jimmy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kenamond, Mark Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Burton, Donald E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Shashkov, Mikhail Jurievich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-27

    In ALE simulations with moving meshes, mesh topology has a direct influence on feature representation and code robustness. In three-dimensional simulations, modeling spherical volumes and features is particularly challenging for a hydrodynamics code. Calculations on traditional spherical meshes (such as spin meshes) often lead to errors and symmetry breaking. Although the underlying differencing scheme may be modified to rectify this, the differencing scheme may not be accessible. This work documents the use of spherical geodesic meshes to mitigate solution-mesh coupling. These meshes are generated notionally by connecting geodesic surface meshes to produce triangular-prismatic volume meshes. This mesh topology is fundamentally different from traditional mesh topologies and displays superior qualities such as topological symmetry. This work describes the geodesic mesh topology as well as motivating demonstrations with the FLAG hydrocode.

  20. Confined detonations with cylindrical and spherical symmetry

    International Nuclear Information System (INIS)

    Linan, A.; Lecuona, A.

    1979-01-01

    An imploding spherical or cylindrical detonation, starting in the interface of the detonantion with an external inert media, used as a reflector, creates on it a strong shock wave moving outward from the interface. An initially weak shock wave appears in the detonated media that travels toward the center, and it could reach the detonation wave, enforcing it in its process of implosion. To describe the fluid field, the Euler s equations are solved by means of expansions valid for the early stages of the process. Isentropic of the type P/pγ-K for the detonated and compressed inert media are used. For liquid or solid reflectors a more appropriate equation is used. (Author) 8 refs

  1. The Psychology of Cows

    Directory of Open Access Journals (Sweden)

    Lori Marino

    2017-11-01

    Full Text Available Domestic cows (Bos taurus are consumed worldwide as beef and veal, kept as dairy product producers, employed as draft animals in labor, and are used for a long list of other products, including leather and manure. But despite global reliance on cows for thousands of years, most people’s perception of them is as plodding herd animals with little individual personality and very simple social relationships or preferences. Yet, a review of the scientific literature on cow behavior points to more complex cognitive, emotional and social characteristics. Moreover, when cow behavior is addressed, it is almost entirely done within the framework of and applied to their use as food commodities. Therefore, there is relatively little attention to the study of cow intelligence, personality and sociality at a basic comparative level. In this review, we examine the current state of scientific knowledge about cows within an objective comparative framework, describing their cognitive, emotional, and social characteristics. Our aim is to provide a more veridical and objective current summary of cow psychology on its own terms and in ways which will facilitate better-informed comparisons with other animals. Moreover, an understanding of the capabilities and characteristics of domestic cows will, it is hoped, advance our understanding of who they are as individuals.

  2. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  3. Spherical rhenium metal powder

    International Nuclear Information System (INIS)

    Leonhardt, T.; Moore, N.; Hamister, M.

    2001-01-01

    The development of a high-density, spherical rhenium powder (SReP) possessing excellent flow characteristics has enabled the use of advanced processing techniques for the manufacture of rhenium components. The techniques that were investigated were vacuum plasma spraying (VPS), direct-hot isostatic pressing (D-HIP), and various other traditional powder metallurgy processing methods of forming rhenium powder into near-net shaped components. The principal disadvantages of standard rhenium metal powder (RMP) for advanced consolidation applications include: poor flow characteristics; high oxygen content; and low and varying packing densities. SReP will lower costs, reduce processing times, and improve yields when manufacturing powder metallurgy rhenium components. The results of the powder characterization of spherical rhenium powder and the consolidation of the SReP are further discussed. (author)

  4. The Spherical Deformation Model

    DEFF Research Database (Denmark)

    Hobolth, Asgar

    2003-01-01

    Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...... a single central section of the object. We use maximum-likelihood-based inference for this purpose and demonstrate the suggested methods on real data....

  5. Spherical hohlraum energetics studies on the SG series laser facility

    Science.gov (United States)

    Huo, Wenyi; Li, Zhichao; Xie, Xufei; Chen, Yaohua; Ren, Guoli; Liu, Jie; Lan, Ke

    2017-10-01

    The integrated experiments at the National Ignition Facility indicates that the radiation asymmetry control in the cylindrical hohlraums is an extremely challenging problem in achieving ignition by using indirect drive. Recently, Lan et al. proposed the octahedral spherical hohlraum which has the natural superiority in providing high radiation symmetry. As new and promising hohlraums, the performance of spherical hohlraum attracts much research interests. Hohlraum energetics is one of the fundamental problems in indirect drive inertial confinement study. We report on the spherical hohlraum experiments performed at the SG series laser facility. At the SGIII-prototype laser facility, we performed the first spherical energetics experiment. The radiation temperature is measured by using an array of flat-response x-ray detectors through a laser entrance hole at different angles. The radiation temperature and M-ban fraction inside the hohlraum are determined by the shock wave technique. At the SGIII laser facility, we performed the first octahedral spherical hohlraum energetics experiment. The 32 of 48 laser beams enter the hohlraum through six laser entrance holes. The radiation flux is measured by 5 FXRDs at different angles. And the radiation temperature inside the hohlraum is determined by the shock wave technique. The repetition of the experimental results is excellent.

  6. Cow's Milk Allergy

    DEFF Research Database (Denmark)

    Høst, Arne; Halken, Susanne

    2014-01-01

    Since the 1930's the scientific literature on cow's milk protein allergy (CMPA) has accumulated. Over the last decade new diagnostic tools and treatment approaches have been developed. The diagnosis of reproducible adverse reactions to cow's milk proteins (CMP), i.e. CMPA, still has to be confirm...... and long-term efficacy remain. Anti-IgE therapy with Omalizumab may improve the safety and efficacy of OIT and may provide benefit in monotherapy....

  7. demystifying the shock of shocking

    African Journals Online (AJOL)

    demystifying the shock of shocking. Beyra Rossouw, MB ChB, MMed. (Paed), DTM, MSc (Sports Medicine),. Certificate Critical Care (Paed). Senior Registrar Paediatric Cardiology, Western. Cape Paediatric Cardiac Services, Red Cross. War Memorial Children's Hospital, University of. Cape Town, and Tygerberg Children's ...

  8. Fundamentals of spherical array processing

    CERN Document Server

    Rafaely, Boaz

    2015-01-01

    This book provides a comprehensive introduction to the theory and practice of spherical microphone arrays. It is written for graduate students, researchers and engineers who work with spherical microphone arrays in a wide range of applications.   The first two chapters provide the reader with the necessary mathematical and physical background, including an introduction to the spherical Fourier transform and the formulation of plane-wave sound fields in the spherical harmonic domain. The third chapter covers the theory of spatial sampling, employed when selecting the positions of microphones to sample sound pressure functions in space. Subsequent chapters present various spherical array configurations, including the popular rigid-sphere-based configuration. Beamforming (spatial filtering) in the spherical harmonics domain, including axis-symmetric beamforming, and the performance measures of directivity index and white noise gain are introduced, and a range of optimal beamformers for spherical arrays, includi...

  9. Cardiogenic shock

    Science.gov (United States)

    ... occur during or after a heart attack (myocardial infarction). These complications include: A large section of heart ... high blood pressure, high cholesterol and triglycerides, or tobacco use Alternative Names Shock - cardiogenic Images Heart, section ...

  10. Shock absorber

    International Nuclear Information System (INIS)

    Housman, J.J.

    1978-01-01

    A shock absorber is described for use in a hostile environment at the end of a blind passage for absorbing impact loads. The shock absorber includes at least one element which occupies the passage and which is comprised of a porous brittle material which is substantially non-degradable in the hostile environment. A void volume is provided in the element to enable the element to absorb a predetermined level of energy upon being crushed due to impact loading

  11. An approximate solution for spherical and cylindrical piston problem

    Indian Academy of Sciences (India)

    presents an example of a flow field in which the flow behind the shock front is highly non-uniform due to ... The unsteady flow of an ideal gas with constant specific heats for spherical or cylindrical symmetry is given ... where &Y uY p are the density, velocity and the pressure of the gas, is the ratio of specific heats; tY r are the ...

  12. Spherical tokamak development in Brazil

    International Nuclear Information System (INIS)

    Ludwig, Gerson Otto; Bosco, Edson Del; Ferreira, Julio Guimaraes

    2003-01-01

    The general characteristics of spherical tokamaks, or spherical tori, with a brief view of work in this area already performed or in progress at several institutions worldwide are described. The paper presents also the steps in the development of the ETE (Experiment Tokamak spheric) project, its research program, technical characteristics and operating conditions as of December, 2002 a the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  13. Spherical tokamak development in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto; Bosco, Edson Del; Ferreira, Julio Guimaraes [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma] (and others)

    2003-07-01

    The general characteristics of spherical tokamaks, or spherical tori, with a brief view of work in this area already performed or in progress at several institutions worldwide are described. The paper presents also the steps in the development of the ETE (Experiment Tokamak spheric) project, its research program, technical characteristics and operating conditions as of December, 2002 a the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  14. The ETE spherical Tokamak project

    International Nuclear Information System (INIS)

    Ludwig, Gerson Otto; Andrade, Maria Celia Ramos de; Barbosa, Luis Filipe Wiltgen

    1999-01-01

    This paper describes the general characteristics of spherical tokamaks, with a brief overview of work in the area of spherical torus already performed or in progress at several institutions. The paper presents also the historical development of the ETE (Spherical Tokamak Experiment) project, its research program, technical characteristics and status of construction in September, 1998 at the Associated plasma Laboratory (LAP) of the National Institute for Space Research (INPE) in Brazil. (author)

  15. The ETE spherical Tokamak project

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto; Andrade, Maria Celia Ramos de; Barbosa, Luis Filipe Wiltgen [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma] [and others]. E-mail: ludwig@plasma.inpe.br

    1999-07-01

    This paper describes the general characteristics of spherical tokamaks, with a brief overview of work in the area of spherical torus already performed or in progress at several institutions. The paper presents also the historical development of the ETE (Spherical Tokamak Experiment) project, its research program, technical characteristics and status of construction in September, 1998 at the Associated plasma Laboratory (LAP) of the National Institute for Space Research (INPE) in Brazil. (author)

  16. Spherical grating spectrometers

    Science.gov (United States)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  17. Converging shocks in elastic-plastic solids.

    Science.gov (United States)

    Ortega, A López; Lombardini, M; Hill, D J

    2011-11-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The examined constitutive laws share a compressible neo-Hookean structure for the internal energy e=e(s)(I(1))+e(h)(ρ,ς), where e(s) accounts for shear through the first invariant of the Cauchy-Green tensor, and e(h) represents the hydrostatic contribution as a function of the density ρ and entropy ς. In the strong-shock limit, reached as the shock approaches the axis or origin r=0, we show that compression effects are dominant over shear deformations. For an isothermal constitutive law, i.e., e(h)=e(h)(ρ), with a power-law dependence e(h) is proportional to ρ(α), shock dynamics predicts that for a converging shock located at r=R(t) at time t, the Mach number increases as M is proportional to [log(1/R)](α), independently of the space index s, where s=2 in cylindrical geometry and 3 in spherical geometry. An alternative isothermal constitutive law with p(ρ) of the arctanh type, which enforces a finite density in the strong-shock limit, leads to M is proportional to R(-(s-1)) for strong shocks. A nonisothermal constitutive law, whose hydrostatic part e(h) is that of an ideal gas, is also tested, recovering the strong-shock limit M is proportional to R(-(s-1)/n(γ)) originally derived by Whitham for perfect gases, where γ is inherently related to the maximum compression ratio that the material can reach, (γ+1)/(γ-1). From these strong-shock limits, we also estimate analytically the density, radial velocity, pressure, and sound speed immediately behind the shock. While the

  18. Miniaturization of Spherical Magnetodielectric Antennas

    DEFF Research Database (Denmark)

    Hansen, Troels Vejle

    ; Arbitrary order of the spherical wave, arbitrary radius of the spherical antenna, as well as arbitrarily large core permeability and/or permittivity, given an inversely proportional frequency variation of the imaginary part(s) and an arbitrary dispersion of the real part(s) - thus describing both lossless...

  19. What's Mad Cow Disease?

    Science.gov (United States)

    ... with them. What Should I Do? Being a kid, you might be wondering about milk. Even though it comes from cows, BSE isn't thought to be spread through milk or milk products. Reviewed by: Larissa Hirsch, MD Date reviewed: October 2013 More on this topic for: Kids Why Do I Need to Wash My Hands? ...

  20. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  1. Toxic shock syndrome

    Science.gov (United States)

    Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

  2. demystifying the shock of shocking

    African Journals Online (AJOL)

    aimed at depolarising a myocardium that is not generating a co-ordinated, perfusing rhythm. Organised QRS complexes cannot be identified and the electrical current is delivered without synchronising with the patient's native rhythm. DC shock should not be delayed once a shockable rhythm is recognised. The longer the ...

  3. THE BEEF COW REPLACEMENT DECISION

    OpenAIRE

    Mathews, Kenneth H., Jr.; Short, Sara D.

    2001-01-01

    This analysis examines effects of several common assumptions on net present values (NPVs) of beef cows. While effects on NPVs vary over a price cycle or successive price cycles, several generalities manifest themselves. A cow is not likely to recover the lost revenue from not having just one calf. Incorporating genetic improvement into the herd increases the probability of an older cow being culled. Variable net replacement/culling rates make sense in the context of cattle inventory and price...

  4. Dairy cow nutrition

    OpenAIRE

    Tame, Mike

    2008-01-01

    This review pulls together the results of over 40 research projects and brings us up to date with the latest in thinking on dairy cow nutrition, incorporates the findings of a wide range of organic trials and draws some clear recommendations on appropriate strategies for forage type and management, supplementary feeding, ration formulation and farming systems. It raises important issues around sustainability versus optimum production and highlights future research priorities.

  5. JUST: Joint Upgraded Spherical Tokamak

    International Nuclear Information System (INIS)

    Azizov, E.A.; Dvorkin, N.Ya.; Filatov, O.G.

    1997-01-01

    The main goals, ideas and the programme of JUST, spherical tokamak (ST) for the plasma burn investigation, are presented. The place and prospects of JUST in thermonuclear investigations are discussed. (author)

  6. Spherical Primary Optical Telescope Testbed

    Data.gov (United States)

    National Aeronautics and Space Administration — This IRAD proposes to continue operation of the Spherical Primary Optical Telescope (SPOT) testbed as an image-based wavefront sensing demonstrator. In addition to...

  7. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  8. Cardiogenic Shock.

    Science.gov (United States)

    Moskovitz, Joshua B; Levy, Zachary D; Slesinger, Todd L

    2015-08-01

    Cardiogenic shock is the leading cause of morbidity and mortality in patients presenting with acute coronary syndrome. Although early reperfusion strategies are essential to the management of these critically ill patients, additional treatment plans are often needed to stabilize and treat the patient before reperfusion may be possible. This article discusses pharmacologic and surgical interventions, their indications and contraindications, management strategies, and treatment algorithms. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Spherical tokamak development in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, G.O.; Del Bosco, E.; Ferreira, J.G.; Berni, L.A.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Ueda, M.; Barroso, J.J.; Castro, P.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma; Barbosa, L.F.W. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo; Patire Junior, H. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Mecanica Espacial e Controle; The high-power microwave sources group

    2003-12-01

    This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics and operating conditions as of December, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  10. Spherical tokamak development in Brazil

    International Nuclear Information System (INIS)

    Ludwig, G.O.; Del Bosco, E.; Ferreira, J.G.; Berni, L.A.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Ueda, M.; Barroso, J.J.; Castro, P.J.; Barbosa, L.F.W.; Patire Junior, H.; The high-power microwave sources group

    2003-01-01

    This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the steps in the development of the ETE (Experimento Tokamak Esferico) project, its research program, technical characteristics and operating conditions as of December, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  11. Shock induced damage and damage threshold of optical K9 glass investigated by laser-driven shock wave

    Science.gov (United States)

    Song, Yunfei; Yu, Guoyang; Jiang, Lilin; Zheng, Xianxu; Liu, Yuqiang; Yang, Yanqiang

    2011-04-01

    The shock wave driven by short laser pulse is used to study the damage of brittle material K9 glass. The damage morphology of K9 glass surface indicates that the material has experienced different loading modes, respectively, at the central area and the surrounding area of the shock wave. At the central area of shock wave, the wavefront is plane and has a uniform pressure distribution, the material mainly suffers a longitudinal shock pressure; but on the edge the shock wave, the wavefront is approximately spherical, besides longitudinal pressure, transverse tensile stress will emerge inside the material. In the latter case, the damage threshold of the material is much smaller than that in the case of compressing by longitudinal pressure only. According to the relationship between damage area and shock pressure, an experimental method is proposed to measure the damage threshold of materials under shock loading. The damage threshold of K9 glass under spherical shock wave is measured to be about 1.12 GPa; and the damage threshold under plane shock wave is estimated to be between 1.82 and 1.98 GPa. They are much bigger than the damage threshold under static pressure. This method could also be used to measure the damage threshold of other materials when loaded by dynamic pressure.

  12. Toxic bovine mastitis caused by Staphylococcus aureus in twin cows.

    Science.gov (United States)

    Rüegsegger; Corti; Sihto; Johler

    2014-11-01

    In this report, we describe two cases of bovine toxic mastitis associated with S. aureus and we provide DNA microarray based characterization data of the strain causing the disease. Both cows had recently calved and suffered from anorexia, pyrexia, and an elevated heart rate. In both animals, at least one mammary gland was swollen, hardened, sensitive to touch, and produced brownish or bloody secretions. The clinical state of the animals deteriorated quickly and both cows had to be euthanized within 48 hours after presentation. The S. aureus strain, which was isolated from the mastitis milk of both cows, was assigned to spa type t267, agr type I, capsule type 5 and CC97, a clonal complex recently identified as the evolutionary origin of two emerging clones of human epidemic community-associated methicillin-resistant S. aureus. The strain did not harbour any genes conferring resistance to antimicrobial agents and we did not detect any genes coding for enterotoxins, toxic shock syndrome toxin, or exfoliative toxins. Taking into consideration that twin cows were affected by this rare disease, we suggest that host factors may play a crucial role in toxic mastitis associated with S. aureus.

  13. Disseminated hemangiosarcoma in a cow

    OpenAIRE

    Stock, Matthew L.; Smith, Billy I.; Engiles, Julie B.

    2011-01-01

    An antemortem diagnosis of disseminated hemangiosarcoma with extensive hepatic and splenic involvement was made in a 9-year-old cow evaluated for lethargy, weight loss, regenerative anemia, thrombocytopenia, and elevated liver enzymes. This is the first report of hemangiosarcoma in a cow with a suspected primary location of the liver and/or spleen.

  14. Disseminated hemangiosarcoma in a cow

    Science.gov (United States)

    Stock, Matthew L.; Smith, Billy I.; Engiles, Julie B.

    2011-01-01

    An antemortem diagnosis of disseminated hemangiosarcoma with extensive hepatic and splenic involvement was made in a 9-year-old cow evaluated for lethargy, weight loss, regenerative anemia, thrombocytopenia, and elevated liver enzymes. This is the first report of hemangiosarcoma in a cow with a suspected primary location of the liver and/or spleen. PMID:21731096

  15. The Rayleigh-Taylor instability in the spherical pinch

    International Nuclear Information System (INIS)

    Chen, H.B.; Hilko, B.; Panarella, E.

    1994-01-01

    The spherical pinch (SP) concept is an outgrowth of the inertial confinement model (ICF). Unlike the ICF where instabilities, especially the Rayleigh-Taylor instability, have been studied extensively, the instability study of the spherical pinch has just begun. The Raleigh-Taylor instability is investigated for the first time in the SP in the present work. By using the simple condition for the Rayleigh-Taylor instability ∇p · ∇p < O (density and pressure gradients have opposite direction), we have qualitatively identified the regions for development of instabilities in the SP. It is found that the explosion phase (central discharge) is stable and instabilities take place in the imploding phase. However, the growth rate for the instability is not in exponential form, and the appearance of the Rayleigh-Taylor instability does not prevent the main shock wave from converging to the center of the sphere

  16. Continuous lactation in dairy cows

    DEFF Research Database (Denmark)

    Madsen, Torben Gosvig; Nielsen, Mette Benedicte Olaf; Andersen, Jens Bech

    2008-01-01

    function may be achievable in continuously milked high-yielding dairy cows as a result of the genetic selection for lactation performance and hence longevity of mammary epithelial cells. The milk production and mammary nutrient uptake in response to omission of the dry period for cows with an expected peak...... milk yield higher than 45 kg/d were studied in 28 Holstein dairy cows managed without bovine somatotropin. Performance and metabolic parameters were followed in late gestation and in the following early lactation. Fourteen cows were milked continuously throughout late gestation, and another 14 dairy...... cows experienced a 7-wk prepartum dry period. Continuous milking during the prepartum period reduced milk production in the following early lactation period by >20%. The reduced milk production could not be readily ascribed to inefficiency of the mechanisms responsible for nutrient uptake...

  17. Stray voltage and robotic milking of dairy cows

    Energy Technology Data Exchange (ETDEWEB)

    Rodenburg, J.; Lang, B. [Ontario Ministry of Agriculture (Canada)

    2009-12-15

    Stray voltage in livestock agriculture is the difference in voltage potential measured between two surfaces that may be contacted simultaneously by an animal. The reactions of animals to mild electric shocks caused by stray voltage have been reported to include behavioural changes, changes in milking characteristics of dairy cows and changes in production performance. It can make cows more reluctant to enter the farm dairy and can induce more frequent dunging and urination in the holding yards or during milking. Milk production may be reduced if avoidance behaviours are severe. This factsheet outlines appropriate testing of a robot site for stray voltage. Correction and prevention options available to reduce or eliminate stray voltage in robotic milking systems, i.e. equipotential plane or slatted floors, are discussed along with advantages and disadvantages of each. The most appropriate solution may depend on the voltage level found, the utility's policies and whether it is new construction or renovation.

  18. One Cow, One Vote

    DEFF Research Database (Denmark)

    Albæk, Svend; Schultz, Christian

    1997-01-01

    We study investment decisions in a farmers' cooperative. Farmers sell their products through the cooperative. Before production takes place the cooperative has to decide on an investment. We study whether voting on investment leads to efficient investment decisions. The answer depends on how...... the number of votes and the cost of the investment are distributed among the farmers. It is shown that in a variety of settings, there is no reason to suppose that voting rules favoring large farmers - "one cow, one vote" rules - are more efficient than simple majority rule...

  19. Shock Prevention

    Science.gov (United States)

    1978-01-01

    The electrician pictured is installing a General Electric Ground Fault Interrupter (GFI), a device which provides protection against electrical shock in the home or in industrial facilities. Shocks due to defective wiring in home appliances or other electrical equipment can cause severe burns, even death. As a result, the National Electrical Code now requires GFIs in all new homes constructed. This particular type of GFI employs a sensing element which derives from technology acquired in space projects by SCI Systems, Inc., Huntsville, Alabama, producer of sensors for GE and other manufacturers of GFI equipment. The sensor is based on the company's experience in developing miniaturized circuitry for space telemetry and other spacecraft electrical systems; this experience enabled SCI to package interruptor circuitry in the extremely limited space available and to produce sensory devices at practicable cost. The tiny sensor measures the strength of the electrical current and detects current differentials that indicate a fault in the functioning of an electrical system. The sensing element then triggers a signal to a disconnect mechanism in the GFI, which cuts off the current in the faulty circuit.

  20. Spherical Demons: Fast Surface Registration

    Science.gov (United States)

    Yeo, B.T. Thomas; Sabuncu, Mert; Vercauteren, Tom; Ayache, Nicholas; Fischl, Bruce; Golland, Polina

    2009-01-01

    We present the fast Spherical Demons algorithm for registering two spherical images. By exploiting spherical vector spline interpolation theory, we show that a large class of regularizers for the modified demons objective function can be efficiently implemented on the sphere using convolution. Based on the one parameter subgroups of diffeomorphisms, the resulting registration is diffeomorphic and fast – registration of two cortical mesh models with more than 100k nodes takes less than 5 minutes, comparable to the fastest surface registration algorithms. Moreover, the accuracy of our method compares favorably to the popular FreeSurfer registration algorithm. We validate the technique in two different settings: (1) parcellation in a set of in-vivo cortical surfaces and (2) Brodmann area localization in ex-vivo cortical surfaces. PMID:18979813

  1. Gravitational Field of Spherical Branes

    Science.gov (United States)

    Gogberashvili, Merab

    The warped solution of Einstein's equations corresponding to the spherical brane in five-dimensional AdS is considered. This metric represents interiors of black holes on both sides of the brane and can provide gravitational trapping of physical fields on the shell. It is found that the analytic form of the coordinate transformations from the Schwarzschild to co-moving frame that exists only in five dimensions. It is shown that in the static coordinates active gravitational mass of the spherical brane, in agreement with Tolman's formula, is negative, i.e. such objects are gravitationally repulsive.

  2. Spherical agglomeration of acetylsalicylic acid

    Directory of Open Access Journals (Sweden)

    Polowczyk Izabela

    2016-01-01

    Full Text Available In this paper spherical agglomeration of acetylsalicylic acid was described. In the first step, the system of good and poor solvents as well as bridging liquid was selected. As a result of a preliminary study, ethyl alcohol, water and carbon tetrachloride were used as the good solvent, poor one, and bridging liquid, respectively. Then, the amount of acetylsalicylic acid and the ratio of the solvents as well as the volume of the bridging liquid were examined. In the last step, the agglomeration conditions, such as mixing intensity and time, were investigated. The spherical agglomerates obtained under optimum conditions could be subjected to a tableting process afterwards.

  3. Cow's milk and goat's milk.

    Science.gov (United States)

    Turck, Dominique

    2013-01-01

    Cow's milk is increasingly suggested to play a role in the development of chronic degenerative, non-communicable disorders whereas goat's milk is advocated as having several health benefits. Cow's milk is a rich and cheap source of protein and calcium, and a valuable food for bone health. Despite their high content in saturated fats, consumption of full-fat dairy products does not seem to cause significant changes in cardiovascular disease risk variables. Early introduction of cow's milk is a strong negative determinant of iron status. Unmodified cow's milk does not meet nutritional requirements of infants although it is acceptable to add small volumes of cow's milk to complementary foods. Cow's milk protein allergy has a prevalence ranging from 2 to 7%, and the age of recovery is usually around 2-3 years. The evidence linking cow's milk intake to a later risk of type 1 diabetes or chronic degenerative, non-communicable disorders (obesity, metabolic syndrome, type 2 diabetes, hypertension) is not convincing. Milk probably protects against colorectal cancer, diets high in calcium are a probable cause of prostate cancer, and there is limited evidence suggesting that high consumption of milk and dairy products increases the risk for prostate cancer. There is no evidence to support the use of a cow's milk-free diet as a primary treatment for individuals with autistic spectrum disorders. Unmodified goat's milk is not suitable for infants because of the high protein and minerals content and of a low folate content. Goat's milk has no clear nutritional advantage over cow's milk and is not less allergenic. The European Food Safety Authority recently stated that proteins from goat's milk can be suitable as a protein source for infant and follow-on formula, provided the final product complies with the compositional criteria laid down in Directive 2006/141/EC. Copyright © 2013 S. Karger AG, Basel.

  4. Spherical Pendulum, Actions, and Spin

    NARCIS (Netherlands)

    Richter, Peter H.; Dullin, Holger R.; Waalkens, Holger; Wiersig, Jan

    1996-01-01

    The classical and quantum mechanics of a spherical pendulum are worked out, including the dynamics of a suspending frame with moment of inertia θ. The presence of two separatrices in the bifurcation diagram of the energy-momentum mapping has its mathematical expression in the hyperelliptic nature of

  5. Testing for Bivariate Spherical Symmetry

    NARCIS (Netherlands)

    Einmahl, J.H.J.; Gantner, M.

    2010-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distri- bution-free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the

  6. A charged spherically symmetric solution

    Indian Academy of Sciences (India)

    A charged spherically symmetric solution. K MOODLEY, S D MAHARAJ and K S GOVINDER. School of Mathematical and Statistical Sciences, University of Natal, Durban 4041, South Africa. Email: maharaj@nu.ac.za. MS received 8 April 2002; revised 7 April 2003; accepted 23 June 2003. Abstract. We find a solution of the ...

  7. Cooperative effects in spherical spasers

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    2017-01-01

    A fully analytical semiclassical theory of cooperative optical processes which occur in an ensemble of molecules embedded in a spherical core-shell nanoparticle is developed from first principles. Both the plasmonic Dicke effect and spaser generation are investigated for the designs in which...

  8. Testing for bivariate spherical symmetry

    NARCIS (Netherlands)

    Einmahl, J.H.J.; Gantner, M.

    2012-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distribution free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the asymptotic

  9. Laplacian eigenmodes for spherical spaces

    International Nuclear Information System (INIS)

    Lachieze-Rey, M; Caillerie, S

    2005-01-01

    The possibility that our space is multi-rather than singly-connected has gained renewed interest after the discovery of the low power for the first multipoles of the CMB by WMAP. To test the possibility that our space is a multi-connected spherical space, it is necessary to know the eigenmodes of such spaces. Except for lens and prism space, and to some extent for dodecahedral space, this remains an open problem. Here we derive the eigenmodes of all spherical spaces. For dodecahedral space, the demonstration is much shorter, and the calculation method much simpler than before. We also apply our method to tetrahedric, octahedric and icosahedric spaces. This completes the knowledge of eigenmodes for spherical spaces, and opens the door to new observational tests of the cosmic topology. The vector space V k of the eigenfunctions of the Laplacian on the 3-sphere S 3 , corresponding to the same eigenvalue λ k = -k(k + 2), has dimension (k + 1) 2 . We show that the Wigner functions provide a basis for such a space. Using the properties of the latter, we express the behaviour of a general function of V k under an arbitrary rotation G of SO(4). This offers the possibility of selecting those functions of V k which remain invariant under G. Specifying G to be a generator of the holonomy group of a spherical space X, we give the expression of the vector space V x k of the eigenfunctions of X. We provide a method to calculate the eigenmodes up to an arbitrary order. As an illustration, we give the first modes for the spherical spaces mentioned

  10. Curved Radio Spectra of Weak Cluster Shocks

    Science.gov (United States)

    Kang, Hyesung; Ryu, Dongsu

    2015-08-01

    In order to understand certain observed features of arc-like giant radio relics such as the rareness, uniform surface brightness, and curved integrated spectra, we explore a diffusive shock acceleration (DSA) model for radio relics in which a spherical shock impinges on a magnetized cloud containing fossil relativistic electrons. Toward this end, we perform DSA simulations of spherical shocks with the parameters relevant for the Sausage radio relic in cluster CIZA J2242.8+5301, and calculate the ensuing radio synchrotron emission from re-accelerated electrons. Three types of fossil electron populations are considered: a delta-function like population with the shock injection momentum, a power-law distribution, and a power law with an exponential cutoff. The surface brightness profile of the radio-emitting postshock region and the volume-integrated radio spectrum are calculated and compared with observations. We find that the observed width of the Sausage relic can be explained reasonably well by shocks with speed {u}{{s}}˜ 3× {10}3 {km} {{{s}}}-1 and sonic Mach number {M}{{s}}˜ 3. These shocks produce curved radio spectra that steepen gradually over (0.1-10){ν }{br} with a break frequency {ν }{br}˜ 1 GHz if the duration of electron acceleration is ˜60-80 Myr. However, the abrupt increase in the spectral index above ˜1.5 GHz observed in the Sausage relic seems to indicate that additional physical processes, other than radiative losses, operate for electrons with {γ }{{e}}≳ {10}4.

  11. Nonplanar electrostatic shock waves in an opposite polarity dust ...

    Indian Academy of Sciences (India)

    A rigorous theoretical investigation has been carried out on the propagation of nonplanar (cylindrical and spherical) dust-acoustic shock waves (DASHWs) in a collisionless four-component unmagnetized dusty plasmasystem containing massive, micron-sized, positively and negatively charged inertial dust grains along with ...

  12. The gravitational shock wave of a massless particle

    NARCIS (Netherlands)

    Hooft, G. 't; Dray, T

    1985-01-01

    The (spherical) gravitational shock wave due to a massless particle moving at the speed of light along the horizon of the Schwarzchild black hole is obtained. Special cases of our procedure yield previous results by Aichelburg and Sexl[1] for a photon in Minkowski vpace and by Penrose [2] for

  13. Rusitec the cow

    International Nuclear Information System (INIS)

    1987-01-01

    Full text: The rumen is an important part of the digestive tract of ruminant animals such as cattle, buffalo, sheep and goats. It contains large numbers of micro-organisms whose function is to break down fibrous feed materials such as grass and straw and convert them to products that can be used by the animal to produce meat, milk, wool or draught power. To study the microbial population of the rumen under controlled laboratory conditions, Dr. J.W. Czerkawski of the Hannah Research Institute, Scotland, U.K., developed an 'artificial cow'. The 'cow', named RUSITEC (from the acronym of 'Rumen Simulation Technique') is today being used as part of a project to analyse different feedstuffs being carried out by the Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) at their joint Agricultural Laboratory at Seibersdorf near Vienna, Austria. In the artificial rumen micro-organisms can be indefinitely maintained by feeding a normal ruminant diet each day and providing the correct physiological conditions in terms of temperature, pH and flow of saliva. As RUSITEC chews its way through different feeds, scientists use radioactive tracing techniques to compare their digestibility. (The higher the digestibility of a foodstuff, the higher the nutritive value that can be derived from it.) By analysing the quality of different feeding materials in this way, scientists are seeking to propose improved diets for domestic animals in the developing world. Photos on this page show RUSITEC at work. Below, the vessels representing the rumen, where microbial fermentation of diets takes place; right, the rumen simulation technique in operation; below right, analysis of the end products of fermentative digestion

  14. Collisionless electrostatic shocks

    DEFF Research Database (Denmark)

    Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

    1970-01-01

    An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

  15. Nutrition of the transition cow

    OpenAIRE

    BEŇASOVÁ, Veronika

    2017-01-01

    This bachelor thesis titled Nutrition of the transition cow deals with nutrition of dairy cows in peripartum period with regard to prevention of development of metabolic diseases. Anatomy of digestive system and physiology of digestive processes are briefly described. Characteristic of nutrients and of the most common feeds used for nutrition of dairy cattle serves as introduction to formulation of dairy rations. Metabolic diseases caused by inadequate nutrition in transition period are the b...

  16. Extended lactation in dairy cows

    DEFF Research Database (Denmark)

    Sorensen, Annette; Muir, D. Donald; Knight, Christopher Harold

    2008-01-01

    Twelve spring-calving and twelve winter-calving cows were managed for extended lactation cycles of 18-months duration, with the former group then completing a second extended lactation. Half of the cows were fed according to standard management practice for the herd; the other half received suppl...... interventions, the results lend support to the economic arguments in favour of extended lactation cycles. The likely welfare benefits of extended lactation are also discussed....

  17. Spherically symmetric elasticity in relativity

    Energy Technology Data Exchange (ETDEWEB)

    Carot, J [Departament de Fisica, Universitat de les Illes Balears, Cra Valldemossa pk 7.5, E-07122 Palma (Spain); Brito, I; Vaz, E G L R, E-mail: jcarot@uib.ca, E-mail: ireneb@mct.uminho.p, E-mail: evaz@mct.uminho.p

    2010-05-01

    The relativistic theory of elasticity is reviewed within the spherically symmetric context with a view towards the modelling of star interiors possessing elastic properties such as the ones expected in neutron stars. Emphasis is placed on generality in the main sections of the paper, and the results are then applied to specific examples. Along the way, a few general results for spacetimes admitting isometries are deduced, and their consequences are fully exploited in the case of spherical symmetry relating them next to the the case in which the material content of the spacetime is some elastic material. This paper extends and generalizes the pioneering work by Magli and Kijowski [1], Magli [2] and [3], and complements, in a sense, that by Karlovini and Samuelsson in their interesting series of papers [4], [5] and [6].

  18. Testing for bivariate spherical symmetry

    OpenAIRE

    Einmahl, J.H.J.; Gantner, M.

    2012-01-01

    An omnibus test for spherical symmetry in R2 is proposed, employing localized empirical likelihood. The thus obtained test statistic is distri- bution-free under the null hypothesis. The asymptotic null distribution is established and critical values for typical sample sizes, as well as the asymptotic ones, are presented. In a simulation study, the good perfor- mance of the test is demonstrated. Furthermore, a real data example is presented.

  19. Geometrical shock dynamics for magnetohydrodynamic fast shocks

    KAUST Repository

    Mostert, W.

    2016-12-12

    We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

  20. Solutocapillary convection in spherical shells

    Science.gov (United States)

    Subramanian, Pravin; Zebib, Abdelfattah; McQuillan, Barry

    2005-01-01

    A linear stability study of solutocapillary driven Marangoni instabilities in small spherical shells is presented. The shells contain a binary fluid with an evaporating solvent. The viscosity is a strong function of the solvent concentration, the inner surface of the shell is assumed impermeable and stress free, while nonlinear boundary conditions are modeled and prescribed at the receding outer boundary. A time-dependent diffusive state is possible and may lose stability through the Marangoni mechanism due to surface tension dependence on solvent concentration (buoyant forces are negligible in this microscale problem). A frozen-time or quasisteady state linear stability analysis is performed to compute the critical Reynolds number and degree of surface harmonics, as well as the maximum growth rate of perturbations at specified parameters. The development of maximum growth rates in time was also computed by solving the initial value problem with random initial conditions. Results from both approaches are in good agreement except at short times where there is dependence on initial conditions. The physical problem models the manufacturing of spherical shells used as targets in inertial confinement fusion experiments where perfect sphericity is demanded for efficient fusion ignition. It is proposed that the Marangoni instability might be the source of observed surface roughness. Comparisons with the available experiments are made with reasonable qualitative and quantitative agreement.

  1. Dairy cow disability weights.

    Science.gov (United States)

    McConnel, Craig S; McNeil, Ashleigh A; Hadrich, Joleen C; Lombard, Jason E; Garry, Franklyn B; Heller, Jane

    2017-08-01

    Over the past 175 years, data related to human disease and death have progressed to a summary measure of population health, the Disability-Adjusted Life Year (DALY). As dairies have intensified there has been no equivalent measure of the impact of disease on the productive life and well-being of animals. The development of a disease-adjusted metric requires a consistent set of disability weights that reflect the relative severity of important diseases. The objective of this study was to use an international survey of dairy authorities to derive disability weights for primary disease categories recorded on dairies. National and international dairy health and management authorities were contacted through professional organizations, dairy industry publications and conferences, and industry contacts. Estimates of minimum, most likely, and maximum disability weights were derived for 12 common dairy cow diseases. Survey participants were asked to estimate the impact of each disease on overall health and milk production. Diseases were classified from 1 (minimal adverse effects) to 10 (death). The data was modelled using BetaPERT distributions to demonstrate the variation in these dynamic disease processes, and to identify the most likely aggregated disability weights for each disease classification. A single disability weight was assigned to each disease using the average of the combined medians for the minimum, most likely, and maximum severity scores. A total of 96 respondents provided estimates of disability weights. The final disability weight values resulted in the following order from least to most severe: retained placenta, diarrhea, ketosis, metritis, mastitis, milk fever, lame (hoof only), calving trauma, left displaced abomasum, pneumonia, musculoskeletal injury (leg, hip, back), and right displaced abomasum. The peaks of the probability density functions indicated that for certain disease states such as retained placenta there was a relatively narrow range of

  2. Dairy cow monitoring by RFID

    Directory of Open Access Journals (Sweden)

    Stevan Stankovski

    2012-02-01

    Full Text Available Dairy cows identification and monitoring on small cattle farms are usually based on the utilization of barcode technology. This kind of identification technology is unsuitable for dairy cows milking and feeding process automation. Radio Frequency Identification (RFID technology is a better solution in this case. This paper describes the research and implementation of the milking cycle´s automated monitoring with the use of RFID tags conducted on a small cattle farm in the Republic of Serbia. This solution is based on RFID system which consists of two parts. First part includes control box, two Ultra High Frequency (UHF RFID readers operating at frequency of 915 MHz and RFID tags glued onto the dairy cow ear labels. Second part includes software modules for acquisition and collecting data from RFID tags to build up an archive due to supervision and analysis of the milking cycle. Reading accuracy of RFID system in the observed period was 99.8 % in average. A group of dairy cows having a settled milking cycle within an interval of 12h ± 5 % had a 1.5 % better yield and a 0.08 better quality in comparison with a group of dairy cows having a milking cycle variance higher than 20 %. RFID system implemented in described way can be easily integrated into a new or existing farm management system in order to have better production results which depend on several factors including settled milking cycles.

  3. A Spherical Aerial Terrestrial Robot

    Science.gov (United States)

    Dudley, Christopher J.

    This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.

  4. Collisions in spherical stellar systems

    Energy Technology Data Exchange (ETDEWEB)

    Polyachenko, V.L.; Shukhman, I.G. (AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    From the set of the equations for the stellar distribution function and for the two-particle correlation in the action- angle variables, by averaging over fast finite motions the general expression for the collisional term of a finite stellar system with ''rare'' Coulomb collisions is obtained. In the case of a spherically symmetrical system with the distribution function f/sub 0/=f/sub 0/(E, L) (E, L being the energy and the angular momentum of a star), the kinetic equation is reduced to the standard form of the two-dimensional Fokker-Planck equations.

  5. Spherical Orbifolds for Cosmic Topology

    International Nuclear Information System (INIS)

    Kramer, Peter

    2012-01-01

    Harmonic analysis is a tool to infer cosmic topology from the measured astrophysical cosmic microwave background CMB radiation. For overall positive curvature, Platonic spherical manifolds are candidates for this analysis. We combine the specific point symmetry of the Platonic manifolds with their deck transformations. This analysis in topology leads from manifolds to orbifolds. We discuss the deck transformations of the orbifolds and give eigenmodes for the harmonic analysis as linear combinations of Wigner polynomials on the 3-sphere. These provide new tools for detecting cosmic topology from the CMB radiation.

  6. Cows, clicks, ciphers, and satire

    Directory of Open Access Journals (Sweden)

    Tom Tyler

    2015-04-01

    Full Text Available The social network game Farmville, which allows players to grow crops, raise animals, and produce a variety of goods, proved enormously successful within a year of its launch in 2009, attracting 110 million Facebook users. However, the game has been criticised for its mindless mechanics, which require little more than repeated clicking on its colourful icons. By way of parody, Ian Bogost’s Cow Clicker permits its players to simply click on a picture of a cow once every six hours. In this essay I extend Bogost’s critique and suggest that Cow Clicker highlights not just the soulless inanity of Farmville gameplay but also the paucity of that game’s portrayal of the painful reality of a dairy cow’s punishing daily existence and untimely end.

  7. Melting under shock compression

    International Nuclear Information System (INIS)

    Bennett, B.I.

    1980-10-01

    A simple model, using experimentally measured shock and particle velocities, is applied to the Lindemann melting formula to predict the density, temperature, and pressure at which a material will melt when shocked from room temperature and zero pressure initial conditions

  8. Toxic Shock Syndrome

    Science.gov (United States)

    ... may also be caused by toxins produced by group A streptococcus (strep) bacteria. Toxic shock syndrome has been associated ... syndrome. The syndrome can also be caused by group A streptococcus (strep) bacteria. Risk factors Toxic shock syndrome can ...

  9. Casimir effect in spherical shells

    International Nuclear Information System (INIS)

    Ruggiero, J.R.

    1985-01-01

    The analytic regularization method is applied to study the Casimir effect for spherical cavities. Although many works have been presented in the past few years, problems related to the elimination of the regulator parameter still remain. A way to calculate the zero point energy of a perfectly conducting spherical shell which is a miscellaneous of those presented early is here proposed, How a cancelation of divergent terms occurs and how a finite parte is obtained after the elimination of the regulator parameter is shown. As a by-product the zero point energy of the interior vibration modes is obtained and this has some relevance to the quarks bag model. This relev ance is also discussed. The calculation of the energy fom the density view is also discussed. Some works in this field are criticized. The logarithmic divergent terms in the zero point energy are studied when the interior and exterior of the sphere are considered as a medium not dispersive and characterized by a dielectric constants ε 1 and ε 2 and peermeability constants μ 1 and μ 2 respectivelly. The logarithmic divergent terms are not present in the case of ε i μ i =K, with K some constant and i=1,2. (author) [pt

  10. National Spherical Torus Experiment (NSTX)

    International Nuclear Information System (INIS)

    Masayuki Ono

    2000-01-01

    The main aim of National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the innovative spherical torus (ST) concept. Physics outcome of the NSTX research program is relevant to near-term applications such as the Volume Neutron Source (VNS) and burning plasmas, and future applications such as the pilot and power plants. The NSTX device began plasma operations in February 1999 and the plasma current was successfully ramped up to the design value of 1 million amperes (MA) on December 14, 1999. The CHI (Coaxial Helicity Injection) and HHFW (High Harmonic Fast Wave) experiments have also started. Stable CHI discharges of up to 133 kA and 130-msec duration have been produced using 20 kA of injected current. Using eight antennas connected to two transmitters, up to 2 MW of HHFW power was successfully coupled to the plasma. The Neutral-beam Injection (NBI) heating system and associated NBI-based diagnostics such as the Charge-exchange Recombination Spectrometer (CHERS) will be operational in October 2000

  11. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  12. Progress in octahedral spherical hohlraum study

    Directory of Open Access Journals (Sweden)

    Ke Lan

    2016-01-01

    Full Text Available In this paper, we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study. From our theoretical study, the octahedral spherical hohlraums with 6 Laser Entrance Holes (LEHs of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7. In addition, the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology. We studied the laser arrangement and constraints of the octahedral spherical hohlraums, and gave a design on the laser arrangement for ignition octahedral hohlraums. As a result, the injection angle of laser beams of 50°–60° was proposed as the optimum candidate range for the octahedral spherical hohlraums. We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields, in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport. We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums, the rugby hohlraums and the cylindrical hohlraums, and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive. Up till to now, we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG laser facilities, including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums, spherical hohlraum energetics on the SGIII prototype laser facility, and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.

