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Sample records for units physical constants

  1. Comments on redefinition of SI units based on fundamental physical constants with fixed values

    CERN Document Server

    Khruschov, V V

    2011-01-01

    Advantages and disadvantages of fixation of fundamental physical constants' values for definition of SI units are considered. The case with a new definition of the mass unit on the base of a fixed value of the Avogadro constant is studied in detail. Criteria on choosing of a optimum FPC set with fixed values for the redefinition of the SI units are suggested. The minimal optimum FPC set that is consistent with the criteria is presented. The set comprises the speed of light, the constant of the ground state hyperfine transition of the caesium-133 atom, the Avogadro constant, the mass of the carbon-12 atom and the absolute magnitude of the electron charge. Comment on the redefinition of the kelvin is also made.

  2. Base units of the SI, fundamental constants and modern quantum physics.

    Science.gov (United States)

    Bordé, Christian J

    2005-09-15

    Over the past 40 years, a number of discoveries in quantum physics have completely transformed our vision of fundamental metrology. This revolution starts with the frequency stabilization of lasers using saturation spectroscopy and the redefinition of the metre by fixing the velocity of light c. Today, the trend is to redefine all SI base units from fundamental constants and we discuss strategies to achieve this goal. We first consider a kinematical frame, in which fundamental constants with a dimension, such as the speed of light c, the Planck constant h, the Boltzmann constant k(B) or the electron mass m(e) can be used to connect and redefine base units. The various interaction forces of nature are then introduced in a dynamical frame, where they are completely characterized by dimensionless coupling constants such as the fine structure constant alpha or its gravitational analogue alpha(G). This point is discussed by rewriting the Maxwell and Dirac equations with new force fields and these coupling constants. We describe and stress the importance of various quantum effects leading to the advent of this new quantum metrology. In the second part of the paper, we present the status of the seven base units and the prospects of their possible redefinitions from fundamental constants in an experimental perspective. The two parts can be read independently and they point to these same conclusions concerning the redefinitions of base units. The concept of rest mass is directly related to the Compton frequency of a body, which is precisely what is measured by the watt balance. The conversion factor between mass and frequency is the Planck constant, which could therefore be fixed in a realistic and consistent new definition of the kilogram based on its Compton frequency. We discuss also how the Boltzmann constant could be better determined and fixed to replace the present definition of the kelvin.

  3. Measurable values, numbers and fundamental physical constants: Is the Boltzmann constant Kb a fundamental physical constant?

    Directory of Open Access Journals (Sweden)

    Bormashenko Edward

    2009-01-01

    Full Text Available The status of fundamental physical constants is discussed. The nature of fundamental physical constants is cleared up, based on the analysis of the Boltzmann constant. A new definition of measurable values, 'mathematical' and 'physical' numbers and fundamental physical constants is proposed. Mathematical numbers are defined as values insensitive to the choice of both units and frames of reference, whereas 'physical numbers' are dimensionless values, insensitive to transformations of units and sensitive to the transformations of the frames of reference. Fundamental constants are classified as values sensitive to transformations of the units and insensitive to transformations of the frames of reference. It is supposed that a fundamental physical constant necessarily allows diminishing the number of independent etalons in a system of units.

  4. The fundamental constants a mystery of physics

    CERN Document Server

    Fritzsch, Harald

    2009-01-01

    The speed of light, the fine structure constant, and Newton's constant of gravity — these are just three among the many physical constants that define our picture of the world. Where do they come from? Are they constant in time and across space? In this book, physicist and author Harald Fritzsch invites the reader to explore the mystery of the fundamental constants of physics in the company of Isaac Newton, Albert Einstein, and a modern-day physicist

  5. New Quasar Studies Keep Fundamental Physical Constant Constant

    Science.gov (United States)

    2004-03-01

    atoms together and the way light interacts with atoms. But are these fundamental physical constants really constant? Are those numbers always the same, everywhere in the Universe and at all times? This is not as naive a question as it may seem. Contemporary theories of fundamental interactions, such as the Grand Unification Theory or super-string theories that treat gravity and quantum mechanics in a consistent way, not only predict a dependence of fundamental physical constants with energy - particle physics experiments have shown the fine structure constant to grow to a value of about 1/128 at high collision energies - but allow for their cosmological time and space variations. A time dependence of the fundamental constants could also easily arise if, besides the three space dimensions, there exist more hidden dimensions. Already in 1955, the Russian physicist Lev Landau considered the possibility of a time dependence of alpha. In the late 1960s, George Gamow in the United States suggested that the charge of the electron, and therefore also alpha, may vary. It is clear however that such changes, if any, cannot be large or they would already have been detected in comparatively simple experiments. Tracking these possible changes thus requires the most sophisticated and precise techniques. Looking back in time In fact, quite strong constraints are already known to exist for the possible variation of the fine structure constant alpha. One such constraint is of geological nature. It is based on measures taken in the ancient natural fission reactor located near Oklo (Gabon, West Africa) and which was active roughly 2,000 million years ago. By studying the distribution of a given set of elements - isotopes of the rare earths, for example of samarium - which were produced by the fission of uranium, one can estimate whether the physical process happened at a faster or slower pace than we would expect it nowadays. Thus we can measure a possible change of the value of the

  6. Surprises in numerical expressions of physical constants

    CERN Document Server

    Amir, Ariel; Tokieda, Tadashi

    2016-01-01

    In science, as in life, `surprises' can be adequately appreciated only in the presence of a null model, what we expect a priori. In physics, theories sometimes express the values of dimensionless physical constants as combinations of mathematical constants like pi or e. The inverse problem also arises, whereby the measured value of a physical constant admits a `surprisingly' simple approximation in terms of well-known mathematical constants. Can we estimate the probability for this to be a mere coincidence, rather than an inkling of some theory? We answer the question in the most naive form.

  7. A Memorandum Report: Physical Constants of MCE

    Science.gov (United States)

    2016-08-01

    A MEMORANDUM REPORT: PHYSICAL CONSTANTS OF MCE ECBC-TR-1289 B.L. Harris CHEMICAL WARFARE SERVICE August 2016 Approved for public release...MCE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Harris , B.L. 5d. PROJECT NUMBER A 1.13 5e. TASK NUMBER 5f...original 1945 publication. Note from Reviewers This version is a reprint with corrections of Harris , B.L. A Memorandum Report: Physical Constants of

  8. Topological Quantization in Units of the Fine Structure Constant

    Energy Technology Data Exchange (ETDEWEB)

    Maciejko, Joseph; /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Qi, Xiao-Liang; /Station Q, UCSB /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Drew, H.Dennis; /Maryland U.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC

    2011-11-11

    Fundamental topological phenomena in condensed matter physics are associated with a quantized electromagnetic response in units of fundamental constants. Recently, it has been predicted theoretically that the time-reversal invariant topological insulator in three dimensions exhibits a topological magnetoelectric effect quantized in units of the fine structure constant {alpha} = e{sup 2}/{h_bar}c. In this Letter, we propose an optical experiment to directly measure this topological quantization phenomenon, independent of material details. Our proposal also provides a way to measure the half-quantized Hall conductances on the two surfaces of the topological insulator independently of each other.

  9. Environment-Dependent Fundamental Physical Constants

    CERN Document Server

    Terazawa, Hidezumi

    2012-01-01

    A theory of special inconstancy, in which some fundamental physical constants such as the fine-structure and gravitational constants may vary, is proposed in pregeometry. In the special theory of inconstancy, the \\alpha-G relation of \\alpha=3\\pi/[16ln(4\\pi/5GM_W^2)] between the varying fine-structure and gravitaional constants (where M_W is the charged weak boson mass) is derived from the hypothesis that both of these constants are related to the same fundamental length scale in nature. Furthermore, it leads to the prediction of dot{{\\alpha}}/\\alpha=(-0.8\\pm2.5)\\times10^{-14}yr^{-1} from the most precise limit of dot{G}/G=(-0.6\\pm2.0)\\times10^{-12}yr^{-1} by Thorsett, which is not only consistent with the recent observation of dot{{\\alpha}}/\\alpha=(0.5\\pm0.5)\\times10^{-14}yr^{-1} by Webb et al. but also feasible for future experimental tests. Also a theory of general inconstancy, in which any fundamental physical constants may vary, is proposed in "more general relativity", by assuming that the space-time is ...

  10. Large numbers hypothesis. IV - The cosmological constant and quantum physics

    Science.gov (United States)

    Adams, P. J.

    1983-01-01

    In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

  11. Large numbers hypothesis. IV - The cosmological constant and quantum physics

    Science.gov (United States)

    Adams, P. J.

    1983-01-01

    In standard physics quantum field theory is based on a flat vacuum space-time. This quantum field theory predicts a nonzero cosmological constant. Hence the gravitational field equations do not admit a flat vacuum space-time. This dilemma is resolved using the units covariant gravitational field equations. This paper shows that the field equations admit a flat vacuum space-time with nonzero cosmological constant if and only if the canonical LNH is valid. This allows an interpretation of the LNH phenomena in terms of a time-dependent vacuum state. If this is correct then the cosmological constant must be positive.

  12. Fundamental units: physics and metrology

    CERN Document Server

    Okun, Lev Borisovich

    2003-01-01

    The problem of fundamental units is discussed in the context of achievements of both theoretical physics and modern metrology. On one hand, due to fascinating accuracy of atomic clocks, the traditional macroscopic standards of metrology (second, metre, kilogram) are giving way to standards based on fundamental units of nature: velocity of light $c$ and quantum of action $h$. On the other hand, the poor precision of gravitational constant $G$, which is widely believed to define the ``cube of theories'' and the units of the future ``theory of everything'', does not allow to use $G$ as a fundamental dimensional constant in metrology. The electromagnetic units in SI are actually based on concepts of prerelativistic classical electrodynamics such as ether, electric permitivity and magnetic permeability of vacuum. Concluding remarks are devoted to terminological confusion which accompanies the progress in basic physics and metrology.

  13. Planck's Constant as a Natural Unit of Measurement

    Science.gov (United States)

    Quincey, Paul

    2013-01-01

    The proposed revision of SI units would embed Planck's constant into the definition of the kilogram, as a fixed constant of nature. Traditionally, Planck's constant is not readily interpreted as the size of something physical, and it is generally only encountered by students in the mathematics of quantum physics. Richard Feynman's…

  14. Physical Properties of Triglycerides IV. Dielectric Constant

    NARCIS (Netherlands)

    Gouw, T.H.; Vlugter, J.C.

    1967-01-01

    Dielectric constants at 20° and at 40° C of a number of triglycerides in the liquid state have been measured. A molar additive function of the dielectric constant, based on a relation derived by J. van Elk, was used in combination with a previously derived equation for triglycerides to give an equat

  15. Physical Basis for a Constant Lag Time

    CERN Document Server

    Socrates, Aristotle

    2012-01-01

    We show that the constant time lag prescription for tidal dissipation follows directly from the equations of motion of a tidally-forced fluid body, given some basic assumptions. They are (i) the equilibrium structure of the forced body is spherically-symmetric (ii) the tidal forcing is weak and non-resonant (iii) dissipation is weak. The lag time is an intrinsic property of the tidally-forced body and is independent of the orbital configuration.

  16. CODATA Recommended Values of the Fundamental Physical Constants: 2014*

    Science.gov (United States)

    Mohr, Peter J.; Newell, David B.; Taylor, Barry N.

    2016-12-01

    This paper gives the 2014 self-consistent set of values of the constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA). These values are based on a least-squares adjustment that takes into account all data available up to 31 December 2014. Details of the data selection and methodology of the adjustment are described. The recommended values may also be found at http://physics.nist.gov/constants.

  17. CODATA Recommended Values of the Fundamental Physical Constants: 2014

    CERN Document Server

    Mohr, Peter J; Taylor, Barry N

    2015-01-01

    This report gives the 2014 self-consistent set of values of the constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA). These values are based on a least-squares adjustment that takes into account all data available up to 31 December 2014. The recommended values may also be found on the World Wide Web at physics.nist.gov/constants.

  18. CODATA Recommended Values of the Fundamental Physical Constants: 2010

    CERN Document Server

    Mohr, Peter J; Newell, David B

    2012-01-01

    This paper gives the 2010 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. The 2010 adjustment takes into account the data considered in the 2006 adjustment as well as the data that became available from 1 January 2007, after the closing date of that adjustment, until 31 December 2010, the closing date of the new adjustment. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the results of least-squares analyses. The 2010 set replaces the previously recommended 2006 CODATA set and may also be found on the World Wide Web at physics.nist.gov/constants.

  19. The Cosmological Constant Problem, an Inspiration for New Physics

    NARCIS (Netherlands)

    Nobbenhuis, Stefanus Johannes Bernardus

    2006-01-01

    We have critically compared different approaches to the cosmological constant problem, which is at the edge of elementary particle physics and cosmology. This problem is deeply connected with the difficulties formulating a theory of quantum gravity. After the 1998 discovery that our universe's

  20. Local Unit Invariance, Back-Reacting Tractors and the Cosmological Constant Problem

    CERN Document Server

    Bonezzi, Roberto; Waldron, Andrew

    2010-01-01

    When physics is expressed in a way that is independent of local choices of unit systems, Riemannian geometry is replaced by conformal geometry. Moreover masses become geometric, appearing as Weyl weights of tractors (conformal multiplets of fields necessary to keep local unit invariance manifest). The relationship between these weights and masses is through the scalar curvature. As a consequence mass terms are spacetime dependent for off-shell gravitational backgrounds, but happily constant for physical, Einstein manifolds. Unfortunately this introduces a naturalness problem because the scalar curvature is proportional to the cosmological constant. By writing down tractor stress tensors (multiplets built from the standard stress tensor and its first and second derivatives), we show how back-reaction solves this naturalness problem. We also show that classical back-reaction generates an interesting potential for scalar fields. We speculate that a proper description of how physical systems couple to scale, coul...

  1. $\\hbar$ as a Physical Constant of Classical Optics and Electrodynamics

    CERN Document Server

    Tremblay, Real; Allen, Claudine Ni

    2015-01-01

    The Planck constant ($\\hbar$) plays a pivotal role in quantum physics. Historically, it has been proposed as postulate, part of a genius empirical relationship $E=\\hbar \\omega$ in order to explain the intensity spectrum of the blackbody radiation for which classical electrodynamic theory led to an unacceptable prediction: The ultraviolet catastrophe. While the usefulness of the Planck constant in various fields of physics is undisputed, its derivation (or lack of) remains unsatisfactory from a fundamental point of view. In this paper, the analysis of the blackbody problem is performed with a series expansion of the electromagnetic field in terms of TE, TM modes in a metallic cavity with small losses, that leads to developing the electromagnetic fields in a \\textit{complete set of orthonormal functions}. This expansion, based on coupled power theory, maintains both space and time together enabling modeling of the blackbody's evolution toward equilibrium. Reaching equilibrium with a multimodal waveguide analysi...

  2. Local unit invariance, back-reacting tractors and the cosmological constant problem

    Science.gov (United States)

    Bonezzi, R.; Corradini, O.; Waldron, A.

    2012-02-01

    When physics is expressed in a way that is independent of local choices of unit systems, Riemannian geometry is replaced by conformal geometry. Moreover masses become geometric, appearing as Weyl weights of tractors (conformal multiplets of fields necessary to keep local unit invariance manifest). The relationship between these weights and masses is through the scalar curvature. As a consequence mass terms are spacetime dependent for off-shell gravitational backgrounds, but happily constant for physical, Einstein manifolds. Unfortunately this introduces a naturalness problem because the scalar curvature is proportional to the cosmological constant. By writing down tractor stress tensors (multiplets built from the standard stress tensor and its first and second derivatives), we show how back-reaction solves this naturalness problem. We also show that classical back-reaction generates an interesting potential for scalar fields. We speculate that a proper description of how physical systems couple to scale, could improve our understanding of naturalness problems caused by the disparity between the particle physics and observed, cosmological constants. We further give some ideas how an ambient description of tractor calculus could lead to a Ricci-flat/CFT correspondence which generalizes the AdS side of Maldacena's duality to a Ricci-flat space of one higher dimension.

  3. Alternative set of defining constants for redefinition of four SI units

    CERN Document Server

    Khruschov, V V

    2016-01-01

    We discuss different sets of defining constants, fixed values of which are considered in connection with the transition to new definitions of four SI units (the kilogram, the mole, the ampere, and the kelvin). The notion of constant's order in a given system of units is suggested. We propose an alternative set of fixed constants applicable for new definitions of the four SI units. We analyse and discuss in detail the set, which consists of the Planck constant, the Avogadro constant, the Boltzmann constant and the magnetic constant.

  4. Confronting Cosmology and New Physics with Fundamental Constants

    CERN Document Server

    Thompson, Rodger I

    2013-01-01

    The values of the fundamental constants such as $\\mu = m_P/m_e$, the proton to electron mass ratio and $\\alpha$, the fine structure constant, are sensitive to the product $\\sqrt{\\zeta_x^2(w+1)}$ where $\\zeta_x$ is a coupling constant between a rolling scalar field responsible for the acceleration of the expansion of the universe and the electromagnetic field with x standing for either $\\mu$ or $\\alpha$. The dark energy equation of state $w$ can assume values different than $-1$ in cosmologies where the acceleration of the expansion is due to a scalar field. In this case the value of both $\\mu$ and $\\alpha$ changes with time. The values of the fundamental constants, therefore, monitor the equation of state and are a valuable tool for determining $w$ as a function of redshift. In fact the rolling of the fundamental constants is one of the few definitive discriminators between acceleration due to a cosmological constant and acceleration due to a quintessence rolling scalar field. $w$ is often given in parameteri...

  5. Units Based on Constants: The Redefinition of the International System of Units

    Science.gov (United States)

    Stenger, J.; Ullrich, J. H.

    2016-03-01

    Recent decisions of the General Conference on Weights and Measures of the Metre Convention have opened the door to a fundamental change of the International System of Units, the SI, in 2018. The revised SI will be based on fixing the numerical values of seven defining constants corresponding to the seven traditional base units. This will bring about basic modifications in the definition of the kilogram, the ampere, the kelvin, and the mole and will have consequences for units derived from them. In contrast, the second, the meter, and the candela will not be affected. This paper describes the motivation and rationale behind this endeavor, introduces the new definitions, and reviews the requirements for the redefinitions as well as the status of the experiments that are currently being carried out to fulfill them. Benefits and a wide-reaching impact for the realization and dissemination of the units are anticipated because innovative technologies with ever-increasing accuracy will emerge, enabling the direct realization over widespread measurement ranges without the definitions themselves having to be changed.

  6. Current Status of the Problem of Cosmological Variability of Fundamental Physical Constants

    Science.gov (United States)

    Varshslovich, D.A.; Ivanchik, A.V.; Orlov, A.V.; Potekhin, A.Y.; Petitjean, P.

    We review the current status of the problem of cosmological variability of fundamental physical constants, provided by modern laboratory experiments, Oklo phenomena analysis, and especially astronomical observations.

  7. Constraining fundamental constants of physics with quasar absorption line systems

    CERN Document Server

    Petitjean, Patrick; Chand, Hum; Ivanchik, Alexander; Noterdaeme, Pasquier; Gupta, Neeraj

    2009-01-01

    We summarize the attempts by our group and others to derive constraints on variations of fundamental constants over cosmic time using quasar absorption lines. Most upper limits reside in the range 0.5-1.5x10-5 at the 3sigma level over a redshift range of approximately 0.5-2.5 for the fine-structure constant, alpha, the proton-to-electron mass ratio, mu, and a combination of the proton gyromagnetic factor and the two previous constants, gp(alpha^2/mu)^nu, for only one claimed variation of alpha. It is therefore very important to perform new measurements to improve the sensitivity of the numerous methods to at least <0.1x10-5 which should be possible in the next few years. Future instrumentations on ELTs in the optical and/or ALMA, EVLA and SKA pathfinders in the radio will undoutedly boost this field by allowing to reach much better signal-to-noise ratios at higher spectral resolution and to perform measurements on molecules in the ISM of high redshift galaxies.

