International tidal gravity reference values at Wuhan station
Institute of Scientific and Technical Information of China (English)
许厚泽; 孙和平; 徐建桥; 陶国祥
2000-01-01
The international tidal gravity reference values at Wuhan station are determined accurately based on the comprehensive analysis of the tidal gravity observations obtained from 8 instruments. By comparing these with those in the tidal models given by Dehant (1997) while considering simultaneously (i) the global satellite altimeters tidal data, and (ii) the Schwiderski global tidal data and the local ones along the coast of China, it is found that the average discrepancy of the amplitude factors and of the phase differences for four main waves are given as 5.2% and 3.6% and as 0.16?and 0.08?respectively. They are improved evidently compared to those determined in early stage, indicating the important procedures in improving the Wuhan international tidal gravity reference values when including the long-series observations obtained with a superconducting gravimeter, and when considering the influence of the ocean loading and of the nearly daily free wobble of the Earth’s core.
The New Gravity System: Changes in International Gravity Base Values and Anomaly Values
1980-10-01
Johannesburg and Capetown , and that the apparent resulting slope defined is fortuitously reinforced by a poor gravity connection between Khartoum and...is indicated by the data for the West African series. This series (Section C) indicates that all values from Madrid through to Capetown except that...mrea) is much the same as that for the northern sector of the mid-continent East Africa series (14.75 mgal) , and since the Capetown value would only
Inherently Unstable Internal Gravity Waves
Liang, Y
2016-01-01
Here we show that there exist internal gravity waves that are inherently unstable, that is, they cannot exist in nature for a long time. The instability mechanism is a one-way (irreversible) harmonic-generation resonance that permanently transfers the energy of an internal wave to its higher harmonics. We show that, in fact, there are countably infinite number of such unstable waves. For the harmonic-generation resonance to take place, nonlinear terms in the free surface boundary condition play a pivotal role, and the instability does not obtain if a simplified boundary condition such as rigid lid or linear form is employed. Harmonic-generation resonance presented here also provides a mechanism for the transfer of the energy of the internal waves to the higher-frequency part of the spectrum where internal waves are more prone to breaking, hence losing energy to turbulence and heat and contributing to oceanic mixing.
Inherently Unstable Internal Gravity Waves
Alam, Reza
2016-11-01
Here we show that there exist internal gravity waves that are inherently unstable, that is, they cannot exist in nature for a long time. The instability mechanism is a one-way (irreversible) harmonic-generation resonance that permanently transfers the energy of an internal wave to its higher harmonics. We show that, in fact, there are countably infinite number of such unstable waves. For the harmonic-generation resonance to take place, nonlinear terms in the free surface boundary condition play a pivotal role, and the instability does not obtain for a linearly-stratified fluid if a simplified boundary condition such as rigid lid or linear form is employed. Harmonic-generation resonance discussed here also provides a mechanism for the transfer of the energy of the internal waves to the higher-frequency part of the spectrum where internal waves are more prone to breaking, hence losing energy to turbulence and heat and contributing to oceanic mixing. Yong Liang (yong.liang@berkeley.edu).
Measuring Gravity in International Trade Flows
Directory of Open Access Journals (Sweden)
E. Young Song
2004-12-01
Full Text Available The purpose of this paper is two-fold. One is to clarify the concept of gravity in international trade flows. The other is to measure the strength of gravity in international trade flows in a way that is consistent with a well-defined concept of gravity. This paper shows that the widely accepted belief that specialization is the source of gravity is not well grounded on theory. We propose to define gravity in international trade as the force that makes the market shares of an exporting country constant in all importing countries, regardless of their sizes. In a stochastic context, we should interpret it as implying that the strength of gravity increases i as the correlation between market shares and market sizes gets weaker and ii as the variance of market shares gets smaller. We estimate an empirical gravity equation thoroughly based on this definition of gravity. We find that a strong degree of gravity exists in most bilateral trade, regardless of income levels of countries, and in trade of most manThe purpose of this paper is two-fold. One is to clarify the concept of gravity in international trade flows. The other is to measure the strength of gravity in international trade flows in a way that is consistent with a well-defined concept of gravity. This paper shows that the widely accepted belief that specialization is the source of gravity is not well grounded on theory. We propose to define gravity in international trade as the force that makes the market shares of an exporting country constant in all importing countries, regardless of their sizes. In a stochastic context, we should interpret it as implying that the strength of gravity increases i as the correlation between market shares and market sizes gets weaker and ii as the variance of market shares gets smaller. We estimate an empirical gravity equation thoroughly based on this definition of gravity. We find that a strong degree of gravity exists in most bilateral trade, regardless of
40 CFR 1065.630 - 1980 international gravity formula.
2010-07-01
... 40 Protection of Environment 32 2010-07-01 2010-07-01 false 1980 international gravity formula. 1065.630 Section 1065.630 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... international gravity formula. The acceleration of Earth's gravity, a g, varies depending on your...
Supersaturation of vertically propagating internal gravity waves
Lindzen, Richard S.
1988-01-01
The usual assumption that vertically propagating internal gravity waves will cease growing with height once their amplitudes are such as to permit convective instability anywhere within the wave is reexamined. Two factors lead to amplitude limitation: (1) wave clipping associated with convective mixing, and (2) energetic constraints associated with the rate at which the wave can supply energy to the convection. It is found that these two factors limit supersaturation to about 50 percent for waves with short horizontal wavelengths and high relative phase speeds. Usually the degree of supersaturation will be much less. These factors also lead to a gradual, rather than sudden, cessation of wave growth with height.
Nonlinear dynamics of hydrostatic internal gravity waves
Energy Technology Data Exchange (ETDEWEB)
Stechmann, Samuel N.; Majda, Andrew J. [New York University, Courant Institute of Mathematical Sciences, NY (United States); Khouider, Boualem [University of Victoria, Department of Mathematics and Statistics, Victoria, BC (Canada)
2008-11-15
Stratified hydrostatic fluids have linear internal gravity waves with different phase speeds and vertical profiles. Here a simplified set of partial differential equations (PDE) is derived to represent the nonlinear dynamics of waves with different vertical profiles. The equations are derived by projecting the full nonlinear equations onto the vertical modes of two gravity waves, and the resulting equations are thus referred to here as the two-mode shallow water equations (2MSWE). A key aspect of the nonlinearities of the 2MSWE is that they allow for interactions between a background wind shear and propagating waves. This is important in the tropical atmosphere where horizontally propagating gravity waves interact together with wind shear and have source terms due to convection. It is shown here that the 2MSWE have nonlinear internal bore solutions, and the behavior of the nonlinear waves is investigated for different background wind shears. When a background shear is included, there is an asymmetry between the east- and westward propagating waves. This could be an important effect for the large-scale organization of tropical convection, since the convection is often not isotropic but organized on large scales by waves. An idealized illustration of this asymmetry is given for a background shear from the westerly wind burst phase of the Madden-Julian oscillation; the potential for organized convection is increased to the west of the existing convection by the propagating nonlinear gravity waves, which agrees qualitatively with actual observations. The ideas here should be useful for other physical applications as well. Moreover, the 2MSWE have several interesting mathematical properties: they are a system of nonconservative PDE with a conserved energy, they are conditionally hyperbolic, and they are neither genuinely nonlinear nor linearly degenerate over all of state space. Theory and numerics are developed to illustrate these features, and these features are
Value Creation in International Business
DEFF Research Database (Denmark)
Vedel, Mette; Servais, Per
2017-01-01
The edited collection brings into focus the meanings, interpretations and the process of value creation in international business. Exploring value creation in the context of emerging and developed economies, Volume 2 takes the perspective of small and medium sized enterprises and examines various...... approaches to value creation in the process of firm internationalization. Providing theoretical and practical insights, the authors open an intellectual debate into what value is, and how it is created through the internationalization activities of firms. Value Creation in International Business...... is a pioneering two volume work intended to provoke theoretical and empirical development in International Business research. Moreover, it is intended as a bridge between concepts derived from general business firm-level research agendas such as value creation and business model, and internationalization...
Internal Gravity Wave Excitation by Turbulent Convection
Lecoanet, Daniel
2012-01-01
We calculate the flux of internal gravity waves (IGWs) generated by turbulent convection in stars. We solve for the IGW eigenfunctions analytically near the radiative-convective interface in a local, Boussinesq, and cartesian domain. We consider both discontinuous and smooth transitions between the radiative and convective regions and derive Green's functions to solve for the IGWs in the radiative region. We find that if the radiative-convective transition is smooth, the IGW flux ~ F_conv (d/H), where F_conv is the flux carried by the convective motions, d is the width of the transition region, and H is the pressure scale height. This can be much larger than the standard result in the literature for a discontinuous radiative-convective transition, which gives a wave flux ~ F_conv M, where M is the convective Mach number. However, in the smooth transition case, the most efficiently excited perturbations will break immediately when they enter the radiative region. The flux of IGWs which do not break and are abl...
Toward an Internal Gravity Wave Spectrum in Global Ocean Models
2015-05-14
Davis Highway, Suite 1204, Arlington VA 22202-4302 Respondents should be aware that notwithstanding any other provision of law , no person shall be...14 MAY 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Toward an Internal Gravity Wave Spectrum in Global...resolution global ocean models forced by atmospheric fields and tides are beginning to display realistic internal gravity wave spectra, especially as
Value Systems in International Business.
Heiba, Farouk I.
Every society has a system of values and seeks to achieve goals which it defines as desirable. To gain insight and a measure of understanding of another culture, international marketers can approach a country as a whole, seek out behavioral premises, obtain a theoretical knowledge of the culture, and learn the country's social heritage.…
Angular Momentum Transport via Internal Gravity Waves in Evolving Stars
Fuller, Jim; Cantiello, Matteo; Brown, Ben
2014-01-01
Recent asteroseismic advances have allowed for direct measurements of the internal rotation rates of many sub-giant and red giant stars. Unlike the nearly rigidly rotating Sun, these evolved stars contain radiative cores that spin faster than their overlying convective envelopes, but slower than they would in the absence of internal angular momentum transport. We investigate the role of internal gravity waves in angular momentum transport in evolving low mass stars. In agreement with previous results, we find that convectively excited gravity waves can prevent the development of strong differential rotation in the radiative cores of Sun-like stars. As stars evolve into sub-giants, however, low frequency gravity waves become strongly attenuated and cannot propagate below the hydrogen burning shell, allowing the spin of the core to decouple from the convective envelope. This decoupling occurs at the base of the sub-giant branch when stars have surface temperatures of roughly 5500 K. However, gravity waves can s...
Internal model of gravity influences configural body processing.
Barra, Julien; Senot, Patrice; Auclair, Laurent
2017-01-01
Human bodies are processed by a configural processing mechanism. Evidence supporting this claim is the body inversion effect, in which inversion impairs recognition of bodies more than other objects. Biomechanical configuration, as well as both visual and embodied expertise, has been demonstrated to play an important role in this effect. Nevertheless, the important factor of body inversion effect may also be linked to gravity orientation since gravity is one of the most fundamental constraints of our biology, behavior, and perception on Earth. The visual presentation of an inverted body in a typical body inversion paradigm turns the observed body upside down but also inverts the implicit direction of visual gravity in the scene. The orientation of visual gravity is then in conflict with the direction of actual gravity and may influence configural processing. To test this hypothesis, we dissociated the orientations of the body and of visual gravity by manipulating body posture. In a pretest we showed that it was possible to turn an avatar upside down (inversion relative to retinal coordinates) without inverting the orientation of visual gravity when the avatar stands on his/her hands. We compared the inversion effect in typical conditions (with gravity conflict when the avatar is upside down) to the inversion effect in conditions with no conflict between visual and physical gravity. The results of our experiment revealed that the inversion effect, as measured by both error rate and reaction time, was strongly reduced when there was no gravity conflict. Our results suggest that when an observed body is upside down (inversion relative to participants' retinal coordinates) but the orientation of visual gravity is not, configural processing of bodies might still be possible. In this paper, we discuss the implications of an internal model of gravity in the configural processing of observed bodies. Copyright © 2016 Elsevier B.V. All rights reserved.
2015-09-30
Interaction of Surface Gravity Waves with Nonlinear Internal Gravity Waves Lian Shen St. Anthony Falls Laboratory and Department of Mechanical...on studying surface gravity wave evolution and spectrum in the presence of surface currents caused by strongly nonlinear internal solitary waves...interaction of surface and internal gravity waves in the South China Sea. We will seek answers to the following questions: 1) How does the wind-wave
Bulatov, Vitaly V
2012-01-01
In this paper, we consider fundamental problems of the dynamics of internal gravity waves. We present analytical and numerical algorithms for calculating the wave fields for a set of values of the parameters, as observed in the ocean. We show that our mathematical models can describe the wave dynamics of the Arctic Basin, taking into account the actual physical characteristics of sea water, topography of its floor, etc. The numerical and analytical results show that the internal gravity waves have a significant effect on underwater sea objects in the Arctic Basin.
Internal gravity waves: Analysis using the periodic, inverse scattering transform
Directory of Open Access Journals (Sweden)
W. B. Zimmerman
1999-01-01
Full Text Available The discrete periodic inverse scattering transform (DPIST has been shown to provide the salient features of nonlinear Fourier analysis for surface shallow water waves whose dynamics are governed by the Korteweg-de Vries (KdV equation - (1 linear superposition of components with power spectra that are invariants of the motion of nonlinear dispersive waves and (2 nonlinear filtering. As it is well known that internal gravity waves also approximately satisfy the KdV equation in shallow stratified layers, this paper investigates the degree to which DPIST provides a useful nonlinear spectral analysis of internal waves by application to simulations and wave tank experiments of internal wave propagation from localized dense disturbances. It is found that DPIST analysis is sensitive to the quantity λ = (r/6s * (ε/μ2, where the first factor depends parametrically on the Richardson number and the background shear and density profiles and the second factor is the Ursell number-the ratio of the dimensionless wave amplitude to the dimensionless squared wavenumber. Each separate wave component of the decomposition of the initial disturbance can have a different value, and thus there is usually just one component which is an invariant of the motion found by DPIST analysis. However, as the physical applications, e.g. accidental toxic gas releases, are usually concerned with the propagation of the longest wavenumber disturbance, this is still useful information. In cases where only long, monochromatic solitary waves are triggered or selected by the waveguide, the entire DPIST spectral analysis is useful.
The International Space University's variable gravity research facility design
Bailey, Sheila G.; Chiaramonte, Francis P.; Davidian, Kenneth J.
1991-01-01
A manned mission to Mars will require long travel times between Earth and Mars. However, exposure to long-duration zero gravity is known to be harmful to the human body. Some of the harmful effects are loss of heart and lung capacity, inability to stand upright, muscular weakness and loss of bone calcium. A variable gravity research facility (VGRF) that would be placed in low Earth orbit (LEO) was designed by students of the International Space University 1989 Summer Session held in Strasbourg, France, to provide a testbed for conducting experiments in the life and physical sciences in preparation for a mission to Mars. This design exercise was unique because it addressed all aspects concerning a large space project. The VGRF design was described which was developed by international participants specializing in the following areas: the politics of international cooperation, engineering, architecture, in-space physiology, material and life science experimentation, data communications, business, and management.
Generation of internal gravity waves by penetrative convection
Pinçon, C; Goupil, M J
2015-01-01
The rich harvest of seismic observations over the past decade provides evidence of angular momentum redistribution in stellar interiors that is not reproduced by current evolution codes. In this context, transport by internal gravity waves can play a role and could explain discrepancies between theory and observations. The efficiency of the transport of angular momentum by waves depends on their driving mechanism. While excitation by turbulence throughout the convective zone has already been investigated, we know that penetrative convection into the stably stratified radiative zone can also generate internal gravity waves. Therefore, we aim at developing a semianalytical model to estimate the generation of IGW by penetrative plumes below an upper convective envelope. We derive the wave amplitude considering the pressure exerted by an ensemble of plumes on the interface between the radiative and convective zones as source term in the equation of momentum. We consider the effect of a thermal transition from a c...
The Initial Value Formulation of Dynamical Chern-Simons Gravity
Delsate, Térence; Witek, Helvi
2014-01-01
We derive an initial value formulation for dynamical Chern-Simons gravity, a modification of general relativity involving parity-violating higher derivative terms. We investigate the structure of the resulting system of partial differential equations thinking about linearization around arbitrary backgrounds. This type of consideration is necessary if we are to establish well-posedness of the Cauchy problem. Treating the field equations as an effective field theory we find that weak necessary conditions for hyperbolicity are satisfied. For the full field equations we find that there are states from which subsequent evolution is not determined. Generically the evolution system closes, but the full field equations are in no sense hyperbolic. In a cursory mode analysis we find that the equations of motion contain terms that may cause ill-posedness of the initial value problem.
Cultural values and international migration
Directory of Open Access Journals (Sweden)
Miryam Rodríguez Monter
2009-05-01
Full Text Available Immigration is one of the most controversial social issues debated nowadays. It is an undeniable fact that the phenomenon is lived in Europe with concern because of its consequences. People who live and coexist in Europe represent a huge cultural variety. Therefore, social and cultural gaps that can affect the basic values of the western societies seem to be inevitable due to the dimensions of the current migration phenomenon. The present studies are based on the European Social Survey Questionnaire (2002, and the Portrait Values Questionnaire (Schwartz, 1992, 2001 and focuses on the relevance of cultural values to explain the acceptance or rejection of the immigrant.. Finally, we emphasize the importance of cultural values -like Harmony or Egalitarianism- for any initiative or social policy which aimes at reducing the problems concerning inmigration in the European context.
Conversion of internal gravity waves into magnetic waves
Lecoanet, D.; Vasil, G. M.; Fuller, J.; Cantiello, M.; Burns, K. J.
2017-04-01
Asteroseismology probes the interiors of stars by studying oscillation modes at a star's surface. Although pulsation spectra are well understood for solar-like oscillators, a substantial fraction of red giant stars observed by Kepler exhibit abnormally low-amplitude dipole oscillation modes. Fuller et al. (2015) suggest this effect is produced by strong core magnetic fields that scatter dipole internal gravity waves (IGWs) into higher multipole IGWs or magnetic waves. In this paper, we study the interaction of IGWs with a magnetic field to test this mechanism. We consider two background stellar structures: one with a uniform magnetic field, and another with a magnetic field that varies both horizontally and vertically. We derive analytic solutions to the wave propagation problem and validate them with numerical simulations. In both cases, we find perfect conversion from IGWs into magnetic waves when the IGWs propagate into a region exceeding a critical magnetic field strength. Downward propagating IGWs cannot reflect into upward propagating IGWs because their vertical wavenumber never approaches zero. Instead, they are converted into upward propagating slow (Alfvénic) waves, and we show they will likely dissipate as they propagate back into weakly magnetized regions. Therefore, strong internal magnetic fields can produce dipole mode suppression in red giants, and gravity modes will likely be totally absent from the pulsation spectra of sufficiently magnetized stars.
Nonlinear reflection of internal gravity wave onto a slope
Raja, Keshav; Sommeria, Joel; Staquet, Chantal; Leclair, Matthieu; Grisouard, Nicolas; Gostiaux, Louis
2016-04-01
reflected wave. We study the momentum and energy budget of the process in order to understand the mechanism of generation of mean flow, its interaction with the wave and account for the loss of wave energy upon reflection. REFERENCES N. Grisouard, M. Leclair, L. Gostiaux and C. Staquet 2013. Large scale energy transfer from an internal gravity wave reflecting on a simple slope IUTAM Symposium Procedia 8 119-128 M. Leclair, K. Raja and C. Staquet 2016. Nonlinear reflection of a two-dimensional finite-width internal gravity wave onto a slope Journal of Fluid Mechanics. in preparation
Conversion of Internal Gravity Waves into Magnetic Waves
Lecoanet, Daniel; Fuller, Jim; Cantiello, Matteo; Burns, Keaton J
2016-01-01
Asteroseismology probes the interiors of stars by studying oscillation modes at a star's surface. Although pulsation spectra are well understood for solar-like oscillators, a substantial fraction of red giant stars observed by Kepler exhibit abnormally low-amplitude dipole oscillation modes. Fuller et al. (2015) suggests this effect is produced by strong core magnetic fields that scatter dipole internal gravity waves (IGWs) into higher multipole IGWs or magnetic waves. In this paper, we study the interaction of IGWs with a magnetic field to test this mechanism. We consider two background stellar structures: one with a uniform magnetic field, and another with a magnetic field that varies both horizontally and vertically. We derive analytic solutions to the wave propagation problem and validate them with numerical simulations. In both cases, we find perfect conversion from IGWs into magnetic waves when the IGWs propagate into a region exceeding a critical magnetic field strength. Downward propagating IGWs canno...
2015-09-30
1 A multiscale nested modeling framework to simulate the interaction of surface gravity waves with nonlinear internal gravity waves...Minnesota LONG-TERM GOALS Our long-term goal is to develop a multiscale nested modeling framework that simulates, with the finest resolution...frameworks such as the proposed HYCOM-LZSNFS-SUNTANS-LES nested model are crucial for understanding multiscale processes that are unresolved, and hence
National Oceanic and Atmospheric Administration, Department of Commerce — The National Geophysical Data Center (NGDC) of NOAA, in cooperation with the National Geodetic Survey of NOAA, have published a Gravity CD-ROM containing observed...
Is International Accounting Education Delivering Pedagogical Value?
Patel, Chris; Millanta, Brian; Tweedie, Dale
2016-01-01
This paper examines whether universities are delivering pedagogical value to international accounting students commensurate with the costs of studying abroad. The paper uses survey and interview methods to explore the extent to which Chinese Learners (CLs) in an Australian postgraduate accounting subject have distinct learning needs. The paper…
Is International Accounting Education Delivering Pedagogical Value?
Patel, Chris; Millanta, Brian; Tweedie, Dale
2016-01-01
This paper examines whether universities are delivering pedagogical value to international accounting students commensurate with the costs of studying abroad. The paper uses survey and interview methods to explore the extent to which Chinese Learners (CLs) in an Australian postgraduate accounting subject have distinct learning needs. The paper…
Titan’s internal structure inferred from its gravity field, shape, and rotation state
Baland, Rose-Marie; Tobie, Gabriel; Lefèvre, Axel; Van Hoolst, Tim
2014-07-01
Several quantities measured by the Cassini-Huygens mission provide insight into the interior of Titan: the second-degree gravity field coefficients, the shape, the tidal Love number, the electric field, and the orientation of its rotation axis. The measured obliquity and tides, as well as the electric field, are evidence for the presence of an internal global ocean beneath the icy shell of Titan. Here we use these different observations together to constrain the density profile assuming a four-layer interior model (ice I shell, liquid water ocean, high pressure ice mantle, and rock core). Even though the observed second degree gravity field is consistent with the hydrostatic relation J2=10C22/3, which is a necessary but not sufficient condition for a synchronous satellite to be in hydrostatic equilibrium, the observed shape of the surface as well as the non-zero degree-three gravity signal indicate some departure from hydrostaticity. Therefore, we do not restrain our range of assumed density profiles to those corresponding to the hydrostatic value of the moment of inertia (0.34). From a range of density profiles consistent with the radius and mass of the satellite, we compute the obliquity of the Cassini state and the tidal Love number k2. The obliquity is computed from a Cassini state model for a satellite with an internal liquid layer, each layer having an ellipsoidal shape consistent with the measured surface shape and gravity field. The observed (nearly hydrostatic) gravity field is obtained by an additional deflection of the ocean-ice I shell interface, assuming that the layers have uniform densities. We show that the measured obliquity can be reproduced only for internal models with a dense ocean (between 1275 and 1350 kg m-3) above a differentiated interior with a full separation of rock and ice. We obtain normalized moments of inertia between 0.31 and 0.33, significantly lower than the expected hydrostatic value (0.34). Evolutionary mechanisms leading to a
Educing the emission mechanism of internal gravity waves in the differentially heat rotating annulus
Rolland, Joran; Hien, Steffen; Achatz, Ulrich; Borchert, Sebastian; Fruman, Mark
2016-04-01
Understanding the lifecycle of gravity waves is fundamental to a good comprehension of the dynamics of the atmosphere. In this lifecycle, the emission mechanisms may be the most elusive. Indeed, while the emission of gravity waves by orography or convection is well understood, the so-called spontaneous emission is still a quite open topic of investigation [1]. This type of emission usually occur very near jet-front systems in the troposphere. In this abstract, we announce our numerical study of the question. Model systems of the atmosphere which can be easily simulated or built in a laboratory have always been an important part of the study of atmospheric dynamics, alongside global simulations, in situ measurements and theory. In the case of the study of the spontaneous emission of gravity waves near jet-front systems, the differentially heated rotating annulus set up has been proposed and extensively used. It comprises of an annular tank containing water: the inner cylinder is kept at a cold temperature while the outer cylinder is kept at a warm temperature. The whole system is rotating. Provided the values of the control parameters (temperature, rotation rate, gap between the cylinders, height of water) are well chosen, the resulting flow mimics the troposphere at midlatitudes: it has a jet stream, and a baroclinic lifecycle develops on top of it. A very reasonable ratio of Brunt-Väisälä frequency over rotation rate of the system can be obtained, so as to be as close to the atmosphere as possible. Recent experiments as well as earlier numerical simulations in our research group have shown that gravity waves are indeed emitted in this set up, in particular near the jet front system of the baroclinic wave [2]. After a first experimental stage of characterising the emitted wavepacket, we focused our work on testing hypotheses on the gravity wave emission mechanism: we have tested and validated the hypothesis of spontaneous imbalance generated by the flow in
Black hole entropy in loop quantum gravity: The role of internal symmetries
Energy Technology Data Exchange (ETDEWEB)
Barbero G, J Fernando, E-mail: fbarbero@iem.cfmac.csic.e [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)
2009-06-01
I will discuss here the role of the internal symmetry group in the computations of black hole entropy in loop quantum gravity according to the standard prescription given by Domagala and Lewandowski. In particular I will show how it is possible to take into account the possible choice of either SO(3) or SU(2) as the internal symmetry groups of general relativity in Loop Quantum Gravity and how this choice changes the combinatorial problem of counting the black hole degrees of freedom.
Chern-Simons expectation values and quantum horizons from loop quantum gravity and the Duflo map.
Sahlmann, Hanno; Thiemann, Thomas
2012-03-16
We report on a new approach to the calculation of Chern-Simons theory expectation values, using the mathematical underpinnings of loop quantum gravity, as well as the Duflo map, a quantization map for functions on Lie algebras. These new developments can be used in the quantum theory for certain types of black hole horizons, and they may offer new insights for loop quantum gravity, Chern-Simons theory and the theory of quantum groups.
Analytical and numerical investigation of nonlinear internal gravity waves
Directory of Open Access Journals (Sweden)
S. P. Kshevetskii
2001-01-01
coincidence of simulation outcomes with analytical ones is revealed and some examples of numerical simulations illustrating wave disintegration into solitons are given. The phenomenon of internal wave mixing is considered and is explained from the point of view of the results obtained. The numerical methods for internal wave simulation are examined. In particular, the influence of difference interval finiteness on a numerical solution is investigated. It is revealed that a numerical viscosity and numerical dispersion can play the role of regularizators to a nonlinear quasistatic problem. To avoid this effect, the grid steps should be taken less than some threshold values found theoretically.
Gravity field and internal structure of Mercury from MESSENGER.
Smith, David E; Zuber, Maria T; Phillips, Roger J; Solomon, Sean C; Hauck, Steven A; Lemoine, Frank G; Mazarico, Erwan; Neumann, Gregory A; Peale, Stanton J; Margot, Jean-Luc; Johnson, Catherine L; Torrence, Mark H; Perry, Mark E; Rowlands, David D; Goossens, Sander; Head, James W; Taylor, Anthony H
2012-04-13
Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/MR(2) = 0.353 ± 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(m)/C = 0.452 ± 0.035. A model for Mercury's radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.
Gamow, George
2003-01-01
A distinguished physicist and teacher, George Gamow also possessed a special gift for making the intricacies of science accessible to a wide audience. In Gravity, he takes an enlightening look at three of the towering figures of science who unlocked many of the mysteries behind the laws of physics: Galileo, the first to take a close look at the process of free and restricted fall; Newton, originator of the concept of gravity as a universal force; and Einstein, who proposed that gravity is no more than the curvature of the four-dimensional space-time continuum.Graced with the author's own draw
He, Yingbin; Chen, Youqi; Tang, Huajun; Yao, Yanmin; Yang, Peng; Chen, Zhongxin
2011-04-01
Spatially explicit ecosystem services valuation and change is a newly developing area of research in the field of ecology. Using the Beijing region as a study area, the authors have developed a spatially explicit ecosystem services value index and implemented this to quantify and spatially differentiate ecosystem services value at 1-km grid resolution. A gravity model was developed to trace spatial change in the total ecosystem services value of the Beijing study area from a holistic point of view. Study results show that the total value of ecosystem services for the study area decreased by 19.75% during the period 1996-2006 (3,226.2739 US$×10(6) in 1996, 2,589.0321 US$×10(6) in 2006). However, 27.63% of the total area of the Beijing study area increased in ecosystem services value. Spatial differences in ecosystem services values for both 1996 and 2006 are very clear. The center of gravity of total ecosystem services value for the study area moved 32.28 km northwestward over the 10 years due to intensive human intervention taking place in southeast Beijing. The authors suggest that policy-makers should pay greater attention to ecological protection under conditions of rapid socio-economic development and increase the area of green belt in the southeastern part of Beijing.
Internal Gravity Waves in the Magnetized Solar Atmosphere. I. Magnetic Field Effects
Vigeesh, G.; Jackiewicz, J.; Steiner, O.
2017-02-01
Observations of the solar atmosphere show that internal gravity waves are generated by overshooting convection, but are suppressed at locations of magnetic flux, which is thought to be the result of mode conversion into magnetoacoustic waves. Here, we present a study of the acoustic-gravity wave spectrum emerging from a realistic, self-consistent simulation of solar (magneto)convection. A magnetic field free, hydrodynamic simulation and a magnetohydrodynamic (MHD) simulation with an initial, vertical, homogeneous field of 50 G flux density were carried out and compared with each other to highlight the effect of magnetic fields on the internal gravity wave propagation in the Sun’s atmosphere. We find that the internal gravity waves are absent or partially reflected back into the lower layers in the presence of magnetic fields and argue that the suppression is due to the coupling of internal gravity waves to slow magnetoacoustic waves still within the high-β region of the upper photosphere. The conversion to Alfvén waves is highly unlikely in our model because there is no strongly inclined magnetic field present. We argue that the suppression of internal waves observed within magnetic flux concentrations may also be due to nonlinear breaking of internal waves due to vortex flows that are ubiquitously present in the upper photosphere and the chromosphere.
2nd International Workshop on Antimatter and Gravity
Scampoli, P
2013-01-01
The purpose of this meeting is to review the experimental and theoretical aspects of the interaction of antimatter with gravity. Tests of the weak equivalence principle with e.g. positronium, muonium and antihydrogen with be discussed. Progress reports on the experiments at the CERN Antiproton Decelerator and on the available future facilities will be presented. A session on the relevance of antimatter with respect to Dark Energy and Dark Matter in the Universe (theory and experiments) is also foreseen.
Vestibular stimulation interferes with the dynamics of an internal representation of gravity.
De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Diaz Artiles, Ana; Seyedmadani, Kimia; Sherwood, David P; Young, Laurence R
2017-11-01
The remembered vanishing location of a moving target has been found to be displaced downward in the direction of gravity (representational gravity) and more so with increasing retention intervals, suggesting that the visual spatial updating recruits an internal model of gravity. Despite being consistently linked with gravity, few inquiries have been made about the role of vestibular information in these trends. Previous experiments with static tilting of observers' bodies suggest that under conflicting cues between the idiotropic vector and vestibular signals, the dynamic drift in memory is reduced to a constant displacement along the body's main axis. The present experiment aims to replicate and extend these outcomes while keeping the observers' bodies unchanged in relation to physical gravity by varying the gravito-inertial acceleration using a short-radius centrifuge. Observers were shown, while accelerated to varying degrees, targets moving along several directions and were required to indicate the perceived vanishing location after a variable interval. Increases of the gravito-inertial force (up to 1.4G), orthogonal to the idiotropic vector, did not affect the direction of representational gravity, but significantly disrupted its time course. The role and functioning of an internal model of gravity for spatial perception and orientation are discussed in light of the results.
Gravity Field and Internal Structure of Mercury from MESSENGER
Smith, David E.; Zuber, Maria T.; Phillips, Roger J.; Solomon, Sean C.; Hauck, Steven A., II; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Peale, Stanton J.; Margot, Jean-Luc; Johnson, Catherine L.; Torrence, Mark H.; Perry, Mark E.; Rowlands, David D.; Goossens, Sander; Head, James W.; Taylor, Anthony H.
2012-01-01
Radio tracking of the MESSENGER spacecraft has provided a model of Mercury's gravity field. In the northern hemisphere, several large gravity anomalies, including candidate mass concentrations (mascons), exceed 100 milli-Galileos (mgal). Mercury's northern hemisphere crust is thicker at low latitudes and thinner in the polar region and shows evidence for thinning beneath some impact basins. The low-degree gravity field, combined with planetary spin parameters, yields the moment of inertia C/M(R(exp 2) = 0.353 +/- 0.017, where M and R are Mercury's mass and radius, and a ratio of the moment of inertia of Mercury's solid outer shell to that of the planet of C(sub m)/C = 0.452 +/- 0.035. A model for Mercury s radial density distribution consistent with these results includes a solid silicate crust and mantle overlying a solid iron-sulfide layer and an iron-rich liquid outer core and perhaps a solid inner core.
International Entrepreneurship: Value Creation Across National Borders
S.J.A. Hessels (Jolanda)
2008-01-01
textabstractThis book investigates antecedents and outcomes of international entrepreneurship. International entrepreneurship as a field of research involves both research into entrepreneurship in multiple countries (cross-country comparisons of the nature and extent of entrepreneurial activity) and
International Entrepreneurship: Value Creation Across National Borders
S.J.A. Hessels (Jolanda)
2008-01-01
textabstractThis book investigates antecedents and outcomes of international entrepreneurship. International entrepreneurship as a field of research involves both research into entrepreneurship in multiple countries (cross-country comparisons of the nature and extent of entrepreneurial activity) and
Multisensory Integration and Internal Models for Sensing Gravity Effects in Primates
Directory of Open Access Journals (Sweden)
Francesco Lacquaniti
2014-01-01
Full Text Available Gravity is crucial for spatial perception, postural equilibrium, and movement generation. The vestibular apparatus is the main sensory system involved in monitoring gravity. Hair cells in the vestibular maculae respond to gravitoinertial forces, but they cannot distinguish between linear accelerations and changes of head orientation relative to gravity. The brain deals with this sensory ambiguity (which can cause some lethal airplane accidents by combining several cues with the otolith signals: angular velocity signals provided by the semicircular canals, proprioceptive signals from muscles and tendons, visceral signals related to gravity, and visual signals. In particular, vision provides both static and dynamic signals about body orientation relative to the vertical, but it poorly discriminates arbitrary accelerations of moving objects. However, we are able to visually detect the specific acceleration of gravity since early infancy. This ability depends on the fact that gravity effects are stored in brain regions which integrate visual, vestibular, and neck proprioceptive signals and combine this information with an internal model of gravity effects.
van Oers, Alexander M.; Maas, Leo R. M.; Bokhove, Onno
2017-02-01
The linear equations governing internal gravity waves in a stratified ideal fluid possess a Hamiltonian structure. A discontinuous Galerkin finite element method has been developed in which this Hamiltonian structure is discretized, resulting in conservation of discrete analogs of phase space and energy. This required (i) the discretization of the Hamiltonian structure using alternating flux functions and symplectic time integration, (ii) the discretization of a divergence-free velocity field using Dirac's theory of constraints and (iii) the handling of large-scale computational demands due to the 3-dimensional nature of internal gravity waves and, in confined, symmetry-breaking fluid domains, possibly its narrow zones of attraction.
A statistical study of variations of internal gravity wave energy characteristics in meteor zone
Gavrilov, N. M.; Kalov, E. D.
1987-01-01
Internal gravity wave (IGW) parameters obtained by the radiometer method have been considered by many other researchers. The results of the processing of regular radiometeor measurements taken during 1979 to 1980 in Obninsk (55.1 deg N, 36.6 deg E) are presented.
Modern Gravity Models of Internal Migration. The Case of Romania
Directory of Open Access Journals (Sweden)
Daniela BUNEA
2012-04-01
Full Text Available Internal migration, although less investigated than international migration, is a key mechanism for adjustment to regional economic shocks, especially when other tools prove useless. But this process has very complex factors of determination which can be economic, social, demographic, environmental, etc. Based on previous international studies, in the case of Romania the robust variables proved to be the population size, the per capita gross domestic product, the road density, an amenity index and the crime rate from a static perspective, and the previous migration, the population size and the amenity index from a dynamic perspective. The techniques I have employed in making this study are the Least Square Dummy Variables (LSDV, or the fixed effects method and the Generalized Method of Moments (GMM, or the dynamic method both applied to panel data.
Design strategies for the International Space University's variable gravity research facility
Bailey, Sheila G.; Chiaramonte, Francis P.; Davidian, Kenneth J.
1990-01-01
A variable gravity research facility named 'Newton' was designed by 58 students from 13 countries at the International Space University's 1989 summer session at the Universite Louis Pasteur, Strasbourge, France. The project was comprehensive in scope, including a political and legal foundation for international cooperation, development and financing; technical, science and engineering issues; architectural design; plausible schedules; and operations, crew issues and maintenance. Since log-term exposure to zero gravity is known to be harmful to the human body, the main goal was to design a unique variable gravity research facility which would find a practical solution to this problem, permitting a manned mission to Mars. The facility would not duplicate other space-based facilities and would provide the flexibility for examining a number of gravity levels, including lunar and Martian gravities. Major design alternatives included a truss versus a tether based system which also involved the question of docking while spinning or despinning to dock. These design issues are described. The relative advantages or disadvantages are discussed, including comments on the necessary research and technology development required for each.
Values and marginal preferences in international business
Maseland, Robbert; van Hoorn, Andre
2010-01-01
In a recent paper in this journal, Maseland and van Hoorn argued that values surveys tend to conflate values and marginal preferences. This assertion has been challenged by Brewer and Venaik, who claim that the wording of most survey items does not suggest that these elicit marginal preferences. Thi
The International Gravity Standardization Net 1971 (I.G.S.N.71)
1972-05-31
DENVER 979 616.26 0.017 9 2 47 IGSN71 ABSOLUTE GRAVITY VALUES IG3 GRAVITY STO NUMBER NAME VALUE ERROR 11998 B GRANO JUNCTION...979 623.46 0.320 1199Ö J GRANO JUNCTION 979 606.59 0.015 TIMES TIEO INT EXT 8 0 6 20 12027 J 12027 K 12027 L 12027 P 12027 Q SAN...302.85 0.030 2 0 13256 J GRANDE PRAIRIE 961 300.99 0.020 17 4 1925Ö K GRANDE PRAIRIE 961 301.04 0.016 5 38 1925Ö L GRANOE PRAIRIE 981 301.11 0.075
The Initial Value Formulation of f(R)-gravity in the metric-affine formalism
Capozziello, Salvatore
2009-01-01
We study the initial value formulation of f(R)-gravity in the metric-affine formalism. The problem is discussed in vacuo, in presence of perfect-fluid matter, Klein-Gordon, Yang-Mills fields. Adopting Gaussian normal coordinates, it can be shown that the problem is always well-formulated and can be also well-posed if, eventually, further constraints are introduced on the Cauchy initial surface.
Internal bores and gravity currents in a two-fluid system
Maruyama, Kiyoshi
2014-01-01
In this paper, a unified theory of internal bores and gravity currents is presented within the framework of the one-dimensional two-layer shallow-water equations. The equations represent four basic physical laws: the theory is developed on the basis of these laws. Though the first three of the four basic laws are apparent, the forth basic law has been uncertain. This paper shows first that this forth basic law can be deduced from the law which is called in this paper the conservation law of circulation. It is then demonstrated that, within the framework of the equations, an internal bore is represented by a shock satisfying the shock conditions that follow from the four basic laws. A gravity current can also be treated within the framework of the equations if the front conditions, i.e. the boundary conditions to be imposed at the front of the current, are known. Basically, the front conditions for a gravity current also follow from the four basic laws. When the gravity current is advancing along a no-slip bou...
International Target Values for Measurement Uncertainties in Nuclear Material Accountancy
Institute of Scientific and Technical Information of China (English)
LIU; Hong-bin; GAO; Qiang
2012-01-01
<正>The IAEA has published a revised version International Target Values (ITVs) 2010 for Measurement Uncertainties in Safeguarding Nuclear Materials in 2010. The report proposes the international target values of measurement uncertainties of the routine measurement methods for the nuclear material accountancy.
Can plume-induced internal gravity waves regulate the core rotation of subgiant stars?
Pinçon, C.; Belkacem, K.; Goupil, M. J.; Marques, J. P.
2017-09-01
Context. The seismic data provided by the space-borne missions CoRoT and Kepler enabled us to probe the internal rotation of thousands of evolved low-mass stars. Subsequently, several studies showed that current stellar evolution codes are unable to reproduce the low core rotation rates observed in these stars. These results indicate that an additional angular momentum transport process is necessary to counteract the spin up due to the core contraction during the post-main sequence evolution. For several candidates, the transport induced by internal gravity waves (IGW) could play a non-negligible role. Aims: We aim to investigate the effect of IGW generated by penetrative convection on the internal rotation of low-mass stars from the subgiant branch to the beginning of the red giant branch. Methods: A semi-analytical excitation model was used to estimate the angular momentum wave flux. The characteristic timescale associated with the angular momentum transport by IGW was computed and compared to the contraction timescale throughout the radiative region of stellar models at different evolutionary stages. Results: We show that IGW can efficiently counteract the contraction-driven spin up of the core of subgiant stars if the amplitude of the radial-differential rotation (between the center of the star and the top of the radiative zone) is higher than a threshold value. This threshold depends on the evolutionary stage and is comparable to the differential rotation rates inferred for a sample of subgiant stars observed by the satellite Kepler. Such an agreement can therefore be interpreted as the consequence of a regulation mechanism driven by IGW. This result is obtained under the assumption of a smooth rotation profile in the radiative region and holds true even if a wide range of values is considered for the parameters of the generation model. In contrast, on the red giant branch, we find that IGW remain insufficient, on their own, to explain the observations because
Deluna, Roperto Jr; Jeon, Narae
2014-01-01
This study was conducted to investigate the determinants of international tourism demand for the Philippines.This study employed a double-log augmented form of gravity model estimated using the robust random effects model.Results revealed that tourist arrival in the Philippines are generally increasing from 2001 to 2012. Empirical estimation was conducted to determine factors affecting Philippine tourism demand. These factors include income, market size, and distance. Relative prices was also...
An Internal Wave as a Frequency Filter for Surface Gravity Waves on Water
Lossow, K
2010-01-01
We consider one-dimensional model of the interaction between surface and the internal gravity water waves. The internal wave is modeled by its basic form: a non-dispersive field with a horizontal current that is uniform over all depth, insignificantly affected by the surface waves, while ignoring surface tension and wind growth/decay effects. The depth is infinite. Approximation for the height of the surface wave on the flow by the "elementary quasi stationary" solutions was found. It was shown that the flow acts as a frequency filter for gravitational waves on water.
De Sá Teixeira, Nuno Alexandre
2014-12-01
Given its conspicuous nature, gravity has been acknowledged by several research lines as a prime factor in structuring the spatial perception of one's environment. One such line of enquiry has focused on errors in spatial localization aimed at the vanishing location of moving objects - it has been systematically reported that humans mislocalize spatial positions forward, in the direction of motion (representational momentum) and downward in the direction of gravity (representational gravity). Moreover, spatial localization errors were found to evolve dynamically with time in a pattern congruent with an anticipated trajectory (representational trajectory). The present study attempts to ascertain the degree to which vestibular information plays a role in these phenomena. Human observers performed a spatial localization task while tilted to varying degrees and referring to the vanishing locations of targets moving along several directions. A Fourier decomposition of the obtained spatial localization errors revealed that although spatial errors were increased "downward" mainly along the body's longitudinal axis (idiotropic dominance), the degree of misalignment between the latter and physical gravity modulated the time course of the localization responses. This pattern is surmised to reflect increased uncertainty about the internal model when faced with conflicting cues regarding the perceived "downward" direction.
Can representational trajectory reveal the nature of an internal model of gravity?
De Sá Teixeira, Nuno; Hecht, Heiko
2014-05-01
The memory for the vanishing location of a horizontally moving target is usually displaced forward in the direction of motion (representational momentum) and downward in the direction of gravity (representational gravity). Moreover, this downward displacement has been shown to increase with time (representational trajectory). However, the degree to which different kinematic events change the temporal profile of these displacements remains to be determined. The present article attempts to fill this gap. In the first experiment, we replicate the finding that representational momentum for downward-moving targets is bigger than for upward motions, showing, moreover, that it increases rapidly during the first 300 ms, stabilizing afterward. This temporal profile, but not the increased error for descending targets, is shown to be disrupted when eye movements are not allowed. In the second experiment, we show that the downward drift with time emerges even for static targets. Finally, in the third experiment, we report an increased error for upward-moving targets, as compared with downward movements, when the display is compatible with a downward ego-motion by including vection cues. Thus, the errors in the direction of gravity are compatible with the perceived event and do not merely reflect a retinotopic bias. Overall, these results provide further evidence for an internal model of gravity in the visual representational system.
Dirt, Gravity, and Lunar-Based Telescopes: The Value Proposition for Astronomy
Lester, D
2007-01-01
The lunar surface has historically been considered an optimal site for a broad range of astronomical telescopes. That assumption, which has come to be somewhat reflexive, is critically examined in this paper and found to be poorly substantiated. The value of the lunar surface for astronomy may be broadly compelling only in comparison to terrestrial sites. It is suggested here that the development and successful operation of the Hubble Space Telescope marked a turning point in the perception of value for free-space siting of astronomical telescopes, and for telescopes on the Moon. As the astronomical community considers the scientific potential of the Vision for Space Exploration (VSE) and the return to the Moon in particular, it should construct a value proposition that includes the tools, technology, and architecture being developed for this return, as these can well be seen as being more astronomically enabling than the lunar surface itself - a destination that offers little more than rocks and gravity. Whi...
A search for free quarks in the micro gravity environment of the International Space Station
Hudspeth, Paul; Klingler, Robert
2000-01-01
Authors propose using the zero-gravity environment of the International Space Station to gather evidence for or against quark particles existing as free radicals in nature. Their proposed method is based on a micro gravity version of 1923 Nobel Prize winner Robert Millikan's oil drop method of determining the fundamental charge on a single electron. Although Millikan's original experiments were carried out in 1909, and showed that all electrical charge exists as whole integer multiples of the fundamental electron unit, Millikan observed and recorded in lab notebooks, the existence of a tiny oil droplet which had a +1/3 partial charge, which he dismissed as an error. Not until the 1960's did quark theory and Particle Accelerators show that protons and neutrons were actually composed of smaller particles called ``quarks'' which indeed bear unique fractional charges. Authors propose observing one millimeter or larger grounded metal spheres suspended in micro gravity between oppositely charged metal plates for telltale motion behavior caused by the fractional charge unique to the quark particle. The ability afforded by micro gravity to use test objects of much greater mass than that of oil droplets equates to being able to perform 100 million Millikan tests in a single run -more by far than the sum total of all the tests ever performed on earth. The significant breakthroughs in terms of deep space propulsion and energy production, hinging on the question of free quark existence, are noted. Preliminary results of basic experimental apparatus construction and testing aboard NASA KC-135 zero-gravity flights are reported, along with recommendations for future experiments. Authors note ideal nature of the experiment in terms of possible student interaction with astronauts and real-time exhibition of testing via the Internet. .