  13. Replacement policies for dairy cows

    DEFF Research Database (Denmark)

    Nielsen, Lars Relund; Kristensen, Anders Ringgaard

    2010-01-01

    In a recent paper a hierarchical Markov decision processes (MDP) with finite state and action space was formulated for the dairy cow replacement problem with stage lengths of 1 d. Bayesian updating was used to predict the performance of each cow in the herd and economic decisions were based...... on the prediction. The model can be used to assist the farmer in replacement decisions on a daily basis and is based on daily milk yield measurements that are available in modern milking systems. This talk will present the results of the paper and discuss directions for further research....

  14. Further Study on Strain Growth in Spherical Containment Vessels Subjected to Internal Blast Loading

    OpenAIRE

    2009-01-01

    Abstract Strain growth is a phenomenon observed in the elastic response of containment vessels subjected to internal blast loading, which is featured by the increased vibration amplitude of the vessel in a later stage. Previous studies attributed the strain growth in spherical containment vessels to the beating between two close vibration modes, the interactions between the vessel vibration and the reflected shock waves and the structural perturbation. In this paper, it is shown th...

  15. Associations of udder-health indicators with cow factors and with intramammary infection in dairy cows

    DEFF Research Database (Denmark)

    Nymann, A K; Persson Waller, K; Bennedsgaard, Torben Werner

    2014-01-01

    in milk from the sampled test milking) were collected from the Swedish milk-recording scheme. Of the sampled cows 485 were considered IMI negative and were used in multivariable mixed-effect linear regression models to investigate associations between cow factors and the udder-health indicators. A second...... modeling including all cows, both IMI negative and IMI positive (256 cows), was also performed. The results showed that all udder-health indicators were affected by cow factors but that different cow factors were associated with different indicators. Intramammary-infection status was significantly...... associated with all udder-health indicators except AP. Parity and milk urea concentration were the only cow factors associated with all indicators in all models. The significant cow factors explained 23% of the variation in SCC and >30% of the variation in LDH, NAGase, and AP in IMI-negative cows, showing...

  16. The ETE spherical Tokamak project. IAEA report

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Gerson Otto; Del Bosco, E.; Berni, L.A.; Ferreira, J.G.; Oliveira, R.M.; Andrade, M.C.R.; Shibata, C.S.; Barroso, J.J.; Castro, P.J.; Patire Junior, H. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma]. E-mail: ludwig@plasma.inpe.br

    2002-07-01

    This paper describes the general characteristics of spherical tokamaks, or spherical tori, with a brief overview of work in this area already performed or in progress at several institutions worldwide. The paper presents also the historical development of the ETE (Spherical Tokamak Experiment) project, its research program, technical characteristics and operating conditions as of October, 2002 at the Associated Plasma Laboratory (LAP) of the National Space Research Institute (INPE) in Brazil. (author)

  17. Relationships between solid spherical and toroidal harmonics

    OpenAIRE

    Majic, Matt; Ru, Eric C. Le

    2018-01-01

    We derive new relationships expressing solid spherical harmonics as series of toroidal harmonics and vice versa. The expansions include regular and irregular spherical harmonics, ring and axial toroidal harmonics of even and odd parity about the plane of the torus. The expansion coefficients are given in terms of a recurrence relation. As an example application we apply one of the expansions to express the potential of a charged conducting torus on a basis of spherical harmonics.

  18. Spherical Collapse in Chameleon Models

    CERN Document Server

    Brax, Ph; Steer, D A

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse depends on the initial comoving size of the inhomogeneity.

  19. Spherical collapse in chameleon models

    International Nuclear Information System (INIS)

    Brax, Ph.; Rosenfeld, R.; Steer, D.A.

    2010-01-01

    We study the gravitational collapse of an overdensity of nonrelativistic matter under the action of gravity and a chameleon scalar field. We show that the spherical collapse model is modified by the presence of a chameleon field. In particular, we find that even though the chameleon effects can be potentially large at small scales, for a large enough initial size of the inhomogeneity the collapsing region possesses a thin shell that shields the modification of gravity induced by the chameleon field, recovering the standard gravity results. We analyse the behaviour of a collapsing shell in a cosmological setting in the presence of a thin shell and find that, in contrast to the usual case, the critical density for collapse in principle depends on the initial comoving size of the inhomogeneity

  20. Cow's milk allergy in children

    African Journals Online (AJOL)

    Cow's milk, hen's egg, and peanuts are the foods most frequently involved. Respiratory manifestations (asthma, allergic rhinitis) are infrequent, especially as isolated symptoms. There is a belief among the lay public that the consumption of milk and dairy products increases the production of mucus in the respiratory tract.

  1. Teat Condition in Dairy Cows

    NARCIS (Netherlands)

    Neijenhuis, F.

    2004-01-01

    The dairy cow's teat is the first line of defence against mastitis pathogens. The milking process may affect the teat's condition, increasing the risk of mastitis. It is well-proven that teat-ends with severe erosions or broken skin will have an increased risk of mastitis. However, more common

  2. Teat condition in dairy cows

    NARCIS (Netherlands)

    Neijenhuis, Francesca

    2004-01-01

    The dairy cow's teat is the first line of defence against mastitis pathogens. The milking process may affect the teat's condition, increasing the risk of mastitis. It is well-proven that teat-ends with severe erosions or broken skin will have an increased risk of mastitis. However, more common

  3. TRANSMISSION AND EMISSION OF SOLAR ENERGETIC PARTICLES IN SEMI-TRANSPARENT SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Kocharov, Leon; Usoskin, Ilya [Sodankylä Geophysical Observatory (Oulu Unit), University of Oulu, P.O. Box 3000, FI-90014 Oulu (Finland); Laitinen, Timo [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Vainio, Rami [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

    2014-06-01

    While major solar energetic particle (SEP) events are associated with coronal mass ejection (CME)-driven shocks in solar wind, accurate SEP measurements reveal that more than one component of energetic ions exist in the beginning of the events. Solar electromagnetic emissions, including nuclear gamma-rays, suggest that high-energy ions could also be accelerated by coronal shocks, and some of those particles could contribute to SEPs in interplanetary space. However, the CME-driven shock in solar wind is thought to shield any particle source beneath the shock because of the strong scattering required for the diffusive shock acceleration. In this Letter, we consider a shock model that allows energetic particles from the possible behind-shock source to appear in front of the shock simultaneously with SEPs accelerated by the shock itself. We model the energetic particle transport in directions parallel and perpendicular to the magnetic field in a spherical shock expanding through the highly turbulent magnetic sector with an embedded quiet magnetic tube, which makes the shock semi-transparent for energetic particles. The model energy spectra and time profiles of energetic ions escaping far upstream of the shock are similar to the profiles observed during the first hour of some gradual SEP events.

  4. Diagnosing radiative shocks from deuterium and tritium implosions on NIF.

    Science.gov (United States)

    Pak, A; Divol, L; Weber, S; Döppner, T; Kyrala, G A; Kilne, J; Izumi, N; Glenn, S; Ma, T; Town, R P; Bradley, D K; Glenzer, S H

    2012-10-01

    During the recent ignition tuning campaign at the National Ignition Facility, layered cryogenic deuterium and tritium capsules were imploded via x-ray driven ablation. The hardened gated x-ray imager diagnostic temporally and spatially resolves the x-ray emission from the core of the capsule implosion at energies above ~8 keV. On multiple implosions, ~200-400 ps after peak compression a spherically expanding radiative shock has been observed. This paper describes the methods used to characterize the radial profile and rate of expansion of the shock induced x-ray emission.

  5. Stability of the spherical form of nuclei

    International Nuclear Information System (INIS)

    Sabry, A.A.

    1976-08-01

    An extension of the mass formula for a spherical nucleus in the drop model to include a largely deformed nucleus of different forms is investigated. It is found that although the spherical form is stable under small deformations from equilibrium, there exists for heavier nuclei another more favourable stable form, which can be approximated by two, or three touching prolate ellipsoids of revolution

  6. Spherically symmetric inhomogeneous dust collapse in higher ...

    Indian Academy of Sciences (India)

    We consider a collapsing spherically symmetric inhomogeneous dust cloud in higher dimensional space-time. ... The existence of strong curvature naked singularities in gravitational collapse of spherically symmetric space-times ... where an over dot denotes partial derivative with respect to t. The functions F(r) and f(r).

  7. How Spherical Is a Cube (Gravitationally)?

    Science.gov (United States)

    Sanny, Jeff; Smith, David

    2015-01-01

    An important concept that is presented in the discussion of Newton's law of universal gravitation is that the gravitational effect external to a spherically symmetric mass distribution is the same as if all of the mass of the distribution were concentrated at the center. By integrating over ring elements of a spherical shell, we show that the…

  8. No regularity singularities exist at points of general relativistic shock wave interaction between shocks from different characteristic families.

    Science.gov (United States)

    Reintjes, Moritz; Temple, Blake

    2015-05-08

    We give a constructive proof that coordinate transformations exist which raise the regularity of the gravitational metric tensor from C 0,1 to C 1,1 in a neighbourhood of points of shock wave collision in general relativity. The proof applies to collisions between shock waves coming from different characteristic families, in spherically symmetric spacetimes. Our result here implies that spacetime is locally inertial and corrects an error in our earlier Proc. R. Soc. A publication, which led us to the false conclusion that such coordinate transformations, which smooth the metric to C 1,1 , cannot exist. Thus, our result implies that regularity singularities (a type of mild singularity introduced in our Proc. R. Soc. A paper) do not exist at points of interacting shock waves from different families in spherically symmetric spacetimes. Our result generalizes Israel's celebrated 1966 paper to the case of such shock wave interactions but our proof strategy differs fundamentally from that used by Israel and is an extension of the strategy outlined in our original Proc. R. Soc. A publication. Whether regularity singularities exist in more complicated shock wave solutions of the Einstein-Euler equations remains open.

  9. Comparison of two methods of detecting purulent vaginal discharge in postpartum dairy cows and effect of intrauterine cephapirin on reproductive performance.

    Science.gov (United States)

    Runciman, D J; Anderson, G A; Malmo, J

    2009-09-01

    Part 1: compare the use of a Metricheck device (a stainless steel probe with a semi-spherical rubber cup attached at one end) to sample the contents of the anterior vagina with a vaginal speculum examination for the diagnosis of pus in the vagina of postpartum dairy cows and to investigate the association of that pus with reproductive performance. Part 2: assess the effect of a single intrauterine infusion of 500 mg cephapirin in cows diagnosed with vaginal purulent or mucopurulent discharge 7 to 28 days after calving on reproductive performance. Six herds were visited fortnightly to examine cows that had calved between 7 and 28 days (n = 423) with both the Metricheck device and a vaginal speculum to score, by each method, the vaginal discharge from 0 (clear or absent) to 3 (purulent) for each animal included in the study. Half of the cows that had a positive discharge score (1 to 3 by either examination method) were then treated with an intrauterine infusion of 500 mg of cephapirin. The relationship between Metricheck score, vaginoscopy score, treatment and reproductive performance was assessed. There was a substantial measure of agreement between each method when scores were analysed by status. Cows that were positive with either method had inferior reproductive performance compared with cows with a score of zero. Treatment of cows diagnosed with a purulent or mucopurulent discharge with intrauterine cephapirin improved reproductive performance in both the vaginoscopy and Metricheck groups.

  10. Intrinsic cylindrical and spherical waves

    International Nuclear Information System (INIS)

    Ludlow, I K

    2008-01-01

    Intrinsic waveforms associated with cylindrical and spherical Bessel functions are obtained by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront. The resulting expressions are Riccati-Bessel functions for both cases and these can be written in terms of amplitude and phase functions of order v and wave variable z. When z is real, it is shown that a spatial phase angle of the intrinsic wave can be defined and this, together with its amplitude function, is systematically investigated for a range of fixed orders and varying z. The derivatives of Riccati-Bessel functions are also examined. All the component functions exhibit different behaviour in the near field depending on the order being less than, equal to or greater than 1/2. Plots of the phase angle can be used to display the locations of the zeros of the general Riccati-Bessel functions and lead to new relations concerning the ordering of the real zeros of Bessel functions and the occurrence of multiple zeros when the argument of the Bessel function is fixed

  11. Osmotic buckling of spherical capsules.

    Science.gov (United States)

    Knoche, Sebastian; Kierfeld, Jan

    2014-11-07

    We study the buckling of elastic spherical shells under osmotic pressure with the osmolyte concentration of the exterior solution as a control parameter. We compare our results for the bifurcation behavior with results for buckling under mechanical pressure control, that is, with an empty capsule interior. We find striking differences for the buckling states between osmotic and mechanical buckling. Mechanical pressure control always leads to fully collapsed states with opposite sides in contact, whereas uncollapsed states with a single finite dimple are generic for osmotic pressure control. For sufficiently large interior osmolyte concentrations, osmotic pressure control is qualitatively similar to buckling under volume control with the volume prescribed by the osmolyte concentrations inside and outside the shell. We present a quantitative theory which also captures the influence of shell elasticity on the relationship between osmotic pressure and volume. These findings are relevant for the control of buckled shapes in applications. We show how the osmolyte concentration can be used to control the volume of buckled shells. An accurate analytical formula is derived for the relationship between the osmotic pressure, the elastic moduli and the volume of buckled capsules. This also allows use of elastic capsules as osmotic pressure sensors or deduction of elastic properties and the internal osmolyte concentration from shape changes in response to osmotic pressure changes. We apply our findings to published experimental data on polyelectrolyte capsules.

  12. Vasogenic shock physiology

    OpenAIRE

    Gkisioti, Sotiria; Mentzelopoulos, Spyros D

    2011-01-01

    Sotiria Gkisioti, Spyros D MentzelopoulosDepartment of Intensive Care Medicine, University of Athens Medical School, Evaggelismos General Hospital, Athens, GreeceAbstract: Shock means inadequate tissue perfusion by oxygen-carrying blood. In vasogenic shock, this circulatory failure results from vasodilation and/or vasoplegia. There is vascular hyporeactivity with reduced vascular smooth muscle contraction in response to α1 adrenergic agonists. Considering vasogenic shock, one can un...

  13. Life Shocks and Homelessness

    OpenAIRE

    Marah A. Curtis; Hope Corman; Kelly Noonan; Nancy Reichman

    2011-01-01

    We exploit an exogenous health shock--the birth of a child with a severe health condition--to investigate the causal effect of a life shock on homelessness. Using survey data from the Fragile Families and Child Wellbeing study that have been augmented with information from hospital medical records, we find that the health shock increases the likelihood of homelessness three years later, particularly in cities with high housing costs. Homelessness is defined using both a traditional measure an...

  14. Shock transformations in quartzite

    Science.gov (United States)

    Badjukov, D. D.; Koslov, E. A.; Zhugin, Yu. N.; Abakshin, E. V.

    1993-01-01

    We report results of studies of experimental shock metamorphism in a quartzite sample. Shock pressure increases in the experiment from a rim to a center of the bowl-shaped sample due to a design of a recovery assembly. The section along an equatorial plane shows a progressive development of shock metamorphism. On the basis of observations, it is proposed that diaplectic glass can be a product of quenching a melt.

  15. Interaction of MHD shocks

    International Nuclear Information System (INIS)

    Gundersen, R.M.

    1983-01-01

    A plane MHD shock wave of arbitrary strength meets a slender body moving at super-true-sonic speed in the opposite direction. The interaction between the given shock wave and the weak shock attached to the slender body is studied for aligned fields for axisymmetrical flow and for both aligned and transverse fields in the two-dimensional case. Formal solutions for the linearized flow in the interaction region are obtained by the use of integral transforms. (author)

  16. Toxic Shock Syndrome (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Toxic Shock Syndrome KidsHealth / For Parents / Toxic Shock Syndrome What's ... en español Síndrome de shock tóxico About Toxic Shock Syndrome Toxic shock syndrome (TSS) is a serious ...

  17. Spherical aberration in contact lens wear.

    Science.gov (United States)

    Lindskoog Pettersson, A; Jarkö, C; Alvin, A; Unsbo, P; Brautaset, R

    2008-08-01

    The aim of the present studies was to investigate the effect on spherical aberration of different non custom-made contact lenses, both with and without aberration control. A wavefront analyser (Zywave, Bausch & Lomb) was used to measure the aberrations in each subject's right eye uncorrected and with the different contact lenses. The first study evaluated residual spherical aberration with a standard lens (Focus Dailies Disposable, Ciba Vision) and with an aberration controlled contact lens (ACCL) (Definition AC, Optical Connection Inc.). The second study evaluated the residual spherical aberrations with a monthly disposable silicone hydrogel lens with aberration reduction (PureVision, Bausch & Lomb). Uncorrected spherical aberration was positive for all pupil sizes in both studies. In the first study, residual spherical aberration was close to zero with the standard lens for all pupil sizes whereas the ACCL over-corrected spherical aberration. The results of the second study showed that the monthly disposable lens also over-corrected the aberration making it negative. The changes in aberration were statistically significant (plenses. Since the amount of aberration varies individually we suggest that aberrations should be measured with lenses on the eye if the aim is to change spherical aberration in a certain direction.

  18. Novel Electrically Small Spherical Electric Dipole Antenna

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2010-01-01

    This paper introduces a novel electrically small spherical meander antenna. Horizontal sections of the meander are composed of wire loops, radii of which are chosen so that the whole structure is conformal to a sphere of radius a. To form the meander the loops are connected by wires at a meridian...... plane. The antenna operates as an electric dipole, i.e. it radiates the TM10 spherical mode. The antenna is self-resonant and can be matched to a wide range of input feed lines without an external matching network. In this paper, a spherical meander antenna of the size ka = 0.27 and the input impedance...

  19. Toxic Shock Syndrome (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Toxic Shock Syndrome KidsHealth / For Teens / Toxic Shock Syndrome What's ... it, then take some precautions. What Is Toxic Shock Syndrome? If you're a girl who's had ...

  20. Shock Probation in Iowa.

    Science.gov (United States)

    Boudouris, James; Turnbull, Bruce W.

    1985-01-01

    Compared characteristics and recidivism of 820 shock probationers with recidivism of parolees, straight probationers, and persons sentenced to residential facilities or halfway houses. The results indicated that age, prior juvenile or adult commitments, unemployment, and marital status were related to recidivism for all male shock probationers.…

  1. Our Favorite Film Shocks

    DEFF Research Database (Denmark)

    Willerslev, Rane; Suhr, Christian

    2014-01-01

    The modern medium of film has long been hailed for its capacity for producing shocks of an entertaining, thought-provoking, or even politically emancipative nature. But what is a shock, how and when does it occur, how long does it last, and are there particular techniques for producing cinematic...

  2. Climate shocks and conflict

    NARCIS (Netherlands)

    Papaioannou, Kostadis J.

    2016-01-01

    This paper offers a historical micro-level analysis of the impact of climate shocks on the incidence of civil conflict in colonial Nigeria (1912-1945). Primary historical sources on court cases, prisoners and homicides are used to capture conflict. To measure climate shocks we use the deviation

  3. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  4. 3D Printing Electrically Small Spherical Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2013-01-01

    3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....

  5. Spherically symmetric inhomogeneous dust collapse in higher ...

    Indian Academy of Sciences (India)

    We consider a collapsing spherically symmetric inhomogeneous dust cloud in higher dimensional space-time. We show that the central singularity of collapse can be a strong curvature or a weak curvature naked singularity depending on the initial density distribution.

  6. Spherical designs and anticoherent spin states

    International Nuclear Information System (INIS)

    Crann, Jason; Pereira, Rajesh; Kribs, David W

    2010-01-01

    Anticoherent spin states are quantum states that exhibit maximally nonclassical behaviour in a certain sense. Any spin state whose Majorana representation is a Platonic solid is called a perfect state. By direct calculation, it has been shown that any perfect state is an anticoherent spin state. We show that any spin state whose Majorana representation is both the orbit of a finite subgroup of O(3) and a spherical t-design must be an anticoherent spin state of order t. Since all Platonic solids are spherical designs, this result gives an explanation of the anticoherence of perfect states and explains their observed order. We also show that any spin state whose Majorana representation lies in any single open hemisphere cannot be anticoherent of any order. This result is then used to give further relations between spherical designs and anticoherent spin states. We also pose some questions relating spherical designs and geometric entanglement.

  7. Transformation of Real Spherical Harmonics under Rotations

    Science.gov (United States)

    Romanowski, Z.; Krukowski, St.; Jalbout, A. F.

    2008-08-01

    The algorithm rotating the real spherical harmonics is presented. The convenient and ready to use formulae for l = 0, 1, 2, 3 are listed. The rotation in R3 space is determined by the rotation axis and the rotation angle; the Euler angles are not used. The proposed algorithm consists of three steps. (i) Express the real spherical harmonics as the linear combination of canonical polynomials. (ii) Rotate the canonical polynomials. (iii) Express the rotated canonical polynomials as the linear combination of real spherical harmonics. Since the three step procedure can be treated as a superposition of rotations, the searched rotation matrix for real spherical harmonics is a product of three matrices. The explicit formulae of matrix elements are given for l = 0, 1, 2, 3, what corresponds to s, p, d, f atomic orbitals.

  8. Spherical stochastic neighbor embedding of hyperspectral data

    CSIR Research Space (South Africa)

    Lunga, D

    2012-07-01

    Full Text Available of spherical coordinates. This allows the use of an Exit probability distribution to discover the nonlinear characteristics that are inherent in hyperspectral data. In addition, the method directly learns the probability distribution over neighboring pixel maps...

  9. Feasibility study for the Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Lazarus, E.A.; Attenberger, S.E.; Baylor, L.R.

    1985-10-01

    The design of the Spherical Torus Experiment (STX) is discussed. The physics of the plasma are given in a magnetohydrodynamic model. The structural aspects and instrumentation of the device are described. 19 refs., 103 figs

  10. Spiral CT manifestations of spherical pneumonia

    International Nuclear Information System (INIS)

    Li Xiaohong; Yang Hongwei; Xu Chunmin; Qin Xiu

    2008-01-01

    Objective: To explore the Spiral CT manifestations and differential diagnosis of spherical pneumonia. Methods: 18 cases of spherical pneumonia and 20 cases of peripheral pulmonary carcinoma were selected, both of them were confirmed by clinic and/or pathology. The SCT findings of both groups were compared retrospectively. Results: Main spiral CT findings of spherical pneumonia were showed as followings: square or triangular lesions adjacent to pleura; with irregular shape, blurry, slightly lobulated margin, sometimes with halo sign. Small inflammatory patches and intensified vascular markings around the lesions were seen. Lesions became smaller or vanished after short-term anti-inflammatory treatment. Conclusion: Spherical pneumonia showed some characteristics on Spiral CT scan, which are helpful in diagnosis and differential diagnosis of this disease. (authors)

  11. 3D Printing Electrically Small Spherical Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2013-01-01

    3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations.......3D printing is applied for rapid prototyping of an electrically small spherical wire antenna. The model is first printed in plastic and subsequently covered with several layers of conductive paint. Measured results are in good agreement with simulations....

  12. A Spherical Electro Optic High Voltage Sensor

    Science.gov (United States)

    1989-06-01

    the application of an electric field applied to the EO crystal, and a photodetector senses the pattern movement. The sensor can be made small (e.g...spherical symmetry simplifies analysis; a uniform£ exists within a spherical dielectric when immursed in a uniform E; conoscopic light production...of an electric field applied to the EO crystal, and a photodetector senses the pattern movement. The sensor can be made small (e.g. < 3mm diam

  13. Economic optimization of selective dry cow treatment

    NARCIS (Netherlands)

    Scherpenzeel, C G M; Hogeveen, H; Maas, L; Lam, T J G M

    2018-01-01

    The objective of this study was to develop a mathematical model to identify a scenario with the lowest costs for mastitis associated with the dry period while restricting the percentage of cows to be dried off with dry cow antimicrobials. Costs of clinical and subclinical mastitis as well as

  14. Brief of requirements of the dairy cow

    NARCIS (Netherlands)

    Cornelissen, J.M.R.; Ursinus, W.W.; Schepers, F.; Groot Koerkamp, P.W.G.; Dixhoorn, van I.D.E.

    2009-01-01

    This report lists the brief of requirements of the dairy cow, based on her needs (also listed). The BoR indicates the actor’s needs with regards to the animal husbandry system. BoR of the main actors are incorporated in the redesign of a dairy husbandry system in the project Cow Power

  15. A velocity probe-based method for continuous detonation and shock measurement in near-field underwater explosion

    Science.gov (United States)

    Li, Kebin; Li, Xiaojie; Yan, Honghao; Wang, Xiaohong; Miao, Yusong

    2017-12-01

    A new velocity probe which permits recording the time history of detonation and shock waves has been developed by improving the commercial on principle and structure. A method based on the probe is then designed to measure the detonation velocity and near-field shock parameters in a single underwater explosion, by which the oblique shock wave front of cylindrical charges and the peak pressure attenuation curve of spherical explosive are obtained. A further derivation of detonation pressure, adiabatic exponent, and other shock parameters is conducted. The present method offers a novel and reliable parameter determination for near-field underwater explosion.

  16. A modified finite element procedure for underwater shock analysis

    International Nuclear Information System (INIS)

    Chan, S.K.

    1990-01-01

    Using the regular finite element method for analyzing wave propagation problems presents difficulties: (a) The finite element mesh gives spurious reflection of the traveling wave and (b) Since a finite element model has to have a finite boundary, the wave is reflected by the outside boundary. However, for underwater shock problems, only the response of the structure is of major interest, not the behavior of the wave itself, and the shock wave can be assumed to be spherical. By taking advantage of the limited scope of the underwater shock problem, a finite element procedure can be developed that eliminates the above difficulties. This procedure not only can give very accurate solutions but it may also include structural nonlinearities and effect of cavitation

  17. Extreme State of Matter: Shock Experiments and Simulations

    Science.gov (United States)

    Fortov, Vladimir

    The behavior of matter at extremely high pressures is very interesting for understanding the structure and evolution of astrophysica objects and many modern energy technologies. Dynamic investigations of warm dense matter at extremely high pressures, based on shock loading, adiabatic release of shocked as well as quasi-isentropic compression are considered. To generate shock waves in the terapascal pressure range, the cylindrical and spherical condensed high explosives, laser and corpuscular beams, high velocity impacts, and soft X-rays were used. The high-resolved temporal diagnostics of the extreme states of plasma were carried out with VIZAR technique, fast acting electron-optical transducers, pyrometers, and high-speed spectrometers equipped with the electron-optical transmission lines. The experimental data obtained and the physical models of behavior of plasma at extremely high pressures, temperatures and strain rates are discussed.

  18. Stress effect on conception rate in Nellore cows submmited to fixed time artificial insemination. Preliminary results

    Directory of Open Access Journals (Sweden)

    Fábio Luis Nogueira Natal

    2013-12-01

    Full Text Available In beef cattle, fixed time artificial insemination (FTAI provides a method to inseminate large numbers of females in a specific time, which result in economical gains due, among others, to a more uniform calf crop. However, FTAI requires frequent manipulation of animals in order to inject hormones and for clinical examination. Consequently, animals seemed stressed in less or higher extent at the time of insemination. This can be a problem because it has been demonstrated that application of an acute stress treatment (electric shock, confinement, restraint and rotation twice a day during the follicular phase of the oestrous cycle prevents the pre-ovulatory LH surge. This study aimed to evaluate if FTAI efficiency of Nellore cows is affected by the degree of stress observed at time of AI. Nellore cows (n=92 were treated (Day 0 with a progesterone intravaginal devise (Primer®, Tecnopec, São Paulo, Brazil containing 1 g of progesterone and injected with estradiol benzoate (2mg EB, Estrogin, AUSA, Brazil. Primer was removed on Day 8 (08:00 AM and administered one injection of cloprostenol (125 mcg, Prolise®, Tecnopec, São Paulo, Brazil. Twenty-four hours later, cows received 2 mg EB and insemination (semen from one sire was done on the afternoon (14:00 to 16:00 PM of day 10. At time of FTAI, the stress condition was classified as 1 (low, 2 (moderate or 3 (high according the reactivity of cows to enter in the squeeze chute and apparent nervous behavior. Pregnancy status was evaluated by transrectal ultrasound on day 40 after FTAI. Data were analyzed by Chi-square test. Cows with moderate or high degree of stress had lower conception rate than low stressed cows (P<0.01. These results suggest that cow temperament must be considered in the planning of FTAI programs. Studies are in progress in order to measure hormonal parameters (cortisol and Alpha amylase that better reflects the “fight-or-flight” response to immediate stressors in order to

  19. Hydrodynamic modelling of the shock ignition scheme for inertial confinement fusion

    International Nuclear Information System (INIS)

    Vallet, Alexandra

    2014-01-01

    The shock ignition concept in inertial confinement fusion uses an intense power spike at the end of an assembly laser pulse. The key features of shock ignition are the generation of a high ablation pressure, the shock pressure amplification by at least a factor of a hundred in the cold fuel shell and the shock coupling to the hot-spot. In this thesis, new semi-analytical hydrodynamic models are developed to describe the ignitor shock from its generation up to the moment of fuel ignition. A model is developed to describe a spherical converging shock wave in a pre-heated hot spot. The self-similar solution developed by Guderley is perturbed over the shock Mach number Ms ≥≥1. The first order correction accounts for the effects of the shock strength. An analytical ignition criterion is defined in terms of the shock strength and the hot-spot areal density. The ignition threshold is higher when the initial Mach number of the shock is lower. A minimal shock pressure of 20 Gbar is needed when it enters the hot-spot. The shock dynamics in the imploding shell is then analyzed. The shock is propagating into a non inertial medium with a high radial pressure gradient and an overall pressure increase with time. The collision with a returning shock coming from the assembly phase enhances further the ignitor shock pressure. The analytical theory allows to describe the shock pressure and strength evolution in a typical shock ignition implosion. It is demonstrated that, in the case of the HiPER target design, a generation shock pressure near the ablation zone on the order of 300-400 Mbar is needed. An analysis of experiments on the strong shock generation performed on the OMEGA laser facility is presented. It is shown that a shock pressure close to 300 Mbar near the ablation zone has been reached with an absorbed laser intensity up to 2 * 10 15 W:cm -2 and a laser wavelength of 351 nm. This value is two times higher than the one expected from collisional laser absorption only

  20. Echocardiography in shock management.

    Science.gov (United States)

    McLean, Anthony S

    2016-08-20

    Echocardiography is pivotal in the diagnosis and management of the shocked patient. Important characteristics in the setting of shock are that it is non-invasive and can be rapidly applied.In the acute situation a basic study often yields immediate results allowing for the initiation of therapy, while a follow-up advanced study brings the advantage of further refining the diagnosis and providing an in-depth hemodynamic assessment. Competency in basic critical care echocardiography is now regarded as a mandatory part of critical care training with clear guidelines available. The majority of pathologies found in shocked patients are readily identified using basic level 2D and M-mode echocardiography. A more comprehensive diagnosis can be achieved with advanced levels of competency, for which practice guidelines are also now available. Hemodynamic evaluation and ongoing monitoring are possible with advanced levels of competency, which includes the use of colour Doppler, spectral Doppler, and tissue Doppler imaging and occasionally the use of more recent technological advances such as 3D or speckled tracking.The four core types of shock-cardiogenic, hypovolemic, obstructive, and vasoplegic-can readily be identified by echocardiography. Even within each of the main headings contained in the shock classification, a variety of pathologies may be the cause and echocardiography will differentiate which of these is responsible. Increasingly, as a result of more complex and elderly patients, the shock may be multifactorial, such as a combination of cardiogenic and septic shock or hypovolemia and ventricular outflow obstruction.The diagnostic benefit of echocardiography in the shocked patient is obvious. The increasing prevalence of critical care physicians experienced in advanced techniques means echocardiography often supplants the need for more invasive hemodynamic assessment and monitoring in shock.

  1. Pediatric Toxic Shock Syndrome

    Directory of Open Access Journals (Sweden)

    Jennifer Yee

    2017-09-01

    Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

  2. Imploding conical shock waves

    Science.gov (United States)

    Paton, R. T.; Skews, B. W.; Rubidge, S.; Snow, J.

    2013-07-01

    The behaviour of conical shock waves imploding axisymmetrically was first studied numerically by Hornung (J Fluid Mech 409:1-12, 2000) and this prompted a limited experimental investigation into these complex flow patterns by Skews et al. (Shock Waves 11:323-326, 2002). Modification of the simulation boundary conditions, resulting in the loss of self-similarity, was necessary to image the flow experimentally. The current tests examine the temporal evolution of these flows utilising a converging conical gap of fixed width fed by a shock wave impinging at its entrance, supported by CFD simulations. The effects of gap thickness, angle and incident shock strength were investigated. The wave initially diffracts around the outer lip of the gap shedding a vortex which, for strong incident shock cases, can contain embedded shocks. The converging shock at exit reflects on the axis of symmetry with the reflected wave propagating outwards resulting in a triple point developing on the incident wave together with the associated shear layer. This axisymmetric shear layer rolls up into a mushroom-shaped toroidal vortex ring and forward-facing jet. For strong shocks, this deforms the Mach disk to the extent of forming a second triple point with the primary shock exhibiting a double bulge. Separate features resembling the Richtmeyer-Meshkov and Kelvin-Helmholtz instabilities were noted in some tests. Aside from the incident wave curvature, the reflection patterns demonstrated correspond well with the V- and DV-types identified by Hornung although type S was not clearly seen, possibly due to the occlusion of the reflection region by the outer diffraction vortex at these early times. Some additional computational work explicitly exploring the limits of the parameter space for such systems has demonstrated the existence of a possible further reflection type, called vN-type, which is similar to the von Neumann reflection for plane waves. It is recommended that the parameter space be

  3. Phosphorus and the dairy cow

    OpenAIRE

    Ekelund, Adrienne

    2003-01-01

    The general aim of the present work was to investigate phosphorus balance in the dairy cow, with reference to the amount and source of phosphorus. Furthermore, biochemical bone markers were used to study the bone turnover during the lactation and dry period. Phosphorus is located in every cell of the body and has more known functions than any other mineral element in the animal body. Phosphorus is also an important constituent of milk, and is therefore required in large amounts in a high yiel...

  4. Associations of udder-health indicators with cow factors and with intramammary infection in dairy cows.

    Science.gov (United States)

    Nyman, A-K; Persson Waller, K; Bennedsgaard, T W; Larsen, T; Emanuelson, U

    2014-09-01

    The objective of this study was to investigate if and how cow factors and intramammary infection (IMI) are associated with 4 different udder-health indicators in dairy cows as a first step in investigating whether the diagnostic performance of these indicators can be improved. The investigated indicators were somatic cell count (SCC), lactate dehydrogenase (LDH), N-acetyl-β-d-glucosaminidase (NAGase), and alkaline phosphatase (AP) measured in milk. In this cross-sectional study, approximately 1,000 cows from 25 dairy herds were sampled for bacteriology (quarter milk samples) during 3 consecutive days: the day before test milking, at the day of test milking, and at the day after test milking. The whole-udder test milking sample was analyzed for milk composition, SCC, LDH, NAGase, and AP. Cow data (parity, breed, milk yield, percentage of milk fat and protein, milk urea concentration, and days in milk from the sampled test milking) were collected from the Swedish milk-recording scheme. Of the sampled cows 485 were considered IMI negative and were used in multivariable mixed-effect linear regression models to investigate associations between cow factors and the udder-health indicators. A second modeling including all cows, both IMI negative and IMI positive (256 cows), was also performed. The results showed that all udder-health indicators were affected by cow factors but that different cow factors were associated with different indicators. Intramammary-infection status was significantly associated with all udder-health indicators except AP. Parity and milk urea concentration were the only cow factors associated with all indicators in all models. The significant cow factors explained 23% of the variation in SCC and >30% of the variation in LDH, NAGase, and AP in IMI-negative cows, showing that LDH, NAGase, and AP are more affected than SCC by cow factors. The IMI status explained 23% of the variation in SCC in the model with all cows but only 7% of the variation in

  5. 33 CFR 157.124 - COW tank washing machines.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false COW tank washing machines. 157....124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo tank. (b) The COW machines in each tank must have sufficient nozzles with the proper diameter, working pressure...

  6. A Self-similar Flow Behind a Shock Wave in a Gravitating or Non ...

    Indian Academy of Sciences (India)

    The propagation of a spherical shock wave in an ideal gas with heat conduction and radiation heat-flux, and with or without self-gravitational effects, is investigated. The initial density of the gas is assumed to obey a power law. The heat conduction is expressed in terms of Fourier's law and the radiation is considered to be of ...

  7. Life shocks and homelessness.

    Science.gov (United States)

    Curtis, Marah A; Corman, Hope; Noonan, Kelly; Reichman, Nancy E

    2013-12-01

    We exploited an exogenous health shock-namely, the birth of a child with a severe health condition-to investigate the effect of a life shock on homelessness in large cities in the United States as well as the interactive effects of the shock with housing market characteristics. We considered a traditional measure of homelessness, two measures of housing instability thought to be precursors to homelessness, and a combined measure that approximates the broadened conceptualization of homelessness under the 2009 Homeless Emergency Assistance and Rapid Transition to Housing Act (2010). We found that the shock substantially increases the likelihood of family homelessness, particularly in cities with high housing costs. The findings are consistent with the economic theory of homelessness, which posits that homelessness results from a conjunction of adverse circumstances in which housing markets and individual characteristics collide.

  8. Electrical Shock: First Aid

    Science.gov (United States)

    ... using a dry, nonconducting object made of cardboard, plastic or wood. Begin CPR if the person shows ... org/first-aid/first-aid-electrical-shock/basics/art-20056695 . Mayo Clinic Footer Legal Conditions and Terms ...

  9. Shock Waves in Supernova Ejecta

    Science.gov (United States)

    Raymond, J. C.

    2018-02-01

    Astrophysical shock waves are a major mechanism for dissipating energy, and by heating and ionizing the gas they produce emission spectra that provide valuable diagnostics for the shock parameters, for the physics of collisionless shocks, and for the composition of the shocked material. Shocks in SN ejecta in which H and He have been burned to heavier elements behave differently than shocks in ordinary astrophysical gas because of their very large radiative cooling rates. In particular, extreme departures from thermal equilibrium among ions and electrons and from ionization equilibrium may arise. This paper discusses the consequences of the enhanced metal abundances for the structure and emission spectra of those shocks.

  10. Unlimited Relativistic Shock Surfing Acceleration

    International Nuclear Information System (INIS)

    Ucer, D.; Shapiro, V. D.

    2001-01-01

    Nonrelativistic shock surfing acceleration at quasiperpendicular shocks is usually considered to be a preacceleration mechanism for slow pickup ions to initiate diffusive shock acceleration. In shock surfing, the particle accelerates along the shock front under the action of the convective electric field of the plasma flow. However, the particle also gains kinetic energy normal to the shock and eventually escapes downstream. We consider the case when ions are accelerated to relativistic velocities. In this case, the ions are likely to be trapped for infinitely long times, because the energy of bounce oscillations tends to decrease during acceleration. This suggests the possibility of unlimited acceleration by shock surfing

  11. Effects of magnetic fields on magnetohydrodynamic cylindrical and spherical Richtmyer-Meshkov instability

    KAUST Repository

    Mostert, W.

    2015-10-06

    The effects of seed magnetic fields on the Richtmyer-Meshkov instability driven by converging cylindrical and spherical implosions in ideal magnetohydrodynamics are investigated. Two different seed field configurations at various strengths are applied over a cylindrical or spherical density interface which has a single-dominant-mode perturbation. The shocks that excite the instability are generated with appropriate Riemann problems in a numerical formulation and the effect of the seed field on the growth rate and symmetry of the perturbations on the density interface is examined. We find reduced perturbation growth for both field configurations and all tested strengths. The extent of growth suppression increases with seed field strength but varies with the angle of the field to interface. The seed field configuration does not significantly affect extent of suppression of the instability, allowing it to be chosen to minimize its effect on implosion distortion. However, stronger seed fields are required in three dimensions to suppress the instability effectively.

  12. Pediatric Toxic Shock Syndrome

    OpenAIRE

    Yee, Jennifer; King, Andrew

    2017-01-01

    Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management....

  13. Statistical Mechanics of Thin Spherical Shells

    Directory of Open Access Journals (Sweden)

    Andrej Košmrlj

    2017-01-01

    Full Text Available We explore how thermal fluctuations affect the mechanics of thin amorphous spherical shells. In flat membranes with a shear modulus, thermal fluctuations increase the bending rigidity and reduce the in-plane elastic moduli in a scale-dependent fashion. This is still true for spherical shells. However, the additional coupling between the shell curvature, the local in-plane stretching modes, and the local out-of-plane undulations leads to novel phenomena. In spherical shells, thermal fluctuations produce a radius-dependent negative effective surface tension, equivalent to applying an inward external pressure. By adapting renormalization group calculations to allow for a spherical background curvature, we show that while small spherical shells are stable, sufficiently large shells are crushed by this thermally generated “pressure.” Such shells can be stabilized by an outward osmotic pressure, but the effective shell size grows nonlinearly with increasing outward pressure, with the same universal power-law exponent that characterizes the response of fluctuating flat membranes to a uniform tension.

  14. Recent Progress on Spherical Torus Research

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Masayuki [PPPL; Kaita, Robert [PPPL

    2014-01-01

    The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A = R0/a) reduced to A ~ 1.5, well below the normal tokamak operating range of A ≥ 2.5. As the aspect ratio is reduced, the ideal tokamak beta β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β ~ 1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation κ, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of attractive fusion energy power source. Since the start of the two megaampere class ST facilities in 2000, National Spherical Torus Experiment (NSTX) in the US and Mega Ampere Spherical Tokamak (MAST) in UK, active ST research has been conducted worldwide. More than sixteen ST research facilities operating during this period have achieved remarkable advances in all of fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era.

  15. Friction factor for water flow through packed beds of spherical and non-spherical particles

    Directory of Open Access Journals (Sweden)

    Kaluđerović-Radoičić Tatjana

    2017-01-01

    Full Text Available The aim of this work was the experimental evaluation of different friction factor correlations for water flow through packed beds of spherical and non-spherical particles at ambient temperature. The experiments were performed by measuring the pressure drop across the bed. Packed beds made of monosized glass spherical particles of seven different diameters were used, as well as beds made of 16 fractions of quartz filtration sand obtained by sieving (polydisperse non-spherical particles. The range of bed voidages was 0.359–0.486, while the range of bed particle Reynolds numbers was from 0.3 to 286 for spherical particles and from 0.1 to 50 for non-spherical particles. The obtained results were compared using a number of available literature correlations. In order to improve the correlation results for spherical particles, a new simple equation was proposed in the form of Ergun’s equation, with modified coefficients. The new correlation had a mean absolute deviation between experimental and calculated values of pressure drop of 9.04%. For non-spherical quartz filtration sand particles the best fit was obtained using Ergun’s equation, with a mean absolute deviation of 10.36%. Surface-volume diameter (dSV necessary for correlating the data for filtration sand particles was calculated based on correlations for dV = f(dm and Ψ = f(dm. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. ON172022

  16. A spherical Taylor-Couette dynamo

    Science.gov (United States)

    Marcotte, Florence; Gissinger, Christophe

    2016-04-01

    We present a new scenario for magnetic field amplification in the planetary interiors where an electrically conducting fluid is confined in a differentially rotating, spherical shell (spherical Couette flow) with thin aspect-ratio. When the angular momentum sufficiently decreases outwards, a primary hydrodynamic instability is widely known to develop in the equatorial region, characterized by pairs of counter-rotating, axisymmetric toroidal vortices (Taylor vortices) similar to those observed in cylindrical Couette flow. We characterize the subcritical dynamo bifurcation due to this spherical Taylor-Couette flow and study its evolution as the flow successively breaks into wavy and turbulent Taylor vortices for increasing Reynolds number. We show that the critical magnetic Reynolds number seems to reach a constant value as the Reynolds number is gradually increased. The role of global rotation on the dynamo threshold and the implications for planetary interiors are finally discussed.