  8. Varying Fine Structure Constant and Black Hole Physics

    CERN Document Server

    Das, S; Das, Saurya; Kunstatter, Gabor

    2003-01-01

    Recent astrophysical observations suggest that the fine structure constant $\\alpha=e^2/\\hbar c$ may be slowly increasing with time. This may be due to an increase of $e$ or a decrease of $c$, or both. In this article, we argue from model independent considerations that this variation should be considered adiabatic. Then, we examine in detail the consequences of such an adiabatic variation in the context of a specific model of quantized charged black holes. We find that the second law of black hole thermodynamics is obeyed, regardless of the origin of the variation, and that interesting constraints arise on the charge and mass of black holes. Finally, we estimate the work done on a black hole of mass $M$ due to the $\\alpha$ variation.

  9. Royal Society, Discussion on the Constants of Physics, London, England, May 25, 26, 1983, Proceedings

    Science.gov (United States)

    1983-12-01

    Various topics dealing with the constants of physics are addressed. The subjects considered include: measurement of the fundamental constants; the search for proton decay; the constancy of G; limits on the variability of coupling constants from the Oklo natural reactor; implications of quasar spectroscopy for constancy of constants; theoretical prospects for understanding the values of fundamental constants; the strong, electromagnetic, and weak couplings; and field theories without fundamental gauge symmetries. Also discussed are: Einstein gravitation as a long-wavelength effective field theory; unification and supersymmetry; phase transitions in the early universe; the cosmological constant; large numbers and ratios in astrophysics and cosmology; dependence of macrophysical phenomena on the values of the fundamental constants; dimensionality; and the anthropic principle and its implications for biological evolution.

  10. Properties of human motor units after prolonged activity at a constant firing rate.

    Science.gov (United States)

    Johnson, K V B; Edwards, S C; Van Tongeren, C; Bawa, P

    2004-02-01

    The primary purpose of this study was to examine if there are changes in the intrinsic properties of spinal motoneurons after prolonged submaximal contractions. To do this, we assessed whether or not the synaptic drive to motoneurons needs to increase in order to maintain a constant firing rate of a motor unit. Recruitment of new units and an increase in total electromyographic (EMG) activity of the muscle of interest were taken as estimates of an increase in synaptic drive. Subjects were asked to maintain a constant firing rate of a clearly identifiable (targeted) motor unit from the first dorsal interosseous muscle for approximately 10 min, while surface EMG and force were recorded simultaneously. For the 60 units studied, the duration of the constant-firing-rate period ranged from 73 to 1,140 s (448 +/- 227 s; mean +/- SD). There was a significant increase ( t-test, prate suggesting an increase in the net excitatory input to the motoneuron pool. Changes occurring simultaneously in other parameters, namely, variability in interspike interval, magnitude of force fluctuations, the duration of motor unit action potentials, and the median power frequency of surface EMG were also computed. The firing rates of 16 concurrently firing motoneurons, not controlled by the subject, remained constant. The key finding of this study is that after prolonged activity, a motoneuron requires a stronger excitatory input to maintain its firing rate. Additional results are indicative of significant changes in the characteristics of the synaptic inputs, changes at the neuromuscular junction (both pre- and postsynaptic regions) and the sarcolemma.

  11. Physical health functioning among United Methodist clergy.

    Science.gov (United States)

    Proeschold-Bell, Rae Jean; LeGrand, Sara

    2012-09-01

    United Methodist clergy have been found to have higher than average self-reported rates of obesity, diabetes, asthma, arthritis, and high blood pressure. However, health diagnoses differ from physical health functioning, which indicates how much health problems interfere with activities of daily living. Ninety-five percent (n = 1726) of all actively serving United Methodist clergy in North Carolina completed the SF-12, a measure of physical health functioning that has US norms based on self-administered survey data. Sixty-two percent (n = 1074) of our sample completed the SF-12 by self-administered formats. We used mean difference tests among self-administered clergy surveys to compare the clergy SF-12 Physical Composite Scores to US-normed scores. Clergy reported significantly better physical health composite scores than their gender- and age-matched peers, despite above average disease burden in the same sample. Although health interventions tailored to clergy that address chronic disease are urgently needed, it may be difficult to elicit participation given pastors' optimistic view of their physical health functioning.

  12. Expression of results in quantum chemistry physical chemistry division commission on physicochemical symbols, terminology and units

    CERN Document Server

    Whiffen, D H

    2013-01-01

    Expression of Results in Quantum Chemistry recommends the appropriate insertion of physical constants in the output information of a theoretical paper in order to make the numerical end results of theoretical work easily transformed to SI units by the reader. The acceptance of this recommendation would circumvent the need for a set of atomic units each with its own symbol and name. It is the traditional use of the phrase """"atomic units"""" in this area which has obscured the real problem. The four SI dimensions of length, mass, time, and current require four physical constants to be permitte

  13. Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

    CERN Document Server

    Hayano, R S

    2010-01-01

    Proceedings of the Japan Academy, Series B Vol. 86 (2010) No. 1 P 1-10 Language: Next Article http://dx.doi.org/10.2183/pjab.86.1 JST.JSTAGE/pjab/86.1 Reviews Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants Ryugo S. HAYANO1) 1) Department of Physics, The University of Tokyo Released 2010/01/14 Keywords: antiproton, CERN, fundamental physical constants, laser spectroscopy Full Text PDF [1604K] Abstracts References(25) Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended val...

  14. Equivalent circuit with complex physical constants and equivalent-parameters-expressed dissipation factors of piezoelectric materials

    Institute of Scientific and Technical Information of China (English)

    Chen Yu; Wen Yu-Mei; Li Ping

    2006-01-01

    The equivalent circuit with complex physical constants for a piezoelectric ceramic in thickness mode is established.In the equivalent circuit, electric components (equivalent circuit parameters) are connected to real and imaginary parts of complex physical coefficients of piezoelectric materials. Based on definitions of dissipation factors, three of them (dielectric, elastic and piezoelectric dissipation factors) are represented by equivalent circuit parameters. Since the equivalent circuit parameters are detectable, the dissipation factors can be easily obtained. In the experiments, the temperature and the stress responses of the three dissipation factors are measured.

  15. The physical constants as biosignature: an anthropic retrodiction of the Selfish Biocosm Hypothesis

    Science.gov (United States)

    Gardner, James N.

    2004-07-01

    Goal 7 of the NASA Astrobiology Roadmap states: "Determine how to recognize signatures of life on other worlds and on early Earth. Identify biosignatures that can reveal and characterize past or present life in ancient samples from Earth, extraterrestrial samples measured in situ, samples returned to Earth, remotely measured planetary atmospheres and surfaces, and other cosmic phenomena." The cryptic reference to "other cosmic phenomena" would appear to be broad enough to include the possible identification of biosignatures embedded in the dimensionless constants of physics. The existence of such a set of biosignatures - a life-friendly suite of physical constants - is a retrodiction of the Selfish Biocosm (SB) hypothesis. This hypothesis offers an alternative to the weak anthropic explanation of our indisputably life-friendly cosmos favoured by (1) an emerging alliance of M-theory-inspired cosmologists and advocates of eternal inflation like Linde and Weinberg, and (2) supporters of the quantum theory-inspired sum-over-histories cosmological model offered by Hartle and Hawking. According to the SB hypothesis, the laws and constants of physics function as the cosmic equivalent of DNA, guiding a cosmologically extended evolutionary process and providing a blueprint for the replication of new life-friendly progeny universes.

  16. Bloch constant of holomorphic mappings on the unit polydisk of C~n

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,we give a definition of Bloch mappings defined in the unit polydisk Dn, which generalizes the concept of Bloch functions defined in the unit disk D.It is known that Bloch theorem fails unless we have some restrictive assumption on holomorphic mappings in several complex variables.We shall establish the corresponding distortion theorems for subfamiliesβ(K)andβloc(K) of Bloch mappings defined in the polydisk Dn,which extend the distortion theorems of Liu and Minda to higher dimensions.As an application,we obtain lower and upper bounds of Bloch constants for various subfamilies of Bloeh mappings defined in Dn.In particular,our results reduce to the classical results of Ahlfors and Landau when n=1.

  17. EDITORIAL: Special Issue on Physical Units

    Science.gov (United States)

    Blackburn, David

    1994-01-01

    The concept of the physical unit is key to the understanding of physics, for it is the link between the theoretical relationships which describe physical quantities and the measurements which confirm or confound their predictions. No topic can be more suitable for treatment in a special issue of Metrologia, for the journal's field is measurement: fine measurements, measurements of fundamental quantities, the relationships between measurements, the processes and conventions which allow measurements to be exchanged, duplicated and confirmed. And if physical quantities are to be measured, reference must be made to the units in which they are expressed. Units, in turn, serve no function in isolation. Used individually, units can convey only the simplest of ideas. When organized, however, so that they are part of a system which is logically coherent, which permits the transfer of measurements from one place to another or from one area of science to another and is recognized universally by those whose work depends on unambiguous statements of quantity, they represent a tool of remarkable power with which to express quantities in a concise and consistent way. This issue describes the units of the Système International d'Unités (SI). It does this in a series of essays, each of which treats the SI in a way which reflects the personal interests and viewpoint of the author. Individual articles deal with the definition and description of units, their historical development and their application in scientific, legal, business, regional and international affairs. There is no pretence that this is a textbook on the SI, for the topic is not covered exhaustively, completely or even uniformly: the purpose of these essays is to show that the SI is ubiquitous, touching many aspects of human endeavour; that it is useful, serving the interests of science, technology and commerce; and that it is not closed, the underlying principles of how to describe, select, define and disseminate

  18. Experimental determination of the Boltzmann constant: An undergraduate laboratory exercise for molecular physics or physical chemistry

    Science.gov (United States)

    Campbell, H. M.; Boardman, B. M.; DeVore, T. C.; Havey, D. K.

    2012-12-01

    This article describes an undergraduate laboratory exercise that uses optical spectroscopy to determine the magnitude and the uncertainty of the Boltzmann constant kb. The more accurate approach uses photoacoustic spectroscopy to measure the Doppler-broadened line profile of individual spectral lines of N2O to extract kb. Measurements and estimates of the uncertainties in the quantities needed to calculate kb from the line profiles are then used to estimate the uncertainty in kb. This experiment is unusual in that it uses advanced laser-based spectroscopy techniques to emphasize standard practices of uncertainty analysis. The core instrumentation is modular and relatively affordable; it requires a tunable single-mode laser, photoreceiver, optical cell, and vacuum pump. If this instrumentation is not available, an alternate approach can be performed which uses the intensity of each rotational transition of an infrared band to measure kb. Although there is more uncertainty using the alternate approach, low concentrations of CO2, DCl, or N2O give reasonable results for the magnitude of kb. Student assessment results indicate retention and mastery of the concept of combined measurement uncertainty.

  19. Precision atomic mass spectrometry with applications to fundamental constants, neutrino physics, and physical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Mount, Brianna J. [Florida State University, Department of Physics (United States); Redshaw, Matthew [National Superconducting Cyclotron Laboratory (United States); Myers, Edmund G., E-mail: myers@nucmar.physics.fsu.edu [Florida State University, Department of Physics (United States)

    2011-07-15

    We present a summary of precision atomic mass measurements of stable isotopes carried out at Florida State University. These include the alkalis {sup 6}Li, {sup 23}Na, {sup 39,41}K, {sup 85,87}Rb, {sup 133}Cs; the rare gas isotopes {sup 84,86}Kr and {sup 129,130,132,136}Xe; {sup 17,18}O, {sup 19}F, {sup 28}Si, {sup 31}P, {sup 32}S; and various isotope pairs of importance to neutrino physics, namely {sup 74,76}Se/{sup 74,76}Ge, {sup 130}Xe/{sup 130}Te, and {sup 115}In/{sup 115}Sn. We also summarize our Penning trap measurements of the dipole moments of PH{sup + } and HCO{sup + }.

  20. Absolute Determination of Optical Constants by a Direct Physical Modeling of Reflection Electron Energy Loss Spectra

    CERN Document Server

    Xu, H; Toth, J; Tokesi, K; Ding, Z J

    2016-01-01

    We present an absolute extraction method of optical constants of metal from the measured reflection electron energy loss (REELS) spectra by using the recently developed reverse Monte Carlo (RMC) technique. The method is based on a direct physical modeling of electron elastic and electron inelastic scattering near the surface region where the surface excitation becomes important to fully describe the spectrum loss feature intensity in relative to the elastic peak intensity. An optimization procedure of oscillator parameters appeared in the energy loss function (ELF) for describing electron inelastic scattering due to the bulk- and surface-excitations was performed with the simulated annealing method by a successive comparison between the measured and Monte Carlo simulated REELS spectra. The ELF and corresponding optical constants of Fe were obtained from the REELS spectra measured at incident energies of 1000, 2000 and 3000 eV. The validity of the present optical data has been verified with the f- and ps-sum r...

  1. Lines of Constant Physics in a Five-Dimensional Gauge-Higgs Unification Scenario

    CERN Document Server

    Alberti, Maurizio; Knechtli, Francesco; Moir, Graham

    2016-01-01

    We report on the progress in the study of a five-dimensional SU(2) Gauge-Higgs Unification model. In this non-perturbative study, the Higgs mechanism is triggered by the spontaneous breaking of a global symmetry. In the same region of the phase diagram, we observe both dimensional reduction and the ratio of Higgs and Z boson masses to take the value known from experiment. We present the first results on the construction of a line of constant physics in this region, including the prediction for the mass scale of the first excited states of the Higgs and gauge bosons.

  2. Possible determination of the physical parameters of the first living cells based on the fundamental physical constants

    Science.gov (United States)

    Atanasov, Atanas Todorov

    2016-12-01

    Here is developed the hypothesis that the cell parameters of unicellular organisms (Prokaryotes and Eukaryotes) are determined by the gravitational constant (G, N.m2 /kg2), Planck constant (h, J.s) and growth rate of cells. By scaling analyses it was shown that the growth rate vgr(m/s) of unicellular bacteria and protozoa is relatively constant parameter, ranging in a narrow window of 10-12 - 10-10 m/s, in comparison to the diapason of cell mass, ranging 10 orders of magnitudes from 10-17 kg in bacteria to 10-7 kg in amoebas. By dimensional analyses it was shown that the combination between the growth rate of cells, gravitational constant and Planck constant gives equations with dimension of mass M(vgr)=(h.vgr/G)½ in kg, length L(v gr)=(hṡG/vgr3)1/2 in meter, time T(vgr)=(hṡG/vgr5)1/2 in seconds, and density ρ ((vgr)=vgr.3.5/hG2 in kg/m3 . For growth rate vgr in diapason of 1×10-11 m/s - 1×10-9.5 m/s the calculated numerical values for mass (3×10-18 -1×10-16 kg), length (5×10-8 -1×10-5 m), time (1×102 -1×106 s) and density (1×10-1 - 1×104 kg/m3) overlaps with diapason of experimentally measured values for cell mass (3×10-18 -1×10-15 kg), volume to surface ratio (1×10-7 -1×10-4 m), doubling time (1×103 -1×107 s), and density (1050 - 1300 kg/m3) in bacteria and protozoa. These equations show that appearance of the first living cells could be mutually connected to the physical constants.

  3. Quarterly report -- Physics unit: October--December, 1953

    Energy Technology Data Exchange (ETDEWEB)

    Davenport, D.E.; Faulkner, J.E.; Ozeroff, J.

    1954-01-11

    This report is intended to be a description of current work being done by the Physics Unit at the Hanford Atomic Products Operation. The work is concerned mainly with the study of graphite-moderated natural uranium reactors for the production of plutonium on a large scale. In addition, varied physics problems associated with the operation of an industrial atomic plant are occasionally dealt with. The report is divided into four sections; lattice physics; nuclear physics; irradiation physics; and plant physics.

  4. Edexcel AS Physics Student Unit Guide

    CERN Document Server

    Benn, Mike

    2009-01-01

    Student Unit Guides are perfect for revision. Each guide is written by an examiner and explains the unit requirements, summarises the relevant unit content and includes a series of specimen questions and answers. There are three sections to each guide:. Introduction - includes advice on how to use the guide, an explanation of the skills being tested by the assessment objectives, an outline of the unit or module and, depending on the unit, suggestions for how to revise effectively and prepare for the examination questions. Content Guidance - provides an examiner's overview of the module's key t

  5. Edexcel A2 Physics Student Unit Guide

    CERN Document Server

    Benn, Mike

    2010-01-01

    Student Unit Guides are perfect for revision. Each guide is written by an examiner and explains the unit requirements, summarises the relevant unit content and includes a series of specimen questions and answers. There are three sections to each guide:. Introduction - includes advice on how to use the guide, an explanation of the skills being tested by the assessment objectives, an outline of the unit or module and, depending on the unit, suggestions for how to revise effectively and prepare for the examination questions. Content Guidance - provides an examiner's overview of the module's key t

  6. High energy physics in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Month, M.

    1985-10-16

    The US program in high energy physics from 1985 to 1995 is reviewed. The program depends primarily upon work at the national accelerator centers, but includes a modest but diversified nonaccelerator program. Involvement of universities is described. International cooperation in high energy physics is discussed, including the European, Japanese, USSR, and the People's Republic of China's programs. Finally, new facilities needed by the US high energy physics program are discussed, with particular emphasis given to a Superconducting Super Collider for achieving ever higher energies in the 20 TeV range. (LEW)

  7. Uniting forces in physics and medicine

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Following the very successful ‘Physics for Health’ workshop held at CERN on 2-4 February this year, a strategy document has recently been issued. It outlines the main issues discussed at the workshop and indicates the most promising avenues in the field of medical applications derived from physics. Rolf Heuer, CERN Director General talks to the participants in the “Physics for Health in Europe” workshop. The response to the first “Physics for Health in Europe” workshop was enthusiastic: more than 400 scientists from 32 countries signed up, submitting 200 abstracts within a few weeks. Between fifty and a hundred people were connected to the live webcast at all times. “We had to close the registration before the planned deadline since the capacity of CERN’s main auditorium had been reached”, says Manjit Dosanjh from the organizing committee. Participants included physicists, medical doctors, experts in radio...

  8. An initial-abstraction, constant-loss model for unit hydrograph modeling for applicable watersheds in Texas

    Science.gov (United States)

    Asquith, William H.; Roussel, Meghan C.

    2007-01-01

    Estimation of representative hydrographs from design storms, which are known as design hydrographs, provides for cost-effective, riskmitigated design of drainage structures such as bridges, culverts, roadways, and other infrastructure. During 2001?07, the U.S. Geological Survey (USGS), in cooperation with the Texas Department of Transportation, investigated runoff hydrographs, design storms, unit hydrographs,and watershed-loss models to enhance design hydrograph estimation in Texas. Design hydrographs ideally should mimic the general volume, peak, and shape of observed runoff hydrographs. Design hydrographs commonly are estimated in part by unit hydrographs. A unit hydrograph is defined as the runoff hydrograph that results from a unit pulse of excess rainfall uniformly distributed over the watershed at a constant rate for a specific duration. A time-distributed, watershed-loss model is required for modeling by unit hydrographs. This report develops a specific time-distributed, watershed-loss model known as an initial-abstraction, constant-loss model. For this watershed-loss model, a watershed is conceptualized to have the capacity to store or abstract an absolute depth of rainfall at and near the beginning of a storm. Depths of total rainfall less than this initial abstraction do not produce runoff. The watershed also is conceptualized to have the capacity to remove rainfall at a constant rate (loss) after the initial abstraction is satisfied. Additional rainfall inputs after the initial abstraction is satisfied contribute to runoff if the rainfall rate (intensity) is larger than the constant loss. The initial abstraction, constant-loss model thus is a two-parameter model. The initial-abstraction, constant-loss model is investigated through detailed computational and statistical analysis of observed rainfall and runoff data for 92 USGS streamflow-gaging stations (watersheds) in Texas with contributing drainage areas from 0.26 to 166 square miles. The analysis is

  9. Unit Invariance as a Unifying Principle of Physics

    CERN Document Server

    Shaukat, Abrar

    2010-01-01

    A basic principle of physics is the freedom to locally choose any unit system when describing physical quantities. Its implementation amounts to treating Weyl invariance as a fundamental symmetry of all physical theories. In this thesis, we study the consequences of this "unit invariance" principle and find that it is a unifying one. Unit invariance is achieved by introducing a gauge field called the scale, designed to measure how unit systems vary from point to point. In fact, by a uniform and simple Weyl invariant coupling of scale and matter fields, we unify massless, massive, and partially massless excitations. As a consequence, masses now dictate the response of physical quantities to changes of scale. This response is calibrated by certain "tractor Weyl weights". Reality of these weights yield Breitenlohner-Freedman stability bounds in anti de Sitter spaces. Another valuable outcome of our approach is a general mechanism for constructing conformally invariant theories. In particular, we provide direct d...