Wziontek, Hartmut; Falk, Reinhard; Bonvalot, Sylvain; Rülke, Axel
2017-04-01
After about 10 years of successful joint operation by BGI and BKG, the International Database for Absolute Gravity Measurements "AGrav" (see references hereafter) was under a major revision. The outdated web interface was replaced by a responsive, high level web application framework based on Python and built on top of Pyramid. Functionality was added, like interactive time series plots or a report generator and the interactive map-based station overview was updated completely, comprising now clustering and the classification of stations. Furthermore, the database backend was migrated to PostgreSQL for better support of the application framework and long-term availability. As comparisons of absolute gravimeters (AG) become essential to realize a precise and uniform gravity standard, the database was extended to document the results on international and regional level, including those performed at monitoring stations equipped with SGs. By this it will be possible to link different AGs and to trace their equivalence back to the key comparisons under the auspices of International Committee for Weights and Measures (CIPM) as the best metrological realization of the absolute gravity standard. In this way the new AGrav database accommodates the demands of the new Global Absolute Gravity Reference System as recommended by the IAG Resolution No. 2 adopted in Prague 2015. The new database will be presented with focus on the new user interface and new functionality, calling all institutions involved in absolute gravimetry to participate and contribute with their information to built up a most complete picture of high precision absolute gravimetry and improve its visibility. A Digital Object Identifier (DOI) will be provided by BGI to contributors to give a better traceability and facilitate the referencing of their gravity surveys. Links and references: BGI mirror site : http://bgi.obs-mip.fr/data-products/Gravity-Databases/Absolute-Gravity-data/ BKG mirror site: http
A nonhydrostatic unstructured-mesh soundproof model for simulation of internal gravity waves
Smolarkiewicz, Piotr; Szmelter, Joanna
2011-12-01
A semi-implicit edge-based unstructured-mesh model is developed that integrates nonhydrostatic soundproof equations, inclusive of anelastic and pseudo-incompressible systems of partial differential equations. The model builds on nonoscillatory forward-in-time MPDATA approach using finite-volume discretization and unstructured meshes with arbitrarily shaped cells. Implicit treatment of gravity waves benefits both accuracy and stability of the model. The unstructured-mesh solutions are compared to equivalent structured-grid results for intricate, multiscale internal-wave phenomenon of a non-Boussinesq amplification and breaking of deep stratospheric gravity waves. The departures of the anelastic and pseudoincompressible results are quantified in reference to a recent asymptotic theory [Achatz et al. 2010, J. Fluid Mech., 663, 120-147)].
Contributions from the Second and Third Internal Gravity Modes for the Vertical Motion Response.
Directory of Open Access Journals (Sweden)
Julio Buchmann
2008-07-01
Full Text Available In earlier papers of a series of real data integrations of the National Center for Atmospheric Research Community ClimateModel with tropical heat anomalies display regions of pronounced subsidence and drying located several thousand kilometers westwardpoleward of the heating for cases of tropical Atlantic heating and tropical east Pacifi c heating. This highly predictable sinking responseis established within the fi rst fi ve days of these integrations. The normal-modes of a set of adiabatic primitive equations linearizedabout a basic state at rest are used to partition model response into gravity-inertia and Rossby modes. The most important contributionfor the vertical motion response comes from the gravity modes added for all vertical modes. The principal emphasis is given upon thecontributions of the second and third internal vertical modes (with equivalent depths on the order of a fews hundred meters for thevertical motion response.
International Accounting Convergence in the Field of Fair Value Measurement
Diana Cozma Ighian
2015-01-01
The investors’ desire for high-quality, internationally comparable financial information that is useful for decision-making in increasingly global capital markets imposed an international convergence, the ultimate goal of which is a single set of international accounting standards that companies worldwide would use for both domestic and cross-border financial reporting. The guidance, set out in IFRS 13 Fair Value Measurement and the update to Topic 820 (formerly referred to as SFAS 157), comp...
International Business Models Developed Through Brokerage Knowledge and Value Creation
DEFF Research Database (Denmark)
Petersen, Nicolaj Hannesbo; Rasmussen, Erik Stavnsager
This paper highlights theoretically and empirically international business model decisions in networks with knowledge sharing and value creation. The paper expands the conceptual in-ternational business model framework for technology-oriented companies to include the focal firm’s network role...
Uotila, U. A.
1978-01-01
In order to use gravity anomalies in geodetic computations and geophysical interpretations, the observed gravity values from which anomalies are derived should be referred to one consistent world wide system. The International Gravity Standardization Net 1971 was adapted by the International Union of Geodesy and Geophysics at Moscow in 1971, the network was result of extensive cooperation by many organizations and individuals around the world. The network contains more than 1800 stations around the world. The data used in the adjustment included more than 25,000 gravimetry, pendulum and absolute measurements.
International Fisheries Agreements and Non-consumptive Values
DEFF Research Database (Denmark)
Pintassilgo, Pedro; Laukkanen, Marita; Kronbak, Lone Grønbæk
The management of internationally shared fish stocks is a major economic, environmental and political issue. According to international law, these resources should be managed cooperatively under international fisheries agreements (IFAs). This paper studies the formation and stability of IFAs...... through a coalition game that accounts for both direct consumptive values (harvesting profits) and non-consumptive values of the fish stock per se. The results show that accounting for non-consumptive values helps conserve the fish stock in that equilibrium fishing efforts are smaller and fish stock...... larger than without non- consumptive values under all possible coalition scenarios (full, partial and no cooperation). However, considering non-consumptive values does not affect the outcome of the game in terms of the prospects for cooperation: even with substantial non-consumptive benefits, the outcome...
International Accounting Convergence in the Field of Fair Value Measurement
Directory of Open Access Journals (Sweden)
Diana Cozma Ighian
2015-09-01
Full Text Available The investors’ desire for high-quality, internationally comparable financial information that is useful for decision-making in increasingly global capital markets imposed an international convergence, the ultimate goal of which is a single set of international accounting standards that companies worldwide would use for both domestic and cross-border financial reporting. The guidance, set out in IFRS 13 Fair Value Measurement and the update to Topic 820 (formerly referred to as SFAS 157, completes a major project of the boards’ joint work to improve IFRSs and US GAAP and to bring about their convergence. This article describes the controversial history of fair value measurement and the main novelties in the field of fair value measurement, arising from the international convergence process.
Abdilghanie, Ammar M.; Diamessis, Peter J.
2012-01-01
Numerical simulations of internal gravity wave (IGW) dynamics typically rely on wave velocity and density fields which are either generated through forcing terms in the governing equations or are explicitly introduced as initial conditions. Both approaches are based on the associated solution to the inviscid linear internal wave equations and, thus, assume weak-amplitude, space-filling waves. Using spectral multidomain-based numerical simulations of the two-dimensional Navier-Stokes equations and focusing on the forcing-driven approach, this study examines the generation and subsequent evolution of large-amplitude IGW packets which are strongly localized in the vertical in a linearly stratified fluid. When the vertical envelope of the forcing terms varies relatively rapid when compared to the vertical wavelength, the associated large vertical gradients in the Reynolds stress field drive a nonpropagating negative horizontal mean flow component in the source region. The highly nonlinear interaction of this mean current with the propagating IGW packet leads to amplification of the wave, a significant distortion of its rear flank, and a substantial decay of its amplitude. Scaling arguments show that the mean flow is enhanced with a stronger degree of localization of the forcing, larger degree of hydrostaticity, and increasing wave packet steepness. Horizontal localization results in a pronounced reduction in mean flow strength mainly on account of the reduced vertical gradient of the wave Reynolds stress. Finally, two techniques are proposed toward the efficient containment of the mean flow at minimal computational cost. The findings of this study are of particular value in overcoming challenges in the design of robust computational process studies of IGW packet (or continuously forced wave train) interactions with a sloping boundary, critical layer, or caustic, where large wave amplitudes are required for any instabilities to develop. In addition, the detailed
Frequency content of sea surface height variability from internal gravity waves to mesoscale eddies
Savage, Anna C.; Arbic, Brian K.; Richman, James G.; Shriver, Jay F.; Alford, Matthew H.; Buijsman, Maarten C.; Thomas Farrar, J.; Sharma, Hari; Voet, Gunnar; Wallcraft, Alan J.; Zamudio, Luis
2017-03-01
High horizontal-resolution (1/12.5° and 1/25°) 41-layer global simulations of the HYbrid Coordinate Ocean Model (HYCOM), forced by both atmospheric fields and the astronomical tidal potential, are used to construct global maps of sea surface height (SSH) variability. The HYCOM output is separated into steric and nonsteric and into subtidal, diurnal, semidiurnal, and supertidal frequency bands. The model SSH output is compared to two data sets that offer some geographical coverage and that also cover a wide range of frequencies—a set of 351 tide gauges that measure full SSH and a set of 14 in situ vertical profilers from which steric SSH can be calculated. Three of the global maps are of interest in planning for the upcoming Surface Water and Ocean Topography (SWOT) two-dimensional swath altimeter mission: (1) maps of the total and (2) nonstationary internal tidal signal (the latter calculated after removing the stationary internal tidal signal via harmonic analysis), with an average variance of 1.05 and 0.43 cm2, respectively, for the semidiurnal band, and (3) a map of the steric supertidal contributions, which are dominated by the internal gravity wave continuum, with an average variance of 0.15 cm2. Stationary internal tides (which are predictable), nonstationary internal tides (which will be harder to predict), and nontidal internal gravity waves (which will be very difficult to predict) may all be important sources of high-frequency "noise" that could mask lower frequency phenomena in SSH measurements made by the SWOT mission.
Multi-symplectic structure of fully-nonlinear weakly-dispersive internal gravity waves
Clamond, Didier
2016-01-01
In this short communication we present the multi-symplectic structure for the two-layer Serre-Green-Naghdi equations describing the evolution of large amplitude internal gravity long waves. We consider only a two-layer stratification with rigid bottom and lid for simplicity, generalisations to several layers being straightforward. This multi-symplectic formulation allows the application of various multi-symplectic integrators (such as Euler or Preissman box schemes) that preserve exactly the multi-symplecticity at the discrete level.
Multi-symplectic structure of fully nonlinear weakly dispersive internal gravity waves
Clamond, Didier; Dutykh, Denys
2016-08-01
In this short communication, we present the multi-symplectic structure for the two-layer Serre-Green-Naghdi equations describing the evolution of large amplitude internal gravity water waves when both layers are shallow. We consider only a two-layer stratification with rigid bottom and lid for simplicity, generalisations to several layers being conceivable. This multi-symplectic formulation allows the application of various multi-symplectic integrators (such as Euler or Preissman box schemes) that preserve exactly the multi-symplecticity at the discrete level.
Espindola, Juan Manuel; Lopez-Loera, Hector; Mena, Manuel; Zamora-Camacho, Araceli
2016-09-01
The Tuxtla Volcanic Field (TVF) is a basaltic volcanic field emerging from the plains of the western margin of the Gulf of Mexico in the Mexican State of Veracruz. Separated by hundreds of kilometers from the Trans-Mexican Volcanic Belt to the NW and the Chiapanecan Volcanic Arc to the SE, it stands detached not only in location but also in the composition of its rocks, which are predominantly alkaline. These characteristics make its origin somewhat puzzling. Furthermore, one of the large volcanoes of the field, San Martin Tuxtla, underwent an eruptive period in historical times (CE 1793). Such volcanic activity conveys particular importance to the study of the TVF from the perspective of volcanology and hazard assessment. Despite the above circumstances, few investigations about its internal structure have been reported. In this work, we present analyses of gravity and aeromagnetic data obtained from different sources. We present the complete Bouguer anomaly of the area and its separation into regional and residual components. The aeromagnetic data were processed to yield the reduction to the pole, the analytic signal, and the upward continuation to complete the interpretation of the gravity analyses. Three-dimensional density models of the regional and residual anomalies were obtained by inversion of the gravity signal adding the response of rectangular prisms at the nodes of a regular grid. We obtained a body with a somewhat flattened top at 16 km below sea level from the inversion of the regional. Three separate slender bodies with tops 6 km deep were obtained from the inversion of the residual. The gravity and magnetic anomalies, as well as the inferred source bodies that produce those geophysical anomalies, lie between the Sontecomapan and Catemaco faults, which are proposed as flower structures associated with an inferred deep-seated fault termed the Veracruz Fault. These fault systems along with magma intrusion at the lower crust are necessary features to
Kiss, John Z; Millar, Katherine D L; Edelmann, Richard E
2012-08-01
While there is a great deal of knowledge regarding plant growth and development in microgravity aboard orbiting spacecraft, there is little information available about these parameters in reduced or fractional gravity conditions (less than the nominal 1g on Earth). Thus, in these experiments using the European Modular Cultivation System on the International Space Station, we studied the interaction between phototropism and gravitropism in the WT and mutants of phytochrome A and B of Arabidopis thaliana. Fractional gravity and the 1 g control were provided by centrifuges in the spaceflight hardware, and unidirectional red and blue illumination followed a white light growth period in the time line of the space experiments. The existence of red-light-based positive phototropism in hypocotyls of seedlings that is mediated by phytochrome was confirmed in these microgravity experiments. Fractional gravity studies showed an attenuation of red-light-based phototropism in both roots and hypocotyls of seedlings occurring due to gravitational accelerations ranging from 0.l to 0.3 g. In contrast, blue-light negative phototropism in roots, which was enhanced in microgravity compared with the 1g control, showed a significant attenuation at 0.3 g. In addition, our studies suggest that the well-known red-light enhancement of blue-light-induced phototropism in hypocotyls is likely due to an indirect effect by the attenuation of gravitropism. However, red-light enhancement of root blue-light-based phototropism may occur via a more direct effect on the phototropism system itself, most likely through the phytochrome photoreceptors. To our knowledge, these experiments represent the first to examine the behavior of flowering plants in fractional or reduced gravity conditions.
The initial value problem of scalar-tensor theories of gravity
Salgado, Marcelo
2007-01-01
The initial value problem of scalar-tensor theories of gravity (STT) is analyzed in the physical (Jordan) frame using a 3+1 decomposition of spacetime. A first order strongly hyperbolic system is obtained for which the well posedness of the Cauchy problem can be established. We provide two simple applications of the 3+1 system of equations: one for static and spherically symmetric spacetimes which allows the construction of unstable initial data (compact objects) for which a further black hole formation and scalar gravitational wave emission can be analyzed, and another application is for homogeneous and isotropic spacetimes that permits to study the dynamics of the Universe in the framework of STT.
The initial value problem of scalar-tensor theories of gravity
Energy Technology Data Exchange (ETDEWEB)
Salgado, Marcelo; Martinez del Rio, David [Instituto de Ciencias Nucleares Universidad Nacional Autonoma de Mexico Apdo. Postal 70-543 Mexico 04510 D.F. (Mexico)
2007-11-15
The initial value problem of scalar-tensor theories of gravity (STT) is analyzed in the physical (Jordan) frame using a 3+1 decomposition of spacetime. A first order strongly hyperbolic system is obtained for which the well posedness of the Cauchy problem can be established. We provide two simple applications of the 3+1 system of equations: one for static and spherically symmetric spacetimes which allows the construction of unstable initial data (compact objects) for which a further black hole formation and scalar gravitational wave emission can be analyzed, and another application is for homogeneous and isotropic spacetimes that permits to study the dynamics of the Universe in the framework of STT.
Vertical heat and salt fluxes induced by inertia-gravity internal waves on sea shelf
Slepyshev, A. A.; Vorotnikov, D. I.
2017-07-01
Free inertia-gravity internal waves are considered in a two-dimensional vertically nonuniform flow in the Boussinesq approximation. The equation for vertical velocity amplitude includes complex factors caused by the gradient of the flow velocity component transverse to the wave-propagation direction; therefore, the eigenfunction and wave frequency are complex. It is shown that the decrement of damping (imaginary correction to the frequency) of 15-min internal waves is two orders of magnitude smaller than the wave frequency; i.e., the waves weakly damp. Vertical wave fluxes of heat and salt are nonzero due to the phase shift between fluctuations of the vertical velocity and temperature (salinity) different from π 2. The vertical component of the Stokes drift speed is also nonzero and contributed into the vertical transport.
An international track wheelchair with a center of gravity directional controller.
Cooper, R A
1989-01-01
An international track wheelchair (ITWC) with a center of gravity directional controller (COGDC) is described in this paper. The rules for international track competition disallow devices designed solely for steering. Equipment has been disqualified for having steering handles, crown compensators, and other lever systems. However, the rules do allow tie-rod linkage and the use of springs for dampening caster flutter. The chair described in this paper exploits the physical properties of wheeled vehicles to achieve directional control on the track. This controller is effective, because turning is only required in one direction. Three such track wheelchairs have been developed and were used at the Paralympics in Seoul, Korea, in October of 1988.
Analysis of International Accounting Regulations with Regards to Fair Value
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Diana COZMA IGHIAN
2010-08-01
Full Text Available Unifying the economical-financial information at an international level represents today, within the context of the globalization and integration of the financial markets around the world, an important and urgent demand. One of the coordinates of accounting globalization is the fair value based valuation system. This tendency arises from the contents of international accounting standards and from the progress of world-wide regulating practice. The economic and market events of the past years have highlighted the importance of fair value measurements used in financial statements and have emphasized the need for consistency and comparability in those measurements infinancial statements prepared around the globe.
Lin, Ying-Tsong; McMahon, Kara G; Lynch, James F; Siegmann, William L
2013-01-01
The acoustic ducting effect by curved nonlinear gravity waves in shallow water is studied through idealized models in this paper. The internal wave ducts are three-dimensional, bounded vertically by the sea surface and bottom, and horizontally by aligned wavefronts. Both normal mode and parabolic equation methods are taken to analyze the ducted sound field. Two types of horizontal acoustic modes can be found in the curved internal wave duct. One is a whispering-gallery type formed by the sound energy trapped along the outer and concave boundary of the duct, and the other is a fully bouncing type due to continual reflections from boundaries in the duct. The ducting condition depends on both internal-wave and acoustic-source parameters, and a parametric study is conducted to derive a general pattern. The parabolic equation method provides full-field modeling of the sound field, so it includes other acoustic effects caused by internal waves, such as mode coupling/scattering and horizontal Lloyd's mirror interference. Two examples are provided to present internal wave ducts with constant curvature and meandering wavefronts.
Measuring the value of internal audit in the banking industry
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Clara-Iulia Zinca (Voiculescu
2016-09-01
The results of the study suggest that most organizations use methods that contain mainly quantitative and less qualitative elements. There are differences between banks and other types of organizations in terms of the methods and practices used, but also on the importance showed to measurement of internal audit value. In addition, the findings confirm that there is room for improving the methods and practices used, so that the audit function gains value and credibility.
NUMERICAL STUDIES OF INTERNAL SOLITARY WAVE GENERATION AND EVOLUTION BY GRAVITY COLLAPSE
Institute of Scientific and Technical Information of China (English)
LIN Zhen-hua; SONG Jin-bao
2012-01-01
In this study,an analysis on the internal wave generation via the gravity collapse mechanism is carried out based on the theoretical formulation and the numerical simulation.With the linear theoretical model,a rectangle shape wave is generated and propagates back and forth in the domain,while a two-dimensional non-hydrostatic numerical model could reproduce all the observed phenomena in the laboratory experiments conducted by Chen et al.(2007),and the related process realistically.The model results further provide more quantitative information in the whole domain,thus allowing an in depth understanding of the corresponding internal solitary wave generation and propagation.It is shown that the initial type of the internal wave is determined by the relative height between the perturbation and the environmental density interface,while the final wave type is related to the relative height of the upper and lower layers of the environmental fluid.The shape of the internal wave generated is consistent with that predicted by the KdV and EKdV theories if its amplitude is small,as the amplitude becomes larger,the performance of the EKdV becomes better after the wave adjusts itself to the ambient stratification and reaches an equilibrium state between the nonlinear and dispersion effects.The evolution of the mechanical energy is also analyzed.
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TIAN Jialei
2015-11-01
Full Text Available By using the ground as the boundary, Molodensky problem usually gets the solution in form of series. Higher order terms reflect the correction between a smooth surface and the ground boundary. Application difficulties arise from not only computational complexity and stability maintenance, but also data-intensiveness. Therefore, in this paper, starting from the application of external gravity disturbance, Green formula is used on digital terrain surface. In the case of ignoring the influence of horizontal component of the integral, the expression formula of external disturbance potential determined by boundary value consisted of ground gravity anomalies and height anomaly difference are obtained, whose kernel function is reciprocal of distance and Poisson core respectively. With this method, there is no need of continuation of ground data. And kernel function is concise, and suitable for the stochastic computation of external disturbing gravity field.
Turbulent mixing driven by mean-flow shear and internal gravity waves in oceans and atmospheres
Baumert, Helmut Z
2012-01-01
This study starts with balances deduced by Baumert and Peters (2004, 2005) from results of stratified-shear experiments made in channels and wind tunnels by Itsweire (1984) and Rohr and Van Atta (1987), and of free-decay experiments in a resting stratified tank by Dickey and Mellor (1980). Using a modification of Canuto's (2002) ideas on turbulence and waves, these balances are merged with an (internal) gravity-wave energy balance presented for the open ocean by Gregg (1989), without mean-flow shear. The latter was augmented by a linear (viscous) friction term. Gregg's wave-energy source is interpreted on its long-wave spectral end as internal tides, topography, large-scale wind, and atmospheric low-pressure actions. In addition, internal eigen waves, generated by mean-flow shear, and the aging of the wave field from a virginal (linear) into a saturated state are taken into account. Wave packets and turbulence are treated as particles (vortices, packets) by ensemble kinetics so that the loss terms in all thre...
Bernknopf, R.; Kuwayama, Y.; Brookshire, D.; Macauley, M.; Zaitchik, B.; Pesko, S.; Vail, P.
2014-12-01
Determining how much to invest in earth observation technology depends in part on the value of information (VOI) that can be derived from the observations. We design a framework and then evaluate the value-in-use of the NASA Gravity Research and Climate Experiment (GRACE) for regional water use and reliability in the presence of drought. As a technology that allows measurement of water storage, the GRACE Data Assimilation System (DAS) provides information that is qualitatively different from that generated by other water data sources. It provides a global, reproducible grid of changes in surface and subsurface water resources on a frequent and regular basis. Major damages from recent events such as the 2012 Midwest drought and the ongoing drought in California motivate the need to understand the VOI from remotely sensed data such as that derived from GRACE DAS. Our conceptual framework models a dynamic risk management problem in agriculture. We base the framework on information from stakeholders and subject experts. The economic case for GRACE DAS involves providing better water availability information. In the model, individuals have a "willingness to pay" (wtp) for GRACE DAS - essentially, wtp is an expression of savings in reduced agricultural input costs and for costs that are influenced by regional policy decisions. Our hypothesis is that improvements in decision making can be achieved with GRACE DAS measurements of water storage relative to data collected from groundwater monitoring wells and soil moisture monitors that would be relied on in the absence of GRACE DAS. The VOI is estimated as a comparison of outcomes. The California wine grape industry has features that allow it to be a good case study and a basis for extrapolation to other economic sectors. We model water use in this sector as a sequential decision highlighting the attributes of GRACE DAS input as information for within-season production decisions as well as for longer-term water reliability.
The Social Value of Knowledge and International Clinical Research.
Wenner, Danielle M
2015-08-01
In light of the growth in the conduct of international clinical research in developing populations, this paper seeks to explore what is owed to developing world communities who host international clinical research. Although existing paradigms for assigning and assessing benefits to host communities offer valuable insight, I criticize their failure to distinguish between those benefits which can justify the conduct of research in a developing world setting and those which cannot. I argue that the justification for human subjects research is fundamentally grounded in the social value of knowledge, and that this value is context-dependent in a manner which should inform our ethical evaluation of the conduct of research in specific settings. I propose a new framework for the assessment of research benefits assigned to developing world host communities, a natural implication of which is to limit the types of research projects which may permissibly be conducted in developing world settings. © 2013 John Wiley & Sons Ltd.
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Bhadauria B.S.
2016-12-01
Full Text Available In this paper, we investigate the combined effect of internal heating and time periodic gravity modulation in a viscoelastic fluid saturated porous medium by reducing the problem into a complex non-autonomous Ginzgburg-Landau equation. Weak nonlinear stability analysis has been performed by using power series expansion in terms of the amplitude of gravity modulation, which is assumed to be small. The Nusselt number is obtained in terms of the amplitude for oscillatory mode of convection. The influence of viscoelastic parameters on heat transfer has been discussed. Gravity modulation is found to have a destabilizing effect at low frequencies and a stabilizing effect at high frequencies. Finally, it is found that overstability advances the onset of convection, more with internal heating. The conditions for which the complex Ginzgburg-Landau equation undergoes Hopf bifurcation and the amplitude equation undergoes supercritical pitchfork bifurcation are studied.
Reasoning about the value of cultural awareness in international collaboration
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Helena Bernáld
Full Text Available As international collaborations become a part of everyday life, cultural awareness becomes crucial for our ability to work with people from other countries. People see, evaluate, and interpret things differently depending on their cultural background and cultural awareness. This includes aspects such as appreciation of different communication patterns, the awareness of different value systems and, not least, to become aware of our own cultural values, beliefs and perceptions. This paper addresses the value of cultural awareness in general through describing how it was introduced in two computer science courses with a joint collaboration between students from the US and Sweden. The cultural seminars provided to the students are presented, as well as a discussion of the students\\' reflections and the teachers\\' experiences. The cultural awareness seminars provided students with a new understanding of cultural differences which greatly improved the international collaboration. Cultural awareness may be especially important for small countries like New Zealand and Sweden, since it could provide an essential edge in collaborations with representatives from more \\'powerful\\' countries.
FODMAPs: food composition, defining cutoff values and international application.
Varney, Jane; Barrett, Jacqueline; Scarlata, Kate; Catsos, Patsy; Gibson, Peter R; Muir, Jane G
2017-03-01
The low-FODMAP diet is a new dietary therapy for the management of irritable bowel syndrome that is gaining in popularity around the world. Developing the low-FODMAP diet required not only extensive food composition data but also the establishment of "cutoff values" to classify foods as low-FODMAP. These cutoff values relate to each particular FODMAP present in a food, including oligosaccharides (fructans and galacto-oligosaccharides), sugar polyols (mannitol and sorbitol), lactose, and fructose in excess of glucose. Cutoff values were derived by considering the FODMAP levels in typical serving sizes of foods that commonly trigger symptoms in individuals with irritable bowel syndrome, as well as foods that were generally well tolerated. The reliability of these FODMAP cutoff values has been tested in a number of dietary studies. The development of the techniques to quantify the FODMAP content of foods has greatly advanced our understanding of food composition. FODMAP composition is affected by food processing techniques and ingredient selection. In the USA, the use of high-fructose corn syrups may contribute to the higher FODMAP levels detected (via excess fructose) in some processed foods. Because food processing techniques and ingredients can vary between countries, more comprehensive food composition data are needed for this diet to be more easily implemented internationally. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.
The international regulation of Informal Value Transfer Systems
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Anand Ajay Shah
2007-12-01
Full Text Available After the 11th September 2001 attacks on the United States international attention quickly focused on the sources and methods of terrorist financing. Among the methods terrorists and other criminal actors use to transfer funds are Informal Value Transfer Systems (IVTS which operate either outside the formal financial sector, or through use of the formal financial sector, but without leaving a full record of the transaction. Though the vast majority of funds moved through IVTS are the earnings of migrant workers and immigrant communities, the lack of uniform worldwide regulation of IVTS provides ample opportunity for abuse and misuse. The international community primarily responded to IVTS concerns through the Financial Action Task Force on Money Laundering, which issued a series of recommendations and best practices for states in regulating IVTS operations. While these recommendations are a secure beginning to regulation of IVTS operating within ethnic communities, they fail to address the more modern forms of IVTS that have come about in the post-Cold War globalised world. Comprehensive recommendations governing all types of IVTS, as well as concerted international cooperation and coordination are necessary to address this global phenomenon.
The international regulation of Informal Value Transfer Systems
Directory of Open Access Journals (Sweden)
Anand Ajay Shah
2007-12-01
Full Text Available After the 11th September 2001 attacks on the United States international attention quickly focused on the sources and methods of terrorist financing. Among the methods terrorists and other criminal actors use to transfer funds are Informal Value Transfer Systems (IVTS which operate either outside the formal financial sector, or through use of the formal financial sector, but without leaving a full record of the transaction. Though the vast majority of funds moved through IVTS are the earnings of migrant workers and immigrant communities, the lack of uniform worldwide regulation of IVTS provides ample opportunity for abuse and misuse. The international community primarily responded to IVTS concerns through the Financial Action Task Force on Money Laundering, which issued a series of recommendations and best practices for states in regulating IVTS operations. While these recommendations are a secure beginning to regulation of IVTS operating within ethnic communities, they fail to address the more modern forms of IVTS that have come about in the post-Cold War globalised world. Comprehensive recommendations governing all types of IVTS, as well as concerted international cooperation and coordination are necessary to address this global phenomenon.
Jaeggi, Adrian; Weigelt, Matthias; Flechtner, Frank; Guentner, Andreas; Mayer-Gürr, Torsten; Martinis, Sandro; Bruinsma, Sean; Flury, Jakob; Bourgogne, Stephane
2015-04-01
A proposal for a European Gravity Service for Improved Emergency Management (EGSIEM) has been submitted in response to the Earth Observation Call EO-1-2014 of the Horizon 2020 Framework Programme. EGSIEM shall demonstrate that observations of the redistribution of water and ice mass derived from the current GRACE mission, the future GRACE-FO mission, and additional data provide critical and complementary information to more traditional Earth Observation products and open the door for innovative approaches to flood and drought monitoring and forecasting. The EGSIEM project has recently started in January 2015. We present the three key objectives that EGSIEM shall address: 1) to establish a scientific combination service to deliver the best gravity products for applications in Earth and environmental science research based on the unified knowledge of the European GRACE community, 2) to establish a near real-time and regional service to reduce the latency and increase the temporal resolution of the mass redistribution products, and 3) to establish a hydrological and early warning service to develop gravity-based indicators for extreme hydrological events and to demonstrate their value for flood and drought forecasting and monitoring services. All of these services shall be tailored to the various needs of the respective communities. Significant efforts shall be devoted to transform the service products into user-friendly and easy-to-interpret data sets and the development of visualization tools.
National Oceanic and Atmospheric Administration, Department of Commerce — This data base (14,559 records) was received in January 1986. Principal gravity parameters include elevation and observed gravity. The observed gravity values are...
National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Absolute Gravity data (78 stations) was received in July 1993. Principal gravity parameters include Gravity Value, Uncertainty, and Vertical Gradient. The...
Influence of plume-induced internal gravity waves on the rotation profile of low-mass stars
Pinçon, C.; Belkacem, K.; Goupil, M. J.
2016-12-01
High-quality seismic data due to the space-borne missions CoRoT and Kepler provide precious information on the core rotation of thousands of stars from the subgiant to the red giant stages. We know today that current stellar evolution codes need for an additional physical mechanism to extract angular momentum from the core to the envelope of evolved low-mass stars and explain the low observed internal rotation. In this framework, internal gravity waves generated by penetrative convection at the top of the radiative region may play a role. In this work, we investigate whether the transport of angular momentum by plume-induced gravity waves may counteract the accelereration due the the strong contraction of the innermost layers. On the red giant branch, we find that the strong radiative damping near the H-burning shell prevents these waves from slowing down the core, so that another process should operate in these stars. Nevertheless, we show that plume-induced gravity waves are a good candidate to regulate the amplitude of the differential rotation in subgiant stars.
1980-12-01
CALIRIATInM ’oollard and Rose (1963) used modified sets of minimum compound quartz pendulum apparatus built by the Gulf Oil Company Research and...is indicated in Turkey, the Persian Gulf region and Pakistan, there is a problem with the data for India. Either there is a marked difference in...14.93 WA 4045 Nicoya 978,2728 .257 87* -14.93 WA 4007 San Jose "K" 978.9792 .964 36 -14.84 GUATEMALA WA 4019 Chahel 978.3717 .356 74* -14.96 WA 4022
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Soner Gokten
2017-04-01
Full Text Available Value Creation Reporting: Answering the Question ‘Value to Whom’ according to the International Integrated Reporting Framework The principal function of integrated reporting is the reporting of value and this phenomenon seems the most philosophical part of the International Framework. This paper discusses what the value concept refers to in the Framework: Value to investors, value to society or value to present and future generations? In this sense, we try to answer this question by highlighting the dynamics of capital formations according to interrelations between capitals and demonstrating the value creation process in the short, medium, and longer term. We show that (1 „profit” is the result of short term value creation, which indicates the „value to value chain stakeholders”, (2 „expected fair value of equity” represents the „value to investors” and (3 „longer term value” represents the „value to society” according to the International Framework. Additionally, we touch on the inadequacies of the current Framework and suggest future research opportunities within the scope of value creation reporting. To our knowledge, this study is the first to provide a detailed framework on the dynamics of capitals usage and it attempts to show the intersection of accounting and finance in terms of value creation reporting.
Cummins, Phil R.; Wahr, John M.
1993-01-01
In this study we consider the influence of the earth's free core nutation (FCN) on diurnal tidal admittance estimates for 11 stations of the globally distributed International Deployment of Accelerometers network. The FCN causes a resonant enhancement of the diurnal admittances which can be used to estimate some properties of the FCN. Estimations of the parameters describing the FCN (period, Q, and resonance strength) are made using data from individual stations and many stations simultaneously. These yield a result for the period of 423-452 sidereal days, which is shorter than theory predicts but is in agreement with many previous studies and suggests that the dynamical ellipticity of the core may be greater than its hydrostatic value.
Hickey, M. P.
1987-01-01
In this paper the propagation and dissipation characteristics of a number of individual internal gravity waves are discussed and compared by using a multilayer, time-averaged model in which the waves lose energy due to viscous, thermal conduction and ion-drag dissipation. From this both the height and horizontal distance (from an assumed 'source') at which the waves achieve a maximum density amplitude may be determined. Such calculations are performed for both a very hot and a very cold thermosphere, and the subsequent differences in the wave characteristics and their relation to the control of orbiting spacecraft for each of these is discussed.
Work Values of Lithuanian University Students: Internal Structure
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Vincentas Lamanauskas
2017-04-01
Full Text Available Individual’s work values define his/her career purposefulness. Individual’s chosen work values allow foreseeing what activity context and career model is important for him/her, seeking to successfully realize oneself in professional activity. Planning his/her professional career an individual is searching for the activity sphere, which could conform not only to his/her personal features, but also to his/her value orientations. Work values important for the individual allow realizing if they form conditions for planning modern career (successfully solve constantly changing activity problems and to correspond to always new raised requirements for a person in the organisation or in labour market, the realisation of which in today’s constantly changing labour market and social context becomes more and more problematic. Empiric research was carried out seeking to discover the work (activity value structure. The research instrument was created by the authors of the research. Two hundred sixty five first-year students from three Lithuanian universities participated in the research. These are the main higher education institutions, preparing teachers in Lithuania. The obtained results show that work value structure of the first year students studying in social and humanitarian science programmes can be expressed by 6 main factors: responsible activity values, active work values, harmony values, reward values, activity style values, and social status values. Also, the main differences were ascertained between female and male work value structure. Responsible activity values, active work values and harmony values were much more important for female than male students.
Voigt, C.; Denker, H.; Timmen, L.
2016-12-01
The latest generation of optical atomic clocks is approaching the level of one part in 1018 in terms of frequency stability and uncertainty. For clock comparisons and the definition of international time scales, a relativistic redshift effect of the clock frequencies has to be taken into account at a corresponding uncertainty level of about 0.1 m2 s-2 and 0.01 m in terms of gravity potential and height, respectively. Besides the predominant static part of the gravity potential, temporal variations must be considered in order to avoid systematic frequency shifts. Time-variable gravity potential components induced by tides and non-tidal mass redistributions are investigated with regard to the level of one part in 1018. The magnitudes and dominant time periods of the individual gravity potential contributions are investigated globally and for specific laboratory sites together with the related uncertainty estimates. The basics of the computation methods are presented along with the applied models, data sets and software. Solid Earth tides contribute by far the most dominant signal with a global maximum amplitude of 4.2 m2 s-2 for the potential and a range (maximum-to-minimum) of up to 1.3 and 10.0 m2 s-2 in terms of potential differences between specific laboratories over continental and intercontinental scales, respectively. Amplitudes of the ocean tidal loading potential can amount up to 1.25 m2 s-2, while the range of the potential between specific laboratories is 0.3 and 1.1 m2 s-2 over continental and intercontinental scales, respectively. These are the only two contributors being relevant at a 10-17 level. However, several other time-variable potential effects can particularly affect clock comparisons at the 10-18 level. Besides solid Earth pole tides, these are non-tidal mass redistributions in the atmosphere, the oceans and the continental water storage.
Unit Values in International Trade and Product Quality
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Chang Hong
2015-06-01
Full Text Available Is the unit value of traded goods representative of quality? To answer this question, we analyze unit value with respect to exporter country’s capacity to export, which is determined by its production cost, tariff, and distance. The change in a country’s export unit value is decomposed into the components associated with pure term-of-trade effect, quality effect, distance effect, and production cost effect. Our empirical results confirm that tariff, distance, and wages all significantly affect the unit values. Furthermore, by comparing CIF and FOB unit values, we show that quality is an important contributor on driving up the unit values: exporters increase unit price to distant trading partners through quality upgrading. This “Washington apple effect” is much larger than the pure distance effect or production cost increase.
Modeling Volcanic Eruption Parameters by Near-Source Internal Gravity Waves
Ripepe, M.; Barfucci, G.; de Angelis, S.; Delle Donne, D.; Lacanna, G.; Marchetti, E.
2016-11-01
Volcanic explosions release large amounts of hot gas and ash into the atmosphere to form plumes rising several kilometers above eruptive vents, which can pose serious risk on human health and aviation also at several thousands of kilometers from the volcanic source. However the most sophisticate atmospheric models and eruptive plume dynamics require input parameters such as duration of the ejection phase and total mass erupted to constrain the quantity of ash dispersed in the atmosphere and to efficiently evaluate the related hazard. The sudden ejection of this large quantity of ash can perturb the equilibrium of the whole atmosphere triggering oscillations well below the frequencies of acoustic waves, down to much longer periods typical of gravity waves. We show that atmospheric gravity oscillations induced by volcanic eruptions and recorded by pressure sensors can be modeled as a compact source representing the rate of erupted volcanic mass. We demonstrate the feasibility of using gravity waves to derive eruption source parameters such as duration of the injection and total erupted mass with direct application in constraining plume and ash dispersal models.
Assessing the Value of U.S. Army International Activities
2006-01-01
of U.S. Army International Activities Tajfel , Henri , Human Groups and Social Categories, Cambridge, U.K.: Cambridge University Press, 1981. Taw...more recent treatment, see Fearon (1997, pp. 68–90). 3 For general discussions, see Tajfel (1981, p. 36), Hogg and Abrams (1998, pp. 31–63), and Goffman
On the Reliability of Unit Value Ratios in International Comparisons
Timmer, Marcel P.
1996-01-01
In this paper reliability indicators are developed for the Laspeyres and Paasche index type currency conversion factors used in the industry of origin approach to international comparisons of output. Given the fact that these conversion factors are calculated on basis of a sampling technique, sampli
Character Values and Their Internalization in Teaching and Learning English at Madrasah
Islami, Milad
2016-01-01
In addition to communicating intellectual-based concepts such as ideas, belief and thought, language is used to communicate norms, values and emotions. As the result, it is important to internalize the character values into the teaching and learning activity of English. The study describes the analysis of the internalization of character values.…
Gunnestad, Arve; Mørreaunet, Sissel; Onyango, Silas
2015-01-01
This article highlights value learning in kindergartens exemplified by the value of forgiveness. Values are basic ideas on human behaviour and they function as a compass that helps children to make choices and priorities in their lives, to choose between good or bad, right or wrong. Value learning is an important part of the educational work in a…
Institute of Scientific and Technical Information of China (English)
徐新禹; 李建成; 邹贤才; 褚永海
2007-01-01
The principle and method for solving three types of satellite gravity gradient boundary value problems by least-squares are discussed in detail. Also, kernel function expressions of the least-squares solution of three geodetic boundary value problems with the observations {Γzz},{Γxz,Γyz} and {Γzz -Γyy,2Γxy} are presented. From the results of recovering gravity field using simulated gravity gradient tensor data, we can draw a conclusion that satellite gravity gradient integral formulas derived from least-squares are valid and rigorous for recovering the gravity field.
Controlling pandemic flu: the value of international air travel restrictions.
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Joshua M Epstein
Full Text Available BACKGROUND: Planning for a possible influenza pandemic is an extremely high priority, as social and economic effects of an unmitigated pandemic would be devastating. Mathematical models can be used to explore different scenarios and provide insight into potential costs, benefits, and effectiveness of prevention and control strategies under consideration. METHODS AND FINDINGS: A stochastic, equation-based epidemic model is used to study global transmission of pandemic flu, including the effects of travel restrictions and vaccination. Economic costs of intervention are also considered. The distribution of First Passage Times (FPT to the United States and the numbers of infected persons in metropolitan areas worldwide are studied assuming various times and locations of the initial outbreak. International air travel restrictions alone provide a small delay in FPT to the U.S. When other containment measures are applied at the source in conjunction with travel restrictions, delays could be much longer. If in addition, control measures are instituted worldwide, there is a significant reduction in cases worldwide and specifically in the U.S. However, if travel restrictions are not combined with other measures, local epidemic severity may increase, because restriction-induced delays can push local outbreaks into high epidemic season. The per annum cost to the U.S. economy of international and major domestic air passenger travel restrictions is minimal: on the order of 0.8% of Gross National Product. CONCLUSIONS: International air travel restrictions may provide a small but important delay in the spread of a pandemic, especially if other disease control measures are implemented during the afforded time. However, if other measures are not instituted, delays may worsen regional epidemics by pushing the outbreak into high epidemic season. This important interaction between policy and seasonality is only evident with a global-scale model. Since the benefit of
Miller, Craig A.; Williams-Jones, Glyn
2016-06-01
A new 3D geophysical model of the Mt Tongariro Volcanic Massif (TgVM), New Zealand, provides a high resolution view of the volcano's internal structure and hydrothermal system, from which we derive implications for volcanic hazards. Geologically constrained 3D inversions of potential field data provides a greater level of insight into the volcanic structure than is possible from unconstrained models. A complex region of gravity highs and lows (± 6 mGal) is set within a broader, ~ 20 mGal gravity low. A magnetic high (1300 nT) is associated with Mt Ngauruhoe, while a substantial, thick, demagnetised area occurs to the north, coincident with a gravity low and interpreted as representing the hydrothermal system. The hydrothermal system is constrained to the west by major faults, interpreted as an impermeable barrier to fluid migration and extends to basement depth. These faults are considered low probability areas for future eruption sites, as there is little to indicate they have acted as magmatic pathways. Where the hydrothermal system coincides with steep topographic slopes, an increased likelihood of landslides is present and the newly delineated hydrothermal system maps the area most likely to have phreatic eruptions. Such eruptions, while small on a global scale, are important hazards at the TgVM as it is a popular hiking area with hundreds of visitors per day in close proximity to eruption sites. The model shows that the volume of volcanic material erupted over the lifespan of the TgVM is five to six times greater than previous estimates, suggesting a higher rate of magma supply, in line with global rates of andesite production. We suggest that our model of physical property distribution can be used to provide constraints for other models of dynamic geophysical processes occurring at the TgVM.
Dilemmas in international research and the value of practical wisdom.
Jarvis, Kimberly
2016-07-18
When conducting research in an international setting, in a country different than that of the researcher, unpredictable circumstances can arise. A study conducted by a novice North American researcher with a vulnerable population in northern Ghana highlights these happenings with an emphasis placed on the ethical challenges encountered. An illustration from the research is used to highlight an ethical dilemma while in the field, and how utilizing a moral decision-making framework can assist in making choices about a participant's right to autonomy, privacy, and confidentiality during the research process. Moral frameworks, however, can never be enough to solve a dilemma since guidelines only describe what to aim for and not how to interpret or use them. Researchers must therefore strive to move beyond these frameworks to employ practical wisdom or phronesis so to combine the right thing to do with the skill required to figure out what the right choice is. The skill of practical wisdom must be acquired because without it international researchers indecisively fumble around with good intentions, often leaving a situation in worse shape than they found it.
International Tables of Glycemic Index and Glycemic Load Values: 2008
Atkinson, Fiona S.; Foster-Powell, Kaye; Brand-Miller, Jennie C.
2008-01-01
OBJECTIVE—To systematically tabulate published and unpublished sources of reliable glycemic index (GI) values. RESEARCH DESIGN AND METHODS—A literature search identified 205 articles published between 1981 and 2007. Unpublished data were also included where the data quality could be verified. The data were separated into two lists: the first representing more precise data derived from testing healthy subjects and the second primarily from individuals with impaired glucose metabolism. RESULTS—...
Interior Alaska Bouguer Gravity Anomaly
National Oceanic and Atmospheric Administration, Department of Commerce — A 1 kilometer Complete Bouguer Anomaly gravity grid of interior Alaska. Only those grid cells within 10 kilometers of a gravity data point have gravity values....
Pantillon, Florian P; Charbonnel, Corinne
2007-01-01
This is the third in a series of papers that deal with angular momentum transport by internal gravity waves. We concentrate on the waves excited by core convection in a 3Msun, Pop I main sequence star. Here, we want to examine the role of the Coriolis acceleration in the equations of motion that describe the behavior of waves and to evaluate its impact on angular momentum transport. We use the so-called traditional approximation of geophysics, which allows variable separation in radial and horizontal components. In the presence of rotation, the horizontal structure is described by Hough functions instead of spherical harmonics. The Coriolis acceleration has two main effects on waves. It transforms pure gravity waves into gravito-inertial waves that have a larger amplitude closer to the equator, and it introduces new waves whose restoring force is mainly the conservation of vorticity. Taking the Coriolis acceleration into account changes the subtle balance between prograde and retrograde waves in non-rotating ...
Stability analysis of a tidally excited internal gravity wave near the centre of a solar-type star
Barker, Adrian
2011-01-01
We perform a stability analysis of a tidally excited nonlinear internal gravity wave near the centre of a solar-type star in two-dimensions. The motivation is to understand the tidal interaction between short-period planets and their solar-type host stars, which involves the launching of gravity waves at the top of the radiation zone that propagate towards the stellar centre. Studying the instabilities of these waves near the centre, where nonlinearities are most important, is essential, since it may have implications for the survival of these planets. When the waves have sufficient amplitude to overturn the stratification, they break and form a critical layer, which efficiently absorbs subsequent ingoing wave angular momentum, and can result in the planet spiralling into the star. However, previous simulations do not find the waves to undergo instability for smaller amplitudes. This work has two aims: to determine any instabilities that set in for small-amplitude waves, and to further understand the breaking...
Training the intern: The value of a pre-intern year in preparing students for practice.
