WorldWideScience

Sample records for mach number increases

  1. Increased Mach Number Capability for the NASA Glenn 10x10 Supersonic Wind Tunnel

    Science.gov (United States)

    Slater, J. W.; Saunders, J. D.

    2015-01-01

    Computational simulations and wind tunnel testing were conducted to explore the operation of the Abe Silverstein Supersonic Wind Tunnel at the NASA Glenn Research Center at test section Mach numbers above the current limit of Mach 3.5. An increased Mach number would enhance the capability for testing of supersonic and hypersonic propulsion systems. The focus of the explorations was on understanding the flow within the second throat of the tunnel, which is downstream of the test section and is where the supersonic flow decelerates to subsonic flow. Methods of computational fluid dynamics (CFD) were applied to provide details of the shock boundary layer structure and to estimate losses in total pressure. The CFD simulations indicated that the tunnel could be operated up to Mach 4.0 if the minimum width of the second throat was made smaller than that used for previous operation of the tunnel. Wind tunnel testing was able to confirm such operation of the tunnel at Mach 3.6 and 3.7 before a hydraulic failure caused a stop to the testing. CFD simulations performed after the wind tunnel testing showed good agreement with test data consisting of static pressures along the ceiling of the second throat. The CFD analyses showed increased shockwave boundary layer interactions, which was also observed as increased unsteadiness of dynamic pressures collected in the wind tunnel testing.

  2. Improving Euler computations at low Mach numbers

    NARCIS (Netherlands)

    Koren, B.; Leer, van B.; Deconinck, H.; Koren, B.

    1997-01-01

    The paper consists of two parts, both dealing with conditioning techniques for lowMach-number Euler-flow computations, in which a multigrid technique is applied. In the first part, for subsonic flows and upwind-discretized, linearized 1-D Euler equations, the smoothing behavior of

  3. Improving Euler computations at low Mach numbers

    NARCIS (Netherlands)

    Koren, B.

    1996-01-01

    This paper consists of two parts, both dealing with conditioning techniques for low-Mach-number Euler-flow computations, in which a multigrid technique is applied. In the first part, for subsonic flows and upwind-discretized linearized 1-D Euler equations, the smoothing behavior of

  4. Very high Mach number shocks - Theory. [in space plasmas

    Science.gov (United States)

    Quest, Kevin B.

    1986-01-01

    The theory and simulation of collisionless perpendicular supercritical shock structure is reviewed, with major emphasis on recent research results. The primary tool of investigation is the hybrid simulation method, in which the Newtonian orbits of a large number of ion macroparticles are followed numerically, and in which the electrons are treated as a charge neutralizing fluid. The principal results include the following: (1) electron resistivity is not required to explain the observed quasi-stationarity of the earth's bow shock, (2) the structure of the perpendicular shock at very high Mach numbers depends sensitively on the upstream value of beta (the ratio of the thermal to magnetic pressure) and electron resistivity, (3) two-dimensional turbulence will become increasingly important as the Mach number is increased, and (4) nonadiabatic bulk electron heating will result when a thermal electron cannot complete a gyrorbit while transiting the shock.

  5. Effects of Mach number on pitot-probe displacement in a turbulent boundary layer

    Science.gov (United States)

    Allen, J. M.

    1974-01-01

    Experimental pitot-probe-displacement data have been obtained in a turbulent boundary layer at a local free-stream Mach number of 4.63 and unit Reynolds number of 6.46 million meter. The results of this study were compared with lower Mach number results of previous studies. It was found that small probes showed displacement only, whereas the larger probes showed not only displacement but also distortion of the shape of the boundary-layer profile. The distortion pattern occurred lower in the boundary layer at the higher Mach number than at the the lower Mach number. The maximum distortion occurred when the center of the probe was about one probe diameter off the test surface. For probes in the wall contact position, the indicated Mach numbers were, for all probes tested, close to the true profile. Pitot-probe displacement was found to increase significantly with increasing Mach number.

  6. Aeroacoustic computation of low Mach number flow

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, K.S.

    1996-12-01

    This thesis explores the possibilities of applying a recently developed numerical technique to predict aerodynamically generated sound from wind turbines. The technique is a perturbation technique that has the advantage that the underlying flow field and the sound field are computed separately. Solution of the incompressible, time dependent flow field yields a hydrodynamic density correction to the incompressible constant density. The sound field is calculated from a set of equations governing the inviscid perturbations about the corrected flow field. Here, the emphasis is placed on the computation of the sound field. The nonlinear partial differential equations governing the sound field are solved numerically using an explicit MacCormack scheme. Two types of non-reflecting boundary conditions are applied; one based on the asymptotic solution of the governing equations and the other based on a characteristic analysis of the governing equations. The former condition is easy to use and it performs slightly better than the characteristic based condition. The technique is applied to the problems of the sound generation of a pulsating sphere, which is a monopole; a co-rotating vortex pair, which is a quadrupole, and the viscous flow over a circular cylinder, which is a dipole. The governing equations are written and solved for spherical, Cartesian, and cylindrical coordinates, respectively, thus, representing three common orthogonal coordinate systems. Numerical results agree very well with the analytical solutions for the problems of the pulsating sphere and the co-rotating vortex pair. Numerical results for the viscous flow over a cylinder are presented and evaluated qualitatively. The technique has potential for applications to airfoil flows as they are on a wind turbine blade, as well as for other low Mach number flows. (au) 2 tabs., 33 ills., 48 refs.

  7. Variation with Mach Number of Static and Total Pressures Through Various Screens

    Science.gov (United States)

    Adler, Alfred A

    1946-01-01

    Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached. Since choking imposes a restriction on the mass rate of flow and maximum losses are incurred at this condition, great care must be taken in selecting the screen mesh and wire dimmeter for an installation so that the choking Mach number is

  8. Mathematical and numerical aspects of low mach number flows

    Energy Technology Data Exchange (ETDEWEB)

    Schochet, St.; Bresch, D.; Grenier, E.; Alazard, T.; Gordner, A.; Sankaran, V.; Massot, M.; Sery, R.; Pebay, P.; Lunch, O.; Mazhorova, O.; Turkel, O.E.; Faille, I.; Danchin, R.; Allain, O.; Birken, P.; Lafitte, O.; Kloczko, T.; Frick, W.; Bui, T.; Dellacherie, S.; Klein, R.; Roe, Ph.; Accary, G.; Braack, M.; Picano, F.; Cadiou, A.; Dinescu, C.; Lesage, A.C.; Wesseling, P.; Heuveline, V.; Jobelin, M.; Weisman, C.; Merkle, C.

    2004-07-01

    Low Mach number flows represent a significant part of the various flows encountered in geophysics, industry or every day life. Paradoxically, the mathematical analysis of the equations governing these flows is difficult and on the practical side, the research of numerical algorithms valid for all flow speeds is continuing to be a challenge. However, in the last decade, both from the theoretical and the numerical sides, significant progresses were made in the understanding and analysis of the equations governing these flows. This conference intends to provide an up-to-date inventory of recent mathematical and numerical results in the analysis of these flows by bringing together both mathematicians and numericists active in this area. In the framework of the conference, a numerical workshop is organized which proposes to compute several challenging low Mach number flows: liquid flow around non-cavitating and cavitating NACA0015 hydrofoil, natural convection with large temperature differences, free convection, free surface flow, vessel pressurization. This document brings together the descriptions of the test cases of the numerical workshop and the abstracts of the conference papers: A 3D high order finite volume method for the prediction of near-critical fluid flows (G. ACCARY, I. RASPO, P. BONTOUX, B. ZAPPOLI); low Mach number limit of the non-isentropic Navier-Stokes equations (T. ALAZARD); simulation of cavitation rolls past a forward step with a bubble model (O. ALLAIN, N. BLASKA, C. LECA); flux preconditioning methods and fire events (P. BIRKEN, A. MEISTER); an adaptive finite element solver for compressible flows: application to heat-driven cavity benchmarks in 2D and 3D (M. BRAACK); comparison of various implicit, explicit, centered and upwind schemes for the simulation of compressed flows on moving mesh (A. CADIOU, M. BUFFAT, L. Le PENVEN, C. Le RIBAULT); low Mach number limit for viscous compressible flows (R. DANCHIN); some Properties of the low Mach number

  9. Physical and numerical modelling of low mach number compressible flows

    International Nuclear Information System (INIS)

    Paillerre, H.; Clerc, S.; Dabbene, F.; Cueto, O.

    1999-01-01

    This article reviews various physical models that may be used to describe compressible flow at low Mach numbers, as well as the numerical methods developed at DRN to discretize the different systems of equations. A selection of thermal-hydraulic applications illustrate the need to take into account compressibility and multidimensional effects as well as variable flow properties. (authors)

  10. Low-Mach number simulations of transcritical flows

    KAUST Repository

    Lapenna, Pasquale E.

    2018-01-08

    A numerical framework for the direct simulation, in the low-Mach number limit, of reacting and non-reacting transcritical flows is presented. The key feature are an efficient and detailed representation of the real fluid properties and an high-order spatial discretization. The latter is of fundamental importance to correctly resolve the largely non-linear behavior of the fluid in the proximity of the pseudo-boiling. The validity of the low-Mach number assumptions is assessed for a previously developed non-reacting DNS database of transcritical and supercritical mixing. Fully resolved DNS data employing high-fidelity thermodynamical models are also used to investigate the spectral characteristic as well as the differences between transcritical and supercritical jets.

  11. Low Mach number asymptotics for reacting compressible fluid flows

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Petzeltová, Hana

    2010-01-01

    Roč. 26, č. 2 (2010), s. 455-480 ISSN 1078-0947 R&D Projects: GA ČR GA201/05/0164 Institutional research plan: CEZ:AV0Z10190503 Keywords : low Mach number * Navier-Stokes-Fourier system * reacting fluids Subject RIV: BA - General Mathematics Impact factor: 0.986, year: 2010 http://www.aimsciences.org/journals/displayArticles.jsp?paperID=4660

  12. Low Mach number limits of compressible rotating fluids

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard

    2012-01-01

    Roč. 14, č. 1 (2012), s. 61-78 ISSN 1422-6928 R&D Projects: GA ČR GA201/08/0315 Institutional research plan: CEZ:AV0Z10190503 Keywords : low Mach number limit * rotating fluid * compressible fluid Subject RIV: BA - General Mathematics Impact factor: 1.415, year: 2012 http://www.springerlink.com/content/635r1116j40t6428/

  13. Numerical simulation of low Mach number reacting flows

    International Nuclear Information System (INIS)

    Bell, J B; Aspden, A J; Day, M S; Lijewski, M J

    2007-01-01

    Using examples from active research areas in combustion and astrophysics, we demonstrate a computationally efficient numerical approach for simulating multiscale low Mach number reacting flows. The method enables simulations that incorporate an unprecedented range of temporal and spatial scales, while at the same time, allows an extremely high degree of reaction fidelity. Sample applications demonstrate the efficiency of the approach with respect to a traditional time-explicit integration method, and the utility of the methodology for studying the interaction of turbulence with terrestrial and astrophysical flame structures

  14. Mach Number effects on turbulent superstructures in wall bounded flows

    Science.gov (United States)

    Kaehler, Christian J.; Bross, Matthew; Scharnowski, Sven

    2017-11-01

    Planer and three-dimensional flow field measurements along a flat plat boundary layer in the Trisonic Wind Tunnel Munich (TWM) are examined with the aim to characterize the scaling, spatial organization, and topology of large scale turbulent superstructures in compressible flow. This facility is ideal for this investigation as the ratio of boundary layer thickness to test section spanwise extent ratio is around 1/25, ensuring minimal sidewall and corner effects on turbulent structures in the center of the test section. A major difficulty in the experimental investigation of large scale features is the mutual size of the superstructures which can extend over many boundary layer thicknesses. Using multiple PIV systems, it was possible to capture the full spatial extent of large-scale structures over a range of Mach numbers from Ma = 0.3 - 3. To calculate the average large-scale structure length and spacing, the acquired vector fields were analyzed by statistical multi-point methods that show large scale structures with a correlation length of around 10 boundary layer thicknesses over the range of Mach numbers investigated. Furthermore, the average spacing between high and low momentum structures is on the order of a boundary layer thicknesses. This work is supported by the Priority Programme SPP 1881 Turbulent Superstructures of the Deutsche Forschungsgemeinschaft.

  15. The Variation of Slat Noise with Mach and Reynolds Numbers

    Science.gov (United States)

    Lockard, David P.; Choudhari, Meelan M.

    2011-01-01

    The slat noise from the 30P30N high-lift system has been computed using a computational fluid dynamics code in conjunction with a Ffowcs Williams-Hawkings solver. By varying the Mach number from 0.13 to 0.25, the noise was found to vary roughly with the 5th power of the speed. Slight changes in the behavior with directivity angle could easily account for the different speed dependencies reported in the literature. Varying the Reynolds number from 1.4 to 2.4 million resulted in almost no differences, and primarily served to demonstrate the repeatability of the results. However, changing the underlying hybrid Reynolds-averaged-Navier-Stokes/Large-Eddy-Simulation turbulence model significantly altered the mean flow because of changes in the flap separation. However, the general trends observed in both the acoustics and near-field fluctuations were similar for both models.

  16. Angular dependence of high Mach number plasma interactions

    International Nuclear Information System (INIS)

    Thomas, V.A.; Brecht, S.H.

    1987-01-01

    In this paper a 2-1/2-dimensional hybrid code is used to examine the collisionless large spatial scale (kc/ω pi ∼ 1) low-frequency (ω ∼ ω ci ) interaction initiated by a plasma shell of finite width traveling at high Alfven Mach number relative to a uniform background plasma. Particular attention is given to the angle of the relative velocity relative to the ambient magnetic field for the range of angles O < θ < π/2. An attempt is made to parameterize some of the important physics including the Alfven ion cyclotron instability, the field-aligned electromagnetic ion counter streaming instability, mixing of the plasma shell with the background ions, and structuring of the interaction region. These results are applicable to various astrophysical interactions such as bow shocks and interplanetary shocks

  17. Numerical solutions of unsteady flows with low inlet Mach numbers

    Czech Academy of Sciences Publication Activity Database

    Punčochářová, Petra; Furst, Jiří; Horáček, Jaromír; Kozel, Karel

    2010-01-01

    Roč. 80, č. 8 (2010), s. 1795-1805 ISSN 0378-4754 R&D Projects: GA AV ČR IAA200760613 Institutional research plan: CEZ:AV0Z20760514 Keywords : finite volume method * unsteady flow * low Mach number * viscous compressible fluid Subject RIV: BI - Acoustics Impact factor: 0.812, year: 2010 http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6V0T-4Y0D67D-1-R&_cdi=5655&_user=640952&_pii=S0378475409003607&_origin=search&_coverDate=04%2F30%2F2010&_sk=999199991&view=c&wchp=dGLbVlb-zSkzk&md5=ed6eaf0a050968ee978714fd54e7f131&ie=/sdarticle.pdf

  18. Study and discretization of kinetic models and fluid models at low Mach number

    International Nuclear Information System (INIS)

    Dellacherie, Stephane

    2011-01-01

    This thesis summarizes our work between 1995 and 2010. It concerns the analysis and the discretization of Fokker-Planck or semi-classical Boltzmann kinetic models and of Euler or Navier-Stokes fluid models at low Mach number. The studied Fokker-Planck equation models the collisions between ions and electrons in a hot plasma, and is here applied to the inertial confinement fusion. The studied semi-classical Boltzmann equations are of two types. The first one models the thermonuclear reaction between a deuterium ion and a tritium ion producing an α particle and a neutron particle, and is also in our case used to describe inertial confinement fusion. The second one (known as the Wang-Chang and Uhlenbeck equations) models the transitions between electronic quantified energy levels of uranium and iron atoms in the AVLIS isotopic separation process. The basic properties of these two Boltzmann equations are studied, and, for the Wang-Chang and Uhlenbeck equations, a kinetic-fluid coupling algorithm is proposed. This kinetic-fluid coupling algorithm incited us to study the relaxation concept for gas and immiscible fluids mixtures, and to underline connections with classical kinetic theory. Then, a diphasic low Mach number model without acoustic waves is proposed to model the deformation of the interface between two immiscible fluids induced by high heat transfers at low Mach number. In order to increase the accuracy of the results without increasing computational cost, an AMR algorithm is studied on a simplified interface deformation model. These low Mach number studies also incited us to analyse on cartesian meshes the inaccuracy at low Mach number of Godunov schemes. Finally, the LBM algorithm applied to the heat equation is justified

  19. High-Mach number, laser-driven magnetized collisionless shocks

    International Nuclear Information System (INIS)

    Schaeffer, Derek B.; Fox, W.; Haberberger, D.; Fiksel, G.; Bhattacharjee, A.

    2017-01-01

    Collisionless shocks are ubiquitous in space and astrophysical systems, and the class of supercritical shocks is of particular importance due to their role in accelerating particles to high energies. While these shocks have been traditionally studied by spacecraft and remote sensing observations, laboratory experiments can provide reproducible and multi-dimensional datasets that provide complementary understanding of the underlying microphysics. We present experiments undertaken on the OMEGA and OMEGA EP laser facilities that show the formation and evolution of high-Mach number collisionless shocks created through the interaction of a laser-driven magnetic piston and magnetized ambient plasma. Through time-resolved, 2-D imaging we observe large density and magnetic compressions that propagate at super-Alfvenic speeds and that occur over ion kinetic length scales. Electron density and temperature of the initial ambient plasma are characterized using optical Thomson scattering. Measurements of the piston laser-plasma are modeled with 2-D radiation-hydrodynamic simulations, which are used to initialize 2-D particle-in-cell simulations of the interaction between the piston and ambient plasmas. The numerical results show the formation of collisionless shocks, including the separate dynamics of the carbon and hydrogen ions that constitute the ambient plasma and their effect on the shock structure. Furthermore, the simulations also show the shock separating from the piston, which we observe in the data at late experimental times.

  20. Mach number scaling of helicopter rotor blade/vortex interaction noise

    Science.gov (United States)

    Leighton, Kenneth P.; Harris, Wesley L.

    1985-01-01

    A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

  1. Role of Turbulent Prandtl Number on Heat Flux at Hypersonic Mach Numbers

    Science.gov (United States)

    Xiao, X.; Edwards, J. R.; Hassan, H. A.; Gaffney, R. L., Jr.

    2007-01-01

    A new turbulence model suited for calculating the turbulent Prandtl number as part of the solution is presented. The model is based on a set of two equations: one governing the variance of the enthalpy and the other governing its dissipation rate. These equations were derived from the exact energy equation and thus take into consideration compressibility and dissipation terms. The model is used to study two cases involving shock wave/boundary layer interaction at Mach 9.22 and Mach 5.0. In general, heat transfer prediction showed great improvement over traditional turbulence models where the turbulent Prandtl number is assumed constant. It is concluded that using a model that calculates the turbulent Prandtl number as part of the solution is the key to bridging the gap between theory and experiment for flows dominated by shock wave/boundary layer interactions.

  2. Effects of rocket jet on stability and control at high Mach numbers

    Science.gov (United States)

    Fetterman, David E , Jr

    1958-01-01

    Paper presents the results of an investigation to determine the jet-interference effects which may occur at high jet static-pressure ratios and high Mach numbers. Tests were made in the Langley 11-inch hypersonic tunnel at a Mach number of 6.86.

  3. Dynamic pressure sensitivity determination with Mach number method

    Science.gov (United States)

    Sarraf, Christophe; Damion, Jean-Pierre

    2018-05-01

    Measurements of pressure in fast transient conditions are often performed even if the dynamic characteristic of the transducer are not traceable to international standards. Moreover, the question of a primary standard in dynamic pressure is still open, especially for gaseous applications. The question is to improve dynamic standards in order to respond to expressed industrial needs. In this paper, the method proposed in the EMRP IND09 ‘Dynamic’ project, which can be called the ‘ideal shock tube method’, is compared with the ‘collective standard method’ currently used in the Laboratoire de Métrologie Dynamique (LNE/ENSAM). The input is a step of pressure generated by a shock tube. The transducer is a piezoelectric pressure sensor. With the ‘ideal shock tube method’ the sensitivity of a pressure sensor is first determined dynamically. This method requires a shock tube implemented with piezoelectric shock wave detectors. The measurement of the Mach number in the tube allows an evaluation of the incident pressure amplitude of a step using a theoretical 1D model of the shock tube. Heat transfer, other actual effects and effects of the shock tube imperfections are not taken into account. The amplitude of the pressure step is then used to determine the sensitivity in dynamic conditions. The second method uses a frequency bandwidth comparison to determine pressure at frequencies from quasi-static conditions, traceable to static pressure standards, to higher frequencies (up to 10 kHz). The measurand is also a step of pressure generated by a supposed ideal shock tube or a fast-opening device. The results are provided as a transfer function with an uncertainty budget assigned to a frequency range, also deliverable frequency by frequency. The largest uncertainty in the bandwidth of comparison is used to trace the final pressure step level measured in dynamic conditions, owing that this pressure is not measurable in a steady state on a shock tube. A reference

  4. Analysis of gas turbine engines using water and oxygen injection to achieve high Mach numbers and high thrust

    Science.gov (United States)

    Henneberry, Hugh M.; Snyder, Christopher A.

    1993-01-01

    An analysis of gas turbine engines using water and oxygen injection to enhance performance by increasing Mach number capability and by increasing thrust is described. The liquids are injected, either separately or together, into the subsonic diffuser ahead of the engine compressor. A turbojet engine and a mixed-flow turbofan engine (MFTF) are examined, and in pursuit of maximum thrust, both engines are fitted with afterburners. The results indicate that water injection alone can extend the performance envelope of both engine types by one and one-half Mach numbers at which point water-air ratios reach 17 or 18 percent and liquid specific impulse is reduced to some 390 to 470 seconds, a level about equal to the impulse of a high energy rocket engine. The envelope can be further extended, but only with increasing sacrifices in liquid specific impulse. Oxygen-airflow ratios as high as 15 percent were investigated for increasing thrust. Using 15 percent oxygen in combination with water injection at high supersonic Mach numbers resulted in thrust augmentation as high as 76 percent without any significant decrease in liquid specific impulse. The stoichiometric afterburner exit temperature increased with increasing oxygen flow, reaching 4822 deg R in the turbojet engine at a Mach number of 3.5. At the transonic Mach number of 0.95 where no water injection is needed, an oxygen-air ratio of 15 percent increased thrust by some 55 percent in both engines, along with a decrease in liquid specific impulse of 62 percent. Afterburner temperature was approximately 4700 deg R at this high thrust condition. Water and/or oxygen injection are simple and straightforward strategies to improve engine performance and they will add little to engine weight. However, if large Mach number and thrust increases are required, liquid flows become significant, so that operation at these conditions will necessarily be of short duration.

  5. Effect of Mach number on thermoelectric performance of SiC ceramics nose-tip for supersonic vehicles

    International Nuclear Information System (INIS)

    Han, Xiao-Yi; Wang, Jun

    2014-01-01

    This paper focus on the effects of Mach number on thermoelectric energy conversion for the limitation of aero-heating and the feasibility of energy harvesting on supersonic vehicles. A model of nose-tip structure constructed with SiC ceramics is developed to numerically study the thermoelectric performance in a supersonic flow field by employing the computational fluid dynamics and the thermal conduction theory. Results are given in the cases of different Mach numbers. Moreover, the thermoelectric performance in each case is predicted with and without Thomson heat, respectively. Due to the increase of Mach number, both the temperature difference and the conductive heat flux between the hot side and the cold side of nose tip are increased. This results in the growth of the thermoelectric power generated and the energy conversion efficiency. With respect to the Thomson effect, over 50% of total power generated converts to Thomson heat, which greatly reduces the thermoelectric power and efficiency. However, whether the Thomson effect is considered or not, with the Mach number increasing from 2.5 to 4.5, the thermoelectric performance can be effectively improved. -- Highlights: • Thermoelectric SiC nose-tip structure for aerodynamic heat harvesting of high-speed vehicles is studied. • Thermoelectric performance is predicted based on numerical methods and experimental thermoelectric parameters. • The effects of Mach number on thermoelectric performance are studied in the present paper. • Results with respect to the Thomson effect are also explored. • Output power and energy efficiency of the thermoelectric nose-tip are increased with the increase of Mach number

  6. Performance Limiting Flow Processes in High-State Loading High-Mach Number Compressors

    National Research Council Canada - National Science Library

    Tan, Choon S

    2008-01-01

    In high-stage loading high-Mach number (HLM) compressors, counter-rotating pairs of discrete vortices are shed at the trailing edge of the upstream blade row at a frequency corresponding to the downstream rotor blade passing frequency...

  7. Derivation of the low Mach number diphasic system. Numerical simulation in mono-dimensional geometry

    International Nuclear Information System (INIS)

    Dellacherie, St.

    2004-01-01

    This work deals with the derivation of a diphasic low Mach number model obtained through a Mach number asymptotic expansion applied to the compressible diphasic Navier Stokes system, expansion which filters out the acoustic waves. This approach is inspired from the work of Andrew Majda giving the equations of low Mach number combustion for thin flame and for perfect gases. When the equations of state verify some thermodynamic hypothesis, we show that the low Mach number diphasic system predicts in a good way the dilatation or the compression of a bubble and has equilibrium convergence properties. Then, we propose an entropic and convergent Lagrangian scheme in mono-dimensional geometry when the fluids are perfect gases and we propose a first approach in Eulerian variables where the interface between the two fluids is captured with a level set technique. (author)

  8. Influences of mach number and flow incidence on aerodynamic losses of steam turbine blade

    International Nuclear Information System (INIS)

    Yoo, Seok Jae; Ng, Wing Fai

    2000-01-01

    An experiment was conducted to investigate the aerodynamic losses of high pressure steam turbine nozzle (526A) subjected to a large range of incident angles (-34 .deg. to 26 .deg. ) and exit Mach numbers (0.6 and 1.15). Measurements included downstream pitot probe traverses, upstream total pressure, and endwall static pressures. Flow visualization techniques such as shadowgraph and color oil flow visualization were performed to complement the measured data. When the exit Mach number for nozzles increased from 0.9 to 1.1 the total pressure loss coefficient increased by a factor of 7 as compared to the total pressure losses measured at subsonic conditions (M 2 <0.9). For the range of incidence tested, the effect of flow incidence on the total pressure losses is less pronounced. Based on the shadowgraphs taken during the experiment, it's believed that the large increase in losses at transonic conditions is due to strong shock/ boundary layer interaction that may lead to flow separation on the blade suction surface

  9. OPACITY BROADENING OF {sup 13}CO LINEWIDTHS AND ITS EFFECT ON THE VARIANCE-SONIC MACH NUMBER RELATION

    Energy Technology Data Exchange (ETDEWEB)

    Correia, C.; De Medeiros, J. R. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 (Brazil); Burkhart, B.; Lazarian, A. [Astronomy Department, University of Wisconsin, Madison, 475 North Charter Street, WI 53711 (United States); Ossenkopf, V.; Stutzki, J. [Physikalisches Institut der Universität zu Köln, Zülpicher Strasse 77, D-50937 Köln (Germany); Kainulainen, J. [Max-Planck-Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Kowal, G., E-mail: caioftc@dfte.ufrn.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, 05508-090 (Brazil)

    2014-04-10

    We study how the estimation of the sonic Mach number (M{sub s} ) from {sup 13}CO linewidths relates to the actual three-dimensional sonic Mach number. For this purpose we analyze MHD simulations that include post-processing to take radiative transfer effects into account. As expected, we find very good agreement between the linewidth estimated sonic Mach number and the actual sonic Mach number of the simulations for optically thin tracers. However, we find that opacity broadening causes M{sub s} to be overestimated by a factor of ≈1.16-1.3 when calculated from optically thick {sup 13}CO lines. We also find that there is a dependence on the magnetic field: super-Alfvénic turbulence shows increased line broadening compared with sub-Alfvénic turbulence for all values of optical depth for supersonic turbulence. Our results have implications for the observationally derived sonic Mach number-density standard deviation (σ{sub ρ/(ρ)}) relationship, σ{sub ρ/〈ρ〉}{sup 2}=b{sup 2}M{sub s}{sup 2}, and the related column density standard deviation (σ {sub N/(N)}) sonic Mach number relationship. In particular, we find that the parameter b, as an indicator of solenoidal versus compressive driving, will be underestimated as a result of opacity broadening. We compare the σ {sub N/(N)}-M{sub s} relation derived from synthetic dust extinction maps and {sup 13}CO linewidths with recent observational studies and find that solenoidally driven MHD turbulence simulations have values of σ {sub N/(N)}which are lower than real molecular clouds. This may be due to the influence of self-gravity which should be included in simulations of molecular cloud dynamics.

  10. Role of Turbulent Prandtl Number on Heat Flux at Hypersonic Mach Number

    Science.gov (United States)

    Xiao, X.; Edwards, J. R.; Hassan, H. A.

    2004-01-01

    Present simulation of turbulent flows involving shock wave/boundary layer interaction invariably overestimates heat flux by almost a factor of two. One possible reason for such a performance is a result of the fact that the turbulence models employed make use of Morkovin's hypothesis. This hypothesis is valid for non-hypersonic Mach numbers and moderate rates of heat transfer. At hypersonic Mach numbers, high rates of heat transfer exist in regions where shock wave/boundary layer interactions are important. As a result, one should not expect traditional turbulence models to yield accurate results. The goal of this investigation is to explore the role of a variable Prandtl number formulation in predicting heat flux in flows dominated by strong shock wave/boundary layer interactions. The intended applications involve external flows in the absence of combustion such as those encountered in supersonic inlets. This can be achieved by adding equations for the temperature variance and its dissipation rate. Such equations can be derived from the exact Navier-Stokes equations. Traditionally, modeled equations are based on the low speed energy equation where the pressure gradient term and the term responsible for energy dissipation are ignored. It is clear that such assumptions are not valid for hypersonic flows. The approach used here is based on the procedure used in deriving the k-zeta model, in which the exact equations that governed k, the variance of velocity, and zeta, the variance of vorticity, were derived and modeled. For the variable turbulent Prandtl number, the exact equations that govern the temperature variance and its dissipation rate are derived and modeled term by term. The resulting set of equations are free of damping and wall functions and are coordinate-system independent. Moreover, modeled correlations are tensorially consistent and invariant under Galilean transformation. The final set of equations will be given in the paper.

  11. Spectroscopic studies of a high Mach-number rotating plasma flow

    International Nuclear Information System (INIS)

    Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi

    2001-01-01

    Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII (γ=468.58 nm) and HeI (γ=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T i increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

  12. Spectroscopic studies of a high Mach-number rotating plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi [Tohoku Univ., Dept. of Electrical Engineering, Sendai, Miyagi (Japan)

    2001-07-01

    Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII ({gamma}=468.58 nm) and HeI ({gamma}=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T{sub i} increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

  13. On the instabilities of supersonic mixing layers - A high-Mach-number asymptotic theory

    Science.gov (United States)

    Balsa, Thomas F.; Goldstein, M. E.

    1990-01-01

    The stability of a family of tanh mixing layers is studied at large Mach numbers using perturbation methods. It is found that the eigenfunction develops a multilayered structure, and the eigenvalue is obtained by solving a simplified version of the Rayleigh equation (with homogeneous boundary conditions) in one of these layers which lies in either of the external streams. This analysis leads to a simple hypersonic similarity law which explains how spatial and temporal phase speeds and growth rates scale with Mach number and temperature ratio. Comparisons are made with numerical results, and it is found that this similarity law provides a good qualitative guide for the behavior of the instability at high Mach numbers. In addition to this asymptotic theory, some fully numerical results are also presented (with no limitation on the Mach number) in order to explain the origin of the hypersonic modes (through mode splitting) and to discuss the role of oblique modes over a very wide range of Mach number and temperature ratio.

  14. Study by the Prandtl-Glauert method of compressibility effects and critical Mach number for ellipsoids of various aspect ratios and thickness ratios

    Science.gov (United States)

    Hess, Robert V; Gardner, Clifford S

    1947-01-01

    By using the Prandtl-Glauert method that is valid for three-dimensional flow problems, the value of the maximum incremental velocity for compressible flow about thin ellipsoids at zero angle of attack is calculated as a function of the Mach number for various aspect ratios and thickness ratios. The critical Mach numbers of the various ellipsoids are also determined. The results indicate an increase in critical Mach number with decrease in aspect ratio which is large enough to explain experimental results on low-aspect-ratio wings at zero lift.

  15. Derivation of the low Mach number diphasic system. Numerical simulation in mono-dimensional geometry; Derivation du systeme diphasique bas Mach. Simulation numerique en geometrie monodimensionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Dellacherie, St

    2004-07-01

    This work deals with the derivation of a diphasic low Mach number model obtained through a Mach number asymptotic expansion applied to the compressible diphasic Navier Stokes system, expansion which filters out the acoustic waves. This approach is inspired from the work of Andrew Majda giving the equations of low Mach number combustion for thin flame and for perfect gases. When the equations of state verify some thermodynamic hypothesis, we show that the low Mach number diphasic system predicts in a good way the dilatation or the compression of a bubble and has equilibrium convergence properties. Then, we propose an entropic and convergent Lagrangian scheme in mono-dimensional geometry when the fluids are perfect gases and we propose a first approach in Eulerian variables where the interface between the two fluids is captured with a level set technique. (author)

  16. A Parametric Study of a Constant-Mach-Number MHD Generator with Nuclear Ionization

    International Nuclear Information System (INIS)

    Braun, J.

    1965-03-01

    The influence of electrical and gas dynamical parameters on the length, of a linear constant-Mach-number MHD duct has been investigated. The gas has been assumed to be ionized by neutron irradiation in the expansion nozzle preceding the MHD duct. Inside the duct the electron recombination is assumed to be governed, by volume recombination. It is found that there exists a distinct domain from which the parameters must be chosen, pressure and Mach number being the most critical ones. If power densities in the order of magnitude 100 MW/m 3 are desired, high magnetic fields and Mach numbers in the supersonic range are needed. The influence of the variation of critical parameters on the channel length is given as a product of simple functions, each containing one parameter

  17. Applicability of higher-order TVD method to low mach number compressible flows

    International Nuclear Information System (INIS)

    Akamatsu, Mikio

    1995-01-01

    Steep gradients of fluid density are the influential factor of spurious oscillation in numerical solutions of low Mach number (M<<1) compressible flows. The total variation diminishing (TVD) scheme is a promising remedy to overcome this problem and obtain accurate solutions. TVD schemes for high-speed flows are, however, not compatible with commonly used methods in low Mach number flows using pressure-based formulation. In the present study a higher-order TVD scheme is constructed on a modified form of each individual scalar equation of primitive variables. It is thus clarified that the concept of TVD is applicable to low Mach number flows within the framework of the existing numerical method. Results of test problems of the moving interface of two-component gases with the density ratio ≥ 4, demonstrate the accurate and robust (wiggle-free) profile of the scheme. (author)

  18. A Parametric Study of a Constant-Mach-Number MHD Generator with Nuclear Ionization

    Energy Technology Data Exchange (ETDEWEB)

    Braun, J

    1965-03-15

    The influence of electrical and gas dynamical parameters on the length, of a linear constant-Mach-number MHD duct has been investigated. The gas has been assumed to be ionized by neutron irradiation in the expansion nozzle preceding the MHD duct. Inside the duct the electron recombination is assumed to be governed, by volume recombination. It is found that there exists a distinct domain from which the parameters must be chosen, pressure and Mach number being the most critical ones. If power densities in the order of magnitude 100 MW/m{sup 3} are desired, high magnetic fields and Mach numbers in the supersonic range are needed. The influence of the variation of critical parameters on the channel length is given as a product of simple functions, each containing one parameter.

  19. Numerical simulation of unsteady compressible low Mach number flow in a channel

    Czech Academy of Sciences Publication Activity Database

    Punčochářová-Pořízková, P.; Kozel, Karel; Horáček, Jaromír; Fürst, J.

    2010-01-01

    Roč. 17, č. 2 (2010), s. 83-97 ISSN 1802-1484 R&D Projects: GA MŠk OC09019 Institutional research plan: CEZ:AV0Z20760514 Keywords : CFD * finite volume method * unsteady flow * low Mach number Subject RIV: BI - Acoustics

  20. Background-oriented schlieren imaging of flow around a circular cylinder at low Mach numbers

    Science.gov (United States)

    Stadler, Hannes; Bauknecht, André; Siegrist, Silvan; Flesch, Robert; Wolf, C. Christian; van Hinsberg, Nils; Jacobs, Markus

    2017-09-01

    The background-oriented schlieren (BOS) imaging method has, for the first time, been applied in the investigation of the flow around a circular cylinder at low Mach numbers (Msuccessive imaging at incremental angular positions around the cylinder. This density distribution has been found to agree well with the pressure measurements and with potential theory where appropriate.

  1. A two-dimensional, TVD numerical scheme for inviscid, high Mach number flows in chemical equilibrium

    Science.gov (United States)

    Eberhardt, S.; Palmer, G.

    1986-01-01

    A new algorithm has been developed for hypervelocity flows in chemical equilibrium. Solutions have been achieved for Mach numbers up to 15 with no adverse effect on convergence. Two methods of coupling an equilibrium chemistry package have been tested, with the simpler method proving to be more robust. Improvements in boundary conditions are still required for a production-quality code.

  2. Turbulent mixing of a slightly supercritical van der Waals fluid at low-Mach number

    International Nuclear Information System (INIS)

    Battista, F.; Casciola, C. M.; Picano, F.

    2014-01-01

    Supercritical fluids near the critical point are characterized by liquid-like densities and gas-like transport properties. These features are purposely exploited in different contexts ranging from natural products extraction/fractionation to aerospace propulsion. Large part of studies concerns this last context, focusing on the dynamics of supercritical fluids at high Mach number where compressibility and thermodynamics strictly interact. Despite the widespread use also at low Mach number, the turbulent mixing properties of slightly supercritical fluids have still not investigated in detail in this regime. This topic is addressed here by dealing with Direct Numerical Simulations of a coaxial jet of a slightly supercritical van der Waals fluid. Since acoustic effects are irrelevant in the low Mach number conditions found in many industrial applications, the numerical model is based on a suitable low-Mach number expansion of the governing equation. According to experimental observations, the weakly supercritical regime is characterized by the formation of finger-like structures – the so-called ligaments – in the shear layers separating the two streams. The mechanism of ligament formation at vanishing Mach number is extracted from the simulations and a detailed statistical characterization is provided. Ligaments always form whenever a high density contrast occurs, independently of real or perfect gas behaviors. The difference between real and perfect gas conditions is found in the ligament small-scale structure. More intense density gradients and thinner interfaces characterize the near critical fluid in comparison with the smoother behavior of the perfect gas. A phenomenological interpretation is here provided on the basis of the real gas thermodynamics properties

  3. Turbulent mixing of a slightly supercritical van der Waals fluid at low-Mach number

    Energy Technology Data Exchange (ETDEWEB)

    Battista, F.; Casciola, C. M. [Department of Mechanical and Aerospace Engineering, Sapienza University, via Eudossiana 18, 00184 Rome (Italy); Picano, F. [Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova (Italy)

    2014-05-15

    Supercritical fluids near the critical point are characterized by liquid-like densities and gas-like transport properties. These features are purposely exploited in different contexts ranging from natural products extraction/fractionation to aerospace propulsion. Large part of studies concerns this last context, focusing on the dynamics of supercritical fluids at high Mach number where compressibility and thermodynamics strictly interact. Despite the widespread use also at low Mach number, the turbulent mixing properties of slightly supercritical fluids have still not investigated in detail in this regime. This topic is addressed here by dealing with Direct Numerical Simulations of a coaxial jet of a slightly supercritical van der Waals fluid. Since acoustic effects are irrelevant in the low Mach number conditions found in many industrial applications, the numerical model is based on a suitable low-Mach number expansion of the governing equation. According to experimental observations, the weakly supercritical regime is characterized by the formation of finger-like structures – the so-called ligaments – in the shear layers separating the two streams. The mechanism of ligament formation at vanishing Mach number is extracted from the simulations and a detailed statistical characterization is provided. Ligaments always form whenever a high density contrast occurs, independently of real or perfect gas behaviors. The difference between real and perfect gas conditions is found in the ligament small-scale structure. More intense density gradients and thinner interfaces characterize the near critical fluid in comparison with the smoother behavior of the perfect gas. A phenomenological interpretation is here provided on the basis of the real gas thermodynamics properties.

  4. Application of a transitional boundary-layer theory in the low hypersonic Mach number regime

    Science.gov (United States)

    Shamroth, S. J.; Mcdonald, H.

    1975-01-01

    An investigation is made to assess the capability of a finite-difference boundary-layer procedure to predict the mean profile development across a transition from laminar to turbulent flow in the low hypersonic Mach-number regime. The boundary-layer procedure uses an integral form of the turbulence kinetic-energy equation to govern the development of the Reynolds apparent shear stress. The present investigation shows the ability of this procedure to predict Stanton number, velocity profiles, and density profiles through the transition region and, in addition, to predict the effect of wall cooling and Mach number on transition Reynolds number. The contribution of the pressure-dilatation term to the energy balance is examined and it is suggested that transition can be initiated by the direct absorption of acoustic energy even if only a small amount (1 per cent) of the incident acoustic energy is absorbed.

  5. Unit Reynolds number, Mach number and pressure gradient effects on laminar-turbulent transition in two-dimensional boundary layers

    Science.gov (United States)

    Risius, Steffen; Costantini, Marco; Koch, Stefan; Hein, Stefan; Klein, Christian

    2018-05-01

    The influence of unit Reynolds number (Re_1=17.5× 106-80× 106 {m}^{-1}), Mach number (M= 0.35-0.77) and incompressible shape factor (H_{12} = 2.50-2.66) on laminar-turbulent boundary layer transition was systematically investigated in the Cryogenic Ludwieg-Tube Göttingen (DNW-KRG). For this investigation the existing two-dimensional wind tunnel model, PaLASTra, which offers a quasi-uniform streamwise pressure gradient, was modified to reduce the size of the flow separation region at its trailing edge. The streamwise temperature distribution and the location of laminar-turbulent transition were measured by means of temperature-sensitive paint (TSP) with a higher accuracy than attained in earlier measurements. It was found that for the modified PaLASTra model the transition Reynolds number (Re_{ {tr}}) exhibits a linear dependence on the pressure gradient, characterized by H_{12}. Due to this linear relation it was possible to quantify the so-called `unit Reynolds number effect', which is an increase of Re_{ {tr}} with Re_1. By a systematic variation of M, Re_1 and H_{12} in combination with a spectral analysis of freestream disturbances, a stabilizing effect of compressibility on boundary layer transition, as predicted by linear stability theory, was detected (`Mach number effect'). Furthermore, two expressions were derived which can be used to calculate the transition Reynolds number as a function of the amplitude of total pressure fluctuations, Re_1 and H_{12}. To determine critical N-factors, the measured transition locations were correlated with amplification rates, calculated by incompressible and compressible linear stability theory. By taking into account the spectral level of total pressure fluctuations at the frequency of the most amplified Tollmien-Schlichting wave at transition location, the scatter in the determined critical N-factors was reduced. Furthermore, the receptivity coefficients dependence on incidence angle of acoustic waves was used to

  6. Assessment of a transitional boundary layer theory at low hypersonic Mach numbers

    Science.gov (United States)

    Shamroth, S. J.; Mcdonald, H.

    1972-01-01

    An investigation was carried out to assess the accuracy of a transitional boundary layer theory in the low hypersonic Mach number regime. The theory is based upon the simultaneous numerical solution of the boundary layer partial differential equations for the mean motion and an integral form of the turbulence kinetic energy equation which controls the magnitude and development of the Reynolds stress. Comparisions with experimental data show the theory is capable of accurately predicting heat transfer and velocity profiles through the transitional regime and correctly predicts the effects of Mach number and wall cooling on transition Reynolds number. The procedure shows promise of predicting the initiation of transition for given free stream disturbance levels. The effects on transition predictions of the pressure dilitation term and of direct absorption of acoustic energy by the boundary layer were evaluated.

  7. Low Mach-number collisionless electrostatic shocks and associated ion acceleration

    Science.gov (United States)

    Pusztai, I.; TenBarge, J. M.; Csapó, A. N.; Juno, J.; Hakim, A.; Yi, L.; Fülöp, T.

    2018-03-01

    The existence and properties of low Mach-number (M≳ 1) electrostatic collisionless shocks are investigated with a semi-analytical solution for the shock structure. We show that the properties of the shock obtained in the semi-analytical model can be well reproduced in fully kinetic Eulerian Vlasov-Poisson simulations, where the shock is generated by the decay of an initial density discontinuity. Using this semi-analytical model, we study the effect of the electron-to-ion temperature ratio and the presence of impurities on both the maximum shock potential and the Mach number. We find that even a small amount of impurities can influence the shock properties significantly, including the reflected light ion fraction, which can change several orders of magnitude. Electrostatic shocks in heavy ion plasmas reflect most of the hydrogen impurity ions.

  8. Axisymmetric vortex method for low-Mach number, diffusion-controlled combustion

    CERN Document Server

    Lakkis, I

    2003-01-01

    A grid-free, Lagrangian method for the accurate simulation of low-Mach number, variable-density, diffusion-controlled reacting flow is presented. A fast-chemistry model in which the conversion rate of reactants to products is limited by the local mixing rate is assumed in order to reduce the combustion problem to the solution of a convection-diffusion-generation equation with volumetric expansion and vorticity generation at the reaction fronts. The solutions of the continuity and vorticity equations, and the equations governing the transport of species and energy, are obtained using a formulation in which particles transport conserved quantities by convection and diffusion. The dynamic impact of exothermic combustion is captured through accurate integration of source terms in the vorticity transport equations at the location of the particles, and the extra velocity field associated with volumetric expansion at low Mach number computed to enforced mass conservation. The formulation is obtained for an axisymmet...

  9. Investigation of side wall effects on an inward scramjet inlet at Mach number 8.6

    Science.gov (United States)

    Rolim, Tiago Cavalcanti

    Experimental and computational studies were conducted to evaluate the performance of a scramjet inlet as the side cowl length is changed. A slender inward turning inlet of a total length of 304.8 mm, a span of 50.8 mm with the compression at 11.54 deg and CR = 4.79 was used. The side cowl lengths were of 0, 50.8 and 76.2 mm. The UTA Hypersonic Shock Tunnel facility was used in the reflected mode. The model was instrumented with nine piezoelectric pressure transducers, for static and total pressure measurements. A wedge was mounted at the rear of the inlet in order to accommodate a Pitot pressure rake. The driven tube was instrumented with three pressure transducers. Two of them were used to measure the incident shock wave speed, and a third one was used for stagnation pressure measurements during a test. Furthermore, a Pitot probe was installed below the model in order to measure the impact pressure on each run, this reading along with the driven sensor readings, allowed us for the calculation of freestream properties. During the experiments, nominal stagnation enthalpy of 0.67 MJ/kg and stagnation pressure of 3.67 MPa were achieved. Freestream conditions were Mach number 8.6 and Reynolds number of 1.94 million per m. Test times were 300 - 500 microseconds. Numerical simulations using RANS with the Wilcox K-w turbulence model were performed using ANSYS Fluent. The results from the static pressure measurements presented a good agreement with CFD predictions. Moreover, the uniformity at the inlet exit was achieved within the experimental precision. The experiments showed that the cowl length has a pronounced effect in the pressure distribution on the inlet and a minor effect in the exit flow Mach number. The numerical results confirmed these trends and showed that a complex flow structure is formed in the cowl-ramp corners; a non-uniform transverse shock structure was found to be related to the cowl leading edge position. Cross flow due to the side expansion

  10. Low Mach and Peclet number limit for a model of stellar tachocline and upper radiative zones

    Directory of Open Access Journals (Sweden)

    Donatella Donatelli

    2016-09-01

    Full Text Available We study a hydrodynamical model describing the motion of internal stellar layers based on compressible Navier-Stokes-Fourier-Poisson system. We suppose that the medium is electrically charged, we include energy exchanges through radiative transfer and we assume that the system is rotating. We analyze the singular limit of this system when the Mach number, the Alfven number, the Peclet number and the Froude number approache zero in a certain way and prove convergence to a 3D incompressible MHD system with a stationary linear transport equation for transport of radiation intensity. Finally, we show that the energy equation reduces to a steady equation for the temperature corrector.

  11. Surfing and drift acceleration at high mach number quasi-perpendicular shocks

    International Nuclear Information System (INIS)

    Amano, T.

    2008-01-01

    Electron acceleration in high Mach number collisionless shocks relevant to supernova remnant is discussed. By performing one- and two-dimensional particle-in-cell simulations of quasi-perpendicular shocks, we find that energetic electrons are quickly generated in the shock transition region through shock surfing and drift acceleration. The electron energization is strong enough to account for the observed injection at supernova remnant shocks. (author)

  12. The Dynamics of Very High Alfvén Mach Number Shocks in Space Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Torbjörn; Burgess, David [School of Physics and Astronomy, Queen Mary University of London, London, E1 4NS (United Kingdom); Scholer, Manfred [Max-Planck-Institut für extraterrestrische Physik, Garching (Germany); Masters, Adam [The Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ (United Kingdom); Sulaiman, Ali H., E-mail: torbjorn.sundberg@gmail.com [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2017-02-10

    Astrophysical shocks, such as planetary bow shocks or supernova remnant shocks, are often in the high or very-high Mach number regime, and the structure of such shocks is crucial for understanding particle acceleration and plasma heating, as well inherently interesting. Recent magnetic field observations at Saturn’s bow shock, for Alfvén Mach numbers greater than about 25, have provided evidence for periodic non-stationarity, although the details of the ion- and electron-scale processes remain unclear due to limited plasma data. High-resolution, multi-spacecraft data are available for the terrestrial bow shock, but here the very high Mach number regime is only attained on extremely rare occasions. Here we present magnetic field and particle data from three such quasi-perpendicular shock crossings observed by the four-spacecraft Cluster mission. Although both ion reflection and the shock profile are modulated at the upstream ion gyroperiod timescale, the dominant wave growth in the foot takes place at sub-proton length scales and is consistent with being driven by the ion Weibel instability. The observed large-scale behavior depends strongly on cross-scale coupling between ion and electron processes, with ion reflection never fully suppressed, and this suggests a model of the shock dynamics that is in conflict with previous models of non-stationarity. Thus, the observations offer insight into the conditions prevalent in many inaccessible astrophysical environments, and provide important constraints for acceleration processes at such shocks.

  13. Effects of Mach Numbers on Side Force, Yawing Moment and Surface Pressure

    Science.gov (United States)

    Sohail, Muhammad Amjad; Muhammad, Zaka; Husain, Mukkarum; Younis, Muhammad Yamin

    2011-09-01

    In this research, CFD simulations are performed for air vehicle configuration to compute the side force effect and yawing moment coefficients variations at high angle of attack and Mach numbers. As the angle of attack is increased then lift and drag are increased for cylinder body configurations. But when roll angle is given to body then side force component is also appeared on the body which causes lateral forces on the body and yawing moment is also produced. Now due to advancement of CFD methods we are able to calculate these forces and moment even at supersonic and hypersonic speed. In this study modern CFD techniques are used to simulate the hypersonic flow to calculate the side force effects and yawing moment coefficient. Static pressure variations along the circumferential and along the length of the body are also calculated. The pressure coefficient and center of pressure may be accurately predicted and calculated. When roll angle and yaw angle is given to body then these forces becomes very high and cause the instability of the missile body with fin configurations. So it is very demanding and serious problem to accurately predict and simulate these forces for the stability of supersonic vehicles.

  14. In-pipe aerodynamic characteristics of a projectile in comparison with free flight for transonic Mach numbers

    Science.gov (United States)

    Hruschka, R.; Klatt, D.

    2018-03-01

    The transient shock dynamics and drag characteristics of a projectile flying through a pipe 3.55 times larger than its diameter at transonic speed are analyzed by means of time-of-flight and pipe wall pressure measurements as well as computational fluid dynamics (CFD). In addition, free-flight drag of the 4.5-mm-pellet-type projectile was also measured in a Mach number range between 0.5 and 1.5, providing a means for comparison against in-pipe data and CFD. The flow is categorized into five typical regimes the in-pipe projectile experiences. When projectile speed and hence compressibility effects are low, the presence of the pipe has little influence on the drag. Between Mach 0.5 and 0.8, there is a strong drag increase due to the presence of the pipe, however, up to a value of about two times the free-flight drag. This is exactly where the nose-to-base pressure ratio of the projectile becomes critical for locally sonic speed, allowing the drag to be estimated by equations describing choked flow through a converging-diverging nozzle. For even higher projectile Mach numbers, the drag coefficient decreases again, to a value slightly below the free-flight drag at Mach 1.5. This behavior is explained by a velocity-independent base pressure coefficient in the pipe, as opposed to base pressure decreasing with velocity in free flight. The drag calculated by CFD simulations agreed largely with the measurements within their experimental uncertainty, with some discrepancies remaining for free-flying projectiles at supersonic speed. Wall pressure measurements as well as measured speeds of both leading and trailing shocks caused by the projectile in the pipe also agreed well with CFD.

  15. Acoustic-hydrodynamic-flame coupling—A new perspective for zero and low Mach number flows

    Science.gov (United States)

    Pulikkottil, V. V.; Sujith, R. I.

    2017-04-01

    A combustion chamber has a hydrodynamic field that convects the incoming fuel and oxidizer into the chamber, thereby causing the mixture to react and produce heat energy. This heat energy can, in turn, modify the hydrodynamic and acoustic fields by acting as a source and thereby, establish a positive feedback loop. Subsequent growth in the amplitude of the acoustic field variables and their eventual saturation to a limit cycle is generally known as thermo-acoustic instability. Mathematical representation of these phenomena, by a set of equations, is the subject of this paper. In contrast to the ad hoc models, an explanation of the flame-acoustic-hydrodynamic coupling, based on fundamental laws of conservation of mass, momentum, and energy, is presented in this paper. In this paper, we use a convection reaction diffusion equation, which, in turn, is derived from the fundamental laws of conservation to explain the flame-acoustic coupling. The advantage of this approach is that the physical variables such as hydrodynamic velocity and heat release rate are coupled based on the conservation of energy and not based on an ad hoc model. Our approach shows that the acoustic-hydrodynamic interaction arises from the convection of acoustic velocity fluctuations by the hydrodynamic field and vice versa. This is a linear mechanism, mathematically represented as a convection operator. This mechanism resembles the non-normal mechanism studied in hydrodynamic theory. We propose that this mechanism could relate the instability mechanisms of hydrodynamic and thermo-acoustic systems. Furthermore, the acoustic-hydrodynamic interaction is shown to be responsible for the convection of entropy disturbances from the inlet of the chamber. The theory proposed in this paper also unifies the observations in the fields of low Mach number flows and zero Mach number flows. In contrast to the previous findings, where compressibility is shown to be causing different physics for zero and low Mach

  16. The Experimental Measurement of Aerodynamic Heating About Complex Shapes at Supersonic Mach Numbers

    Science.gov (United States)

    Neumann, Richard D.; Freeman, Delma C.

    2011-01-01

    In 2008 a wind tunnel test program was implemented to update the experimental data available for predicting protuberance heating at supersonic Mach numbers. For this test the Langley Unitary Wind Tunnel was also used. The significant differences for this current test were the advances in the state-of-the-art in model design, fabrication techniques, instrumentation and data acquisition capabilities. This current paper provides a focused discussion of the results of an in depth analysis of unique measurements of recovery temperature obtained during the test.

  17. Experimental Surface Pressure Data Obtained on 65 deg Delta Wing Across Reynolds Number and Mach Number Ranges. Volume 2; Small-Radius Leading Edge

    Science.gov (United States)

    Chu, Julio; Luckring, James M.

    1996-01-01

    An experimental wind tunnel test of a 65 deg. delta wing model with interchangeable leading edges was conducted in the Langley National Transonic Facility (NTF). The objective was to investigate the effects of Reynolds and Mach numbers on slender-wing leading-edge vortex flows with four values of wing leading-edge bluntness. Experimentally obtained pressure data are presented without analysis in tabulated and graphical formats across a Reynolds number range of 6 x 10(exp 6) to 84 x 10(exp 6) at a Mach number of 0.85 and across a Mach number range of 0.4 to 0.9 at Reynolds numbers of 6 x 10(exp 6) and 60 x 10(exp 6). Normal-force and pitching-moment coefficient plots for these Reynolds number and Mach number ranges are also presented.

  18. A study of sonic boom overpressure trends with respect to weight, altitude, Mach number, and vehicle shaping

    Science.gov (United States)

    Needleman, Kathy E.; Mack, Robert J.

    1990-01-01

    This paper presents and discusses trends in nose shock overpressure generated by two conceptual Mach 2.0 configurations. One configuration was designed for high aerodynamic efficiency, while the other was designed to produce a low boom, shaped-overpressure signature. Aerodynamic lift, sonic boom minimization, and Mach-sliced/area-rule codes were used to analyze and compute the sonic boom characteristics of both configurations with respect to cruise Mach number, weight, and altitude. The influence of these parameters on the overpressure and the overpressure trends are discussed and conclusions are given.

  19. Low Mach number analysis of idealized thermoacoustic engines with numerical solution.

    Science.gov (United States)

    Hireche, Omar; Weisman, Catherine; Baltean-Carlès, Diana; Le Quéré, Patrick; Bauwens, Luc

    2010-12-01

    A model of an idealized thermoacoustic engine is formulated, coupling nonlinear flow and heat exchange in the heat exchangers and stack with a simple linear acoustic model of the resonator and load. Correct coupling results in an asymptotically consistent global model, in the small Mach number approximation. A well-resolved numerical solution is obtained for two-dimensional heat exchangers and stack. The model assumes that the heat exchangers and stack are shorter than the overall length by a factor of the order of a representative Mach number. The model is well-suited for simulation of the entire startup process, whereby as a result of some excitation, an initially specified temperature profile in the stack evolves toward a near-steady profile, eventually reaching stationary operation. A validation analysis is presented, together with results showing the early amplitude growth and approach of a stationary regime. Two types of initial excitation are used: Random noise and a small periodic wave. The set of assumptions made leads to a heat-exchanger section that acts as a source of volume but is transparent to pressure and to a local heat-exchanger model characterized by a dynamically incompressible flow to which a locally spatially uniform acoustic pressure fluctuation is superimposed.

  20. Thermodynamic analysis on optimum performance of scramjet engine at high Mach numbers

    International Nuclear Information System (INIS)

    Zhang, Duo; Yang, Shengbo; Zhang, Silong; Qin, Jiang; Bao, Wen

    2015-01-01

    In order to predict the maximum performance of scramjet engine at flight conditions with high freestream Mach numbers, a thermodynamic model of Brayton cycle was utilized to analyze the effects of inlet pressure ratio, fuel equivalence ratio and the upper limit of gas temperature to the specific thrust and the fuel impulse of the scramjet considering the characteristics of non-isentropic compression in the inlet. The results show that both the inlet efficiency and the temperature limit in the combustor have remarkable effects on the overall engine performances. Different with the ideal Brayton cycles assuming isentropic compression without upper limit of gas temperature, both the maximum specific thrust and the maximum fuel impulse of a scramjet present non-monotonic trends against the fuel equivalence ratio in this study. Considering the empirical design efficiencies of inlet, there is a wide range of fuel equivalence ratios in which the fuel impulses remain at high values. Moreover, the maximum specific thrust can also be achieved with a fuel equivalence ratio near this range. Therefore, it is possible to achieve an overall high performance in a scramjet at high Mach numbers. - Highlights: • Thermodynamic analysis with Brayton cycle on overall performances of scramjet. • The compression loss in the inlet was considered in predicting scram-mode operation. • Non-monotonic trends of engine performances against fuel equivalence ratio.

  1. Effects of the Mach number on the evolution of vortex-surface fields in compressible Taylor-Green flows

    Science.gov (United States)

    Peng, Naifu; Yang, Yue

    2018-01-01

    We investigate the evolution of vortex-surface fields (VSFs) in compressible Taylor-Green flows at Mach numbers (Ma) ranging from 0.5 to 2.0 using direct numerical simulation. The formulation of VSFs in incompressible flows is extended to compressible flows, and a mass-based renormalization of VSFs is used to facilitate characterizing the evolution of a particular vortex surface. The effects of the Mach number on the VSF evolution are different in three stages. In the early stage, the jumps of the compressive velocity component near shocklets generate sinks to contract surrounding vortex surfaces, which shrink vortex volume and distort vortex surfaces. The subsequent reconnection of vortex surfaces, quantified by the minimal distance between approaching vortex surfaces and the exchange of vorticity fluxes, occurs earlier and has a higher reconnection degree for larger Ma owing to the dilatational dissipation and shocklet-induced reconnection of vortex lines. In the late stage, the positive dissipation rate and negative pressure work accelerate the loss of kinetic energy and suppress vortex twisting with increasing Ma.

  2. ELECTRON ACCELERATIONS AT HIGH MACH NUMBER SHOCKS: TWO-DIMENSIONAL PARTICLE-IN-CELL SIMULATIONS IN VARIOUS PARAMETER REGIMES

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yosuke [Department of Physics, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522 (Japan); Amano, Takanobu; Hoshino, Masahiro, E-mail: ymatumot@astro.s.chiba-u.ac.jp [Department of Earth and Planetary Science, University of Tokyo, Hongo 1-33, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2012-08-20

    Electron accelerations at high Mach number collisionless shocks are investigated by means of two-dimensional electromagnetic particle-in-cell simulations with various Alfven Mach numbers, ion-to-electron mass ratios, and the upstream electron {beta}{sub e} (the ratio of the thermal pressure to the magnetic pressure). We find electrons are effectively accelerated at a super-high Mach number shock (M{sub A} {approx} 30) with a mass ratio of M/m = 100 and {beta}{sub e} = 0.5. The electron shock surfing acceleration is an effective mechanism for accelerating the particles toward the relativistic regime even in two dimensions with a large mass ratio. Buneman instability excited at the leading edge of the foot in the super-high Mach number shock results in a coherent electrostatic potential structure. While multi-dimensionality allows the electrons to escape from the trapping region, they can interact with the strong electrostatic field several times. Simulation runs in various parameter regimes indicate that the electron shock surfing acceleration is an effective mechanism for producing relativistic particles in extremely high Mach number shocks in supernova remnants, provided that the upstream electron temperature is reasonably low.

  3. Tests of Full-Scale Helicopter Rotors at High Advancing Tip Mach Numbers and Advance Ratios

    Science.gov (United States)

    Biggers, James C.; McCloud, John L., III; Stroub, Robert H.

    2015-01-01

    As a continuation of the studies of reference 1, three full-scale helicopter rotors have been tested in the Ames Research Center 40- by SO-foot wind tunnel. All three of them were two-bladed, teetering rotors. One of the rotors incorporated the NACA 0012 airfoil section over the entire length of the blade. This rotor was tested at advance ratios up to 1.05. Both of the other rotors were tapered in thickness and incorporated leading-edge camber over the outer 20 percent of the blade radius. The larger of these rotors was tested at advancing tip Mach numbers up to 1.02. Data were obtained for a wide range of lift and propulsive force, and are presented without discussion.

  4. Sensitivity of boundary-layer stability to base-state distortions at high Mach numbers

    Science.gov (United States)

    Park, Junho; Zaki, Tamer

    2017-11-01

    The stability diagram of high-speed boundary layers has been established by evaluating the linear instability modes of the similarity profile, over wide ranges of Reynolds and Mach numbers. In real flows, however, the base state can deviate from the similarity profile. Both the base velocity and temperature can be distorted, for example due to roughness and thermal wall treatments. We review the stability problem of high-speed boundary layer, and derive a new formulation of the sensitivity to base-state distortion using forward and adjoint parabolized stability equations. The new formulation provides qualitative and quantitative interpretations on change in growth rate due to modifications of mean-flow and mean-temperature in heated high-speed boundary layers, and establishes the foundation for future control strategies. This work has been funded by the Air Force Office of Scientific Research (AFOSR) Grant: FA9550-16-1-0103.

  5. Engineering method for aero-propulsive characteristics at hypersonic Mach numbers

    Science.gov (United States)

    Goradia, Suresh; Torres, Abel O.; Stack, Sharon H.; Everhart, Joel L.

    1991-01-01

    An engineering method has been developed for the rapid analysis of external aerodynamics and propulsive performance characteristics of airbreathing vehicles at hypersonic Mach numbers. This method, based on the theory of characteristics, has been developed to analyze fuselage-wing body combinations and body flaps with blunt or sharp leading/trailing edges. Arbitrary ratio of specific heat for the flowing medium can be specified in the program. Furthermore, the capability exists in the code to compute the inviscid inlet mass capture and momentum flux. The method is under development for computations of pressure distribution, and flow characteristics in the inlet, along with the effect of viscosity. Correlative studies have been performed for representative hypersonic configurations using the current method. The results of these correlations for various aerodynamics parameters are encouraging.

  6. Measurement and Analysis of the Noise Radiated by Low Mach Number Centrifugal Blowers.

    Science.gov (United States)

    Yeager, David Marvin

    An investigation was performed of the broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices. An interdisciplinary experimental approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Results showed that the centrifugal blower is a distributed, random noise source, unlike an axial fan which exhibited the effects of a coherent, interacting source distribution. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. Both circumferential and spanwise mean flow nonuniformities were identified along with a region of increased turbulence just downstream of the scroll cutoff. The fluid incidence angle, normally taken as an indicator of blower performance, was estimated from mean flow data as deviating considerably from an ideal impeller design. An investigation of the noise radiated from the single, isolated airfoil was performed using modern correlation and spectral analysis techniques. Radiation from the single blade in flow was characterized using newly developed expressions for the correlation area and the dipole source strength per unit area, and from the relationship between the blade surface pressure and the incident turbulent flow field. Results

  7. Study of Perturbations on High Mach Number Blast Waves in Various Gasses

    Science.gov (United States)

    Edens, A.; Adams, R.; Rambo, P.; Shores, J.; Smith, I.; Atherton, B.; Ditmire, T.

    2006-10-01

    We have performed a series of experiments examining the properties of high Mach number blast waves. Experiments were conducted on the Z-Beamlet^1 laser at Sandia National Laboratories. We created blast waves in the laboratory by using 10 J- 1000 J laser pulses to illuminate millimeter scale solid targets immersed in gas. Our experiments studied the validity of theories forwarded by Vishniac and Ryu^2-4 to explain the dynamics of perturbations on astrophysical blast waves. These experiments consisted of an examination of the evolution of perturbations of known primary mode number induced on the surface of blast waves by means of regularly spaced wire arrays. The temporal evolution of the amplitude of the induced perturbations relative to the mean radius of the blast wave was fit to a power law in time. Measurements were taken for a number of different mode numbers and background gasses and the results show qualitative agreement with previously published theories for the hydrodynamics of thin shell blast wave. The results for perturbations on nitrogen gas have been recently published^5. .^1 P. K. Rambo, I. C. Smith, J. L. Porter, et al., Applied Optics 44, 2421 (2005). ^2 D. Ryu and E. T. Vishniac, Astrophysical Journal 313, 820 (1987). ^3 D. Ryu and E. T. Vishniac, Astrophysical Journal 368, 411 (1991). ^4 E. T. Vishniac, Astrophysical Journal 274, 152 (1983). ^5 A. D. Edens, T. Ditmire, J. F. Hansen, et al., Physical Review Letters 95 (2005).

  8. Analytic MHD Theory for Earth's Bow Shock at Low Mach Numbers

    Science.gov (United States)

    Grabbe, Crockett L.; Cairns, Iver H.

    1995-01-01

    A previous MHD theory for the density jump at the Earth's bow shock, which assumed the Alfven M(A) and sonic M(s) Mach numbers are both much greater than 1, is reanalyzed and generalized. It is shown that the MHD jump equation can be analytically solved much more directly using perturbation theory, with the ordering determined by M(A) and M(s), and that the first-order perturbation solution is identical to the solution found in the earlier theory. The second-order perturbation solution is calculated, whereas the earlier approach cannot be used to obtain it. The second-order terms generally are important over most of the range of M(A) and M(s) in the solar wind when the angle theta between the normal to the bow shock and magnetic field is not close to 0 deg or 180 deg (the solutions are symmetric about 90 deg). This new perturbation solution is generally accurate under most solar wind conditions at 1 AU, with the exception of low Mach numbers when theta is close to 90 deg. In this exceptional case the new solution does not improve on the first-order solutions obtained earlier, and the predicted density ratio can vary by 10-20% from the exact numerical MHD solutions. For theta approx. = 90 deg another perturbation solution is derived that predicts the density ratio much more accurately. This second solution is typically accurate for quasi-perpendicular conditions. Taken together, these two analytical solutions are generally accurate for the Earth's bow shock, except in the rare circumstance that M(A) is less than or = 2. MHD and gasdynamic simulations have produced empirical models in which the shock's standoff distance a(s) is linearly related to the density jump ratio X at the subsolar point. Using an empirical relationship between a(s) and X obtained from MHD simulations, a(s) values predicted using the MHD solutions for X are compared with the predictions of phenomenological models commonly used for modeling observational data, and with the predictions of a

  9. Particle image velocimetry measurements of Mach 3 turbulent boundary layers at low Reynolds numbers

    Science.gov (United States)

    Brooks, J. M.; Gupta, A. K.; Smith, M. S.; Marineau, E. C.