  10. Physical Therapy Intervention in the Neonatal Intensive Care Unit

    Science.gov (United States)

    Byrne, Eilish; Garber, June

    2013-01-01

    This article presents the elements of the Intervention section of the Infant Care Path for Physical Therapy in the Neonatal Intensive Care Unit (NICU). The types of physical therapy interventions presented in this path are evidence-based and the suggested timing of these interventions is primarily based on practice knowledge from expert…

  11. Asymptotics of physical solutions to the Lorentz-Dirac equation for planar motion in constant electromagnetic fields

    Science.gov (United States)

    Kazinski, P. O.; Shipulya, M. A.

    2011-06-01

    We present a study of planar physical solutions to the Lorentz-Dirac equation in a constant electromagnetic field. In this case, we reduced the Lorentz-Dirac equation to one second-order differential equation. We obtained the asymptotics of physical solutions to this equation at large proper times. It turns out that, in a crossed constant uniform electromagnetic field with vanishing invariants, a charged particle enters a universal regime at large times. We found that the ratios of momentum components that tend to constants are determined only by the external field. This effect is essentially due to a radiation reaction. There is no such effect for the Lorentz equation in this field.

  12. Asymptotics of physical solutions to the Lorentz-Dirac equation for a planar motion in constant electromagnetic fields

    CERN Document Server

    Kazinski, P O

    2010-01-01

    We present a study of planar physical solutions to the Lorentz-Dirac equation in a constant electromagnetic field. In this case, we reduced the Lorentz-Dirac equation to the one second order differential equation. We found the asymptotics of physical solutions to this equation at large proper times. It turns out that, in the crossed constant uniform electromagnetic field with vanishing invariants, a charged particle goes to a universal regime at large times. We found the ratio of momentum components which tends to a constant determined only by the external field. This effect is essentially due to a radiation reaction. There is no such an effect for the Lorentz equation in this field.

  13. Strategic Priorities for Physical Activity Surveillance in the United States.

    Science.gov (United States)

    Fulton, Janet E; Carlson, Susan A; Ainsworth, Barbara E; Berrigan, David; Carlson, Cynthia; Dorn, Joan M; Heath, Gregory W; Kohl, Harold W; Lee, I-Min; Lee, Sarah M; Másse, Louise C; Morrow, James R; Gabriel, Kelley Pettee; Pivarnik, James M; Pronk, Nicolaas P; Rodgers, Anne B; Saelens, Brian E; Sallis, James F; Troiano, Richard P; Tudor-Locke, Catrine; Wendel, Arthur

    2016-10-01

    Develop strategic priorities to guide future physical activity surveillance in the United States. The Centers for Disease Control and Prevention and the American College of Sports Medicine convened a scientific roundtable of physical activity and measurement experts. Participants summarized the current state of aerobic physical activity surveillance for adults, focusing on practice and research needs in three areas: 1) behavior, 2) human movement, and 3) community supports. Needs and challenges for each area were identified. At the conclusion of the meeting, experts identified one overarching strategy and five strategic priorities to guide future surveillance. The identified overarching strategy was to develop a national plan for physical activity surveillance similar to the U.S. National Physical Activity Plan for promotion. The purpose of the plan would be to enhance coordination and collaboration within and between sectors, such as transportation and public health, and to address specific strategic priorities identified at the roundtable. These strategic priorities were used 1) to identify and prioritize physical activity constructs; 2) to assess the psychometric properties of instruments for physical activity surveillance; 3) to provide training and technical assistance for those collecting, analyzing, or interpreting surveillance data; 4) to explore accessing data from alternative sources; and 5) to improve communication, translation, and dissemination about estimates of physical activity from surveillance systems. This roundtable provided strategic priorities for physical activity surveillance in the United States. A first step is to develop a national plan for physical activity surveillance that would provide an operating framework from which to execute these priorities.

  14. Women in physics in the United States: Recruitment and retention

    Science.gov (United States)

    Abramzon, Nina; Benson, Patrice; Bertschinger, Edmund; Blessing, Susan; Cochran, Geraldine L.; Cox, Anne; Cunningham, Beth; Galbraith-Frew, Jessica; Johnson, Jolene; Kerby, Leslie; Lalanne, Elaine; O'Donnell, Christine; Petty, Sara; Sampath, Sujatha; Seestrom, Susan; Singh, Chandralekha; Spencer, Cherrill; Woodle, Kathryne Sparks; Yennello, Sherry

    2015-12-01

    Initiatives to increase the number, persistence, and success of women in physics in the United States reach preteen girls through senior women. Programs exist at both the local and national levels. In addition, researchers have investigated issues related to gender equity in physics and physics education. Anecdotal evidence suggests increased media coverage of the underrepresentation of women in science. All of these efforts are motivated and made more effective by the continued collection and presentation of data on the presence, persistence, and promise of women in physics.

  15. The Atomic Mass Unit, the Avogadro Constant, and the Mole: A Way to Understanding

    Science.gov (United States)

    Baranski, Andrzej

    2012-01-01

    Numerous articles have been published that address problems encountered in teaching basic concepts of chemistry such as the atomic mass unit, Avogadro's number, and the mole. The origin of these problems is found in the concept definitions. If these definitions are adjusted for teaching purposes, understanding could be improved. In the present…

  16. Influence of sulfur physical properties in Claus unit operation

    Energy Technology Data Exchange (ETDEWEB)

    Larraz Mora, R.; Arvelo Alvarez, R. [Chemical Engineering Dept., Univ. of la Laguna, Tenerife (Spain)

    2002-09-01

    The Claus process is an efficient way of removing H{sub 2}S from acid gas streams and it has been widely practiced in industries such as natural gas processing, oil refining and metal smelting. Increasingly strict pollution control regulations require maximum sulfur recovery and high stream factor from the Claus units in order to minimize sulfur-containing effluents. As has been widely reported Claus unit's damages mainly occur during start up and shutdown. These operations involve scheduled warm-up and cool-down of the unit, usually burning refinery fuel-gas, which if not properly made can produce severe pipe and equipment plugging as well as catalyst deactivation. Sulfur products remaining in the unit during a shutdown period can produce dramatic unit corrosion episodes diminishing sulfur recovery unit stream factor. In the present paper some guidelines are given based on sulfur physical properties singularities which help to improve start-up/shut-down procedures. (orig.)

  17. Quantum Theory without Planck's Constant

    CERN Document Server

    Ralston, John P

    2012-01-01

    Planck's constant was introduced as a fundamental scale in the early history of quantum mechanics. We find a modern approach where Planck's constant is absent: it is unobservable except as a constant of human convention. Despite long reference to experiment, review shows that Planck's constant cannot be obtained from the data of Ryberg, Davisson and Germer, Compton, or that used by Planck himself. In the new approach Planck's constant is tied to macroscopic conventions of Newtonian origin, which are dispensable. The precision of other fundamental constants is substantially improved by eliminating Planck's constant. The electron mass is determined about 67 times more precisely, and the unit of electric charge determined 139 times more precisely. Improvement in the experimental value of the fine structure constant allows new types of experiment to be compared towards finding "new physics." The long-standing goal of eliminating reliance on the artifact known as the International Prototype Kilogram can be accompl...

  18. Effect of medium dielectric constant on the physical properties of single-walled carbon nanotubes

    NARCIS (Netherlands)

    Gao, J.; Gomulya, W.; Loi, M. A.

    2013-01-01

    The photophysical properties of semiconducting single walled carbon nanotubes (SWNTs) in different environments are analyzed by steady-state and time-resolved photoluminescence (PL) spectroscopy. The PL emission of SWNTs shows a red shift with the increase of the dielectric constant of the

  19. Training programs in medical physics in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Lanzl, L H

    1977-01-01

    The history of the field of medical physics in the United States is reviewed; the importance of the development of the nuclear reactor and particle accelerators to medical physics is pointed out. Conclusions and recommendations of an IAEA/WHO seminar on the training of medical physicists (in 1972) are given and compared with existing programs in the US. It is concluded that the recommendations of the IAEA are, for the most part, followed. 1 table. (RWR)

  20. A relation between the right triangle and circular tori with constant mean curvature in the unit 3-sphere

    Directory of Open Access Journals (Sweden)

    Abdênago Barros

    2004-12-01

    Full Text Available In this note we will show that the inverse image under the stereographic projection of a circular torus of revolution in the 3-dimensional euclidean space has constant mean curvature in the unit 3-sphere if and only if their radii are the catet and the hypotenuse of an appropriate right triangle.Neste artigo mostraremos que a imagem inversa pela projeção estereográfica de um toro circular de revolução no espaço euclidiano de dimensão 3 tem curvatura média constante se e somente se os seus raios são o cateto e a hipotenusa de um triângulo retângulo apropriado.

  1. cVEMP morphology changes with recording electrode position, but single motor unit activity remains constant.

    Science.gov (United States)

    Rosengren, Sally M; Colebatch, James G; Borire, Adeniyi; Straumann, Dominik; Weber, Konrad P

    2016-04-15

    Cervical vestibular evoked myogenic potentials (cVEMPs) recorded over the lower quarter of the sternocleidomastoid (SCM) muscle in normal subjects may have opposite polarity to those recorded over the midpoint. It has thus been suggested that vestibular projections to the lower part of SCM might be excitatory rather than inhibitory. We tested the hypothesis that the SCM muscle receives both inhibitory and excitatory vestibular inputs. We recorded cVEMPs in 10 normal subjects with surface electrodes placed at multiple sites along the anterior (sternal) component of the SCM muscle. We compared several reference sites: sternum, ipsilateral and contralateral earlobes, and contralateral wrist. In five subjects, single motor unit responses were recorded at the upper, middle, and lower parts of the SCM muscle using concentric needle electrodes. The surface cVEMP had the typical positive-negative polarity at the midpoint of the SCM muscle. In all subjects, as the recording electrode was moved toward each insertion point, p13 amplitude became smaller and p13 latency increased, then the polarity inverted to a negative-positive waveform (n1-p1). Changing the reference site did not affect reflex polarity. There was a significant short-latency change in activity in 61/63 single motor units, and in each case this was a decrease or gap in firing, indicating an inhibitory reflex. Single motor unit recordings showed that the reflex was inhibitory along the entire SCM muscle. The cVEMP surface waveform inversion near the mastoid and sternal insertion points likely reflects volume conduction of the potential occurring with increasing distance from the motor point.

  2. Developing an Appropriate Goalball Unit for Secondary Physical Education

    Science.gov (United States)

    Laughlin, Michael K.; Happel, Kathleen

    2016-01-01

    Goalball, a sport designed for those with visual impairments, is a competitive and recreational sport enjoyed by athletes around the world. Students with and without visual impairments can experience positive outcomes when teachers appropriately include a goalball unit as part of their inclusive secondary physical education curriculum. This…

  3. Reflector antenna analysis using physical optics on Graphics Processing Units

    DEFF Research Database (Denmark)

    Borries, Oscar Peter; Sørensen, Hans Henrik Brandenborg; Dammann, Bernd

    2014-01-01

    The Physical Optics approximation is a widely used asymptotic method for calculating the scattering from electrically large bodies. It requires significant computational work and little memory, and is thus well suited for application on a Graphics Processing Unit. Here, we investigate...... the performance of an implementation and demonstrate that while there are some implementational pitfalls, a careful implementation can result in impressive improvements....

  4. Perceptions of a disability sport unit in general physical education.

    Science.gov (United States)

    Grenier, Michelle; Collins, Karen; Wright, Steven; Kearns, Catherine

    2014-01-01

    The purpose of this qualitative study was to assess the effectiveness of a disability sport unit in shaping perceptions of disability. Data from interviews, observations, and documents were collected on 87 elementary-aged students, one physical education teacher, and one teaching intern. Comparisons were drawn between fifth graders engaged in a five-week disability sport unit to fourth graders participating in their standard physical education curriculum. Findings revealed differences in the way fourth and fifth graders came to view individuals with disabilities. The results support an analysis of curriculum development that underscores the significance of the social model in positively impacting constructions of disability. Recommendations include the use of disability sports in physical education as an effective strategy for educating students in game play, knowledge of the Paralympics, and the inclusion of individuals with disabilities in a variety of sporting venues.

  5. On Geometric Probability, Holography, Shilov Boundaries and the Four Physical Coupling Constants of Nature

    Directory of Open Access Journals (Sweden)

    Castro C.

    2005-07-01

    Full Text Available By recurring to Geometric Probability methods, it is shown that the coupling constants, αEM; αW; αC associated with Electromagnetism, Weak and the Strong (color force are given by the ratios of the ratios of the measures of the Shilov boundaries Q2=S1×RP1; Q3=S2×RP1; S5, respectively, with respect to the ratios of the measures μ[Q5]/μN[Q5] associated with the 5D conformally compactified real Minkowski spacetime ˉ M5 that has the same topology as the Shilov boundary Q5 of the 5 complex-dimensional poly-disc D5. The homogeneous symmetric complex domain D5=SO(5,2/SO(5×SO(2 corresponds to the conformal relativistic curved 10 real-dimensional phase space H10 associated with a particle moving in the 5D Anti de Sitter space AdS5. The geometric coupling constant associated to the gravitational force can also be obtained from the ratios of the measures involving Shilov boundaries. We also review our derivation of the observed vacuum energy density based on the geometry of de Sitter (Anti de Sitter spaces.

  6. The time course of the effects of constant-angle and constant-torque stretching on the muscle-tendon unit.

    Science.gov (United States)

    Herda, T J; Costa, P B; Walter, A A; Ryan, E D; Cramer, J T

    2014-02-01

    The purpose of the present study was to examine the time course of passive range of motion (PROM), passive torque (PASTQ), and musculo-tendinous stiffness (MTS) responses during constant-angle (CA) and constant-torque (CT) stretching of the leg flexors. Eleven healthy men [mean ± standard deviation (SD): age = 21.5 ± 2.3 years] performed 16 30-s bouts of CA and CT stretching of the leg flexors. PROM, PASTQ , and MTS were measured during stretches 1, 2, 4, 8, and 16. For PROM and PASTQ , there were no differences between CA and CT stretching treatments (P > 0.05); however, there were stretch-related differences (P stretching (collapsed across CA and CT stretching) with additional increases up to 8 min of stretching. PASTQ decreased following one 30-s bout of stretching (collapsed across CA and CT stretching) and continued to decrease up to 4 min of stretching. In contrast, only the CT stretching treatment resulted in changes to MTS (P stretching, with subsequent decreases in MTS up to 6 min of stretching. These results suggested that CT stretching may be more appropriate than a stretch held at a constant muscle length for decreasing MTS.

  7. B-meson decay constants from improved lattice nonrelativistic QCD with physical u, d, s, and c quarks.

    Science.gov (United States)

    Dowdall, R J; Davies, C T H; Horgan, R R; Monahan, C J; Shigemitsu, J

    2013-05-31

    We present the first lattice QCD calculation of the decay constants f(B) and f(B(s)) with physical light quark masses. We use configurations generated by the MILC Collaboration including the effect of u, d, s, and c highly improved staggered quarks in the sea at three lattice spacings and with three u/d quark mass values going down to the physical value. We use improved nonrelativistic QCD (NRQCD) for the valence b quarks. Our results are f(B)=0.186(4) GeV, f(B(s))=0.224(4) GeV, f(B(s))/f(B)=1.205(7), and M(B(s))-M(B)=85(2) MeV, superseding earlier results with NRQCD b quarks. We discuss the implications of our results for the standard model rates for B((s))→μ(+)μ(-) and B→τν.

  8. Elastic constants of calcite

    Science.gov (United States)

    Peselnick, L.; Robie, R.A.

    1962-01-01

    The recent measurements of the elastic constants of calcite by Reddy and Subrahmanyam (1960) disagree with the values obtained independently by Voigt (1910) and Bhimasenachar (1945). The present authors, using an ultrasonic pulse technique at 3 Mc and 25??C, determined the elastic constants of calcite using the exact equations governing the wave velocities in the single crystal. The results are C11=13.7, C33=8.11, C44=3.50, C12=4.82, C13=5.68, and C14=-2.00, in units of 1011 dyncm2. Independent checks of several of the elastic constants were made employing other directions and polarizations of the wave velocities. With the exception of C13, these values substantially agree with the data of Voigt and Bhimasenachar. ?? 1962 The American Institute of Physics.

  9. Leptonic-decay-constant ratio f(K+)/f(π+) from lattice QCD with physical light quarks.

    Science.gov (United States)

    Bazavov, A; Bernard, C; DeTar, C; Foley, J; Freeman, W; Gottlieb, Steven; Heller, U M; Hetrick, J E; Kim, J; Laiho, J; Levkova, L; Lightman, M; Osborn, J; Qiu, S; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2013-04-26

    A calculation of the ratio of leptonic decay constants f(K+)/f(π+) makes possible a precise determination of the ratio of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |V(us)|/|V(ud)| in the standard model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f(K+)/f(π+) numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ≈ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f(K+)/f(π+) = 1.1947(26)(37), where the errors are statistical and total systematic, respectively. This is our first physics result from our N(f) = 2+1+1 ensembles, and the first calculation of f(K+)/f(π+) from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f(K+)/f(π+), with an error comparable to the current world average. When combined with experimental measurements of the leptonic branching fractions, it leads to a precise determination of |V(us)|/|V(ud)| = 0.2309(9)(4) where the errors are theoretical and experimental, respectively.

  10. Leptonic decay-constant ratio f_{K^+}/f_{pi^+} from lattice QCD with physical light quarks

    CERN Document Server

    Bazavov, A; DeTar, C; Foley, J; Freeman, W; Gottlieb, Steven; Heller, U M; Hetrick, J E; Kim, J; Laiho, J; Levkova, L; Lightman, M; Osborn, J; Qiu, S; Sugar, R L; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    A calculation of the ratio of leptonic decay constants f_{K^+}/f_{\\pi^+} makes possible a precise determination of the ratio of CKM matrix elements |V_{ud}|/|V_{us}| in the Standard Model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f_{K^+}/f_{\\pi^+} numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ~ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f_{K^+}/f_{\\pi^+} = 1.1970 (29)(57), where the errors are statistical and total systematic, respectively. This is the first physics result from our N_f = 2+1+1 ensembles, and the first calculation of f_{K^+}/f_{\\pi^+} from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f_{K^+}/f_{\\pi^+}, with...

  11. Communication between professionals from physical rehabilitation unit and deaf clients

    Directory of Open Access Journals (Sweden)

    Wiliam César Alves Machado

    2015-11-01

    Full Text Available Objective: to identify how professionals from the local public physical rehabilitation unit communicate with deaf peopleseeking specialized care. Methods: exploratory descriptive study with qualitative approach conducted with 32 professionalsworking in physical rehabilitation through self-reporting instrument. Results: two thematic categories emerged from dataanalysis: Using the Brazilian Sign Language, and Improvising communication strategies to interact with deaf patients. Whenprofessionals improvise strategies to communicate with the deaf, it might create barriers that negatively affect the qualityof services provided to this population. Conclusion: communication is inefficient, and effective initiatives focused on thequalification of professionals working in rehabilitation can contribute for them to master the Brazilian Sign Language,ensuring adequate care to deaf clients/patients, in the same way as those provided to people without hearing impairment.