Dare, Anna; Fancourt, Nicholas; Robinson, Elizabeth; Wilkinson, Tim; Bagg, Warwick
2009-08-01
To evaluate the clinical and professional development that occurs during a New Zealand trainee intern year in preparation for the first house officer role. A quantitative questionnaire was distributed to all trainee interns (year 6) and year 5 medical students in New Zealand at the end of the 2007 academic year. This survey assessed self-reported competency and performance across clinical, professional and role development domains. Response rate was 65% (457/702). Compared to year 5 students, trainee interns reported significantly greater competence and performance levels across all three domains. The greatest improvement occurred in the independent performance of procedural skills (trainee interns: 77%, year 5: 35%, p interns: 94%, year 5: 56%, p intern year, 92% of students felt prepared to be a junior doctor, versus only 53% at the end of their 5th year (p intern year is important in preparing graduates for the intern role. The year affords increased responsibility and practical experience, whilst retaining an educational focus, facilitating the move from competence towards performance. Preparedness for practice was substantially higher following the New Zealand trainee intern year than has been reported with other pre-intern placements.
Chefranov, Sergey G
2013-01-01
The condition of internal gravity waves (IGW) parametric excitation in the rotating fluid layer heated from above, with the layer vibration along the vertical axis or with periodic modulation in time of the vertical temperature distribution, is obtained. We show the dual role of the molecular dissipative effects that may lead not only to the wave oscillations damping, but also to emergence of hydrodynamic dissipative instability (DI) in some frequency band of IGW. This DI also may take place for the localized in horizontal plane tornado-like disturbances, horizontal scale of which does not exceed the character vertical scale for the fluid layer of the finite depth. Investigated parametric resonance mechanism of IGW generation in ocean and atmosphere during and before earthquakes allows monitoring of such waves (with double period with respect to the period of vibration or temperature gradient modulation) as precursors of these devastating phenomena.
National Oceanic and Atmospheric Administration, Department of Commerce — The Decade of North American Geology (DNAG) gravity grid values, spaced at 6 km, were used to produce the Gravity Anomaly Map of North America (1987; scale...
Book Review: Is Fair Value Fair? Financial Reporting from an International Perspective
DEFF Research Database (Denmark)
Thinggaard, Frank
2005-01-01
This is a review of Henk Langendijk, Dirk Swagerman and Willem Verhoog (Eds) "Is Fair Value Fair? Financial Reporting from an International Perspective," Chichester: John Wiley, 2003, ISBN 0 470 85028 0.......This is a review of Henk Langendijk, Dirk Swagerman and Willem Verhoog (Eds) "Is Fair Value Fair? Financial Reporting from an International Perspective," Chichester: John Wiley, 2003, ISBN 0 470 85028 0....
Garbarz, Alan; Vásquez, Yerko
2008-01-01
We study exact solutions to Cosmological Topologically Massive Gravity (CTMG) coupled to Topologically Massive Electrodynamics (TME) at special values of the coupling constants. For the particular case of the so called chiral point l\\mu_G=1, vacuum solutions (with vanishing gauge field) are exhibited. These correspond to a one-parameter deformation of GR solutions, and are continuously connected to the extremal Banados-Teitelboim-Zanelli black hole (BTZ) with bare constants J=-lM. In CTMG this extremal BTZ turns out to be massless, and thus it can be regarded as a kind of ground state. For certain range of parameters, our solution exhibits an event horizon located at finite geodesic distance. Although the solution is not asymptotically AdS_3 in the sense of Brown-Henneaux boundary conditions, it does obey the weakened asymptotic recently proposed by Grumiller and Johansson. Consequently, we discuss the computation of the conserved chages in terms of the stress-tensor in the boundary, and we find that the sign...
Directory of Open Access Journals (Sweden)
B. B. Zhao
2011-02-01
Full Text Available A singular value decomposition (SVD program on MATLAB platform was effectively used to handle gravity signals for the Tongshi gold field. Firstly, the gravity signals were decomposed into different eigenimages with the help of singular value decomposition method (SVD. Secondly, the thresholds between the eigenvalues reflecting different layers of ore-controlling factors were established by multi-fractal method. Finally images reflecting different layers of ore-controlling factors were rebuilt. This yielded two layers of two-dimensional singular value images that depict regional and local ore-controlling factors, respectively.
Blainey, J.B.; Ferre, T. P. A.; Cordova, J.T.
2007-01-01
Pumping of an unconfined aquifer can cause local desaturation detectable with high-resolution gravimetry. A previous study showed that signal-to-noise ratios could be predicted for gravity measurements based on a hydrologic model. We show that although changes should be detectable with gravimeters, estimations of hydraulic conductivity and specific yield based on gravity data alone are likely to be unacceptably inaccurate and imprecise. In contrast, a transect of low-quality drawdown data alone resulted in accurate estimates of hydraulic conductivity and inaccurate and imprecise estimates of specific yield. Combined use of drawdown and gravity data, or use of high-quality drawdown data alone, resulted in unbiased and precise estimates of both parameters. This study is an example of the value of a staged assessment regarding the likely significance of a new measurement method or monitoring scenario before collecting field data. Copyright 2007 by the American Geophysical Union.
Dare to Dream: Personal Values, Life Goals, and International Students in New Zealand.
Zhang, Kaili C; Zhang, Abraham
2016-10-12
It has been well identified and supported in the literature that values and life goals are associated with one's general well-being. However, there have been few studies on values and life goals among international students in New Zealand. This study addressed this lack of research by focusing on the life goals and personal values among international students in three tertiary institutes in New Zealand. Based on the literature review, the hypothesis of this study is that international students' intrinsic life goals are positively correlated with their spiritual values. In contrast, extrinsic goals did not have similar effects. The Aspirations Index, which was used to assess life goals, and the Schwartz' value survey, which measured the students' personal values, were both distributed to the participants. Follow-up interviews with 24 of the participants were also conducted. Findings revealed that spiritual values were positively correlated with intrinsic goals and that extrinsic goals did not have similar effects. As the research findings showed that spiritual values were positively correlated with intrinsic goals, helping international students to find meaning and purpose in life may promote their well-being, and the learning and growth of international students can be improved by incorporating spiritual values and cultural aspects in college education. The authors also argue that a holistic approach to college education for international students is needed.
2009-10-09
phenomena came later with Korteweg and de Vries and their description of the KdV solu- tions to the one dimensional problem (see [1]) for a brief... KdV ) equation, which describes the dynamics of weakly- nonlinear dispersive waves, for the internal-waves problem. Under the assumption that the...internal solitary waves are ’long’ and that they are traveling in a ’shallow’ layer (this will be made more precise be- low), the governing ( KdV
Static roll-tilt over 5 minutes locally distorts the internal estimate of direction of gravity.
Tarnutzer, A A; Bockisch, C J; Straumann, D; Marti, S; Bertolini, G
2014-12-01
The subjective visual vertical (SVV) indicates perceived direction of gravity. Even in healthy human subjects, roll angle-dependent misestimations, roll overcompensation (A-effect, head-roll > 60° and <135°) and undercompensation (E-effect, head-roll < 60°), occur. Previously, we demonstrated that, after prolonged roll-tilt, SVV estimates when upright are biased toward the preceding roll position, which indicates that perceived vertical (PV) is shifted by the prior tilt (Tarnutzer AA, Bertolini G, Bockisch CJ, Straumann D, Marti S. PLoS One 8: e78079, 2013). Hypothetically, PV in any roll position could be biased toward the previous roll position. We asked whether such a "global" bias occurs or whether the bias is "local". The SVV of healthy human subjects (N = 9) was measured in nine roll positions (-120° to +120°, steps = 30°) after 5 min of roll-tilt in one of two adaptation positions (±90°) and compared with control trials without adaptation. After adapting, adjustments were shifted significantly (P < 0.05) toward the previous adaptation position for nearby roll-tilted positions (±30°, ±60°) and upright only. We computationally simulated errors based on the sum of a monotonically increasing function (producing roll undercompensation) and a mixture of Gaussian functions (representing roll overcompensation centered around PV). In combination, the pattern of A- and E-effects could be generated. By shifting the function representing local overcompensation toward the adaptation position, the experimental postadaptation data could be fitted successfully. We conclude that prolonged roll-tilt locally distorts PV rather than globally shifting it. Short-term adaptation of roll overcompensation may explain these shifts and could reflect the brain's strategy to optimize SVV estimates around recent roll positions. Thus postural stability can be improved by visually-mediated compensatory responses at any sustained body-roll orientation.
Impact of internal gravity waves on the rotation profile inside pre-main sequence low-mass stars
Charbonnel, C; Amard, L; Palacios, A; Talon, S
2013-01-01
We study the impact of internal gravity waves (IGW), meridional circulation, shear turbulence, and stellar contraction on the internal rotation profile and surface velocity evolution of solar metallicity low-mass pre-main sequence stars. We compute a grid of rotating stellar evolution models with masses between 0.6 and 2.0Msun taking these processes into account for the transport of angular momentum, as soon as the radiative core appears and assuming no more disk-locking from that moment on.IGW generation along the PMS is computed taking Reynolds-stress and buoyancy into account in the bulk of the stellar convective envelope and convective core (when present). Redistribution of angular momentum within the radiative layers accounts for damping of prograde and retrograde IGW by thermal diffusivity and viscosity in corotation resonance. Over the whole mass range considered, IGW are found to be efficiently generated by the convective envelope and to slow down the stellar core early on the PMS. In stars more massi...
Near-surface current meter array measurements of internal gravity waves
Energy Technology Data Exchange (ETDEWEB)
Jones, H.B.E. [Lawrence Livermore National Lab., CA (United States)
1994-11-15
We have developed various processing algorithms used to estimate the wave forms produced by hydrodynamic Internal Waves. Furthermore, the estimated Internal Waves are used to calculate the Modulation Transfer Function (MTF) which relates the current and strain rate subsurface fields to surface scattering phenomenon imaged by radar. Following a brief discussion of LLNL`s measurement platform (a 10 sensor current meter array) we described the generation of representative current and strain rate space-time images from measured or simulated data. Then, we present how our simulation capability highlighted limitations in estimating strain rate. These limitations spurred the application of beamforming techniques to enhance our estimates, albeit at the expense of collapsing our space-time images to 1-D estimates. Finally, we discuss progress with regard to processing the current meter array data captured during the recent Loch Linnhe field trials.
2009-10-09
are compared to results from Korteweg D’Vries theory. Good agreement is obtained for dispersion estimates using wavelet analysis and those from KdV ...analysis and those from KdV theory. 1 Background Internal waves (IWs) occur throughout the world’s oceans and seas. Well known examples in- clude IWs...recognize that KdV theory describes a two-layer model and the IWs under Understanding the Earth as a Complex System 235 investigation occur in a
Holota, Petr; Nesvadba, Otakar
2014-05-01
In geodesy mathematical techniques for gravity field studies that rest on the concept of the so-called classical solution of boundary value problems, have a rather traditional position. Nevertheless, the range of the tools for treating problems in this field is much wider. For instance the concept of the weak solution met with a considerable attention. From this point of view the approach is associated with constructing the respective integral kernels or Green's function in case we consider the classical solution concept or with the choice and constructing basis functions in case we are lucking for the weak solution of the problem. Within the tools considered we discuss also the use of reproducing kernels. In both the cases (classical or weak) the construction of the apparatus above represents and important technical step. It is not elementary, but for a number of fundamental boundary value problems the solution is known, in particular in the case of a spherical solution domain. The sphere, however, is rather far from the real shape of the Earth, which is interpreted here in terms of a functional analytic norm. The distance has a negative effect on any attempt to reach the solution of the boundary value problems considered (and to bridge the departure of the Earth's surface from the sphere) by an iteration procedure based on a successive application of a solution technique developed for the spherical boundary. From this point of view the construction of the integral kernels and basis functions for an oblate ellipsoid of revolution means a step closer towards reality. In this contribution we on the one hand give an overview of the results already achieved and subsequently develop the topic. The summation of series of ellipsoidal harmonics is one of the key problems in this connection. Hypergeometric functions and series are applied too. We also show where the use of Legendre elliptic integrals adds to the solution of the problem. It is interesting that they do not
Properties of internal planetary-scale inertio gravity waves in the mesosphere
Directory of Open Access Journals (Sweden)
H. G. Mayr
2004-11-01
Full Text Available At high latitudes in the upper mesosphere, horizontal wind oscillations have been observed with periods around 10h. Waves with such a period are generated in our Numerical Spectral Model (NSM, and they are identified as planetary-scale inertio gravity waves (IGW. These IGWs have periods between 9 and 11h and appear above 60km in the zonal mean (m=0, as well as in m=1 to 4, propagating eastward and westward. Under the influence of the Coriolis force, the amplitudes of the waves propagating westward are larger at high latitudes than those propagating eastward. The waves grow in magnitude at least up to about 100km and have vertical wavelengths around 25km. Applying a running window of 15 days for spectral analysis, the amplitudes in the wind field are typically between 10 and 20m/s and can reach 30m/s in the westward propagating component for m=1 at the poles. In the temperature perturbations, the wave amplitudes above 100km are typically 5K and as large as 10K for m=0 at the poles. The IGWs are intermittent but reveal systematic seasonal variations, with the largest amplitudes occurring generally in late winter and spring. Numerical experiments show that such waves are also generated without excitation of the migrating tides. The amplitudes and periods then are similar, indicating that the tides are not essential to generate the waves. However, the seasonal variations without tides are significantly different, which leads to the conclusion that non linear interactions between the semidiurnal tide and planetary waves must contribute to the excitation of the IGWs. Directly or indirectly through the planetary waves, the IGWs are apparently excited by the instabilities that arise in the zonal mean circulation. When the solar heating is turned off for m=0, both the PWs and IGWs essentially disappear. That the IGWs and PWs have common roots in their excitation mechanism is also indicated by the striking similarity of their seasonal variations in the
International Diversification, Product Strategy, And Firm Value:Evidence From Korea
Donseung Choi; Eunho Cho
2014-01-01
Existing studies showed inconsistent results for the relationship between international diversification (ID) and firm value. Thus, we primarily examine whether each MNCs product strategy moderates the relationship between ID and firm value. The results show that MNCs product strategy moderates the relationship between ID and firm value as measured by Tobins Q. Specifically, a positive relationship exists between ID and firm value in the firm group pursuing a cost leadership strategy, whereas ...
Maddison, Angus; Ooststroom, Harry van
1993-01-01
This study is part of the ICOP (International Comparison of Output and Productivity) project of the University of Groningen. It presents international comparisons of levels of value added, productivity and purchasing power parities (PPPs) in agriculture for 13 countries for 1975. An early version of
Gubbi, Sathyajit R.; Aulakh, Preet S.; Ray, Sougata; Sarkar, M. B.; Chittoor, Raveendra
2010-01-01
While overseas acquisitions by emerging-economy firms are gaining increased attention from the business press, our understanding of whether and why this inorganic mode of international expansion creates value to acquirer firms is limited. We argue that international acquisitions facilitate internali
Character Values and Their Internalization in Teaching and Learning English at Madrasah
Directory of Open Access Journals (Sweden)
Milad Islami
2016-12-01
Full Text Available Language is more than to express the ideas, believe, and thought or as intellectual based, it also expresses the norms, values, and even emotions. As the result, it is important to internalize the character values into the teaching and learning activity of English. Since the focus of this study was on the analysis of the internalization of character values without any experimental or manipulated settings involved, the design of this study was qualitative. The results showed that there were at least six character values performed by the students in learning English, they were independent, hardworking ethos, curiosity, democratic attitude, communicative manner, and reading interest. In addition, the character values were internalized by the English teacher into the process of teaching and learning even though she did not realize it.
Abdollahi, Alireza; Nozarian, Zohreh
2016-01-01
Background: Accumulation of pleural and peritoneal fluid is seen in some diseases. In order to diagnose the disease and start the treatment, one of the most important actions will be to differentiate between exudates and transudates. The objective of this study was to determine the diagnostic value of measuring the specific gravity of the fluid through refractometer and strip in differentiation of exudates from transudates. Methods: The serum of patients was evaluated for protein, LDH, cholesterol, bilirubin and albumin. The fluid was evaluated for the number of white blood cells, protein, LDH, cholesterol, bilirubin and albumin. Then the fluids were divided into exduate and transudate categories based on Light and Gradient criteria. Finally, the specific gravity of the fluids was measured by refractometer, Erma, Japan and Medi-Test Combi II. The categorized fluids were compared with Gold Standards (final diagnosis) so that the sensitivity and specificity of Light and Gradient criteria in the transudate-exudate differentiation were specified. Results: In comparison with Light criteria, the cut off level of 1022 specific gravity measured by refractometer for pleural effusion has sensitivity, specificity of 92.1%, 68.1%respectively. In evaluation of peritoneal fluid considering cut off point 1023, measured by refractometer has reliable sensitivity 92.4%, specificity 70.4 compared with standard gradient method. Conclusion: Differentiating transudate from exudates by measuring its special gravity by refractometer will have acceptable sensitivity and specificity, and when rapidity is necessary or access to lab equipment is limited, this method could be used. PMID:28855928
Lunar gravity affects leaf movement of Arabidopsis thaliana in the International Space Station.
Fisahn, Joachim; Klingelé, Emile; Barlow, Peter
2015-06-01
Cyclic leaf ascent and descent occur in synchrony and phase congruence with the lunisolar tidal force under a broad range of conditions. Digitized records of the vertical leaf movements of Arabidopsis thaliana were collected under space flight conditions in the International Space Station (ISS). Oscillations of leaf movements with periods of 45 and 90 min were found under light-adapted conditions, whereas in darkness, the periods were 45, 90, and 135 min. To demonstrate the close relationship between these oscillations and cyclical variations of the lunisolar gravitational force, we estimated the oscillations of the in-orbit lunisolar tide as they apply to the ISS, with the aid of the Etide software application. In general, in-orbit lunisolar gravitational profiles exhibited a periodicity of 45 min. Alignment of these in-orbit oscillations with the oscillations of Arabidopsis leaf movement revealed high degrees of synchrony and a congruence of phase. These data corroborate previous results which suggested a correlative relationship and a possible causal link between leaf movement rhythms obtained on ground and the rhythmic variation of the lunisolar tidal force.
Perceived value congruence and attitudes toward international relations and foreign policies
Wetherell, Geoffrey; Benson, Or'Shaundra; Reyna, Christine; Brandt, Mark J
2015-01-01
Much of the justification for granting foreign aid is to support nations and international policies promoting one's national values. However, little to no research has examined how perceptions of similarity between nations, especially value similarity, drive feelings toward other nations and policy
The value relevance of direct cash flows under international financial reporting standards
Clacher, I.; de Ricquebourg, AD; Hodgson, A.
2013-01-01
This study examines if there has been a change in the value relevance of direct cash flow components since the adoption of International Financial Reporting Standards (IFRS) in Australia. Our results show that for both industrial and extractive firms direct cash flow statements are value relevant under Australian Generally Accepted Accounting Principles (AGAAP) and remain so after the adoption of IFRS. In addition, for industrial firms there is a significant increase in the value relevance of...
Initial-value problem for the Gardner equation applied to nonlinear internal waves
Rouvinskaya, Ekaterina; Kurkina, Oxana; Kurkin, Andrey; Talipova, Tatiana; Pelinovsky, Efim
2017-04-01
The Gardner equation is a fundamental mathematical model for the description of weakly nonlinear weakly dispersive internal waves, when cubic nonlinearity cannot be neglected. Within this model coefficients of quadratic and cubic nonlinearity can both be positive as well as negative, depending on background conditions of the medium, where waves propagate (sea water density stratification, shear flow profile) [Rouvinskaya et al., 2014, Kurkina et al., 2011, 2015]. For the investigation of weakly dispersive behavior in the framework of nondimensional Gardner equation with fixed (positive) sign of quadratic nonlinearity and positive or negative cubic nonlinearity {eq1} partial η/partial t+6η( {1± η} )partial η/partial x+partial ^3η/partial x^3=0, } the series of numerical experiments of initial-value problem was carried out for evolution of a bell-shaped impulse of negative polarity (opposite to the sign of quadratic nonlinear coefficient): {eq2} η(x,t=0)=-asech2 ( {x/x0 } ), for which amplitude a and width x0 was varied. Similar initial-value problem was considered in the paper [Trillo et al., 2016] for the Korteweg - de Vries equation. For the Gardner equation with different signs of cubic nonlinearity the initial-value problem for piece-wise constant initial condition was considered in detail in [Grimshaw et al., 2002, 2010]. It is widely known, for example, [Pelinovsky et al., 2007], that the Gardner equation (1) with negative cubic nonlinearity has a family of classic solitary wave solutions with only positive polarity,and with limiting amplitude equal to 1. Therefore evolution of impulses (2) of negative polarity (whose amplitudes a were varied from 0.1 to 3, and widths at the level of a/2 were equal to triple width of solitons with the same amplitude for a 1) was going on a universal scenario with the generation of nonlinear Airy wave. For the Gardner equation (1) with the positive cubic nonlinearity coefficient there exist two one-parametric families of
Nahra, Henry K.; Hall, Nancy R.; Hasan, Mohammad M.; Wagner, James D.; May, Rochelle L.; Mackey, Jeffrey R.; Kolacz, John S.; Butcher, Robert L.; Frankenfield, Bruce J.; Mudawar, Issam;
2013-01-01
Flow boiling and condensation have been identified as two key mechanisms for heat transport that are vital for achieving weight and volume reduction as well as performance enhancement in future space systems. Since inertia driven flows are demanding on power usage, lower flows are desirable. However, in microgravity, lower flows are dominated by forces other than inertia (like the capillary force). It is of paramount interest to investigate limits of low flows beyond which the flow is inertial enough to be gravity independent. One of the objectives of the Flow Boiling and Condensation Flight Experiment sets to investigate these limits for flow boiling and condensation. A two-phase flow loop consisting of a Flow Boiling Module and two Condensation Modules has been developed to experimentally study flow boiling condensation heat transfer in the reduced gravity environment provided by the reduced gravity platform. This effort supports the development of a flow boiling and condensation facility for the International Space Station (ISS). The closed loop test facility is designed to deliver the test fluid, FC-72 to the inlet of any one of the test modules at specified thermodynamic and flow conditions. The zero-g-aircraft tests will provide subcooled and saturated flow boiling critical heat flux and flow condensation heat transfer data over wide range of flow velocities. Additionally, these tests will verify the performance of all gravity sensitive components, such as evaporator, condenser and accumulator associated with the two-phase flow loop. We will present in this paper the breadboard development and testing results which consist of detailed performance evaluation of the heater and condenser combination in reduced and normal gravity. We will also present the design of the reduced gravity aircraft rack and the results of the ground flow boiling heat transfer testing performed with the Flow Boiling Module that is designed to investigate flow boiling heat transfer and
Personal-organisational value conflicts and job satisfaction of internal construction stakeholders
Directory of Open Access Journals (Sweden)
Babak Panahi
2016-03-01
Full Text Available This paper concerns the issue of value conflicts in construction organizations. This research was conducted in the Malaysian construction industry to fill the gap in the knowledge in areas of organizational behaviour in the construction industry in terms of the possible effects of conflicts on the job satisfaction of internal construction stakeholders. The conflicts considered are those rooted in differences between personal and organizational values. This research targeted professional project consultants identified as architects, engineers, and quantity surveyors as the internal construction stakeholders in Malaysia. The personal-organizational values and the level of job satisfaction of the stakeholders were assessed using a questionnaire survey. To achieve the research objective, comparative and hierarchical regression analyses were performed. The results generated by the analyses indicated a high level of value conflicts in the construction organizations which significantly and negatively affected job satisfaction of the internal stakeholders. Therefore this research, through investigating the potential effect of value conflicts on the stakeholders’ job satisfaction, reveals the importance of the interaction between personal and organizational values in construction organizations which contributes to the extant literature of organizational behaviour in construction.
Stochastic gravity: beyond semiclassical gravity
Energy Technology Data Exchange (ETDEWEB)
Verdaguer, E [Departament de Fisica Fonamental and CER en Astrofisica, Fisica de Particules i Cosmologia, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)
2007-05-15
The back-reaction of a classical gravitational field interacting with quantum matter fields is described by the semiclassical Einstein equation, which has the expectation value of the quantum matter fields stress tensor as a source. The semiclassical theory may be obtained from the quantum field theory of gravity interacting with N matter fields in the large N limit. This theory breaks down when the fields quantum fluctuations are important. Stochastic gravity goes beyond the semiclassical limit and allows for a systematic and self-consistent description of the metric fluctuations induced by these quantum fluctuations. The correlation functions of the metric fluctuations obtained in stochastic gravity reproduce the correlation functions in the quantum theory to leading order in an 1/N expansion. Two main applications of stochastic gravity are discussed. The first, in cosmology, to obtain the spectrum of primordial metric perturbations induced by the inflaton fluctuations, even beyond the linear approximation. The second, in black hole physics, to study the fluctuations of the horizon of an evaporating black hole.
Heffron, Sean; Maresco, Peter A.
2014-01-01
The value of an international experience--especially for students of business--continues to be an area of focus at colleges and universities. Students across all disciplines within the business curriculum: accounting, economics, finance, management, marketing, or sport management are expected by employers to possess knowledge of, and appreciation…
Waheed, M.
2013-01-01
The studies in this dissertation collectively show the inclusion and presence of values in international political speeches as well as their effects on citizens’ opinion. As this research path has not yet been explored by previous scholars, this dissertation fills in many gaps in research and
Waheed, M.
2013-01-01
The studies in this dissertation collectively show the inclusion and presence of values in international political speeches as well as their effects on citizens’ opinion. As this research path has not yet been explored by previous scholars, this dissertation fills in many gaps in research and contri
A diagnostic test for apraxia in stroke patients: internal consistency and diagnostic value.
Heugten, C.M. van; Dekker, J.; Deelman, B.G.; Stehmann-Saris, F.C.; Kinebanian, A.
1999-01-01
The internal consistency and the diagnostic value of a test for apraxia in patients having had a stroke are presented. Results indicate that the items of the test form a strong and consistent scale: Cronbach's alpha as well as the results of a Mokken scale analysis present good reliability and good
A Diagnostic Test for Apraxia in Stroke Patients : Internal consistency and diagnostic value
van Heugten, C.M.; Dekker, J.; Deelman, B.G.; Stehmann-Saris, J.C; Kinebanian, A
1999-01-01
The internal consistency and the diagnostic value of a test for apraxia in patients having had a stroke are presented. Results indicate that the items of the test form a strong and consistent scale: Cronbach's alpha as well as the results of a Mokken scale analysis present good reliability and good
International Students' Perceptions of the Value of U.S. Higher Education
Urban, Ewa; Palmer, Louann Bierlein
2016-01-01
We examined international students' perceptions of the personal and professional value they receive from higher education in the United States. Results indicated that students' professional outcomes were significantly lower than their expectations related to their professional development, while students benefited personally to a much greater…
Linton, Dale B.
2015-01-01
In this qualitative grounded theory study, 24 participants, referred to as "third culture kids" (or TCKs), ages 18-30 years, who had previously attended international Christian schools were interviewed to determine the dispositions they valued in their teachers. Incorporating principles of grounded theory, a series of rigorous steps were…
Internal Branding: Using Performance Technology To Create an Organization Focused on Customer Value.
Tosti, Donald T.; Stotz, Rodger
2000-01-01
Presents a performance technology approach to revenue enhancement, with the goal of improving customer retention through building customer value. Topics include internal branding, a way to make sure that what the company delivers matches what's promised in the advertising; product versus service brands; and customer satisfaction, including…
Internal Branding: Using Performance Technology To Create an Organization Focused on Customer Value.
Tosti, Donald T.; Stotz, Rodger
2000-01-01
Presents a performance technology approach to revenue enhancement, with the goal of improving customer retention through building customer value. Topics include internal branding, a way to make sure that what the company delivers matches what's promised in the advertising; product versus service brands; and customer satisfaction, including…
Personal values, subjective well-being and destination-loyalty intention of international students.
Jamaludin, N L; Sam, D L; Sandal, G M; Adam, A A
2016-01-01
What are the factors that predict international students' destination-loyalty intention? This is the main question this paper addresses, using an online survey among 396 (short-term, N = 182) and (long-term, N = 214) international students at a Norwegian university. Structural equation model-AMOS was conducted to examine relationships among personal values, subjective well-being and destination-loyalty intentions. The results showed that: (1) universalism was positively related to subjective well-being for short-term students; and (2) subjective well-being was positively related to destination-loyalty intention for all groups. We found that relatively stable and happy individuals might be important for ensuring destination-loyalty intentions. Results also indicated that personal values that emphasize justice and equity are also important for short-term international students' well-being.
Seeking the Light: Gravity Without the Influence of Gravity
Sack, Fred; Kern, Volker; Reed, Dave; Etheridge, Guy (Technical Monitor)
2002-01-01
All living things sense gravity like humans might sense light or sound. The Biological Research In Canisters (BRIC-14) experiment, explores how moss cells sense and respond to gravity and light. This experiment studies how gravity influences the internal structure of moss cells and seeks to understand the influences of the spaceflight environment on cell growth. This knowledge will help researchers understand the role of gravity in the evolution of cells and life on earth.
The Social Value of Knowledge and the Responsiveness Requirement for International Research.
Wenner, Danielle M
2017-02-01
Ethicists have long recognized that two necessary features of ethical research are scientific validity and social value. Yet despite a significant literature surrounding the validity component of this dictate, until recently there has been little attention paid to unpacking what the social value component might require. This article introduces a framework for assessing the social value of research, and in particular, for determining whether a given research program is likely to have significant social value of the kind necessary to fulfill the social value requirement. The article goes on to illustrate how this framework can provide a clearer account of the responsiveness requirement, an ethical dictum that is oft-repeated but whose content and value as a guideline in international research remains contested. Although I introduce this conception of social value in the context of the responsiveness requirement, the account offered can, and is intended to, stand alone as a tool for the assessment of the social value of research. As such it can be usefully applied to discussions about the value of comparative effectiveness trials, the assessment of the continued proliferation of me-too drugs and the research done to develop them, the demand for public access to study-generated data, and persistent deficits in the publication of negative results. © 2017 John Wiley & Sons Ltd.
Diaz, Pablo; Walton, Mark
2016-01-01
With the aim of investigating the relation between gravity and non-locality at the classical level, we study a bilocal scalar field model. Bilocality introduces new (internal) degrees of freedom that can potentially reproduce gravity. We show that the equations of motion of the massless branch of the free bilocal model match those of linearized gravity. We also discuss higher orders of perturbation theory, where there is self-interaction in both gravity and the bilocal field sectors.
Introduction to Loop Quantum Gravity
Mercuri, Simone
2010-01-01
The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a description of some general arguments and an introduction to the canonical theory of gravity, I review the background independent approach to quantum gravity, giving only a brief survey of Loop Quantum Gravity.
DEFF Research Database (Denmark)
Forsberg, René; Sideris, M.G.; Shum, C.K.
2005-01-01
The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also...... unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges...... is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella "level-2" IAG service (incorporating the International Gravity Bureau, International Geoid Service...
Dani Foo; Bin Liu; Howard Davey
2009-01-01
To gauge the effect of the 2001 official "harmonisation" of the Chinese Accounting Standards (CAS) and International Accounting Standards (IAS) regimes, we examine all companies that simultaneously issued both A and B shares in both the SHSE and SZSE using the Weetman, Jones and Gray (1998) Index of Comparability, testing for differences between companiesâ€™ reported earnings and equities. Ohlsonâ€™s Value Relevance Model (Ohlson, 1995) is also used, associating stock prices with both earning...
THE INTRINSIC EXPLANATORY VALUE OF SOCIAL CONSTRUCTIVISM IN INTERNATIONAL RELATIONS THEORY
Directory of Open Access Journals (Sweden)
Ts. V. Karkalanov
2016-01-01
Full Text Available Why has constructivism emerged as an important force in the field of international relations and politics in the end of the 20th century? Why constructivism and not any other theoretical approach? The constructivist perspective of international relations appeared as a counterbalance to rationalism that was entrenched in US Political Science throughout the last decades. Analyzing the contemporary state of world affairs through the prism of social constructivism provides us with a unique understanding of how intersubjective perceptions lead to unique epistemic interpretations of reality, which form the ideological framework within which social constructs are being generated. Constructivism succeeds not only in identifying the motives behind the behavior of international actors, but also in unfolding the mechanism through which those motives are being envisaged and accepted through the process of social construction – here lies the greatest value of the constructivist approach in IR theory. Culture formation, nation building, imagined communities, security complexes – the constructivist approach remains an invaluable tool in the arsenal of political analysts, seeking to understand how culture, history, social order, religion, and language project their infl uence on the international arena and ultimately: why international players behave the way they do?
Galanti, Eli; Kaspi, Yohai
2016-10-01
In light of the first orbits of Juno at Jupiter, we discuss the Juno gravity experiment and possible initial results. Relating the flow on Jupiter and Saturn to perturbations in their density field is key to the analysis of the gravity measurements expected from both the Juno (Jupiter) and Cassini (Saturn) spacecraft during 2016-17. Both missions will provide latitude-dependent gravity fields, which in principle could be inverted to calculate the vertical structure of the observed cloud-level zonal flow on these planets. Current observations for the flow on these planets exists only at the cloud-level (0.1-1 bar). The observed cloud-level wind might be confined to the upper layers, or be a manifestation of deep cylindrical flows. Moreover, it is possible that in the case where the observed wind is superficial, there exists deep interior flow that is completely decoupled from the observed atmospheric flow.In this talk, we present a new adjoint based inverse model for inversion of the gravity measurements into flow fields. The model is constructed to be as general as possible, allowing for both cloud-level wind extending inward, and a decoupled deep flow that is constructed to produce cylindrical structures with variable width and magnitude, or can even be set to be completely general. The deep flow is also set to decay when approaching the upper levels so it has no manifestation there. The two sources of flow are then combined to a total flow field that is related to the density anomalies and gravity moments via a dynamical model. Given the measured gravitational moments from Jupiter and Saturn, the dynamical model, together with the adjoint inverse model are used for optimizing the control parameters and by this unfolding the deep and surface flows. Several scenarios are examined, including cases in which the surface wind and the deep flow have comparable effects on the gravity field, cases in which the deep flow is dominating over the surface wind, and an extreme
DEFF Research Database (Denmark)
Kumar, Rajesh; Nti, Kofi O
2004-01-01
discrepancies that may emerge during the course of an alliance. They argue that national culture affects alliance evolution by influencing partners sensitivity to discrepancy detection , shaping the nature of attributions they make, and by affecting the partners reactions to discrepancies. They focus...... on differences in three value orientations among cultures. activity orientation, mastery over nature, and assumptions about human nature are the value orientations that affect alliance functioning. The author/s argue that alliances are prone to interpretational, attributional, and behavioral conflicts......The article assesses the role played by national cultural values in shaping the evolution of international strategic alliances. The authors build on a systems dynamic model of alliance evolution in which the developmental path of an alliance depends on how the partners manage process and outcome...
Cram, Jennifer M.; Pielke, Roger A.; Cotton, William R.
1992-01-01
Results of an observational and numerical study of the squall line that occurred on June 17-18, 1978, are presented. This squall line was initially triggered by the strong surface convergence along a cold front and stretched from Illinois to the Texas Panhandle. The squall line was aligned with the surface front during its initial development, but then propagated faster than the front, resulting in a separation of approximately 200 km by 0300 UTC and 300-400 km by 0600 UTC. The Colorado State University Regional Atmospheric Modeling System is used to model the squall-line development and propagation. Results are described from several experiments that tested the sensitivity to the use of the Kuo-type cumulus parameterization scheme and grid-scale microphysical processes. The movement of the squall line in the model is shown to be due to the propagation of a deep tropospheric internal gravity wave in a CISK-like process. The thermal and dynamic perturbations associated with the hypothesized wave are shown to be consistent with internal gravity wave theory.
A commitment to high-value care education from the internal medicine community.
Smith, Cynthia D; Levinson, Wendy S
2015-05-05
The Alliance for Academic Internal Medicine, American Board of Internal Medicine (ABIM), ABIM Foundation, and American College of Physicians are collaborating to enhance the education of physicians in high-value care (HVC) and make its practice an essential competency in undergraduate and postgraduate education by 2017. This article serves as the organizations' formal commitment to providing a foundation of HVC education on which others may build. The 5 key targets for HVC education are experiential learning and curriculum, environment and culture, clinical support, regulatory requirements, and sustainability. The goal is to train future health care professionals for whom HVC is part of normal practice, thus providing patients with improved clinical outcomes at a lower cost.
`Iconoclastic', Categorical Quantum Gravity
Raptis, I
2005-01-01
This is a two-part, `2-in-1' paper. In Part I, the introductory talk at `Glafka--2004: Iconoclastic Approaches to Quantum Gravity' international theoretical physics conference is presented in paper form (without references). In Part II, the more technical talk, originally titled ``Abstract Differential Geometric Excursion to Classical and Quantum Gravity'', is presented in paper form (with citations). The two parts are closely entwined, as Part I makes general motivating remarks for Part II.
Arambewela, Rodney; Hall, John
2013-01-01
The article investigates the interactional effects of internal and external university learning environments, and the influence of personal values, in the satisfaction formation process of international postgraduate students from Asia. Past research on student satisfaction has been narrowly focused on certain aspects of the university internal…
Arambewela, Rodney; Hall, John
2013-01-01
The article investigates the interactional effects of internal and external university learning environments, and the influence of personal values, in the satisfaction formation process of international postgraduate students from Asia. Past research on student satisfaction has been narrowly focused on certain aspects of the university internal…
National Research Council Canada - National Science Library
de Rham, Claudia
2014-01-01
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP...
Claudia de Rham
2016-01-01
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...
de Rham, Claudia
2014-01-01
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...
2014-01-01
We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...
Bianchi, Eugenio
The following sections are included: * Introduction * Topological Field Theory and Gravity * Classical Spinfoam Gravity: Degrees of Freedom and Foams * Unitary Representations of the Rotation and the Lorentz Group * Boundary Variables and the Loop Quantum Gravity Hilbert Space * Spinfoam Partition Function and the Vertex Amplitude * Cellular Quantum Geometry: A Single Atom of Space * Cellular Quantum Geometry: Coherent Spin-networks * Vertex-amplitude Asymptotics and Regge Gravity * Reconstructing a Semiclassical Spacetime * Conclusions * References
Kaladze, Tamaz; Kahlon, Laila
Nonlinear dynamics of coupled internal-gravity (IG) and alfven electromagnetic planetary waves in the weakly ionized ionospheric E-layer is investigated. Under such coupling new type of alfven waves is revealed. It is shown that such short wavelength turbulence of IG and alfvén waves is unstable with respect to the excitation of low-frequency and large-scale perturbations of the zonal flow and magnetic field. A set of coupled equations describing the nonlinear interaction of coupled IG and alfven waves with zonal flows is derived. The nonlinear mechanism of the instability is driven by the advection of vorticity and is based on the parametric excitation of convective cells by finite-amplitude coupled IG and alfven waves leading to the inverse energy cascade toward the longer wavelength. The growth rates of the corresponding instability and the conditions for driving them are determined. The possibility of generation of the intense mean magnetic field is shown.
Almaz, Ekrem
2015-05-01
Internal bremsstrahlung (IB) accompanying the β(-) decay of (204)Tl was measured using a 5.08×5.08cm(2) NaI(Tl) detector employing a magnetic deflection method in the range of 10-760keV. A novel approach, the Singular Value Decomposition (SVD), is applied to unfold the raw detector spectrum of (204)Tl. Unfolded IB spectrum is compared with the KUB theory. The measured spectrum is found to show fairly good agreement with the KUB theory in the energy range of 100-600keV. The distribution beyond the 600keV takes a positive deviation from the theory. Copyright © 2015. Published by Elsevier Ltd.
Exposure limits for nanoparticles: report of an international workshop on nano reference values.
van Broekhuizen, Pieter; van Veelen, Wim; Streekstra, Willem-Henk; Schulte, Paul; Reijnders, Lucas
2012-07-01
This article summarizes the outcome of the discussions at the international workshop on nano reference values (NRVs), which was organized by the Dutch trade unions and employers' organizations and hosted by the Social Economic Council in The Hague in September 2011. It reflects the discussions of 80 international participants representing small- and medium-size enterprises (SMEs), large companies, trade unions, governmental authorities, research institutions, and non-governmental organizations (NGOs) from many European countries, USA, India, and Brazil. Issues that were discussed concerned the usefulness and acceptability of precaution-based NRVs as a substitute for health-based occupational exposure limits (OELs) and derived no-effect levels (DNELs) for manufactured nanoparticles (NPs). Topics concerned the metrics for measuring NPs, the combined exposure to manufactured nanomaterials (MNMs) and process-generated NPs, the use of the precautionary principle, the lack of information about the presence of nanomaterials, and the appropriateness of soft regulation for exposure control. The workshop concluded that the NRV, as an 8-h time-weighted average, is a comprehensible and useful instrument for risk management of professional use of MNMs with a dispersible character. The question remains whether NRVs, as advised for risk management by the Dutch employers' organization and trade unions, should be under soft regulation or that a more binding regulation is preferable.
Development of a high-value care subscore on the internal medicine in-training examination.
Ryskina, Kira L; Korenstein, Deborah; Weissman, Arlene; Masters, Philip; Alguire, Patrick; Smith, Cynthia D
2014-11-18
Although high-value care (HVC) that balances benefits of tests or treatments against potential harms and costs has been a recently emphasized competency for internal medicine (IM) residents, few tools to assess residents' knowledge of HVC are available. To describe the development and initial results of an HVC subscore of the Internal Medicine In-Training Examination (IM-ITE). The HVC concepts were introduced to IM-ITE authors during question development. Three physicians independently reviewed each examination question for selection in the HVC subscore according to 6 HVC principles. The final subscore was determined by consensus. Data from the IM-ITE administered in October 2012 were analyzed at the program level. U.S. IM residency programs. 362 U.S. IM residency programs with IM-ITE data for at least 10 residents. Program-level performance on the HVC subscore was compared with performance on the overall IM-ITE, the Dartmouth Atlas hospital care intensity (HCI) index of the program's primary training hospital, and residents' attitudes about HVC assessed with a voluntary survey. The HVC subscore comprised 38 questions, including 21 (55%) on managing conservatively when appropriate and 14 (37%) on identifying low-value care. Of the 362 U.S. IM programs in the sample, 41% were in a different quartile when ranked based on the HVC subscore compared with overall IM-ITE performance. Rankings by HVC subscore and HCI index were modestly inversely associated, with 30% of programs ranked in the same quartile based on both measures. Knowledge of HVC assessed from examination vignettes may not reflect practice of HVC. Although the HVC subscore has face validity and can contribute to evaluation of residents' HVC knowledge, additional tools are needed to accurately measure residents' proficiency in HVC. None.
National Research Council Canada - National Science Library
Hanson, Trevor; Cameron, Coady; Hildebrand, Eric
2014-01-01
International roughness index (IRI) values were calculated from multi-step processing of accelerometer data collected using three smartphone devices in three consumer vehicles under 11 test scenarios on a 1000 m stretch of secondary...
Durante, D.; Iess, L.; Racioppa, P.; Armstrong, J. W.; Lunine, J. I.; Stevenson, D. J.; Tortora, P.
2016-12-01
Since its arrival at Saturn in 2004, Cassini performed nine flybys devoted to the determination of Titan's gravity field and its tidal variations. The last gravity flyby of the mission (T122) took place on Aug. 10, 2016. We will present an updated gravity solution, based on all available data. These include also an additional flyby (T110, March 2015, primarily devoted to the imaging Titan's north polar lakes) carried out with the low gain antenna. This flyby was particularly valuable because closest approach occurred at high latitude (75°N), over an area not previously sampled. Published gravity results (Iess et al., 2012) indicated that Titan is subject to large eccentricity tides in response to Saturn's time varying forcing field. The magnitude of the response quadrupole field, controlled by the Love number k2, was used to infer the existence of an internal ocean. The new gravity field determination provides a better estimate of k2, to a level of a few percent. In addition to a full 3x3 field, the new solution includes also higher degree and order harmonic coefficients (such as J4) and offers an improved map of gravity anomalies. The updated geoid and its associated uncertainty could be used to refine the gravity-altimetry correlative analysis and for improved interpretation of radar altimetric data.
Urban, Ewa L.
2012-01-01
This study used a cross-sectional survey to examine the perceptions of undergraduate and graduate international students enrolled at a public university in the Midwest, regarding the personal and professional value they receive from their higher education experience. In addition, the study explored international students' perceptions of the…
Rivas-Ruiz, R; Méndez-Sánchez, L; Castelán-Martínez, O D; Clark, P; Tamayo, J; Talavera, J O; Huitrón, G; Salmerón-Castro, J
2016-01-01
The aim of this study was to compare international reference values (RV) for tibial and radial speed of sound (SoS) assessed by quantitative ultrasound (QUS) in pediatric populations. These values were compared by age and country of origin in a systematic review with meta-analysis from studies published on QUS (Sunlight Omnisense). A search was carried out in electronic databases. Nine studies with 6963 patients were included in the meta-analysis. For the newborn populations, 3 studies (from Italy, Portugal, and Israel) were used. These studies included subjects with 27-42 wk gestational age. The mean difference (Portugal-Israel) was found to be 23.62 m/s [95% confidence interval [CI] 6.29, 40.95]. Additionally, no difference was found between Italy-Portugal (p = 0.69), or Italy-Israel (p = 0.28). In pediatric populations, we compared 8 studies from Canada, Mexico, Israel, Greece, Portugal, and Turkey. No significant differences found for SoS RV between Israel-Turkey, Israel-Greece, or Israel-Canada (p > 0.05). Significant differences were found in Mexico-Israel -105.29 m/s (95% CI -140.05, -70.54) (p pediatric populations between Mexico and other countries (Israel, Portugal, Greece, Turkey, and Canada).