  17. Design and implementation of spherical ultrasonic motor.

    Science.gov (United States)

    Mashimo, Tomoaki; Toyama, Shigeki; Ishida, Hiroshi

    2009-11-01

    We present a mechanical design and implementation of spherical ultrasonic motor (SUSM) that is an actuator with multiple rotational degrees of freedom (multi-DOF). The motor is constructed of 3 annular stators and a spherical rotor and is much smaller and simpler than conventional multi-DOF mechanisms such as gimbals using servomotors. We designed a novel SUSM using experimental data from a single annular stator and a finite element method. The SUSM using a spherical rotor of diameter 20 mm without any reduction gear has demonstrated advantages of high responsiveness, good accuracy, and high torque at low speed. The dynamic implementation of SUSM was consistent with the driving model of SUSM based on a friction drive.

  18. Elastic properties of spherically anisotropic piezoelectric composites

    International Nuclear Information System (INIS)

    En-Bo, Wei; Guo-Qing, Gu; Ying-Ming, Poon

    2010-01-01

    Effective elastic properties of spherically anisotropic piezoelectric composites, whose spherically anisotropic piezoelectric inclusions are embedded in an infinite non-piezoelectric matrix, are theoretically investigated. Analytical solutions for the elastic displacements and the electric potentials under a uniform external strain are derived exactly. Taking into account of the coupling effects of elasticity, permittivity and piezoelectricity, the formula is derived for estimating the effective elastic properties based on the average field theory in the dilute limit. An elastic response mechanism is revealed, in which the effective elastic properties increase as inclusion piezoelectric properties increase and inclusion dielectric properties decrease. Moreover, a piezoelectric response mechanism, of which the effective piezoelectric response vanishes due to the symmetry of spherically anisotropic composite, is also disclosed. (condensed matter: structure, thermal and mechanical properties)

  19. Electromagnetic cloaking in higher order spherical cloaks

    Science.gov (United States)

    Sidhwa, H. H.; Aiyar, R. P. R. C.; Kulkarni, S. V.

    2017-06-01

    The inception of transformation optics has led to the realisation of the invisibility devices for various applications, one of which is spherical cloaking. In this paper, a formulation for a higher-order spherical cloak has been proposed to reduce its physical thickness significantly by introducing a nonlinear relation between the original and transformed coordinate systems and it has been verified using the ray tracing approach. Analysis has been carried out to observe the anomalies in the variation of refractive index for higher order cloaks indicating the presence of poles in the relevant equations. Furthermore, a higher-order spherical cloak with predefined values of the material characteristics on its inner and outer surfaces has been designed for practical application.

  20. Dynamics of a spherical minority game

    International Nuclear Information System (INIS)

    Galla, T; Coolen, A C C; Sherrington, D

    2003-01-01

    We present an exact dynamical solution of a spherical version of the batch minority game (MG) with random external information. The control parameters in this model are the ratio of the number of possible values for the public information over the number of agents, and the radius of the spherical constraint on the microscopic degrees of freedom. We find a phase diagram with three phases: two without anomalous response (an oscillating versus a frozen state) and a further frozen phase with divergent integrated response. In contrast to standard MG versions, we can also calculate the volatility exactly. Our study reveals similarities between the spherical and the conventional MG, but also intriguing differences. Numerical simulations confirm our analytical results

  1. Background reduction of a spherical gaseous detector

    Energy Technology Data Exchange (ETDEWEB)

    Fard, Ali Dastgheibi [Laboratoire Souterrain de Modane, France ali.dastgheibi-fard@lsm.in2p3.fr (France); Loaiza, Pia; Piquemal, Fabrice [Laboratoire Souterrain de Modane (France); Giomataris, Ioannis; Gray, David; Gros, Michel; Magnier, Patrick; Navick, Xavier-François [CEA Saclay - IRFU/SEDI - 91191 Gif sur Yvette (France); Savvidis, Ilias [Aristotle University of Thessaloniki (Greece)

    2015-08-17

    The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a novel type of detector. It consists of a large spherical volume filled with gas, using a single detection readout channel. The detector allows 100 % detection efficiency. SEDINE is a low background version of SPC installed at the Laboratoire Souterrain de Modane (LSM) underground laboratory (4800 m.w.e) looking for rare events at very low energy threshold, below 100 eV. This work presents the details on the chemical cleaning to reduce internal {sup 210}Pb surface contamination on the copper vessel and the external radon reduction achieved via circulation of pure air inside anti-radon tent. It will be also show the radon measurement of pure gases (Ar, N, Ne, etc) which are used in the underground laboratory for the low background experiments.

  2. Electrostatic axisymmetric mirror with removable spherical aberration

    International Nuclear Information System (INIS)

    Birmuzaev, S.B.; Serikbaeva, G.S.; Hizirova, M.A.

    1999-01-01

    The electrostatic axisymmetric mirror, assembled from three coaxial cylinders with an equal diameter d and under the potential v1, v2 and v3, was computed. The proportions of geometrical and electric parameters of the mirror, with which the spherical 3-order aberration may be eliminated, were determined. The computation outcomes of the case, when the focal power of the mirror is enough large and the object plane in the focus is out of its field, are presented (Fig. 1 - potentials proportion that makes elimination of the spherical aberration possible; Fig. 2 - the focus coordinates when the spherical aberration is eliminated). The geometrical values are presented by d, and the electric ones are presented by v1. The figures on the curves present a length of the second (middle) electrode. The zero point is located in the middle of the gap between the first and second electrodes The investigated mirror may be used as a lens for the transmission electron microscope

  3. Confined detonations with cylindrical and spherical symmetry; Detonaciones confinadas con simetria esferica y cilindrica

    Energy Technology Data Exchange (ETDEWEB)

    Linan, A.; Lecuona, A.

    1979-07-01

    An imploding spherical or cylindrical detonation, starting in the interface of the detonantion with an external inert media, used as a reflector, creates on it a strong shock wave moving outward from the interface. An initially weak shock wave appears in the detonated media that travels toward the center, and it could reach the detonation wave, enforcing it in its process of implosion. To describe the fluid field, the Euler s equations are solved by means of expansions valid for the early stages of the process. Isentropic of the type P/p{gamma}-K for the detonated and compressed inert media are used. For liquid or solid reflectors a more appropriate equation is used. (Author) 8 refs.

  4. Development of a spherical neutron rem monitor

    International Nuclear Information System (INIS)

    Panchal, C.G.; Madhavi, V.; Bansode, P.Y.; Jakati, R.K.; Ghodgaonkar, M.D.; Desai, S.S.; Shaikh, A.M.; Sathian, V.

    2007-01-01

    A new neutron rem monitor based on spherical LINUS with the state of art electronic circuits has been designed in Electronics Division. This prototype instrument encompasses a spherical double polythene moderator to improve an isotropic response and a lead layer to extend its energy response compared to the conventional neutron rem monitors. A systematic testing and calibration of the energy and directional response of the prototype monitor have been carried out. Although the monitor is expected to perform satisfactorily upto an energy ∼ 55 MeV, at present its response has been tested upto 5 MeV. (author)

  5. Stability of spherical gravitating collisionless systems

    Energy Technology Data Exchange (ETDEWEB)

    Polyachenko, V.L.

    1988-03-01

    A unified method that uses a procedure, established in the paper, for reducing the problem of the stability of a spherical system to the analogous problem of perturbations of the simplest form in a corresponding cylindrical system provides the framework for investigating the stability of collisionless star clusters with different types of anisotropy of the velocity distribution. For spherical systems embedded in a massive halo or possessing a large central mass, equations - in the simplest case integral equations - for the eigenfunctions and eigenfrequencies of the oscillations are derived.

  6. Overview of spherical tokamak research in Japan

    Science.gov (United States)

    Takase, Y.; Ejiri, A.; Fujita, T.; Fukumoto, N.; Fukuyama, A.; Hanada, K.; Idei, H.; Nagata, M.; Ono, Y.; Tanaka, H.; Uchida, M.; Horiuchi, R.; Kamada, Y.; Kasahara, H.; Masuzaki, S.; Nagayama, Y.; Oishi, T.; Saito, K.; Takeiri, Y.; Tsuji-Iio, S.

    2017-10-01

    Nationally coordinated research on spherical tokamak is being conducted in Japan. Recent achievements include: (i) plasma current start-up and ramp-up without the use of the central solenoid by RF waves (in electron cyclotron and lower hybrid frequency ranges), (ii) plasma current start-up by AC Ohmic operation and by coaxial helicity injection, (iii) development of an advanced fuelling technique by compact toroid injection, (iv) ultra-long-pulse operation and particle control using a high temperature metal wall, (v) access to the ultra-high-β regime by high-power reconnection heating, and (vi) improvement of spherical tokamak plasma stability by externally applied helical field.

  7. Electrode shapes for spherical Pierce flow

    International Nuclear Information System (INIS)

    Mueller, D.W.

    1981-01-01

    The problem of obtaining the electrode shapes to produce a conically converging proton beam that has constant current density over each spherical surface of convergence is treated in spherical coordinates. A cone is taken from the Langmuir and Blodgett solution for the region within, and at the edge of, the conically converging beam. A solution for the LaPlace equation, required for the region outside the beam, is in terms of a power series in r and the Legendre polynomials of cos phi

  8. Hydrogen storage in spherical nanoporous carbons

    Science.gov (United States)

    Terrés, E.; Panella, B.; Hayashi, T.; Kim, Y. A.; Endo, M.; Dominguez, J. M.; Hirscher, M.; Terrones, H.; Terrones, M.

    2005-02-01

    We report H 2 storage capacities up to 2.7 wt% at 77 K in spherical nanoporous carbons exhibiting periodic arrays of pores and surface areas between 946 and 1646 m 2/g. The materials were produced via the pyrolysis of sucrose (C 12H 22O 11) embedded inside a spherical form of MCM-48 at 1000 °C in an inert atmosphere. Our results open up new possibilities for producing carbon nanomaterials with large surface areas, which are able to store hydrogen with attractive yields.

  9. Cows aboveground, protons down below

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    On display at Fort l'Écluse from 19 June to 18 September, the works of Augenblick combine photography, sound and video to create a striking instant parallel between the "real world" and the world of particle physics.   The cows are grazing quietly, blissfully unaware of the mini-Big Bang occurring silently 100 metres beneath them. Curious to compare these two worlds - the visible and the invisible, day-to-day life and particle physics - Laurent Mulot, a multi-disciplinary artist whose work delves into some of the planet's more unusual places, has come up with a unique artistic concept. Called Augenblick (German for "instant"), to emphasise that the images relate to the same point in time, his project uses photography, video and sound to superimpose scenes from everyday life and scenes from science. "The idea came to me in June 2008," says Laurent Mulot, "when Jean-Paul Martin, a research scientist at the Institute of Nuclear...

  10. Cow cleanliness and digital dermatitis

    DEFF Research Database (Denmark)

    Nielsen, Bodil Højlund

    2012-01-01

    Digital dermatitis (DD) is an infectious cattle disease presumably caused by Treponema spp. It results in painful, ulcerative lesions in the skin of the distal extremities and can be associated with lameness in affected animals. Today, DD is a very prevalent disease in the dairy industry and ther......Digital dermatitis (DD) is an infectious cattle disease presumably caused by Treponema spp. It results in painful, ulcerative lesions in the skin of the distal extremities and can be associated with lameness in affected animals. Today, DD is a very prevalent disease in the dairy industry...... with DD lesions. Three commercial dairy herds were studied for twelve weeks with weekly observations of DD. The cows’ feet were washed on the left side in an automatic hoof washer, whereas feet in the right side were left unwashed and thus acted as a negative control. Washed legs in parity 1 and 3+ cows...

  11. Dynamics of Laser-Driven Shock Waves in Solid Targets

    Science.gov (United States)

    Aglitskiy, Y.; Karasik, M.; Velikovich, A. L.; Serlin, V.; Weaver, J.; Schmitt, A. J.; Obenschain, S. P.; Grun, J.; Metzler, N.; Zalesak, S. T.; Gardner, J. H.; Oh, J.; Harding, E. C.

    2009-11-01

    Accurate shock timing is a key issue of both indirect- and direct-drive laser fusions. The experiments on the Nike laser at NRL presented here were made possible by improvements in the imaging capability of our monochromatic x-ray diagnostics based on Bragg reflection from spherically curved crystals. Side-on imaging implemented on Nike makes it possible to observe dynamics of the shock wave and ablation front in laser-driven solid targets. We can choose to observe a sequence of 2D images or a continuous time evolution of an image resolved in one spatial dimension. A sequence of 300 ps snapshots taken using vanadium backlighter at 5.2 keV reveals propagation of a shock wave in a solid plastic target. The shape of the shock wave reflects the intensity distribution in the Nike beam. The streak records with continuous time resolution show the x-t trajectory of a laser-driven shock wave in a 10% solid density DVB foam.

  12. Study of shock-coalescence on the LIL laser facility

    Directory of Open Access Journals (Sweden)

    Debras G.

    2013-11-01

    Full Text Available We use the LIL (Ligne d'Intégration Laser facility to study the coalescence of two planar shocks in an indirectly-driven planar sample of polystyrene. This experiment represents the preliminary stage of the future shock-timing campaign for the Laser Megajoule (LMJ. The main objectives are to validate the experimental concept and to test the numerical simulations. We used a gold spherical hohlraum to convert into X-ray the 351 nm wavelength laser pulse and to initiate the two shocks in the sample. To access time resolved shock velocities and temperature, we used two rear-side diagnostics: a VISAR (Velocity Interferometer System for Any Reflection working at two different wavelengths and a streaked optical self-emission diagnostic. We observed the coalesced shock, in good agreement with the numerical simulations. We also observed a loss of signal during the first nanoseconds probably due to sample heating from the hohlraum X-ray flux.

  13. Modelling Cow Behaviour Using Stochastic Automata

    DEFF Research Database (Denmark)

    Jónsson, Ragnar Ingi

    This report covers an initial study on the modelling of cow behaviour using stochastic automata with the aim of detecting lameness. Lameness in cows is a serious problem that needs to be dealt with because it results in less profitable production units and in reduced quality of life...... for the affected livestock. By featuring training data consisting of measurements of cow activity, three different models are obtained, namely an autonomous stochastic automaton, a stochastic automaton with coinciding state and output and an autonomous stochastic automaton with coinciding state and output, all...... of which describe the cows' activity in the two regarded behavioural scenarios, non-lame and lame. Using the experimental measurement data the different behavioural relations for the two regarded behavioural scenarios are assessed. The three models comprise activity within last hour, activity within last...

  14. Selected milk quality parameters in cured cows

    OpenAIRE

    HRUBEŠOVÁ, Kristýna

    2014-01-01

    The work deals with the monitoring of selected indicators of milk quality including residues of inhibitory substances (RIS) in the milk of cows treated with selected groups of antibiotics. It contains an analysis of selected factors that act on these indicators. The theoretical part deals with the inhibitory substances, their effects on the human body and the processing technology. The paper describes the application of antibiotics to treat mastitis and drying off cows including factors that ...

  15. TAX REFORM AND BEEF COW REPLACEMENT STRATEGY

    OpenAIRE

    Innes, Robert; Carman, Hoy F.

    1988-01-01

    This paper models optimal beef cow replacement strategy in a stochastic environment under U.S. income tax rules effective before and after the Tax Reform Act of 1986. Under each tax regime, the producer's buy versus raise decision and optimal culling age choice are analyzed. Per-cow profit levels are also calculated. Results of the numerical analysis indicate that tax law changes, particularly the loss of the capital gains exclusion and restrictions on preproduction expensing, will have signi...

  16. Flow and scour around spherical bodies

    DEFF Research Database (Denmark)

    Truelsen, Christoffer

    2003-01-01

    4, an experimental study on the scour around spherical bodies and self-burial in sand for steady current and waves has been carried out. The effect of the contraction of streamlines is found to be the key element in the scour process both for steady current and waves. Furthermore, it is demonstrated...

  17. Spherical collapse models with clustered dark energy

    Science.gov (United States)

    Chang, Chia-Chun; Lee, Wolung; Ng, Kin-Wang

    2018-03-01

    We investigate the clustering effect of dark energy (DE) in the formation of galaxy clusters using the spherical collapse model. Assuming a fully clustered DE component, the spherical overdense region is treated as an isolated system which conserves the energy separately for both matter and DE inside the spherical region. Then, by introducing a parameter r to characterize the degree of DE clustering, which is defined by the nonlinear density contrast ratio of matter to DE at turnaround in the recollapsing process, i.e. r ≡δde,taNL /δm,taNL, we are able to uniquely determine the spherical collapsing process and hence obtain the virialized overdensity Δvir through a proper virialization scheme. Estimation of the virialized overdensities from current observation on galaxy clusters suggests that 0 . 5 clustered DE with w < - 0 . 9. Also, we compare our method to the linear perturbation theory that deals with the growth of DE perturbation at early times. While both results are consistent with each other, our method is practically simple and it shows that the collapse process is rather independent of initial DE perturbation and its evolution at early times.

  18. Preparations of spherical polymeric particles from Tanzanian ...

    African Journals Online (AJOL)

    Spherical Polymeric Particles (SPP) have been prepared from Tanzanian Cashew Nut Shell Liquid (CNSL) by suspension polymerization technique involving either step-growth or chain- growth polymerization mechanisms. The sizes of the SPP, which ranged from 0.1 to 2.0 mm were strongly influenced by the amounts of ...

  19. Nonlinear evolution of stellar spherical systems

    Energy Technology Data Exchange (ETDEWEB)

    Polyachenko, V.L. (AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1981-03-01

    A universal method for computer realization of collisionless models according to a given distribution function is suggested. By employing this method it is shown that the development of instabilities in spherically-symmetric systems with nearly radial trajectories of the system constituents leads to a distinct elliptical deformation of the system.

  20. Brachistochrone of a Spherical Uniform Mass Distribution

    OpenAIRE

    Mitchell, David R.

    2006-01-01

    We solve the brachistochrone problem for a particle travelling through a spherical mass distribution of uniform density. We examine the connection between this problem and the popular "gravity elevator" result. The solution is compared to the well known brachistochrone problem of a particle in a uniform gravitational field.

  1. Compressive sensing with a spherical microphone array

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Xenaki, Angeliki

    2016-01-01

    A wave expansion method is proposed in this work, based on measurements with a spherical microphone array, and formulated in the framework provided by Compressive Sensing. The method promotes sparse solutions via ‘1-norm minimization, so that the measured data are represented by few basis functions...

  2. Sparse acoustic imaging with a spherical array

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Xenaki, Angeliki

    2015-01-01

    proposes a plane wave expansion method based on measurements with a spherical microphone array, and solved in the framework provided by Compressed Sensing. The proposed methodology results in a sparse solution, i.e. few non-zero coefficients, and it is suitable for both source localization and sound field...

  3. Added Mass of a Spherical Cap Body

    Czech Academy of Sciences Publication Activity Database

    Šimčík, Miroslav; Punčochář, Miroslav; Růžička, Marek

    2014-01-01

    Roč. 118, OCT 18 (2014), s. 1-8 ISSN 0009-2509 R&D Projects: GA MŠk(CZ) LD13018 Institutional support: RVO:67985858 Keywords : spherical cap * added mass * single particle Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.337, year: 2014

  4. Exact solutions of the spherically symmetric multidimensional ...

    African Journals Online (AJOL)

    The complete orthonormalised energy eigenfunctions and the energy eigenvalues of the spherically symmetric isotropic harmonic oscillator in N dimensions, are obtained through the methods of separation of variables. Also, the degeneracy of the energy levels are examined. KEY WORDS: - Schrödinger Equation, Isotropic ...

  5. Current drive in spherical tokamak plasmas

    International Nuclear Information System (INIS)

    Storer, R.

    1999-01-01

    The early experiments on a spherical rotamak showed that a rotating magnetic field could be used to drive substantial currents and create a compact torus magnetic field configuration. The theoretical analysis of the spherical rotamak has been essentially confined to this class. Recent experiments on the Flinders Rotamak-ST have included a toroidal field, produced by a current-carrying central rod, with encouraging results; for it has been shown that an enhanced current can be driven with this configuration which is the equivalent of a spherical tokamak. This paper will be devoted to a theoretical and computational analysis of this situation. We use a model where the rotating magnetic field is applied to a spherical plasma, with the rotating field oriented parallel to the equatorial plane, taken to be the x-y plane. In our model the ions form a uniform background and the frequency of the rotating Held is very much less than the electron cyclotron frequency (with respect to the rotating field strength) and very much greater than the ion cyclotron frequency. This condition is satisfied by the rotamak experiments

  6. Dynamical instabilities in spherical stellar systems

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, J.; Hut, P.; Goodman, J.

    1986-01-01

    The first numerical examples of spherical stellar systems in equilibrium, which are unstable on a dynamical time scale, were found by Henon using N-body code with enforced spherical symmetry. Henon's models have been reexamined using a code which includes nonradical forces to quadrupole order; the key results have been checked using a direct-summation Aarseth code. The radial instability reported by Henon is confirmed; in addition, two nonradial instabilities have been found. In the first kind, seen in models with predominantly radial orbits, the system permanently loses spherical symmetry and settles into a strongly triaxial ellipsoid. In the second kind, which appears in models with nearly circular orbits, the mass distribution exhibits quadrupole-mode oscillations. Analytic estimates and physical interpretations are presented for all three instabilities. The nonradial instabilities are found even in cases where the distribution function decreases with energy, suggesting that dynamical instabilities may be more common in spherical systems than had been previously thought. 25 references.

  7. Collapsing spherical null shells in general relativity

    Directory of Open Access Journals (Sweden)

    S Khakshournia

    2011-03-01

    Full Text Available In this work, the gravitational collapse of a spherically symmetric null shell with the flat interior and a charged Vaidya exterior spacetimes is studied. There is no gravitational impulsive wave present on the null hypersurface which is shear-free and contracting. It follows that there is a critical radius at which the shell bounces and starts expanding.

  8. Determining a Sonographic Nomogram for Gallbladder Spherical ...

    African Journals Online (AJOL)

    The Gallbladder spherical index (GBSI) of 380 volunteers (215 males and 165 females) was assessed using ultrasonography and a model formula to establish a nomogram for a Nigerian population of Igbo descent. The length, width and height of their gallbladders were measured after an overnight fast. Using the model ...

  9. Stability of stagnation via an expanding accretion shock wave

    Energy Technology Data Exchange (ETDEWEB)

    Velikovich, A. L.; Giuliani, J. L. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Murakami, M. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Taylor, B. D. [Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375 (United States); Zalesak, S. T. [Berkeley Research Associates, Beltsville, Maryland 20705 (United States); Iwamoto, Y. [Ehime University, Matsuyama, Ehime Pref. 790-8577 (Japan)

    2016-05-15

    Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

  10. Stability of stagnation via an expanding accretion shock wave

    Science.gov (United States)

    Velikovich, A. L.; Murakami, M.; Taylor, B. D.; Giuliani, J. L.; Zalesak, S. T.; Iwamoto, Y.

    2016-05-01

    Stagnation of a cold plasma streaming to the center or axis of symmetry via an expanding accretion shock wave is ubiquitous in inertial confinement fusion (ICF) and high-energy-density plasma physics, the examples ranging from plasma flows in x-ray-generating Z pinches [Maron et al., Phys. Rev. Lett. 111, 035001 (2013)] to the experiments in support of the recently suggested concept of impact ignition in ICF [Azechi et al., Phys. Rev. Lett. 102, 235002 (2009); Murakami et al., Nucl. Fusion 54, 054007 (2014)]. Some experimental evidence indicates that stagnation via an expanding shock wave is stable, but its stability has never been studied theoretically. We present such analysis for the stagnation that does not involve a rarefaction wave behind the expanding shock front and is described by the classic ideal-gas Noh solution in spherical and cylindrical geometry. In either case, the stagnated flow has been demonstrated to be stable, initial perturbations exhibiting a power-law, oscillatory or monotonic, decay with time for all the eigenmodes. This conclusion has been supported by our simulations done both on a Cartesian grid and on a curvilinear grid in spherical coordinates. Dispersion equation determining the eigenvalues of the problem and explicit formulas for the eigenfunction profiles corresponding to these eigenvalues are presented, making it possible to use the theory for hydrocode verification in two and three dimensions.

  11. Life Shocks and Homelessness

    Science.gov (United States)

    Corman, Hope; Noonan, Kelly; Reichman, Nancy E.

    2014-01-01

    We exploited an exogenous health shock—namely, the birth of a child with a severe health condition—to investigate the effect of a life shock on homelessness in large cities in the United States as well as the interactive effects of the shock with housing market characteristics. We considered a traditional measure of homelessness, two measures of housing instability thought to be precursors to homelessness, and a combined measure that approximates the broadened conceptualization of homelessness under the 2009 Homeless Emergency Assistance and Rapid Transition to Housing Act (2010). We found that the shock substantially increases the likelihood of family homelessness, particularly in cities with high housing costs. The findings are consistent with the economic theory of homelessness, which posits that homelessness results from a conjunction of adverse circumstances in which housing markets and individual characteristics collide. PMID:23868747

  12. Physics of Collisionless Shocks Space Plasma Shock Waves

    CERN Document Server

    Balogh, André

    2013-01-01

    The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats both subcritical shocks, which dissipate flow energy by generating anomalous resistance or viscosity, and supercritical shocks. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecti...

  13. The Shock Routine

    DEFF Research Database (Denmark)

    van Hooren, Franca; Kaasch, Alexandra; Starke, Peter

    2014-01-01

    in Australia, Belgium, the Netherlands and Sweden over the course of four global economic shocks, we ask whether the notion of critical junctures is useful in understanding the nature of change triggered by crisis. The main empirical finding is that fundamental change in the aftermath of an exogenous shock...... is the exception rather than the rule. Instead, incremental ‘crisis routines’ based on existing policy instruments are overwhelmingly used to deal with economic hardship. We discuss these findings in the light of the psychological ‘threat-rigidity’ effect and reflect on their consequences for theories...

  14. Euthanasia of Danish dairy cows evaluated in two questionnaire surveys

    DEFF Research Database (Denmark)

    Thomsen, Peter; Sørensen, Jan Tind

    2008-01-01

    a random sample of 196 Danish dairy farmers that had reported a dead cow to the Danish Cattle Database in 2002 and 196 dairy farmers that had reported a dead cow in 2006. Our objectives were to evaluate the proportion of euthanized cows, changes in the behaviour of farmers regarding euthanasia of cows over...... the years and possible reasons for these changes. Results It seems that the threshold for euthanasia of cows among farmers has changed. Farmers generally reported a lower threshold for euthanasia compared to 5-10 years ago. Conclusions The threshold for euthanasia of cows has, according to the dairy farmers...

  15. Cow Effects and Estimation of Success of First and Following Inseminations in Dutch Dairy Cows

    NARCIS (Netherlands)

    Inchaisri, C.; Jorritsma, R.; Vernooij, J.C.M.; Vos, P.L.A.M.; Weijden, van der G.C.; Hogeveen, H.

    2011-01-01

    The objective of this research was to determine the contribution of cow factors to the probability of successful insemination accounting for the serial number of inseminations in analysis. The investigation was performed with 101 297 insemination records in 51 525 lactations of different cows from

  16. Spherical Bessel transform via exponential sum approximation of spherical Bessel function

    Science.gov (United States)

    Ikeno, Hidekazu

    2018-02-01

    A new algorithm for numerical evaluation of spherical Bessel transform is proposed in this paper. In this method, the spherical Bessel function is approximately represented as an exponential sum with complex parameters. This is obtained by expressing an integral representation of spherical Bessel function in complex plane, and discretizing contour integrals along steepest descent paths and a contour path parallel to real axis using numerical quadrature rule with the double-exponential transformation. The number of terms in the expression is reduced using the modified balanced truncation method. The residual part of integrand is also expanded by exponential functions using Prony-like method. The spherical Bessel transform can be evaluated analytically on arbitrary points in half-open interval.

  17. Gastrointestinal perfusion in septic shock.

    NARCIS (Netherlands)

    Haren, E.M. van; Sleight, J.W.; Pickkers, P.; Hoeven, J.G. van der

    2007-01-01

    Septic shock is characterised by vasodilation, myocardial depression and impaired microcirculatory blood flow, resulting in redistribution of regional blood flow. Animal and human studies have shown that gastrointestinal mucosal blood flow is impaired in septic shock. This is consistent with

  18. Associations of dairy cow behavior, barn hygiene, cow hygiene, and risk of elevated somatic cell count.

    Science.gov (United States)

    Devries, T J; Aarnoudse, M G; Barkema, H W; Leslie, K E; von Keyserlingk, M A G

    2012-10-01

    Poor dairy cow hygiene has been consistently associated with elevated somatic cell count (SCC) and the risk of subclinical mastitis. The objective of this study was to determine the associations between dairy cow standing and lying behavior, barn hygiene, cow hygiene, and the risk of experiencing elevated SCC. Lactating Holstein dairy cows (n=69; 86 ± 51 DIM; parity: 2.0 ± 1.2; means ± SD), kept in 1 of 2 groups, were monitored over a 4-mo period. Each group contained 61 ± 1 (mean ± SD) cows over the study period; complete data were obtained from 37 and 32 animals within each respective group. Cows were housed in a sand-bedded, freestall barn with 2 symmetrical pens, each with a free cow traffic automatic milking system. To vary barn hygiene, in 4 consecutive 28-d periods, alley manure scrapers in each of the 2 pens were randomly assigned to frequencies of operation of 3, 6, 12, and 24 times per day. During the last 7 d of each period, cow hygiene (upper leg/flank, lower legs, and udder; scale of 1 = very clean to 4 = very dirty) and stall hygiene (number of 0.15×0.15-m squares contaminated with manure in a 1.20×1.65-m grid) were recorded. Standing and lying behavior of the cows were collected during those days using data loggers. Individual-cow SCC was recorded at the beginning and end of each 28-d period. Elevated SCC was used as an indicator of subclinical mastitis; incidence of elevated SCC was defined as having a SCC >200,000 cells/mL at the end of each 28-d period, when SCC was cows having poorer hygiene. Poor udder hygiene was associated with poor stall hygiene. Longer lying duration was associated with poor hygiene of the upper legs/flank and udder. Greater premilking standing duration was associated with poor udder hygiene and decreased frequency of lying bouts was associated with poor hygiene of the lower legs. Higher milk yield was associated with poor hygiene of the udder and lower legs; multiparous cows had poorer hygiene of the upper legs

  19. Pediatric cardiogenic shock: Current perspectives

    OpenAIRE

    Subhranshu Sekhar Kar

    2015-01-01

    Cardiogenic shock is a pathophysiologic state where an abnormality of cardiac function is responsible for the failure of the cardiovascular system to meet the metabolic needs of the body tissues.Though it is less common than hypovolemia as the primary etiology in paediatric shock, eventually myocardial function is affected because of reduced perfusion in all forms of shock. Myocardial malfunction, in other forms of shock, is secondary to ischemia, acidosis, drugs, toxins or inflammation. Card...

  20. Associations of herd- and cow-level factors, cow lying behavior, and risk of elevated somatic cell count in free-stall housed lactating dairy cows.

    Science.gov (United States)

    Watters, M E Alexandrea; Meijer, Karin M A; Barkema, Herman W; Leslie, Kenneth E; von Keyserlingk, Marina A G; Devries, Trevor J

    2013-09-01

    Recent evidence suggests that the risk of intramammary infection in dairy cows is related to lying patterns. The objectives of this study were to quantify the standing and lying behavior of dairy cows milked 3×/d, determine the cow- and herd-level factors associated with these behaviors, and relate these findings to the risk of an elevated somatic cell count (SCC). Five commercial free-stall dairy herds in Eastern Ontario, milking 3×/d, were enrolled in a longitudinal study. Forty Holstein-Friesian cows/herd were randomly selected as focal animals based on days in milk (cow SCC was recorded at the beginning of each period and end of the final period. Elevated SCC (eSCC) was used as an indicator of subclinical mastitis. A new incident eSCC was defined as an individual cow that started the period with a SCC cows for hygiene and lameness. Throughout the course of the study, cows averaged 11.2h/d of lying time, split into 8.6 lying bouts/d that were on average 84.6 min in length. Later lactation cows had longer daily lying times that were split into fewer lying bouts of longer duration than cows earlier in lactation. Lame cows had longer daily lying times and lying bout durations than non-lame cows. Cows with greater milk yield had lower lying times than lower producing cows. Average post-milking standing time across the study herds was 103 min. Manipulation of feed (feed delivery or push-up) by the stockperson, in the hour before milking or shortly thereafter, resulted in the longest post-milking standing times. Over the study period, 48 new eSCC were detected, resulting in a mean herd incidence rate of 0.91 eSCC/cow-year at risk for all study herds. A non-linear relationship between post-milking standing time and eSCC incidence was found; compared to those cows that lie down cows that lie down for the first time >90 min after milking had a lower risk of acquiring a new eSCC. The risk of experiencing an eSCC was also increased in multiparous cows, and in those cows

  1. Teleconnected food supply shocks

    Science.gov (United States)

    Bren d'Amour, Christopher; Wenz, Leonie; Kalkuhl, Matthias; Steckel, Jan Christoph; Creutzig, Felix

    2016-03-01

    The 2008-2010 food crisis might have been a harbinger of fundamental climate-induced food crises with geopolitical implications. Heat-wave-induced yield losses in Russia and resulting export restrictions led to increases in market prices for wheat across the Middle East, likely contributing to the Arab Spring. With ongoing climate change, temperatures and temperature variability will rise, leading to higher uncertainty in yields for major nutritional crops. Here we investigate which countries are most vulnerable to teleconnected supply-shocks, i.e. where diets strongly rely on the import of wheat, maize, or rice, and where a large share of the population is living in poverty. We find that the Middle East is most sensitive to teleconnected supply shocks in wheat, Central America to supply shocks in maize, and Western Africa to supply shocks in rice. Weighing with poverty levels, Sub-Saharan Africa is most affected. Altogether, a simultaneous 10% reduction in exports of wheat, rice, and maize would reduce caloric intake of 55 million people living in poverty by about 5%. Export bans in major producing regions would put up to 200 million people below the poverty line at risk, 90% of which live in Sub-Saharan Africa. Our results suggest that a region-specific combination of national increases in agricultural productivity and diversification of trade partners and diets can effectively decrease future food security risks.

  2. SHOCK-INDUCED LUMINESCENCE

    Science.gov (United States)

    When a 270 kilobar shock wave emerges from an illuminated aluminum surface in a vacuum, blue light is emitted. This phenomenon is affected...acoustoelectric effect). The electrons reach the aluminum oxide layer and, falling into the ionized F’ centers, emit blue light .

  3. Health Shocks and Retirement:

    DEFF Research Database (Denmark)

    Datta Gupta, Nabanita; Larsen, Mona

    benefits in Denmark nor by the promotion of corporate social responsibility initiatives since the mid-1990s. In the late 1990s, however, the retirement rate following a health shock is reduced to 3% with the introduction of the subsidized employment program (fleksjob) but this effect is not strongly...

  4. Shock tube Multiphase Experiments

    Science.gov (United States)

    Middlebrooks, John; Allen, Roy; Paudel, Manoj; Young, Calvin; Musick, Ben; McFarland, Jacob

    2017-11-01

    Shock driven multiphase instabilities (SDMI) are unique physical phenomena that have far-reaching practical applications in engineering and science. The instability is present in high energy explosions, scramjet combustors, and supernovae events. The SDMI arises when a multiphase interface is impulsively accelerated by the passage of a shockwave. It is similar in development to the Richtmyer-Meshkov (RM) instability however, particle-to-gas coupling is the driving mechanism of the SDMI. As particle effects such as lag and phase change become more prominent, the SDMI's development begins to significantly deviate from the RM instability. We have developed an experiment for studying the SDMI in our shock tube facility. In our experiments, a multiphase interface is created using a laminar jet and flowed into the shock tube where it is accelerated by the passage of a planar shockwave. The interface development is captured using CCD cameras synchronized with planar laser illumination. This talk will give an overview of new experiments conducted to examine the development of a shocked cylindrical multiphase interface. The effects of Atwood number, particle size, and a second acceleration (reshock) of the interface will be discussed.

  5. STEREO interplanetary shocks and foreshocks

    Energy Technology Data Exchange (ETDEWEB)

    Blanco-Cano, X. [Instituto de Geofisica, UNAM, CU, Coyoacan 04510 DF (Mexico); Kajdic, P. [IRAP-University of Toulouse, CNRS, Toulouse (France); Aguilar-Rodriguez, E. [Instituto de Geofisica, UNAM, Morelia (Mexico); Russell, C. T. [ESS and IGPP, University of California, Los Angeles, 603 Charles Young Drive, Los Angeles, CA 90095 (United States); Jian, L. K. [NASA Goddard Space Flight Center, Greenbelt, MD and University of Maryland, College Park, MD (United States); Luhmann, J. G. [SSL, University of California Berkeley (United States)

    2013-06-13

    We use STEREO data to study shocks driven by stream interactions and the waves associated with them. During the years of the extended solar minimum 2007-2010, stream interaction shocks have Mach numbers between 1.1-3.8 and {theta}{sub Bn}{approx}20-86 Degree-Sign . We find a variety of waves, including whistlers and low frequency fluctuations. Upstream whistler waves may be generated at the shock and upstream ultra low frequency (ULF) waves can be driven locally by ion instabilities. The downstream wave spectra can be formed by both, locally generated perturbations, and shock transmitted waves. We find that many quasiperpendicular shocks can be accompanied by ULF wave and ion foreshocks, which is in contrast to Earth's bow shock. Fluctuations downstream of quasi-parallel shocks tend to have larger amplitudes than waves downstream of quasi-perpendicular shocks. Proton foreshocks of shocks driven by stream interactions have extensions dr {<=}0.05 AU. This is smaller than foreshock extensions for ICME driven shocks. The difference in foreshock extensions is related to the fact that ICME driven shocks are formed closer to the Sun and therefore begin to accelerate particles very early in their existence, while stream interaction shocks form at {approx}1 AU and have been producing suprathermal particles for a shorter time.

  6. Shock Waves in Gas Dynamics

    Directory of Open Access Journals (Sweden)

    Abdolrahman Razani

    2007-11-01

    Full Text Available Shock wave theory was studied in literature by many authors. This article presents a survey with references about various topics related to shock waves: Hyperbolic conservation laws, Well-posedness theory, Compactness theory, Shock and reaction-diffusion wave, The CJ and ZND theory, Existence of detonation in Majda's model, Premixed laminar flame, Multidimensional gas flows, Multidimensional Riemann problem.

  7. Shock wave treatment in medicine

    Indian Academy of Sciences (India)

    Urology has long been the only medical field for shock waves in medicine. Meanwhile shock waves have been used in orthopedics and traumatology to treat insertion tendinitis, avascular necrosis of the head of femur and other necrotic bone alterations. Another field of shock wave application is the treatment of tendons, ...

  8. Fascinating World of Shock Waves

    Indian Academy of Sciences (India)

    Srimath

    travelling at supersonic speeds (more than the sound speed at local temperature) then one can see a shock wave around the body as shown in Figure 1. Dissipation of energy, rapid changes in velocity, presure, temperature and flow turning are some of the features associated with shock waves. Obviously the word 'shock.

  9. Shock wave treatment in medicine

    Indian Academy of Sciences (India)

    Unknown

    compared to urology where shock waves are used for disintegration. [Shrivastava S K and Kailash 2005 Shock wave treatment in medicine; J. Biosci. 30 269–275]. 1. Introduction. Extracorporeal generated shock waves have been intro- duced for medical therapy approximately 20 years back to disintegrate kidney stones.

  10. Nonlinear reflection of a spherically divergent N-wave from a plane surface: Optical interferometry measurements in air

    Energy Technology Data Exchange (ETDEWEB)

    Karzova, M., E-mail: masha@acs366.phys.msu.ru [Laboratoire de Mécanique des Fluides et d’Acoustique, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully (France); Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Yuldashev, P.; Khokhlova, V. [Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Ollivier, S.; Blanc-Benon, Ph. [Laboratoire de Mécanique des Fluides et d’Acoustique, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully (France)

    2015-10-28

    Mach stem is a well-known structure typically observed in the process of strong (acoustic Mach numbers greater than 0.4) step-shock waves reflection from a rigid boundary. However, this phenomenon has been much less studied for weak shocks in nonlinear acoustic fields where Mach numbers are in the range from 0.001 to 0.01 and pressure waveforms have more complicated waveforms than step shocks. The goal of this work was to demonstrate experimentally how nonlinear reflection occurs in air for very weak spherically divergent acoustic spark-generated pulses resembling an N-wave. Measurements of reflection patterns were performed using a Mach-Zehnder interferometer. A thin laser beam with sub-millimeter cross-section was used to obtain the time resolution of 0.4 µs, which is 6 times higher than the time resolution of the condenser microphones. Pressure waveforms were reconstructed using the inverse Abel transform applied to the phase of the signal measured by the interferometer. The Mach stem formation was observed experimentally as a result of collision of the incident and reflected shock pulses. It was shown that irregular reflection of the pulse occurred in a dynamic way and the length of the Mach stem increased linearly while the pulse propagated along the surface. Since the front shock of the spark-generated pulse was steeper than the rear shock, irregular type of reflection was observed only for the front shock of the pulse while the rear shock reflection occurred in a regular regime.

  11. Technical notes. Spherical harmonics approximations of neutron transport

    Energy Technology Data Exchange (ETDEWEB)

    Demeny, A.; Dede, K.M.; Erdei, K.

    1976-12-01

    A double-range spherical harmonics approximation obtained by expanding the angular flux separately in the two regions combined with the conventional single-range spherical harmonics is found to give superior description of neutron transport.

  12. Laboratory measurements of shock propagation through spherical cavities in an optically accessible polymer.

    Energy Technology Data Exchange (ETDEWEB)

    Chojnicki, Kirsten; Cooper, Marcia A.; Guo, Shuyue

    2017-11-01

    Pore-scale aperture effects on flow in pore networks was studied in the laboratory to provide a parameterization for use in transport models. Four cases were considered: regular and irregular pillar/pore alignment with and without an aperture. The velocity field of each case was measured and simulated, providing quantitatively comparable results. Two aperture effect parameterizations were considered: permeability and transmission. Permeability values varied by an order of magnitude between the cases with and without apertures. However, transmission did not correlate with permeability. Despite having much greater permeability the regular aperture case permitted less transmission than the regular case. Moreover, both irregular cases had greater transmission than the regular cases, a difference not supported by the permeabilities. Overall, these findings suggest that pore-scale aperture effects on flow though a pore-network may not be adequately captured by properties such as permeability for applications that are interested in determining particle transport volume and timing.

  13. Spontaneous spherical symmetry breaking in atomic confinement

    Science.gov (United States)

    Sveshnikov, Konstantin; Tolokonnikov, Andrey

    2017-07-01

    The effect of spontaneous breaking of initial SO(3) symmetry is shown to be possible for an H-like atom in the ground state, when it is confined in a spherical box under general boundary conditions of "not going out" through the box surface (i.e. third kind or Robin's ones), for a wide range of physically reasonable values of system parameters. The most novel and nontrivial result, which has not been reported previously, is that such an effect takes place not only for attractive, but also for repulsive interactions of atomic electrons with the cavity environment. Moreover, in the limit of a large box size R ≫ aB the regime of an atom, soaring over a plane with boundary condition of "not going out", is reproduced, rather than a spherically symmetric configuration, which would be expected on the basis of the initial SO(3) symmetry of the problem.

  14. Optical properties of spherical gold mesoparticles

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Kuznetsov, A. I.; Novikov, S. M.

    2012-01-01

    Optical properties of spherical gold particles with diameters of 150-650 nm (mesoparticles) are studied by reflectance spectroscopy. Particles are fabricated by laser-induced transfer of metallic droplets onto metal and dielectric substrates. Contributions of higher multipoles (beyond the quadrup......Optical properties of spherical gold particles with diameters of 150-650 nm (mesoparticles) are studied by reflectance spectroscopy. Particles are fabricated by laser-induced transfer of metallic droplets onto metal and dielectric substrates. Contributions of higher multipoles (beyond...... results obtained in homogeneous environment is demonstrated. Multipole resonance features in the experimental reflection spectra of particles located on a gold substrate, in the wavelength range of 500-1000 nm, are discussed and theoretically analyzed on the basis of finite-difference time...

  15. Quality metric for spherical panoramic video

    Science.gov (United States)

    Zakharchenko, Vladyslav; Choi, Kwang Pyo; Park, Jeong Hoon

    2016-09-01

    Virtual reality (VR)/ augmented reality (AR) applications allow users to view artificial content of a surrounding space simulating presence effect with a help of special applications or devices. Synthetic contents production is well known process form computer graphics domain and pipeline has been already fixed in the industry. However emerging multimedia formats for immersive entertainment applications such as free-viewpoint television (FTV) or spherical panoramic video require different approaches in content management and quality assessment. The international standardization on FTV has been promoted by MPEG. This paper is dedicated to discussion of immersive media distribution format and quality estimation process. Accuracy and reliability of the proposed objective quality estimation method had been verified with spherical panoramic images demonstrating good correlation results with subjective quality estimation held by a group of experts.