  12. Dog Walking and Physical Activity in the United States

    Directory of Open Access Journals (Sweden)

    Sandra A. Ham, MS

    2006-03-01

    Full Text Available Introduction Dog walking is a purposeful physical activity that may have health benefits for humans and canines. A descriptive epidemiology of the contribution of dog walking to physically active lifestyles among dog walkers in the United States has not been previously reported. Methods Data on youth and adults who reported walking for pet care trips (N = 1282 on the National Household Travel Survey 2001 were analyzed for number of trips, proportion walking a dog for at least 10 minutes on one trip, and accumulation of 30 minutes or more in 1 day of walks lasting at least 10 minutes. Results In 1 day, 58.9% of dog walkers took two or more walks, 80.2% took at least one walk of 10 minutes or more, and 42.3% accumulated 30 minutes or more from walks lasting at least 10 minutes each. There were no significant differences by sex, family income, or categories of urbanization. Conclusion Walking a dog may contribute to a physically active lifestyle and should be promoted as a strategy that fits within the framework set forth by the Task Force on Community Preventive Services for Physical Activity.

  13. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

    CERN Document Server

    Bazavov, A; Bouchard, C M; DeTar, C; Du, D; El-Khadra, A X; Foley, J; Freeland, E D; Gámiz, E; Gottlieb, Steven; Heller, U M; Kim, J; Komijani, J; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S; Zhou, R

    2014-01-01

    We compute the leptonic decay constants $f_{D^+}$, $f_{D_s}$, and $f_{K^+}$, and the quark-mass ratios $m_c/m_s$ and $m_s/m_l$ in unquenched lattice QCD using the experimentally determined value of $f_{\\pi^+}$ for normalization. We use the MILC Highly Improved Staggered Quark (HISQ) ensembles with four dynamical quark flavors --- up, down, strange, and charm --- and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacings ranging from $a\\approx 0.06$ fm to $0.15$ fm are included in the analysis to control the extrapolation to the continuum limit. Our primary results are $f_{D^+} = 212.6(0.4)({}^{+1.0}_{-1.2})\\ \\mathrm{MeV}$, $f_{D_s} = 249.0(0.3)({}^{+1.1}_{-1.5})\\ \\mathrm{MeV}$, and $f_{D_s}/f_{D^+} = 1.1712(10)({}^{+29}_{-32})$, where the errors are statistical and total systematic, respectively. The errors on ...

  14. Physical Unclonable Function with Multiplexing Units and its Evaluation

    Science.gov (United States)

    Yoshikawa, Masaya; Asai, Toshiya; Shiozaki, Mitsuru; Fujino, Takeshi

    Recently, semiconductor counterfeiting has become an increasingly serious problem. Therefore, techniques to prevent the counterfeit by using random characteristic patterns that are difficult to control artificially have attracted attention. The physical unclonable function (PUF) is one of the techniques. It is a method to derive ID information peculiar to a device by detecting random physical features that cannot be controlled during the device's manufacture. Because information such as the ID information is difficult to replicate, PUF is used as a technique to prevent counterfeiting. Several studies have been reported on PUF. Arbiter PUF, which utilizes the difference in signal propagation delay between selectors, is the typical method of composing PUF using delay characteristics. This paper proposed a new PUF which is based on the arbiter PUF. The proposed PUF introduces new multiplexing selector units. It attempts to generate an effective response using the orders of three signal arrivals. Experiments using FPGAs verify the validity of the proposed PUF. Although Uniqueness is deteriorated, Correctness, Steadiness, Randomness and Resistance against the machine learning attacks are improved in comparison with conventional one.

  15. Low-pressure effective fluorescence lifetimes and photo-physical rate constants of one- and two-ring aromatics

    Science.gov (United States)

    Benzler, Thorsten; Faust, Stephan; Dreier, Thomas; Schulz, Christof

    2015-12-01

    One- and two-ring aromatics such as toluene and naphthalene are frequently used molecular tracer species in laser-induced fluorescence (LIF) imaging diagnostics. Quantifying LIF signal intensities requires knowledge of the photo-physical processes that determine the fluorescence quantum yield. Collision-induced and intramolecular energy transfer processes in the excited electronic state closely interact under practical conditions. They can be separated through experiments at variable low pressures. Effective fluorescence lifetimes of gaseous toluene, 1,2,4-trimethylbenzene, anisole, naphthalene, and 1-methylnaphthalene diluted in CO2 were measured after picosecond laser excitation at 266 nm and time-resolved detection of fluorescence intensities. Measurements in an optically accessible externally heated cell between 296 and 475 K and 0.010-1 bar showed that effective fluorescence lifetimes generally decrease with temperature, while the influence of the bath-gas pressure depends on the respective target species and temperature. The results provide non-radiative and fluorescence rate constants and experimentally validate the effect of photo-induced cooling.

  16. A Physically-Intuitive Method for Calculation of the Local Lattice Constant from a High-Resolution Transmission Electron Microscopy Image by Fourier Analysis

    CERN Document Server

    Teherani, James T

    2013-01-01

    We have developed a physically-intuitive method to calculate the local lattice constant as a function of position in a high-resolution transmission electron microscopy image by performing a two-dimensional fast Fourier transform. We apply a Gaussian filter with appropriate spatial full-width-half-max (FWHM) bandwidth to the image centered at the desired location to calculate the local lattice constant (as opposed to the average lattice constant). Fourier analysis of the filtered image yields the vertical and horizontal lattice constants at this location. The process is repeated by stepping the Gaussian filter across the image to produce a set of local lattice constants in the vertical and horizontal direction as a function of position in the image. The method has been implemented in a freely available tool on nanoHUB.

  17. Physical and Visual Accessibilities in Intensive Care Units: A Comparative Study of Open-Plan and Racetrack Units.

    Science.gov (United States)

    Rashid, Mahbub; Khan, Nayma; Jones, Belinda

    2016-01-01

    This study compared physical and visual accessibilities and their associations with staff perception and interaction behaviors in 2 intensive care units (ICUs) with open-plan and racetrack layouts. For the study, physical and visual accessibilities were measured using the spatial analysis techniques of Space Syntax. Data on staff perception were collected from 81 clinicians using a questionnaire survey. The locations of 2233 interactions, and the location and length of another 339 interactions in these units were collected using systematic field observation techniques. According to the study, physical and visual accessibilities were different in the 2 ICUs, and clinicians' primary workspaces were physically and visually more accessible in the open-plan ICU. Physical and visual accessibilities affected how well clinicians' knew their peers and where their peers were located in these units. Physical and visual accessibilities also affected clinicians' perception of interaction and communication and of teamwork and collaboration in these units. Additionally, physical and visual accessibilities showed significant positive associations with interaction behaviors in these units, with the open-plan ICU showing stronger associations. However, physical accessibilities were less important than visual accessibilities in relation to interaction behaviors in these ICUs. The implications of these findings for ICU design are discussed.

  18. Measurement Units and Physical Dimensions of Fractance-Part II: Fractional-Order Measurement Units and Physical Dimensions of Fractance and Rules for Fractors in Series and Parallel

    National Research Council Canada - National Science Library

    Pu, Yi-Fei

    2016-01-01

    Here and in the companion paper (Part I), a novel conceptual framework on the measurement units and physical dimensions of fractance and rules for fractors in series and parallel is mainly discussed...

  19. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

    Energy Technology Data Exchange (ETDEWEB)

    Bazavov, A.; Bernard, C.; Komijani, J.; Bouchard, C. M.; DeTar, C.; Foley, J.; Levkova, L.; Du, D.; Laiho, J.; El-Khadra, A. X.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kim, J.; Toussaint, D.; Kronfeld, A. S.; Mackenzie, P. B.; Simone, J. N.; Van de Water, R. S.; Zhou, R.; Neil, E. T.; Sugar, R.

    2014-10-30

    We compute the leptonic decay constants fD+, fDs, and fK+ and the quark-mass ratios mc/ms and ms/ml in unquenched lattice QCD using the experimentally determined value of fπ+ for normalization. We use the MILC highly improved staggered quark ensembles with four dynamical quark flavors—up, down, strange, and charm—and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacings ranging from a0.06 to 0.15 fm are included in the analysis to control the extrapolation to the

  20. Unique Physically Anchored Cryptographic Theoretical Calculation of the Fine-Structure Constant {\\alpha} Matching both the g/2 and Interferometric High-Precision Measurements

    CERN Document Server

    Rhodes, Charles Kirkham

    2010-01-01

    The fine-structure constant {\\alpha}, the dimensionless number that represents the strength of electromagnetic coupling in the limit of sufficiently low energy interactions, is the crucial fundamental physical parameter that governs a nearly limitless range of phenomena involving the interaction of radiation with materials. Ideally, the apparatus of physical theory should be competent to provide a calculational procedure that yields a quantitatively correct value for {\\alpha} and the physical basis for its computation. This study presents the first demonstration of an observationally anchored theoretical procedure that predicts a unique value for {\\alpha} that stands in full agreement with the best (~370 ppt) high-precision experimental determinations. In a directly connected cryptographic computation, the method that gives these results also yields the magnitude of the cosmological constant {\\Omega}{\\Lambda} in conformance with the observational data and the condition of perfect flatness ({\\Omega}{\\Lambda} +...

  1. Charmed and light pseudoscalar meson decay constants from four-flavor lattice QCD with physical light quarks

    Energy Technology Data Exchange (ETDEWEB)

    Bazavov, A.; Bernard, C.; Komijani, J.; Bouchard, C. M.; DeTar, C.; Foley, J.; Levkova, L.; Du, D.; Laiho, J.; El-Khadra, A. X.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kim, J.; Toussaint, D.; Kronfeld, A. S.; Mackenzie, P. B.; Simone, J. N.; Van de Water, R. S.; Zhou, R.; Neil, E. T.; Sugar, R.

    2014-10-30

    We compute the leptonic decay constants fD+, fDs, and fK+ and the quark-mass ratios mc/ms and ms/ml in unquenched lattice QCD using the experimentally determined value of fπ+ for normalization. We use the MILC highly improved staggered quark ensembles with four dynamical quark flavors—up, down, strange, and charm—and with both physical and unphysical values of the light sea-quark masses. The use of physical pions removes the need for a chiral extrapolation, thereby eliminating a significant source of uncertainty in previous calculations. Four different lattice spacings ranging from a0.06 to 0.15 fm are included in the analysis to control the extrapolation to the

  2. Predictors of physical restraint use in Canadian intensive care units.

    Science.gov (United States)

    Luk, Elena; Sneyers, Barbara; Rose, Louise; Perreault, Marc M; Williamson, David R; Mehta, Sangeeta; Cook, Deborah J; Lapinsky, Stephanie C; Burry, Lisa

    2014-03-24

    Physical restraint (PR) use in the intensive care unit (ICU) has been associated with higher rates of self-extubation and prolonged ICU length of stay. Our objectives were to describe patterns and predictors of PR use. We conducted a secondary analysis of a prospective observational study of analgosedation, antipsychotic, neuromuscular blocker, and PR practices in 51 Canadian ICUs. Data were collected prospectively for all mechanically ventilated adults admitted during a two-week period. We tested for patient, treatment, and hospital characteristics that were associated with PR use and number of days of use, using logistic and Poisson regression respectively. PR was used on 374 out of 711 (53%) patients, for a mean number of 4.1 (standard deviation (SD) 4.0) days. Treatment characteristics associated with PR were higher daily benzodiazepine dose (odds ratio (OR) 1.05, 95% confidence interval (CI) 1.00 to 1.11), higher daily opioid dose (OR 1.04, 95% CI 1.01 to 1.06), antipsychotic drugs (OR 3.09, 95% CI 1.74 to 5.48), agitation (Sedation-Agitation Scale (SAS) >4) (OR 3.73, 95% CI 1.50 to 9.29), and sedation administration method (continuous and bolus versus bolus only) (OR 3.09, 95% CI 1.74 to 5.48). Hospital characteristics associated with PR indicated patients were less likely to be restrained in ICUs from university-affiliated hospitals (OR 0.32, 95% CI 0.17 to 0.61). Mainly treatment characteristics were associated with more days of PR, including: higher daily benzodiazepine dose (incidence rate ratio (IRR) 1.07, 95% CI 1.01 to 1.13), daily sedation interruption (IRR 3.44, 95% CI 1.48 to 8.10), antipsychotic drugs (IRR 15.67, 95% CI 6.62 to 37.12), SAS <3 (IRR 2.62, 95% CI 1.08 to 6.35), and any adverse event including accidental device removal (IRR 8.27, 95% CI 2.07 to 33.08). Patient characteristics (age, gender, Acute Physiology and Chronic Health Evaluation II score, admission category, prior substance abuse, prior psychotropic medication, pre

  3. Women in physics in the United States: recruitment and retention

    CERN Document Server

    Abramzon, Nina; Bertschinger, Edmund; Blessing, Susan; Cochran, Geraldine L; Cox, Anne; Cunningham, Beth A; Galbraith-Frew, Jessica; Johnson, Jolene; Kerby, Leslie; Lalanne, Elaine; ODonnell, Christine; Petty, Sara; Sampath, Sujatha; Singh, Chandralekha; Spencer, Cherrill; Woodle, Kathryne Sparks; Yenello, Sherry

    2016-01-01

    Initiatives to increase the number, persistence, and success of women in physics in the US reach pre-teen girls through senior women. Programs exist at both the local and national levels. In addition, researchers have investigated issues related to gender equity in physics and physics education. Anecdotal evidence suggests increased media coverage of the underrepresentation of women in science. All of these efforts are both motivated and made more effective by the collection and presentation of data on the presence, persistence, and promise of women in physics.

  4. A Comparative Analysis of Army Physical Readiness Test Results of AMEDD Units Without Formal Physical Training Programs

    Science.gov (United States)

    1984-06-01

    on active duty. Another reason is that physical fitness is an integral part of many units’ daily training regimen. With the emphasis now on Total...departure from previous physical fitness programs. Individual programs account for differences in age and sex , and enable soldiers to establish personal...for the Army.6 Within the U.S. Army, the component of physical fitness is governed by AR 350-15. This regulation directs that all Active Army personnel

  5. Use of Physical Restraints in Dutch Intensive Care Units: A Prospective Multicenter Study

    NARCIS (Netherlands)

    Kooi, A.W. van der; Peelen, L.M.; Raijmakers, R.J.; Vroegop, R.L.; Bakker, D.F.; Tekatli, H.; Boogaard, M.H.W.A. van den; Slooter, A.J.

    2015-01-01

    BACKGROUND: Increasing evidence indicates that harmful effects are associated with the use of physical restraint. OBJECTIVES: To characterize the use of physical restraint in intensive care units. Prevalence, adherence to protocols, and correlates of the use of physical restraint were determined.

  6. Physical Improvements in Exciter/Igniter Units Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project consists of developing a prototype exciter/igniter unit that can operate to a subset of expected flight performance requirements. The main focus...

  7. Benefits of Implementing a Dance Unit in Physical Education

    Science.gov (United States)

    Bajek, Mary; Richards, K. Andrew R.; Ressler, James

    2015-01-01

    This article discusses the benefits of participating in a dance curriculum, as well as how dance relates to the National Standards. It also provides insight into how physical educators can overcome the barriers to teaching dance in their programs.

  8. Physical Improvements in Exciter/Igniter Units Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 2 project consists of the physical integration of our Phase 1 small, compact exciter with a "flight like" igniter or spark plug capable of...

  9. Benefits of Implementing a Dance Unit in Physical Education

    Science.gov (United States)

    Bajek, Mary; Richards, K. Andrew R.; Ressler, James

    2015-01-01

    This article discusses the benefits of participating in a dance curriculum, as well as how dance relates to the National Standards. It also provides insight into how physical educators can overcome the barriers to teaching dance in their programs.

  10. CCEA as physics student unit guide unit 1 : forces, energy and electricity

    CERN Document Server

    Cosgrove, Ferguson

    2014-01-01

    Perfect for revision, these guides explain the unit requirements, summarise the content and include specimen questions with graded answers. Each full-colour New Edition Student Unit Guide provides ideal preparation for your unit exam:. - Feel confident you understand the unit: each guide comprehensively covers the unit content and includes topic summaries, knowledge check questions and a reference index. - Get to grips with the exam requirements: the specific skills on which you will be tested are explored and explained. - Analyse exam-style questions: graded student responses will help you fo

  11. An economic order quantity model with ramp type demand rate, constant deterioration rate and unit production cost

    Directory of Open Access Journals (Sweden)

    Manna Prasenjit

    2016-01-01

    Full Text Available We have developed an order level inventory system for deteriorating items with demand rate as a ramp type function of time. The finite production rate is proportional to the demand rate and the deterioration rate is independent of time. The unit production cost is inversely proportional to the demand rate. The model with no shortages case is discussed considering that: (a the demand rate is stabilized after the production stopping time and (b the demand is stabilized before the production stopping time. Optimal costs are determined for two different cases.

  12. An initial abstraction and constant loss model, and methods for estimating unit hydrographs, peak streamflows, and flood volumes for urban basins in Missouri

    Science.gov (United States)

    Huizinga, Richard J.

    2014-01-01

    Streamflow data, basin characteristics, and rainfall data from 39 streamflow-gaging stations for urban areas in and adjacent to Missouri were used by the U.S. Geological Survey in cooperation with the Metropolitan Sewer District of St. Louis to develop an initial abstraction and constant loss model (a time-distributed basin-loss model) and a gamma unit hydrograph (GUH) for urban areas in Missouri. Study-specific methods to determine peak streamflow and flood volume for a given rainfall event also were developed.

  13. National Curriculum for Physical Education in the United States

    Science.gov (United States)

    Oh, Junghwan; Graber, Kim C.

    2017-01-01

    Since the publication of "A Nation at Risk," some scholars have argued that a national curriculum and national testing are necessary to hold school personnel accountable for student achievement and, ultimately, to raise educational standards. The idea of developing a nationwide curriculum has been widely debated in the United States,…

  14. Future particle-physics projects in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, D. S. [Fermilab

    2015-08-25

    Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.

  15. Edexcel A2 physics student unit 5 : physics from creation to collapse

    CERN Document Server

    Benn, Mike

    2013-01-01

    Perfect for revision, these guides explain the unit requirements, summarise the content and include specimen questions with graded answers. Each full-colour New Edition Student Unit Guide provides ideal preparation for your unit exam:.; Feel confident you understand the unit: each guide comprehensively covers the unit content and includes topic summaries, knowledge check questions and a reference index.; Get to grips with the exam requirements: the specific skills on which you will be tested are explored and explained.; Analyse exam-style questions: graded student responses will help you focus

  16. Fundamentals of Physics for Engineering I (Unit guides). Academic year 2013-2014

    OpenAIRE

    2013-01-01

    Guides to the units of course "Fundamentals of Physics for Engineering I". Degree in Sound and Image in Telecommunication Engineering. Polytechnic School of the University of Alicante. Academic year 2013-2014.

  17. Fundamentals of Engineering Physics I (Unit guides). Academic year 2015-2016

    OpenAIRE

    2015-01-01

    Guides to the units of course "Fundamentals of Engineering Physics I". Degree in Sound and Image in Telecommunication Engineering. Polytechnic School of the University of Alicante. Academic year 2015-2016.

  18. Fundamentals of Engineering Physics I (Summaries of the units). Academic year 2015-2016

    OpenAIRE

    2015-01-01

    Summaries of the units of course "Fundamentals of Engineering Physics I". Degree in Sound and Image in Telecommunication Engineering. Polytechnic School of the University of Alicante. Academic year 2015-2016.

  19. Fundamentals of Physics for Engineering I (Unit guides). Academic year 2014-2015

    OpenAIRE

    2014-01-01

    Guides to the units of course "Fundamentals of Physics for Engineering I". Degree in Sound and Image in Telecommunication Engineering. Polytechnic School of the University of Alicante. Academic year 2014-2015.