Gravity currents at Ormen Lange
Energy Technology Data Exchange (ETDEWEB)
Vikeboe, Frode; Berntsen, Jarle; Furnes, Gunnar
2001-12-01
Time series of temperature and velocities at Ormen Lange, located in the Storegga region off mid-Norway, indicate that close to the seabed, at depths ranging from 500-1000 m, large temperature fluctuations are accompanied by short peak values in speed. The extreme events are driven by strong pressure gradients, due to strong atmospheric low pressures and/or internal pressure fronts between warmer Atlantic Water (AW) and colder Norwegian Sea Water (NSW). Along the shelf slope at OL we may get steepening of the iso surfaces of density, separating AW and NSW, due to strong Ekman veering during storms or approaching internal density fronts. During such events the density surfaces tend to undershoot their equilibrium level, and as the forcing weakens, the suppressed water may run up along the shelf slope. In this run up phase, peak values in the velocities are often found. As a result of the run up phase, heavy water may be elevated onto the shelf. Subsequently dense fluid will spread under the influence of forces produced by its own buoyancy and motions of this form are often referred to as gravity currents. They are characterised by the distinctive nature of the front, which consists of a raised head leading a shallower flow behind. The shape of the head and body of the gravity current, along with velocity, depend on a range of parameters. This report investigates the velocities that may occur with parameters of relevance for Ormen Lange. (author)
Finnegan, Alan; Finnegan, Sara; McKenna, Hugh; McGhee, Stephen; Ricketts, Lynda; McCourt, Kath; Warren, Jem; Thomas, Mike
2016-01-01
Between 2001 and 2014, British military nurses served in Afghanistan caring for both Service personnel and local nationals of all ages. However, there have been few research studies assessing the effectiveness of the military nurses' operational role and no papers naming the core values and characteristics. This paper is from the only qualitative nursing study completed during this period where data was collected in the War Zone. To explore the characteristics and values that are intrinsic to military nurses in undertaking their operational role. A constructivist grounded theory was utilised. The authors designed the interview schedule, and then following a pilot study, conducted and transcribed the discussions. Informed consent and UK Ministry of Defence Research Ethical Committee approval was obtained. Camp Bastion Hospital, Afghanistan, in 2013. Semi-structured interviews were conducted with 18 British Armed Forces nurses. A theoretical model was developed that identifies the intrinsic characteristics and values required to be a military nurse. Nursing care delivered within the operational environment was perceived as outstanding. Nurses consciously detached themselves from any legal processes and treated each casualty as a vulnerable patient, resulting in care, compassion and dignity being provided for all patients, irrespective of their background, beliefs or affiliations. The study findings provide military nurses with a framework for a realistic personal development plan that will allow them to build upon their strengths as well as to identify and ameliorate potential areas of weakness. Placing nurses first, with a model that focusses on the requirements of a good nurse has the potential to lead to better patient care, and improve the quality of the tour for defence nurses. These findings have international implications and have the potential for transferability to any level of military or civilian nursing practice. Crown Copyright © 2015. Published by
Cotte, Michel
2015-08-01
Practical approach of Dark Sky places as possible WH sites leads some of us to underline the exceptional role of high mountain observatories as “Windows to the Universe” for the Human being. Till today, such places keep very important dark sky properties and consequently important astronomical functions.We have to take count that quality of the sky at a given place and dark sky conservation policy is something very important, but not enough by itself to justify inscription on the WH List. It must be related to important cultural or/and natural value. That means presence of significant heritage features in the field of astronomy and science for listing as WH cultural property, or with other natural attributes of exceptional significance to be listed as WH natural property. Case of both natural and cultural WH high value place is also possible as “mixt WH site”.The Dark Sky place must also meet to a sufficient integrity/authenticity degree for the today tangible heritage of astronomy and to a very significant contribution to the international history of science and astronomy as intangible attribute of the place. That point must be demonstrated by a serious comparative analysis with similar places in the world and in the region. In case of serial nomination as examined there, each individual site must contribute significantly to the Outstanding Universal Value of the global series.First, we intend to give a short account of the today trend for a possible serial nomination of the most significant high mountain observatory keeping important heritage of their major periods for the sky observation (Western Europe, Chile, North America, etc.).Second, communication will present a case study with Pic du Midi in French Pyrenees, coming from the early origin of mountain scientific stations and observatories (end of 19th C) in Europe, with a long, continuous and important astronomical and scientific history till today with active programs of sky and atmosphere
Campbell, Joyce K; Ortiz, Michael V; Ottolini, Mary C; Birch, Sarah; Agrawal, Dewesh
2017-04-01
Optimizing clinical proficiency and education of residents has become more important with restricted residency duty hours. Our objective was to investigate how interns spend their time on inpatient rotations and the perceived educational value of workday activities. We performed a descriptive self-work sampling study using a personal digital assistant (PDA) to randomly query interns on inpatient rotations in real time regarding their activity and the perceived educational value of that activity on a 4-point Likert scale. A total of 31 interns participated on 88 workdays over a 5-month period, generating 2082 samples from which the average workday was modeled. Time spent using the electronic health record (EHR) accounted for 33% of intern time, communicating with the health care team 23%, educational activities 17%, and time with patients and families 12%. Time with patients and families was perceived to be the most educational part of clinical service. Time spent using the EHR was perceived as the least educational. Interns perceived clinical service as excellent or good 37% of the time, while planned educational activities were perceived as excellent or good 81% of the time. Interns spend the majority of their time using the EHR and communicating with the health care team. Interns perceive time spent in planned educational activities has more educational value than time spent in clinical service. The distribution of daily activities is discordant with the perceived educational value of those activities. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.
Scherer, G F E; Pietrzyk, P
2014-01-01
Arabidopsis roots on 45° tilted agar in 1-g grow in wave-like figures. In addition to waves, formation of root coils is observed in several mutants compromised in gravitropism and/or auxin transport. The knockdown mutant ppla-I-1 of patatin-related phospholipase-A-I is delayed in root gravitropism and forms increased numbers of root coils. Three known factors contribute to waving: circumnutation, gravisensing and negative thigmotropism. In microgravity, deprivation of wild type (WT) and mutant roots of gravisensing and thigmotropism and circumnutation (known to slow down in microgravity, and could potentially lead to fewer waves or increased coiling in both WT and mutant). To resolve this, mutant ppla-I-1 and WT were grown in the BIOLAB facility in the International Space Station. In 1-g, roots of both types only showed waving. In the first experiment in microgravity, the mutant after 9 days formed far more coils than in 1-g but the WT also formed several coils. After 24 days in microgravity, in both types the coils were numerous with slightly more in the mutant. In the second experiment, after 9 days in microgravity only the mutant formed coils and the WT grew arcuated roots. Cell file rotation (CFR) on the mutant root surface in microgravity decreased in comparison to WT, and thus was not important for coiling. Several additional developmental responses (hypocotyl elongation, lateral root formation, cotyledon expansion) were found to be gravity-influenced. We tentatively discuss these in the context of disturbances in auxin transport, which are known to decrease through lack of gravity. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.
Disinvestment and Value-Based Purchasing Strategies for Pharmaceuticals: An International Review.
Parkinson, Bonny; Sermet, Catherine; Clement, Fiona; Crausaz, Steffan; Godman, Brian; Garner, Sarah; Choudhury, Moni; Pearson, Sallie-Anne; Viney, Rosalie; Lopert, Ruth; Elshaug, Adam G
2015-09-01
mainly taken the form of price reductions, especially when market failures are perceived to exist, and restricting treatment to subpopulations, particularly when a drug is no longer considered value for money. There is considerable experimentation internationally in mechanisms for disinvestment and the opportunity for countries to learn from each other. Ongoing evaluation of disinvestment strategies is essential, and ought to be reported in the peer-reviewed literature.
Absolute Gravity Datum in the Age of Cold Atom Gravimeters
Childers, V. A.; Eckl, M. C.
2014-12-01
The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant
Thiemann, Franziska; Fleming, Euan M.; Mueller, Rolf A.E.
2012-01-01
Globalization results when markets become more integrated because of reduced transaction and transport costs. These costs have fallen because of sustained advances in transport technology and, more dramatically, in digital information and communication technology (ICT). Although communication costs tend to be a minor component of total trading costs, reductions in these costs may strongly stimulate international trade. The empirical evidence in support of this effect is, however, scant and it...
Deciphering Jupiter's atmospheric dynamics using the upcoming Juno gravity measurements
Kaspi, Yohai; Galanti, Eli
2016-07-01
This summer, the Juno spacecraft will arrive at Jupiter in course for close flybys of the planet, obtaining a high precision gravity spectrum of Jupiter. This data can be used to estimate the depth of Jupiter's observed cloud-level wind, and decipher the possible internal flows, that might be decoupled from the surface wind. In this talk, we discuss the Juno gravity experiment, and the possible outcomes with regard to the flows on Jupiter. We show several ways in which the gravity spectrum might be used to study the large scale flows: 1. measurements of the high order even harmonics which beyond J10 are dominated by the dynamics; 2. measurements of odd gravity harmonics which have no contribution from a static planet, and therefore are a pure signature of dynamics; 3. upper limits on the depth of the surface flow can be obtained by comparing low order even harmonics from dynamical models to the difference between the measured low order even harmonics and the largest possible values of a static planet; 4. direct latitudinally varying measurements of the gravity field exerted on the spacecraft. We will discuss how these methods may be applied given the expected sensitivities of the Juno gravity experiment. In addition, we present an inverse adjoint model, which allows given the gravity data, to infer the flows that produce it. This will allow, hopefully, to make significant progress in one of the longest-standing question in planetary atmospheric dynamics regarding the nature of the flows on the giant planets.
Energy Technology Data Exchange (ETDEWEB)
Healey, D.L. [Geological Survey, Denver, CO (USA)
1983-12-31
A large density contrast exists between the Paleozoic rocks (including the rocks of Climax stock) and less dense, Tertiary volcanic rocks and alluvium. This density contrast ranges widely, and herein for interpretive purposes, is assumed to average 0.85 Mg/m{sup 3} (megagrams per cubic meter). The large density contrast makes the gravity method a useful tool with which to study the interface between these rock types. However, little or no density contrast is discernible between the sedimentary Paleozoic rocks that surround the Climax stock and the intrusive rocks of the stock itself. Therefore the gravity method can not be used to define the configuration of the stock. Gravity highs coincide with outcrops of the dense Paleozoic rocks, and gravity lows overlie less-dense Tertiary volcanic rocks and Quaternary alluvium. The positions of three major faults (Boundary, Yucca, and Butte faults) are defined by steep gravity gradients. West of the Climax stock, the Tippinip fault has juxtaposed Paleozoic rocks of similar density, and consequently, has no expression in the gravity data in that area. The gravity station spacing, across Oak Spring Butte, is not sufficient to adequately define any gravity expression of the Tippinip fault. 18 refs., 5 figs.
Rouvinskaya, Ekaterina; Kurkin, Andrey; Kurkina, Oxana
2017-04-01
Intensive internal gravity waves influence bottom topography in the coastal zone. They induce substantial flows in the bottom layer that are essential for the formation of suspension and for the sediment transport. It is necessary to develop a mathematical model to predict the state of the seabed near the coastline to assess and ensure safety during the building and operation of the hydraulic engineering constructions. There are many models which are used to predict the impact of storm waves on the sediment transport processes. Such models for the impact of the tsunami waves are also actively developing. In recent years, the influence of intense internal waves on the sedimentation processes is also of a special interest. In this study we adapt one of such models, that is based on the advection-diffusion equation and allows to study processes of resuspension under the influence of internal gravity waves in the coastal zone, for solving the specific practical problems. During the numerical simulation precomputed velocity values are substituted in the advection - diffusion equation for sediment concentration at each time step and each node of the computational grid. Velocity values are obtained by the simulation of the internal waves' dynamics by using the IGW Research software package for numerical integration of fully nonlinear two-dimensional (vertical plane) system of equations of hydrodynamics of inviscid incompressible stratified fluid in the Boussinesq approximation bearing in mind the impact of barotropic tide. It is necessary to set the initial velocity and density distribution in the computational domain, bottom topography, as well as the value of the Coriolis parameter and, if necessary, the parameters of the tidal wave to carry out numerical calculations in the software package IGW Research. To initialize the background conditions of the numerical model we used data records obtained in the summer in the southern part of the shelf zone of Sakhalin Island
Mashhoon, Bahram
2017-01-01
Relativity theory is based on a postulate of locality, which means that the past history of the observer is not directly taken into account. This book argues that the past history should be taken into account. In this way, nonlocality---in the sense of history dependence---is introduced into relativity theory. The deep connection between inertia and gravitation suggests that gravity could be nonlocal, and in nonlocal gravity the fading gravitational memory of past events must then be taken into account. Along this line of thought, a classical nonlocal generalization of Einstein's theory of gravitation has recently been developed. A significant consequence of this theory is that the nonlocal aspect of gravity appears to simulate dark matter. According to nonlocal gravity theory, what astronomers attribute to dark matter should instead be due to the nonlocality of gravitation. Nonlocality dominates on the scale of galaxies and beyond. Memory fades with time; therefore, the nonlocal aspect of gravity becomes wea...
Directory of Open Access Journals (Sweden)
Sugiyarti Fatma Laela
2016-10-01
Full Text Available Lingkungan bisnis yang semakin dinamis yang berdampak pada perubahan operasional bisnis juga direspon oleh audit internal. Audit internal yang pada awalnya difokuskan sebagai penilai independen, kemudian semakin luas fungsi dan perannya untuk memastikan efektifitas internal control dan selanjutnya aktif terlibat dalam proses risk management yang merupakan bagian dari corporate governance. Dengan metode kajian literatur, tulisan ini akan membahas peran penting auditor internal dalam meningkatkan nilai perusahaan. Selain keterlibatannya dalam pengembangan sistem pengendalian internal, hasil pekerjaan auditor internal sangat menentukan reliance ekternal audit dan komite audit dalam mengevaluasi dan memeriksa kinerja manajemen. Pekerjaan audit internal menjadi semakin komplek dan rumit yang dapat mempengaruhi kualitas pekerjaannya. Seiring dengan semakin diversified-nya organisasi dan kemajuan teknologi auditor internal dituntut untuk menguasai pengetahuan yang beragam dan mendalam baik dari sisi general technical knowledge maupun specific technical knoweldge sesuai dengan industrinya. Oleh karena itu, tulisan ini juga akan membahas indikator kualitas auditor, tantangan yang dihadapi serta solusinya. Salah satu upaya peningkatan kualitas kerja auditor internal adalah melalui outsourcing fungsi auditÂ internal.
Study of values and interpersonal perception in cosmonauts on board of international space station
Vinokhodova, A. G.; Gushin, V. I.
2014-01-01
The increased heterogeneity of International Space Station (ISS) crews' composition (in terms of nationality, profession and gender) together with stressful situations, due to space flight, can have a significant impact on group interaction and cohesion, as well as on communications with Mission Control Center (MCC) and the success of the mission as a whole. Culturally related differences in values, goals, and behavioral norms could influence mutual perception and, thus, cohesive group formation. The purpose of onboard "Interaction-Attitudes" experiment is to study the patterns of small group (space crew) behavior in extended space flight. Onboard studies were performed in the course of ISS Missions 19-30 with participation of twelve Russian crewmembers. Experimental schedule included 3 phases: preflight training and Baseline Data Collection; inflight activities once in two weeks; post-flight measurement. We used Personal Self-Perception and Attitudes (PSPA) software for analyzing subjects' attitudes toward social environment (crewmembers and MCC). It is based on the semantic differential and the repertory grid technique. To study the content of interpersonal perception we used content-analysis with participation of the experts, independently attributing each construct to the 17 semantic categories, which were described in our previous study. The data obtained demonstrated that the system of values and personal attitudes in the majority of participated cosmonauts remained mostly stable under stress-factors of extended space flight. Content-analysis of the important criteria elaborated by the subjects for evaluation of their social environment, showed that the most valuable personal traits for cosmonauts were those that provided the successful fulfillment of professional activity (motivation, intellectual level, knowledge, and self-discipline) and good social relationships (sociability, friendship, and tolerance), as well. Post-flight study of changes in perceptions
Clément, Gilles
2007-01-01
Protecting the health, safety, and performance of exploration-class mission crews against the physiological deconditioning resulting from long-term weightlessness during transit and long-term reduced gravity during surface operations will require effective, multi-system countermeasures. Artificial gravity, which would replace terrestrial gravity with inertial forces generated by rotating the transit vehicle or by short-radius human centrifuge devices within the transit vehicle or surface habitat, has long been considered a potential solution. However, despite its attractiveness as an efficient
Lexa, Frank James; Berlin, Jonathan W
2005-03-01
In this article, the authors cover tools for financial modeling. Commonly used time lines and cash flow diagrams are discussed. Commonly used but limited terms such as payback and breakeven are introduced. The important topics of the time value of money and discount rates are introduced to lay the foundation for their use in modeling and in more advanced metrics such as the internal rate of return. Finally, the authors broach the more sophisticated topic of net present value.
Transplanckian inflation as gravity echoes
Energy Technology Data Exchange (ETDEWEB)
Barenboim, G., E-mail: Gabriela.Barenboim@uv.es; Vives, O.
2015-09-02
In this work, we show that, in the presence of non-minimal coupling to gravity, it is possible to generate sizeable tensor modes in single-field models without transplanckian field values. These transplanckian field values apparently needed in Einstein gravity to accommodate the experimental results may only be due to our insistence of imposing a minimal coupling of the inflaton field to gravity in a model with non-minimal couplings. We present three simple single-field models that prove that it is possible to accommodate a large tensor-to-scalar ratio without requiring transplanckian field values within the slow-roll regime.
DEFF Research Database (Denmark)
Kumar, Rajesh; Nti, Kofi O
2004-01-01
on differences in three value orientations among cultures. activity orientation, mastery over nature, and assumptions about human nature are the value orientations that affect alliance functioning. The author/s argue that alliances are prone to interpretational, attributional, and behavioral conflicts...... originating from differences in value orientations among partners. The three value orientations are shown to be the most useful in explaining the dynamics of alliances....
Lujan, Richard E.
2001-01-01
A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.
Roth, Guy; Kanat-Maymon, Yaniv; Bibi, Uri
2011-01-01
Background: This study examined students' perceptions of autonomy-supportive teaching (AST) and its relations to internalization of pro-social values and bullying in class. Aims: We hypothesized that: (1) teachers' AST, which involves provision of rationale and taking the student's perspective, would relate positively to students' identified…
Do employers value international study and internships? A comparative analysis of 31 countries
Van Mol, C.
2017-01-01
International student mobility is often promoted as enhancing graduates’ employability in globalised labour markets. Nevertheless, empirical evidence on this assumed causal link remains limited. Particularly the perspectives of employers remains understudied. Therefore, in this paper I analyse (1)
Fritts, David
1987-02-01
Gravity waves contributed to the establishment of the thermal structure, small scale (80 to 100 km) fluctuations in velocity (50 to 80 m/sec) and density (20 to 30%, 0 to peak). Dominant gravity wave spectrum in the middle atmosphere: x-scale, less than 100 km; z-scale, greater than 10 km; t-scale, less than 2 hr. Theorists are beginning to understand middle atmosphere motions. There are two classes: Planetary waves and equatorial motions, gravity waves and tidal motions. The former give rise to variability at large scales, which may alter apparent mean structure. Effects include density and velocity fluctuations, induced mean motions, and stratospheric warmings which lead to the breakup of the polar vortex and cooling of the mesosphere. On this scale are also equatorial quasi-biennial and semi-annual oscillations. Gravity wave and tidal motions produce large rms fluctuations in density and velocity. The magnitude of the density fluctuations compared to the mean density is of the order of the vertical wavelength, which grows with height. Relative density fluctuations are less than, or of the order of 30% below the mesopause. Such motions may cause significant and variable convection, and wind shear. There is a strong seasonal variation in gravity wave amplitude. Additional observations are needed to address and quantify mean and fluctuation statistics of both density and mean velocity, variability of the mean and fluctuations, and to identify dominant gravity wave scales and sources as well as causes of variability, both temporal and geographic.
Newburgh, Ronald
2010-01-01
It's both surprising and rewarding when an old, standard problem reveals a subtlety that expands its pedagogic value. I realized recently that the role of gravity in the range equation for a projectile is not so simple as first appears. This realization may be completely obvious to others but was quite new to me.
Newburgh, Ronald
2010-01-01
It's both surprising and rewarding when an old, standard problem reveals a subtlety that expands its pedagogic value. I realized recently that the role of gravity in the range equation for a projectile is not so simple as first appears. This realization may be completely obvious to others but was quite new to me.
The value of an intercâmbio: brazilian student mobility, bilateralism & international education
Directory of Open Access Journals (Sweden)
Eric Spears
2014-05-01
Full Text Available Brazil’s emergence in the global economy as a member of the BRIC (Brazil, Russia, India, China, and South Africa states has prompted the federal government to establish the Brazilian Scientific Mobility Program (Science Without Borders in order to advance the country’s social capital and infrastructure in STEM (Science, Technology, Engineering, and Math related disciplines and industries. Public and private investment in the Scientific Mobility Program has transformed the way in which Brazilian government, universities, and citizenry places value the intercâmbio (student exchange experience in the United States. STEM-related disciplines are now disproportionately funded versus social sciences, humanities, and fine arts fields. This development has altered the way in which student mobility in the United States is given worth and changed the trajectory of international education in Brazil. This research provides a conceptual analysis of the Brazilian Scientific Mobility Program by using a critical political economy perspective. The essay conceptualizes the Science Without Borders initiative at global, national, and local levels. This research also explores what implications the bilateral U.S.-Brazil Educational Partnership may have on future policy, practice, and ultimately, funding of Brazilian student mobility. A emergência do Brasil no âmbito da economia mundializada como participante do BRIC (Brasil, Rússia, Índia, China e África do Sul mobilizou o governo federal brasileiro a estabelecer um programa estatal de mobilidade acadêmica (Programa Ciência sem Fronteiras de modo a fazer avançar o capital social do país (general intellect e a infraestrutura em STEM (Ciência, Tecnologia, Engenharia e Matemática relacionadas à indústria. Investimentos públicos e privados no programa de mobilidade acadêmica transformaram o modo como o governo brasileiro e as universidades valorizam o intercâmbio estudantil com os Estados Unidos. As
Mather, R. S.
1973-01-01
Procedures for obtaining position from surface gravity observations are reviewed and their relevance assessed in the context of the application of modern geodetic techniques to programs of Earth and ocean physics. Solutions based on the use of surface layer techniques, the discrete value approach, and the development from Green's theorem are stated in summary, the latter being extended to order e cubed in the height anomaly. The representation of the surface gravity field which is required in order that this accuracy may be achieved is discussed. Interim techniques which could be used in the absence of such a representation are also outlined.
THE INTRINSIC EXPLANATORY VALUE OF SOCIAL CONSTRUCTIVISM IN INTERNATIONAL RELATIONS THEORY
2016-01-01
Why has constructivism emerged as an important force in the field of international relations and politics in the end of the 20th century? Why constructivism and not any other theoretical approach? The constructivist perspective of international relations appeared as a counterbalance to rationalism that was entrenched in US Political Science throughout the last decades. Analyzing the contemporary state of world affairs through the prism of social constructivism provides us with a unique unders...
Alber, Hans-Dieter
1998-01-01
This book contributes to the mathematical theory of systems of differential equations consisting of the partial differential equations resulting from conservation of mass and momentum, and of constitutive equations with internal variables. The investigations are guided by the objective of proving existence and uniqueness, and are based on the idea of transforming the internal variables and the constitutive equations. A larger number of constitutive equations from the engineering sciences are presented. The book is therefore suitable not only for specialists, but also for mathematicians seeking for an introduction in the field, and for engineers with a sound mathematical background.
Suwandaratne, Nuwanthi; Hu, Juan; Siriwardana, Kumudu; Gadogbe, Manuel; Zhang, Dongmao
2016-04-05
Thiols, including organothiol and thiol-containing biomolecules, are among the most important classes of chemicals that are used broadly in organic synthesis, biological chemistry, and nanosciences. Thiol pKa values are key indicators of thiol reactivity and functionality. Reported herein is an internally referenced Raman-based pH titration method that enables reliable quantification of thiol pKa values for both mono- and dithiols in water. The degree of thiol ionization is monitored directly using the peak intensity of the S-H stretching feature in the 2600 cm(-1) region relative to an internal reference peak as a function of the titration solution's pH. The thiol pKa values and Raman activity relative to its internal reference were then determined by curve fitting the experimental data with equations derived on the basis of the Henderson-Hasselbalch equation. Using this Raman titration method, we determined for the first time the first and second thiol pKa values for 1,2-benzenedithiol in water. This Raman-based method is convenient to implement, and its underlying theory is easy to follow. It should therefore have broad application for thiol pKa determinations and verification.
Bilateral internal carotid agenesis: value of CT angiography and correlation to embryogenesis
Energy Technology Data Exchange (ETDEWEB)
Pilleul, F.; Rouviere, O. [Dept. of Radiology, Hopital Edouard Herriot, Lyon (France); Guibaud, L.; Pracros, J.P. [Dept. of Pediatric Imaging, Hopital Debrousse, Lyon (France); Badinand, N. [Dept. of Pediatric Neurology, Hopital Debrousse, Lyon (France)
2001-05-01
Bilateral internal carotid artery agenesis is an uncommon disease, difficult to differentiate from bilateral carotid artery thrombosis. A few case reports have described the contribution of conventional angiogram to make the diagnosis and recognize the anatomic details of this rare malformation. Advantages of CT angiography as a non-invasive radiologic tool are discussed in this case report. (orig.)
Alagaraja, Meera
2013-01-01
Purpose: The purpose of this article is to outline the role of human resource development (HRD) in Lean strategy as the context for assessing interactions with internal customers. Identifying the perceived gap in role expectations and fulfillment emphasizes important priorities and offers tangible measures for assessing HRD contributions. A focus…
Generalizing unimodular gravity
Saez-Gomez, Diego
2016-01-01
The so-called unimodular version of General Relativity is revisited, which assumes the trace-free part of the equations instead of the usual Einstein equations, what leads naturally to a cosmological constant that may compensate the large value of quantum fluctuations. Here we extend such formalism to some extensions of General Relativity that have drawn a lot of attention over the last years, as $f(R)$ gravity (or its equivalent scalar-tensor picture) and Gauss-Bonnet gravity. The corresponding unimodular version of such theories is constructed. From the classical point of view, the unimodular versions of such extensions are completely equivalent to their originals, but an effective cosmological constant arises naturally, what may provide a richer description of the universe evolution. Moreover, conformal transformations within unimodular gravities lead to some corrections that may affect their solutions. Here we analyze the case of Starobisnky inflation and compared with the original one.
Gravity and the cells of gravity receptors in mammals
Ross, M. D.
Two new findings, that crystals located in the inner ear gravity receptors of mammals have the internal organization requisite for the piezoelectric property, and that sensory hair cells of these same receptors possess contractile-appearing striated organelles, have prompted the author to model mammalian gravity receptors in the ear on the principles of piezoelectricity and bioenergetics. This model is presented and a brief discussion of its implications for the possible effects of weightlessness follows.
Wave Propagation in Modified Gravity
Lindroos, Jan Ø; Mota, David F
2015-01-01
We investigate the propagation of scalar waves induced by matter sources in the context of scalar-tensor theories of gravity which include screening mechanisms for the scalar degree of freedom. The usual approach when studying these theories in the non-linear regime of cosmological perturbations is based on the assumption that scalar waves travel at the speed of light. Within General Relativity such approximation is good and leads to no loss of accuracy in the estimation of observables. We find, however, that mass terms and non-linearities in the equations of motion lead to propagation and dispersion velocities significantly different from the speed of light. As the group velocity is the one associated to the propagation of signals, a reduction of its value has direct impact on the behavior and dynamics of nonlinear structures within modified gravity theories with screening. For instance, the internal dynamics of galaxies and satellites submerged in large dark matter halos could be affected by the fact that t...
Celada, Mariano; Montesinos, Merced
2016-01-01
$BF$ gravity comprises all the formulations of gravity that are based on deformations of $BF$ theory. Such deformations consist of either constraints or potential terms added to the topological $BF$ action that turn some of the gauge degrees of freedom into physical ones, particularly giving rise to general relativity. The $BF$ formulations have provided new and deep insights into many classical and quantum aspects of the gravitational field, setting the foundations for the approach to quantum gravity known as spinfoam models. In this review, we present a self-contained and unified treatment of the $BF$ formulations of $D$-dimensional general relativity and other related models, focusing on the classical aspects of them and including some new results.
Kiefer, Claus
2012-01-01
The search for a quantum theory of the gravitational field is one of the great open problems in theoretical physics. This book presents a self-contained discussion of the concepts, methods and applications that can be expected in such a theory. The two main approaches to its construction - the direct quantisation of Einstein's general theory of relativity and string theory - are covered. Whereas the first attempts to construct a viable theory for the gravitational field alone, string theory assumes that a quantum theory of gravity will be achieved only through a unification of all the interactions. However, both employ the general method of quantization of constrained systems, which is described together with illustrative examples relevant for quantum gravity. There is a detailed presentation of the main approaches employed in quantum general relativity: path-integral quantization, the background-field method and canonical quantum gravity in the metric, connection and loop formulations. The discussion of stri...
Celada, Mariano; González, Diego; Montesinos, Merced
2016-11-01
BF gravity comprises all the formulations of gravity that are based on deformations of BF theory. Such deformations consist of either constraints or potential terms added to the topological BF action that turn some of the gauge degrees of freedom into physical ones, particularly giving rise to general relativity. The BF formulations have provided new and deep insights into many classical and quantum aspects of the gravitational field, setting the foundations for the approach to quantum gravity known as spinfoam models. In this review, we present a self-contained and unified treatment of the BF formulations of D-dimensional general relativity and other related models, focusing on the classical aspects of them and including some new results.
Mihaela Gruiescu; Corina Ioanăs; Adriana Florina Popa
2010-01-01
As the present financial markets have broadened and deepened, increasing numbers of firms are utilizing innovative financial instruments to accomplish business objectives and enhance shareholder value. It is crucial for the financial managers to keep abreast of available financial instruments, the business settings in which these instruments can create—and destroy—value, and modern analysis techniques for these instruments. A financial manager also should possess a basic understanding of the ...
An international meta-analysis of values of travel time savings.
Shires, J D; de Jong, G C
2009-11-01
Values of travel time savings are often used in cost-benefit analysis of transport projects and policies, and also to compute generalised travel costs. There has been considerable debate as to whether different research methods (e.g. stated versus revealed preference) will lead to different values of travel time savings, and which segmentations (e.g. by income or mode) are most important to capture the heterogeneity in these values. In addition there are many countries where no specific valuation studies have been done. In this paper new equations are estimated on the outcomes of value of travel time savings studies from various countries. In the data set, several countries appear more than once, which is taken into account by estimating random effects panel models. The meta-analysis sheds some new light on the variation of the value of travel time savings by income, country, travel purpose, mode, distance and by survey method. Furthermore, the resulting meta-models are applied to produce new values of travel time savings for business travel, commuting and for other purposes in passenger transport, for 25 European Union Member states. Similar methods could be used to statistically analyse studies carried out on other non-monetary effects, both for transport and non-transport projects, and for inclusion in cost-benefit analysis.
GOCE and Future Gravity Missions for Geothermal Energy Exploitation
Pastorutti, Alberto; Braitenberg, Carla; Pivetta, Tommaso; Mariani, Patrizia
2016-08-01
Geothermal energy is a valuable renewable energy source the exploitation of which contributes to the worldwide reduction of consumption of fossil fuels oil and gas. The exploitation of geothermal energy is facilitated where the thermal gradient is higher than average leading to increased surface heat flow. Apart from the hydrologic circulation properties which depend on rock fractures and are important due to the heat transportation from the hotter layers to the surface, essential properties that increase the thermal gradient are crustal thinning and radiogenic heat producing rocks. Crustal thickness and rock composition form the link to the exploration with the satellite derived gravity field, because both induce subsurface mass changes that generate observable gravity anomalies. The recognition of gravity as a useful investigation tool for geothermal energy lead to a cooperation with ESA and the International Renewable Energy Agency (IRENA) that included the GOCE derived gravity field in the online geothermal energy investigation tool of the IRENA database. The relation between the gravity field products as the free air gravity anomaly, the Bouguer and isostatic anomalies and the heat flow values is though not straightforward and has not a unique relationship. It is complicated by the fact that it depends on the geodynamical context, on the geologic context and the age of the crustal rocks. Globally the geological context and geodynamical history of an area is known close to everywhere, so that a specific known relationship between gravity and geothermal potential can be applied. In this study we show the results of a systematic analysis of the problem, including some simulations of the key factors. The study relies on the data of GOCE and the resolution and accuracy of this satellite. We also give conclusions on the improved exploration power of a gravity mission with higher spatial resolution and reduced data error, as could be achieved in principle by flying
Experimental simulation of gravity currents in erodible bed
Bateman, A.; La Roca, M.; Medina, V.
2009-04-01
Gravity currents are commonly met in nature, when a flow of denser fluid moves into a less dense one. A typical example of a gravity current is given by the sea water which flows into the bottom of a river during the summer, in correspondence of the estuary, when the river's discharge attains low values. In this case, dangerous consequences can occur, because of the polluting of the aquifer caused by the salty water. Density currents also occurs in lakes and reservoirs, because of a change in temperature or because a flood, both can produce some environmental impacts that are of interest to the local water Agency of the different countries. Of particular relevance is also the interaction of the gravity current with the movement of the sediments from the bottom of the bed. The international state of the art is particularly concerned with experimental and numerical investigation on gravity currents on fixed and porous bed [1-2-3], while, to the authors' knowledge, the interaction of a gravity current with an erodible bed is still an open field of investigation. In this paper experiments concerning with the propagation of a gravity current over fixed and erodible bed are presented. The experiments, conducted at the laboratory of Hydraulics of the Universitat Politecnica de Catalunya (actually in the Prof. Bateman's blue room), were concerned with a transparent tank 2 m long, 0.2 m wide and 0.3 m deep, partly filled with salty water and partly with fresh water, up to a depth of 0.28 m. The salty water, whose density was in the range 1050John E. Simpson. Gravity Currents [3] J.J. Monaghan, R.A.F. Cas, A.M. Kos, M. Hallworth, Gravity currents descending a ramp in a stratified tank, The Journal of Fluid Mechanics, Vol. 379, 1999
Allen, James C.; Bergstrom, John C.
2003-01-01
Because of pressures to convert natural areas to commercial economic development uses, protecting natural areas in developing countries is a major challenge. A developing country may desire to protect natural areas, but relatively high out-of-pocket and opportunity costs of protection may pose considerable hurdles. To help protect natural areas in a developing country, the international community often gets involved; for example, providing funds to purchase and preserve natural areas such as ...
Charles A Funk; Jonathan D Arthurs; Len J Treviño; Jeff Joireman
2010-01-01
The escalation of international offshoring and outsourcing in recent years has resulted in a proliferation of “hybrid products” for the typical multinational enterprise, with multiple country affiliations for branding, design, manufacture, assembly and parts sourcing. However, little has been written regarding the impact of consumer animosity on such hybrid activities, or the role of universal values in a hybrid production animosity model. In this paper we extend the consumer animosity litera...
Energy Technology Data Exchange (ETDEWEB)
Berg, Vande B.C.; Lecouvet, F.E.; Maldague, B.; Malghem, J. [Department of Radiology, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium); Poilvache, P. [Department of Orthopedic Surgery, Cliniques Universitaires St. Luc, Universite Catholique de Louvain, Brussels (Belgium)
2002-07-01
Computed tomography imaging has achieved excellent multiplanar capability and submillimeter spatial resolution due to the development of the spiral acquisition mode and multidetector row technology. Multidetector spiral CT arthrography (CTA) yields valuable information for the assessment of internal derangement of the joints. This article focuses on the value of spiral CTA of the knee in the assessment of the meniscus, anterior cruciate ligament, and hyaline cartilage lesions. Advantages and disadvantages of spiral CTA with respect to MR imaging are presented. (orig.)
Stochastic Gravity: Theory and Applications
Directory of Open Access Journals (Sweden)
Hu Bei Lok
2008-05-01
Full Text Available Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein–Langevin equation, which has, in addition, sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued stress-energy bitensor, which describes the fluctuations of quantum-matter fields in curved spacetimes. A new improved criterion for the validity of semiclassical gravity may also be formulated from the viewpoint of this theory. In the first part of this review we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to the correlation functions. The functional approach uses the Feynman–Vernon influence functional and the Schwinger–Keldysh closed-time-path effective action methods. In the second part, we describe three applications of stochastic gravity. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic-gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, using the Einstein–Langevin equation, we discuss the backreaction of Hawking radiation and the behavior of metric fluctuations for both the quasi-equilibrium condition of a black-hole in a box and the fully nonequilibrium condition of an evaporating black hole spacetime. Finally, we briefly discuss the theoretical structure of stochastic gravity in relation to quantum gravity and point out
Directory of Open Access Journals (Sweden)
Kenneth Chan
2010-11-01
Full Text Available The presence of retropharyngeal tissue mass often raises the suspicion of malignancy, especially in elderly patients. This prompts urgent biopsy to investigate tissue histology. We discuss a case where this is contraindicated as the retropharyngeal mass was illustrated by CT scanning and confirmed with MRI to be a tortuous coursing internal carotid artery. An awareness of this unusual anatomical variation and a careful interpretation of imaging studies both at the stage of differential diagnosis and pre-operative screening are essential to avoid damage to important structures, causing unnecessary complications.
Directory of Open Access Journals (Sweden)
Maria Cassella
2010-09-01
Full Text Available Institutional repositories represent extremely innovative technology, but repository managers still struggle to bring together a critical mass of content and to demonstrate their overall impact on research. In this paper I propose a set of Performance Indicators (PIs to assess institutional repositories’ success. Fourteen internal indicators are selected and inserted in the quadruple ‘balanced scorecard’ perspective. Three more indicators from an external perspective are then proposed and discussed by the author. I hope that this study will foster the development of standard Performance Indicators for IRs in the very near future, in order to help IR managers to demonstrate their repositories’ cost-effectiveness and success.
Impact of parenting styles on adolescents' self-esteem and internalization of values in Spain.
Martínez, Isabel; García, José Fernando
2007-11-01
The relationship of parenting styles with adolescents' outcomes was analyzed within a sample of Spanish adolescents. A sample of 1456 teenagers from 13 to 16 years of age, of whom 54.3% were females, reported on their parents' child-rearing practices. The teenagers' parents were classified into one of four groups (authoritative, authoritarian, indulgent, or neglectful). The adolescents were then contrasted on two different outcomes: (1) priority given to Schwartz's self-transcendence (universalism and benevolence) and conservation (security, conformity, and tradition) values and (2) level of self-esteem (appraised in five domains: academic, social, emotional, family and physical). The results show that Spanish adolescents from indulgent households have the same or better outcomes than adolescents from authoritative homes. Parenting is related with two self-esteem dimensions--academic and family--and with all the self-transcendence and conservation values. Adolescents of indulgent parents show highest scores in self-esteem whereas adolescents from authoritarian parents obtain the worst results. In contrast, there were no differences between the priority given by adolescents of authoritative and indulgent parents to any of the self-transcendence and conservation values, whereas adolescents of authoritarian and neglectful parents, in general, assign the lowest priority to all of these values.
Pipinos, Savas
2010-01-01
This article describes one classroom activity in which the author simulates the Newtonian gravity, and employs the Euclidean Geometry with the use of new technologies (NT). The prerequisites for this activity were some knowledge of the formulae for a particle free fall in Physics and most certainly, a good understanding of the notion of similarity…
Pipinos, Savas
2010-01-01
This article describes one classroom activity in which the author simulates the Newtonian gravity, and employs the Euclidean Geometry with the use of new technologies (NT). The prerequisites for this activity were some knowledge of the formulae for a particle free fall in Physics and most certainly, a good understanding of the notion of similarity…
Aviation Impacts on Property Values and Management: The Case of Suvarnabhumi International Airport
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Patcharin Limlomwongse Suksmith
2015-07-01
Full Text Available Many countries have developed policies and measures to deal with the external impact of aviation on the wider community. There is, however, often controversy and lack of acceptance of some measures, such as compensation, in the communities affected by aviation. Such measures are often felt to be ineffective and perceived as unfair. A clear and objective model for determining compensation would be helpful to reduce controversy. The objective of this study is therefore to examine the relationship between aviation impacts and property values in the case of Thailand's Suvarnabhumi Airport for application to the possible improvement of compensation packages. Multiple regression analysis was used to determine the relationship between five common impacts of aviation (safety, noise, scenery, air pollution, and traffic and property value change, with data from a survey of sample communities around the airport. The results, both for the overall neighborhood and for separate land used types, show that only noise and air pollution demonstrate significant negative relations with property value. The effect of noise drives a higher impact on property price than the effect of air pollution. The main contribution of this research is to improve developing country compensation models by applied measurement from regression analysis to identify factors with significant impacts, using property value change as proxy to measure the impact of the airport. For example, in the case of Thailand, a compensation model should consider noise and air pollution as the main factors rather than consider only noise contour area. The higher weight on noise should be designed to reflect land use types. Furthermore the market value of property loss should be taken into account when designing a compensation package. The survey and regression method used in this study can be adapted for finding relevant factors and suggesting appropriate compensation for other environmental and
Directory of Open Access Journals (Sweden)
Đajić Sanja
2012-01-01
Full Text Available International investment cases show the frequent use of good faith arguments by both investors and respondent states. These cases also illustrate how parties and tribunals tend to conceptualize the good faith principle which has become an important rule of international investment law. This article will explore recent trends in order to assess the importance of this argument for both parties and at different stages of the proceeding. This article will also provide an overview of responses given by the tribunals faced with good faith arguments. Whereas claimants have traditionally relied on this concept to argue the breach of fair and equitable treatment and legitimate expectations, recent cases such as Inceysa, Phoenix and TSA Spectrum, indicate a new defense strategy for respondent states. Given the fact that investment tribunals have shown willingness to treat the good faith principle as autonomous and as a self-standing standard, the possibilities for respondent states have increased. Respondent states can rely on good faith to deny the right of claimants to seize the tribunal (Article 41(5 of the ICSID Rules, to challenge the jurisdiction of the tribunal or admissibility, to contest the right of the claimant to have a decision in its favor, or to challenge the right to compensation.
国际竞争的价值分析%The Value Analysis for International Competition
Institute of Scientific and Technical Information of China (English)
宋树理
2013-01-01
The competition among enterprises between developing countries and developed countries is helpful for efficiency dis⁃tribution of resources of these countries in the world market,but it may also reduce their social welfare.According to labor val⁃ue theory,using the dynamic game method,the paper analyses the type of competition,then proves the existence of the opti⁃mal conditions of international competition maximizing these countries’ social welfare.This means that governments could in⁃tervene the international production behavior of enterprises in their own countries,then it will realize a win-win benefits in in⁃ternational competition between developed and developing countries.% 文章在劳动价值论的基础上，对不同发展程度国家的企业竞争的动态博弈分析证明，存在使这些国家社会福利最大化的最优竞争条件。这意味着这些国家都可以通过影响本国企业的国际生产行为，实现国际竞争的利益双赢。
Directory of Open Access Journals (Sweden)
Abdul Hakim
2011-09-01
Full Text Available This paper uncovers the nature of conditional correlations between and volatility spilloversacross bond, stock and foreign exchange in Indonesia, Malaysia, the Philippines, and Thailand.Using various multivariate Generalized Autoregressive Conditional Heteroscedasticity(GARCH models, it finds the evidence of highly persistence in the conditional variance,volatility spillovers across assets, and time-varying conditional correlations in all markets. Italso provides Value-at-Risk forecast based on the estimated models. Assuming normal distribution,the tests suggest that incorporating volatility spillovers and time-varying conditionalcorrelations does not help in providing Value-at-Risk forecasts. Assuming t distribution, thetests suggest that incorporating volatility spillovers provides better VaR forecasts.Keywords: conditional correlations, volatility spillovers, VaR forecast
Stepanishen, P. R.; Ramakrishna, S.
1994-09-01
A new internal source distribution method is combined with the singular value decomposition method to determine the acoustic impedance and associated impulse response for an infinite cylinder with a plane of symmetry and a normal velocity with a specified circumferential variation. An internal linear distribution of unknown monopole and/or dipole line sources along the plane of symmetry is determined to match the specified harmonic normal velocity on the surface in a least mean square error sense. After the discretization of the source distributions, the subsequent solution of a set or sets of linear algebraic equations for the internal source distributions is obtained using the singular value decomposition method. Line integrals for the associated surface pressure, the acoustic impedance and the corresponding impulse response are then simply evaluated by quadrature methods. Numerical results for the acoustic impedances and associated impulse responses are presented for circular cylinders vibrating with various natural in vacuo modal shapes. Numerical results for acoustic impedances and associated impulse responses for elliptical cylinders vibrating with various natural in vacuo modal shapes are then presented, and their characteristics are discussed and compared to the corresponding results for circular cylinders.
Chiral gravity in higher dimensions
Ootsuka, T; Ura, K; Ootsuka, Takayoshi; Tanaka, Erico; Ura, Kousuke
2003-01-01
We construct a chiral theory of gravity in 7 and 8 dimensions, which are equivalent to Einstein-Cartan theory using less variables. In these dimensions, we can construct such higher dimensional chiral gravity because of the existence of gravitational instanton. The octonionic-valued variables in the theory represent the deviation from the gravitational instanton, and from their non-associativity, prevents the theory to be SO(n) gauge invariant. Still the chiral gravity holds G_2 (7-D), and Spin(7) (8-D) gauge symmetry.
Cohen, Lori R.; Milyavskaya, Marina; Koestner, Richard
2009-01-01
The present study examined the way in which children attending Orthodox Jewish schools internalize the value of both their Jewish studies and secular studies, as well as the value of Jewish cultural practices. A distinction was made between identified internalization, where children perceive Jewish studies and Jewish culture to be an important…
Badmus, Medinat
2007-01-01
This study investigated the level of degree to which the home Economics teachers developed value internalization and commitment for the implementation of the National Junior Secondary School Home Economics Curriculum (NJSSHEC). It also determined the state and qualification influence on the level of degree of value internalization and commitment…
Prognostic Value of Homotypic Cell Internalization by Nonprofessional Phagocytic Cancer Cells
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Manuela Schwegler
2015-01-01
Full Text Available Background. In this study, we investigated the prognostic role of homotypic tumor cell cannibalism in different cancer types. Methods. The phenomenon of one cell being internalized into another, which we refer to as “cell-in-cell event,” was assessed in 416 cases from five head and neck cancer cohorts, as well as one anal and one rectal cancer cohort. The samples were processed into tissue microarrays and immunohistochemically stained for E-cadherin and cleaved caspase-3 to visualize cell membranes and apoptotic cell death. Results. Cell-in-cell events were found in all of the cohorts. The frequency ranged from 0.7 to 17.3 cell-in-cell events per mm2. Hardly any apoptotic cells were found within the cell-in-cell structures, although apoptotic cell rates were about 1.6 to two times as high as cell-in-cell rates of the same tissue sample. High numbers of cell-in-cell events showed adverse effects on patients’ survival in the head and neck and in the rectal cancer cohorts. In multivariate analysis, high frequency was an adverse prognostic factor for overall survival in patients with head and neck cancer (p=0.008. Conclusion. Cell-in-cell events were found to predict patient outcomes in various types of cancer better than apoptosis and proliferation and might therefore be used to guide treatment strategies.
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John R.F. Gladman
2008-06-01
Full Text Available In this paper, I argue that the International Classification of Functioning, Disability and Health (ICF, proposed by the World Health Organization, provides not only a model to understand health, but a model to understand rehabilitation and geri-atric medicine. The ICF proposes that poor health is defined by a complex product of the interactions between several domains: body functions and structures (and impairments of them, activities (and limitations in their performance, par-ticipation (and restrictions to it, the physical and social environment (which may be facilitating or hindering and per-sonal factors. I propose that the ICF allows a logical classification of the potential interventions that are possible to improve health during rehabilitation or geriatric practice. These interventions may target each of the domains of health in the ICF. An example is given illustrating this approach in the management of a person who has fallen. This model of rehabilitation illustrates that rehabilitation is a complex multidisciplinary process, comprising restorative and adaptive strategies including the use of assistive technologies, and which is reliant upon careful assessment and care planning.
Internal Alignment of the SLD Vertex Detector using a Matrix Singular Value Decomposition Technique
Energy Technology Data Exchange (ETDEWEB)
Su, Dong
2002-01-03
The tracking resolution and vertex finding capabilities of the SLD experiment depend upon a precise knowledge of the location and orientation of the 96 elements of the SLD pixel vertex detector (VXD3) in 3D space. At the heart of the deterministic procedure described here to align the 96 CCDs is the matrix inversion technique of singular value decomposition (SVD). This tool is employed to unfold the detector geometry corrections from the track hit residual data in the VXD3. The algorithm is adapted to perform an optimal {chi}{sup 2} minimization by careful treatment of the errors and correlations in the residual measurements. The general form of the problems that might be solved with this technique is discussed. The tracking resolution obtained with the aligned geometry is compared with the starting point, based on an optical survey of the CCDs, and is shown to achieve the design performance.
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MARIJA NIKOLIC
2013-12-01
Full Text Available The trend towards foreign investments in Serbia has been in rapid progress in recent years. The biggest and most valuable numbers of investments are coming from Italy. The authors’ expectation is that the trend of Italian investments in future will continue; therefore it is of high importance for the representatives of both countries’ business sectors to understand and accept differences and similarities to the other country’s business culture. Research of cultural differences between two nations , which are considered like a frame of business culture, helps avoiding possible misunderstandings and improving business cooperation between two countries. Having in mind students of economics and management, on one hand like future leaders of Italian and Serbian business and on other like representatives of the current education value system in the field of economics and management, this study consists of an application of the 7-D Hofstede Model. The application of the model takes place through the administration of two surveys done by students of Serbian Megatrend University, in Belgrade, and Italian Università degli Studi Gabriele d’Annunzio, in Pescara.