  16. Imaging with Spherically Bent Crystals or Reflectors

    Energy Technology Data Exchange (ETDEWEB)

    Bitter, M; Hill, K W; Scott, S; Ince-Cushman, A; Reinke, M; Podpaly, Y; Rice, J E; Beiersdorfer, P

    2010-06-01

    This paper consists of two parts: Part I describes the working principle of a recently developed x-ray imaging crystal spectrometer, where the astigmatism of spherically bent crystals is being used with advantage to record spatially resolved spectra of highly charged ions for Doppler measurements of the ion-temperature and toroidal plasmarotation- velocity profiles in tokamak plasmas. This type of spectrometer was thoroughly tested on NSTX and Alcator C-Mod, and its concept was recently adopted for the design of the ITER crystal spectrometers. Part II describes imaging schemes, where the astigmatism has been eliminated by the use of matched pairs of spherically bent crystals or reflectors. These imaging schemes are applicable over a wide range of the electromagnetic radiation, which includes microwaves, visible light, EUV radiation, and x-rays. Potential applications with EUV radiation and x-rays are the diagnosis of laserproduced plasmas, imaging of biological samples with synchrotron radiation, and lithography.

  17. Spherical harmonics and integration in superspace

    International Nuclear Information System (INIS)

    Bie, H de; Sommen, F

    2007-01-01

    In this paper, the classical theory of spherical harmonics in R m is extended to superspace using techniques from Clifford analysis. After defining a super-Laplace operator and studying some basic properties of polynomial null-solutions of this operator, a new type of integration over the supersphere is introduced by exploiting the formal equivalence with an old result of Pizzetti. This integral is then used to prove orthogonality of spherical harmonics of different degree, Green-like theorems and also an extension of the important Funk-Hecke theorem to superspace. Finally, this integration over the supersphere is used to define an integral over the whole superspace, and it is proven that this is equivalent with the Berezin integral, thus providing a more sound definition of the Berezin integral

  18. Shock Dynamics in Stellar Outbursts. I. Shock Formation

    Energy Technology Data Exchange (ETDEWEB)

    Ro, Stephen; Matzner, Christopher D., E-mail: ro@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada)

    2017-05-20

    Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, luminous blue variable eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of stars set in motion by strong acoustic pulses and wave trains, focusing on nonlinear wave propagation, shock formation, and an early phase of the development of a weak shock. We identify the shock formation radius, showing that a heuristic estimate based on crossing characteristics matches an exact expansion around the wave front and verifying both with numerical experiments. Our general analytical condition for shock formation applies to one-dimensional motions within any static environment, including both eruptions and implosions. We also consider the early phase of shock energy dissipation. We find that waves of super-Eddington acoustic luminosity always create shocks, rather than damping by radiative diffusion. Therefore, shock formation is integral to super-Eddington outbursts.

  19. Spherical Cancer Models in Tumor Biology

    Directory of Open Access Journals (Sweden)

    Louis-Bastien Weiswald

    2015-01-01

    Full Text Available Three-dimensional (3D in vitro models have been used in cancer research as an intermediate model between in vitro cancer cell line cultures and in vivo tumor. Spherical cancer models represent major 3D in vitro models that have been described over the past 4 decades. These models have gained popularity in cancer stem cell research using tumorospheres. Thus, it is crucial to define and clarify the different spherical cancer models thus far described. Here, we focus on in vitro multicellular spheres used in cancer research. All these spherelike structures are characterized by their well-rounded shape, the presence of cancer cells, and their capacity to be maintained as free-floating cultures. We propose a rational classification of the four most commonly used spherical cancer models in cancer research based on culture methods for obtaining them and on subsequent differences in sphere biology: the multicellular tumor spheroid model, first described in the early 70s and obtained by culture of cancer cell lines under nonadherent conditions; tumorospheres, a model of cancer stem cell expansion established in a serum-free medium supplemented with growth factors; tissue-derived tumor spheres and organotypic multicellular spheroids, obtained by tumor tissue mechanical dissociation and cutting. In addition, we describe their applications to and interest in cancer research; in particular, we describe their contribution to chemoresistance, radioresistance, tumorigenicity, and invasion and migration studies. Although these models share a common 3D conformation, each displays its own intrinsic properties. Therefore, the most relevant spherical cancer model must be carefully selected, as a function of the study aim and cancer type.

  20. New mathematical framework for spherical gravitational collapse

    International Nuclear Information System (INIS)

    Giambo, Roberto; Giannoni, Fabio; Magli, Giulio; Piccione, Paolo

    2003-01-01

    A theorem, giving necessary and sufficient condition for naked singularity formation in spherically symmetric non-static spacetimes under hypotheses of physical acceptability, is formulated and proved. The theorem relates the existence of singular null geodesics to the existence of regular curves which are supersolutions of the radial null geodesic equation, and allows us to treat all the known examples of naked singularities from a unified viewpoint. New examples are also found using this approach, and perspectives are discussed. (letter to the editor)

  1. Characteristics and Manufacture of Spherical Smokeless Powders

    OpenAIRE

    Botelho, Fernanda Diniz; Galante, Erick Braga Ferrão; Mendes, Álvaro José Boareto

    2015-01-01

    ABSTRACT: Smokeless propellants have been studied and manufactured for many decades. They can exist in various physical forms and also can have different properties according to the use of each propellant. One important form of smokeless powders is the ball powder, which has spherical grains. The manufacture process of the ball powder has many advantages over the usual way to manufacture a smokeless powder. For example, unstable and even deteriorated nitrocellulose, after being stabilized aga...

  2. Spherical cancer models in tumor biology.

    Science.gov (United States)

    Weiswald, Louis-Bastien; Bellet, Dominique; Dangles-Marie, Virginie

    2015-01-01

    Three-dimensional (3D) in vitro models have been used in cancer research as an intermediate model between in vitro cancer cell line cultures and in vivo tumor. Spherical cancer models represent major 3D in vitro models that have been described over the past 4 decades. These models have gained popularity in cancer stem cell research using tumorospheres. Thus, it is crucial to define and clarify the different spherical cancer models thus far described. Here, we focus on in vitro multicellular spheres used in cancer research. All these spherelike structures are characterized by their well-rounded shape, the presence of cancer cells, and their capacity to be maintained as free-floating cultures. We propose a rational classification of the four most commonly used spherical cancer models in cancer research based on culture methods for obtaining them and on subsequent differences in sphere biology: the multicellular tumor spheroid model, first described in the early 70s and obtained by culture of cancer cell lines under nonadherent conditions; tumorospheres, a model of cancer stem cell expansion established in a serum-free medium supplemented with growth factors; tissue-derived tumor spheres and organotypic multicellular spheroids, obtained by tumor tissue mechanical dissociation and cutting. In addition, we describe their applications to and interest in cancer research; in particular, we describe their contribution to chemoresistance, radioresistance, tumorigenicity, and invasion and migration studies. Although these models share a common 3D conformation, each displays its own intrinsic properties. Therefore, the most relevant spherical cancer model must be carefully selected, as a function of the study aim and cancer type. Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.

  3. Particles in spherical electromagnetic radiation fields

    International Nuclear Information System (INIS)

    Mitter, H.; Thaller, B.

    1984-03-01

    If the time-dependence of a Hamiltonian can be compensated by an appropriate symmetry transformation, the corresponding quantum mechanical problem can be reduced to an effectively stationary one. With this result we investigate the behavior of nonrelativistic particles in a spherical radiation field produced by a rotating source. Then the symmetry transformation corresponds to a rotation. We calculate the transition probabilities in Born approximation. The extension to problems involving an additional Coulomb potential is briefly discussed. (Author)

  4. Diffusion of spherical particles in microcavities

    OpenAIRE

    Imperio, A.; Padding, J. T.; Briels, W. J.

    2011-01-01

    The diffusive motion of a colloidal particle trapped inside a small cavity filled with fluid is reduced by hydrodynamic interactions with the confining walls. In this work, we study these wall effects on a spherical particle entrapped in a closed cylinder. We calculate the diffusion coefficient along the radial, azimuthal and axial direction for different particle positions. At all locations the diffusion is smaller than in a bulk fluid and it becomes anisotropic near the container's walls. W...

  5. Current drive for spherical tokamak plasmas

    International Nuclear Information System (INIS)

    Storer, R.

    1999-01-01

    Very low aspect ratio spherical tokamaks have proved to have some very useful and remarkable properties including very high values of the plasma pressure to magnetic field pressure. Following the construction of the Start tokamak, a number of such configurations have been constructed. One of the difficulties encountered is in providing sufficient inductive current drive due to the competing requirements of the need to keep the aspect ratio low and providing the space for the central current-carrying rod with an internal inductive coil. An alternative current drive technique would be very useful. In a parallel development it has been shown that a rotating magnetic field can drive a significant non-linear Hall current in a spherical plasma. Successful experiments of this concept have been made with a device called the Rotamak. In its original configuration this device was a field reversed configuration without a toroidal magnetic field but with a vertical field to establish the magnetic hydrodynamical equilibrium. However, recent modifications have shown that increased current can be driven if a central current-carrying rod is used to provide an applied toroidal field. The new Rotamak has then a spherical tokamak magnetic field structure. This work will present new calculations which model the above structure and include the effect of the applied toroidal field in addition to the steady vertical field and the rotating (current-drive) magnetic field. The problem is fully three dimensional and non-linear and involves the application of interesting computational techniques. The potential of using the rotating field current drive technique for spherical tokamaks will be evaluated

  6. Cow Dung Ingestion and Inhalation Dependence: A Case Report

    Science.gov (United States)

    Khairkar, Praveen; Tiple, Prashant; Bang, Govind

    2009-01-01

    Although abuse of several unusual inhalants had been documented, addiction to cow dung fumes or their ashes has not been reported in medical literature as yet. We are reporting a case of cow dung dependence in ingestion and inhalational form.

  7. Fusion potential for spherical and compact tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Sandzelius, Mikael

    2003-02-01

    The tokamak is the most successful fusion experiment today. Despite this, the conventional tokamak has a long way to go before being realized into an economically viable power plant. In this master thesis work, two alternative tokamak configurations to the conventional tokamak has been studied, both of which could be realized to a lower cost. The fusion potential of the spherical and the compact tokamak have been examined with a comparison of the conventional tokamak in mind. The difficulties arising in the two configurations have been treated from a physical point of view concerning the fusion plasma and from a technological standpoint evolving around design, materials and engineering. Both advantages and drawbacks of either configuration have been treated relative to the conventional tokamak. The spherical tokamak shows promising plasma characteristics, notably a high {beta}-value but have troubles with high heat loads and marginal tritium breeding. The compact tokamak operates at a high plasma density and a high magnetic field enabling it to be built considerably smaller than any other tokamak. The most notable down-side being high heat loads and neutron transport problems. With the help of theoretical reactor studies, extrapolating from where we stand today, it is conceivable that the spherical tokamak is closer of being realized of the two. But, as this study shows, the compact tokamak power plant concept offers the most appealing prospect.

  8. Fusion potential for spherical and compact tokamaks

    International Nuclear Information System (INIS)

    Sandzelius, Mikael

    2003-02-01

    The tokamak is the most successful fusion experiment today. Despite this, the conventional tokamak has a long way to go before being realized into an economically viable power plant. In this master thesis work, two alternative tokamak configurations to the conventional tokamak has been studied, both of which could be realized to a lower cost. The fusion potential of the spherical and the compact tokamak have been examined with a comparison of the conventional tokamak in mind. The difficulties arising in the two configurations have been treated from a physical point of view concerning the fusion plasma and from a technological standpoint evolving around design, materials and engineering. Both advantages and drawbacks of either configuration have been treated relative to the conventional tokamak. The spherical tokamak shows promising plasma characteristics, notably a high β-value but have troubles with high heat loads and marginal tritium breeding. The compact tokamak operates at a high plasma density and a high magnetic field enabling it to be built considerably smaller than any other tokamak. The most notable down-side being high heat loads and neutron transport problems. With the help of theoretical reactor studies, extrapolating from where we stand today, it is conceivable that the spherical tokamak is closer of being realized of the two. But, as this study shows, the compact tokamak power plant concept offers the most appealing prospect

  9. Errors when shock waves interact due to numerical shock width

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, R.

    1993-03-04

    A simple test problem proposed by Noh, a strong shock reflecting from a rigid wall, demonstrates a generic problem with numerical shock capturing algorithms at boundaries that Noh called ``excess wall heating.`` We show that the same type of numerical error occurs in general when shock waves interact. The underlying cause is the non-uniform convergence to the hyperbolic solution of the inviscid limit of the solution to the PDEs with viscosity. The error can be understood from an analysis of the asymptotic solution. For a propagating shock, there is a difference in the total energy of the parabolic wave relative to the hyperbolic shock. Moreover, the relative energy depends on the strength of the shock. The error when shock waves interact is due to the difference in the relative energies between the incoming and outgoing shock waves. It is analogous to a phase shift in a scattering matrix. A conservative differencing scheme correctly describes the Hugoniot jump conditions for a steady propagating shock. Therefore, the error from the asymptotics occurs in the transient when the waves interact. The entropy error that occurs in the interaction region remains localized but does not dissipate. A scaling argument shows that as the viscosity coefficient goes to zero, the error shrinks in spatial extend but is constant in magnitude. Noh`s problem of the reflection of a shock from a rigid wall is equivalent to the symmetric impact of two shock waves of the opposite family. The asymptotic argument shows that the same type of numerical error would occur when the shocks are of unequal strength. Thus, Noh`s problem is indicative of a numerical error that occurs when shocks interact due to the numerical shock width.

  10. Errors when shock waves interact due to numerical shock width

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, R.

    1993-03-04

    A simple test problem proposed by Noh, a strong shock reflecting from a rigid wall, demonstrates a generic problem with numerical shock capturing algorithms at boundaries that Noh called excess wall heating.'' We show that the same type of numerical error occurs in general when shock waves interact. The underlying cause is the non-uniform convergence to the hyperbolic solution of the inviscid limit of the solution to the PDEs with viscosity. The error can be understood from an analysis of the asymptotic solution. For a propagating shock, there is a difference in the total energy of the parabolic wave relative to the hyperbolic shock. Moreover, the relative energy depends on the strength of the shock. The error when shock waves interact is due to the difference in the relative energies between the incoming and outgoing shock waves. It is analogous to a phase shift in a scattering matrix. A conservative differencing scheme correctly describes the Hugoniot jump conditions for a steady propagating shock. Therefore, the error from the asymptotics occurs in the transient when the waves interact. The entropy error that occurs in the interaction region remains localized but does not dissipate. A scaling argument shows that as the viscosity coefficient goes to zero, the error shrinks in spatial extend but is constant in magnitude. Noh's problem of the reflection of a shock from a rigid wall is equivalent to the symmetric impact of two shock waves of the opposite family. The asymptotic argument shows that the same type of numerical error would occur when the shocks are of unequal strength. Thus, Noh's problem is indicative of a numerical error that occurs when shocks interact due to the numerical shock width.

  11. Effect of Particle Morphology on Critical Conditions for Shock-Initiated Reactions in Titanium-Silicon Powder Mixtures

    Science.gov (United States)

    Frost, David; Jette, Francois; Goroshin, Samuel; Higgins, Andrew; Lee, Julian

    2009-06-01

    The effect of titanium particle morphology on the shock sensitivity of titanium-silicon powder mixtures has been investigated experimentally. The powder mixtures were tested in a planar recovery capsule, with the shock loading produced by a high explosive Tetryl booster charge placed on top of the capsule and a PMMA attenuator. Reactions were not observed for stoichiometric mixtures of large (75 -- 106 μm), spherical Ti particles with fine (effects which lowered the temperature for the onset of exothermic reaction of the shocked sample by about 80^oC.

  12. Oblique shock waves in granular flows over bluff bodies

    Directory of Open Access Journals (Sweden)

    Gopan Nandu

    2017-01-01

    Full Text Available Granular flows around an object have been the focus of numerous analytical, experimental and simulation studies. The structure and nature of the oblique shock wave developed when a quasi-two dimensional flow of spherical granular particles streams past an immersed, fixed cylindrical obstacle forms the focus of this study. The binary granular mixture, consisting of particles of the same diameter but different material properties, is investigated by using a modified LIGGGHTS package as the simulation engine. Variations in the solid fraction and granular temperature within the resulting flow are studied. The Mach number is calculated and is used to distinguish between the subsonic and the supersonic regions of the bow shock.

  13. Acceleration of galactic cosmic rays in shock waves

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1981-06-01

    The old problem of the origin of cosmic rays has triggered off fresh interest owing to the discovery of a new model which enables a lot of energy to be transferred to a small number of particles on the one hand and the discovery of the coronal environment in which this transfer occurs, on the other. In this paper, interest is taken in the galactic cosmic rays and an endeavour is made to find out if the model can reveal the existence of cosmic rays over a wide energy range. The existence of an energy break, predicted by the model, was recognized fairly early but, in the literature, it varies from 30 GeV ro 10 6 GeV according to the authors. A study has been made of the two main causes of an energy break: the sphericity of the shock and the life time of the shock wave [fr

  14. Cow's milk proteins in human milk.

    Science.gov (United States)

    Coscia, A; Orrù, S; Di Nicola, P; Giuliani, F; Rovelli, I; Peila, C; Martano, C; Chiale, F; Bertino, E

    2012-01-01

    Cow's milk proteins (CMPs) are among the best characterized food allergens. Cow's milk contains more than twenty five different proteins, but only whey proteins alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin (BSA), and lactoferrin, as well as the four caseins, have been identified as allergens. Aim of this study was to investigate by proteomics techniques cow's milk allergens in human colostrum of term and preterm newborns' mothers, not previously detected, in order to understand if such allergens could be cause of sensitization during lactation. Term colostrum samples from 62 healthy mothers and preterm colostrum samples from 11 healthy mothers were collected for this purpose. The most relevant finding was the detection of the intact bovine alpha-S1-casein in both term and preterm colostrum. Using this method, which allows direct proteins identification, beta-lactoglobulin was not detected in any of colostrum samples. According to our results bovine alpha 1 casein that is considered a major cow's milk allergen is readily secreted in human milk: further investigations are needed in order to clarify if alpha-1-casein has a major role in sensitization or tolerance to cow's milk of exclusively breastfed predisposed infants.

  15. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  16. PENETRATION OF A SOUND FIELD THROUGH A MULTILAYERED SPHERICAL SHELL

    Directory of Open Access Journals (Sweden)

    G. Ch. Shushkevich

    2013-01-01

    Full Text Available An analytical solution of the boundary problem describing the process of penetration of thesound field of a spherical emitter located inside a thin unclosed spherical shell through a permeable multilayered spherical shell is considered. The influence of some parameters of the problem on the value of the sound field weakening (screening coefficient is studied via a numerical simulation.

  17. PENETRATION OF A SOUND FIELD THROUGH A MULTILAYERED SPHERICAL SHELL

    OpenAIRE

    G. Ch. Shushkevich; N. N. Kiselyova

    2013-01-01

    An analytical solution of the boundary problem describing the process of penetration of thesound field of a spherical emitter located inside a thin unclosed spherical shell through a permeable multilayered spherical shell is considered. The influence of some parameters of the problem on the value of the sound field weakening (screening) coefficient is studied via a numerical simulation.

  18. Diagnosis of pregnancy in dairy cows based on the progesterone ...

    African Journals Online (AJOL)

    pregnant cows, correctly classifying 98,0% of all cases (98,9% of pregnant cows and 97,1% of non-pregnant cows), when the discriminating level for progesterone was set at 5 ng/ml milk. At the same level of progeste- rone this function correctly classified 94,4% of all cases belonging to a different sample of dairy cows. This.

  19. Beef Cow Numbers, Crop Acreage, and Crop Policy

    OpenAIRE

    Barry W. Bobst; Joe T. Davis

    1987-01-01

    Land use shifts between cropland and pasture affect the demand for beef cow inventories because economically viable cow-calf enterprises are pasture-based. Econometric analysis indicates an inverse relationship of −36.6 thousand head of beef cows per million acre change in harvested cropland. Curtailment of the expansion phase of the current cattle cycle and subsequent declines in cow numbers is in part attributable to large acreages converted from pasture to cropland in the early 1980s. Conv...

  20. Quality Evaluation of Yoghurt from Cowmilk, Soymilk amd Cow ...

    African Journals Online (AJOL)

    Proximate analyses carried out on samples of cow milk, soymilk and cow/soymilk Yoghurts showed significant difference (P<0.05) in the % crude protein, crude fat and carbohydrate contents. For crude protein they were 3.49 ± 0.04, 2.78 ± 0.13 and 2.02 ± 0.4 for cow yoghurt, cow/soy yoghurt and soy yoghurt respectively.

  1. Bubble Dynamics and Shock Waves

    CERN Document Server

    2013-01-01

    This volume of the Shock Wave Science and Technology Reference Library is concerned with the interplay between bubble dynamics and shock waves. It is divided into four parts containing twelve chapters written by eminent scientists. Topics discussed include shock wave emission by laser generated bubbles (W Lauterborn, A Vogel), pulsating bubbles near boundaries (DM Leppinen, QX Wang, JR Blake), interaction of shock waves with bubble clouds (CD Ohl, SW Ohl), shock propagation in polydispersed bubbly liquids by model equations (K Ando, T Colonius, CE Brennen. T Yano, T Kanagawa,  M Watanabe, S Fujikawa) and by DNS (G Tryggvason, S Dabiri), shocks in cavitating flows (NA Adams, SJ Schmidt, CF Delale, GH Schnerr, S Pasinlioglu) together with applications involving encapsulated bubble dynamics in imaging (AA Doinikov, A Novell, JM Escoffre, A Bouakaz),  shock wave lithotripsy (P Zhong), sterilization of ships’ ballast water (A Abe, H Mimura) and bubbly flow model of volcano eruptions ((VK Kedrinskii, K Takayama...

  2. Effect of abdominal waste on biogas production from cow dung ...

    African Journals Online (AJOL)

    Studies have been carried out on the production of biogas from mixture of cow abdominal waste and its dung. The rate of biogas production and cumulative volume of the gas produced was compared with that of pure cow dung under the same experimental conditions. The result shows that the mixture of the cow abdominal ...

  3. Factors affecting reproductive performance of dairy cow in Algeria ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2017-01-11

    Jan 11, 2017 ... first artificial insemination (MG1; n = 62 dairy cows), cows presenting clinical mastitis between the first artificial insemination ... study clearly indicate that, clinical mastitis decreases reproductive performance of dairy cows. Key words: ... shift towards higher production per animal, inadequate nutrition, poor ...

  4. Body Temperature Versus Microclimate Selection in Heat Stressed Dairy Cows

    Science.gov (United States)

    The purpose of this study is to characterize the thermoregulatory responses of unrestrained heat-stressed dairy cows within a freestall environment using fan and spray configurations for cooling cows while lying or standing. An experimental treatment sprayed individual cows lying in freestalls from ...

  5. Economics of Local Cow Milk Products Marketing in Kwara State ...

    African Journals Online (AJOL)

    This study examined the local cow milk products marketing in Nigeria, using Kwara as a case study. Specifically, the study appraised socio-economic characteristics of local cow milk products marketers, the marketing profile and identified problems limiting marketing activities for local cow milk products. For the study 75 ...

  6. Behaviour of dairy cows under modern housing and management

    NARCIS (Netherlands)

    Wierenga, H.K.

    1991-01-01

    The results of behavioural studies of dairy cows' behaviour under some modern housing and management conditions are presented. Social dominance in dairy cows is studied and methods to describe social dominance are discussed. The lying behaviour of dairy cows is studied under various

  7. Clinical practice. Diagnosis and treatment of cow's milk allergy

    NARCIS (Netherlands)

    Kneepkens, C. M. Frank; Meijer, Yolanda

    Introduction Cow's milk allergy (CMA) is thought to affect 2-3% of infants. The signs and symptoms are nonspecific and may be difficult to objectify, and as the diagnosis requires cow's milk elimination followed by challenge, often, children are considered cow's milk allergic without proven

  8. producing dairy cows fed conventional forages, wheat straw

    African Journals Online (AJOL)

    Chewing activity, metabolic profile and performance of high- producing dairy cows fed conventional forages, wheat straw or rice straw. ... South African Journal of Animal Science ... Twelve lactating Holstein cows were used in a replicated (n = 4) 3 × 3 Latin square design experiment with three periods of 21 days. Cows were ...

  9. CHAPA, BEEF COW/CALF HEALTH AND PRODUCTIVITY AUDIT, PART III: BEEF COW/CALF HEALTH MANAGEMENT

    OpenAIRE

    Dargatz, David

    1994-01-01

    As part of the National Animal Health Monitoring System (NAHMS ), USDA:APHIS:Veterinary Services conducted a national study of beef production, the Beef Cow/Calf Health and Productivity Audit (CHAPA). This study was designed to provide both participants and the industry with information on cow/calf health, productivity, and management practices. Data for Part III: Beef Cow/Calf Health & Health Management were collected by federal and state veterinary officers (VMO's) in 18 of the largest cow/...

  10. Short communication: Cow- and herd-level prevalence of hypoglycemia in hyperketonemic postpartum dairy cows.

    Science.gov (United States)

    Dubuc, J; Buczinski, S

    2018-02-07

    The objective of this study was to quantify the prevalence of hypoglycemia in hyperketonemic dairy cows during the early postpartum period. A prospective observational study was conducted in 100 dairy herds selected by convenience. Within all participating herds, 40 cows (or the entire herd if smaller than 40 cows) were enrolled in the study (total of 3,776 enrolled cows). Herds were visited every 2 wk by an animal health technician. Cows were bled from their coccygeal vessels once between 1 and 14 d in milk, and cow-side testing was performed for ketonemia and glycemia using a device validated in cattle (Precision Xtra, Abbott, Mississauga, ON, Canada). Hyperketonemia was defined as β-hydroxybutyrate ≥1.4 mmol/L, and hypoglycemia was defined as glucose ≤2.2 mmol/L. Descriptive statistics were computed at the cow and herd levels. The cow-level prevalence of hyperketonemia, hypoglycemia, and simultaneous hypoglycemia and hyperketonemia was 20.0% (757/3,776), 13.8% (642/3,776), and 6.2% (235/3,776), respectively. Within the subset of hyperketonemic cows only, the prevalence of hypoglycemia was 31.0% (235/757). At the herd level, the median prevalence was 17.5% (minimum: 5.0%, first quartile: 10.0%, third quartile: 22.5%, maximum: 77.5%) for hyperketonemia, 15.0% (minimum: 5.0%, first quartile: 12.5%, third quartile: 20.0%, maximum: 47.5%) for hypoglycemia, and 7.5% (minimum: 2.5%, first quartile: 5.0%, third quartile: 12.5%, maximum: 17.5%) for simultaneous hypoglycemia and hyperketonemia. The herd-level median prevalence of hypoglycemia within the subset of hyperketonemic cows only was 30.6% (minimum: 2.5%, first quartile: 20.0%, third quartile: 39.1%, maximum: 63.0%). The results from this study show that the prevalence of simultaneous hyperketonemia and hypoglycemia is relatively low in the overall early postpartum cow population but also that approximately one third of hyperketonemic cows are hypoglycemic, which might represent an opportunity to improve

  11. POSTURAL SHOCK IN PREGNANCY

    Science.gov (United States)

    Wilkening, Ralph L.; Knauer, John; Larson, Roger K.

    1955-01-01

    Signs and symptoms of shock may be produced in some patients in late pregnancy by putting them in the dorsal recumbent posture. Change from this position will relieve the condition. The features of the supine hypotensive syndrome can be duplicated by applying pressure to the abdomen with the patient in a lateral position. The postural variations of venous pressure, blood pressure, and pulse appear to be due to obstruction of venous return from the lower portion of the body caused by the large uterus of late pregnancy compressing the vena cava. When shock is observed in a woman in late pregnancy, she should be turned to a lateral position before more active measures of treatment are begun. ImagesFigure 1. PMID:14351983

  12. Radiative relativistic shock adiabate

    International Nuclear Information System (INIS)

    Tsintsadze, L.N.; Nishikawa, K.

    1997-01-01

    The influences of thermal radiation on the state equation of shock waves, derived in the previous paper [L. N. Tsintsadze, Phys. Plasmas 2, 4462 (1995)], are studied and a series of relations of thermodynamic quantities that hold for shock waves are derived. It is shown that the presence of radiation can strongly change the compressibility of the plasma. It is well known that for polytropic gases the compressibility cannot change more than four times the initial value in the case of nonrelativistic temperatures. The numerical calculations show that there are no such restrictions, when the radiation energy exceeds the kinetic energy of the plasma. The ultrarelativistic temperature range is also covered in our numerical calculations. Also studied are the influences of the radiation on the PT and the TV diagrams. A significant modification due to radiation is found in every case studied. copyright 1997 American Institute of Physics

  13. [Cow's milk protein allergy through human milk].

    Science.gov (United States)

    Denis, M; Loras-Duclaux, I; Lachaux, A

    2012-03-01

    Cow's milk protein allergy (CMPA) is the first allergy that affects infants. In this population, the incidence rate reaches 7.5%. The multiplicity and aspecificity of the symptoms makes its diagnosis sometimes complicated, especially in the delayed type (gastrointestinal, dermatological, and cutaneous). CMPA symptoms can develop in exclusively breastfed infants with an incidence rate of 0.5%. It, therefore, raises questions about sensitization to cow's milk proteins through breast milk. Transfer of native bovine proteins such as β-lactoglobulin into the breast milk is controversial: some authors have found bovine proteins in human milk but others point to cross-reactivity between human milk proteins and cow's milk proteins. However, it seems that a small percentage of dietary proteins can resist digestion and become potentially allergenic. Moreover, some authors suspect the transfer of some of these dietary proteins from the maternal bloodstream to breast milk, but the mechanisms governing sensitization are still being studied. Theoretically, CMPA diagnosis is based on clinical observations, prick-test or patch-test results, and cow's milk-specific IgE antibody concentration. A positive food challenge test usually confirms the diagnosis. No laboratory test is available to make a certain diagnosis, but the detection of eosinophil cationic protein (ECP) in the mother's milk, for example, seems to be advantageous since it is linked to CMA. Excluding cow's milk from the mother's diet is the only cure when she still wants to breastfeed. Usually, cow's milk proteins are reintroduced after 6 months of exclusion. Indeed, the prognosis for infants is very good: 80% acquire a tolerance before the age of 3 or 4 years. Mothers should not avoid dairy products during pregnancy and breastfeeding as preventive measures against allergy. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  14. Shock resistance testing

    International Nuclear Information System (INIS)

    Pouard, M.

    1984-03-01

    In the framework of mechanical tests and to answer the different requests for tests, the T.C.R (Transport Conditionnement et Retraitement) laboratory got test facilities. These installations allow to carry out tests of resistance to shocks, mainly at the safety level of components of nuclear power plants, mockups of transport casks for fuel elements and transport containers for radioactive materials. They include a tower and a catapult. This paper give a decription of the facilities and explain their operation way [fr

  15. Behaviour of dairy cows under free or forced cow traffic in a simulated automatic milking system environment.

    NARCIS (Netherlands)

    Lauwere, de C.C.K.; Hendriks, M.M.B.; Metz, J.H.M.; Schouten, W.G.P.

    1998-01-01

    The introduction of fully automatic milking systems (AMS) on dairy farms can only succeed if cows visit the system more or less voluntarily, at regular intervals. This can be arranged by either forced or free cow traffic. In the case of forced cow traffic, the AMS is the only route from the lying

  16. Characterization of shocked beryllium

    Directory of Open Access Journals (Sweden)

    Papin P.A.

    2012-08-01

    Full Text Available While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. In the current work, high strain rate tests were conducted using both explosive drive and a gas gun to accelerate the material. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. Two constitutive strength (plasticity models, the Preston-Tonks-Wallace (PTW and Mechanical Threshold Stress (MTS models, were calibrated using common quasi-static and Hopkinson bar data. However, simulations with the two models give noticeably different results when compared with the measured experimental wave profiles. The experimental results indicate that, even if fractured by the initial shock loading, the Be remains sufficiently intact to support a shear stress following partial release and subsequent shock re-loading. Additional “arrested” drive shots were designed and tested to minimize the reflected tensile pulse in the sample. These tests were done to both validate the model and to put large shock induced compressive loads into the beryllium sample.

  17. Detection of Subclinical Ketosis in Dairy Cows

    Directory of Open Access Journals (Sweden)

    Zhigang Zhang, Guowen Liu1, Hongbin Wang, Xiaobing Li1 and Zhe Wang1*

    2012-05-01

    Full Text Available Ketosis is a common metabolic disorder frequently observed in dairy cows during the early lactation period. It is characterized by increased levels of ketone bodies in the blood, urine, and milk. Subclinical ketosis (SCK in dairy cattle is an excess level of circulating ketone bodies in the absence of clinical signs of ketosis. Usually, detection of SCK is carried out by testing the ketone concentrations in blood, urine, and milk. Here, This review overview the detection methods for SCK in dairy cows, including cowside and laboratory tests.

  18. Numerical study of shock waves in non-ideal magnetogasdynamics (MHD

    Directory of Open Access Journals (Sweden)

    Addepalli Ramu

    2016-01-01

    Full Text Available One-dimensional unsteady adiabatic flow of strong converging shock waves in cylindrical or spherical symmetry in MHD, which is propagating into plasma, is analyzed. The plasma is assumed to be non-ideal gas whose equation of state is of Mie–Gruneisen type. Suitable transformations reduce the governing equations into ordinary differential equations of Poincare type. In the present work, McQueen and Royce equations of state (EOS have been considered with suitable material constants and the spherical and cylindrical cases are worked out in detail to investigate the behavior and the influence on the shock wave propagation by energy input and β(ρ/ρ0, the measure of shock strength. The similarity solution is valid for adiabatic flow as long as the counter pressure is neglected. The numerical technique applied in this paper provides a global solution to the implosion problem for the flow variables, the similarity exponent α for different Gruneisen parameters. It is shown that increasing β(ρ/ρ0 does not automatically decelerate the shock front but the velocity and pressure behind the shock front increases quickly in the presence of the magnetic field and decreases slowly and become constant. This becomes true whether the piston is accelerated, is moving at constant speed or is decelerated. These results are presented through the illustrative graphs and tables. The magnetic field effects on the flow variables through a medium and total energy under the influence of strong magnetic field are also presented.

  19. Comparison of Chamcham manufactured from cow milk and buffalo milk

    OpenAIRE

    Haque, M.A.; Rashid, M.H.; Kajal, M.F.I.; Istiak, M.S.

    2012-01-01

    This experiment was conducted to study quality of Chamcham manufactured from cow milk and to compare it with Chamcham manufactured from buffalo milk and mixture of cow and buffalo milk. Three types of Chamcham were prepared from cow milk(A), buffalo milk(B) and 50% cow +50% buffalo milk(C).In this experiment the quality of prepared Chamcham were evaluated with the help of chemical test. The moisture, total solids, protein, fat, ash and carbohydrate contents of cow milk and buffalo milk Chamch...

  20. Chiral pion dynamics for spherical nucleon bags

    International Nuclear Information System (INIS)

    Vento, V.; Rho, M.; Nyman, E.M.; Jun, J.H.; Brown, G.E.; CEA Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette

    1980-01-01

    A chirally symmetric quark-bag model for the nucleon is obtained by introducing an explicit, classical, pion field exterior to the bag. The coupling at the bag surface is determined by the requirement of a conserved axial-vector current. The pion field satisfies equations of motion corresponding to the non-linear sigma-model. We study on this paper the simplified case where the bag and the pion field are spherically symmetric. Corrections due to gluon exchange between the quarks are ignored along with other interactions which split the N- and Δ-masses. The equations of motion for the pion field are solved and we find a substantial pion pressure at the bag surface, along with an attractive contribution to the nucleon self-energy. The total energy of the system, bag plus meson cloud, turns out to be approximately Msub(n)c 2 for a wide range of bag radii, from 1.5 fm down to about 0.5 fm. Introduction of a form factor for the pion would extend the range of possible radii to even smaller values. We propose that the bag with the smallest allowed radius be identified with the 'little bag' discussed before. One surprising result of the paper is that as long as one restricts to spherically symmetric bags, restoring chiral symmetry to the bag model makes the axial-vector current coupling constant gsub(A) to be always too large compared with the experimental value for any bag radius, suggesting a deviation from spherical symmetry for the intrinsic bag wave functions of the 'ground-state' hadrons. (orig.)

  1. Uniform illumination of spherical laser fusion targets

    International Nuclear Information System (INIS)

    Howard, J.E.

    1977-01-01

    Uniformity of illumination of spherical laser fusion targets is calculated for eight, twelve, and twenty beams arranged according to the symmetry of the Platonic solids. Uniformity is optimized by varying the f/no. of ideal aberration-free lenses, amount of beam overlap, and the shape of the spatial beam profile. The numerical results show twenty-beam illumination to be slightly better than twelve-beam illumination, with eight beams running a poor third. Refractive energy losses due to nonorthogonal illumination and the implications for the design of a practical laser fusion reactor are discussed

  2. Space Radiation Detector with Spherical Geometry

    Science.gov (United States)

    Wrbanek, John D. (Inventor); Fralick, Gustave C. (Inventor); Wrbanek, Susan Y. (Inventor)

    2012-01-01

    A particle detector is provided, the particle detector including a spherical Cherenkov detector, and at least one pair of detector stacks. In an embodiment of the invention, the Cherenkov detector includes a sphere of ultraviolet transparent material, coated by an ultraviolet reflecting material that has at least one open port. The Cherenkov detector further includes at least one photodetector configured to detect ultraviolet light emitted from a particle within the sphere. In an embodiment of the invention, each detector stack includes one or more detectors configured to detect a particle traversing the sphere.

  3. Spherical conformal models for compact stars

    Energy Technology Data Exchange (ETDEWEB)

    Takisa, P.M.; Maharaj, S.D.; Manjonjo, A.M.; Moopanar, S. [University of KwaZulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics and Computer Science, Durban (South Africa)

    2017-10-15

    We consider spherical exact models for compact stars with anisotropic pressures and a conformal symmetry. The conformal symmetry condition generates an integral relationship between the gravitational potentials. We solve this condition to find a new anisotropic solution to the Einstein field equations. We demonstrate that the exact solution produces a relativistic model of a compact star. The model generates stellar radii and masses consistent with PSR J1614-2230, Vela X1, PSR J1903+327 and Cen X-3. A detailed physical examination shows that the model is regular, well behaved and stable. The mass-radius limit and the surface red shift are consistent with observational constraints. (orig.)

  4. The spherical tokamak fusion power plant

    International Nuclear Information System (INIS)

    Wilson, H.R.; Voss, G.; Ahn, J.W.

    2003-01-01

    The design of a 1GW(e) steady state fusion power plant, based on the spherical tokamak concept, has been further iterated towards a fully self-consistent solution taking account of plasma physics, engineering and neutronics constraints. In particular a plausible solution to exhaust handling is proposed and the steam cycle refined to further improve efficiency. The physics design takes full account of confinement, MHD stability and steady state current drive. It is proposed that such a design may offer a fusion power plant which is easy to maintain: an attractive feature for the power plants following ITER. (author)

  5. Galileon radiation from a spherical collapsing shell

    Energy Technology Data Exchange (ETDEWEB)

    Martín-García, Javier [Instituto de Física Teórica UAM/CSIC,C/ Nicolás Cabrera 15, E-28049 Madrid (Spain); Vázquez-Mozo, Miguel Á. [Instituto Universitario de Física Fundamental y Matemáticas (IUFFyM),Universidad de Salamanca, Plaza de la Merced s/n, E-37008 Salamanca (Spain)

    2017-01-17

    Galileon radiation in the collapse of a thin spherical shell of matter is analyzed. In the framework of a cubic Galileon theory, we compute the field profile produced at large distances by a short collapse, finding that the radiated field has two peaks traveling ahead of light fronts. The total energy radiated during the collapse follows a power law scaling with the shell’s physical width and results from two competing effects: a Vainshtein suppression of the emission and an enhancement due to the thinness of the shell.

  6. Spherical Panoramas for Astrophysical Data Visualization

    Science.gov (United States)

    Kent, Brian R.

    2017-05-01

    Data immersion has advantages in astrophysical visualization. Complex multi-dimensional data and phase spaces can be explored in a seamless and interactive viewing environment. Putting the user in the data is a first step toward immersive data analysis. We present a technique for creating 360° spherical panoramas with astrophysical data. The three-dimensional software package Blender and the Google Spatial Media module are used together to immerse users in data exploration. Several examples employing these methods exhibit how the technique works using different types of astronomical data.

  7. Biliary clearance of bromosulfophthalein in healthy and ketotic Holstein cows

    Directory of Open Access Journals (Sweden)

    Danijela Kirovski

    2013-09-01

    Full Text Available Ketosis is a metabolic disorder closely associated with liver lipidosis. Numerous tests have been developed to detect hepatic dysfunction in dairy cows. Bromosulfophthalein (BSP clearance is established as a sensitive index of hepatic function. The objective of this study was to examine the difference of biliary excretion of BSP between ketotic and healthy Holstein cows and to correlate this excretion with other indicators of liver dysfunction. Twenty puerperal Holstein cows divided in two groups (10 cows each were involved in the study. The first group included healthy and the second group ketotic cows. Blood samples were taken 10 days after parturition. Concentrations of total protein, albumin, total bilirubin, Ca, P, total lipids, urea and glucose were determined. Immediately after blood sampling, BSP test was performed. Blood samples were taken 5 and 45 minutes after injection, and the percentage of retained pigment in the sample obtained at minute 45 was calculated. Blood albumin and glucose concentrations were significantly higher in healthy then ketotic cows. Total bilirubin concentration was significantly higher in ketotic than healthy cows. BSP excretion was significantly higher in ketotic compared to healthy cows. There was a significant positive correlation between BSP values and total bilirubin concentrartions in both healthy and ketotic cows and a significant negative correlation between BSP values and glucose concentrartions in both healthy and ketotic cows. In conclusion, biliary clearance of BSP may be used as a reliable method for the detection of hepatic dysfunction associated with clinical symptoms of ketosis in dairy cows.

  8. Cow?s milk allergy: evidence-based diagnosis and management for the practitioner

    OpenAIRE

    Lifschitz, Carlos; Szajewska, Hania

    2014-01-01

    This review summarizes current evidence and recommendations regarding cow?s milk allergy (CMA), the most common food allergy in young children, for the primary and secondary care providers. The diagnostic approach includes performing a medical history, physical examination, diagnostic elimination diets, skin prick tests, specific IgE measurements, and oral food challenges. Strict avoidance of the offending allergen is the only therapeutic option. Oral immunotherapy is being studied, but it is...

  9. Effects of different dosages of propylene glycol in dry cows and cows in early lactation.

    Science.gov (United States)

    Maurer, Michaela; Peinhopf, Walter; Gottschalk, Jutta; Einspanier, Almut; Koeller, Gabor; Wittek, Thomas

    2017-11-01

    In this Research Paper we hypothesised that the temporary insulin resistance seen during the transition period in dairy cows may cause significant differences in the efficacy of PG at different sampling periods and that in some cases this effect will be dose dependent. Eighty four sampling sets were generated by studying 7 multiparous Holstein cows repeatedly at 4 sampling periods of 3 d length (dry cows: days 40, 39 and 38 antepartum; close up cows: days 10, 9 and 8 antepartum; fresh cows: days 3, 4 and 5 post-partum; lactating cows: days 38, 39 and 40 post-partum). On each of these days 3 h after morning feeding propylene glycol was drenched in different dosages of 100, 300 or 500 ml once per day (cross over study). The different doses were applied in an alternating order (Latin square). Blood samples were taken before, every 30 min up to 4 h, after 6 and 12 h after PG application. Following parameters have been measured: insulin, non-esterified fatty acids (NEFA), betahydroxybutyrate (BHB), bilirubin, cholesterol, potassium, aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH). Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) was calculated. It was found that glucose, insulin, NEFA, BHB, bilirubin and potassium concentrations were influenced differently by the three defined dosages of propylene glycol at four different sampling periods. Whereas RQUICKI, cholesterol, AST and GLDH did not differ between the sampling periods and treatments. The major results of the study are that the effect of PG is dose-dependent and that the effect of PG is depending on the time of application according to calving. It can be concluded that in fresh cows higher dosages are necessary to provoke similar effects in comparison to dry, close up and lactating cows. Although the study did not compare to topdressing of PG from the results it is reasonable to believe that bolus application of a specific PG volume is necessary to provoke the effect.