    2018-05-01

    Particle image velocimetry (PIV) measurements of Mach 3 turbulent boundary layers (TBL) have been performed under low Reynolds number conditions, Re_τ =200{-}1000, typical of direct numerical simulations (DNS). Three reservoir pressures and three measurement locations create an overlap in parameter space at one research facility. This allows us to assess the effects of Reynolds number, particle response and boundary layer thickness separate from facility specific experimental apparatus or methods. The Morkovin-scaled streamwise fluctuating velocity profiles agree well with published experimental and numerical data and show a small standard deviation among the nine test conditions. The wall-normal fluctuating velocity profiles show larger variations which appears to be due to particle lag. Prior to the current study, no detailed experimental study characterizing the effect of Stokes number on attenuating wall-normal fluctuating velocities has been performed. A linear variation is found between the Stokes number ( St) and the relative error in wall-normal fluctuating velocity magnitude (compared to hot wire anemometry data from Klebanoff, Characteristics of Turbulence in a Boundary Layer with Zero Pressure Gradient. Tech. Rep. NACA-TR-1247, National Advisory Committee for Aeronautics, Springfield, Virginia, 1955). The relative error ranges from about 10% for St=0.26 to over 50% for St=1.06. Particle lag and spatial resolution are shown to act as low-pass filters on the fluctuating velocity power spectral densities which limit the measurable energy content. The wall-normal component appears more susceptible to these effects due to the flatter spectrum profile which indicates that there is additional energy at higher wave numbers not measured by PIV. The upstream inclination and spatial correlation extent of coherent turbulent structures agree well with published data including those using krypton tagging velocimetry (KTV) performed at the same facility.

  10. Aerodynamic Characteristics of a Revised Target Drone Vehicle at Mach Numbers from 1.60 to 2.86

    Science.gov (United States)

    Blair, A. B., Jr.; Babb, C. Donald

    1968-01-01

    An investigation has been conducted in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a revised target drone vehicle through a Mach number range from 1.60 to 2.86. The vehicle had canard surfaces and a swept clipped-delta wing with twin tip-mounted vertical tails.

  11. A Critical Shock Mach Number for Particle Acceleration in the Absence of Pre-existing Cosmic Rays: M = √5

    NARCIS (Netherlands)

    Vink, J.; Yamazaki, R.

    2014-01-01

    It is shown that, under some generic assumptions, shocks cannot accelerate particles unless the overall shock Mach number exceeds a critical value M > √5. The reason is that for M ≤ √5 the work done to compress the flow in a particle precursor requires more enthalpy flux than the system can sustain.

  12. Effect of finite cavity width on flow oscillation in a low-Mach-number cavity flow

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ke; Naguib, Ahmed M. [Michigan State University, East Lansing, MI (United States)

    2011-11-15

    The current study is focused on examining the effect of the cavity width and side walls on the self-sustained oscillation in a low Mach number cavity flow with a turbulent boundary layer at separation. An axisymmetric cavity geometry is employed in order to provide a reference condition that is free from any side-wall influence, which is not possible to obtain with a rectangular cavity. The cavity could then be partially filled to form finite-width geometry. The unsteady surface pressure is measured using microphone arrays that are deployed on the cavity floor along the streamwise direction and on the downstream wall along the azimuthal direction. In addition, velocity measurements using two-component Laser Doppler Anemometer are performed simultaneously with the array measurements in different azimuthal planes. The compiled data sets are used to investigate the evolution of the coherent structures generating the pressure oscillation in the cavity using linear stochastic estimation of the velocity field based on the wall-pressure signature on the cavity end wall. The results lead to the discovery of pronounced harmonic pressure oscillations near the cavity's side walls. These oscillations, which are absent in the axisymmetric cavity, are linked to the establishment of a secondary mean streamwise circulating flow pattern near the side walls and the interaction of this secondary flow with the shear layer above the cavity. (orig.)

  13. Measurement and analysis of the noise radiated by low Mach numbers centrifugal blowers

    Science.gov (United States)

    Yeager, D. M.; Lauchle, G. C.

    1987-11-01

    The broad band, aerodynamically generated noise in low tip-speed Mach number, centrifugal air moving devices is investigated. An interdisciplinary approach was taken which involved investigation of the aerodynamic and acoustic fields, and their mutual relationship. The noise generation process was studied using two experimental vehicles: (1) a scale model of a homologous family of centrifugal blowers typical of those used to cool computer and business equipment, and (2) a single blade from a centrifugal blower impeller which was placed in a known, controllable flow field. The radiation characteristics of the model blower were investigated by measuring the acoustic intensity distribution near the blower inlet and comparing it with the intensity near the inlet to an axial flow fan. Aerodynamic studies of the flow field in the inlet and at the discharge to the rotating impeller were used to assess the mean flow distribution through the impeller blade channels and to identify regions of excessive turbulence near the rotating blade row. New frequency-domain expressions for the correlation area and dipole source strength per unit area on a surface immersed in turbulence were developed which can be used to characterize the noise generation process over a rigid surface immersed in turbulence. An investigation of the noise radiated from the single, isolated airfoil (impeller blade) was performed using modern correlation and spectral analysis techniques.

  14. Plasma wave profiles of Earth's bow shock at low Mach number: ISEE 3 observations on the far flank

    International Nuclear Information System (INIS)

    Greenstadt, E.W.; Coroniti, F.V.; Moses, S.L.; Smith, E.J.

    1992-01-01

    The Earth's bow shock is weak along its distant flanks where the projected component of solar wind velocity normal to the hyperboloidal surface is only a fraction of the total free stream velocity, severely reducing the local Mach number. The authors present a survey of selected crossings far downstream from the subsolar shock, delineating the overall plasma wave (pw) behavior of a selected set of nearly perpendicular crossings and another set of limited Mach number but broad geometry; they include their immediate upstream regions. The result is a generalizable pw signature, or signatures, of low Mach number shocks and some likely implications of those signatures for the weak shock's plasma physical processes on the flank. They find the data consistent with the presence of ion beam interactions producing noise ahead of the shock in the ion acoustic frequency range. One subcritical case was found whose pw noise was presumably related to a reflected ion population just as in stronger events. The presence or absence, and the amplitudes, of pw activity are explainable by the presence or absence of a population of upstream ions controlled by the component of interplanetary magnetic field normal to the solar wind flow

  15. Nonlinear theory of nonstationary low Mach number channel flows of freely cooling nearly elastic granular gases.

    Science.gov (United States)

    Meerson, Baruch; Fouxon, Itzhak; Vilenkin, Arkady

    2008-02-01

    We employ hydrodynamic equations to investigate nonstationary channel flows of freely cooling dilute gases of hard and smooth spheres with nearly elastic particle collisions. This work focuses on the regime where the sound travel time through the channel is much shorter than the characteristic cooling time of the gas. As a result, the gas pressure rapidly becomes almost homogeneous, while the typical Mach number of the flow drops well below unity. Eliminating the acoustic modes and employing Lagrangian coordinates, we reduce the hydrodynamic equations to a single nonlinear and nonlocal equation of a reaction-diffusion type. This equation describes a broad class of channel flows and, in particular, can follow the development of the clustering instability from a weakly perturbed homogeneous cooling state to strongly nonlinear states. If the heat diffusion is neglected, the reduced equation becomes exactly soluble, and the solution develops a finite-time density blowup. The blowup has the same local features at singularity as those exhibited by the recently found family of exact solutions of the full set of ideal hydrodynamic equations [I. Fouxon, Phys. Rev. E 75, 050301(R) (2007); I. Fouxon,Phys. Fluids 19, 093303 (2007)]. The heat diffusion, however, always becomes important near the attempted singularity. It arrests the density blowup and brings about previously unknown inhomogeneous cooling states (ICSs) of the gas, where the pressure continues to decay with time, while the density profile becomes time-independent. The ICSs represent exact solutions of the full set of granular hydrodynamic equations. Both the density profile of an ICS and the characteristic relaxation time toward it are determined by a single dimensionless parameter L that describes the relative role of the inelastic energy loss and heat diffusion. At L>1 the intermediate cooling dynamics proceeds as a competition between "holes": low-density regions of the gas. This competition resembles Ostwald

  16. Semi-implicit iterative methods for low Mach number turbulent reacting flows: Operator splitting versus approximate factorization

    Science.gov (United States)

    MacArt, Jonathan F.; Mueller, Michael E.

    2016-12-01

    Two formally second-order accurate, semi-implicit, iterative methods for the solution of scalar transport-reaction equations are developed for Direct Numerical Simulation (DNS) of low Mach number turbulent reacting flows. The first is a monolithic scheme based on a linearly implicit midpoint method utilizing an approximately factorized exact Jacobian of the transport and reaction operators. The second is an operator splitting scheme based on the Strang splitting approach. The accuracy properties of these schemes, as well as their stability, cost, and the effect of chemical mechanism size on relative performance, are assessed in two one-dimensional test configurations comprising an unsteady premixed flame and an unsteady nonpremixed ignition, which have substantially different Damköhler numbers and relative stiffness of transport to chemistry. All schemes demonstrate their formal order of accuracy in the fully-coupled convergence tests. Compared to a (non-)factorized scheme with a diagonal approximation to the chemical Jacobian, the monolithic, factorized scheme using the exact chemical Jacobian is shown to be both more stable and more economical. This is due to an improved convergence rate of the iterative procedure, and the difference between the two schemes in convergence rate grows as the time step increases. The stability properties of the Strang splitting scheme are demonstrated to outpace those of Lie splitting and monolithic schemes in simulations at high Damköhler number; however, in this regime, the monolithic scheme using the approximately factorized exact Jacobian is found to be the most economical at practical CFL numbers. The performance of the schemes is further evaluated in a simulation of a three-dimensional, spatially evolving, turbulent nonpremixed planar jet flame.

  17. A conservative, thermodynamically consistent numerical approach for low Mach number combustion. Part I: Single-level integration

    Science.gov (United States)

    Nonaka, Andrew; Day, Marcus S.; Bell, John B.

    2018-01-01

    We present a numerical approach for low Mach number combustion that conserves both mass and energy while remaining on the equation of state to a desired tolerance. We present both unconfined and confined cases, where in the latter the ambient pressure changes over time. Our overall scheme is a projection method for the velocity coupled to a multi-implicit spectral deferred corrections (SDC) approach to integrate the mass and energy equations. The iterative nature of SDC methods allows us to incorporate a series of pressure discrepancy corrections naturally that lead to additional mass and energy influx/outflux in each finite volume cell in order to satisfy the equation of state. The method is second order, and satisfies the equation of state to a desired tolerance with increasing iterations. Motivated by experimental results, we test our algorithm on hydrogen flames with detailed kinetics. We examine the morphology of thermodiffusively unstable cylindrical premixed flames in high-pressure environments for confined and unconfined cases. We also demonstrate that our algorithm maintains the equation of state for premixed methane flames and non-premixed dimethyl ether jet flames.

  18. Evaluation of Blended Wing-Body Combinations with Curved Plan Forms at Mach Numbers Up to 3.50

    Science.gov (United States)

    Holdaway, George H.; Mellenthin, Jack A.

    1960-01-01

    This investigation is a continuation of the experimental and theoretical evaluation of the effects of wing plan-form variations on the aerodynamic performance characteristics of blended wing-body combinations. The present report compares previously tested straight-edged delta and arrow models which have leading-edge sweeps of 59.04 and 70-82 deg., respectively, with related models which have plan forms with curved leading and trailing edges designed to result in the same average sweeps in each case. All the models were symmetrical, without camber, and were generally similar having the same span, length, and aspect ratios. The wing sections had an average value of maximum thickness ratio of about 4 percent of the local wing chords in a streamwise direction. The wing sections were computed by varying their shapes along with the body radii (blending process) to match the selected area distribution and the given plan form. The models were tested with transition fixed at Reynolds numbers of roughly 4,000,000 to 9,000,000, based on the mean aerodynamic chord of the wing. The characteristic effect of the wing curvature of the delta and arrow models was an increase at subsonic and transonic speeds in the lift-curve slopes which was partially reflected in increased maximum lift-drag ratios. Curved edges were not evaluated on a diamond plan form because a preliminary investigation indicated that the curvature considered would increase the supersonic zero-lift wave drag. However, after the test program was completed, a suitable modification for the diamond plan form was discovered. The analysis presented in the appendix indicates that large reductions in the zero-lift wave drag would be obtained at supersonic Mach numbers if the leading- and trailing-edge sweeps are made to differ by indenting the trailing edge and extending the root of the leading edge.

  19. Numerical Study on the Effect of Non-Equilibrium Condensation on Drag Divergence Mach Number in a Transonic Moist Air Flow

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seung Min [GyeongBuk Technopark, Gyeongsan (Korea, Republic of); Kang, Hui Bo; Kwon, Young Doo; Kwon, Soon Bum [Kyungpook Nat’l Univ., Daegu (Korea, Republic of)

    2016-12-15

    In the present study, the effects of non-equilibrium condensation on the drag divergence Mach number with the angle of attack in a transonic 2D moist air flow of NACA0012 are investigated using the TVD finite difference scheme. For the same α, the maximum upstream Mach number of the shock wave, Mmax, and the size of supersonic bubble decrease with the increase in Φ{sub 0}. For the same M{sub ∞}, Φ{sub 0}, and T{sub 0}, the length of the non-equilibrium condensation zone Δ{sub z} decreases with increasing Φ{sub 0}. On the other hand, because of the attenuating effect of non-equilibrium condensation on wave drag, which is related to the interaction between the shock wave and the boundary layer, the drag coefficient C{sub D} decreases with an increase in Φ{sub 0} for the same M{sub ∞} and α. For the same α, M{sub D} increases with increasing Φ{sub 0}, while M{sub D} decreases with an increase in α.

  20. Lattice Boltzmann method and gas-kinetic BGK scheme in the low-Mach number viscous flow simulations

    International Nuclear Information System (INIS)

    Xu Kun; He Xiaoyi

    2003-01-01

    Both lattice Boltzmann method (LBM) and the gas-kinetic BGK scheme are based on the numerical discretization of the Boltzmann equation with collisional models, such as, the Bhatnagar-Gross-Krook (BGK) model. LBM tracks limited number of particles and the viscous flow behavior emerges automatically from the intrinsic particle stream and collisions process. On the other hand, the gas-kinetic BGK scheme is a finite volume scheme, where the time-dependent gas distribution function with continuous particle velocity space is constructed and used in the evaluation of the numerical fluxes across cell interfaces. Currently, LBM is mainly used for low Mach number, nearly incompressible flow simulation. For the gas-kinetic scheme, the application is focusing on the high speed compressible flows. In this paper, we are going to compare both schemes in the isothermal low-Mach number flow simulations. The methodology for developing both schemes will be clarified through the introduction of operator splitting Boltzmann model and operator averaging Boltzmann model. From the operator splitting Boltzmann model, the error rooted in many kinetic schemes, which are based on the decoupling of particle transport and collision, can be easily understood. As to the test case, we choose to use the 2D cavity flow since it is one of the most extensively studied cases. Detailed simulation results with different Reynolds numbers, as well as the benchmark solutions, are presented

  1. LES of Supersonic Turbulent Channel Flow at Mach Numbers 1.5 and 3

    Science.gov (United States)

    Raghunath, Sriram; Brereton, Giles

    2009-11-01

    LES of compressible, turbulent, body-force driven, isothermal-wall channel flows at Reτ of 190 and 395 at moderate supersonic speeds (Mach 1.5 and 3) are presented. Simulations are fully resolved in the wall-normal direction without the need for wall-layer models. SGS models for incompressible flows, with appropriate extensions for compressibility, are tested a priori/ with DNS results and used in LES. Convergence of the simulations is found to be sensitive to the initial conditions and to the choice of model (wall-normal damping) in the laminar sublayer. The Nicoud--Ducros wall adapting SGS model, coupled with a standard SGS heat flux model, is found to yield results in good agreement with DNS.

  2. Numerical resolution of the Navier-Stokes equations for a low Mach number by a spectral method

    International Nuclear Information System (INIS)

    Frohlich, Jochen

    1990-01-01

    The low Mach number approximation of the Navier-Stokes equations, also called isobar, is an approximation which is less restrictive than the one due to Boussinesq. It permits strong density variations while neglecting acoustic phenomena. We present a numerical method to solve these equations in the unsteady, two dimensional case with one direction of periodicity. The discretization uses a semi-implicit finite difference scheme in time and a Fourier-Chebycheff pseudo-spectral method in space. The solution of the equations of motion is based on an iterative algorithm of Uzawa type. In the Boussinesq limit we obtain a direct method. A first application is concerned with natural convection in the Rayleigh-Benard setting. We compare the results of the low Mach number equations with the ones in the Boussinesq case and consider the influence of variable fluid properties. A linear stability analysis based on a Chebychev-Tau method completes the study. The second application that we treat is a case of isobaric combustion in an open domain. We communicate results for the hydrodynamic Darrieus-Landau instability of a plane laminar flame front. [fr

  3. Impact of Shock Front Rippling and Self-reformation on the Electron Dynamics at Low-Mach-number Shocks

    Science.gov (United States)

    Yang, Zhongwei; Lu, Quanming; Liu, Ying D.; Wang, Rui

    2018-04-01

    Electron dynamics at low-Mach-number collisionless shocks are investigated by using two-dimensional electromagnetic particle-in-cell simulations with various shock normal angles. We found: (1) The reflected ions and incident electrons at the shock front provide an effective mechanism for the quasi-electrostatic wave generation due to the charge-separation. A fraction of incident electrons can be effectively trapped and accelerated at the leading edge of the shock foot. (2) At quasi-perpendicular shocks, the electron trapping and reflection is nonuniform due to the shock rippling along the shock surface and is more likely to take place at some locations accompanied by intense reflected ion-beams. The electron trapping process has a periodical evolution over time due to the shock front self-reformation, which is controlled by ion dynamics. Thus, this is a cross-scale coupling phenomenon. (3) At quasi-parallel shocks, reflected ions can travel far back upstream. Consequently, quasi-electrostatic waves can be excited in the shock transition and the foreshock region. The electron trajectory analysis shows these waves can trap electrons at the foot region and reflect a fraction of them far back upstream. Simulation runs in this paper indicate that the micro-turbulence at the shock foot can provide a possible scenario for producing the reflected electron beam, which is a basic condition for the type II radio burst emission at low-Mach-number interplanetary shocks driven by Coronal Mass Ejections (CMEs).

  4. An improved method to experimentally determine temperature and pressure behind laser-induced shock waves at low Mach numbers

    International Nuclear Information System (INIS)

    Hendijanifard, Mohammad; Willis, David A

    2011-01-01

    Laser-matter interactions are frequently studied by measuring the propagation of shock waves caused by the rapid laser-induced material removal. An improved method for calculating the thermo-fluid parameters behind shock waves is introduced in this work. Shock waves in ambient air, induced by pulsed Nd : YAG laser ablation of aluminium films, are measured using a shadowgraph apparatus. Normal shock solutions are applied to experimental data for shock wave positions and used to calculate pressure, temperature, and velocity behind the shock wave. Non-dimensionalizing the pressure and temperature with respect to the ambient values, the dimensionless pressure and temperature are estimated to be as high as 90 and 16, respectively, at a time of 10 ns after the ablation pulse for a laser fluence of F = 14.5 J cm -2 . The results of the normal shock solution and the Taylor-Sedov similarity solution are compared to show that the Taylor-Sedov solution under-predicts pressure when the Mach number of the shock wave is small. At a fluence of 3.1 J cm -2 , the shock wave Mach number is less than 3, and the Taylor-Sedov solution under-predicts the non-dimensional pressure by as much as 45%.

  5. A combined volume-of-fluid method and low-Mach-number approach for DNS of evaporating droplets in turbulence

    Science.gov (United States)

    Dodd, Michael; Ferrante, Antonino

    2017-11-01

    Our objective is to perform DNS of finite-size droplets that are evaporating in isotropic turbulence. This requires fully resolving the process of momentum, heat, and mass transfer between the droplets and surrounding gas. We developed a combined volume-of-fluid (VOF) method and low-Mach-number approach to simulate this flow. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. We also demonstrate the schemes robustness when performing DNS of an evaporating droplet in forced isotropic turbulence.

  6. Effect of external stores on the stability and control characteristics of a delta wing fighter model at Mach numbers from 0.60 to 2.01

    Science.gov (United States)

    Spearman, M. L.

    1983-01-01

    An investigation has been made to determine the effects of external stores on the stability and control characteristics of a delta wing fighter airplane model at Mach numbers from 0.60 to 2.01 for a Reynolds number of 3.0 X 1 million per foot. The angle-of-attack range was from about -4 degrees to 20 degrees at a sideslip angle of 0 degrees for the transonic tests, and from about -4 degrees to 10 degrees at sideslip angles of 0 degrees and 3 degrees for the supersonic tests. In general, the results of the tests indicated no seriously detrimental effects of the stores on the stability and control characteristics of the model but did show an increase in the minimum drag level throughout the Mach number range. However, the drag-due-to-lift was such that for subsonic/transonic speeds, the drag at higher lifts was essentially unaffected and the indications are that the maneuvering capability may not be impaired by the stores.

  7. Investigation of the NACA 4-(3)(8)-045 Two-blade Propellers at Forward Mach Numbers to 0.725 to Determine the Effects of Compressibility and Solidity on Performance

    Science.gov (United States)

    Stack, John; Draley, Eugene C; Delano, James B; Feldman, Lewis

    1950-01-01

    As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle. The magnitude of the efficiency losses varied from 9 percent to 22 percent per 0.1 increase in tip Mach number above the critical value. The range of advance ratio for peak efficiency decreased markedly with increase of forward speed. The general form of the changes in thrust and power coefficients was found to be similar to the changes in airfoil lift coefficient with changes in Mach number. Efficiency losses due to compressibility effects decreased with increase of blade width. The results indicated that the high level of propeller efficiency obtained at low speeds could be maintained to forward sea-level speeds exceeding 500 miles per hour.

  8. Experimental evaluation of wall Mach number distributions of the octagonal test section proposed for NASA Lewis Research Center's altitude wind tunnel

    Science.gov (United States)

    Harrington, Douglas E.; Burley, Richard R.; Corban, Robert R.

    1986-01-01

    Wall Mach number distributions were determined over a range of test-section free-stream Mach numbers from 0.2 to 0.92. The test section was slotted and had a nominal porosity of 11 percent. Reentry flaps located at the test-section exit were varied from 0 (fully closed) to 9 (fully open) degrees. Flow was bled through the test-section slots by means of a plenum evacuation system (PES) and varied from 0 to 3 percent of tunnel flow. Variations in reentry flap angle or PES flow rate had little or no effect on the Mach number distributions in the first 70 percent of the test section. However, in the aft region of the test section, flap angle and PES flow rate had a major impact on the Mach number distributions. Optimum PES flow rates were nominally 2 to 2.5 percent wtih the flaps fully closed and less than 1 percent when the flaps were fully open. The standard deviation of the test-section wall Mach numbers at the optimum PES flow rates was 0.003 or less.

  9. Effect of initial conditions and Mach number on the Richtmyer-Meshkov instability in ICF like conditions

    Science.gov (United States)

    Rao, Pooja; She, Dan; Lim, Hyunkyung; Glimm, James

    2015-11-01

    The qualitative and quantitative effect of initial conditions (linear and non-linear) and high Mach number (1.3 and 1.45) is studied on the turbulent mixing induced by the Richtmyer-Meshkov instability in idealized ICF conditions. The Richtmyer-Meshkov instability seeds Rayleigh-taylor instabilities in ICF experiments and is one of the factors that contributes to reduced performance of ICF experiments. Its also found in collapsing cores of stars and supersonic combustion. We use the Stony Brook University code, FronTier, which is verified via a code comparison study against the AMR multiphysics code FLASH, and validated against vertical shock tube experiments done by the LANL Extreme Fluids Team. These simulations are designed as a step towards simulating more realistic ICF conditions and quantifying the detrimental effects of mixing on the yield.

  10. Experimental investigation of the effects of blowing conditions and Mach number on the unsteady behavior of coolant ejection through a trailing edge cutback

    International Nuclear Information System (INIS)

    Barigozzi, Giovanna; Armellini, Alessandro; Mucignat, Claudio; Casarsa, Luca

    2012-01-01

    Highlights: ► Flow visualization and PIV documented the presence of large coherent structures. ► The presence of coherent structures is documented up to the vane trailing edge. ► Shape and direction of rotation of vortices change with injection conditions. ► Vortices morphology influences the film cooling effectiveness distributions. ► A Mach number increase moves vortices closer to the wall. - Abstract: The present paper shows the results of an experimental investigation into the unsteadiness of coolant ejection at the trailing edge of a highly loaded nozzle vane cascade. The trailing edge cooling scheme features a pressure side cutback with film cooling slots, stiffened by evenly spaced ribs in an inline configuration. Cooling air is also ejected through two rows of cylindrical holes placed upstream of the cutback. Tests were performed with a low inlet turbulence intensity level (Tu 1 = 1.6%), changing the cascade operating conditions from low speed (M 2is = 0.2) up to high subsonic regime (M 2is = 0.6), and with coolant to main stream mass flow ratio varied within the 0.5–2.0% range. Particle Image Velocimetry (PIV) and flow visualizations were used to investigate the unsteady mixing process taking place between coolant and main flow downstream of the cutback, up to the trailing edge. For all the tested conditions, the results show the presence of large coherent structures, which presence is still evident up to the trailing edge. Their shape and direction of rotation change with injection conditions, as a function of coolant to mainstream velocity ratio, strongly influencing the thermal protection capability of the injected coolant flow. The Mach number increase is only responsible for a positioning of such vortical structures closer to the wall, while the Strouhal number almost remains unchanged.

  11. Influence of Mach Number and Dynamic Pressure on Cavity Tones and Freedrop Trajectories

    Science.gov (United States)

    2014-03-27

    18 LU-SGS Lower Upper-Symmetric Gauss Seidel . . . . . . . . . . . . . . . . . . 18 SSOR Successive Symmetric Over...complexity, the number of iterations necessary to gain convergence causes the simulation to be too expensive. The modern CFD method of overset or...solvers are Alternating Direction Implicit (ADI) Beam-Warming, Steger- Warming, Lower Upper-Symmetric Gauss Seidel (LU-SGS), and Successive Symmetric

  12. Practical computational aeroacoustics for compact surfaces in low mach number flows

    DEFF Research Database (Denmark)

    Pradera-Mallabiabarrena, Ainara; Keith, Graeme; Jacobsen, Finn

    2011-01-01

    compared to the wavelength of interest. This makes it possible to focus on the surface source term of the Ffowcs Williams-Hawkings equation. In this paper, in order to illustrate the basic method for storing and utilizing data from the CFD analysis, the flow past a circular cylinder at a Reynolds number...

  13. Rocket-Model Investigation of the Longitudinal Stability, Drag, and Duct Performance Characteristics of the North American MX-770 (X-10) Missile at Mach Numbers from 0.80 to 1.70

    Science.gov (United States)

    Bond, Aleck C.; Swanson, Andrew G.

    1953-01-01

    A free-flight 0.12-scale rocket-boosted model of the North American MX-770 (X-10) missile has been tested in flight by the Pilotless Aircraft Research Division of the Langley Aeronautical Laboratory. Drag, longitudinal stability, and duct performance data were obtained at Mach numbers from 0.8 to 1.7 covering a Reynolds number range of about 9 x 10(exp 6) to 24 x 10(exp 6) based on wing mean aerodynamic chord. The lift-curve slope, static stability, and damping-in-pitch derivatives showed similar variations with Mach number, the parameters increasing from subsonic values in the transonic region and decreasing in the supersonic region. The variations were for the most part fairly smooth. The aerodynamic center of the configuration shifted rearward in the transonic region and moved forward gradually in the supersonic region. The pitching effectiveness of the canard control surfaces was maintained throughout the flight speed range, the supersonic values being somewhat greater than the subsonic. Trim values of angle of attack and lift coefficient changed abruptly in the transonic region, the change being associated with variations in the out-of-trim pitching moment, control effectiveness, and aerodynamic-center travel in this speed range. Duct total-pressure recovery decreased with increase in free-stream Mach number and the values were somewhat less than normal-shock recovery. Minimum drag data indicated a supersonic drag coefficient about twice the subsonic drag coefficient and a drag-rise Mach number of approximately 0.90. Base drag was small subsonically but was about 25 percent of the minimum drag of the configuration supersonically.

  14. Flight Investigation at Low Angles of Attack to Determine the Longitudinal Stability and Control Characteristics of a Cruciform Canard Missile Configuration with a Low-Aspect-Ratio Wing and Blunt Nose at Mach Numbers from 1.2 to 2.1

    Science.gov (United States)

    Brown, Clarence A , Jr

    1957-01-01

    A full- scale rocket-powered model of a cruciform canard missile configuration with a low- aspect - ratio wing and blunt nose has been flight tested by the Langley Pilotless Aircraft Research Division. Static and dynamic longitudinal stability and control derivatives of this interdigitated canard-wing missile configuration were determined by using the pulsed- control technique at low angles of attack and for a Mach number range of 1.2 to 2.1. The lift - curve slope showed only small nonlinearities with changes in control deflection or angle of attack but indicated a difference in lift- .curve slope of approximately 7 percent for the two control deflections of delta = 3.0 deg and delta= -0.3 deg . The large tail length of the missile tested was effective in producing damping in pitch throughout the Mach number range tested. The aerodynamic- center location was nearly constant with Mach number for the two control deflections but was shown to be less stable with the larger control deflection. The increment of lift produced by the controls was small and positive throughout the Mach number range tested, whereas the pitching moment produced by the controls exhibited a normal trend of reduced effectiveness with increasing Mach number.The effectiveness of the controls in producing angle of attack, lift, and pitching moment was good at all Mach numbers tested.

  15. Wing Tip Drag Reduction at Nominal Take-Off Mach Number: An Approach to Local Active Flow Control with a Highly Robust Actuator System

    Directory of Open Access Journals (Sweden)

    Matthias Bauer

    2016-10-01

    Full Text Available This paper discusses wind tunnel test results aimed at advancing active flow control technology to increase the aerodynamic efficiency of an aircraft during take-off. A model of the outer section of a representative civil airliner wing was equipped with two-stage fluidic actuators between the slat edge and wing tip, where mechanical high-lift devices fail to integrate. The experiments were conducted at a nominal take-off Mach number of M = 0.2. At this incidence velocity, separation on the wing section, accompanied by increased drag, is triggered by the strong slat edge vortex at high angles of attack. On the basis of global force measurements and local static pressure data, the effect of pulsed blowing on the complex flow is evaluated, considering various momentum coefficients and spanwise distributions of the actuation effort. It is shown that through local intensification of forcing, a momentum coefficient of less than c μ = 0.6 % suffices to offset the stall by 2.4°, increase the maximum lift by more than 10% and reduce the drag by 37% compared to the uncontrolled flow.

  16. Analytical and Experimental Investigation of Inlet-engine Matching for Turbojet-powered Aircraft at Mach Numbers up to 2.0

    Science.gov (United States)

    Esenwein, Fred T; Schueller, Carl F

    1952-01-01

    An analysis of inlet-turbojet-engine matching for a range of Mach numbers up to 2.0 indicates large performance penalties when fixed-geometry inlets are used. Use of variable-geometry inlets, however, nearly eliminates th The analysis was confirmed experimentally by investigating at Mach numbers of 0, 0.63, and 1.5 to 2.0 two single oblique-shock-type inlets of different compression-ramp angles, which simulated a variable-geometry configuration. The experimental investigation indicated that total-pressure recoveries comparable withose attainable with well designed nose inlets were obtained with the side inlets when all the boundary layer ahead of the inlets was removed. Serious drag penalties resulted at a Mach number of 2.0 from the use of blunt-cowl leading edges. However, sharp-lip inlets produced large losses in thrust for the take-off condition. These thrust penalties which are associated with the the low-speed operation of the sharp-lip inlet designs can probably be avoided without impairing the supersonic performance of the inlet by the use of auxiliary inlets or blow-in doors.

  17. Effect of nose bluntness and afterbody shape on aerodynamic characteristics of a monoplanar missile concept with bodies of circular and elliptical cross sections at a Mach number of 2.50

    Science.gov (United States)

    Graves, E. B.; Fournier, R. H.

    1979-01-01

    The tests were performed at a Mach number of 2.50 and at angles of attack from about -4 deg to 32 deg. The results indicate that increasing nose bluntness increases zero lift drag and decreases both the maximum lift-drag ratio and the level of directional stability. The center of pressure generally moves forward with increasing nose size; however, small nose radii on the modified elliptical configurations move the center of pressure rearward. The circular bodied configurations exhibit the greatest longitudinal stability and the least directional stability. Concepts with the variable geometry afterbody contour display the most directional stability and the greatest zero lift drag.

  18. Performance, Stability, and Control Investigation at Mach Numbers from 0.60 to 1.05 of a Model of the "Swallow" with Outer Wing Panels Swept 75 degree with and without Power Simulations

    Science.gov (United States)

    Schmeer, James W.; Cassetti, Marlowe D.

    1960-01-01

    An investigation of the performance, stability, and control characteristics of a variable-sweep arrow-wing model with the outer wing panels swept 75 deg. has been conducted in the Langley 16-foot transonic tunnel. Four outboard engines located above and below the wing provided propulsive thrust, and, by deflecting in the pitch direction and rotating in the lateral plane, also produced control forces. The engine nacelles incorporated swept lateral and vertical fins for aerodynamic stability and control. Jet-off data were obtained with flow-through nacelles, simulating inlet flow; jet thrust and hot-jet interference effects were obtained with faired-nose nacelles housing hydrogen peroxide gas generators. Six-component force and moment data were obtained at Mach numbers from 0.60 to 1.05 through a range of angles of attack and angles of side-slip. Control characteristics were obtained by deflecting the nacelle-fin combinations as elevators, rudders, and ailerons at several fixed angles for each control. The results indicate that the basic wing-body configuration becomes neutrally stable or unstable at a lift coefficient of 0.15; addition of nacelles with fins delayed instability to a lift coefficient of 0.30. Addition of nacelles to the wing-body configuration increased minimum drag from 0.0058 to 0.0100 at a Mach number of 0.60 and from 0.0080 to 0.0190 at a Mach number of 1.05 with corresponding reductions in maximum lift-drag ratio of 12 percent and 33 percent, respectively. The nacelle-fin combinations were ineffective as longitudinal controls but were adequate as directional and lateral controls. The model with nacelles and fins was directionally and laterally stable; the stability generally increased with increasing lift. Jet interference effects on stability and control characteristics were small but the adverse effects on drag were greater than would be expected for isolated nacelles.

  19. CFD simulation with Code-Saturne of the light gas stratification erosion by a vertical air gas injection using a Low Mach number algorithm

    International Nuclear Information System (INIS)

    Hou Bingxu; Yu Jiyang; Senechal, Dorothee; Mechitoua, Namane; Min Jiesheng; Chen Guofei

    2015-01-01

    During CFD simulations of the flows at low Mach number regime, the classical assumption which neglects the dilatable effect of gas is no longer applicable when the temperature variation or the concentration variation of the mixture's components is too large in the fluid domain. To be able to correctly predict the flow at such a regime, some authors have recourse to a Low Mach number algorithm. This algorithm is based on the well-known pressure-based algorithm or elliptic solver for incompressible flows, SIMPLE, with a modification for the treatment of the pressure which is split into two parts (the hydrodynamic pressure and the thermodynamic pressure) and a dilatable term added in the mass equation. This algorithm has been implemented in the CFD code, Code_—Saturne, developed by EDF R and D, and applied for the CFD simulations of the erosion phenomena of light gas stratification by air injection. This paper is devoted to the analytical work with the Low Mach number algorithm based on the ST1 series of the SETH-2 campaign provided by the OECD project on the PANDA test facility of PSI. The first part is focused on a mesh sensitivity analysis, which is a common procedure for CFD codes validation. The second part of the paper presents a comparison between the CFD results obtained with the standard algorithms used for incompressible flows and the Low Mach number algorithm. The third part is an analysis of the CFD results obtained on the reference mesh with both different Froude numbers corresponding to the tests ST1_—7 (Fr=6.04) and ST1_—10 (Fr=7.95) from the ST1 series. In the last part the authors perform the knowledge of the initial light gas distribution effect on the stratification erosion and the capability of the CFD codes to predict this phenomenon with an area governed by diffusion regime (at the top of the vessel) and another one by forced convection near the injection. (author)

  20. Non-thermal electron acceleration in low Mach number collisionless shocks. II. Firehose-mediated Fermi acceleration and its dependence on pre-shock conditions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xinyi; Narayan, Ramesh [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sironi, Lorenzo [NASA Einstein Postdoctoral Fellow. (United States)

    2014-12-10

    Electron acceleration to non-thermal energies is known to occur in low Mach number (M{sub s} ≲ 5) shocks in galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Using two-dimensional (2D) particle-in-cell (PIC) plasma simulations, we showed in Paper I that electrons are efficiently accelerated in low Mach number (M{sub s} = 3) quasi-perpendicular shocks via a Fermi-like process. The electrons bounce between the upstream region and the shock front, with each reflection at the shock resulting in energy gain via shock drift acceleration. The upstream scattering is provided by oblique magnetic waves that are self-generated by the electrons escaping ahead of the shock. In the present work, we employ additional 2D PIC simulations to address the nature of the upstream oblique waves. We find that the waves are generated by the shock-reflected electrons via the firehose instability, which is driven by an anisotropy in the electron velocity distribution. We systematically explore how the efficiency of wave generation and of electron acceleration depend on the magnetic field obliquity, the flow magnetization (or equivalently, the plasma beta), and the upstream electron temperature. We find that the mechanism works for shocks with high plasma beta (≳ 20) at nearly all magnetic field obliquities, and for electron temperatures in the range relevant for galaxy clusters. Our findings offer a natural solution to the conflict between the bright radio synchrotron emission observed from the outskirts of galaxy clusters and the low electron acceleration efficiency usually expected in low Mach number shocks.

  1. Effects of Inlet Modification and Rocket-Rack Extension on the Longitudinal Trim and Low-Lift Drag of the Douglas F5D-1 Airplane as Obtained with a 0.125-Scale Rocket-Boosted Model between Mach Numbers of 0.81 and 1.64, TED No. NACA AD 399

    Science.gov (United States)

    Hastings, Earl C., Jr.; Dickens, Waldo L.

    1957-01-01

    A flight investigation was conducted to determine the effects of an inlet modification and rocket-rack extension on the longitudinal trim and low-lift drag of the Douglas F5D-1 airplane. The investigation was conducted with a 0.125-scale rocket-boosted model which was flight tested at the Langley Pilotless Aircraft Research Station at Wallops Island, Va. Results indicate that the combined effects of the modified inlet and fully extended rocket racks on the trim lift coefficient and trim angle of attack were small between Mach numbers of 0.94 and 1.57. Between Mach numbers of 1.10 and 1.57 there was an average increase in drag coefficient of about o,005 for the model with modified inlet and extended rocket racks. The change in drag coefficient due to the inlet modification alone is small between Mach numbers of 1.59 and 1.64

  2. Lift, Drag, Static Stability, and Buffet Boundaries of a Model of the McDonnell F3H-1N Airplane at Mach Numbers from 0.40 to 1.27, TED No. NACA DE 351

    Science.gov (United States)

    Crabill, Norman L.

    1956-01-01

    The National Advisory Committee for Aeronautics has conducted a flight test of a model approximating the McDonnell F3H-lN airplane configuration to determine its pitch-up and buffet boundaries, as well as the usual longitudinal stability derivatives obtainable from the pulsed- tail technique. The test was conducted by the freely flying rocket- boosted model technique developed at the Langley Laboratory; results were obtained at Mach numbers from 0.40 to 1.27 at corresponding Reynolds numbers of 2.6 x 10(exp 6) and 9.0 x 10(exp 6). The phenomena of pitch-up, buffet, and maximum lift were encountered at Mach numbers between 0.42 and 0.85. The lift-curve slope and wing-root bending-moment slope increased with increasing angle of attack, whereas the static stability decreased with angle of attack at subsonic speeds and increased at transonic speeds. There was little change in trim at low lift at transonic speeds.

  3. Aerodynamic characteristics of wings designed with a combined-theory method to cruise at a Mach number of 4.5

    Science.gov (United States)

    Mack, Robert J.

    1988-01-01

    A wind-tunnel study was conducted to determine the capability of a method combining linear theory and shock-expansion theory to design optimum camber surfaces for wings that will fly at high-supersonic/low-hypersonic speeds. Three force models (a flat-plate reference wing and two cambered and twisted wings) were used to obtain aerodynamic lift, drag, and pitching-moment data. A fourth pressure-orifice model was used to obtain surface-pressure data. All four wing models had the same planform, airfoil section, and centerbody area distribution. The design Mach number was 4.5, but data were also obtained at Mach numbers of 3.5 and 4.0. Results of these tests indicated that the use of airfoil thickness as a theoretical optimum, camber-surface design constraint did not improve the aerodynamic efficiency or performance of a wing as compared with a wing that was designed with a zero-thickness airfoil (linear-theory) constraint.

  4. Application of supersonic linear theory and hypersonic impact methods to three nonslender hypersonic airplane concepts at Mach numbers from 1.10 to 2.86

    Science.gov (United States)

    Pittman, J. L.

    1979-01-01

    Aerodynamic predictions from supersonic linear theory and hypersonic impact theory were compared with experimental data for three hypersonic research airplane concepts over a Mach number range from 1.10 to 2.86. The linear theory gave good lift prediction and fair to good pitching-moment prediction over the Mach number (M) range. The tangent-cone theory predictions were good for lift and fair to good for pitching moment for M more than or equal to 2.0. The combined tangent-cone theory predictions were good for lift and fair to good for pitching moment for M more than or equal to 2.0. The combined tangent-cone/tangent-wedge method gave the least accurate prediction of lift and pitching moment. The zero-lift drag was overestimated, especially for M less than 2.0. The linear theory drag prediction was generally poor, with areas of good agreement only for M less than or equal to 1.2. For M more than or equal to 2.), the tangent-cone method predicted the zero-lift drag most accurately.

  5. An Evaluation of the Roll-Rate Stabilization System of the Sidewinder Missile at Mach Numbers from 0.9 to 2.3

    Science.gov (United States)

    Nason, Martin L.; Brown, Clarence A., Jr.; Rock, Rupert S.

    1955-01-01

    A linear stability analysis and flight-test investigation has been performed on a rolleron-type roll-rate stabilization system for a canard-type missile configuration through a Mach number range from 0.9 to 2.3. This type damper provides roll damping by the action of gyro-actuated uncoupled wing-tip ailerons. A dynamic roll instability predicted by the analysis was confirmed by flight testing and was subsequently eliminated by the introduction of control-surface damping about the rolleron hinge line. The control-surface damping was provided by an orifice-type damper contained within the control surface. Steady-state rolling velocities were at all times less than 1 radian per second between the Mach numbers of 0.9 to 2.3 on the configurations tested. No adverse longitudinal effects were experienced in flight because of the tendency of the free-floating rollerons to couple into the pitching motion at the low angles of attack and disturbance levels investigated herein after the introduction of control-surface damping.

  6. Adaptive multilevel mesh refinement method for the solution of low Mach number reactive flows; Methode adaptative de raffinement local multi-niveaux pour le calcul d'ecoulements reactifs a faible nombre de Mach

    Energy Technology Data Exchange (ETDEWEB)

    Core, X.

    2002-02-01

    The isobar approximation for the system of the balance equations of mass, momentum, energy and chemical species is a suitable approximation to represent low Mach number reactive flows. In this approximation, which neglects acoustics phenomena, the mixture is hydrodynamically incompressible and the thermodynamic effects lead to an uniform compression of the system. We present a novel numerical scheme for this approximation. An incremental projection method, which uses the original form of mass balance equation, discretizes in time the Navier-Stokes equations. Spatial discretization is achieved through a finite volume approach on MAC-type staggered mesh. A higher order de-centered scheme is used to compute the convective fluxes. We associate to this discretization a local mesh refinement method, based on Flux Interface Correction technique. A first application concerns a forced flow with variable density which mimics a combustion problem. The second application is natural convection with first small temperature variations and then beyond the limit of validity of the Boussinesq approximation. Finally, we treat a third application which is a laminar diffusion flame. For each of these test problems, we demonstrate the robustness of the proposed numerical scheme, notably for the density spatial variations. We analyze the gain in accuracy obtained with the local mesh refinement method. (author)

  7. Low-Lift Drag of the Grumman F9F-9 Airplane as Obtained by a 1/7.5-Scale Rocket-Boosted Model and by Three 1/45.85-Scale Equivalent-Body Models between Mach Numbers of 0.8 and 1.3, TED No. NACA DE 391

    Science.gov (United States)

    Stevens, Joseph E.

    1955-01-01

    Low-lift drag data are presented herein for one 1/7.5-scale rocket-boosted model and three 1/45.85-scale equivalent-body models of the Grumman F9F-9 airplane, The data were obtained over a Reynolds number range of about 5 x 10(exp 6) to 10 x 10(exp 6) based on wing mean aerodynamic chord for the rocket model and total body length for the equivalent-body models. The rocket-boosted model showed a drag rise of about 0,037 (based on included wing area) between the subsonic level and the peak supersonic drag coefficient at the maximum Mach number of this test. The base drag coefficient measured on this model varied from a value of -0,0015 in the subsonic range to a maximum of about 0.0020 at a Mach number of 1.28, Drag coefficients for the equivalent-body models varied from about 0.125 (based on body maximum area) in the subsonic range to about 0.300 at a Mach number of 1.25. Increasing the total fineness ratio by a small amount raised the drag-rise Mach number slightly.

  8. A modification to linearized theory for prediction of pressure loadings on lifting surfaces at high supersonic Mach numbers and large angles of attack

    Science.gov (United States)

    Carlson, H. W.

    1979-01-01

    A new linearized-theory pressure-coefficient formulation was studied. The new formulation is intended to provide more accurate estimates of detailed pressure loadings for improved stability analysis and for analysis of critical structural design conditions. The approach is based on the use of oblique-shock and Prandtl-Meyer expansion relationships for accurate representation of the variation of pressures with surface slopes in two-dimensional flow and linearized-theory perturbation velocities for evaluation of local three-dimensional aerodynamic interference effects. The applicability and limitations of the modification to linearized theory are illustrated through comparisons with experimental pressure distributions for delta wings covering a Mach number range from 1.45 to 4.60 and angles of attack from 0 to 25 degrees.

  9. LOW MACH NUMBER MODELING OF CONVECTION IN HELIUM SHELLS ON SUB-CHANDRASEKHAR WHITE DWARFS. II. BULK PROPERTIES OF SIMPLE MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, A. M.; Zingale, M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Nonaka, A.; Almgren, A. S.; Bell, J. B. [Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2016-08-10

    The dynamics of helium shell convection driven by nuclear burning establish the conditions for runaway in the sub-Chandrasekhar-mass, double-detonation model for SNe Ia, as well as for a variety of other explosive phenomena. We explore these convection dynamics for a range of white dwarf core and helium shell masses in three dimensions using the low Mach number hydrodynamics code MAESTRO. We present calculations of the bulk properties of this evolution, including time-series evolution of global diagnostics, lateral averages of the 3D state, and the global 3D state. We find a variety of outcomes, including quasi-equilibrium, localized runaway, and convective runaway. Our results suggest that the double-detonation progenitor model is promising and that 3D dynamic convection plays a key role.

  10. Pitot pressure measurements in flow fields behind circular-arc nozzles with exhaust jets at subsonic free-stream Mach numbers. [langley 16 foot transonic tunnel

    Science.gov (United States)

    Mason, M. L.; Putnam, L. E.

    1979-01-01

    The flow field behind a circular arc nozzle with exhaust jet was studied at subsonic free stream Mach numbers. A conical probe was used to measure the pitot pressure in the jet and free stream regions. Pressure data were recorded for two nozzle configurations at nozzle pressure ratios of 2.0, 2.9, and 5.0. At each set of test conditions, the probe was traversed from the jet center line into the free stream region at seven data acquisition stations. The survey began at the nozzle exit and extended downstream at intervals. The pitot pressure data may be applied to the evaluation of computational flow field models, as illustrated by a comparison of the flow field data with results of inviscid jet plume theory.

  11. Effect of nozzle and vertical-tail variables on the performance of a 3-surface F-15 model at transonic Mach numbers. [Langley 16 foot transonic tunnel

    Science.gov (United States)

    Pendergraft, O. C., Jr.; Bare, E. A.

    1982-01-01

    An investigation was conducted in the Langley 16 foot transonic tunnel to determine the longitudinal aerodynamic characteristics of twin two dimensional nozzles and twin baseline axisymmetric nozzles installed on a fully metric 0.047 scale model of the F-15 three surface configuration (canards, wing, horizontal tails). The effects on performance of two dimensional nozzle in flight thrust reversing, locations and orientation of the vertical tails, and deflections of the horizontal tails were also determined. Test data were obtained at static conditions and at Mach numbers from 0.60 to 1.20 over an angle of attack range from -2 deg to 15 deg. Nozzle pressure ratio was varied from jet off to about 6.5.

  12. A non-conformal finite element/finite volume scheme for the non-structured grid-based approximation of low Mach number flows

    International Nuclear Information System (INIS)

    Ansanay-Alex, G.

    2009-01-01

    The development of simulation codes aimed at a precise simulation of fires requires a precise approach of flame front phenomena by using very fine grids. The need to take different spatial scale into consideration leads to a local grid refinement and to a discretization with homogeneous grid for computing time and memory purposes. The author reports the approximation of the non-linear convection term, the scalar advection-diffusion in finite volumes, numerical simulations of a flow in a bent tube, of a three-dimensional laminar flame and of a low Mach number an-isotherm flow. Non conformal finite elements are also presented (Rannacher-Turek and Crouzeix-Raviart elements)

  13. Longitudinal Stability and Control Characteristics as Determined by the Rocket-model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-aspect-ratio Wing Having Trailing-edge Flap Controls for a Mach Number Range of 0.7 to 1.

    Science.gov (United States)

    Baber, Hal T , Jr; Moul, Martin T

    1955-01-01

    Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle - of-attack range of this test (0 deg to 8 deg). The aerodynamic-center location for angles of attack near 50 remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near 0 deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of 0 deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle -of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

  14. Longitudinal Stability and Control Characteristics as Determined by the Rocket-Model Technique for an Inline, Cruciform, Canard Missile Configuration with a Low-Aspect-Ratio Wing Having Trailing-Edge Flap Controls for a Mach Number Range of 0.7 to 1.8

    Science.gov (United States)

    Baber, H. T., Jr.; Moul, M. T.

    1955-01-01

    Two full-scale models of an inline, cruciform, canard missile configuration having a low-aspect-ratio wing equipped with flap-type controls were flight tested in order to determine the missile's longitudinal aerodynamic characteristics. Stability derivatives and control and drag characteristics are presented for a range of Mach number from 0.7 to 1.8. Nonlinear lift and moment curves were noted for the angle-of-attack range of this test (0 deg to 8 deg ). The aerodynamic-center location for angles of attack near 5 deg remained nearly constant for supersonic speeds at 13.5 percent of the mean aerodynamic chord; whereas for angles of attack near O deg, there was a rapid forward movement of the aerodynamic center as the Mach number increased. At a control deflection of O deg, the missile's response to the longitudinal control was in an essentially fixed space plane which was not coincident with the pitch plane as a result of the missile rolling. As a consequence, stability characteristics were determined from the resultant of pitch and yaw motions. The damping-in-pitch derivatives for the two angle-of-attack ranges of the test are in close agreement and varied only slightly with Mach number. The horn-balanced trailing-edge flap was effective in producing angle of attack over the Mach number range.

  15. Flight Measurements of Average Skin-Friction Coefficients on a Parabolic Body of Revolution (NACA RM-10) at Mach Numbers from 1.0 to 3.7

    Science.gov (United States)

    Loposer, J. Dan; Rumsey, Charles B.

    1954-01-01

    Measurement of average skin-friction coefficients have been made on six rocket-powered free-flight models by using the boundary-layer rake technique. The model configuration was the NACA RM-10, a 12.2-fineness-ratio parabolic body of revolution with a flat base. Measurements were made over a Mach number range from 1 to 3.7, a Reynolds number range 40 x 10(exp 6) to 170 x 10(exp 6) based on length to the measurement station, and with aerodynamic heating conditions varying from strong skin heating to strong skin cooling. The measurements show the same trends over the test ranges as Van Driest's theory for turbulent boundary layer on a flat plate. The measured values are approximately 7 percent higher than the values of the flat-plate theory. A comparison which takes into account the differences in Reynolds number is made between the present results and skin-friction measurements obtained on NACA RM-10 scale models in the Langley 4- by 4-foot supersonic pressure tunnel, the Lewis 8- by 6-foot supersonic tunnel, and the Langley 9-inch supersonic tunnel. Good agreement is shown at all but the lowest tunnel Reynolds number conditions. A simple empirical equation is developed which represents the measurements over the range of the tests.

  16. Local skin friction coefficients and boundary layer profiles obtained in flight from the XB-70-1 airplane at Mach numbers up to 2.5

    Science.gov (United States)

    Fisher, D. F.; Saltzman, E. J.

    1973-01-01

    Boundary-layer and local friction data for Mach numbers up to 2.5 and Reynolds numbers up to 3.6 x 10 to the 8th power were obtained in flight at three locations on the XB-70-1 airplane: the lower forward fuselage centerline (nose), the upper rear fuselage centerline, and the upper surface of the right wing. Local skin friction coefficients were derived at each location by using (1) a skin friction force balance, (2) a Preston probe, and (3) an adaptation of Clauser's method which derives skin friction from the rake velocity profile. These three techniques provided consistent results that agreed well with the von Karman-Schoenherr relationship for flow conditions that are quasi-two-dimensional. At the lower angles of attack, the nose-boom and flow-direction vanes are believed to have caused the momentum thickness at the nose to be larger than at the higher angles of attack. The boundary-layer data and local skin friction coefficients are tabulated. The wind-tunnel-model surface-pressure distribution ahead of the three locations and the flight surface-pressure distribution ahead of the wing location are included.

  17. Local flow measurements at the inlet spike tip of a Mach 3 supersonic cruise airplane

    Science.gov (United States)

    Johnson, H. J.; Montoya, E. J.

    1973-01-01

    The flow field at the left inlet spike tip of a YF-12A airplane was examined using at 26 deg included angle conical flow sensor to obtain measurements at free-stream Mach numbers from 1.6 to 3.0. Local flow angularity, Mach number, impact pressure, and mass flow were determined and compared with free-stream values. Local flow changes occurred at the same time as free-stream changes. The local flow usually approached the spike centerline from the upper outboard side because of spike cant and toe-in. Free-stream Mach number influenced the local flow angularity; as Mach number increased above 2.2, local angle of attack increased and local sideslip angle decreased. Local Mach number was generally 3 percent less than free-stream Mach number. Impact-pressure ratio and mass flow ratio increased as free-stream Mach number increased above 2.2, indicating a beneficial forebody compression effect. No degradation of the spike tip instrumentation was observed after more than 40 flights in the high-speed thermal environment encountered by the airplane. The sensor is rugged, simple, and sensitive to small flow changes. It can provide accurate imputs necessary to control an inlet.

  18. Incompressible boundary-layer stability analysis of LFC experimental data for sub-critical Mach numbers. M.S. Thesis

    Science.gov (United States)

    Berry, S. A.

    1986-01-01

    An incompressible boundary-layer stability analysis of Laminar Flow Control (LFC) experimental data was completed and the results are presented. This analysis was undertaken for three reasons: to study laminar boundary-layer stability on a modern swept LFC airfoil; to calculate incompressible design limits of linear stability theory as applied to a modern airfoil at high subsonic speeds; and to verify the use of linear stability theory as a design tool. The experimental data were taken from the slotted LFC experiment recently completed in the NASA Langley 8-Foot Transonic Pressure Tunnel. Linear stability theory was applied and the results were compared with transition data to arrive at correlated n-factors. Results of the analysis showed that for the configuration and cases studied, Tollmien-Schlichting (TS) amplification was the dominating disturbance influencing transition. For these cases, incompressible linear stability theory correlated with an n-factor for TS waves of approximately 10 at transition. The n-factor method correlated rather consistently to this value despite a number of non-ideal conditions which indicates the method is useful as a design tool for advanced laminar flow airfoils.

  19. The Aerodynamic Characteristics in Pitch of a 1/15-Scale Model of the Grumman F11F-1 Airplane at Mach Numbers of 1.41, 1.61, and 2.01, TED No. NACA DE 390

    Science.gov (United States)

    Driver, Cornelius

    1956-01-01

    Tests have been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.41, 1.61, and 2.01 to determine the static longitudinal stability and control characteristics of various arrangements of the Grumman F11F-1 airplane. Tests were made of the complete model and various combinations of its component parts and, in addition, the effects of various body modifications, a revised vertical tail, and wing fences on the longitudinal characteristics were determined. The results indicate that for a horizontal-tail incidence of -10 deg the trim lift coefficient varied from 0.29 at a Mach number of 1.61 to 0.23 at a Mach number of 2.01 with a corresponding decrease in lift-drag trim from 3.72 to 3.15. Stick-position instability was indicated in the low-supersonic-speed range. A photographic-type nose modification resulted in slightly higher values of minimum drag coefficient but did not significantly affect the static stability or lift-curve slope. The minimum drag coefficient for the complete model with the production nose remained essentially constant at 0.047 throughout the Mach number range investigated.

  20. Wind-tunnel calibration of a combined pitot-static tube and vane-type flow-angularity indicator at Mach numbers of 1.61 and 2.01

    Science.gov (United States)

    Sinclair, Archibald R; Mace, William D

    1956-01-01

    A limited calibration of a combined pitot-static tube and vane-type flow-angularity indicator has been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.61 and 2.01. The results indicated that the angle-of-yaw indications were affected by unsymmetric shock effects at low angles of attack.

  1. Theoretical and Experimental Analysis of Low-Drag Supersonic Inlets Having a Circular Cross Section and a Central Body at Mach Numbers 3.30, 2.75, and 2.45

    Science.gov (United States)

    Ferri, Antonio; Nucci, Louis M

    1954-01-01

    Contains theoretical and experimental analysis of circular inlets having a central body at Mach numbers of 3.30, 2.75, and 2.45. The inlets have been designed in order to have low drag and high pressure recovery. The pressure recoveries obtained are of the same order of magnitude as those previously obtained by inlets having very large external drag.

  2. Numerical simulation of divergent rocket-based-combined-cycle performances under the flight condition of Mach 3

    Science.gov (United States)

    Cui, Peng; Xu, WanWu; Li, Qinglian

    2018-01-01

    Currently, the upper operating limit of the turbine engine is Mach 2+, and the lower limit of the dual-mode scramjet is Mach 4. Therefore no single power systems can operate within the range between Mach 2 + and Mach 4. By using ejector rockets, Rocket-based-combined-cycle can work well in the above scope. As the key component of Rocket-based-combined-cycle, the ejector rocket has significant influence on Rocket-based-combined-cycle performance. Research on the influence of rocket parameters on Rocket-based-combined-cycle in the speed range of Mach 2 + to Mach 4 is scarce. In the present study, influences of Mach number and total pressure of the ejector rocket on Rocket-based-combined-cycle were analyzed numerically. Due to the significant effects of the flight conditions and the Rocket-based-combined-cycle configuration on Rocket-based-combined-cycle performances, flight altitude, flight Mach number, and divergence ratio were also considered. The simulation results indicate that matching lower altitude with higher flight Mach numbers can increase Rocket-based-combined-cycle thrust. For another thing, with an increase of the divergent ratio, the effect of the divergent configuration will strengthen and there is a limit on the divergent ratio. When the divergent ratio is greater than the limit, the effect of divergent configuration will gradually exceed that of combustion on supersonic flows. Further increases in the divergent ratio will decrease Rocket-based-combined-cycle thrust.

  3. Use of a pitot-static probe for determining wing section drag in flight at Mach numbers from 0.5 to approximately 1.0

    Science.gov (United States)

    Montoya, L. C.; Economu, M. A.; Cissell, R. E.

    1974-01-01

    The use of a pitot-static probe to determine wing section drag at speeds from Mach 0.5 to approximately 1.0 was evaluated in flight. The probe unit is described and operational problems are discussed. Typical wake profiles and wing section drag coefficients are presented. The data indicate that the pitot-static probe gave reliable results up to speeds of approximately 1.0.

  4. A Whitham-Theory Sonic-Boom Analysis of the TU-144 Aircraft at a Mach Number of 2.2

    Science.gov (United States)

    Mack, Robert J.

    1999-01-01

    . Therefore, an analysis of the Tu-144 was made to obtain predictions of pressure signature shape and shock strengths at cruise conditions so that the range and characteristics of the required pressure gages could be determined well in advance of the tests. Cancellation of the sonic-boom signature measurement part of the tests removed the need for these pressure gages. Since CFD methods would be used to analyze the aerodynamic performance of the Tu-144 and make similar pressure signature predictions, the relatively quick and simple Whitham-theory pressure signature predictions presented in this paper could be used for comparisons. Pressure signature predictions of sonic-boom disturbances from the Tu- 144 aircraft were obtained from geometry derived from a three-view description of the production aircraft. The geometry was used to calculate aerodynamic performance characteristics at supersonic-cruise conditions. These characteristics and Whitham/Walkden sonic-boom theory were employed to obtain F-functions and flow-field pressure signature predictions at a Mach number of 2.2, at a cruise altitude of 61000 feet, and at a cruise weight of 350000 pounds.

  5. Increasing the octane number of gasoline using functionalized carbon nanotubes

    International Nuclear Information System (INIS)

    Kish, Sara Safari; Rashidi, Alimorad; Aghabozorg, Hamid Reza; Moradi, Leila

    2010-01-01

    The octane number is one of the characteristics of spark-ignition fuels such as gasoline. Octane number of fuels can be improved by addition of oxygenates such as ethanol, MTBE (methyl tert-butyl ether), TBF (tertiary butyl formate) and TBA (tertiary butyl alcohol) as well as their blends with gasoline that reduce the cost impact of fuels. Carbon nanotubes (CNTs) are as useful additives for increasing the octane number. Functionalized carbon nanotubes containing amide groups have a high reactivity and can react with many chemicals. These compounds can be solubilized in gasoline to increase the octane number. In this study, using octadecylamine and dodecylamine, CNTs were amidated and the amino-functionalized carbon nanotubes were added to gasoline. Research octane number analysis showed that these additives increase octane number of the desired samples. X-ray diffraction (XRD), Fourier transforms infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetry analyses (TGA) were used for characterization of the prepared functionalized carbon nanotubes.

  6. Increasing the octane number of gasoline using functionalized carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kish, Sara Safari [Faculty of Chemistry, Islamic Azad University, North Tehran Branch, Tehran (Iran, Islamic Republic of); Rashidi, Alimorad, E-mail: rashidiam@ripi.ir [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Blvd. Azadi Sport Complex, Tehran 14665-1998 (Iran, Islamic Republic of); Aghabozorg, Hamid Reza [Catalysis Research Center, Research Institute of Petroleum Industry (RIPI), Tehran (Iran, Islamic Republic of); Moradi, Leila [Faculty of Chemistry, Kashan University, Kashan (Iran, Islamic Republic of)

    2010-03-15

    The octane number is one of the characteristics of spark-ignition fuels such as gasoline. Octane number of fuels can be improved by addition of oxygenates such as ethanol, MTBE (methyl tert-butyl ether), TBF (tertiary butyl formate) and TBA (tertiary butyl alcohol) as well as their blends with gasoline that reduce the cost impact of fuels. Carbon nanotubes (CNTs) are as useful additives for increasing the octane number. Functionalized carbon nanotubes containing amide groups have a high reactivity and can react with many chemicals. These compounds can be solubilized in gasoline to increase the octane number. In this study, using octadecylamine and dodecylamine, CNTs were amidated and the amino-functionalized carbon nanotubes were added to gasoline. Research octane number analysis showed that these additives increase octane number of the desired samples. X-ray diffraction (XRD), Fourier transforms infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetry analyses (TGA) were used for characterization of the prepared functionalized carbon nanotubes.

  7. Comparison of analytical and experimental steadyand unsteady-pressure distributions at Mach number 0.78 for a high-aspect-ratio supercritical wing model with oscillating control surfaces

    Science.gov (United States)

    Mccain, W. E.

    1984-01-01

    The unsteady aerodynamic lifting surface theory, the Doublet Lattice method, with experimental steady and unsteady pressure measurements of a high aspect ratio supercritical wing model at a Mach number of 0.78 were compared. The steady pressure data comparisons were made for incremental changes in angle of attack and control surface deflection. The unsteady pressure data comparisons were made at set angle of attack positions with oscillating control surface deflections. Significant viscous and transonic effects in the experimental aerodynamics which cannot be predicted by the Doublet Lattice method are shown. This study should assist development of empirical correction methods that may be applied to improve Doublet Lattice calculations of lifting surface aerodynamics.

  8. [Increase in number of operations for stress urinary incontinence

    NARCIS (Netherlands)

    Vierhout, M.E.

    2005-01-01

    Since the introduction of the minimally invasive tension-free vaginal tape (TVT) the number of operations performed for treatment of stress urinary incontinence has increased dramatically from over 1600 in 1999 to more than 4200 in 2003. Both gynaecologists and urologists now perform more TVTs and

  9. Ernst Mach a deeper look : documents and new perspectives

    CERN Document Server

    1992-01-01

    Ernst Mach -- A Deeper Look has been written to reveal to English-speaking readers the recent revival of interest in Ernst Mach in Europe and Japan. The book is a storehouse of new information on Mach as a philosopher, historian, scientist and person, containing a number of biographical and philosophical manuscripts publihsed for the first time, along with correspondence and other matters published for the first time in English. The book also provides English translations of Mach's controversies with leading physicists and psychologists, such as Max Planck and Carl Stumpf, and offers basic evidence for resolving Mach's position on atomism and Einstein's theory of relativity. Mach's scientific, philosophical and personal influence in a number of countries -- Austria, Germany, Bohemia and Yugoslavia among them -- has been carefully explored and many aspects detailed for the first time. All of the articles are eminently readable, especially those written by Mach's sister. They are deeply researched, new interpre...

  10. In Brief: Refugee numbers could increase due to climate change

    Science.gov (United States)

    Zielinski, Sarah

    2007-05-01

    Climate change could push the number of refugees globally to more than one billion by 2050, according to a new report from the British charity Christian Aid. Currently, there are about 155 million `internally displaced persons' worldwide, driven from their homes due to conflict, ethnic persecution, or natural disasters. The addition of climate change and growing population numbers could exacerbate these ongoing problems. In the report, Mali is presented as a case study where ongoing climate change is forcing farmers to find other ways to feed their families; one result is an increased number of people attempting to migrate to Europe. The report calls on rich nations to devote US$100 billion each year to help poor people adapt to changing weather patterns. The report, ``Human tide: the real migration crisis,'' is available at http://www.christian-aid.org.uk/indepth/705caweekreport/

  11. Transonic Aerodynamic Characteristics of a Wing-Body Combination having a 52.5 deg Sweptback Wing of Aspect Ratio 3 with Conical Camber and Designed for a Mach Number of the Square Root of 2

    Science.gov (United States)

    Igoe, William B.; Re, Richard J.; Cassetti, Marlowe

    1961-01-01

    An investigation has been made of the effects of conical wing camber and supersonic body indentation on the aerodynamic characteristics of a wing-body configuration at transonic speeds. Wing aspect ratio was 3.0, taper ratio was 0.1, and quarter-chord line sweepback was 52.5 deg with airfoil sections of 0.03 thickness ratio. The tests were conducted in the Langley 16-foot transonic tunnel at various Mach numbers from 0.80 to 1.05 at angles of attack from -4 deg to 14 deg. The cambered-wing configuration achieved higher lift-drag ratios than a similar plane-wing configuration. The camber also reduced the effects of wing-tip flow separation on the aerodynamic characteristics. In general, no stability or trim changes below wing-tip flow separation resulted from the use of camber. The use of supersonic body indentation improved the lift-drag ratios at Mach numbers from 0.96 to 1.05.

  12. About the parametric interplay between ionic mach number, body-size, and satellite potential in determining the ion depletion in the wake of the S3-2 Satellite

    International Nuclear Information System (INIS)

    Samir, U.; Wildman, P.J.; Rich, F.; Brinton, H.C.; Sagalyn, R.C.

    1981-01-01

    Measurements of ion current, electron temperature, and density and values of satellite potential from the U.S. Air Force Satellite S3-2 together with ion composition measurements from the Atmosphere Explorer (AE-E) satellite were used to examine the variation of the ratio α = [I/sub +/(wake)]/[I/sub +/(ambient)] (where I/sub +/ is the ion current) with altitude and to examine the significance of the parametric interplay between ionic Mach number, normalized body size R/sub D/( = R0/lambda/sub D/, where R 0 is the satellite radius and lambda/sub D/ is the ambient debye length) and normalized body potenital phi/sub N/( = ephis/KT/sub e/, where phi/sub s/ is the satellite potential, T/sub e/ is the electron temperature, and e and K are constants). It was possible to separate between the influence of R/sub D/ and phi/sub N/ on α for a specific range parameters. Uncertainty, however, remains regarding the competiton between R/sub D/ and S(H + ) and S(O + ) are oxygen and hydrogen ionic Mach numbers, respectively) in determining the ion distribution in the nearest vicincity to the satellite surface. A brief discussion relevant to future experiments in the area of body plasma flow interactions to be conducted on board the Shuttle/Spacelab facility, is also included

  13. Patient organizations in Finland: increasing numbers and great variation.

    Science.gov (United States)

    Toiviainen, Hanna K; Vuorenkoski, Lauri H; Hemminki, Elina K

    2010-09-01

    There is very little research on patient organizations (POs), even though their numbers and influence seem to be increasing. The purpose of this study was to describe the establishment, membership, size, organization, decision making and basic funding of national POs in Finland. National POs (n = 130) were identified from their umbrella organizations and by Internet searches. Data were collected from POs' web pages (87% of POs had one), Finland's Slot Machine Association (RAY, an important public financier of POs), a relevant survey done by a local TV-company, and interviews and written materials of POs. Some current national POs were established around the turn of the 19(th) century. The rate of establishment of new POs increased from the 1970s and particularly in the 1990s when POs were characterized by increasing specialization. POs focused on different patient groups and diseases and were founded by philanthropists, physicians, patients, parents and the drug industry. Members could be patients, patient relatives, health-care professionals and organizations. POs widely varied in memberships (20-145 000, in 2002) and in number of paid personnel (0-1395, in 2002), organizational structure and decision making. Interest groups and financiers were often represented in decision-making organs. Activities included mutual support and service production, and, increasingly, informing and lobbying. POs had wide domestic and international co-operation and networking. Drug industry marketing was visible on PO web pages. Budget sizes varied (4000-15 million euros, in 2001). The main public financier was RAY. The old national POs were large and part of national social and health care, but newer ones were often established for mutual support and lobbying. National POs are not uniform but characterized by great variation. The number of national POs is increasing suggesting tighter competition for financing and visibility in the future.