ANALISIS WASTE DALAM ALIRAN MATERIAL INTERNAL DENGAN VALUE STREAM MAPPING PADA PT XYZ
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Ketut Gita Ayu
2012-05-01
Full Text Available The main focus of the research is excess inventory and motion waste which commonly occur in warehouse and production floor. This research is carried out to minimize the average level and eliminate unnecessary motions, with consideration of electronic pull and traceability system characteristics. Product X, the highest-selling product, is the object of this research. To identify the current condition, the current state Value Stream Mapping (VSM is developed as the basis to arrange improvement plan to minimize the wastes. Safety stock is determined through average and maximum consumption difference; and reorder point is determined to comply with pull approach. Average inventory level is calculated using continuous review method. The simulation was conducted and it was shown that 8.29 minutes is the maximum lateness. Thus, safety stock and reorder point are adjusted accordingly to anticipate stockout due to lateness. The improvement of process cycle efficiency is shown to increase from 4.1 % to 5.1 % as projected in future state VSM.
Directory of Open Access Journals (Sweden)
Marian Tukuta
2015-02-01
Full Text Available Background: Until recently, procurement was seen as a necessity only. In fact, in many developing economies the profession is still being treated as a ‘back-office’ function. However, not much has been done to explore and address challenges facing procurement professionals in developing economies.Objectives: The purpose of this article was to examine the critical role played by the procurement function in business and to reveal the challenges faced by procurement professionals in developing economies as well as to suggest solutions to these challenges.Method: A sequential literary analysis was used, complemented by cross-country qualitative data gathered from one hundred diverse procurement practitioners from Botswana, Namibia and Zimbabwe. These were primarily participants in a series of procurement workshops run by the researchers from January to June 2014.Results: Findings suggested that limited recognition, increasing unethical behaviour, poor supplier service delivery, poor regulatory environment, varying supplier standards and poor corporate governance are the main challenges faced by the procurement profession in these countries.Conclusion: The study’s findings imply that there is limited understanding regarding the role procurement plays in both government and non-government institutions in developing economies. The article suggests solutions which procurement professionals and organisations can implement in order to unlock the potential value in the procurement function.
Martínez, Isabel; García, José Fernando
2008-01-01
The relation between parenting styles and adolescent outcomes was analyzed in a sample of 1,198 15-18-year-old Brazilians. The adolescents were classified into 1 of 4 groups (Authoritative, Authoritarian, Indulgent, and Neglectful) on the basis of their own ratings of their parents on two dimensions: Acceptance/ Involvement and Strictness/Imposition. The adolescents were then contrasted along two different outcomes: (1) priority given to Schwartz Self-transcendence and Conservation values, and (2) level of Self-esteem (appraised in 5 domains: Academic, Social, Emotional, Family, and Physical). Results showed that Authoritative and Indulgent parenting is associated with the highest internalization of Self-Transcendence and Conservation values of teenagers, whereas Authoritarian parenting is associated with the lowest. On the other hand, adolescents with Indulgent parents have equal or higher levels of Self-esteem than adolescents with Authoritative parents, while adolescents raised in Authoritarian and Neglectful homes have the lowest scores in Self-Esteem.
Directory of Open Access Journals (Sweden)
Pešić-Tomić Vesna
2014-01-01
Full Text Available The objective of this paper is an effort to view the possibilities of integrated use of target costing, activity based costing and Kaizen concept in the internal value chain as the central link of the entire chain. The idea is to stimulate the company management to think about the costs, position they take in the structure of price cost and their influence on forming the sales price since it is very important to produce right product for the consumer, of desired quality and functionality but along with as low production costs as possible. It is therefore needed to construct the right design of a product and provide its production at the shortest possible time along with as low costs as possible which will impact the efficiency of the entire value chain.
Iwamoto, Derek Kenji; LIU, WILLIAM MING
2010-01-01
The current study investigated the direct and moderating effects of racial identity, ethnic identity, Asian values, and race-related stress on positive psychological well-being among 402 Asian American and Asian international college students. Results revealed that the racial identity statuses Internalization, Immersion-Emersion, Dissonance, Asian values and Ethnic Identity Affirmation and Belonging were significant predictors of well-being. Asian values, Dissonance and Conformity were found ...
Turning on gravity with the Higgs mechanism
Alexander, Stephon; Magueijo, Joao
2016-01-01
We investigate how a Higgs mechanism could be responsible for the emergence of gravity in extensions of Einstein theory. In this scenario, at high energies, symmetry restoration could "turn off" gravity, with dramatic implications for cosmology and quantum gravity. The sense in which gravity is muted depends on the details of the implementation. In the most extreme case gravity's dynamical degrees of freedom would only be unleashed after the Higgs field acquires a non-trivial vacuum expectation value, with gravity reduced to a topological field theory in the symmetric phase. We might also identify the Higgs and the Brans-Dicke fields in such a way that in the unbroken phase Newton's constant vanishes, decoupling matter and gravity. We discuss the broad implications of these scenarios.
Kristensen, Finn Børlum; Lampe, Kristian; Wild, Claudia; Cerbo, Marina; Goettsch, Wim; Becla, Lidia
2017-02-01
The HTA Core Model(®) as a science-based framework for assessing dimensions of value was developed as a part of the European network for Health Technology Assessment project in the period 2006 to 2008 to facilitate production and sharing of health technology assessment (HTA) information, such as evidence on efficacy and effectiveness and patient aspects, to inform decisions. It covers clinical value as well as organizational, economic, and patient aspects of technologies and has been field-tested in two consecutive joint actions in the period 2010 to 2016. A large number of HTA institutions were involved in the work. The model has undergone revisions and improvement after iterations of piloting and can be used in a local, national, or international context to produce structured HTA information that can be taken forward by users into their own frameworks to fit their specific needs when informing decisions on technology. The model has a broad scope and offers a common ground to various stakeholders through offering a standard structure and a transparent set of proposed HTA questions. It consists of three main components: 1) the HTA ontology, 2) methodological guidance, and 3) a common reporting structure. It covers domains such as effectiveness, safety, and economics, and also includes domains covering organizational, patient, social, and legal aspects. There is a full model and a focused rapid relative effectiveness assessment model, and a third joint action is to continue till 2020. The HTA Core Model is now available for everyone around the world as a framework for assessing value. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.
Talon, Suzanne
2008-01-01
This is the fourth in a series of papers that deal with angular momentum transport by internal gravity waves in stellar interiors. Here, we want to examine the potential role of waves in other evolutionary phases than the main sequence. We study the evolution of a 3Msun Population I model from the pre-main sequence to the early-AGB phase and examine whether waves can lead to angular momentum redistribution and/or element diffusion at the external convection zone boundary. We find that, although waves produced by the surface convection zone can be ignored safely for such a star during the main sequence, it is not the case for later evolutionary stages. In particular, angular momentum transport by internal waves could be quite important at the end of the sub-giant branch and during the early-AGB phase. Wave-induced mixing of chemicals is expected during the early-AGB phase.
关于内部审计为企业增加价值的思考%Reflections on Adding Value through Internal Audit
Institute of Scientific and Technical Information of China (English)
翟美红
2013-01-01
The paper starts by introducing the idea of adding value through internal audit ,following which it deals with the specific forms of value that can be delivered by internal audit ,and discusses the major ways to realize value adding through internal audit .% 从内部审计工作增加价值的理念出发，分析了内部审计增加价值的具体体现，探讨了内部审计增加价值的主要途径。
Quantum gravity corrections to the standard model Higgs in Einstein and $R^2$ gravity
Abe, Yugo; Inami, Takeo
2016-01-01
We evaluate quantum gravity corrections to the standard model Higgs potential $V(\\phi)$ a la Coleman-Weinberg and examine the stability question of $V(\\phi)$ at scales of Planck mass $M_{\\rm Pl}$. We compute the gravity one-loop corrections by using the momentum cut-off in Einstein gravity. The gravity corrections affect the potential in a significant manner for the value of $\\Lambda= (1 - 3)M_{\\rm Pl}.$ In view of reducing the UV cut-off dependence we also make a similar study in the $R^2$ gravity.
DEFF Research Database (Denmark)
Kennedy, C.; Anderson, J.; Snyder, N.;
2010-01-01
residues based on limited data sets affords business value by enabling informed product development decisions about the likelihood for MRL compliance for varied product use scenarios. Predicted residues can additionally support the design and conduct of time-constrained interdependent studies required......Crop Protection Product (CPP) national registrations and/or international trade require magnitude and decline of residue data for treated produce. These data are used to assess human dietary risk and establish legal limits (Maximum Residue Limits, MRLs) for traded produce. The ability to predict...... for product registrations. While advances in predicting residues for the case of foliar applications of CPPs have been achieved, predictions for the case of soil applications of CPPs provide additional challenge. The adaptation of a newly developed dynamic model to CPP product use scenarios will be explored...
Molzon, J A; Giaquinto, A; Lindstrom, L; Tominaga, T; Ward, M; Doerr, P; Hunt, L; Rago, L
2011-04-01
The International Conference on Harmonisation (ICH) is an unparalleled undertaking, which has brought together drug regulatory authorities and pharmaceutical trade associations from Europe, Japan, and the United States, to discuss the scientific and technical aspects of medical product registration. Launched in 1990, the value and benefits of ICH to regulators are being realized. ICH has harmonized submission requirements and created a harmonized submission format that is relieving both companies and regulatory authorities of the burdens of assembling and reviewing separate submissions for each region. As more countries embrace ICH guidelines, we anticipate additional benefits, including the promotion of good review practices and, ultimately, a common regulatory language that will facilitate further interactions among global drug regulatory authorities.
Liao, Kelly Yu-Hsin; Wei, Meifen
2014-01-01
The theoretical model proposed by Berry and colleagues (Berry, 1997; Berry, Kim, Minde, & Mok, 1987) highlights the importance of identifying moderators in the acculturation process. Accordingly, the current study examined the Asian cultural value of family recognition through achievement (FRTA) and contingency of self-worth on academic competence (CSW-AC) as moderators in the association between academic stress and positive affect among Chinese international students. A total of 370 Chinese international students completed online surveys. Results from a hierarchical regression indicated that while academic stress was negatively associated with positive affect, FRTA was positively associated with positive affect. In other words, those with high academic stress reported a lower level of positive affect. However, individuals who endorsed high levels of FRTA reported a higher level of positive affect. In addition, results also revealed a significant interaction between academic stress and CSW-AC on positive affect. Thus, the study's finding supported the moderator role of CSW-AC. Simple effect analyses were conducted to examine the significant interaction. The results showed that higher levels of CSW-AC strengthened the negative association between academic stress and positive affect but lower levels of CSW-AC did not. Future research directions and implications are discussed.
Directory of Open Access Journals (Sweden)
Hajji Salman
2011-10-01
Full Text Available Abstract Background No published data is currently available that describes the dietary patterns or physiological profiles of athletes participating on the Kuwaiti national fencing team and its potential impact on health and physical performance. The purpose of this investigation was to: 1 collect baseline data on nutrient intake 2 collect, analyze and report baseline for body composition, plasma lipid and lipoprotein concentrations during the competitive season, 3 compare the results with the international norms, 4 and provide necessary health and nutritional information in order to enhance the athletes' performance and skills. Methods Fifteen national-class fencers 21.5 ± 2.6 years of age participated in this study. Food intake was measured using a 3-day food record. Body composition was estimated using both the BOD POD and Body Mass Index (BMI. Total blood lipid profiles and maximum oxygen consumption was measured for each of the subjects during the competitive season. Results The results of the present study showed significant differences in dietary consumption in comparison with the recommended dietary allowances (RDA. The blood lipids profile and body composition (BMI and % body fat were in normal range in comparison with international norms However, the average VO2 max value was less than the value of the other fencers. Conclusion Due to the results of the research study, a dietary regimen can be designed that would better enhance athletic performance and minimize any health risks associated with nutrition. Percent body fat and BMI will also be categorized for all players. In addition, the plasma blood tests will help to determine if any of the players have an excessive level of lipids or any blood abnormalities. The outcomes of present study will have a direct impact on the players health and therefore their skills and athletic performance.
Nash, Patrick Lee
2010-01-01
A theory of a new gravitational interaction is described. This theory follows naturally from a new Lagrangian formulation of Maxwell's theory for photons and electrons (and positrons) whose associated Euler Lagrange equations imply the conventional Maxwell equations, but which possesses new \\textbf{\\emph{bosonic}} spinor degrees of freedom that may be associated with a new type of fundamental gravitational interaction. The precise character of this gravitational interaction with a photon vector potential is explicitly defined in terms of a local U(1)-invariant Lagrangian in Eq.[\\ref{Lagrangian3}]. However in Section \\ref{ssec:Simple-Cosmolo-Model}, in order to parallel the well known Friedmann model in cosmology, a phenomenological description of the new gravitational interaction coupled to Newton-Einstein gravity that is sourced by an ideal fluid is discussed. % % To lay the foundation for a description of the new gravitational interaction our new formulation of Maxwell's theory must first be described. It i...
Magueijo, J; Magueijo, Joao; Smolin, Lee
2004-01-01
Non-linear special relativity (or doubly special relativity) is a simple framework for encoding properties of flat quantum space-time. In this paper we show how this formalism may be generalized to incorporate curvature (leading to what might be called ``doubly general relativity''). We first propose a dual to non-linear realizations of relativity in momentum space, and show that for such a dual the space-time invariant is an energy-dependent metric. This leads to an energy-dependent connection and curvature, and a simple modification to Einstein's equations. We then examine solutions to these equations. We find the counterpart to the cosmological metric, and show how cosmologies based upon our theory of gravity may solve the ``horizon problem''. We discuss the Schwarzchild solution, examining the conditions for which the horizon is energy dependent. We finally find the weak field limit.
Lombard, John
2016-01-01
We introduce the construction of a new framework for probing discrete emergent geometry and boundary-boundary observables based on a fundamentally a-dimensional underlying network structure. Using a gravitationally motivated action with Forman weighted combinatorial curvatures and simplicial volumes relying on a decomposition of an abstract simplicial complex into realized embeddings of proper skeletons, we demonstrate properties such as a minimal volume-scale cutoff, the necessity of a positive-definite cosmological constant as a regulator for non-degenerate geometries, and naturally emergent simplicial structures from Metropolis network evolution simulations with no restrictions on attachment rules or regular building blocks. We see emergent properties which echo results from both the spinfoam formalism and causal dynamical triangulations in quantum gravity, and provide analytical and numerical results to support the analogy. We conclude with a summary of open questions and intent for future work in develop...
Newtonian gravity in loop quantum gravity
Smolin, Lee
2010-01-01
We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.
Newtonian gravity in loop quantum gravity
Smolin, Lee
2010-01-01
We apply a recent argument of Verlinde to loop quantum gravity, to conclude that Newton's law of gravity emerges in an appropriate limit and setting. This is possible because the relationship between area and entropy is realized in loop quantum gravity when boundaries are imposed on a quantum spacetime.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
It is recognized widely nowadays that the superconducting gravimeter (SG) is a kind of best relative gravimeter with high observing precision, good continuity and stability. However, it is necessary to calibrate the direct output (change in voltage) by using scale value (calibration factor) before getting the change of the real gravity field. Studies show that the accuracy of the scale value will influence the late analysis and explanation of the observa-tions. By using absolute gravity measurements of a FG5 absolute gravimeter (AG) at Wuhan international tidal gravity fundamental station (two campaigns each for 3 days) and by using known tidal parameters at the same station, the calibration factors of the SG and their precision are studied in detail in this paper.
A Possible Mechanism of Gravity
Lev, F M
2003-01-01
We consider systems of two free particles in de Sitter invariant quantum theory and calculate the mean value of the mass operator for such systems. It is shown that, in addition to the well known relativistic contribution (and de Sitter antigravity which is small when the de Sitter radius is large), there also exists a contribution caused by the fact that certain decomposition coefficients have different phases. Such a contribution is negative and proportional to the particle masses in the nonrelativistic approximation. In particular, for a class of two-body wave functions the mean value is described by standard Newtonian gravity and post Newtonian corrections in General Relativity. This poses the problem whether gravity can be explained without using the notion of interaction at all. We discuss a hypothesis that gravity is a manifestation of Galois fields in quantum physics.
Lineal gravity from planar gravity
Achúcarro, A
1993-01-01
We show how to obtain the two-dimensional black hole action by dimensional reduction of the three-dimensional Einstein action with a non-zero cosmological constant. Starting from the Chern-Simons formulation of 2+1 gravity, we obtain the 1+1 dimensional gauge formulation given by Verlinde. Remarkably, the proposed reduction shares the relevant features of the formulation of Cangemi and Jackiw, without the need for a central charge in the algebra. We show how the Lagrange multipliersin these formulations appear naturally as the remnants of the three dimensional connection associated to symmetries that have been lostin the dimensional reduction. The proposed dimensional reduction involves a shift in the three dimensional connection whose effect is to make the length of the extra dimension infinite.
Dando, O
1999-01-01
We examine the field equations of a self-gravitating texture in low-energy superstring gravity, allowing for an arbitrary coupling of the texture field to the dilaton. Both massive and massless dilatons are considered. For the massless dilaton, we find that non-singular spacetimes only exist for certain values of the coupling, dependent on the gravitational strength of the texture. For the massive dilaton, the texture induces a long-range dilaton cloud, but we expect the gravitational behaviour of the defect to be similar to that found in Einstein theory. We compare these results with those found for other global topological defects.
Soones, Tacara N; O'Brien, Bridget C; Julian, Katherine A
2015-09-01
In order to teach residents how to work in interprofessional teams, educators in graduate medical education are implementing team-based care models in resident continuity clinics. However, little is known about the impact of interprofessional teams on residents' education in the ambulatory setting. To identify factors affecting residents' experience of team-based care within continuity clinics and the impact of these teams on residents' education. This was a qualitative study of focus groups with internal medicine residents. Seventy-seven internal medicine residents at the University of California San Francisco at three continuity clinic sites participated in the study. Qualitative interviews were audiotaped and transcribed. The authors used a general inductive approach with sensitizing concepts in four frames (structural, human resources, political and symbolic) to develop codes and identify themes. Residents believed that team-based care improves continuity and quality of care. Factors in four frames affected their ability to achieve these goals. Structural factors included communication through the electronic medical record, consistent schedules and regular team meetings. Human resources factors included the presence of stable teams and clear roles. Political and symbolic factors negatively impacted team-based care, and included low staffing ratios and a culture of ultimate resident responsibility, respectively. Regardless of the presence of these factors or resident perceptions of their teams, residents did not see the practice of interprofessional team-based care as intrinsically educational. Residents' experiences practicing team-based care are influenced by many principles described in the interprofessional teamwork literature, including understanding team members' roles, good communication and sufficient staffing. However, these attributes are not correlated with residents' perceptions of the educational value of team-based care. Including residents in
Institute of Scientific and Technical Information of China (English)
Qin Wang; Yan Qin; Su-Yi Kang; Xiao-Hui He; Peng Liu; Sheng Yang; Sheng-Yu Zhou
2016-01-01
Background:The International Prognostic Score (IPS) was developed based on the data of Western advanced Hodgkin lymphoma (HL) patients treated before 1992.Only a few studies ever evaluated the application value of IPS in Chinese population or in patients treated in the contemporary era whose outcomes has improved significantly than before.Methods:We conducted a retrospective study involving 208 previously untreated Chinese advanced HL patients,who were admitted to Cancer Hospital Chinese Academy of Medical Sciences from January 1,1999 to April 30,2015 and received uniform first-line treatment.The prognostic value of both IPS and the seven IPS factors for freedom-from progression (FFP) and overall survival (OS) was assessed in this population.The statistical methods included Kaplan-Meier methodology,log-rank testing,and Cox proportional hazard regression analysis.Results:With a median follow-up time of 79 months (range,15-210 months),the 5-year FFP and OS were 78.8％ and 86.0％ respectively,which improved obviously compared with the original IPS study.The IPS remained prognostic for both FFP (P =0.041) and OS (P =0.013),but the range narrowed obviously,with 5-year FFP ranging from 87.2％ to 61.5％,5-year OS ranging from 94.1％ to 69.2％,and the separation of survival curves was not as good as before.Only two of the seven IPS factors showed a significant independent prognostic value in the multivariate analysis:Stage Ⅳ (for FFP,hazard ratio [HR] =2.219,95％ confidence interval [CI]:1.148-3.948,P =0.016;for OS,HR =2.491,95％ CI:1.159-5.355,P =0.019) and hemoglobin ＜105 g/L (for FFP,HR =2.136,95％ CI:1.123-4.060,P =0.021;for OS,HR =2.345,95％ CI:1.099-5.042,P =0.028).A simple prognostic score calculated by adding one point each for any of the two factors was prognostic both for FFP (P ＜ 0.001) and OS (P ＜ 0.001) with the survival curves separating very well,but the range still narrowed.Conclusions:The IPS has decreased the prognostic value in Chinese
Energy Technology Data Exchange (ETDEWEB)
Lamon, Raphael
2010-06-29
Quantum gravity is an attempt to unify general relativity with quantum mechanics which are the two highly successful fundamental theories of theoretical physics. The main difficulty in this unification arises from the fact that, while general relativity describes gravity as a macroscopic geometrical theory, quantum mechanics explains microscopic phenomena. As a further complication, not only do both theories describe different scales but also their philosophical ramifications and the mathematics used to describe them differ in a dramatic way. Consequently, one possible starting point of an attempt at a unification is quantum mechanics, i.e. particle physics, and try to incorporate gravitation. This pathway has been chosen by particle physicists which led to string theory. On the other hand, loop quantum gravity (LQG) chooses the other possibility, i.e. it takes the geometrical aspects of gravity seriously and quantizes geometry. The first part of this thesis deals with a generalization of loop quantum cosmology (LQC) to toroidal topologies. LQC is a quantization of homogenous solutions of Einstein's field equations using tools from LQG. First the general concepts of closed topologies is introduced with special emphasis on Thurston's theorem and its consequences. It is shown that new degrees of freedom called Teichmueller parameters come into play and their dynamics can be described by a Hamiltonian. Several numerical solutions for a toroidal universe are presented and discussed. Following the guidelines of LQG this dynamics are rewritten using the Ashtekar variables and numerical solutions are shown. However, in order to find a suitable Hilbert space a canonical transformation must be performed. On the other hand this transformation makes the quantization of geometrical quantities less tractable such that two different ways are presented. It is shown that in both cases the spectrum of such geometrical operators depends on the initial value problem
Sensitivity of gravity gradient sensors for future planetary missions
Sotin, C.; Gratton, R.; Flokstra, J.
2003-04-01
Gravity gradient sensors technology may provide important information on the internal structure of planets if they can accommodate the specific requirements for space exploration. The present study investigate the sensitivity required for these devices to answer questions such as the presence of oceans within icy satellites of the outer planets or the depth of mass anomalies on Mars and to characterize Mercury's gravity field. Europa, the second Galilean satellite, may have an ocean in between an outer ice I layer and the silicate core. Life is even envisaged at the interface between the core and the ocean. However, gravity measurements can provide a proof of such an ocean whereas the geological information and geophysical information obtained so far (magnetic field, gravity field) are not conclusive. We show that he sensitivity of the gradiometer must be equal to 100 mEtvos to determine the moment of inertia, 10 mEtvos to determine whether there is an ocean (value of k2), and less than 1 mEtvos if one wants to determine the depth of the ocean. In the case of Mars, the study describes the sensitivity required to determine the compensation depth of relief in agreement with the recent MGS data obtained by Doppler shift measurements. A preliminary study for Mercury shows that gradiometers could be very complementary to the usual radio science measurements in order to determine the depth of the core/mantle boundary and the structure of the lithosphere beneath impact craters.
Gravity Aided Navigation Precise Algorithm with Gauss Spline Interpolation
Directory of Open Access Journals (Sweden)
WEN Chaobin
2015-01-01
Full Text Available The gravity compensation of error equation thoroughly should be solved before the study on gravity aided navigation with high precision. A gravity aided navigation model construction algorithm based on research the algorithm to approximate local grid gravity anomaly filed with the 2D Gauss spline interpolation is proposed. Gravity disturbance vector, standard gravity value error and Eotvos effect are all compensated in this precision model. The experiment result shows that positioning accuracy is raised by 1 times, the attitude and velocity accuracy is raised by 1～2 times and the positional error is maintained from 100~200 m.
Linker, Patrick
2016-01-01
A couple of quantum gravity theories were proposed to make theoretical predictions about the behavior of gravity. The most recent approach to quantum gravity, called E-theory, is proposed mathematical, but there is not formulated much about what dynamics of gravity this theory proposes. This research paper treats the main results of the application of E-theory to General relativity involving conservation laws and scattering of particles in presence of gravity. Also the low-energy limit of thi...
2014-01-01
The Article deals with issues of improving methods of planning and carrying out internal audit in conditions of risk-oriented approach to audit according to the indices of value-based management system - VBM (Value Based Management) using the risk card (risk matrix). A risk card (risk matrix) method has been disclosed taking into account risk level of each of the key factors influencing joint-stock company value rates. Recommendations have been given and abstract of working document has been ...
Three-dimensional tricritical gravity
Bergshoeff, Eric A.; de Haan, Sjoerd; Merbis, Wout; Rosseel, Jan; Zojer, Thomas
2012-01-01
We consider a class of parity-even, six-derivative gravity theories in three dimensions. After linearizing around anti-de Sitter space, the theories have one massless and two massive graviton solutions for generic values of the parameters. At a special, so-called tricritical, point in parameter spac
Institute of Scientific and Technical Information of China (English)
安玉林; 郭良辉; 张明华
2015-01-01
In the previous textbooks of gravitational prospecting, the computation of gravity emendation values arising from mass of the Earth's crust at the distance over 2 km from the observation point is confined only to an area of circular ring 2.0~166.7 km in breadth and the computation expressions coming into existence in the orthogonal coordinate system are adopted. China Geological Survey has generalized in recent years the computation program of gravity emendation value that adopts the computation expressions both in the or⁃thogonal coordinate system and in the spherical coordinate system;nevertheless, the computation of gravity emendation values remains confined to an area of circular ring 2.0~166.7 km in breadth and fails to take into account the gravitation arising from mass of the Earth's crust at the distance over 166.7 km from the observation point. 10 years ago, the authors deduced alone gravity expression of the hexahedron with a spherical crust form and other expressions re⁃lated to the computation of gravity emendation values. After this, adopting these expressions, the authors conducted researches on high precision computation and numerical value characteristics of gravity emendation values arising from mass of the Earth's crust in pure spherical coordinate system, with the following computation achievements obtained: ① high precision computation result of "Gravity Emendation Value arising from Mass of the Earth's Crust at Distance Over 169 km From Observation Point" ( GEVMECDO 169 km FOP ) at the square grid 40 km in breadth on whole Earth's land and ocean surface; ② high precision computation achievements of GEVMECDO 169 km FOP at longitude and latitude grid of China's continent;③ high precision computation achievements of GEVM⁃ECDO 169km FOP at the square grid 0.556km in breadth in local 3°×2° area along the large curved portion of the Yarlung Zang Zang⁃bo River. Based on analyzing numerical values distribution characteristics of
Directory of Open Access Journals (Sweden)
Frédéric Gosselin
Full Text Available BACKGROUND: Recent approaches mixing frequentist principles with bayesian inference propose internal goodness-of-fit (GOF p-values that might be valuable for critical analysis of bayesian statistical models. However, GOF p-values developed to date only have known probability distributions under restrictive conditions. As a result, no known GOF p-value has a known probability distribution for any discrepancy function. METHODOLOGY/PRINCIPAL FINDINGS: We show mathematically that a new GOF p-value, called the sampled posterior p-value (SPP, asymptotically has a uniform probability distribution whatever the discrepancy function. In a moderate finite sample context, simulations also showed that the SPP appears stable to relatively uninformative misspecifications of the prior distribution. CONCLUSIONS/SIGNIFICANCE: These reasons, together with its numerical simplicity, make the SPP a better canonical GOF p-value than existing GOF p-values.
Dubovsky, Sergei L.
2004-10-01
We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group. We find that at general values of mass parameters the massive graviton has six propagating degrees of freedom, and some of them are ghosts or lead to rapid classical instabilities. However, there is a number of different regions in the mass parameter space where massive gravity is described by a consistent low-energy effective theory with cutoff ~ (mMPl)1/2. This theory is free of rapid instabilities and vDVZ discontinuity. Each of these regions is characterized by certain fine-tuning relations between mass parameters, generalizing the Fierz Pauli condition. In some cases the required fine-tunings are consequences of the existence of the subgroups of the diffeomorphism group that are left unbroken by the graviton mass. We found two new cases, when the resulting theories have a property of UV insensitivity, i.e. remain well behaved after inclusion of arbitrary higher dimension operators without assuming any fine-tunings among the coefficients of these operators, besides those enforced by the symmetries. These theories can be thought of as generalizations of the ghost condensate model with a smaller residual symmetry group. We briefly discuss what kind of cosmology can one expect in massive gravity and argue that the allowed values of the graviton mass may be quite large, affecting growth of primordial perturbations, structure formation and, perhaps, enhancing the backreaction of inhomogeneities on the expansion rate of the Universe.
Liouville mode in Gauge/Gravity Duality
Moskalets, Tatiana
2014-01-01
We establish solutions corresponding to AdS4 static charged black holes with inhomogeneous two-dimensional horizon surfaces of constant curvature. Depending on the choice of 2D constant curvature space, the metric potential of internal geometry of the horizon satisfies the elliptic wave/elliptic Liouville equations. We calculate the charge diffusion and transport coefficients in the hydrodynamic limit of Gauge/Gravity duality and observe the exponential suppression in the diffusion coefficient and in the shear viscosity-per-entropy density ratio in presence of inhomogeneity on black hole horizons with planar, spherical and hyperbolic geometry. We discuss subtleties of the developed approach for a planar black hole with inhomogeneity distribution on the horizon surface in more detail and find, among others, a trial distribution function, which generates values of the shear viscosity-per-entropy density ratio falling into the experimentally relevant range. The obtained solutions are also extended to higher-dime...
Gravity observations for hydrocarbon reservoir monitoring
Glegola, M.A.
2013-01-01
In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The
Freidel, Laurent; Pranzetti, Daniele
2016-01-01
In this work we study canonical gravity in finite regions for which we introduce a generalisation of the Gibbons-Hawking boundary term including the Immirzi parameter. We study the canonical formulation on a spacelike hypersuface with a boundary sphere and show how the presence of this term leads to an unprecedented type of degrees of freedom coming from the restoration of the gauge and diffeomorphism symmetry at the boundary. In the presence of a loop quantum gravity state, these boundary degrees of freedom localize along a set of punctures on the boundary sphere. We demonstrate that these degrees of freedom are effectively described by auxiliary strings with a 3-dimensional internal target space attached to each puncture. We show that the string currents represent the local frame field, that the string angular momenta represent the area flux and that the string stress tensor represents the two dimensional metric on the boundary of the region of interest. Finally, we show that the commutators of these broken...
Padmanabhan, T
2015-01-01
The equations of motion describing all physical systems, except gravity, remain invariant if a constant is added to the Lagrangian. In the conventional approach, gravitational theories break this symmetry exhibited by all other physical systems. Restoring this symmetry to gravity and demanding that gravitational field equations should also remain invariant under the addition of a constant to a Lagrangian, leads to the interpretation of gravity as the thermodynamic limit of the kinetic theory of atoms of space. This approach selects, in a very natural fashion, Einstein's general relativity in $d=4$. Developing this paradigm at a deeper level, one can obtain the distribution function for the atoms of space and connect it up with the thermodynamic description of spacetime. This extension relies on a curious fact that the quantum spacetime endows each event with a finite area but zero volume. This approach allows us determine the numerical value of the cosmological constant and suggests a new perspective on cosmo...
Gravity Anomaly Assessment Using Ggms and Airborne Gravity Data Towards Bathymetry Estimation
Tugi, A.; Din, A. H. M.; Omar, K. M.; Mardi, A. S.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Yazid, N.
2016-09-01
The Earth's potential information is important for exploration of the Earth's gravity field. The techniques of measuring the Earth's gravity using the terrestrial and ship borne technique are time consuming and have limitation on the vast area. With the space-based measuring technique, these limitations can be overcome. The satellite gravity missions such as Challenging Mini-satellite Payload (CHAMP), Gravity Recovery and Climate Experiment (GRACE), and Gravity-Field and Steady-State Ocean Circulation Explorer Mission (GOCE) has introduced a better way in providing the information on the Earth's gravity field. From these satellite gravity missions, the Global Geopotential Models (GGMs) has been produced from the spherical harmonics coefficient data type. The information of the gravity anomaly can be used to predict the bathymetry because the gravity anomaly and bathymetry have relationships between each other. There are many GGMs that have been published and each of the models gives a different value of the Earth's gravity field information. Therefore, this study is conducted to assess the most reliable GGM for the Malaysian Seas. This study covered the area of the marine area on the South China Sea at Sabah extent. Seven GGMs have been selected from the three satellite gravity missions. The gravity anomalies derived from the GGMs are compared with the airborne gravity anomaly, in order to figure out the correlation (R2) and the root mean square error (RMSE) of the data. From these assessments, the most suitable GGMs for the study area is GOCE model, GO_CONS_GCF_2_TIMR4 with the R2 and RMSE value of 0.7899 and 9.886 mGal, respectively. This selected model will be used in the estimating the bathymetry for Malaysian Seas in future.
GRAVITY ANOMALY ASSESSMENT USING GGMS AND AIRBORNE GRAVITY DATA TOWARDS BATHYMETRY ESTIMATION
Directory of Open Access Journals (Sweden)
A. Tugi
2016-09-01
Full Text Available The Earth’s potential information is important for exploration of the Earth’s gravity field. The techniques of measuring the Earth’s gravity using the terrestrial and ship borne technique are time consuming and have limitation on the vast area. With the space-based measuring technique, these limitations can be overcome. The satellite gravity missions such as Challenging Mini-satellite Payload (CHAMP, Gravity Recovery and Climate Experiment (GRACE, and Gravity-Field and Steady-State Ocean Circulation Explorer Mission (GOCE has introduced a better way in providing the information on the Earth’s gravity field. From these satellite gravity missions, the Global Geopotential Models (GGMs has been produced from the spherical harmonics coefficient data type. The information of the gravity anomaly can be used to predict the bathymetry because the gravity anomaly and bathymetry have relationships between each other. There are many GGMs that have been published and each of the models gives a different value of the Earth’s gravity field information. Therefore, this study is conducted to assess the most reliable GGM for the Malaysian Seas. This study covered the area of the marine area on the South China Sea at Sabah extent. Seven GGMs have been selected from the three satellite gravity missions. The gravity anomalies derived from the GGMs are compared with the airborne gravity anomaly, in order to figure out the correlation (R2 and the root mean square error (RMSE of the data. From these assessments, the most suitable GGMs for the study area is GOCE model, GO_CONS_GCF_2_TIMR4 with the R2 and RMSE value of 0.7899 and 9.886 mGal, respectively. This selected model will be used in the estimating the bathymetry for Malaysian Seas in future.
Supersymmetrizing Massive Gravity
Malaeb, Ola
2013-01-01
When four scalar fields with global Lorentz symmetry are coupled to gravity and take a vacuum expectation value breaking diffeomorphism invariance spontaneously, the graviton becomes massive. This model is supersymmetrized by considering four N=1 chiral superfields with global Lorentz symmetry. When the scalar components of the chiral multiplets z^A acquire a vacuum expectation value, both diffeomorphism invariance and local supersymmetry are broken spontaneously. The global Lorentz index A becomes identified with the space-time Lorentz index making the scalar fields z^A vectors and the chiral spinors \\psi^A spin-3/2 Rarita-Schwinger fields. The global supersymmetry is promoted to a local one using the rules of tensor calculus of coupling the N=1 supergravity Lagrangian to the four chiral multiplets. We show that the spectrum of the model in the broken phase consists of a massive spin-2 field, two massive spin-3/2 fields with different mass and a massive vector.
Empirical Foundations of Relativistic Gravity
Ni, W T
2005-01-01
In 1859, Le Verrier discovered the mercury perihelion advance anomaly. This anomaly turned out to be the first relativistic-gravity effect observed. During the 141 years to 2000, the precisions of laboratory and space experiments, and astrophysical and cosmological observations on relativistic gravity have been improved by 3 orders of magnitude. In 1999, we envisaged a 3-6 order improvement in the next 30 years in all directions of tests of relativistic gravity. In 2000, the interferometric gravitational wave detectors began their runs to accumulate data. In 2003, the measurement of relativistic Shapiro time-delay of the Cassini spacecraft determined the relativistic-gravity parameter gammaγ with a 1.5-order improvement. In October 2004, Ciufolini and Pavlis reported a measurement of the Lense-Thirring effect on the LAGEOS and LAGEOS2 satellites to 10 percent of the value predicted by general relativity. In April 2004, Gravity Probe B was launched and has been accumulating science data for more than ...
Liouville mode in gauge/gravity duality
Energy Technology Data Exchange (ETDEWEB)
Moskalets, Tatiana [Karazin Kharkov National University, Department of Physics and Technology, Kharkov (Ukraine); Nurmagambetov, Alexei [Karazin Kharkov National University, Department of Physics and Technology, Kharkov (Ukraine); Akhiezer Institute for Theoretical Physics of NSC KIPT, Kharkov (Ukraine)
2015-11-15
We establish solutions corresponding to AdS{sub 4} static charged black holes with inhomogeneous two-dimensional horizon surfaces of constant curvature. Depending on the choice of the 2D constant curvature space, the metric potential of the internal geometry of the horizon satisfies the elliptic wave/elliptic Liouville equations. We calculate the charge diffusion and transport coefficients in the hydrodynamic limit of gauge/gravity duality and observe the exponential suppression in the diffusion coefficient and in the shear viscosity-per-entropy density ratio in the presence of an inhomogeneity on black hole horizons with planar, spherical, and hyperbolic geometry. We discuss the subtleties of the approach developed for a planar black hole with inhomogeneity distribution on the horizon surface in more detail and find, among others, a trial distribution function, which generates values of the shear viscosity-per-entropy density ratio falling within the experimentally relevant range. The solutions obtained are also extended to higher-dimensional AdS space. We observe two different DC conductivities in 4D and higher-dimensional effective strongly coupled dual media and formulate conditions under which the appropriate ratio of different conductivities is qualitatively the same as that observed in an anisotropic strongly coupled fluid. We briefly discuss ways of how the Liouville field could appear in condensed matter physics and outline prospects of further employing the gauge/gravity duality in CMP problems. (orig.)
Liouville mode in gauge/gravity duality
Energy Technology Data Exchange (ETDEWEB)
Moskalets, Tatiana, E-mail: tatyana.moskalets@gmail.com [Department of Physics and Technology, Karazin Kharkov National University, 4 Svobody Sq., 61022, Kharkov, UA (Ukraine); Nurmagambetov, Alexei, E-mail: ajn@kipt.kharkov.ua [Department of Physics and Technology, Karazin Kharkov National University, 4 Svobody Sq., 61022, Kharkov, UA (Ukraine); Akhiezer Institute for Theoretical Physics of NSC KIPT, 1 Akademicheskaya St., 61108, Kharkov, UA (Ukraine)
2015-11-25
We establish solutions corresponding to AdS{sub 4} static charged black holes with inhomogeneous two-dimensional horizon surfaces of constant curvature. Depending on the choice of the 2D constant curvature space, the metric potential of the internal geometry of the horizon satisfies the elliptic wave/elliptic Liouville equations. We calculate the charge diffusion and transport coefficients in the hydrodynamic limit of gauge/gravity duality and observe the exponential suppression in the diffusion coefficient and in the shear viscosity-per-entropy density ratio in the presence of an inhomogeneity on black hole horizons with planar, spherical, and hyperbolic geometry. We discuss the subtleties of the approach developed for a planar black hole with inhomogeneity distribution on the horizon surface in more detail and find, among others, a trial distribution function, which generates values of the shear viscosity-per-entropy density ratio falling within the experimentally relevant range. The solutions obtained are also extended to higher-dimensional AdS space. We observe two different DC conductivities in 4D and higher-dimensional effective strongly coupled dual media and formulate conditions under which the appropriate ratio of different conductivities is qualitatively the same as that observed in an anisotropic strongly coupled fluid. We briefly discuss ways of how the Liouville field could appear in condensed matter physics and outline prospects of further employing the gauge/gravity duality in CMP problems.
Meyer, Gregory J; Shaffer, Thomas W; Erdberg, Philip; Horn, Sandra L
2015-01-01
This article describes 3 studies evaluating normative reference data for the Rorschach Comprehensive System (CS; Exner, 2003, 2007), with a particular focus on the viability of the Composite International Reference Values (CIRVs) that were compiled from 21 adult studies by Meyer, Erdberg, and Shaffer (2007). Study 1 documented how the CIRV norms are virtually identical when organized into 3 groups differentiated by the quality of their data collection effort, including an optimal group of 4 samples that relied on multiple experienced examiners and provided ongoing quality control over administration and coding. Analyses also showed that relative to the group of more optimal samples, the group of less optimal samples did not produce more variability in summary scores within or across samples or lower interrater reliability for coding. Study 2 used the existing CS reference norms to generate T scores for the CIRV means and documented how the CS norms make other samples of healthy nonpatients look psychologically impaired in multiple domains. Study 3 documented with examples from 4 different countries how 2 sets of within-country local norms produced notably different results on some variables, which compromises the ability of local norms to be used instead of the CIRVs. Taken together, the 3 studies provide support for the use of CIRVs in clinical practice as norms that are generalizable across samples, settings, languages, and cultures and that account for the natural variability that is present when clinicians and researchers contend with the ambiguity contained in the standard CS reference materials concerning the proper ways to administer and code. We conclude by urging CS users to rely on the CIRVs when making clinical inferences and to adopt alternative methods of ensuring they are following cohesively standardized administration and coding guidelines.
内部控制、公司诉讼和公司价值%Internal Control,Corporate Lawsuits and Firm Value
Institute of Scientific and Technical Information of China (English)
林斌; 周美华; 舒伟; 刘春丽
2013-01-01
Five Chinese government authorities and regulatory bodies jointly issued the Basic Standard for Enterprise Internal Control (C-SOX)in June 2008,which requires listed companies established within the territory of mainland China to establish,evaluate and assess the effectiveness of their internal controls,and encourage large and medium-sized Chinese en-terprises which are non-listed to fulfill these requirements.C-SOX stipulates that one of the internal control objectives is to provide reasonable assurance to realize the compliance of laws and regulations.However,whether the internal control can achieve this objective and im-prove firm value is still full of doubt.Considering these factors,we use corporate lawsuits data in Chinese capital market from 2000 to 2007 to investigate the relationship among inter-nal control,corporate lawsuits and firm value. Based on the contract theory,internal control is an important internal mechanism to en-sure the contract implementation.If internal control is not effective enough,there is of great probability that the stakeholders will seek for external mechanism to protect their own inter-est,such as lawsuits.As a result,companies with weaker internal control are more likely to be involved in litigation,which will influence firm value. We use empirical research method to solve these issues and find that:(1 )Compared to the firms with better internal control,the probability of being litigated is higher in firms with worse internal control;(2)Compared to other firms,the litigated firms have lower firm val-ue;(3)Further,among the litigated firms,the worse the internal control quality,the lower the firm value.In summary,internal control could enhance the compliance activity in firm’s operation,avoid the loss caused by lawsuit,and further improve firm value. Our paper makes three primary contributions.First,we extend the literature of lawsuit. There are few studies on the causes of lawsuit,and our results offer a new angle to discover
Testing Gravity on Accelerators
Kalaydzhyan, Tigran
2016-01-01
Weak equivalence principle (WEP) is one of the cornerstones of the modern theories of gravity, stating that the trajectory of a freely falling test body is independent of its internal structure and composition. Even though WEP is known to be valid for the normal matter with a high precision, it has never been experimentally confirmed for relativistic matter and antimatter. We make an attempt to constrain possible deviations from WEP utilizing the modern accelerator technologies. We analyze the (absence of) vacuum Cherenkov radiation, photon decay, anomalous synchrotron losses and the Compton spectra to put limits on the isotropic Lorentz violation and further convert them to the constraints on the difference between the gravitational and inertial masses of the relativistic electrons/positrons. Our main result is the 0.1% limit on the mentioned difference.
Dualities and emergent gravity: Gauge/gravity duality
de Haro, Sebastian
2017-08-01
In this paper I develop a framework for relating dualities and emergence: two notions that are close to each other but also exclude one another. I adopt the conception of duality as 'isomorphism', from the physics literature, cashing it out in terms of three conditions. These three conditions prompt two conceptually different ways in which a duality can be modified to make room for emergence; and I argue that this exhausts the possibilities for combining dualities and emergence (via coarse-graining). I apply this framework to gauge/gravity dualities, considering in detail three examples: AdS/CFT, Verlinde's scheme, and black holes. My main point about gauge/gravity dualities is that the theories involved, qua theories of gravity, must be background-independent. I distinguish two senses of background-independence: (i) minimalistic and (ii) extended. I argue that the former is sufficiently strong to allow for a consistent theory of quantum gravity; and that AdS/CFT is background-independent on this account; while Verlinde's scheme best fits the extended sense of background-independence. I argue that this extended sense should be applied with some caution: on pain of throwing the baby (general relativity) out with the bath-water (extended background-independence). Nevertheless, it is an interesting and potentially fruitful heuristic principle for quantum gravity theory construction. It suggests some directions for possible generalisations of gauge/gravity dualities. The interpretation of dualities is discussed; and the so-called 'internal' vs. 'external' viewpoints are articulated in terms of: (i) epistemic and metaphysical commitments; (ii) parts vs. wholes. I then analyse the emergence of gravity in gauge/gravity dualities in terms of the two available conceptualisations of emergence; and I show how emergence in AdS/CFT and in Verlinde's scenario differ from each other. Finally, I give a novel derivation of the Bekenstein-Hawking black hole entropy formula based on
Directory of Open Access Journals (Sweden)
Katsuya Hasegawa
2014-04-01
Full Text Available The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6 were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (<0.001 g. Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of −0.3~−0.4 j (g/s induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.
Hasegawa, Katsuya; de Campos, Priscila S; Zeredo, Jorge L; Kumei, Yasuhiro
2014-04-24
The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6) were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and μ g (high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%-200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of -0.3~-0.4 j (g/s) induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.
... medlineplus.gov/ency/article/003587.htm Urine specific gravity test To use the sharing features on this page, please enable JavaScript. Urine specific gravity is a laboratory test that shows the concentration ...
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (24,284 records) were compiled by the U. S. Geological Survey. This data base was received on February 23, 1993. Principal gravity...
Northern Oklahoma Gravity Data
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (710 records) were compiled by Professor Ahern. This data base was received in June 1992. Principal gravity parameters include latitude,...
National Oceanic and Atmospheric Administration, Department of Commerce — The Central Andes gravity data (6,151 records) were compiled by Professor Gotze and the MIGRA Group. This data base was received in April, 1997. Principal gravity...
Cadiz, California Gravity Data
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (32 records) were gathered by Mr. Seth I. Gutman for AridTech Inc., Denver, Colorado using a Worden Prospector gravity meter. This data base...