  10. Thermal shock behaviour of ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, G.; Saadaoui, M.; Chevalier, J.; Olagnon, C. [Groupe d' Etude de Metallurgie Physique UMR, Institut National des Sciences Appliquees de Lyon, Villeurbanne (France)

    2000-07-01

    Thermal shock of ceramics is complex to analyse because of the important number of parameters to take into account. Thermal shock analysis has been refined by considering the dependence with temperature of the different parameters. From the temperature evolution in the specimen, the stress and stress intensity factor (SIF) profiles can be calculated. This allows the prediction of the crack evolution during thermal shock. Thermal shock experiments conducted by using an in-situ acoustic emission (AE) apparatus allow the determination of the time of unstable crack growth. The effect of crack growth resistance (R-curve behaviour) can be taken into account and, if it is significant, the thermal shock resistance of ceramics can be improved. The fracture mechanical analysis was used to determine the R-curve behaviour of alumina material subjected to thermal shock. A good agreement is observed between predictions of thermal fracture theory based on fracture mechanics and experimental results. (orig.)

  11. Finnish exchange students' culture shock

    OpenAIRE

    Pekkala, Karoliina

    2015-01-01

    This bachelor’s thesis is written about culture shock experienced by the exchange students from Finland. It is commissioned by an international students exchange organisation located in Finland. The aim of the research was to find out how much the host country affects the culture shock and to identify aspects that affect the adaptation of the students. The goal is to provide the future exchange students with advise on coping with culture shock. Theoretical framework consists of defining w...

  12. Eight Annual Conference on Shock

    Science.gov (United States)

    1985-11-01

    University 2) "Role of Eicosanoids in Disease States Other Than Shock" Perry V. Halushka, MD, PhD Medical University of South Carolina, Charleston 3...anoxemia re- sults in improved myocardial function and augments energy reserves of myocardial gly- cogen(MG). As many patients with heart disease also have...pretreated (30 min) shocked and sham control rats. SAO shock was induced by occlusions of the coeliac and superior mesenteric arteries for 60 mins. Plasma

  13. Reproductive performance of artificially inseminated dairy cows ...

    African Journals Online (AJOL)

    The objectives of the study were to generate a reliable field data set and analyze it to determine reproductive parameters/indices. A total of 280 and 400 households keeping 158 and 709 cows and heifers in Rwanda and Tanzania respectively were studied. Reproductive events: dates of heat, AI or NS, service number, sire ...

  14. Relationship with BSE (Mad Cow Disease)

    Science.gov (United States)

    ... Form Controls Cancel Submit Search the CDC Variant Creutzfeldt-Jakob Disease (vCJD) Note: Javascript is disabled or is not ... for Travelers Surveillance Treatment Related Links Prion Diseases Creutzfeldt-Jakob Disease (CJD) Bovine Spongiform Encephalopathy (BSE), or Mad Cow ...

  15. Mad Cow Disease-Bovine Spongiform Encephalopathy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 4. Mad Cow Disease - Bovine Spongiform Encephalopathy. Ashutosh ... HP Agricultural University, Palampur 176 662, India. DES (Vety. Sei.) KVK (P A U) Old Gurunanak College Building Hardochhani Road Gurdaspur Punjab 143 521 India.

  16. Automated behaviour monitoring in dairy cows

    NARCIS (Netherlands)

    Mol, de R.M.; Verhoeven, P.H.F.M.; Hogewerf, P.H.; Ipema, A.H.

    2011-01-01

    Acceleration sensors in a Wireless Sensor Network (WSN) were used to monitor the behaviour of dairy cows. The data processing from 3D acceleration into behaviour classification (lying, standing or walking) was based on a two-steps method: first the distinction between lying and standing/walking was

  17. Silage alcohols in dairy cow nutrition

    DEFF Research Database (Denmark)

    Raun, Birgitte Marie Løvendahl

    Corn silages with high propanol concentrations has been suspected to cause reduced feed intake and health problems for dairy cows in the post-pattum transition period. With the increasing use of hetero fermentative inoculants to support corn silage fermentation it is likely that silage concentrat...

  18. Role of mast cells in cow metritis

    Directory of Open Access Journals (Sweden)

    Wang Guo-Qing

    2016-06-01

    Full Text Available Introduction: Bovine postpartum metritis causes great losses. Mast cell (MC-released mediators participate in uterine inflammation and immune response, but their role in postpartum metritis in cows has not been reported. This study investigated the effect of endometrial MC on the disorder.

  19. Hepatitis in growth promotor treated cows

    NARCIS (Netherlands)

    Groot, M.J.

    2002-01-01

    Adult female beef cattle found positive for stanozolol in the urine were investigated for liver pathology. In all the animals toxic hepatitis was found, including cholestasis, periportal fibrosis and inflammation, focal necrosis and blood filled lacunae. As no clinical data of the cows were

  20. Reproductive performance by dairy cows fed supplemental ...

    African Journals Online (AJOL)

    Clinical metabolic disorders and clinical puerperal complications were not affected by chromium methionine supplementation. The results of this experiment showed that chromium methionine supplementation in multiparous dairy cows diet may improve their reproductive performance in transition period. Key words: Dairy ...

  1. Status of National Spherical Torus Experiment (NSTX)*

    Science.gov (United States)

    Ono, Masayuki

    2001-10-01

    The main aim of National Spherical Torus Experiment (NSTX) is to establish the fusion physics principles of the innovative spherical torus (ST) concept. The NSTX experimental facility has been operating reliably and its capabilities steadily improving. Due to relatively efficient ohmic current drive and benign halo current behavior, the plasma current was increased to 1.4 MA, which is well above the design value of 1 MA. The plasmas at 1 MA are now routinely heated by NBI to the average toroidal beta value of 20 percent range at 3 kG with electrons and ions in the 1-2 keV range. Even with the “L-mode” edge, the energy confinement time can well exceed the so-called L-mode (and even H-mode) scaling values. As a part of ST tool development, High Harmonic Fast Wave (HHFW) heating has demonstrated efficient electron heating with the central electron temperatures reaching 3.7 keV. HHFW induced H-modes have been also observed. For CHI (Coaxial Helicity Injection) non-inductive start-up, CHI discharges of up to 300 kA of toroidal current and 300 msec duration have been produced from zero current using = 25 kA of injected current. The poster presentation will also include the near term NSTX facility upgrade plan.

  2. Clusters of polyhedra in spherical confinement

    Science.gov (United States)

    Teich, Erin G.; van Anders, Greg; Klotsa, Daphne; Dshemuchadse, Julia; Glotzer, Sharon C.

    2016-01-01

    Dense particle packing in a confining volume remains a rich, largely unexplored problem, despite applications in blood clotting, plasmonics, industrial packaging and transport, colloidal molecule design, and information storage. Here, we report densest found clusters of the Platonic solids in spherical confinement, for up to N=60 constituent polyhedral particles. We examine the interplay between anisotropic particle shape and isotropic 3D confinement. Densest clusters exhibit a wide variety of symmetry point groups and form in up to three layers at higher N. For many N values, icosahedra and dodecahedra form clusters that resemble sphere clusters. These common structures are layers of optimal spherical codes in most cases, a surprising fact given the significant faceting of the icosahedron and dodecahedron. We also investigate cluster density as a function of N for each particle shape. We find that, in contrast to what happens in bulk, polyhedra often pack less densely than spheres. We also find especially dense clusters at so-called magic numbers of constituent particles. Our results showcase the structural diversity and experimental utility of families of solutions to the packing in confinement problem. PMID:26811458

  3. Quasi-spherical direct drive fusion.

    Energy Technology Data Exchange (ETDEWEB)

    VanDevender, J. Pace; Abbott, Lucas M.; Langston, William L.; McDaniel, Dillon Heirman; Nash, Thomas J.; Roderick, Norman Frederick; Silva, M.

    2007-01-01

    The authors present designs of quasi-spherical direction drive z-pinch loads for machines such as ZR at 28 MA load current with a 150 ns implosion time (QSDDI). A double shell system for ZR has produced a 2D simulated yield of 12 MJ, but the drive for this system on ZR has essentially no margin. A double shell system for a 56 MA driver at 150 ns implosion has produced a simulated yield of 130 MJ with considerable margin in attaining the necessary temperature and density-radius product for ignition. They also represent designs for a magnetically insulated current amplifier, (MICA), that modify the attainable ZR load current to 36 MA with a 28 ns rise time. The faster pulse provided by a MICA makes it possible to drive quasi-spherical single shell implosions (QSDD2). They present results from 1D LASNEX and 2D MACH2 simulations of promising low-adiabat cryogenic QSDD2 capsules and 1D LASNEX results of high-adiabat cryogenic QSDD2 capsules.

  4. Spherical aggregates composed of gold nanoparticles

    International Nuclear Information System (INIS)

    Chen, C-C; Kuo, P-L; Cheng, Y-C

    2009-01-01

    Alkylated triethylenetetramine (C12E3) was synthesized and used as both a reductant in the preparation of gold nanoparticles by the reduction of HAuCl 4 and a stabilizer in the subsequent self-assembly of the gold nanoparticles. In acidic aqueous solution, spherical aggregates (with a diameter of about 202 ± 22 nm) of gold nanoparticles (with the mean diameter of ∼18.7 nm) were formed. The anion-induced ammonium adsorption of the alkylated amines on the gold nanoparticles was considered to provide the electrostatic repulsion and steric hindrance between the gold nanoparticles, which constituted the barrier that prevented the individual particles from coagulating. However, as the amino groups became deprotonated with increasing pH, the ammonium adsorption was weakened, and the amino groups were desorbed from the gold surface, resulting in discrete gold particles. The results indicate that the morphology of the reduced gold nanoparticles is controllable through pH-'tunable' aggregation under the mediation of the amino groups of alkylated amine to create spherical microstructures.

  5. Herd factors associated with dairy cow mortality.

    Science.gov (United States)

    McConnel, C; Lombard, J; Wagner, B; Kopral, C; Garry, F

    2015-08-01

    Summary studies of dairy cow removal indicate increasing levels of mortality over the past several decades. This poses a serious problem for the US dairy industry. The objective of this project was to evaluate associations between facilities, herd management practices, disease occurrence and death rates on US dairy operations through an analysis of the National Animal Health Monitoring System's Dairy 2007 survey. The survey included farms in 17 states that represented 79.5% of US dairy operations and 82.5% of the US dairy cow population. During the first phase of the study operations were randomly selected from a sampling list maintained by the National Agricultural Statistics Service. Only farms that participated in phase I and had 30 or more dairy cows were eligible to participate in phase II. In total, 459 farms had complete data for all selected variables and were included in this analysis. Univariable associations between dairy cow mortality and 162 a priori identified operation-level management practices or characteristics were evaluated. Sixty of the 162 management factors explored in the univariate analysis met initial screening criteria and were further evaluated in a multivariable model exploring more complex relationships. The final weighted, negative binomial regression model included six variables. Based on the incidence rate ratio, this model predicted 32.0% less mortality for operations that vaccinated heifers for at least one of the following: bovine viral diarrhea, infectious bovine rhinotracheitis, parainfluenza 3, bovine respiratory syncytial virus, Haemophilus somnus, leptospirosis, Salmonella, Escherichia coli or clostridia. The final multivariable model also predicted a 27.0% increase in mortality for operations from which a bulk tank milk sample tested ELISA positive for bovine leukosis virus. Additionally, an 18.0% higher mortality was predicted for operations that used necropsies to determine the cause of death for some proportion of dead

  6. Non-relativistic Radiation Mediated Shock Breakouts. III. Spectral Properties of Supernova Shock Breakout

    Science.gov (United States)

    Sapir, Nir; Katz, Boaz; Waxman, Eli

    2013-09-01

    The spectrum of radiation emitted following shock breakout from a star's surface with a power-law density profile ρvpropxn is investigated. Assuming planar geometry, local Compton equilibrium, and bremsstrahlung emission as the dominant photon production mechanism, numerical solutions are obtained for the photon number density and temperature profiles as a function of time for hydrogen-helium envelopes. The temperature solutions are determined by the breakout shock velocity v 0 and the pre-shock breakout density ρ0 and depend weakly on the value of n. Fitting formulae for the peak surface temperature at breakout as a function of v 0 and ρ0 are provided, with {T}_peak\\approx 9.44\\exp {[12.63(v_0/c)^{1/2}]} \\,eV, and the time dependence of the surface temperature is tabulated. The time integrated emitted spectrum is a robust prediction of the model, determined by {T}_peak and v 0 alone and insensitive to details of light travel time or slight deviations from spherical symmetry. Adopting commonly assumed progenitor parameters, breakout luminosities of ≈1045 erg s-1 and ≈1044 erg s-1 in the 0.3-10 keV band are expected for blue supergiant (BSG) and red supergiant (RSG)/He-WR progenitors, respectively ( {T}_peak is well below the band for RSGs, unless their radius is ~1013 cm). >30 detections of SN 1987A-like (BSG) breakouts are expected over the lifetime of ROSAT and XMM-Newton. An absence of such detections would imply either that the typical parameters assumed for BSG progenitors are grossly incorrect or that their envelopes are not hydrostatic. The observed spectrum and duration of XRF 080109/SN 2008D are in tension with a non-relativistic breakout from a stellar surface interpretation.

  7. Myths of "shock therapy".

    Science.gov (United States)

    Fink, M

    1977-09-01

    The author discusses the myths of the ECT process--that shock and the convulsion are essential, memory loss and brain damage are inescapable, and little is known of the process--and assesses the fallacies in these ideas. Present views of the ECT process suggest that its mode of action in depression may best be described as a prolonged form of diencephalic stimulation, particularly useful to affect the hypothalamic dysfunctions that characterize depressive illness. The author emphasizes the need for further study of this treatment modality and for self-regulation by the profession.

  8. Viscous shock layer solutions for turbulent flow of radiating gas mixtures in chemical equilibrium

    Science.gov (United States)

    Anderson, E. C.; Moss, J. N.

    1975-01-01

    The viscous shock layer equations for hypersonic laminar and turbulent flows of radiating or nonradiating gas mixtures in chemical equilibrium are presented for two-dimensional and axially symmetric flow fields. Solutions are obtained using an implicit finite difference scheme and results are presented for hypersonic flow over spherically blunted cone configurations at free stream conditions representative of entry into the atmosphere of Venus. These data are compared with solutions obtained using other methods of analysis.

  9. Viscous-shock-layer solutions for turbulent flow of radiating gas mixtures in chemical equilibrium

    Science.gov (United States)

    Anderson, E. C.; Moss, J. N.

    1975-01-01

    The viscous-shock-layer equations for hypersonic laminar and turbulent flows of radiating or nonradiating gas mixtures in chemical equilibrium are presented for two-dimensional and axially-symmetric flow fields. Solutions were obtained using an implicit finite-difference scheme and results are presented for hypersonic flow over spherically-blunted cone configurations at freestream conditions representative of entry into the atmosphere of Venus. These data are compared with solutions obtained using other methods of analysis.

  10. Genetic parameters for cow weight at calving and at calf weaning in ...

    African Journals Online (AJOL)

    A study was conducted to compare mature cow weight in the South African Simmental population when defined as the weight of the cow at calving or the weight of the cow at weaning of the calf. Data included in the analysis were 14458 records for cow weight at calving (CWT-C) representing 6534 cows and 18871 records ...

  11. The prediction of spherical aberration with schematic eyes.

    Science.gov (United States)

    Liou, H L; Brennan, N A

    1996-07-01

    Many model eyes have been proposed; they differ in optical characteristics and therefore have different aberrations and image quality. In predicting the visual performance of the eye, we are most concerned with the central foveal vision. Spherical aberration is the only on-axis monochromatic aberration and can be used as a criterion to assess the degree of resemblance of eye models to the human eye. We reviewed and compiled experimental values of the spherical aberration of the eye, calculated the spherical aberration of several different categories of model eyes and compared the calculated results to the experimental data. Results show an over-estimation of spherical aberration by all models, the finite schematic eyes predicting values of spherical aberration closest to the experimental data. Current model eyes do not predict the average experimental values of the spherical aberration of the eye. A new model eye satisfying this assessment criterion is required for investigations of the visual performance of the eye.

  12. Euthanasia of Danish dairy cows evaluated in two questionnaire surveys

    Directory of Open Access Journals (Sweden)

    Sørensen Jan

    2008-08-01

    Full Text Available Abstract Background Mortality risk in Danish dairy cows has more than doubled since 1990 (from 2% in 1990 to 5% in 2005. Until now, registrations about dead cows in the Danish Cattle Database have not included information about whether the cow died unassisted or was euthanized. Methods We interviewed a random sample of 196 Danish dairy farmers that had reported a dead cow to the Danish Cattle Database in 2002 and 196 dairy farmers that had reported a dead cow in 2006. Our objectives were to evaluate the proportion of euthanized cows, changes in the behaviour of farmers regarding euthanasia of cows over the years and possible reasons for these changes. Results It seems that the threshold for euthanasia of cows among farmers has changed. Farmers generally reported a lower threshold for euthanasia compared to 5–10 years ago. Conclusion The threshold for euthanasia of cows has, according to the dairy farmers, become lower. This might have positive impacts on animal welfare as more seriously ill cows are euthanized in the herds and not put through a period of suffering associated with disease and treatment or transported to a slaughterhouse in poor condition.

  13. Panchgavya and cow products: A trail for the holy grail

    Directory of Open Access Journals (Sweden)

    Ashwinikumar A. Raut

    2018-01-01

    Full Text Available For millennia, cow has been central to Indian economy, life and culture. There are innumerable references-Vedic and subsequent to the sacred significance of cow. The benefits of cow have been described at length in relation to agriculture, environment, health, economy and spiritual progress. However, the socio-political issues surrounding cow as a sacred animal have raised acrimonious debates. In Ayurveda also, there is a long tradition of using cow products for positive health, pharmaceutical processes and in therapeutics. There have been quite a few studies on the activity, efficacy, safety and acceptability of Panchagavya and other cow products. Paradoxically, many cow products available in the market for human consumption require improved standardization and proper regulation.Integration of cowpathy (Govaidyak in traditional Indian systems of medicine has been natural, based on their common dravyagunavigyan. But if its integration with conventional medicine is contemplated, we will need better understanding of the ingredients of cow products, their pharmacokinetics, pharmacodynamics and therapeutic ratio. A rational beginning can be made by data collection of experiential and anecdotal responses. A meticulous analysis of database of panchgavya and other cow products should look for temporal relationships, biological plausibility and translational potential before embarking on state-of-the-art experimental and clinical studies for selected indications. Keywords: Panchgavya, Cow products, Cowpathy, Govaidyak

  14. Application of spherical gratings in synchrotron radiation spectroscopy

    International Nuclear Information System (INIS)

    Hogrefe, H.; Howells, M.R.; Hoyer, E.

    1986-05-01

    The recent development in gracing incidence grating monochromator design is discussed and the performance limiting for such instruments are examined. Especially the aberrations of toroidal and spherical gratings are investigated using the optical path function concept. It is shown that large radius spherical gratings, which can be produced with better slope tolerances than aspherics, also yield smaller overall line curvature than toroids. Therefore, a new simple spherical grating monochromator design is proposed and its performance is analyzed

  15. Analysis of spherical thermo-acoustic radiation in gas

    OpenAIRE

    Hanping Hu; Zedong Wang; Hao Wu; Yandong Wang

    2012-01-01

    A general solution of the spherical thermo-acoustic (TA) radiation from any solid in gas is derived by using a fully thermally-mechanically coupled TA model. Therefore, the characteristics and regularities of spherical TA emission can be studied more completely. It is shown that flat amplitude-frequency response, the most important feature for planar TA emission from technical standpoint, still exists for spherical TA emission, and changes with the radius of a sphere, thickness of TA sample, ...

  16. 30th International Symposium on Shock Waves

    CERN Document Server

    Sadot, Oren; Igra, Ozer

    2017-01-01

    These proceedings collect the papers presented at the 30th International Symposium on Shock Waves (ISSW30), which was held in Tel-Aviv Israel from July 19 to July 24, 2015. The Symposium was organized by Ortra Ltd. The ISSW30 focused on the state of knowledge of the following areas: Nozzle Flow, Supersonic and Hypersonic Flows with Shocks, Supersonic Jets, Chemical Kinetics, Chemical Reacting Flows, Detonation, Combustion, Ignition, Shock Wave Reflection and Interaction, Shock Wave Interaction with Obstacles, Shock Wave Interaction with Porous Media, Shock Wave Interaction with Granular Media, Shock Wave Interaction with Dusty Media, Plasma, Magnetohyrdrodynamics, Re-entry to Earth Atmosphere, Shock Waves in Rarefied Gases, Shock Waves in Condensed Matter (Solids and Liquids), Shock Waves in Dense Gases, Shock Wave Focusing, Richtmyer-Meshkov Instability, Shock Boundary Layer Interaction, Multiphase Flow, Blast Waves, Facilities, Flow Visualization, and Numerical Methods. The two volumes serve as a reference ...

  17. Canonical quantization of spherically symmetric dust collapse

    Science.gov (United States)

    Vaz, Cenalo; Witten, Louis

    2011-12-01

    Quantum gravity effects are likely to play a crucial role in determining the outcome of gravitational collapse during its final stages. In this contribution we will outline a canonical quantization of the LeMaitre-Tolman-Bondi (LTB) models, which describe the collapse of spherical, inhomogeneous, non-rotating dust. Although there are many models of gravitational collapse, this particular class of models stands out for its simplicity and the fact that both black holes and naked singularity end states may be realized on the classical level, depending on the initial conditions. We will obtain the appropriate Wheeler-DeWitt equation and then solve it exactly, after regularization on a spatial lattice. The solutions describe Hawking radiation and provide an elegant microcanonical description of black hole entropy, but they raise other questions, most importantly concerning the nature of gravity's fundamental degrees of freedom.

  18. Effects of coating spherical iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, Irena; Motte, Laurence; Aoun, Bachir; Li, Tao; Ren, Yang; Sun, Chengjun; Saboungi, Marie-Louise

    2017-01-01

    We investigate the effect of several coatings applied in biomedical applications to iron oxide nanoparticles on the size, structure and composition of the particles. The four structural techniques employed - TEM, DLS, VSM, SAXS and EXAFS - show no significant effects of the coatings on the spherical shape of the bare nanoparticles, the average sizes or the local order around the Fe atoms. The NPs coated with hydroxylmethylene bisphosphonate or catechol have a lower proportion of magnetite than the bare and citrated ones, raising the question whether the former are responsible for increasing the valence state of the oxide on the NP surfaces and lowering the overall proportion of magnetite in the particles. VSM measurements show that these two coatings lead to a slightly higher saturation magnetization than the citrate. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazu and Dr. Federica Migliardo.

  19. Spherically-Convergent, Advanced-Fuel Systems

    Science.gov (United States)

    Barnes, D. C.; Nebel, R. A.; Schauer, M. M.; Umstadter, K. R.

    1998-11-01

    Combining nonneutral electron confinement with spherical ion convergence leads to a cm sized reactor volume with high power density.(R. A. Nebel and D. C. Barnes, Fusion Technol.), to appear (1998); D. C. Barnes and R. A. Nebel, Phys. of Plasmas 5, 2498 (1998). This concept is being investigated experimentally,(D. C. Barnes, T. B. Mitchell, and M. M. Schauer, Phys. Plasmas) 4, 1745 (1997). and results will be reported. We argue that D-D operation of such a system offers all the advantages of aneutronic fusion cycles. In particular, no breeding or large tritium inventory is required, and material problems seem tractable based on previous LWR experience. In addition the extremely small unit size leads to a massively modular system which is easily maintained and repaired, suggesting a very high availability. It may also be possible to operate such a system with low or aneutronic fuels. Preliminary work in this direction will be presented.

  20. Space Propulsion via Spherical Torus Fusion Reactor

    International Nuclear Information System (INIS)

    Williams, Craig H.; Juhasz, Albert J.; Borowski, Stanley K.; Dudzinski, Leonard A.

    2003-01-01

    A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 204 days, with an initial mass in low Earth orbit of 1630 mt. Engineering conceptual design, analysis, and assessment were performed on all major systems including nuclear fusion reactor, magnetic nozzle, power conversion, fast wave plasma heating, fuel pellet injector, startup/re-start fission reactor and battery, and other systems. Detailed fusion reactor design included analysis of plasma characteristics, power balance and utilization, first wall, toroidal field coils, heat transfer, and neutron/X-ray radiation

  1. Laser Pulse Heating of Spherical Metal Particles

    Directory of Open Access Journals (Sweden)

    Michael I. Tribelsky

    2011-12-01

    Full Text Available We consider the general problem of laser pulse heating of spherical metal particles with the sizes ranging from nanometers to millimeters. We employ the exact Mie solution of the diffraction problem and solve the heat-transfer equation to determine the maximum temperature rise at the particle surface as a function of optical and thermometric parameters of the problem. Primary attention is paid to the case when the thermal diffusivity of the particle is much larger than that of the environment, as it is in the case of metal particles in fluids. We show that, in this case, for any given duration of the laser pulse, the maximum temperature rise as a function of the particle size reaches a maximum at a certain finite size of the particle. We suggest simple approximate analytical expressions for this dependence, which cover the entire parameter range of the problem and agree well with direct numerical simulations.

  2. Nuclear structure investigations on spherical nuclei

    International Nuclear Information System (INIS)

    Heisenberg, J.; Calarco, J.; Dawson, J.; Hersman, F.W.

    1989-09-01

    This report discusses the following topics: electron scattering studies on spherical nuclei; electron scattering from collective states in deformed nuclei; proton and pion scattering studies; 12 C(e,e'p) and 16 O(e,e'p); 12 C(e,e'α) and 16 O(e,e'α); studies at high q at Bates; measurements with rvec e at Bates; 12 C(γ,p); future directions in giant resonance studies; proton knockout from 16 O; quasielastic studies at Bates; triple coincidence studies of nuclear correlations; contributions to (e,e'2p) at KIKHEF; contributions to instrumentation at CEBAF; instrumentation development at UNH; the Bates large acceptance spectrometer toroid; shell model and core polarization calculations; and the relativistic nuclear model

  3. Convection patterns in a spherical fluid shell

    Science.gov (United States)

    Feudel, F.; Bergemann, K.; Tuckerman, L. S.; Egbers, C.; Futterer, B.; Gellert, M.; Hollerbach, R.

    2011-04-01

    Symmetry-breaking bifurcations have been studied for convection in a nonrotating spherical shell whose outer radius is twice the inner radius, under the influence of an externally applied central force field with a radial dependence proportional to 1/r5. This work is motivated by the GeoFlow experiment, which is performed under microgravity condition at the International Space Station where this particular central force can be generated. In order to predict the observable patterns, simulations together with path-following techniques and stability computations have been applied. Branches of axisymmetric, octahedral, and seven-cell solutions have been traced. The bifurcations producing them have been identified and their stability ranges determined. At higher Rayleigh numbers, time-periodic states with a complex spatiotemporal symmetry are found, which we call breathing patterns.

  4. Simple spherical ablative-implosion model

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, F.J.; Steele, J.T.; Larsen, J.T.

    1980-06-23

    A simple model of the ablative implosion of a high-aspect-ratio (shell radius to shell thickness ratio) spherical shell is described. The model is similar in spirit to Rosenbluth's snowplow model. The scaling of the implosion time was determined in terms of the ablation pressure and the shell parameters such as diameter, wall thickness, and shell density, and compared these to complete hydrodynamic code calculations. The energy transfer efficiency from ablation pressure to shell implosion kinetic energy was examined and found to be very efficient. It may be possible to attach a simple heat-transport calculation to our implosion model to describe the laser-driven ablation-implosion process. The model may be useful for determining other energy driven (e.g., ion beam) implosion scaling.

  5. Saltation movement of large spherical particles

    Science.gov (United States)

    Chara, Z.; Dolansky, J.; Kysela, B.

    2017-07-01

    The paper presents experimental and numerical investigations of the saltation motion of a large spherical particle in an open channel. The channel bottom was roughed by one layer of glass rods of diameter 6 mm. The plastic spheres of diameter 25.7 mm and density 1160 kgm-3 were fed into the water channel and theirs positions were viewed by a digital camera. Two light sheets were placed above and under the channel, so the flow was simultaneously lighted from the top and the bottom. Only particles centers of which moved through the light sheets were recorded. Using a 2D PIV method the trajectories of the spheres and the velocity maps of the channel flow were analyzed. The Lattice-Boldzmann Method (LBM) was used to simulate the particle motion.

  6. A multiball read-out for the spherical proportional counter

    Science.gov (United States)

    Giganon, A.; Giomataris, I.; Gros, M.; Katsioulas, I.; Navick, X. F.; Tsiledakis, G.; Savvidis, I.; Dastgheibi-Fard, A.; Brossard, A.

    2017-12-01

    We present a novel concept of proportional gas amplification for the read-out of the spherical proportional counter. The standard single-ball read-out presents limitations for large diameter spherical detectors and high-pressure operations. We have developed a multi-ball read-out system which consists of several balls placed at a fixed distance from the center of the spherical vessel. Such a module can tune the volume electric field at the desired value and can also provide detector segmentation with individual ball read-out. In the latter case, the large volume of the vessel becomes a spherical time projection chamber with 3D capabilities.

  7. Investigation of spherical and concentric mechanism of compound droplets

    Directory of Open Access Journals (Sweden)

    Meifang Liu

    2016-07-01

    Full Text Available Polymer shells with high sphericity and uniform wall thickness are always needed in the inertial confined fusion (ICF experiments. Driven by the need to control the shape of water-in-oil (W1/O compound droplets, the effects of the density matching level, the interfacial tension and the rotation speed of the continuing fluid field on the sphericity and wall thickness uniformity of the resulting polymer shells were investigated and the spherical and concentric mechanisms were also discussed. The centering of W1/O compound droplets, the location and movement of W1/O compound droplets in the external phase (W2 were significantly affected by the density matching level of the key stage and the rotation speed of the continuing fluid field. Therefore, by optimizing the density matching level and rotation speed, the batch yield of polystyrene (PS shells with high sphericity and uniform wall thickness increased. Moreover, the sphericity also increased by raising the oil/water (O/W2 interfacial tension, which drove a droplet to be spherical. The experimental results show that the spherical driving force is from the interfacial tension affected by the two relative phases, while the concentric driving force, as a resultant force, is not only affected by the three phases, but also by the continuing fluid field. The understanding of spherical and concentric mechanism can provide some guidance for preparing polymer shells with high sphericity and uniform wall thickness.

  8. Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sanjiva Lele

    2012-10-01

    The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNS databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is

  9. Spherical microwave confinement and ball lightning

    Science.gov (United States)

    Robinson, William Richard

    This dissertation presents the results of research done on unconventional energy technologies from 1995 to 2009. The present civilization depends on an infrastructure that was constructed and is maintained almost entirely using concentrated fuels and ores, both of which will run out. Diffuse renewable energy sources rely on this same infrastructure, and hence face the same limitations. I first examined sonoluminescence directed toward fusion, but demonstrated theoretically that this is impossible. I next studied Low Energy Nuclear Reactions and developed methods for improving results, although these have not been implemented. In 2000, I began Spherical Microwave Confinement (SMC), which confines and heats plasma with microwaves in a spherical chamber. The reactor was designed and built to provide the data needed to investigate the possibility of achieving fusion conditions with microwave confinement. A second objective was to attempt to create ball lightning (BL). The reactor featured 20 magnetrons, which were driven by a capacitor bank and operated in a 0.2 s pulse mode at 2.45 GHz. These provided 20 kW to an icosahedral array of 20 antennas. Video of plasmas led to a redesign of the antennas to provide better coupling of the microwaves to the plasma. A second improvement was a grid at the base of the antennas, which provided corona electrons and an electric field to aid quick formation of plasmas. Although fusion conditions were never achieved and ball lightning not observed, experience gained from operating this basic, affordable system has been incorporated in a more sophisticated reactor design intended for future research. This would use magnets that were originally planned. The cusp geometry of the magnetic fields is suitable for electron cyclotron resonance in the same type of closed surface that in existing reactors has generated high-temperature plasmas. Should ball lightning be created, it could be a practical power source with nearly ideal

  10. Fluid Fuel Fluctuations in the Spherical Tank

    Directory of Open Access Journals (Sweden)

    H. D. Nguyen

    2014-01-01

    Full Text Available Many authors tried to solve a task concerning small fluctuations of the incompressible ideal liquid, which partially fills a stationary tank of any shape. There is a long list of references to this subject. The article presents a task solution on own fluctuations of liquid in spherical capacity, with boundary conditions on a free surface and a surface with a resistance – drain surface. Relevance of problem consists in assessment of influence of intra tank devices (measuring, intaking, damping devices, etc. on the liquid fuel fluctuations. The special attention is paid to finding the own values and frequencies of the equations of disturbed flow fluctuations with dissipation available on the boundary surfaces. In contrast to the previous examples, the lowering speed and the free surface area at undisturbed state are variable.The article also considers a variation formulation of the auxiliary boundary tasks. In solution of variation tasks, the attached Legendre's functions were used as coordinate functions. Further, after substitution of the variation tasks solution in the boundary conditions and the subsequent mathematical operations the characteristic equation was obtained. To obtain solutions of the cubic characteristic equation Cardano formulas were used. The article also considers the task on the own motions of liquid filling a capacity between two concentric spheres and flowing out via the intake in case there is a free surface. Reliability of the obtained numerical results is confirmed by comparison with calculation results of frequencies resulting from solutions of a task on the own fluctuations of liquid in the spherical capacity with the constant depth of liquid. All numerical calculations were performed using the Matlab environment.

  11. Electric Shock Injuries in Children

    Science.gov (United States)

    ... Español Text Size Email Print Share Electric Shock Injuries in Children Page Content ​When the human body comes into ... can cause anything from minor discomfort to serious injury (even death). Young children, particularly toddlers, experience electric shock most often when ...

  12. Shock wave treatment in medicine

    Indian Academy of Sciences (India)

    Unknown

    to open surgery, the cost of the ESWT is very reasonable. But nevertheless it is necessary to improve the basic un ... In second group, shock waves are used to measure distances because of the low energy loss over large distances ... pared to a piezoelectric hydrophone. The rise time of an electrohydraulic generated shock ...

  13. Molecular diagnostics of interstellar shocks

    Science.gov (United States)

    Hartquist, T. W.; Dalgarno, A.; Oppenheimer, M.

    1980-01-01

    The chemistry of molecules in shocked regions of the interstellar gas is considered and calculations are carried out for a region subjected to a shock at a velocity of 8 km/sec. Substantial enhancements are predicted in the concentrations of the molecules H2S, SO, and SiO compared to those anticipated in cold interstellar clouds.

  14. Floating shock fitting via Lagrangian adaptive meshes

    Science.gov (United States)

    Vanrosendale, John

    1995-01-01

    In recent work we have formulated a new approach to compressible flow simulation, combining the advantages of shock-fitting and shock-capturing. Using a cell-centered on Roe scheme discretization on unstructured meshes, we warp the mesh while marching to steady state, so that mesh edges align with shocks and other discontinuities. This new algorithm, the Shock-fitting Lagrangian Adaptive Method (SLAM), is, in effect, a reliable shock-capturing algorithm which yields shock-fitted accuracy at convergence.

  15. Oscillating nonlinear acoustic shock waves

    DEFF Research Database (Denmark)

    Gaididei, Yuri; Rasmussen, Anders Rønne; Christiansen, Peter Leth

    2016-01-01

    We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show...... that at resonance a stationary state arise consisting of multiple oscillating shock waves. Off resonance driving leads to a nearly linear oscillating ground state but superimposed by bursts of a fast oscillating shock wave. Based on a travelling wave ansatz for the fluid velocity potential with an added 2'nd order...... polynomial in the space and time variables, we find analytical approximations to the observed single shock waves in an infinitely long tube. Using perturbation theory for the driven acoustic system approximative analytical solutions for the off resonant case are determined....

  16. Sound wave generation by a spherically symmetric outburst and AGN feedback in galaxy clusters II: impact of thermal conduction.

    Science.gov (United States)

    Tang, Xiaping; Churazov, Eugene

    2018-04-01

    We analyze the impact of thermal conduction on the appearance of a shock-heated gas shell which is produced when a spherically symmetric outburst of a supermassive black hole inflates bubbles of relativistic plasma at the center of a galaxy cluster. The presence of the hot and low-density shell can be used as an ancillary indicator for a high rate of energy release during the outburst, which is required to drive strong shocks into the gas. Here we show that conduction can effectively erase such shell, unless the diffusion of electrons is heavily suppressed. We conclude that a more robust proxy to the energy release rate is the ratio between the shock radius and bubble radius. We also revisited the issue of sound waves dissipation induced by thermal conduction in a scenario, where characteristic wavelength of the sound wave is set by the total energy of the outburst. For a fiducial short outburst model, the dissipation length does not exceed the cooling radius in a typical cluster, provided that the conduction is suppressed by a factor not larger than ˜100. For quasi-continuous energy injection neither the shock-heated shell nor the outgoing sound wave are important and the role of conduction is subdominant.

  17. Viscoelastic shock wave in ballistic gelatin behind soft body armor.

    Science.gov (United States)

    Liu, Li; Fan, Yurun; Li, Wei

    2014-06-01

    Ballistic gelatins are widely used as a surrogate of biological tissue in blunt trauma tests. Non-penetration impact tests of handgun bullets on the 10wt% ballistic gelatin block behind soft armor were carried out in which a high-speed camera recorded the crater׳s movement and pressure sensors imbedded in the gelatin block recorded the pressure waves at different locations. The observed shock wave attenuation indicates the necessity of considering the gelatin׳s viscoelasticity. A three-element viscoelastic constitutive model was adopted, in which the relevant parameters were obtained via fitting the damping free oscillations at the beginning of the creep-mode of rheological measurement, and by examining the data of published split Hopkinson pressure bar (SHPB) experiments. The viscoelastic model is determined by a retardation time of 5.5×10(-5)s for high oscillation frequencies and a stress relaxation time of 2.0-4.5×10(-7)s for shock wave attenuation. Using the characteristic-line method and the spherical wave assumption, the propagation of impact pressure wave front and the subsequent unloading profile can be simulated using the experimental velocity boundary condition. The established viscoelastic model considerably improves the prediction of shock wave attenuation in the ballistic gelatin. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Sickness behavior in dairy cows during Escherichia coli mastitis

    DEFF Research Database (Denmark)

    Fogsgaard, Katrine Kop; Røntved, Christine Maria; Sørensen, Peter

    2012-01-01

    -recorded on 5 consecutive days, d −2 to +2 after challenge when the cows were not disturbed by humans. The behavior of the animals was compared among all days. Infection with E. coli altered the behavior of the dairy cows. Time spent feeding was lower in the initial 24 h after infection compared......The consequences of mastitis in terms of dairy cow behavior are relatively unknown. Future assessment of dairy cow welfare during mastitis will be facilitated by knowledge about the potential of mastitis to induce sickness behavior. Our aim was to examine behavior of dairy cows in the period from 2...... d before (d −2 and −1) to 3 d (d 0, 1, and 2) after experimental intramammary challenge with Escherichia coli. Effects of experimentally induced mastitis on behavior were examined in 20 primiparous Danish Holstein-Friesian cows, all 3 to 6 wk after calving and kept in tie stalls. After evening...

  19. Computation of higher spherical harmonics moments of the angular flux for neutron transport problems in spherical geometry

    International Nuclear Information System (INIS)

    Sahni, D.C.; Sharma, A.

    2000-01-01

    The integral form of one-speed, spherically symmetric neutron transport equation with isotropic scattering is considered. Two standard problems are solved using normal mode expansion technique. The expansion coefficients are obtained by solving their singular integral equations. It is shown that these expansion coefficients provide a representation of all spherical harmonics moments of the angular flux as a superposition of Bessel functions. It is seen that large errors occur in the computation of higher moments unless we take certain precautions. The reasons for this phenomenon are explained. They throw some light on the failure of spherical harmonics method in treating spherical geometry problems as observed by Aronsson

  20. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

    Understanding the causes and effects of explosions is important to experts in a broad range of disciplines, including the military, industrial and environmental research, aeronautic engineering, and applied mathematics. Offering an introductory review of historic research, Shock Waves and Explosions brings analytic and computational methods to a wide audience in a clear and thorough way. Beginning with an overview of the research on combustion and gas dynamics in the 1970s and 1980s, the author brings you up to date by covering modeling techniques and asymptotic and perturbative methods and ending with a chapter on computational methods.Most of the book deals with the mathematical analysis of explosions, but computational results are also included wherever they are available. Historical perspectives are provided on the advent of nonlinear science, as well as on the mathematical study of the blast wave phenomenon, both when visualized as a point explosion and when simulated as the expansion of a high-pressure ...

  1. Eliminative behaviour of dairy cows at pasture

    DEFF Research Database (Denmark)

    Whistance, Lindsay Kay; Sinclair, Liam A.; Arney, David Richard

    2011-01-01

    Despite a strong avoidance of grazing near dung patches, cattle have traditionally been considered not to avoid bodily contact with faeces, regardless of any risk of disease. Little is understood of the behaviour of pasture-kept dairy cows at the time of defaecation and therefore, the eliminative...... behaviour of 40 Holstein-Friesian cows was observed at pasture for6 heach day between morning and afternoon milking for a total of24 h. Lying (l), standing (s) and walking (w) behaviours were recorded pre, during and post-elimination. Sequences of 3–6 changes in these behaviours were recorded if expressed...... observed events (uppercase letters denote behaviour during defaecation). In all recorded events, 383 stood and 54 walked whilst defaecating (P

  2. Iodine-129 in man, cow and deer

    International Nuclear Information System (INIS)

    Ballad, R.V.; Tan, S.H.; Johnson, J.E.; Holman, D.W.; Hennecke, E.W.; Manuel, O.K.

    1978-01-01

    Concentrations of 129 I and values of the 129 I/ 127 I ratio have been measured in over forty individual thyroids of human, cow and deer from Missouri. Deer thyroids show an average value of 129 I/ 127 I = 1.8 x 10 -8 and 129 I concentrations of 3 x 10 -3 pCi per g of thyroid (wet weight). Thyroids of cow and human show successively lower values of the 129 I/ 127 I ratio and for the 129 I content due to dilution of 129 I from the natural geochemical cycle with mineral iodine in their diets. Analyses on a few thyroids from other areas are also reported. (author)

  3. Pasteurella multocida mastitis in cow - case report

    Directory of Open Access Journals (Sweden)

    Milanov Dubravka

    2017-01-01

    Full Text Available Pasteurella (P. multocida is a heterogeneous species of Gram-negative bacteria which are common commensals of the upper respiratory system of various mammal and bird species, but are also opportunistic contagious zoonotic pathogens which cause a wide spectre of infections in domestic animals and humans. P. multocida is a rare cause of mastitis in dairy cows. The source of infection mainly remains unknown, mastitis usually is acute, and the therapy by intramammary administration of antibiotics does not lead to satisfactory results. Lethality is possible due to presence of endotoxins in blood. Literature data on P. multocida mastitis in dairy cows is particularly scarce, which is why such a case is described in the current work, with past medical history, clinical findings, laboratory diagnostics and therapeutic approach. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 31071 and Grant no. III 46002

  4. Shock physics with the nova laser for ICF applications. Revision 1

    International Nuclear Information System (INIS)

    Hammel, B.A.; Cauble, R.; Celliers, P.

    1995-01-01

    The physics of high pressure shocks plays a central role in Inertial Confinement Fusion (ICF). In indirect drive ICF, x-rays from a gold cavity (hohlraum) are used to ablatively drive a series of high pressure shocks into a spherical target (capsule). These shocks converge at the center, compressing the fuel and forming a hot dense core. The target performance, such as peak fuel density and temperature and neutron yield, depends critically on hock timing, and material compressibility. Accurate predictions of NIF target performance depends critically on shock timing and material compressibility. Current measurement techniques enable us to accurately determine shock timing in planar samples of abator material as a function of laser drive. Although this technique does not separately address uncertainties in material EOS and opacity, it does allow us to tune the laser drive until the desired shock timing is achieved. Experiments to directly address the EOS of D 2 ice are planned to further increase the margin for ignition in current target designs

  5. Analytical solution of the problem of a shock wave in the collapsing gas in Lagrangian coordinates

    Science.gov (United States)

    Kuropatenko, V. F.; Shestakovskaya, E. S.

    2016-10-01

    It is proposed the exact solution of the problem of a convergent shock wave and gas dynamic compression in a spherical vessel with an impermeable wall in Lagrangian coordinates. At the initial time the speed of cold ideal gas is equal to zero, and a negative velocity is set on boundary of the sphere. When t > t0 the shock wave spreads from this point into the gas. The boundary of the sphere will move under the certain law correlated with the motion of the shock wave. The trajectories of the gas particles in Lagrangian coordinates are straight lines. The equations determining the structure of the gas flow between the shock front and gas border have been found as a function of time and Lagrangian coordinate. The dependence of the entropy on the velocity of the shock wave has been found too. For Lagrangian coordinates the problem is first solved. It is fundamentally different from previously known formulations of the problem of the self-convergence of the self-similar shock wave to the center of symmetry and its reflection from the center, which was built up for the infinite area in Euler coordinates.