  14. Flight and wind-tunnel calibrations of a flush airdata sensor at high angles of attack and sideslip and at supersonic Mach numbers

    Science.gov (United States)

    Moes, Timothy R.; Whitmore, Stephen A.; Jordan, Frank L., Jr.

    1993-01-01

    A nonintrusive airdata-sensing system was calibrated in flight and wind-tunnel experiments to an angle of attack of 70 deg and to angles of sideslip of +/- 15 deg. Flight-calibration data have also been obtained to Mach 1.2. The sensor, known as the flush airdata sensor, was installed on the nosecap of an F-18 aircraft for flight tests and on a full-scale F-18 forebody for wind-tunnel tests. Flight tests occurred at the NASA Dryden Flight Research Facility, Edwards, California, using the F-18 High Alpha Research Vehicle. Wind-tunnel tests were conducted in the 30- by 60-ft wind tunnel at the NASA LaRC, Hampton, Virginia. The sensor consisted of 23 flush-mounted pressure ports arranged in concentric circles and located within 1.75 in. of the tip of the nosecap. An overdetermined mathematical model was used to relate the pressure measurements to the local airdata quantities. The mathematical model was based on potential flow over a sphere and was empirically adjusted based on flight and wind-tunnel data. For quasi-steady maneuvering, the mathematical model worked well throughout the subsonic, transonic, and low supersonic flight regimes. The model also worked well throughout the angle-of-attack and sideslip regions studied.

  15. Increasing the number of spin-outs from Danish universities

    DEFF Research Database (Denmark)

    Andersen, Lars-Ulrik Aaen

    2011-01-01

    In this paper I describe some of the barriers and motivations involved in the process of creating spin-out companies from Danish universities – based on a study carried out at the Technical University of Denmark (DTU). Even if procedures are established to support the spin-out process...... in the spin-out process the study reveals some of the barriers of the employees at the universities but also the other stakeholders view on the process. The investigation also reveals the various motivations for starting up a spin-out company and input to what the university/department can do to facilitate......, there are still barriers that hinder the process. In this paper I investigate these barriers and the possible motivations that could increase the number of spin-outs. I also discuss some of the processes and tools that could be implemented to support the process. Based on interviews with a number of stakeholders...

  16. A non-conformal finite element/finite volume scheme for the non-structured grid-based approximation of low Mach number flows; Un schema elements finis non-conformes/volumes finis pour l'approximation en maillages non-structures des ecoulements a faible nombre de Mach

    Energy Technology Data Exchange (ETDEWEB)

    Ansanay-Alex, G.

    2009-06-17

    The development of simulation codes aimed at a precise simulation of fires requires a precise approach of flame front phenomena by using very fine grids. The need to take different spatial scale into consideration leads to a local grid refinement and to a discretization with homogeneous grid for computing time and memory purposes. The author reports the approximation of the non-linear convection term, the scalar advection-diffusion in finite volumes, numerical simulations of a flow in a bent tube, of a three-dimensional laminar flame and of a low Mach number an-isotherm flow. Non conformal finite elements are also presented (Rannacher-Turek and Crouzeix-Raviart elements)

  17. Aerodynamic interactions from reaction controls for lateral control of the M2-F2 lifting-body entry configuration at transonic and supersonic and supersonic Mach numbers. [wind tunnel tests

    Science.gov (United States)

    Bailey, R. O.; Brownson, J. J.

    1979-01-01

    Tests were conducted in the Ames 6 by 6 foot wind tunnel to determine the interaction of reaction jets for roll control on the M2-F2 lifting-body entry vehicle. Moment interactions are presented for a Mach number range of 0.6 to 1.7, a Reynolds number range of 1.2 x 10 to the 6th power to 1.6 x 10 to the 6th power (based on model reference length), an angle-of-attack range of -9 deg to 20 deg, and an angle-of-sideslip range of -6 deg to 6 deg at an angle of attack of 6 deg. The reaction jets produce roll control with small adverse yawing moment, which can be offset by horizontal thrust component of canted jets.

  18. Increased mast cell numbers in a calcaneal tendon overuse model.

    Science.gov (United States)

    Pingel, J; Wienecke, J; Kongsgaard, M; Behzad, H; Abraham, T; Langberg, H; Scott, A

    2013-12-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats were divided in two groups: running group (n = 12); sedentary control group (n = 12). The running-group was exposed to the HIUR exercise protocol for 7 weeks. The calcaneal tendons of both hind limbs were dissected. The right tendon was used for histologic analysis using Bonar score, immunohistochemistry, and second harmonic generation microscopy (SHGM). The left tendon was used for quantitative polymerase chain reaction (qPCR) analysis. An increased tendon cell density in the runners were observed compared to the controls (P = 0.05). Further, the intensity of immunostaining of protein kinase B, P = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further that these changes are associated with an increased mast cell density. © 2013 The Authors. Scand J Med Sci Sports published by John Wiley & Sons Ltd.

  19. Increased mast cell numbers in a calcaneal tendon overuse model

    DEFF Research Database (Denmark)

    Pingel, Jessica; Wienecke, Jacob; Kongsgaard Madsen, Mads

    2013-01-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats...... = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density...... (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further...

  20. Increasing effective number of neutrinos by decaying particles

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, K.; Kawasaki, M.; Nakayama, K.; Senami, M. [Tokyo Univ. (Japan). Inst. for Cosmic Ray Research; Takahashi, F. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2007-03-15

    We present models of decaying particles to increase the effective number of neutrinos N{sub {nu}} after big bang nucleosynthesis but before the structure formation begins. We point out that our scenario not only solves the discrepancy between the constraints on N{sub {nu}} from these two epochs, but also provides a possible answer to deeper inconsistency in the estimation of the matter power spectrum amplitude at small scales, represented by {sigma}{sub 8}, between the WMAP and some small scale matter power measurements such as the Lyman-{alpha} forest and weak lensing. We consider (a) saxion decay into two axions; (b) gravitino decay into axino and axion; (c) Dirac right-handed sneutrino decay into gravitino and right-handed neutrino. (orig.)

  1. Numbers of women faculty in the geosciences increasing, but slowly

    Science.gov (United States)

    Wolfe, C. J.

    2001-12-01

    Why are there so few women faculty in the geosciences, while there are large numbers of women undergraduate and graduate students? According to National Science Foundation (NSF) estimates for 1995 in the Earth, atmospheric, and oceanic sciences, women made up 34% of the bachelor's degrees awarded, 35% of the graduate students enrolled, and 22% of the doctorates granted. Yet progress has been slower in achieving adequate representation of women geoscientists in academia, where women represent only 12% of the overall faculty. This talk will present the results of a survey I conducted on the status of women faculty at the 20 top-ranked geology programs, which was originally published as a feature article in Eos [Wolfe, 1999]. Data from the 1997 AGI Directory of Geoscience Departments were used to compare the numbers of women faculty at different departments, as well as to consider the distribution of men and women faculty by year of Ph.D. Strong inequities were found to exist between the individual departments. The percentages of women in the departments ranged from 0% to as high as 23%, and 37% of the departments had either one woman faculty member or none. Histograms of the faculty sorted by year of Ph.D. showed that clear generational differences existed between the sets of men and women faculty. Thirty-nine percent of the men obtained their Ph.D. prior to 1970, whereas only 3% of the women obtained their Ph.D. before this date. The majority of women faculty members (64%) received their Ph.D. after 1980, but a minority of men (31%) received their degrees after 1980. In the 1960s and 1970s, the geosciences expanded and departments employed a high percentage of recent Ph.D.s, but hiring of young faculty decreased in the 1980s and 1990s. In contrast, the numbers of women graduate students only began to rise after 1970, and thus the quantity of women Ph.D.s increased as the number of young hires decreased. Two problems appeared evident from this study using 1997 data

  2. Flight Test of the Lateral Stability of a 0.133-Scale Model of the Convair XFY-1 Airplane with Windmilling Propellers at Mach Numbers from 0.70 to 1.12 (TED No. NACA DE 369)

    Science.gov (United States)

    Hollinger, James A.; Mitcham, Grady L.

    1955-01-01

    A flight test of a rocket-propelled model of the Convair XFY-1 airplane was conducted to determine the lateral stability and control characteristics, The 0.133-scale model had windmilling propellers for this test, which covered a Mach number range of O.70 to 1.12. The center of gravity was located at 13.9 percent of the mean aerodynamic chord. The methods of analysis included both a solution by vector diagrams and simple one- and two-degree-of-freedom methods. The model was both statically and dynamically stable throughout the speed range of the testa The roll damping was good, and the slope of the side-force curve varied little with speed. The rudder was effective throughout the test speed range, although it was reduced to about 43 percent of its subsonic value at supersonic speeds.

  3. Pitot-Pressure Measurements in Flow Fields Behind a Rectangular Nozzle with Exhaust Jet for Free-Stream Mach Numbers of 0.00, 0.60, and 1.20

    Science.gov (United States)

    Putnam, L. E.; Mercer, C. E.

    1986-01-01

    An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to measure the flow field in and around the jet exhaust from a nonaxisymmetric nozzle configuration. The nozzle had a rectangular exit with a width-to-height ratio of 2.38. Pitot-pressure measurements were made at five longitudinal locations downstream of the nozzle exit. The maximum distance downstream of the exit was about 5 nozzle heights. These measurements were made at free-stream Mach numbers of 0.00, 0.60, and 1.20 with the nozzle operating at a ratio of nozzle total pressure to free-stream static pressure of 4.0. The jet exhaust was simulated with high-pressure air that had an exit total temperature essentially equal to the free-stream total temperature.

  4. A pressure-based semi-implicit space-time discontinuous Galerkin method on staggered unstructured meshes for the solution of the compressible Navier-Stokes equations at all Mach numbers

    Science.gov (United States)

    Tavelli, Maurizio; Dumbser, Michael

    2017-07-01

    We propose a new arbitrary high order accurate semi-implicit space-time discontinuous Galerkin (DG) method for the solution of the two and three dimensional compressible Euler and Navier-Stokes equations on staggered unstructured curved meshes. The method is pressure-based and semi-implicit and is able to deal with all Mach number flows. The new DG scheme extends the seminal ideas outlined in [1], where a second order semi-implicit finite volume method for the solution of the compressible Navier-Stokes equations with a general equation of state was introduced on staggered Cartesian grids. Regarding the high order extension we follow [2], where a staggered space-time DG scheme for the incompressible Navier-Stokes equations was presented. In our scheme, the discrete pressure is defined on the primal grid, while the discrete velocity field and the density are defined on a face-based staggered dual grid. Then, the mass conservation equation, as well as the nonlinear convective terms in the momentum equation and the transport of kinetic energy in the energy equation are discretized explicitly, while the pressure terms appearing in the momentum and energy equation are discretized implicitly. Formal substitution of the discrete momentum equation into the total energy conservation equation yields a linear system for only one unknown, namely the scalar pressure. Here the equation of state is assumed linear with respect to the pressure. The enthalpy and the kinetic energy are taken explicitly and are then updated using a simple Picard procedure. Thanks to the use of a staggered grid, the final pressure system is a very sparse block five-point system for three dimensional problems and it is a block four-point system in the two dimensional case. Furthermore, for high order in space and piecewise constant polynomials in time, the system is observed to be symmetric and positive definite. This allows to use fast linear solvers such as the conjugate gradient (CG) method. In

  5. Measurements of Heat Transfer and Boundary-Layer Transition on an 8-Inch-Diameter Hemisphere-Cylinder in Free Flight for a Mach Number Range of 2.00 to 3.88

    Science.gov (United States)

    Garland, Benjamine J.; Chauvin, Leo T.

    1957-01-01

    Measurements of aerodynamic heat transfer have been made along the hemisphere and cylinder of a hemisphere-cylinder rocket-propelled model in free flight up to a Mach number of 3.88. The test Reynolds number based on free-stream condition and diameter of model covered a range from 2.69 x l0(exp 6) to 11.70 x 10(exp 6). Laminar, transitional, and turbulent heat-transfer coefficients were obtained. The laminar data along the body agreed with laminar theory for blunt bodies whereas the turbulent data along the cylinder were consistently lower than that predicted by the turbulent theory for a flat plate. Measurements of heat transfer at the stagnation point were, in general, lower than the theory for stagnation-point heat transfer. When the Reynolds number to the junction of the hemisphere-cylinder was greater than 6 x l0(exp 6), the transitional Reynolds number varied from 0.8 x l0(exp 6) to 3.0 x 10(exp 6); however, than 6 x l(exp 6) when the Reynolds number to the junction was less, than the transitional Reynolds number varied from 7.0 x l0(exp 6) to 24.7 x 10(exp 6).

  6. Mach's holographic principle

    International Nuclear Information System (INIS)

    Khoury, Justin; Parikh, Maulik

    2009-01-01

    Mach's principle is the proposition that inertial frames are determined by matter. We put forth and implement a precise correspondence between matter and geometry that realizes Mach's principle. Einstein's equations are not modified and no selection principle is applied to their solutions; Mach's principle is realized wholly within Einstein's general theory of relativity. The key insight is the observation that, in addition to bulk matter, one can also add boundary matter. Given a space-time, and thus the inertial frames, we can read off both boundary and bulk stress tensors, thereby relating matter and geometry. We consider some global conditions that are necessary for the space-time to be reconstructible, in principle, from bulk and boundary matter. Our framework is similar to that of the black hole membrane paradigm and, in asymptotically anti-de Sitter space-times, is consistent with holographic duality.

  7. Increasing living donor kidney transplantation numbers in Budapest.

    Science.gov (United States)

    Bäcker, H; Piros, L; Langer, R M

    2013-01-01

    Living related kidney donations (LRD) have had a significant impact on therapy of kidney diseases. Due to their ease of scheduling in the general surgery program and better half-life of about 21.6 versus 13.8 years for deceased donor kidneys, this approach has revolutionized nephrology and transplantation medicine. Since the first Hungarian LRD which was performed in 1974 in Budapest, Hungary, donations have expanded especially in the last 3 years. This has been followed in 2000 by living unrelated kidney donations (LURD). Since 2000 LURD can be also performed in Hungary. From the 251 LRD in our country in the last 3 years, 79 living donations have accounted for nearly one-third of the cases. In comparison of 2008, and 2011 the absolute numbers of LRD as well as LURD have more than doubled from 9 to 20 and 6 to 14 respectively. Based on international ranking data from the global observatory on donation and transplantation Budapest has improved from 1.20 in 2000 to 6.20 LRD per million persons (p.m.p.) in 2010. The increase in LURD has also led to some side effects: an increase in recipient age from 26 years in 2000 to 46 in 2011 and greater HLA mismatches. In 2010, Budapest ranked higher than Croatia or Portugal but still behind Germany (8.13 LRD p.m.p.) and the leading countries: the Netherlands (28.49 LRD p.m.p.) and Norway (16.94 LRD p.m.p.). Because of the tremendous progress in LRD, the gap between today's leading countries and Budapest is closing. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Fast IMRT by increasing the beam number and reducing the number of segments

    Directory of Open Access Journals (Sweden)

    Bratengeier Klaus

    2011-12-01

    Full Text Available Abstract Purpose The purpose of this work is to develop fast deliverable step and shoot IMRT technique. A reduction in the number of segments should theoretically be possible, whilst simultaneously maintaining plan quality, provided that the reduction is accompanied by an increased number of gantry angles. A benefit of this method is that the segment shaping could be performed during gantry motion, thereby reducing the delivery time. The aim was to find classes of such solutions whose plan quality can compete with conventional IMRT. Materials/Methods A planning study was performed. Step and shoot IMRT plans were created using direct machine parameter optimization (DMPO as a reference. DMPO plans were compared to an IMRT variant having only one segment per angle ("2-Step Fast". 2-Step Fast is based on a geometrical analysis of the topology of the planning target volume (PTV and the organs at risk (OAR. A prostate/rectum case, spine metastasis/spinal cord, breast/lung and an artificial PTV/OAR combination of the ESTRO-Quasimodo phantom were used for the study. The composite objective value (COV, a quality score, and plan delivery time were compared. The delivery time for the DMPO reference plan and the 2-Step Fast IMRT technique was measured and calculated for two different linacs, a twelve year old Siemens Primus™ ("old" linac and two Elekta Synergy™ "S" linacs ("new" linacs. Results 2-Step Fast had comparable or better quality than the reference DMPO plan. The number of segments was smaller than for the reference plan, the number of gantry angles was between 23 and 34. For the modern linac the delivery time was always smaller than that for the reference plan. The calculated (measured values showed a mean delivery time reduction of 21% (21% for the new linac, and of 7% (3% for the old linac compared to the respective DMPO reference plans. For the old linac, the data handling time per beam was the limiting factor for the treatment time

  9. Fast IMRT by increasing the beam number and reducing the number of segments

    International Nuclear Information System (INIS)

    Bratengeier, Klaus; Gainey, Mark B; Flentje, Michael

    2011-01-01

    The purpose of this work is to develop fast deliverable step and shoot IMRT technique. A reduction in the number of segments should theoretically be possible, whilst simultaneously maintaining plan quality, provided that the reduction is accompanied by an increased number of gantry angles. A benefit of this method is that the segment shaping could be performed during gantry motion, thereby reducing the delivery time. The aim was to find classes of such solutions whose plan quality can compete with conventional IMRT. A planning study was performed. Step and shoot IMRT plans were created using direct machine parameter optimization (DMPO) as a reference. DMPO plans were compared to an IMRT variant having only one segment per angle ('2-Step Fast'). 2-Step Fast is based on a geometrical analysis of the topology of the planning target volume (PTV) and the organs at risk (OAR). A prostate/rectum case, spine metastasis/spinal cord, breast/lung and an artificial PTV/OAR combination of the ESTRO-Quasimodo phantom were used for the study. The composite objective value (COV), a quality score, and plan delivery time were compared. The delivery time for the DMPO reference plan and the 2-Step Fast IMRT technique was measured and calculated for two different linacs, a twelve year old Siemens Primus™ ('old' linac) and two Elekta Synergy™ 'S' linacs ('new' linacs). 2-Step Fast had comparable or better quality than the reference DMPO plan. The number of segments was smaller than for the reference plan, the number of gantry angles was between 23 and 34. For the modern linac the delivery time was always smaller than that for the reference plan. The calculated (measured) values showed a mean delivery time reduction of 21% (21%) for the new linac, and of 7% (3%) for the old linac compared to the respective DMPO reference plans. For the old linac, the data handling time per beam was the limiting factor for the treatment time reduction. 2-Step

  10. The large lungs of elite swimmers: an increased alveolar number?

    Science.gov (United States)

    Armour, J; Donnelly, P M; Bye, P T

    1993-02-01

    chest depth, but by developing physically wider chests, containing an increased number of alveoli, rather than alveoli of increased size. However, in this cross-sectional study, hereditary factors cannot be ruled out, although we believe them to be less likely.

  11. Static Longitudinal and Lateral Stability Characteristics of an 0.065-Scale Model of the Chance Vought XRSSM-N-9a (REGULUS II) Missile at Mach Numbers from 1.6 to 2.0 (TED No. NACA AD 3122)

    Science.gov (United States)

    Hofstetter, William R.

    1957-01-01

    The static longitudinal and lateral stability charaetefistics of an 0 .065-scale model of the XRSSM-N-9a (REGULUS II) Missile at Mach number range of 1.6 to 2.0 at a Reynolds number per foot of 2.0(exp 8)

  12. Permutations avoiding an increasing number of length-increasing forbidden subsequences

    Directory of Open Access Journals (Sweden)

    Elena Barcucci

    2000-12-01

    Full Text Available A permutation π is said to be τ-avoiding if it does not contain any subsequence having all the same pairwise comparisons as τ. This paper concerns the characterization and enumeration of permutations which avoid a set F j of subsequences increasing both in number and in length at the same time. Let F j be the set of subsequences of the form σ(j+1(j+2, σ being any permutation on {1,...,j}. For j=1 the only subsequence in F 1 is 123 and the 123-avoiding permutations are enumerated by the Catalan numbers; for j=2 the subsequences in F 2 are 1234 2134 and the (1234,2134 avoiding permutations are enumerated by the Schröder numbers; for each other value of j greater than 2 the subsequences in F j are j! and their length is (j+2 the permutations avoiding these j! subsequences are enumerated by a number sequence {a n } such that C n ≤ a n ≤ n!, C n being the n th Catalan number. For each j we determine the generating function of permutations avoiding the subsequences in F j according to the length, to the number of left minima and of non-inversions.

  13. Effects of Inlet Modification and Rocket-Rack Extension on the Longitudinal Trim and Low-Lift Drag of the Douglas F5D-1 Airplane as Obtained with a 0.125-Scale Rocket-Boosted Model Between Mach Numbers of 0.81 and 1.64: TED No. NACA AD 399

    Science.gov (United States)

    Hastings, Earl C., Jr.; Dickens, Waldo L.

    1957-01-01

    A flight investigation was conducted to determine the effects of inlet modification and rocket-rack extension on the longitudinal trim and low-lift drag of the Douglas F5D-1 airplane. The investigation was conducted with a 0.125-scale rocket-boosted model between Mach Numbers of 0.81 and 1.64. This paper presents the changes in trim angle of attack, trim lift coefficient, and low-lift drag caused by the modified inlets alone over a small part of the test Mach number range and by a combination of the modified inlets and extended rocket racks throughout the remainder of the test.

  14. Photodensitometric tracing of Mach bands and its significance

    International Nuclear Information System (INIS)

    Yoo, Shi Joon; Cho, Kyung Sik; Kang, Heung Sik; Cho, Byung Jae

    1984-01-01

    Mach bands, a visual phenomenon resulting from lateral inhibitory impulses in the retina, are recognized as lucent or dense lines at the borders of different radiographic densities. A number of clinical situations have been described in which Mach bands may cause difficulty in radiographic diagnosis. Photodensitometric measurement of the film can differentiate the true change in film density from the Mach band which is an optical illusion. Authors present several examples of photodensitometric tracings of Mach bands, with the brief review of the mechanism of their production

  15. Poppet valve control of throat stability bypass to increase stable airflow range of a Mach 2.5. inlet with 60 percent internal contraction

    Science.gov (United States)

    Mitchell, G. A.; Sanders, B. W.

    1975-01-01

    The throat of a Mach 2.5 inlet with a coldpipe termination was fitted with a stability-bypass system. System variations included several stability bypass entrance configurations. Poppet valves controlled the bypass airflow. The inlet stable airflow range achieved with each configuration was determined for both steady state conditions and internal pulse transients. Results are compared with those obtained without a stability bypass system. Transient results were also obtained for the inlet with a choke point at the diffuser exit and for the inlet with large and small stability bypass plenum volumes. Poppet valves at the stability bypass exit provided the inlet with a stable airflow range of 20 percent or greater at all static and transient conditions.

  16. Estimation of supersonic fighter jet airfoil data and low speed aerodynamic analysis of airfoil section at the Mach number 0.15

    Science.gov (United States)

    Sogukpinar, Haci

    2018-02-01

    In this paper, some of the NACA 64A series airfoils data are estimated and aerodynamic properties are calculated to facilitate great understandings effect of relative thickness on the aerodynamic performance of the airfoil by using COMSOL software. 64A201-64A204 airfoils data are not available in literature therefore 64A210 data are used as reference data to estimate 64A201, 64A202, 64A203, 64A204 airfoil configurations. Numerical calculations are then conducted with the angle of attack from -12° to +16° by using k-w turbulence model based on the finite-volume approach. The lift and drag coefficient are one of the most important parameters in studying the airplane performance. Therefore lift, drag and pressure coefficient around selected airfoil are calculated and compared at the Reynolds numbers of 6 × 106 and also stalling characteristics of airfoil section are investigated and presented numerically.

  17. Transonic Aerodynamic Loading Characteristics of a Wing-Body-Tail Combination Having a 52.5 deg. Sweptback Wing of Aspect Ratio 3 With Conical Wing Camber and Body Indentation for a Design Mach Number of Square Root of 2

    Science.gov (United States)

    Cassetti, Marlowe D.; Re, Richard J.; Igoe, William B.

    1961-01-01

    An investigation has been made of the effects of conical wing camber and body indentation according to the supersonic area rule on the aerodynamic wing loading characteristics of a wing-body-tail configuration at transonic speeds. The wing aspect ratio was 3, taper ratio was 0.1, and quarter-chord-line sweepback was 52.5 deg. with 3-percent-thick airfoil sections. The tests were conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05 and at angles of attack from 0 deg. to 14 deg., with Reynolds numbers based on mean aerodynamic chord varying from 7 x 10(exp 6) to 8 x 10(exp 6). Conical camber delayed wing-tip stall and reduced the severity of the accompanying longitudinal instability but did not appreciably affect the spanwise load distribution at angles of attack below tip stall. Body indentation reduced the transonic chordwise center-of-pressure travel from about 8 percent to 5 percent of the mean aerodynamic chord.

  18. Number of women faculty in the geosciences increasing, but slowly

    Science.gov (United States)

    Wolfe, Cecily J.

    Why are there so few women faculty in the geosciences, while there are large numbers of women undergraduate and graduate students? According to National Science Foundation (NSF) estimates [e.g.,NSF, 1996] for 1995 in the Earth, atmospheric, and oceanic sciences, women made up 34% of the bachelor's degrees awarded, 35% of the graduate students enrolled, and 22% of the doctorates granted. Yet progress has been slower in achieving adequate representation of women geoscientists in academia, where women represent only 12% of the faculty. The barriers confronting the advancement of women scientists are complex and difficult to unravel. Proposed factors include cultural stereotypes, childhood socialization, lack of women mentors and role models, lack of critical mass, family responsibilities, dual-career-couple status, isolation from collegial networks, different research and publishing strategy, and less adequate access to institutional resources [c.f., Widnall, 1988; Zuckerman et al., 1991].

  19. High-resolution flow field measurements in the rotor passage of a low-mach number turbine for different tip geometries; Hochaufgeloeste Stroemungsfeldvermessungen in der Rotorpassage einer Niedermachzahlturbine fuer verschiedene Schaufelspitzengeometrien

    Energy Technology Data Exchange (ETDEWEB)

    Kegalj, Martin

    2013-11-01

    In axial turbines tip leakage forms a large portion of the overall losses. Applying a shroud is very aerodynamically useful, but the higher mechanical loads of the revolving rotor blading exposed to a high thermal load and the higher costs suggest a shroudless configuration is better. The main parameter in the tip leakage loss is the tip gap height, which cannot be reduced arbitrarily as a running gap is necessary due to thermal expansion and vibration of the jet engine. The pressure ratio between pressure and suction of the rotor blade forces the fluid over the blade tip and leads to the formation of the tip leakage vortex. Reduced turning and losses caused by vortices and subsequent mixing are responsible for the reduced efficiency. Using a squealer cavity on the flat blade tip is a feasible way to reduce the aerodynamic losses. A portion of the kinetic energy of the tip leakage flow is dissipated while entering the cavity; the flow exiting the cavity enters the passage with reduced momentum and reduced tip gap mass flow. A 1(1)/(2) stage low mach number turbine was used to investigate the influence of tip geometry. Aerodynamic measurements, performed with five-hole probes, two-component hot-wire anemometer, unsteady wall pressure sensors, stereo and borescopic particle-image-velocimetry setups and oil and dye flow visualization, found small differences in the flow velocities and angles between the flat and squealer tip configuration in the measurement planes downstream of the rotor. The measurement uncertainty proves the difficulty of determining the influence of the squealer cavity on the blade row outflow with global measurement data. To gather information on the flow close to the casing inside the rotor passage is only possible with non-intrusive laser measurement techniques. Comparison of the different tip geometries is still difficult due to the small differences in the absolute flow data. The use of the {lambda}{sub 2} vortex criterion enables an objective

  20. Flight Determination of the Longitudinal Stability Characteristics of a 0.133-Scale Rocket-Powered Model of the Consolidated Vultee XFY-1 Airplane without Propellers at Mach Numbers from 0.73 to 1.19, TED No. NACA DE 369

    Science.gov (United States)

    Hastings, Earl E., Jr.; Mitcham, Grady L.

    1954-01-01

    A flight test has been conducted to determine the longitudinal stability and control,characteristics of a 0.133-scale model of the Consolidated Vultee XFY-1 airplane without propellers for the Mach number range between 0.73 and 1.19.

  1. Performance, Stability, and Control Investigation at Mach Numbers from 0.4 to 0.9 of a Model of the "Swallow" with Outer Wing Panels Swept 25 degree with and without Power Simulation

    Science.gov (United States)

    Runckel, Jack F.; Schmeer, James W.; Cassetti, Marlowe D.

    1960-01-01

    An investigation of the performance, stability, and control characteristics of a variable-sweep arrow-wing model (the "Swallow") with the outer wing panels swept 25 deg has been conducted in the Langley 16-foot transonic tunnel. The wing was uncambered and untwisted and had RAE 102 airfoil sections with a thickness-to-chord ratio of 0.14 normal to the leading edge. Four outboard engines located above and below the wing provided propulsive thrust, and, by deflecting in the pitch direction and rotating in the lateral plane, also produced control forces. A pair of swept lateral fins and a single vertical fin were mounted on each engine nacelle to provide aerodynamic stability and control. Jets-off data were obtained with flow-through nacelles, stimulating the effects of inlet flow; jet thrust and hot-jet interference effects were obtained with faired-nose nacelles housing hydrogen peroxide gas generators. Six-component force and moment data were obtained through a Mach number range of 0.40 to 0.90 at angles of attack and angles of sideslip from 0 deg to 15 deg. Longitudinal, directional, and lateral control were obtained by deflecting the nacelle-fin combinations as elevators, rudders, and ailerons at several fixed angles for each control.

  2. Aeroacoustic computation of low mach number flow

    Energy Technology Data Exchange (ETDEWEB)

    Skriver Dahl, K. [Risoe National Laboratory, Roskilde (Denmark)

    1997-12-31

    The possibilities of applying a recently developed numerical technique to predict aerodynamically generated sound from wind turbines is explored. The technique is a perturbation technique that has the advantage that the underlying flow field and the sound field are computed separately. Solution of the incompressible, time dependent flow field yields a hydrodynamic density correction to the incompressible constant density. The sound field is calculated from a set of equations governing the inviscid perturbations about the corrected flow field. Here, the emphasis is placed on the computation of the sound field. The nonlinear partial differential equations governing the sound fields are solved numerically using an explicit MacCormack scheme. Two types of non-reflecting boundary conditions are applied; one based on the asymptotic solution of the governing equations and the other based on a characteristic analysis of the governing equations. The former condition is easy to use and it performs slightly better than the charcteristic based condition. The technique is applied to the problems of the sound generation of a co-rotating vortex pair, which is a quadrupole, and the viscous flow over a circular cylinder, which is a dipole. Numerical results agree very well with the analytical solution for the problem of the co-rotating vortex pair. Numerical results for the viscous flow over a cylinder are presented and evaluated qualitatively. (au)

  3. Mach's principle and rotating universes

    International Nuclear Information System (INIS)

    King, D.H.

    1990-01-01

    It is shown that the Bianchi 9 model universe satisfies the Mach principle. These closed rotating universes were previously thought to be counter-examples to the principle. The Mach principle is satisfied because the angular momentum of the rotating matter is compensated by the effective angular momentum of gravitational waves. A new formulation of the Mach principle is given that is based on the field theory interpretation of general relativity. Every closed universe with 3-sphere topology is shown to satisfy this formulation of the Mach principle. It is shown that the total angular momentum of the matter and gravitational waves in a closed 3-sphere topology universe is zero

  4. Heat-Transfer and Pressure Measurements from a Flight Test of the Third 1/18-Scale Model of the Titan Intercontinental Ballistic Missile up to a Mach Number of 3.86 and Reynolds Number per Foot of 23.5 x 10(exp 6) and a Comparison with Heat Transfer

    Science.gov (United States)

    Graham, John B., Jr.

    1958-01-01

    Heat-transfer and pressure measurements were obtained from a flight test of a 1/18-scale model of the Titan intercontinental ballistic missile up to a Mach number of 3.86 and Reynolds number per foot of 23.5 x 10(exp 6) and are compared with the data of two previously tested 1/18-scale models. Boundary-layer transition was observed on the nose of the model. Van Driest's theory predicted heat-transfer coefficients reasonably well for the fully laminar flow but predictions made by Van Driest's theory for turbulent flow were considerably higher than the measurements when the skin was being heated. Comparison with the flight test of two similar models shows fair repeatability of the measurements for fully laminar or turbulent flow.

  5. Combustion-Powered Actuation for Dynamic Stall Suppression - Simulations and Low-Mach Experiments

    Science.gov (United States)

    Matalanis, Claude G.; Min, Byung-Young; Bowles, Patrick O.; Jee, Solkeun; Wake, Brian E.; Crittenden, Tom; Woo, George; Glezer, Ari

    2014-01-01

    An investigation on dynamic-stall suppression capabilities of combustion-powered actuation (COMPACT) applied to a tabbed VR-12 airfoil is presented. In the first section, results from computational fluid dynamics (CFD) simulations carried out at Mach numbers from 0.3 to 0.5 are presented. Several geometric parameters are varied including the slot chordwise location and angle. Actuation pulse amplitude, frequency, and timing are also varied. The simulations suggest that cycle-averaged lift increases of approximately 4% and 8% with respect to the baseline airfoil are possible at Mach numbers of 0.4 and 0.3 for deep and near-deep dynamic-stall conditions. In the second section, static-stall results from low-speed wind-tunnel experiments are presented. Low-speed experiments and high-speed CFD suggest that slots oriented tangential to the airfoil surface produce stronger benefits than slots oriented normal to the chordline. Low-speed experiments confirm that chordwise slot locations suitable for Mach 0.3-0.4 stall suppression (based on CFD) will also be effective at lower Mach numbers.

  6. A finite element method with a high order L{sup 2} decomposition devoted to the simulation of diphasic low Mach number flows; Une methode elements finis a decomposition L{sup 2} d'ordre eleve motivee par la simulation d'ecoulement diphasique bas mach

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, T

    2006-05-15

    This work deals with the discretization of Navier-Stokes equations using different finite element methods adapted to the problem of two-phase flows. These methods must be of high order to limit the presence of spurious flows (which contradict the establishment of a physical equilibrium) and to verify energy conservation properties. Several solutions are proposed which seem to fulfill these expectations. A reformulation of the six-equation system adapted to low Mach two-phase flows has been also proposed. These methods have been implemented into the Trio-U code of CEA Grenoble, but have been tested only on simple 'academic' configurations. (J.S.)

  7. Gyro precession and Mach's principle

    International Nuclear Information System (INIS)

    Eby, P.

    1979-01-01

    The precession of a gyroscope is calculated in a nonrelativistic theory due to Barbour which satisfies Mach's principle. It is shown that the theory predicts both the geodetic and motional precession of general relativity to within factors of order 1. The significance of the gyro experiment is discussed from the point of view of metric theories of gravity and this is contrasted with its significance from the point of view of Mach's principle. (author)

  8. Mach-Like Structure in a Patronic-Hadronic Transport Model at RHIC Energies

    International Nuclear Information System (INIS)

    Ma, Y.G.; Ma, G.L.; Zhang, S.

    2008-01-01

    Recent RHIC experimental results indicated an exotic partonic matter may be created in central Au + Au collisions at dollars sqrt (s ( NN))dollars =200 GeV. When a parton with high transverse momentum (jet) passes through the new matter, jet will quench. The lost energy will be redistributed into the medium. Experimentally the soft scattered particles which carry the lost energy have been reconstructed via di-hadron angular correlations of charged particles and a hump structure on away side in di-hadron $ Delta phi$ correlation has been observed in central Au + Au collisions [1,2]. Some interpretations, such as Mach-cone shock wave and gluon Cherenkov-like radiation mechanism etc, have been proposed to explain the splitting behavior of the away side peaks. However, quantitative understanding of the experimental observation has yet to be established. In this work, we use a multi-phase transport (AMPT) model to make a detailed simulation for di-hadron or tri-hadron azimuthal correlation for central Au + Au collisions at dollars sqrt(s ( NN)) dollars =200 GeV. The hump structure on away side (we called Mach-like structure later) in the di-hadron and tri-hadron azimuthal correlations has been observed [3,4,5]. Furthermore, the time evolution of Mach-like structure is presented [6]. With the increasing of the lifetime of partonic matter, Mach-like structure develops by strong parton cascade process. Not only the splitting parameter but also the number of associated hadrons (dollarsN ( h) (assoc)dollars) increases with the lifetime of partonic matter and partonic interaction cross section. Both the explosion of dollarsN ( h) (assoc)dollars following the formation of Mach-like structure and the corresponding results of three-particle correlation support that a partonic Mach-like behavior can be produced by a collective coupling of partons because of the strong parton cascade mechanism. Therefore, the studies about Mach-like structure may give us some critical information

  9. Mach's predictions and relativistic cosmology

    International Nuclear Information System (INIS)

    Heller, M.

    1989-01-01

    Deep methodological insight of Ernst Mach into the structure of the Newtonian mechanics allowed him to ask questions, the importance of which can be appreciated only today. Three such Mach's ''predictions'' are briefly presented, namely: the possibility of the existence of an allpervading medium which could serve as an universal frame of reference and which has actually been discovered in the form of the microwave background radiation, a certain ''smoothness'' of the Universe which is now recognized as the Robertson-Walker symmetries and the possibility of the experimental verification of the mass anisotropy. 11 refs. (author)

  10. When increasing distraction helps learning: Distractor number and content interact in their effects on memory.

    Science.gov (United States)

    Nussenbaum, Kate; Amso, Dima; Markant, Julie

    2017-11-01

    Previous work has demonstrated that increasing the number of distractors in a search array can reduce interference from distractor content during target processing. However, it is unclear how this reduced interference influences learning of target information. Here, we investigated how varying the amount and content of distraction present in a learning environment affects visual search and subsequent memory for target items. In two experiments, we demonstrate that the number and content of competing distractors interact in their influence on target selection and memory. Specifically, while increasing the number of distractors present in a search array made target detection more effortful, it did not impair learning and memory for target content. Instead, when the distractors contained category information that conflicted with the target, increasing the number of distractors from one to three actually benefitted learning and memory. These data suggest that increasing numbers of distractors may reduce interference from conflicting conceptual information during encoding.

  11. Ernst Mach: pedagog a technik

    Czech Academy of Sciences Publication Activity Database

    Těšínská, Emilie; Landa, Ivan; Drahoš, Jiří

    2016-01-01

    Roč. 66, č. 3 (2016), s. 167-174 ISSN 0009-0700 Institutional support: RVO:67985955 ; RVO:68378114 ; RVO:67985858 Keywords : Ernst Mach * pedagogy * experiments * general education * ballistics * Doppler principle Subject RIV: AB - History; CF - Physical ; Theoretical Chemistry (UCHP-M)

  12. Effects of increased vertebral number on carcass weight in PIC pigs.

    Science.gov (United States)

    Huang, Jieping; Zhang, Mingming; Ye, Runqing; Ma, Yun; Lei, Chuzhao

    2017-12-01

    Variation of the vertebral number is associated with carcass traits in pigs. However, results from different populations do not match well with others, especially for carcass weight. Therefore, effects of increased vertebral number on carcass weight were investigated by analyzing the relationship between two loci multi-vertebra causal loci (NR6A1 g.748 C > T and VRTN g.20311_20312ins291) and carcass weight in PIC pigs. Results from the association study between vertebral number and carcass weight showed that increased thoracic number had negative effects on carcass weight, but the results were not statistically significant. Further, VRTN Ins/Ins genotype increased more than one thoracic than that of Wt/Wt genotype on average in this PIC population. Meanwhile, there was a significant negative effect of VRTN Ins on carcass weight (P carcass weight in PIC pigs. © 2017 Japanese Society of Animal Science.

  13. Increased Flap Weight and Decreased Perforator Number Predict Fat Necrosis in DIEP Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Carolyn L. Mulvey, BS

    2013-05-01

    Conclusions: Flaps with increasing weight have increased risk of fat necrosis. These data suggest that inclusion of more than 1 perforator may decrease odds of fat necrosis in large flaps. Perforator flap breast reconstruction can be performed safely; however, considerations concerning race, body mass index, staging with tissue expanders, perforator number, and flap weight may optimize outcomes.

  14. Lamotrigine increases the number of BrdU-labeled cellsinthe rat hippocampus

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Strandberg, Joakim; Lindquist, Catarina

    2010-01-01

    Antidepressant medication and electroconvulsive therapy stabilize mood symptoms and increase hippocampal neurogenesis. We examined whether lamotrigine, suggested to give rise to mood-stabilizing and antidepressant effects in addition to its antiepileptic properties, also increases the number of n...... in the granule cell layer of the dentate gyrus showed an increased number of newborn cells in rats receiving lamotrigine (42.6±3.5 cells/slice) compared with valproate (31.6±2.8) and controls (32.2±3.1; P...

  15. Lamotrigine increases the number of BrdU-labeled cells in the rat hippocampus

    DEFF Research Database (Denmark)

    Kondziella, Daniel; Strandberg, Joakim; Lindquist, Catarina

    2011-01-01

    Antidepressant medication and electroconvulsive therapy stabilize mood symptoms and increase hippocampal neurogenesis. We examined whether lamotrigine, suggested to give rise to mood-stabilizing and antidepressant effects in addition to its antiepileptic properties, also increases the number of n...... in the granule cell layer of the dentate gyrus showed an increased number of newborn cells in rats receiving lamotrigine (42.6 ± 3.5 cells/slice) compared with valproate (31.6 ± 2.8) and controls (32.2 ± 3.1; P...

  16. Increase of the blocking temperature of Fe–Ag granular multilayers with increasing number of the layers

    Energy Technology Data Exchange (ETDEWEB)

    Balogh, Judit [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kaptás, Dénes, E-mail: kaptas.denes@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kiss, László F. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Dézsi, István [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Nakanishi, Akio [Department of Physics, Shiga University of Medical Science, Shiga 520-2192 (Japan); Devlin, Eamonn; Vasilakaki, Marianna; Margaris, George; Trohidou, Kalliopi N. [Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Aghia Paraskevi, 15310 Athens (Greece)

    2016-03-01

    Multilayers of 0.4 nm Fe and 5 nm Ag with repetition number, n=1, 2, 5, 10 and 20 were prepared by vacuum evaporation onto Si wafer. The blocking temperature was determined by measuring the field cooled and zero field cooled magnetization curves with a SQUID magnetometer and it was found to increase by almost an order of magnitude from around 20 K for the single Fe layer sample up to around 160 K for n=20. Significant increase of the average size of the superparamagnetic Fe grains by increasing the number of the Fe layers was excluded by conversion electron Mössbauer spectroscopy measurements of the paramagnetic state. The role of the dipole–dipole interactions and their interplay with the out-of-plain magnetic anisotropy in the variation of the blocking temperature has been investigated by Monte-Carlo simulations. - Highlights: • Multilayers of [0.4 nm Fe/5 nm Ag]{sub n} (n=1,2,5,10, and 20) were grown over Si. • Large increase of the superparamagnetic blocking temperature up to n=10 is observed. • The average Fe grain size does not change in the subsequent layers. • Perpendicular anisotropy enhances the dipolar coupling and the blocking temperature.

  17. Elementary physical approach to Mach's principle and its observational basis

    International Nuclear Information System (INIS)

    Horak, Z.

    1979-01-01

    It is shown that Mach's principle and the general principle of relativity are logical consequences of a 'materialistic postulate' and that general relativity implies the validity of Mach's principle for a static (or quasistatic) homogeneous and isotropic universe, spatially self-enclosed. The finite velocity of propagation of gravitational field does not imply a retardation of inertial forces due to the distant masses and therefore does not exclude the validity of Mach's principle. Similarly, the experimentally verified isotropy of inertia is compatible with this principle. The recent observational evidence of very high isotropy of the actual universe proves that the 'anti-Machian' Godel world model must be rejected as a nonphysical one. This suggests the possibility of a renaissance of Einstein's first cosmological model by considering-in the spirit of an older idea of Herbert Dingle-a superlarge-scale quasistatic universe consisting of an unknown number of statistically oscillating regions similar to our own, momentarily expanding, metagalaxy. (author)

  18. [Increasing number of child abuse cases in Sweden--in accordance with reality?].

    Science.gov (United States)

    Nilsson, C; Horgby, K; Borres, M P

    2001-05-09

    The number of police reports on child assault shows an increasing trend during the last two decades in Sweden. The purpose of this article is to present possible explanations. Increased awareness of child abuse, legislative reforms, changes in attitudes toward corporal punishment and violence in general, and changed routines within schools can explain the increasing trend in police reporting. An actual increase in the rate of child abuse is possible but less likely. Reports of increasingly violent behavior among young people must be taken seriously.

  19. The abnormal increase of the leukocyte number observed in the inhabitants of Nishiyama area, Nagasaki Prefecture

    International Nuclear Information System (INIS)

    Honda, Koya

    2013-01-01

    The Nishiyama area, Nagasaki Prefecture has been known by that the black rain fell after dropping atomic bomb. The abnormal increase of the leukocyte number was measured in the inhabitants of Nishiyama area, Nagasaki Prefecture after dropping atomic bomb. This phenomenon differs from the general knowledge that the leukocyte number decreases by the radiation exposure. This has been noticed as a rare record confirmed by the residual radiation effect to the human body using the group data. (M.H.)

  20. The number of Japanese radiologic technologists will be increased in 40 years.

    Science.gov (United States)

    Araseki, Miwa; Yokooka, Yuki; Ishikawa, Tomoki; Ogasawara, Katsuhiko

    2013-07-01

    It is essential to predict the long-term supply and demand for the number of radiologic technologists as medical resources. However, it is difficult to predict the number of Japanese radiologic technologists due to complex and intertwining factors. Our purpose in this study was to predict the future number of radiologic technologists using the concept of system dynamics (SD), and to clarify the effects of relevant factors. In order to estimate the number of Japanese radiologic technologists, we constructed a flow diagram using the concept of SD. We simulated the number of radiologic technologists for the following 4 cases: maintaining the status quo, a change in the pass rate for the national examination, a change in the post-graduate employment rate, and a change in the rate of continuing education. The result for the predicted number of radiologic technologists was 50,509 in 20 years, which is 4,394 (9.5%) more than the present number, and 50,166 in 40 years, which is 4,051 (8.8%) more than the present number. For the factors influencing the number of technologists, the influence of the pass rate on the national examination and that of the rate for post-graduate employment was larger than that of the rate of continuing education in graduate school. The number of Japanese radiologic technologists will increase until 2033 and decrease until 2042, and it does not change after 2042 in case of maintaining the status quo. Implementing the concept of SD allowed us easily to clarify the factors influencing the predicted number of radiologic technologists.

  1. Diffusive wave in the low Mach limit for non-viscous and heat-conductive gas

    Science.gov (United States)

    Liu, Yechi

    2018-06-01

    The low Mach number limit for one-dimensional non-isentropic compressible Navier-Stokes system without viscosity is investigated, where the density and temperature have different asymptotic states at far fields. It is proved that the solution of the system converges to a nonlinear diffusion wave globally in time as Mach number goes to zero. It is remarked that the velocity of diffusion wave is proportional with the variation of temperature. Furthermore, it is shown that the solution of compressible Navier-Stokes system also has the same phenomenon when Mach number is suitably small.

  2. Increasing The Number of Embryos Transferred from Two to Three, Does not Increase Pregnancy Rates in Good Prognosis Patients

    Directory of Open Access Journals (Sweden)

    Mahnaz Ashrafi

    2015-10-01

    Full Text Available Background: To compare the pregnancy outcomes after two embryos versus three embryos transfers (ETs in women undergoing in vitro fertilization (IVF/intracytoplasmic sperm injection (ICSI cycles. Materials and Methods: This retrospective study was performed on three hundred eighty seven women with primary infertility and with at least one fresh embryo in good quality in order to transfer at each IVF/ICSI cycle, from September 2006 to June 2010. Patients were categorized into two groups according to the number of ET as follows: ET2 and ET3 groups, indicating two and three embryos were respectively transferred. Pregnancy outcomes were compared between ET2 and ET3 groups. Chi square and student t tests were used for data analysis. Results: Clinical pregnancy and live birth rates were similar between two groups. The rates of multiple pregnancies were 27 and 45.2% in ET2 and ET3 groups, respectively. The rate of multiple pregnancies in young women was significantly increased when triple instead of double embryos were transferred. Logistic regression analysis indicated two significant prognostic variables for live birth that included number and quality of transferred embryos; it means that the chance of live birth following ICSI treatment increased 3.2-fold when the embryo with top quality (grade A was transferred, but the number of ET had an inverse relationship with live birth rate; it means that probability of live birth in women with transfer of two embryos was three times greater than those who had three ET. Conclusion: Due to the difficulty of implementation of the elective single-ET technique in some infertility centers in the world, we suggest transfer of double instead of triple embryos when at least one good quality embryo is available for transfer in women aged 39 years or younger. However, to reduce the rate of multiple pregnancies, it is recommended to consider the elective single ET strategy.

  3. Low AMY1 Gene Copy Number Is Associated with Increased Body Mass Index in Prepubertal Boys.

    Directory of Open Access Journals (Sweden)

    M Loredana Marcovecchio

    Full Text Available Genome-wide association studies have identified more than 60 single nucleotide polymorphisms associated with Body Mass Index (BMI. Additional genetic variants, such as copy number variations (CNV, have also been investigated in relation to BMI. Recently, the highly polymorphic CNV in the salivary amylase (AMY1 gene, encoding an enzyme implicated in the first step of starch digestion, has been associated with obesity in adults and children. We assessed the potential association between AMY1 copy number and a wide range of BMI in a population of Italian school-children.744 children (354 boys, 390 girls, mean age (±SD: 8.4±1.4years underwent anthropometric assessments (height, weight and collection of saliva samples for DNA extraction. AMY1 copies were evaluated by quantitative PCR.A significant increase of BMI z-score by decreasing AMY1 copy number was observed in boys (β: -0.117, p = 0.033, but not in girls. Similarly, waist circumference (β: -0.155, p = 0.003, adjusted for age was negatively influenced by AMY1 copy number in boys. Boys with 8 or more AMY1 copy numbers presented a significant lower BMI z-score (p = 0.04 and waist circumference (p = 0.01 when compared to boys with less than 8 copy numbers.In this pediatric-only, population-based study, a lower AMY1 copy number emerged to be associated with increased BMI in boys. These data confirm previous findings from adult studies and support a potential role of a higher copy number of the salivary AMY1 gene in protecting from excess weight gain.

  4. Robert Musil versus Ernst Mach

    Directory of Open Access Journals (Sweden)

    Jalón, Mauricio

    2010-06-01

    Full Text Available On Mach’s Theories (DT of R. Musil rejects that the scientific representation tends to build a clear and complete inventory of facts. Mach finds himself obliged to presuppose constant relationships in nature; but this regularity of phenomena implies that the law is something more than a «table», that its mere dependencies are pushed into the background, and that a theoretical relationship in Physics is much more than an order relationship. His conception of scientific economy as a «natural adaptation» implies a biological monism opposed to the characteristic dualities of an empiricist.

    Sobre las teorías de Mach (TD de R. Musil rebate que la representación científica tienda a construir un claro y completo inventario de hechos. Pues Mach se ve obligado a presuponer relaciones constantes en la naturaleza; pero esta regularidad de los fenómenos implica que la ley es algo más que cierto «cuadro», que las meras dependencias que defiende están en un segundo plano y que una relación teórica en física es mucho más que una relación de orden. Su concepción de la economía científica como «adaptación natural» significa un monismo biológico opuesto a las dualidades propias de un empirista.

  5. Rotating detectors and Mach's principle

    International Nuclear Information System (INIS)

    Paola, R.D.M. de; Svaiter, N.F.

    2000-08-01

    In this work we consider a quantum version of Newton s bucket experiment in a fl;at spacetime: we take an Unruh-DeWitt detector in interaction with a real massless scalar field. We calculate the detector's excitation rate when it is uniformly rotating around some fixed point and the field is prepared in the Minkowski vacuum and also when the detector is inertial and the field is in the Trocheries-Takeno vacuum state. These results are compared and the relations with Mach's principle are discussed. (author)

  6. Recovery Temperature, Transition, and Heat Transfer Measurements at Mach 5

    Science.gov (United States)

    Brinich, Paul F.

    1961-01-01

    Schlieren, recovery temperature, and heat-transfer measurements were made on a hollow cylinder and a cone with axes alined parallel to the stream. Both the cone and cylinder were equipped with various bluntnesses, and the tests covered a Reynolds number range up to 20 x 10(exp 6) at a free-stream Mach number of 4.95 and wall to free-stream temperature ratios from 1.8 to 5.2 (adiabatic). A substantial transition delay due to bluntness was found for both the cylinder and the cone. For the present tests (Mach 4.95), transition was delayed by a factor of 3 on the cylinder and about 2 on the cone, these delays being somewhat larger than those observed in earlier tests at Mach 3.1. Heat-transfer tests on the cylinder showed only slight effects of wall temperature level on transition location; this is to be contrasted to the large transition delays observed on conical-type bodies at low surface temperatures at Mach 3.1. The schlieren and the peak-recovery-temperature methods of detecting transition were compared with the heat-transfer results. The comparison showed that the first two methods identified a transition point which occurred just beyond the end of the laminar run as seen in the heat-transfer data.

  7. A METHOD OF INCREASING THE NUMBER OF TOURISTS IN ROMANIA: SIBIU – EUROPEAN CAPITAL OF CULTURE

    Directory of Open Access Journals (Sweden)

    Gabriela Cecilia STĂNCIULESCU

    2016-06-01

    Full Text Available The title of European Capital of Culture could help immensely a city and its surrounding region from cultural, social and economic pointd of view. Cultural activity in the city is gaining momentum and new categories of tourists are attracted here. To determine if being a cultural capital influenced or not the growth and/or decrease trend as regards the number of tourists that came to Sibiu in a consecutive period of 23 years, the starting point was that this event had a major impact on tourists. The present paper is a quantitative research based on the number of Romanian and foreign tourists accommodated in structures of tourist receptions with functions of tourist accommodation. The conclusions of this article respond to these questions: Being a European Capital of Culture attracts or not more tourists than usual? The increase in the number of tourists was proportional with the effort of the authorities involved in the project?

  8. Periodontal Dressing-containing Green Tea Epigallocathechin gallate Increases Fibroblasts Number in Gingival Artifical Wound Model

    Directory of Open Access Journals (Sweden)

    Ardisa U. Pradita

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Green tea leaf (Camellia sinensis is one of herbal plants that is used for traditional medicine. Epigallocatechin gallate (EGCG in green tea is the most potential polyphenol component and has the strongest biological activity. It is known that EGCG has potential effect on wound healing. Objective: This study aimed to determine the effect of adding green tea EGCG into periodontal dressing on the number of fibroblasts after gingival artificial wound in animal model. Methods: Gingival artifical wound model was performed using 2mm punch biopsy on 24 rabbits (Oryctolagus cuniculus. The animals were divided into two groups. Periodontal dressing with EGCG and without EGCG was applied to the experimental and control group, respectively. Decapitation period was scheduled at day 3, 5, and 7 after treatment. Histological analysis to count the number of fibroblasts was performed. Results: Number of fibroblasts was significantly increased in time over the experimental group treated with EGCG periodontal dressing compared to control (p<0.05. Conclusion: EGCG periodontal dressing could increase the number of fibroblast, therefore having role in wound healing after periodontal surgery in animal model.DOI: 10.14693/jdi.v20i3.197

  9. Mefloquine resistance in Plasmodium falciparum and increased pfmdr1 gene copy number.

    Science.gov (United States)

    Price, Ric N; Uhlemann, Anne-Catrin; Brockman, Alan; McGready, Rose; Ashley, Elizabeth; Phaipun, Lucy; Patel, Rina; Laing, Kenneth; Looareesuwan, Sornchai; White, Nicholas J; Nosten, François; Krishna, Sanjeev

    The borders of Thailand harbour the world's most multidrug resistant Plasmodium falciparum parasites. In 1984 mefloquine was introduced as treatment for uncomplicated falciparum malaria, but substantial resistance developed within 6 years. A combination of artesunate with mefloquine now cures more than 95% of acute infections. For both treatment regimens, the underlying mechanisms of resistance are not known. The relation between polymorphisms in the P falciparum multidrug resistant gene 1 (pfmdr1) and the in-vitro and in-vivo responses to mefloquine were assessed in 618 samples from patients with falciparum malaria studied prospectively over 12 years. pfmdr1 copy number was assessed by a robust real-time PCR assay. Single nucleotide polymorphisms of pfmdr1, P falciparum chloroquine resistance transporter gene (pfcrt) and P falciparum Ca2+ ATPase gene (pfATP6) were assessed by PCR-restriction fragment length polymorphism. Increased copy number of pfmdr1 was the most important determinant of in-vitro and in-vivo resistance to mefloquine, and also to reduced artesunate sensitivity in vitro. In a Cox regression model with control for known confounders, increased pfmdr1 copy number was associated with an attributable hazard ratio (AHR) for treatment failure of 6.3 (95% CI 2.9-13.8, p<0.001) after mefloquine monotherapy and 5.4 (2.0-14.6, p=0.001) after artesunate-mefloquine therapy. Single nucleotide polymorphisms in pfmdr1 were associated with increased mefloquine susceptibility in vitro, but not in vivo. Amplification in pfmdr1 is the main cause of resistance to mefloquine in falciparum malaria. Multidrug resistant P falciparum malaria is common in southeast Asia, but difficult to identify and treat. Genes that encode parasite transport proteins maybe involved in export of drugs and so cause resistance. In this study we show that increase in copy number of pfmdr1, a gene encoding a parasite transport protein, is the best overall predictor of treatment failure with

  10. Increased numbers of spleen colony forming units in B cell deficient CBA/N mice

    International Nuclear Information System (INIS)

    Wiktor-Jedrzejczak, W.; Krupienicz, A.; Scher, I.

    1986-01-01

    The formation of exogenous and endogenous spleen colonies was studied in immune-defective mice expressing the CBA/N X-linked xid gene. Bone marrow and spleen cells of immune deficient mice formed increased numbers of eight-day exogenous spleen colonies when transferred to either normal or B cell deficient lethally irradiated recipients. Moreover, defective mice showed increased formation of five-day endogenous spleen colonies (derived from transient endogenous colony forming units; T-CFU) and of ten-day endogenous spleen colonies (derived from CFU-S). Among the possible mechanisms responsible for the observed effects, the most probable appears the one in which decreased numbers of B cell precursors stimulate stem cell pools through a feedback mechanism. (orig.) [de

  11. Understanding the increase in the number of childbirth-related leave beneficiaries in Serbia

    Directory of Open Access Journals (Sweden)

    Stanić Katarina

    2017-01-01

    Full Text Available Over the past number of years, the public expenditures for childbirth-related leave benefits have more than doubled – in 2015 amounted to 0.7% GDP in relation to 0.3% GDP in 2002. This increase can mainly be attributed to the increased number of beneficiaries that grew consistently from 24 thousand in 2002 up to 40 thousand in 2015, despite the fact that the annual number of live births has been almost continually decreasing and the registered employment has dropped by almost 20 per cent in the observed period. One of the clear reasons explaining part of this increase is the extension of 3+ order of birth leaves in 2006, from one to two years, which can explain the increase of around 3.5 thousand of beneficiaries. Another reason is high number of beneficiaries using special child-care leave meant for parents with children with disabilities, but which, in reality, is very often used simply as the extension of parental leave. The average number of special child-care leave beneficiaries in the second half of 2015 amounted to 2.8 thousand. When these two effects are taken into account, we still notice significant increase of beneficiaries of around 10 thousand in the observed period. Fictitious employment during the pregnancy can explain this increase to some extent. Available data unambiguously show that a number of women formally employing during the second and third trimester of pregnancy has increased from 800 in 2002 to almost 3.5 thousand monthly average in the second half of 2015. There are two flaws of the childbirth-related leave programme in Serbia, which together lead to the constant increase of the number of beneficiaries. First is the lack of flexibility of the programme, both in terms of eligibility for acquiring the right as well as in terms of flexibility in use. Maternity/parental leave benefit may acquire only those in „standard employment” i.e. employed under employment contract (and entrepreneurs while other type of

  12. Sexual activity increases the number of newborn cells in the accessory olfactory bulb of male rats.

    Directory of Open Access Journals (Sweden)

    Wendy ePortillo

    2012-07-01

    Full Text Available In rodents, sexual behavior depends on the adequate detection of sexually relevant stimuli. The olfactory bulb (OB is a region of the adult mammalian brain undergoing constant cell renewal by continuous integration of new granular and periglomerular neurons in the accessory (AOB and main (MOB olfactory bulbs. The proliferation, migration, survival, maturation, and integration of these new cells to the OB depend on the stimulus that the subjects received. We have previously shown that 15 days after females control (paced the sexual interaction an increase in the number of cells is observed in the AOB. No changes are observed in the number of cells when females are not allowed to control the sexual interaction. In the present study we investigated if in male rats sexual behavior increases the number of new cells in the OB. Male rats were divided in five groups: 1 males that did not receive any sexual stimulation, 2 males that were exposed to female odors, 3 males that mated for 1 h and could not pace their sexual interaction, 4 males that paced their sexual interaction and ejaculated 1 time and 5 males that paced their sexual interaction and ejaculated 3 times. All males received three injections of the DNA synthesis marker bromodeoxyuridine at 1h intervals, starting 1h before the beginning of the behavioral test. Fifteen days later, males were sacrificed and the brains were processed to identify new cells and to evaluate if they differentiated into neurons. The number of newborn cells increased in the granular cell layer (also known as the internal cell layer of the AOB in males that ejaculated one or three times controlling (paced the rate of the sexual interaction. Some of these new cells were identified as neurons. In contrast, no significant differences were found in the mitral cell layer (also known as the external cell layer and glomerular cell layer of the AOB. In addition, no significant differences were found between groups in the MOB in

  13. Copy number increase of ACTN4 is a prognostic indicator in salivary gland carcinoma

    International Nuclear Information System (INIS)

    Watabe, Yukio; Mori, Taisuke; Yoshimoto, Seiichi; Nomura, Takeshi; Shibahara, Takahiko; Yamada, Tesshi; Honda, Kazufumi

    2014-01-01

    Copy number increase (CNI) of ACTN4 has been associated with poor prognosis and metastatic phenotypes in various human carcinomas. To identify a novel prognostic factor for salivary gland carcinoma, we investigated the copy number of ACTN4. We evaluated DNA copy number of ACTN4 in 58 patients with salivary gland carcinoma by using fluorescent in situ hybridization (FISH). CNI of ACTN4 was recognized in 14 of 58 patients (24.1%) with salivary gland carcinoma. The cases with CNI of ACTN4 were closely associated with histological grade (P = 0.047) and vascular invasion (P = 0.033). The patients with CNI of ACTN4 had a significantly worse prognosis than the patients with normal copy number of ACTN4 (P = 0.0005 log-rank test). Univariate analysis by the Cox proportional hazards model showed that histological grade, vascular invasion, and CNI of ACTN4 were independent risk factors for cancer death. Vascular invasion (hazard ratio [HR]: 7.46; 95% confidence interval [CI]: 1.98–28.06) and CNI of ACTN4 (HR: 3.23; 95% CI: 1.08–9.68) remained as risk factors for cancer death in multivariate analysis. Thus, CNI of ACTN4 is a novel indicator for an unfavorable outcome in patients with salivary gland carcinoma

  14. Cases requiring increased number of repositioning maneuvers in benign paroxysmal positional vertigo

    Directory of Open Access Journals (Sweden)

    Mukadder Korkmaz

    Full Text Available ABSTRACT INTRODUCTION: Benign paroxysmal positional vertigo (BPPV is a clinical syndrome that is proposed to be caused by dislocated utricular debris into semicircular canals. Although the majority of patients are treated by one or two repositioning maneuvers, some of the patients need repeated maneuvers for relief. OBJECTIVE: The goal of this study was to investigate the factors associated with patients with benign paroxysmal positional vertigo who required multiple repositioning procedures for treatment. METHODS: Data were obtained from the clinical records of 153 patients diagnosed with benign paroxysmal positional vertigo. Patients were treated by repositioning maneuvers. Demographic data and the factors including age, sex, canal type, duration of symptoms, comorbidities and number of repositioning maneuvers for relief were documented for statistical analysis. RESULTS: Age, sex, canal type and the duration of symptoms had no impact on the number of maneuvers. The most common comorbidity was spine problems. Hypertension was the only comorbidity that significantly associated with increased number of maneuvers. CONCLUSION: The presence of hypertension is a risk factor for repeated maneuvers in benign paroxysmal positional vertigo treatment. Physicians should be aware of the increased probability of repeated repositioning maneuvers in these group of patients. The role of comorbidities and vascular factors need to be further clarified in the course of benign paroxysmal positional vertigo.

  15. Cases requiring increased number of repositioning maneuvers in benign paroxysmal positional vertigo.

    Science.gov (United States)

    Korkmaz, Mukadder; Korkmaz, Hakan

    2016-01-01

    Benign paroxysmal positional vertigo (BPPV) is a clinical syndrome that is proposed to be caused by dislocated utricular debris into semicircular canals. Although the majority of patients are treated by one or two repositioning maneuvers, some of the patients need repeated maneuvers for relief. The goal of this study was to investigate the factors associated with patients with benign paroxysmal positional vertigo who required multiple repositioning procedures for treatment. Data were obtained from the clinical records of 153 patients diagnosed with benign paroxysmal positional vertigo. Patients were treated by repositioning maneuvers. Demographic data and the factors including age, sex, canal type, duration of symptoms, comorbidities and number of repositioning maneuvers for relief were documented for statistical analysis. Age, sex, canal type and the duration of symptoms had no impact on the number of maneuvers. The most common comorbidity was spine problems. Hypertension was the only comorbidity that significantly associated with increased number of maneuvers. The presence of hypertension is a risk factor for repeated maneuvers in benign paroxysmal positional vertigo treatment. Physicians should be aware of the increased probability of repeated repositioning maneuvers in these group of patients. The role of comorbidities and vascular factors need to be further clarified in the course of benign paroxysmal positional vertigo. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  16. Extreme Wildlife Declines and Concurrent Increase in Livestock Numbers in Kenya: What Are the Causes?

    Directory of Open Access Journals (Sweden)

    Joseph O Ogutu

    Full Text Available There is growing evidence of escalating wildlife losses worldwide. Extreme wildlife losses have recently been documented for large parts of Africa, including western, Central and Eastern Africa. Here, we report extreme declines in wildlife and contemporaneous increase in livestock numbers in Kenya rangelands between 1977 and 2016. Our analysis uses systematic aerial monitoring survey data collected in rangelands that collectively cover 88% of Kenya's land surface. Our results show that wildlife numbers declined on average by 68% between 1977 and 2016. The magnitude of decline varied among species but was most extreme (72-88% and now severely threatens the population viability and persistence of warthog, lesser kudu, Thomson's gazelle, eland, oryx, topi, hartebeest, impala, Grevy's zebra and waterbuck in Kenya's rangelands. The declines were widespread and occurred in most of the 21 rangeland counties. Likewise to wildlife, cattle numbers decreased (25.2% but numbers of sheep and goats (76.3%, camels (13.1% and donkeys (6.7% evidently increased in the same period. As a result, livestock biomass was 8.1 times greater than that of wildlife in 2011-2013 compared to 3.5 times in 1977-1980. Most of Kenya's wildlife (ca. 30% occurred in Narok County alone. The proportion of the total "national" wildlife population found in each county increased between 1977 and 2016 substantially only in Taita Taveta and Laikipia but marginally in Garissa and Wajir counties, largely reflecting greater wildlife losses elsewhere. The declines raise very grave concerns about the future of wildlife, the effectiveness of wildlife conservation policies, strategies and practices in Kenya. Causes of the wildlife declines include exponential human population growth, increasing livestock numbers, declining rainfall and a striking rise in temperatures but the fundamental cause seems to be policy, institutional and market failures. Accordingly, we thoroughly evaluate wildlife

  17. Extreme Wildlife Declines and Concurrent Increase in Livestock Numbers in Kenya: What Are the Causes?

    Science.gov (United States)

    Ogutu, Joseph O.; Piepho, Hans-Peter; Said, Mohamed Y.; Ojwang, Gordon O.; Njino, Lucy W.; Kifugo, Shem C.; Wargute, Patrick W.