  20. Assessment of physical work load at visual display unit workstations : Ergonomic applications and gender aspects

    OpenAIRE

    Karlqvist, Lena

    1997-01-01

    From the department of Occupational Health, Karolinska Hospital, Stockholm, Department of Ergonomics, National Institute for Working Life, Solna, and the Department of Surgical Sciences K3, Section for Rehabilitation Medicine, Karolinska Institute, Stockholm. Assessment of physical work load at visual display unit workstations Ergonomic applications and gender aspects Lena Karlqvist Arbete och Hälsa I997:9 .Local physical workload at visual display unit(VDU) wor...

  1. Physical Therapy Observation and Assessment in the Neonatal Intensive Care Unit

    Science.gov (United States)

    Byrne, Eilish; Campbell, Suzann K.

    2013-01-01

    This article presents the elements of the Observation and Assessment section of the Infant Care Path for Physical Therapy in the Neonatal Intensive Care Unit (NICU). The types of physical therapy assessments presented in this path are evidence-based and the suggested timing of these assessments is primarily based on practice knowledge from expert…

  2. Electromagnetism Unit of an Introductory University Physics Course: The Influence of a Reform-Based Tutorial

    Science.gov (United States)

    Barrett, Sarah Elizabeth; Hazari, Zahra; Fatholahzadeh, Baharak; Harrison, David M.

    2012-01-01

    Many students enrolled in university physics have little interest in the subject matter, a trend more pronounced in females. This study assesses students' conceptual understanding and interest during the electrochemistry unit of a physics course for nonphysics majors that was revised in light of consistently low ratings from its students. The…

  3. Clinical decision making on the use of physical restraint in intensive care units

    Directory of Open Access Journals (Sweden)

    Xinqian Li

    2014-12-01

    Full Text Available Physical restraint is a common nursing intervention in intensive care units and nurses often use it to ensure patients' safety and to prevent unexpected accidents. However, existing literature indicated that the use of physical restraint is a complex one because of inadequate rationales, the negative physical and emotional effects on patients, but the lack of perceived alternatives. This paper is aimed to interpret the clinical decision-making theories related to the use of physical restraint in intensive care units in order to facilitate our understanding on the use of physical restraint and to evaluate the quality of decisions made by nurses. By reviewing the literature, intuition and heuristics are the main decision-making strategies related to the use of physical restraint in intensive care units because the rapid and reflexive nature of intuition and heuristics allow nurses to have a rapid response to urgent and emergent cases. However, it is problematic if nurses simply count their decision-making on experience rather than incorporate research evidence into clinical practice because of inadequate evidence to support the use of physical restraint. Besides that, such a rapid response may lead nurses to make decisions without adequate assessment and thinking and therefore biases and errors may be generated. Therefore, despite the importance of intuition and heuristics in decision-making in acute settings on the use of physical restraint, it is recommended that nurses should incorporate research evidence with their experience to make decisions and adequate assessment before implementing physical restraint is also necessary.

  4. Physical Activity Patterns of Acute Stroke Patients Managed in a Rehabilitation Focused Stroke Unit

    Directory of Open Access Journals (Sweden)

    Tanya West

    2013-01-01

    Full Text Available Background. Comprehensive stroke unit care, incorporating acute care and rehabilitation, may promote early physical activity after stroke. However, previous information regarding physical activity specific to the acute phase of stroke and the comprehensive stroke unit setting is limited to one stroke unit. This study describes the physical activity undertaken by patients within 14 days after stroke admitted to a comprehensive stroke unit. Methods. This study was a prospective observational study. Behavioural mapping was used to determine the proportion of the day spent in different activities. Therapist reports were used to determine the amount of formal therapy received on the day of observation. The timing of commencement of activity out of bed was obtained from the medical records. Results. On average, patients spent 45% (SD 25 of the day in some form of physical activity and received 58 (SD 34 minutes per day of physiotherapy and occupational therapy combined. Mean time to first mobilisation out of bed was 46 (SD 32 hours post-stroke. Conclusions. This study suggests that commencement of physical activity occurs earlier and physical activity is at a higher level early after stroke in this comprehensive stroke unit, when compared to studies of other acute stroke models of care.

  5. Tuning physical properties by assembling subnanometer inorganic and organic units

    Science.gov (United States)

    Zhang, Yong; Parilla, P. A.; Ahrenkiel, S. P.; Mascarenhas, A.; Islam, Z.; Ren, Y.; Lee, P. L.; McNevin, M. J.; Naumov, I.; Fu, H. X.; Huang, X. Y.; Li, J.

    2008-03-01

    Designing inorganic-organic hybrid materials in a nanoscopic scale allows taking the full advantage of the two worlds, which has recently been demonstrated in a new family of hybrid crystalline materials that are the fully ordered assemblies of sub-nanometer scale inorganic units (e.g., few monolayer-thick slab, single atomic chain) and organic molecules[1].They have been shown to exhibit a number of unique properties that are not readily available in either of the components or their nanostructures: for instance, strongly enhanced exciton-polariton absorption and exciton binding energy[2], a massive bandgap blue shift (˜ 2 eV) from that of the bulk inorganic semiconductor[3], and fine-tuning of thermal expansion and achieving zero-thermal expansio[4]. They have great potential for applications in areas including transparent conducting materials, thermoelectric materials, UV optoelectronic devices, because of their unusual electronic, vibrational and optical properties and the flexibility in tailoring the material properties adapting to the specific application requirements. .[1] X. H. Huang et al., JACS 125, 7049 (03). [2] Y. Zhang et al., PRL 96, 26405 (06). [3] B. Fluegel et al., PRB 70, 205308 (04). [4] Y. Zhang et al., PRL 99, 215901 (07).

  6. Varying Constants

    CERN Document Server

    Damour, Thibault Marie Alban Guillaume

    2003-01-01

    We review some string-inspired theoretical models which incorporate a correlated spacetime variation of coupling constants while remaining naturally compatible both with phenomenological constraints coming from geochemical data (Oklo; Rhenium decay) and with present equivalence principle tests. Barring unnatural fine-tunings of parameters, a variation of the fine-structure constant as large as that recently ``observed'' by Webb et al. in quasar absorption spectra appears to be incompatible with these phenomenological constraints. Independently of any model, it is emphasized that the best experimental probe of varying constants are high-precision tests of the universality of free fall, such as MICROSCOPE and STEP. Recent claims by Bekenstein that fine-structure-constant variability does not imply detectable violations of the equivalence principle are shown to be untenable.

  7. Moving the Barricades to Physical Activity: A Qualitative Analysis of Open Streets Initiatives Across the United States.

    Science.gov (United States)

    Eyler, Amy A; Hipp, J Aaron; Lokuta, Julie

    2015-01-01

    Ciclovía, or Open Streets initiatives, are events where streets are opened for physical activity and closed to motorized traffic. Although the initiatives are gaining popularity in the United States, little is known about planning and implementing them. The goals of this paper are to explore the development and implementation of Open Streets initiatives and make recommendations for increasing the capacity of organizers to enhance initiative success. Phenomenology with qualitative analysis of structured interviews was used. Study setting was urban and suburban communities in the United States. Study participants were organizers of Open Streets initiatives in U.S. cities. Using a list of 47 events held in 2011, 27 lead organizers were interviewed by telephone about planning, implementation, and lessons learned. The interviews were digitally recorded and transcribed. A phenomenologic approach was used, an initial coding tool was developed after reviewing a sample of transcripts, and constant comparative coding methodology was applied. Themes and subthemes were generated from codes. The most common reasons for initiation were to highlight or improve health and transportation. Most initiatives aimed to reach the general population, but some targeted families, children, or specific neighborhoods. Getting people to understand the concept of Open Streets was an important challenge. Other challenges included lack of funding and personnel, and complex logistics. These initiatives democratize public space for citizens while promoting physical activity, social connectedness, and other broad agendas. There are opportunities for the research community to contribute to the expanse and sustainability of Open Streets, particularly in evaluation and dissemination.

  8. Systematic harmonic power laws inter-relating multiple fundamental constants

    Science.gov (United States)

    Chakeres, Donald; Buckhanan, Wayne; Andrianarijaona, Vola

    2017-01-01

    Power laws and harmonic systems are ubiquitous in physics. We hypothesize that 2, π, the electron, Bohr radius, Rydberg constant, neutron, fine structure constant, Higgs boson, top quark, kaons, pions, muon, Tau, W, and Z when scaled in a common single unit are all inter-related by systematic harmonic powers laws. This implies that if the power law is known it is possible to derive a fundamental constant's scale in the absence of any direct experimental data of that constant. This is true for the case of the hydrogen constants. We created a power law search engine computer program that randomly generated possible positive or negative powers searching when the product of logical groups of constants equals 1, confirming they are physically valid. For 2, π, and the hydrogen constants the search engine found Planck's constant, Coulomb's energy law, and the kinetic energy law. The product of ratios defined by two constants each was the standard general format. The search engine found systematic resonant power laws based on partial harmonic fraction powers of the neutron for all of the constants with products near 1, within their known experimental precision, when utilized with appropriate hydrogen constants. We conclude that multiple fundamental constants are inter-related within a harmonic power law system.

  9. Natural units in physics, and the curious case of the radian

    Science.gov (United States)

    Quincey, Paul

    2016-11-01

    Sets of natural units, like ‘atomic units’, are sometimes used to simplify the equations of physics. This choice of units can be seen as a way of showing the relationships between quantities in their simplest form, in specialised situations, while still being correct. The unit system used for teaching, the SI, is instead designed primarily to be a set of units that can be applied consistently across all areas of science, commerce and industry. The SI also gives priority to emphasising the distinction between different quantities, by (most of the time) giving different units to different quantities, rather than producing the simplest possible equations. It is not widely appreciated that the SI treats the radian as the natural unit for angle, the only unit to be treated this way, with consequent issues for clear distinctions between quantities involving angles. The system that the SI would become if this anomaly were removed is presented. Rather than advocating this major change to the SI itself, it is proposed to highlight the existence of the underlying system to clarify how angles are handled physics, to make it easier to include angles in software calculations, and as an example of how the choice of unit system affects the equations we use.

  10. KARAKTERISASI CANGKANG KERANG MENGGUNAKAN XRD DAN X RAY PHYSICS BASIC UNIT

    OpenAIRE

    2012-01-01

    Cangkang kerang jenis Anadara Granosa merupakan bahan keramik yang  termasuk ke dalam jenis zat padat kristal. Sebagai langkah awal dilakukan penelitian dengan sampel cangkang kerang (CaCO3)  yaitu melakukan karakterisasi menggunakan dua  alat yang berbeda yaitu X Ray Diffraction (XRD) dan X Ray Physics Basic Unit, ini dilakukan untuk mengetahui perbedaan antara kedua alat tersebut. Dalam karakterisasi cangkang kerang (CaCO3) menggunakan X–Ray Diffraction dan X – Ray Physics Basic  Unit  taha...

  11. 40 CFR 270.165 - When may I begin physical construction of new units permitted under the RAP?

    Science.gov (United States)

    2010-07-01

    ... of new units permitted under the RAP? 270.165 Section 270.165 Protection of Environment ENVIRONMENTAL... PERMIT PROGRAM Remedial Action Plans (RAPs) Getting A Rap Approved § 270.165 When may I begin physical construction of new units permitted under the RAP? You must not begin physical construction of new units...

  12. MATHEMATICAL CONSTANTS.

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, H.P.; Potter, Elinor

    1971-03-01

    This collection of mathematical data consists of two tables of decimal constants arranged according to size rather than function, a third table of integers from 1 to 1000, giving some of their properties, and a fourth table listing some infinite series arranged according to increasing size of the coefficients of the terms. The decimal values of Tables I and II are given to 20 D.

  13. Hemaka's constant

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    As proposed in a previous paper, the decorations of ancient objects can provide some information on the approximate evaluations of constant {\\pi}, the ratio of circumference to diameter. Here we discuss some disks found in the tomb of Hemaka, the chancellor of a king of the First Dynasty of Egypt, about 3000 BC. The discussion is based on measurements of the dimensionless ratio of lengths.

  14. Structural change of the physical economy. Decomposition analysis of physical and hybrid-unit input-output tables

    Energy Technology Data Exchange (ETDEWEB)

    Hoekstra, R.

    2003-10-01

    Economic processes generate a variety of material flows, which cause resource problems through the depletion of natural resources and environmental issues due to the emission of pollutants. This thesis presents an analytical method to study the relationship between the monetary economy and the 'physical economy'. In particular, this method can assess the impact of structural change in the economy on physical throughput. The starting point for the approach is the development of an elaborate version of the physical input-output table (PIOT), which acts as an economic-environmental accounting framework for the physical economy. In the empirical application, hybrid-unit input-output (I/O) tables, which combine physical and monetary information, are constructed for iron and steel, and plastic products for the Netherlands for the years 1990 and 1997. The impact of structural change on material flows is analyzed using Structural Decomposition Analysis (SDA), whic specifies effects such as sectoral shifts, technological change, and alterations in consumer spending and international trade patterns. The study thoroughly reviews the application of SDA to environmental issues, compares the method with other decomposition methods, and develops new mathematical specifications. An SDA is performed using the hybrid-unit input-output tables for the Netherlands. The results are subsequently used in novel forecasting and backcasting scenario analyses for the period 1997-2030. The results show that dematerialization of iron and steel, and plastics, has generally not occurred in the recent past (1990-1997), and will not occur, under a wide variety of scenario assumptions, in the future (1997-2030)

  15. Stochastic and Historical Resonances of the Unit in Physics and Psychometrics

    Science.gov (United States)

    Fisher, William P., Jr.

    2011-01-01

    Humphry's article, "The Role of the Unit in Physics and Psychometrics," offers fundamental clarifications of measurement concepts that Fisher hopes will find a wide audience. In particular, parameterizing discrimination while preserving statistical sufficiency will indeed provide greater flexibility in accounting "for the effects of empirical…

  16. The "Earth Physics" Workshops Offered by the Earth Science Education Unit

    Science.gov (United States)

    Davies, Stephen

    2012-01-01

    Earth science has a part to play in broadening students' learning experience in physics. The Earth Science Education Unit presents a range of (free) workshops to teachers and trainee teachers, suggesting how Earth-based science activities, which show how we understand and use the planet we live on, can easily be slotted into normal science…

  17. The "Earth Physics" Workshops Offered by the Earth Science Education Unit

    Science.gov (United States)

    Davies, Stephen

    2012-01-01

    Earth science has a part to play in broadening students' learning experience in physics. The Earth Science Education Unit presents a range of (free) workshops to teachers and trainee teachers, suggesting how Earth-based science activities, which show how we understand and use the planet we live on, can easily be slotted into normal science…

  18. Natural Environments, Obesity, and Physical Activity in Nonmetropolitan Areas of the United States

    Science.gov (United States)

    Michimi, Akihiko; Wimberly, Michael C.

    2012-01-01

    Purpose: To assess the associations of the natural environment with obesity and physical activity in nonmetropolitan areas of the United States among representative samples by using 2 indices of outdoor activity potential (OAP) at the county level. Methods: We used the data from 457,820 and 473,296 noninstitutionalized adults aged over 18 years…

  19. Exercise and limitations in physical activity levels among new dialysis patients in the United States: an epidemiologic study.

    LENUS (Irish Health Repository)

    Stack, Austin G

    2008-12-01

    Epidemiologic studies of physical activity among patients with end-stage renal disease (ESRD) are lacking. The aim of this study was to describe the patterns of physical activity among new dialysis patients in the United States.

  20. Soil washing physical separations test procedure - 300-FF-1 operable unit

    Energy Technology Data Exchange (ETDEWEB)

    Belden, R.D.

    1993-10-08

    This procedure provides the operations approach, a field sampling plan, and laboratory procedures for a soil washing test to be conducted by Alternative Remedial Technologies, Inc. (ART) in the 300-FF-1 area at the Hanford site. The {open_quotes}Quality Assurance Project Plan for the Soil Washing Physical Separations Test, 300-FF-1 Operable Unit,{close_quotes} Hanford, Washington, Alternative Remedial Technologies, Inc., February 1994 (QAPP) is provided in a separate document that presents the procedural and organizational guidelines for this test. This document describes specifications, responsibilities, and general procedures to be followed to conduct physical separation soil treatability tests in the North Process Pond of the 300-FF-1 Operable Unit (OU) at the Hanford Site. These procedures are based on the {open_quotes}300-FF-1 Physical Separations CERCLA Treatability Test Plan, DOE/RL 92-2l,{close_quotes} (DOE-RL 1993).

  1. Physical restraint: experiences, attitudes and opinions of adult intensive care unit nurses.

    Science.gov (United States)

    Freeman, Samantha; Hallett, Christine; McHugh, Gretl

    2016-03-01

    Patients within the adult intensive care unit have the potential to develop delirium and agitation. This can result in the patient displaying unwanted behaviours such as attempting to remove the medical devices to which they are attached. Some adult intensive care units within the UK are starting to adopt physical restraint as a method of managing unwanted behaviours. To determine the experiences, attitudes and opinions of adult intensive care nurses in relation to the application of physical restraint. Questionnaire survey. A postal questionnaire was distributed to all nurses (n = 192) within two purposefully selected large adult intensive care units in the UK. Data were collected between November 2012 and February 2013. The questionnaire was completed by 38·9% (n = 75) of the nurses contacted. All believed that physical restraint had a place, with the majority of the view that the reason for its application was to maintain patient safety. Some expressed discomfort about the use of physical restraint. Nurses were happy to discuss the use of restraint with families. There was a perceived need for training and support for nursing staff as well as the need for medical staff to support the decision-making process. Nurses require more support and evidence to base their decision-making upon. They require guidance from professional bodies as well as support from medical colleagues. The findings have limited generalizability as they can only be applied to the units accessed and the response rate was poor. Alternative approaches such as pain management, sleep promotion and the involvement of relatives need to be explored before physical restraint policy can be written. Further research is required into the safety of physical restraint, alternative methods of managing the risk of agitation and identifying predisposing factors to accidental device removal. © 2015 British Association of Critical Care Nurses.

  2. Examination of ethical dilemmas experienced by adult intensive care unit nurses in physical restraint practices.

    Science.gov (United States)

    Yönt, Gülendam Hakverdioğlu; Korhan, Esra Akin; Dizer, Berna; Gümüş, Fatma; Koyuncu, Rukiye

    2014-01-01

    Nurses are more likely to face the dilemma of whether to resort to physical restraints or not and have a hard time making that decision. This is a descriptive study. A total of 55 nurses participated in the research. For data collection, a question form developed by researchers to determine perceptions of ethical dilemmas by nurses in the application of physical restraint was used. A descriptive analysis was made by calculating the mean, standard deviation, and maximum and minimum values. The nurses expressed (36.4%) having difficulty in deciding to use physical restraint. Nurses reported that they experience ethical dilemmas mainly in relation to the ethic principles of nonmaleficence, beneficence, and convenience. We have concluded that majority of nurses working in critical care units apply physical restraint to patients, although they are facing ethical dilemmas concerning harm and benefit principles during the application.