  6. Optimal Replacement and Management Policies for Beef Cows

    OpenAIRE

    W. Marshall Frasier; George H. Pfeiffer

    1994-01-01

    Beef cow replacement studies have not reflected the interaction between herd management and the culling decision. We demonstrate techniques for modeling optimal beef cow replacement intervals and discrete management policies by incorporating the dynamic effects of management on future productivity when biological response is uncertain. Markovian decision analysis is used to identify optimal beef cow management on a ranch typical of the Sandhills region of Nebraska. Issues of breeding season l...

  7. Antibiogram profile of pathogens isolated from processed cow meat

    African Journals Online (AJOL)

    2016-06-30

    Jun 30, 2016 ... Cow meat or beef is the culinary name for meat from bovines especially cattle. The generic name of cow meat is Bos taurus and the habitable weather of Bos taurus includes temperature of 101.50F (38.60C) and ability to live in a harsh terrains (Li et al., 2006). The processing of cow meat begins from ...

  8. Pasteurella multocida mastitis in cow - case report

    OpenAIRE

    Milanov Dubravka; Aleksić Nevenka; Todorović Dalibor; Bugarski Dejan

    2017-01-01

    Pasteurella (P.) multocida is a heterogeneous species of Gram-negative bacteria which are common commensals of the upper respiratory system of various mammal and bird species, but are also opportunistic contagious zoonotic pathogens which cause a wide spectre of infections in domestic animals and humans. P. multocida is a rare cause of mastitis in dairy cows. The source of infection mainly remains unknown, mastitis usually is acute, and the therapy by intramammary administration of antibiotic...

  9. Pasteurella multocida mastitis in cow: Case report

    OpenAIRE

    Milanov, Dubravka; Aleksić, Nevenka; Todorović, Dalibor; Bugarski, Dejan

    2017-01-01

    Pasteurella (P.) multocida is a heterogeneous species of Gram-negative bacteria which are common commensals of the upper respiratory system of various mammal and bird species, but are also opportunistic contagious zoonotic pathogens which cause a wide spectre of infections in domestic animals and humans. P. multocida is a rare cause of mastitis in dairy cows. The source of infection mainly remains unknown, mastitis usually is acute, and the therapy by intramammary administration of antibiotic...

  10. Hypomagnesaemia in beef cows wintered in Ontario.

    OpenAIRE

    Hidiroglou, M; Thompson, B K; Ho, S K; Proulx, J G

    1981-01-01

    A field experiment was undertaken in northern Ontario in order to assess the magnesium status of beef cattle raised in the area. Magnesium status was assessed using several criteria including blood and urine magnesium levels, and bone biopsy samples. Eighteen groups each containing four pregnant Shorthorn beef cows were used. Each of the following three mineral feeds were offered to six groups throughout the experiment: a mineral feed without magnesium, a mineral feed containing 8% magnesium ...

  11. Nutrition and fertility in dairy cow

    OpenAIRE

    Rossi, Federico

    2012-01-01

    Nutrition has an important impact on the reproductive performance of dairy cattle. Energy is the major nutrient required by adult cattle and inadequate energy intake has a detrimental impact on reproductive activity of bovine. Cows under negative energy balance have extended periods of anovulation. Postpartum anestrus, as well as infertility, is magnified by losses of body condition during the early postpartum period. Resumption of ovulatory cycles is associated with energy balance, but s...

  12. Robotic milking of dairy cows: a Review

    Directory of Open Access Journals (Sweden)

    Renata Maculan

    2016-03-01

    Full Text Available An innovative technology that currently tries to gain market share are milking robots. Despite the high costs, robotic milking may produce benefits for the farmer and for animals submitted to this system. The objective of this study was to perform a literature review on the use of robotic milking of dairy cows, addressing aspects such as implementation and functioning of the system and effect on milking frequency, milk production and composition, somatic cell count, mastitis, reproduction, and animal welfare. The results showed that the programming of the robot depends on the number of animals to be milked daily and on the milking frequency adopted in each batch. The implementation of the system mainly depends on the site where the facilities will be built and already existing structures on the farm. The milking frequency is higher for high-producing cows and at the beginning of lactation and is influenced by the palatability of the concentrate offered at the time of milking. Frequencies higher than three times per day reduce total milk fat production and increase the concentration of free fatty acids. The incidence of mastitis and somatic cell count tend to increase in the first three months after implementation of the system. After the second year, udder health tends to improve, normalizing mastitis incidence and somatic cell count. Reproduction of the cows is not affected if dry matter intake compensates the higher energy expenditure required for higher milk productions. Robotic milking improves cow welfare since the animals voluntarily turn to the robot when they feel discomfort.

  13. Plasma progesterone levels in progesterone treated cows

    International Nuclear Information System (INIS)

    Grosskopf, J.F.W.; Van Niekerk, C.H.; Morgenthal, J.C.

    1979-01-01

    A technique for the radioimmunoassay of progesterone in plasma is described. In one trial the oestrous cycles of four cycling cows and in another trial of one non-cycling cow and two cycling heifers were synchronized by the administration of progesterone. Each female received either 50 mg or 0,1 mg/kg of progesterone intramuscularly on alternate days in two courses of four and six injections respectively. Blood samples of the animals were collected either daily or two-daily before, over the entire period of treatment and for eight days after the last progesterone injection. The results of the progesterone assays are represented graphically for each individual cow or heifer. The plasma progesterone levels during treatment were maintained reasonably well at levels corresponding to those normally encountered during the luteal phase of the cycle. The progesterone levels, however, did not drop as rapidly as desired after the last injection but might have been influenced by a residual corpus luteum from a previous ovulation

  14. Vermicomposting of Vegetable Wastes Using Cow Dung

    Directory of Open Access Journals (Sweden)

    K. Muthukumaravel

    2008-01-01

    Full Text Available Municipal solid wastes are mainly from domestic and commercial areas containing recyclable toxic substances, compostable organic matter and others. With rapid increase in population, the generation of municipal solid wastes has increased several folds during last few years. Disposal of solid wastes can be done by methods like land filling, incineration, recycling, conversion into biogas, disposal into sea and composting. Vermicomposting is one of the recycling technologies which will improve the quality of the products. The present study aims to find out the possibility of utilization of vegetable wastes for vermiculture. Earthworm Megascolex mauritii cultured in plastic trays (45 x 30 x 30 cm containing soil alone (control (T1, soil + cow dung (T2, soil + vegetable waste (T3 and soil + vegetable waste + cow dung (T4 for 60 days. Nutrient values were determined from the compost and compared with that of the control. From these results, it was found that NPK values were maximum in compost obtained from vegetable waste with the use of cow dung.

  15. Factors affecting the reproductive potential of dairy cows

    International Nuclear Information System (INIS)

    Folman, Y.; Rosenberg, M.; Kaim, M.

    1990-01-01

    Various factors that affect fertility were examined in high yielding dairy cows. In cows treated for the synchronization of oestrous cycles, manifestation of oestrus following synchronization treatment was affected by the body condition score in the winter; 74% of the cows had a low score. Primiparous cows that were thin or fat had a low conception rate. The conception rate of multiparous cows with different body condition scores did not differ in the winter. However, in the summer, thin, medium-low, medium-high and fat cows had a conception rate of 15, 36, 48 and 27%, respectively (P 4 ) levels five days before the first post-partum AI affected conception rates. Primiparous cows with low (≤2 ng/mL), medium (2.1-4.0 ng/mL) and high (≥4.1 ng/mL) P 4 levels had a conception rate of 28, 17 and 61%, respectively (P 4 had a conception rate of 25, 46 and 52%, respectively (P<0.02). Cows in their fifth or later lactation that were fed straw as their sole roughage had a conception rate of 23% and a 120 day pregnancy rate of 23%. Cows of the same parities that were fed hay had a conception rate of 50% (P<0.05) and a pregnancy rate of 80% (P<0.005). (author). 15 refs, 5 tabs

  16. The nasal mycoplasmal flora of healthy calves and cows.

    Science.gov (United States)

    ter Laak, E A; Noordergraaf, J H; Boomsluiter, E

    1992-10-01

    The nasal mycoplasmal flora of 270 healthy cows from 27 herds in the Netherlands and 35 healthy calves from 7 of these herds was examined. Various methods for isolating mycoplasmas were compared. The prevalence of the various species was as follows: Ureaplasma diversum in 3 (9%) calves; Mycoplasma dispar in 14 (40%) calves; M. bovis in 1 (3%) calf; M. bovirhinis in 23 (66%) calves and 16 (6%) cows; M. bovoculi in 8 (23%) calves and 53 (20%) cows; M. canis in 1 (3%) calf; M. equirhinis in 2 (1%) cows; M. conjunctivae in 2 (1%) cows; Acholeplasma laidlawii in 1 (3%) calf and 3 (1%) cows; and A. axanthum in 7 (3%) cows. The noses of healthy calves were less frequently colonized by the pathogenic species U. diversum and contained fewer U. diversum and M. dispar organisms than the noses of pneumonic calves. We concluded that the mycoplasmal flora of calves and healthy cows was quite different and also that cows play only a minor role in the epidemiology of pathogenic mycoplasma species of calves in the Netherlands.

  17. The use of the milk progesterone assay in cows

    International Nuclear Information System (INIS)

    Bamberg, E.; Choi, H.S.; Moestl, E.

    1981-01-01

    The progesterone concentration in milk-fat was determined in samples from 167 cows in 51 herds taken on day 0, 6 and 20 after artificial insemination. The rectal palpation verified pregnancy in 85% of the cows classified on their milk-progesterone concentration as ''probably pregnant''. According to the milk progesterone concentration it was possible already three weeks after artificial insemination to classify 25% of all examined cows as ''non pregnant''. Seven cows were inseminated at an inappropriate time as revealed by a high progesterone concentration in milk-fat on the day of insemination. The relevance of milk progesterone determinations as an aid for veterinary surgeons is briefly discussed. (author)

  18. A model to estimate insulin sensitivity in dairy cows

    Directory of Open Access Journals (Sweden)

    Holtenius Kjell

    2007-10-01

    Full Text Available Abstract Impairment of the insulin regulation of energy metabolism is considered to be an etiologic key component for metabolic disturbances. Methods for studies of insulin sensitivity thus are highly topical. There are clear indications that reduced insulin sensitivity contributes to the metabolic disturbances that occurs especially among obese lactating cows. Direct measurements of insulin sensitivity are laborious and not suitable for epidemiological studies. We have therefore adopted an indirect method originally developed for humans to estimate insulin sensitivity in dairy cows. The method, "Revised Quantitative Insulin Sensitivity Check Index" (RQUICKI is based on plasma concentrations of glucose, insulin and free fatty acids (FFA and it generates good and linear correlations with different estimates of insulin sensitivity in human populations. We hypothesized that the RQUICKI method could be used as an index of insulin function in lactating dairy cows. We calculated RQUICKI in 237 apparently healthy dairy cows from 20 commercial herds. All cows included were in their first 15 weeks of lactation. RQUICKI was not affected by the homeorhetic adaptations in energy metabolism that occurred during the first 15 weeks of lactation. In a cohort of 24 experimental cows fed in order to obtain different body condition at parturition RQUICKI was lower in early lactation in cows with a high body condition score suggesting disturbed insulin function in obese cows. The results indicate that RQUICKI might be used to identify lactating cows with disturbed insulin function.

  19. Oestrus Detection in Dairy Cows Using Likelihood Ratio Tests

    DEFF Research Database (Denmark)

    Jónsson, Ragnar Ingi; Björgvinssin, Trausti; Blanke, Mogens

    2008-01-01

    were identified for the ensemble and for the individual cows. A diurnal filter was adapted to remove the daily variation of the individual. Change detection algorithms were designed for the actual probability densities, which were Rayleigh distributed with individual parameters for each cow....... A generalized likelihood ratio algorithm was derived for the compensated activity signal and detection algorithm was tested on 2323 days of activity, which contained 42 oestruses on 12 cows in total. The application of statistical change detection methods is a new approach for detecting oestrus in dairy cows...... and the results are shown to outperform earlier approaches in respect to combined statistics of false alarms and missed detections...

  20. Pediatric cardiogenic shock: Current perspectives

    Directory of Open Access Journals (Sweden)

    Subhranshu Sekhar Kar

    2015-01-01

    Full Text Available Cardiogenic shock is a pathophysiologic state where an abnormality of cardiac function is responsible for the failure of the cardiovascular system to meet the metabolic needs of the body tissues.Though it is less common than hypovolemia as the primary etiology in paediatric shock, eventually myocardial function is affected because of reduced perfusion in all forms of shock. Myocardial malfunction, in other forms of shock, is secondary to ischemia, acidosis, drugs, toxins or inflammation. Cardiogenic shock is a low output state characterized by elevated filling pressures, neurohormonal activation with the evidence of end-organ hypoperfusion. The management is challenging and consists of a combination of conventional cardio-respiratory support, vasoactive medications with correction of the anatomic cardiac defects. Treatment options like Extracorporeal membrane oxygenation and Ventricular assist devices provide a bridge to recovery, surgery or transplant. As cardiogenic shock in children carries a high risk of morbidity and mortality, emphasis should be placed on expedient management to arrest the pathophysiological cascade and avoid hypotension.This article aims to review the aetio-pathophysiological basis of pediatric cardiogenic shock, diagnostic options, recent advances in management modalities and outcome.

  1. Micas in experimentally shocked gneiss

    Science.gov (United States)

    Lambert, P.; Mackinnon, I. D. R.

    1984-01-01

    Powder-propellant guns are used to shock biotites and muscovites from a gneiss at pressures between 18 and 70 GPa. It is shown that shock in biotite and muscovite can produce homogeneous and devolatilized glasses within microseconds. Shock-deformed micas are found to exhibit fracturing, kinking, and complex extinction patterns over the entire pressure range investigated. Localized melting of micas commences at 33 GPa and reaches completion at 70 GPa. Even though melted biotite and muscovite are opaque optically, they exhibit extensive microvesiculation and flow when observed with the SEM. It is confirmed through electron diffraction that biotite and muscovite have transformed to a glass. The distribution of vesicles in shock-vitrified mica reveals escape of volatiles within the short duration of the shock experiment. It is noted that experimentally shocked biotite and muscovite undergo congruent melting. It is noted that the compositions of the glasses are similar to the unshocked micas except for volatiles (H2O loss and and K loss). These unusual glasses produced from mica can be quenched by rapid cooling conditions during the shock experiment. On the basis of the results, it is pointed out that the extremely low H2O content of tektites can be reconciled with a terrestrial origin by impact.

  2. Rapid Prototyping of Electrically Small Spherical Wire Antennas

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.

    2014-01-01

    It is shown how modern rapid prototyping technologies can be applied for quick and inexpensive, but still accurate, fabrication of electrically small wire antennas. A well known folded spherical helix antenna and a novel spherical zigzag antenna have been fabricated and tested, exhibiting...

  3. Stability of transparent spherically symmetric thin shells and wormholes

    International Nuclear Information System (INIS)

    Ishak, Mustapha; Lake, Kayll

    2002-01-01

    The stability of transparent spherically symmetric thin shells (and wormholes) to linearized spherically symmetric perturbations about static equilibrium is examined. This work generalizes and systematizes previous studies and explores the consequences of including the cosmological constant. The approach shows how the existence (or not) of a domain wall dominates the landscape of possible equilibrium configurations

  4. Improved endpoint bounds for the lacunary spherical maximal operator

    OpenAIRE

    Cladek, Laura; Krause, Ben

    2017-01-01

    We prove new endpoint bounds for the lacunary spherical maximal operator and as a consequence obtain almost everywhere pointwise convergence of lacunary spherical means for functions locally in $L\\log\\log\\log L(\\log\\log\\log\\log L)^{1+\\epsilon}$ for any $\\epsilon>0$.

  5. Cylindrical and spherical dust-acoustic wave modulations in dusty ...

    Indian Academy of Sciences (India)

    The nonlinear wave modulation of planar and non-planar (cylindrical and spherical) dust-acoustic waves (DAW) propagating in dusty plasmas, in the presence of non-extensive distributions for ions and electrons is investigated. By employing multiple scales technique, a cylindrically and spherically modified nonlinear ...

  6. A proposal for a spherical option in WIMS

    International Nuclear Information System (INIS)

    Roth, M.J.

    1982-05-01

    A description is presented of how a spherical option may be put into WIMS-E. There is no proposal to make any change to WIMSD4, but some recommendations are made as to how spherical geometry may be simulated in WIMSD4 or indeed in WIMS-E prior to these proposed changes. (U.K.)

  7. Characterizing Student Mathematics Teachers' Levels of Understanding in Spherical Geometry

    Science.gov (United States)

    Guven, Bulent; Baki, Adnan

    2010-01-01

    This article presents an exploratory study aimed at the identification of students' levels of understanding in spherical geometry as van Hiele did for Euclidean geometry. To do this, we developed and implemented a spherical geometry course for student mathematics teachers. Six structured, "task-based interviews" were held with eight student…

  8. Characterization of diffusivity based on spherical array processing

    DEFF Research Database (Denmark)

    Nolan, Melanie; Fernandez Grande, Efren; Jeong, Cheol-Ho

    2015-01-01

    The purpose of this study is to assess the diffuse field conditions in a reverberant space using a sound field reconstruction method based on spherical microphone array measurements. Spherical microphone arrays are particularly well suited for applications in non-anechoic enclosures, where the so...

  9. Cylindrical and spherical dust-acoustic wave modulations in dusty ...

    Indian Academy of Sciences (India)

    Abstract. The nonlinear wave modulation of planar and non-planar (cylindrical and spherical) dust-acoustic waves (DAW) propagating in dusty plasmas, in the presence of non-extensive distribu- tions for ions and electrons is investigated. By employing multiple scales technique, a cylindrically and spherically modified ...

  10. Demonstrating close-packing of atoms using spherical bubble gums ...

    African Journals Online (AJOL)

    In this paper, the use of spherical bubble gums (Gum Balls) to demonstrate the close-packing of atoms and ions is presented. Spherical bubble gums having distinctive colours were used to illustrate the different layers in variety of crystalline packing and the formation of tetrahedral and octahedral holes. Students with ...

  11. Initial value formulation for the spherically symmetric dust solution

    International Nuclear Information System (INIS)

    Liu, H.

    1990-01-01

    An initial value formulation for the dust solution with spherical symmetry is given explicitly in which the initial distributions of dust and its velocity on an initial surface are chosen to be the initial data. As special cases, the Friedmann universe, the Schwarzschild solution in comoving coordinates, and a spherically symmetric and radially inhomogeneous cosmological model are derived

  12. Effect of the spherical Earth on a simple pendulum

    OpenAIRE

    Burko, Lior M.

    2003-01-01

    We consider the period of a simple pendulum in the gravitational field of the spherical Earth. Effectively, gravity is enhanced compared with the often used flat Earth approximation, such that the period of the pendulum is shortened. We discuss the flat Earth approximation, and show when the corrections due to the spherical Earth may be of interest.

  13. demonstrating close-packing of atoms using spherical bubble gums

    African Journals Online (AJOL)

    Admin

    ABSTRACT: In this paper, the use of spherical bubble gums (Gum Balls) to demonstrate the close-packing of atoms and ions is presented. Spherical bubble gums having distinctive colours were used to illustrate the different layers in variety of crystalline packing and the formation of tetrahedral and octahedral holes.

  14. Theory and applications of spherical microphone array processing

    CERN Document Server

    Jarrett, Daniel P; Naylor, Patrick A

    2017-01-01

    This book presents the signal processing algorithms that have been developed to process the signals acquired by a spherical microphone array. Spherical microphone arrays can be used to capture the sound field in three dimensions and have received significant interest from researchers and audio engineers. Algorithms for spherical array processing are different to corresponding algorithms already known in the literature of linear and planar arrays because the spherical geometry can be exploited to great beneficial effect. The authors aim to advance the field of spherical array processing by helping those new to the field to study it efficiently and from a single source, as well as by offering a way for more experienced researchers and engineers to consolidate their understanding, adding either or both of breadth and depth. The level of the presentation corresponds to graduate studies at MSc and PhD level. This book begins with a presentation of some of the essential mathematical and physical theory relevant to ...

  15. Creep stresses in a spherical shell under steady state temperature

    Science.gov (United States)

    Verma, Gaurav; Rana, Puneet

    2017-10-01

    The paper investigates the problem of creep of a spherical structure under the influence of steady state temperature. The problem of creep in spherical shell is solved by using the concept of generalized strain measures and transition hypothesis given by Seth. The problem has reduced to non-linear differential equation for creep transition. This paper deals with the non-linear behaviour of spherical shell under thermal condition. The spherical shell structures are easily vulnerable to creep, shrinkage and thermal effects; a thorough understanding of their time-dependent behaviour has been fully established. The paper aims to provide thermal creep analysis to enhance the effective design and long life of shells, and a theoretical model is developed for calculating creep stresses and strains in a spherical shell with purpose. Results obtained for the problem are depicted graphically.

  16. INTERFERENCE OF COUNTERPROPAGATING SHOCK WAVES

    Directory of Open Access Journals (Sweden)

    P. V. Bulat

    2015-03-01

    Full Text Available The subject of study. We examined the interaction of counterpropagating shock waves. The necessity of counterpropagating shock waves studying occurs at designing of high Mach number modern internal compression air intakes, Ramjets with subsonic and supersonic combustion, in asymmetrical supersonic nozzles and in some other cases. In a sense, this problem is a generalization of the case of an oblique shock reflection from the wall or from the plane of symmetry. With the renewed vigor, the interest to this problem emerged at the end of the 90s. This was due to the start of the programs for flight study at hypersonic speeds. The first experiments performed with air intakes, which realized the interaction of counterpropagating shock waves have shown that the change in flow velocity is accompanied by abrupt alteration of shock-wave structure, the occurrence of nonstationary and oscillatory phenomena. With an increase of flow velocity these phenomena undesirable for aircraft structure became more marked. The reason is that there are two fundamentally different modes of interaction of counterpropagating shock waves: a four-wave regular and a five-wave irregular. The transition from one mode to another can be nonstationary abrupt or gradual, it can also be accompanied by hysteresis. Main results. Criteria for the transition from regular reflection of counterpropagating shock waves to irregular are described: the criterion of von Neumann and the stationary Mach configuration criterion. We described areas in which the transition from one reflection type to another is possible only in abrupt way, as well as areas of possible gradual transition. Intensity dependences of the reflected shock waves from the intensity of interacting counterpropagating shocks were given. Qualitative pictures of shock-wave structures arising from the interaction of counterpropagating shock waves were shown. Calculation results of the intensity of outgoing gas

  17. A collisionless shock wave experiment

    International Nuclear Information System (INIS)

    Winske, D.; Jones, M.E.; Sgro, A.G.; Thomas, V.A.

    1995-01-01

    Collisionless shock waves are a very important heating mechanism for plasmas and are commonly found in space and astrophysical environments. Collisionless shocks were studied in the laboratory more than 20 years ago, and more recently in space via in situ satellite measurements. The authors propose a new laboratory shock wave experiment to address unresolved issues related to the differences in the partition of plasma heating between electrons and ions in space and laboratory plasmas, which can have important implications for a number of physical systems

  18. Shocks in the Early Universe.

    Science.gov (United States)

    Pen, Ue-Li; Turok, Neil

    2016-09-23

    We point out a surprising consequence of the usually assumed initial conditions for cosmological perturbations. Namely, a spectrum of Gaussian, linear, adiabatic, scalar, growing mode perturbations not only creates acoustic oscillations of the kind observed on very large scales today, it also leads to the production of shocks in the radiation fluid of the very early Universe. Shocks cause departures from local thermal equilibrium as well as create vorticity and gravitational waves. For a scale-invariant spectrum and standard model physics, shocks form for temperatures 1  GeVUniverse as early as 10^{-30}  sec after the big bang.

  19. Simulation of mechanical shock environments

    International Nuclear Information System (INIS)

    Lalanne, Christian.

    1975-07-01

    Shocks can produce a severe mechanical environment which must be taken into account when designing and developing new equipments. After some mathematical (Laplace and Fourier transforms) and mechanical recalls (response of a one degree freedom system to a sinusoidal excitation), different analysis methods are compared, these methods being the most used now to compare relative severities of tests and establish specifications. A few chapter deal with the different properties of simple, easy to produce, shock shapes. Then some now-in-use programmators or shock-machines specifications are shown. A final chapter concerns acceleration transducers [fr

  20. Plasma viscosity with mass transport in spherical inertial confinement fusion implosion simulations

    Energy Technology Data Exchange (ETDEWEB)

    Vold, E. L.; Molvig, K. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Joglekar, A. S. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Ortega, M. I. [University of New Mexico, Albuquerque, New Mexico 87131 (United States); Moll, R. [University of California, Santa Cruz, California 95064 (United States); Fenn, D. [Florida State University, Tallahassee, Florida 32306 (United States)

    2015-11-15

    The effects of viscosity and small-scale atomic-level mixing on plasmas in inertial confinement fusion (ICF) currently represent challenges in ICF research. Many current ICF hydrodynamic codes ignore the effects of viscosity though recent research indicates viscosity and mixing by classical transport processes may have a substantial impact on implosion dynamics. We have implemented a Lagrangian hydrodynamic code in one-dimensional spherical geometry with plasma viscosity and mass transport and including a three temperature model for ions, electrons, and radiation treated in a gray radiation diffusion approximation. The code is used to study ICF implosion differences with and without plasma viscosity and to determine the impacts of viscosity on temperature histories and neutron yield. It was found that plasma viscosity has substantial impacts on ICF shock dynamics characterized by shock burn timing, maximum burn temperatures, convergence ratio, and time history of neutron production rates. Plasma viscosity reduces the need for artificial viscosity to maintain numerical stability in the Lagrangian formulation and also modifies the flux-limiting needed for electron thermal conduction.

  1. Excitation of Alfvenic instabilities in spherical tokamaks

    International Nuclear Information System (INIS)

    McClements, K.G.; Appel, L.C.; Hole, M.J.; Thyagaraja, A.

    2003-01-01

    Understanding energetic particle confinement in spherical tokamak (STs) is important for optimising the design of ST power plants, and provides a testbed for theoretical modelling under conditions of strong toroidicity and shaping, and high beta. MHD analysis of some recent beam-heated discharges in the MAST ST indicates that high frequency modes observed in these discharges can be identified as toroidal Alfven Eigenmodes (TAEs) and elliptical Alfven Eigenmodes (EAEs). It is possible that such modes could strongly enhance fusion alpha-particle transport in an ST power plant. Computations of TAE growth rates for one particular MAST discharge, made using the HAGIS guiding centre code and benchmarked against analytical estimates, indicate strong drive by sub-Alfvenic neutral beam ions. HAGIS computations using higher mode amplitudes than those observed indicate that whereas co-passing beam ions provide the bulk of he TAE drive, counter-passing ions provide the dominant component of TAE-induced particle losses. Axisymmetric Alfvenic mode activity has been detected during ohmic discharges in MAST. These observations are shown by computational modelling to be consistent with the excitation of global Alfven Eigenmodes (GAEs) with n=0 and low m, driven impulsively by low frequency MHD. (author)

  2. Effects of coating spherical iron oxide nanoparticles.

    Science.gov (United States)

    Milosevic, Irena; Motte, Laurence; Aoun, Bachir; Li, Tao; Ren, Yang; Sun, Chengjun; Saboungi, Marie-Louise

    2017-01-01

    We investigate the effect of several coatings applied in biomedical applications to iron oxide nanoparticles on the size, structure and composition of the particles. The four structural techniques employed - TEM, DLS, VSM, SAXS and EXAFS - show no significant effects of the coatings on the spherical shape of the bare nanoparticles, the average sizes or the local order around the Fe atoms. The NPs coated with hydroxylmethylene bisphosphonate or catechol have a lower proportion of magnetite than the bare and citrated ones, raising the question whether the former are responsible for increasing the valence state of the oxide on the NP surfaces and lowering the overall proportion of magnetite in the particles. VSM measurements show that these two coatings lead to a slightly higher saturation magnetization than the citrate. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Transitions between compound states of spherical nuclei

    International Nuclear Information System (INIS)

    Kadmenskii, S.G.; Markushev, V.P.; Furman, V.I.

    1980-01-01

    Wigner's statistical matrices are used to study the average reduced g widths and their dispersion for g transitions from a compound state c to another state f, with a lower excitation energy but of arbitrary complexity, for spherical nuclei. It is found that the Porter--Thomas distribution holds for the g widths for all cases of practical interest. In g transitions between compound states c and c' with E/sub g/< or =2 MeV, the most important transitions are M1 transitions involving the major many-quasiparticle components of state c and E1 transitions involving the minor components of state c. It is shown that the strength functions predicted by the various theories for M1 and E1 transitions between compound states with E/sub g/< or =2 MeV are similar. Preference is assigned to the M1-transition version because of experimental results on (n,ga) reactions with thermal and resonance neutrons

  4. Dynamical evolution of spherical stellar systems

    International Nuclear Information System (INIS)

    Lee, H.M.

    1986-01-01

    The dynamical effect of heavy mass stars formed out of successive mergers among tidally captured binaries of evolution of spherical stellar systems is investigated. To maximize such effect assumed all tidally captured systems become mergers. Stellar evolution is simulated by computing mean age of mass group and applying death rate as function of mean age. For stellar systems with N = 10 5-6 , combined effect of three body binary heating among heavy mass stars and stellar evolution provides energy to drive post collapse expansion; long-term evolution is dominated by stellar evolution. Long-term behavior of clusters is similar to tidally captured binaries assuming no merger. Observed chemical inhomogeneities among stars in globular clusters may also be explained by stellar mergers. Three-body heating is important in small-N systems, while stellar evolution dominates evolution of large N systems. The effect of primordial degenerate stars is investigated in the second study. Very hard binaries composed of degenerate-normal pair form via tidal capture process and moderately hard degenerate-degenerate binaries form via three-body process. If initial degenerate population is large, initial core-collapse phase may be approximated as collapse of degenerate star. Three-body binaries among degenerate stars eventually provide enough energy to stop collapse and cause reexpansion

  5. Drop impact on spherical soft surfaces

    Science.gov (United States)

    Chen, Simeng; Bertola, Volfango

    2017-08-01

    The impact of water drops on spherical soft surfaces is investigated experimentally through high-speed imaging. The effect of a convex compliant surface on the dynamics of impacting drops is relevant to various applications, such as 3D ink-jet printing, where drops of fresh material impact on partially cured soft substrates with arbitrary shape. Several quantities which characterize the morphology of impacting drops are measured through image-processing, including the maximum and minimum spreading angles, length of the wetted curve, and dynamic contact angle. In particular, the dynamic contact angle is measured using a novel digital image-processing scheme based on a goniometric mask, which does not require edge fitting. It is shown that the surface with a higher curvature enhances the retraction of the spreading drop; this effect may be due to the difference of energy dissipation induced by the curvature of the surface. In addition, the impact parameters (elastic modulus, diameter ratio, and Weber number) are observed to significantly affect the dynamic contact angle during impact. A quantitative estimation of the deformation energy shows that it is significantly smaller than viscous dissipation.

  6. A spherical cavity model for quadrupolar dielectrics

    Science.gov (United States)

    Dimitrova, Iglika M.; Slavchov, Radomir I.; Ivanov, Tzanko; Mosbach, Sebastian

    2016-03-01

    The dielectric properties of a fluid composed of molecules possessing both dipole and quadrupole moments are studied based on a model of the Onsager type (molecule in the centre of a spherical cavity). The dielectric permittivity ɛ and the macroscopic quadrupole polarizability αQ of the fluid are related to the basic molecular characteristics (molecular dipole, polarizability, quadrupole, quadrupolarizability). The effect of αQ is to increase the reaction field, to bring forth reaction field gradient, to decrease the cavity field, and to bring forth cavity field gradient. The effects from the quadrupole terms are significant in the case of small cavity size in a non-polar liquid. The quadrupoles in the medium are shown to have a small but measurable effect on the dielectric permittivity of several liquids (Ar, Kr, Xe, CH4, N2, CO2, CS2, C6H6, H2O, CH3OH). The theory is used to calculate the macroscopic quadrupolarizabilities of these fluids as functions of pressure and temperature. The cavity radii are also determined for these liquids, and it is shown that they are functions of density only. This extension of Onsager's theory will be important for non-polar solutions (fuel, crude oil, liquid CO2), especially at increased pressures.

  7. Spherical images and inextensible curved folding

    Science.gov (United States)

    Seffen, Keith A.

    2018-02-01

    In their study, Duncan and Duncan [Proc. R. Soc. London A 383, 191 (1982), 10.1098/rspa.1982.0126] calculate the shape of an inextensible surface folded in two about a general curve. They find the analytical relationships between pairs of generators linked across the fold curve, the shape of the original path, and the fold angle variation along it. They present two special cases of generator layouts for which the fold angle is uniform or the folded curve remains planar, for simplifying practical folding in sheet-metal processes. We verify their special cases by a graphical treatment according to a method of Gauss. We replace the fold curve by a piecewise linear path, which connects vertices of intersecting pairs of hinge lines. Inspired by the d-cone analysis by Farmer and Calladine [Int. J. Mech. Sci. 47, 509 (2005), 10.1016/j.ijmecsci.2005.02.013], we construct the spherical images for developable folding of successive vertices: the operating conditions of the special cases in Duncan and Duncan are then revealed straightforwardly by the geometric relationships between the images. Our approach may be used to synthesize folding patterns for novel deployable and shape-changing surfaces without need of complex calculation.

  8. The spheric tokamak programme at Culham

    International Nuclear Information System (INIS)

    Sykes, A.

    1999-01-01

    The Spherical Tokamak (ST) is the low aspect ratio limit of the conventional tokamak, and appears to offer attractive physics properties in a simpler device. The START (Small Tight Aspect Ratio Tokamak) experiment provided the world's first demonstration of the properties of hot plasmas in an ST configuration, and was operational at Culham from January 1991 to March 1998, obtaining plasma current of up to 300 kA and pulse durations of ∼ 50 ms. Its successor, MAST is scheduled to obtain first plasma in Autumn 1998 and is a purpose built, high vacuum machine designed to have a tenfold increase in plasma volume with plasma currents up to 2 MA. Current drive and heating will be by a combination of induction-compression as on START, a high-performance central solenoid, 1.5 MW ECRH and 5 MW of Neutral Beam Injection. The promising results from START are reviewed, and the many challenges posed for the next generation of purpose-built STs (such as MAST) are described. (author)

  9. Synchrotron radiation from spherically accreting black holes

    International Nuclear Information System (INIS)

    Ipser, J.R.; Price, R.H.

    1982-01-01

    Spherical accretion onto a Schwartzchild black hole, of gas with frozen-in magnetic field, is studied numerically and analytically for a range of hole masses and accretion rates in which synchrotron emission is the dominant radiative mechanism. At small radii the equipartition of magnetic, kinetic, and gravitational energy is assumed to apply, and the gas is heated by dissipation of infalling magnetic energy, turbulent energy, etc. The models can be classified into three types: (a) synchrotron cooling negligible, (b) synchrotron cooling important but synchrotron self-absorption negligible, (c) synchrotron cooling and self-absorption important. In the first case gas temperatures become very high near the horizon but luminosity efficiencies (luminosity/mass-energy accretion rate) are low. In cases (b) and (c) the gas flow near the horizon is essentially isothermal and luminosity efficiencies are fairly high. The analysis and results for the isothermal cases (b) and (c) are valid only for moderate dissipative heating and synchrotron self-absorption. If self-absorption is very strong or if dissipated energy is comparable to infall energy, Comptonization effects, not included in the analysis, become important

  10. Plasmonic and silicon spherical nanoparticle antireflective coatings.

    Science.gov (United States)

    Baryshnikova, K V; Petrov, M I; Babicheva, V E; Belov, P A

    2016-03-01

    Over the last decade, plasmonic antireflecting nanostructures have been extensively studied to be utilized in various optical and optoelectronic systems such as lenses, solar cells, photodetectors, and others. The growing interest to all-dielectric photonics as an alternative optical technology along with plasmonics motivates us to compare antireflective properties of plasmonic and all-dielectric nanoparticle coatings based on silver and crystalline silicon respectively. Our simulation results for spherical nanoparticles array on top of amorphous silicon show that both silicon and silver coatings demonstrate strong antireflective properties in the visible spectral range. For the first time, we show that zero reflectance from the structure with silicon coatings originates from the destructive interference of electric- and magnetic-dipole responses of nanoparticle array with the wave reflected from the substrate, and we refer to this reflection suppression as substrate-mediated Kerker effect. We theoretically compare the silicon and silver coating effectiveness for the thin-film photovoltaic applications. Silver nanoparticles can be more efficient, enabling up to 30% increase of the overall absorbance in semiconductor layer. Nevertheless, silicon coatings allow up to 64% absorbance increase in the narrow band spectral range because of the substrate-mediated Kerker effect, and band position can be effectively tuned by varying the nanoparticles sizes.

  11. Spherical Process Models for Global Spatial Statistics

    KAUST Repository

    Jeong, Jaehong

    2017-11-28

    Statistical models used in geophysical, environmental, and climate science applications must reflect the curvature of the spatial domain in global data. Over the past few decades, statisticians have developed covariance models that capture the spatial and temporal behavior of these global data sets. Though the geodesic distance is the most natural metric for measuring distance on the surface of a sphere, mathematical limitations have compelled statisticians to use the chordal distance to compute the covariance matrix in many applications instead, which may cause physically unrealistic distortions. Therefore, covariance functions directly defined on a sphere using the geodesic distance are needed. We discuss the issues that arise when dealing with spherical data sets on a global scale and provide references to recent literature. We review the current approaches to building process models on spheres, including the differential operator, the stochastic partial differential equation, the kernel convolution, and the deformation approaches. We illustrate realizations obtained from Gaussian processes with different covariance structures and the use of isotropic and nonstationary covariance models through deformations and geographical indicators for global surface temperature data. To assess the suitability of each method, we compare their log-likelihood values and prediction scores, and we end with a discussion of related research problems.

  12. Shock parameter calculations at weak interplanetary shock waves

    Directory of Open Access Journals (Sweden)

    J. M. Gloag

    2005-02-01

    Full Text Available A large set of interplanetary shock waves observed using the Ulysses spacecraft is analysed in order to determine their local parameters. For the first time a detailed analysis is extended to the thermodynamic properties of a large number of events. The intention is to relate the shock parameters to the requirements set by MHD shock theory. A uniform approach is adopted in the selection of up and downstream regions for this analysis and applied to all the shock waves. Initially, the general case of a 3 component adiabatic plasma is considered. However, the calculation of magnetosonic and Alfvénic Mach numbers and the ratio of downstream to upstream entropy produce some unexpected results. In some cases there is no clear increase in entropy across the shock and also the magnetosonic Mach number can be less than 1. It is found that a more discerning use of data along with an empirical value for the polytropic index can raise the distribution of downstream to upstream entropy ratios to a more acceptable level. However, it is also realised that many of these shocks are at the very weakest end of the spectrum and associated phenomena may also contribute to the explanation of these results.

  13. Quasilinear simulations of interplanetary shocks and Earth's bow shock

    Science.gov (United States)

    Afanasiev, Alexandr; Battarbee, Markus; Ganse, Urs; Vainio, Rami; Palmroth, Minna; Pfau-Kempf, Yann; Hoilijoki, Sanni; von Alfthan, Sebastian

    2016-04-01

    We have developed a new self-consistent Monte Carlo simulation model for particle acceleration in shocks. The model includes a prescribed large-scale magnetic field and plasma density, temperature and velocity profiles and a self-consistently computed incompressible ULF foreshock under the quasilinear approximation. Unlike previous analytical treatments, our model is time dependent and takes full account of the anisotropic particle distributions and scattering in the wave-particle interaction process. We apply the model to the problem of particle acceleration at traveling interplanetary (IP) shocks and Earth's bow shock and compare the results with hybrid-Vlasov simulations and spacecraft observations. A qualitative agreement in terms of spectral shape of the magnetic fluctuations and the polarization of the unstable mode is found between the models and the observations. We will quantify the differences of the models and explore the region of validity of the quasilinear approach in terms of shock parameters. We will also compare the modeled IP shocks and the bow shock, identifying the similarities and differences in the spectrum of accelerated particles and waves in these scenarios. The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA). The Academy of Finland is thanked for financial support. We acknowledge the computational resources provided by CSC - IT Centre for Science Ltd., Espoo.

  14. Shock wave dynamics derivatives and related topics

    CERN Document Server

    Emanuel, George

    2012-01-01

    "...this monograph develops an esoteric niche within shock wave theory. …treats shock waves from an analytical approach assuming perfect gas. Emanuel has made significant contributions to the theory of shock waves and has selected a number of topics that reflect those contributions."-Shock Waves, 2013.

  15. Sound wave generation by a spherically symmetric outburst and AGN feedback in galaxy clusters

    Science.gov (United States)

    Tang, Xiaping; Churazov, Eugene

    2017-07-01

    We consider the evolution of an outburst in a uniform medium under spherical symmetry, having in mind active galactic nucleus feedback in the intracluster medium. For a given density and pressure of the medium, the spatial structure and energy partition at a given time tage (since the onset of the outburst) are fully determined by the total injected energy Einj and the duration tb of the outburst. We are particularly interested in the late phase evolution when the strong shock transforms into a sound wave. We studied the energy partition during such transition with different combinations of Einj and tb. For an instantaneous outburst with tb → 0, which corresponds to the extension of classic Sedov-Taylor solution with counter-pressure, the fraction of energy that can be carried away by sound waves is ≲12 per cent of Einj. As tb increases, the solution approaches the 'slow piston' limit, with the fraction of energy in sound waves approaching zero. We then repeat the simulations using radial density and temperature profiles measured in Perseus and M87/Virgo clusters. We find that the results with a uniform medium broadly reproduce an outburst in more realistic conditions once proper scaling is applied. We also develop techniques to map intrinsic properties of an outburst (Einj, tb and tage) to the observables like the Mach number of the shock and radii of the shock and ejecta. For the Perseus cluster and M87, the estimated (Einj, tb and tage) agree with numerical simulations tailored for these objects with 20-30 per cent accuracy.

  16. Shock Thermodynamic Applied Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Shock Thermodynamic Applied Research Facility (STAR) facility, within Sandia’s Solid Dynamic Physics Department, is one of a few institutions in the world with a...

  17. Second sound shock waves in rotating superfluid helium

    International Nuclear Information System (INIS)

    Torczynski, J.R.

    1983-01-01

    Second sound shock waves have been used to examine the breakdown of superfluidity in bulk He II. The maximum counterflow velocity achieved in this manner was measured at a variety of temperatures and pressures. The results are found to agree with predictions of vortex nucleation theories (Langer and Fisher, 1967) in their pressure and temperature dependences although it was shown that dissipation occurred only near the heater. A simple scaling argument is suggested, assuming breakdown occurs near the heater. A vortex dynamics model of breakdown (following the method of Turner, private communication) is developed. To examine the effect of vorticity on breakdown, second sound shocks were produced in rotating helium. Experiments were performed in which the shocks propagated either along or normal to the axis of rotation, called axial and transverse cases, respectively. In both cases the decay was seen to increase monotonically with the rotation rate. Furthermore, the decay was ongoing rather than being confined to a narrow region near the heater. However, the extraordinary dissipation in the transverse case seemed to be related primarily to the arrival of secondary waves from the heater-sidewall boundary. An explanation of this difference is put forth in terms of vortex nucleation in the bulk fluid, using ideas similar to Crocco's Theorem. In order to examine the breakdown of superfluidity away from walls in nonrotation fluid, spherically converging second shocks were produced. The temperature jumps of the waves were measured, and exact numerical solutions of the two-fluid jump conditions (Moody, 1983) were used to calculate the relative velocity in each case

  18. Shock wave velocity and shock pressure for low density powders : A novel approach

    NARCIS (Netherlands)

    Dijken, D.K.; Hosson, J.Th.M. De

    1994-01-01

    A novel approach is presented to predict the shock wave velocity as well as the shock wave pressure in powder materials. It is shown that the influence of the specific volume behind the shock wave on shock wave velocity and shock pressure decreases with decreasing initial powder density. The new

  19. SHOCK-WAVE VELOCITY AND SHOCK PRESSURE FOR LOW-DENSITY POWDERS - A NOVEL-APPROACH

    NARCIS (Netherlands)

    DIJKEN, DK; DEHOSSON, JTM

    1994-01-01

    A novel approach is presented to predict the shock wave velocity as well as the shock wave pressure in powder materials. It is shown that the influence of the specific volume behind the shock wave on shock wave velocity and shock pressure decreases with decreasing initial powder density. The new

  20. Sepsis and septic shock

    Science.gov (United States)

    Hotchkiss, Richard S.; Moldawer, Lyle L.; Opal, Steven M.; Reinhart, Konrad; Turnbull, Isaiah R.; Vincent, Jean-Louis

    2017-01-01

    For more than two decades, sepsis was defined as a microbial infection that produces fever (or hypothermia), tachycardia, tachypnoea and blood leukocyte changes. Sepsis is now increasingly being considered a dysregulated systemic inflammatory and immune response to microbial invasion that produces organ injury for which mortality rates are declining to 15–25%. Septic shock remains defined as sepsis with hyperlactataemia and concurrent hypotension requiring vasopressor therapy, with in-hospital mortality rates approaching 30–50%. With earlier recognition and more compliance to best practices, sepsis has become less of an immediate life-threatening disorder and more of a long-term chronic critical illness, often associated with prolonged inflammation, immune suppression, organ injury and lean tissue wasting. Furthermore, patients who survive sepsis have continuing risk of mortality after discharge, as well as long-term cognitive and functional deficits. Earlier recognition and improved implementation of best practices have reduced in-hospital mortality, but results from the use of immunomodulatory agents to date have been disappointing. Similarly, no biomarker can definitely diagnose sepsis or predict its clinical outcome. Because of its complexity, improvements in sepsis outcomes are likely to continue to be slow and incremental. PMID:28117397

  1. Theoretical Insight into Shocked Gases

    Energy Technology Data Exchange (ETDEWEB)

    Leiding, Jeffery Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-29

    I present the results of statistical mechanical calculations on shocked molecular gases. This work provides insight into the general behavior of shock Hugoniots of gas phase molecular targets with varying initial pressures. The dissociation behavior of the molecules is emphasized. Impedance matching calculations are performed to determine the maximum degree of dissociation accessible for a given flyer velocity as a function of initial gas pressure.