    2016-01-01

    There is growing evidence of escalating wildlife losses worldwide. Extreme wildlife losses have recently been documented for large parts of Africa, including western, Central and Eastern Africa. Here, we report extreme declines in wildlife and contemporaneous increase in livestock numbers in Kenya rangelands between 1977 and 2016. Our analysis uses systematic aerial monitoring survey data collected in rangelands that collectively cover 88% of Kenya’s land surface. Our results show that wildlife numbers declined on average by 68% between 1977 and 2016. The magnitude of decline varied among species but was most extreme (72–88%) and now severely threatens the population viability and persistence of warthog, lesser kudu, Thomson’s gazelle, eland, oryx, topi, hartebeest, impala, Grevy’s zebra and waterbuck in Kenya’s rangelands. The declines were widespread and occurred in most of the 21 rangeland counties. Likewise to wildlife, cattle numbers decreased (25.2%) but numbers of sheep and goats (76.3%), camels (13.1%) and donkeys (6.7%) evidently increased in the same period. As a result, livestock biomass was 8.1 times greater than that of wildlife in 2011–2013 compared to 3.5 times in 1977–1980. Most of Kenya’s wildlife (ca. 30%) occurred in Narok County alone. The proportion of the total “national” wildlife population found in each county increased between 1977 and 2016 substantially only in Taita Taveta and Laikipia but marginally in Garissa and Wajir counties, largely reflecting greater wildlife losses elsewhere. The declines raise very grave concerns about the future of wildlife, the effectiveness of wildlife conservation policies, strategies and practices in Kenya. Causes of the wildlife declines include exponential human population growth, increasing livestock numbers, declining rainfall and a striking rise in temperatures but the fundamental cause seems to be policy, institutional and market failures. Accordingly, we thoroughly evaluate

  18. Increased numbers of Foxp3-positive regulatory T cells in gastritis, peptic ulcer and gastric adenocarcinoma

    Science.gov (United States)

    Cheng, Hsin-Hung; Tseng, Guan-Ying; Yang, Hsiao-Bai; Wang, Hung-Jung; Lin, Hwai-Jeng; Wang, Wen-Ching

    2012-01-01

    AIM: To determine the number of regulatory T cells (Tregs) in gastric mucosa of patients with gastritis, peptic ulcers and gastric cancer. METHODS: This study was a retrospective analysis of gastric antrum biopsy specimens from healthy controls (n = 22) and patients with gastritis (n = 30), peptic ulcer (n = 83), or gastric cancer (n = 32). Expression of CD4, CD25 and Foxp3 was determined by immunohistochemistry in three consecutive sections per sample. RESULTS: Compared with healthy controls, there was an increased number of CD25+ and Foxp3+ cells in patients with gastritis (P = 0.004 and P = 0.008), peptic ulcer (P gastritis (P gastritis and peptic ulcer groups. PMID:22228968

  19. Potential host number in cuckoo bees (Psithyrus subgen. increases toward higher elevations

    Directory of Open Access Journals (Sweden)

    Jean-Nicolas Pradervand

    2013-07-01

    Full Text Available In severe and variable conditions, specialized resource selection strategies should be less frequent because extinction risks increase for species that depend on a single and unstable resource. Psithyrus (Bombus subgenus Psithyrus are bumblebee parasites that usurp Bombus nests and display inter‐specific variation in the number of hosts they parasitize. Using a phylogenetic comparative framework, we show that Psithyrus species at higher elevations display a higher number of hosts species compared with species restricted to lower elevations. Species inhabiting high elevations also cover a larger temperature range, suggesting that species able to occur in colder conditions may benefit from recruitment from populations occurring in warmer conditions. Our results provide evidence for an ‘altitudinal niche breadth hypothesis’ in parasitic species, showing a decrease in the parasites’ specialization along the elevational gradient, and also suggesting that Rapoport’s rule might apply to Psithyrus. 

  20. Does the chromatic Mach bands effect exist?

    Science.gov (United States)

    Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

    2009-06-30

    The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

  1. Human Traumatic Brain Injury Results in Oligodendrocyte Death and Increases the Number of Oligodendrocyte Progenitor Cells.

    Science.gov (United States)

    Flygt, Johanna; Gumucio, Astrid; Ingelsson, Martin; Skoglund, Karin; Holm, Jonatan; Alafuzoff, Irina; Marklund, Niklas

    2016-06-01

    Oligodendrocyte (OL) death may contribute to white matter pathology, a common cause of network dysfunction and persistent cognitive problems in patients with traumatic brain injury (TBI). Oligodendrocyte progenitor cells (OPCs) persist throughout the adult CNS and may replace dead OLs. OL death and OPCs were analyzed by immunohistochemistry of human brain tissue samples, surgically removed due to life-threatening contusions and/or focal brain swelling at 60.6 ± 75 hours (range 4-192 hours) postinjury in 10 severe TBI patients (age 51.7 ± 18.5 years). Control brain tissue was obtained postmortem from 5 age-matched patients without CNS disorders. TUNEL and CC1 co-labeling was used to analyze apoptotic OLs, which were increased in injured brain tissue (p The OPC markers Olig2, A2B5, NG2, and PDGFR-α were used. In contrast to the number of single-labeled Olig2, A2B5, NG2, and PDGFR-α-positive cells, numbers of Olig2 and A2B5 co-labeled cells were increased in TBI samples (p human TBI results in OL death and increases in OPCs postinjury, which may influence white matter function following TBI. © 2016 American Association of Neuropathologists, Inc. All rights reserved.

  2. Dark matter versus Mach's principle.

    Science.gov (United States)

    von Borzeszkowski, H.-H.; Treder, H.-J.

    1998-02-01

    Empirical and theoretical evidence show that the astrophysical problem of dark matter might be solved by a theory of Einstein-Mayer type. In this theory up to global Lorentz rotations the reference system is determined by the motion of cosmic matter. Thus one is led to a "Riemannian space with teleparallelism" realizing a geometric version of the Mach-Einstein doctrine. The field equations of this gravitational theory contain hidden matter terms where the existence of hidden matter is inferred safely from its gravitational effects. It is argued that in the nonrelativistic mechanical approximation they provide an inertia-free mechanics where the inertial mass of a body is induced by the gravitational action of the comic masses. Interpreted form the Newtonian point of view this mechanics shows that the effective gravitational mass of astrophysical objects depends on r such that one expects the existence of dark matter.

  3. Wire number doubling in plasma-shell regime increases z-accelerator x-ray power

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A. [and others

    1997-11-01

    Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40{+-}20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the {open_quotes}plasma shell{close_quotes} regime, where the plasmas generated by the individual wires merge prior to the inward implosion of the entire array.

  4. Wire number doubling in plasma-shell regime increases z-accelerator x-ray power

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A.

    1997-11-01

    Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40±20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the 'plasma shell' regime, where the plasmas generated by the individual wires merge prior to the inward implosion of the entire array

  5. Wire number doubling in plasma-shell regime increases Z-accelerator X-ray power

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A.

    1997-01-01

    Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40 ± 20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the plasma shell regime, where the plasma generated by the individual wires merge prior to the inward implosion of the entire array

  6. Wire number doubling in plasma-shell regime increases Z-accelerator X-ray power

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Spielman, R.B.; Chandler, G.A. [and others

    1997-12-01

    Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated x-ray power relative to the electrical power at the insulator stack of the z accelerator by (40 {+-} 20)% for 8.75- and 20-mm-radii z-pinch wire arrays. Radiation-magneto-hydrodynamic calculations suggest that the arrays were operating in the plasma shell regime, where the plasma generated by the individual wires merge prior to the inward implosion of the entire array.

  7. Increase in number of helminth species from Dutch red foxes over a 35-year period.

    Science.gov (United States)

    Franssen, Frits; Nijsse, Rolf; Mulder, Jaap; Cremers, Herman; Dam, Cecile; Takumi, Katsuhisa; van der Giessen, Joke

    2014-04-03

    The red fox (Vulpes vulpes) is host to a community of zoonotic and other helminth species. Tracking their community structure and dynamics over decades is one way to monitor the long term risk of parasitic infectious diseases relevant to public and veterinary health. We identified 17 helminth species from 136 foxes by mucosal scraping, centrifugal sedimentation/flotation and the washing and sieving technique. We applied rarefaction analysis to our samples and compared the resulting curve to the helminth community reported in literature 35 years ago. Fox helminth species significantly increased in number in the last 35 years (p-value <0.025). Toxascaris leonina, Mesocestoides litteratus, Trichuris vulpis and Angiostrongylus vasorum are four new veterinary-relevant species. The zoonotic fox tapeworm (E. multilocularis) was found outside the previously described endemic regions in the Netherlands. Helminth fauna in Dutch red foxes increased in biodiversity over the last three decades.

  8. Bats Increase the Number of Cultivable Airborne Fungi in the "Nietoperek" Bat Reserve in Western Poland.

    Science.gov (United States)

    Kokurewicz, Tomasz; Ogórek, Rafał; Pusz, Wojciech; Matkowski, Krzysztof

    2016-07-01

    The "Nietoperek" bat reserve located in Western Poland is one of the largest bat hibernation sites in the European Union with nearly 38,000 bats from 12 species. Nietoperek is part of a built underground fortification system from WWII. The aims of the study were (1) to determine the fungal species composition and changes during hibernation season in relation to bat number and microclimatic conditions and (2) evaluate the potential threat of fungi for bat assemblages and humans visiting the complex. Airborne fungi were collected in the beginning, middle and end of hibernation period (9 November 2013 and 17 January and 15 March 2014) in 12 study sites, one outside and 11 inside the complex. Ambient temperature (T a) and relative humidity (RH) were measured by the use of data loggers, and species composition of bats was recorded from the study sites. The collision method (Air Ideal 3P) sampler was used to detect 34 species of airborne fungi including Pseudogymnoascus destructans (Pd). The density of airborne fungi isolated from the outdoor air samples varied from 102 to 242 CFU/1 m(3) of air and from 12 to 1198 CFU in the underground air samples. There was a positive relationship between number of bats and the concentration of fungi. The concentration of airborne fungi increased with the increase of bats number. Analysis of other possible ways of spore transport to the underground indicated that the number of bats was the primary factor determining the number of fungal spores in that hibernation site. Microclimatic conditions where Pd was found (median 8.7 °C, min-max 6.1-9.9 °C and 100 %, min-max 77.5-100.0 %) were preferred by hibernating Myotis myotis and Myotis daubentonii; therefore, these species are most probably especially prone to infection by this fungi species. The spores of fungi found in the underground can be pathogenic for humans and animals, especially for immunocompromised persons, even though their concentrations did not exceed limits and

  9. Family of airfoil shapes for rotating blades. [for increased power efficiency and blade stability

    Science.gov (United States)

    Noonan, K. W. (Inventor)

    1983-01-01

    An airfoil which has particular application to the blade or blades of rotor aircraft such as helicopters and aircraft propellers is described. The airfoil thickness distribution and camber are shaped to maintain a near zero pitching moment coefficient over a wide range of lift coefficients and provide a zero pitching moment coefficient at section Mach numbers near 0.80 and to increase the drag divergence Mach number resulting in superior aircraft performance.

  10. Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme

    Directory of Open Access Journals (Sweden)

    Mustafa Ulutas

    2010-01-01

    Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.

  11. Increased number of mast cells in the dermis in actinic keratosis lesions effectively treated with imiquimod.

    Science.gov (United States)

    Oyama, Satomi; Funasaka, Yoko; Tsuchiya, Shin-Ichi; Kawana, Seiji; Saeki, Hidehisa

    2017-08-01

    Actinic keratosis (AK) is a cutaneous cancer in situ which develops as a result of excessive exposure to ultraviolet (UV). Toll-like receptor (TLR)7 agonist imiquimod is a topical immune response modifier and is effective for the treatment of non-melanoma skin cancers. Recently, the diagnostic role of the dermatoscope has been reported in the course of treatment of AK. In addition, mast cells are now considered to contribute to both the innate and adaptive immune systems in topical imiquimod therapy. We assessed the effect of imiquimod treatment by dermatoscopic and immunohistochemical findings in 14 patients with a total of 21 AK lesions. With the dermatoscope, though the mean erythema score was not significantly different between the cured lesions and the unresponsive lesions, the erythema/red pseudo-network ("strawberry") pattern was decreased significantly in the cured lesions. By immunohistochemistry, the number of Ki-67-positive proliferative cells in the epidermis was decreased and that of CD117-positive mast cells in the dermis was increased in the responding lesions. To the best of our knowledge, this is the first study demonstrating that the number of mast cells in the dermis was increased in AK lesions effectively treated with imiquimod. Our present result suggests that mast cells may contribute an antitumor effect in human skin treated with topical imiquimod. © 2017 Japanese Dermatological Association.

  12. Maternal undernutrition significantly impacts ovarian follicle number and increases ovarian oxidative stress in adult rat offspring.

    Directory of Open Access Journals (Sweden)

    Angelica B Bernal

    Full Text Available BACKGROUND: We have shown recently that maternal undernutrition (UN advanced female pubertal onset in a manner that is dependent upon the timing of UN. The long-term consequence of this accelerated puberty on ovarian function is unknown. Recent findings suggest that oxidative stress may be one mechanism whereby early life events impact on later physiological functioning. Therefore, using an established rodent model of maternal UN at critical windows of development, we examined maternal UN-induced changes in offspring ovarian function and determined whether these changes were underpinned by ovarian oxidative stress. METHODOLOGY/PRINCIPAL FINDINGS: Our study is the first to show that maternal UN significantly reduced primordial and secondary follicle number in offspring in a manner that was dependent upon the timing of maternal UN. Specifically, a reduction in these early stage follicles was observed in offspring born to mothers undernourished throughout both pregnancy and lactation. Additionally, antral follicle number was reduced in offspring born to all mothers that were UN regardless of whether the period of UN was restricted to pregnancy or lactation or both. These reductions were associated with decreased mRNA levels of genes critical for follicle maturation and ovulation. Increased ovarian protein carbonyls were observed in offspring born to mothers UN during pregnancy and/or lactation and this was associated with peroxiredoxin 3 hyperoxidation and reduced mRNA levels; suggesting compromised antioxidant defence. This was not observed in offspring of mothers UN during lactation alone. CONCLUSIONS: We propose that maternal UN, particularly at a time-point that includes pregnancy, results in reduced offspring ovarian follicle numbers and mRNA levels of regulatory genes and may be mediated by increased ovarian oxidative stress coupled with a decreased ability to repair the resultant oxidative damage. Together these data are suggestive of

  13. The impact of the 2008 economic crisis on the increasing number of young psychiatric inpatients.

    Science.gov (United States)

    Medel-Herrero, Alvaro; Gomez-Beneyto, Manuel

    2017-11-21

    Little is published about the impact of the 2008 economic crisis on mental health services in Spain. An interrupted time series analysis was conducted to investigate a potential short-term association between the 2008 economic crisis and the number of psychiatric hospital admissions. The timing of the intervention (April 2008) was based on observed changes in Gross Domestic Product (GDP). Data on 1,152,880 psychiatric inpatients from the national Hospital Morbidity Survey, 69 months before and after the onset of the economic crisis (April 2008), were analyzed. Age-adjusted psychiatric (ICD9 290-319) hospital discharge rates significantly increased from April 2008, matching the onset of the crisis, especially for inpatients aged 15-24 years old and to a less extend for inpatients aged 25-34 years old. Other age groups were not affected. There was a significant increase in diagnoses for disturbance of conduct and emotions, depression, neurotic and personality disorders and alcohol and drug disorders; however, diagnoses for mental retardation and organic psychosis for 15-34 years old inpatients were unaffected. Psychiatric hospital admissions abruptly increased in April 2008, coinciding with the onset of the economic crisis. We identified age groups and diagnoses affected. Increased hospitalizations were found only at the age-ranges most affected by the rise in unemployment. The diagnoses affected were those most sensitive to environmental changes. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Determining integral density distribution in the mach reflection of shock waves

    Science.gov (United States)

    Shevchenko, A. M.; Golubev, M. P.; Pavlov, A. A.; Pavlov, Al. A.; Khotyanovsky, D. V.; Shmakov, A. S.

    2017-05-01

    We present a method for and results of determination of the field of integral density in the structure of flow corresponding to the Mach interaction of shock waves at Mach number M = 3. The optical diagnostics of flow was performed using an interference technique based on self-adjusting Zernike filters (SA-AVT method). Numerical simulations were carried out using the CFS3D program package for solving the Euler and Navier-Stokes equations. Quantitative data on the distribution of integral density on the path of probing radiation in one direction of 3D flow transillumination in the region of Mach interaction of shock waves were obtained for the first time.

  15. Increased Number of Langerhans Cells in the Epidermis of Diabetic Foot Ulcers Correlates with Healing Outcome

    Science.gov (United States)

    Stojadinovic, Olivera; Yin, Natalie; Lehmann, Janin; Pastar, Irena; Kirsner, Robert S.; Tomic-Canic, Marjana

    2015-01-01

    Langerhans cells (LCs) are a specialized subset of epidermal dendritic cells. They represent one of the first cells of immunological barrier and play an important role during the inflammatory phase of acute wound healing. Despite considerable progress in our understanding of the immunopathology of diabetes mellitus and its associated co-morbidities such as diabetic foot ulcers (DFUs), considerable gaps in our knowledge exist. In this study, we utilized the human ex vivo wound model and confirmed the increased epidermal LCs at wound edges during early phases of wound healing. Next, we aimed to determine differences in quantity of LCs between normal human and diabetic foot skin and to learn if the presence of LCs correlates with the healing outcome in DFUs. We utilized immunofluorescence to detect CD207+ LCs in specimens from normal and diabetic foot skin and DFU wound edges. Specimens from DFUs were collected at the initial visit and 4 weeks at the time when the healing outcome was determined. DFUs that decreased in size by >50% were considered to be healing, while DFUs with a size reduction of healing. Quantitative assessment of LCs showed a higher number of LCs in healing when compared to non–healing DFU’s. Our findings provide evidence that LCs are present in higher number in diabetic feet than normal foot skin. Healing DFUs show a higher number of LCs compared to non-healing DFUs. These findings indicate that the epidermal immune barrier plays an important role in the DFU healing outcome and may offer new therapeutic avenues targeting LC in non-healing DFUs. PMID:24277309

  16. Medical Student Summer Externship Program: Increasing the Number Matching in Family Practice

    Directory of Open Access Journals (Sweden)

    Holly Cronau

    2004-02-01

    Full Text Available Background and Objectives. The number of US allopathic medical school graduates choosing a residency in family medicine has fallen from 13.4% in 1999 to 10.5% in 2002. Concern about declining numbers has led to the development of programs to provide medical students exposure to family medicine outside the clerkship. This paper reports on the development and longitudinal achievements of a clinical summer externship program 1993 to 1999. Methods. The program description, practice settings, students’ experiences, and department commitment are described. The purpose of this prospective study is to determine the percentage of family medicine summer externship participants (n=115 who match into family medicine. Results. During the six years studied, 49 (43.4% of the participants matched into family medicine. Program participants viewed the program favorably, mean = 5.82 out of 6. Conclusions. The Ohio State University Department of Family Medicine Medical Student Summer Externship Program demonstrates an effective educational experience that can increase and/or attain the proportion of students going into family medicine at the time of graduation

  17. Increased number of IgG4-positive plasma cells in chronic rhinosinusitis.

    Science.gov (United States)

    Ohno, Keiko; Kimura, Yurika; Matsuda, Yoko; Takahashi, Masatoki; Honjyou, Motomu; Arai, Tomio; Tsutsumi, Takeshi

    2017-02-01

    High levels of IgG4-positive plasma cells were observed in tissue samples from ∼30% of patients with chronic rhinosinusitis who satisfied the comprehensive diagnostic criteria for IgG4-related disease. Detection of increased numbers of IgG4-positive plasma cells in the nasal cavity or paranasal sinuses might not be sufficient to make a diagnosis of IgG4-related rhinosinusitis, and a comprehensive evaluation is required. This study aimed to clarify the clinicopathological characteristics of IgG4-positive plasma cells in patients with chronic rhinosinusitis. This study examined nasal mucosal specimens from 35 patients and assigned them to high-IgG4 and low-IgG4 groups based on infiltration of IgG4-positive plasma cells. It compared the pathological characteristics of the two groups, including the presence of fibrosis, phlebitis, hyperplasia of the nasal glands and infiltration of inflammatory cells. No cases of chronic rhinosinusitis showed storiform fibrosis or obliterative phlebitis. The mean number of IgG4-positive plasma cells in samples from all patients was 29.8 ± 40.3/high-power field. Eleven of the 35 cases (31.4%) were classified as high-IgG4. Hyperplasia of the nasal glands was observed significantly more frequently in the high-IgG4 group than in the low-IgG4 group (p = .03).

  18. Hybrid PV/wind system with quinary asymmetric inverter without increasing DC-link number

    Directory of Open Access Journals (Sweden)

    Aida Baghbany Oskouei

    2016-06-01

    Full Text Available This paper suggests quinary asymmetric inverter with coupled inductors and transformer, and uses it in hybrid system including photovoltaic (PV and wind. This inverter produces twenty-five-level voltage in addition to merits of multilevel inverter, has only one DC source. Then, it is adequate for hybrid systems, which prevents increasing DC-link and makes control of system easy. Proposed structure also provides isolation in the system and the switch numbers are reduced in this topology compared with other multilevel structures. In this system, battery is used as backup, where PV and wind have complementary nature. The performance of proposed inverter and hybrid system is validated with simulation results using MATLAB/SIMULINK software and experimental results based PCI-1716 data acquisition system.

  19. The increasing number of women with postgraduate qualifications in physics in Ecuador

    Science.gov (United States)

    Guitarra, Silvana; Niebeskikwiat, Dario; Paredes, Cecilia; Ayala, Paola

    2013-03-01

    Although the social reality in Ecuador is similar to that in most Latin American countries, support for research in fundamental and applied sciences has gained in importance in the last few years. An Ecuadorian team participated for the first time in the IUPAP International Conference on Women in Physics in 2005, when no woman in the country had yet earned a postgraduate degree. By the 2011 ICWIP Conference, the number of women with PhD degrees had increased five times, whereas the trend for men remained the same. This paper gives an overview on how the Ecuadorian research community has started to work together on a national initiative to improve the human and infrastructure capacity to develop science and technology, with support from the government and the science-related ministries.

  20. Increased levels of mitochondrial DNA copy number in patients with vitiligo.

    Science.gov (United States)

    Vaseghi, H; Houshmand, M; Jadali, Z

    2017-10-01

    Oxidative stress is known to be involved in the pathogenesis of autoimmune diseases such as vitiligo. Evidence suggests that the human mitochondrial DNA copy number (mtDNAcn) is vulnerable to damage mediated by oxidative stress. The purpose of this study was to examine and compare peripheral blood mtDNAcn and oxidative DNA damage byproducts (8-hydroxy-2-deoxyguanosine; 8-OHdG) in patients with vitiligo and healthy controls (HCs). The relative mtDNAcn and the oxidative damage (formation of 8-OHdG in mtDNA) of each sample were determined by real-time quantitative PCR. Blood samples were obtained from 56 patients with vitiligo and 46 HCs. The mean mtDNAcn and the degree of mtDNA damage were higher in patients with vitiligo than in HCs. These data suggest that increase in mtDNAcn and oxidative DNA damage may be involved in the pathogenesis of vitiligo. © 2017 British Association of Dermatologists.

  1. Laser-driven Mach waves for gigabar-range shock experiments

    Science.gov (United States)

    Swift, Damian; Lazicki, Amy; Coppari, Federica; Saunders, Alison; Nilsen, Joseph

    2017-10-01

    Mach reflection offers possibilities for generating planar, supported shocks at higher pressures than are practical even with laser ablation. We have studied the formation of Mach waves by algebraic solution and hydrocode simulation for drive pressures at much than reported previously, and for realistic equations of state. We predict that Mach reflection continues to occur as the drive pressure increases, and the pressure enhancement increases monotonically with drive pressure even though the ``enhancement spike'' characteristic of low-pressure Mach waves disappears. The growth angle also increases monotonically with pressure, so a higher drive pressure seems always to be an advantage. However, there are conditions where the Mach wave is perturbed by reflections. We have performed trial experiments at the Omega facility, using a laser-heated halfraum to induce a Mach wave in a polystyrene cone. Pulse length and energy limitations meant that the drive was not maintained long enough to fully support the shock, but the results indicated a Mach wave of 25-30 TPa from a drive pressure of 5-6 TPa, consistent with simulations. A similar configuration should be tested at the NIF, and a Z-pinch driven configuration may be possible. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. Plasma adiponectin levels correlate positively with an increasing number of components of frailty in male elders.

    Directory of Open Access Journals (Sweden)

    Jaw-Shiun Tsai

    Full Text Available OBJECTIVE: Frailty is an important geriatric syndrome. Adiponectin is an important adipokine that regulates energy homeostasis. The aim of this study is to investigate the relationship between plasma adiponectin levels and frailty in elders. METHODS: The demographic data, body weight, metabolic and inflammatory parameters, including plasma glucose, total cholesterol, triglyceride, tumor necrosis factor alpha (TNF-α, c-reactive protein (CRP and adiponectin levels, were assessed. The frailty score was assessed using the Fried Frailty Index (FFI. RESULTS: The mean (SD age of the 168 participants [83 (49.4% men and 85 (50.6% women] was 76.86 (6.10 years. Judged by the FFI score, 42 (25% elders were robust, 92 (54.7% were pre-frail, and 34 (20.3% were frail. The mean body mass index was 25.19 (3.42 kg/m(2. The log-transformed mean (SD plasma adiponectin (µg/mL level was 1.00 (0.26. The log-transformed mean plasma adiponectin (µg/mL levels were 0.93 (0.23 in the robust elders, 1.00 (0.27 in the pre-frail elders, and 1.10 (0.22 in the frail elders, and the differences between these values were statistically significant (p  = 0.012. Further analysis showed that plasma adiponectin levels rose progressively with an increasing number of components of frailty in all participants as a whole (p for trend  = 0.024 and males (p for trend  = 0.037, but not in females (p for trend  = 0.223. CONCLUSION: Plasma adiponectin levels correlate positively with an increasing number of components of frailty in male elders. The difference between the sexes suggests that certain sex-specific mechanisms may exist to affect the association between adiponectin levels and frailty.

  3. Maximal exercise increases mucosal associated invariant T cell frequency and number in healthy young men.

    Science.gov (United States)

    Hanson, Erik D; Danson, Eli; Nguyen-Robertson, Catriona V; Fyfe, Jackson J; Stepto, Nigel K; Bartlett, David B; Sakkal, Samy

    2017-11-01

    Mucosal associated invariant T (MAIT) cells have properties of the innate and acquired immune systems. While the response to vigorous exercise has been established for most leukocytes, MAIT cells have not been investigated. Therefore, the purpose was to determine if MAIT cell lymphocytosis occurs with acute maximal aerobic exercise and if this response is influenced by exercise duration, cardiovascular fitness, or body composition. Twenty healthy young males with moderate fitness levels performed an extended graded exercise test until volitional fatigue. Peripheral blood mononuclear cells were isolated from venous blood obtained prior and immediately after exercise and were labeled to identify specific T cell populations using flow cytometry. The percentage of MAIT cells relative to total T cells significantly increased from 3.0 to 3.8% and absolute MAIT cell counts increased by 2.2-fold following maximal exercise. MAIT cell subpopulation proportions were unchanged with exercise. Within cytotoxic T lymphocytes (CTL), MAIT cells consisted of 8% of these cells and this remained constant after exercise. MAIT cell counts and changes with exercise were not affected by body composition, VO 2peak , or exercise duration. Maximal exercise doubled MAIT cell numbers and showed preferential mobilization within total T cells but the response was not influenced by fitness levels, exercise duration, or body composition. These results suggest that acute exercise could be used to offset MAIT cell deficiencies observed with certain pathologies. MAIT cells also make up a substantial proportion of CTLs, which may have implications for cytotoxicity assays using these cells.

  4. Hospital costs fell as numbers of LVADs were increasing: experiences from Oslo University Hospital

    Directory of Open Access Journals (Sweden)

    Mishra Vinod

    2012-08-01

    Full Text Available Abstract Background The current study was undertaken to examine total hospital costs per patient of a consecutive implantation series of two 3rd generation Left Ventricle Assist Devices (LVAD. Further we analyzed if increased clinical experience would reduce total hospital costs and the gap between costs and the diagnosis related grouped (DRG-reimbursement. Method Cost data of 20 LVAD implantations (VentrAssist™ from 2005-2009 (period 1 were analyzed together with costs from nine patients using another LVAD (HeartWare™ from 2009-June 2011 (period 2. For each patient, total costs were calculated for three phases - the pre-LVAD implantation phase, the LVAD implantation phase and the post LVAD implant phase. Patient specific costs were obtained prospectively from patient records and included personnel resources, medication, blood products, blood chemistry and microbiology, imaging and procedure costs including operating room costs. Overhead costs were registered retrospectively and allocated to the specific patient by predefined allocation keys. Finally, patient specific costs and overhead costs were aggregated into total hospital costs for each patient. All costs were calculated in 2011-prices. We used regression analyses to analyze cost variations over time and between the different devices. Results The average total hospital cost per patient for the pre-LVAD, LVAD and post-LVAD for period 1 was $ 585, 513 (range 132, 640- 1 247, 299, and the corresponding DRG- reimbursement (2009 was $ 143, 192 . The mean LOS was 54 days (range 12- 127. For period 2 the total hospital cost per patient was $ 413, 185 (range 314, 540- 622, 664 and the corresponding DRG- reimbursement (2010 was $ 136, 963. The mean LOS was 49 days (range 31- 93. The estimates from the regression analysis showed that the total hospital costs, excluding device costs, per patient were falling as the number of treated patients increased. The estimate from the trend variable was -14

  5. Incremental Value of Increasing Number of Arterial Grafts: The Effect of Diabetes Mellitus.

    Science.gov (United States)

    Schwann, Thomas A; El Hage Sleiman, Abdul Karim M; Yammine, Maroun B; Tranbaugh, Robert F; Engoren, Milo; Bonnell, Mark R; Habib, Robert H

    2018-06-01

    Multiarterial coronary grafting with two arterial grafts leads to improved survival compared with conventional single artery based on left internal thoracic artery to left anterior descending artery and saphenous vein grafts. We investigated whether extending arterial grafting to three or more arterial grafts further improves survival, and whether such a benefit is modified by diabetes mellitus. We analyzed 15-year coronary artery bypass graft surgery mortality data in 11,931 patients (age 64.3 ± 10.5 years; 3,484 women [29.2%]; 4,377 [36.7%] with diabetes mellitus) derived from three US institutions (1994 to 2011). All underwent primary isolated left internal thoracic artery to left anterior descending artery grafting with at least two grafts: one artery (n = 6,782; 56.9%); two arteries (n = 3,678; 30.8%); or three or more arteries (n = 1,471; 12.3%). Long-term survival was estimated by Kaplan-Meier methods. Propensity score matching and comprehensive covariate adjustment (Cox regression) were used to derive long-term risk-adjusted hazard ratio (HR) with 95% confidence interval (CI) for increasing number of arterial grafts in the overall cohort and for diabetes and no-diabetes cohorts. Radial artery (94%) and right internal thoracic artery (6%) were used as additional arterial grafts. Multivariate analysis in all patients showed that diabetes was associated with decreased survival (HR 1.43, 95% CI: 1.34 to 53), whereas increasing number of arterial grafts was associated with decreased mortality (one artery HR 1.0 [reference]; two arteries HR 0.87, 95% CI: 0.80 to 0.95; and three arteries HR 0.83, 95% CI: 0.72 to 0.95). Pairwise comparisons also showed an incremental benefit of additional arterial grafts: two arteries versus one artery, HR 0.89 (95% CI: 0.80 to 0.98); and three arteries versus one artery, HR 0.80 (95% CI: 0.68 to 0.94). A three-artery versus two-artery survival advantage trend was also noted, but was not significant in either the overall study

  6. Interplay between Mach cone and radial expansion in jet events

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Y., E-mail: tachibana@nt.phys.s.u-tokyo.ac.jp [Theoretical Research Division, Nishina Center, RIKEN, Wako 351-0198 (Japan); Department of Engineering, Nishinippon Institute of Technology, Fukuoka 800-0344 (Japan); Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Hirano, T., E-mail: hirano@sophia.ac.jp [Department of Physics, Sophia University, Tokyo 102-8554 (Japan)

    2016-12-15

    We study the hydrodynamic response to jet propagation in the expanding QGP and investigate how the particle spectra after the hydrodynamic evolution of the QGP reflect it. We perform simulations of the space-time evolution of the QGP in gamma-jet events by solving (3+1)-dimensional ideal hydrodynamic equations with source terms. Mach cone is induced by the jet energy deposition and pushes back the radial flow of the expanding background. Especially in the case when the jet passage is off-central one, the number of particles emitted in the direction of the push back decreases. This is the signal including the information about the formation of the Mach cone and the jet passage in the QGP fluid.

  7. Interplay between Mach cone and radial expansion in jet events

    International Nuclear Information System (INIS)

    Tachibana, Y.; Hirano, T.

    2016-01-01

    We study the hydrodynamic response to jet propagation in the expanding QGP and investigate how the particle spectra after the hydrodynamic evolution of the QGP reflect it. We perform simulations of the space-time evolution of the QGP in gamma-jet events by solving (3+1)-dimensional ideal hydrodynamic equations with source terms. Mach cone is induced by the jet energy deposition and pushes back the radial flow of the expanding background. Especially in the case when the jet passage is off-central one, the number of particles emitted in the direction of the push back decreases. This is the signal including the information about the formation of the Mach cone and the jet passage in the QGP fluid.

  8. Carbon monoxide improves neuronal differentiation and yield by increasing the functioning and number of mitochondria.

    Science.gov (United States)

    Almeida, Ana S; Sonnewald, Ursula; Alves, Paula M; Vieira, Helena L A

    2016-08-01

    The process of cell differentiation goes hand-in-hand with metabolic adaptations, which are needed to provide energy and new metabolites. Carbon monoxide (CO) is an endogenous cytoprotective molecule able to inhibit cell death and improve mitochondrial metabolism. Neuronal differentiation processes were studied using the NT2 cell line, which is derived from human testicular embryonic teratocarcinoma and differentiates into post-mitotic neurons upon retinoic acid treatment. CO-releasing molecule A1 (CORM-A1) was used do deliver CO into cell culture. CO treatment improved NT2 neuronal differentiation and yield, since there were more neurons and the total cell number increased following the differentiation process. CO supplementation enhanced the mitochondrial population in post-mitotic neurons derived from NT2 cells, as indicated by an increase in mitochondrial DNA. CO treatment during neuronal differentiation increased the extent of the classical metabolic change that occurs during neuronal differentiation, from glycolytic to more oxidative metabolism, by decreasing the ratio of lactate production and glucose consumption. The expression of pyruvate and lactate dehydrogenases was higher, indicating an augmented oxidative metabolism. Moreover, these findings were corroborated by an increased percentage of (13) C incorporation from [U-(13) C]glucose into the tricarboxylic acid cycle metabolites malate and citrate, and also glutamate and aspartate in CO-treated cells. Finally, under low levels of oxygen (5%), which enhances glycolytic metabolism, some of the enhancing effects of CO on mitochondria were not observed. In conclusion, our data show that CO improves neuronal and mitochondrial yield by stimulation of tricarboxylic acid cycle activity, and thus oxidative metabolism of NT2 cells during the process of neuronal differentiation. The process of cell differentiation is coupled with metabolic adaptations. Carbon monoxide (CO) is an endogenous cytoprotective

  9. Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia

    Science.gov (United States)

    Calloway, Cassandra

    2016-01-01

    BACKGROUND. Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia. METHODS. Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA4977) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions. RESULTS. Compared with healthy controls, Mt/N and ΔmtDNA4977 frequency were elevated in thalassemia (P = 0.038 and P 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* 40/1 × 107 mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008). CONCLUSION. Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia. FUNDING. This project was supported by Children’s Hospital & Research Center Oakland Institutional Research Award and by the National Center for Advancing Translational Sciences, NIH, through UCSF-CTSI grant UL1 TR000004. PMID:27583305

  10. Familiarity increases the number of remembered Pokémon in visual short-term memory.

    Science.gov (United States)

    Xie, Weizhen; Zhang, Weiwei

    2017-05-01

    Long-term memory (LTM) can influence many aspects of short-term memory (STM), including increased STM span. However, it is unclear whether LTM enhances the quantitative or qualitative aspect of STM. That is, do we retain a larger number of representations or more precise representations in STM for familiar stimuli than unfamiliar stimuli? This study took advantage of participants' prior rich multimedia experience with Pokémon, without investing on laboratory training to examine how prior LTM influenced visual STM. In a Pokémon visual STM change detection task, participants remembered more first-generation Pokémon characters that they were more familiar with than recent-generation Pokémon characters that they were less familiar with. No significant difference in memory quality was found when quantitative and qualitative effects of LTM were isolated using receiver operating characteristic (ROC) analyses. Critically, these effects were absent in participants who were unfamiliar with first-generation Pokémon. Furthermore, several alternative interpretations were ruled out, including general video-gaming experience, subjective Pokémon preference, and verbal encoding. Together, these results demonstrated a strong link between prior stimulus familiarity in LTM and visual STM storage capacity.

  11. Entropy-based viscous regularization for the multi-dimensional Euler equations in low-Mach and transonic flows

    Energy Technology Data Exchange (ETDEWEB)

    Marc O Delchini; Jean E. Ragusa; Ray A. Berry

    2015-07-01

    We present a new version of the entropy viscosity method, a viscous regularization technique for hyperbolic conservation laws, that is well-suited for low-Mach flows. By means of a low-Mach asymptotic study, new expressions for the entropy viscosity coefficients are derived. These definitions are valid for a wide range of Mach numbers, from subsonic flows (with very low Mach numbers) to supersonic flows, and no longer depend on an analytical expression for the entropy function. In addition, the entropy viscosity method is extended to Euler equations with variable area for nozzle flow problems. The effectiveness of the method is demonstrated using various 1-D and 2-D benchmark tests: flow in a converging–diverging nozzle; Leblanc shock tube; slow moving shock; strong shock for liquid phase; low-Mach flows around a cylinder and over a circular hump; and supersonic flow in a compression corner. Convergence studies are performed for smooth solutions and solutions with shocks present.

  12. An increase in the number of admitted patients with exercise-induced rhabdomyolysis.

    Science.gov (United States)

    Aalborg, Christian; Rød-Larsen, Cecilie; Leiro, Ingjerd; Aasebø, Willy

    2016-10-01

    Rhabdomyolysis may lead to serious complications, and treatment is both time-consuming and costly. The condition can be caused by many factors, including intense exercise. The purpose of this study was to investigate whether the number of hospitalisations due to exercise-induced rhabdomyolysis has changed in recent years. We describe the disease course in hospitalised patients, and compare disease course in individuals with exercise-induced rhabdomyolysis and rhabdomyolysis due to other causes. The study is a systematic review of medical records from Akershus University Hospital for the years 2008 and 2011 – 14. All hospitalised patients with diagnostic codes M62.8, M62.9 and T79.6 and creatine kinase levels > 5 000 IU/l were included. The cause of the rhabdomyolysis was recorded in addition to patient characteristics and the results of various laboratory tests. Of 161 patients who were hospitalised with rhabdomyolysis during the study period, 44 cases (27  %) were classified as exercise-induced. In 2008 there were no admissions due to exercise-induced rhabdomyolysis; in 2011 and 2012 there were six and four admissions respectively, while in 2014 there were 22. This gives an estimated incidence of 0.8/100 000 in 2012 and 4.6/100 000 in 2014. Strength-training was the cause of hospitalisation in 35 patients (80  % of the exercise-induced cases). Three patients (7  % of the exercise-induced cases) had transient stage 1 kidney injury, but there were no cases with stage 2 or stage 3 injury. By comparison, 52  % of patients with rhabdomyolysis due to another cause had kidney injury, of which 28  % was stage 2 or 3. The number of persons hospitalised with exercise-induced rhabdomyolysis has increased four-fold from 2011 to 2014, possibly due to changes in exercise habits in the population. None of the patients with exercise-induced rhabdomyolysis had serological signs of kidney injury upon hospital discharge.

  13. Mach cones in space and laboratory dusty magnetoplasmas

    International Nuclear Information System (INIS)

    Mamun, A.A.; Shukla, P.K

    2004-07-01

    We present a rigorous theoretical investigation on the possibility for the formation of Mach cones in both space and laboratory dusty magnetoplasmas. We find the parametric regimes for which different types of Mach cones, such as dust acoustic Mach cones, dust magneto-acoustic Mach cones, oscillonic Mach cones, etc. are formed in space and laboratory dusty magnetoplasmas. We also identify the basic features of such different classes of Mach cones (viz. dust- acoustic, dust magneto-acoustic, oscillonic Mach cones, etc.), and clearly explain how they are relevant to space and laboratory dusty manetoplasmas. (author)

  14. Emergent gravity of fractons: Mach's principle revisited

    Science.gov (United States)

    Pretko, Michael

    2017-07-01

    Recent work has established the existence of stable quantum phases of matter described by symmetric tensor gauge fields, which naturally couple to particles of restricted mobility, such as fractons. We focus on a minimal toy model of a rank 2 tensor gauge field, consisting of fractons coupled to an emergent graviton (massless spin-2 excitation). We show how to reconcile the immobility of fractons with the expected gravitational behavior of the model. First, we reformulate the fracton phenomenon in terms of an emergent center of mass quantum number, and we show how an effective attraction arises from the principles of locality and conservation of center of mass. This interaction between fractons is always attractive and can be recast in geometric language, with a geodesiclike formulation, thereby satisfying the expected properties of a gravitational force. This force will generically be short-ranged, but we discuss how the power-law behavior of Newtonian gravity can arise under certain conditions. We then show that, while an isolated fracton is immobile, fractons are endowed with finite inertia by the presence of a large-scale distribution of other fractons, in a concrete manifestation of Mach's principle. Our formalism provides suggestive hints that matter plays a fundamental role, not only in perturbing, but in creating the background space in which it propagates.

  15. Increasing the Number of Canadian Indigenous Students in STEM at the University of Regina, Saskatchewan, Canada

    Science.gov (United States)

    St-Jacques, J. M.; McGee, S.; Janze, R.; Longman, M.; Pete, S.; Starblanket, N.

    2016-12-01

    Canadian Indigenous people are an extremely poorly represented group in STEM today due to major barriers in obtaining a high school and then a university education. Approximately 10% of the undergraduate student population out of a total 12,600 students at the University of Regina, Regina, Saskatchewan, is First Nations, Métis or Inuit. The university is located in a catchment region where 30% of the population is First Nations or Métis. Approximately 100 students majoring in the sciences, mathematics and engineering have self-declared themselves to be Indigenous. For the past two years, we have been running a pilot project, the Initiative to Support and Increase the Number of Indigenous Students in the Sciences, Mathematics and Engineering at the Aboriginal Student Centre, with financial support from the Deans of Science and Engineering. We provide student networking lunches, Indigenous scientist and engineer speakers and mentors and supplemental tutoring. Our program is actively supported and guided by Elder Noel Starblanket, former president of the National Indian Brotherhood (now the Assembly of First Nations). Our students are greatly interested in the health and environmental sciences (particularly water quality), with a sprinkling of physics, mathematics and engineering majors. Our students have gone on to graduate work with prestigious scholarships and a paid internship in engineering. We report here on various lessons learned: the involvement of elders is key, as is the acceptance of non-traditional academic paths, and any STEM support program must respect Indigenous culture. There is great interest in science and engineering on the part of these students, if scientists and engineers are willing to listen and learn to talk with these students on their own terms.

  16. An empirical study to detect effective factors to increase number of moviegoers

    Directory of Open Access Journals (Sweden)

    Yasaman Giyahi

    2012-08-01

    Full Text Available In this paper, we present an empirical study to detect important factors, which could increase the number of moviegoers. The study distributes a questionnaire among different people at four age groups including 35.2% (men, and 64.8% (women, most of them are single (between 21 to 30 years living at 3- to 4-member families, holding BA degree with 4 to 7 million Rials monthly salary. Inferential statistics tests, including Kolmogorov–Smirnov, binominal or ratio, Chi Square and Friedman, show that type of story, genre and artists, casts are considered as the most important factors in selection of film while quality of sound, seat comfort, ventilation of cinema hall are regarded as the most important factors in selection of cinema. In addition, cinema is not predominant pastime or hobby of individuals during holidays and existence of more attractive pastimes than cinema is the most important factor, which hinders individuals from going to cinema. Individuals go to cinema fewer than three times a year, primarily during the afternoon of holidays at the weekend. TV teasers and word of mouth advertisements are the most significant publicity tools for those individuals who intend to go to cinema halls. These two factors, i.e. TV teasers and word of mouth advertisements, are the most significant sources of studying individuals for the selection of film. Individuals almost select their favorite movies before going to cinema and if ticket is finished at the box office of cinema, they suspend watching film in another time and finally, they re-plan watching film. It should be noted that satisfaction of individuals from cinema is much more effective than their satisfaction from film.

  17. Increasing the number of feminist scientists: why feminist aims are not served by the Underdetermination Thesis

    Science.gov (United States)

    Intemann, Kristen

    2008-11-01

    Recent feminist philosophers of science have argued that feminist values can contribute to rational decisions about which scientific theories to accept. On this view, increasing the number of feminist scientists is important for ensuring rational and objective theory acceptance. The Underdetermination Thesis has played a key role in arguments for this view [Anderson (1995) Hypatia 10(3), 50 84; Hankinson Nelson (1990) Who knows? From Quine to a feminist empiricism. Temple University Press, Philadelphia; Longino (1990) Science as social knowledge. Princeton University Press, Princeton; Longino (2002) The fate of knowledge. Princeton University Press, Princeton; Kourany (2003) Philosophy of Science 70, 1 14]. This thesis is alleged to open an argumentative “gap” between evidence and theory acceptance and provide a rationale for filling the gap with feminist values. While I agree with the conclusion that feminist values can contribute to rational decisions about which theories to accept, I argue that the Underdetermination Thesis cannot support this claim. First, using earlier arguments [Laudan (1990) in: R. Giere (ed) Minnesota studies in the philosophy of science, vol 14, pp 267 297; Slezak (1991) International Studies in Philosophy of Science 5, 241 256; Pinnick (1994) Philosophy of Science 61, 664 657] I show that Underdetermination cannot, by itself, establish that feminist values should fill the gap in theory acceptance. Secondly, I argue that the very use of the Underdetermination Thesis concedes that feminist values are extra-scientific, a-rational, factors in theory acceptance. This concession denies feminists grounds to explain why their values contribute to rational scientific reasoning. Finally, I propose two alternative ways to explain how feminist values can contribute to rational theory acceptance that do not rely on Underdetermination.

  18. Increasing number of authors per paper in Korean science and technology papers

    Directory of Open Access Journals (Sweden)

    Hyunju Jang

    2016-08-01

    Full Text Available We examined changes in the number of authors per paper for science and technology papers (agricultural sciences, engineering and technologies, medical sciences, and natural sciences in Korea. We employed the Scopus database to examine the change in the number of authors in papers, which were published from 2000 to 2015 in the 234 Korean academic journals indexed on Scopus. We found that the global trend of growth in the number of authors per paper is evident in Korea as well. While there was little evidence of a correlation with the citation per paper, a positive correlation was found between with the field-weighted citation impact, another measure of a paper’s impact, in medical and natural science papers. In terms of the type of collaboration, we found that international collaboration papers had the highest number of authors, followed by national and institutional collaborations. The number of authors per paper was highest for those published in the top 10% journals by Source Normalized Impact per Paper, followed by Scopus-indexed journals, while papers published in Korea Citation Index had the lowest number of authors per paper. We propose that the rise in the number of authors per paper in Korean papers may be ascribed to many Korean research programs encouraging group research and the widespread availability of the internet, which has stimulated joint research efforts and encouraged international collaboration.

  19. Low Mach number limit for a model of accretion disk

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Ducomet, B.; Nečasová, Šárka

    2018-01-01

    Roč. 38, č. 7 (2018), s. 3239-3268 ISSN 1078-0947 R&D Projects: GA ČR GA13-00522S; GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : Navier-Stokes-Fourier-Poisson system * magnetohydrodynamics * radiating transfer Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.099, year: 2016 http://aimsciences.org/article/doi/10.3934/dcds.2018141

  20. Low Mach number limit for a model of accretion disk

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Ducomet, B.; Nečasová, Šárka

    2018-01-01

    Roč. 38, č. 7 (2018), s. 3239-3268 ISSN 1078-0947 R&D Projects: GA ČR GA13-00522S; GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : Navier-Stokes-Fourier-Poisson system * magnetohydrodynamics * radiating transfer Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.099, year: 2016 http://aimsciences.org/ article /doi/10.3934/dcds.2018141

  1. Miscellaneous: Various Low-Mach-Number Fluid Problems and Motions

    Science.gov (United States)

    Zeytounian, Radyadour Kh.

    In this last chapter, we consider, first, in Sect. 7.1, mainly the asymptotic derivation of the KZK equation of nonlinear acoustics, which generalizes the well-known Burgers' unsteady one-dimensional dissipative model equation (Burgers 1948) to an equation with a diffraction and parabolic effect.

  2. Modelling of high-enthalpy, high-Mach number flows

    International Nuclear Information System (INIS)

    Degrez, G; Lani, A; Panesi, M; Chazot, O; Deconinck, H

    2009-01-01

    A review is made of the computational models of high-enthalpy flows developed over the past few years at the von Karman Institute and Universite Libre de Bruxelles, for the modelling of high-enthalpy hypersonic (re-)entry flows. Both flows in local thermo-chemical equilibrium (LTE) and flows in thermo-chemical non-equilibrium (TCNEQ) are considered. First, the physico-chemical models are described, i.e. the set of conservation laws, the thermodynamics, transport phenomena and chemical kinetics models. Particular attention is given to the correct modelling of elemental (LTE flows) and species (chemical non-equilibrium-CNEQ-flows) transport. The numerical algorithm, based on a state-of-the-art finite volume discretization, is then briefly described. Finally, selected examples are included to illustrate the capabilities of the developed solver. (review article)

  3. Can the developer be the user? A possible explanation for the increasing number of customer complaints in consumer electronics

    NARCIS (Netherlands)

    Luyk - de Visser, I.M.; Lu, Y.; Brombacher, A.C.

    2008-01-01

    Different business trends within consumer electronics industry have resulted in an increasing number of customer complaints in the after-market. Research into this increasing number by Den Ouden indicates that 85% of the complaints can be traced back to decisions made in the product creation process

  4. Increasing gland number and red pigments in St. John's wort in vitro ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... casein, mannitol and sucrose. The highest percentage of calli containing red pigments was observed in the culture medium which had 500 or 0.0 mg l-1 hydrolyzed casein and 20 g l-1 sucrose, without mannitol. Glands were observed on all the produced leaves. Number of glands and percentage of leaves.

  5. TOP1 gene copy numbers are increased in cancers of the bile duct and pancreas

    DEFF Research Database (Denmark)

    Grunnet, Mie; Calatayud, Dan; Schultz, Nicolai Aa.

    2015-01-01

    ) poison. Top1 protein, TOP1 gene copy number and mRNA expression, respectively, have been proposed as predictive biomarkers of response to irinotecan in other cancers. Here we investigate the occurrence of TOP1 gene aberrations in cancers of the bile ducts and pancreas. Material and methods. TOP1...

  6. Acoustic Radiation From a Mach 14 Turbulent Boundary Layer

    Science.gov (United States)

    Zhang, Chao; Duan, Lian; Choudhari, Meelan M.

    2016-01-01

    Direct numerical simulations (DNS) are used to examine the turbulence statistics and the radiation field generated by a high-speed turbulent boundary layer with a nominal freestream Mach number of 14 and wall temperature of 0:18 times the recovery temperature. The flow conditions fall within the range of nozzle exit conditions of the Arnold Engineering Development Center (AEDC) Hypervelocity Tunnel No. 9 facility. The streamwise domain size is approximately 200 times the boundary-layer thickness at the inlet, with a useful range of Reynolds number corresponding to Re 450 ?? 650. Consistent with previous studies of turbulent boundary layer at high Mach numbers, the weak compressibility hypothesis for turbulent boundary layers remains applicable under this flow condition and the computational results confirm the validity of both the van Driest transformation and Morkovin's scaling. The Reynolds analogy is valid at the surface; the RMS of fluctuations in the surface pressure, wall shear stress, and heat flux is 24%, 53%, and 67% of the surface mean, respectively. The magnitude and dominant frequency of pressure fluctuations are found to vary dramatically within the inner layer (z/delta 0.< or approx. 0.08 or z+ < or approx. 50). The peak of the pre-multiplied frequency spectrum of the pressure fluctuation is f(delta)/U(sub infinity) approx. 2.1 at the surface and shifts to a lower frequency of f(delta)/U(sub infinity) approx. 0.7 in the free stream where the pressure signal is predominantly acoustic. The dominant frequency of the pressure spectrum shows a significant dependence on the freestream Mach number both at the wall and in the free stream.

  7. Protected Time for Research During Orthopaedic Residency Correlates with an Increased Number of Resident Publications.

    Science.gov (United States)

    Williams, Benjamin R; Agel, Julie A; Van Heest, Ann E

    2017-07-05

    The Accreditation Council for Graduate Medical Education (ACGME) requires orthopaedic residency programs to promote scholarship and research, which manifest differently among programs. We assess the impact of protected research time during orthopaedic residency on the number of resident publications. Rotation schedules and resident names were collected from 125 ACGME-accredited U.S. orthopaedic residency programs. Protected research time was classified as 1 of 3 types: (1) block time, (2) longitudinal time, or (3) no dedicated time. In April 2016, we searched residents in postgraduate year (PGY)-3 to PGY-5 on pubmed.gov to generate all orthopaedic publications with a PubMed identifier published during residency. Each publication's 2015 Thomson Reuters Journal Citation Reports 5-Year Journal Impact Factor and resident first authorship were noted. The number of PubMed identifiers for each program was summed and was divided by the number of residents in PGY-3 to PGY-5, giving a mean number of publications per resident. The relationship between output and program research time was compared using t tests and analysis of variance (ANOVA). A total of 1,690 residents were included, with an overall mean number (and standard deviation) of 1.2 ± 2.4 publications per resident. Eighty-seven programs reported block time, 14 programs reported longitudinal time, and 24 programs reported no time. There was a significant difference (p = 0.02) in the mean number of publications per resident when compared between programs with protected time (1.1 ± 1.2 publications) and programs with no protected time (0.6 ± 0.5 publication). One-way ANOVA demonstrated a significant mean difference across the 3 groups (p publications than block time at 1.0 ± 1.0 publication or no time at 0.6 ± 0.5 publication, a difference that persisted when adjusted to include only impact factors of >0 and exclude case reports (p = 0.0015). Both the presence of and the type of dedicated research time correlate

  8. Mach's principle and space-time structure

    International Nuclear Information System (INIS)

    Raine, D.J.

    1981-01-01

    Mach's principle, that inertial forces should be generated by the motion of a body relative to the bulk of matter in the universe, is shown to be related to the structure imposed on space-time by dynamical theories. General relativity theory and Mach's principle are both shown to be well supported by observations. Since Mach's principle is not contained in general relativity this leads to a discussion of attempts to derive Machian theories. The most promising of these appears to be a selection rule for solutions of the general relativistic field equations, in which the space-time metric structure is generated by the matter content of the universe only in a well-defined way. (author)

  9. Electronic pairing mechanism due to band modification with increasing pair number

    International Nuclear Information System (INIS)

    Mizia, J.

    1995-01-01

    It is shown that a shift of an electron band with electron occupation number n, which is changing during the transition to the superconducting state, can lower the total energy of the system. In fact it will bring a negative contribution to the pairing potential, which is proportional to the product of the electron band shift with occupation number and the charge transfer during the transition to the superconducting state. The shift of the electron band comes from the change of stresses and the change of correlation effects in the CuO 2 plane with n, that in turn is caused by the changing oxygen concentration. This model explains the phenomenological success of Hirsch's model, which gives no explanation how the band shift in energy can give rise to superconductivity. (orig.)

  10. Optimization of OT-MACH Filter Generation for Target Recognition

    Science.gov (United States)

    Johnson, Oliver C.; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    An automatic Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter generator for use in a gray-scale optical correlator (GOC) has been developed for improved target detection at JPL. While the OT-MACH filter has been shown to be an optimal filter for target detection, actually solving for the optimum is too computationally intensive for multiple targets. Instead, an adaptive step gradient descent method was tested to iteratively optimize the three OT-MACH parameters, alpha, beta, and gamma. The feedback for the gradient descent method was a composite of the performance measures, correlation peak height and peak to side lobe ratio. The automated method generated and tested multiple filters in order to approach the optimal filter quicker and more reliably than the current manual method. Initial usage and testing has shown preliminary success at finding an approximation of the optimal filter, in terms of alpha, beta, gamma values. This corresponded to a substantial improvement in detection performance where the true positive rate increased for the same average false positives per image.

  11. Increased progesterone receptor expression in uterine leiomyoma: correlation with age, number of leiomyomas, and clinical symptoms.

    Science.gov (United States)

    Tsigkou, Anastasia; Reis, Fernando M; Lee, Meng H; Jiang, Bingjie; Tosti, Claudia; Centini, Gabriele; Shen, Fang-Rong; Chen, You-Guo; Petraglia, Felice

    2015-07-01

    To investigate the possible correlation between progesterone receptor (PR) expression in uterine leiomyoma or adjacent myometrium and patient's age, size/number of leiomyomas, or clinical symptoms such as dysmenorrhea, acyclic pelvic pain, or menstrual and intermenstrual uterine bleeding. Cross-sectional study. Referral center. Sixty-two Chinese women undergoing elective hysterectomy for uterine leiomyomata. None. Evaluation of PR-total and PR-B mRNA with real-time polymerase chain reaction; PR-A and PR-B proteins quantified by Western blot in leiomyoma tissue and myometrium; symptoms rated by the patients using visual analog scores. The PR-B mRNA and PR-A and PR-B proteins were more concentrated in leiomyomas than in matched myometrium. A direct correlation between PR-B mRNA levels in leiomyoma and age (r = 0.347) and number of tumors (r = 0.295) was found. Conversely, there was an inverse correlation between PR-B mRNA levels in leiomyoma and dysmenorrhea (r = -0.260) and intermenstrual bleeding (r = -0.266). Multiple regression analysis indicated that age (β = 0.363) and the number of myomas (β = 0.296) were independently associated with PR-B mRNA levels in leiomyoma tissue. The levels of PR-B mRNA in leiomyoma tissue are directly associated with the number of tumors and inversely correlated with the intensity of intermenstrual bleeding and dysmenorrhea, suggesting that PR signaling may favor leiomyoma growth while attenuating clinical symptoms. This duality should be taken into account in the clinical management of patients with symptomatic uterine leiomyoma. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Increasing fetal ovine number per gestation alters fetal plasma clinical chemistry values.

    Science.gov (United States)

    Zywicki, Micaela; Blohowiak, Sharon E; Magness, Ronald R; Segar, Jeffrey L; Kling, Pamela J

    2016-08-01

    Intrauterine growth restriction (IUGR) is interconnected with developmental programming of lifelong pathophysiology. IUGR is seen in human multifetal pregnancies, with stepwise rises in fetal numbers interfering with placental nutrient delivery. It remains unknown whether fetal blood analyses would reflect fetal nutrition, liver, and excretory function in the last trimester of human or ovine IUGR In an ovine model, we hypothesized that fetal plasma biochemical values would reflect progressive placental, fetal liver, and fetal kidney dysfunction as the number of fetuses per gestation rose. To determine fetal plasma biochemical values in singleton, twin, triplet, and quadruplet/quintuplet ovine gestation, we investigated morphometric measures and comprehensive metabolic panels with nutritional measures, liver enzymes, and placental and fetal kidney excretory measures at gestational day (GD) 130 (90% gestation). As anticipated, placental dysfunction was supported by a stepwise fall in fetal weight, fetal plasma glucose, and triglyceride levels as fetal number per ewe rose. Fetal glucose and triglycerides were directly related to fetal weight. Plasma creatinine, reflecting fetal renal excretory function, and plasma cholesterol, reflecting placental excretory function, were inversely correlated with fetal weight. Progressive biochemical disturbances and growth restriction accompanied the rise in fetal number. Understanding the compensatory and adaptive responses of growth-restricted fetuses at the biochemical level may help explain how metabolic pathways in growth restriction can be predetermined at birth. This physiological understanding is important for clinical care and generating interventional strategies to prevent altered developmental programming in multifetal gestation. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  13. Glucocorticoid receptor number predicts increase in amygdala activity after severe stress

    NARCIS (Netherlands)

    Geuze, Elbert; van Wingen, Guido A.; van Zuiden, Mirjam; Rademaker, Arthur R.; Vermetten, Eric; Kavelaars, Annemieke; Fernández, Guillén; Heijnen, Cobi J.

    2012-01-01

    Introduction: Individuals who are exposed to a traumatic event are at increased risk of developing psychiatric disorders such as posttraumatic stress disorder (PTSD). Studies have shown that increased amygdala activity is frequently found in patients with PTSD. In addition, pre-trauma glucocorticoid

  14. The slaughter of increased numbers of pregnant cows in Tanga abattoir, Tanzania: A cause for concern?

    Directory of Open Access Journals (Sweden)

    Emmanuel S. Swai

    2015-08-01

    Full Text Available Information on the level of foetal wastage in slaughtered cattle in Tanzania is limited. A three-month observational study (April – June 2014 of animals slaughtered at the Tanga abattoir in Tanga region, Tanzania was carried out to determine the number of pregnant cows slaughtered. The total number of cattle slaughtered during the study period was 3643, representing a monthly kill average of 1214 and a daily kill average of 40. Over 98% of the cattle presented to the abattoir for slaughter were local breed (Tanzania shorthorn zebu and most were above 3 years of age. Improved breeds of cattle represented only 1.3% of all slaughters. Of the cattle slaughtered, 2256 (61.9% were female and 1387 (38.1% were male. A total of 655 slaughtered cows were pregnant, representing a foetal wastage of 29.1%. Of the 655 recovered foetuses, 333 (50.8% were male and 322 (49.2% were female. Of the recovered foetuses, 25.8% were recovered in the first, 42.7% in the second and 31.6% in the third trimester. This study indicates cases of significant foetal losses, negatively impacting future replacement stock as a result of the slaughter of pregnant animals. The indiscriminate slaughter of pregnant cows suggests that existing animal welfare legislation is not sufficiently enforced and routine veterinary ante-mortem inspection of trade animals is failing to prevent the high level of foetal wastage.

  15. Reduced probability of smoking cessation in men with increasing number of job losses and partnership breakdowns

    DEFF Research Database (Denmark)

    Kriegbaum, Margit; Larsen, Anne Mette; Christensen, Ulla

    2011-01-01

    and to study joint exposure to both. Methods Birth cohort study of smoking cessation of 6232 Danish men born in 1953 with a follow-up at age 51 (response rate 66.2%). History of unemployment and cohabitation was measured annually using register data. Information on smoking cessation was obtained...... by a questionnaire. Results The probability of smoking cessation decreased with the number of job losses (ranging from 1 OR 0.54 (95% CI 0.46 to 0.64) to 3+ OR 0.41 (95% CI 0.30 to 0.55)) and of broken partnerships (ranging from 1 OR 0.74 (95% CI 0.63 to 0.85) to 3+ OR 0.50 (95% CI 0.39 to 0.63)). Furthermore......–23 years (OR 0.44, 95% CI 0.37 to 0.52)). Those who never cohabited and experienced one or more job losses had a particular low chance of smoking cessation (OR 0.19, 95% CI 0.12 to 0.30). Conclusion The numbers of job losses and of broken partnerships were both inversely associated with probability...

  16. Confidence in Nuclear Weapons as Numbers Decrease and Time Since Testing Increases

    Science.gov (United States)

    Adams, Marvin

    2011-04-01

    As numbers and types of nuclear weapons are reduced, the U.S. objective is to maintain a safe, secure and effective nuclear deterrent without nuclear-explosive testing. A host of issues combine to make this a challenge. An evolving threat environment may prompt changes to security systems. Aging of weapons has led to ``life extension programs'' that produce weapons that differ in some ways from the originals. Outdated and changing facilities pose difficulties for life-extension, surveillance, and dismantlement efforts. A variety of factors can make it a challenge to recruit, develop, and retain outstanding people with the skills and experience that are needed to form the foundation of a credible deterrent. These and other issues will be discussed in the framework of proposals to reduce and perhaps eliminate nuclear weapons.

  17. Increased number of anaerobic bacteria in the infected root canal in type 2 diabetic rats.

    Science.gov (United States)

    Iwama, Akihiro; Morimoto, Taisuke; Tsuji, Masahito; Nakamura, Koki; Higuchi, Naoya; Imaizumi, Ichiro; Shibata, Naoki; Yamasaki, Masahiro; Nakamura, Hiroshi

    2006-05-01

    The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.

  18. [High-level expression of heterologous protein based on increased copy number in Saccharomyces cerevisiae].

    Science.gov (United States)

    Zhang, Xinjie; He, Peng; Tao, Yong; Yang, Yi

    2013-11-04

    High-level expression system of heterologous protein mediated by internal ribosome entry site (IRES) in Saccharomyces cerevisiae was constructed, which could be used for other applications of S. cerevisiae in metabolic engineering. We constructed co-expression cassette (promoter-mCherry-TIF4631 IRES-URA3) containing promoters Pilv5, Padh2 and Ptdh3 and recombined the co-expression cassette into the genome of W303-1B-A. The URA3+ transformants were selected. By comparing the difference in the mean florescence value of mCherry in transformants, the effect of three promoters was detected in the co-expression cassette. The copy numbers of the interested genes in the genome were determined by Real-Time PCR. We analyzed genetic stability by continuous subculturing transformants in the absence of selection pressure. To verify the application of co-expression cassette, the ORF of mCherry was replaced by beta-galactosidase (LACZ) and xylose reductase (XYL1). The enzyme activities and production of beta-galactosidase and xylose reductase were detected. mCherry has been expressed in the highest-level in transformants with co-expression cassette containing Pilv5 promoter. The highest copy number of DNA fragment integrating in the genome was 47 in transformants containing Pilv5. The engineering strains showed good genetic stability. Xylose reductase was successfully expressed in the co-expression cassette containing Pilv5 promoter and TIF4631 IRES. The highest enzyme activity was 0. 209 U/mg crude protein in the transformants WIX-10. Beta-galactosidase was also expressed successfully. The transformants that had the highest enzyme activity was WIL-1 and the enzyme activity was 12.58 U/mg crude protein. The system mediated by Pilv5 promoter and TIF4631 IRES could express heterologous protein efficiently in S. cerevisiae. This study offered a new strategy for expression of heterologous protein in S. cerevisiae and provided sufficient experimental evidence for metabolic engineering

  19. Mach's principle in spatially homogeneous spacetimes

    International Nuclear Information System (INIS)

    Tipler, F.J.

    1978-01-01

    On the basis of Mach's Principle it is concluded that the only singularity-free solution to the empty space Einstein equations is flat space. It is shown that the only singularity-free solution to the empty space Einstein equations which is spatially homogeneous and globally hyperbolic is in fact suitably identified Minkowski space. (Auth.)

  20. Extracurricular Activities Targeted towards Increasing the Number of Engineers Working in the Field of Precision Agriculture

    DEFF Research Database (Denmark)

    Larsen, Leon Bonde; Stark Olsen, Kent; Ahrenkiel, Linda

    SERVICE ROBOTS in precision agriculture have the potential to ensure a more competitive and sustainable production, but the lack of skilled engineers within this area is limiting the industry’s ability to develop new and innovative agricultural technology products. Part of the reason...... is that engineers and scientists have little knowledge about agricultural technology, and they therefore choose to work in other domains. It is hypothesised that introducing engineering students to precision agriculture through practical work with small-scale service robots will increase their interest...... in agriculture and agricultural technology. This article presents the results of an interdisciplinary extracurricular activity for first year engineering students carried out in the Fall 2012 at the University of Southern Denmark. The case was based on practical group-work centered around an agricultural mobile...

  1. Increased numbers of orexin/hypocretin neurons in a genetic rat depression model

    DEFF Research Database (Denmark)

    Mikrouli, Elli; Wörtwein, Gitta; Soylu, Rana

    2011-01-01

    The Flinders Sensitive Line (FSL) rat is a genetic animal model of depression that displays characteristics similar to those of depressed patients including lower body weight, decreased appetite and reduced REM sleep latency. Hypothalamic neuropeptides such as orexin/hypocretin, melanin......-concentrating hormone (MCH) and cocaine and amphetamine regulated transcript (CART), that are involved in the regulation of both energy metabolism and sleep, have recently been implicated also in depression. We therefore hypothesized that alterations in these neuropeptide systems may play a role in the development...... of the FSL phenotype with both depressive like behavior, metabolic abnormalities and sleep disturbances. In this study, we first confirmed that the FSL rats displayed increased immobility in the Porsolt forced swim test compared to their control strain, the Flinders Resistant Line (FRL), which is indicative...