  3. Impact of a hybrid TGfU-Sport Education unit on student motivation in physical education.

    Science.gov (United States)

    Gil-Arias, Alexander; Harvey, Stephen; Cárceles, Adrián; Práxedes, Alba; Del Villar, Fernando

    2017-01-01

    The Teaching Games for Understanding (TGfU) and Sport Education (SE) pedagogical models share several objectives and pedagogical processes. Despite this seemingly uncanny relationship, few studies have examined the efficacy of a hybrid TGfU/SE pedagogical model, particularly how a teacher's utilization of such a model impacts on student motivation. The purpose of the current study was to investigate the effect a hybrid TGfU/SE unit, in comparison to direct instruction, on students' perceptions of various aspects of their motivation to engage in physical education (autonomous motivation, basic psychological needs, enjoyment and intention to be physically active). A crossover design was utilized, using the technique of counterbalancing. One group experienced a hybrid SE/TGfU unit first, followed by a unit of direct instruction. A second group experienced the units in the opposite order. Participants were 55 students. The intervention was conducted over a total of 16 lessons. The hybrid unit was designed according to the characteristics of SE by using seasons, roles, persistent teams, etc. Learning tasks set by the teacher during individual lessons, however, were designed according to the pedagogical principles of TGfU. Student motivation data was generated using validated questionnaires. Results showed that regardless of the order of intervention, the two groups showed significant improvements in autonomy, competence and enjoyment when they were taught using the hybrid model. Instead, in the variables autonomous motivation, relatedness and intention to be physically active there were no significant improvements in one group. These results demonstrate that it is possible to design varied learning situations in which affiliation, leadership and trust are fostered, while tasks are adapted to the characteristics of the students. All this can cause greater autonomous motivation, and consequently, perceived competence in the student, a positive image of the sport to

  4. Screening constant by unit nuclear charge calculations of resonance energies and widths of the 3pns 1,3P° and 3pnd 1P° Rydberg series of Mg-like (Z=13-26) ions

    Science.gov (United States)

    Khatri, Indu; Goyal, Arun; Diouldé Ba, Mamadou; Faye, Maurice; Sow, Malick; Sakho, Ibrahima; Singh, A. K.; Mohan, Man; Wagué, Ahmadou

    2017-01-01

    Resonance energies and total natural width of the 3pns 1P° and 3pnd 1P° Rydberg series of Mg-like (Z=13-26) ions are reported. Resonance energies of the Mg-like Al+ belonging to the 3pns 3P°→ 2 p63 p 1/2 0 2P and 3pns 3P°→ 2 p63 p3/2 0 3P transitions are also tabulated. The calculations are made in the framework of the Screening constant by unit nuclear charge (SCUNC) formalism. Excellent agreements between experiments at ALS and R-matrix calculations are obtained for both 3pns 1,3P° and 3pnd 1P° Rydberg series of the Mg-like Al+ ions. The present results for Mg-like Si2+, S4+, Cl5+, and Ar6+, compared with the only existing R-matrix calculations indicate lack of accuracy in the Mg-like Si2+ data obtained from noniterative formulation of the eigenchannel R-matrix method. New precise data for Mg-like P3+, K7+, Ca8+, Sc9+, Ti10+, V11+, Cr12+, Mn13+, and Fe14+ ions are presented as useful guidelines for investigators focusing their challenge on the Photoionization of Mg-like heavy charged ions in connection with their application in laboratory, astrophysics, and plasma physics.

  5. Early Rehabilitation in the Intensive Care Unit: Preventing Physical and Mental Health Impairments

    OpenAIRE

    Parker, Ann; Sricharoenchai, Thiti; Needham, Dale M.

    2013-01-01

    Survivors of critical illness often experience new or worsening impairments in physical, cognitive and/or mental health, referred to as post-intensive care syndrome (PICS). Such impairments can be long-lasting and negatively impact survivors’ quality of life. Early rehabilitation in the intensive care unit (ICU), while patients remain on life-support therapies, may reduce the complications associated with PICS. This article addresses evidence-based rehabilitation interventions to reduce the p...

  6. Early Rehabilitation in the Intensive Care Unit: Preventing Physical and Mental Health Impairments

    OpenAIRE

    Parker, Ann; Sricharoenchai, Thiti; Needham, Dale M.

    2013-01-01

    Survivors of critical illness often experience new or worsening impairments in physical, cognitive and/or mental health, referred to as post-intensive care syndrome (PICS). Such impairments can be long-lasting and negatively impact survivors’ quality of life. Early rehabilitation in the intensive care unit (ICU), while patients remain on life-support therapies, may reduce the complications associated with PICS. This article addresses evidence-based rehabilitation interventions to reduce the p...

  7. A Physical Unit for Value - Econophysics as Arbiter between Finance and Economics

    CERN Document Server

    Defilla, S

    2006-01-01

    Finance and accounting often ignore money illusion, whereas economics treats it by using consumer baskets for making multilateral purchasing power comparisons between currencies. Such baskets are variable socio-economic phenomena and their use as numeraire (= value or real price unit) creates inconsistency as it confuses a measurement unit with a measurement result. Econophysics could do better and define a physical value unit in the Standard International (SI = metric) format based upon the exergetic (= objective) value of Planck Energy (1956.1 MJ). Planck units form a natural system of units that is independent of culture or civilization. We define a new value unit named walras (Wal) in h. of the economist L. Walras. By chance, one Wal is equal to the annual real cost of physiological energy consumption of the Sleeping Beauty, i.e. of a reference person at minimal activity. This corresponds to the annual minimum real cost of life. This pilot research uses official disaggregated Swiss Producer and Consumer P...

  8. Mechanism for a Decaying Cosmological Constant

    CERN Document Server

    Bisabr, Y

    2002-01-01

    A mechanism is introduced to reduce a large cosmological constant to a sufficiently small value consistent with observational upper limit. The basic ingradient in this mechanism is a distinction which has been made between the two unit systems used on cosmology and particle physics. We have used a conformal invariant gravitational model to define a particular conformal frame in terms of the large scale properties of the universe. It is then argued that the contributions of mass scales in particle physics to the vacuum energy density should be considered in a different conformal frame. In this manner a cancellation mechanism is presented in which the conformal factor plays a key role to relax the large effective cosmological constant.

  9. [Physical restraint use in critical care units. Perceptions of patients and their families].

    Science.gov (United States)

    Pérez de Ciriza Amatriain, A I; Nicolás Olmedo, A; Goñi Viguria, R; Regaira Martínez, E; Margall Coscojuela, M A; Asiain Erro, M C

    2012-01-01

    The use of physical restraints in Intensive Care Units (ICU) is common although little is known about patients' and relatives' perceptions of this use. 1) To analyze the prevalence and use of physical restraints in a general adult ICU; 2) to know the perceptions of patients who experienced use of physical restraints and; 3) to know the perceptions of relatives of patients who used physical restraints. This descriptive study, which used both quantitative and qualitative methods, was carried out in an adult ICU. For the first objective, all the patients (101) who had used any kind of physical restraint were analysed. For the second and third objectives, 30 patients and 30 relatives were interviewed using the guidelines of Strumpf & Evans as modified by Hardin (1993). All interviews were recorded, fully transcribed and then submitted to a language content analysis using the method of Hsieh & Shannon. The only physical restraint used was the wrist restraint with a prevalence of 43.47%. Seventy-two percent of patients wore the restraint ≤12h and 28%>12h. Analysis of the patient interviews revealed 4 main themes: acceptance of the restraint conditioned by beliefs and information provided; feelings and sensations caused by the use of the restraint; alternatives proposed and future repercussions. Three themes emerged from the interviews with relatives: impressions caused by the use of the restrictions; reasons for accepting or rejecting them; alternatives to the use of restraints. Most patients used physical restraints for a short period of time and only the wrist restraint was used. Patients using physical restraints and their relatives expressed a wide range of feelings and sensations, with no negative future repercussions. In general, they agreed with the use of restraints although more precise information would lead to greater acceptance. Copyright © 2011 Elsevier España, S.L. y SEEIUC. All rights reserved.

  10. Prevalence of fruit and vegetable consumption and physical activity by race/ethnicity--United States, 2005.

    Science.gov (United States)

    2007-04-06

    Diets high in fruits and vegetables and participation in regular physical activity are associated with a lower risk for several chronic diseases and conditions. The National Cholesterol Education Program and the American Cancer Society both emphasize lifestyle modifications that include diet and physical activity to reduce disease risk. These are also two of the strategies implemented by states participating in CDC's Nutrition and Physical Activity Program to Prevent Obesity and Other Chronic Diseases. To examine the combined prevalence of 1) consumption of fruits and vegetables five or more times per day and 2) regular physical activity among U.S. adults by race/ethnicity, CDC analyzed self-reported data from the 2005 Behavioral Risk Factor Surveillance System (BRFSS). This report describes the results of that analysis, which indicated that the combined prevalence of these two behavioral strategies was higher among men of multiple/other races (16.5%) compared with non-Hispanic white men (12.6%). In addition, only 12.6% of non-Hispanic black women and 14.8% of Hispanic women, compared with 17.4% of non-Hispanic white women, engaged in these two behavioral strategies. These results underscore the need to promote diets high in fruits and vegetables and regular physical activity among all populations in the United States and among racial and ethnic minority communities in particular.

  11. United States Physical Therapists' Knowledge About Joint Hypermobility Syndrome Compared with Fibromyalgia and Rheumatoid Arthritis.

    Science.gov (United States)

    Russek, Leslie N; LaShomb, Emily A; Ware, Amy M; Wesner, Sarah M; Westcott, Vanessa

    2016-03-01

    Joint hypermobility syndrome (JHS) is one of the most common inherited connective tissue disorders. It causes significant pain and disability for all age groups, ranging from developmental delay among children to widespread chronic pain in adults. Experts in JHS assert that the condition is under-recognized and poorly managed. The aim of this study was to assess US physical therapists' knowledge about JHS compared with other causes of widespread pain and activity limitations: fibromyalgia, juvenile rheumatoid arthritis and adult rheumatoid arthritis. Cross-sectional, Internet-based survey of randomly selected members of the American Physical Therapy Association and descriptive statistics were used to explore physical therapists' knowledge about JHS, fibromyalgia, juvenile rheumatoid arthritis and adult rheumatoid arthritis, and chi square was used to compare knowledge about the different conditions. The response rate was 15.5% (496). Although 36% recognized the Beighton Scale for assessing joint hypermobility, only 26.8% of respondents were familiar with the Brighton Criteria for diagnosing JHS. Few respondents (11-19%) realized that JHS has extra-articular features such as anxiety disorder, fatigue, headache, delayed motor development, easy bruising and sleep disturbance. Physical therapists working in environments most likely to see patients with JHS underestimated the likely prevalence in their patient population. The results suggest that many physical therapists in the United States are not familiar with the diagnostic criteria, prevalence or common clinical presentation of JHS. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Contemporary Issues of Social Justice: A Focus on Race and Physical Education in the United States.

    Science.gov (United States)

    Harrison, Louis; Clark, Langston

    2016-09-01

    Ongoing events in the United States show the continual need to address issues of social justice in every social context. Of particular note in this article, the contemporary national focus on race has thrust social justice issues into the forefront of the country's conscious. Although legal segregation has ran its course, schools and many neighborhoods remain, to a large degree, culturally, ethnically, linguistically, economically, and racially segregated and unequal (Orfield & Lee, 2005). Even though an African American president presently occupies the White House, the idea of a postracial America remains an unrealized ideal. Though social justice and racial discussions are firmly entrenched in educational research, investigations that focus on race are scant in physical education literature. Here, we attempt to develop an understanding of social justice in physical education with a focus on racial concerns. We purposely confine the examination to the U.S. context to avoid the dilution of the importance of these issues, while recognizing other international landscapes may differ significantly. To accomplish this goal, we hope to explicate the undergirding theoretical tenants of critical race theory and culturally relevant pedagogy in relation to social justice in physical education. Finally, we make observations of social justice in the physical education and physical education teacher education realms to address and illuminate areas of concern.

  13. Direct spectroscopic observation of singlet oxygen quenching and kinetic studies of physical and chemical singlet oxygen quenching rate constants of synthetic antioxidants (BHA, BHT, and TBHQ) in methanol.

    Science.gov (United States)

    Lee, Jun Hyun; Jung, Mun Yhung

    2010-08-01

    Singlet oxygen quenching by synthetic antioxidants (BHA, BHT, and TBHQ) was directly observed by spectroscopic monitoring of luminescence at 1268 nm. The luminescence data showed unambiguous evidence of singlet oxygen quenching by synthetic phenolic antioxidants with the highest activity for TBHQ, followed by BHA and BHT. The protective activities of these synthetic antioxidants on alpha-terpinene oxidation with chemically-induced singlet oxygen under dark further confirmed their singlet oxygen quenching abilities. Total singlet oxygen quenching rate constants (k(r) + k(q)) of BHA, BHT, and TBHQ were determined in a system containing alpha-terpinene (as a singlet oxygen trap) and methylene blue (as a sensitizer) during light irradiation, and the values were 5.14 x 10(7), 3.41 x 10(6), and 1.99 x 10(8) M(-1)s(-1), respectively. After the k(r) value of alpha-terpinene was first determined, the k(r) values of the synthetic antioxidants were calculated by measuring their relative reaction rates with singlet oxygen to that of alpha-terpinene under the identical conditions. The k(r) values of the BHA, BHT, and TBHQ were 3.90 x 10(5), 1.23 x 10(5), and 2.93 x 10(6), M(-1)s(-1). The percent partition of chemical quenching over total singlet oxygen quenching (k(r) x 100)/(k(r) + k(q)) for BHA, BHT, and TBHQ were 0.76%, 3.61%, and 1.47%, respectively. The results showed that the synthetic antioxidants quench singlet oxygen almost exclusively through the mechanism of physical quenching. This represents the first report on the singlet oxygen quenching mechanism of these synthetic antioxidants. Practical Application: The synthetic antioxidants, especially TBHQ, have been found to have a strong singlet oxygen quenching ability. This article also clearly showed that singlet oxygen quenching by synthetic antioxidants was mainly by the physical quenching mechanism. The results suggested that these synthetic antioxidants, especially TBHQ, could be used practically for the protection

  14. A ten-year experience of physical Intimate partner violence (IPV) in a French forensic unit.

    Science.gov (United States)

    Savall, Frédéric; Lechevalier, Agathe; Hérin, Fabrice; Vergnault, Marion; Telmon, Norbert; Bartoli, Christophe

    2017-02-01

    Forensic units have a central role to play in healthy public policy, by the collection and management of violence. This study aims to describe the characteristics of physical Intimate Partner Violence (IPV) against men reported over 10 years in the forensic unit of Toulouse (France) and to compare them with the characteristics of physical IPV against women over the same period. All the medico-legal reports of male victims over 18 years of age between 2005 and 2014 were analyzed. Female victims over 18 years of age in the same period were randomized by year in order to study a similar number of individuals. We analyzed 712 forensic reports of male victims and 865 forensic reports of female victims. Repeated consultation concerned 20.5% of women and 7.5% of men (p origin of the process of violence are difficult to apprehend in such a dyadic context. The findings should be interpreted with caution, but they provide original and substantial material, which can be useful in recognizing victims and in developing preventive strategies. With this aim, forensic units have a central role to play in the collection of violence and in individualized management. In France, this subject has not been extensively studied and future research is needed to emphasize the characteristics of IPV in order to better understand the phenomenon and to create and assess public policies in order to prevent it.

  15. Physical fitness and nutritional status of polish ground force unit recruits.

    Science.gov (United States)

    Tomczak, A; Bertrandt, J; Kłos, A

    2012-12-01

    The purpose of the work was to conduct an examination of the physical fitness and nutritional status of recruits (221 men beginning military service in the infantry unit). Soldiers' physical efficiency was estimated using 4 tests: standing long jump, pull-ups on bar, 30-second sit-ups and 1000-metre run. The nutritional status assessment was done based on anthropometric measurements including measurements of body height, body mass and selected skin fold thickness. The study group of soldiers were the best at sit-ups (46.33 points). They got over 40 points for the 1000-metre run (43.68 points) and for pull-ups on bar (41.69 points). They obtained the lowest scores for standing long jumps (30.77 points). About 14% of recruits were overweight and 4.1% underweight. Recruits enrolling in the infantry unit present a low physical fitness level. Overweight and obesity occurrence, and particularly underweight, in recruits testify to improper nutrition before beginning military service.

  16. Using Graphics Processing Units to solve the classical N-body problem in physics and astrophysics

    CERN Document Server

    Spera, Mario

    2014-01-01

    Graphics Processing Units (GPUs) can speed up the numerical solution of various problems in astrophysics including the dynamical evolution of stellar systems; the performance gain can be more than a factor 100 compared to using a Central Processing Unit only. In this work I describe some strategies to speed up the classical N-body problem using GPUs. I show some features of the N-body code HiGPUs as template code. In this context, I also give some hints on the parallel implementation of a regularization method and I introduce the code HiGPUs-R. Although the main application of this work concerns astrophysics, some of the presented techniques are of general validity and can be applied to other branches of physics such as electrodynamics and QCD.

  17. Can compactifications solve the cosmological constant problem?

    Energy Technology Data Exchange (ETDEWEB)

    Hertzberg, Mark P. [Institute of Cosmology, Department of Physics and Astronomy, Tufts University,574 Boston Ave, Medford, MA 02155 (United States); Center for Theoretical Physics, Department of Physics,Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, MA 02139 (United States); Masoumi, Ali [Institute of Cosmology, Department of Physics and Astronomy, Tufts University,574 Boston Ave, Medford, MA 02155 (United States)

    2016-06-30

    Recently, there have been claims in the literature that the cosmological constant problem can be dynamically solved by specific compactifications of gravity from higher-dimensional toy models. These models have the novel feature that in the four-dimensional theory, the cosmological constant Λ is much smaller than the Planck density and in fact accumulates at Λ=0. Here we show that while these are very interesting models, they do not properly address the real cosmological constant problem. As we explain, the real problem is not simply to obtain Λ that is small in Planck units in a toy model, but to explain why Λ is much smaller than other mass scales (and combinations of scales) in the theory. Instead, in these toy models, all other particle mass scales have been either removed or sent to zero, thus ignoring the real problem. To this end, we provide a general argument that the included moduli masses are generically of order Hubble, so sending them to zero trivially sends the cosmological constant to zero. We also show that the fundamental Planck mass is being sent to zero, and so the central problem is trivially avoided by removing high energy physics altogether. On the other hand, by including various large mass scales from particle physics with a high fundamental Planck mass, one is faced with a real problem, whose only known solution involves accidental cancellations in a landscape.

  18. Physical fitness and anthropometric characteristics in professional soccer players of the United Arab Emirates

    Directory of Open Access Journals (Sweden)

    M. Magalhães Sales

    2014-09-01

    Conclusion: The anthropometric profile of soccer players that act in the United Arab Emirates is similar to others around the world. However, regarding the physical fitness, results are still inconclusive, since findings from other studies suggest that the anaerobic power of our sample is alike or lower than other elite players throughout the world. Likewise indirect VO2max, especially given the acknowledged limitations of obtaining indirectly this variable. In addition, making an analysis by playing position, the results of this study are similar to previous research.

  19. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, John P., E-mail: john.gibbons@marybird.com [Department of Physics, Mary Bird Perkins Cancer Center, Baton Rouge, Louisiana 70809 (United States); Antolak, John A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Followill, David S. [Department of Radiation Physics, UT M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Klein, Eric E. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Lam, Kwok L. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109 (United States); Palta, Jatinder R. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Roback, Donald M. [Department of Radiation Oncology, Cancer Centers of North Carolina, Raleigh, North Carolina 27607 (United States); Reid, Mark [Department of Medical Physics, Fletcher-Allen Health Care, Burlington, Vermont 05401 (United States); Khan, Faiz M. [Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-03-15

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D{sub 0}{sup ′}, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D{sub 0}{sup ′} = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D{sub 0}{sup ′} ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of d{sub m}, with D{sub 0}{sup ′} = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  20. Monitor unit calculations for external photon and electron beams: Report of the AAPM Therapy Physics Committee Task Group No. 71.

    Science.gov (United States)

    Gibbons, John P; Antolak, John A; Followill, David S; Huq, M Saiful; Klein, Eric E; Lam, Kwok L; Palta, Jatinder R; Roback, Donald M; Reid, Mark; Khan, Faiz M

    2014-03-01

    A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D'0, that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D'0 = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D'0 ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D'0 = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism.