  2. The microphysics of collisionless shock waves

    DEFF Research Database (Denmark)

    Marcowith, Alexandre; Bret, Antoine; Bykov, Andrei

    2016-01-01

    Collisionless shocks, that is shocks mediated by electromagnetic processes, are customary in space physics and in astrophysics. They are to be found in a great variety of objects and environments: magnetospheric and heliospheric shocks, supernova remnants, pulsar winds and their nebulæ, active...... galactic nuclei, gamma-ray bursts and clusters of galaxies shock waves. Collisionless shock microphysics enters at different stages of shock formation, shock dynamics and particle energization and/or acceleration. It turns out that the shock phenomenon is a multi-scale non-linear problem in time and space....... It is complexified by the impact due to high-energy cosmic rays in astrophysical environments. This review adresses the physics of shock formation, shock dynamics and particle acceleration based on a close examination of available multi-wavelength or in situ observations, analytical and numerical developments...

  3. Shock shapes on blunt bodies in hypersonic-hypervelocity helium, air, and CO2 flows, and calibration results in Langley 6-inch expansion tube

    Science.gov (United States)

    Miller, C. G., III

    1975-01-01

    Shock shape results for flat-faced cylinders, spheres, and spherically blunted cones in various test gases, along with preliminary results from a calibration study performed in the Langley 6-inch expansion tube are presented. Free-stream velocities from 5 to 7 km/sec are generated at hypersonic conditions with helium, air, and CO2, resulting in normal shock density ratios from 4 to 19. Ideal-gas shock shape predictions, in which an effective ratio of specific heats is used as input, are compared with the measured results. The effect of model diameter is examined to provide insight to the thermochemical state of the flow in the shock layer. The regime for which equilibrium exists in the shock layer for the present air and CO2 test conditions is defined. Test core flow quality, test repeatability, and comparison of measured and predicted expansion-tube flow quantities are discussed.

  4. Modeling the Interaction of Mineral Dust with Solar Radiation: Spherical versus Non-spherical Particles

    Science.gov (United States)

    Hoshyaripour, A.; Vogel, B.; Vogel, H.

    2017-12-01

    Mineral dust, emitted from arid and semi-arid regions, is the most dominant atmospheric aerosol by mass. Beside detrimental effect on air quality, airborne dust also influences the atmospheric radiation by absorbing and scattering solar and terrestrial radiation. As a result, while the long-term radiative impacts of dust are important for climate, the short-term effects are significant for the photovoltaic energy production. Therefore, it is a vital requirement to accurately forecast the effects of dust on energy budget of the atmosphere and surface. To this end, a major issue is the fact that dust particles are non-spherical. Thus, the optical properties of such particles cannot be calculated precisely using the conventional methods like Mie theory that are often used in climate and numerical weather forecast models. In this study, T-Matrix method is employed, which is able to treat the non-sphericity of particles. Dust particles are assumed to be prolate spheroids with aspect ratio of 1.5 distributed in three lognormal modes. The wavelength-dependent refractive indices of dust are used in T-Matrix algorithm to calculate the extinction coefficient, single scattering albedo, asymmetry parameter and backscattering ratio at different wavelengths. These parameters are then implemented in ICON-ART model (ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases) to conduct a global simulation with 80 km horizontal resolution and 90 vertical levels. April 2014 is selected as the simulation period during which North African dust plumes reached central Europe and Germany. Results show that treatment of non-sphericity reduces the dust AOD in the range of 10 to 30%/. The impacts on diffuse and direct radiation at global, regional and local scales show strong dependency on the size distribution of the airborne dust. The implications for modeling and remote sensing the dust impacts on solar energy are also discussed.

  5. Focusing of Shear Shock Waves

    Science.gov (United States)

    Giammarinaro, Bruno; Espíndola, David; Coulouvrat, François; Pinton, Gianmarco

    2018-01-01

    Focusing is a ubiquitous way to transform waves. Recently, a new type of shock wave has been observed experimentally with high-frame-rate ultrasound: shear shock waves in soft solids. These strongly nonlinear waves are characterized by a high Mach number, because the shear wave velocity is much slower, by 3 orders of magnitude, than the longitudinal wave velocity. Furthermore, these waves have a unique cubic nonlinearity which generates only odd harmonics. Unlike longitudinal waves for which only compressional shocks are possible, shear waves exhibit cubic nonlinearities which can generate positive and negative shocks. Here we present the experimental observation of shear shock wave focusing, generated by the vertical motion of a solid cylinder section embedded in a soft gelatin-graphite phantom to induce linearly vertically polarized motion. Raw ultrasound data from high-frame-rate (7692 images per second) acquisitions in combination with algorithms that are tuned to detect small displacements (approximately 1 μ m ) are used to generate quantitative movies of gel motion. The features of shear shock wave focusing are analyzed by comparing experimental observations with numerical simulations of a retarded-time elastodynamic equation with cubic nonlinearities and empirical attenuation laws for soft solids.

  6. Neutrophil Activation During Septic Shock.

    Science.gov (United States)

    Stiel, Laure; Meziani, Ferhat; Helms, Julie

    2018-04-01

    In addition to their well-known role as the cellular mediators of immunity, key other roles have been identified for neutrophils during septic shock. Importantly, neutrophils indeed play a critical role in the recently described immunothrombosis concept and in septic shock-induced coagulopathy. Septic shock is one of the most severe forms of infection, characterized by an inadequate host response to the pathogenic organism. This host response involves numerous defense mechanisms with an intense cellular activation, including neutrophil activation. Neutrophils are key cells of innate immunity through complex interactions with vascular cells and their activation may participate in systemic tissue damages. Their activation also leads to the emission of neutrophil extracellular traps, which take part in both pathogen circumscription and phagocytosis, but also in coagulation activation. Neutrophils thus stand at the interface between hemostasis and immunity, called immunothrombosis.The present review will develop a cellular approach of septic shock pathophysiology focusing on neutrophils as key players of septic shock-induced vascular cell dysfunction and of the host response, associating immunity and hemostasis. We will therefore first develop the role of neutrophils in the interplay between innate and adaptive immunity, and will then highlight recent advances in our understanding of immunothrombosis septic shock-induced coagulopathy.

  7. Computations of slowly moving shocks

    International Nuclear Information System (INIS)

    Karni, S.; Canic, S.

    1997-01-01

    Computations of slowly moving shocks by shock capturing schemes may generate oscillations are generated already by first-order schemes, but become more pronounced in higher-order schemes which seem to exhibit different behaviors: (i) the first-order upwind (UW) scheme which generates strong oscillations and (ii) the Lax-Friedrichs scheme which appears not to generate any disturbances at all. A key observation is that in the UW case, the numerical viscosity in the shock family vanishes inside the slow shock layer. Simple scaling arguments show the third-order effects on the solution may no longer be neglected. We derive the third-order modified equation for the UW scheme and regard the oscillatory solution as a traveling wave solution of the parabolic modified equation for the perturbation. We then look at the governing equation for the perturbation, which points to a plausible mechanism by which postshock oscillations are generated. It contains a third-order source term that becomes significant inside the shock layer, and a nonlinear coupling term which projects the perturbation on all characteristic fields, including those not associated with the shock family. 5 refs., 8 figs

  8. Spherical warm shield design for infrared imaging systems

    Science.gov (United States)

    Tian, Qijie; Chang, Songtao; He, Fengyun; Li, Zhou; Qiao, Yanfeng

    2017-09-01

    The F-number matching is the primary means to suppress stray radiation for infrared imaging systems. However, it is difficult to achieve exact F-number matching, owing to the restriction from detectors, or multiple F-number design. Hence, an additional shield is required to block the certain thermal radiation. Typical shield is called flat warm shield, which is flat and operates at room temperature. For flat warm shield, it cannot suppress stray radiation while achieving F-number matching. To overcome the restriction, a spherical reflective warm shield is required. First of all, the detailed theory of spherical warm shield design is developed on basis of the principle that stray radiation cannot directly reach the infrared focal plane array. According to the theory developed above, a polished spherical warm shield, whose radius is 18 mm, is designed to match an F/2 infrared detector with an F/4 infrared imaging system. Then, the performance and alignment errors of the designed spherical warm shield are analyzed by simulation. Finally, a contrast experiment between the designed spherical warm shield and two differently processed flat warm shields is performed in a chamber with controllable inside temperatures. The experimental results indicate that the designed spherical warm shield cannot only achieve F-number matching but suppress stray radiation sufficiently. Besides, it is demonstrated that the theory of spherical warm shield design developed in this paper is valid and can be employed by arbitrary infrared imaging systems.

  9. Spherical Accretion in a Uniformly Expanding Universe

    Science.gov (United States)

    Colpi, Monica; Shapiro, Stuart L.; Wasserman, Ira

    1996-10-01

    We consider spherically symmetric accretion of material from an initially homogeneous, uniformly expanding medium onto a Newtonian point mass M. The gas is assumed to evolve adiabatically with a constant adiabatic index F, which we vary over the range Γ ɛ [1, 5/3]. We use a one-dimensional Lagrangian code to follow the spherical infall of material as a function of time. Outflowing shells gravitationally bound to the point mass fall back, giving rise to a inflow rate that, after a rapid rise, declines as a power law in time. If there were no outflow initially, Bondi accretion would result, with a characteristic accretion time-scale ta,0. For gas initially expanding at a uniform rate, with a radial velocity U = R/t0 at radius R, the behavior of the flow at all subsequent times is determined by ta,0/t0. If ta,0/t0 ≫ 1, the gas has no time to respond to pressure forces, so the fluid motion is nearly collisionless. In this case, only loosely bound shells are influenced by pressure gradients and are pushed outward. The late-time evolution of the mass accretion rate Mdot is close to the result for pure dust, and we develop a semianalytic model that accurately accounts for the small effect of pressure gradients in this limit. In the opposite regime, ta,0/t0 ≪ 1, pressure forces significantly affect the motion of the gas. At sufficiently early times, t ≤ ttr, the flow evolved along a sequence of quasi-stationary, Bondi-like states, with a time-dependent Mdot determined by the slowly varying gas density at large distances. However, at later times, t ≥ ttr, the fluid flow enters a dustllke regime; ttr is the time when the instantaneous Bondi accretion radius reaches the marginally bound radius. The transition time ttr depends sensitively on ta,0/t0 for a given Γ and can greatly exceed t0. We show that there exists a critical value Γ = 11/9, below which the transition from fluid to ballistic motion disappears. As one application of our calculations, we consider the

  10. The impact of the form of the Euler equations for radial flow in cylindrical and spherical coordinates on numerical conservation and accuracy

    Science.gov (United States)

    Crittenden, P. E.; Balachandar, S.

    2018-03-01

    The radial one-dimensional Euler equations are often rewritten in what is known as the geometric source form. The differential operator is identical to the Cartesian case, but source terms result. Since the theory and numerical methods for the Cartesian case are well-developed, they are often applied without modification to cylindrical and spherical geometries. However, numerical conservation is lost. In this article, AUSM^+ -up is applied to a numerically conservative (discrete) form of the Euler equations labeled the geometric form, a nearly conservative variation termed the geometric flux form, and the geometric source form. The resulting numerical methods are compared analytically and numerically through three types of test problems: subsonic, smooth, steady-state solutions, Sedov's similarity solution for point or line-source explosions, and shock tube problems. Numerical conservation is analyzed for all three forms in both spherical and cylindrical coordinates. All three forms result in constant enthalpy for steady flows. The spatial truncation errors have essentially the same order of convergence, but the rate constants are superior for the geometric and geometric flux forms for the steady-state solutions. Only the geometric form produces the correct shock location for Sedov's solution, and a direct connection between the errors in the shock locations and energy conservation is found. The shock tube problems are evaluated with respect to feature location using an approximation with a very fine discretization as the benchmark. Extensions to second order appropriate for cylindrical and spherical coordinates are also presented and analyzed numerically. Conclusions are drawn, and recommendations are made. A derivation of the steady-state solution is given in the Appendix.

  11. Nuclear moments of nuclei near sphericity

    International Nuclear Information System (INIS)

    El Hajjaji, O.

    1987-05-01

    Magnetic and electric hyperfine interactions are studied by means of low temperature nuclear orientation. The magnetic moment of the 149 Gd isotope and that of 151 Gd are determined. The values follow the same trend as literature values of neighbouring nuclei. The calculated moments of the 7/2 - states using the Mottelson-Nilsson model without configuration mixing are nearly independent of deformation. Thus we assign the decrease of the magnetic moment versus neutron number to many particle coupling in the f shell. The Moessbauer effect detection of nuclear orientation is discussed. Two series of experiences are performed with different finalities. In the first one we determined the electric quadrupole moments of 125m Te and 129 Te. The quadrupole moments confirm the nearly spherical shape of these nuclei. In the second series we describe the Moessbauer effect of the radiation emitted by the daigleter nucleus of 125 I, implanted in two semiconductor matrices, locally oriented at low temperature by the electric field gradient of impurity-vacancy coupling. Despite the difficulty of the cooling down of Te nuclei to lattice temperature, we have shown the existence of the electric field gradient of implanted I into Si and α-Sn and determined their signs. The level mixing resonance is applied on oriented nuclei technique to determine the weak prolate deformation of silver nuclei. Studying the Δm = 3 resonance of 107 Ag m , we etablished the quadrupole moment of this state, which is in good agreement with the theoretical estimations of Moeller and Nix [fr

  12. HFE and Spherical Cryostats MC Study

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Jason P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-09-26

    The copper vessel containing the nEXO TPC is surrounded by a buffer of HFE, a liquid refrigerant with very low levels of radioactive element contamination. The HFE is contained within the cryostat’s inner vessel, which is in turn inside the outer vessel. While some HFE may be necessary for stable cooling of nEXO, it is possible that using substantially more than necessary for thermal reasons will help reduce backgrounds originating in the cryostats. Using a larger amount of HFE is accomplished by making the cryostat vessels larger. By itself, increasing the cryostat size somewhat increases the background rate, as the thickness of the cryostat wall must increase at larger sizes. However, the additional space inside the cryostat will be filled with HFE which can absorb gamma rays headed for the TPC. As a result, increasing the HFE reduces the number of backgrounds reaching the TPC. The aim of this study was to determine the relationship between HFE thickness and background rate. Ultimately, this work should support choosing a cryostat and HFE size that satisfies nEXO’s background budget. I have attempted to account for every consequence of changing the cryostat size, although naturally this remains a work in progress until a final design is achieved. At the moment, the scope of the study includes only the spherical cryostat design. This study concludes that increasing cryostat size reduces backgrounds, reaching neglible backgrounds originating from the cryostat at the largest sizes. It also shows that backgrounds originating from the inherent radioactivity of the HFE plateau quickly, so may be considered essentially fixed at any quantity of HFE.

  13. Cows and cow-slaughter in India : religious, political and social aspects

    NARCIS (Netherlands)

    S.M. Batra (Swaraj)

    1981-01-01

    textabstractIndia is a land of sacred cows. They are abundant in the fields, are present with gods in every temple, figure prominently in Parliament and Assemblies, are the deciding factor in elections, and are the subject of judgement in the highest court of India. The sacredness has attained such

  14. Crystal structure of a small heat-shock protein from Xylella fastidiosa reveals a distinct high-order structure.

    Science.gov (United States)

    Fonseca, Emanuella Maria Barreto; Scorsato, Valéria; Dos Santos, Marcelo Leite; Júnior, Atilio Tomazini; Tada, Susely Ferraz Siqueira; Dos Santos, Clelton Aparecido; de Toledo, Marcelo Augusto Szymanski; de Souza, Anete Pereira; Polikarpov, Igor; Aparicio, Ricardo

    2017-04-01

    Citrus variegated chlorosis is a disease that attacks economically important citrus plantations and is caused by the plant-pathogenic bacterium Xylella fastidiosa. In this work, the structure of a small heat-shock protein from X. fastidiosa (XfsHSP17.9) is reported. The high-order structures of small heat-shock proteins from other organisms are arranged in the forms of double-disc, hollow-sphere or spherical assemblies. Unexpectedly, the structure reported here reveals a high-order architecture forming a nearly square cavity.

  15. Quality control of raw cows' milk by headspace analysis

    NARCIS (Netherlands)

    Hettinga, K.A.; Valenberg, van H.J.F.; Hooijdonk, van A.C.M.

    2008-01-01

    This study investigated whether headspace analysis of volatile components can be used for monitoring the quality of raw cows¿ milk. The detection of different quality defects caused by cows¿ feed, microbiological and chemical contamination, as well as enzymatic deterioration was studied. Fresh raw

  16. Effect of abdominal waste on biogas production from cow dung ...

    African Journals Online (AJOL)

    The result shows that the mixture of the cow abdominal waste and its dung started yielding biogas within 24hours. The pure dung started producing appreciable biogas after 7 days. The result further indicates that the cumulative volume of biogas produced was dependant on the amount of pure cow dung. The fresh and ...

  17. Laryngeal obstruction caused by lymphoma in an adult dairy cow

    OpenAIRE

    Lardé, Hélène; Nichols, Sylvain; Babkine, Marie; Chénier, Sonia

    2014-01-01

    A Holstein cow was presented for inspiratory dyspnea. Endoscopic evaluation revealed swollen arytenoids and a presumptive diagnosis of bilateral arytenoidal chondritis was made. A partial arytenoidectomy was performed, the right arytenoid was submitted for histopathology, and a diagnosis of laryngeal lymphoma was made. Due to the poor prognosis, the cow was euthanized.

  18. PRODUCTION OF BIOG S FROM COW DUNG, WEEDS ND ...

    African Journals Online (AJOL)

    USER

    2017-05-26

    May 26, 2017 ... Abstract. Biogas production was carried out using cow dung, weeds, orange peelings and corn cob. Four different set of experiments were set up to demonstrate the production of biogas by the anaerobic fermentation of weeds and domestic waste; to determine the ratios of cow dung to weeds, orange ...

  19. Modelling of ammonia emissions from dairy cow houses

    NARCIS (Netherlands)

    Monteny, G.J.

    2000-01-01

    Dairy cow husbandry contributes to environmental acidification through the emission of ammonia. In-depth knowledge on the processes and variable factors that play a role in the emission of ammonia from dairy cow houses benefits the production of emission data, the development of low

  20. SOME FACTORS AFFECTING FERTILITY IN DRY COWS IN ...

    African Journals Online (AJOL)

    one-month group, a cow was considered pregnant when a viable embryo of normal size was observed. The results of this experiment are summarised in. Table 1. Significantly fewer oestrous cycles were observed in Africanders than in Herefords. Heifers had fewer oes· trous cycles than cows. Ovulation accompanied 150 ...

  1. Evaluation of fertility traits of Friesian X Bunaji dairy cows ...

    African Journals Online (AJOL)

    Data from 13 primaparous and 47 multiparous Friesian-Bunaji (F1) crossbred cows were used to evaluate the reproductive performance of Friesian x Bunaji dairy cows. Four fertility traits; days to first insemination (DFI), days open (DO), Non-return rate 56 days after first insemination (NRR56) and numbers of insemination ...

  2. Metabolic acclimation to heat stress in farm housed Holstein cows ...

    African Journals Online (AJOL)

    The aim of this study was to determine the effects of body condition score to metabolic acclimation in heat stressed Holstein cows. Body condition of cows had no effect on any of the tested parameters during the thermal neutral period, except for the percentage of protein in milk. Heat stress has been demonstrated to have ...

  3. Supplementation of quality protein to high producing Jersey cows ...

    African Journals Online (AJOL)

    Evelen

    This trial was conducted to test the hypothesis that early lactation cows grazing ryegrass pasture and receiving maize ..... Soest, 1970), in vitro organic matter digestibility (IVOMD; Tilley & Terry, 1963 as modified by Engels &. Van der ..... lactation Holstein-Friesian cows grazing temperate ad tropical pastures. Aust. J. Exp.

  4. Metabolic acclimation to heat stress in farm housed Holstein cows ...

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... heat stress as compared to normal and thin cows (significantly lower production and milk quality, and significantly higher rectal ... acclimation is characterized by reduced dry matter intake and milk yield and increased water ..... increase) with increased consumption of its own reserves occurs in obese cows ...

  5. Serum electrolyte values of cows during third trimester of pregnancy ...

    African Journals Online (AJOL)

    Some serum electrolyte values of 170 cows in eight settled cattle herds in Zaria, Northern Nigeria during the third trimester of pregnancy and first two weeks of lactation were determined. The cows were sampled once weekly during the third trimester of pregnancy and early lactation (first two weeks) periods for two ...

  6. Short Communication: The performance of beef cows on Digitaria ...

    African Journals Online (AJOL)

    Digitaria eriantha silage, ensiled when the plants were in the late flowering stage (March), was fed ad lib to mature, non-pregnant, dry Hereford cows from mid-May to mid-September. The average daily gain during a 98-day feeding period was 0.35 kg/cow. The estimated quantity and quality of the daily dry matter intake ...

  7. Farmers' attitude toward the introduction of selective dry cow therapy

    NARCIS (Netherlands)

    Scherpenzeel, C G M; Tijs, S H W; den Uijl, I E M; Santman-Berends, I M G A; Velthuis, A G J; Lam, T J G M

    2016-01-01

    The attitude of Dutch dairy farmers toward selective dry cow treatment (SDCT) is unknown, although a favorable mindset toward application of SDCT seems crucial for successful implementation. Given the fact that blanket dry cow treatment has been strongly promoted until recently, the implementation

  8. Rare fetal monster in Holstein crossbred cow | Sharma | Open ...

    African Journals Online (AJOL)

    A Sharma, P Kumar, M Singh, NK Vasishta, R Jaswal. Abstract. This report describes a rare case of conjoined female twin monster (Monocephalus Thoracopagus Tetrabrachius Tetrapus Dicaudatus) in a Holstein Friesian pluriparous crossbred cow. Keywords: Cow, Fetus, Holstein Friesian, Monster, Twins. Full Text:.

  9. Derivation of standard lactation curves for South African dairy cows ...

    African Journals Online (AJOL)

    South African cows displayed more variation in yields compared to those of Holstein cows in the Netherlands and Ireland. Season of calving had a pronounced effect on the shape of the Standard Lactation Curve, while the combination of calving age and lactation affected both the shape and level of the curves. Expected ...

  10. SUITABILITY OF BURNT AND CRUSHED COW BONES AS ...

    African Journals Online (AJOL)

    The suitability of burnt and crushed cow bones (BCCB) as partial replacement for fine aggregate in concrete was studied. The percentages of replacements of fine aggregates of 0, 10, 20, 30, 40 and 50%, respectively of BCCB were tested considering 1: 2: 4 and 1: 11/2 :3 concrete mix ratios. The cow bones were burnt for ...

  11. Biomarkers and mechanisms of natural disease resistance in dairy cows

    NARCIS (Netherlands)

    Altena, van S.E.C.

    2016-01-01

    The aim of this thesis was to define and test biomarkers for disease resistance in dairy cows and to determine the underlying mechanism in natural disease resistance. The health status of the cows is an important issue in dairy farming. Due to the mandatory reduction in the use of antibiotics,

  12. Occupational cow horn eye injuries in Ibadan, Nigeria | Ibrahim ...

    African Journals Online (AJOL)

    This case series aims to describe the clinical features, management, and outcome of occupational eye injuries caused by cow horns and to recommend possible preventive measures. A review of patients with cow horn inflicted eye injuries seen at the University College Hospital, Ibadan between January 2006, and ...

  13. the occurrence of post partum anoestrus in bonsmara cows on ...

    African Journals Online (AJOL)

    Post pactum anoestrus, as a cause of reproductive failure in ranch cows has been extensively studied, but little information is available for range cows in the Transvaal. Highveld. lactation has been found to delay reconception. (Symington & Hall, 1967) and both plane of nutrition. (Wiltbank, Rowden, Ingalls, Gregory & Koch, ...

  14. Energy metabolism of dairy cows fed on grass

    NARCIS (Netherlands)

    Bruinenberg, M.H.; Honing, Y. van der; Agnew, R.E.; Yan, T.; Vuuren, A.M. van; Valk, H.

    2002-01-01

    Production performance of grass-fed dairy cows is often lower than expected from the estimated energy supply. To explain the overestimation of the energy content of grass for dairy cows, data from energy balance trials from three different laboratories (Wageningen, Lelystad and Hillsborough) were

  15. Fish meal supplementation to early lactation Jersey cows grazing ...

    African Journals Online (AJOL)

    This trial was conducted to test the hypothesis that early lactation cows grazing ryegrass pasture and receiving maize and mineral supplementation could respond to additional supplementation with a protein source such as fish meal. Multiparous Jersey cows in early to mid lactation that grazed annual ryegrass pasture in ...

  16. Seroprevalence of Mycoplasma bovis infection in dairy cows in ...

    African Journals Online (AJOL)

    Seroprevalence of Mycoplasma bovis infection in dairy cows in subtropical southern China. ... Dairy cows with the history of 5 pregnancies had the highest seroprevalence (33.3%). However, no statistically significant association was found between M. bovis infection and age or number of pregnancies (p > 0.05). All the ...

  17. The natural history of cow's milk protein allergy/intolerance

    DEFF Research Database (Denmark)

    Høst, A; Jacobsen, H P; Halken, S

    1995-01-01

    , but evidence for type III (immune complex) reactions and type IV (cell mediated reactions) have been demonstrated as reviewed by Høst (1994) and Ortolani & Vighi (1995). Non immunologically reactions against cow's milk protein(s) are defined as CMPI. However, it should be stressed that many studies on 'cow...

  18. Reduction of slaughter value of paratuberculosis-infected dairy cows

    DEFF Research Database (Denmark)

    Kudahl, Anne Braad; Nielsen, Søren Saxmose

    2009-01-01

    The aim of this study was to evaluate the effects of infection with Mycobacterium avium subsp. paratuberculosis (MAP) on slaughter weight and slaughter value of dairy cows. Two datasets were analyzed: 1) recordings from 1,031 cows in herds in a pilot-study to control MAP infections; and 2) record...

  19. Staphylococcus aureus in mastitic crossbreed cows and its ...

    African Journals Online (AJOL)

    A cross sectional study was conducted in dairy farms of Addis Ababa city from. November 2011 to April 2012 to estimate the prevalence of Staphylococcus aureus and its associated risk factors in mastitic dairy cows. Milk samples were collected from 153 (50 clinical and 103 subclinical) mastitic lactating crossbred cows and.

  20. Antibacterial activities of lactic acid bacteria isolated from cow ...

    African Journals Online (AJOL)

    Objective: To determine the antimicrobial activity of cow's intestinal Lactic acid bacteria (LAB) against enteric commensals. Method: ... Conclusion: This study shows that LAB from cow faeces possess considerable antimicrobial activity against resistant Es- cherichia ... tries1. The meat from cattle, goat, sheep, pig and poul-.

  1. Dairy cows with prolonged calving seek additional isolation

    DEFF Research Database (Denmark)

    Rørvang, Maria Vilain; Herskin, Mette S.; Jensen, Margit Bak

    2017-01-01

    and management practices that better align with the motivations of the cow. This study examined dairy cow preferences for individual calving pens by offering 3 different levels of isolation (tall and narrow, low and wide, and tall and wide) by analyzing the association between precalving behavior, choice...... that interactions between motivation for isolation seeking and calving behavior exist....

  2. Elevated Apoptosis in the Liver of Dairy Cows with Ketosis

    Directory of Open Access Journals (Sweden)

    Xiliang Du

    2017-09-01

    Full Text Available Background/Aims: Dairy cows with ketosis are characterized by oxidative stress and hepatic damage. The aim of this study was to investigate hepatic oxidative stress and the apoptotic status of ketotic cows, as well as the underlying apoptosis pathway. Methods: The blood aspartate aminotransferase (AST, alanine aminotransferase (ALT, glutamate dehydrogenase (GLDH and gamma-glutamyl transferase (GGT activities and the haptoglobin (HP, serum amyloid A (SAA and serum apoptotic cytokeratin 18 neo-epitope M30 (CK18 M30 concentrations were determined by commercially available kits and ELISA kits, respectively. Liver histology, TUNEL and Oil red O staining were performed in liver tissue samples. TG contents were measured using an enzymatic kit; Caspase 3 assays were carried out using the Caspase 3 activity assay kit; oxidation and antioxidant markers were measured using biochemical kits; apoptosis pathway were determined by qRT-PCR and western blot. Results: Ketotic cows displayed hepatic fat accumulation. The hepatic malondialdehyde (MDA content was significantly increased, but the activities of catalase (CAT, superoxide dismutase (SOD and glutathione peroxidase (GSH-Px were markedly decreased in ketotic cows compared with control cows, indicating that ketotic cows displayed severe oxidative stress. Significantly higher serum levels of the hepatic damage markers AST, ALT, GGT and GLDH were observed in ketotic cows than in control cows. The blood concentration of the apoptotic marker CK18 M30 and the number of TUNEL-positive cells in the liver of ketotic cows were 1.19- and 2.61-fold, respectively, higher than the values observed in control cows. Besides, Caspase 3 activity was significantly increased in the liver of ketosis cows. Importantly, the levels of phosphorylated c-Jun N-terminal kinase (JNK and p38 mitogen-activated protein kinase (p38MAPK were significantly increased but the level of phosphorylated extracellular signal-regulated kinase1

  3. Elevated Apoptosis in the Liver of Dairy Cows with Ketosis.

    Science.gov (United States)

    Du, Xiliang; Chen, Liang; Huang, Dan; Peng, Zhicheng; Zhao, Chenxu; Zhang, Yuming; Zhu, Yiwei; Wang, Zhe; Li, Xinwei; Liu, Guowen

    2017-01-01

    Dairy cows with ketosis are characterized by oxidative stress and hepatic damage. The aim of this study was to investigate hepatic oxidative stress and the apoptotic status of ketotic cows, as well as the underlying apoptosis pathway. The blood aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase (GGT) activities and the haptoglobin (HP), serum amyloid A (SAA) and serum apoptotic cytokeratin 18 neo-epitope M30 (CK18 M30) concentrations were determined by commercially available kits and ELISA kits, respectively. Liver histology, TUNEL and Oil red O staining were performed in liver tissue samples. TG contents were measured using an enzymatic kit; Caspase 3 assays were carried out using the Caspase 3 activity assay kit; oxidation and antioxidant markers were measured using biochemical kits; apoptosis pathway were determined by qRT-PCR and western blot. Ketotic cows displayed hepatic fat accumulation. The hepatic malondialdehyde (MDA) content was significantly increased, but the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were markedly decreased in ketotic cows compared with control cows, indicating that ketotic cows displayed severe oxidative stress. Significantly higher serum levels of the hepatic damage markers AST, ALT, GGT and GLDH were observed in ketotic cows than in control cows. The blood concentration of the apoptotic marker CK18 M30 and the number of TUNEL-positive cells in the liver of ketotic cows were 1.19- and 2.61-fold, respectively, higher than the values observed in control cows. Besides, Caspase 3 activity was significantly increased in the liver of ketosis cows. Importantly, the levels of phosphorylated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38MAPK) were significantly increased but the level of phosphorylated extracellular signal-regulated kinase1/2 (ERK1/2) was markedly decreased, which

  4. On the unique reconstruction of induced spherical magnetizations

    International Nuclear Information System (INIS)

    Gerhards, Christian

    2016-01-01

    Recovering spherical magnetizations m from magnetic field data in the exterior is a highly non-unique problem. A spherical Hardy–Hodge decomposition supplies information on what contributions of the magnetization m are recoverable but it does not supply geophysically suitable constraints on m that would guarantee uniqueness for the entire magnetization. In this paper, we focus on the case of induced spherical magnetizations and show that uniqueness is guaranteed if one assumes that the magnetization is compactly supported on the sphere. The results are based on ideas presented in (Baratchart et al 2013 Inverse Problems 29 015004) for the planar setting. (paper)

  5. Non-Spherical Microcapsules for Increased Core Content Volume Delivery

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    The goal of this project was to advance microencapsulation from the standard spherical microcapsule to a non-spherical, high-aspect ratio (HAR), elongated microcapsule. This was to be accomplished by developing reproducible methods of synthesizing or fabricating robust, non-spherical, HAR microcapsules. An additional goal of this project was to develop the techniques to the point where scale-up of these methods could be examined. Additionally, this project investigated ways to apply the microencapsulation techniques developed as part of this project to self-healing formulations.

  6. The natural history of cow's milk protein allergy/intolerance

    DEFF Research Database (Denmark)

    Høst, A; Jacobsen, H P; Halken, S

    1995-01-01

    to cow's milk protein(s) may be due to the interaction between one or more milk proteins and one or more immune mechanisms, possible any of the four basic types of hypersensitivity reactions. Immunologically mediated reactions are defined as CMPA. Mostly, CMPA is caused by IgE-mediated (type I) reactions......, but evidence for type III (immune complex) reactions and type IV (cell mediated reactions) have been demonstrated as reviewed by Høst (1994) and Ortolani & Vighi (1995). Non immunologically reactions against cow's milk protein(s) are defined as CMPI. However, it should be stressed that many studies on 'cow......'s milk allergy' have not investigated the immunological basis of the clinical reactions. In most instances of cow's milk protein hypersensitivity only diagnostic investigations such as skin prick test and RAST indicative of IgE-mediated reactions are performed. In fact, CMPA cannot be ruled out unless...

  7. Cow's urine poisoning in Nigeria. Experimental observations in mice.

    Science.gov (United States)

    Oyebola, D D; Elegbe, R A

    1975-06-01

    The method of preparation and administration of "cow's urine" and the signs and symptoms of cow's urine poisoning have been described. Experimental investigations were carried out in mice to assess the toxicity ot this concoction. Effect of the preparation was compared with that of pure nicotine. The effect of each component used in preparing the concoction was also tested. Results of the experiments show that both "cow's urine" and nicotine cause excitement in low doses and cause convulsion and/or death in higher doses. Both also depress respiration. The role of "cow's urine" toxicity following administration to patients with convulsion and the possible aetiology of the neurological sequelae of "cow's urine" poisoning are discussed.

  8. Skin injuries on the body and thigh of dairy cows

    DEFF Research Database (Denmark)

    Enevoldsen, Carsten; Gröhn, Y.T.; Thysen, Iver

    1994-01-01

    An epidemiological study was conducted in 18 dairy herds with the objective to characterize those groups of cows where skin injuries to the body and thighs occurred most frequently. Data were analyzed with multivariable logistic regression. The epidemiologic patterns were different in first...... depending on month of calving (significant interaction). Injuries occurred most frequently among high yielding cows. Severe reproductive, metabolic, and/or infectious diseases were associated with injuries. In later lactations some degree of injury occurred among 13.4% of 832 cows in lactations 2 to 9 where...... and later lactations. In first lactation some degree of injury occurred among 7.7% of 1793 cows. For most cows occurrence of sole ulcer was positively associated with injury while occurrence of heel horn erosion was negatively associated with injury. The association between injury and body weight differed...

  9. Pressurized thermal shock (PTS)

    International Nuclear Information System (INIS)

    Rosso, Ricardo D.; Ventura, Mirta A.

    2006-01-01

    In the present work, a description of Thermal Shock in Pressurized conditions (PTS), and its influence in the treatment of the integrity of the pressure vessel (RPV) of a Pressurized Water Reactor (PWR) and/or of a Heavy water Pressurized water Reactor (PHWR) is made. Generally, the analysis of PTS involves a process of three stages: a-) Modeling with a System Code of relevant thermohydraulics transients in reference with the thermal shock; b-) The local distribution of temperatures in the downcomer and the heat transference coefficients from the RPV wall to the fluid, are determined; c-) The fracture mechanical analysis. These three stages are included in this work: Results with the thermohydraulics code Relap5/mod.3, are obtained, for a LOCA scenario in the hot leg of the cooling System of the Primary System of the CAN-I reactor. The method used in obtaining results is described. A study on the basis of lumped parameters of the local evolutions of the temperature of the flow is made, in the downcomer of the reactor pressure vessel. The purpose of this study is to determine how the intensification of the stress coefficient, varies in function of the emergency injected water during the thermohydraulic transients that take place under the imposed conditions in the postulated scene. Specially, it is considered a 50 cm 2 break, located in the neighborhoods of the pressurized with the corresponding hot leg connection. This size is considered like the most critical. The method used to obtain the results is described. The fracture mechanical analysis is made. From the obtained results we confirmed that we have a simple tool of easy application in order to analyze phenomena of the type PTS in the postulated scenes by break in the cold and hot legs of the primary system. This methodology of calculus is completely independent of the used ones by the Nucleoelectrica Argentina S.A. (NASA) in the analysis of the PTS phenomena in the CAN-I. The results obtained with the adopted

  10. Shocking findings in Manipur.

    Science.gov (United States)

    Sehgal, P N

    1991-08-01

    A sero-surveillance program in the state of Manipur, India revealed an alarmingly high rate of HIV infection, detected primarily among intravenous drug users. Previous surveillance had indicated that heterosexual intercourse was the leading mode of HIV transmission, and in 1989, no HIV infections had been detected in Manipur. But in February 1990, 5 HIV-positive cases were reported, and by May 1991, 1263 had been reported -- 93.9% of them among intravenous drug users. This came as shocking news, considering that at the same time only 5131 HIV cases had been reported in all of India. Although Manipur makes up only 0.91% of the country's population, the state's intravenous drug account for 23.1% of the nation's HIV cases. Manipur has an estimated 30,000 drug addicts, approximately 1/2 of which are intravenous drug users. Heroin is easily available in Manipur, due to the fact that the state shares a common international border of 352 km with Myanmar, one of the 3 countries that make up Southeast Asia's heroin producing "Golden Triangle." The author stresses, however, that drug abuse is not the cause of the transmission of HIV. It is the sharing of needles and syringes among intravenous drug users that creates the risk of infection, and preventive measures should reflect that fact. Besides discouraging drug use, preventive measures will require a dual strategy: 1) until they are cured, intravenous drug users should be given sterilized needles and syringes to avoid sharing; and 2) the law needs to be revised so that drug addicts are treated as patients and not as criminals. The Voluntary Health Association of India has begun to discuss such measures with governmental and nongovernmental organizations involved in the prevention and control of AIDS.

  11. Next-Step Spherical Torus Experiment and Spherical Torus Strategy in the Fusion Energy Development Path

    International Nuclear Information System (INIS)

    Ono, M.; Peng, M.; Kessel, C.; Neumeyer, C.; Schmidt, J.; Chrzanowski, J.; Darrow, D.; Grisham, L.; Heitzenroeder, P.; Jarboe, T.; Jun, C.; Kaye, S.; Menard, J.; Raman, R.; Stevenson, T.; Viola, M.; Wilson, J.; Woolley, R.; Zatz, I.

    2003-01-01

    A spherical torus (ST) fusion energy development path which is complementary to proposed tokamak burning plasma experiments such as ITER is described. The ST strategy focuses on a compact Component Test Facility (CTF) and higher performance advanced regimes leading to more attractive DEMO and Power Plant scale reactors. To provide the physics basis for the CTF an intermediate step needs to be taken which we refer to as the ''Next Step Spherical Torus'' (NSST) device and examine in some detail herein. NSST is a ''performance extension'' (PE) stage ST with the plasma current of 5-10 MA, R = 1.5 m, and Beta(sub)T less than or equal to 2.7 T with flexible physics capability. The mission of NSST is to: (1) provide a sufficient physics basis for the design of CTF, (2) explore advanced operating scenarios with high bootstrap current fraction/high performance regimes, which can then be utilized by CTF, DEMO, and Power Plants, and (3) contribute to the general plasma/fusion science of high beta toroidal plasmas. The NSST facility is designed to utilize the Tokamak Fusion Test Reactor (or similar) site to minimize the cost and time required for the design and construction

  12. Bovine Spongiform Encephalopathy (BSE, Mad Cow Disease

    Directory of Open Access Journals (Sweden)

    G. K. Bruckner

    1997-07-01

    Full Text Available Mad Cow Disease or BSE (Bovine Spongiform Encephalopathy became a household name internationally and also in South Africa. International hysteria resulted following reports of a possible link between a disease diagnosed in cattle in Britain and a variant of the disease diagnosed in humans after the presumed ingestion or contact with meat from infected cattle. The European Union instituted a ban on the importation of beef from the United Kingdom during March 1996 that had a severe effect on the beef industry in the UK and also resulted in a world wide consumer resistance against beef consumption.

  13. Evaluation of Cow Milk Electrical Conductivity Measurements

    Directory of Open Access Journals (Sweden)

    Constantin Gavan

    2017-11-01

    Full Text Available The efficiency of subclinical mastitis diagnosis using an electrical conductivity (EC meter was evaluated in the dairy farm of Agricultural Research and Development Station ( ARDS Simnic Craiova. The results were compared with those obtained by using the California Mastitis Test (CMT and the Somatic Cell Count (SCC.The milk quarter samples ( 1176 from Holstein Friesian cows were analyzed between September and December 2015. The EC evaluation with  the EC meter  ,showed a high proportion of results differing from SCC and CMT results. The CMT still shows to be the most accessible and efficient test in comparison to the EC meter tested.

  14. Maxillary osteosarcoma in a beef suckler cow

    Directory of Open Access Journals (Sweden)

    Prins Diether G J

    2012-07-01

    Full Text Available Abstract A ten-year-old beef suckler cow was referred to the Scottish Centre for Production Animal Health & Food Safety of the University of Glasgow, because of facial swelling in the region of the right maxilla. The facial swelling was first noticed three months earlier and was caused by a slow growing oral mass which contained displaced, loosely embedded teeth. The radiographic, laboratory and clinicopathological findings are described. Necropsy, gross pathology and histological findings confirmed the mass as a maxillary osteosarcoma.

  15. Using GnRH to Improve Cow Fecundity after Calving

    Directory of Open Access Journals (Sweden)

    Nicolae Păcală

    2012-05-01

    Full Text Available At dairy cows, the increase in milk production is associated with the decrease of heat manifestation and conception rates. GnRH is mostly used for treatment of different problems of the reproductive function and for improving the pregnancy rates in cows. The aim of our paper was to contribute to increase of conception rates, at cows with ovarian activity, at first AI after calving. The experiments were conducted on 58 cows, from Romanian Black Spotted breed (Frezian and 53 cows from Romanian Spotted breed (Simmental. The animals were divided into lots as follows: for Romanian Black Spotted breed 33 of the cows in were in experimental lot and 25 were in control lot, for Romanian Spotted breed 29 ere in experimental lot and 24 were in control lot. The females form experimental lots were treated with 100 mcg (2ml Ovarelin (GnRH, at the first AI, after VWP. At the cows form Romanian Black Spotted, from the 33 females in experimental lot, 12 did not return into heat after insemination, which represents a conception rate of 36.4%. At the cows form Romanian Spotted, form the 29 cows in experimental lot 8 did not return into heat after insemination, representing a conception rate of 44.8%. Administration of 100 mcg GnRH (2 ml Ovarelin at the time of AI determines a significant increase of the conception rate with 8.4-11.5%, compared with control lot. It appears that the cows from Romanian Spotted reacts better at GnRH treatment (44.8% conception rate, compared with Romanian Black Spotted (36.4 % conception rate.

  16. Interlaboratory evaluation of a cow's milk allergy mouse model to assess the allergenicity of hydrolysed cow's milk based infant formulas

    NARCIS (Netherlands)

    Esch, B.C.A.M. van; Bilsen, J.H.M. van; Jeurink, P.V.; Garssen, J.; Penninks, A.H.; Smit, J.J.; Pieters, R.H.H.; Knippels, L.M.J.