  2. Does use of a PACS increase the number of images per study? A case study in ultrasound.

    Science.gov (United States)

    Horii, Steven; Nisenbaum, Harvey; Farn, James; Coleman, Beverly; Rowling, Susan; Langer, Jill; Jacobs, Jill; Arger, Peter; Pinheiro, Lisa; Klein, Wendy; Reber, Michele; Iyoob, Christopher

    2002-03-01

    The purpose of this study was to determine if the use of a picture archiving and communications system (PACS) in ultrasonography increased the number of images acquired per examination. The hypothesis that such an increase does occur was based on anecdotal information; this study sought to test the hypothesis. A random sample of all ultrasound examination types was drawn from the period 1998 through 1999. The ultrasound PACS in use (ACCESS; Kodak Health Information Systems, Dallas, TX) records the number of grayscale and color images saved as part of each study. Each examination in the sample was checked in the ultrasound PACS database,.and the number of grayscale and color images was recorded. The comparison film-based sample was drawn from the period 1994 through 1995. The number of examinations of each type selected was based on the overall statistics of the section; that is, the sample was designed to represent the approximate frequency with which the various examination types are done. For film-based image counts, the jackets were retrieved, and the number of grayscale and color images were counted. The number of images obtained per examination (for most examinations) in ultrasound increased with PACS use. This was more evident with some examination types (eg, pelvis). This result, however, has to be examined for possible systematic biases because ultrasound practice has changed over the time since the authors stopped using film routinely. The use of PACS in ultrasonography was not associated with an increase in the number of images per examination based solely on the use of PACS, with the exception of neonatal head studies. Increases in the number of images per study was otherwise associated with examinations for which changes in protocols resulted in the increased image counts.

  3. Marshak Lectureship: Women in Physics: Increasing in Number, and What Else?

    Science.gov (United States)

    Meza-Montes, Lilia

    2013-03-01

    Latin America is a region with high contrasts. With abundant natural resources and home of several celebrities among the wealthiest in the world, the zone has elevated indexes of poverty. In spite of this, and mostly thanks to the continuing intense efforts of the scientific community, it has been possible to create many excellence research centers. In contrast, illiteracy and lack of access to information and communication technologies are widely spread across our countries. Attitudes toward women have even coined a term, machismo. The situation of female physicists in this scenario is analyzed. We present a statistical overview of the participation of women as students or researchers in physics and related areas, for countries where data are available. Initiatives and ongoing programs to support and promote participation of women in science are discussed. Beyond statistics, some comments are given, as expressed by colleagues about work environment and gender issues in general, which have been collected through several years of exchanging concerns on the topic. Mexico and Brazil are discussed in more detail. Finally, we propose some joint actions to increase and improve the participation of women in our scientific field, which will give rise to better conditions for us but will also contribute to building a more equitable and developed region. Member of IUPAP Working Group on Women in Physics.

  4. Rare Copy Number Variants in NRXN1 and CNTN6 Increase Risk for Tourette Syndrome.

    Science.gov (United States)

    Huang, Alden Y; Yu, Dongmei; Davis, Lea K; Sul, Jae Hoon; Tsetsos, Fotis; Ramensky, Vasily; Zelaya, Ivette; Ramos, Eliana Marisa; Osiecki, Lisa; Chen, Jason A; McGrath, Lauren M; Illmann, Cornelia; Sandor, Paul; Barr, Cathy L; Grados, Marco; Singer, Harvey S; Nöthen, Markus M; Hebebrand, Johannes; King, Robert A; Dion, Yves; Rouleau, Guy; Budman, Cathy L; Depienne, Christel; Worbe, Yulia; Hartmann, Andreas; Müller-Vahl, Kirsten R; Stuhrmann, Manfred; Aschauer, Harald; Stamenkovic, Mara; Schloegelhofer, Monika; Konstantinidis, Anastasios; Lyon, Gholson J; McMahon, William M; Barta, Csaba; Tarnok, Zsanett; Nagy, Peter; Batterson, James R; Rizzo, Renata; Cath, Danielle C; Wolanczyk, Tomasz; Berlin, Cheston; Malaty, Irene A; Okun, Michael S; Woods, Douglas W; Rees, Elliott; Pato, Carlos N; Pato, Michele T; Knowles, James A; Posthuma, Danielle; Pauls, David L; Cox, Nancy J; Neale, Benjamin M; Freimer, Nelson B; Paschou, Peristera; Mathews, Carol A; Scharf, Jeremiah M; Coppola, Giovanni

    2017-06-21

    Tourette syndrome (TS) is a model neuropsychiatric disorder thought to arise from abnormal development and/or maintenance of cortico-striato-thalamo-cortical circuits. TS is highly heritable, but its underlying genetic causes are still elusive, and no genome-wide significant loci have been discovered to date. We analyzed a European ancestry sample of 2,434 TS cases and 4,093 ancestry-matched controls for rare ( 1 Mb), singleton events (OR = 2.28, 95% CI [1.39-3.79], p = 1.2 × 10 -3 ) and known, pathogenic CNVs (OR = 3.03 [1.85-5.07], p = 1.5 × 10 -5 ). We also identified two individual, genome-wide significant loci, each conferring a substantial increase in TS risk (NRXN1 deletions, OR = 20.3, 95% CI [2.6-156.2]; CNTN6 duplications, OR = 10.1, 95% CI [2.3-45.4]). Approximately 1% of TS cases carry one of these CNVs, indicating that rare structural variation contributes significantly to the genetic architecture of TS. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Increasing the number of steps walked each day improves physical fitness in Japanese community-dwelling adults.

    Science.gov (United States)

    Okamoto, N; Nakatani, T; Okamoto, Y; Iwamoto, J; Saeki, K; Kurumatani, N

    2010-04-01

    We aimed to investigate the effects of increasing the number of steps each day on physical fitness, and the change in physical fitness according to the angiotensin-converting enzyme (ACE) genotype. A total of 174 participants were randomly assigned to two groups. Subjects in group A were instructed for 24-week trial to increase the number of steps walked each day, while subjects in group B were instructed to engage in brisk walking, at a target heart rate, for 20 min or more a day on two or more days a week. The values of the 3-min shuttle stamina walk test (SSWT) and the 30-s chair-stand test (CS-30) significantly increased, but no differences in increase were found between the groups. A significant relationship was found between the percentage increase in SSWT values and the increase in the number of steps walked by 1 500 steps or more per day over their baseline values. Our results suggest that increasing the number of steps walked daily improves physical fitness. No significant relationships were observed between the change in physical fitness and ACE genotypes. Copyright Georg Thieme Verlag KG Stuttgart . New York.

  6. All-optical negabinary adders using Mach-Zehnder interferometer

    Science.gov (United States)

    Cherri, A. K.

    2011-02-01

    In contrast to optoelectronics, all-optical adders are proposed where all-optical signals are used to represent the input numbers and the control signals. In addition, the all-optical adders use the negabinary modified signed-digit number representation (an extension of the negabinary number system) to represent the input digits. Further, the ultra-speed of the designed circuits is achieved due to the use of ultra-fast all-optical switching property of the semiconductor optical amplifier and Mach-Zehnder interferometer (SOA-MZI). Furthermore, two-bit per digit binary encoding scheme is employed to represent the trinary values of the negabinary modified signed-digits.

  7. DUF1220 copy number is linearly associated with increased cognitive function as measured by total IQ and mathematical aptitude scores

    Science.gov (United States)

    Davis, Jonathon M.; Searles, Veronica B.; Anderson, Nathan; Keeney, Jonathon; Raznahan, Armin; Horwood, L. John; Fergusson, David M.; Kennedy, Martin A.; Giedd, Jay

    2014-01-01

    DUF1220 protein domains exhibit the greatest human lineage-specific copy number expansion of any protein-coding sequence in the genome, and variation in DUF1220 copy number has been linked to both brain size in humans and brain evolution among primates. Given these findings, we examined associations between DUF1220 subtypes CON1 and CON2 and cognitive aptitude. We identified a linear association between CON2 copy number and cognitive function in two independent populations of European descent. In North American males, an increase in CON2 copy number corresponded with an increase in WISC IQ (R2 = 0.13, p = 0.02), which may be driven by males aged 6–11 (R2 = 0.42, p = 0.003). We utilized ddPCR in a subset as a confirmatory measurement. This group had 26–33 copies of CON2 with a mean of 29, and each copy increase of CON2 was associated with a 3.3-point increase in WISC IQ (R2 = 0.22, p = 0.045). In individuals from New Zealand, an increase in CON2 copy number was associated with an increase in math aptitude ability (R2 = 0.10 p = 0.018). These were not confounded by brain size. To our knowledge, this is the first study to report a replicated association between copy number of a gene coding sequence and cognitive aptitude. Remarkably, dosage variations involving DUF1220 sequences have now been linked to human brain expansion, autism severity and cognitive aptitude, suggesting that such processes may be genetically and mechanistically inter-related. The findings presented here warrant expanded investigations in larger, well-characterized cohorts. PMID:25287832

  8. Ozone synthesis improves by increasing number density of plasma channels and lower voltage in a nonthermal plasma

    Science.gov (United States)

    Arif Malik, Muhammad; Hughes, David

    2016-04-01

    Improvements in ozone synthesis from air and oxygen by increasing the number density of plasma channels and lower voltage for the same specific input energy (SIE) were explored in a nonthermal plasma based on a sliding discharge. The number of plasma channels and energy per pulse increased in direct proportion to the increase in the effective length of the anode (the high voltage electrode). Decreasing the discharge gap increased the energy per pulse for the same length and allowed the installation of more electrode pairs in the same space. It allowed the increase of the number of plasma channels in the same space to achieve the same SIE at a lower peak voltage with less energy per plasma channel. The ozone concentration gradually increased to ~1500 ppmv (140 to 50 g kWh-1) from air and to ~6000 ppmv (400 to 200 g kWh-1) from oxygen with a gradual increase in the SIE to ~200 J L-1, irrespective of the variations in electrode geometry, applied voltage or flow rate of the feed gas. A gradual increase in SIE beyond 200 J L-1 gradually increased the ozone concentration to a certain maximum value followed by a decline, but the rate of increase and the maximum value was higher for the greater number of plasma channels and lower peak voltage combination. The maximum ozone concentration was ~5000 ppmv (~30 g kWh-1) from air and ~22 000 ppmv (~80 g kWh-1) from oxygen. The results are explained on the basis of characteristics of the plasma and ozone synthesis mechanism.

  9. The QTL GNP1 Encodes GA20ox1, Which Increases Grain Number and Yield by Increasing Cytokinin Activity in Rice Panicle Meristems.

    Science.gov (United States)

    Wu, Yuan; Wang, Yun; Mi, Xue-Fei; Shan, Jun-Xiang; Li, Xin-Min; Xu, Jian-Long; Lin, Hong-Xuan

    2016-10-01

    Cytokinins and gibberellins (GAs) play antagonistic roles in regulating reproductive meristem activity. Cytokinins have positive effects on meristem activity and maintenance. During inflorescence meristem development, cytokinin biosynthesis is activated via a KNOX-mediated pathway. Increased cytokinin activity leads to higher grain number, whereas GAs negatively affect meristem activity. The GA biosynthesis genes GA20oxs are negatively regulated by KNOX proteins. KNOX proteins function as modulators, balancing cytokinin and GA activity in the meristem. However, little is known about the crosstalk among cytokinin and GA regulators together with KNOX proteins and how KNOX-mediated dynamic balancing of hormonal activity functions. Through map-based cloning of QTLs, we cloned a GA biosynthesis gene, Grain Number per Panicle1 (GNP1), which encodes rice GA20ox1. The grain number and yield of NIL-GNP1TQ were significantly higher than those of isogenic control (Lemont). Sequence variations in its promoter region increased the levels of GNP1 transcripts, which were enriched in the apical regions of inflorescence meristems in NIL-GNP1TQ. We propose that cytokinin activity increased due to a KNOX-mediated transcriptional feedback loop resulting from the higher GNP1 transcript levels, in turn leading to increased expression of the GA catabolism genes GA2oxs and reduced GA1 and GA3 accumulation. This rebalancing process increased cytokinin activity, thereby increasing grain number and grain yield in rice. These findings uncover important, novel roles of GAs in rice florescence meristem development and provide new insights into the crosstalk between cytokinin and GA underlying development process.

  10. High Glucose-Induced Oxidative Stress Increases the Copy Number of Mitochondrial DNA in Human Mesangial Cells

    Directory of Open Access Journals (Sweden)

    Ghada Al-Kafaji

    2013-01-01

    Full Text Available Oxidative damage to mitochondrial DNA (mtDNA has been linked to the pathogenicity of diabetic nephropathy. We tested the hypothesis that mtDNA copy number may be increased in human mesangial cells in response to high glucose-induced reactive oxygen species (ROS to compensate for damaged mtDNA. The effect of manganese superoxide dismutase mimetic (MnTBAP on glucose-induced mtDNA copy number was also examined. The copy number of mtDNA was determined by real-time PCR in human mesangial cells cultured in 5 mM glucose, 25 mM glucose, and mannitol (osmotic control, as well as in cells cultured in 25 mM glucose in the presence and absence of 200 μM MnTBAP. Intracellular ROS was assessed by confocal microscopy and flow cytometry in human mesangial cells. The copy number of mtDNA was significantly increased when human mesangial cells were incubated with 25 mM glucose compared to 5 mM glucose and mannitol. In addition, 25 mM glucose rapidly generated ROS in the cells, which was not detected in 5 mM glucose. Furthermore, mtDNA copy number was significantly decreased and maintained to normal following treatment of cells with 25 mM glucose and MnTBAP compared to 25 mM glucose alone. Inclusion of MnTBAP during 25 mM glucose incubation inhibited mitochondrial superoxide in human mesangial cells. Increased mtDNA copy number in human mesangial cells by high glucose could contribute to increased mitochondrial superoxide, and prevention of mtDNA copy number could have potential in retarding the development of diabetic nephropathy.

  11. An implicit turbulence model for low-Mach Roe scheme using truncated Navier-Stokes equations

    Science.gov (United States)

    Li, Chung-Gang; Tsubokura, Makoto

    2017-09-01

    The original Roe scheme is well-known to be unsuitable in simulations of turbulence because the dissipation that develops is unsatisfactory. Simulations of turbulent channel flow for Reτ = 180 show that, with the 'low-Mach-fix for Roe' (LMRoe) proposed by Rieper [J. Comput. Phys. 230 (2011) 5263-5287], the Roe dissipation term potentially equates the simulation to an implicit large eddy simulation (ILES) at low Mach number. Thus inspired, a new implicit turbulence model for low Mach numbers is proposed that controls the Roe dissipation term appropriately. Referred to as the automatic dissipation adjustment (ADA) model, the method of solution follows procedures developed previously for the truncated Navier-Stokes (TNS) equations and, without tuning of parameters, uses the energy ratio as a criterion to automatically adjust the upwind dissipation. Turbulent channel flow at two different Reynold numbers and the Taylor-Green vortex were performed to validate the ADA model. In simulations of turbulent channel flow for Reτ = 180 at Mach number of 0.05 using the ADA model, the mean velocity and turbulence intensities are in excellent agreement with DNS results. With Reτ = 950 at Mach number of 0.1, the result is also consistent with DNS results, indicating that the ADA model is also reliable at higher Reynolds numbers. In simulations of the Taylor-Green vortex at Re = 3000, the kinetic energy is consistent with the power law of decaying turbulence with -1.2 exponents for both LMRoe with and without the ADA model. However, with the ADA model, the dissipation rate can be significantly improved near the dissipation peak region and the peak duration can be also more accurately captured. With a firm basis in TNS theory, applicability at higher Reynolds number, and ease in implementation as no extra terms are needed, the ADA model offers to become a promising tool for turbulence modeling.

  12. The number of preproghrelin mRNA expressing cells is increased in mice with activity-based anorexia.

    Science.gov (United States)

    François, Marie; Barde, Swapnali; Achamrah, Najate; Breton, Jonathan; do Rego, Jean-Claude; Coëffier, Moïse; Hökfelt, Tomas; Déchelotte, Pierre; Fetissov, Sergueï O

    2015-06-01

    Plasma levels of ghrelin, an orexigenic peptide, are increased during conditions of chronic starvation, such as in patients with anorexia nervosa. However, it is not known whether such increase can be related to the number of preproghrelin mRNA-expressing cells in the stomach, and if chronic starvation may activate a tentative central ghrelin production. In this work, in situ hybridization technique was used to analyze the presence and number of preproghrelin mRNA-expressing cells in the stomach and the hypothalamus of mice with activity-based anorexia (ABA) induced by the combination of running wheel activity with progressive, during 10 days, feeding-time restriction (FTR) and compared with sedentary FTR, ABA pair-fed (PF) and ad libitum-fed control mice. All food-restricted mice lost more than 20% of body weight. Body weight loss was similar in ABA and PF mice, but it was more pronounced than in FTR mice. Food intake was also lower in ABA than in FTR mice. Preproghrelin mRNA-expressing cells in the stomach were increased proportionally to the body weight loss in all food-restricted groups with the highest number in ABA mice. No preproghrelin mRNA-producing cells were detectable in the hypothalamus of either control or food-restricted mice. Thus, the increased number of gastric preproghrelin mRNA-producing cells during chronic starvation proportionally to the body weight loss and reduced food intake may underlie increased plasma ghrelin. Hyperactivity-induced anorexia appears to further increase the number of preproghrelin mRNA-producing cells in the stomach. No evidence was found for ghrelin expression in the hypothalamus, not even in any of the present experimental models. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The increasing number of surgical procedures for female genital fistula in England: analysis of Hospital Episode Statistics (HES) data.

    Science.gov (United States)

    Ismail, S I M F

    2015-01-01

    The aim of this study was to describe the number and trend of surgical procedures for female genital fistula in England. An online search of Hospital Episode Statistics (HES) data was carried out. Data were available for the 4-year period from 2002-03 until 2005-06. The total number of surgical procedures carried out for female genital fistula steadily increased by 28.7% from 616 in 2002-03 to 793 in 2005-06. The number of surgical procedures performed for rectovaginal fistula exceeded the total number of surgical procedures carried out for vesicovaginal and urethrovaginal fistula in each year of the study period. This pattern needs to be monitored and investigated further.

  14. Implications for Equity and Diversity of Increasing International Student Numbers in European Universities: Policies and Practice in Four National Contexts

    Science.gov (United States)

    Haapakoski, Jani; Pashby, Karen

    2017-01-01

    This paper examines the main rationales for and possible implications of the policy of increasing international student numbers in higher education (HE). Drawing on critical discourse analysis, we map key themes emerging from two sets of data--university strategy documents and interviews with staff--collected at eight universities in four national…

  15. Human vision model in relation to characteristics of shapes for the Mach band effect.

    Science.gov (United States)

    Wu, Bo-Wen; Fang, Yi-Chin

    2015-10-01

    For human vision to recognize the contours of objects means that, as the contrast variation at the object's edges increases, so will the Mach band effect of human vision. This paper more deeply investigates the relationship between changes in the contours of an object and the Mach band effect of human vision. Based on lateral inhibition and the Mach band effect, we studied subjects' eyes as they watched images of different shapes under a fixed brightness at 34  cd/m2, with changes of contrast and spatial frequency. Three types of display were used: a television, a computer monitor, and a projector. For each display used, we conducted a separate experiment for each shape. Although the maximum values for the contrast sensitivity function curves of the displays were different, their variations were minimal. As the spatial frequency changed, the diminishing effect of the different lines also was minimal. However, as the shapes at the contour intersections were modified by the Mach band effect, a greater degree of variation occurred. In addition, as the spatial frequency at a contour intersection increased, the Mach band effect became lower, along with changes in the corresponding contrast sensitivity function curve. Our experimental results on the characteristics of human vision have led to what we believe is a new vision model based on tests with different shapes. This new model may be used for future development and implementation of an artificial vision system.

  16. Chemotherapy alters the increased numbers of myeloid-derived suppressor and regulatory T cells in children with acute lymphoblastic leukemia.

    Science.gov (United States)

    Salem, Mohamed Labib; El-Shanshory, Mohamed R; Abdou, Said H; Attia, Mohamed S; Sobhy, Shymaa M; Zidan, Mona F; Zidan, Abdel-Aziz A

    2018-04-01

    Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children. The precise mechanism behind the relapse in this disease is not clearly known. One possible mechanism could be the accumulation of immunosuppressive cells, including myeloid-derived suppressor cells (MDSCs) and T regulatory cells (T regs ) which we and others have reported to mediate suppression of anti-tumor immune responses. In this study, we aimed to analyze the numbers of these cells in a population of B-ALL pediatric patients. Peripheral blood samples withdrawn from B-ALL pediatric patients (n = 45 before, during and after the induction phase of chemotherapy. Using multi parametric flow cytometric analysis. MDSCs were identified as Lin - HLA-DR - CD33 + CD11b + ; and T reg cells were defined as CD4 + CD25 + CD127 -/low . Early diagnosed B-ALL patients showed significant increases in the numbers of MDSCs and T regs as compared to healthy volunteers. During induction of chemotherapy, however, the patients showed higher and lower numbers of MDSCs and T reg cells, respectively as compared to early diagnosed patients (i.e., before chemotherapy). After induction of chemotherapy, the numbers of MDSCs and T reg cells showed higher increases and decreases, respectively as compared to the numbers in patients during chemotherapy. Our results indicate that B-ALL patients harbor high numbers of both MDSCs and T regs cells. This pilot study opens a new avenue to investigate the mechanism mediating the emergence of these cells on larger number of B-ALL patients at different treatment stages.

  17. An automatic braking system that stabilizes leukocyte rolling by an increase in selectin bond number with shear.

    Science.gov (United States)

    Chen, S; Springer, T A

    1999-01-11

    Wall shear stress in postcapillary venules varies widely within and between tissues and in response to inflammation and exercise. However, the speed at which leukocytes roll in vivo has been shown to be almost constant within a wide range of wall shear stress, i.e., force on the cell. Similarly, rolling velocities on purified selectins and their ligands in vitro tend to plateau. This may be important to enable rolling leukocytes to be exposed uniformly to activating stimuli on endothelium, independent of local hemodynamic conditions. Wall shear stress increases the rate of dissociation of individual selectin-ligand tether bonds exponentially (, ) thereby destabilizing rolling. We find that this is compensated by a shear-dependent increase in the number of bonds per rolling step. We also find an increase in the number of microvillous tethers to the substrate. This explains (a) the lack of firm adhesion through selectins at low shear stress or high ligand density, and (b) the stability of rolling on selectins to wide variation in wall shear stress and ligand density, in contrast to rolling on antibodies (). Furthermore, our data successfully predict the threshold wall shear stress below which rolling does not occur. This is a special case of the more general regulation by shear of the number of bonds, in which the number of bonds falls below one.

  18. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species.

    Science.gov (United States)

    Moorhouse, Tom P; Poole, Alison E; Evans, Laura C; Bradley, David C; Macdonald, David W

    2014-02-01

    Invasive species are a major cause of species extinction in freshwater ecosystems, and crayfish species are particularly pervasive. The invasive American signal crayfish Pacifastacus leniusculus has impacts over a range of trophic levels, but particularly on benthic aquatic macroinvertebrates. Our study examined the effect on the macroinvertebrate community of removal trapping of signal crayfish from UK rivers. Crayfish were intensively trapped and removed from two tributaries of the River Thames to test the hypothesis that lowering signal crayfish densities would result in increases in macroinvertebrate numbers and taxon richness. We removed 6181 crayfish over four sessions, resulting in crayfish densities that decreased toward the center of the removal sections. Conversely in control sections (where crayfish were trapped and returned), crayfish density increased toward the center of the section. Macroinvertebrate numbers and taxon richness were inversely correlated with crayfish densities. Multivariate analysis of the abundance of each taxon yielded similar results and indicated that crayfish removals had positive impacts on macroinvertebrate numbers and taxon richness but did not alter the composition of the wider macroinvertebrate community. Synthesis and applications: Our results demonstrate that non-eradication-oriented crayfish removal programmes may lead to increases in the total number of macroinvertebrates living in the benthos. This represents the first evidence that removing signal crayfish from riparian systems, at intensities feasible during control attempts or commercial crayfishing, may be beneficial for a range of sympatric aquatic macroinvertebrates.

  19. Characteristics of the mach disk in the underexpanded jet in which the back pressure continuously changes with time

    Science.gov (United States)

    Irie, T.; Yasunobu, T.; Kashimura, H.; Setoguchi, T.

    2003-05-01

    When the high-pressure gas is exhausted to the vacuum chamber from the nozzle, the underexpanded supersonic jet contained with the Mach disk is generally formed. The eventual purpose of this study is to clarify the unsteady phenomenon of the underexpanded free jet when the back pressure continuously changes with time. The characteristic of the Mach disk has been clarified in consideration of the diameter and position of it by the numerical analysis in this paper. The sonic jet of the exit Mach number Me=1 is assumed and the axisymmetric conservational equation is solved by the TVD method in the numerical calculation. The diameter and position of the Mach disk differs with the results of a steady jet and the influence on the continuously changing of the back pressure is evidenced from the comparison with the case of steady supersonic jet.

  20. Exhaustive physical exercise increases the number of colonic preneoplastic lesions in untrained rats treated with a chemical carcinogen.

    Science.gov (United States)

    Demarzo, Marcelo Marcos Piva; Garcia, Sérgio Britto

    2004-12-08

    Aberrant crypt foci (ACF) have been used for early detection of factors that influence colorectal carcinogenesis in rats. It has been observed that exhaustive exercise increases free radical DNA oxidative damage and depresses immune function, events also related to the increased risk for cancer development. Fifteen days after a single exhaustive swimming bout in untrained rats treated with a colon carcinogen, we observed a statistically significant increased number of ACF when compared to the non-exercised group. Thus, we concluded that exhaustive exercise increased the susceptibility for colon cancer in rats. From our finding and literature data, we hypothesize that, similarly to the suggested relationship between exercise and infections, exercise could be protective against cancer or it could increase the risk for this disease depending on its type, dose and duration.

  1. Hybrid Brain–Computer Interface Techniques for Improved Classification Accuracy and Increased Number of Commands: A Review

    Science.gov (United States)

    Hong, Keum-Shik; Khan, Muhammad Jawad

    2017-01-01

    In this article, non-invasive hybrid brain–computer interface (hBCI) technologies for improving classification accuracy and increasing the number of commands are reviewed. Hybridization combining more than two modalities is a new trend in brain imaging and prosthesis control. Electroencephalography (EEG), due to its easy use and fast temporal resolution, is most widely utilized in combination with other brain/non-brain signal acquisition modalities, for instance, functional near infrared spectroscopy (fNIRS), electromyography (EMG), electrooculography (EOG), and eye tracker. Three main purposes of hybridization are to increase the number of control commands, improve classification accuracy and reduce the signal detection time. Currently, such combinations of EEG + fNIRS and EEG + EOG are most commonly employed. Four principal components (i.e., hardware, paradigm, classifiers, and features) relevant to accuracy improvement are discussed. In the case of brain signals, motor imagination/movement tasks are combined with cognitive tasks to increase active brain–computer interface (BCI) accuracy. Active and reactive tasks sometimes are combined: motor imagination with steady-state evoked visual potentials (SSVEP) and motor imagination with P300. In the case of reactive tasks, SSVEP is most widely combined with P300 to increase the number of commands. Passive BCIs, however, are rare. After discussing the hardware and strategies involved in the development of hBCI, the second part examines the approaches used to increase the number of control commands and to enhance classification accuracy. The future prospects and the extension of hBCI in real-time applications for daily life scenarios are provided. PMID:28790910

  2. Hybrid Brain-Computer Interface Techniques for Improved Classification Accuracy and Increased Number of Commands: A Review.

    Science.gov (United States)

    Hong, Keum-Shik; Khan, Muhammad Jawad

    2017-01-01

    In this article, non-invasive hybrid brain-computer interface (hBCI) technologies for improving classification accuracy and increasing the number of commands are reviewed. Hybridization combining more than two modalities is a new trend in brain imaging and prosthesis control. Electroencephalography (EEG), due to its easy use and fast temporal resolution, is most widely utilized in combination with other brain/non-brain signal acquisition modalities, for instance, functional near infrared spectroscopy (fNIRS), electromyography (EMG), electrooculography (EOG), and eye tracker. Three main purposes of hybridization are to increase the number of control commands, improve classification accuracy and reduce the signal detection time. Currently, such combinations of EEG + fNIRS and EEG + EOG are most commonly employed. Four principal components (i.e., hardware, paradigm, classifiers, and features) relevant to accuracy improvement are discussed. In the case of brain signals, motor imagination/movement tasks are combined with cognitive tasks to increase active brain-computer interface (BCI) accuracy. Active and reactive tasks sometimes are combined: motor imagination with steady-state evoked visual potentials (SSVEP) and motor imagination with P300. In the case of reactive tasks, SSVEP is most widely combined with P300 to increase the number of commands. Passive BCIs, however, are rare. After discussing the hardware and strategies involved in the development of hBCI, the second part examines the approaches used to increase the number of control commands and to enhance classification accuracy. The future prospects and the extension of hBCI in real-time applications for daily life scenarios are provided.

  3. Hybrid Brain–Computer Interface Techniques for Improved Classification Accuracy and Increased Number of Commands: A Review

    Directory of Open Access Journals (Sweden)

    Keum-Shik Hong

    2017-07-01

    Full Text Available In this article, non-invasive hybrid brain–computer interface (hBCI technologies for improving classification accuracy and increasing the number of commands are reviewed. Hybridization combining more than two modalities is a new trend in brain imaging and prosthesis control. Electroencephalography (EEG, due to its easy use and fast temporal resolution, is most widely utilized in combination with other brain/non-brain signal acquisition modalities, for instance, functional near infrared spectroscopy (fNIRS, electromyography (EMG, electrooculography (EOG, and eye tracker. Three main purposes of hybridization are to increase the number of control commands, improve classification accuracy and reduce the signal detection time. Currently, such combinations of EEG + fNIRS and EEG + EOG are most commonly employed. Four principal components (i.e., hardware, paradigm, classifiers, and features relevant to accuracy improvement are discussed. In the case of brain signals, motor imagination/movement tasks are combined with cognitive tasks to increase active brain–computer interface (BCI accuracy. Active and reactive tasks sometimes are combined: motor imagination with steady-state evoked visual potentials (SSVEP and motor imagination with P300. In the case of reactive tasks, SSVEP is most widely combined with P300 to increase the number of commands. Passive BCIs, however, are rare. After discussing the hardware and strategies involved in the development of hBCI, the second part examines the approaches used to increase the number of control commands and to enhance classification accuracy. The future prospects and the extension of hBCI in real-time applications for daily life scenarios are provided.

  4. Supersonic and transonic Mach probe for calibration control in the Trisonic Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Alexandru Marius PANAIT

    2017-12-01

    Full Text Available A supersonic and high speed transonic Pitot Prandtl is described as it can be implemented in the Trisonic Wind Tunnel for calibration and verification of Mach number precision. A new calculation method for arbitrary precision Mach numbers is proposed and explained. The probe is specially designed for the Trisonic wind tunnel and would greatly simplify obtaining a precise Mach calibration in the critical high transonic and low supersonic regimes, where typically wind tunnels exhibit poor performance. The supersonic Pitot Prandtl combined probe is well known in the aerospace industry, however the proposed probe is a derivative of the standard configuration, combining a stout cone-cylinder probe with a supersonic Pitot static port which allows this configuration to validate the Mach number by three methods: conical flow method – using the pressure ports on a cone generatrix, the Schlieren-optical method of shock wave angle photogrammetry and the Rayleigh supersonic Pitot equation, while having an aerodynamic blockage similar to that of a scaled rocket model commonly used in testing. The proposed probe uses an existing cone-cylinder probe forebody and support, adding only an afterbody with a support for a static port.

  5. The Effect of Increasing Numbers of Horses of Undefined Breed on Horse Breeding in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Iveta Bihuncová

    2015-01-01

    Full Text Available The objective of the present study was to analyse the numbers and division of horses of undefined breed. At the present time this group is the most numerous in the entire population of horses. Horses of undefined breed do not come under any breeder union which would provide reports about these horses; these horses are only registered and breeders are informed only about their numbers. Our study is the first to deal with the problem of increasing numbers of horses of undefined breed. The database contained 22 211 horses not entered registered in any of the stud books. In the database we filed approved horses born between 1972 and 1 September 2012 and horses registered from 1987. The data were processed in the Excel programme and results were evaluated in graphs. The most frequent horse in this group was the warm-blood type (n = 9 303, pony type (n = 6 285, cold-blooded type (n = 2 663 and unlisted horses (n = 2 278. Since 2001 the number of registered horses of undefined breed has increased. The most numerous dams of horses of undefined breed is the Czech warm-blood with 1 912 offspring; dams of the English Thoroughbred with 552 offspring and mares of the utility Huzule horse with 492 offspring. In the group of registered horses of undefined breed the Czech warm-blood appears in the pedigree of 507 colts and the American Paint Horse in the pedigree of sires of 506 colts. Why the numbers of horses of undefined breed are increasing is the boom of leisure horsemanship and unqualified horse breeding.

  6. The increasing of odontoblast-like cell number on direct pulp capping of Rattus norvegicus using chitosan

    OpenAIRE

    Prananingrum, Widyasri

    2010-01-01

    Background: Pulpal perforation care with direct pulp capping in the case of reversible pulpitis due to mechanical trauma was performed with chitosan which has the ability to facilitate migration, proliferation, and progenitor cell differentiation. Purpose: The purpose of this study was to determine the increasing number of odontoblast-like cells in direct pulp capping dental care of Rattus norvegicus using chitosan for seven and fourteen days. Methods: Samples were molars of male Rattus norve...

  7. Increasing the number of inter-arch contacts improves mastication in adults with Down syndrome: a prospective controlled trial.

    Science.gov (United States)

    Hennequin, Martine; Mazille, Marie-Noëlle; Cousson, Pierre-Yves; Nicolas, Emmanuel

    2015-06-01

    Feeding difficulties due to their condition have been widely described for babies, children and adults with Down syndrome (DS). A previous study demonstrated that, compared with wearing a placebo appliance, wearing an occlusal appliance increased inter-arch dental contacts, improved the oral health status of adults with DS and normalised their mandibular rest position. This longitudinal prospective controlled trial aimed to evaluate whether increasing inter-arch contacts in adults with DS would lead to improved masticatory efficiency. Fourteen subjects with DS (mean age±SD: 28.5±9.3years) and twelve controls without DS (24.6±1.0years) were video recorded while chewing samples of carrot and peanuts with and without an oral appliance that was designed to equalise the number of posterior functional units (PFUs) in both groups. Three parameters were collected during mastication for 15cycles and until swallowing: food refusals, food bolus granulometry (D50) and kinematic parameters of the chewing process (number of cycles, chewing duration and cycle frequency within the chewing sequence). In the DS group, increasing the number of PFUs led to a decrease in bolus particle size, to fewer masticatory cycles needed to produce a bolus ready for swallowing and to a decrease in the occurrence of food refusal, while mean chewing frequency did not vary. In the control group, bolus granulometry and chewing time increased with appliance wear while mean chewing frequency decreased. These changes clearly indicate a functional improvement in subjects with DS. This study also demonstrated a causal relationship between the number of functional pairs of posterior teeth and improved mastication. Any evaluation of feeding behaviour in persons with DS should consider inter-arch dental contacts as an explicative variable for feeding problems and their nutritional and respiratory consequences. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Hybrid Brain–Computer Interface Techniques for Improved Classification Accuracy and Increased Number of Commands: A Review

    OpenAIRE

    Hong, Keum-Shik; Khan, Muhammad Jawad

    2017-01-01

    In this article, non-invasive hybrid brain–computer interface (hBCI) technologies for improving classification accuracy and increasing the number of commands are reviewed. Hybridization combining more than two modalities is a new trend in brain imaging and prosthesis control. Electroencephalography (EEG), due to its easy use and fast temporal resolution, is most widely utilized in combination with other brain/non-brain signal acquisition modalities, for instance, functional near infrared spec...

  9. Increased number of sex chromosomes affects height in a nonlinear fashion: a study of 305 patients with sex chromosome aneuploidy

    DEFF Research Database (Denmark)

    Ottesen, Anne-Marie; Aksglaede, Lise; Garn, Inger

    2010-01-01

    Tall stature and eunuchoid body proportions characterize patients with 47,XXY Klinefelter syndrome, whereas patients with 45,X Turner syndrome are characterized by impaired growth. Growth is relatively well characterized in these two syndromes, while few studies describe the growth of patients wi......,XXXX (n = 13), and -1.0 (-3.5 to -0.8) in 49,XXXXX (n = 3). Height increased with an increasing number of extra X or Y chromosomes, except in males with five, and in females with four or five sex chromosomes, consistent with a nonlinear effect on height....

  10. Acupuncture attenuates cognitive deficits and increases pyramidal neuron number in hippocampal CA1 area of vascular dementia rats.

    Science.gov (United States)

    Li, Fang; Yan, Chao-Qun; Lin, Li-Ting; Li, Hui; Zeng, Xiang-Hong; Liu, Yi; Du, Si-Qi; Zhu, Wen; Liu, Cun-Zhi

    2015-04-28

    Decreased cognition is recognized as one of the most severe and consistent behavioral impairments in dementia. Experimental studies have reported that acupuncture may improve cognitive deficits, relieve vascular dementia (VD) symptoms, and increase cerebral perfusion and electrical activity. Multi-infarction dementia was modeled in rats with 3% microemboli saline suspension. Two weeks after acupuncture at Zusanli (ST36), all rats were subjected to a hidden platform trial to test their 3-day spatial memory using the Morris water maze test. To estimate the numbers of pyramidal neuron, astrocytes, and synaptic boutons in hippocampal CA1 area, we adopted an unbiased stereology method to accurately sample and measure the size of cells. We found that acupuncture at ST36 significantly decreased the escape latency of VD rats. In addition, acupuncture significantly increased the pyramidal neuron number in hippocampal CA1 area (P area in any of the groups (P > 0.05). These findings suggest that acupuncture may improve cognitive deficits and increase pyramidal neuron number of hippocampal CA1 area in VD rats.

  11. Increasing numbers of nonaneurysmal subarachnoid hemorrhage in the last 15 years: antithrombotic medication as reason and prognostic factor?

    Science.gov (United States)

    Konczalla, Juergen; Kashefiolasl, Sepide; Brawanski, Nina; Senft, Christian; Seifert, Volker; Platz, Johannes

    2016-06-01

    OBJECT Subarachnoid hemorrhage (SAH) is usually caused by a ruptured intracranial aneurysm, but in some patients no source of hemorrhage can be detected. More recent data showed increasing numbers of cases of spontaneous nonaneurysmal SAH (NASAH). The aim of this study was to analyze factors, especially the use of antithrombotic medications such as systemic anticoagulation or antiplatelet agents (aCPs), influencing the increasing numbers of cases of NASAH and the clinical outcome. METHODS Between 1999 and 2013, 214 patients who were admitted to the authors' institution suffered from NASAH, 14% of all patients with SAH. Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months. Risk factors were identified based on the outcome. RESULTS The number of patients with NASAH increased significantly in the last 15 years of the study period. There was a statistically significant increase in the rate of nonperimesencephalic (NPM)-SAH occurrence and aCP use, while the proportion of elderly patients remained stable. Favorable outcome (mRS 0-2) was achieved in 85% of cases, but patients treated with aCPs had a significantly higher risk for an unfavorable outcome. Further analysis showed that elderly patients, and especially the subgroup with a Fisher Grade 3 bleeding pattern, had a high risk for an unfavorable outcome, whereas the subgroup of NPM-SAH without a Fisher Grade 3 bleeding pattern had a favorable outcome, similar to perimesencephalic (PM)-SAH. CONCLUSIONS Over the years, a significant increase in the number of patients with NASAH has been observed. Also, the rate of aCP use has increased significantly. Risk factors for an unfavorable outcome were age > 65 years, Fisher Grade 3 bleeding pattern, and aCP use. Both "PM-SAH" and "NPM-SAH without a Fisher Grade 3 bleeding pattern" had excellent outcomes. Patients with NASAH and a Fisher Grade 3 bleeding pattern had a significantly higher risk for an unfavorable outcome and death. Therefore, for further

  12. The number of Foxp3-positive regulatory T cells is increased in Helicobacter pylori gastritis and gastric cancer.

    Science.gov (United States)

    Jang, Tae Jung

    2010-01-15

    Helicobacter pylori (H. pylori) colonization induces vigorous innate and specific immune responses; however, the infection is not removed, a state of chronic active gastritis persists for life if untreated. Recent studies have shown that CD4(+) CD25(+) Foxp3-positive regulatory T cells (Tregs) suppress the immune response to H. pylori. Persistent H. pylori-associated gastritis is closely associated with gastric carcinogenesis. We investigated the number of Tregs in the context of H. pylori colonization in chronic gastritis, examined the relationship between it and histopathological findings and compared it with that of gastric dysplasia and adenocarcinoma. This study was based on the analysis of gastric biopsy specimens from 126 cases of H. pylori-associated gastritis, 16 cases of H. pylori-negative gastritis, 17 cases of gastric dysplasia, and 25 cases of gastric adenocarcinoma. The number of Tregs was elevated in H. pylori-associated gastritis, where it was positively correlated with the grade of chronic inflammation and the number of lymphoid follicles. It was significantly elevated in adenocarcinomas compared to chronic gastritis and gastric dysplasia. In summary, the number of Tregs is increased in H. pylori-associated gastritis and gastric cancer. Copyright 2009 Elsevier GmbH. All rights reserved.

  13. Chronically reinforced, operant olfactory conditioning increases the number of newborn GABAergic olfactory periglomerular neurons in the adult rat.

    Science.gov (United States)

    Tapia-Rodríguez, Miguel; Esquivelzeta-Rabell, José F; Gutiérrez-Ospina, Gabriel

    2012-12-01

    The mammalian brain preserves the ability to replace olfactory periglomerular cells (PGC) throughout life. Even though we have detailed a great deal the mechanisms underlying stem and amplifying cells maintenance and proliferation, as well as those modulating migration and differentiation, our knowledge on PGC phenotypic plasticity is at best fragmented and controversial. Here we explored whether chronically reinforced olfactory conditioning influences the phenotype of newborn PGC. Accordingly, olfactory conditioned rats showed increased numbers of GAD 65/67 positive PGC. Because such phenotypic change was not accompanied neither by increments in the total number of PGC, or periglomerular cell nuclei labeled with bromodeoxyuridine, nor by reductions in the number of tyrosine hydroxylase (TH), calbindin (CB) or calretinin (CR) immunoreactive PGC, we speculate that increments in the number of GABAergic PGC occur at the expense of other PGC phenotypes. In any event, these results support that adult newborn PGC phenotype may be subjected to phenotypic plasticity influenced by sensory stimulation. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Mach Stability Improvements Using an Existing Second Throat Capability at the National Transonic Facility

    Science.gov (United States)

    Chan, David T.; Balakrishna, Sundareswara; Walker, Eric L.; Goodliff, Scott L.

    2015-01-01

    Recent data quality improvements at the National Transonic Facility have an intended goal of reducing the Mach number variation in a data point to within plus or minus 0.0005, with the ultimate goal of reducing the data repeatability of the drag coefficient for full-span subsonic transport models at transonic speeds to within half a drag count. This paper will discuss the Mach stability improvements achieved through the use of an existing second throat capability at the NTF to create a minimum area at the end of the test section. These improvements were demonstrated using both the NASA Common Research Model and the NTF Pathfinder-I model in recent experiments. Sonic conditions at the throat were verified using sidewall static pressure data. The Mach variation levels from both experiments in the baseline tunnel configuration and the choked tunnel configuration will be presented and the correlation between Mach number and drag will also be examined. Finally, a brief discussion is given on the consequences of using the second throat in its location at the end of the test section.

  15. Scramjet Combustor Characteristics at Hypervelocity Condition over Mach 10 Flight

    Science.gov (United States)

    Takahashi, M.; Komuro, T.; Sato, K.; Kodera, M.; Tanno, H.; Itoh, K.

    2009-01-01

    To investigate possibility of reduction of a scramjet combustor size without thrust performance loss, a two-dimensional constant-area combustor of a previous engine model was replaced with the one with 23% lower-height. With the application of the lower-height combustor, the pressure in the combustor becomes 50% higher and the combustor length for the optimal performance becomes 43% shorter than the original combustor. The combustion tests of the modified engine model were conducted using a large free-piston driven shock tunnel at flow conditions corresponding to the flight Mach number from 9 to 14. CFD was also applied to the engine internal flows. The results showed that the mixing and combustion heat release progress faster to the distance and the combustor performance similar to that of the previous engine was obtained with the modified engine. The reduction of the combustor size without the thrust performance loss is successfully achieved by applying the lower-height combustor.

  16. Luteal-phase ovarian stimulation increases the number of mature oocytes in older women with severe diminished ovarian reserve.

    Science.gov (United States)

    Rashtian, Justin; Zhang, John

    2018-03-22

    In older women with severe diminished ovarian response (DOR), in vitro fertilization (IVF) treatment is much less successful due to the low number of mature oocytes collected. The objective of this study was to assess whether follicular-phase stimulation (FPS) and luteal-phase stimulation (LPS) in the same menstrual cycle (double ovarian stimulation) in older women with severe DOR will produce a higher number of oocytes compared to FPS alone. Women with DOR (n = 69; mean age = 42.4) who underwent double ovarian stimulation for IVF were included. Women underwent ovarian stimulation in FPS using clomiphene citrate, letrozole, and gonadotropins followed by oocyte retrieval. The next day following oocyte retrieval, women underwent a second ovarian stimulation (LPS) using the same medications followed by a second oocyte retrieval. T-test was performed in order to compare the clinical characteristics and outcome in the same participant between FPS and LPS. Although antral follicle count at the start of FPS tended to be higher than at the start of the LPS cycle, there was no statistically significant difference between the duration of ovarian stimulation, peak estradiol levels, number of small (FPS alone. The addition of LPS to the conventional FPS increases the number of mature oocytes retrieved in the same IVF cycle, thus potentially increasing the chances of pregnancy in older women with severe DOR. AFC: antral follicle count; BMI: body mass index; DOR: diminished ovarian reserve; E2: estradiol; FPS: follicular-phase stimulation; FSH: follicle stimulating hormone; GnRH: gonadotropin-releasing hormone; HCG: human chorionic gonadotropin; IRB: institutional review board; IVF: in vitro fertilization; LH: luteinizing hormone; LPS: luteal-phase stimulation; MII: metaphase II.

  17. The increased number of osteoblasts and capillaries in orthodontic tooth movement post-administration of Robusta coffee extract

    Directory of Open Access Journals (Sweden)

    H. Herniyati

    2017-06-01

    Full Text Available Background: The application of orthodontic forces subjects blood capillaries to considerable pressure, resulting in hypoxia on the pressure side. Vascular endothelial growth factor (VEGF, expressed in osteoblasts represents an important mitogen that induces angiogenesis. Osteoblasts and blood capillaries play an important role in bone formation. Robusta coffee contains chlorogenic acid and caffeic acid both of which produce antioxidant effects capable of reducing oxidative stress in osteoblasts. Purpose: The aim of this study was to analyze the effects of Robusta coffee extract on the number of osteoblasts and blood capillaries in orthodontic tooth movement. Methods: This research constituted a laboratory-based experimental study involving the use of sixteen male rodents divided into two groups, namely; control group (C consisting of eight mice given orthodontic mechanical force (OMF and a treatment group (T containing eight mice administered OMF and dried Robusta coffee extract at a dose of 20mg/ 100 g BW. The OMF was performed by installing a ligature wire on the maxillary right first molar and both maxillary incisors. In the following stage, the maxillary right first molar was moved to the mesial using Tension Gauze with a Nickel Titanium Orthodontic closed coil spring. Observation was subsequently undertaken on the 15th day by extracting the maxillary right first and second molar with their periodontal tissues. Thereafter, histological examination was performed using hematoxylin-eosin (HE staining technique to measure the number of osteoblasts and blood capillaries on the mesial and distal periodontal ligaments of the maxillary right first molar. Results: The administration of Robusta coffee extract increases the number of blood capillaries and osteoblasts on both the pressure and tension sides were found to be significantly higher in the T group compared to the C group (p<0,05. Conclusion: Robusta coffee extract increase the number of

  18. An analysis of psychotropic drug sales. Increasing sales of selective serotonin reuptake inhibitors are closely related to number of products.

    Science.gov (United States)

    Nielsen, Margrethe; Gøtzsche, Peter

    2011-01-01

    Prescribing of selective serotonin reuptake inhibitors (SSRIs) has increased dramatically. To compare the sales of benzodiazepines and SSRIs within the primary care sector in Denmark and relate changes in usage to number of indications and products on the market. We used data from various sources to establish the sales curves of psychotropic drugs in the period 1970 to 2007, based on the Anatomic Therapeutic Classification system and Defined Daily Doses. Fluctuations in sales of psychotropic drugs that cannot be explained by disease prevalence were caused by changes in sales of the benzodiazepines and SSRIs. We found a decline in the sales of benzodiazepines after a peak in 1986, likely due to the recognition that they cause dependence. From a low level in 1992, we found that the sales of SSRIs increased almost linearly by a factor of 18, up to 44 DDD per 1000 inhabitants, which was closely related to the number of products on the market that increased by a factor of 16. Sales of antidepressant drugs are mainly determined by market availability of products indicating that marketing pressures are playing an important role. Thus the current level of use of SSRIs may not be evidence-based, which is supported by studies showing that the effect of SSRIs has been overestimated.

  19. Determination of increased mean drag coefficients for a cylinder vibrating at low values of Keulegan-Carpenter number

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Riveros

    2014-06-01

    Full Text Available There is an increasing demand for the development of a reliable technology for wind turbines in deepwaters.Therefore, offshore wind turbine technology is receiving great amount of attention by the research community. Nevertheless, the dynamic response prediction of the support system for offshore wind turbines is still challenging due to the nonlinear and self-regulated nature of the Vortex Induced Vibration (VIV process. In this paper, the numerical implementation of a computational fluid dynamics-based approach for determination of increased mean drag coefficient is presented. The numerical study is conducted at low values of Keulegan-Carpenter number in order to predict the increment of drag force due to cross-flow motion. The simulation results are then compared with previously developed empirical formulations. Good agreement is observed in these comparisons.

  20. Higher Education in Brazil and the policies for increasing the number of vacancies from Reuni: advances and controversies

    Directory of Open Access Journals (Sweden)

    Maria Célia Borges

    2012-01-01

    Full Text Available This paper presents a discussion on the policies to expand Higher Education, stating the influences of neoliberalism and explaining the contradictions in legislation and reforms at this level of education in Brazil after the 1990s. It questions the model of the New University with regard to the Brazilian reality and the poor investments available for such a reform. It calls attention to the danger of prioritizing the increase in the number of vacancies instead of the quality of teaching, something which would represent the scrapping of the public university. It highlights the contradictions of Reuni, with improvised actions and conditioning of funds, through the achievement of goals. On one hand, it recognizes the increasing number of vacancies in Higher Education and, on the other, it reaffirms that democratization of access requires universities with financial autonomy, well-structured courses with innovative curricula, qualified professors, adequate infrastructure, and high quality teaching, with research aiming the production of new knowledge, as well as university extension.

  1. Decreased number of interneurons and increased seizures in neuropilin 2 deficient mice: implications for autism and epilepsy.

    Science.gov (United States)

    Gant, John C; Thibault, Oliver; Blalock, Eric M; Yang, Jun; Bachstetter, Adam; Kotick, James; Schauwecker, Paula E; Hauser, Kurt F; Smith, George M; Mervis, Ron; Li, YanFang; Barnes, Gregory N

    2009-04-01

    Clinically, perturbations in the semaphorin signaling system have been associated with autism and epilepsy. The semaphorins have been implicated in guidance, migration, differentiation, and synaptic plasticity of neurons. The semaphorin 3F (Sema3F) ligand and its receptor, neuropilin 2 (NPN2) are highly expressed within limbic areas. NPN2 signaling may intimately direct the apposition of presynaptic and postsynaptic locations, facilitating the development and maturity of hippocampal synaptic function. To further understand the role of NPN2 signaling in central nevous system (CNS) plasticity, structural and functional alterations were assessed in NPN2 deficient mice. In NPN2 deficient mice, we measured seizure susceptibility after kainic acid or pentylenetetrazol, neuronal excitability and synaptic throughput in slice preparations, principal and interneuron cell counts with immunocytochemical protocols, synaptosomal protein levels with immunoblots, and dendritic morphology with Golgi-staining. NPN2 deficient mice had shorter seizure latencies, increased vulnerability to seizure-related death, were more likely to develop spontaneous recurrent seizure activity after chemical challenge, and had an increased slope on input/output curves. Principal cell counts were unchanged, but GABA, parvalbumin, and neuropeptide Y interneuron cell counts were significantly reduced. Synaptosomal NPN2 protein levels and total number of GABAergic synapses were decreased in a gene dose-dependent fashion. CA1 pyramidal cells showed reduced dendritic length and complexity, as well as an increased number of dendritic spines. These data suggest the novel hypothesis that the Sema 3F signaling system's role in appropriate placement of subsets of hippocampal interneurons has critical downstream consequences for hippocampal function, resulting in a more seizure susceptible phenotype.

  2. Receptivity of Boundary Layer over a Blunt Wedge due to Freestream Pulse Disturbances at Mach 6

    Directory of Open Access Journals (Sweden)

    Jianqiang Shi

    2016-01-01

    Full Text Available Direct numerical simulation (DNS of a hypersonic compressible flow over a blunt wedge with fast acoustic disturbances in freestream is performed. The receptivity characteristics of boundary layer to freestream pulse acoustic disturbances are numerically investigated at Mach 6, and the frequency effects of freestream pulse wave on boundary layer receptivity are discussed. Results show that there are several main disturbance mode clusters in boundary layer under acoustic pulse wave, and the number of main disturbance clusters decreases along the streamwise. As disturbance wave propagates from upstream to downstream direction, the component of the modes below fundamental frequency decreases, and the component of the modes above second harmonic components increases quickly in general. There are competition and disturbance energy transfer between different boundary layer modes. The nose boundary layer is dominated by the nearby mode of fundamental frequency. The number of the main disturbance mode clusters decreases as the freestream disturbance frequency increases. The frequency range with larger growth narrows along the streamwise. In general, the amplitudes of both fundamental mode and harmonics become larger with the decreasing of freestream disturbance frequency. High frequency freestream disturbance accelerates the decay of disturbance wave in downstream boundary layer.

  3. Maillard reaction products from highly heated food prevent mast cell number increase and inflammation in a mouse model of colitis.

    Science.gov (United States)

    Al Amir, Issam; Dubayle, David; Héron, Anne; Delayre-Orthez, Carine; Anton, Pauline M

    2017-12-01

    Links between food and inflammatory bowel diseases (IBDs) are often suggested, but the role of food processing has not been extensively studied. Heat treatment is known to cause the loss of nutrients and the appearance of neoformed compounds such as Maillard reaction products. Their involvement in gut inflammation is equivocal, as some may have proinflammatory effects, whereas other seem to be protective. As IBDs are associated with the recruitment of immune cells, including mast cells, we raised the hypothesis that dietary Maillard reaction products generated through heat treatment of food may limit the colitic response and its associated recruitment of mast cells. An experimental model of colitis was used in mice submitted to mildly and highly heated rodent food. Adult male mice were divided in 3 groups and received nonheated, mildly heated, or highly heated chow during 21 days. In the last week of the study, each group was split into 2 subgroups, submitted or not (controls) to dextran sulfate sodium (DSS) colitis. Weight variations, macroscopic lesions, colonic myeloperoxidase activity, and mucosal mast cell number were evaluated at the end of the experiment. Only highly heated chow significantly prevented DSS-induced weight loss, myeloperoxidase activity, and mast cell number increase in the colonic mucosa of DSS-colitic mice. We suggest that Maillard reaction products from highly heated food may limit the occurrence of inflammatory phases in IBD patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Increasing Student’s Character Values by Utilizing Combination of Team Accelerated Instruction (TAI and Numbered Heads Together (NHT

    Directory of Open Access Journals (Sweden)

    Ita Nuryana

    2016-06-01

    Full Text Available This research aims to obtain empirical evidence of the effectiveness of combining Team Accelerated Instruction (TAI and Numbered Heads Together (NHT learning strategies in teaching Investments to improve students’ discipline, creativity, diligence, and participation. Population was students who enrolled in Intermediate Financial Accounting 2 course in Economics Education Department; Economics Faculty of Universitas Negeri Semarang The sample of the research consists of 48 students. Data were collected by using observations, interviews, and documentation. The stages of the research include planning, implementation, monitoring and evaluation, analysis, and reflection. Findings show that the combination of TAI and NHT does not improve students’ learning outcomes even thought it manages to increase students’ pre-test score in learning Investments as well as their participation in classroom.

  5. Experimental study of a laminar premixed LFG/air flame in a slot burner using Mach-Zehnder interferometry

    Directory of Open Access Journals (Sweden)

    Najafian Ashrafi Zabihollah

    2016-01-01

    Full Text Available An experimental study was conducted to investigate the influence of Reynolds number and equivalence ratio on flame temperature field and thermal flame height of laminar premixed LFG fuel. Mach-Zehnder interferometry technique is used to obtain an insight to the overall temperature field. The slot burner with large aspect ratio (L/W, length of L=60 mm and width of W=6 mm was used to eliminate the three- dimensional effect of temperature field. Two kinds of mixed fuels, LFG70 (70%CH4- 30%CO2 on volume basis and LFG50 (50%CH4- 50%CO2 were used to investigate flame characteristics under the test conditions of 100 ≤ Re ≤ 600 and 0.7 ≤ φ ≤ 1.3. The present measurement reveals that the variation of maximum flame temperature with increment of Reynolds number is mainly due to heat transfer effects and is negligible. On the other hand, the equivalence ratio and fuel composition have a noticeable effect on flame temperature. In addition, the results show that the LFG flames compared to the CH4 ones have a lower flame temperature. With increment of CO2 volume fraction at lean combustion, thermal flame height is augmented while at stoichiometric and rich combustion, its value reduced. Thermal flame height augments linearly by Reynolds number increase, while its increment at rich mixture is higher and the effect of Reynolds number at lean mixtures is insignificant. For validation of experimental results from Mach-Zehnder Interferometry, K-type thermocouples are used at peripherally low and moderate isotherm lines.

  6. Signatures derived from increase in SHARPIN gene copy number are associated with poor prognosis in patients with breast cancer

    Directory of Open Access Journals (Sweden)

    Diane Ojo

    2017-12-01

    Full Text Available We report three signatures produced from SHARPIN gene copy number increase (GCN-Increase and their effects on patients with breast cancer (BC. In the Metabric dataset (n = 2059, cBioPortal, SHARPIN GCN-Increase occurs preferentially or mutual exclusively with mutations in TP53, PIK3CA, and CDH1. These genomic alterations constitute a signature (SigMut that significantly correlates with reductions in overall survival (OS in BC patients (n = 1980; p = 1.081e−6. Additionally, SHARPIN GCN-Increase is associated with 4220 differentially expressed genes (DEGs. These DEGs are enriched in activation of the pathways regulating cell cycle progression, RNA transport, ribosome biosynthesis, DNA replication, and in downregulation of the pathways related to extracellular matrix. These DEGs are thus likely to facilitate the proliferation and metastasis of BC cells. Additionally, through forward (FWD and backward (BWD stepwise variate selections among the top 160 downregulated and top 200 upregulated DEGs using the Cox regression model, a 6-gene (SigFWD and a 50-gene (SigBWD signature were derived. Both signatures robustly associate with decreases in OS in BC patients within the Curtis (n = 1980; p = 6.16e−11 for SigFWD; p = 1.06e−10, for SigBWD and TCGA cohort (n = 817; p = 4.53e−4 for SigFWD and p = 0.00525 for SigBWD. After adjusting for known clinical factors, SigMut (HR 1.21, p = 0.0297, SigBWD (HR 1.25, p = 0.0263, and likely SigFWD (HR 1.17, p = 0.062 remain independent risk factors of BC deaths. Furthermore, the proportion of patients positive for these signatures is significantly increased in ER−, Her2-enriched, basal-like, and claudin-low BCs compared to ER+ and luminal BCs. Collectively, these SHARPIN GCN-Increase-derived signatures may have clinical applications in management of patients with BC.

  7. Job losses and accumulated number of broken partnerships increase risk of premature mortality in Danish men born in 1953

    DEFF Research Database (Denmark)

    Kriegbaum, Margit; Christensen, Ulla; Lund, Rikke

    2009-01-01

    OBJECTIVE: To investigate how accumulation of job losses and broken partnerships affect the risk of premature mortality, and to study joint exposure to both events. METHODS: Birth cohort study of 9789 Danish men born in 1953 with follow-up of events between the ages of 40 and 51. RESULTS: The adj......OBJECTIVE: To investigate how accumulation of job losses and broken partnerships affect the risk of premature mortality, and to study joint exposure to both events. METHODS: Birth cohort study of 9789 Danish men born in 1953 with follow-up of events between the ages of 40 and 51. RESULTS......: The adjusted hazard rates for premature mortality was 1.44 (95% CI = 1.15 to 1.80) for individuals with one job loss, 1.55 (1.13 to 2.13) for individuals with one broken partnership, and 2.15 (95% CI = 1.49 to 3.10) for individuals with two or more broken partnerships. CONCLUSIONS: Experience of at least one...... job loss increased the risk of premature mortality. The risk of premature mortality increased with the number of broken partnerships. There was no statistical interaction between job losses and broken partnerships....

  8. Red kidney bean (Phaseolus vulgaris lectin stimulation increases the number of enterochromaffin cells in the small intestine of suckling piglets

    Directory of Open Access Journals (Sweden)

    Zacharko-Siembida Anna

    2014-06-01

    Full Text Available The quantities and distribution patterns of serotonin-immunoreactive (serotonin-IR enterochromaffin cells (EC were studied immunohistochemically in the small intestine of suckling piglets stimulated with red kidney bean lectin, and in nonstimulated, control animals. The co-expression patterns of serotonin with somatostatin (SOM or corticotropin releasing-factor (CRF were also studied. After the lectin treatment, the increased numbers of EC were noted in the duodenum of experimental animals. Lectin stimulation did not change the proportions of EC in the jejunum and ileum. In the duodenal epithelium of the lectin-stimulated piglets, the vast majority of serotonin-IR EC were distributed at the basis of crypts. After the lectin administration, the proportions of serotonin-IR/SOM-IR EC were statistically similar in all sections of the small intestine. No upregulation of CRF was found in duodenal, jejunal, and ileal EC of lectin-treated animals. The findings demonstrated that red kidney bean lectin increased the serotonin reservoir in the duodenum, and thus may be an effective stimulant of the gut maturation in suckling mammals.

  9. Increased certification of semi-device independent random numbers using many inputs and more post-processing

    International Nuclear Information System (INIS)

    Mironowicz, Piotr; Tavakoli, Armin; Hameedi, Alley; Marques, Breno; Bourennane, Mohamed; Pawłowski, Marcin

    2016-01-01

    Quantum communication with systems of dimension larger than two provides advantages in information processing tasks. Examples include higher rates of key distribution and random number generation. The main disadvantage of using such multi-dimensional quantum systems is the increased complexity of the experimental setup. Here, we analyze a not-so-obvious problem: the relation between randomness certification and computational requirements of the post-processing of experimental data. In particular, we consider semi-device independent randomness certification from an experiment using a four dimensional quantum system to violate the classical bound of a random access code. Using state-of-the-art techniques, a smaller quantum violation requires more computational power to demonstrate randomness, which at some point becomes impossible with today’s computers although the randomness is (probably) still there. We show that by dedicating more input settings of the experiment to randomness certification, then by more computational postprocessing of the experimental data which corresponds to a quantum violation, one may increase the amount of certified randomness. Furthermore, we introduce a method that significantly lowers the computational complexity of randomness certification. Our results show how more randomness can be generated without altering the hardware and indicate a path for future semi-device independent protocols to follow. (paper)

  10. The competitor release effect applied to carnivore species: how red foxes can increase in numbers when persecuted

    Directory of Open Access Journals (Sweden)

    Lozano, J.

    2013-01-01

    Full Text Available The objective of our study was to numerically simulate the population dynamics of a hypothetical community of three species of small to medium–sized carnivores subjected to non–selective control within the context of the competitor release effect (CRE. We applied the CRE to three carnivore species, linking interspecific competition with predator control efforts. We predicted the population response of European badger, the red fox and the pine marten to this wildlife management tool by means of numerical simulations. The theoretical responses differed depending on the intrinsic rate of growth (r, although modulated by the competition coefficients. The red fox, showing the highest r value, can increase its populations despite predator control efforts if control intensity is moderate. Populations of the other two species, however, decreased with control efforts, even reaching extinction. Three additional theoretical predictions were obtained. The conclusions from the simulations were: 1 predator control can play a role in altering the carnivore communities; 2 red fox numbers can increase due to control; and 3 predator control programs should evaluate the potential of unintended effects on ecosystems.

  11. The Red Rectangle: An Astronomical Example of Mach Bands?

    Science.gov (United States)

    Brecher, K.

    2005-12-01

    Recently, the Hubble Space Telescope (HST) produced spectacular images of the "Red Rectangle". This appears to be a binary star system undergoing recurrent mass loss episodes. The image-processed HST photographs display distinctive diagonal lightness enhancements. Some of the visual appearance undoubtedly arises from actual variations in the luminosity distribution of the light of the nebula itself, i.e., due to limb brightening. Psychophysical enhancement similar to the Vasarely or pyramid effect also seems to be involved in the visual impression conveyed by the HST images. This effect is related to Mach bands (as well as to the Chevreul and Craik-O'Brien-Cornsweet effects). The effect can be produced by stacking concentric squares (or other geometrical figures such as rectangles or hexagons) of linearly increasing or decreasing size and lightness, one on top of another. We have constructed controllable Flash applets of this effect as part of the NSF supported "Project LITE: Light Inquiry Through Experiments". They can be found in the vision section of the LITE web site at http://lite.bu.edu. Mach band effects have previously been seen in medical x-ray images. Here we report for the first time the possibility that such effects play a role in the interpretation of astronomical images. Specifically, we examine to what extent the visual impressions of the Red Rectangle and other extended astronomical objects are purely physical (photometric) in origin and to what degree they are enhanced by psychophysical processes. To help assess the relative physical and psychophysical contributions to the perceived lightness effects, we have made use of a center-surround (Difference of Gaussians) filter we developed for MatLab. We conclude that local (lateral inhibition) and longer range human visual perception effects probably do contribute to the lightness features seen in astronomical objects like the Red Rectangle. Project LITE is supported by NSF Grant # DUE-0125992.

  12. Increasing the Overall Quality and the Number of Women and Hispanic Geoscientists for the Workforce: Rebuilding an Undergraduate Program

    Science.gov (United States)

    Ford, M. T.; McGehee, T. L.

    2014-12-01

    Over the past ten years, the Geosciences Program at Texas A&M University-Kingsville has increased the number of Geology majors 400%, and in the past five years we have graduated 62 students, an increase of 800%. Of these graduates, 37% were Hispanic or African-American and 26% were women. Our graduates are high-achievers with 13% also graduating from the Honor's College (campus-wide rate is less than 1.5%) and that included three women and two Hispanic graduates. Two of these recent graduates are doctoral candidates and eleven are master's candidates at major universities. Of these, three master's candidates are Hispanic, including two women, and one doctoral candidate is a Hispanic woman. The recent productivity and quality changes in this program are attributed to our shift toward an undergraduate, student-centered focus. The increases in productivity resulted from the development of strong relationships with community colleges across the state and significant efforts in recruitment and retention. The major changes in quality included implementation of a strong field-oriented focus with full faculty participation, a strong undergraduate research program, a well-developed recruitment and retention plan, a GIS Certification incorporated into the geology degree, and a culture change to further student professional development. We have maintained over 50 majors in our program for the past three years through increased faculty presentations at high-schools and community colleges, a good University recruiting staff, and quarterly newsletters, focused on student achievements, sent to all prospective students and parents inquiring about the geology major. The resurgence of the oil and gas industry and the retirement of geoscientists have provided a steady stream of job opportunities for our graduates. The 79% that are not pursuing a graduate education accepted jobs after graduation. These include oil and gas entry level jobs, mining jobs, teaching jobs, and geospatial

  13. Increased numbers of CD4+ and CD8+ T cells in lesional skin of cats with allergic dermatitis.

    Science.gov (United States)

    Roosje, P J; van Kooten, P J; Thepen, T; Bihari, I C; Rutten, V P; Koeman, J P; Willemse, T

    1998-07-01

    The aim of this study was to characterize T cells in the skin of cats with an allergic dermatitis histologically compatible with atopic dermatitis, since T cells play an important role in the pathogenesis of atopic dermatitis in humans. We observed a significantly greater number of T cells in lesional skin of domestic short-haired cats with allergic dermatitis (n = 10; median age 5.8 years) than in the skin of healthy control animals (n = 10; median age 5.0 years). In the skin of the healthy control animals, one or two CD4+ cells and no CD8+ cells were found. A predominant increase of CD4+ T cells and a CD4+/CD8+ ratio (mean +/- SD: 3.9 +/- 2.0) was found in the lesional skin of 10 cats with allergic dermatitis. The CD4+/CD8+ cell ratio in the skin of healthy control animals could not be determined because of the absence of CD8+ cells. The CD4+/CD8+ cell ratio in the peripheral blood of 10 cats with allergic dermatitis (mean +/- SD: 1.9 +/- 0.4) did not differ significantly from that in 10 healthy control animals (2.2 +/- 0.4). The CD4+/CD8+ cell ratio and predominance of CD4+ T cells in the lesional skin of cats with allergic dermatitis is comparable to that found in atopic dermatitis in humans. In addition, the observed increase of CD4+ T cells in the nonlesional skin of cats with allergic dermatitis compared to the skin of healthy cats is similar to what is seen in humans. Cytokines produced by T cells and antigen-specific T cells are important mediators in the inflammatory cascade resulting in atopic dermatitis in humans. This study is a first step to investigate their role in feline allergic dermatitis.