  1. Physical Aggression and Mindfulness among College Students: Evidence from China and the United States

    Directory of Open Access Journals (Sweden)

    Yu Gao

    2016-05-01

    Full Text Available Background: The link between trait mindfulness and several dimensions of aggression (verbal, anger and hostility has been documented, while the link between physical aggression and trait mindfulness remains less clear. Method: We used two datasets: one United States sample from 300 freshmen males from Clemson University, South Carolina and a Chinese sample of 1516 freshmen students from Shanghai University of Finance and Economics. Multiple regressions were conducted to examine the association between mindfulness (measured by Mindful Attention and Awareness Scale (MAAS and each of the four subscales of aggression. Results: Among the Clemson sample (N = 286, the mindfulness scale had a significant negative association with each of the four subscales of aggression: Hostility: β = −0.62, p < 0.001; Verbal: β = −0.37, p < 0.001; Physical: β = −0.29, p < 0.001; Anger: β = −0.44, p < 0.001. Among the Shanghai male subsample, the mindfulness scale had a significant negative association with each of the four subscales of aggression: Hostility: β = −0.57, p < 0.001; Verbal: β = −0.37, p < 0.001; Physical: β = −0.35, p < 0.001; Anger: β = −0.58, p < 0.001. Among the Shanghai female subsample (N = 512, the mindfulness scale had a significant negative association with each of the four subscales of aggression: Hostility: β = −0.62, p < 0.001; Verbal: β = −0.41, p < 0.001; Physical: β = −0.52, p < 0.001; and Anger: β = −0.64, p < 0.001. Discussion: Our study documents the negative association between mindfulness and physical aggression in two non-clinical samples. Future studies could explore whether mindfulness training lowers physical aggression among younger adults.

  2. The introduction of individual treatment by resident physical therapists in primary care units

    Directory of Open Access Journals (Sweden)

    Chandra da Silveira Langoni

    2012-09-01

    Full Text Available Objectives: To assess the effect on clinical indicators of the introduction of individual weekly physical therapy sessions in five Primary Health Care units in Porto Alegre, RS. Methods: The medical records from 59 patients were analyzed. They were treated between April 2010 and May 2011 by two physical therapists from the Multidisciplinary Residency Program in Family and Community Health at the Pontifical Catholic University of Rio Grande do Sul. Data was collected for the determination of the sociodemographic (gender, age, marital status and occupation and clinical profiles (medical diagnosis, medication intake, number of medications and the presence of pain, dyspnea, or urinary loss. Data was analyzed using Student’s t test, Mann Whitney, Chi-square and Fisher’s exact test; the odds ratio was used when a significant association has been identified. Results: Most participants were female (81.4%, adult (62%, who did not cohabitated (62.7%, domestic workers (35.6% with musculoskeletal and connective tissue disorders (86.4%. Thirty-two participants took medicine at the beginning of the intervention and, at the end, only five did so. After treatment, the amount of administered medications was also significantly reduced. The score of the Visual Analogue Scale (pain or dyspnea was significantly reduced at the end of an average of 7.7 ± 3.2 sessions. Those users who reported having followed the domiciliary advice had an 8.3 times greater chance of being discharged. Conclusions: The weekly physical therapy sessions carried out at Primary Care units reduced symptoms, the use and amount of medication taken by the users treated and achieved greater success among those who followed the domiciliary advice given by the resident physical therapists.

  3. Physical properties by geologic unit in the southern San Luis Basin, New Mexico

    Science.gov (United States)

    Grauch, V. J.; Drenth, Benjamin J.

    2016-01-01

    Physical properties of geologic units are important for geophysical interpretation because they provide the tie between lithology and geophysical fields. For gravity data, the applicable physical property is bulk density, which is the overall mass per unit volume of rocks, sediments, and their pore spaces. Bulk dry density is the mass per unit volume measured when the sample is dry. Saturated density is the mass per unit volume measured when the sample is saturated with fresh water, which has a density of 1,000 kg/m^3. The two values are commonly compared in order to determine the porosity of a sample, that is, the percentage of the volume that is composed of open space. Density is commonly reported in kilograms per cubic meter in the International System of Units (SI). For magnetic data, the applicable physical property is total magnetization, which is determined by the quantity of naturally occurring magnetic minerals in rocks and sediments, and the nature of their permanent magnetizations. Total magnetization is the vector sum of two components: remanent and induced (Blakely, 1995; Hansen and others, 2005). The induced component is a function of the quantity of magnetic minerals (commonly magnetite) and is a vector that is always oriented parallel to the present-day Earth’s magnetic field. The quantity of magnetic minerals is proportional to magnetic susceptibility, a property that can be measured from hand samples or outcrops. Measurements using these instruments provide values of volume magnetic susceptibility as opposed to mass magnetic susceptibility, which is commonly obtained in the laboratory. Values of magnetic susceptibility represent a ratio, and so are unitless, but the system of units must be specified for the values to be useful. Data reported here are in International System of Units (SI). The remanent component represents the vector sum of all permanent magnetizations held by the magnetic minerals, which have fixed directions irrespective of the

  4. Knowledge, attitude and practice of intensive care unit nurses about physical restraint.

    Science.gov (United States)

    Suliman, Mohammad; Aloush, Sami; Al-Awamreh, Khitam

    2017-09-01

    Physical restraint is mainly used in intensive care units (ICUs) to prevent delirious or agitated patients from removing tubes and lines connected to them. However, inappropriate use of physical restraint could have many detrimental physical effects on the patient, such as nerve damage, asphyxiation or even death. The aim of the study is to investigate nurses' knowledge, attitude and practice of physical restraint in ICUs in Jordanian hospitals, about which little is known. A descriptive and cross-sectional design was used. A convenience sample of 400 nurses working in three public hospitals and one university-affiliated hospital from different geographical regions in Jordan was selected. An Arabic version of the Physical Restraint Questionnaire (PRQ) was used to collect the data. A total of 300 completed questionnaires were returned, with a response rate of 75%. Of the total sample, 51% were males, 65.7% were from public hospitals and 80.3% held a bachelor's degree. The mean score in the knowledge section was 9.7 (SD =1.7) out of 15; in the attitude section, it was 24.7 (SD = 4.8) out of 33; and in the practice section, it was 30.9 (SD = 3.5) out of 42. Nurses who reported previous related education scored higher on the knowledge section (mean = 10.7; SD = 1.4) than nurses who reported no previous related education (mean = 9.1; SD = 1.6; p < .001). However, no significant differences between these categories were found in relation to attitude and practice. The study demonstrated some lack of knowledge and unsafe practices regarding physical restraint in ICUs in Jordan. It suggests improving nurses' knowledge, attitude and practices through in-service education on best practice for physical restraint, developing policies/guidelines and providing adequate staff and equipment to maintain patient safety and prevent complications. Conducting education programmes on physical restraint for ICU nurses and providing other preventive strategies

  5. 'Syncing' Up with the Quinn-Rand-Strogatz Constant: Hurwitz-ZetaFunctions in Non-Linear physics

    Energy Technology Data Exchange (ETDEWEB)

    Durgin, Natalie J.; Garcia, Sofia M.; Flournoy, Tamara; Bailey,David H.

    2007-12-01

    This work extends the analytical and computationalinvestigation of the Quinn-Rand-Strogatz (QRS) constants from non-linearphysics. The QRS constants (c1, c2, ..., cN) are found in a Winfreeoscillator mean-field system used to examine the transition of coupledoscillators as they lose synchronization. The constants are part of anasymptotic expansion of a function related to the oscillatorsynchronization. Previous work used high-precision software packages toevaluate c1 to 42 decimal-digits, which made it possible to recognize andprove that c1 was the root of a certain Hurwitz-zeta function. Thisallowed a value of c2 to beconjectured in terms of c1. Therefore thereis interest in determining the exact values of these constants to highprecision in the hope that general relationships can be establishedbetween the constants and the zeta functions. Here, we compute the valuesof the higher order constants (c3, c4) to more than 42-digit precision byextending an algorithm developed by D.H. Bailey, J.M. Borwein and R.E.Crandall. Several methods for speeding up the computation are exploredand an alternate proof that c1 is the root of a Hurwitz-zeta function isattempted.

  6. Creating healing intensive care unit environments: physical and psychological considerations in designing critical care areas.

    Science.gov (United States)

    Bazuin, Doug; Cardon, Kerrie

    2011-01-01

    A number of elements contribute to a healing ICU environment. The layout of a critical care unit helps create an environment that supports caregiving, which helps alleviate a host of work-related stresses. A quieter environment, one that includes family and friends, dotted with windows and natural light, creates a space that makes people feel balanced and reassured. A healing environment responds to the needs of all the people within a critical care unit-those who receive or give care and those who support patients and staff. Critical care units should be designed to focus on healing the body, the mind, and the senses. The design and policies of that department can be created in such a way to provide a sense of calm and balance. The physical environment has an impact on patient outcomes; the psychological environment can, too. A healing ICU environment will balance both. The authors discuss the ways in which architecture, interior design, and behavior contribute to a healing ICU environment.

  7. Self-Efficacy and Participation in Physical and Social Activity among Older Adults in Spain and the United States

    Science.gov (United States)

    Perkins, Jessica M.; Multhaup, Kristi S.; Perkins, H. Wesley; Barton, Cole

    2008-01-01

    Purpose: We explored Bandura's self-efficacy theory as applied to older adult (aged 63-92) participation in physical and social activity in a cross-cultural study. Design and Methods: Older adults in Spain (n = 53) and the United States (n = 55) completed questions regarding self-efficacy, outcome expectancy, and participation in physical and…

  8. Workshop Physics Activity Guide, Module 2: Mechanics II, Momentum, Energy, Rotational and Harmonic Motion, and Chaos (Units 8 - 15)

    Science.gov (United States)

    Laws, Priscilla W.

    2004-05-01

    The Workshop Physics Activity Guide is a set of student workbooks designed to serve as the foundation for a two-semester calculus-based introductory physics course. It consists of 28 units that interweave text materials with activities that include prediction, qualitative observation, explanation, equation derivation, mathematical modeling, quantitative experiments, and problem solving. Students use a powerful set of computer tools to record, display, and analyze data, as well as to develop mathematical models of physical phenomena. The design of many of the activities is based on the outcomes of physics education research. The Workshop Physics Activity Guide is supported by an Instructor's Website that: (1) describes the history and philosophy of the Workshop Physics Project; (2) provides advice on how to integrate the Guide into a variety of educational settings; (3) provides information on computer tools (hardware and software) and apparatus; and (4) includes suggested homework assignments for each unit. Log on to the Workshop Physics Project website at http://physics.dickinson.edu/ Workshop Physics is a component of the Physics Suite--a collection of materials created by a group of educational reformers known as the Activity Based Physics Group. The Physics Suite contains a broad array of curricular materials that are based on physics education research, including: Understanding Physics, by Cummings, Laws, Redish and Cooney (an introductory textbook based on the best-selling text by Halliday/Resnick/Walker) RealTime Physics Laboratory Modules Physics by Inquiry (intended for use in a workshop setting) Interactive Lecture Demonstration Tutorials in Introductory Physics Activity Based Tutorials (designed primarily for use in recitations)

  9. Clinical and Economic Burden of Mental Disorders Among Children With Chronic Physical Conditions, United States, 2008–2013

    OpenAIRE

    Suryavanshi, Manasi S.; Yang, Yi

    2016-01-01

    Introduction The prevalence of chronic physical and mental disorders is increasing among children and adolescents in the United States. In this study, we investigated the association between mental health disorders and chronic physical conditions among children, and we assessed whether having mental disorders is associated with increased health care costs for children with chronic physical conditions, using Medical Expenditure Panel Survey data from 2008 through 2013. Methods Children aged 5 ...

  10. Patterns in Nature Forming Patterns in Minds: An Evaluation of an Introductory Physics Unit

    Science.gov (United States)

    Sheaffer, Christopher Ryan

    Educators are increasingly focused on the process over the content. In science especially, teachers want students to understand the nature of science and investigation. The emergence of scientific inquiry and engineering design teaching methods have led to the development of new teaching and evaluation methods that concentrate on steps in a process rather than facts in a topic. Research supports the notion that an explicit focus on the scientific process can lead to student science knowledge gains. In response to new research and standards many teachers have been developing teaching methods that seem to work well in their classrooms, but lack the time and resources to test them in other classroom environments. A high school Physics teacher (Bradford Hill) has developed a unit called Patterns in Nature (PIN) with objectives relating mathematical modeling to the scientific process. Designed for use in his large public school classroom, the unit was taken and used in a charter school with small classes. This study looks at specifically whether or not the PIN unit effectively teaches students how to graph the data they gather and fit an appropriate mathematical pattern, using that model to predict future measurements. Additionally, the study looks at the students' knowledge and views about the nature of science and the process of scientific investigation as it is affected by the PIN unit. Findings show that students are able to identify and apply patterns to data, but have difficulties explaining the meaning of the math. Students' show increases in their knowledge of the process of science, and the majority develop positive views about science in general. A major goal of this study is to place this unit in the cyclical process of Design-Based Research and allow for Pattern in Nature's continuous improvement, development and evaluation. Design-Based Research (DBR) is an approach that can be applied to the implementation and evaluation of classroom materials. This method

  11. The current state of physical therapy pain curricula in the United States: a faculty survey.

    Science.gov (United States)

    Hoeger Bement, Marie K; Sluka, Kathleen A

    2015-02-01

    Insufficient pain education is problematic across the health care spectrum. Recent educational advancements have been made to combat the deficits in pain education to ensure that health care professionals are proficient in assessing and managing pain. The purpose of this survey was to determine the extent of pain education in current Doctorate of Physical Therapy schools in the United States, including how pain is incorporated into the curriculum, the amount of time spent teaching about pain, and the resources used to teach about pain. The survey consisted of 10 questions in the following subject areas: basic science mechanisms and concepts about pain, pain assessment, pain management, and adequacy of pain curriculum. The overall response was 77% (167/216) for the first series of responses of the survey (Question 1), whereas 62% completed the entire survey (Questions 2-10). The average contact hours teaching about pain was 31 ± 1.8 (mean ± standard error of the mean) with a range of 5 to 115 hours. The majority of schools that responded covered the science of pain, assessment, and management. Less than 50% of respondents were aware of the Institute of Medicine report on pain or the International Association for the Study of Pain guidelines for physical therapy pain education. Only 61% of respondents believed that their students received adequate education in pain management. Thus, this survey demonstrated how pain education is incorporated into physical therapy schools and highlighted areas for improvement such as awareness of recent educational advancements. This article demonstrates how pain education is incorporated into physical therapy curricula within accredited programs. Understanding the current structure of pain education in health professional curriculum can serve as a basis to determine if recent publications of guidelines and competencies impact education. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

  12. A revolution without tooth and claw-redefining the physical base units.

    Science.gov (United States)

    Pietsch, Wolfgang

    2014-06-01

    A case study is presented of a recent proposal by the major metrology institutes to redefine four of the physical base units, namely kilogram, ampere, mole, and kelvin. The episode shows a number of features that are unusual for progress in an objective science: for example, the progress is not triggered by experimental discoveries or theoretical innovations; also, the new definitions are eventually implemented by means of a voting process. In the philosophical analysis, I will first argue that the episode provides considerable evidence for confirmation holism, i.e. the claim that central statements in fundamental science cannot be tested in isolation; second, that the episode satisfies many of the criteria which Kuhn requires for scientific revolutions even though one would naturally classify it as normal science. These two observations are interrelated since holism can provide within normal science a possible source of future revolutionary periods.

  13. Physical and mental health status of Iraqi refugees resettled in the United States.

    Science.gov (United States)

    Taylor, Eboni M; Yanni, Emad A; Pezzi, Clelia; Guterbock, Michael; Rothney, Erin; Harton, Elizabeth; Montour, Jessica; Elias, Collin; Burke, Heather

    2014-12-01

    We conducted a survey among Iraqi refugees resettled in the United States to assess their physical and mental health status and healthcare access and utilization following the initial 8-month, post-arrival period. We randomly selected Iraqi refugees: ≥18 years of age; living in the United States for 8–36 months; and residents of Michigan, California, Texas and Idaho. Participants completed a household questionnaire and mental health assessment. We distributed 366 surveys. Seventy-five percent of participants had health insurance at the time of the survey; 43 % reported delaying or not seeking care for a medical problem in the past year. Sixty percent of participants reported one chronic condition; 37 % reported ≥2 conditions. The prevalence of emotional distress, anxiety, and depression was approximately 50 % of participants; 31 % were at risk for post-traumatic stress disorder. Iraqi refugees in this evaluation reported a high prevalence of chronic conditions and mental health symptoms despite relatively high access to healthcare. It is important for resettlement partners to be aware of the distinctive health concerns of this population to best address needs within this community.

  14. The Hubble Constant.

    Science.gov (United States)

    Jackson, Neal

    2015-01-01

    I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H0 values of around 72-74 km s(-1) Mpc(-1), with typical errors of 2-3 km s(-1) Mpc(-1). This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67-68 km s(-1) Mpc(-1) and typical errors of 1-2 km s(-1) Mpc(-1). The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.

  15. Theoretical approaches to the steady-state statistical physics of interacting dissipative units

    Science.gov (United States)

    Bertin, Eric

    2017-02-01

    The aim of this review is to provide a concise overview of some of the generic approaches that have been developed to deal with the statistical description of large systems of interacting dissipative ‘units’. The latter notion includes, e.g. inelastic grains, active or self-propelled particles, bubbles in a foam, low-dimensional dynamical systems like driven oscillators, or even spatially extended modes like Fourier modes of the velocity field in a fluid. We first review methods based on the statistical properties of a single unit, starting with elementary mean-field approximations, either static or dynamic, that describe a unit embedded in a ‘self-consistent’ environment. We then discuss how this basic mean-field approach can be extended to account for spatial dependences, in the form of space-dependent mean-field Fokker-Planck equations, for example. We also briefly review the use of kinetic theory in the framework of the Boltzmann equation, which is an appropriate description for dilute systems. We then turn to descriptions in terms of the full N-body distribution, starting from exact solutions of one-dimensional models, using a matrix-product ansatz method when correlations are present. Since exactly solvable models are scarce, we also present some approximation methods which can be used to determine the N-body distribution in a large system of dissipative units. These methods include the Edwards approach for dense granular matter and the approximate treatment of multiparticle Langevin equations with colored noise, which models systems of self-propelled particles. Throughout this review, emphasis is put on methodological aspects of the statistical modeling and on formal similarities between different physical problems, rather than on the specific behavior of a given system.

  16. Safety and feasibility of femoral catheters during physical rehabilitation in the intensive care unit.

    Science.gov (United States)

    Damluji, Abdulla; Zanni, Jennifer M; Mantheiy, Earl; Colantuoni, Elizabeth; Kho, Michelle E; Needham, Dale M

    2013-08-01

    Femoral catheters pose a potential barrier to early rehabilitation in the intensive care unit (ICU) due to concerns, such as catheter removal, local trauma, bleeding, and infection. We prospectively evaluated the feasibility and safety of physical therapy (PT) in ICU patients with femoral catheters. We evaluated consecutive medical ICU patients who received PT with a femoral venous, arterial, or hemodialysis catheter(s) in situ. Of 1074 consecutive patients, 239 (22%) received a femoral catheter (81% venous, 29% arterial, 6% hemodialysis; some patients had >1 catheter). Of those, 101 (42%) received PT interventions, while the catheter was in situ, for a total of 253 sessions over 210 medical ICU (MICU) days. On these 210 MICU days, the highest daily activity level achieved was 49 (23%) standing or walking, 57 (27%) sitting, 25 (12%) supine cycle ergometry, and 79 (38%) in-bed exercises. During 253 PT sessions, there were no catheter-related adverse events giving a 0% event rate (95% upper confidence limit of 2.1% for venous catheters). Physical therapy interventions in MICU patients with in situ femoral catheters appear to be feasible and safe. The presence of a femoral catheter should not automatically restrict ICU patients to bed rest. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Varying constants, Gravitation and Cosmology

    CERN Document Server

    Uzan, Jean-Philippe

    2010-01-01

    Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. It is thus of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We thus detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, Solar system observations, meteorites dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describ...