Classical Weyl Transverse Gravity
Oda, Ichiro
2016-01-01
We study various classical aspects of the Weyl transverse (WTDiff) gravity in a general space-time dimension. First of all, we clarify a classical equivalence among three kinds of gravitational theories, those are, the conformally-invariant scalar tensor gravity, Einstein's general relativity and the WTDiff gravity via the gauge fixing procedure. Secondly, we show that in the WTDiff gravity the cosmological constant is a mere integration constant as in unimodular gravity, but it does not receive any radiative corrections unlike the unimodular gravity. A key point in this proof is to construct a covariantly conserved energy-momentum tensor, which is achieved on the basis of this equivalence relation. Thirdly, we demonstrate that the Noether current for the Weyl transformation is identically vanishing, thereby implying that the Weyl symmetry existing in both the conformally-invariant scalar tensor gravity and the WTDiff gravity is a "fake" symmetry. We find it possible to extend this proof to all matter fields,...
Zucchini, R
1995-01-01
A lagrangian euclidean model of Drinfeld--Sokolov (DS) reduction leading to general W--algebras on a Riemann surface of any genus is presented. The background geometry is given by the DS principal bundle K associated to a complex Lie group G and an SL(2,\\Bbb C) subgroup S. The basic fields are a hermitian fiber metric H of K and a (0,1) Koszul gauge field A^* of K valued in a certain negative graded subalgebra \\goth x of \\goth g related to \\goth s. The action governing the H and A^* dynamics is the effective action of a DS field theory in the geometric background specified by H and A^*. Quantization of H and A^* implements on one hand the DS reduction and on the other defines a novel model of 2d gravity, DS gravity. The gauge fixing of the DS gauge symmetry yields an integration on a moduli space of DS gauge equivalence classes of A^* configurations, the DS moduli space. The model has a residual gauge symmetry associated to the DS gauge transformations leaving a given field A^* invariant. This is the DS count...
Bukley, Angie; Paloski, William; Clement, Gilles
2006-01-01
This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.
Terrestrial Gravity Fluctuations
Harms, Jan
2015-12-01
Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10-23 Hz-1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of
Terrestrial Gravity Fluctuations.
Harms, Jan
2015-01-01
Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10(-23) Hz(-1/2) above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of
Terrestrial Gravity Fluctuations
Directory of Open Access Journals (Sweden)
Jan Harms
2015-12-01
Full Text Available Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10^–23 Hz^–1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our
Terrestrial Gravity Fluctuations
Harms, Jan
2015-01-01
The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.
Rainbow gravity and scale-invariant fluctuations
Amelino-Camelia, Giovanni; Gubitosi, Giulia; Magueijo, Joao
2013-01-01
We re-examine a recently proposed scenario where the deformed dispersion relations associated with a flow of the spectral dimension to a UV value of 2 leads to a scale-invariant spectrum of cosmological fluctuations, without the need for inflation. In that scenario Einstein gravity was assumed. The theory displays a wavelength-dependent speed of light but by transforming to a suitable "rainbow frame" this feature can be removed, at the expense of modifying gravity. We find that the ensuing rainbow gravity theory is such that gravity switches off at high energy (or at least leads to a universal conformal coupling). This explains why the fluctuations are scale-invariant on all scales: there is no horizon scale as such. For dispersion relations that do not lead to exact scale invariance we find instead esoteric inflation in the rainbow frame. We argue that these results shed light on the behaviour of gravity under the phenomenon of dimensional reduction.
Institute of Scientific and Technical Information of China (English)
卢志刚; 张晓旭
2012-01-01
由于电子商务声誉联盟的声誉能力、声誉风险和声誉成本三个主要分配因素存在模糊性和随机性的缺点,难以得到量化,以及Shapley值法本身存在的局限性,因此利用云重心评判法对Shapley值法进行修正.云理论主要体现定性与定量之间的不确定性转换,有效地解决概念的模糊性和随机性.修正后的Shapley分配法有效地提高了联盟分配的准确性,并通过算例证实了此方法的合理性和适用性,为电子商务声誉联盟的收益分配问题提供依据.%Because the three major allocation factors of the e-commerce reputation alliance, the reputation capability, reputation costs and reputation risk are so fuzzy and random that it is difficult to quantify, and also because Shapley value method exists inherent limitations, the cloud gravity center judgment was used to revise Shapley value. The cloud theory that is mainly applied to uncertainly conversion between the qualitative and quantitative issues provides effective solution to the concept of fuzziness and randomness. Revised Shapley distribution method effectively improved the accuracy of the allocation of the e-commerce reputation Alliance, The rationality and applicability of this method were confirmed by using concrete example. This method provides the basis for the distribution of profit of the e-commerce reputation alliance.
Bergshoeff, E.; Pope, C.N.; Stelle, K.S.
1990-01-01
We discuss the notion of higher-spin covariance in w∞ gravity. We show how a recently proposed covariant w∞ gravity action can be obtained from non-chiral w∞ gravity by making field redefinitions that introduce new gauge-field components with corresponding new gauge transformations.
商业银行内部审计的价值增值研究%Research on Value-Added Role of Commercial Banks’ Internal Audit
Institute of Scientific and Technical Information of China (English)
傅剑; 陈华伟
2014-01-01
促进组织完善治理与增加价值，已经成为内部审计新的目标。本文分析了我国商业银行内部审计目标定位及其在增加价值方面的优势，并从转变商业银行内部审计的工作重心、拓展风险管理领域、改善组织内部控制等方面探讨了如何充分发挥内部审计作用以增加组织价值。%Improving organizational governance and adding value, have become the new targets of internal audit.This pa-per analyzes China's commercial bank's internal audit target and the advantage of adding value, and discusses how to give full play the role of internal audit to add value to the organization from shifting focus of the commercial bank's internal audit, ex-panding risk management areas, improving internal controls and other aspects of the organization.
Gravity current jump conditions, revisited
Ungarish, Marius; Hogg, Andrew J.
2016-11-01
Consider the flow of a high-Reynolds-number gravity current of density ρc in an ambient fluid of density ρa in a horizontal channel z ∈ [ 0 , H ] , with gravity in - z direction. The motion is often modeled by a two-layer formulation which displays jumps (shocks) in the height of the interface, in particular at the leading front of the dense layer. Various theoretical models have been advanced to predict the dimensionless speed of the jump, Fr = U /√{g' h } ; g' , h are reduced gravity and jump height. We revisit this problem and using the Navier-Stokes equations, integrated over a control volume embedding the jump, derive balances of mass and momentum fluxes. We focus on understanding the closures needed to complete this model and we show the vital need to understand the pressure head losses over the jump, which we show can be related to the vorticity fluxes at the boundaries of the control volume. Our formulation leads to two governing equations for three dimensionless quantities. Closure requires one further assumption, depending on which we demonstrate that previous models for gravity current fronts and internal bores can be recovered. This analysis yield new insights into existing results, and also provides constraints for potential new formulae.
Dijk, van D.; Trienekens, J.H.
2011-01-01
This volume presents seven case studies of global value chains alongside two theoretical chapters concerning these chains. The contributors explore a wide range of issues relevant to value chains: the impact of global value chains on local upgrading strategies, the role of governance structures
DEFF Research Database (Denmark)
Nordsmark, Marianne; Loncaster, Julie; Aquino-Parsons, Christina
2006-01-01
BACKGROUND AND PURPOSE: Hypoxia adversely affects treatment outcome in human uterine cervical cancer. Here, we present the results of a prospective international multi-centre study evaluating the prognostic value of pre-treatment tumour oxygen partial pressure (pO(2)) and the hypoxia marker...
Kokko, Sirpa; Dillon, Patrick
2011-01-01
This paper explores relationships between crafts, craft education and cultural heritage as reflected in the individual experiences and collective values of fifteen female university students of different nationalities. The students (all trainee teachers) were following a course in crafts and craft education as part of an International Study…
Maxfield, Travis; Sethi, Savdeep
2017-02-01
We study the dynamics of gravitational lumps. By a lump, we mean a metric configuration that asymptotes to a flat space-time. Such lumps emerge in string theory as strong coupling descriptions of D-branes. We provide a physical argument that the broken global symmetries of such a background, generated by certain large diffeomorphisms, constrain the dynamics of localized modes. These modes include the translation zero modes and any localized tensor modes. The constraints we find are gravitational analogues of those found in brane physics. For the example of a Taub-NUT metric in eleven-dimensional supergravity, we argue that a critical value for the electric field arises from standard gravity without higher derivative interactions.
Maxfield, Travis
2016-01-01
We study the dynamics of gravitational lumps. By a lump, we mean a metric configuration that asymptotes to a flat space-time. Such lumps emerge in string theory as strong coupling descriptions of D-branes. We provide a physical argument that the broken global symmetries of such a background, generated by certain large diffeomorphisms, constrain the dynamics of localized modes. These modes include the translation zero modes and any localized tensor modes. The constraints we find are gravitational analogues of those found in brane physics. For the example of a Taub-NUT metric in eleven-dimensional supergravity, we argue that a critical value for the electric field arises from standard gravity without higher derivative interactions.
Quantization of Emergent Gravity
Yang, Hyun Seok
2013-01-01
Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as spacetime admits a symplectic structure, in other words, a microscopic spacetime becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC spacetime, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing spacetime itself, leading to a dynamical NC spacetime. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background independent formulation where spacetime as well as matter fields is equally emergent from a universal vacuum of quantum gravity.
Quantization of emergent gravity
Yang, Hyun Seok
2015-02-01
Emergent gravity is based on a novel form of the equivalence principle known as the Darboux theorem or the Moser lemma in symplectic geometry stating that the electromagnetic force can always be eliminated by a local coordinate transformation as far as space-time admits a symplectic structure, in other words, a microscopic space-time becomes noncommutative (NC). If gravity emerges from U(1) gauge theory on NC space-time, this picture of emergent gravity suggests a completely new quantization scheme where quantum gravity is defined by quantizing space-time itself, leading to a dynamical NC space-time. Therefore the quantization of emergent gravity is radically different from the conventional approach trying to quantize a phase space of metric fields. This approach for quantum gravity allows a background-independent formulation where space-time and matter fields are equally emergent from a universal vacuum of quantum gravity.
Fulford, K. W. M
2011-01-01
In the current climate of dramatic advances in the neurosciences, it has been widely assumed that the diagnosis of mental disorder is a matter exclusively for value-free science. Starting from a detailed case history, this paper describes how, to the contrary, values come into the diagnosis of mental disorders, directly through the criteria at the heart of psychiatry’s most scientifically grounded classification, the American Psychiatric Association’s DSM (Diagnostic and Statistical Manual). Various possible interpretations of the prominence of values in psychiatric diagnosis are outlined. Drawing on work in the Oxford analytic tradition of philosophy, it is shown that, properly understood, the prominence of psychiatric diagnostic values reflects the necessary engagement of psychiatry with the diversity of individual human values. This interpretation opens up psychiatric diagnostic assessment to the resources of a new skills-based approach to working with complex and conflicting values (also derived from analytic philosophy) called ‘values-based practice.’ Developments in values-based practice in training, policy and research in mental health are briefly outlined. The paper concludes with an indication of how the integration of values-based with evidence-based approaches provides the basis for psychiatric practice in the twenty-first century that is both science-based and person-centred. PMID:21694963
Directory of Open Access Journals (Sweden)
Fulford KWM
2011-01-01
Full Text Available In the current climate of dramatic advances in the neurosciences, it has been widely assumed that the diagnosis of mental disorder is a matter exclusively for value-free science. Starting from a detailed case history, this paper describes how, to the contrary, values come into the diagnosis of mental disorders, directly through the criteria at the heart of psychiatry′s most scientifically grounded classification, the American Psychiatric Association′s DSM (Diagnostic and Statistical Manual. Various possible interpretations of the prominence of values in psychiatric diagnosis are outlined. Drawing on work in the Oxford analytic tradition of philosophy, it is shown that, properly understood, the prominence of psychiatric diagnostic values reflects the necessary engagement of psychiatry with the diversity of individual human values. This interpretation opens up psychiatric diagnostic assessment to the resources of a new skills-based approach to working with complex and conflicting values (also derived from analytic philosophy called ′values-based practice.′ Developments in values-based practice in training, policy and research in mental health are briefly outlined. The paper concludes with an indication of how the integration of values-based with evidence-based approaches provides the basis for psychiatric practice in the twenty-first century that is both science-based and person-centred.
Directory of Open Access Journals (Sweden)
K. W. M. Fulford
2011-03-01
Full Text Available In the current climate of dramatic advances in the neurosciences, it has been widely assumed that the diagnosis of mental disorder is a matter exclusively for value-free science. Starting from a detailed case history, this paper describes how, to the contrary, values come into the diagnosis of mental disorders, directly through the criteria at the heart of psychiatry's most scientifically grounded classification, the American Psychiatric Association's DSM (Diagnostic and Statistical Manual. Various possible interpretations of the prominence of values in psychiatric diagnosis are outlined. Drawing on work in the Oxford analytic tradition of philosophy, it is shown that, properly understood, the prominence of psychiatric diagnostic values reflects the necessary engagement of psychiatry with the diversity of individual human values. This interpretation opens up psychiatric diagnostic assessment to the resources of a new skills-based approach to working with complex and conflicting values (also derived from analytic philosophy called 'values-based practice.' Developments in values-based practice in training, policy and research in mental health are briefly outlined. The paper concludes with an indication of how the integration of values-based with evidence-based approaches provides the basis for psychiatric practice in the twenty-first century that is both science-based and person-centred.
Excursion into Quantum Gravity via Inflation
Calmet, Xavier
2014-01-01
The discovery of B-modes, and their effect on the fit to inflationary parameters, opens a window to explore quantum gravity. In this paper we adopt an effective theory approach to study quantum gravity effects in inflation. We apply this approach to chaotic and $\\phi^4$ inflation, and find that BICEP2 constrains these new operators to values which are consistent with the effective theory approach. This result opens the possibility to study quantum gravity in a systematic fashion, including its effect on Higgs inflation and other Starobisnky-like models.
The Value Basis of University Internal Governance:Educational Justice Perspective%论大学的内部治理：教育正义的视角
Institute of Scientific and Technical Information of China (English)
解瑞红
2015-01-01
University internal governance is the coordination of various interest subjects in universities. Education justice is the basic value of University governance, University internal governance should be based on the educational justice. But in reality, the pursuit of utility, the administrative guidance, the dependent culture leads to the lack of education justice in the internal governance of universities. Through the multiple interests of the main body of the university internal control and evaluation and the evaluation of the university regulations of the system to ensure that the university internal governance has always been based on the value of education justice.%大学内部治理是对大学内部各种利益主体关系的协调。教育正义是大学治理最基本的价值前提，大学内部治理应当以教育正义为依据。但现实中大学对功利的追求、行政的泛化、依附的文化导致大学内部治理中教育正义缺失，需要通过多元利益主体参与和评价大学内部治理以及大学章程的制度保障来确保大学内部治理始终以教育正义为价值依据。
Autonomous orbit determination via Kalman filtering of gravity gradients
Sun; Chen,De; Macabiau, Christophe; Han
2016-01-01
International audience; Spaceborne gravity gradients are proposed in this paper to provide autonomous orbit determination capabilities for near Earth satellites. The gravity gradients contain useful position information which can be extracted by matching the observations with a precise gravity model. The extended Kalman filter is investigated as the principal estimator. The stochastic model of orbital motion, the measurement equation and the model configuration are discussed for the filter de...
Time evolution in the presence of gravity
Pulido, A; Tresguerres, R; Pulido, Antonio; Tiemblo, Alfredo; Tresguerres, Romualdo
2001-01-01
We present a suggestion on the interpretation of canonical time evolution when gravitation is present, based on the nonlinear gauge approach to gravity. Essentially, our proposal consists of an internal-time concept, with the time variable taken from the dynamical fields characteristic of the nonlinear realization of the internal time-translational symmetry. Physical time evolution requires the latter symmetry to be broken. After disregarding other breaking mechanisms, we appeal to the Jordan-Brans-Dicke action, conveniently interpreted, to achieve that goal. We show that nontrivial time evolution follows, the special relativistic limit being recovered in the absence of gravity.
Gravity variation before Kunlun mountain pass western MS=8.1 earthquake
Institute of Scientific and Technical Information of China (English)
祝意青; 王双绪; 江在森; 朱桂芝; 李辉; 张永志
2003-01-01
The relation between the gravity variation features and MS=8.1 earthquake in Qinghai-Xizang monitoring area is analyzed preliminarily, by using spatial dynamic variation results of regional gravity field from absolute gravity and relative gravity observation in 1998 and 2000. The results show that: 1) MS=8.1 earthquakein Kulun mountain pass western occurred in the gravity variation high gradient near gravity(s high negative variation; 2) The main tectonic deformation and energy accumulation before MS=8.1 earthquake are distributed at south side of the epicenter; 3) The range of gravity(s high negative variation at east of the MS=8.1 earthquake epicenter relatively coincides with that rupture region according to field geology investigation; 4) Gravity variation distribution in high negative value region is just consistent with the second shear strain(s high value region of strain field obtained from GPS observation.
Quantum corrections to unimodular gravity
Energy Technology Data Exchange (ETDEWEB)
Álvarez, Enrique; González-Martín, Sergio; Herrero-Valea, Mario [Instituto de Física Teórica UAM/CSIC,C/Nicolas Cabrera, 13-15, C.University Cantoblanco, 28049 Madrid (Spain); Departamento de Física Teórica,Universidad Autónoma de Madrid, 20849 Madrid (Spain); Martín, Carmelo P. [Universidad Complutense de Madrid (UCM), Departamento de Física Téorica I,Facultad de Ciencias Físicas, Av. Complutense S/N (Ciudad University), 28040 Madrid (Spain)
2015-08-17
The problem of the comological constant appears in a new light in Unimodular Gravity. In particular, the zero momentum piece of the potential (that is, the constant piece independent of the matter fields) does not automatically produce a cosmological constant proportional to it. The aim of this paper is to give some details on a calculation showing that quantum corrections do not renormalize the classical value of this observable.
Wilson loops in CDT quantum gravity
Ambjorn, J; Jurkiewicz, J; Loll, R
2015-01-01
By explicit construction, we show that one can in a simple way introduce and measure gravitational holonomies and Wilson loops in lattice formulations of nonperturbative quantum gravity based on (Causal) Dynamical Triangulations. We use this set-up to investigate a class of Wilson line observables associated with the world line of a point particle coupled to quantum gravity, and deduce from their expectation values that the underlying holonomies cover the group manifold of SO(4) uniformly
基于价值链管理的内部控制构建思想%Constructing Thoughts of Internal Control Based on Value Chain Management
Institute of Scientific and Technical Information of China (English)
张其镇
2011-01-01
Development and application of information technology and value chain theory provide a good opportunity to improve the management level of enterprise and gain a competitive advantage. This paper, combining with the value chain theory, analyzes the key steps to build the internal control which can adapt to the management of value chain under the guidance of the internal control structure. This paper .argues that internal control should be value-added activities which take getting a competitive advantage as the strategic goal, take theall kinds of "flow" in business as the main line of control and constantly self-perfect.%信息技术与价值链理论的发展与应用,为提高企业管理水平,获得竞争优势提供了一个良好的契机.本文结合价值链理论,分析了在内部控制结构指导下构建一个能适应价值链管理的内部控制的关键步骤.本文认为,内部控制应是一个以获取竞争优势为战略目标,以企业内各种"流"为控制主线并能不断自我完善的增值活动.
Energy Technology Data Exchange (ETDEWEB)
Cruz, J.
2009-07-01
Communication both internal and external in the Cofrentes Nuclear Power plant has become an essential element. In fact, it always has been. Over the past 25 years, we have strived to consolidate communication plans that, today, provided us with a large body of knowledge in this field. (Author)
Wang, Yuxin; Hulstijn, Joris; Tan, Yao-Hua
2016-01-01
With increasing international trade and growing emphasis on security and efficiency, enhanced information and data-sharing between different stakeholders in global supply chains is required. Currently, data quality is not only problematic for traders, but also for various government agencies that ar
DEFF Research Database (Denmark)
Christensen, U C; Krøyer, K; Sander, B
2009-01-01
AIM: To determine the effect of internal limiting membrane (ILM) peeling on anatomical and functional success rates in stage 2 and 3 idiopathic macular hole surgery (MHS). METHODS: Randomised clinical trial of stage 2 and 3 idiopathic macular hole without visible epiretinal fibrosis and with less...
Scaling Exponents for Lattice Quantum Gravity in Four Dimensions
Hamber, Herbert W
2015-01-01
In this work nonperturbative aspects of quantum gravity are investigated using the lattice formulation, and some new results are presented for critical exponents, amplitudes and invariant correlation functions. Values for the universal scaling dimensions are compared with other nonperturbative approaches to gravity in four dimensions, and specifically to the conjectured value for the universal critical exponent $\
Directory of Open Access Journals (Sweden)
Pedro L. Faggion
2005-08-01
Full Text Available Adjustment strategies associated to the methodology applied used to the implantation of a gravity network of high precision in Paraná are presented. A network was implanted with stations in 21 places in the State of Paraná and one in the state of São Paulo To reduce the risk of the losing of points of that gravity network, they were established on the points of the GPS High Precision Network of Paraná, which possess a relatively homogeneous geographical distribution. For each one of the gravity lines belonging to the loops implanted for the network, it was possible to obtain three or six observations. In the first strategy, of adjustment investigated, for the net, it was considered, as observation, the medium value of the observations obtained for each gravity line. In the second strategy, of the adjustment, the observations were considered independent. The comparison of those strategies revealed that only the precision criteria is not enough to indicate the great solution of a gravity network. It was verified that there is need to use an additional criterion for analysis of the adjusted solution of the network, besides the precision criteria. The reliability criterion for geodesic networks, which becomes separated in reliability internal and external reliability it was used. The reliability internal it was used to verify the rigidity with which the network reacts in the detection and quantification of existent gross errors in the observations, and the reliability external in the quantification of the influence on the adjusted parameters of the errors non located. They are presented the aspects that differentiate the obtained solutions, when they combine the precision criteria and reliability criteria in the analysis of the quality of a gravity network.
Micro-gravity Isolation using only Electro-magnetic Actuators
DEFF Research Database (Denmark)
Vinther, D.; Alminde, Lars; Bisgaard, Morten
2004-01-01
In this paper the design, construction and test of a free floating micro-gravity isolation platform to reduce the acceleration dose on zero gravity experiments on e.g. the International Space Station (ISS) is discussed. During the project a system is specified and constructed whereupon it is test...
Brown, Kerry A; de Wit, Liesbeth; Timotijevic, Lada; Sonne, Anne-Mette; Lähteenmäki, Liisa; Brito Garcia, Noé; Jeruszka-Bielak, Marta; Sicińska, Ewa; Moore, Alana N; Lawrence, Mark; Raats, Monique M
2015-06-01
Transparent evidence-based decision making has been promoted worldwide to engender trust in science and policy making. Yet, little attention has been given to transparency implementation. The degree of transparency (focused on how uncertain evidence was handled) during the development of folate and vitamin D Dietary Reference Values was explored in three a priori defined areas: (i) value request; (ii) evidence evaluation; and (iii) final values. Qualitative case studies (semi-structured interviews and desk research). A common protocol was used for data collection, interview thematic analysis and reporting. Results were coordinated via cross-case synthesis. Australia and New Zealand, Netherlands, Nordic countries, Poland, Spain and UK. Twenty-one interviews were conducted in six case studies. Transparency of process was not universally observed across countries or areas of the recommendation setting process. Transparency practices were most commonly seen surrounding the request to develop reference values (e.g. access to risk manager/assessor problem formulation discussions) and evidence evaluation (e.g. disclosure of risk assessor data sourcing/evaluation protocols). Fewer transparency practices were observed to assist with handling uncertainty in the evidence base during the development of quantitative reference values. Implementation of transparency policies may be limited by a lack of dedicated resources and best practice procedures, particularly to assist with the latter stages of reference value development. Challenges remain regarding the best practice for transparently communicating the influence of uncertain evidence on the final reference values. Resolving this issue may assist the evolution of nutrition risk assessment and better inform the recommendation setting process.
Pirkola, Patrik
2016-01-01
The surface gravity on Mars is smaller than the surface gravity on Earth, resulting in longer falling times. This effect can be simulated on Earth by taking advantage of air resistance and buoyancy, which cause low density objects to fall slowly enough to approximate objects falling on the surface of Mars. We describe a computer simulation based on an experiment that approximates Martian gravity, and verify our numerical results by performing the experiment.
Directory of Open Access Journals (Sweden)
Rongjia Yang
2014-08-01
Full Text Available If we assume that the source of thermodynamic system, ρ and p, are also the source of gravity, then either thermal quantities, such as entropy, temperature, and chemical potential, can induce gravitational effects, or gravity can induce thermal effects. We find that gravity can be seen as entropic force only for systems with constant temperature and zero chemical potential. The case for Newtonian approximation is discussed.
Trugenberger, Carlo A
2016-01-01
In a recently developed approach, geometry is modelled as an emergent property of random networks. Here I show that one of these models I proposed is exactly quantum gravity defined in terms of the combinatorial Ricci curvature recently derived by Ollivier. Geometry in the weak (classical) gravity regime arises in a phase transition driven by the condensation of short graph cycles. The strong (quantum) gravity regime corresponds to "small world" random graphs with logarithmic distance scaling.
Mielke, E W
2006-01-01
Anomalies in Yang-Mills type gauge theories of gravity are reviewed. Particular attention is paid to the relation between the Dirac spin, the axial current j_5 and the non-covariant gauge spin C. Using diagrammatic techniques, we show that only generalizations of the U(1)- Pontrjagin four--form F^ F= dC arise in the chiral anomaly, even when coupled to gravity. Implications for Ashtekar's canonical approach to quantum gravity are discussed.
2014-01-01
Recently, a lot of changes in the legislation governing the Brazilian accounting practices initiated the alignment of Brazil to the internationalization process of accounting. In this context, this article aims to verify if the process of convergence to international accounting standards impacted the value relevance of accounting information such as Earnings per Share (LPA) and Equity per Share (PLPA), of the non-financial companies most traded on BM&FBOVESPA. This is done by testing the ...
Directory of Open Access Journals (Sweden)
Amrita Kapur
2016-03-01
Full Text Available This article examines the unexplored potential for the International Criminal Court’s (ICC direct engagement with States to influence national prosecutorial priorities for international crimes, and how this may be leveraged to improve criminal prosecutions for crimes of sexual violence in particular. The article focuses on the intersection of two phenomenona: first, how international norms can influence national behaviour; and second, how systemic failures to prosecute crimes of sexual violence can be challenged. The article centres on engagement between the ICC and States pursuant to the principle of complementarity in The Rome Statute, as manifested in preliminary examinations. Drawing on the transnational legal process (TLP framework, the article suggests how complementarity can be utilized to promote national compliance with the international norm of criminal accountability for international crimes. By examining ICC documents and practice, the article contends that exposing the gendered dimensions of State de-prioritization of sexual violence crimes will enable the ICC, as an international institution interacting with these regimes, to better facilitate gender-sensitive criminal justice responses to international crimes. Este artículo analiza el potencial inexplorado del compromiso directo entre la Corte Penal Internacional (CPI y los estados para influir en las prioridades nacionales procesales por crímenes internacionales, y cómo esto se puede aprovechar para mejorar en particular los procesos penales por delitos de violencia sexual. El artículo pone el acento en en la intersección de dos fenómenos: en primer lugar, cómo pueden influir las normas internacionales en el comportamiento nacional; y en segundo lugar, cómo se pueden impugnar los fallos sistémicos para enjuiciar los crímenes de violencia sexual. El artículo se centra en el compromiso entre la CPI y los estados, en virtud del principio de complementariedad del
Gravity Independent Compressor Project
National Aeronautics and Space Administration — We propose to develop and demonstrate a small, gravity independent, vapor compression refrigeration system using a linear motor compressor which effectively...
Classical Weyl transverse gravity
Energy Technology Data Exchange (ETDEWEB)
Oda, Ichiro [University of the Ryukyus, Department of Physics, Faculty of Science, Nishihara, Okinawa (Japan)
2017-05-15
We study various classical aspects of the Weyl transverse (WTDiff) gravity in a general space-time dimension. First of all, we clarify a classical equivalence among three kinds of gravitational theories, those are, the conformally invariant scalar tensor gravity, Einstein's general relativity and the WTDiff gravity via the gauge-fixing procedure. Secondly, we show that in the WTDiff gravity the cosmological constant is a mere integration constant as in unimodular gravity, but it does not receive any radiative corrections unlike the unimodular gravity. A key point in this proof is to construct a covariantly conserved energy-momentum tensor, which is achieved on the basis of this equivalence relation. Thirdly, we demonstrate that the Noether current for the Weyl transformation is identically vanishing, thereby implying that the Weyl symmetry existing in both the conformally invariant scalar tensor gravity and the WTDiff gravity is a ''fake'' symmetry. We find it possible to extend this proof to all matter fields, i.e. the Weyl-invariant scalar, vector and spinor fields. Fourthly, it is explicitly shown that in the WTDiff gravity the Schwarzschild black hole metric and a charged black hole one are classical solutions to the equations of motion only when they are expressed in the Cartesian coordinate system. Finally, we consider the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology and provide some exact solutions. (orig.)
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Animesh Mukherjee
1991-01-01
Full Text Available Based upon Biot's [1965] theory of initial stresses of hydrostatic nature produced by the effect of gravity, a study is made of surface waves in higher order visco-elastic media under the influence of gravity. The equation for the wave velocity of Stonely waves in the presence of viscous and gravitational effects is obtained. This is followed by particular cases of surface waves including Rayleigh waves and Love waves in the presence of viscous and gravity effects. In all cases the wave-velocity equations are found to be in perfect agreement with the corresponding classical results when the effects of gravity and viscosity are neglected.
Mass Inflation in Brans-Dicke gravity
Pina-Avelino, P; Herdeiro, C A R
2009-01-01
A detailed non-linear analysis of the internal structure of spherical, charged black holes that are accreting scalar matter is performed in the framework of the Brans-Dicke theory of gravity. We choose the lowest value of the Brans-Dicke parameter that is compatible with observational constraints. First, the homogeneous approximation is used. It indicates that mass inflation occurs and that the variations of the Brans-Dicke scalar inside the black hole, which could in principle be large in the absence of mass inflation, become small when mass inflation does occur. Then, a full non-linear numerical study of the black hole interior perturbed by a self-gravitating massless uncharged scalar-field is performed. We use an algorithm with adaptive mesh refinement capabilities. In this way, the changes in the internal structure of the black hole caused by mass inflation are determined, as well as the induced variations of the Brans-Dicke scalar, confirming, qualitatively, the indications given by the homogeneous appro...
Cosmological Hints of Modified Gravity ?
Di Valentino, Eleonora; Silk, Joseph
2016-01-01
The recent measurements of Cosmic Microwave Background temperature and polarization anisotropies made by the Planck satellite have provided impressive confirmation of the $\\Lambda$CDM cosmological model. However interesting hints of slight deviations from $\\Lambda$CDM have been found, including a $95 \\%$ c.l. preference for a "modified gravity" structure formation scenario. In this paper we confirm the preference for a modified gravity scenario from Planck 2015 data, find that modified gravity solves the so-called $A_{lens}$ anomaly in the CMB angular spectrum, and constrains the amplitude of matter density fluctuations to $\\sigma_8=0.815_{-0.048}^{+0.032}$, in better agreement with weak lensing constraints. Moreover, we find a lower value for the reionization optical depth of $\\tau=0.059\\pm0.020$ (to be compared with the value of $\\tau= 0.079 \\pm 0.017$ obtained in the standard scenario), more consistent with recent optical and UV data. We check the stability of this result by considering possible degeneraci...
1997-03-01
re–inforce their social perception of those core values our senior leadership have articulated. According to Kurt Lewin , “lectures and other abstract...motivated because life in the company has meaning for them.1 —Terrence E. Deal and Allan A. Kennedy Corporate Cultures Kurt Lewin defines re–education as
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Annette Kainu
2016-09-01
Full Text Available Background: New Finnish (Kainu2015 and international Global Lung Function Initiative (GLI2012 reference values for spirometry were recently published. The aim of this study is to compare the interpretative consequences of adopting these new reference values with older, currently used Finnish reference values (Viljanen1982 in the general population of native Finns. Methods: Two Finnish general population samples including 1,328 adults (45% males aged 21–74 years were evaluated. Airway obstruction was defined as a reduced ratio of forced expiratory volume in one second (FEV1/forced vital capacity (FVC, possible restrictive pattern as reduced FVC, and decreased ventilatory capacity as reduced FEV1 below their respective 2.5th percentiles. The severity gradings of reduced lung function were also compared. Results: Using the Kainu2015 reference values, the prevalence of airway obstruction in the population was 5.6%; using GLI2012 it was 4.0% and with Viljanen1982 it was 13.0%. Possible restrictive pattern was found in 4.2% using the Kainu2015 values, in 2.0% with GLI2012, and 7.9% with the Viljanen1982 values. The prevalence of decreased ventilatory capacity was 6.8, 4.0, and 13.3% with the Kainu2015, GLI2012 and Viljanen1982 values, respectively. Conclusions: The application of the GLI2012 reference values underestimates the prevalence of abnormal spirometric findings in native Finns. The adoption of the Kainu2015 reference values reduces the prevalences of airways obstruction, decreased ventilatory capacity, and restrictive impairment by approximately 50%. Changing from the 2.5th percentile, the previously used lower limit of normal, to the 5th percentile recommended by the American Thoracic Society/European Respiratory Society will not increase the prevalence of abnormal findings in the implementation of spirometry reference values.
Study on tidal gravity observations obtained at stations Zhongshan and Changcheng, Antarctic
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Based on the international tidal gravity reference values at station Wuhan, the tidal gravity parameters, including the amplitude factors and phase differences are determined accurately by using the observations with three La-Coste-Romberg (LCR) gravimeters (G-589, ET-20 and ET-21) at stations Zhongshan and Changcheng in the Ant-arctic, respectively. The standard deviations of the determined amplitude factors of the main tidal waves are better than 0.5%. The amplitude of each tidal wave observed at station Zhongshan is much less than that of the same wave at station Changcheng. The differences of amplitude factors in the diurnal band (O1) at these two stations are less than 7% while those in the semi-diurnal band (M2) are larger than 40%. The influences of meteorology factors, such as atmospheric pressure and temperature, on the tidal gravity observations are very obvious. The oceanic loading effects on the tidal gravity are also very prominent. It is found that the amplitude of the final residual vec-tor of every tidal wave reduces significantly after oceanic correction based on the Schwiderski's global co-tides. However, because the local oceanic loading is not taken into account, the discrepancies of amplitude factors of wave O1 observed at Zhongshan from the corresponding values of theoretical tidal model are about 4%, and 9% at Changcheng.
Galathea-3: A global marine gravity profile
DEFF Research Database (Denmark)
Strykowski, Gabriel; Cordua, Knud Skou; Forsberg, René
2012-01-01
topography. This paper reports on the second experiment in which a continuous marine gravity profile along the ship’s route was measured. The focus of the paper is on the practical aspects of such large scale world wide operation and on the challenges of the data processing. Furthermore, the processed free......-air gravity values are compared to 3 global models: EGM96, EGM08 and DNSC08. Even though the along-track resolution of marine data is higher than the resolution in any global gravity model (which influences the direct comparison of the collected marine data to the model) the statistics for the residual free......-air gravity anomalies show, that EGM08 and DNSC08 are better models than EGM96 for all Galathea-3 legs. Some areas along the ships route are quite challenging for modellers....
Galathea-3: A global marine gravity profile
DEFF Research Database (Denmark)
Strykowski, Gabriel; Cordua, Knud Skou; Forsberg, René
2012-01-01
-air gravity values are compared to 3 global models: EGM96, EGM08 and DNSC08. Even though the along-track resolution of marine data is higher than the resolution in any global gravity model (which influences the direct comparison of the collected marine data to the model) the statistics for the residual free......-air gravity anomalies show, that EGM08 and DNSC08 are better models than EGM96 for all Galathea-3 legs. Some areas along the ships route are quite challenging for modellers....... topography. This paper reports on the second experiment in which a continuous marine gravity profile along the ship’s route was measured. The focus of the paper is on the practical aspects of such large scale world wide operation and on the challenges of the data processing. Furthermore, the processed free...
Stochastic Gravity: Theory and Applications
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Hu Bei Lok
2004-01-01
Full Text Available Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. The noise kernel is the vacuum expectation value of the (operator-valued stress-energy bi-tensor which describes the fluctuations of quantum matter fields in curved spacetimes. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity, showing the link from the mean value of the stress-energy tensor to their correlation functions. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh closed-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical and stochastic contents of the theory such as dissipation, fluctuations, noise, and decoherence. We then focus on the properties of the stress-energy bi-tensor. We obtain a general expression for the noise kernel of a quantum field defined at two distinct points in an arbitrary curved spacetime as products of covariant derivatives of the quantum field's Green function. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime. We offer an analytical solution of the Einstein-Langevin equation and compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint, which can go beyond the standard treatment by incorporating the full quantum effect of the inflaton fluctuations. Third, we discuss the backreaction
New Techniques for Absolute Gravity Measurements.
1983-01-07
Hammond, J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J. A., and Iliff, R. L. (1979) The AFGL absolute gravity system...International Gravimetric Bureau, No. L:I-43. 7. Hammond. J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J.A., and
The strange equation of quantum gravity
2015-01-01
Appeared in the Classical and Quantum Gravity Focus issue: Milestones of general relativity. 7 pages; International audience; Disavowed by one its fathers, ill defined, never empirically tested, the Wheeler-DeWitt equation has nevertheless had a powerful influence on fundamental physics. A well deserved one.
Gravity data from the San Pedro River Basin, Cochise County, Arizona
Kennedy, Jeffrey R.; Winester, Daniel
2011-01-01
The U.S. Geological Survey, Arizona Water Science Center in cooperation with the National Oceanic and Atmospheric Administration, National Geodetic Survey has collected relative and absolute gravity data at 321 stations in the San Pedro River Basin of southeastern Arizona since 2000. Data are of three types: observed gravity values and associated free-air, simple Bouguer, and complete Bouguer anomaly values, useful for subsurface-density modeling; high-precision relative-gravity surveys repeated over time, useful for aquifer-storage-change monitoring; and absolute-gravity values, useful as base stations for relative-gravity surveys and for monitoring gravity change over time. The data are compiled, without interpretation, in three spreadsheet files. Gravity values, GPS locations, and driving directions for absolute-gravity base stations are presented as National Geodetic Survey site descriptions.
Ellegaard, Chris; Freytag, Per V.
2010-01-01
Reports on supply chain management (SCM) failure are becoming more frequent in the SCM literature, despite widespread recognition of the business potential associated with such optimizations of operational buyer-supplier interfaces. Some failures can be ascribed to imbalances in the net benefits realized by the buying and supplying company implementing SCM. Failed SCM initiatives hurt the buying company’s customer attractiveness and limit opportunities for long term value creation with suppli...
Lane, R H; Erickson, R L
1988-01-01
Fat acidity values were determined on 8 commercially available flours by the American Association of Cereal Chemists method (AACC-02-01A) and by the International Organization for Standardization method (ISO-7305). Comparisons of means obtained by these 2 methods indicated that the ISO method produced results that were 1.4-2.5 times greater (P less than 0.001) than those for the AACC method. These data are consistent with a previous report which indicated that acidic materials (phosphates and amino acids) other than fatty acids are extracted by 95% alcohol (ISO method), whereas fatty acids alone are extracted by petroleum ether (AACC method). Fat acidity values obtained by AACC methodology employing Soxhlet and continuous extraction were also compared. No difference in fat acidity means existed with respect to extraction technique except for an aged whole wheat flour sample which produced a higher value (P = 0.05) by continuous extraction.
DEFF Research Database (Denmark)
Christensen, Ulrik Correll
2009-01-01
, but during the past decade focus has especially been on internal limiting membrane (ILM) peeling as adjuvant therapy for increasing closure rates. With increasing use of ILM peeling and indocyanine green (ICG) staining, which is used for specific visualization of the ILM, concerns about the safety...... rate than surgery without ILM peeling (95% versus 45%). The overall functional results confirm that surgery for macular hole generally leads to favourable visual results, with two-thirds of eyes regaining reading vision (>or=20/40). Macular hole surgery can be considered a safe procedure with a low...... incidence of sight-threatening adverse events; the retinal detachment rate was 2.2%. Visual outcomes in eyes with primary hole closure were not significantly different between the intervention groups; however, for the stage 2 subgroup with primary macular hole closure, there was a trend towards a better...
Kan, Nahomi; Maki, Takuya; Shiraishi, Kiyoshi
2016-10-01
We propose a model of gravity in which a General Relativity metric tensor and an effective metric generated from a single scalar formulated in geometric scalar gravity are mixed. We show that the model yields the exact Schwarzschild solution, along with accelerating behavior of scale factors in cosmological solutions.
No consistent bimetric gravity?
Deser, S; Waldron, A
2013-01-01
We discuss the prospects for a consistent, nonlinear, partially massless (PM), gauge symmetry of bimetric gravity (BMG). Just as for single metric massive gravity, ultimate consistency of both BMG and the putative PM BMG theory relies crucially on this gauge symmetry. We argue, however, that it does not exist.
Krasnov, Kirill
2016-01-01
Self-dual gravity is a diffeomorphism invariant theory in four dimensions that describes two propagating polarisations of the graviton and has a negative mass dimension coupling constant. Nevertheless, this theory is not only renormalisable but quantum finite, as we explain. We also collect various facts about self-dual gravity that are scattered across the literature.
Masters, Roy
2010-03-01
Flowing global gravitation initially produced space without time or mass. Space-time and mass are properties of flowing global gravitation. From its fabric, primal mass spins spontaneously giving rise to local gravitational space-time curvatures. Global gravity is the unifying background field. Gravity began flowing from its singularity with a big whoosh. It curves with angular rotational precession, creating a spatial geometry similar to the windings of a ball of string. Three-dimensional global gravity swirls locally into massive densities. Concurrently with these densities, local gravity curvatures of space-time arise. The expanse between celestial objects is not completely empty, void space as generally believed; it is antecedent gravity, a prerequisite associated field necessary for originating the first quantum particles. Gravity is dark energy; gravity's spin, as the second fundamental force, is electromagnetic dark matter. Electromagnetic masses attract then gravity compresses hot, dense and small---then bang, the first hydrogen star of which there are many. There may have been many big bangs, but no Big Bang that ultimately created the universe.
Directory of Open Access Journals (Sweden)
Niels Christian Hvidt
2016-08-01
Full Text Available Modern healthcare research has only in recent years investigated the impact of health care workers’ religious and other moral values on medical practice, interaction with patients, and ethically complex decision-making. Thus far, no international data exist on the way such values vary across different countries. We therefore established the NERSH International Collaboration on Values in Medicine with datasets on physician religious characteristics and values based on the same survey instrument. The present article provides (a an overview of the development of the original and optimized survey instruments, (b an overview of the content of the NERSH data pool at this stage and (c a brief review of insights gained from articles published with the questionnaire. The questionnaire was developed in 2002, after extensive pretesting in the United States and subsequently translated from English into other languages using forward-backward translations with Face Validations. In 2013, representatives of several national research groups came together and worked at optimizing the survey instrument for future use on the basis of the existing datasets. Research groups were identified through personal contacts with researchers requesting to use the instrument, as well as through two literature searches. Data were assembled in Stata and synchronized for their comparability using a matched intersection design based on the items in the original questionnaire. With a few optimizations and added modules appropriate for cultures more secular than that of the United States, the survey instrument holds promise as a tool for future comparative analyses. The pool at this stage consists of data from eleven studies conducted by research teams in nine different countries over six continents with responses from more than 6000 health professionals. Inspection of data between groups suggests large differences in religious and other moral values across nations and cultures
Directory of Open Access Journals (Sweden)
W. L. Lodder
2013-01-01
Full Text Available Objective. This study was conducted to assess the value of CT and MR imaging in the preoperative evaluation of ICA encasement. Methods. Based upon three patient groups this study was performed. Retrospective analysis of 260 neck dissection reports from 2001 to 2010 was performed to determine unexpected peroperative-diagnosed encasement. Two experienced head and neck radiologists reviewed 12 scans for encasement. Results. In four out of 260 (1.5% patients undergoing neck dissection, preoperative imaging was false negative as there was peroperative encasement of the ICA. Of 380 patients undergoing preoperative imaging, the radiologist reported encasement of the ICA in 25 cases. In 342 cases no encasement was described, 125 of these underwent neck dissection, and 2 had encasement peroperatively. The interobserver variation kappa varied from 0.273 to 1 for the different characteristics studied. Conclusion. These retrospectively studied cohorts demonstrate that preoperative assessment of encasement of the ICA using MRI and/or CT was of value in evaluation of ICA encasement and therefore contributively in selecting operable patients (without ICA encasement, since in only 1.5% encasement was missed. However, observer variation affects the reliability of this feature.
Cosmography in F(G) modified gravity
Setare, M R
2012-01-01
Investigating the accelerated expansion of the universe with cosmography is a best method to constraint cosmological models. In this work, in the $F(G)$ modified gravity framework, we obtain equations of motion in a flat FRW metric. Then we reconstruct the present day values of $F(G)$ and its derivatives with the cosmographic parameters on the only assumption that the universe is homogenous and isotropic on large scale. Also we investigate the conditions of cosmologically viable $F(G)$ gravity models with the fiducial data set values.
Multidimensional Gravity with Einstein Internal Spaces
Ivashchuk, V D
1996-01-01
A multidimensional gravitational model on the manifold $M = M_0 \\times For $N_0 = dim M_0 > 2$ the $\\sigma$ model representation is considered and it is shown that the corresponding Euclidean Toda-like system does not satisfy the Adler-van-Moerbeke criterion. For $M_0 = R^{N_0}$, $N_0 = 3, 4, 6$ (and the total dimension $D = dim M = 11, 10, 11$, respectively) nonsingular spherically symmetric solutions to vacuum Einstein equations are obtained and their generalizations to arbitrary signatures are considered. It is proved that for a non-Euclidean signature the Riemann tensor squared of the solutions diverges on certain hypersurfaces in $R^{N_0}$.
Similitude Modeling of Internal Gravity Wave Spectra
1991-08-01
scope of this paper.] GM biof the GMm72,i75sformalism, 72,75 uses basis of the GM 72, 75 formalism, E’B ()A(1w ) (3.1) )2 (w max E ( k) kv (c) = EB (co) 2...that the new prediction that addressed right now is whether or not the predictions are Wu (w3) will be proportional to c as the latter changes with
Role of Cultural Values in International Business Management%论文化价值观在国际商务管理中的作用
Institute of Scientific and Technical Information of China (English)
何守仁; 李晓琳; 陈婷婷
2012-01-01
文化价值观在国际商务管理中起着非常重要的作用.因此,了解各种各样的文化因素至关重要.分析判断不同文化碰撞时会出现的问题.商务管理人员应该掌握文化因素以至成功地处理日常商务并避免跨文化冲突.%Cultural values often play a crucial part in the performance of international business. It is, therefore, of vital importance to have a clear about various cultural factors. In fact, such factors should be kept in mind by those who are responsible for international business management so that they can cope with their daily management successfully and can avoid intercultural conflicts.