    2013-01-01

    This study describes two phases of a multi-phase project aiming to validate a mouse model for cow's milk allergy to assess the potential allergenicity of hydrolysed cow's milk based infant formulas (claim support EC-directive 2006/141/E). The transferability and the discriminatory power of this

  17. NON-RELATIVISTIC RADIATION MEDIATED SHOCK BREAKOUTS. III. SPECTRAL PROPERTIES OF SUPERNOVA SHOCK BREAKOUT

    Energy Technology Data Exchange (ETDEWEB)

    Sapir, Nir; Waxman, Eli [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Katz, Boaz [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2013-09-01

    The spectrum of radiation emitted following shock breakout from a star's surface with a power-law density profile {rho}{proportional_to}x{sup n} is investigated. Assuming planar geometry, local Compton equilibrium, and bremsstrahlung emission as the dominant photon production mechanism, numerical solutions are obtained for the photon number density and temperature profiles as a function of time for hydrogen-helium envelopes. The temperature solutions are determined by the breakout shock velocity v{sub 0} and the pre-shock breakout density {rho}{sub 0} and depend weakly on the value of n. Fitting formulae for the peak surface temperature at breakout as a function of v{sub 0} and {rho}{sub 0} are provided, with T{sub peak} approx. 9.44 exp [12.63(v{sub 0}/c){sup 1/2}] eV, and the time dependence of the surface temperature is tabulated. The time integrated emitted spectrum is a robust prediction of the model, determined by T{sub peak} and v{sub 0} alone and insensitive to details of light travel time or slight deviations from spherical symmetry. Adopting commonly assumed progenitor parameters, breakout luminosities of Almost-Equal-To 10{sup 45} erg s{sup -1} and Almost-Equal-To 10{sup 44} erg s{sup -1} in the 0.3-10 keV band are expected for blue supergiant (BSG) and red supergiant (RSG)/He-WR progenitors, respectively (T{sub peak} is well below the band for RSGs, unless their radius is {approx}10{sup 13} cm). >30 detections of SN 1987A-like (BSG) breakouts are expected over the lifetime of ROSAT and XMM-Newton. An absence of such detections would imply either that the typical parameters assumed for BSG progenitors are grossly incorrect or that their envelopes are not hydrostatic. The observed spectrum and duration of XRF 080109/SN 2008D are in tension with a non-relativistic breakout from a stellar surface interpretation.

  18. Emission enhancement within gold spherical nanocavity arrays.

    Science.gov (United States)

    Jose, Bincy; Steffen, Ronald; Neugebauer, Ute; Sheridan, Eoin; Marthi, Reena; Forster, Robert J; Keyes, Tia E

    2009-12-14

    Gold nanocavity arrays were prepared on fluorine-doped tin oxide on glass by electrochemical deposition of gold through monolayers of polystyrene spheres. The impact of the resulting spherical cap architecture on the photophysics of solutions and self-assembled monolayers of luminophore encapsulated within the nanocavities is reported for the first time. From conventional confocal fluorescence microscopy, the emission intensity of solutions of [Ru(bpy)(2)(Qbpy)](2+) (where bpy is 2,2'-bipyridyl and Qbpy is 2,2':4,4'':4,4''-quarterpyridyl) and fullerene (C(60)) encapsulated within the 820 nm diameter nanocavities was demonstrated to increase by approximately an order of magnitude compared with that of the associated bulk solution. Comparison was also made with the emission observed for luminophore solution encapsulated in cobalt nanocavities of comparable dimensions, where plasmonic interactions are not anticipated. Again, approximately an order of magnitude enhancement was observed for the gold arrays. Luminescence lifetime imaging revealed that the enhancement of the emission intensity of this solution within the nanocavity was accompanied by a small but significant decrease in the luminescent lifetime for [Ru(bpy)(2)(Qbpy)](2+). Enhancement was, in addition, strongly influenced by the wavelength of excitation, suggesting that plasmonics may play a role in the enhancement of the excitation process. An important observation from confocal imaging studies was that the dimensions of the luminophore emission field from solution within the cavities were significantly smaller than the dimensions of the cavity aperture and corresponded to a little more than that of the point spread function of the microscope. This indicates that its origin is significantly smaller than the wavelength of the emitted light and suggests that luminescence enhancement is highly localised. When the array was filled with a solution of [Ru(bpy)(2)(Qbpy)](2+) the emission spectrum of this complex

  19. Cool-season annual pastures with clovers to supplement wintering beef cows nursing calves

    Science.gov (United States)

    Every December, for 3 years, 87 beef cows, nursing cows, (594 ' 9.8 kg; calving season, September to November) were stratified by body condition score, body weight, cow age, and calf gender. They were divided randomly into 6 groups and assigned to 1 of 6 cool-season annual swards (0.45 hectares/cow...

  20. DEM simulation of non-spherical granular segregation in hopper

    Science.gov (United States)

    Tao, He; Zhong, Wenqi; Jin, Baosheng; Ren, Bing

    2013-07-01

    Discrete element model (DEM) was developed to simulate the non-spherical particles such as cornshaped particle, ellipsoidal particle and cylinder particle. Multi-element particle model was used to describe the non-spherical particle that means the non-spherical particle was constructed by several overlapping spheres. And the simulation was validated by the experiment. In addition, the flow characteristic of particle discharging in the hopper was researched for different diameter ratio. The result shows that the segregation phenomenon emerged as described in the previous researcher. The effect of the particle shape, particle diameter ratio and particle density ratio on the segregation was studied. The result shows that there is big difference of segregation for different particle shape. The extent of segregation for ellipsoidal particles is the largest, and that of the spherical particles is the smallest. The segregation extent increases significantly with the diameter ratio. And varying particle density ratios do not affect the segregation results significantly.

  1. Turbulence Modulation by Non-Spherical Particles

    DEFF Research Database (Denmark)

    Mandø, Matthias

    This study deals with the interaction between turbulence and non-spherical particles and represents an extension of the modeling framework for particleladen flows. The effect of turbulence on particles is commonly referred to as turbulent dispersion while the effect of particles on the carrier....... This study encompass an outlook on existing work, an experimental study, development of a numerical model and a case study advancing the modeling techniques for pulverized coal combustion to deal with larger non-spherical biomass particles. Firstly, existing knowledge concerning the motion of non......-spherical particles and turbulence modulation are outlined. A complete description of the motion of non-spherical particles is still lacking. However, evidence suggests that the equation of motion for a sphere only represent an asymptotical value for a more general, but yet unformulated, description of the motion...

  2. Development of a hydrothermal method to synthesize spherical ...

    African Journals Online (AJOL)

    Vis spectroscopy. Through these techniques, it was found that the pure ZnSe nanoparticles have a zinc blend structure and in a spherical form with average diameter of 30 nm. KEY WORDS: ZnSe, Nanosphere, Hydrothermal, Surfactant. Bull.

  3. On solvable spherical subgroups of semisimple algebraic groups (report version)

    OpenAIRE

    Avdeev, Roman

    2010-01-01

    A new approach to classification of solvable spherical subgroups of semisimple algebraic groups is considered. This approach is completely different from the known approach by D. Luna and provides an explicit classification.

  4. Shell closure at {ital N}=164: Spherical or deformed?

    Energy Technology Data Exchange (ETDEWEB)

    Rigol, J. [Joint Institute for Nuclear Research, 141980 Dubna (Russia)

    1997-02-01

    Brenner {ital et al}. [1] recently reported the apparent evidence for a spherical shell at {ital N}=164. Some arguments are given which may make it necessary to reconsider this conclusion. {copyright} {ital 1997} {ital The American Physical Society}

  5. Some comments on the hydrogen atom in a spherical enclosure

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Koo, E.L.; Zimerman, A.H.

    1980-01-01

    Some properties of the ground state energy solutions for the hydrogen atom in a spherical enclosure are discussed. The application of the many-point Pade approximants to this kind of systems inside a box is consider also. (Author) [pt

  6. Aircraft navigation and surveillance analysis for a spherical earth

    Science.gov (United States)

    2014-10-01

    This memorandum addresses a fundamental function in surveillance and navigation analysis : quantifying the geometry of two or more locations relative to each other and to a spherical earth. Here, geometry refers to: (a) points (idealized lo...

  7. Modelling and Simulation Analysis of Rolling Motion of Spherical Robot

    Science.gov (United States)

    Kamis, N. N.; Embong, A. H.; Ahmad, S.

    2017-11-01

    This paper presents the findings of modelling, control and analysis of the spherical rolling robot based on pendulum driven within the simulation environment. The spherical robot is modelled using Lagrange function based on the equation of rolling motion. PD-type Fuzzy logic controller (FLC) was designed to control the position of the spherical robot where 25 rules were constructed to control the rolling motion of spherical robot. It was then integrated with the model developed in Simulink-Matlab environment. The output scaling factor (output gain) of the FLC was heuristically tuned to improve the system performance. The simulation results show that the FLC managed to eliminate the overshoot response and demonstrated better performance with 29.67% increasing in settling time to reach 0.01% of steady state error.

  8. The Shock Dynamics of Heterogeneous YSO Jets: 3D Simulations Meet Multi-epoch Observations

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E. C.; Frank, A. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Lebedev, S. V. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom)

    2017-03-10

    High-resolution observations of young stellar object (YSO) jets show them to be composed of many small-scale knots or clumps. In this paper, we report results of 3D numerical simulations designed to study how such clumps interact and create morphologies and kinematic patterns seen in emission line observations. Our simulations focus on clump scale dynamics by imposing velocity differences between spherical, over-dense regions, which then lead to the formation of bow shocks as faster clumps overtake slower material. We show that much of the spatial structure apparent in emission line images of jets arises from the dynamics and interactions of these bow shocks. Our simulations show a variety of time-dependent features, including bright knots associated with Mach stems where the shocks intersect, a “frothy” emission structure that arises from the presence of the Nonlinear Thin Shell Instability along the surfaces of the bow shocks, and the merging and fragmentation of clumps. Our simulations use a new non-equilibrium cooling method to produce synthetic emission maps in H α and [S ii]. These are directly compared to multi-epoch Hubble Space Telescope observations of Herbig–Haro jets. We find excellent agreement between features seen in the simulations and the observations in terms of both proper motion and morphologies. Thus we conclude that YSO jets may be dominated by heterogeneous structures and that interactions between these structures and the shocks they produce can account for many details of YSO jet evolution.

  9. Mold-free fabrication of 3D microfeatures using laser-induced shock pressure

    Science.gov (United States)

    Nagarajan, Balasubramanian; Castagne, Sylvie; Wang, Zhongke

    2013-03-01

    This paper reports on the fabrication of microfeatures on metallic foils using laser-induced shock forming without the assistance of micromold patterns. A mold-free laser shock forming technique, Flexible Pad Laser Shock Forming (FPLSF) has been developed and demonstrated to fabricate near-spherical microcraters on thin copper foils through the laser-generated plasma shock inducing plastic deformation on the copper foil. It is found that the crater formation strongly depends on the laser energy fluence applied to ablate an ablative overlay which is on top of the copper foil for plasma shock generation. Microfeatures with deformation depth of 80 μm to130 μm and radius of 485 μm to 616 μm were formed on 25 μm thick copper foils for the laser fluence of 7.3 J/cm2 to 20 J/cm2 while using aluminum foil as the ablative overlay and silicone rubber as a flexible support instead of a micromold. Fabrication of crater arrays on copper foils was also demonstrated successfully.

  10. A comparative study on laser induced shock cleaning of radioactive contaminants in air and water

    Science.gov (United States)

    Kumar, Aniruddha; Prasad, Manisha; Bhatt, R. B.; Behere, P. G.; Biswas, D. J.

    2018-03-01

    Efficient removal of Uranium-di-oxide (UO2) particulates from stainless steel surface was effected by Nd-YAG laser induced plasma shock waves in air as well as in water environment. The propagation velocity of the generated shock wave was measured by employing the photo-acoustic probe deflection method. Monitoring of the alpha activity of the sample with a ZnS (Ag) scintillation detector before and after the laser exposure allowed the estimation of decontamination efficiency defined as the percentage removal of the initial activity. Experiments were carried out to study the effect of laser pulse energy, number of laser exposures, orientation of the sample, the separation between the substrate surface and the onset point of the shock wave on the de-contamination efficiency. The most optimised cleaning was found to occur when the laser beam impinged normally on the sample that was immersed in water and placed at a distance of ∼0.7 mm from the laser focal spot. Analysis of the cleaned surface by optical microscopes established that laser induced shock cleaning in no way altered the surface property. The shock force generated in both air and water has been estimated theoretically and has been found to exceed the Van der Waal's binding force for spherical contaminant particulate.

  11. Acceleration of Solar Energetic Particles at a Fast Traveling Shock in Non-uniform Coronal Conditions

    Science.gov (United States)

    Le Roux, J. A.; Arthur, A. D.

    2017-09-01

    Time-dependent solar energetic particle (SEP) acceleration is investigated at a fast, nearly parallel spherical traveling shock in the strongly non-uniform corona by solving the standard focused transport equation for SEPs and transport equations for parallel propagating Alfvén waves that form a set of coupled equations. This enables the modeling of self-excitation of Alfvén waves in the inertial range by SEPs ahead of the shock and its role in enhancing the efficiency of the diffusive shock acceleration (DSA) of SEPs in a self-regulatory fashion. Preliminary results suggest that, because of the highly non-uniform coronal conditions that the shock encounters, both DSA and wave excitation are highly time-dependent processes. Thus, DSA spectra of SEPs strongly deviate from the simple power-law prediction of standard steady-state DSA theory and initially strong wave excitation weakens rapidly. Consequently, the ability of DSA to produce high energy SEPs in the corona of ∼1 GeV, as observed in the strongest gradual SEP events, appears to be strongly curtailed at a fast nearly parallel shock, but further research is needed before final conclusions can be drawn.

  12. Prediction of massive bleeding. Shock index and modified shock index.

    Science.gov (United States)

    Terceros-Almanza, L J; García-Fuentes, C; Bermejo-Aznárez, S; Prieto-Del Portillo, I J; Mudarra-Reche, C; Sáez-de la Fuente, I; Chico-Fernández, M

    2017-12-01

    To determine the predictive value of the Shock Index and Modified Shock Index in patients with massive bleeding due to severe trauma. Retrospective cohort. Severe trauma patient's initial attention at the intensive care unit of a tertiary hospital. Patients older than 14 years that were admitted to the hospital with severe trauma (Injury Severity Score >15) form January 2014 to December 2015. We studied the sensitivity (Se), specificity (Sp), positive and negative predictive value (PV+ and PV-), positive and negative likelihood ratio (LR+ and LR-), ROC curves (Receiver Operating Characteristics) and the area under the same (AUROC) for prediction of massive hemorrhage. 287 patients were included, 76.31% (219) were male, mean age was 43,36 (±17.71) years and ISS was 26 (interquartile range [IQR]: 21-34). The overall frequency of massive bleeding was 8.71% (25). For Shock Index: AUROC was 0.89 (95% confidence intervals [CI] 0.84 to 0.94), with an optimal cutoff at 1.11, Se was 91.3% (95% CI: 73.2 to 97.58) and Sp was 79.69% (95% CI: 74.34 to 84.16). For the Modified Shock Index: AUROC was 0.90 (95% CI: 0.86 to 0.95), with an optimal cutoff at 1.46, Se was 95.65% (95% CI: 79.01 to 99.23) and Sp was 75.78% (95% CI: 70.18 to 80.62). Shock Index and Modified Shock Index are good predictors of massive bleeding and could be easily incorporated to the initial workup of patients with severe trauma. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  13. Effect of Rolling Resistance in Dem Models With Spherical Bodies

    Directory of Open Access Journals (Sweden)

    Dubina Radek

    2016-12-01

    Full Text Available The rolling resistance is an artificial moment arising on the contact of two discrete elements which mimics resistance of two grains of complex shape in contact rolling relatively to each other. The paper investigates the influence of rolling resistance on behaviour of an assembly of spherical discrete elements. Besides the resistance to rolling, the contacts between spherical particles obey the Hertzian law in normal straining and Coulomb model of friction in shear.

  14. Spherical coated particle fuel for fuel elements of HTGR

    International Nuclear Information System (INIS)

    Chernikov, A.S.; Permyakov, L.N.; Mikhailichenko, L.I.; Nezhevenko, L.B.; Gudovich, A.P.; Landin, N.A.; Ljutikov, R.A.; Solovjev, G.I.

    1985-01-01

    The main results of the investigations on the development of spherical particles fuel for fuel elements of HTGR are described. Typical characteristics of UO 2 spherical particles (size, shape, density, microstructure etc.) and PyC and SiC protective layers (thickness, density, fission product release etc.) are presented. Sol-gel technique and slip casting are used for spheroidization; deposition of protective layers is carried out in the fluidized bed apparatus

  15. Features of spherical uranium-graphite HTGR fuel elements control

    International Nuclear Information System (INIS)

    Kreindlin, I.I.; Oleynikov, P.P.; Shtan, A.S.

    1985-01-01

    Control features of spherical HTGR uranium-graphite fuel elements with spherical coated fuel particles are mainly determined by their specific construction and fabrication technology. The technology is chiefly based on methods of ceramic fuel (fuel microspheres fabrication) and graphite production practice it is necessary to deal with a lot of problems from determination of raw materials properties to final fuel elements testing. These procedures are described

  16. Fluorescence of molecules placed near a spherical particle: Rabi splitting

    Directory of Open Access Journals (Sweden)

    M.M. Dvoynenko

    2017-12-01

    Full Text Available Theoretical study of spontaneously emitted spectra of point-like source placed near spherical Ag particle was performed. It was shown that near-field electromagnetic interaction between a point-like emitter and spherical Ag particle leads to strong coupling between them at very small emitter-metal surface distances. It was shown that values of Rabi splitting are quantitatively close to that of emitter-flat substrate interaction.

  17. Whispering modes in anisotropic and isotropic dielectric spherical resonators

    International Nuclear Information System (INIS)

    Le Floch, Jean-Michel; Anstie, James David; Tobar, Michael Edmund; Hartnett, John Gideon; Bourgeois, Pierre-Yves; Cros, Dominique

    2006-01-01

    The properties of degenerate whispering spherical modes within a fused silica and sapphire dielectric resonator have been investigated. However, departure from spherical symmetry occurs due to the support structure and anisotropy of the material. Finite element modeling is used to predicted the lifting of the frequency degeneracy, and is confirmed by experiment. Further optimization of the sapphire resonator to realize a Michelson-Morley experiment is discussed

  18. Electron heating at interplanetary shocks

    International Nuclear Information System (INIS)

    Feldman, W.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.; Zwickl, R.D.

    1982-01-01

    Data for 41 forward interplanetary shocks measured between August 1978 and December 1979 show that the ratio of downstream to upstream electron temperatures, T/sub e/(d/u) is variable in the range between 1.0 (isothermal) and 3.0. On average, (T/sub e/(d/u) = 1.5 with a standard deviation, sigma e = 0.5. This ratio is less than the average ratio of proton temperatures across the same shocks, (T/sub p/(d/u)) = 3.3 with sigma p = 2.5 as well as the average ratio of electron temperatures across the earth's bow shock. Individual samples of T/sub e/(d/u) and T/sub p/(d/u) appear to be weakly correlated with the number density ratio. However the amounts of electron and proton heating are well correlated with each other as well as with the bulk velocity difference across each shock. The stronger shocks appear to heat the protons relatively more efficiently than they heat the electrons

  19. Shock processing of interstellar grains

    International Nuclear Information System (INIS)

    Seab, C.G.; Shull, J.M.

    1986-01-01

    Shock processing plays an important role in the life of a typical interstellar grain. Shocks of 100 km/s-l or greater can destroy about 50% of the grain material under appropriate preshock conditions of density and magnetic field. The destruction occurs by grain-grain collisions and nonthermal sputtering for steady state radiative shocks and by thermal sputtering for fast adiabatic shocks. The evaluation of the lifetime of grains against shock destruction depends on models of the interstellar medium (ISM) structure and on supernova remnants (SNR) evolution. Results from various authors give lifetimes between 10 to the 8th and 10 to the 9th power years, compared to typical injection times for new grains of a few times 10 to the 9th power years. These numbers require that a major portion of the interstellar silicon bearing grain material must be formed by grain growth in the ISM. At the same time, the presence of isotopic anomalies in some meteorites implies that at least some grains must survive from their formation in SNRs or red giant winds through incorporation into the solar system

  20. The influence of Borna disease viral infection on dairy cow reproduction.

    Science.gov (United States)

    Hagiwara, Katsuro; Ando, Tatsuya; Koiwa, Masateru

    2012-04-01

    We investigated the influence of Borna disease virus (BDV) infection on the clinical state of dairy cows. Sera from 149 cows were examined using enzyme-linked immunosorbent assay and western blotting detect antibodies to the BDV-nucleoprotein antigen. Among 149 investigated cows, 25 (16.8%) showed a positive reaction to BDV antigen. No significant difference existed in milk production or medical history between seropositive and seronegative cows. Although the estrus cycle appeared normal even in the seropositive cows, the frequency of artificial insemination and calving-to-conception intervals significantly increased in seropositive cows. Therefore, fertilization failure was recognized in the BDV-antibody positive cows.

  1. Pressure Hull Analysis under Shock Loading

    Directory of Open Access Journals (Sweden)

    Ya-Jung Lee

    2008-01-01

    Full Text Available The hull of high performance submarines must resist underwater shock loading due to exploding torpedoes or depth bombs. An underwater shock involving an initial shock wave and successive bubble pulsating waves is so complex that a theoretical technique for deriving shock pressure distribution is required for improving simulation efficiency. Complete shock loading is obtained theoretically in this work, and responses of a submarine pressure hull are calculated using ABAQUS USA (Underwater Shock Analysis codes. In the long run, this deflection and stress data will assist in examining the structural arrangement of the submarine pressure hull.

  2. Why the Nature of Oil Shocks Matters

    International Nuclear Information System (INIS)

    Archanskaia, Elizaveta; Hubert, Paul; Creel, Jerome

    2009-03-01

    This article studies the impact of oil shocks on the macro-economy in two ways insofar unexploited in the literature. The analysis is conducted at the global level, and it explicitly accounts for the potentially changing nature of oil shocks. Based on an original world GDP series and a grouping of oil shocks according to their nature, we find that oil supply shocks negatively impact world growth, contrary to oil demand shocks, pro-cyclical in their nature. This result is robust at the national level for the US. Furthermore, endogenous monetary policy is shown to have no counter-cyclical effects in the context of an oil demand shock. (authors)

  3. Shock, diaschisis and von Monakow

    Directory of Open Access Journals (Sweden)

    Eliasz Engelhardt

    2013-07-01

    Full Text Available The concept of shock apparently emerged in the middle of the 18th century (Whyett as an occurrence observed experimentally after spinal cord transection, and identified as "shock" phenomenon one century later (Hall. The concept was extended (Brown-Séquard and it was suggested that brain lesions caused functional rupture in regions distant from the injured one ("action à distance". The term "diaschisis" (von Monakow, proposed as a new modality of shock, had its concept broadened, underpinned by observations of patients, aiming at distinguishing between symptoms of focal brain lesions and transitory effects they produced, attributable to depression of distant parts of the brain connected to the injured area. Presently, diaschisis is related mainly to cerebrovascular lesions and classified according to the connection fibers involved, as proposed by von Monakow. Depression of metabolism and blood flow in regions anatomically separated, but related by connections with the lesion, allows observing diaschisis with neuroimaging.

  4. Inflammatory biomarkers are associated with ketosis in periparturient Holstein cows.

    Science.gov (United States)

    Abuajamieh, Mohannad; Kvidera, Sara K; Fernandez, Maria V Sanz; Nayeri, Amir; Upah, Nathan C; Nolan, Erin A; Lei, Sam M; DeFrain, Jeffery M; Green, Howard B; Schoenberg, Katie M; Trout, William E; Baumgard, Lance H

    2016-12-01

    Ketosis is a prevalent periparturient metabolic disorder and we hypothesize that lipopolysaccharide (LPS) infiltration may play a key role in its etiology. Study objectives were to characterize biomarkers of inflammation during the transition period in healthy and clinically diagnosed ketotic cows. Cows were retrospectively categorized into one of two groups: healthy and clinically diagnosed ketotic. Two data sets were utilized; the first dataset (Study A) was obtained as a subset of cows (n=16) enrolled in a larger experiment conducted at the Iowa State University Dairy utilizing Holstein cows (8 healthy; 8 ketotic), and the second dataset (Study B; 22 healthy; 22 ketotic) was obtained from a commercial farm. For both experiments, blood samples were collected prior to and following calving. Ketotic cows in both studies had reduced milk production compared to healthy cows (P6 fold and ~4 fold; P=0.04 and P=0.03), and lipopolysaccharide binding protein (66 and 45%; Pketosis in transition dairy cows. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Evaluation of oxidative stress in brucella infected cows

    Directory of Open Access Journals (Sweden)

    N. Kataria

    2010-05-01

    Full Text Available Oxidative stress can influence the metabolism of cells in vital organs of the body. Oxidative stress is extremely dangerous as it does not exhibit any symptom and is recognisable with great difficulty by means of laboratory methods. It can be monitored with several biomarkers like antioxidants and pro-oxidants which can be assessed in serum. The inexorableness of exposure of cows to brucella infection makes oxidative stress associated with this infection an appropriate field of investigation. There is paucity of work to detect stress, which is essential to take timely corrective measures and to save the animal population. Therefore the investigation was carried out to evaluate oxidative stress in the cows suffering from brucellosis. For this serum iomarkers of oxidative stress viz. vitamin C, vitamin E, catalase, monoamine oxidase, glutathione reductase, superoxide dismutase, glutathione, xanthine oxidase, oxidase and peroxidase were determined. Results indicated that vitamin C, vitamin E and glutathione activity decreased significantly in affected cows as compared to healthy cows. Serum catalase, superoxide dismutase, monoamine oxidase, glutathione reductase, xanthine oxidase, oxidase and peroxidase activities increased significantly in affected cows as compared to healthy cows. Decreased activity of vitamin C, vitamin E and glutathione indicated towards their depletion which generally occurs in the oxidative stress to scavenge the free radicals. It was concluded that oxidative stress was there in the animals. This study recommends the use of antioxidants in affected cows

  6. Managing variations in dairy cow nutrient supply under grazing.

    Science.gov (United States)

    Peyraud, J L; Delagarde, R

    2013-03-01

    Grazed pasture, which is the cheapest source of nutrients for dairy cows, should form the basis of profitable and low-input animal production systems. Management of high-producing dairy cows at pasture is thus a major challenge in most countries. The objective of the present paper is to review the factors that can affect nutrient supply for grazing dairy cows in order to point out areas with scope for improvement on managing variations in nutrient supply to achieve high animal performance while maintaining efficient pasture utilisation per hectare (ha). Reviewing the range in animal requirements, intake capacity and pasture nutritive values shows that high-producing cows cannot satisfy their energy requirements from grazing alone and favourable to unfavourable situations for grazing dairy cows may be classified according to pasture quality and availability. Predictive models also enable calculation of supplementation levels required to meet energy requirements in all situations. Solutions to maintain acceptable level of production per cow and high output per ha are discussed. Strategies of concentrate supplementation and increasing use of legumes in mixed swards are the most promising. It is concluded that although high-producing cow cannot express their potential milk production at grazing, there is scope to improve animal performance at grazing given recent developments in our understanding of factors influencing forage intake and digestion of grazed forages.

  7. Explicit and implicit multidimensional compact high-resolution shock-capturing methods: Formulation

    International Nuclear Information System (INIS)

    Yee, H.C.

    1997-01-01

    Two families of explicit and implicit compact high-resolution shock-capturing methods for the multidimensional compressible Euler equations for fluid dynamics are constructed. Some of these schemes can be fourth- and sixth-order accurate away from discontinuities. For the semi-discrete case their shock-capturing properties are of the total variation diminishing (TVD), total variation bounded (TVB), total variation diminishing in the mean (TVDM), essentially nonoscillatory (ENO), or positive type of scheme for 1D scalar hyperbolic conservation laws and are positive schemes in more than one dimension. These higher-order compact schemes require the same grid stencil per spatial direction as their second-order noncompact cousins. The added terms over the second-order noncompact cousins involve extra vector additions but no added flux evaluations. Due to the construction, these schemes can be viewed as approximations to genuinely multidimensional schemes in the sense that they might produce less distortion in spherical type shocks and are more accurate in vortex type flows than schemes based purely on 1D extensions. The extension of these families of compact schemes to coupled nonlinear systems can be accomplished using the Roe approximate Riemann solver, the generalized Steger and Warming flux-vector splitting, or the van Leer type flux-vector splitting. Modification to existing high-resolution second- or third-order noncompact shock-capturing computer codes is minimal. High-resolution shock-capturing properties can also be achieved via a variant of the second-order Lax-Friedrichs numerical flux without the use of Riemann solvers for coupled nonlinear systems with comparable operations count to their classical shock-capturing counterparts. An efficient and compatible high-resolution shock-capturing filter for spatially fourth- and six-order classical compact and noncompact schemes is discussed

  8. Status and future prospects of the spherical torus research. Exploratory Spherical Torus experiments. Approach from the Tokamak

    International Nuclear Information System (INIS)

    Sykes, A.

    2000-01-01

    The optimistic predictions for the Spherical Torus (Spherical Tokamak) have been verified in a range of small devices world-wide. Although some equilibrium features (e.g. the naturally large elongation) were fully expected, the ST appears to have substantially improved energy confinement, beta exceeding the Troyon scaling, and a resilience to the major disruption. These exploratory experiments have produced great interest in the ST concept. (author)

  9. Peripartal leukogram in cows with and without retained placenta

    Directory of Open Access Journals (Sweden)

    Lužajić Tijana

    2014-01-01

    Full Text Available The aim of this study was to investigate whether prepartal leukogram in cows with retained placenta could indicate the presence of subclinical systemic inflammatory response before the onset of disease. After calving, sixteen highly pregnant Holstein cows, aged 3 to 9 years, without clinical signs of the disease prior to calving were divided into two groups: the first group (n=9 were animals without retained placenta, or any visible inflammation after birth; the second group (n=7 were cows with retained placenta. Blood was sampled three times before parturition, at intervals of one week, and once 24 hours after birth. The number of total leukocytes, segmented and non segmented neutrophilic granulocytes (NG, lymphocytes and monocytes were determined by standard laboratory techniques. The results have shown that in the group of cows with retained placenta the number of mature neutrophils was slightly elevated in the third, second and last week before calving, and equal number of non segmented neutrophils in regard to the group with no retention. The results have also shown that, in both groups of cows, 24 hours after calving, the number of total leukocytes and the number of segmented neutrophils decreased, but the number of the non segmented neutrophils increased. Based on this, we can conclude that cows with retained placenta had no systemic inflammatory response during three weeks prepartal period, but 24 hours after calving, systemic inflammatory response was documented in all the cows. Moreover, the intensity of inflammatory response in cows with retained placenta was not more pronounced in comparison to cows without retained placenta. [Projekat Ministarstva nauke Republike Srbije, br. 175061

  10. Risk factors for postpartum anestrus in crossbred cows in Bangladesh

    International Nuclear Information System (INIS)

    Kamal, M.M.; Uddin Bhuiyan, M.M.; Parveen, N.; Momont, H.W.; Shamsuddin, M.

    2016-01-01

    Full text: Ultrasonography and a structured questionnaire were used in a cross-sectional study to gather data on the prevalence and risk factors for anestrus in crossbred cows at ≥60 days postpartum in 273 smallholder farms. The prevalence of anestruc was 18%. The odds ratio (OR) for true anestrus was 17.52 and 2.81 times higher (P < 0.05) in cows with poor (≤2.0) and excessive (>3.5) body condition score (BCS), respectively, compared to those with optimal BCS (2.5-3.5), 2.82 times higher in suckled than in nonsuckled cows (P = 0.03), and 2.53 times higher in cows that calved during the cold season than in those that calved during the hot season (P = 0.03). The OR for anestrus was 1.62 times higher (P = 0.017) in cows managed by an employee than in those managed by the farmers themselves (P = 0.001), and 2.66 times higher (P = 0.003) in small farms (≤5 cows) than in large farms (≥11 cows). The OR was 0.71 to 0.46 times lower in farms having a guaranteed market to sell milk than those with an uncertain traditional milk market (P < 0.05). Maintaining optimal BCS of cows, farmers' training on management of cattle reproduction, and development of a market linkage to sell milk would improve the number of cows for breeding by 60 days postpartum. (author)

  11. Spherical grating based x-ray Talbot interferometry

    International Nuclear Information System (INIS)

    Cong, Wenxiang; Xi, Yan; Wang, Ge

    2015-01-01

    Purpose: Grating interferometry is a state-of-the-art x-ray imaging approach, which can acquire information on x-ray attenuation, phase shift, and small-angle scattering simultaneously. Phase-contrast imaging and dark-field imaging are very sensitive to microstructural variation and offers superior contrast resolution for biological soft tissues. However, a common x-ray tube is a point-like source. As a result, the popular planar grating imaging configuration seriously restricts the flux of photons and decreases the visibility of signals, yielding a limited field of view. The purpose of this study is to extend the planar x-ray grating imaging theory and methods to a spherical grating scheme for a wider range of preclinical and clinical applications. Methods: A spherical grating matches the wave front of a point x-ray source very well, allowing the perpendicular incidence of x-rays on the grating to achieve a higher visibility over a larger field of view than the planer grating counterpart. A theoretical analysis of the Talbot effect for spherical grating imaging is proposed to establish a basic foundation for x-ray spherical gratings interferometry. An efficient method of spherical grating imaging is also presented to extract attenuation, differential phase, and dark-field images in the x-ray spherical grating interferometer. Results: Talbot self-imaging with spherical gratings is analyzed based on the Rayleigh–Sommerfeld diffraction formula, featuring a periodic angular distribution in a polar coordinate system. The Talbot distance is derived to reveal the Talbot self-imaging pattern. Numerical simulation results show the self-imaging phenomenon of a spherical grating interferometer, which is in agreement with the theoretical prediction. Conclusions: X-ray Talbot interferometry with spherical gratings has a significant practical promise. Relative to planar grating imaging, spherical grating based x-ray Talbot interferometry has a larger field of view and

  12. Sepsis and Septic Shock Strategies.

    Science.gov (United States)

    Armstrong, Bracken A; Betzold, Richard D; May, Addison K

    2017-12-01

    Three therapeutic principles most substantially improve organ dysfunction and survival in sepsis: early, appropriate antimicrobial therapy; restoration of adequate cellular perfusion; timely source control. The new definitions of sepsis and septic shock reflect the inadequate sensitivity, specify, and lack of prognostication of systemic inflammatory response syndrome criteria. Sequential (sepsis-related) organ failure assessment more effectively prognosticates in sepsis and critical illness. Inadequate cellular perfusion accelerates injury and reestablishing perfusion limits injury. Multiple organ systems are affected by sepsis and septic shock and an evidence-based multipronged approach to systems-based therapy in critical illness results in improve outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Shock/shock interactions between bodies and wings

    Directory of Open Access Journals (Sweden)

    Gaoxiang XIANG

    2018-02-01

    Full Text Available This paper examines the Shock/Shock Interactions (SSI between the body and wing of aircraft in supersonic flows. The body is simplified to a flat wedge and the wing is assumed to be a sharp wing. The theoretical spatial dimension reduction method, which transforms the 3D problem into a 2D one, is used to analyze the SSI between the body and wing. The temperature and pressure behind the Mach stem induced by the wing and body are obtained, and the wave configurations in the corner are determined. Numerical validations are conducted by solving the inviscid Euler equations in 3D with a Non-oscillatory and Non-free-parameters Dissipative (NND finite difference scheme. Good agreements between the theoretical and numerical results are obtained. Additionally, the effects of the wedge angle and sweep angle on wave configurations and flow field are considered numerically and theoretically. The influences of wedge angle are significant, whereas the effects of sweep angle on wave configurations are negligible. This paper provides useful information for the design and thermal protection of aircraft in supersonic and hypersonic flows. Keywords: Body and wing, Flow field, Hypersonic flow, Shock/shock interaction, Wave configurations

  14. Clinical ketosis and standing behavior in transition cows.

    Science.gov (United States)

    Itle, A J; Huzzey, J M; Weary, D M; von Keyserlingk, M A G

    2015-01-01

    Ketosis is a common disease in dairy cattle, especially in the days after calving, and it is often undiagnosed. The objective of this study was to compare the standing behavior of dairy cows with and without ketosis during the days around calving to determine if changes in this behavior could be useful in the early identification of sick cows. Serum β-hydroxybutyrate (BHBA) was measured in 184 cows on a commercial dairy farm twice weekly from 2 to 21d after calving. Standing behavior was measured from 7d before calving to 21d after calving using data loggers. Retrospectively, 15 cows with clinical ketosis (3 consecutive BHBA samples >1.2mmol/L and at least one sample of BHBA >2.9mmol/L) were matched with 15 nonketotic cows (BHBA ketosis occurred 4.5±2.1d after calving. Total daily standing time was longer for clinically ketotic cows compared with nonketotic cows during wk -1 (14.3±0.6 vs. 12.0±0.7h/d) and on d 0 (17.2±0.9 vs. 12.7±0.9h/d) but did not differ during the other periods. Clinically ketotic cows exhibited fewer standing bouts compared with nonketotic cows on d 0 only (14.6±1.9 vs. 20.9±1.8bouts/d). Average standing bout duration was also longer for clinically ketotic cows on d 0 compared with nonketotic cows [71.3min/bout (CI: 59.3 to 85.5) vs. 35.8min/bout (CI: 29.8 to 42.9)] but was not different during the other periods. Differences in standing behavior in the week before and on the day of calving may be useful for the early detection of clinical ketosis in dairy cows. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Starch Digestion and Phosphorus Excretion in Lactating Dairy Cows

    OpenAIRE

    Guyton, Autumn Deanne

    2002-01-01

    The effects of starch and phosphorus (P) source on P partitioning and ruminal phytase activity were evaluated in eight lactating cows (113 DIM). Four cows were ruminaly cannulated. Cows were randomly assigned to treatments in a duplicated 4x4 Latin square with four, 18-d periods. Diets included dry ground corn (DG) or steam flaked corn (SF), with a no supplemental P (low P diet; 0.34% P) or supplemental purified phytic acid (PA; 0.45% P) to provide additional P from an organic source. Total c...

  16. Monitoring cow activity and rumination time for an early detection of heat stress in dairy cow

    Science.gov (United States)

    Abeni, Fabio; Galli, Andrea

    2017-03-01

    The aim of this study was to explore the use of cow activity and rumination time by precision livestock farming tools as early alert for heat stress (HS) detection. A total of 58 Italian Friesian cows were involved in this study during summer 2015. Based on the temperature humidity index (THI), two different conditions were compared on 16 primiparous and 11 multiparous, to be representative of three lactation phases: early (15-84 DIM), around peak (85-154 DIM), and plateau (155-224 DIM). A separate dataset for the assessment of the variance partition included all the cows in the herd from June 7 to July 16. The rumination time (RT2h, min/2 h) and activity index (AI2h, bouts/2 h) were summarized every 2-h interval. The raw data were used to calculate the following variables: total daily RT (RTt), daytime RT (RTd), nighttime RT (RTn), total daily AI (AIt), daytime AI (AId), and nighttime AI (AIn). Either AIt and AId increased, whereas RTt, RTd, and RTn decreased with higher THI in all the three phases. The highest decrease was recorded for RTd and ranged from 49 % (early) to 45 % (plateau). The contribution of the cow within lactation phase was above 60 % of the total variance for AI traits and a share from 33.9 % (for RTt) to 54.8 % (RTn) for RT traits. These observations must be extended to different feeding managements and different animal genetics to assess if different thresholds could be identified to set an early alert system for the farmer.

  17. Measures to improve dairy cow foot health: consequences for farmer income and dairy cow welfare.

    Science.gov (United States)

    Bruijnis, M R N; Hogeveen, H; Stassen, E N

    2013-01-01

    Dairy farming in western countries with cubicle housing is an efficient way of dairy farming. Though, a disadvantage is the high prevalence and incidence of foot disorders (clinical and subclinical), which cause high economic losses and also seriously impair the welfare of dairy cattle. To point out the importance of reducing the amount and severity of foot disorders, advice to farmers should include information about the scale of the problem and the consequences in terms of economics and animal welfare. To provide support in making decisions on implementing intervention measures, insight into costs and benefits of different measures should be available. The objective of this study, therefore, is to provide more insight into the costs and benefits, for farmer and cow, of different intervention measures to improve dairy cow foot health. Intervention measures were modeled when they were applicable on a dairy farm with cubicle housing and when sufficient information was available in literature. Net costs were calculated as the difference between the costs of the measure and the economic benefits resulting from the measure. Welfare benefits were calculated as well. Cost-effective measures are: improving lying surface (mattress and bedding, €7 and €1/cow per year, respectively), reducing stocking density (break even) and performing additional foot trimming (€1/cow per year). Simultaneously, these measures have a relative high welfare benefit. Labor costs play an important role in the cost-effectiveness of labor-intensive measures. More insight into cost-effectiveness and welfare benefits of intervention measures can help to prioritize when choosing between intervention measures.

  18. Cow`s milk protein allergy awareness and practice among Turkish pediatricians: A questionnaire-survey.

    Science.gov (United States)

    Yüce, Aysel; Dalgıç, Buket; Çullu-Çokuğraş, Fügen; Çokuğraş, Haluk; Kansu, Aydan; Alptekin-Sarıoğlu, Aysugül; Şekerel, Bülent Enis

    2017-01-01

    Yüce A, Dalgıç B, Çullu-Çokuğraş F, Çokuğraş H, Kansu A, Alptekin-Sarıoğlu A, Şekerel BE. Cow`s milk protein allergy awareness and practice among Turkish pediatricians: A questionnaire-survey. Turk J Pediatr 2017; 59: 233-243. Region-specific recommendations for the prevention, diagnosis, and treatment of cow`s milk protein allergy (CMPA) are not available in Turkey. This cross-sectional questionnaire-survey was designed to evaluate CMPA awareness and practice among Turkish pediatricians. A total of 410 pediatricians were included based on their voluntary participation. Questionnaires elicited demographic data and pediatricians` awareness and practice of CMPA in infants and children. Atopic dermatitis (91.5%), diarrhea (88.0%) and significant blood in stool (85.9%) were the most common symptoms considered suggestive of CMPA. Continuation of breast feeding via elimination of CMP containing products from maternal diet was the most commonly selected (79.0%) therapeutic option in exclusively breast-fed infants diagnosed with CMPA. Amino acid-based formula was the most commonly selected formula in a non-exclusively breast-fed infant with CMPA, for infants presenting with anaphylaxis (58.8%), enterocolitis (40.7%) or multiple food allergies (52.0%), and also for at-risk infants (40.2%). Earliest time to re-challenge was identified to be 6 months by 52.0% of pediatricians. In conclusion, our findings revealed high awareness of CMPA among Turkish pediatricians in terms of clinical presentation and first priority diagnostic tests. However, CMPA practice among Turkish pediatricians needs to be improved in terms of avoidance of other mammalian milks, selection of therapeutic formulas among non-exclusively breast-fed infants and at-risk infants consistent with guideline-based indications and cost-effectivity.

  19. Kinetic Simulations of Particle Acceleration at Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Caprioli, Damiano [Princeton University; Guo, Fan [Los Alamos National Laboratory

    2015-07-16

    Collisionless shocks are mediated by collective electromagnetic interactions and are sources of non-thermal particles and emission. The full particle-in-cell approach and a hybrid approach are sketched, simulations of collisionless shocks are shown using a multicolor presentation. Results for SN 1006, a case involving ion acceleration and B field amplification where the shock is parallel, are shown. Electron acceleration takes place in planetary bow shocks and galaxy clusters. It is concluded that acceleration at shocks can be efficient: >15%; CRs amplify B field via streaming instability; ion DSA is efficient at parallel, strong shocks; ions are injected via reflection and shock drift acceleration; and electron DSA is efficient at oblique shocks.

  20. 29th International Symposium on Shock Waves

    CERN Document Server

    Ranjan, Devesh

    2015-01-01

    This proceedings present the results of the 29th International Symposium on Shock Waves (ISSW29) which was held in Madison, Wisconsin, U.S.A., from July 14 to July 19, 2013. It was organized by the Wisconsin Shock Tube Laboratory, which is part of the College of Engineering of the University of Wisconsin-Madison. The ISSW29 focused on the following areas: Blast Waves, Chemically Reactive Flows, Detonation and Combustion,  Facilities, Flow Visualization, Hypersonic Flow, Ignition, Impact and Compaction, Industrial Applications, Magnetohydrodynamics, Medical and Biological Applications, Nozzle Flow, Numerical Methods, Plasmas, Propulsion, Richtmyer-Meshkov Instability, Shock-Boundary Layer Interaction, Shock Propagation and Reflection, Shock Vortex Interaction, Shock Waves in Condensed Matter, Shock Waves in Multiphase Flow, as well as Shock Waves in Rarefield Flow. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 29 and individuals interes...