  14. Effects of increasing number of rings on the ion sensing ability of CdSe quantum dots: a theoretical study

    Science.gov (United States)

    Malik, Pragati; Kakkar, Rita

    2018-04-01

    A computational study on the structural and electronic properties of a special class of artificial atoms, known as quantum dots, has been carried out. These are semiconductors with unique optical and electronic properties and have been widely used in various applications, such as bio-sensing, bio-imaging, and so on. We have considered quantum dots belonging to II-VI types of semiconductors, due to their wide band gap, possession of large exciton binding energies and unique optical and electronic properties. We have studied their applications as chemical ion sensors by beginning with the study of the ion sensing ability of (CdSe) n ( n = 3, 6, 9 which are in the size range of 0.24, 0.49, 0.74 nm, respectively) quantum dots for cations of the zinc triad, namely Zn2+, Cd2+, Hg2+, and various anions of biological and environmental importance, and studied the effect of increasing number of rings on their ion sensing ability. The various structural, electronic, and optical properties, their interaction energies, and charge transfer on interaction with metal ions and anions have been calculated and reported. Our studies indicate that the CdSe quantum dots can be employed as sensors for both divalent cations and anions, but they can sense cations better than anions.

  15. The number of articles submitted to the Journal of the Faculty of Medicine experienced a dramatic increase

    Directory of Open Access Journals (Sweden)

    Franklin Escobar-Córdoba

    2017-06-01

    Full Text Available The Journal of the Faculty of Medicine of Universidad Nacional de Colombia has undergone important changes in the past years; the amount of articles submitted for initiating the editorial process has increased, in the same manner as the amount of articles received in English language, and the rejection rate, which is now around 40%. The number of international authors has also grown, thus demonstrating that the publication has achieved greater visibility and recognition. In this context, the following articles have been selected for the first issue of Volume 69 of the Journal of the Faculty of Medicine: “Is parricide a stable phenomenon? An analysis of parricide offenders in a forensic hospital” (1 is a study written by an important group of Brazilian authors, who demonstrate their expertise in one of the crimes that causes most social upheaval due to its broad implications. Parricide immediately attracts attention as it is easily linked to the presence of a mental disorder, which is actually corroborated by this study, since it shows that most parricides are young adult males, who have a low level of education, are single, with no criminal history and schizophrenic; in addition, few cases show antisocial personality disorders.

  16. A dominant lineage of Mycoplasma bovis is associated with an increased number of severe mastitis cases in cattle.

    Science.gov (United States)

    Bürki, Sibylle; Spergser, Joachim; Bodmer, Michèle; Pilo, Paola

    2016-11-30

    Mycoplasma bovis is the most frequent etiologic agent of bovine mycoplasmosis. It causes various diseases in bovines and considerable economic loss due to the lack of effective treatment or preventive measures such as vaccination. In contrast to the US, where M. bovis-mastitis has been reported for a long time, M. bovis infections in Switzerland and Austria were predominantly associated with pneumonia and subclinical mastitis. However, since 2007 the situation has changed with the emergence of severe M. bovis-associated mastitis cases in both countries. In order to evaluate the molecular epidemiology of the bacteria isolated from these infections, recent and old Swiss, along with recent Austrian M. bovis isolates were analyzed by a typing method displaying intermediate resolution of evolutionary relationships among isolates called Multi-Locus Sequence Typing (MLST). The analysis of Swiss and Austrian M. bovis isolates revealed two major lineages. Isolates collected since 2007 in both countries cluster in the lineage I including ST5, ST33, ST34, 36, and ST38-40 (clonal complex 1), while all Swiss isolates recovered before 2007 cluster in the lineage II comprising ST17 and ST35 (clonal complex 5). Further investigations are necessary to understand if lineage I has a higher predilection or virulence toward mammary gland cells than the old lineage or if other factors are involved in the increased number of severe mastitis cases. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Sensori-motor synchronisation variability decreases as the number of metrical levels in the stimulus signal increases.

    Science.gov (United States)

    Madison, Guy

    2014-03-01

    Timing performance becomes less precise for longer intervals, which makes it difficult to achieve simultaneity in synchronisation with a rhythm. The metrical structure of music, characterised by hierarchical levels of binary or ternary subdivisions of time, may function to increase precision by providing additional timing information when the subdivisions are explicit. This hypothesis was tested by comparing synchronisation performance across different numbers of metrical levels conveyed by loudness of sounds, such that the slowest level was loudest and the fastest was softest. Fifteen participants moved their hand with one of 9 inter-beat intervals (IBIs) ranging from 524 to 3,125 ms in 4 metrical level (ML) conditions ranging from 1 (one movement for each sound) to 4 (one movement for every 8th sound). The lowest relative variability (SD/IBI<1.5%) was obtained for the 3 longest IBIs (1600-3,125 ms) and MLs 3-4, significantly less than the smallest value (4-5% at 524-1024 ms) for any ML 1 condition in which all sounds are identical. Asynchronies were also more negative with higher ML. In conclusion, metrical subdivision provides information that facilitates temporal performance, which suggests an underlying neural multi-level mechanism capable of integrating information across levels. © 2013.

  18. Exposure to inorganic arsenic is associated with increased mitochondrial DNA copy number and longer telomere length in peripheral blood.

    Directory of Open Access Journals (Sweden)

    Syeda Shegufta Ameer

    2016-08-01

    Full Text Available Background: Exposure to inorganic arsenic (iAs through drinking water causes cancer. Alterations in mitochondrial DNA copy number (mtDNAcn and telomere length in blood have been associated with cancer risk. We elucidated if arsenic exposure alters mtDNAcn and telomere length in individuals with different arsenic metabolizing capacity.Methods: We studied two groups in the Salta province, Argentina, one in the Puna area of the Andes (N=264, 89% females and one in Chaco (N=169, 75% females. We assessed arsenic exposure as the sum of arsenic metabolites [iAs, methylarsonic acid (MMA, dimethylarsinic acid (DMA] in urine (U-As using high-performance liquid chromatography coupled with hydride generation and inductively coupled plasma mass spectrometry. Efficiency of arsenic metabolism was expressed as percentage of urinary metabolites. MtDNAcn and telomere length were determined in blood by real-time PCR. Results: Median U-As was 196 (5 - 95 percentile: 21 - 537 µg/L in Andes and 80 (5 - 95 percentile: 15 - 1637 µg/L in Chaco. The latter study group had less-efficient metabolism, with higher %iAs and %MMA in urine compared with the Andean group. U-As was significantly associated with increased mtDNAcn (log2 transformed to improve linearity in Chaco (β=0.027 per 100 µg/L, p=0.0085; adjusted for age and sex, but not in Andes (β=0.025, p=0.24. U-As was also associated with longer telomere length in Chaco (β=0.016, p=0.0066 and Andes (β=0.0075, p=0.029. In both populations, individuals with above median %iAs showed significantly higher mtDNAcn and telomere length compared with individuals with below median %iAs. Conclusions: Arsenic was associated with increased mtDNAcn and telomere length, particularly in individuals with less-efficient arsenic metabolism, a group who may have increased risk for arsenic-related cancer.

  19. Patient outcome of emergency laparotomy improved with increasing "number of surgeons on-call" in a university hospital: Audit loop.

    Science.gov (United States)

    Hussain, Anwar; Mahmood, Fahad; Teng, Chui; Jafferbhoy, Sadaf; Luke, David; Tsiamis, Achilleas

    2017-11-01

    Emergency laparotomy is a commonly performed high-mortality surgical procedure. The National Emergency Laparotomy Network (NELA) published an average mortality rate of 11.1% and a median length of stay equivalent to 16.3 days in patients undergoing emergency laparotomy. This study presents a completed audit loop after implementing the change of increasing the number of on-call surgeons in the general surgery rota of a university hospital. The aim of this study was to evaluate the outcomes of emergency laparotomy in a single UK tertiary centre after addition of one more consultant in the daily on-call rota. This is a retrospective study involving patients who underwent emergency laparotomy between March to May 2013 (first audit) and June to August 2015 (second audit). The study parameters stayed the same. The adult patients undergoing emergency laparotomy under the general surgical take were included. Appendicectomy, cholecystectomy and simple inguinal hernia repair patients were excluded. Data was collected on patient demographics, ASA, morbidity, 30-day mortality and length of hospital stay. Statistical analysis including logistic regression was performed using SPSS. During the second 3-month period, 123 patients underwent laparotomy compared to 84 in the first audit. Median age was 65(23-93) years. 56.01% cases were ASA III or above in the re-audit compared to 41.9% in the initial audit. 38% patients had bowel anastomosis compared to 35.7% in the re-audit with 4.2% leak rate in the re-audit compared to 16.6% in the first audit. 30-day mortality was 10.50% in the re-audit compared to 21% and median length of hospital stay 11 days in the re-audit compared to 16 days. The lower ASA grade was significantly associated with increased likelihood of being alive, as was being female, younger age and not requiring ITU admission post-operatively. However, having a second on-call consultant was 2.231 times more likely to increase the chances of patients not dying (p = 0

  20. Froude number fractions to increase walking pattern dynamic similarities: application to plantar pressure study in healthy subjects.

    Science.gov (United States)

    Moretto, P; Bisiaux, M; Lafortune, M A

    2007-01-01

    The purpose of this study was to determine if using similar walking velocities obtained from fractions of the Froude number (N(Fr)) and leg length can lead to kinematic and kinetic similarities and lower variability. Fifteen male subjects walked on a treadmill at 0.83 (VS(1)) and 1.16ms(-1) (VS(2)) and then at two similar velocities (V(Sim27) and V(Sim37)) determined from two fractions of the N(Fr) (0.27 and 0.37) so that the average group velocity remained unchanged in both conditions (VS(1)=V (Sim27)andVS(2)=V (Sim37)). N(Fr) can theoretically be used to determine walking velocities proportional to leg lengths and to establish dynamic similarities between subjects. This study represents the first attempt at using this approach to examine plantar pressure. The ankle and knee joint angles were studied in the sagittal plane and the plantar pressure distribution was assessed with an in-shoe measurement device. The similarity ratios were computed from anthropometric parameters and plantar pressure peaks. Dynamically similar conditions caused a 25% reduction in leg joint angles variation and a 10% significant decrease in dimensionless pressure peak variability on average of five footprint locations. It also lead to heel and under-midfoot pressure peaks proportional to body mass and to an increase in the number of under-forefoot plantar pressure peaks proportional to body mass and/or leg length. The use of walking velocities derived from N(Fr) allows kinematic and plantar pressure similarities between subjects to be observed and leads to a lower inter-subject variability. In-shoe pressure measurements have proven to be valuable for the understanding of lower extremity function. Set walking velocities used for clinical assessment mask the effects of body size and individual gait mechanics. The anthropometric scaling of walking velocities (fraction of N(Fr)) should improve identification of unique walking strategies and pathological foot functions.

  1. In-stream measurements of combustion during Mach 5 to 7 tests of the Hypersonic Research Engine (HRE)

    Science.gov (United States)

    Lezberg, Erwin A.; Metzler, Allen J.; Pack, William D.

    1993-01-01

    Results of in-stream combustion measurements taken during Mach 5 to 7 true simulation testing of the Hypersonic Research Engine/Aerothermodynamic Integration Model (HRE/AIM) are presented. These results, the instrumentation techniques, and configuration changes to the engine installation that were required to test this model are described. In test runs at facility Mach numbers of 5 to 7, an exhaust instrumentation ring which formed an extension of the engine exhaust nozzle shroud provided diagnostic measurements at 10 circumferential locations in the HRE combustor exit plane. The measurements included static and pitot pressures using conventional conical probes, combustion gas temperatures from cooled-gas pyrometer probes, and species concentration from analysis of combustion gas samples. Results showed considerable circumferential variation, indicating that efficiency losses were due to nonuniform fuel distribution or incomplete mixing. Results using the Mach 7 facility nozzle but with Mach 6 temperature simulation, 1590 to 1670 K, showed indications of incomplete combustion. Nitric oxide measurements at the combustor exit peaked at 2000 ppmv for stoichiometric combustion at Mach 6.

  2. A fast spatial scanning combination emissive and mach probe for edge plasma diagnosis

    International Nuclear Information System (INIS)

    Lehmer, R.D.; LaBombard, B.; Conn, R.W.

    1989-04-01

    A fast spatially scanning emissive and mach probe has been developed for the measurement of plasma profiles in the PISCES facility at UCLA. A pneumatic cylinder is used to drive a multiple tip probe along a 15cm stroke in less than 400msec, giving single shot profiles while limiting power deposition to the probe. A differentially pumped sliding O-ring seal allows the probe to be moved between shots to infer two and three dimensional profiles. The probe system has been used to investigate the plasma potential, density, and parallel mach number profiles of the presheath induced by a wall surface and scrape-off-layer profile modifications in biased limiter simulation experiments. Details of the hardware, data acquisition electronics, and tests of probe reliability are discussed. 30 refs., 24 figs

  3. Krypton tagging velocimetry in a turbulent Mach 2.7 boundary layer

    Science.gov (United States)

    Zahradka, D.; Parziale, N. J.; Smith, M. S.; Marineau, E. C.

    2016-05-01

    The krypton tagging velocimetry (KTV) technique is applied to the turbulent boundary layer on the wall of the "Mach 3 Calibration Tunnel" at Arnold Engineering Development Complex (AEDC) White Oak. Profiles of velocity were measured with KTV and Pitot-pressure probes in the Mach 2.7 turbulent boundary layer comprised of 99 % {N}2/1 % Kr at momentum-thickness Reynolds numbers of {Re}_{\\varTheta }= 800, 1400, and 2400. Agreement between the KTV- and Pitot-derived velocity profiles is excellent. The KTV and Pitot velocity data follow the law of the wall in the logarithmic region with application of the Van Driest I transformation. The velocity data are analyzed in the outer region of the boundary layer with the law of the wake and a velocity-defect law. KTV-derived streamwise velocity fluctuation measurements are reported and are consistent with data from the literature. To enable near-wall measurement with KTV (y/δ ≈ 0.1-0.2), an 800-nm longpass filter was used to block the 760.2-nm read-laser pulse. With the longpass filter, the 819.0-nm emission from the re-excited Kr can be imaged to track the displacement of the metastable tracer without imaging the reflection and scatter from the read-laser off of solid surfaces. To operate the Mach 3 AEDC Calibration Tunnel at several discrete unit Reynolds numbers, a modification was required and is described herein.

  4. The increasing of odontoblast-like cell number on direct pulp capping of Rattus norvegicus using chitosan

    Directory of Open Access Journals (Sweden)

    Widyasri Prananingrum

    2010-12-01

    Full Text Available Background: Pulpal perforation care with direct pulp capping in the case of reversible pulpitis due to mechanical trauma was performed with chitosan which has the ability to facilitate migration, proliferation, and progenitor cell differentiation. Purpose: The purpose of this study was to determine the increasing number of odontoblast-like cells in direct pulp capping dental care of Rattus norvegicus using chitosan for seven and fourteen days. Methods: Samples were molars of male Rattus norvegicus strain wistar, aged between 8–16 weeks, divided into two treatment groups, namely group I given chitosan and group II as a control group given Ca(OH2. Those Rattus norvegicus’ occlusal molar teeth were prepared with class I cavity, and then chitosan and Ca(OH2 were applied as the pulp capping materials. Afterwards, glasss ionomer cement type IX was used as a restoration material. Their teeth and jaw were then cut on the seventh day and the fourteenth day. Next, histopathological examination was carried out to observe the odontoblast like cells. All data were then analyzed by t test. Degree of confidence obtained, finally, was 95%. Results: The results obtained showed that the significant differences of odontoblast like cells on the seventh day observation was 0.001 (p = 0.001, and on the fourteenth day observation was 0.002 (p = 0.002. Conclusion: The number of odontoblast-like cells in direct pulp capping dental care of rattus norvegicus using chitosan is higher than the one using Ca(OH2 for seven and fourteen days.Latar belakang: Perawatan perforasi pulpa pada kasus pulpitis reversible karena trauma mekanis bur dilakukan direct pulp capping dengan cara pemberian bahan secara topikal pada daerah perforasi. Kitosan memiliki kemampuan untuk memfasilitasi migrasi, proliferasi dan diferensiasi sel progenitor pulpa. Tujuan: Tujuan penelitian ini adalah untuk menentukan jumlah peningkatan odontoblas-like cell pada perawatan direct pulp capping gigi

  5. Computational Fluid Dynamics (CFD) Image of Hyper-X Research Vehicle at Mach 7 with Engine Operating

    Science.gov (United States)

    1997-01-01

    This computational fluid dynamics (CFD) image shows the Hyper-X vehicle at a Mach 7 test condition with the engine operating. The solution includes both internal (scramjet engine) and external flow fields, including the interaction between the engine exhaust and vehicle aerodynamics. The image illustrates surface heat transfer on the vehicle surface (red is highest heating) and flowfield contours at local Mach number. The last contour illustrates the engine exhaust plume shape. This solution approach is one method of predicting the vehicle performance, and the best method for determination of vehicle structural, pressure and thermal design loads. The Hyper-X program is an ambitious series of experimental flights to expand the boundaries of high-speed aeronautics and develop new technologies for space access. When the first of three aircraft flies, it will be the first time a non-rocket engine has powered a vehicle in flight at hypersonic speeds--speeds above Mach 5, equivalent to about one mile per second or approximately 3,600 miles per hour at sea level. Hyper-X, the flight vehicle for which is designated as X-43A, is an experimental flight-research program seeking to demonstrate airframe-integrated, 'air-breathing' engine technologies that promise to increase payload capacity for future vehicles, including hypersonic aircraft (faster than Mach 5) and reusable space launchers. This multiyear program is currently underway at NASA Dryden Flight Research Center, Edwards, California. The Hyper-X schedule calls for its first flight later this year (2000). Hyper-X is a joint program, with Dryden sharing responsibility with NASA's Langley Research Center, Hampton, Virginia. Dryden's primary role is to fly three unpiloted X-43A research vehicles to validate engine technologies and hypersonic design tools as well as the hypersonic test facility at Langley. Langley manages the program and leads the technology development effort. The Hyper-X Program seeks to significantly

  6. Experimental investigation of liquid jet injection into Mach 6 hypersonic crossflow

    Energy Technology Data Exchange (ETDEWEB)

    Beloki Perurena, J. [von Karman Institute for Fluid Dynamics, Rhode-Saint-Genese (Belgium)]|[RWTH Aachen University, Shock Wave Laboratory, Aachen (Germany); Asma, C.O. [von Karman Institute for Fluid Dynamics, Rhode-Saint-Genese (Belgium)]|[Ghent University, Department of Flow, Heat and Combustion Mechanics, Ghent (Belgium); Theunissen, R. [von Karman Institute for Fluid Dynamics, Rhode-Saint-Genese (Belgium)]|[Delft University of Technology, Faculty of Aerospace Engineering, Delft (Netherlands); Chazot, O. [von Karman Institute for Fluid Dynamics, Rhode-Saint-Genese (Belgium)

    2009-03-15

    The injection of a liquid jet into a crossing Mach 6 air flow is investigated. Experiments were conducted on a sharp leading edge flat plate with flush mounted injectors. Water jets were introduced through different nozzle shapes at relevant jet-to-air momentum-flux ratios. Sufficient temporal resolution to capture small scale effects was obtained by high-speed recording, while directional illumination allowed variation in field of view. Shock pattern and flow topology were visualized by Schlieren-technique. Correlations are proposed on relating water jet penetration height and lateral extension with the injection ratio and orifice diameter for circular injector jets. Penetration height and lateral extension are compared for different injector shapes at relevant jet-to-air momentum-flux ratios showing that penetration height and lateral extension decrease and increase, respectively, with injector's aspect ratio. Probability density function analysis has shown that the mixing of the jet with the crossflow is completed at a distance of x/d{sub j}{proportional_to} 40, independent of the momentum-flux ratio. Mean velocity profiles related with the liquid jet have been extracted by means of an ensemble correlation PIV algorithm. Finally, frequency analyses of the jet breakup and fluctuating shock pattern are performed using a fast Fourier algorithm and characteristic Strouhal numbers of St=0.18 for the liquid jet breakup and of St=0.011 for the separation shock fluctuation are obtained. (orig.)

  7. Patterned Roughness for Cross-flow Transition Control at Mach 6

    Science.gov (United States)

    Arndt, Alexander; Matlis, Eric; Semper, Michael; Corke, Thomas

    2017-11-01

    Experiments are performed to investigate patterned discrete roughness for transition control on a sharp right-circular cone at an angle of attack at Mach 6.0. The approach to transition control is based on exciting less-amplified (subcritical) stationary cross-flow (CF) modes that suppress the growth of the more-amplified (critical) CF modes, and thereby delay transition. The experiments were performed in the Air Force Academy Ludwieg Tube which is a conventional (noisy) design. The cone model is equipped with a motorized 3-D traversing mechanism that mounts on the support sting. The traversing mechanism held a closely-spaced pair of fast-response total pressure Pitot probes. The model utilized a removable tip to exchange between different tip-roughness conditions. Mean flow distortion x-development indicated that the transition Reynolds number increased by 25% with the addition of the subcritical roughness. The energy in traveling disturbances was centered in the band of most amplified traveling CF modes predicted by linear theory. The spatial pattern in the amplitude of the traveling CF modes indicated a nonlinear (sum and difference) interaction between the stationary and traveling CF modes that might explain differences in Retrans between noisy and quiet environments. Air Force Grant FA9550-15-1-0278.

  8. Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training

    DEFF Research Database (Denmark)

    Olsen, Steen; Aagaard, Per; Kadi, Fawzi

    2006-01-01

    The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned to stren......The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (19-26 years) were assigned...

  9. Di-hadron azimuthal correlation and Mach-like cone structure in a parton/hadron transport model

    International Nuclear Information System (INIS)

    Ma, G.L.; Zhang, S.; Ma, Y.G.; Huang, H.Z.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zuo, J.X.

    2006-01-01

    In the framework of a multi-phase transport model (AMPT) with both partonic and hadronic interactions, azimuthal correlations between trigger particles and associated scattering particles have been studied by the mixing-event technique. The momentum ranges of these particles are 3 T trig T assoc T trig T assoc NN =200 GeV. A Mach-like structure has been observed in correlation functions for central collisions. By comparing scenarios with and without parton cascade and hadronic rescattering, we show that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure of the associated particle azimuthal correlations. The contribution of hadronic dynamical process cannot be ignored in the emergence of Mach-like correlations of the soft scattered associated hadrons. However, hadronic rescattering alone cannot reproduce experimental amplitude of Mach-like cone on away-side, and the parton cascade process is essential to describe experimental amplitude of Mach-like cone on away-side. In addition, both the associated multiplicity and the sum of p T decrease, while the T > increases, with the impact parameter in the AMPT model including partonic dynamics from string melting scenario

  10. What Motivates an Ever Increasing Number of Students to Enroll in Part-Time Taught Postgraduate Awards?

    Science.gov (United States)

    Ho, Amaly; Kember, David; Hong, Celina

    2012-01-01

    There has been a substantial rise in the number of students enrolling in part-time taught postgraduate awards. This study investigates the reasons or motivation for students to spend significant amounts on tutorial fees and find time alongside work, family and social commitments to take a taught postgraduate award. Data were gathered through…

  11. Isolation and characterization of novel mutations in the pSC101 origin that increase copy number

    DEFF Research Database (Denmark)

    Thompson, Mitchell G.; Sedaghatian, Nima; Barajas, Jesus F.

    2018-01-01

    /cell) based plasmids, respectively. The mutant copy number variants retained compatibility with p15a, pBBR, and ColE1 origins of replication. These pSC101 variants may be useful in future metabolic engineering efforts that require medium or high-copy vectors compatible with p15a- and ColE1-based plasmids....

  12. Biochemical failure after radical prostatectomy in intermediate-risk group men increases with the number of risk factors

    Directory of Open Access Journals (Sweden)

    Nobuki Furubayashi

    2017-01-01

    Conclusion: The number of intermediate risk factors is significantly associated with the PSA failure-free survival rate after radical prostatectomy in the intermediate-risk group. Patients classified into the intermediate-risk group based on all three intermediate risk factors are less likely to achieve a complete cure through surgery alone.

  13. When larger brains do not have more neurons: Increased numbers of cells are compensated by decreased average cell size across mouse individuals

    Directory of Open Access Journals (Sweden)

    Suzana eHerculano-Houzel

    2015-06-01

    Full Text Available There is a strong trend toward increased brain size in mammalian evolution, with larger brains composed of more and larger neurons than smaller brains across species within each mammalian order. Does the evolution of increased numbers of brain neurons, and thus larger brain size, occur simply through the selection of individuals with more and larger neurons, and thus larger brains, within a population? That is, do individuals with larger brains also have more, and larger, neurons than individuals with smaller brains, such that allometric relationships across species are simply an extension of intraspecific scaling? Here we show that this is not the case across adult male mice of a similar age. Rather, increased numbers of neurons across individuals are accompanied by increased numbers of other cells and smaller average cell size of both types, in a trade-off that explains how increased brain mass does not necessarily ensue. Fundamental regulatory mechanisms thus must exist that tie numbers of neurons to numbers of other cells and to average cell size within individual brains. Finally, our results indicate that changes in brain size in evolution are not an extension of individual variation in numbers of neurons, but rather occur through step changes that must simultaneously increase numbers of neurons and cause cell size to increase, rather than decrease.

  14. Chewing suppresses the stress-induced increase in the number of pERK-immunoreactive cells in the periaqueductal grey.

    Science.gov (United States)

    Yamada, Kentaro; Narimatsu, Yuri; Ono, Yumie; Sasaguri, Ken-Ichi; Onozuka, Minoru; Kawata, Toshitsugu; Yamamoto, Toshiharu

    2015-07-10

    We investigated the effects of chewing under immobilization stress on the periaqueductal gray (PAG) matter using phosphorylated extracellular signal-regulated kinase (pERK) as a marker of responding cells. Immobilization stress increased pERK-immunoreactive cells in the PAG. Among four subdivisions of the PAG, the increase of immunoreactive cells was remarkable in the dorsolateral and ventrolateral subdivisions. However, increase of pERK-immunoreactive cells by the immobilization stress was not so evident in the dorsomedial and lateral subdivisions. The chewing under immobilization stress prevented the stress-induced increase of pERK-immunoreactive cells in the dorsolateral and ventrolateral subdivisions with statistical significances (p<0.05). Again, chewing effects on pERK-immunoreactive cells were not visible in the dorsomedial and lateral subdivisions. These results suggest that the chewing alleviates the PAG (dorsolateral and ventrolateral subdivisions) responses to stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. The intellectual quadrangle: Mach-Boltzmann-Planck-Einstein

    International Nuclear Information System (INIS)

    Broda, E.

    1981-01-01

    These four men were influential in the transition from classical to modern physics. They interacted as scientists, often antagonistically. Thus Boltzmann was the greatest champion of the atom, while Mach remained unconvinced all his life. As a aphysicist, Einstein was greatly influenced by both Mach and Boltzmann, although Mach in the end rejected relativity as well. Because of his work on statistical mechanics, fluctuations, and quantum theory, Einstein has been called the natural successor to Boltzmann. Planck also was influenced by Mach at first. Hence he and Boltzmann were adversaries antil Planck converted to atomistics in 1900 and used the statistical interpretation of entropy to establish his radiation law. Planck accepted relativity early, but in quantum theory he was for a long time partly opposed to Einstein, and vice versa - Einstein considered Planck's derivation of his radiation law as unsound, while Planck could not accept the light quantum. In the case of all four physicists, science was interwoven with philosophy. Boltzmann consistently fought Mach's positivism, while Planck and Einstein moved from positivism to realism. All were also, though in very different ways, actively interested in public affairs. (orig.)

  16. Ex vivo lung perfusion to improve donor lung function and increase the number of organs available for transplantation.

    Science.gov (United States)

    Valenza, Franco; Rosso, Lorenzo; Coppola, Silvia; Froio, Sara; Palleschi, Alessandro; Tosi, Davide; Mendogni, Paolo; Salice, Valentina; Ruggeri, Giulia M; Fumagalli, Jacopo; Villa, Alessandro; Nosotti, Mario; Santambrogio, Luigi; Gattinoni, Luciano

    2014-06-01

    This paper describes the initial clinical experience of ex vivo lung perfusion (EVLP) at the Fondazione Ca' Granda in Milan between January 2011 and May 2013. EVLP was considered if donor PaO2 /FiO2 was below 300 mmHg or if lung function was doubtful. Donors with massive lung contusion, aspiration, purulent secretions, pneumonia, or sepsis were excluded. EVLP was run with a low-flow, open atrium and low hematocrit technique. Thirty-five lung transplants from brain death donors were performed, seven of which after EVLP. EVLP donors were older (54 ± 9 years vs. 40 ± 15 years, EVLP versus Standard, P donor organs and resulted in successful transplants with lungs that would have otherwise been rejected (ClinicalTrials.gov number: NCT01967953). © 2014 The Authors. Transplant International published by John Wiley & Sons Ltd on behalf of Steunstichting ESOT.

  17. Meta-analysis identifies 29 additional ulcerative colitis risk loci, increasing the number of confirmed associations to 47

    DEFF Research Database (Denmark)

    Anderson, Carl A; Boucher, Gabrielle; Lees, Charlie W

    2011-01-01

    Genome-wide association studies and candidate gene studies in ulcerative colitis have identified 18 susceptibility loci. We conducted a meta-analysis of six ulcerative colitis genome-wide association study datasets, comprising 6,687 cases and 19,718 controls, and followed up the top association...... signals in 9,628 cases and 12,917 controls. We identified 29 additional risk loci (P associated loci to 47. After annotating associated regions using GRAIL, expression quantitative trait loci data and correlations with non-synonymous SNPs, we...... identified many candidate genes that provide potentially important insights into disease pathogenesis, including IL1R2, IL8RA-IL8RB, IL7R, IL12B, DAP, PRDM1, JAK2, IRF5, GNA12 and LSP1. The total number of confirmed inflammatory bowel disease risk loci is now 99, including a minimum of 28 shared association...

  18. Effect of increasing diffusion gradient direction number on diffusion tensor imaging fiber tracking in the human brain

    International Nuclear Information System (INIS)

    Yao, Xu Fang; Liang, Bie Bei; Xia, Tian; Huang, Qin Ming; Zhuang, Song Lin; Yu, Tong Gang

    2015-01-01

    To assess the effects of varying the number of diffusion gradient directions (NDGDs) on diffusion tensor fiber tracking (FT) in human brain white matter using tract characteristics. Twelve normal volunteers underwent diffusion tensor imaging (DTI) scanning with NDGDs of 6, 11, 15, 21, and 31 orientations. Three fiber tract groups, including the splenium of the corpus callosum (CC), the entire CC, and the full brain tract, were reconstructed by deterministic DTI-FT. Tract architecture was first qualitatively evaluated by visual observation. Six quantitative tract characteristics, including the number of fibers (NF), average length (AL), fractional anisotropy (FA), relative anisotropy (RA), mean diffusivity (MD), and volume ratio (VR) were measured for the splenium of the CC at the tract branch level, for the entire CC at tract level, and for the full brain tract at the whole brain level. Visual results and those of NF, AL, FA, RA, MD, and VR were compared among the five different NDGDs. The DTI-FT with NDGD of 11, 15, 21, and 31 orientations gave better tracking results compared with NDGD of 6 after the visual evaluation. NF, FA, RA, MD, and VR values with NDGD of six were significantly greater (smallest p = 0.001 to largest p = 0.042) than those with four other NDGDs (11, 15, 21, or 31 orientations), whereas AL measured with NDGD of six was significantly smaller (smallest p = 0.001 to largest p = 0.041) than with four other NDGDs (11, 15, 21, or 31 orientations). No significant differences were observed in the results among the four NDGD groups of 11, 15, 21, and 31 directions (smallest p = 0.059 to largest p = 1.000). The main fiber tracts were detected with NDGD of six orientations; however, the use of larger NDGD (> or = 11 orientations) could provide improved tract characteristics at the expense of longer scanning time.

  19. Effect of increasing diffusion gradient direction number on diffusion tensor imaging fiber tracking in the human brain

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Xu Fang; Liang, Bie Bei; Xia, Tian; Huang, Qin Ming; Zhuang, Song Lin [School of Optical-Electrical and Computer Engineering, Shanghai Medical Instrument College, University of Shanghai for Science and Technology, Shanghai (China); Yu, Tong Gang [Dept. of Radiology, Huashan Hospital, Fudan University, Shanghai (China)

    2015-04-15

    To assess the effects of varying the number of diffusion gradient directions (NDGDs) on diffusion tensor fiber tracking (FT) in human brain white matter using tract characteristics. Twelve normal volunteers underwent diffusion tensor imaging (DTI) scanning with NDGDs of 6, 11, 15, 21, and 31 orientations. Three fiber tract groups, including the splenium of the corpus callosum (CC), the entire CC, and the full brain tract, were reconstructed by deterministic DTI-FT. Tract architecture was first qualitatively evaluated by visual observation. Six quantitative tract characteristics, including the number of fibers (NF), average length (AL), fractional anisotropy (FA), relative anisotropy (RA), mean diffusivity (MD), and volume ratio (VR) were measured for the splenium of the CC at the tract branch level, for the entire CC at tract level, and for the full brain tract at the whole brain level. Visual results and those of NF, AL, FA, RA, MD, and VR were compared among the five different NDGDs. The DTI-FT with NDGD of 11, 15, 21, and 31 orientations gave better tracking results compared with NDGD of 6 after the visual evaluation. NF, FA, RA, MD, and VR values with NDGD of six were significantly greater (smallest p = 0.001 to largest p = 0.042) than those with four other NDGDs (11, 15, 21, or 31 orientations), whereas AL measured with NDGD of six was significantly smaller (smallest p = 0.001 to largest p = 0.041) than with four other NDGDs (11, 15, 21, or 31 orientations). No significant differences were observed in the results among the four NDGD groups of 11, 15, 21, and 31 directions (smallest p = 0.059 to largest p = 1.000). The main fiber tracts were detected with NDGD of six orientations; however, the use of larger NDGD (> or = 11 orientations) could provide improved tract characteristics at the expense of longer scanning time.

  20. Farm Business Management Analysis: Adjusting the Farm Business to Increase Profit. Unit III. Volume 15, Number 3. Instructor's Guide.

    Science.gov (United States)

    Denker, Robert; And Others

    Designed primarily for Missouri vocational agricultural instructors participating in the Farm Business Management Analysis Program, this instructor's guide, consisting of 10 lessons, deals with adjusting a farm business to increase profits. The following topics are covered in the individual lessons: law and the farm family, planning income tax…

  1. Method of producing a diesel fuel blend having a pre-determined flash-point and pre-determined increase in cetane number

    Science.gov (United States)

    Waller, Francis Joseph; Quinn, Robert

    2004-07-06

    The present invention relates to a method of producing a diesel fuel blend having a pre-determined flash-point and a pre-determined increase in cetane number over the stock diesel fuel. Upon establishing the desired flash-point and increase in cetane number, an amount of a first oxygenate with a flash-point less than the flash-point of the stock diesel fuel and a cetane number equal to or greater than the cetane number of the stock diesel fuel is added to the stock diesel fuel in an amount sufficient to achieve the pre-determined increase in cetane number. Thereafter, an amount of a second oxygenate with a flash-point equal to or greater than the flash-point of the stock diesel fuel and a cetane number greater than the cetane number of the stock diesel fuel is added to the stock diesel fuel in an amount sufficient to achieve the pre-determined increase in cetane number.

  2. Ectopic phytocystatin expression increases nodule numbers and influences the responses of soybean (Glycine max) to nitrogen deficiency.

    Science.gov (United States)

    Quain, Marian D; Makgopa, Matome E; Cooper, James W; Kunert, Karl J; Foyer, Christine H

    2015-04-01

    Cysteine proteases and cystatins have many functions that remain poorly characterised, particularly in crop plants. We therefore investigated the responses of these proteins to nitrogen deficiency in wild-type soybeans and in two independent transgenic soybean lines (OCI-1 and OCI-2) that express the rice cystatin, oryzacystatin-I (OCI). Plants were grown for four weeks under either a high (5 mM) nitrate (HN) regime or in the absence of added nitrate (LN) in the absence or presence of symbiotic rhizobial bacteria. Under the LN regime all lines showed similar classic symptoms of nitrogen deficiency including lower shoot biomass and leaf chlorophyll. However, the LN-induced decreases in leaf protein and increases in root protein tended to be smaller in the OCI-1 and OCI-2 lines than in the wild type. When LN-plants were grown with rhizobia, OCI-1 and OCI-2 roots had significantly more crown nodules than wild-type plants. The growth nitrogen regime had a significant effect on the abundance of transcripts encoding vacuolar processing enzymes (VPEs), LN-dependent increases in VPE2 and VPE3 transcripts in all lines. However, the LN-dependent increases of VPE2 and VPE3 transcripts were significantly lower in the leaves of OCI-1 and OCI-2 plants than in the wild type. These results show that nitrogen availability regulates the leaf and root cysteine protease, VPE and cystatin transcript profiles in a manner that is in some cases influenced by ectopic OCI expression. Moreover, the OCI-dependent inhibition of papain-like cysteine proteases favours increased nodulation and enhanced tolerance to nitrogen limitation, as shown by the smaller LN-dependent decreases in leaf protein observed in the OCI-1 and OCI-2 plants relative to the wild type. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Heat transfer to surface and gaps of RSI tile arrays in turbulent flow at Mach 10.3

    Science.gov (United States)

    Throckmorton, D. A.

    1974-01-01

    Heat transfer to gap walls and surface of a simulated reusable surface insulation (RSI) tile array are presented. The data were obtained in the thick, turbulent tunnel wall boundary layer of the Langley Continuous Flow Hypersonic Tunnel at a freestream Mach number of 10.3 and a freestream unit Reynolds number of one million. Pertinent test variables were: (1) tile array orientation (staggered and in-line), (2) gap width, (3) flow angularity, and (4) tile mismatch.

  4. Computation of Mach reflection from rigid and yielding surfaces

    International Nuclear Information System (INIS)

    Buckingham, A.C.; Wilson, S.S.

    1976-01-01

    The present discussion centers on a theoretical description of one aspect of the irregular or Mach reflection from solid surfaces. The discussion is restricted to analytical considerations and some preliminary results using model approximations to the surface interaction phenomena. Currently, full numerical simulations of the irregular reflection surface interaction dynamics have not been obtained since the method is still under development. Discussion of the numerical method is, therefore, restricted to some special procedures for the gas-solid surface boundary dynamics. The discussion is divided into an introductory section briefly describing a particular Mach reflection process. Subsequently, some of the considerations on boundary conditions are submitted for numerical treatment of the gas-solid interface. Analysis and discussion of a yielding solid surface subjected to impulsive loading from an intense gas shock wave follows. This is used as a guide for the development of the numerical procedure. Mach reflection processes are then briefly reviewed with special attention for similitude and singular perturbation features

  5. Changes in human dendritic cell number and function in severe obesity may contribute to increased susceptibility to viral infection.

    LENUS (Irish Health Repository)

    O'Shea, D

    2013-02-26

    Dendritic cells (DCs) are key immune sentinels linking the innate and adaptive immune systems. DCs recognise danger signals and initiate T-cell tolerance, memory and polarisation. They are critical cells in responding to a viral illness. Obese individuals have been shown to have an impaired response to vaccinations against virally mediated conditions and to have an increased susceptibility to multi-organ failure in response to viral illness. We investigated if DCs are altered in an obese cohort (mean body mass index 51.7±7.3 kg m(-2)), ultimately resulting in differential T-cell responses. Circulating DCs were found to be significantly decreased in the obese compared with the lean cohort (0.82% vs 2.53%). Following Toll-like receptor stimulation, compared with lean controls, DCs generated from the obese cohort upregulated significantly less CD83 (40% vs 17% mean fluorescence intensity), a molecule implicated in the elicitation of T-cell responses, particularly viral responses. Obese DCs produced twofold more of the immunosuppressive cytokine interleukin (IL)-10 than lean controls, and in turn stimulated fourfold more IL-4-production from allogenic naive T cells. We conclude that obesity negatively impacts the ability of DCs to mature and elicit appropriate T-cell responses to a general stimulus. This may contribute to the increased susceptibility to viral infection observed in severe obesity.International Journal of Obesity advance online publication, 26 February 2013; doi:10.1038\\/ijo.2013.16.

  6. Increasing the Number of Outpatients Receiving Spiritual Assessment: A Pain and Palliative Care Service Quality Improvement Project.

    Science.gov (United States)

    Gomez-Castillo, Blanca J; Hirsch, Rosemarie; Groninger, Hunter; Baker, Karen; Cheng, M Jennifer; Phillips, Jayne; Pollack, John; Berger, Ann M

    2015-11-01

    Spirituality is a patient need that requires special attention from the Pain and Palliative Care Service team. This quality improvement project aimed to provide spiritual assessment for all new outpatients with serious life-altering illnesses. Percentage of new outpatients receiving spiritual assessment (Faith, Importance/Influence, Community, Address/Action in care, psychosocial evaluation, chaplain consults) at baseline and postinterventions. Interventions included encouraging clinicians to incorporate adequate spiritual assessment into patient care and implementing chaplain covisits for all initial outpatient visits. The quality improvement interventions increased spiritual assessment (baseline vs. postinterventions): chaplain covisits (25.5% vs. 50%), Faith, Importance/Influence, Community, Address/Action in care completion (49% vs. 72%), and psychosocial evaluation (89% vs. 94%). Improved spiritual assessment in an outpatient palliative care clinic setting can occur with a multidisciplinary approach. This project also identifies data collection and documentation processes that can be targeted for improvement. Published by Elsevier Inc.

  7. Application of distilled white vinegar in the cloaca to counter the increase in Campylobacter numbers on broiler skin during feather removal.

    Science.gov (United States)

    Berrang, M E; Smith, D P; Hinton, A

    2006-02-01

    Because of the escape of highly contaminated gut contents from the cloaca of positive carcasses, Campylobacter numbers recovered from broiler carcass skin samples increase during automated feather removal. Vinegar is known to have antimicrobial action. The objective of this study was to determine the effect of vinegar placed in the cloaca prior to feather removal on the numbers of Campylobacter recovered from broiler breast skin. Broilers were stunned, killed, and bled in a pilot processing plant. Vinegar was placed in the colons of the chickens prior to scalding. Carcasses were scalded, and Campylobacter numbers were determined on breast skin before and after passage through a commercial-style feather-picking machine. Campylobacter numbers recovered from the breast skin of untreated control carcasses increased during feather removal from 1.3 log CFU per sample prior to defeathering to 4.2 log afterward. Placement of water in the colon before scalding had no effect on Campylobacter numbers. Campylobacter numbers recovered from the breast skin of carcasses treated with vinegar also increased during defeathering but to a significantly lesser extent. Treated carcasses experienced only a 1-log increase from 1.6 log CFU per sample before feather removal to 2.6 log CFU per sample afterward. Application of an effective food-grade antimicrobial in the colon prior to scald can limit the increase in Campylobacter contamination of broiler carcasses during defeathering.

  8. Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

    Science.gov (United States)

    Larson, Diane L.; Rabie, Paul A.; Droege, Sam; Larson, Jennifer L.; Haar, Milton

    2016-01-01

    The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on the probability of long-term effects on plant-pollinator interactions and the stability of network structure. Here we describe changes in network topology and modular structure of infested and non-infested networks during the flowering season of the generalist non-native flowering plant, Cirsium arvense in mixed-grass prairie at Badlands National Park, South Dakota, USA. Objectives were to compare network-level effects of infestation as they propagate over the season in infested and non-infested (with respect to C. arvense) networks. We characterized plant-pollinator networks on 5 non-infested and 7 infested 1-ha plots during 4 sample periods that collectively covered the length of C. arvense flowering period. Two other abundantly-flowering invasive plants were present during this time: Melilotus officinalis had highly variable floral abundance in both C. arvense-infested and non-infested plots andConvolvulus arvensis, which occurred almost exclusively in infested plots and peaked early in the season. Modularity, including roles of individual species, and network topology were assessed for each sample period as well as in pooled infested and non-infested networks. Differences in modularity and network metrics between infested and non-infested networks were limited to the third and fourth sample periods, during flower senescence of C. arvenseand the other invasive species; generality of pollinators rose concurrently, suggesting rewiring of the network and a lag effect of earlier floral abundance. Modularity was lower and number of connectors higher in infested

  9. Cluster lot quality assurance sampling: effect of increasing the number of clusters on classification precision and operational feasibility.

    Science.gov (United States)

    Okayasu, Hiromasa; Brown, Alexandra E; Nzioki, Michael M; Gasasira, Alex N; Takane, Marina; Mkanda, Pascal; Wassilak, Steven G F; Sutter, Roland W

    2014-11-01

    To assess the quality of supplementary immunization activities (SIAs), the Global Polio Eradication Initiative (GPEI) has used cluster lot quality assurance sampling (C-LQAS) methods since 2009. However, since the inception of C-LQAS, questions have been raised about the optimal balance between operational feasibility and precision of classification of lots to identify areas with low SIA quality that require corrective programmatic action. To determine if an increased precision in classification would result in differential programmatic decision making, we conducted a pilot evaluation in 4 local government areas (LGAs) in Nigeria with an expanded LQAS sample size of 16 clusters (instead of the standard 6 clusters) of 10 subjects each. The results showed greater heterogeneity between clusters than the assumed standard deviation of 10%, ranging from 12% to 23%. Comparing the distribution of 4-outcome classifications obtained from all possible combinations of 6-cluster subsamples to the observed classification of the 16-cluster sample, we obtained an exact match in classification in 56% to 85% of instances. We concluded that the 6-cluster C-LQAS provides acceptable classification precision for programmatic action. Considering the greater resources required to implement an expanded C-LQAS, the improvement in precision was deemed insufficient to warrant the effort. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Themudo, Raquel; Johansson, Lars; Ebeling-Barbier, Charlotte; Ahlstroem, Haakan; Bjerner, Tomas [Uppsala University Hospital, Department of Radiology, Uppsala (Sweden); Lind, Lars [Uppsala University Hospital, Department of Medicine, Uppsala (Sweden)

    2017-02-15

    In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time. From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium. In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75. The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time. (orig.)

  11. Effects of a combined Bleomycin/radiotherapy on the increase of cell numbers in Ehrlich ascitic carcinoma

    International Nuclear Information System (INIS)

    Mueller, W.A.

    1980-01-01

    The effects of separate and combined application of the cytostatic Bleomycin and X-radiation on the multiplication of the Ehrlich ascitic tumour cells in vivo and on the survival time of tumourous mice was examined by applying automatic, electronic cell counting. If this cytostatic is administered alone up to 100 mg/kg the growth curve of the EAT-cells shows, after a 24 hours' delay, hardly any difference to that of untreated tumour cells. The separate administration of such Bleomycin doses and the separate X-radiation of the EAT cells with doses of up to 1000 rad had no significant influence on the survival time of tumourous mice. The combined application of Bleomycin and X-radiation elongates the 50%-survival time of the tumourous mice. If the X-radiation takes place 12 hours after the Bleomycin treatment the animals survive longer than is the case with simultaneous treatment. Although no dose effect curves could be set up the results obtained let assume a synergistic effect of Bleomycin and irradiation which is especially significant if the radiation is carried out 12 hours after a Bleomycin treatment. The reasons of this are assumed to lie in the increased radiation sensitivity of the tumour cells caused by the bleomycin-induced partial synchronisation of the EAT cells. (orig.) [de

  12. Number of Published Randomized Controlled Multi Center Trials Testing Pharmacological Interventions or Devices Is Increasing in Both Medical and Surgical Specialties

    DEFF Research Database (Denmark)

    Danielsen, Anne Kjaergaard; Okholm, Cecilie; Pommergaard, Hans-Christian

    2014-01-01

    : The object of this study was to investigate the development in the organization of multicenter studies, the distribution of studies within different clinical specialties, across continents, and investigate the differences related to testing various interventions. METHODS AND MATERIALS: A literature search...... was done in MEDLINE for multicenter studies published in 1995, 2000, 2005, and 2010, respectively. Data extraction identified data related to clinical specialties, interventions, participating patients, departments, countries, and continents. RESULTS: The number of multicenter studies increased from 112...... as the number of participating departments increased during the time span, though the increase in studies was most evident in Europe and North America compared with the rest of the world....

  13. ADDITION POLYUNSATURATED FATTY ACIDS IN THE DIET INCREASES THE NUMBER AND SIZE OF FOLLICLES IN COWS FED UNDER TROPICAL GRAZING SYSTEM

    Directory of Open Access Journals (Sweden)

    G. Cansino-Arroyo

    2014-08-01

    Full Text Available The objective was determined the effect of polyunsaturated fatty acids (PUFAS on the number and follicular size in cows fed under tropical grazing during the dry season and rainy season. Using a group of cows PUFAS (GA, dry: n=9 and rain: n=13 maintained under grazing continuo, which received a nutritional supplement, with the addition of 5 % of PUFAS in the supplement. A second control group (GT; dry: n=13 and rain: n=9, kept in the same conditions as the previous group, without PUFAS. The number of follicles was greater during the rainy season than during dry (P=0.0001. Cows GT nutritional supplement did not improve the number of follicles between 2 times (P ≥ 0.7. However, the addition of PUFAS to supplement increases the number of follicles during the rainy season (P=0.002. Otherwise, when the cows were ovulation hormonally stimulated are not noted an increase in the number of follicles in cows with or without PUFAS in the supplement. With these results, we can conclude that the number of follicles is affected by perceived conditions, besides that addition of PUFAS increases the number of follicles during the rainy season in tropical grazing cows.

  14. Unbiased cell quantification reveals a continued increase in the number of neocortical neurones during early post-natal development in mice

    DEFF Research Database (Denmark)

    Lyck, Lise; Krøigård, Thomas; Finsen, Bente

    2007-01-01

    The post-natal growth spurt of the mammalian neocortex has been attributed to maturation of dendritic arborizations, growth and myelination of axons, and addition of glia. It is unclear whether this growth may also involve recruitment of additional neurones. Using stereological methods, we analysed...... the number of neurones and glia in the neocortex during post-natal development in two separate strains of mice. Cell counting by the optical fractionator revealed that the number of neurones increased 80-100% from the time of birth to post-natal day (P)16, followed by a reduction by approximately 25...... was delayed until P16. The number of glia reached its maximum at P16, whereas the number of oligodendroglia, identified using a transgenic marker, increased until P55, the latest time of observation. Neurones continued to accumulate in the developing neocortex during the first 2 weeks of post...

  15. Zebularine treatment is associated with deletion of FT-B1 leading to an increase in spikelet number in bread wheat.

    Science.gov (United States)

    Finnegan, E Jean; Ford, Brett; Wallace, Xiaomei; Pettolino, Filomena; Griffin, Patrick T; Schmitz, Robert J; Zhang, Peng; Barrero, Jose M; Hayden, Matthew J; Boden, Scott A; Cavanagh, Colin A; Swain, Steve M; Trevaskis, Ben

    2018-06-01

    The number of rachis nodes (spikelets) on a wheat spike is a component of grain yield that correlates with flowering time. The genetic basis regulating flowering in cereals is well understood, but there are reports that flowering time can be modified at a high frequency by selective breeding, suggesting that it may be regulated by both epigenetic and genetic mechanisms. We investigated the role of DNA methylation in regulating spikelet number and flowering time by treating a semi-spring wheat with the demethylating agent, Zebularine. Three lines with a heritable increase in spikelet number were identified. The molecular basis for increased spikelet number was not determined in 2 lines, but the phenotype showed non-Mendelian inheritance, suggesting that it could have an epigenetic basis. In the remaining line, the increased spikelet phenotype behaved as a Mendelian recessive trait and late flowering was associated with a deletion encompassing the floral promoter, FT-B1. Deletion of FT-B1 delayed the transition to reproductive growth, extended the duration of spike development, and increased spikelet number under different temperature regimes and photoperiod. Transiently disrupting DNA methylation can generate novel flowering behaviour in wheat, but these changes may not be sufficiently stable for use in breeding programs. © 2018 John Wiley & Sons Ltd.

  16. MACH MIT: Deutsches Wochenende am Karlsfluss (MACH MIT: a German Week-End on the Charles River).

    Science.gov (United States)

    Reizes, Sonia; Kramsch, Claire J.

    1980-01-01

    Describes a joint high school/college pilot program planned by Massachusetts foreign language teachers and hosted by M.I.T. The success of the program dubbed "MACH MIT Total Immersion German Weekend" is attributed to the concept of active involvement, which was implemented through games, seminars, shows, cooking and other activities.…

  17. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

    Directory of Open Access Journals (Sweden)

    Cecilia Cuatianquiz Lima

    2016-03-01

    Full Text Available Secondary cavity nesting (SCN birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011. In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

  18. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes.

    Science.gov (United States)

    Cuatianquiz Lima, Cecilia; Macías Garcia, Constantino

    2016-01-01

    Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January-October 2009-2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

  19. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

    Science.gov (United States)

    Cuatianquiz Lima, Cecilia

    2016-01-01

    Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity. PMID:26998410

  20. An extract of pomegranate fruit and galangal rhizome increases the numbers of motile sperm: a prospective, randomised, controlled, double-blinded trial.

    Science.gov (United States)

    Fedder, Maja D K; Jakobsen, Henrik B; Giversen, Ina; Christensen, Lars P; Parner, Erik T; Fedder, Jens

    2014-01-01

    Pomegranate fruit (Punica granatum) and galangal (Alpinia galanga) have separately been shown to stimulate spermatogenesis and to increase sperm counts and motility in rodents. Within traditional medicine, pomegranate fruit has long been used to increase fertility, however studies on the effect on spermatogenesis in humans have never been published. With this study we investigated whether oral intake of tablets containing standardised amounts of extract of pomegranate fruit and powder of greater galangal rhizome (Punalpin) would increase the total number of motile spermatozoa. The study was designed as a prospective, randomized, controlled, double-blinded trial. Enrolment was based on the mean total number of motile spermatozoa of two ejaculates. The participants delivered an ejaculate after 4-8 days of tablet intake and two ejaculates just before they stopped taking the tablets. Seventy adult men with a semen quality not meeting the standards for commercial application at Nordic Cryobank, but without azoospermia, were included in the study. Participants were randomized to take tablets containing extract of pomegranate fruit (standardised with respect to punicalagin A+B, punicalin and ellagic acid) and freeze-dried rhizome of greater galangal (standardised with respect to 1'S-1'-acetoxychavicol acetate) or placebo on a daily basis for three months. Sixty-six participants completed the intervention (active treatment: n = 34; placebo: n = 32). After the intervention the total number of motile spermatozoa was increased in participants treated with plant extracts compared with the placebo group (p = 0.026). After three months of active treatment, the average total number of motile sperm increased by 62% (from 23.4 to 37.8 millions), while for the placebo group, the number of motile sperm increased by 20%. Sperm morphology was not affected by the treatment. Our findings may help subfertile men to gain an improved amount of motile ejaculated sperm by taking tablets

  1. Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder?

    Science.gov (United States)

    Kessing, L V; Andersen, P K

    2004-12-01

    Several findings suggest that some patients with depressive or bipolar disorder may be at increased risk of developing dementia. The present study aimed to investigate whether the risk of developing dementia increases with the number of affective episodes in patients with depressive disorder and in patients with bipolar disorder. This was a case register study including all hospital admissions with primary affective disorder in Denmark during 1970-99. The effect of the number of prior episodes leading to admission on the rate of readmission with a diagnosis of dementia following the first discharge after 1985 was estimated. A total of 18,726 patients with depressive disorder and 4248 patients with bipolar disorder were included in the study. The rate of a diagnosis of dementia on readmission was significantly related to the number of prior affective episodes leading to admission. On average, the rate of dementia tended to increase 13% with every episode leading to admission for patients with depressive disorder and 6% with every episode leading to admission for patients with bipolar disorder, when adjusted for differences in age and sex. On average, the risk of dementia seems to increase with the number of episodes in depressive and bipolar affective disorders.

  2. Measurements of flows in the DIII-D divertor by Mach probes

    International Nuclear Information System (INIS)

    Boedo, J.A.; Lehmer, R.; Moyer, R.A.; Watkins, J.G.; Porter, G.D.; Evans, T.E.; Leonard, A.W.; Schaffer, M.J.

    1998-06-01

    First measurements of Mach number of background plasma in the DIII-D divertor are presented in conjunction with temperature T e and density n e using a fast scanning probe array. To validate the probe measurements, the authors compared the T e , n e and J sat data to Thomson scattering data and find good overall agreement in attached discharges and some discrepancy for T e and n e in detached discharges. The discrepancy is mostly due to the effect of large fluctuations present during detached plasmas on the probe characteristic; the particle flux is accurately measured in every case. A composite 2-D map of measured flows is presented for an ELMing H-mode discharge and they focus on some of the details. They have also documented the temperature, density and Mach number in the private flux region of the divertor and the vicinity of the X-point, which are important transition regions that have been little studied or modeled. Background parallel plasma flows and electric fields in the divertor region show a complex structure

  3. Does the risk of developing dementia increase with the number of episodes in patients with depressive disorder and in patients with bipolar disorder?

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Andersen, Per Kragh

    2004-01-01

    OBJECTIVE: Several findings suggest that some patients with depressive or bipolar disorder may be at increased risk of developing dementia. The present study aimed to investigate whether the risk of developing dementia increases with the number of affective episodes in patients with depressive...... following the first discharge after 1985 was estimated. A total of 18,726 patients with depressive disorder and 4248 patients with bipolar disorder were included in the study. RESULTS: The rate of a diagnosis of dementia on readmission was significantly related to the number of prior affective episodes...... leading to admission. On average, the rate of dementia tended to increase 13% with every episode leading to admission for patients with depressive disorder and 6% with every episode leading to admission for patients with bipolar disorder, when adjusted for differences in age and sex. CONCLUSION...

  4. Blunt body near wake flow field at Mach 6

    Science.gov (United States)

    Horvath, Thomas J.; McGinley, Catherine B.; Hannemann, Klaus

    1996-01-01

    Tests were conducted in a Mach 6 flow to examine the reattachment process of an axisymmetric free shear layer associated with the near wake of a 70 deg. half angle, spherically blunted cone with a cylindrical after body. Model angle of incidence was fixed at 0 deg. and free-stream Reynolds numbers based on body diameter ranged from 0.5 x 10(exp 6) to 4 x 10(exp 6). The sensitivity of wake shear layer transition on reattachment heating was investigated. The present perfect gas study was designed to compliment results obtained previously in facilities capable of producing real gas effects. The instrumented blunted cone model was designed primarily for testing in high enthalpy hypervelocity shock tunnels in both this country and abroad but was amenable for testing in conventional hypersonic blowdown wind tunnels as well. Surface heating rates were inferred from temperature - time histories from coaxial surface thermocouples on the model forebody and thin film resistance gages along the model base and cylindrical after body. General flow feature (bow shock, wake shear layer, and recompression shock) locations were visually identified by schlieren photography. Mean shear layer position and growth were determined from intrusive pitot pressure surveys. In addition, wake surveys with a constant temperature hot-wire anemometer were utilized to qualitatively characterize the state of the shear layer prior to reattachment. Experimental results were compared to laminar perfect gas predictions provided by a 3-D Navier Stokes code (NSHYP). Shear layer impingement on the instrumented cylindrical after body resulted in a localized heating maximum that was 21 to 29 percent of the forebody stagnation point heating. Peak heating resulting from the reattaching shear layer was found to be a factor of 2 higher than laminar predictions, which suggested a transitional shear layer. Schlieren flow visualization and fluctuating voltage time histories and spectra from the hot wire surveys

  5. Endurance Exercise Mobilizes Developmentally Early Stem Cells into Peripheral Blood and Increases Their Number in Bone Marrow: Implications for Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2016-01-01

    Full Text Available Endurance exercise has been reported to increase the number of circulating hematopoietic stem/progenitor cells (HSPCs in peripheral blood (PB as well as in bone marrow (BM. We therefore became interested in whether endurance exercise has the same effect on very small embryonic-like stem cells (VSELs, which have been described as a population of developmentally early stem cells residing in BM. Mice were run daily for 1 hour on a treadmill for periods of 5 days or 5 weeks. Human volunteers had trained in long-distance running for one year, six times per week. FACS-based analyses and RT-PCR of murine and human VSELs and HSPCs from collected bone marrow and peripheral blood were performed. We observed that endurance exercise increased the number of VSELs circulating in PB and residing in BM. In parallel, we observed an increase in the number of HSPCs. These observations were subsequently confirmed in young athletes, who showed an increase in circulating VSELs and HSPCs after intensive running exercise. We provide for the first time evidence that endurance exercise may have beneficial effects on the expansion of developmentally early stem cells. We hypothesize that these circulating stem cells are involved in repairing minor exercise-related tissue and organ injuries.

  6. Quantitative Global Heat Transfer in a Mach-6 Quiet Tunnel

    Science.gov (United States)

    Sullivan, John P.; Schneider, Steven P.; Liu, Tianshu; Rubal, Justin; Ward, Chris; Dussling, Joseph; Rice, Cody; Foley, Ryan; Cai, Zeimin; Wang, Bo; hide

    2012-01-01

    This project developed quantitative methods for obtaining heat transfer from temperature sensitive paint (TSP) measurements in the Mach-6 quiet tunnel at Purdue, which is a Ludwieg tube with a downstream valve, moderately-short flow duration and low levels of heat transfer. Previous difficulties with inferring heat transfer from TSP in the Mach-6 quiet tunnel were traced to (1) the large transient heat transfer that occurs during the unusually long tunnel startup and shutdown, (2) the non-uniform thickness of the insulating coating, (3) inconsistencies and imperfections in the painting process and (4) the low levels of heat transfer observed on slender models at typical stagnation temperatures near 430K. Repeated measurements were conducted on 7 degree-half-angle sharp circular cones at zero angle of attack in order to evaluate the techniques, isolate the problems and identify solutions. An attempt at developing a two-color TSP method is also summarized.

  7. Laser produced plasma density measurement by Mach-Zehnder interferometry

    International Nuclear Information System (INIS)

    Vaziri, A.; Kohanzadeh, Y.; Mosavi, R.K.

    1976-06-01

    This report describes an optical interferometric method of measuring the refractive index of the laser-produced plasma, giving estimates of its electron density. The plasma is produced by the interaction of a high power pulsed CO 2 laser beam with a solid target in the vacuum. The time varying plasma has a transient electron density. This transient electron density gives rise to a changing plasma refractive index. A Mach-Zehnder ruby laser interferometer is used to measure this refractive index change

  8. Maternal Exercise during Pregnancy Increases BDNF Levels and Cell Numbers in the Hippocampal Formation but Not in the Cerebral Cortex of Adult Rat Offspring.

    Directory of Open Access Journals (Sweden)

    Sérgio Gomes da Silva

    Full Text Available Clinical evidence has shown that physical exercise during pregnancy may alter brain development and improve cognitive function of offspring. However, the mechanisms through which maternal exercise might promote such effects are not well understood. The present study examined levels of brain-derived neurotrophic factor (BDNF and absolute cell numbers in the hippocampal formation and cerebral cortex of rat pups born from mothers exercised during pregnancy. Additionally, we evaluated the cognitive abilities of adult offspring in different behavioral paradigms (exploratory activity and habituation in open field tests, spatial memory in a water maze test, and aversive memory in a step-down inhibitory avoidance task. Results showed that maternal exercise during pregnancy increased BDNF levels and absolute numbers of neuronal and non-neuronal cells in the hippocampal formation of offspring. No differences in BDNF levels or cell numbers were detected in the cerebral cortex. It was also observed that offspring from exercised mothers exhibited better cognitive performance in nonassociative (habituation and associative (spatial learning mnemonic tasks than did offspring from sedentary mothers. Our findings indicate that maternal exercise during pregnancy enhances offspring cognitive function (habituation behavior and spatial learning and increases BDNF levels and cell numbers in the hippocampal formation of offspring.

  9. Low temperature-induced DNA hypermethylation attenuates expression of RhAG, an AGAMOUS homolog, and increases petal number in rose (Rosa hybrida).

    Science.gov (United States)

    Ma, Nan; Chen, Wen; Fan, Tiangang; Tian, Yaran; Zhang, Shuai; Zeng, Daxing; Li, Yonghong

    2015-10-05

    Flower development is central to angiosperm reproduction and is regulated by a broad range of endogenous and exogenous stimuli. It has been well documented that ambient temperature plays a key role in controlling flowering time; however, the mechanisms by which temperature regulates floral organ differentiation remain largely unknown. In this study, we show that low temperature treatment significantly increases petal number in rose (Rosa hybrida) through the promotion of stamen petaloidy. Quantitative RT-PCR analysis revealed that the expression pattern of RhAG, a rose homolog of the Arabidopsis thaliana AGAMOUS C-function gene, is associated with low temperature regulated flower development. Silencing of RhAG mimicked the impact of low temperature treatments on petal development by significantly increasing petal number through an increased production of petaloid stamens. In situ hybridization studies further revealed that low temperature restricts its spatial expression area. Analysis of DNA methylation level showed that low temperature treatment enhances the methylation level of the RhAG promoter, and a specific promoter region that was hypermethylated at CHH loci under low temperature conditions, was identified by bisulfite sequencing. This suggests that epigenetic DNA methylation contributes to the ambient temperature modulation of RhAG expression. Our results provide highlights in the role of RhAG gene in petal number determination and add a new layer of complexity in the regulation of floral organ development. We propose that RhAG plays an essential role in rose flower patterning by regulating petal development, and that low temperatures increase petal number, at least in part, by suppressing RhAG expression via enhancing DNA CHH hypermethylation of the RhAG promoter.

  10. SU-E-T-568: Improving Normal Brain Sparing with Increasing Number of Arc Beams for Volume Modulated Arc Beam Radiosurgery of Multiple Brain Metastases

    International Nuclear Information System (INIS)

    Hossain, S; Hildebrand, K; Ahmad, S; Larson, D; Ma, L; Sahgal, A

    2014-01-01

    Purpose: Intensity modulated arc beams have been newly reported for treating multiple brain metastases. The purpose of this study was to determine the variations in the normal brain doses with increasing number of arc beams for multiple brain metastases treatments via the TrueBeam Rapidarc system (Varian Oncology, Palo Alto, CA). Methods: A patient case with 12 metastatic brain lesions previously treated on the Leksell Gamma Knife Perfexion (GK) was used for the study. All lesions and organs at risk were contoured by a senior radiation oncologist and treatment plans for a subset of 3, 6, 9 and all 12 targets were developed for the TrueBeam Rapidarc system via 3 to 7 intensity modulated arc-beams with each target covered by at least 99% of the prescribed dose of 20 Gy. The peripheral normal brain isodose volumes as well as the total beam-on time were analyzed with increasing number of arc beams for these targets. Results: All intensisty modulated arc-beam plans produced efficient treatment delivery with the beam-on time averaging 0.6–1.5 min per lesion at an output of 1200 MU/min. With increasing number of arc beams, the peripheral normal brain isodose volumes such as the 12-Gy isodose line enclosed normal brain tissue volumes were on average decreased by 6%, 11%, 18%, and 28% for the 3-, 6-, 9-, 12-target treatment plans respectively. The lowest normal brain isodose volumes were consistently found for the 7-arc treatment plans for all the cases. Conclusion: With nearly identical beam-on times, the peripheral normal brain dose was notably decreased when the total number of intensity modulated arc beams was increased when treating multiple brain metastases. Dr Sahgal and Dr Ma are currently serving on the board of international society of stereotactic radiosurgery

  11. A comparison of shock-cloud and wind-cloud interactions: effect of increased cloud density contrast on cloud evolution

    Science.gov (United States)

    Goldsmith, K. J. A.; Pittard, J. M.

    2018-05-01

    The similarities, or otherwise, of a shock or wind interacting with a cloud of density contrast χ = 10 were explored in a previous paper. Here, we investigate such interactions with clouds of higher density contrast. We compare the adiabatic hydrodynamic interaction of a Mach 10 shock with a spherical cloud of χ = 103 with that of a cloud embedded in a wind with identical parameters to the post-shock flow. We find that initially there are only minor morphological differences between the shock-cloud and wind-cloud interactions, compared to when χ = 10. However, once the transmitted shock exits the cloud, the development of a turbulent wake and fragmentation of the cloud differs between the two simulations. On increasing the wind Mach number, we note the development of a thin, smooth tail of cloud material, which is then disrupted by the fragmentation of the cloud core and subsequent `mass-loading' of the flow. We find that the normalized cloud mixing time (tmix) is shorter at higher χ. However, a strong Mach number dependence on tmix and the normalized cloud drag time, t_{drag}^' }, is not observed. Mach-number-dependent values of tmix and t_{drag}^' } from comparable shock-cloud interactions converge towards the Mach-number-independent time-scales of the wind-cloud simulations. We find that high χ clouds can be accelerated up to 80-90 per cent of the wind velocity and travel large distances before being significantly mixed. However, complete mixing is not achieved in our simulations and at late times the flow remains perturbed.

  12. Increasing number of fractured ribs is not predictive of the severity of splenic injury following blunt trauma: an analysis of a National Trauma Registry database.