Villalobos Reyes, Marjorie; Mederico, Maracelly; Paoli de Valeri, Mariela; Briceño, Yajaira; Zerpa, Yajaira; Gómez-Pérez, Roald; Camacho, Nolis; Martínez, José Luis; Valeri, Lenín; Arata-Bellabarba, Gabriela
2014-11-01
To obtain local reference values for blood lipids and blood pressure (BP), and to determine the prevalence of metabolic syndrome (MS) in children and adolescents from Mérida, Venezuela, and to compare results using local and international cut-off values. The study enrolled 916 participants of both sexes aged 9-18 years of age from educational institutions. Demographic, anthropometric, and BP data were collected. Fasting blood glucose and lipid profile were measured. Percentile distribution of lipid and BP values was done by age group and sex. Prevalence of MS was estimated based on the NCEP-ATPIII classification (as modified by Cook et al.) and the classification of the International Diabetes Federation, using percentiles of Mérida and the USA as cut-off points. Agreement between both classifications was estimated using the kappa test (κ). Prevalence of MS was 2.2% by Cook-Merida percentiles, as compared to 1.8% by Cook-USA percentiles, a moderate agreement (κ=0.54). Agreement between Cook et al. and IDF using Merida percentiles was weak (κ=0.28). There was a higher frequency of abdominal obesity, hypertriglyceridemia and hypertension, and a lower frequency of low HDL-C using Mérida percentiles. The risk (odds ratio) of having MS is greater if abdominal obesity exists (OR: 98.63, CI: 22.45-433.35, p=0.0001). MS was significantly more common in obese subjects (18.3%, p=0.0001). Prevalence of MS in this sample of children and adolescents was 2.2%. Lipid and BP values were lower in Venezuelan as compared to US, European, and Asian children and adolescents, and similar to those in Latin-American references. Own reference values are required for accurate diagnosis of MS, as well as a worldwide consensus on its diagnostic criteria. Copyright © 2014 SEEN. Published by Elsevier Espana. All rights reserved.
Wallace, Jason A; Wang, Yuhang; Shi, Chuanyin; Pastoor, Kevin J; Nguyen, Bao-Linh; Xia, Kai; Shen, Jana K
2011-12-01
Proton uptake or release controls many important biological processes, such as energy transduction, virus replication, and catalysis. Accurate pK(a) prediction informs about proton pathways, thereby revealing detailed acid-base mechanisms. Physics-based methods in the framework of molecular dynamics simulations not only offer pK(a) predictions but also inform about the physical origins of pK(a) shifts and provide details of ionization-induced conformational relaxation and large-scale transitions. One such method is the recently developed continuous constant pH molecular dynamics (CPHMD) method, which has been shown to be an accurate and robust pK(a) prediction tool for naturally occurring titratable residues. To further examine the accuracy and limitations of CPHMD, we blindly predicted the pK(a) values for 87 titratable residues introduced in various hydrophobic regions of staphylococcal nuclease and variants. The predictions gave a root-mean-square deviation of 1.69 pK units from experiment, and there were only two pK(a)'s with errors greater than 3.5 pK units. Analysis of the conformational fluctuation of titrating side-chains in the context of the errors of calculated pK(a) values indicate that explicit treatment of conformational flexibility and the associated dielectric relaxation gives CPHMD a distinct advantage. Analysis of the sources of errors suggests that more accurate pK(a) predictions can be obtained for the most deeply buried residues by improving the accuracy in calculating desolvation energies. Furthermore, it is found that the generalized Born implicit-solvent model underlying the current CPHMD implementation slightly distorts the local conformational environment such that the inclusion of an explicit-solvent representation may offer improvement of accuracy.
Dubovsky, S L
2004-01-01
We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group using the explicitly covariant language. We find that at general values of mass parameters the massive graviton has six propagating degrees of freedom, and some of them are ghosts or lead to rapid classical instabilities. However, there is a number of different regions in the mass parameter space where massive gravity can be described by a consistent low-energy effective theory with cutoff $\\sim\\sqrt{mM_{Pl}}$ free of rapid instabilities and vDVZ discontinuity. Each of these regions is characterized by certain fine-tuning relations between mass parameters, generalizing the Fierz--Pauli condition. In some cases the required fine-tunings are consequences of the existence of the subgroups of the diffeomorphism group that are left unbroken by the graviton mass. We found two new cases, when the resulting theories have a property of UV insensitivity, i.e. remain well behaved after inclusion of ...
Induced gravity II: grand unification
Einhorn, Martin B.; Jones, D. R. Timothy
2016-05-01
As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an SO(10) gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking SO(10) to SU(5)⊗U(1), while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale v. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action giving a positive dilaton (mass)2 from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling constants also lie within the range of convergence of the Euclidean path integral, so there is hope that there will be candidates for sensible vacua. Although open questions remain concerning unitarity of all such renormalizable models of gravity, it is not obvious that, in curved backgrounds such as those considered here, unitarity is violated. In any case, any violation that may remain will be suppressed by inverse powers of the reduced Planck mass.
Nonlocal Gravity in the Solar System
Chicone, C
2015-01-01
The implications of the recent classical nonlocal generalization of Einstein's theory of gravitation for gravitational physics in the Solar System are investigated. In this theory, the nonlocal character of gravity simulates dark matter. Nonlocal gravity in the Newtonian regime involves a reciprocal kernel with three spatial parameters, of which two have already been determined from the rotation curves of spiral galaxies and the internal dynamics of clusters of galaxies. However, the short-range parameter a_0 remains to be determined. In this connection, the nonlocal contribution to the perihelion precession of a planetary orbit is estimated and a preliminary lower limit on a_0 is determined.
Nonlocal gravity in the solar system
Chicone, C.; Mashhoon, B.
2016-04-01
The implications of the recent classical nonlocal generalization of Einstein’s theory of gravitation for gravitational physics in the solar system are investigated. In this theory, the nonlocal character of gravity appears to simulate dark matter. Nonlocal gravity in the Newtonian regime involves a reciprocal kernel with three spatial parameters, of which two have already been determined from the rotation curves of spiral galaxies and the internal dynamics of clusters of galaxies. However, the short-range parameter a 0 remains to be determined. In this connection, the nonlocal contribution to the perihelion precession of a planetary orbit is estimated and a preliminary lower limit on a 0 is determined.
Gravity in Non-Commutative Geometry
Chamseddine, A H; Fröhlich, J
1993-01-01
We study general relativity in the framework of non-commutative differential geometry. In particular, we introduce a gravity action for a space-time which is the product of a four dimensional manifold by a two-point space. In the simplest situation, where the Riemannian metric is taken to be the same on the two copies of the manifold, one obtains a model of a scalar field coupled to Einstein gravity. This field is geometrically interpreted as describing the distance between the two points in the internal space.
内部审计促进企业价值增值的新思考%New Thought of Internal Audit Promote Enterprise Value Added
Institute of Scientific and Technical Information of China (English)
郭文尧
2012-01-01
In the trend of economic globalization,multinational corporation develops diversified business and brings out multiple operational risk,all of these influence the market economy of our country environment and development.Internal audit face the market economic system reform,also must adjust their role and function.Since this century internal audit have developed from two aspects of theory and practice,and have expanded to add value and improve for institutional mechanism＇s efficiency level step by step,and this view has been gradually recognized and accepted by the theory and practice.Therefore,it is a problem that how to develop the internal audit function and eventually increase the value of the enterprise value.And many scholars have made the focus of attention and discussed on the problem.%在全球经济一体化的趋势下,跨国公司开展多样化经营所带来的多重经营风险,一直都在影响着我国市场经济的环境和发展。内部审计面对市场经济体制的变革,必须及时调整其角色和职能。本世纪以来,内部审计从理论和实务两方面的发展,逐步扩展到为机构增加价值和提高机构效率的层面,这一观点也逐渐被理论界和实务界所认可和接受。如何拓展内部审计增值的职能并最终增加企业价值的问题,已成为目前众多学者关注和探讨的焦点。
Establishment of National Gravity Base Network of Iran
Hatam Chavari, Y.; Bayer, R.; Hinderer, J.; Ghazavi, K.; Sedighi, M.; Luck, B.; Djamour, Y.; Le Moign, N.; Saadat, R.; Cheraghi, H.
2009-04-01
A gravity base network is supposed to be a set of benchmarks uniformly distributed across the country and the absolute gravity values at the benchmarks are known to the best accessible accuracy. The gravity at the benchmark stations are either measured directly with absolute devices or transferred by gravity difference measurements by gravimeters from known stations. To decrease the accumulation of random measuring errors arising from these transfers, the number of base stations distributed across the country should be as small as possible. This is feasible if the stations are selected near to the national airports long distances apart but faster accessible and measurable by a gravimeter carried in an airplane between the stations. To realize the importance of such a network, various applications of a gravity base network are firstly reviewed. A gravity base network is the required reference frame for establishing 1st , 2nd and 3rd order gravity networks. Such a gravity network is used for the following purposes: a. Mapping of the structure of upper crust in geology maps. The required accuracy for the measured gravity values is about 0.2 to 0.4 mGal. b. Oil and mineral explorations. The required accuracy for the measured gravity values is about 5 µGal. c. Geotechnical studies in mining areas for exploring the underground cavities as well as archeological studies. The required accuracy is about 5 µGal and better. d. Subsurface water resource explorations and mapping crustal layers which absorb it. An accuracy of the same level of previous applications is required here too. e. Studying the tectonics of the Earth's crust. Repeated precise gravity measurements at the gravity network stations can assist us in identifying systematic height changes. The accuracy of the order of 5 µGal and more is required. f. Studying volcanoes and their evolution. Repeated precise gravity measurements at the gravity network stations can provide valuable information on the gradual
Gravity currents from a dam-break in a rotating channel
Helfrich, Karl R.; Mullarney, Julia C.
2005-08-01
The generation of a gravity current by the release of a semi-infinite region of buoyant fluid of depth H overlying a deeper, denser and quiescent lower layer in a rotating channel of width w is considered. Previous studies have focused on the characteristics of the gravity current head region and produced relations for the gravity current speed c_{b} and width w_b as a functions of the local current depth along the wall h_b, reduced gravity g', and Coriolis frequency f. Here, the dam-break problem is solved analytically by the method of characteristics assuming reduced-gravity flow, uniform potential vorticity and a semigeostrophic balance. The solution makes use of a local gravity current speed relation c_{b} = c_b(h_b,ldots) and a continuity constraint at the head to close the problem. The initial value solution links the local gravity current properties to the initiating dam-break conditions. The flow downstream of the dam consists of a rarefaction joined to a uniform gravity current with width w_b (≤ w) and depth on the right-hand wall of h_b, terminated at the head moving at speed c_b. The solution gives h_b, c_b, w_b and the transport of the boundary current as functions of w/L_R, where L_R = √{g' H}/f is the deformation radius. The semigeostrophic solution compares favourably with numerical solutions of a single-layer shallow-water model that internally develops a leading bore. Existing laboratory experiments are re-analysed and some new experiments are undertaken. Comparisons are also made with a three-dimensional shallow-water model. These show that lateral boundary friction is the primary reason for differences between the experiments and the semigeostrophic theory. The wall no-slip condition is identified as the primary cause of the experimentally observed decrease in gravity current speed with time. A model for the viscous decay is developed and shown to agree with both experimental and numerical model data.
Phenomenological Quantum Gravity
Hossenfelder, Sabine
2009-01-01
If the history of science has taught us anything, it's that persistence and creativity makes the once impossible possible. It has long been thought experimental tests of quantum gravity are impossible. But during the last decade, several different approaches have been proposed that allow us to test, if not the fundamental theory of quantum gravity itself, so at least characteristic features this theory can have. For the first time we can probe experimentally domains in which quantum physics and gravity cohabit, in spite of our failure so far to make a convincing marriage of them on a theoretical level.
Smith, Cynthia D
2012-08-21
Health care expenditures are projected to reach nearly 20% of the U.S. gross domestic product by 2020. Up to $765 billion of this spending has been identified as potentially avoidable; many of the avoidable costs have been attributed to unnecessary services. Postgraduate trainees have historically received little specific training in the stewardship of health care resources and minimal feedback on resource utilization and its effect on the cost of care. This article describes a new curriculum that was developed collaboratively by the Alliance for Academic Internal Medicine and the American College of Physicians to address this training gap. The curriculum introduces a simple, stepwise framework for delivering high-value care and focuses on teaching trainees to incorporate high-value, cost-conscious care principles into their clinical practice. It consists of ten 1-hour, case-based, interactive sessions designed to be flexibly incorporated into the existing conference structure of a residency training program.
Christensen, Ulrik Correll
2009-12-01
Idiopathic macular hole is characterized by a full thickness anatomic defect in the foveal retina leading to loss of central vision, metamorphopsia and a central scotoma. Classic macular hole surgery consists of vitrectomy, posterior vitreous cortex separation and intraocular gas tamponade, but during the past decade focus has especially been on internal limiting membrane (ILM) peeling as adjuvant therapy for increasing closure rates. With increasing use of ILM peeling and indocyanine green (ICG) staining, which is used for specific visualization of the ILM, concerns about the safety of the procedure have arisen. At present, it is not known whether ICG-assisted ILM peeling potentially reduces the functional outcome after macular hole surgery. The purpose of the present PhD thesis was to examine whether ICG-assisted ILM peeling offers surgical and functional benefit in macular hole surgery. We conducted a randomized clinical trial including 78 pseudophakic patients with idiopathic macular hole stages 2 and 3. Patients were randomly assigned to macular hole surgery consisting of (i) vitrectomy alone without instrumental retinal surface contact (non-peeling), (ii) vitrectomy plus 0.05% isotonic ICG-assisted ILM peeling or (iii) vitrectomy plus 0.15% trypan blue (TB)-assisted ILM peeling. Morphologic and functional outcomes were assessed 3, 6 and 12 months after surgery. The results show that surgery with ILM peeling, for both stages 2 and 3 macular holes, is associated with a significantly higher closure rate than surgery without ILM peeling (95% versus 45%). The overall functional results confirm that surgery for macular hole generally leads to favourable visual results, with two-thirds of eyes regaining reading vision (>or=20/40). Macular hole surgery can be considered a safe procedure with a low incidence of sight-threatening adverse events; the retinal detachment rate was 2.2%. Visual outcomes in eyes with primary hole closure were not significantly different
Merchant, Naseema B; Federman, Daniel G
2017-08-01
Bedside rounds/rounding (BDR) is an important tool for patient-centered care and trainee education. This study aimed at understanding the attitudes toward BDR among residents and attending physicians. A survey was conducted using the Qualtrics survey tool. Responses were measured using a five-point Likert scale. The survey was sent to 301 attending physicians and 195 residents. Attending physicians conducted BDR 19% of the time. The preferred mode of rounding for residents was hallway and/or conference room rounding (67%). The major barriers to BDR were concern for causing confusion in or alarm to patients (attending physicians 49%, residents 77%) and prolongation of rounds (attending physicians 47%, residents 72%). The major advantages to BDR were increased likelihood of using patient-friendly language (attending physicians 84%, residents 69%) and the potential to improve trainees' oral presentations and physical examination skills (attending physicians 71%, residents 54%). Attending physicians reported having adequate skills to conduct BDR (95%) and potential opportunity to be better teachers with this mode of rounding (69%). Residents reported having some previous experience with BDR (46%) and agreed that BDR is an important skill for residents (62%). Only 34% of residents agreed that BDR allowed them to learn more about patient care compared with other modes of rounding, however. Our study showed that our participants perceive BDR positively. Endorsed benefits include the ability to use patient-friendly language, the potential to improve trainees' clinical skills, and an opportunity to become better teachers. The reported major barriers to BDR were potential concern for patient confusion and prolongation of rounds. Despite some prior exposure reported by residents and adequate attending skills, the frequency and preference for BDR remains low and the residents remain uncertain about the educational value of BDR. The evaluation of other factors that contribute
Institute of Scientific and Technical Information of China (English)
郭晓娟; 王艳; 许勤; 陈天艳
2011-01-01
Objective To comprehend professional values of nursing interns and to find out factors that influence their values. Methods A total of 224 nursing interns were requested to fill out Nursing Professional Values Scale(NPVS) and a self-designed questionnaire which was related to factors that influenced students＇ opinions. Results The average points of dimensions of NPVS ranged from 3.05 to 3.96. Of the 26 items, the scores of 3 items ranked the highest: updating knowledge or skills through a variety of approaches, protecting patients＇privacy,and rejecting being involved into nursing work which goes against ethical requirement. Students with different educational levels,college entrance options, sources of students, internship length and parents＇educational level had significantly different scores in some dimensions of NPVS (P＜0.05 for all). Parenting styles, launch of professional values education,methods of professional values education, professional values of nursing teachers, professional values of peers, knowledge learned from the internship, social status of nurses, ect. conspired to affect nursing students＇professional values (P＜0.05, P＜0. 01). Conclusion A majority of nursing students hold a positive or neutral attitude towards their career. Their professional values are influenced by a lot of factors. Much remains to be done in an attempt to help students bring about a positive attitude towards nursing career.%目的 探讨实习护生职业价值观的相关影响因素.方法 采用护士职业价值观量表和自行设计的实习护生职业价值观影响因素问卷,对224名实习护生进行调查.结果 实习护生职业价值观各条目均分为3.05～3.96;实习护生职业价值观26个条目得分排序前3项的为通过各种学习途径以更新自己的理论或技能、维护患者的隐私权和拒绝参与违背伦理要求的护理工作;不同学历、入学志愿选择方式、生源、实习时间、父亲的文化程
Way to Expand Enterprises' Capital Value Through Internal Audit%实现内部审计价值增值的途径探究
Institute of Scientific and Technical Information of China (English)
杨秋岭
2015-01-01
随着市场经济的发展变化，企业规模日益扩大，企业组织结构越发复杂多样，内部审计要适应这种变化的趋势就要明确定位，增强业务独立性；加强企业流程管理，提高审计工作信息化程度；提升内部审计人员素质，强化内部审计团队建设，唯有这样才能实现内部审计在企业中实现价值增值。%As the rapid development of economy, the bigger expansion enterprise has made, the more complicated the organization structure enterprises have. In order to adapt to the trend, internal audit should clearify its role, strengthen the independence of business affairs, improve the flow management, enhance the level of information, upgrade the personnel quality and promote internal team-building, which will realize the expansion of captial value on internal audit.
Oda, Ichiro
2016-01-01
We propose a topological model of induced gravity (pregeometry) where both Newton's coupling constant and the cosmological constant appear as integration constants in solving field equations. The matter sector of a scalar field is also considered, and by solving field equations it is shown that various types of cosmological solutions in the FRW universe can be obtained. A detailed analysis is given of the meaning of the BRST transformations, which make the induced gravity be a topological field theory, by means of the canonical quantization analysis, and the physical reason why such BRST transformations are needed in the present formalism is clarified. Finally, we propose a dynamical mechanism for fixing the Lagrange multiplier fields by following the Higgs mechanism. The present study clearly indicates that the induced gravity can be constructed at the classical level without recourse to quantum fluctuations of matter and suggests an interesting relationship between the induced gravity and the topological qu...
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (55,907 records) were gathered by various governmental organizations (and academia) using a variety of methods. This data base was received...
Zinoviev, Yury M
2012-01-01
The equations of the relativistic causal Newton gravity law for the planets of the solar system are studied in the approximation when the Sun rests at the coordinates origin and the planets do not iteract between each other.
Infrared Modifications Of Gravity
Rombouts, J
2005-01-01
In this thesis, we study theories that modify gravity at very large distances. Motivated by recent observations in cosmology, such as the dimming of type Ia supernovae and flattening of rotation curves of galaxies, we study two classes of theories that attempt to explain these observations as due to a change in the laws of gravity at large distances rather than due to the presence of new forms of exotic energy and matter. The first class of theories is massive gravity, obtained by adding a mass term to the action for the gravitational fluctuation in Einstein's general relativity. The second class of models we study are braneworlds that provide infrared modified gravity, in specific the Dvali-Gabadadze-Porrati model and its extension to higher codimensional branes. We stress in our discussion the field theoretical consistency, both classically and quantum-mechanically, of these models.
Capozziello, Salvatore
2011-01-01
Extended Theories of Gravity can be considered a new paradigm to cure shortcomings of General Relativity at infrared and ultraviolet scales. They are an approach that, by preserving the undoubtedly positive results of Einstein's Theory, is aimed to address conceptual and experimental problems recently emerged in Astrophysics, Cosmology and High Energy Physics. In particular, the goal is to encompass, in a self-consistent scheme, problems like Inflation, Dark Energy, Dark Matter, Large Scale Structure and, first of all, to give at least an effective description of Quantum Gravity. We review the basic principles that any gravitational theory has to follow. The geometrical interpretation is discussed in a broad perspective in order to highlight the basic assumptions of General Relativity and its possible extensions in the general framework of gauge theories. Principles of such modifications are presented, focusing on specific classes of theories like f (R)-gravity and scalar-tensor gravity in the metric and Pala...
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (65,164 records) were gathered by various governmental organizations (and academia) using a variety of methods. The data base was received...
Bueno, Pablo; Cano, Pablo A.
2016-11-01
We drastically simplify the problem of linearizing a general higher-order theory of gravity. We reduce it to the evaluation of its Lagrangian on a particular Riemann tensor depending on two parameters, and the computation of two derivatives with respect to one of those parameters. We use our method to construct a D -dimensional cubic theory of gravity which satisfies the following properties: (1) it shares the spectrum of Einstein gravity, i.e., it only propagates a transverse and massless graviton on a maximally symmetric background; (2) it is defined in the same way in general dimensions; (3) it is neither trivial nor topological in four dimensions. Up to cubic order in curvature, the only previously known theories satisfying the first two requirements are the Lovelock ones. We show that, up to cubic order, there exists only one additional theory satisfying requirements (1) and (2). Interestingly, this theory is, along with Einstein gravity, the only one which also satisfies (3).
National Oceanic and Atmospheric Administration, Department of Commerce — In 1985, Dr. William F. Haxby of the Lamont-Doherty Geological Observatory of Columbia University prepared this data base of free-air gravity anomalies, based on the...
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (71 records) were gathered by various governmental organizations (and academia) using a variety of methods. This data base was received in...
Phenomenological Quantum Gravity
Kimberly, D; Kimberly, Dagny; Magueijo, Joao
2005-01-01
These notes summarize a set of lectures on phenomenological quantum gravity which one of us delivered and the other attended with great diligence. They cover an assortment of topics on the border between theoretical quantum gravity and observational anomalies. Specifically, we review non-linear relativity in its relation to loop quantum gravity and high energy cosmic rays. Although we follow a pedagogic approach we include an open section on unsolved problems, presented as exercises for the student. We also review varying constant models: the Brans-Dicke theory, the Bekenstein varying $\\alpha$ model, and several more radical ideas. We show how they make contact with strange high-redshift data, and perhaps other cosmological puzzles. We conclude with a few remaining observational puzzles which have failed to make contact with quantum gravity, but who knows... We would like to thank Mario Novello for organizing an excellent school in Mangaratiba, in direct competition with a very fine beach indeed.
De Bakker, B V; Bakker, Bas de; Smit, Jan
1994-01-01
We look at gravitational attraction in simplicial gravity using the dynamical triangulation method. On the dynamical triangulation configurations we measure quenched propagators of a free massive scalar field. The masses measured from these propagators show that gravitational attraction is present.
Garland, G D; Wilson, J T
2013-01-01
The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp
Ong, Wee Loon; Schouwenburg, Maartje G; van Bommel, Annelotte C M; Stowell, Caleb; Allison, Kim H; Benn, Karen E; Browne, John P; Cooter, Rodney D; Delaney, Geoff P; Duhoux, Francois P; Ganz, Patricia A; Hancock, Patricia; Jagsi, Reshma; Knaul, Felicia M; Knip, Anne M; Koppert, Linetta B; Kuerer, Henry M; McLaughin, Sarah; Mureau, Marc A M; Partridge, Ann H; Reid, Dereesa Purtell; Sheeran, Lisa; Smith, Thomas J; Stoutjesdijk, Mark J; Vrancken Peeters, Marie Jeanne T F D; Wengström, Yvonne; Yip, Cheng-Har; Saunders, Christobel
2016-12-29
A major challenge in value-based health care is the lack of standardized health outcomes measurements, hindering optimal monitoring and comparison of the quality of health care across different settings globally. The International Consortium for Health Outcomes Measurement (ICHOM) assembled a multidisciplinary international working group, comprised of 26 health care providers and patient advocates, to develop a standard set of value-based patient-centered outcomes for breast cancer (BC). The working group convened via 8 teleconferences and completed a follow-up survey after each meeting. A modified 2-round Delphi method was used to achieve consensus on the outcomes and case-mix variables to be included. Patient focus group meetings (8 early or metastatic BC patients) and online anonymized surveys of 1225 multinational BC patients and survivors were also conducted to obtain patients' input. The standard set encompasses survival and cancer control, and disutility of care (eg, acute treatment complications) outcomes, to be collected through administrative data and/or clinical records. A combination of multiple patient-reported outcomes measurement (PROM) tools is recommended to capture long-term degree of health outcomes. Selected case-mix factors were recommended to be collected at baseline. The ICHOM will endeavor to achieve wide buy-in of this set and facilitate its implementation in routine clinical practice in various settings and institutions worldwide.
Membrane solutions to Horava gravity
Argüelles, Carlos R
2010-01-01
We investigated purely gravitational membrane solutions to Ho\\v rava nonrelativistic theory of gravity with detailed balance in $3+1$ dimensions. We find that for arbitrary values of the running parameter $\\lambda>1/3$ two branches of membrane solutions exist, and that in the special case $\\lambda=1$ one of them is degenerate, the lapse function being undetermined. For negative values of the cosmological constant, the solution contains a single membrane sitting at the center of a space, which extends infinitely in the transverse direction approaching a Lifshitz metric. For positive values of the cosmological constant, the solution represents a space that is bounded in the transverse direction, with two parallel membranes hidden behind event horizons sitting at each of the boundaries.
Measurement of absolute gravity acceleration in Firenze
de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.
2011-01-01
This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) μGal and (980 492 048.3 ± 3.0) μGal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.
Measurement of absolute gravity acceleration in Firenze
Directory of Open Access Journals (Sweden)
M. de Angelis
2011-01-01
Full Text Available This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy. In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0 μGal and (980 492 048.3 ± 3.0 μGal for the European Laboratory for Non-Linear Spectroscopy (LENS and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.
Quantum massive conformal gravity
Energy Technology Data Exchange (ETDEWEB)
Faria, F.F. [Universidade Estadual do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil)
2016-04-15
We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard first order canonical quantization method. It is shown that quantum massive conformal gravity is renormalizable but has ghost states. A possible decoupling of these ghost states at high energies is discussed. (orig.)
Skirzewski, Aureliano
2014-01-01
We develop a topological theory of gravity with torsion where metric has a dynamical rather than a kinematical origin. This approach towards gravity resembles pre-geometrical approaches in which a fundamental metric does not exist, but the affine connection gives place to a local inertial structure. Such feature reminds us of Mach's principle, that assumes the inertial forces should have dynamical origin. Additionally, a Newtonian gravitational force is obtained in the non-relativistic limit of the theory.
Gravity Before Einstein and Schwinger Before Gravity
Trimble, Virginia L.
2012-05-01
Julian Schwinger was a child prodigy, and Albert Einstein distinctly not; Schwinger had something like 73 graduate students, and Einstein very few. But both thought gravity was important. They were not, of course, the first, nor is the disagreement on how one should think about gravity that is being highlighted here the first such dispute. The talk will explore, first, several of the earlier dichotomies: was gravity capable of action at a distance (Newton), or was a transmitting ether required (many others). Did it act on everything or only on solids (an odd idea of the Herschels that fed into their ideas of solar structure and sunspots)? Did gravitational information require time for its transmission? Is the exponent of r precisely 2, or 2 plus a smidgeon (a suggestion by Simon Newcomb among others)? And so forth. Second, I will try to say something about Scwinger's lesser known early work and how it might have prefigured his "source theory," beginning with "On the Interaction of Several Electrons (the unpublished, 1934 "zeroth paper," whose title somewhat reminds one of "On the Dynamics of an Asteroid," through his days at Berkeley with Oppenheimer, Gerjuoy, and others, to his application of ideas from nuclear physics to radar and of radar engineering techniques to problems in nuclear physics. And folks who think good jobs are difficult to come by now might want to contemplate the couple of years Schwinger spent teaching elementary physics at Purdue before moving on to the MIT Rad Lab for war work.
Emergent perspective of gravity and dark energy
Institute of Scientific and Technical Information of China (English)
T.Padmanabhan
2012-01-01
There is sufficient amount of internal evidence in the nature of gravitational theories to indicate that gravity is an emergent phenomenon like,e.g,elasticity.Such an emergent nature is most apparent in the structure of gravitational dynamics.It is,however,possible to go beyond the field equations and study the space itself as emergent in a well-defined manner in (and possibly only in) the context of cosmology.In the first part of this review,I describe various pieces of evidence which show that gravitational field equations are emergent.In the second part,I describe a novel way of studying cosmology in which I interpret the expansion of the universe as equivalent to the emergence of space itself.In such an approach,the dynamics evolves towards a state of holographic equipartition,characterized by an equality in the number of bulk and surface degrees of freedom in a region bounded by the Hubble radius.This principle correctly reproduces the standard evolution of a Friedmann universe.Further,(a) it demands the existence of an early inflationary phase as well as late time acceleration for its successful implementation and (b) allows us to link the value of late time cosmological constant to the e-folding factor during inflation.
Generalized BF state in quantum gravity
Yamashita, Shinji; Fukuda, Makoto
2014-01-01
The BF state is known as a simple wave function which satisfies three constraints in canonical quantum gravity without a cosmological constant. It is constructed from a product of the group delta functions. Applying the chiral asymmetric extension, the BF state is generalized to the state for the real values of the Barbero-Immirzi parameter.
Gravity observations for hydrocarbon reservoir monitoring
Glegola, M.A.
2013-01-01
In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The ad
Estimating Janka hardness from specific gravity for tropical and temperate species
Michael C. Wiemann; David W. Green
2007-01-01
Using mean values for basic (green) specific gravity and Janka side hardness for individual species obtained from the world literature, regression equations were developed to predict side hardness from specific gravity. Statistical and graphical methods showed that the hardnessâspecific gravity relationship is the same for tropical and temperate hardwoods, but that the...
Institute of Scientific and Technical Information of China (English)
徐炜; 曹腾飞
2016-01-01
本文以A股上市公司为样本数据，运用因子分析法构建企业内部绩效综合指标和企业市场价值综合指标，将高管薪酬与综合指标相结合，构成与企业业绩相联系的业绩薪酬指标，然后将国有企业与非国有企业的业绩薪酬指标进行对比，实证检验国有企业高管薪酬管控的必要性。同时，本文认为国有企业高管薪酬管控应参考高管为企业创造的市场价值，企业实际经营状况与市场估值差距越大，则国有企业高管经营成果与市场预期差距越大，通过构建企业内部绩效和市场价值对高管薪酬影响的模型，发现企业市场价值对高管薪酬有负向影响，进而可以以企业市场价值作为高管薪酬管控的参考依据。%By designing the comprehensive indexes of internal performance and market value with the factor analysis method based on A-share listed companies' data,this paper combines the executives' salary index with the comprehensive index to create a performance-salary index.Next,by comparing the comprehensive index between state-owned enterprises and private enterprises,it concludes that it is necessary to control salary in state-owned enterprises.Then,the salary control should accord with the market value created by executives.If the difference between the actual operating results and market valuation is large,the gap between the result of executive operation and market expectation will be big.By constructing the model of which internal performance and market value influence executive salary,this paper concludes that market value has a negative effect on executive salary,so market value index can be an instruction for salary controlling.
The Bransfield Gravity Current
Sangrà, Pablo; Stegner, Alexander; Hernández-Arencibia, Mónica; Marrero-Díaz, Ángeles; Salinas, Carolina; Aguiar-González, Borja; Henríquez-Pastene, Cristian; Mouriño-Carballido, Beatriz
2017-01-01
Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying special attention to the recirculation of the BC at the northeastern tip and northern slopes of the SSI. We observed that when the northeastward-flowing BC reaches the northeastern tip of the SSI, it recirculates around an anticyclonic mesoscale eddy that has not previously been reported in this region. Part of this recirculating water then proceeds southwest along the northern SSI shelf break as a narrow baroclinic jet and another part join the Antarctic Circumpolar Current. Consequently, the cross-slope gradients of properties strengthen, and the southern boundary of the Antarctic Circumpolar Current becomes a nearly submesoscale ( 10 km) front. Second, we compare the observations with buoyant gravity current laboratory experiments in an open basin setup where the SSI topographic barrier is represented by a central wall. The resulting circulation of the buoyant gravity current around the wall mirrors our in situ observations. First, a narrow buoyant gravity current flows northeastward along the southern boundary of the wall. Once the head of the buoyant gravity current reaches the tip of the wall, a recirculating anticyclonic vortex is generated, and the buoyant gravity current then proceeds westward along the north side of the wall. This circulation of the BC around the SSI as a buoyant gravity current may contribute to the fertilization of the waters around the SSI, as suggested by previously reported distributions of nutrients and phytoplankton.
Hairs of discrete symmetries and gravity
Directory of Open Access Journals (Sweden)
Kang Sin Choi
2017-06-01
Full Text Available Gauge symmetries are known to be respected by gravity because gauge charges carry flux lines, but global charges do not carry flux lines and are not conserved by gravitational interaction. For discrete symmetries, they are spontaneously broken in the Universe, forming domain walls. Since the realization of discrete symmetries in the Universe must involve the vacuum expectation values of Higgs fields, a string-like configuration (hair at the intersection of domain walls in the Higgs vacua can be realized. Therefore, we argue that discrete charges are also respected by gravity.
Hairs of discrete symmetries and gravity
Choi, Kang Sin; Kim, Jihn E.; Kyae, Bumseok; Nam, Soonkeon
2017-06-01
Gauge symmetries are known to be respected by gravity because gauge charges carry flux lines, but global charges do not carry flux lines and are not conserved by gravitational interaction. For discrete symmetries, they are spontaneously broken in the Universe, forming domain walls. Since the realization of discrete symmetries in the Universe must involve the vacuum expectation values of Higgs fields, a string-like configuration (hair) at the intersection of domain walls in the Higgs vacua can be realized. Therefore, we argue that discrete charges are also respected by gravity.
Thermodynamics of black holes in rainbow gravity
Banerjee, Ritwick
2016-01-01
In this paper, we investigate the thermodynamic properties of black holes under the influence of rainbow gravity. In the metric of Schwarzschild, Reissner-Nordstrom and Reissner-Nordstrom-de-Sitter black hole surrounded by quintessence, we consider a rainbow function and derive the existence of remnant and critical masses of a black hole. Using the Hawking temperature relation we derive the heat capacity and the entropy of the rainbow gravity inspired black holes and closely study the relation between entropy and area of the horizon for different values of n of the rainbow function.
Exotic smoothness and quantum gravity
Energy Technology Data Exchange (ETDEWEB)
Asselmeyer-Maluga, T, E-mail: torsten.asselmeyer-maluga@dlr.d [German Aerospace Center, Berlin, Germany and Loyola University, New Orleans, LA (United States)
2010-08-21
Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (2009 arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the 'smoothness structure' part of the path integral in quantum gravity assuming that the 'sum over geometries' is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery in the manner of Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, for the construction of an exotic 4-manifold using the knot 5{sub 2} and the Whitehead link Wh. By using Mostow rigidity, we obtain a topological contribution to the expectation value of the volume. Furthermore, we obtain a justification of area quantization.
Fluid mechanics of directional solidification at reduced gravity
Chen, C. F.
1992-01-01
The primary objective of the proposed research is to provide additional groundbased support for the flight experiment 'Casting and Solidification Technology' (CAST). This experiment is to be performed in the International Microgravity Laboratory-1 (IML-1) scheduled to be flown on a space shuttle mission scheduled for 1992. In particular, we will provide data on the convective motion and freckle formation during directional solidification of NH4Cl from its aqueous solution at simulated parameter ranges equivalent to reducing the gravity from the sea-level value down to 0.1 g or lower. The secondary objectives of the proposed research are to examine the stability phenomena associated with the onset of freckles and the mechanisms for their subsequent growth and decline (to eventual demise of some) by state-of-the-art imaging techniques and to formulate mathematical models for the prediction of the observed phenomena.
G\\"odel solution in the bumblebee gravity
Nascimento, J R; Santos, A F; Jesus, W D R
2014-01-01
Here, we consider a gravity theory involving a spontaneous Lorentz symmetry breaking called the bumblebee model. We show that, at certain values of the bumblebee field, the G\\"odel metric is consistent within this theory.
On singularities of capillary surfaces in the absence of gravity
Directory of Open Access Journals (Sweden)
V. Roytburd
1983-01-01
trapezoidal domains in the absence of gravity when the boundary contact angle declines from 90° to some critical value. We also discuss a result on the behavior of solutions in more general domains that confirms numerical calculations.
Bouguer Gravity Anomaly Map of Bangladesh (grav8bg)
U.S. Geological Survey, Department of the Interior — This coverage includes arcs and arc labels that hold the Bouguer Gravity anomaly value for contours and type contours of the original map of Bangladesh with the same...
Ensemble Averaged Gravity Theory
Khosravi, Nima
2016-01-01
We put forward the idea that all the theoretically consistent models of gravity have a contribution to the observed gravity interaction. In this formulation each model comes with its own Euclidean path integral weight where general relativity (GR) automatically has the maximum weight in high-curvature regions. We employ this idea in the framework of Lovelock models and show that in four dimensions the result is a specific form of $f(R,G)$ model. This specific $f(R,G)$ satisfies the stability conditions and has self-accelerating solution. Our model is consistent with the local tests of gravity since its behavior is same as GR for high-curvature regimes. In low-curvature regime the gravity force is weaker than GR which can interpret as existence of a repulsive fifth force for very large scales. Interestingly there is an intermediate-curvature regime where the gravity force is stronger in our model than GR. The different behavior of our model in comparison with GR in both low- and intermediate-curvature regimes ...
Locally localized gravity and geometric transitions
Energy Technology Data Exchange (ETDEWEB)
Bazeia, Dionisio [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-970 Joao Pessoa, Paraiba (Brazil)]. E-mail: bazeia@fisica.ufpb.br; Brito, Francisco A. [Departamento de Fisica, Universidade Federal de Campina Grande, 58109-970 Campina Grande, Paraiba (Brazil); Gomes, Adalto Rodrigues [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58051-970 Joao Pessoa, Paraiba (Brazil); Departamento de Ciencias Exatas, Centro Federal de Educacao Tecnologica do Maranhao, 65025-001 Sao Luis, Maranhao (Brazil)
2004-11-01
In this paper we analyze the local localization of gravity in AdS{sub 4} thick brane embedded in AdS{sub 5} space. The 3-brane is modelled by domain wall solution of a theory with a bulk scalar field coupled to five-dimensional gravity. In addition to small four-dimensional cosmological constant, the vacuum expectation value (vev) of the scalar field controls the emergence of a localized four-dimensional quasi-zero mode. We introduce high temperature effects, and we show that gravity localization on a thick 3-brane is favored below a critical temperature T{sub c}. These investigations suggest the appearance of another critical temperature T*, where the thick 3-brane engenders the geometric (author)
Stochastic Gravity A Primer with Applications
Hu, B L
2003-01-01
Stochastic semiclassical gravity of the 90's is a theory naturally evolved from semiclassical gravity of the 70's and 80's. It improves on the semiclassical Einstein equation with source given by the expectation value of the stress-energy tensor of quantum matter fields in curved spacetimes by incorporating an additional source due to their fluctuations. In stochastic semiclassical gravity the main object of interest is the noise kernel, the vacuum expectation value of the (operator-valued) stress-energy bi-tensor, and the centerpiece is the (stochastic) Einstein-Langevin equation. We describe this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh close-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical ...
Lattice Models of Quantum Gravity
Bittner, E R; Holm, C; Janke, W; Markum, H; Riedler, J
1998-01-01
Standard Regge Calculus provides an interesting method to explore quantum gravity in a non-perturbative fashion but turns out to be a CPU-time demanding enterprise. One therefore seeks for suitable approximations which retain most of its universal features. The $Z_2$-Regge model could be such a desired simplification. Here the quadratic edge lengths $q$ of the simplicial complexes are restricted to only two possible values $q=1+\\epsilon\\sigma$, with Ising model. To test whether this simpler model still contains the essential qualities of the standard Regge Calculus, we study both models in two dimensions and determine several observables on the same lattice size. In order to compare expectation values, e.g. of the average curvature or the Liouville field susceptibility, we employ in both models the same functional integration measure. The phase structure is under current investigation using mean field theory and numerical simulation.
Gravity data for the Island of Hawai`i, Hawaii
Kauahikaua, James P.
2017-01-01
This data set includes gravity measurements for the Island of Hawai`i collected as the source data for "Deep magmatic structures of Hawaiian volcanoes, imaged by three-dimensional gravity models" (Kauahikaua, Hildenbrand, and Webring, 2000). Data for 3,611 observations are stored as a single table and disseminated in .CSV format. Each observation record includes values for field station ID, latitude and longitude (in both Old Hawaiian and WGS84 projections), elevation, and Observed Gravity value. See associated publication for reduction and interpretation of these data.
Gravity field modelling and gravimetry
Directory of Open Access Journals (Sweden)
Krynski Jan
2015-12-01
Full Text Available The summary of research activities concerning gravity field modelling and gravimetric works performed in Poland in the period of 2011-2014 is presented. It contains the results of research on geoid modelling in Poland and other countries, evaluation of global geopotential models, determination of temporal variations of the gravity field with the use of data from satellite gravity space missions, absolute gravity surveys for the maintenance and modernization of the gravity control in Poland and overseas, metrological aspects in gravimetry, maintenance of gravimetric calibration baselines, and investigations of the nontidal gravity changes. The bibliography of the related works is given in references.
Characterizing repulsive gravity with curvature eigenvalues
Luongo, Orlando; Quevedo, Hernando
2014-10-01
Repulsive gravity has been investigated in several scenarios near compact objects by using different intuitive approaches. Here, we propose an invariant method to characterize regions of repulsive gravity, associated to black holes and naked singularities. Our method is based upon the behavior of the curvature tensor eigenvalues, and leads to an invariant definition of a repulsion radius. The repulsion radius determines a physical region, which can be interpreted as a repulsion sphere, where the effects due to repulsive gravity naturally arise. Further, we show that the use of effective masses to characterize repulsion regions can lead to coordinate-dependent results whereas, in our approach, repulsion emerges as a consequence of the spacetime geometry in a completely invariant way. Our definition is tested in the spacetime of an electrically charged Kerr naked singularity and in all its limiting cases. We show that a positive mass can generate repulsive gravity if it is equipped with an electric charge or an angular momentum. We obtain reasonable results for the spacetime regions contained inside the repulsion sphere whose size and shape depend on the value of the mass, charge and angular momentum. Consequently, we define repulsive gravity as a classical relativistic effect by using the geometry of spacetime only.
Energy Technology Data Exchange (ETDEWEB)
Gulec, Seza A.; Suthar, Rekha R.; Barot, Tushar C. [Jackson North Medical Center, Florida International University College of Medicine, North Miami Beach, FL (United States); Pennington, Kenneth [Center for Cancer Care, Goshen, IN (United States)
2011-07-15
Functional tumor volume (FTV) and total lesion glycolysis (TLG) are measures of metabolic activity of tumors determined by fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images. These parameters could potentially have clinical value in response to treatment evaluation and disease prognostication. The objectives of this study were to investigate the relationship between functional tumor parameters (FTV and TLG) and clinical outcomes in patients with colorectal cancer liver metastases (CRCLM) undergoing {sup 90}Y-resin microsphere selective internal radiation therapy (SIRT) (SIR-Spheres {sup registered}, Sirtex Medical Limited, Lane Cove, NSW, Australia). FDG PET/CT studies of 20 patients with unresectable CRCLM who underwent {sup 90}Y SIRT under a phase II clinical trial were analyzed. FTV and TLG were calculated using PET VCAR (GE Healthcare, Milwaukee, WI, USA) on pretreatment and 4-week posttreatment scans. The effects of pretreatment and posttreatment functional tumor activity on patient survival were evaluated using Kaplan-Meier survival curves. The median survival in the study group was 14.8 months (range 2.0-27.7 months). The median survival for patients with pretreatment FTV values of above and below 200 cc were 11.2 and 26.9 months, respectively (p < 0.05). The median survival for patients with 4-week posttreatment FTV values of above and below 30 cc were 10.9 and 26.9 months, respectively (p < 0.05). The median survival for patients with pretreatment TLG values of above and below 600 g were 11.2 and 26.9 months, respectively (p < 0.05). The median survival for patients with 4-week posttreatment TLG values of above and below 100 g were 10.9 and 26.9 months, respectively (p < 0.05). Pretreatment and posttreatment FTV and TLG showed very strong association with survival. These values can be useful quantitative criteria for patient selection and disease prognostication when {sup 90}Y SIRT is contemplated in patients with CRCLM. (orig.)
Airborne Gravity: NGS' Gravity Data for EN08 (2013)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Vermont, New Hampshire, Massachusettes, Maine, and Canada collected in 2013 over 1 survey. This data set is part of the Gravity...
Airborne Gravity: NGS' Gravity Data for EN01 (2011)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Canada, and Lake Ontario collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the...
Airborne Gravity: NGS' Gravity Data for CS01 (2014)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alabama and Florida collected in 2008 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...
Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...
Airborne Gravity: NGS' Gravity Data for CS03 (2009)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas and Louisiana collected in 2009 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...
Airborne Gravity: NGS' Gravity Data for TS01 (2014)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Puerto Rico and the Virgin Islands collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the...
Airborne Gravity: NGS' Gravity Data for EN04 (2013)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Michigan and Lake Huron collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...
Airborne Gravity: NGS' Gravity Data for AN03 (2010)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...
Airborne Gravity: NGS' Gravity Data for EN06 (2016)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Maine, Canada, and the Atlantic Ocean collected in 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the...
Airborne Gravity: NGS' Gravity Data for EN05 (2012)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Minnesota, Wisconsin, and Michigan collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the...
Airborne Gravity: NGS' Gravity Data for PN01 (2014)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for California and Oregon collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...
Airborne Gravity: NGS' Gravity Data for ES01 (2013)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of...
Airborne Gravity: NGS' Gravity Data for CN03 (2014)
National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2014 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...
Jain, Bhuvnesh
2010-01-01
Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the universe. We review recent developments in modified gravity theories, focusing on higher dimensional approaches and chameleon/f(R) theories. We classify these models in terms of the screening mechanisms that enable such theories to approach general relativity on small scales (and thus satisfy solar system constraints). We describe general features of the modified Friedman equation in such theories. The second half of this review describes experimental tests of gravity in light of the new theoretical approaches. We summarize the high precision tests of gravity on laboratory and solar system scales. We describe in some detail tests on astrophysical scales ranging from ~kpc (galaxy scales) to ~Gpc (large-scale structure). These tests rely on the growth and inter-relationship of perturbations in the metric potentials, density and velocity fields which can be measured using gravitational lensi...
Directory of Open Access Journals (Sweden)
Cahill R. T.
2015-10-01
Full Text Available A new quantum gravity experiment is reported with the data confirming the generali- sation of the Schrödinger equation to include the interaction of the wave function with dynamical space. Dynamical space turbulence, via this interaction process, raises and lowers the energy of the electron wave function, which is detected by observing conse- quent variations in the electron quantum barrier tunnelling rate in reverse-biased Zener diodes. This process has previously been reported and enabled the measurement of the speed of the dynamical space flow, which is consistent with numerous other detection experiments. The interaction process is dependent on the angle between the dynamical space flow velocity and the direction of the electron flow in the diode, and this depen- dence is experimentally demonstrated. This interaction process explains gravity as an emergent quantum process, so unifying quantum phenomena and gravity. Gravitational waves are easily detected.