    Science.gov (United States)

    Boris, Kessel; Forat, Swaid; Itamar, Ashkenazi; Oded, Olsha; Kobi, Peleg; Adi, Givon; Igor, Jeroukhimov; Ricardo, Alfici

    2014-05-01

    Association between rib fractures and incidence of abdominal solid organs injury is well described. However, the correlation between the number of fractured ribs and severity of splenic injury is not clear. The purpose of this study was to assess whether an increasing number of rib fractures predicts the severity of splenic injury in blunt trauma patients. A retrospective cohort study involving blunt trauma patients with concomitant splenic injuries and rib fractures, between the years 1998 and 2012, registered in the Israeli National Trauma Registry. Of 321,618 patients with blunt mechanism of trauma, 57,130 had torso injuries, and of these 14,651 patients sustained rib fractures, and 3691 patients suffered from splenic injury. Concomitant splenic injury occurred in 1326 of the patients with rib fractures (9.1%), as compared to 2365 patients sustaining splenic injury without rib fractures (5.6%). The incidence of splenic injury among patients sustaining 5 or more rib fractures was significantly higher compared to patients suffering from 1 to 4 rib fractures. Among patients with splenic injury, the tendency to sustain associated rib fractures increased steadily with age. Patients with concomitant rib fractures had higher Injury Severity Score (ISS), but similar mortality rates, compared to patients with splenic injury without rib fractures. Among patients with concomitant rib fractures and splenic injury, there was no relation between the number of fractured ribs and the severity of splenic injury, neither as a whole group, nor after stratification according to the mechanism of injury. Although the presence of rib fractures increases the probability of splenic injury in blunt torso trauma, there is no relation between the number of fractured ribs and splenic injury severity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Ultraflat and broadband optical frequency comb generator based on cascaded two dual-electrode Mach-Zehnder modulators

    Science.gov (United States)

    Qu, Kun; Zhao, Shanghong; Li, Xuan; Tan, Qinggui; Zhu, Zihang

    2018-04-01

    A novel scheme for the generation of ultraflat and broadband optical frequency comb (OFC) is proposed based on cascaded two dual-electrode Mach-Zehnder modulators (DE-MZM). The first DE-MZM can generate a four-comb-line OFC, then the OFC is injected into the second DE-MZM as a carrier, which can increase the number of comb lines. Our modified scheme finally can generate a broadband OFC with high flatness by simply modifying the electrical power and the bias voltage of the DE-MZM. Theoretical analysis and simulation results reveal that a 16-comb-line OFC with a frequency spacing that two times the frequency of the RF signal can be obtained. The power fluctuation of the OFC lines is 0.48 dB and the unwanted-mode suppression ratio (UMSR) can reach 16.5 dB. Additionally, whether the bias drift of the DE-MZMs has little influence on the power fluctuation is also analyzed. These results demonstrate the robustness of our scheme and verify its good accuracy and high stability with perfect flatness.

  14. Increased numbers of CD38 molecules on bright CD8+ T lymphocytes in infectious mononucleosis caused by Epstein–Barr virus infection

    Science.gov (United States)

    ŽIDOVEC LEPEJ, S; VINCE, A; ÐAKOVIĆ RODE, O; REMENAR, A; JEREN, T

    2003-01-01

    The aim of this study was to quantify the expression of CD38 on CD8+ T lymphocytes of patients with infectious mononucleosis (IM) caused by Epstein–Barr virus (EBV) and cytomegalovirus (CMV). CD38 quantification technique chosen for this study was based on the enumeration of CD38 antibody binding sites in comparison to the quantification standards rather than determining relative fluorescence, which is difficult to standardize. The study enrolled 19 patients with typical clinical and laboratory parameters compatible with EBV-induced IM as well as 10 patients with atypical clinical presentation of this disease. Furthermore, CD38 expression was analysed in a group of 13 patients with IM caused by CMV infection. CD38 quantification was performed within 6 days of the presentation of symptoms. All three groups of IM patients showed a statistically significant increase in the number of anti-CD38 antibody binding sites (which correspond to the number of CD38 molecules) on bright CD8+ T lymphocytes compared to healthy controls. The numbers of CD38 molecules expressed on CD8+ T lymphocytes did not differ significantly between IM patients with typical and atypical clinical presentation of the disease. Patients with CMV-induced IM had significantly lower numbers of CD38 molecules expressed on CD8+ T lymphocytes. Therefore, we conclude that CD38 quantification could be helpful in differential diagnostics of IM cases with atypical clinical presentation. PMID:12930365

  15. High Intensity Interval Training Increases Natural Killer Cell Number and Function in Obese Breast Cancer-challenged Mice and Obese Women.

    Science.gov (United States)

    Barra, Nicole G; Fan, Isabella Y; Gillen, Jenna B; Chew, Marianne; Marcinko, Katarina; Steinberg, Gregory R; Gibala, Martin J; Ashkar, Ali A

    2017-12-01

    High intensity interval training (HIIT) boosts natural killer (NK) cell number and activity in normal weight breast cancer patients; however, whether this occurs in obese individuals is not well established. The goal of this study was to determine whether HIIT effectively boosts NK cells as a therapeutic strategy against breast cancer in an obese mouse model and in overweight/obese women. Diet induced female C57Bl/6 obese mice were assigned to undergo HIIT for four weeks or remain sedentary. Female participants were subjected to a six weeks HIIT protocol. HIIT mice acclimatized to treadmill running were subsequently injected with 5 × 10 5 polyoma middle T (MT) breast cancer cells intravenously. NK cell number and activation were monitored using flow cytometry, and tumor burden or lipid content evaluated from histological lung and liver tissues, respectively. In both mice and humans, circulating NK cell number and activation (CD3-NK1.1+CD27+ and CD3-CD56+, respectively) markedly increased immediately after HIIT. HIIT obese mice had reduced lung tumor burden compared to controls following MT challenge, and had diminished hepatic lipid deposition despite minimal body weight loss. Our findings demonstrate that HIIT can benefit obese individuals by enhancing NK cell number and activity, reducing tumor burden, and enhancing metabolic health.

  16. A large increase of sour taste receptor cells in Skn-1-deficient mice does not alter the number of their sour taste signal-transmitting gustatory neurons.

    Science.gov (United States)

    Maeda, Naohiro; Narukawa, Masataka; Ishimaru, Yoshiro; Yamamoto, Kurumi; Misaka, Takumi; Abe, Keiko

    2017-05-01

    The connections between taste receptor cells (TRCs) and innervating gustatory neurons are formed in a mutually dependent manner during development. To investigate whether a change in the ratio of cell types that compose taste buds influences the number of innervating gustatory neurons, we analyzed the proportion of gustatory neurons that transmit sour taste signals in adult Skn-1a -/- mice in which the number of sour TRCs is greatly increased. We generated polycystic kidney disease 1 like 3-wheat germ agglutinin (pkd1l3-WGA)/Skn-1a +/+ and pkd1l3-WGA/Skn-1a -/- mice by crossing Skn-1a -/- mice and pkd1l3-WGA transgenic mice, in which neural pathways of sour taste signals can be visualized. The number of WGA-positive cells in the circumvallate papillae is 3-fold higher in taste buds of pkd1l3-WGA/Skn-1a -/- mice relative to pkd1l3-WGA/Skn-1a +/+ mice. Intriguingly, the ratio of WGA-positive neurons to P2X 2 -expressing gustatory neurons in nodose/petrosal ganglia was similar between pkd1l3-WGA/Skn-1a +/+ and pkd1l3-WGA/Skn-1a -/- mice. In conclusion, an alteration in the ratio of cell types that compose taste buds does not influence the number of gustatory neurons that transmit sour taste signals. Copyright © 2017. Published by Elsevier B.V.

  17. Physical Activity Increases the Total Number of Bone-Marrow-Derived Mesenchymal Stem Cells, Enhances Their Osteogenic Potential, and Inhibits Their Adipogenic Properties

    Directory of Open Access Journals (Sweden)

    Monika Marędziak

    2015-01-01

    Full Text Available Aging and sedentary lifestyle are common nowadays and are associated with the increasing number of chronic diseases. Thus, physical activity is recommended as one of three healthy behavior factors that play a crucial role in health prophylaxis. In the present study, we were interested whether physical activity influences the number and potential of bone-marrow-derived mesenchymal stem cells BMMSCs. In this study, four-week-old male C57Bl/6 mice were trained on a treadmill at progressive speeds over a 5-week period. Comparisons made between exercised (EX and sedentary animal groups revealed (i significantly higher number of MSCs in EX animals, (ii elevated alkaline phosphatase (ALP activity, (iii increased level of osteopontin (OPN and osteocalcin (OCL, and (iv reduced marrow cavity fat. The results obtained support the thesis that EX may play a substantial role in the regeneration of mesenchymal tissues. Therefore, EX may represent a novel, nonpharmacological strategy of slowing down age-related decline of the musculoskeletal functions.

  18. Increasing the number and signal-to-noise ratio of OBS traces with supervirtual refraction interferometry and free-surface multiples

    KAUST Repository

    Bharadwaj, P.; Wang, X.; Schuster, Gerard T.; McIntosh, K.

    2013-01-01

    The theory of supervirtual interferometry is modified so that free-surface related multiple refractions can be used to enhance the signal-to-noise ratio (SNR) of primary refraction events by a factor proportional to√Ns, where Ns is the number of post-critical sources for a specified refraction multiple. We also show that refraction multiples can be transformed into primary refraction events recorded at virtual hydrophones located between the actual hydrophones. Thus, data recorded by a coarse sampling of ocean bottom seismic (OBS) stations can be transformed, in principle, into a virtual survey with P times more OBS stations, where P is the order of the visible free-surface related multiple refractions. The key assumption is that the refraction arrivals are those of head waves, not pure diving waves. The effectiveness of this method is validated with both synthetic OBS data and an OBS data set recorded offshore from Taiwan. Results show the successful reconstruction of far-offset traces out to a source-receiver offset of 120 km. The primary supervirtual traces increase the number of pickable first arrivals from approximately 1600 to more than 3100 for a subset of the OBS data set where the source is only on one side of the recording stations. In addition, the head waves associated with the first-order free-surface refraction multiples allow for the creation of six new common receiver gathers recorded at virtual OBS station located about half way between the actual OBS stations. This doubles the number of OBS stations compared to the original survey and increases the total number of pickable traces from approximately 1600 to more than 6200. In summary, our results with the OBS data demonstrate that refraction interferometry can sometimes more than quadruple the number of usable traces, increase the source-receiver offsets, fill in the receiver line with a denser distribution of OBS stations, and provide more reliable picking of first arrivals. Apotential liability

  19. Increasing the number and signal-to-noise ratio of OBS traces with supervirtual refraction interferometry and free-surface multiples

    KAUST Repository

    Bharadwaj, P.

    2013-01-10

    The theory of supervirtual interferometry is modified so that free-surface related multiple refractions can be used to enhance the signal-to-noise ratio (SNR) of primary refraction events by a factor proportional to√Ns, where Ns is the number of post-critical sources for a specified refraction multiple. We also show that refraction multiples can be transformed into primary refraction events recorded at virtual hydrophones located between the actual hydrophones. Thus, data recorded by a coarse sampling of ocean bottom seismic (OBS) stations can be transformed, in principle, into a virtual survey with P times more OBS stations, where P is the order of the visible free-surface related multiple refractions. The key assumption is that the refraction arrivals are those of head waves, not pure diving waves. The effectiveness of this method is validated with both synthetic OBS data and an OBS data set recorded offshore from Taiwan. Results show the successful reconstruction of far-offset traces out to a source-receiver offset of 120 km. The primary supervirtual traces increase the number of pickable first arrivals from approximately 1600 to more than 3100 for a subset of the OBS data set where the source is only on one side of the recording stations. In addition, the head waves associated with the first-order free-surface refraction multiples allow for the creation of six new common receiver gathers recorded at virtual OBS station located about half way between the actual OBS stations. This doubles the number of OBS stations compared to the original survey and increases the total number of pickable traces from approximately 1600 to more than 6200. In summary, our results with the OBS data demonstrate that refraction interferometry can sometimes more than quadruple the number of usable traces, increase the source-receiver offsets, fill in the receiver line with a denser distribution of OBS stations, and provide more reliable picking of first arrivals. Apotential liability

  20. Chronic levodopa administration followed by a washout period increased number and induced phenotypic changes in striatal dopaminergic cells in MPTP-monkeys.

    Directory of Open Access Journals (Sweden)

    Carla DiCaudo

    Full Text Available In addition to the medium spiny neurons the mammalian striatum contains a small population of GABAergic interneurons that are immunoreactive for tyrosine hydroxylase (TH, which dramatically increases after lesions to the nigrostriatal pathway and striatal delivery of neurotrophic factors. The regulatory effect of levodopa (L-Dopa on the number and phenotype of these cells is less well understood. Eleven macaques (Macaca fascicularis were included. Group I (n = 4 received 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP and L-Dopa; Group II (n = 4 was treated with MPTP plus vehicle and Group III (n = 3 consist of intact animals (control group. L-Dopa and vehicle were given for 1 year and animals sacrificed 6 months later. Immunohistochemistry against TH was used to identify striatal and nigral dopaminergic cells. Double and triple labeling immunofluorescence was performed to detect the neurochemical characteristics of the striatal TH-ir cells using antibodies against: TH, anti-glutamate decarboxylase (GAD(67 anti-calretinin (CR anti-dopa decarboxylase (DDC and anti-dopamine and cyclic AMP-regulated phosphoprotein (DARPP-32. The greatest density of TH-ir striatal cells was detected in the striatum of the L-Dopa treated monkeys and particularly in its associative territory. None of the striatal TH-ir cell expressed DARPP-32 indicating they are interneurons. The percentages of TH-ir cells that expressed GAD67 and DDC was approximately 50%. Interestingly, we found that in the L-Dopa group the number of TH/CR expressing cells was significantly reduced. We conclude that chronic L-Dopa administration produced a long-lasting increase in the number of TH-ir cells, even after a washout period of 6 months. L-Dopa also modified the phenotype of these cells with a significant reduction of the TH/CR phenotype in favor of an increased number of TH/GAD cells that do not express CR. We suggest that the increased number of striatal TH-ir cells might be involved

  1. Vildagliptin, but not glibenclamide, increases circulating endothelial progenitor cell number: a 12-month randomized controlled trial in patients with type 2 diabetes.

    Science.gov (United States)

    Dei Cas, Alessandra; Spigoni, Valentina; Cito, Monia; Aldigeri, Raffaella; Ridolfi, Valentina; Marchesi, Elisabetta; Marina, Michela; Derlindati, Eleonora; Aloe, Rosalia; Bonadonna, Riccardo C; Zavaroni, Ivana

    2017-02-23

    Fewer circulating endothelial progenitor cells (EPCs) and increased plasma (C-term) stromal cell-derived factor 1α (SDF-1α), a substrate of DPP-4, are biomarkers, and perhaps mediators, of cardiovascular risk and mortality. Short-term/acute treatment with DPP-4 inhibitors improve EPC bioavailability; however, long-term effects of DPP-4i on EPCs bioavailability/plasma (C-term) SDF-1α are unknown. Randomized (2:1) open-label trial to compare the effects of vildagliptin (V) (100 mg/day) vs glibenclamide (G) (2.5 mg bid to a maximal dose of 5 mg bid) on circulating EPC levels at 4 and 12 months of treatment in 64 patients with type 2 diabetes in metformin failure. At baseline, and after 4 and 12 months, main clinical/biohumoral parameters, inflammatory biomarkers, concomitant therapies, EPC number (CD34 + /CD133 + /KDR + /10 6 cytometric events) and plasma (C-term) SDF-1α (R&D system) were assessed. Baseline characteristics were comparable in the two groups. V and G similarly and significantly (p < 0.0001) improved glucose control. At 12 months, V significantly increased EPC number (p < 0.05) and significantly reduced (C-term) SDF-1α plasma levels (p < 0.01) compared to G, with no differences in inflammatory biomarkers. V exerts a long-term favorable effect on EPC and (C-term) SDF-1α levels at glucose equipoise, thereby implying a putative beneficial effect on vascular integrity. Trial registration Clinical Trials number: NCT01822548; name: Effect of Vildagliptin vs. Glibenclamide on Circulating Endothelial Progenitor Cell Number Type 2 Diabetes. Registered 28 March, 2013.

  2. Icariin protects rats against 5/6 nephrectomy-induced chronic kidney failure by increasing the number of renal stem cells.

    Science.gov (United States)

    Huang, Zhongdi; He, Liqun; Huang, Di; Lei, Shi; Gao, Jiandong

    2015-10-21

    Chronic kidney disease poses a serious health problem worldwide with increasing prevalence and lack of effective treatment. This study aimed to investigate the mechanism of icariin in alleviating chronic renal failure induced by 5/6 nephrectomy in rats. The chronic renal failure model was established by a two-phased 5/6 nephrectomy procedure. The model rats were given daily doses of water or icariin for 8 weeks. The kidney morphology was checked by HE staining. The levels of blood urea nitrogen, serum creatinine, and serum uric acid were measured by colometric methods. The expression of specified genes was analyzed by quantitative real-time PCR and immunohistochemical staining. The number of renal stem/progenitor cells was analyzed by CD133 and CD24 immunohistochemical staining. Icariin protected against CDK-caused damages to kidney histology and improved renal function, significantly reduced levels of BUN, creatinine, and uric acid. Icariin inhibited the expression level of TGF-β1 whereas upregulated HGF, BMP-7, WT-1, and Pax2 expression. Moreover, ccariin significantly increased the expression of CD24, CD133, Osr1, and Nanog in remnant kidney and the numbers of CD133(+)/CD24(+) renal stem/progenitor cells. These data demonstrated that icariin effectively alleviated 5/6 nephrectomy induced chronic renal failure through increasing renal stem/progenitor cells.

  3. Increasing Leaf Vein Density via Mutagenesis in Rice Results in an Enhanced Rate of Photosynthesis, Smaller Cell Sizes and Can Reduce Interveinal Mesophyll Cell Number

    Directory of Open Access Journals (Sweden)

    Aryo B. Feldman

    2017-11-01

    Full Text Available Improvements to leaf photosynthetic rates of crops can be achieved by targeted manipulation of individual component processes, such as the activity and properties of RuBisCO or photoprotection. This study shows that simple forward genetic screens of mutant populations can also be used to rapidly generate photosynthesis variants that are useful for breeding. Increasing leaf vein density (concentration of vascular tissue per unit leaf area has important implications for plant hydraulic properties and assimilate transport. It was an important step to improving photosynthetic rates in the evolution of both C3 and C4 species and is a foundation or prerequisite trait for C4 engineering in crops like rice (Oryza sativa. A previous high throughput screen identified five mutant rice lines (cv. IR64 with increased vein densities and associated narrower leaf widths (Feldman et al., 2014. Here, these high vein density rice variants were analyzed for properties related to photosynthesis. Two lines were identified as having significantly reduced mesophyll to bundle sheath cell number ratios. All five lines had 20% higher light saturated photosynthetic capacity per unit leaf area, higher maximum carboxylation rates, dark respiration rates and electron transport capacities. This was associated with no significant differences in leaf thickness, stomatal conductance or CO2 compensation point between mutants and the wild-type. The enhanced photosynthetic rate in these lines may be a result of increased RuBisCO and electron transport component amount and/or activity and/or enhanced transport of photoassimilates. We conclude that high vein density (associated with altered mesophyll cell length and number is a trait that may confer increased photosynthetic efficiency without increased transpiration.

  4. Should warfarin or aspirin be stopped prior to prostate biopsy? An analysis of bleeding complications related to increasing sample number regimes

    International Nuclear Information System (INIS)

    Chowdhury, R.; Abbas, A.; Idriz, S.; Hoy, A.; Rutherford, E.E.; Smart, J.M.

    2012-01-01

    Aim: To determine whether patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy with increased sampling numbers are more likely to experience bleeding complications and whether warfarin or low-dose aspirin are independent risk factors. Materials and methods: 930 consecutive patients with suspected prostatic cancer were followed up after biopsy. Warfarin/low-dose aspirin was not stopped prior to the procedure. An eight to 10 sample regime TRUS-guided prostate biopsy was performed and patients were offered a questionnaire to complete 10 days after the procedure, to determine any immediate or delayed bleeding complications. Results: 902 patients returned completed questionnaires. 579 (64.2%) underwent eight core biopsies, 47 (5.2%) underwent nine, and 276 (30.6%) underwent 10. 68 were taking warfarin [mean international normalized ratio (INR) = 2.5], 216 were taking low-dose aspirin, one was taking both, and 617 were taking neither. 27.9% of those on warfarin and 33.8% of those on aspirin experienced haematuria. 37% of those on no blood-thinning medication experienced haematuria. 13.2% of those on warfarin and 14.4% of those on aspirin experienced rectal bleeding. 11.5% of those on no blood-thinning medication experienced rectal bleeding. 7.4% of those on warfarin and 12% of those on aspirin experienced haematospermia. 13.8% of those on neither experienced haematospermia. Regression analysis showed a significant association between increasing sampling number and occurrence of all bleeding complication types. There was no significant association between minor bleeding complications and warfarin use; however, there was a significant association between minor bleeding complications and low-dose aspirin use. There was no severe bleeding complication. Conclusion: There is an increased risk of bleeding complications following TRUS-guided prostate biopsy with increased sampling numbers but these are minor. There is also an increased risk with low

  5. Enhancement of phase space density by increasing trap anisotropy in a magneto-optical trap with a large number of atoms

    International Nuclear Information System (INIS)

    Vengalattore, M.; Conroy, R.S.; Prentiss, M.G.

    2004-01-01

    The phase space density of dense, cylindrical clouds of atoms in a 2D magneto-optic trap is investigated. For a large number of trapped atoms (>10 8 ), the density of a spherical cloud is limited by photon reabsorption. However, as the atom cloud is deformed to reduce the radial optical density, the temperature of the atoms decreases due to the suppression of multiple scattering leading to an increase in the phase space density. A density of 2x10 -4 has been achieved in a magneto-optic trap containing 2x10 8 atoms

  6. Maternal high-protein diet during pregnancy, but not during suckling, induced altered expression of an increasing number of hepatic genes in adult mouse offspring.

    Science.gov (United States)

    Vanselow, Jens; Kucia, Marzena; Langhammer, Martina; Koczan, Dirk; Metges, Cornelia C

    2016-04-01

    Indirect effects of a high-protein maternal diet are not well understood. In this study, we analyzed short-term and sustainable effects of a prenatal versus early postnatal maternal high-protein diet on growth and hepatic gene expression in mouse offspring. Dams were exposed to an isoenergetic high-protein (HP, 40 % w/w) diet during pregnancy or lactation. Growth and hepatic expression profiles of male offspring were evaluated directly after weaning and 150 days after birth. Offspring from two dietary groups, high-protein diet during pregnancy and control diet during lactation (HPC), and control diet during pregnancy and high-protein diet during lactation (CHP), were compared with offspring (CC) from control-fed dams. Maternal CHP treatment was associated with sustained offspring growth retardation, but decreased numbers of affected hepatic genes in adults compared to weanlings. In contrast, offspring of the HPC group did not show persistent effects on growth parameters, but the number of affected hepatic genes was even increased at adult age. In both dietary groups, however, only a small subset of genes was affected in weanlings as well as in adults. We conclude that (1) prenatal and early postnatal maternal HP diet caused persistent, but (2) different effects and partially complementary trends on growth characteristics and on the hepatic transcriptome and associated pathways and that (3) only a small number of genes and associated upstream regulators might be involved in passing early diet-induced imprints to adulthood.

  7. High Mach Number Scramjet Test Flows in the X3 Expansion Tube

    Science.gov (United States)

    Gildfind, D. E.; Sancho, J.; Morgan, R. G.

    The University of Queensland (UQ) has two free-piston driven expansion tube facilities; X2 has a total length of 23 m and was originally commissioned in 1995 [1]; X3 is much longer at 62 m, and was commissioned in 2001 [2].

  8. ASYMPTOTIC STEADY-STATE SOLUTION TO A BOW SHOCK WITH AN INFINITE MACH NUMBER

    Energy Technology Data Exchange (ETDEWEB)

    Yalinewich, Almog; Sari, Re’em [Racah Institute of Physics, the Hebrew University, 91904, Jerusalem (Israel)

    2016-08-01

    The problem of a cold gas flowing past a stationary obstacle is considered. We study the bow shock that forms around the obstacle and show that at large distances from the obstacle the shock front forms a parabolic solid of revolution. The profiles of the hydrodynamic variables in the interior of the shock are obtained by solution of the hydrodynamic equations in parabolic coordinates. The results are verified with a hydrodynamic simulation. The drag force on the obstacle is also calculated. Finally, we use these results to model the bow shock around an isolated neutron star.

  9. Stability with respect to domain of the low Mach number limit of compressible viscous fluids

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Karper, T.; Kreml, Ondřej; Stebel, Jan

    2013-01-01

    Roč. 23, č. 13 (2013), s. 2465-2493 ISSN 0218-2025 R&D Projects: GA ČR GA201/09/0917 Institutional research plan: CEZ:AV0Z10190503 Keywords : incompressible limit * domain dependence * Navier-Stokes system Subject RIV: BA - General Mathematics Impact factor: 2.351, year: 2013 http://www.worldscientific.com/doi/abs/10.1142/S0218202513500371

  10. On the low Mach number limit of compressible flows in exterior moving domains

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Kreml, Ondřej; Mácha, Václav; Nečasová, Šárka

    2016-01-01

    Roč. 16, č. 3 (2016), s. 705-722 ISSN 1424-3199 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : compressible Navier-Stokes system * incompressible limit * moving domain Subject RIV: BA - General Mathematics Impact factor: 1.038, year: 2016 http://link.springer.com/article/10.1007%2Fs00028-016-0338-2

  11. Practical computational aeroacoustics for complex confined scattering geometries in low mach number flows

    DEFF Research Database (Denmark)

    Pradera-Mallabiabarrena, Ainara; Jacobsen, Finn; Svendsen, Christian

    2013-01-01

    -compact surfaces are involved. Here the generation of noise is dominated by the interaction of the flow with a surface whose maximum dimension is shorter than the wavelength of interest. The analysis is based on the surface-source term of the Ffowcs Williams-Hawkings equation. The acoustic source data of the flow...

  12. Investigation of Shock Diffusers at Mach Number 1.85. 1 - Projecting Single Shock Cones

    Science.gov (United States)

    1947-06-17

    cylindrical simulated combustion chamber was used to vary the outlet area of the flow through the diffuser. The pitot -static rake, located as shown in the...and II. Proc. Roy. Soc. (London), ser. A, vol. 139, no 838, Feb. 1, 1933, pp. 278-311. 5. Wyatt, DeMarquis D., and Hunczak, Henry R.: An...Simulated combustion u chamber A 90° W •—Conical damper S Static-pressure orifice ps pitot -static ""rake’ NATIONAL ADVISORY

  13. Measurement and Analysis of the Noise Radiated by Low Mach Numbers Centrifugal Blowers

    Science.gov (United States)

    1987-11-01

    Lang, V Manager of the IBM Poughkeepsie Acoustics Laboratory, for his understanding and support. I would also like to express my gratitude to the IBM...ficl.l. Knowlede p of these quantities provides important information on the relative strength of thL :cro- a dynamic noise sources on the blade... manageability . The model blower design was thus determined by scaling all of the linear dimensions of the reference device by 2.0 and by maintaining • all of

  14. High Angle of Attack Missile Aerodynamics at Mach Numbers 0.30 to 1.5

    Science.gov (United States)

    1980-11-01

    I AFWAL-TR-80-3070 I 45~//1° 4. N3B2 Cn 3d . 35 10 -2 36 30 37 50 2- S Cy ’ -1I __- 40 0 45 CAh ------ 50 -555 70- * 6C 50 504 40 ZS 8 9 LO R*N a 4. 5...Continued) 36. Drescher, H., "Messung Der Auf Querange-Sti"mte Zylinder Ausgeubten Zeitlich Verabderten Druck ," Z.F. Flugwss, Vol. 4, No. 1/2, 1956

  15. Low Mach and Peclet number limit for a model of stellar tachocline and upper radiative zones

    Czech Academy of Sciences Publication Activity Database

    Donatelli, D.; Ducomet, B.; Kobera, M.; Nečasová, Šárka

    2016-01-01

    Roč. 2016, Č. 245 (2016), s. 1-31 ISSN 1072-6691 R&D Projects: GA ČR GA16-03230S Institutional support: RVO:67985840 Keywords : Navier-Stokes-Fourier-Poisson system * radiation transfer * compressible magnetohydrodynamics Subject RIV: BA - General Math ematics Impact factor: 0.954, year: 2016 http://ejde. math .txstate.edu/Volumes/2016/245/abstr.html

  16. Turbulent boundary layer noise : direct radiation at Mach number 0.5

    OpenAIRE

    Gloerfelt , Xavier; Berland , Julien

    2013-01-01

    International audience; Boundary layers constitute a fundamental source of aerodynamic noise. A turbulent boundary layer over a plane wall can provide an indirect contribution to the noise by exciting the structure, and a direct noise contribution. The latter part can play a significant role even if its intensity is very low, explaining why it is hardly measured unambiguously. In the present study, the aerodynamic noise generated by a spatially developing turbulent boundary layer is computed ...

  17. Increase in the number of distributed power generation installations in electricity distribution grids - Literature; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Literatur

    Energy Technology Data Exchange (ETDEWEB)

    Gottsponer, O.; Mauchle, P.

    2003-07-01

    This is the tenth and last part of a final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This ninth appendix to the main report presents an overview and details of the literature and internet sources used in the project. Also, similar projects that discuss the problem area dealt with are briefly described. These include the Dispower, EDIson, DEMS, AMOEVES and ELSAD projects.

  18. Effect of plant extracts and an essential oil on the control of brown spot disease, tillering, number of panicles and yield increase in rice

    DEFF Research Database (Denmark)

    Nguefack, Julienne; Wulff, Ednar Gadelha; Dongmo, J. Blaise Lekagne

    2013-01-01

    disease, the tillering, the number of panicles and the yield increase in rice were evaluated under laboratory and field conditions. In vitro, the growth of both fungi was completely inhibited by the EO of C. citrinus and C. citratus at 4,520 mu g/ml and 452 mu g/ml, respectively. For solvent extracts...... in the non-treated and treated samples with a low incidence (0-4 of B. oryzae. Under field conditions, the combined use of the essential oil of C. citrinus as a seed treatment and spraying the plants with 2 % ethanol followed by 2 % (w/v) aqueous extracts of C. citrinus or C. citratus increased the emergence......, we concluded that the EO and solvent extracts of C. citrinus and C. citratus have potential as control agents against brown spot and other seed-borne fungal diseases in rice under both conventional and organic farming....

  19. Increased numbers of preexisting memory CD8 T cells and decreased T-bet expression can restrain terminal differentiation of secondary effector and memory CD8 T cells.

    Science.gov (United States)

    Joshi, Nikhil S; Cui, Weiguo; Dominguez, Claudia X; Chen, Jonathan H; Hand, Timothy W; Kaech, Susan M

    2011-10-15

    Memory CD8 T cells acquire effector memory cell properties after reinfection and may reach terminally differentiated, senescent states ("Hayflick limit") after multiple infections. The signals controlling this process are not well understood, but we found that the degree of secondary effector and memory CD8 T cell differentiation was intimately linked to the amount of T-bet expressed upon reactivation and preexisting memory CD8 T cell number (i.e., primary memory CD8 T cell precursor frequency) present during secondary infection. Compared with naive cells, memory CD8 T cells were predisposed toward terminal effector (TE) cell differentiation because they could immediately respond to IL-12 and induce T-bet, even in the absence of Ag. TE cell formation after secondary (2°) or tertiary infections was dependent on increased T-bet expression because T-bet(+/-) cells were resistant to these phenotypic changes. Larger numbers of preexisting memory CD8 T cells limited the duration of 2° infection and the amount of IL-12 produced, and consequently, this reduced T-bet expression and the proportion of 2° TE CD8 T cells that formed. Together, these data show that over repeated infections, memory CD8 T cell quality and proliferative fitness is not strictly determined by the number of serial encounters with Ag or cell divisions, but is a function of the CD8 T cell differentiation state, which is genetically controlled in a T-bet-dependent manner. This differentiation state can be modulated by preexisting memory CD8 T cell number and the intensity of inflammation during reinfection. These results have important implications for vaccinations involving prime-boost strategies.

  20. Rotating detectors and Mach's principle

    Energy Technology Data Exchange (ETDEWEB)

    Paola, R.D.M. de; Svaiter, N.F

    2000-08-01

    In this work we consider a quantum version of Newton{sup s} bucket experiment in a fl;at spacetime: we take an Unruh-DeWitt detector in interaction with a real massless scalar field. We calculate the detector's excitation rate when it is uniformly rotating around some fixed point and the field is prepared in the Minkowski vacuum and also when the detector is inertial and the field is in the Trocheries-Takeno vacuum state. These results are compared and the relations with Mach's principle are discussed. (author)

  1. Increased Numbers of NK Cells, NKT-Like Cells, and NK Inhibitory Receptors in Peripheral Blood of Patients with Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Ying Tang

    2013-01-01

    Full Text Available T cells and B cells participate in the pathogenesis of COPD. Currently, NK cells and NKT cells have gained increasing attention. In the present study, 19 COPD patients and 12 healthy nonsmokers (HNS were recruited, and their pulmonary function was assessed. The frequencies of CD3+ T, CD4+ T, CD8+ T, B, NK, and NKT-like cells were determined using flow cytometry. The frequencies of spontaneous and inducible IFN-γ+ or CD107a+ NK and NKT-like cells as well as activating or inhibitory receptors were also detected. The potential association of lymphocyte subsets with disease severity was further analyzed. Significantly decreased numbers of CD3+ and CD4+ T cells, and the CD4+/CD8+ ratio, but increased numbers of CD3−CD56+ NK and CD3+CD56+ NKT-like cells were observed in COPD patients compared to HNS. The frequencies of inducible IFN-γ-secreting NK and NKT-like cells were less in COPD patients. The frequencies of CD158a and CD158b on NK cells and CD158b on NKT-like cells were greater. The frequency of CD158b+ NK cells was negatively correlated with FEV1% prediction and FEV1/FVC. Our data indicate that COPD patients have immune dysfunction, and higher frequencies of inhibitory NK cells and NKT-like cells may participate in the pathogenesis of COPD.

  2. Inhibition of muscle fibrosis results in increases in both utrophin levels and the number of revertant myofibers in Duchenne muscular dystrophy.

    Science.gov (United States)

    Levi, Oshrat; Genin, Olga; Angelini, Corrado; Halevy, Orna; Pines, Mark

    2015-09-15

    Duchenne Muscular Dystrophy is characterized by: near absence of dystrophin in skeletal muscles; low percentage of revertant myofibers; up-regulation of utrophin synthesis; and a high degree of muscle fibrosis. In patient quadriceps femoris biopsies (n = 6, ages between 3-9 years) an inverse correlation was observed between the levels of collagen type I - representing fibrosis - and the levels of utrophin. This correlation was independent of the patient's age and was observed in the entire muscle biopsy sections. In the mdx mice diaphragm (n = 6/group), inhibition of fibrosis by halofuginone resulted in increases in the levels of utrophin. The utrophin/fibrosis relationships were not limited to collagen type I, but also applied to other constituents of the fibrosis machinery. The inverse correlation was found also in old mdx mice with established fibrosis. In addition, inhibition of collagen type I levels was associated with increases in the numbers of revertant myofibers, both as single myofibers and in clusters in the diaphragm and the gastrocnemius. In summary, our results demonstrate an inverse correlation between the level of muscle fibrosis and the level of utrophin and that of the number of revertant myofibers. These findings may reveal common links between the fibrotic and utrophin-synthesis pathways and offer new insights into the regulation of utrophin synthesis.

  3. Dehydroepiandrosterone increases the number and dendrite maturation of doublecortin cells in the dentate gyrus of middle age male Wistar rats exposed to chronic mild stress.

    Science.gov (United States)

    Herrera-Pérez, J J; Martínez-Mota, L; Jiménez-Rubio, G; Ortiz-López, L; Cabrera-Muñoz, E A; Galindo-Sevilla, N; Zambrano, E; Hernández-Luis, F; Ramírez-Rodríguez, G B; Flores-Ramos, M

    2017-03-15

    Aging increases the vulnerability to stress and risk of developing depression. These changes have been related to a reduction of dehydroepiandrosterone (DHEA) levels, an adrenal steroid with anti-stress effects. Also, adult hippocampal neurogenesis decreases during aging and its alteration or impaired is related to the development of depression. Besides, it has been hypothesized that DHEA increases the formation of new neurons. However, it is unknown whether treatment with DHEA in aging may stimulate the dendrite maturation of newborn neurons and reversing depressive-like signs evoked by chronic stress exposure. Here aged male rats (14 months old) were subjected to a scheme of chronic mild stress (CMS) during six weeks, received a treatment with DHEA from the third week of CMS. Changes in body weight and sucrose preference (SP) were measured once a week. DHEA levels were measured in serum, identification of doublecortin-(DCX)-, BrdU- and BrdU/NeuN-labeled cells was done in the dentate gyrus of the hippocampus. CMS produced a gradual reduction in the body weight, but no changes in the SP were observed. Treatment enhanced levels of DHEA, but lack of recovery on body weight of stressed rats. Aging reduced the number of DCX-, BrdU- and BrdU/NeuN- cells but DHEA just significantly increased the number of DCX-cells in rats under CMS and controls, reaching levels of young non-stressed rats (used here as a reference of an optimal status of health). In rats under CMS, DHEA facilitated dendritic maturation of immature new neurons. Our results reveal that DHEA improves neural plasticity even in conditions of CMS in middle age rats. Thus, this hormone reverted the decrement of DCX-cells caused during normal aging. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Reflected rarefactions, double regular reflection, and mach waves in aluminum and beryllium

    International Nuclear Information System (INIS)

    Neal, T.

    1975-01-01

    A number of shock techniques which can be used to obtain high-pressure equation-of-state information between the principal Hugoniot and the principal adiabat are illustrated. A rarefaction wave in aluminum shocked to 27.7 GPa [277 kbar] is examined with radiographic techniques and the bulk sound speed is determined. The two stage compression which occurs in a double shock may be attained by colliding two shocks and observing regular reflection. A radiographic method which uses this phenomenon to measure a three-stage compression of aluminum to a density of 4.7 Mg/m 3 and beryllium to a density of 3.1 Mg/m 3 is presented. The results of a Mach reflection experiment in aluminum are found to disagree substantially with the simple three-shock model. A modified model, consistent with observations, is discussed. In all cases the Gruneisen parameter is determined. (U.S.)

  5. Calibration of the 7—Equation Transition Model for High Reynolds Flows at Low Mach

    Science.gov (United States)

    Colonia, S.; Leble, V.; Steijl, R.; Barakos, G.

    2016-09-01

    The numerical simulation of flows over large-scale wind turbine blades without considering the transition from laminar to fully turbulent flow may result in incorrect estimates of the blade loads and performance. Thanks to its relative simplicity and promising results, the Local-Correlation based Transition Modelling concept represents a valid way to include transitional effects into practical CFD simulations. However, the model involves coefficients that need tuning. In this paper, the γ—equation transition model is assessed and calibrated, for a wide range of Reynolds numbers at low Mach, as needed for wind turbine applications. An aerofoil is used to evaluate the original model and calibrate it; while a large scale wind turbine blade is employed to show that the calibrated model can lead to reliable solutions for complex three-dimensional flows. The calibrated model shows promising results for both two-dimensional and three-dimensional flows, even if cross-flow instabilities are neglected.

  6. Iodine Tagging Velocimetry in a Mach 10 Wake

    Science.gov (United States)

    Balla, Robert Jeffrey

    2013-01-01

    A variation on molecular tagging velocimetry (MTV) [1] designated iodine tagging velocimetry (ITV) is demonstrated. Molecular iodine is tagged by two-photon absorption using an Argon Fluoride (ArF) excimer laser. A single camera measures fluid displacement using atomic iodine emission at 206 nm. Two examples ofMTVfor cold-flowmeasurements areN2OMTV [2] and Femtosecond Laser Electronic Excitation Tagging [3]. These, like most MTV methods, are designed for atmospheric pressure applications. Neither can be implemented at the low pressures (0.1- 1 Torr) in typical hypersonic wakes. Of all the single-laser/singlecamera MTV approaches, only Nitric-Oxide Planar Laser Induced Fluorescence-based MTV [4] has been successfully demonstrated in a Mach 10 wake. Oxygen quenching limits transit times to 500 ns and accuracy to typically 30%. The present note describes the photophysics of the ITV method. Off-body velocimetry along a line is demonstrated in the aerothermodynamically important and experimentally challenging region of a hypersonic low-pressure near-wake in a Mach 10 air wind tunnel. Transit times up to 10 µs are demonstrated with conservative errors of 10%.

  7. Susceptibility for Lupus Nephritis by Low Copy Number of the FCGR3B Gene Is Linked to Increased Levels of Pathogenic Autoantibodies

    Directory of Open Access Journals (Sweden)

    Johannes C. Nossent

    2013-01-01

    Full Text Available Low copy number (CN of the FCGR3B gene reduces FCGR3B membrane expression on neutrophils and results in clearance of a smaller amount of immune complex. We investigated FCGR3B CN in relation to the clinical phenotype in a Caucasian SLE cohort (. FCGR3B CN was determined by three different qPCR parameter estimations (Ct−, Cy0, and cpD1 and confirmed by the FCGR2C/FCGR2A paralog ratio test. Clinical and serological data were then analyzed for their association with FCGR3B CN. Low FCGR3B CN (2. In multivariate analyses, LN was independently associated with anti-C1q-Ab levels ( and low FCGR3B CN (. We conclude that the susceptibility for LN in patients with low FCGR3B CN is linked to increased levels of pathogenic autoantibodies.

  8. A novel design of an automatic lighting control system for a wireless sensor network with increased sensor lifetime and reduced sensor numbers.

    Science.gov (United States)

    Mohamaddoust, Reza; Haghighat, Abolfazl Toroghi; Sharif, Mohamad Javad Motahari; Capanni, Niccolo

    2011-01-01

    Wireless sensor networks (WSN) are currently being applied to energy conservation applications such as light control. We propose a design for such a system called a lighting automatic control system (LACS). The LACS system contains a centralized or distributed architecture determined by application requirements and space usage. The system optimizes the calculations and communications for lighting intensity, incorporates user illumination requirements according to their activities and performs adjustments based on external lighting effects in external sensor and external sensor-less architectures. Methods are proposed for reducing the number of sensors required and increasing the lifetime of those used, for considerably reduced energy consumption. Additionally we suggest methods for improving uniformity of illuminance distribution on a workplane's surface, which improves user satisfaction. Finally simulation results are presented to verify the effectiveness of our design.

  9. A Novel Design of an Automatic Lighting Control System for a Wireless Sensor Network with Increased Sensor Lifetime and Reduced Sensor Numbers

    Science.gov (United States)

    Mohamaddoust, Reza; Haghighat, Abolfazl Toroghi; Sharif, Mohamad Javad Motahari; Capanni, Niccolo

    2011-01-01

    Wireless sensor networks (WSN) are currently being applied to energy conservation applications such as light control. We propose a design for such a system called a Lighting Automatic Control System (LACS). The LACS system contains a centralized or distributed architecture determined by application requirements and space usage. The system optimizes the calculations and communications for lighting intensity, incorporates user illumination requirements according to their activities and performs adjustments based on external lighting effects in external sensor and external sensor-less architectures. Methods are proposed for reducing the number of sensors required and increasing the lifetime of those used, for considerably reduced energy consumption. Additionally we suggest methods for improving uniformity of illuminance distribution on a workplane’s surface, which improves user satisfaction. Finally simulation results are presented to verify the effectiveness of our design. PMID:22164114

  10. Effects of long-term moderate exercise and increase in number of daily steps on serum lipids in women: randomised controlled trial [ISRCTN21921919

    Directory of Open Access Journals (Sweden)

    Mirbod Seyed

    2002-01-01

    Full Text Available Abstract Background This study was designed to evaluate the effects of a 24-month period of moderate exercise on serum lipids in menopausal women. Methods The subjects (40–60 y were randomly divided into an exercise group (n = 14 and a control group (n = 13. The women in the exercise group were asked to participate in a 90-minute physical education class once a week and to record their daily steps as measured by a pedometer for 24 months. Results Mean of daily steps was significantly higher in the exercise group from about 6,800 to over 8,500 steps (P P Conclusions These results suggest that daily exercise as well as increasing the number of daily steps can improve the profile of serum lipids.

  11. Study on the high speed scramjet characteristics at Mach 10 to 15 flight condition

    Science.gov (United States)

    Takahashi, M.; Itoh, K.; Tanno, H.; Komuro, T.; Sunami, T.; Sato, K.; Ueda, S.

    A scramjet engine model, designed to establish steady and strong combustion at free-stream conditions corresponding to Mach 12 flight, was tested in a large free-piston driven shock tunnel. Combustion tests of a previous engine model showed that combustion heat release obtained in the combustor was not sufficient to maintain strong combustion. For a new scramjet engine model, the inlet compression ratio was increased to raise the static temperature and density of the flow at the combustor entrance. As a result of the aerodynamic design change, the pressure rise due to combustion increased and the duration of strong combustion conditions in the combustor was extended. A hyper-mixer injector designed to enhance mixing and combustion by introducing streamwise vortices was applied to the new engine model. The results showed that the hyper mixer injector was very effective in promoting combustion heat release and establishing steady and strong combustion in the combustor.

  12. Increased number of papers co-authored by professor and his students in humanities and social sciences journals published in Korea

    Directory of Open Access Journals (Sweden)

    Rae Seong Hong

    2017-02-01

    Full Text Available Humanities and social sciences studies in Korea have remarkably low rates of co-authorship between professors and students. We chose a bibliometrics-based approach to characterize changes in the ratio of joint authorship between professors and students. Articles classified in the humanities and social sciences sectors that were published in journals registered in the Korean Citation Index during 2 phases over a 10-year period—2004 to 2006 (phase 1 and 2011 to 2013 (phase 2—were used as the main source for the analysis. The study results can be summarized as follows: first, the overall number of co-authored articles drastically increased from phase 1 to phase 2; the percentage of co-authorship articles increased from 34.8% to 47.7%, and the percentage of co-authorship between students and professors rose from 9.9% to 20.7%. This trend was particularly noticeable in the social sciences, such as accounting, social welfare, and economics/business administration. Second, papers written by scholars from Seoul National University, Yonsei University, and Korea University were often published in high-impact factor journals. Among those articles, the rate of professor-student co-authorship increased by 21.6% for 7 years. Third, the increase in professor-student co-authored articles published in high- impact factor journals was even sharper. These findings indicate that perceptions of professor-student co-authorship have changed in the humanities and social sciences. In the near future, positive perceptions toward joint research and joint authorship between professors and students are expected to become more widespread.

  13. Increase in the number of distributed power generation installations in electricity distribution grids - Storage technologies; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Grundlagen der Speicher

    Energy Technology Data Exchange (ETDEWEB)

    Luechinger, P.

    2003-07-01

    This is the fifth part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. This fourth appendix to the main report describes six ways of storing electricity, including accumulators, super caps, super-conducting magnetic and flywheel energy storage units. The accumulator technologies discussed include lead-acid, nickel-cadmium and sodium-sulphur batteries. Each of these types of power storage technologies is briefly described. The characteristics of these various types of storage are compared.

  14. Increasing biopsy number and sampling from gastric body improve the sensitivity of rapid urease test in patients with peptic ulcer bleeding.

    Science.gov (United States)

    Lee, Tzong-Hsi; Lin, Chien-Chu; Chung, Chen-Shuan; Lin, Cheng-Kuan; Liang, Cheng-Chao; Tsai, Kuang-Chau

    2015-02-01

    Previous studies demonstrated that the sensitivity of rapid urease test (RUT) for diagnosis of Helicobacter pylori infection decreased during peptic ulcer bleeding. We designed this study and tried to find a better method to improve the detection rate of H. pylori infection at the same session of endoscopic diagnosis of peptic ulcer bleeding. We prospectively enrolled 116 patients with peptic ulcer bleeding. These patients received intravenous proton pump inhibitor and then received upper gastrointestinal endoscopy within 24 h after arrival. We took one piece of biopsy from gastric antrum (Group 1), four pieces from gastric antrum (Group 2), and one piece from the gastric body (Group 3) for three separate RUTs, respectively. (13)C-urease breath test was used as gold standard for diagnosis of H. pylori infection. There were 74 patients (64 %) with positive (13)C-urease breath test. Among these 74 patients, 45 patients had positive RUT (sensitivity: 61 %) in Group 1; 55 patients had positive RUT (sensitivity: 74 %) in Group 2; 54 patients had positive RUT (sensitivity: 73 %) in Group 3. There were significant differences between Group 1 and Group 2 (p = 0.02) and between Group 1 and Group 3 (p = 0.022). The sensitivity of RUT was 61 % during peptic ulcer bleeding. The sensitivity of RUT can be increased significantly by increased biopsy number from gastric antrum or biopsy from gastric body.

  15. Increasing Number and Proportion of Adverse Obstetrical Outcomes among Women Living with HIV in the Ottawa Area: A 20-Year Clinical Case Series

    Directory of Open Access Journals (Sweden)

    Sarah Buchan

    2016-01-01

    Full Text Available Background. The prevalence and associated risks with adverse obstetrical outcomes among women living with HIV are not well measured. The objective of this study was to longitudinally investigate the prevalence and correlates of adverse obstetrical outcomes among women with HIV. Methods. This 20-year (1990–2010 clinical case series assessed the prevalence of adverse obstetrical outcomes among pregnant women with HIV receiving care at The Ottawa Hospital (TOH. General estimating equation modeling was used to identify factors independently associated with adverse obstetrical outcomes, while controlling for year of childbirth clustering. Results. At TOH, there were 127 deliveries among 94 women (1990–2010: 22 preterm births, 9 births with low birth weight, 12 births small for gestational age, and 4 stillbirths. Per year, the odds of adverse obstetrical outcomes increased by 15% (OR: 1.15, 95% CI: 1.03–1.30. Psychiatric illness (AOR: 2.64, 95% CI: 1.12–6.24, teen pregnancy (AOR: 3.35, 95% CI: 1.04–1.46, and recent immigrant status (AOR: 7.24, 95% CI: 1.30–40.28 were the strongest correlates of adverse obstetrical outcomes. Conclusions. The increasing number and proportion of adverse obstetrical outcomes among pregnant women with HIV over the past 20 years highlight the need for social supports and maternal and child health interventions, especially among adolescents, new immigrants, and those with a history of mental illness.

  16. Increase in the number of distributed power generation installations in electricity distribution grids - General requirements; Zunahme der dezentralen Energieerzeugungsanlagen in elektrischen Verteilnetzen: Rahmenbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, G.; Mauchle, P.

    2003-07-01

    This is the third part of a ten-part final report for the Swiss Federal Office of Energy (SFOE) on a project that looked into potential problems relating to the Swiss electricity distribution grid with respect to the increasing number of distributed power generation facilities being put into service. The identification of special conditions for the grid's operation and future development that take increasing decentralised power production into account are discussed. The results of the project activities encompass the analysis and evaluation of various problem areas associated with planning and management of the grid during normal operation and periods of malfunction, as well as required modifications to safety systems and grid configurations. The first part of this second appendix to the main report examines the electrical conditions and requirements that have to be met by distributed production facilities. These include limits for voltage and frequency, synchronisation aspects, protection, reactive power questions and islanding. Also, recommendations are made on the assessment of grid reactions and on the avoidance of non-permissible effects on the grid's audio-frequency remote control apparatus. A second part examines the situation concerning the connection of distributed power units to the grid and grid topologies. The last chapter lists relevant standards and guidelines.

  17. Number of addictive substances used related to increased risk of unnatural death: A combined medico-legal and case-record study

    Directory of Open Access Journals (Sweden)

    Lindgren Anna

    2009-08-01

    Full Text Available Abstract Background Substance use disorders have repeatedly been found to lead to premature death, i.e. drug-related death by disease, fatal intoxications, or trauma (accidents, suicide, undetermined suicide, and homicide. The present study examined the relationship between multi-drug substance use and natural and unnatural death. Methods All consecutive, autopsied patients who had been in contact with the Addiction Centre in Malmö University Hospital from 1993 to 1997 inclusive were investigated. Drug abuse was investigated blindly in the case records and related to the cause of death in 387 subjects. Results Every substance apart from alcohol used previously in life added to the risk of unnatural death in a linear way. There were independent increased risks of fatal heroin overdoses or undetermined suicide. Death by suicide and violent death were unrelated to additional abuse. Conclusion The number of drugs used was related to an increased risk of unnatural death by undetermined suicide (mainly fatal intoxications and heroin overdose.

  18. An increasing number of qualitative research papers in oncology and palliative care: does it mean a thorough development of the methodology of research?

    Directory of Open Access Journals (Sweden)

    Brunelli Cinzia

    2004-01-01

    Full Text Available Abstract Background In the second half of the nineties, a scientific debate about the usefulness of qualitative research in medicine began in the main medical journals as well as the amount of "qualitative" papers published on peer reviewed journals has noticeably increased during these last years. Nevertheless the label of qualitative methodology has been assigned to an heterogeneous collection of studies. Some of them show a complete awareness of the specificity of this kind of research, while others are still largely influenced by the quantitative paradigm prevailing in the medical field. The concern with the rigour and credibility of qualitative methods has lead to the development of a number of checklist for assessing qualitative research. The purposes of this review were to describe the quality of the development of qualitative research in the medical field, focusing on oncology and palliative care, and to discuss the applicability of a descriptive checklist. Methods A review was conducted on Medline and PsycINFO databases. On the basis of their abstract, papers found have been classified considering: publication year, kind of journal, paper type, data gathering method, sample size and declared methodological approach. A sub sample of the previous papers was than selected and their methodological characteristics were evaluated based on a descriptive checklist. Results 351 abstracts and 26 full papers were analysed. An increase over time in the number of qualitative studies is evident. While most of the papers before 1999 were published on nursing journals (43%, afterwards also medical journals were largely represented. Psychological journals increased from 7% to 12%. The 22% of studies used a sample size lower than 15 and the 15% did not specify the sample size in the abstract. The methodological approach was also often not specified and the percentage increased in the second time period (from 73% to 80%. Grounded theory was the most

  19. Classical and quantum non-linear optical applications using the Mach-Zehnder interferometer

    Science.gov (United States)

    Prescod, Andru

    Mach Zehnder (MZ) modulators are widely employed in a variety of applications, such as optical communications, optical imaging, metrology and encryption. In this dissertation, we explore two non-linear MZ applications; one classified as classical and one as quantum, in which the Mach Zehnder interferometer is used. In the first application, a classical non-linear application, we introduce and study a new electro-optic highly linear (e.g., >130 dB) modulator configuration. This modulator makes use of a phase modulator (PM) in one arm of the MZ interferometer (MZI) and a ring resonator (RR) located on the other arm. The modulator performance is obtained through the control of a combination of internal and external parameters. These parameters include the RR-coupling ratio (internal parameter); the RF power split ratio and the RF phase bias (external parameters). Results show the unique and superior features, such as high linearity (SFDR˜133 dB), modulation bandwidth extension (as much as 70%) over the previously proposed and demonstrated Resonator-Assisted Mach Zehnder (RAMZ) design. Furthermore the proposed electro-optic modulator of this dissertation also provides an inherent SFDR compensation capability, even in cases where a significant waveguide optical loss exists. This design also shows potential for increased flexibility, practicality and ease of use. In the second application, a quantum non-linear application, we experimentally demonstrate quantum optical coherence tomography (QOCT) using a type II non-linear crystal (periodically-poled potassium titanyl phosphate (KTiOPO4) or PPKTP). There have been several publications discussing the merits and disadvantages of QOCT compared to OCT and other imaging techniques. First, we discuss the issues and solutions for increasing the efficiency of the quantum entangled photons. Second, we use a free space QOCT experiment to generate a high flux of these quantum entangled photons in two orthogonal polarizations, by

  20. Phytophthora megakarya and Phytophthora palmivora, Closely Related Causal Agents of Cacao Black Pod Rot, Underwent Increases in Genome Sizes and Gene Numbers by Different Mechanisms

    Science.gov (United States)

    Ali, Shahin S.; Shao, Jonathan; Lary, David J.; Kronmiller, Brent A.; Shen, Danyu; Strem, Mary D.; Amoako-Attah, Ishmael; Akrofi, Andrew Yaw; Begoude, B.A. Didier; ten Hoopen, G. Martijn; Coulibaly, Klotioloma; Kebe, Boubacar Ismaël; Melnick, Rachel L.; Guiltinan, Mark J.; Tyler, Brett M.; Meinhardt, Lyndel W.

    2017-01-01

    Phytophthora megakarya (Pmeg) and Phytophthora palmivora (Ppal) are closely related species causing cacao black pod rot. Although Ppal is a cosmopolitan pathogen, cacao is the only known host of economic importance for Pmeg. Pmeg is more virulent on cacao than Ppal. We sequenced and compared the Pmeg and Ppal genomes and identified virulence-related putative gene models (PGeneM) that may be responsible for their differences in host specificities and virulence. Pmeg and Ppal have estimated genome sizes of 126.88 and 151.23 Mb and PGeneM numbers of 42,036 and 44,327, respectively. The evolutionary histories of Pmeg and Ppal appear quite different. Postspeciation, Ppal underwent whole-genome duplication whereas Pmeg has undergone selective increases in PGeneM numbers, likely through accelerated transposable element-driven duplications. Many PGeneMs in both species failed to match transcripts and may represent pseudogenes or cryptic genetic reservoirs. Pmeg appears to have amplified specific gene families, some of which are virulence-related. Analysis of mycelium, zoospore, and in planta transcriptome expression profiles using neural network self-organizing map analysis generated 24 multivariate and nonlinear self-organizing map classes. Many members of the RxLR, necrosis-inducing phytophthora protein, and pectinase genes families were specifically induced in planta. Pmeg displays a diverse virulence-related gene complement similar in size to and potentially of greater diversity than Ppal but it remains likely that the specific functions of the genes determine each species’ unique characteristics as pathogens. PMID:28186564

  1. Characteristics of health professions schools, public school systems, and community-based organizations in successful partnerships to increase the numbers of underrepresented minority students entering health professions education.

    Science.gov (United States)

    Carline, Jan D; Patterson, Davis G

    2003-05-01

    To identify characteristics of health professions schools, public schools, and community-based organizations in successful partnerships to increase the number of underrepresented minority students entering health professions. The Robert Wood Johnson Foundation and the W. K. Kellogg Foundation funded the Health Professions Partnership Initiative program developed from Project 3000 by 2000 of the Association of American Medical Colleges. Semi-structured interviews were completed with awardees and representatives of the funding agencies, the national program office, and the national advisory committee between the fall of 2000 and the summer of 2002. Site visits were conducted at ten sites, with representatives of partner institutions, teachers, parents, and children. Characteristics that supported and hindered development of successful partnerships were identified using an iterative qualitative approach. Successful partnerships included professional schools that had a commitment to community service. Successful leaders could work in both cultures of the professional and public schools. Attitudes of respect and listening to the needs of partners were essential. Public school governance supported innovation. Happenstance and convergence of interests played significant roles in partnership development. The most telling statement was "We did it, together." This study identifies characteristics associated with smoothly working partnerships, and barriers to successful program development. Successful partnerships can form the basis on which educational interventions are built. The study is limited by the definition of success used, and its focus on one funded program. The authors were unable to identify outcomes in terms of numbers of children influenced by programs or instances in which lasting changes in health professions schools had occurred.

  2. Adaptation to acidic soil is achieved by increased numbers of cis-acting elements regulating ALMT1 expression in Holcus lanatus.

    Science.gov (United States)

    Chen, Zhi Chang; Yokosho, Kengo; Kashino, Miho; Zhao, Fang-Jie; Yamaji, Naoki; Ma, Jian Feng

    2013-10-01

    Yorkshire fog (Holcus lanatus), which belongs to the Poaceae family and is a close relative of the agronomic crop oat (Avena sativa), is a widely adaptable grass species that is able to grow on highly acidic soils with high levels of Al, but the mechanism underlying the high Al tolerance is unknown. Here, we characterized two accessions of H. lanatus collected from an acid plot (soil pH 3.6, HL-A) and a neutral plot (pH 7.1, HL-N) in terms of Al tolerance, organic acid anion secretion and related gene expression. In response to Al (pH 4.5), the HL-A roots secreted approximately twice as much malate as the HL-N roots, but there was no difference in citrate secretion. Cloning of the gene HlALMT1 responsible for malate secretion showed that the encoded amino acid sequence did not differ between two accessions, but the expression level in the outer cell layers of the HL-A roots was twice as high as in the HL-N roots. This difference was not due to the genomic copy number, but was due to the number of cis-acting elements for an Al-responsive transcription factor (HlART1) in the promoter region of HlALMT1, as demonstrated by both a yeast one-hybrid assay and a transient assay in tobacco protoplasts. Furthermore, introduction of HlALMT1 driven by the HL-A promoter into rice resulted in significantly more Al-induced malate secretion than introduction of HlALMT1 driven by the HL-N promoter. These findings indicate that the adaptation of H. lanatus to acidic soils may be achieved by increasing number of cis-acting elements for ART1 in the promoter region of the HlALMT1 gene, enhancing the expression of HlALMT1 and the secretion of malate. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  3. Quantum Anatomy of the Classical Interference of n-Photon States in a Mach-Zehnder Interferometer

    International Nuclear Information System (INIS)

    Ramírez-Cruz, N; Velázquez, V; Bastarrachea-Magnani, M A

    2016-01-01

    In this work we present the theory for the quantum interference of states with an arbitrary number of photons in a Mach-Zehnder interferometer. We express the mathematical description of the interference in an algebraic way. We show the interference pattern of an average of a n photons input state corresponds to the classical interference pattern, which tells us the last comes from a quantum interference statistical average. Then, we propose to use this scheme to study the statistical transition from quantum to classical interference. (paper)

  4. Ernst Mach, George Sarton and the Empiry of Teaching Science Part I

    Science.gov (United States)

    Siemsen, Hayo

    2012-01-01

    George Sarton had a strong influence on modern history of science. The method he pursued throughout his life was the method he had discovered in Ernst Mach's "Mechanics" when he was a student in Ghent. Sarton was in fact throughout his life implementing a research program inspired by the epistemology of Mach. Sarton in turn inspired many…

  5. 3-D Wizardry: Design in Papier-Mache, Plaster, and Foam.

    Science.gov (United States)

    Wolfe, George

    Papier-mache, plaster, and foam are inexpensive and versatile media for 3-dimensional classroom and studio art experiences. They can be used equally well by elementary, high school, or college students. Each medium has its own characteristic. Papier-mache is pliable but dries into a hard, firm surface that can be waterproofed. Plaster can be…

  6. Germanium on silicon mid-infrared waveguides and Mach-Zehnder interferometers

    NARCIS (Netherlands)

    Malik, A.; Muneeb, M.; Shimura, Y.; Campenhout, van J.; Loo, van de R.; Roelkens, G.C.

    2013-01-01

    In this paper we describe Ge-on-Si waveguides and Mach-Zehnder interferometers operating in the 5.2 - 5.4 µm wavelength range. 3dB/cm waveguide losses and Mach-Zehnder interferometers with 20dB extinction ratio are presented.

  7. Sub-shot-noise phase sensitivity with a Bose-Einstein condensate Mach-Zehnder interferometer

    International Nuclear Information System (INIS)

    Pezze, L.; Smerzi, A.; Collins, L.A.; Berman, G.P.; Bishop, A.R.

    2005-01-01

    Bose-Einstein condensates (BEC), with their coherence properties, have attracted wide interest for their possible application to ultraprecise interferometry and ultraweak force sensors. Since condensates, unlike photons, are interacting, they may permit the realization of specific quantum states needed as input of an interferometer to approach the Heisenberg limit, the supposed lower bound to precision phase measurements. To this end, we study the sensitivity to external weak perturbations of a representative matter-wave Mach-Zehnder interferometer whose input are two Bose-Einstein condensates created by splitting a single condensate in two parts. The interferometric phase sensitivity depends on the specific quantum state created with the two condensates, and, therefore, on the time scale of the splitting process. We identify three different regimes, characterized by a phase sensitivity Δθ scaling with the total number of condensate particles N as (i) the standard quantum limit Δθ∼1/N 1/2 (ii) the sub shot-noise Δθ∼1/N 3/4 , and the (iii) the Heisenberg limit Δθ∼1/N. However, in a realistic dynamical BEC splitting, the 1/N limit requires a long adiabaticity time scale, which is hardly reachable experimentally. On the other hand, the sub-shot-noise sensitivity Δθ∼1/N 3/4 can be reached in a realistic experimental setting. We also show that the 1/N 3/4 scaling is a rigorous upper bound in the limit N→∞, while keeping constant all different parameters of the bosonic Mach-Zehnder interferometer

  8. Investigation of Mach-Zehnder interferometer properties based on PLC technology

    Science.gov (United States)

    Ren, Mei-zhen; Zhang, Jia-shun; An, Jun-ming; Wang, Yue; Wang, Liang-liang; Li, Jian-guang; Wu, Yuan-da; Yin, Xiao-jie; Hu, Xiong-wei

    2018-05-01

    We report investigations of three types of silica-based thermo-optic modulating Mach-Zehnder interferometers (MZIs). They are widely used in optical communication and quantum photonics. Three types of MZIs are fabricated. The waveguide structure and fabrication process are paid special attention. The power consumption is less than 250 mW for all MZIs. The polarization dependent loss (PDL) at the same attenuation using the upper heater is less than that using the lower heater for the three types of MZIs. In addition, it is found that the PDL at the same attenuation increases gradually for π, 2π and 0 phase differences. The measured response time of the three types of MZIs is less than 1.8 ms.

  9. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  10. Mach's principle and the rest mass of the graviton

    International Nuclear Information System (INIS)

    Woodward, J.F.; Crowley, R.J.; Yourgrau, W.

    1975-01-01

    The question of the graviton rest mass is briefly discussed and then it is shown that the Sciama-Dicke formulation of Mach's principle admits, in the linear approximation, the calculation of the graviton rest mass. One finds that the value of the graviton rest mass depends on the cosmological model adopted, the mean matter density in the universe, the speed of light, and the constant of gravitation. The value obtained for an infinite, stationary universe is 7.6 times 10 -67 g. The value for evolutionary cosmological models is found to depend critically on the mass and ''radius'' of the universe, both null and non-null values occurring only for certain values of these parameters. Problems that arise as a consequence of the linear approximation are pointed out

  11. On-chip Mach-Zehnder interferometer for OCT systems

    Science.gov (United States)

    van Leeuwen, Ton G.; Akca, Imran B.; Angelou, Nikolaos; Weiss, Nicolas; Hoekman, Marcel; Leinse, Arne; Heideman, Rene G.

    2018-04-01

    By using integrated optics, it is possible to reduce the size and cost of a bulky optical coherence tomography (OCT) system. One of the OCT components that can be implemented on-chip is the interferometer. In this work, we present the design and characterization of a Mach-Zehnder interferometer consisting of the wavelength-independent splitters and an on-chip reference arm. The Si3N4 was chosen as the material platform as it can provide low losses while keeping the device size small. The device was characterized by using a home-built swept source OCT system. A sensitivity value of 83 dB, an axial resolution of 15.2 μm (in air) and a depth range of 2.5 mm (in air) were all obtained.

  12. How the mach phenomenon and shape affect the radiographic appearance of skeletal structures

    International Nuclear Information System (INIS)

    Papageorges, M.

    1991-01-01

    The shape of skeletal structures and their position relative to the x-ray beam have a considerable effect on their radiographic appearance. Depending on the thickness of the cortical or subchondral bone, skeletal structures display the characteristics of either homogeneous or compound lamellar structures. Convex homogeneous structures are associated with a negative Mach line, and concave homogeneous structures are associated with a positive Mach line. Convex compound lamellar structures are associated with a negative Mach band and visualization of the lamina (subchondral or cortical bone) is reduced. Concave compound lamellar structures are associated with a positive Mach band and visualization of the lamina is enhanced. The combined effect of Mach phenomenon, shape, and thickness enhances visualization of some skeletal surfaces and make others imperceptible. These principles are very useful to correctly identify complex skeletal structures and avoid misinterpretations

  13. [Thought Experiments of Economic Surplus: Science and Economy in Ernst Mach's Epistemology].

    Science.gov (United States)

    Wulz, Monika

    2015-03-01

    Thought Experiments of Economic Surplus: Science and Economy in Ernst Mach's Epistemology. Thought experiments are an important element in Ernst Mach's epistemology: They facilitate amplifying our knowledge by experimenting with thoughts; they thus exceed the empirical experience and suspend the quest for immediate utility. In an economical perspective, Mach suggested that thought experiments depended on the production of an economic surplus based on the division of labor relieving the struggle for survival of the individual. Thus, as frequently emphasized, in Mach's epistemology, not only the 'economy of thought' is an important feature; instead, also the socioeconomic conditions of science play a decisive role. The paper discusses the mental and social economic aspects of experimental thinking in Mach's epistemology and examines those within the contemporary evolutionary, physiological, and economic contexts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Developmental exposure to second-hand smoke increases adult atherogenesis and alters mitochondrial DNA copy number and deletions in apoE(-/- mice.