Porrati, Massimo
2011-01-01
Recently proposed "critical" higher-derivative gravities in $AdS_D$ $D>3$ are expected to carry logarithmic representation of the Anti de Sitter isometry group. In this note, we quantize linear fluctuations of these critical gravities, which are known to be either identical with linear fluctuations of Einstein's gravity or else satisfy logarithmic boundary conditions at spacial infinity. We identify the scalar product uniquely defined by the symplectic structure implied by the classical action, and show that it does not posses null vectors. Instead, we show that the scalar product between any two Einstein modes vanishes, while the scalar product of an Einstein mode with a logarithmic mode is generically nonzero. This is the basic property of logarithmic representation that makes them neither unitary nor unitarizable.
Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana
2016-08-01
GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope
Modesto, Leonardo
2013-01-01
We hereby present a class of multidimensional higher derivative theories of gravity that realizes an ultraviolet completion of Einstein general relativity. This class is marked by a "non-polynomal" entire function (form factor), which averts extra degrees of freedom (including ghosts) and improves the high energy behavior of the loop amplitudes. By power counting arguments, it is proved that the theory is super-renormalizable in any dimension, i.e. only one-loop divergences survive. Furthermore, in odd dimensions there are no counter terms for pure gravity and the theory turns out to be "finite." Finally, considering the infinite tower of massive states coming from dimensional reduction, quantum gravity is finite in even dimension as well.
Intrinsic Time Quantum Gravity
Yu, Hoi Lai
2016-01-01
Correct identification of the true gauge symmetry of General Relativity being 3d spatial diffeomorphism invariant(3dDI) (not the conventional infinite tensor product group with principle fibre bundle structure), together with intrinsic time extracted from clean decomposition of the canonical structure yields a self-consistent theory of quantum gravity. A new set of fundamental commutation relations is also presented. The basic variables are the eight components of the unimodular part of the spatial dreibein and eight SU(3) generators which correspond to Klauder's momentric variables that characterize a free theory of quantum gravity. The commutation relations are not canonical, but have well defined group theoretical meanings. All fundamental entities are dimensionless; and the quantum wave functionals are preferentially in the dreibein representation. The successful quantum theory of gravity involves only broad spectrum of knowledge and deep insights but no exotic idea.
How to make old and dense gravity data consistent with the latest gravity data? -Example in Japan-
Miyazaki, T.
2016-12-01
Generally, old gravity data aren't consistent with newer data even if there markers remain intact. Such discrepancy often reaches more than 100 micro Gal, which is much larger than measurement errors. Therefore, to make use of the historic gravity data together with current gravity data for various uses e.g. geoid construction, estimation of subsurface structure, precise land gravity survey etc., the adjustment of old data to the latest gravity value. Here, we developed such a conversion method. Simple interpolation method isn't useful for this purpose because raw gravity difference data include local contribution that reduce spatial coherence of gravity data. So we must correct the local tectonic effect assimilating other geodetic observations. We assume that differences between new and old gravity data are composed of contribution of crustal deformation effect and that of data processing method/reference system. Moreover, crustal deformation effect is decomposed into height variation and density variation of crust caused by earthquakes. First, we estimated effect of height variation at a marker between the observations. We use continuous GNSS observation data to estimate contribution after 2003, and spirit leveling data before 2003. These data are interpolated in space and time. The gravity change by height variation was calculated using a bouguer gravity gradient depending old observation period of each marker. Second, effect of density variation is estimated by a rectangle fault model using half-space elastic dislocation theory. Then we assumed that residuals represent systematic offset caused by the difference of data processing method/reference system. Now the offset distribution may be evaluated by spatial interpolation thanks to the enhanced spatial coherence of residuals after correcting for local tectonic effect. Consequently, we got a gravity difference distribution which can make old gravity data consistent with new one within 45 micro Gal in precision.
Tribology Experiment in Zero Gravity
Pan, C. H. T.; Gause, R. L.; Whitaker, A. F.; Finckenor, M. M.
2015-01-01
A tribology experiment in zero gravity was performed during the orbital flight of Spacelab 1 to study the motion of liquid lubricants over solid surfaces. The absence of a significant gravitational force facilitates observation of such motions as controlled by interfacial and capillary forces. Two experimental configurations were used. One deals with the liquid on one solid surface, and the other with the liquid between a pair of closed spaced surfaces. Time sequence photographs of fluid motion on a solid surface yielded spreading rate data of several fluid-surface combinations. In general, a slow spreading process as governed by the tertiary junction can be distinguished from a more rapid process which is driven by surface tension controlled internal fluid pressure. Photographs were also taken through the transparent bushings of several experimental journal bearings. Morphology of incomplete fluid films and its fluctuation with time suggest the presence or absence of unsteady phenomena of the bearing-rotor system in various arrangements.
Bimetric gravity and dark matter
Bernard, Laura; Heisenberg, Lavinia
2015-01-01
We review some recent proposals for relativistic models of dark matter in the context of bimetric gravity. The aim is to solve the problems of cold dark matter (CDM) at galactic scales, and to reproduce the phenomenology of the modified Newtonian dynamics (MOND), while still being in agreement with the standard cosmological model $\\Lambda$-CDM at large scales. In this context a promising alternative is dipolar dark matter (DDM) in which two different species of dark matter particles are separately coupled to the two metrics of bigravity and are linked together by an internal vector field. The phenomenology of MOND then results from a mechanism of gravitational polarization. Probably the best formulation of the model is within the framework of recently developed massive bigravity theories. Then the gravitational sector of the model is safe by construction, but a ghostly degree of freedom in the decoupling limit is still present in the dark matter sector. Future work should analyse the cosmological solutions of...
The gravity field observations and products at IGFS
Barzaghi, Riccardo; Vergos, George; Bonvalot, Sylvain; Barthelmes, Franz; Reguzzoni, Mirko; Wziontek, Hartmut; Kelly, Kevin
2017-04-01
The International Gravity Field Service (IGFS) is a service of the International Association of Geodesy (IAG) that was established in 2003 at the IAG/IUGG General Assembly in Sapporo (Japan). This service aims at coordinating the actions of the IAG services related to the Earth gravity field, i.e. the Bureau Gravimétrique International (BGI), the International Service for the Geoid (ISG), the International Geodynamics and Earth Tides Service (IGETS), the International Center for Global Earth Models (ICGEM) and the International Digital Elevation Model Service (IDEMS). Also, via its Central Bureau hosted at the Aristotle University of Thessaloniki (Greece), IGFS provides a link to the Global Geodetic Observing System (GGOS) bureaus in order to communicate their requirements and recommendations to the IGFS-Centers. In this work, a presentation is given on the recent activities of the service, namely those related to the contributions to the implementation of: the International Height Reference System/Frame; the Global Geodetic Reference System/Frame; the new Global Absolute Gravity Reference System/Frame. Particularly, the impact that these activities have in improving the estimation of the Earth's gravity field, either at global and local scale, is highlighted also in the framework of GGOS.
Gravity and Heater Size Effects on Pool Boiling Heat Transfer
Kim, Jungho; Raj, Rishi
2014-01-01
The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.
Regulation of flexible arms under gravity
Energy Technology Data Exchange (ETDEWEB)
De Luca, A. [Univ. di Roma, Rome (Italy). Dipt. di Informatica e Sistemistica; Siciliano, B. [Univ. di Napoli Federico, Napoli (Italy). Dipt. di Informatica e Sistemistica
1993-08-01
A simple controller is presented for the regulation problem of robot arms with flexible links under gravity. It consists of a joint PD feedback plus a constant feedforward. Global asymptotic stability of the reference equilibrium state is shown under a structural assumption about link elasticity and a mild condition on the proportional gain. The result holds also in the absence of internal damping of the flexible arm. A numerical case study is presented.
General Covariance in Gravity at a Lifshitz Point
Horava, Petr
2011-01-01
This paper is based on the invited talks delivered by the author at GR 19: the 19th International Conference on General Relativity and Gravitation, Ciudad de M\\'exico, M\\'exico, July 2010. In Part 1, we briefly review some of the main features of quantum gravity with anisotropic scaling, and comment on its possible relation to the causal dynamical triangulations (CDT) approach to lattice quantum gravity. Part 2 explains the construction of gravity with anisotropic scaling with an extended gauge symmetry -- essentially a nonrelativistic version of general covariance. This extra symmetry eliminates the scalar graviton polarization, and thus brings the theory closer to general relativity at long distances.
Chiou, Dah-Wei
2014-01-01
This article presents an "in-a-nutshell" yet self-contained introductory review on loop quantum gravity (LQG) -- a background-independent, nonperturbative approach to a consistent quantum theory of gravity. Instead of rigorous and systematic derivations, it aims to provide a general picture of LQG, placing emphasis on the fundamental ideas and their significance. The canonical formulation of LQG, as the central topic of the article, is presented in a logically orderly fashion with moderate details, while the spin foam theory, black hole thermodynamics, and loop quantum cosmology are covered briefly. Current directions and open issues are also summarized.
Charges for linearized gravity
Aksteiner, Steffen
2013-01-01
Maxwell test fields as well as solutions of linearized gravity on the Kerr exterior admit non-radiating modes, i.e. non-trivial time-independent solutions. These are closely related to conserved charges. In this paper we discuss the non-radiating modes for linearized gravity, which may be seen to correspond to the Poincare Lie-algebra. The 2-dimensional isometry group of Kerr corresponds to a 2-parameter family of gauge-invariant non-radiating modes representing infinitesimal perturbations of mass and azimuthal angular momentum. We calculate the linearized mass charge in terms of linearized Newman-Penrose scalars.
Deser, S; Ong, Y C; Waldron, A
2014-01-01
The method of characteristics is a key tool for studying consistency of equations of motion; it allows issues such as predictability, maximal propagation speed, superluminality, unitarity and acausality to be addressed without requiring explicit solutions. We review this method and its application to massive gravity theories to show the limitations of these models' physical viability: Among their problems are loss of unique evolution, superluminal signals, matter coupling inconsistencies and micro-acausality (propagation of signals around local closed timelike/causal curves). We extend previous no-go results to the entire three-parameter range of massive gravity theories. It is also argued that bimetric models suffer a similar fate.
Brans–Dicke gravity theory from topological gravity
Energy Technology Data Exchange (ETDEWEB)
Inostroza, C.; Salazar, A.; Salgado, P.
2014-06-27
We consider a model that suggests a mechanism by which the four dimensional Brans–Dicke gravity theory may emerge from the topological gravity action. To achieve this goal, both the Lie algebra and the symmetric invariant tensor that define the topological gravity Lagrangian are constructed by means of the Lie algebra S-expansion procedure with an appropriate abelian semigroup S.
SATELLITE GRAVITY SURVEYING TECHNOLOGY AND RESEARCH OF EARTH'S GRAVITY FIELD
Institute of Scientific and Technical Information of China (English)
Ning Jinsheng
2003-01-01
This is a summarized paper. Two topics are discussed: Firstly, the concept, development and application of four kinds of satellite gravity surveying technology are introduced; Secondly, some problems of theory and method, which must be considered in the study of the Earth's gravity field based on satellite gravity data, are expounded.
Energy Technology Data Exchange (ETDEWEB)
Kukuk, Guido M.; Muertz, Petra; Traeber, Frank; Meyer, Carsten; Ullrich, Jan; Schild, Hans H.; Willinek, Winfried A. [University of Bonn, Department of Radiology, Bonn (Germany); Gieseke, Juergen [University of Bonn, Department of Radiology, Bonn (Germany); Philips Healthcare, Best (Netherlands); Ahmadzadehfar, Hojjat; Ezziddin, Samer [University of Bonn, Department of Nuclear Medicine, Bonn (Germany)
2014-02-15
To evaluate diffusion-weighted MRI with acquisition of three b-values and calculation of fractioned ADCs for response evaluation of neuroendocrine liver metastases undergoing selective internal radiotherapy (SIRT). Ten consecutive patients with neuroendocrine liver metastases underwent MRI before and following SIRT. Diffusion-weighted imaging included acquisition of the b-values 0, 50 and 800 s/mm{sup 2} and calculation of ADC{sub (50,800)}, ADC{sub (0,50)} and ADC{sub (0,800)} maps. According to therapy response, lesions were categorised into group A [≥20 % reduction of the longest diameter (LD) in comparison to baseline MRI] and group B (<20 % reduction of the LD). Twelve out of 31 metastases were categorised as group A and 19 out of 31 metastases were categorised as group B. Pretherapeutic values of ADC{sub (0,800)} and ADC{sub (50,800)} did not differ significantly between the two groups; however, ADC{sub (0,50)} was 32 % lower in group A (P = 0.049). ADC{sub (0,800)} and ADC{sub (50,800)} increased significantly after therapy in both groups, however, group differences were not statistically significant. Conversely, the increase in ADC{sub (0,50)} was about a factor of 7 larger in group A than in group B (P = 0.023). Our study showed that the ADC{sub (0,50)} is a promising biomarker for response assessment of neuroendocrine liver metastases following SIRT. (orig.)
Wietholter, Jon P; Ponte, Charles D; Long, Dustin M
2016-10-24
Few publications have addressed the perceptions of pharmacists and physicians regarding the value of clinical pharmacist services. A survey-based study was conducted to determine whether Internal Medicine (IM) and Family Medicine (FM) pharmacists and physicians differed in their attitudes regarding the benefits of collaboration in an acute care setting. The primary objective was to evaluate perceived differences regarding self-assessment of value between IM and FM pharmacists. The secondary objective was to evaluate perceived differences of clinical pharmacist benefit between IM and FM physicians. An eight-item questionnaire assessed the attitudes and beliefs of pharmacists and physicians regarding the value of clinical pharmacy services. Surveys were emailed and participants marked their responses using a 7-point Likert scale for each item. Demographic data and overall comments were collected from each participant. Overall, 167 surveys were completed. When comparing cumulative physician and pharmacist responses, none of the eight questions showed significant differences. Statistically significant differences were noted when comparing IM and FM clinical pharmacists on five of the eight survey items; for each of these items, FM pharmacists had more favourable perceptions than their IM counterparts. No statistically significant differences were noted when comparing responses of IM and FM physicians. This study found that FM pharmacists perceived a greater benefit regarding participation in inpatient acute care rounds when compared to their IM pharmacist counterparts. Future studies are necessary to determine if other medical specialties' perceptions of clinical pharmacy provision differ from our findings and to evaluate the rationale behind specific attitudes and behaviours. © 2016 Royal Pharmaceutical Society.
Dorais, Gregory A.
2015-01-01
This document defines the design concept for a ground-based, extended-stay hypergravity facility as a precursor for space-based artificial-gravity facilities that extend the permanent presence of both human and non-human life beyond Earth in artificial-gravity settlements. Since the Earth's current human population is stressing the environment and the resources off-Earth are relatively unlimited, by as soon as 2040 more than one thousand people could be living in Earthorbiting artificial-gravity habitats. Eventually, the majority of humanity may live in artificialgravity habitats throughout this solar system as well as others, but little is known about the longterm (multi-generational) effects of artificial-gravity habitats on people, animals, and plants. In order to extend life permanently beyond Earth, it would be useful to create an orbiting space facility that generates 1g as well as other gravity levels to rigorously address the numerous challenges of such an endeavor. Before doing so, developing a ground-based artificial-gravity facility is a reasonable next step. Just as the International Space Station is a microgravity research facility, at a small fraction of the cost and risk a ground-based artificial-gravity facility can begin to address a wide-variety of the artificial-gravity life-science questions and engineering challenges requiring long-term research to enable people, animals, and plants to live off-Earth indefinitely.
Gravity Data for South America
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data (152,624 records) were compiled by the University of Texas at Dallas. This data base was received in June 1992. Principal gravity parameters...
Scalable Gravity Offload System Project
National Aeronautics and Space Administration — A scalable gravity offload device simulates reduced gravity for the testing of various surface system elements such as mobile robots, excavators, habitats, and...
Gravity Station Data for Portugal
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 3064 records. This data base was received in April 1997. Principal gravity parameters include Free-air Anomalies which have been...
Interior Alaska Gravity Station Data
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 9416 records. This data base was received in March 1997. Principal gravity parameters include Free-air Anomalies which have been...
Gravity Station Data for Spain
National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 28493 records. This data base was received in April 1997. Principal gravity parameters include Free-air Anomalies which have been...
Gravity separation for oil wastewater treatment
Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Krstev, Aleksandar
2010-01-01
In this paper, the applications of gravity separation for oil wastewater treatment are presented. Described is operation on conventional gravity separation and parallel plate separation. Key words: gravity separation, oil, conventional gravity separation, parallel plate separation.
Gravity separation for oil wastewater treatment
Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Krstev, Aleksandar
2010-01-01
In this paper, the applications of gravity separation for oil wastewater treatment are presented. Described is operation on conventional gravity separation and parallel plate separation. Key words: gravity separation, oil, conventional gravity separation, parallel plate separation.
Induced Gravity II: Grand Unification
Einhorn, Martin B
2016-01-01
As an illustration of a renormalizable, asymptotically-free model of induced gravity, we consider an $SO(10)$ gauge theory interacting with a real scalar multiplet in the adjoint representation. We show that dimensional transmutation can occur, spontaneously breaking $SO(10)$ to $SU(5){\\otimes}U(1),$ while inducing the Planck mass and a positive cosmological constant, all proportional to the same scale $v$. All mass ratios are functions of the values of coupling constants at that scale. Below this scale (at which the Big Bang may occur), the model takes the usual form of Einstein-Hilbert gravity in de Sitter space plus calculable corrections. We show that there exist regions of parameter space in which the breaking results in a local minimum of the effective action, and a {\\bf positive} dilaton $(\\hbox{mass})^2$ from two-loop corrections associated with the conformal anomaly. Furthermore, unlike the singlet case we considered previously, some minima lie within the basin of attraction of the ultraviolet fixed ...
Exotic Smoothness and Quantum Gravity
Asselmeyer-Maluga, Torsten
2010-01-01
Since the first work on exotic smoothness in physics, it was folklore to assume a direct influence of exotic smoothness to quantum gravity. Thus, the negative result of Duston (arXiv:0911.4068) was a surprise. A closer look into the semi-classical approach uncovered the implicit assumption of a close connection between geometry and smoothness structure. But both structures, geometry and smoothness, are independent of each other. In this paper we calculate the "smoothness structure" part of the path integral in quantum gravity assuming that the "sum over geometries" is already given. For that purpose we use the knot surgery of Fintushel and Stern applied to the class E(n) of elliptic surfaces. We mainly focus our attention to the K3 surfaces E(2). Then we assume that every exotic smoothness structure of the K3 surface can be generated by knot or link surgery a la Fintushel and Stern. The results are applied to the calculation of expectation values. Here we discuss the two observables, volume and Wilson loop, f...
The weak gravity conjecture and scalar fields
Palti, Eran
2017-08-01
We propose a generalisation of the Weak Gravity Conjecture in the presence of scalar fields. The proposal is guided by properties of extremal black holes in N=2 supergravity, but can be understood more generally in terms of forbidding towers of stable gravitationally bound states. It amounts to the statement that there must exist a particle on which the gauge force acts more strongly than gravity and the scalar forces combined. We also propose that the scalar force itself should act on this particle stronger than gravity. This implies that generically the mass of this particle decreases exponentially as a function of the scalar field expectation value for super-Planckian variations, which is behaviour predicted by the Refined Swampland Conjecture. In the context of N=2 supergravity the Weak Gravity Conjecture bound can be tied to bounds on scalar field distances in field space. Guided by this, we present a general proof that for any linear combination of moduli in any Calabi-Yau compactification of string theory the proper field distance grows at best logarithmically with the moduli values for super-Planckian distances.
Quantum gravity corrections in Chandrasekhar limits
Moussa, Mohamed
2017-01-01
It is agreed that Chandrasekhar mass and central density of white dwarfs are independent, which means that there is a whole series of stars having radius and central density as parameters that all have the same Chandrasekhar mass. In this article the influence of a quantum gravity is shown so the Chandrasekhar limits (mass and radius) depend explicitly on the central density and gravity parameters. A new polytropic relation between degenerate pressure of the star and its density is investigated. This leads to a modification in Lane-Emden equation and mass and radius formulas of the star. A modified Lane-Emden equation is solved numerically with consideration to the mass density of the star depends on its radius. The solution was used in calculating the mass and radius limit of the white dwarf. It was found that mass and radius limits decrease due to increase in central density and gravity parameters in a comparison with the original values. We can say that central density and quantum gravity constitute a new tool that can help to make the theoretical values corresponding to experimental observations apply in a better manner.
DEFF Research Database (Denmark)
Skielboe, Andreas
Gravity governs the evolution of the universe on the largest scales, and powers some of the most extreme objects at the centers of galaxies. Determining the masses and kinematics of galaxy clusters provides essential constraints on the large-scale structure of the universe, and act as direct probes...
Artificial Gravity Research Plan
Gilbert, Charlene
2014-01-01
This document describes the forward working plan to identify what countermeasure resources are needed for a vehicle with an artificial gravity module (intermittent centrifugation) and what Countermeasure Resources are needed for a rotating transit vehicle (continuous centrifugation) to minimize the effects of microgravity to Mars Exploration crewmembers.
Noncommutative Symmetries and Gravity
Aschieri, P
2006-01-01
Spacetime geometry is twisted (deformed) into noncommutative spacetime geometry, where functions and tensors are now star-multiplied. Consistently, spacetime diffeomorhisms are twisted into noncommutative diffeomorphisms. Their deformed Lie algebra structure and that of infinitesimal Poincare' transformations is defined and explicitly constructed. This allows to construct a noncommutative theory of gravity.
The Bransfield Gravity Current
Sangrà, P.; Stegner, A.; Hernández-Arencibia, Mónica; Márrero-Díaz, A.; Salinas, C.; Aguiar-González, B.; Henríquez-Pastene, C.H.; Mouriño-Carballido, B.
2017-01-01
Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying spec
Directory of Open Access Journals (Sweden)
Rovelli Carlo
1998-01-01
Full Text Available The problem of finding the quantum theory of the gravitational field, and thus understanding what is quantum spacetime, is still open. One of the most active of the current approaches is loop quantum gravity. Loop quantum gravity is a mathematically well-defined, non-perturbative and background independent quantization of general relativity, with its conventional matter couplings. Research in loop quantum gravity today forms a vast area, ranging from mathematical foundations to physical applications. Among the most significant results obtained are: (i The computation of the physical spectra of geometrical quantities such as area and volume, which yields quantitative predictions on Planck-scale physics. (ii A derivation of the Bekenstein-Hawking black hole entropy formula. (iii An intriguing physical picture of the microstructure of quantum physical space, characterized by a polymer-like Planck scale discreteness. This discreteness emerges naturally from the quantum theory and provides a mathematically well-defined realization of Wheeler's intuition of a spacetime ``foam''. Long standing open problems within the approach (lack of a scalar product, over-completeness of the loop basis, implementation of reality conditions have been fully solved. The weak part of the approach is the treatment of the dynamics: at present there exist several proposals, which are intensely debated. Here, I provide a general overview of ideas, techniques, results and open problems of this candidate theory of quantum gravity, and a guide to the relevant literature.
Energy Technology Data Exchange (ETDEWEB)
Bao, Ruoyu; /Chicago U., EFI /Chicago U.; Carena, Marcela; /Fermilab; Lykken, Joseph; /Chicago U., EFI /Chicago U. /Fermilab; Park, Minjoon; /Chicago U., EFI /Chicago U.; Santiago, Jose; /Fermilab
2005-11-01
Gravity in five-dimensional braneworld backgrounds often exhibits problematic features, including kinetic ghosts, strong coupling, and the vDVZ discontinuity. These problems are an obstacle to producing and analyzing braneworld models with interesting and potentially observable modifications of 4d gravity. We examine these problems in a general AdS{sub 5}/AdS{sub 4} setup with two branes and localized curvature from arbitrary brane kinetic terms. We use the interval approach and an explicit ''straight'' gauge-fixing. We compute the complete quadratic gauge-fixed effective 4d action, as well as the leading cubic order corrections. We compute the exact Green's function for gravity as seen on the brane. In the full parameter space, we exhibit the regions which avoid kinetic ghosts and tachyons. We give a general formula for the strong coupling scale, i.e. the energy scale at which the linearized treatment of gravity breaks down, for relevant regions of the parameter space. We show how the vDVZ discontinuity can be naturally but nontrivially avoided by ultralight graviton modes. We present a direct comparison of warping versus localized curvature in terms of their effects on graviton mode couplings. We exhibit the first example of DGP-like crossover behavior in a general warped setup.
DEFF Research Database (Denmark)
Skielboe, Andreas
Gravity governs the evolution of the universe on the largest scales, and powers some of the most extreme objects at the centers of galaxies. Determining the masses and kinematics of galaxy clusters provides essential constraints on the large-scale structure of the universe, and act as direct probes...
Torsion formulation of gravity
Energy Technology Data Exchange (ETDEWEB)
Lledo, M A; Sommovigo, L, E-mail: Maria.Lledo@ific.uv.e, E-mail: Luca.Sommovigo@mfn.unipmn.i [Departament de Fisica Teorica, Universitat de Valencia, and IFIC (Centro mixto CSIC-UVEG) C/Dr Moliner, 50, E-46100 Burjassot (Valencia) (Spain)
2010-03-21
We explain precisely what it means to have a connection with torsion as a solution of the Einstein equations. While locally the theory remains the same, the new formulation allows for topologies that would have been excluded in the standard formulation of gravity. In this formulation it is possible to couple arbitrary torsion to gauge fields without breaking the gauge invariance.
The Bransfield Gravity Current
Sangrà, P.; Stegner, A.; Hernández-Arencibia, Mónica; Márrero-Díaz, A.; Salinas, C.; Aguiar-González, B.; Henríquez-Pastene, C.H.; Mouriño-Carballido, B.
2017-01-01
Using in situ data and laboratory experiments, we show that the circulation of the Bransfield Current (BC) around the South Shetland Islands (SSI) may be characterized in terms of a propagating buoyant gravity current. First, we describe the SSI hydrography and some drifter trajectories, paying
Burla, Santoshkumar; Mueller, Vitali; Flury, Jakob; Jovanovic, Nemanja
2016-04-01
CHAMP, GRACE and GOCE missions have been successful in the field of satellite geodesy (especially to improve Earth's gravity field models) and have established the necessity towards the next generation gravity field missions. Especially, GRACE has shown its capabilities beyond any other gravity field missions. GRACE Follow-On mission is going to continue GRACE's legacy which is almost identical to GRACE mission with addition of laser interferometry. But these missions are not only quite expensive but also takes quite an effort to plan and to execute. Still there are few drawbacks such as under-sampling and incapability of exploring new ideas within a single mission (ex: to perform different orbit configurations with multi satellite mission(s) at different altitudes). The budget is the major limiting factor to build multi satellite mission(s). Here, we offer a solution to overcome these drawbacks using cubesat/ nanosatellite mission. Cubesats are widely used in research because they are cheaper, smaller in size and building them is easy and faster than bigger satellites. Here, we design a 3D model of GRACE like mission with available sensors and explain how the Attitude and Orbit Control System (AOCS) works. The expected accuracies on final results of gravity field are also explained here.
Variable gravity research facility
Allan, Sean; Ancheta, Stan; Beine, Donna; Cink, Brian; Eagon, Mark; Eckstein, Brett; Luhman, Dan; Mccowan, Daniel; Nations, James; Nordtvedt, Todd
1988-01-01
Spin and despin requirements; sequence of activities required to assemble the Variable Gravity Research Facility (VGRF); power systems technology; life support; thermal control systems; emergencies; communication systems; space station applications; experimental activities; computer modeling and simulation of tether vibration; cost analysis; configuration of the crew compartments; and tether lengths and rotation speeds are discussed.
Van Kooy, L.; Mooij, M.; Rem, P.
2004-01-01
Separations by density, such as the separation of non-ferrous scrap into light and heavy alloys, are often realized by means of heavy media. In principle, kinetic gravity separations in water can be faster and cheaper, because they do not rely on suspensions or salt solutions of which the density
Loop quantum gravity and observations
Barrau, A
2014-01-01
Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We review here some possible ways to observe loop quantum gravity effects either in the framework of cosmology or in astroparticle physics.
Three-dimensional Gravity, Holography and Black Holes
Lashkari, Nima
Gauge/gravity dualities and the matrix model provide us with exploratory frameworks for the study of quantum gravity (QG) in the presence of a cosmological constant that is negative or zero, respectively. Currently, in all the known examples instring theory, the gravity theory contains complicated matter fields and interactions. However, the idea of describing theories of quantum gravity in terms of dual non-gravitational theories, i.e. holography, has proven to go well beyond these examples. Motivated by holography, in the course of this thesis we explore simple models of quantum gravity with the goal of obtaining insight into non-perturbative QG, in particular the physics of black holes. We consider three-dimensional gravity with a negative cosmological constant. Weuse Ricci flow techniques to study flows between the potential vacua of topologically massive gravity and show that for large values of the Chern-Simons coupling anti-de Sitter space is the ground state. Moreover, we study spontaneous symmetry-breaking in vacua of theories of gravity coupled to scalars and gauge fields and find examples of discrete symmetry-breaking phases with exotic thermodynamic properties. We study three-dimensional gravity with a positive cosmological constant as a theory of quantum cosmology. We compute the full non-perturbative Euclidean partition function of de Sitter gravity by evaluating the gravity path integral on physically relevant Euclidean continuations of the static patch. The partition function diverges in a non-regularizable way and we interpret this as a hint that the theory does not exist at a quantum level. As we show however, the inclusion of the simplest form of interaction, the Chern-Simons term, removes the undesirable divergences.
Solar Gravity Modes: Present and Future
Turck-Chièze, S
2005-01-01
Gravity modes are the best probes to study the solar radiative zone dynamics, especially in the nuclear core. These modes remain difficult to observe, but they are essential ingredients for progressing on the evolution of the Sun-Earth relationship at the level of centuries. Today, the knowledge of the internal dynamics comes from acoustic modes and concerns mainly the external 2% of the solar mass. Nevertheless, the flat rotation profile of the radiative zone compels physics beyond the standard framework. I summarize different attempts to look for gravity modes and the results obtained after 8 years of observation with the GOLF/SoHO instrument. Some gravity mode candidates (at 1mm/s level) have appeared with more than 98% confidence level as quadruplets or quintuplets. These patterns, if confirmed as gravity modes, may reveal very exciting physics of the solar core. Getting information on rotation and magnetic field in the solar core are real keys to simulate a complete dynamical solar picture. The understan...
Supermassive screwed cosmic string in dilaton gravity
Energy Technology Data Exchange (ETDEWEB)
Bezerra, V B [Departamento de Fisica, Universidade Federal da ParaIba, 58059-970, Joao Pessoa, PB (Brazil); Ferreira, Cristine N [Nucleo de Fisica, Centro Federal de Educacao Tecnologica de Campos, Rua Dr Siqueira, 273-Parque Dom Bosco, 28030-130, Campos dos Goytacazes, RJ (Brazil); Cuesta, H J Mosquera [Instituto de Cosmologia, Relatividade e AstrofIsica (ICRA-BR), Centro Brasileiro de Pesquisas Fisicas, Rua Dr Xavier Sigaud 150, Urca 22290-180, Rio de Janeiro, RJ (Brazil)
2006-06-21
The early universe might have undergone phase transitions at energy scales much higher than the one corresponding to the grand unified theories (GUT) scales. At these higher energy scales, the transition at which gravity separated from all other interactions, the so-called Planck era, more massive strings called supermassive cosmic strings could have been produced, with energy of about 10{sup 19} GeV. The dynamics of strings formed with this energy scale cannot be described by means of the weak-field approximation, as in the standard procedure for ordinary GUT cosmic strings. As suggested by string theories, at this extreme energy, gravity may be transmitted by some kind of scalar field (usually called the dilaton) in addition to the tensor field of Einstein's theory of gravity. It is then permissible to tackle the issue regarding the dynamics of supermassive cosmic strings within this framework. With this aim, we obtain the gravitational field of a supermassive screwed cosmic string in a scalar-tensor theory of gravity. We show that for the supermassive configuration, exact solutions of scalar-tensor screwed cosmic strings can be found in connection with the Bogomol'nyi limit. We show that the generalization of Bogomol'nyi arguments to the Brans-Dicke theory is possible when torsion is present and we obtain an exact solution in this supermassive regime, with the dilaton solution obtained by consistency with internal constraints.
Plant biology in reduced gravity on the Moon and Mars.
Kiss, J Z
2014-01-01
While there have been numerous studies on the effects of microgravity on plant biology since the beginning of the Space Age, our knowledge of the effects of reduced gravity (less than the Earth nominal 1 g) on plant physiology and development is very limited. Since international space agencies have cited manned exploration of Moon/Mars as long-term goals, it is important to understand plant biology at the lunar (0.17 g) and Martian levels of gravity (0.38 g), as plants are likely to be part of bioregenerative life-support systems on these missions. First, the methods to obtain microgravity and reduced gravity such as drop towers, parabolic flights, sounding rockets and orbiting spacecraft are reviewed. Studies on gravitaxis and gravitropism in algae have suggested that the threshold level of gravity sensing is around 0.3 g or less. Recent experiments on the International Space Station (ISS) showed attenuation of phototropism in higher plants occurs at levels ranging from 0.l g to 0.3 g. Taken together, these studies suggest that the reduced gravity level on Mars of 0.38 g may be enough so that the gravity level per se would not be a major problem for plant development. Studies that have directly considered the impact of reduced gravity and microgravity on bioregenerative life-support systems have identified important biophysical changes in the reduced gravity environments that impact the design of these systems. The author suggests that the current ISS laboratory facilities with on-board centrifuges should be used as a test bed in which to explore the effects of reduced gravity on plant biology, including those factors that are directly related to developing life-support systems necessary for Moon and Mars exploration.
Directory of Open Access Journals (Sweden)
A. V. Vikulin
2015-09-01
Full Text Available Gravity phenomena related to the Earth movements in the Solar System and through the Galaxy are reviewed. Such movements are manifested by geological processes on the Earth and correlate with geophysical fields of the Earth. It is concluded that geodynamic processes and the gravity phenomena (including those of cosmic nature are related. The state of the geomedium composed of blocks is determined by stresses with force moment and by slow rotational waves that are considered as a new type of movements [Vikulin, 2008, 2010]. It is shown that the geomedium has typical rheid properties [Carey, 1954], specifically an ability to flow while being in the solid state [Leonov, 2008]. Within the framework of the rotational model with a symmetric stress tensor, which is developed by the authors [Vikulin, Ivanchin, 1998; Vikulin et al., 2012a, 2013], such movement of the geomedium may explain the energy-saturated state of the geomedium and a possibility of its movements in the form of vortex geological structures [Lee, 1928]. The article discusses the gravity wave detection method based on the concept of interactions between gravity waves and crustal blocks [Braginsky et al., 1985]. It is concluded that gravity waves can be recorded by the proposed technique that detects slow rotational waves. It is shown that geo-gravitational movements can be described by both the concept of potential with account of gravitational energy of bodies [Kondratyev, 2003] and the nonlinear physical acoustics [Gurbatov et al., 2008]. Based on the combined description of geophysical and gravitational wave movements, the authors suggest a hypothesis about the nature of spin, i.e. own moment as a demonstration of the space-time ‘vortex’ properties.
Kim, Jinsoo; Lee, Youngcheol; Cha, Sungyeoul; Choi, Chuluong; Lee, Seongkyu
2013-07-12
This paper proposes a smartphone-based network real-time kinematic (RTK) positioning and gravity-surveying application (app) that allows semi-real-time measurements using the built-in Bluetooth features of the smartphone and a third-generation or long-term evolution wireless device. The app was implemented on a single smartphone by integrating a global navigation satellite system (GNSS) controller, a laptop, and a field-note writing tool. The observation devices (i.e., a GNSS receiver and relative gravimeter) functioned independently of this system. The app included a gravity module, which converted the measured relative gravity reading into an absolute gravity value according to tides; meter height; instrument drift correction; and network adjustments. The semi-real-time features of this app allowed data to be shared easily with other researchers. Moreover, the proposed smartphone-based gravity-survey app was easily adaptable to various locations and rough terrain due to its compact size.
Relation between Gravity Field Feature and Tectonics and Earthquakes in Taiwan and Its Adjacent Seas
Institute of Scientific and Technical Information of China (English)
张赤军; 方剑
2001-01-01
Short wave gravity anomaly is correlated to sea floor topography in the gravity field of Taiwan and its adjacent seas. Gravity values of 200 × 10-5ms-2 at Yushang and -160 × 10-5ms-2 at Liuqiu sea trench are respectively the maximum and minimum gravity values in this area.Bouguer gravity anomaly reflects not only Moho interface undulation, but also fault distribution.The inflexion of gradient belt of Bouguer gravity anomaly is a spot liable to earthquakes. Middlelong wave geoid is the best data to invert crustal thickness. We calculate crustal thickness by using geoid data, and the maximum value is 38km; the minimum value is 12km in Taiwan and its adjacent seas.
The Impact of Geological Structures On The Gravity Field
Marti, U.
In general, a uniform standard density value is used for the calculation of topographic effects for gravity field modelling in Switzerland. Only a limited number of promi- nent mass anomalies is treated with an individual density. In some regions this causes problems in predicting the surface gravity or the deflections of the vertical. An actual example is the construction of a new 57 km railway tunnel, where accurate deflec- tions of the vertical are needed for the orientation of gyroscope measurements. It was rather doubtful if our standard national gravity field model would fulfil the accuracy demands. Therefore, a refinement of the gravity field model was performed by digi- tising all the relevant geological structures in the vicinity of the planned tunnel. This lead to a 3D density model of irregularly shaped polyhedrons. Their influence on the gravity field (potential, gravity, deflections of the vertical and their first derivatives) are calculated rigorously. First results of this study are now available and reveal that the influences of the geological structures on the deflections of the vertical and on gravity are rather small (1 - 2 arcsec, 3 - 5 mgal) in the investigated region and they are at the limit of significance for the technical applications of levelling or gyroscope mea- surements. The largest effects are caused by quaternary sediments with a large density contrast and by some gneiss structures, which show only a small density contrast but their total mass can cause considerable anomalies in the gravity field.
Gravity survey in the San Luis Valley area, Colorado
Gaca, J. Robert; Karig, Daniel E.
1965-01-01
During the summers of 1963 and 1964, a regional gravity survey covering 6,000 square miles of the San Luis Valley and surrounding areas was made to determine subsurface basement configurations and to guide future crustal studies. The San Luis Valley, a large intermontane basin, is a segment of the Rio Grande trough, a reef system characterized by volcanism, normal faulting, and tilted fault blocks. The gravity data, accurate to about 0.5 mgal, were reduced to complete-Bouguer anomaly values. The Bouguer-anomaly gravity map delineates a series of en-echelon gravity highs in the central and western San Luis Valley. These gravity highs are interpreted as horsts of Precambrian rock buried by basin fill. A series of en-echelon gravity lows along the eastern edge of the Valley is interpreted as a graben filled with sedimentary and igneous rock estimated to be up to 30,000 ft thick. The relatively high regional gravity over the Sangre de Cristo Mountains suggests that these mountains are locally uncompensated. A subcircular gravity low in the Bonanza area is interpreted as an indication of low-density volcanic rocks within a caldera structure.
Directory of Open Access Journals (Sweden)
Fahmueller Yvonne
2012-01-01
Full Text Available Abstract Background Selective Internal Radiation Therapy (SIRT is a new and effective locoregional anticancer therapy for colorectal cancer patients with liver metastases. Markers for prediction of therapy response and prognosis are needed for the individual management of those patients undergoing SIRT. Methods Blood samples were prospectively and consecutively taken from 49 colorectal cancer patients with extensive hepatic metastases before, three, six, 24 and 48 h after SIRT to analyze the concentrations of nucleosomes and further laboratory parameters, and to compare them with the response to therapy regularly determined 3 months after therapy and with overall survival. Results Circulating nucleosomes, cytokeratin-19 fragments (CYFRA 21-1, carcinoembryonic antigen (CEA, C-reactive protein (CRP and various liver markers increased already 24 h after SIRT. Pretherapeutical levels of CYFRA 21-1, CEA, cancer antigen 19-9 (CA 19-9, asparate-aminotransferase (AST and lactate dehydrogenase (LDH as well as 24 h values of nucleosomes were significantly higher in patients suffering from disease progression (N = 35 than in non-progressive patients (N = 14. Concerning overall survival, CEA, CA 19-9, CYFRA 21-1, CRP, LDH, AST, choline esterase (CHE, gamma-glutamyl-transferase, alkaline phosphatase, and amylase (all 0 h, 24 h and nucleosomes (24 h were found to be prognostic relevant markers in univariate analyses. In multivariate Cox-Regression analysis, the best prognostic model was obtained for the combination of CRP and AST. When 24 h values were additionally included, nucleosomes (24 h further improved the existing model. Conclusion Panels of biochemical markers are helpful to stratify pretherapeutically colorectal cancer patients for SIR-therapy and to early estimate the response to SIR-therapy.
Industrial processes influenced by gravity
Ostrach, Simon
1988-01-01
In considering new directions for low gravity research with particular regard to broadening the number and types of industrial involvements, it is noted that transport phenomena play a vital role in diverse processes in the chemical, pharmaceutical, food, and biotech industries. Relatively little attention has been given to the role of gravity in such processes. Accordingly, numerous industrial processes and phenomena are identified which involve gravity and/or surface tension forces. Phase separations and mixing are examples that will be significantly different in low gravity conditions. A basis is presented for expanding the scope of the low gravity research program and the potential benefits of such research is indicated.
Gravity a very short introduction
Clifton, Timothy
2017-01-01
Gravity is one of the four fundamental interactions that exist in nature and is essential for understanding the behaviour of the Universe, and all astrophysical bodies within it. Yet it remains puzzling. Gravity: A Very Short Introduction looks at the development of our understanding of gravity since the early observations of Kepler, Newtonian theory, and Einstein’s theory of gravity. It also discusses the recent detection of waves of gravitational radiation that were predicted by Einstein. This VSI concludes by considering the testing and application of General Relativity in astrophysics and cosmology, and looks at dark energy and efforts such as string theory to combine gravity with quantum mechanics.
Massive and modified gravity as self-gravitating media
Ballesteros, Guillermo; Pilo, Luigi
2016-01-01
We study the effective field theory that describes the low-energy physics of self-gravitating media. The field content consists of four derivatively coupled scalar fields that can be identified with the internal comoving coordinates of the medium. Imposing SO(3) internal spatial invariance, the theory describes supersolids. Stronger symmetry requirements lead to superfluids, solids and perfect fluids, at lowest order in derivatives. In the unitary gauge, massive gravity emerges, being thus the result of a continuous medium propagating in spacetime. Our results can be used to explore systematically the effects and signatures of modifying gravity consistently at large distances. The dark sector is then described as a self-gravitating medium with dynamical and thermodynamic properties dictated by internal symmetries. These results indicate that the divide between dark energy and modified gravity, at large distance scales, is simply a gauge choice.
Bouzid, Wajih; Abbes, Chedly; Gabtni, Hakim; Hassine, Mouna
2016-04-01
Jbel Rheouis situated in south west of Sidi Bouzid, central Tunisia, is a complex structure located at a tectonic node between N-S, NE-SW and NW-SE corridors. It was considered as a diapir containing the most complete series of The Upper Triassic formation in Central Tunisia. The good quality of preserved fossils markers especially at the limestone levels made it possible for Burollet (1952) to propose a lithostratigraphic description of the Rheouis Formation. This stratigraphy was clarified by Soussi and Abbes (2004) basing on new paleontological, palynological and outcrops detailed mapping data. Thus, they assigned the base of this outcrops series to Carnian and its top to Rhaetian. Using these geological and lithostratigraphic data we suspects that the base of the Rheouis formation formed by black limestone can be correlated to the Rehach limestone in the South of Tunisia where this level is laying on a clayey sandstones level identified as the Lower Triassic outcrops. In this concept, this study intend to investigate the Rheouis structure and to identify it's nature basing on the intra salt structures identification and the nature of the Lower Triassic sediments buried beneath the Black limestones, using a combination of geological, lithostratigraphic and geophysical (gravity) data. The gravity data used in this work were obtained from the ONM with a mesh of 1Km /1Km. All the data were merged and reduced using the 1967 International gravity formula. Free air and Bouguer gravity correction were made using sea level as a datum and 2.4 g/cm³ as a reduction density. The Bouguer anomaly map shows a variation in anomaly values range from -12.5 mGal to -4.5 mGal with a contrasted anomaly distribution. This map present 5 gravity maxima and 4 gravity minima where the major direction of those maxima and minima are N-S, NE-SW and NW-SE. The presence of a relative positive anomaly concentrated J.Rheouis can be explained by a mass excess probably due to the uplift of the
Anomalous dimension in semiclassical gravity
Alesci, Emanuele
2011-01-01
The description of the phase space of relativistic particles coupled to three-dimensional Einstein gravity requires momenta which are coordinates on a group manifold rather than on ordinary Minkowski space. The corresponding field theory turns out to be a non-commutative field theory on configuration space and a group field theory on momentum space. Using basic non-commutative Fourier transform tools we introduce the notion of non-commutative heat-kernel associated with the Laplacian on the non-commutative configuration space. We show that the spectral dimension associated to the non-commutative heat kernel varies with the scale reaching a non-integer value smaller than three for Planckian diffusion scales.
Observational Constraints on Exponential Gravity
Yang, Louis; Luo, Ling-Wei; Geng, Chao-Qiang
2010-01-01
We study the observational constraints on the exponential gravity model of f(R)=-beta*Rs(1-e^(-R/Rs)). We use the latest observational data including Supernova Cosmology Project (SCP) Union2 compilation, Two-Degree Field Galaxy Redshift Survey (2dFGRS), Sloan Digital Sky Survey Data Release 7 (SDSS DR7) and Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP7) in our analysis. From these observations, we obtain a lower bound on the model parameter beta at 1.27 (95% CL) but no appreciable upper bound. The constraint on the present matter density parameter is 0.245< Omega_m^0<0.311 (95% CL). We also find out the best-fit value of model parameters on several cases.
Modifying Gravity at Low Redshift
Brax, Philippe; Davis, Anne-Christine; Shaw, Douglas
2010-01-01
We consider the growth of cosmological perturbations in modified gravity models where a scalar field mediates a non-universal Yukawa force between different matter species. The growth of the density contrast is altered for scales below the Compton wave-length of the scalar field. As the universe expands, the Compton wave-length varies in time in such a way that scales which where outside the range of the scalar field force may feel it at a lower redshift. In this case, both the exponent $\\gamma$ measuring the growth of Cold Dark Matter perturbations and the shift function representing the ratio of the two Newtonian potentials $\\psi$ and $\\phi$ may differ from their values in General Relativity at low redshift.
Gravity Capillary Standing Water Waves
Alazard, Thomas; Baldi, Pietro
2015-09-01
The paper deals with the 2D gravity-capillary water waves equations in their Hamiltonian formulation, addressing the question of the nonlinear interaction of a plane wave with its reflection off a vertical wall. The main result is the construction of small amplitude, standing (namely periodic in time and space, and not travelling) solutions of Sobolev regularity, for almost all values of the surface tension coefficient, and for a large set of time-frequencies. This is an existence result for a quasi-linear, Hamiltonian, reversible system of two autonomous pseudo-PDEs with small divisors. The proof is a combination of different techniques, such as a Nash-Moser scheme, microlocal analysis and bifurcation analysis.
DEFF Research Database (Denmark)
Sørensen, Olav Jull
The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool......The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool...
DEFF Research Database (Denmark)
Sørensen, Olav Jull
The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool......The conference paper aims to develop the global value chain concept by including corporate internal value adding activities and competition to the basic framework in order to turn the global value chain into a strategic management tool...