    Directory of Open Access Journals (Sweden)

    Jessica L Fetterman

    Full Text Available Cardiovascular disease is a major cause of morbidity and mortality in the United States. While many studies have focused upon the effects of adult second-hand smoke exposure on cardiovascular disease development, disease development occurs over decades and is likely influenced by childhood exposure. The impacts of in utero versus neonatal second-hand smoke exposure on adult atherosclerotic disease development are not known. The objective of the current study was to determine the effects of in utero versus neonatal exposure to a low dose (1 mg/m(3 total suspended particulate of second-hand smoke on adult atherosclerotic lesion development using the apolipoprotein E null mouse model. Consequently, apolipoprotein E null mice were exposed to either filtered air or second-hand smoke: (i in utero from gestation days 1-19, or (ii from birth until 3 weeks of age (neonatal. Subsequently, all animals were exposed to filtered air and sacrificed at 12-14 weeks of age. Oil red-O staining of whole aortas, measures of mitochondrial damage, and oxidative stress were performed. Results show that both in utero and neonatal second-hand smoke exposure significantly increased adult atherogenesis in mice compared to filtered air controls. These changes were associated with changes in aconitase and mitochondrial superoxide dismutase activities consistent with increased oxidative stress in the aorta, changes in mitochondrial DNA copy number and deletion levels. These studies show that in utero or neonatal exposure to second-hand smoke significantly influences adult atherosclerotic lesion development and results in significant alterations to the mitochondrion and its genome that may contribute to atherogenesis.

  15. Developmental exposure to second-hand smoke increases adult atherogenesis and alters mitochondrial DNA copy number and deletions in apoE(-/-) mice.

    Science.gov (United States)

    Fetterman, Jessica L; Pompilius, Melissa; Westbrook, David G; Uyeminami, Dale; Brown, Jamelle; Pinkerton, Kent E; Ballinger, Scott W

    2013-01-01

    Cardiovascular disease is a major cause of morbidity and mortality in the United States. While many studies have focused upon the effects of adult second-hand smoke exposure on cardiovascular disease development, disease development occurs over decades and is likely influenced by childhood exposure. The impacts of in utero versus neonatal second-hand smoke exposure on adult atherosclerotic disease development are not known. The objective of the current study was to determine the effects of in utero versus neonatal exposure to a low dose (1 mg/m(3) total suspended particulate) of second-hand smoke on adult atherosclerotic lesion development using the apolipoprotein E null mouse model. Consequently, apolipoprotein E null mice were exposed to either filtered air or second-hand smoke: (i) in utero from gestation days 1-19, or (ii) from birth until 3 weeks of age (neonatal). Subsequently, all animals were exposed to filtered air and sacrificed at 12-14 weeks of age. Oil red-O staining of whole aortas, measures of mitochondrial damage, and oxidative stress were performed. Results show that both in utero and neonatal second-hand smoke exposure significantly increased adult atherogenesis in mice compared to filtered air controls. These changes were associated with changes in aconitase and mitochondrial superoxide dismutase activities consistent with increased oxidative stress in the aorta, changes in mitochondrial DNA copy number and deletion levels. These studies show that in utero or neonatal exposure to second-hand smoke significantly influences adult atherosclerotic lesion development and results in significant alterations to the mitochondrion and its genome that may contribute to atherogenesis.

  16. Developmental Exposure to Second-Hand Smoke Increases Adult Atherogenesis and Alters Mitochondrial DNA Copy Number and Deletions in apoE−/− Mice

    Science.gov (United States)

    Fetterman, Jessica L.; Pompilius, Melissa; Westbrook, David G.; Uyeminami, Dale; Brown, Jamelle; Pinkerton, Kent E.; Ballinger, Scott W.

    2013-01-01

    Cardiovascular disease is a major cause of morbidity and mortality in the United States. While many studies have focused upon the effects of adult second-hand smoke exposure on cardiovascular disease development, disease development occurs over decades and is likely influenced by childhood exposure. The impacts of in utero versus neonatal second-hand smoke exposure on adult atherosclerotic disease development are not known. The objective of the current study was to determine the effects of in utero versus neonatal exposure to a low dose (1 mg/m3 total suspended particulate) of second-hand smoke on adult atherosclerotic lesion development using the apolipoprotein E null mouse model. Consequently, apolipoprotein E null mice were exposed to either filtered air or second-hand smoke: (i) in utero from gestation days 1–19, or (ii) from birth until 3 weeks of age (neonatal). Subsequently, all animals were exposed to filtered air and sacrificed at 12–14 weeks of age. Oil red-O staining of whole aortas, measures of mitochondrial damage, and oxidative stress were performed. Results show that both in utero and neonatal second-hand smoke exposure significantly increased adult atherogenesis in mice compared to filtered air controls. These changes were associated with changes in aconitase and mitochondrial superoxide dismutase activities consistent with increased oxidative stress in the aorta, changes in mitochondrial DNA copy number and deletion levels. These studies show that in utero or neonatal exposure to second-hand smoke significantly influences adult atherosclerotic lesion development and results in significant alterations to the mitochondrion and its genome that may contribute to atherogenesis. PMID:23825571

  17. Tjirtamai--'to care for': a nursing education model designed to increase the number of Aboriginal nurses in a rural and remote Queensland community.

    Science.gov (United States)

    West, Roianne; West, Leeona; West, Karen; Usher, Kim

    In 2009, a nursing education model was locally designed and delivered to support the interest of a group of Aboriginal community members living in a rural and remote town in Queensland, specifically to prepare for entry into further nursing education. Named 'Tjirtamai' by the traditional owners of the area, the program was offered in recognition of the challenges faced by Aboriginal people when they enter nursing education courses and as a way to increase the local number of Aboriginal nurses. This program, while funded by the Government, had unprecedented support and involvement from both the local Aboriginal and wider community. The model offered multiple exit points, assistance with financial and other known challenges for Aboriginal and Torres Strait Islander students, and included contextualised literacy and numeracy. Of the 38 Aboriginal students who enrolled in the course, 26 students completed. Of those students, 18 have since enrolled in a bachelor degree in nursing while another 4 enrolled in a diploma of nursing. This paper provides an overview of the course and its outcomes.

  18. Increased number of intestinal villous M cells in levamisole - pretreated weaned pigs experimentally infected with F4ac+ enterotoxigenic Escherichia coli strain

    Directory of Open Access Journals (Sweden)

    H. Valpotić

    2010-07-01

    Full Text Available Immunoprophylaxis of porcine postweaning colibacillosis (PWC caused by enterotoxigenic Escherichia coli (ETEC expressing F4 fimbriae is an unsolved problem. Just as ETEC strains can exploit intestinal microfold (M cells as the entry portal for infection, their high transcytotic ability make them an attractive target for mucosally delivered vaccines, adjuvants and therapeutics. We have developed a model of parenteral/oral immunization of 4-weeks-old pigs with either levamisole or vaccine candidate F4ac+ non-ETEC strain to study their effects on de novo differentiation of antigen-sampling M cells. Identification, localization and morphometric quantification of cytokeratin 18 positive M cells in the ileal mucosa of 6-weeks-old pigs revealed that they were: 1 exclusively located within villous epithelial layer, 2 significantly numerous (P< 0.01 in levamisole pretreated/challenged pigs, and 3 only slightly, but not significantly numerous in vaccinated/challenged pigs compared with non-pretreated/challenged control pigs. The fact that levamisole may affect the M cells frequency by increasing their numbers, makes it an interesting adjuvant to study development of an effective M cell-targeted vaccine against porcine PWC.

  19. Generation of sub-Poissonian photon number distribution

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Ramanujam, P. S.

    1990-01-01

    An optimization of a nonlinear Mach-Zehnder interferometer to produce sub-Poissonian photon number distribution is proposed. We treat the system quantum mechanically and estimate the mirror parameters, the nonlinearity of the medium in the interferometer, and the input power to obtain minimal...... output uncertainty in the photon number. The power efficiency of the system is shown to be high....

  20. Peripheral innate immune challenge exaggerated microglia activation, increased the number of inflammatory CNS macrophages, and prolonged social withdrawal in socially defeated mice.

    Science.gov (United States)

    Wohleb, Eric S; Fenn, Ashley M; Pacenta, Ann M; Powell, Nicole D; Sheridan, John F; Godbout, Jonathan P

    2012-09-01

    Repeated social defeat (RSD) activates neuroendocrine pathways that have a significant influence on immunity and behavior. Previous studies from our lab indicate that RSD enhances the inflammatory capacity of CD11b⁺ cells in the brain and promotes anxiety-like behavior in an interleukin (IL)-1 and β-adrenergic receptor-dependent manner. The purpose of this study was to determine the degree to which mice subjected to RSD were more responsive to a secondary immune challenge. Therefore, RSD or control (HCC) mice were injected with saline or lipopolysaccharide (LPS) and activation of brain CD11b⁺ cells and behavioral responses were determined. Peripheral LPS (0.5 mg/kg) injection caused an extended sickness response with exaggerated weight loss and prolonged social withdrawal in socially defeated mice. LPS injection also amplified mRNA expression of IL-1β, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS), and CD14 in enriched CD11b⁺ cells isolated from socially defeated mice. In addition, IL-1β mRNA levels in enriched CD11b⁺ cells remained elevated in socially defeated mice 24 h and 72 h after LPS. Moreover, microglia and CNS macrophages isolated from socially defeated mice had the highest CD14 expression after LPS injection. Both social defeat and LPS injection increased the percentage of CD11b⁺/CD45(high) macrophages in the brain and the number of inflammatory macrophages (CD11b⁺/CD45(high)/CCR2⁺) was highest in RSD-LPS mice. Anxiety-like behavior was increased by social defeat, but was not exacerbated by the LPS challenge. Nonetheless, reduced locomotor activity and increased social withdrawal were still present in socially defeated mice 72 h after LPS. Last, LPS-induced microglia activation was most evident in the hippocampus of socially defeated mice. Taken together, these findings demonstrate that repeated social defeat enhanced the neuroinflammatory response and caused prolonged sickness following innate immune challenge

  1. Modeling Turbulent Combustion for Variable Prandtl and Schmidt Number

    Science.gov (United States)

    Hassan, H. A.

    2004-01-01

    This report consists of two abstracts submitted for possible presentation at the AIAA Aerospace Science Meeting to be held in January 2005. Since the submittal of these abstracts we are continuing refinement of the model coefficients derived for the case of a variable Turbulent Prandtl number. The test cases being investigated are a Mach 9.2 flow over a degree ramp and a Mach 8.2 3-D calculation of crossing shocks. We have developed an axisymmetric code for treating axisymmetric flows. In addition the variable Schmidt number formulation was incorporated in the code and we are in the process of determining the model constants.

  2. Alloy synthesis using the mach stem region in an axial symmetric implosive shock: Understanding the pressure strain-temperature contributions

    Energy Technology Data Exchange (ETDEWEB)

    Staudhammer, Karl P.

    2004-01-01

    The Mach stem region in an axial symmetric shock implosion has generally been avoided in the dynamic consolidation of powders for a number of reasons. The prime reason being that the convergence of the shock waves in the cylindrical axis produce enormous pressures and concomitant temperatures that have melted tungsten. This shock wave convergence consequently results in a discontinuity in the hydro-code calculations. Dynamic deformation experiments on gold plated 304L stainless steel powders were undertaken. These experiments utilized pressures of 0.08 to 1.0 Mbar and contained a symmetric radial melt region along the central axis of the sample holder. To understand the role of deformation in a porous material, the pressure, and temperature as well as the deformation heat and associated defects must be accounted for. When the added heat of consolidation deformation exceeds the melt temperature of the 304 powders, a melt zone results that can consume large regions of the compact while still under the high-pressure pulse. As the shock wave traverses the sample and is removed in a momentum trap, its pressure/temperature are quenched. It is within this region that very high diffusion/alloying occurs and has been observed in the gold plated powders. Anomalous increases of gold diffusion into 304 stainless steel have been observed via optical microscopy, scanning electron microscopy and EDAX measurements. Values exceeding 1200 m/sec have been measured and correlated to the powder sizes, size distribution and packing density, concomitant with sample container strains ranging from 2.0% to 26%.

  3. The Malnutrition-Related Increase in Early Visceralization of Leishmania donovani Is Associated with a Reduced Number of Lymph Node Phagocytes and Altered Conduit System Flow

    Science.gov (United States)

    Ibrahim, Marwa K.; Barnes, Jeffrey L.; Anstead, Gregory M.; Jimenez, Fabio; Travi, Bruno L.; Peniche, Alex G.; Osorio, E. Yaneth; Ahuja, Seema S.; Melby, Peter C.

    2013-01-01

    In a murine model of moderate childhood malnutrition we found that polynutrient deficiency led to a 4–5-fold increase in early visceralization of L. donovani (3 days post-infection) following cutaneous infection and a 16-fold decrease in lymph node barrier function (pmalnutrition-related parasite dissemination we analyzed the cellularity, architecture, and function of the skin-draining lymph node. There was no difference in the localization of multiple cell populations in the lymph node of polynutrient deficient (PND) mice, but there was reduced cellularity with fewer CD11c+dendritic cells (DCs), fibroblastic reticular cells (FRCs), MOMA-2+ macrophages, and CD169+ subcapsular sinus macrophage (p<0.05 for all) compared to the well-nourished (WN) mice. The parasites were equally co-localized with DCs associated with the lymph node conduit network in the WN and PND mice, and were found in the high endothelial venule into which the conduits drain. When a fluorescent low molecular weight (10 kD) dextran was delivered in the skin, there was greater efflux of the marker from the lymph node conduit system to the spleens of PND mice (p<0.04), indicating that flow through the conduit system was altered. There was no evidence of disruption of the conduit or subcapsular sinus architecture, indicating that the movement of parasites into the subcortical conduit region was due to an active process and not from passive movement through a leaking barrier. These results indicate that the impaired capacity of the lymph node to act as a barrier to dissemination of L. donovani infection is associated with a reduced number of lymph node phagocytes, which most likely leads to reduced capture of parasites as they transit through the sinuses and conduit system. PMID:23967356

  4. Linear and nonlinear development of controlled disturbances in the supersonic boundary layer on a swept wing at Mach 2.5

    International Nuclear Information System (INIS)

    Kolosov, G L; Kosinov, A D

    2016-01-01

    Experimental data on the linear and nonlinear wave train development in 3D supersonic boundary layer over a 45° swept-wing at Mach number 2.5 are presented. Travelling artificial disturbances were introduced in the boundary layer by periodical glow discharge at frequencies 10 and 20 kHz. The spatial-temporal and spectral-wave characteristics of the wave train of unstable disturbances in the linear region are obtained. It is shown that the additional peaks in β '-spectra arise for both subharmonic and fundamental frequencies. The experiments indicate the presence of subharmonic resonance mechanism in 3D boundary layer at Mach number 2.5. (paper)

  5. Understanding the strategies employed to cope with increased numbers of AIDS-orphaned children in families in rural settings: a case of Mbeya Rural District, Tanzania.

    Science.gov (United States)

    Fauk, Nelsensius Klau; Mwakinyali, Silivano Edson; Putra, Sukma; Mwanri, Lillian

    2017-02-07

    The purpose of this study was to understand the strategies employed by families that adopt Acquired Immune Deficiency Syndrome (AIDS)-orphaned children (Adoptive families) for coping with and mitigating the impact of AIDS in Mbeya Rural District, Tanzania. High numbers of AIDS-orphaned children aged below 18 years in Mbeya Region have led to increasing the burden of families caring for them. Understanding the coping strategies and impact mitigation activities employed by adoptive families is important in order to develop programmes to help them. This study employed a qualitative method for data collection (one-on-one in-depth interviews). The respondents included 12 male and 8 female heads of families that provide essential care for AIDS-orphaned children in Mbeya Rural District in Tanzania. The framework approach was used to analyse the data that were collected from 15 July to 15 August 2010. The study findings revealed that adoptive families faced several challenges including financial constraints due to increased needs for basic essentials such as health care expenses, school fees and food. Further impacts on adoptive families included shortage of work opportunities and limited time to address these challenges. To mitigate these challenges, adoptive families employed a range of coping strategies including selling family assets and renting out parts of cultivable land for extra cash. Task reallocation which involved the AIDS-orphaned children entering the labour force was also employed as a strategy to mitigate challenges and involved de-enrolling of children from schools so they could take part in income-generating activities in order to earn supplementary family income. The creation of additional income-generating activities such as poultry farming were other coping mechanisms employed, and these received support from both non-governmental organisations (NGOs) and governmental organisations, including the Isangati Agricultural Development Organization (local

  6. Working with Instruments: Ernst Mach as Material Epistemologist, a Short Introduction.

    Science.gov (United States)

    Hoffmann, Christoph; Métraux, Alexandre

    2016-12-01

    With the death of Ernst Mach on February 19, 1916, one day after his seventy-eighth birthday, a question finally became explicit that had been looming for some time. It was as simple as it was fundamental: who, in the end, was this man, a scientist or a philosopher? The importance of this question for contemporaries can easily be gleaned from the obituaries that appeared in the weeks following Mach's death: one in the Physikalische Zeitschrift, written by Albert Einstein, and another in the Archiv für die Geschichte der Philosophie, written by Mach's former student Heinrich Gomperz. They both addressed this critical issue in plain words. Einstein stressed that Mach "was not a philosopher who chose the natural sciences as the object of his speculation, but a many-sided, interested, diligent scientist who also took visible pleasure in detailed questions outside the burning issues of general interest" (Einstein 1916, 104; translation cited in Blackmore 1992, 158). Gomperz in turn first emphasized the great loss science had experienced with Mach's death, asking subsequently whether "the suffering science is physics or philosophy?" (Gomperz 1916, 321). His answer broadly followed Einstein's conclusion; relying on Mach's own words, he reminded his readers that Mach never claimed to be a philosopher, but merely was looking for a viewpoint that transcended the disciplinary constraints of particular scientific activities.

  7. Boundary-Layer Instability Measurements in a Mach-6 Quiet Tunnel

    Science.gov (United States)

    Berridge, Dennis C.; Ward, Christopher, A. C.; Luersen, Ryan P. K.; Chou, Amanda; Abney, Andrew D.; Schneider, Steven P.

    2012-01-01

    Several experiments have been performed in the Boeing/AFOSR Mach-6 Quiet Tunnel at Purdue University. A 7 degree half angle cone at 6 degree angle of attack with temperature-sensitive paint (TSP) and PCB pressure transducers was tested under quiet flow. The stationary crossflow vortices appear to break down to turbulence near the lee ray for sufficiently high Reynolds numbers. Attempts to use roughness elements to control the spacing of hot streaks on a flared cone in quiet flow did not succeed. Roughness was observed to damp the second-mode waves in areas influenced by the roughness, and wide roughness spacing allowed hot streaks to form between the roughness elements. A forward-facing cavity was used for proof-of-concept studies for a laser perturber. The lowest density at which the freestream laser perturbations could be detected was 1.07 x 10(exp -2) kilograms per cubic meter. Experiments were conducted to determine the transition characteristics of a streamwise corner flow at hypersonic velocities. Quiet flow resulted in a delayed onset of hot streak spreading. Under low Reynolds number flow hot streak spreading did not occur along the model. A new shock tube has been built at Purdue. The shock tube is designed to create weak shocks suitable for calibrating sensors, particularly PCB-132 sensors. PCB-132 measurements in another shock tube show the shock response and a linear calibration over a moderate pressure range.

  8. Experiments on a smooth wall hypersonic boundary layer at Mach 6

    Science.gov (United States)

    Neeb, Dominik; Saile, Dominik; Gülhan, Ali

    2018-04-01

    The turbulent boundary layer along the surface of high-speed vehicles drives shear stress and heat flux. Although essential to the vehicle design, the understanding of compressible turbulent boundary layers at high Mach numbers is limited due to the lack of available data. This is particularly true if the surface is rough, which is typically the case for all technical surfaces. To validate a methodological approach, as initial step, smooth wall experiments were performed. A hypersonic turbulent boundary layer at Ma = 6 (Ma_e=5.4) along a 7{}° sharp cone model at low Reynolds numbers Re_{θ } ≈ 3000 was characterized. The mean velocities in the boundary layer were acquired by means of Pitot pressure and particle image velocimetry (PIV) measurements. Furthermore, the PIV data were used to extract turbulent intensities along the profile. The mean velocities in the boundary layer agree with numerical data, independent of the measurement technique. Based on the profile data, three different approaches to extract the skin friction velocity were applied and show favorable comparison to literature and numerical data. The extracted values were used for inner and outer scaling of the van Driest transformed velocity profiles which are in good agreement to incompressible theoretical data. Morkovin scaled turbulent intensities show ambiguous results compared to literature data which may be influenced by inflow turbulence level, particle lag and other measurement uncertainties.

  9. Ultra-Abrupt Tapered Fiber Mach-Zehnder Interferometer Sensors

    Directory of Open Access Journals (Sweden)

    Lanying Zhou

    2011-05-01

    Full Text Available A fiber inline Mach-Zehnder interferometer (MZI consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10 made by stretching. The proposed fabrication method is very low cost, 1/20–1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30–350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3–5 fold by fabricating an inline micro–trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N2 is tested by the MZI sensor coated with MFI–type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

  10. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  11. Mach-Zehnder atom interferometer inside an optical fiber

    Science.gov (United States)

    Xin, Mingjie; Leong, Wuiseng; Chen, Zilong; Lan, Shau-Yu

    2017-04-01

    Precision measurement with light-pulse grating atom interferometry in free space have been used in the study of fundamental physics and applications in inertial sensing. Recent development of photonic band-gap fibers allows light for traveling in hollow region while preserving its fundamental Gaussian mode. The fibers could provide a very promising platform to transfer cold atoms. Optically guided matter waves inside a hollow-core photonic band-gap fiber can mitigate diffraction limit problem and has the potential to bring research in the field of atomic sensing and precision measurement to the next level of compactness and accuracy. Here, we will show our experimental progress towards an atom interferometer in optical fibers. We designed an atom trapping scheme inside a hollow-core photonic band-gap fiber to create an optical guided matter waves system, and studied the coherence properties of Rubidium atoms in this optical guided system. We also demonstrate a Mach-Zehnder atom interferometer in the optical waveguide. This interferometer is promising for precision measurements and designs of mobile atomic sensors.

  12. Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential

    International Nuclear Information System (INIS)

    Berrada, T.

    2014-01-01

    Mach-Zehnder interferometry with interacting Bose-Einstein condensates in a double-well potential Particle-wave duality has enabled the construction of interferometers for massive particles such as electrons, neutrons, atoms or molecules. Implementing atom interferometry has required the development of analogues to the optical beam-splitters, phase shifters or recombiners to enable the coherent, i.e. phase-preserving manipulation of quantum superpositions. While initially demonstrating the wave nature of particles, atom interferometers have evolved into some of the most advanced devices for precision measurement, both for technological applications and tests of the fundamental laws of nature. Bose- Einstein condensates (BEC) of ultracold atoms are particular matter waves: they exhibit a collective many-body wave function and macroscopic coherence properties. As such, they have often been considered as an analogue to optical laser elds and it is natural to wonder whether BECs can provide to atom interferometry a similar boost as the laser brought to optical interferometry. One fundamental dierence between atomic BECs and lasers elds is the presence of atomic interactions, yielding an intrinsic non-linearity. On one hand, interactions can lead to eects destroying the phase coherence and limiting the interrogation time of trapped BEC interferometers. On the other hand, they can be used to generate nonclassical (e.g. squeezed) states to improve the sensitivity of interferometric measurements beyond the standard quantum limit (SQL). In this thesis, we present the realization of a full Mach-Zehnder interferometric sequence with trapped, interacting BECs con ned on an atom chip. Our interferometer relies on the coherent manipulation of a BEC in a magnetic double-well potential. For this purpose, we developed a novel type of matter-wave recombiner, an element which so far was missing in BEC atom optics. We have been able to exploit interactions to generate a squeezed

  13. Mechanisms of topoisomerase I (TOP1) gene copy number increase in a stage III colorectal cancer patient cohort

    DEFF Research Database (Denmark)

    Smith, David Hersi; Christensen, Ib Jarle; Jensen, Niels Frank

    2013-01-01

    Topoisomerase I (Top1) is the target of Top1 inhibitor chemotherapy. The TOP1 gene, located at 20q12-q13.1, is frequently detected at elevated copy numbers in colorectal cancer (CRC). The present study explores the mechanism, frequency and prognostic impact of TOP1 gene aberrations in stage III C...

  14. Hadron Azimuthal Correlations and Mach-like Structures in a Partonic/Hadronic Transport Model

    International Nuclear Information System (INIS)

    Ma, G.L.; Zhang, S.; Ma, Y.G.; Cai, X.Z.; Chen, J.H.; He, Z.J.; Huang, H.Z.; Long, J.L.; Shen, W.Q.; Shi, X.H.; Zhong, C.; Zuo, J.X.

    2007-01-01

    With a multi-phase transport model (AMPT) with both partonic and hadronic interactions, two- and three-particle azimuthal correlations in Au + Au collisions at s NN =200 GeV have been studied by the mixing-event technique. A Mach-like structure has been observed in two- and three-particle correlations in central collisions. It has been found that both partonic and hadronic dynamical mechanisms contribute to the Mach-like structure. However, only hadronic rescattering is unable to reproduce experimental amplitude of Mach-like structure, and parton cascade process is indispensable. The results of three-particle correlation indicate a partonic Mach-like shock wave can be produced by strong parton cascade in central Au+Au collisions

  15. Hypervelocity Wind Tunnel No. 9 Mach 7 Thermal Structural Facility Verification and Calibration

    National Research Council Canada - National Science Library

    Lafferty, John

    1996-01-01

    This report summarizes the verification and calibration of the new Mach 7 Thermal Structural Facility located at the White Oak, Maryland, site of the Dahlgren Division, Naval Surface Warfare Center...

  16. Electrical crosstalk in integrated Mach-Zehnder modulators caused by a shared ground path

    NARCIS (Netherlands)

    Yao, W.; Gilardi, G.; Smit, M.K.; Wale, M.J.

    2015-01-01

    We show that the majority of electrical crosstalk between integrated Mach-Zehnder modulators can be caused by a shared ground path and demonstrate that in its absence crosstalk and related transmission penalty is greatly reduced.

  17. Digital integrated control of a Mach 2.5 mixed-compression supersonic inlet and an augmented mixed-flow turbofan engine

    Science.gov (United States)

    Batterton, P. G.; Arpasi, D. J.; Baumbick, R. J.

    1974-01-01

    A digitally implemented integrated inlet-engine control system was designed and tested on a mixed-compression, axisymmetric, Mach 2.5, supersonic inlet with 45 percent internal supersonic area contraction and a TF30-P-3 augmented turbofan engine. The control matched engine airflow to available inlet airflow. By monitoring inlet terminal shock position and over-board bypass door command, the control adjusted engine speed so that in steady state, the shock would be at the desired location and the overboard bypass doors would be closed. During engine-induced transients, such as augmentor light-off and cutoff, the inlet operating point was momentarily changed to a more supercritical point to minimize unstarts. The digital control also provided automatic inlet restart. A variable inlet throat bleed control, based on throat Mach number, provided additional inlet stability margin.

  18. Progression of periodontal inflammation in adolescents is associated with increased number of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Fusobacterium nucleatum.

    Science.gov (United States)

    Yang, Ning-Yan; Zhang, Quan; Li, Jin-Lu; Yang, Sheng-Hui; Shi, Qing

    2014-05-01

    The study aims to evaluate the change of related subgingival periodontopathogens among different stage of gingivitis in adolescent and assess the relationship between periodontopathogens and the progression of periodontal inflammation. A total of 77 subgingival plaque samples from 35 adolescent individuals were divided into three groups including gingivitis group (mild, 15 samples; moderate, 16 samples; severe, 15 samples), chronic periodontitis group (15 samples) and healthy group (15 samples). Real-time PCR was used to quantitate Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Fusobacterium nucleatum in subgingival plaque samples. All species, except for F. nucleatum, were detected in samples from gingivitis and periodontitis groups in significantly greater number than in those from healthy group (P periodontitis group in significantly greater number than in those from moderate-to-severe gingivitis group (P periodontal inflammation in adolescents. Examination of periodontopathogens number in adolescents may be of some value for monitoring of periodontal disease development. © 2013 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. [Investigation of Empiricism. On Ernst Mach's Conception of the Thought Experiment].

    Science.gov (United States)

    Krauthausen, Karin

    2015-03-01

    Investigation of Empiricism. On Ernst Mach's Conception of the Thought Experiment. The paper argues that Ernst Mach's conception of the thought experiment from 1897/1905 holds a singular position in the lively discussions and repeated theorizations that have continued up to the present in relation to this procedure. Mach derives the thought experiment from scientific practice, and does not oppose it to the physical experiment, but, on the contrary, endows it with a robust relation to the facts. For Mach, the thought experiment is a reliable means of determining empiricism, and at the same time a real, because open and unbiased, experimenting. To shed light on this approach, the paper carries out a close reading of the relevant texts in Mach's body of writings (in their different stages of revision) and proceeds in three steps: first, Mach's processual understanding of science will be presented, which also characterizes his research and publication practice (I. 'Aperçu' and 'Sketch'. Science as Process and Projection); then in a second step the physiological and biological justification and valorization of memory and association will be examined with which Mach limits the relevance of categories such as consciousness and will (II. The Biology of Consciousness. Or The Polyp Colony); against this background, thirdly, the specific empiricism can be revealed that Mach inscribes into the thought experiment by on the one hand founding it in the memory and association, and on the other by tracing it back to geometry, which he deploys as an experimenting oriented to experience (III. Thinking and Experience. The Thought Experiment). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Revisiting Einstein's Happiest Thought: On Ernst Mach and the Early History of Relativity

    Science.gov (United States)

    Staley, Richard

    2016-03-01

    This paper argues we should distinguish three phases in the formation of relativity. The first involved relational approaches to perception, and physiological and geometrical space and time in the 1860s and 70s. The second concerned electrodynamics and mechanics (special relativity). The third concerned mechanics, gravitation, and physical and geometrical space and time. Mach's early work on the Doppler effect, together with studies of visual and motor perception linked physiology, physics and psychology, and offered new approaches to physiological space and time. These informed the critical conceptual attacks on Newtonian absolutes that Mach famously outlined in The Science of Mechanics. Subsequently Mach identified a growing group of ``relativists,'' and his critiques helped form a foundation for later work in electrodynamics (in which he did not participate). Revisiting Mach's early work will suggest he was still more important to the development of new approaches to inertia and gravitation than has been commonly appreciated. In addition to what Einstein later called ``Mach's principle,'' I will argue that a thought experiment on falling bodies in Mach's Science of Mechanics also provided a point of inspiration for the happy thought that led Einstein to the equivalence principle.

  1. Influence of increasing numbers of RE-inverters on the power quality in the distribution grids: A PQ case study of a representative wind turbine and photovoltaic system

    Institute of Scientific and Technical Information of China (English)

    Przemyslaw JANIK; Grzegorz KOSOBUDZKI; Harald SCHWARZ

    2017-01-01

    This paper presents the selected power quality (PQ) indicia of a wind generator and a photovoltaic installation considered to be the representative of medium voltage and low voltage distribution grids.The analysis of measured values suggests that the decrease in PQ is a case of specific combination of distributed generation,grid parameters and load behaviour.Modem generators have a limited impact on PQ.On the other hand,fluctuations in power generation are regarded as an emerging PQ indicator.The growing number of distributed renewable installations causes stochastic,variable,and hardly predictable power flows in the distribution grid.The nature of fluctuations in wind and solar generation is different.In both cases,new indexes for the quantification of fluctuations are needed and are yet not standardised.Proper assessment of these fluctuations enables definition of useful fluctuation limits and rules for optimal storage system integration.

  2. LYMPHOCYTIC THYROIDITIS IS ASSOCIATED WITH INCREASED NUMBER OF BENIGN CERVICAL NODES AND FEWER CENTRAL NECK COMPARTMENT METASTATIC LYMPH NODES IN PATIENTS WITH DIFFERENTIATED THYROID CANCER.

    Science.gov (United States)

    Donangelo, Ines; Walts, Ann E; Bresee, Catherine; Braunstein, Glenn D

    2016-10-01

    Whether or not autoimmune thyroid disease influences the progression of differentiated thyroid cancer (DTC) remains controversial. Findings of previous studies are influenced by lead time bias and/or procedure bias selection. These biases can be reduced by studying a single-institution patient population that underwent a similar extent of surgical resection. From a cohort of 660 patients with DTC who underwent thyroidectomy, we retrospectively studied 357 patients who underwent total thyroidectomy and central compartment node dissection (CCND) for DTC between 2003 and 2013. Forty-one percent (140/345) of study patients had lymphocytic thyroiditis (LT), and 30% (91/301) had serum positive for thyroglobulin antibody (TgAb). LT was reported in 78% of the TgAb-positive cases. Sixty percent (213/357) of cases had metastatic thyroid carcinoma in 1 or more neck lymph nodes (55% [198/357] central compartment, and 22% [77/356] lateral compartment). Patients with LT had fewer metastatic cervical lymph nodes than those with no LT (2.7 ± 4.7 vs 3.5 ± 4.8, respectively, P = .0285). Patients with positive TgAb and thyroiditis had a larger number of benign cervical lymph nodes removed than those with negative TgAb or no LT. No significant difference was observed in age, tumor size, multifocality, extrathyroidal extension, vascular invasion, or frequency of cervical lymph node metastasis between TgAb-negative and -positive cases or between cases with and without LT. Lymphocytic thyroiditis is associated with fewer central neck compartment metastatic lymph nodes and a larger number of excised reactive benign cervical lymph nodes. Whether this association indicates a protective role of thyroid autoimmunity in lymph node spreading remains unclear. CCND = central compartment node dissection DTC = differentiated thyroid cancer HT = Hashimoto thyroiditis LT = lymphocytic thyroiditis TgAb = thyroglobulin antibody TPO = thyroid peroxidase.

  3. Hypothalamic growth hormone-releasing hormone (GHRH) cell number is increased in human illness, but is not reduced in Prader-Willi syndrome or obesity

    NARCIS (Netherlands)

    Goldstone, Anthony P.; Unmehopa, Unga A.; Swaab, Dick F.

    2003-01-01

    Acute illness leads to increased GH, but reduced IGF-I secretion, while both are reduced in chronic illness. Prader-Willi syndrome (PWS) is a genetic obesity syndrome, with GH deficiency a feature independent of obesity. Reduced GH secretion may result from decreased hypothalamic release of

  4. The total length of myocytes and capillaries, and total number of myocyte nuclei in the rat heart are time-dependently increased by growth hormone

    DEFF Research Database (Denmark)

    Brüel, Annemarie; Oxlund, Hans; Nyengaard, Jens Randel

    2005-01-01

    /kg/day) or vehicle for 5, 10, 20, 40, or 80 days. From the left ventricle (LV) histological sections were made and stereological methods applied. Linear regression showed that GH time-dependently increased: LV volume (r=0.96, P

  5. Military Payloads Hosted on Commercial Satellites: How Can the Space and Missile Systems Center Increase the Number of Commercially Hosted Military Payload Contract Awards

    Science.gov (United States)

    2015-12-01

    in-orbit op- erations averaged between 17 and 22 percent of the cost of the insured satellite; some markets fetched premiums as high as 30 percent.18...coupled device (CCD) visual cameras Echostar-XI & ICO-G1 2008 x2 NAISa US Coast Guard national automatic identification system Orbcomm 2008 IRIS Cisco ...The relocation of a commercial satellite to a market with increased demands could yield a significant return on investment for the commer- cial owner

  6. Increased kilo-electron-volt x-ray yields from Z-pinch plasmas by mixing elements of similar atomic numbers

    International Nuclear Information System (INIS)

    Deeney, C.; LePell, P.D.; Failor, B.H.; Wong, S.L.; Apruzese, J.P.; Whitney, K.G.; Thornhill, J.W.; Davis, J.; Yadlowsky, E.; Hazelton, R.C.; Moschella, J.J.; Nash, T.; Loter, N.

    1995-01-01

    Magnesium-coated aluminum wire array Z pinch plasmas have been tested on a 4-MA, 6-TW pulsed electrical generator. A mixture of 80% aluminum and 20% magnesium is observed to maximize the radiated kilovolt x-ray yield at ≥50 kJ, which is 50% higher than that obtained with pure aluminum. Spectroscopic analysis and collisional radiative equilbrium models with radiation transport are employed to show that the aluminum-magnesium mixture reduces the opacity of the strongest emission lines, thus increasing the yield by increasing the probability of photon escape. Furthermore, the spectroscopic data also point to the presence of a strong temperature gradient in the pinched plasma that results in the outer magnesium coating of the wires having a higher electron temperature in the pinch. This temperature difference also plays a role in enhancing the kilovolt x-ray yield. The observation of a higher magnesium electron temperature offers evidence that the magnesium reaches the axis first, forming a core that is compressed and heated by the imploding mass of aluminum. Since the emissions from the core are not absorbed by the outer aluminum, the yields are increased. By comparison, aluminum-magnesium alloys imploded on a different but similar generator do not show a temperature difference

  7. STAT3 polymorphism and Helicobacter pylori CagA strains with higher number of EPIYA-C segments independently increase the risk of gastric cancer

    International Nuclear Information System (INIS)

    Rocha, Gifone A; Rocha, Andreia MC; Gomes, Adriana D; Faria, César LL Jr; Melo, Fabrício F; Batista, Sérgio A; Fernandes, Viviane C; Almeida, Nathálie BF; Teixeira, Kádima N; Brito, Kátia S; Queiroz, Dulciene Maria Magalhães

    2015-01-01

    Because to date there is no available study on STAT3 polymorphism and gastric cancer in Western populations and taking into account that Helicobacter pylori CagA EPIYA-C segment deregulates SHP-2/ERK-JAK/STAT3 pathways, we evaluated whether the two variables are independently associated with gastric cancer. We included 1048 subjects: H. pylori-positive patients with gastric carcinoma (n = 232) and with gastritis (n = 275) and 541 blood donors. Data were analyzed using logistic regression model. The rs744166 polymorphic G allele (p = 0.01; OR = 1.76; 95 % CI = 1.44-2.70), and CagA-positive (OR = 12.80; 95 % CI = 5.58-19.86) status were independently associated with gastric cancer in comparison with blood donors. The rs744166 polymorphism (p = 0.001; OR = 1.64; 95 % CI = 1.16-2.31) and infection with H. pylori CagA-positive strains possessing higher number of EPIYA-C segments (p = 0.001; OR = 2.28; 95 % CI = 1.41-3.68) were independently associated with gastric cancer in comparison with gastritis. The association was stronger when host and bacterium genotypes were combined (p < 0.001; OR = 3.01; 95 % CI = 2.29-3.98). When stimulated with LPS (lipopolysaccharide) or Pam3Cys, peripheral mononuclear cells of healthy carriers of the rs744166 GG and AG genotypes expressed higher levels of STAT3 mRNA than those carrying AA genotype (p = 0.04 for both). The nuclear expression of phosphorylated p-STAT3 protein was significantly higher in the antral gastric tissue of carriers of rs744166 GG genotype than in carriers of AG and AA genotypes. Our study provides evidence that STAT3 rs744166 G allele and infection with CagA-positive H. pylori with higher number of EPIYA-C segments are independent risk factors for gastric cancer. The odds ratio of having gastric cancer was greater when bacterium and host high risk genotypes were combined

  8. Increasing the number of unloading/reambulation cycles does not adversely impact body composition and lumbar bone mineral density but reduces tissue sensitivity

    Science.gov (United States)

    Gupta, Shikha; Manske, Sarah L.; Judex, Stefan

    2013-11-01

    A single exposure to hindlimb unloading leads to changes in body mass, body composition and bone, but the consequences of multiple exposures are not yet understood. Within a 18 week period, adult C57BL/6 male mice were exposed to 1 (1x-HLU), 2 (2x-HLU) or 3 (3x-HLU) cycles of 2 weeks of hindlimb unloading (HLU) followed by 4 weeks of reambulation (RA), or served as ambulatory age-matched controls. In vivo μCT longitudinally tracked changes in abdominal adipose and lean tissues, lumbar vertebral apparent volumetric bone mineral density (vBMD) and upper hindlimb muscle cross-sectional area before and after the final HLU and RA cycle. During the final HLU cycle, significant decreases in total adipose tissue and vertebral vBMD in the three experimental groups occurred such that there were no significant between-group differences at the beginning of the final RA cycle. However, the magnitude of the HLU induced losses diminished in mice undergoing their 2nd or 3rd HLU cycle. Irrespective of the number of HLU/RA cycles, total adipose tissue and vertebral vBMD recovered and were no different from age-matched controls after the final RA period. In contrast, upper hindlimb muscle cross-sectional area was significantly lower than controls in all unloaded groups after the final RA period. These results suggest that tissues in the abdominal region are more resilient to multiple bouts of unloading and more amenable to recovery during reambulation than the peripheral musculoskeletal system.

  9. Effects of retinal growth factor and of the increase of the number of subcultures on sulfated glycosaminoglycans of bovine lens epithelial cells

    International Nuclear Information System (INIS)

    Moczar, E.; Courtois, Y.

    1981-01-01

    Sulfated glycosaminoglycans of cultured bovine lens epithelial cells grown in the presence and in the absence of a retinal growth factor were investigated comparatively. The newly formed [ 35 S] sulfate-labeled glycosaminoglycans were analysed in the extra-, peri- and intracellular compartments of early (4-5th) and late (17-18h) subcultures. The following results were obtained: (1) Cultured lens epithelial cells grown in the presence or in the absence of the growth factor synthesize chondroitin 4- and 6-sulfates and dermatan sulfate, with heparan sulfate as the main component, the pericellular compartments were particularly rich in heparan sulfate; (2) The distribution pattern of the glycosaminoglycans changes during successive subcultures; the proportion of heparan sulfate increases in the pericellular compartment, the dermatan sulfate to chondroitin sulfate ratio increases in all three compartments; (3) In contrast to the drastic decrease in the fibronectin levels in the presence of growth factor in the early subcultures, only minor differences were found between the glycosaminoglycan patterns for the treated and non-treated cells. ( orig.)

  10. Increased Numbers of CD4+CD25+ and CD8+CD25+ T-Cells in Peripheral Blood of Patients with Rheumatoid Arthritis with Parvovirus B19 Infection.

    Science.gov (United States)

    Naciute, Milda; Maciunaite, Gabriele; Mieliauskaite, Diana; Rugiene, Rita; Zinkeviciene, Aukse; Mauricas, Mykolas; Murovska, Modra; Girkontaite, Irute

    2017-01-01

    To investigate T-cell subpopulations in peripheral blood of human parvovirus B19 DNA-positive (B19 + ) and -negative (B19 - ) patients with rheumatoid arthritis (RA) and healthy persons. Blood samples were collected from 115 patients with RA and 47 healthy volunteers; 27 patients with RA and nine controls were B19 + Cluster of differentiation (CD) 4, 8, 25 and 45RA were analyzed on blood cells. CD25 expression on CD4 + CD45RA + , CD4 + CD45RA - , CD8 + CD45RA + , CD8 + CD45RA - subsets were analyzed by flow cytometry. The percentage of CD25 low and CD25 hi cells was increased on CD4 + CD45RA + , CD4 + CD45RA - T-cells and the percentage of CD25 + cells was increased on CD8 + CD45RA + , CD8 + CD45RA - T-cells of B19 + patients with RA in comparison with B19 - patients and controls. Raised levels of CD4 and CD8 regulatory T-cells in B19 + RA patients could cause down-regulation of antiviral clearance mechanisms and lead to activation of persistent human parvovirus B19 infection in patients with RA. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  11. Mach's Principle to Hubble's Law and Light Relativity

    Science.gov (United States)

    Zhang, Tianxi

    2018-01-01

    Discovery of the redshift-distance relation to be linear (i.e. Hubble's law) for galaxies in the end of 1920s instigated us to widely accept expansion of the universe, originated from a big bang around 14 billion years ago. Finding of the redshift-distance relation to be weaker than linear for distant type Ia supernovae nearly two decades ago further precipitated us to largely agree with recent acceleration of the universe, driven by the mysterious dark energy. The time dilation measured for supernovae has been claimed as a direct evidence for the expansion of the universe, but scientists could not explain why quasars and gamma-ray bursts had not similar time dilations. Recently, an anomaly was found in the standard template for the width of supernova light curves to be proportional to the wavelength, which exactly removed the time dilation of supernovae and hence was strongly inconsistent with the conventional redshift mechanism. In this study, we have derived a new redshift-distance relation from Mach's principle with light relativity that describes the effect of light on spacetime as well as the influence of disturbed spacetime on the light inertia or frequency. A moving object or photon, because of its continuously keeping on displacement, disturbs the rest of the entire universe or distorts/curves the spacetime. The distorted or curved spacetime then generates an effective gravitational force to act back on the moving object or photon, so that reduces the object inertia or photon frequency. Considering the disturbance of spacetime by a photon is extremely weak, we have modelled the effective gravitational force to be Newtonian and derived the new redshift-distance relation that can not only perfectly explain the redshift-distance measurement of distant type Ia supernovae but also inherently obtain Hubble's law as an approximate at small redshift. Therefore, the result obtained from this study does neither support the acceleration of the universe nor the

  12. Nozzle design study for a quasi-axisymmetric scramjet-powered vehicle at Mach 7.9 flight conditions

    Science.gov (United States)

    Tanimizu, Katsuyoshi; Mee, David J.; Stalker, Raymond J.; Jacobs, Peter A.

    2013-09-01

    A nozzle shape optimization study for a quasi-axisymmetric scramjet has been performed for a Mach 7.9 operating condition with hydrogen fuel, aiming at the application of a hypersonic airbreathing vehicle. In this study, the nozzle geometry which is parameterized by a set of design variables, is optimized for the single objective of maximum net thrust using an in-house CFD solver for inviscid flowfields with a simple force prediction methodology. The combustion is modelled using a simple chemical reaction code. The effects of the nozzle design on the overall vehicle performance are discussed. For the present geometry, net thrust is achieved for the optimized vehicle design. The results of the nozzle-optimization study show that performance is limited by the nozzle area ratio that can be incorporated into the vehicle without leading to too large a base diameter of the vehicle and increasing the external drag of the vehicle. This study indicates that it is very difficult to achieve positive thrust at Mach 7.9 using the basic geometry investigated.

  13. News Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

    Science.gov (United States)

    2010-05-01

    Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

  14. TGF-β1 Improves Biomechanical Strength by Extracellular Matrix Accumulation Without Increasing the Number of Tenogenic Lineage Cells in a Rat Rotator Cuff Repair Model.

    Science.gov (United States)

    Arimura, Hitoshi; Shukunami, Chisa; Tokunaga, Takuya; Karasugi, Tatsuki; Okamoto, Nobukazu; Taniwaki, Takuya; Sakamoto, Hidetoshi; Mizuta, Hiroshi; Hiraki, Yuji

    2017-08-01

    Transforming growth factor β1 (TGF-β1) positively regulates the tenogenic marker genes scleraxis ( Scx) and tenomodulin ( Tnmd) in mesenchymal progenitors in vitro. However, little is known about the effect of TGF-β1 on the expression of tenogenic markers during rotator cuff (RC) healing in rats. TGF-β1 improves the biomechanical properties and histological maturity of reparative tissue in a rat RC repair model by stimulating the growth of tenogenic cells. Controlled laboratory study. Adult male Sprague-Dawley rats (N = 180) underwent unilateral supraspinatus tendon-to-bone surgical repair and were randomly treated with a gelatin hydrogel presoaked in TGF-β1 (100 ng) or phosphate-buffered saline. The effects of TGF-β1 on RC healing were investigated at 2, 4, 6, 8, and 12 weeks postoperatively by immunostaining for proliferating cell nuclear antigen, by real-time reverse transcription polymerase chain reaction and in situ hybridization or immunostaining for enthesis-related markers (SRY-box containing gene 9 [ Sox9], Scx, and Tnmd), and by real-time reverse transcription polymerase chain reaction and immunostaining for type I and III collagen. At 6 and 12 weeks postoperatively, biomechanical testing, micro-computed tomography, and biochemical analysis were also performed. At 2 and 4 weeks postoperatively, mesenchymal stem cell-related markers, phospho-Smad2, and matrix metalloproteinase 9 (MMP-9) and MMP-13 were assessed by immunostaining. The TGF-β1-treated group had significantly higher ultimate load to failure and tissue volume at 6 and 12 weeks postoperatively and a higher collagen content at 12 weeks compared with the saline group. Tendon-related gene expression, histological maturity, cell proliferation, and mesenchymal stem cell-related marker immunoreactivity were not affected by exogenously administrated TGF-β1 at all time points. In the TGF-β1-treated group, the percentage of phospho-Smad2-positive cells within the healing tissue increased

  15. Finding of coagulase negative staphylococci in the herd with an increased number of somatic cells in milk and their antimicrobial susceptibility

    Directory of Open Access Journals (Sweden)

    Katić Vera

    2013-01-01

    Full Text Available Coagulase-negative staphylococci (CNS are generally considered to be opportunistic pathogens. Controlling CNS mastitis is difficult because the epidemiology is not clear, and the CNS group consists of about 40 different Staphylococcus species. Therefore, the aim of this study was to determine the prevalence of coagulasenegative staphylococci in milk of the cows with subclinical mastitis, as well as to determine different CNS species isolated from quarter milk samples for their susceptibility to antimicrobials used commonly for mastitis therapy. On the farm where there was found an increase of somatic cells in bulk milk, 112 dairy cows were examined by mastitis test. From 52 udder quarters where mastitis test showed an increase of somatic cells, milk samples were taken for bacteriological examination. For isolating the causes of mastitis there was used blood agar. Identification of the causative agents of mastitis was carried out on the basis of colony appearance on blood agar and their physiological characteristics. Coagulasepositive staphylococci sensitivity which cause mastitis was tested by Kirby Bauer method. For susceptibility testing there were used commercially produced discs containing: 10 IU penicillin, amoxicillin/clavulanic acid (20 +10 μg, cloxacillin 25 μg, 30 μg amoxicillin, cephalexin 30 μg, ceftiofur 30 μg, 15 μg lincomycin, gentamicin and tetracycline 30 μg. The sensitivity of microorganisms was evaluated on the basis of inhibition zone diameter recommended by the manufacturer and was labeled as sensitive (S moderately sensitive (I or resistant (R. Coagulase-negative staphylococci were isolated from 61.53% of samples from cows with subclinical mastitis, making them the most common cause of subclinical mastitis. The highest resistance of coagulase-negative staphylococci was found to penicillin G (58.33% of isolates. Full sensitivity of coagulase-negative staphylococci was found to amoxicillin / clavulanic acid (100% of

  16. Establishment of Aedes aegypti (L.) in mountainous regions in Mexico: Increasing number of population at risk of mosquito-borne disease and future climate conditions.

    Science.gov (United States)

    Equihua, Miguel; Ibáñez-Bernal, Sergio; Benítez, Griselda; Estrada-Contreras, Israel; Sandoval-Ruiz, César A; Mendoza-Palmero, Fredy S

    2017-02-01

    The study was conducted in the central region of Veracruz Mexico, in the metropolitan area of Xalapa. It is a mountainous area where Aedes aegypti (L.) is not currently endemic. An entomological survey was done along an elevation gradient using the Ae. aegypti occurrences at different life cycle stages. Seven sites were sampled and a total of 24 mosquito species were recorded: 9 species were found in urban areas, 18 in non-urban areas with remnant vegetation, and 3 occurred in both environments. Ae. aegypti was found only in the urban areas, usually below 1200m a.s.l., but in this study was recorded for the first time at 1420m a.s.l. These occurrences, together with additional distribution data in the state of Veracruz were used to developed species distribution models using Maxlike software in R to identify the current projected suitable areas for the establishment of this vector and the human populations that might be affected by dengue transmission at higher elevations. Its emergence in previously unsuitable places appears to be driven by both habitat destruction and biodiversity loss associated with biotic homogenization. A border study using data from the edges of the vector's distribution might allow sensitive monitoring to detect any changes in this mosquito's distribution pattern, and any changes in the anthropic drivers or climate that could increase transmission risk. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Rayleigh Scattering Density Measurements, Cluster Theory, and Nucleation Calculations at Mach 10

    Science.gov (United States)

    Balla, R. Jeffrey; Everhart, Joel L.

    2012-01-01

    In an exploratory investigation, quantitative unclustered laser Rayleigh scattering measurements of density were performed in the air in the NASA Langley Research Center's 31 in. Mach 10 wind tunnel. A review of 20 previous years of data in supersonic and Mach 6 hypersonic flows is presented where clustered signals typically overwhelmed molecular signals. A review of nucleation theory and accompanying nucleation calculations are also provided to interpret the current observed lack of clustering. Data were acquired at a fixed stagnation temperature near 990Kat five stagnation pressures spanning 2.41 to 10.0 MPa (350 to 1454 psi) using a pulsed argon fluoride excimer laser and double-intensified charge-coupled device camera. Data averaged over 371 images and 210 pixels along a 36.7mmline measured freestream densities that agree with computed isentropic-expansion densities to less than 2% and less than 6% at the highest and lowest densities, respectively. Cluster-free Mach 10 results are compared with previous clustered Mach 6 and condensation-free Mach 14 results. Evidence is presented indicating vibrationally excited oxygen and nitrogen molecules are absorbed as the clusters form, release their excess energy, and inhibit or possibly reverse the clustering process. Implications for delaying clustering and condensation onset in hypersonic and hypervelocity facilities are discussed.

  18. High Mach flow associated with plasma detachment in JT-60U

    International Nuclear Information System (INIS)

    Hatayama, A.; Hoshino, K.; Miyamoto, K.

    2003-01-01

    Recent new results of the high Mach flows associated with plasma detachment are presented on the basis of numerical simulations by a 2-D edge simulation code (the B2-Eirene code) and their comparisons with experiments in JT-60U W-shaped divertor plasma. High Mach flows appear near the ionization front away from the target plate. The plasma static pressure rapidly drops, while the total pressure is kept almost constant near the ionization front, because the ionization front near the X-point is clearly separated from the momentum loss region near the target plate. Redistribution from static to dynamic pressure without a large momentum loss is confirmed to be a possible mechanism of the high Mach flows. It has been also shown that the radial structure of the high Mach flow near the X point away from the target plate has a strong correlation with the DOD (Degree of Detachment) at the target plate. Also, we have made systematic analyses on the high Mach flows for both the 'Open' geometry and the 'W-shaped' geometry of JT-60U in order to clarify the geometric effects on the flows. (author)

  19. Energy, Metaphysics, and Space: Ernst Mach's Interpretation of Energy Conservation as the Principle of Causality

    Science.gov (United States)

    Guzzardi, Luca

    2014-06-01

    This paper discusses Ernst Mach's interpretation of the principle of energy conservation (EC) in the context of the development of energy concepts and ideas about causality in nineteenth-century physics and theory of science. In doing this, it focuses on the close relationship between causality, energy conservation and space in Mach's antireductionist view of science. Mach expounds his thesis about EC in his first historical-epistemological essay, Die Geschichte und die Wurzel des Satzes von der Erhaltung der Arbeit (1872): far from being a new principle, it is used from the early beginnings of mechanics independently from other principles; in fact, EC is a pre-mechanical principle which is generally applied in investigating nature: it is, indeed, nothing but a form of the principle of causality. The paper focuses on the scientific-historical premises and philosophical underpinnings of Mach's thesis, beginning with the classic debate on the validity and limits of the notion of cause by Hume, Kant, and Helmholtz. Such reference also implies a discussion of the relationship between causality on the one hand and space and time on the other. This connection plays a major role for Mach, and in the final paragraphs its importance is argued in order to understand his antireductionist perspective, i.e. the rejection of any attempt to give an ultimate explanation of the world via reduction of nature to one fundamental set of phenomena.

  20. Experimental results of a Mach 10 conical-flow derived waverider to 14-X hypersonic aerospace vehicle

    Directory of Open Access Journals (Sweden)

    Tiago Cavalcanti Rolim

    2011-05-01

    Full Text Available This paper presents a research in the development of the 14-X hypersonic airspace vehicle at Institute for Advanced Studies (IEAv from Department of Science and Aerospace Technology (DCTA of the Brazilian Air Force (FAB. The 14-X project objective is to develop a higher efficient satellite launch alternative, using a Supersonic Combustion Ramjet (SCRAMJET engine and waverider aerodynamics. For this development, the waverider technology is under investigation in Prof. Henry T. Nagamatsu Aerothermodynamics and Hypersonics Laboratory (LHTN, in IEAv/DCTA. The investigation has been conducted through ground test campaigns in Hypersonic Shock Tunnel T3. The 14-X Waverider Vehicle characteristic was verified in shock tunnel T3 where surface static pressures and pitot pressure for Mach number 10 were measured and, using Schlieren photographs Diagnostic Method, it was possible to identify a leading-edge attached shock wave in 14-X lower surface.

  1. MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel.

    Science.gov (United States)

    Jiang, Naibo; Webster, Matthew; Lempert, Walter R; Miller, Joseph D; Meyer, Terrence R; Ivey, Christopher B; Danehy, Paul M

    2011-02-01

    Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1 MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified.

  2. Hupa Numbers.

    Science.gov (United States)

    Bennett, Ruth, Ed.; And Others

    An introduction to the Hupa number system is provided in this workbook, one in a series of numerous materials developed to promote the use of the Hupa language. The book is written in English with Hupa terms used only for the names of numbers. The opening pages present the numbers from 1-10, giving the numeral, the Hupa word, the English word, and…

  3. Triangular Numbers

    Indian Academy of Sciences (India)

    Admin

    Triangular number, figurate num- ber, rangoli, Brahmagupta–Pell equation, Jacobi triple product identity. Figure 1. The first four triangular numbers. Left: Anuradha S Garge completed her PhD from. Pune University in 2008 under the supervision of Prof. S A Katre. Her research interests include K-theory and number theory.

  4. Proth Numbers

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-02-01

    Full Text Available In this article we introduce Proth numbers and prove two theorems on such numbers being prime [3]. We also give revised versions of Pocklington’s theorem and of the Legendre symbol. Finally, we prove Pepin’s theorem and that the fifth Fermat number is not prime.

  5. Effects of flow separation and cove leakage on pressure and heat-transfer distributions along a wing-cove-elevon configuration at Mach 6.9. [Langley 8-ft high temperature tunnel test

    Science.gov (United States)

    Deveikis, W. D.

    1983-01-01

    External and internal pressure and cold-wall heating-rate distributions were obtained in hypersonic flow on a full-scale heat-sink representation of the space shuttle orbiter wing-elevon-cove configuration in an effort to define effects of flow separation on cove aerothermal environment as a function of cove seal leak area, ramp angle, and free-stream unit Reynolds number. Average free-stream Mach number from all tests was 6.9; average total temperature from all tests was 3360 R; free-stream dynamic pressure ranged from about 2 to 9 psi; and wing angle of attack was 5 deg (flow compression). For transitional and turbulent flow separation, increasing cove leakage progressively increased heating rates in the cove. When ingested mass flow was sufficient to force large reductions in extent of separation, increasing cove leakage reduced heating rates in the cove to those for laminar attached flow. Cove heating-rate distributions calculated with a method that assumed laminar developing channel flow agreed with experimentally obtained distributions within root-mean-square differences that varied between 11 and 36 percent where cove walls were parallel for leak areas of 50 and 100 percent.

  6. Coherence of Mach fronts during heterogeneous supershear earthquake rupture propagation: Simulations and comparison with observations

    Science.gov (United States)

    Bizzarri, A.; Dunham, Eric M.; Spudich, P.

    2010-01-01

    We study how heterogeneous rupture propagation affects the coherence of shear and Rayleigh Mach wavefronts radiated by supershear earthquakes. We address this question using numerical simulations of ruptures on a planar, vertical strike-slip fault embedded in a three-dimensional, homogeneous, linear elastic half-space. Ruptures propagate spontaneously in accordance with a linear slip-weakening friction law through both homogeneous and heterogeneous initial shear stress fields. In the 3-D homogeneous case, rupture fronts are curved owing to interactions with the free surface and the finite fault width; however, this curvature does not greatly diminish the coherence of Mach fronts relative to cases in which the rupture front is constrained to be straight, as studied by Dunham and Bhat (2008a). Introducing heterogeneity in the initial shear stress distribution causes ruptures to propagate at speeds that locally fluctuate above and below the shear wave speed. Calculations of the Fourier amplitude spectra (FAS) of ground velocity time histories corroborate the kinematic results of Bizzarri and Spudich (2008a): (1) The ground motion of a supershear rupture is richer in high frequency with respect to a subshear one. (2) When a Mach pulse is present, its high frequency content overwhelms that arising from stress heterogeneity. Present numerical experiments indicate that a Mach pulse causes approximately an ω−1.7 high frequency falloff in the FAS of ground displacement. Moreover, within the context of the employed representation of heterogeneities and over the range of parameter space that is accessible with current computational resources, our simulations suggest that while heterogeneities reduce peak ground velocity and diminish the coherence of the Mach fronts, ground motion at stations experiencing Mach pulses should be richer in high frequencies compared to stations without Mach pulses. In contrast to the foregoing theoretical results, we find no average elevation

  7. Cost-effective evolution of research prototypes into end-user tools: The MACH case study

    DEFF Research Database (Denmark)

    Störrle, Harald

    2017-01-01

    's claim by fellow scientists, and (3) demonstrate the utility and value of the research contribution to any interested parties. However, turning an exploratory prototype into a “proper” tool for end-users often entails great effort. Heavyweight mainstream frameworks such as Eclipse do not address...... this issue; their steep learning curves constitute substantial entry barriers to such ecosystems. In this paper, we present the Model Analyzer/Checker (MACH), a stand-alone tool with a command-line interpreter. MACH integrates a set of research prototypes for analyzing UML models. By choosing a simple...... command line interpreter rather than (costly) graphical user interface, we achieved the core goal of quickly deploying research results to a broader audience while keeping the required effort to an absolute minimum. We analyze MACH as a case study of how requirements and constraints in an academic...

  8. Hyper-X Mach 7 Scramjet Design, Ground Test and Flight Results

    Science.gov (United States)

    Ferlemann, Shelly M.; McClinton, Charles R.; Rock, Ken E.; Voland, Randy T.

    2005-01-01

    The successful Mach 7 flight test of the Hyper-X (X-43) research vehicle has provided the major, essential demonstration of the capability of the airframe integrated scramjet engine. This flight was a crucial first step toward realizing the potential for airbreathing hypersonic propulsion for application to space launch vehicles. However, it is not sufficient to have just achieved a successful flight. The more useful knowledge gained from the flight is how well the prediction methods matched the actual test results in order to have confidence that these methods can be applied to the design of other scramjet engines and powered vehicles. The propulsion predictions for the Mach 7 flight test were calculated using the computer code, SRGULL, with input from computational fluid dynamics (CFD) and wind tunnel tests. This paper will discuss the evolution of the Mach 7 Hyper-X engine, ground wind tunnel experiments, propulsion prediction methodology, flight results and validation of design methods.

  9. Penetration Characteristics of Air, Carbon Dioxide and Helium Transverse Sonic Jets in Mach 5 Cross Flow

    Directory of Open Access Journals (Sweden)

    Erinc Erdem

    2014-12-01

    Full Text Available An experimental investigation of sonic air, CO2 and Helium transverse jets in Mach 5 cross flow was carried out over a flat plate. The jet to freestream momentum flux ratio, J, was kept the same for all gases. The unsteady flow topology was examined using high speed schlieren visualisation and PIV. Schlieren visualisation provided information regarding oscillating jet shear layer structures and bow shock, Mach disc and barrel shocks. Two-component PIV measurements at the centreline, provided information regarding jet penetration trajectories. Barrel shocks and Mach disc forming the jet boundary were visualised/quantified also jet penetration boundaries were determined. Even though J is kept the same for all gases, the penetration patterns were found to be remarkably different both at the nearfield and the farfield. Air and CO2 jet resulted similar nearfield and farfield penetration pattern whereas Helium jet spread minimal in the nearfield.

  10. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  11. On integral formulation of the Mach principle in a conformally flat space

    International Nuclear Information System (INIS)

    Mal'tsev, V.K.

    1976-01-01

    The integral formulation of the Mach principle represents a rather complicated mathematical formalism in which many aspects of the physical content of theory are not clear. Below an attempt is made to consider the integral representation for the most simple case of conformally flat spaces. The fact that this formalism there is only one scalar function makes it possible to analyse in more detail many physical peculiarities of this representation of the Mach principle: the absence of asymptotically flat spaces, problems of inertia and gravity, constraints on state equations, etc

  12. MACHe3: A new generation detector for non-baryonic dark matter direct detection

    International Nuclear Information System (INIS)

    Santos, D.; Mayet, F.; Perrin, G.; Moulin, E.; Bunkov, Yu. M.; Godfrin, H.; Krusius, M.

    2002-01-01

    MACHe3 (MAtrix of Cells of superfluid 3 H e) is a project of a new detector for direct Dark Matter (DM) search, using superfluid 3 He as a sensitive medium. An experiment on a prototype cell has been performed and the st results reported here are encouraging to develop of a multicell prototype. In order to investigate the discovery potential of MACHe3, and its complementarity with other DM detectors, a phenomenological study done with the DarkSUSY code is shown. (authors)

  13. Numerical study on increasing mass flow ratio by energy deposition of high frequency pulsed laser

    International Nuclear Information System (INIS)

    Wang Diankai; Hong Yanji; Li Qian

    2013-01-01

    The mass flow ratio (MFR) of air breathing ramjet inlet would be decreased, when the Mach number is lower than the designed value. High frequency pulsed laser energy was deposited upstream of the cowl lip to reflect the stream so as to increase the MFR. When the Mach number of the flow was 5.0, and the static pressure and temperature of the flow were 2 551.6 Pa and 116.7 K, respectively, two-dimensional non-stationary compressible RANS equations were solved with upwind format to study the mechanisms of increasing MFR by high frequency pulsed laser energy deposition. The laser deposition frequency was 100 kHz and the average power was 500 W. The crossing point of the first forebody oblique shock and extension line of cowl lip was selected as the expected point. Then the deposition position was optimized by searching near the expected point. The results indicate that with the optimization of laser energy deposition position, the MFR would be increased from 63% to 97%. The potential value of increasing MFR by high frequency pulsed laser energy deposition was proved. The method for selection of the energy deposition position was also presented. (authors)

  14. Eulerian numbers

    CERN Document Server

    Petersen, T Kyle

    2015-01-01

    This text presents the Eulerian numbers in the context of modern enumerative, algebraic, and geometric combinatorics. The book first studies Eulerian numbers from a purely combinatorial point of view, then embarks on a tour of how these numbers arise in the study of hyperplane arrangements, polytopes, and simplicial complexes. Some topics include a thorough discussion of gamma-nonnegativity and real-rootedness for Eulerian polynomials, as well as the weak order and the shard intersection order of the symmetric group. The book also includes a parallel story of Catalan combinatorics, wherein the Eulerian numbers are replaced with Narayana numbers. Again there is a progression from combinatorics to geometry, including discussion of the associahedron and the lattice of noncrossing partitions. The final chapters discuss how both the Eulerian and Narayana numbers have analogues in any finite Coxeter group, with many of the same enumerative and geometric properties. There are four supplemental chapters throughout, ...

  15. Ernst Mach and George Sarton's Successors: The Implicit Role Model of Teaching Science in USA and Elsewhere, Part II

    Science.gov (United States)

    Siemsen, Hayo

    2013-01-01

    George Sarton had a strong influence on modern history of science. The method he pursued throughout his life was the method he had discovered in Ernst Mach's "Mechanics" when he was a student in Ghent. Sarton was in fact throughout his life implementing a research program inspired by the epistemology of Mach. Sarton in turn inspired many…

  16. Transfinite Numbers

    Indian Academy of Sciences (India)

    Transfinite Numbers. What is Infinity? S M Srivastava. In a series of revolutionary articles written during the last quarter of the nineteenth century, the great Ger- man mathematician Georg Cantor removed the age-old mistrust of infinity and created an exceptionally beau- tiful and useful theory of transfinite numbers. This is.

  17. Effect of technological deviation on aerodynamic efficiency of reaction blades of steam and gas turbines at high Mach nos

    International Nuclear Information System (INIS)

    Husain, Z.

    1991-01-01

    During manufacture and assembly of steam and gas turbine blades there are always some technological deviation and is meant local increase or decrease in dimension at certain sections of the profile improper stagger angle of long blades during assembly etc. In this paper the effect of oversize in dimensions at certain important places along a reaction profile has been studied. The technological deviation has been made by sticking thin aluminium foils of 0.3 mm thickness and 15 mm width at inlet and exit tips of reactive profiles and its effect on aerodynamic efficiency at mach. nos ranging from 0.7 to 1.1. The object of performing these tests was to obtain comprehensive data based on which information suitable tolerances could be recommended during manufacture of these blades

  18. Chocolate Numbers

    OpenAIRE

    Ji, Caleb; Khovanova, Tanya; Park, Robin; Song, Angela

    2015-01-01

    In this paper, we consider a game played on a rectangular $m \\times n$ gridded chocolate bar. Each move, a player breaks the bar along a grid line. Each move after that consists of taking any piece of chocolate and breaking it again along existing grid lines, until just $mn$ individual squares remain. This paper enumerates the number of ways to break an $m \\times n$ bar, which we call chocolate numbers, and introduces four new sequences related to these numbers. Using various techniques, we p...

  19. Number theory

    CERN Document Server

    Andrews, George E

    1994-01-01

    Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl

  20. On the Use of a Virtual Mach-Zehnder Interferometer in the Teaching of Quantum Mechanics

    Science.gov (United States)

    Pereira, Alexsandro; Ostermann, Fernanda; Cavalcanti, Claudio

    2009-01-01

    For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…