  18. Genetic distance as an alternative to physical distance for definition of gene units in association studies.

    Science.gov (United States)

    Rodriguez-Fontenla, Cristina; Calaza, Manuel; Gonzalez, Antonio

    2014-05-28

    Some association studies, as the implemented in VEGAS, ALIGATOR, i-GSEA4GWAS, GSA-SNP and other software tools, use genes as the unit of analysis. These genes include the coding sequence plus flanking sequences. Polymorphisms in the flanking sequences are of interest because they involve cis-regulatory elements or they inform on untyped genetic variants trough linkage disequilibrium. Gene extensions have customarily been defined as ±50 Kb. This approach is not fully satisfactory because genetic relationships between neighbouring sequences are a function of genetic distances, which are only poorly replaced by physical distances. Standardized recombination rates (SRR) from the deCODE recombination map were used as units of genetic distances. We searched for a SRR producing flanking sequences near the ±50 Kb offset that has been common in previous studies. A SRR≥2 was selected because it led to gene extensions with median length=45.3 Kb and the simplicity of an integer value. As expected, boundaries of the genes defined with the ±50 Kb and with the SRR≥2 rules were rarely concordant. The impact of these differences was illustrated with the interpretation of top association signals from two large studies including many hits and their detailed analysis based in different criteria. The definition based in genetic distance was more concordant with the results of these studies than the based in physical distance. In the analysis of 18 top disease associated loci form the first study, the SRR≥2 genes led to a fully concordant interpretation in 17 loci; the ±50 Kb genes only in 6. Interpretation of the 43 putative functional genes of the second study based in the SRR≥2 definition only missed 4 of the genes, whereas the based in the ±50 Kb definition missed 10 genes. A gene definition based on genetic distance led to results more concordant with expert detailed analyses than the commonly used based in physical distance. The genome coordinates for each

  19. Characterising physical habitats and fluvial hydromorphology: A new system for the survey and classification of river geomorphic units

    Science.gov (United States)

    Belletti, Barbara; Rinaldi, Massimo; Bussettini, Martina; Comiti, Francesco; Gurnell, Angela M.; Mao, Luca; Nardi, Laura; Vezza, Paolo

    2017-04-01

    Geomorphic units are the elementary spatial physical features of the river mosaic at the reach scale that are nested within the overall hydromorphological structure of a river and its catchment. Geomorphic units also constitute the template of physical habitats for the biota. The assessment of river hydromorphological conditions is required by the European Water Framework Directive 2000/60 (WFD) for the classification and monitoring of water bodies and is useful for establishing links between their physical and biological conditions. The spatial scale of geomorphic units, incorporating their component elements and hydraulic patches, is the most appropriate to assess these links. Given the weakness of existing methods for the characterisation and assessment of geomorphic units and physical habitats (e.g., lack of a well-defined spatiotemporal framework, terminology issues, etc.), a new system for the survey and characterisation of river geomorphic units is needed that fits within a geomorphologically meaningful framework. This paper presents a system for the survey and classification of geomorphic units (GUS, geomorphic units survey and classification system) aimed at characterising physical habitats and stream morphology. The method is embedded into a multiscale, hierarchical framework for the analysis of river hydromorphological conditions. Three scales of geomorphic units are considered (i.e., macro-units, units, sub-units), organised within two spatial domains (i.e., bankfull channel and floodplain). Different levels of characterisation can be applied, depending on the aims of the survey: broad, basic, and detailed level. At each level, different, complementary information is collected. The method is applied by combining remote sensing analysis and field survey, according to the spatial scale and the level of description required. The method is applicable to most of fluvial conditions, and has been designed to be flexible and adaptable according to the

  20. 300-FF-1 Operable Unit physical separation of soils pilot plant study

    Energy Technology Data Exchange (ETDEWEB)

    Freeman-Pollard, J.R.

    1994-01-15

    Alternative Remedial Technologies, Inc. (ART) was selected in a competitive selection process to conduct a pilot study for the physical separation of soils in the North Process Pond of the 300 Area at the Hanford Site. In January 1994, ART mobilized its 15 tons-per-hour pilot plant to the site. The plant was initially staged in a commercial area to allow for pretest inspections and minor modifications. The plant was specifically designed for use as a physical separations unit and consisted of a feed hopper, wet screens, hydrocyclones, as well as settling and dewatering equipment. The plant was supported in the field with prescreening equipment, mobile generators, air compressors, and water storage tanks. The plant was moved into the surface contamination area on March 24, 1994. The testing was conducted during the period March 23, 1994 through April 13, 1994. Two soil types were treated during the testing: a natural soil contaminated with low levels of uranium, cesium, cobalt, and heavy metals, and a natural soil contaminated with a uranium carbonate material that was visually recognizable by the presence of a green sludge material in the soil matrix. The ``green`` material contained significantly higher levels of the same contaminants. Both source materials were treated by the plant in a manner that fed the material, produced clean gravel and sand fractions, and concentrated the contaminants in a sludge cake. Process water was recycled during the operations. The testing was extremely successful in that for both source waste streams, it was demonstrated that volume reductions of greater than 90% could be achieved while also meeting the test performance criteria. The volume reduction for the natural soils averaged a 93.8%, while the ``green`` soils showed a 91.4% volume reduction.

  1. Workforce Projections 2010-2020: Annual Supply and Demand Forecasting Models for Physical Therapists Across the United States.

    Science.gov (United States)

    Landry, Michel D; Hack, Laurita M; Coulson, Elizabeth; Freburger, Janet; Johnson, Michael P; Katz, Richard; Kerwin, Joanne; Smith, Megan H; Wessman, Henry C Bud; Venskus, Diana G; Sinnott, Patricia L; Goldstein, Marc

    2016-01-01

    Health human resources continue to emerge as a critical health policy issue across the United States. The purpose of this study was to develop a strategy for modeling future workforce projections to serve as a basis for analyzing annual supply of and demand for physical therapists across the United States into 2020. A traditional stock-and-flow methodology or model was developed and populated with publicly available data to produce estimates of supply and demand for physical therapists by 2020. Supply was determined by adding the estimated number of physical therapists and the approximation of new graduates to the number of physical therapists who immigrated, minus US graduates who never passed the licensure examination, and an estimated attrition rate in any given year. Demand was determined by using projected US population with health care insurance multiplied by a demand ratio in any given year. The difference between projected supply and demand represented a shortage or surplus of physical therapists. Three separate projection models were developed based on best available data in the years 2011, 2012, and 2013, respectively. Based on these projections, demand for physical therapists in the United States outstrips supply under most assumptions. Workforce projection methodology research is based on assumptions using imperfect data; therefore, the results must be interpreted in terms of overall trends rather than as precise actuarial data-generated absolute numbers from specified forecasting. Outcomes of this projection study provide a foundation for discussion and debate regarding the most effective and efficient ways to influence supply-side variables so as to position physical therapists to meet current and future population demand. Attrition rates or permanent exits out of the profession can have important supply-side effects and appear to have an effect on predicting future shortage or surplus of physical therapists. © 2016 American Physical Therapy

  2. Feasibility and safety of in-bed cycling for physical rehabilitation in the intensive care unit.

    Science.gov (United States)

    Kho, Michelle E; Martin, Robert A; Toonstra, Amy L; Zanni, Jennifer M; Mantheiy, Earl C; Nelliot, Archana; Needham, Dale M

    2015-12-01

    The purpose was to evaluate the feasibility and safety of in-bed cycle ergometry as part of routine intensive care unit (ICU) physical therapist (PT) practice. Between July 1, 2010, and December 31, 2011, we prospectively identified all patients admitted to a 16-bed medical ICU receiving cycling by a PT, prospectively collected data on 12 different potential safety events, and retrospectively conducted a chart review to obtain specific details of each cycling session. Six hundred eighty-eight patients received PT interventions, and 181 (26%) received a total of 541 cycling sessions (median [interquartile range {IQR}] cycling sessions per patient, 2 [1-4]). Patients' mean (SD) age was 57 (17) years, and 103 (57%) were male. The median (IQR) time from medical ICU admission to first PT intervention and first cycling session was 2 (1-4) and 4 (2-6) days, respectively, with a median (IQR) cycling session duration of 25 (18-30) minutes. On cycling days, the proportion of patients receiving mechanical ventilation, vasopressor infusions, and continuous renal replacement therapy was 80%, 8%, and 7%, respectively. A single safety event occurred, yielding a 0.2% event rate (95% upper confidence limit, 1.0%). Use of in-bed cycling as part of routine PT interventions in ICU patients is feasible and appears safe. Further study of the potential benefits of early in-bed cycling is needed. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Positive experiences in physical education through teacher intervention in the teaching unit futsal.

    Directory of Open Access Journals (Sweden)

    Ángel Abós Catalán

    2015-09-01

    Full Text Available The interpersonal style used by the teacher of Physical Education (PE in their classes can trigger consequences for students inside and outside the classroom. Grounded in self-determination theory and achievement goal theory, the aim of the study was to analyze the relationship between motivational climate and support of the basic psychological needs (BPN generated by the PE teacher in the teaching unit (TU of futsal, with consequences of enjoyment and boredom, as well as the predisposition toward EF experienced by students. The sample was composed of 70 students (32 men and 38 women year 4th of compulsory Secondary Education, aged 15 to 17 years (M age = 15.31, SD = 0.49. The variables measured at the end of the TU were: motivational climate (EPCM, support of the BPN (CANPB and affective consequences (SSI the content of futsal and the predisposition towards PE (PEPS. The results of correlation analysis showed that the task climate and support of the BPN in the TU futsal, correlated positively and significantly with enjoyment and some predisposing factors toward PE, while doing it in reverse with boredom. Therefore, given the relationship between what happens in the classroom and outside it, seems necessary that teachers of PE generates a task climate and support of the BPN in each of curricular content, to students adopt life-styles more active and healthy. 

  4. Unit physics performance of a mix model in Eulerian fluid computations

    Energy Technology Data Exchange (ETDEWEB)

    Vold, Erik [Los Alamos National Laboratory; Douglass, Rod [Los Alamos National Laboratory

    2011-01-25

    In this report, we evaluate the performance of a K-L drag-buoyancy mix model, described in a reference study by Dimonte-Tipton [1] hereafter denoted as [D-T]. The model was implemented in an Eulerian multi-material AMR code, and the results are discussed here for a series of unit physics tests. The tests were chosen to calibrate the model coefficients against empirical data, principally from RT (Rayleigh-Taylor) and RM (Richtmyer-Meshkov) experiments, and the present results are compared to experiments and to results reported in [D-T]. Results show the Eulerian implementation of the mix model agrees well with expectations for test problems in which there is no convective flow of the mass averaged fluid, i.e., in RT mix or in the decay of homogeneous isotropic turbulence (HIT). In RM shock-driven mix, the mix layer moves through the Eulerian computational grid, and there are differences with the previous results computed in a Lagrange frame [D-T]. The differences are attributed to the mass averaged fluid motion and examined in detail. Shock and re-shock mix are not well matched simultaneously. Results are also presented and discussed regarding model sensitivity to coefficient values and to initial conditions (IC), grid convergence, and the generation of atomically mixed volume fractions.

  5. The Hubble Constant

    Directory of Open Access Journals (Sweden)

    Neal Jackson

    2015-09-01

    Full Text Available I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H_0 values of around 72–74 km s^–1 Mpc^–1, with typical errors of 2–3 km s^–1 Mpc^–1. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67–68 km s^–1 Mpc^–1 and typical errors of 1–2 km s^–1 Mpc^–1. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.

  6. Varying Constants, Gravitation and Cosmology

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Uzan

    2011-03-01

    Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

  7. Varying Constants, Gravitation and Cosmology.

    Science.gov (United States)

    Uzan, Jean-Philippe

    2011-01-01

    Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

  8. Varying Constants, Gravitation and Cosmology

    Science.gov (United States)

    Uzan, Jean-Philippe

    2011-12-01

    Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

  9. Static and dynamic loads on the bottom row of armour units: A theoretical and physical model study

    NARCIS (Netherlands)

    Van de Koppel, M.A.; Muilwijk, M.; Verhagen, H.J.

    2012-01-01

    A physical model study on the row averaged static and dynamic load on the bottom row of single layer armour units in order to investigate the influence of various parameters such as the number of rows on the slope of a breakwater and the initial relative packing density.

  10. Static and dynamic loads on the bottom row of armour units: A theoretical and physical model study

    NARCIS (Netherlands)

    Van de Koppel, M.A.; Muilwijk, M.; Verhagen, H.J.

    2012-01-01

    A physical model study on the row averaged static and dynamic load on the bottom row of single layer armour units in order to investigate the influence of various parameters such as the number of rows on the slope of a breakwater and the initial relative packing density.

  11. 78 FR 79017 - Zion Solutions, LLC; Zion Nuclear Power Station, Units 1 and 2; Exemption From Certain Physical...

    Science.gov (United States)

    2013-12-27

    ... COMMISSION Zion Solutions, LLC; Zion Nuclear Power Station, Units 1 and 2; Exemption From Certain Physical... shut down facility and responsibility for its decommissioning was transferred to ZionSolutions (ZS), a subsidiary of EnergySolutions. ZS was established solely for the purpose of acquiring and decommissioning...

  12. Substance Use, Mental Disorders and Physical Health of Caribbeans at-Home Compared to Those Residing in the United States

    Directory of Open Access Journals (Sweden)

    Krim K. Lacey

    2015-01-01

    Full Text Available This study compares the health conditions of domestic Caribbeans with those living in the United States to explore how national context and migration experiences might influence substance use (i.e., alcohol or drug and other mental and physical health conditions. The study is based upon probability samples of non-institutionalized Caribbeans living in the United States (1621, Jamaica (1216 and Guyana (2068 18 years of age and over. Employing descriptive statistics and multivariate analytic procedures, the results revealed that substance use and other physical health conditions and major depressive disorder and mania vary by national context, with higher rates among Caribbeans living in the United States. Context and generation status influenced health outcomes. Among first generation black Caribbeans, residing in the United States for a longer length of time is linked to poorer health outcomes. There were different socio-demographic correlates of health among at-home and abroad Caribbeans. The results of this study support the need for additional research to explain how national context, migratory experiences and generation status contribute to understanding substance use and mental disorders and physical health outcomes among Caribbean first generation and descendants within the United States, compared to those remaining in the Caribbean region.

  13. Association of proximity and density of parks and objectively measured physical activity in the United States: A systematic review.

    Science.gov (United States)

    Bancroft, Carolyn; Joshi, Spruha; Rundle, Andrew; Hutson, Malo; Chong, Catherine; Weiss, Christopher C; Genkinger, Jeanine; Neckerman, Kathryn; Lovasi, Gina

    2015-08-01

    One strategy for increasing physical activity is to create and enhance access to park space. We assessed the literature on the relationship of parks and objectively measured physical activity in population-based studies in the United States (US) and identified limitations in current built environment and physical activity measurement and reporting. Five English-language scholarly databases were queried using standardized search terms. Abstracts were screened for the following inclusion criteria: 1) published between January 1990 and June 2013; 2) US-based with a sample size greater than 100 individuals; 3) included built environment measures related to parks or trails; and 4) included objectively measured physical activity as an outcome. Following initial screening for inclusion by two independent raters, articles were abstracted into a database. Of 10,949 abstracts screened, 20 articles met the inclusion criteria. Five articles reported a significant positive association between parks and physical activity. Nine studies found no association, and six studies had mixed findings. Our review found that even among studies with objectively measured physical activity, the association between access to parks and physical activity varied between studies, possibly due to heterogeneity of exposure measurement. Self-reported (vs. independently-measured) neighborhood park environment characteristics and smaller (vs. larger) buffer sizes were more predictive of physical activity. We recommend strategies for further research, employing standardized reporting and innovative study designs to better understand the relationship of parks and physical activity.

  14. Domesticating Physics: Introductory Physics Textbooks for Women in Home Economics in the United States, 1914-1955

    Science.gov (United States)

    Behrman, Joanna

    2017-01-01

    Technologies such as electrical appliances entered American households on a large scale only after many decades of promotion to the public. The genre of "household physics" textbooks was one such form of promotion that was directed towards assumed white, female and largely middle-class home economics students. Published from the 1910s to…

  15. Domesticating Physics: Introductory Physics Textbooks for Women in Home Economics in the United States, 1914-1955

    Science.gov (United States)

    Behrman, Joanna

    2017-01-01

    Technologies such as electrical appliances entered American households on a large scale only after many decades of promotion to the public. The genre of "household physics" textbooks was one such form of promotion that was directed towards assumed white, female and largely middle-class home economics students. Published from the 1910s to…

  16. Effect of Hetero Atom on the Hammett’s Reaction Constant (ρ from the Physical Basis of Dissociation Equilibriums of (Dithio Benzoic Acids and (Thio Phenols and Its Application to Solvolysis Reactions and Some Free Radical Reactions

    Directory of Open Access Journals (Sweden)

    Jagannadham Vandanapu

    2012-01-01

    Full Text Available The emergence of putative Hammett equation in mid 1930s was a boon to physical-organic chemists to elucidate the reaction mechanisms of several organic reactions. Based on the concept of this equation several hundreds of papers have emerged in chemical literature in the last century on the effect of structure, on reactivity, and very few on thermodynamic stability and kinetic reactivity of intermediates. In this article an attempt is made to explain the effect of hetero atom on Hammett’s reaction constant (ρ taking the dissociation equilibriums of benzoic acids, dithiobenzoic acids, phenols, and thiophenols.

  17. Reliability of Wearable Inertial Measurement Units to Measure Physical Activity in Team Handball.

    Science.gov (United States)

    Luteberget, Live S; Holme, Benjamin R; Spencer, Matt

    2017-09-05

    The purpose of this study was to assess the reliability and sensitivity of commercially available inertial measurement units (IMU) to measure physical activity in team handball. Twenty-two handball players were instrumented with two IMUs (OptimEye S5, Catapult Sports, Australia) taped together. They participated in either a laboratory assessment (n=10), consisting of seven team handball specific tasks, or field assessment (n=12) conducted in twelve training sessions. Variables, including PlayerLoad™ and inertial movement analysis (IMA) magnitude and counts, were extracted from the manufactures software. IMA count was divided into intensity bands of low (1.5-2.5m·s(-1)), medium (2.5-3.5m·s(-1)), high (>3.5m·s(-1)), medium/high (>2.5m·s(-1)), and total (>1.5m·s(-1)). Reliability between devices and sensitivity was established using coefficient of variation (CV) and smallest worthwhile difference (SWD). Laboratory assessment : IMA magnitude showed a good reliability (CV: 3.1%) in well-controlled tasks. CV increased (4.4-6.7%) in more complex tasks. Field assessment : Total IMA count (CV: 1.8%, SWD: 2.5%), PlayerLoad™ (CV: 0.9 % SWD: 2.1%), and its associated variables (CV: 0.4-1.7%) showed a good reliability, well below the SWD. However, the CV of IMA increased when categorized into intensity bands (2.9-5.6%). The reliability of IMA count were good, when data was displayed as total, high or medium/high counts. A good reliability for PlayerLoad™ and associated variables was evident. The CV of the aforementioned variables was well below the SWD, suggesting that OptimEye IMU and its software are sensitive for use in team handball.

  18. Age, sex, and racial differences in harsh physical punishment: results from a nationally representative United States sample.

    Science.gov (United States)

    Taillieu, Tamara L; Afifi, Tracie O; Mota, Natalie; Keyes, Katherine M; Sareen, Jitender

    2014-12-01

    The purpose of this research was to examine age, sex, and racial differences in the prevalence of harsh physical punishment in childhood in a nationally representative sample of the United States. Data were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) collected in 2004 and 2005 (n=34,653). Logistic regression analyses were conducted to examine age, sex, and racial differences in the prevalence of harsh physical punishment. Results suggest that the prevalence of harsh physical punishment has been decreasing among more recently born age groups; however, there appear to be sex and racial differences in this trend over time. The magnitude of the decrease appears to be stronger for males than for females. By race, the decrease in harsh physical punishment over time is only apparent among Whites; Black participants demonstrate little change over time, and harsh physical punishment seems to be increasing over time among Hispanics. Prevention and intervention efforts that educate about the links of physical punishment to negative outcomes and alternative non-physical discipline strategies may be particularly useful in reducing the prevalence of harsh physical punishment over time.

  19. Social Environments and Physical Aggression among 21,107 Students in the United States and Canada

    Science.gov (United States)

    Pickett, William; Iannotti, Ronald J.; Simons-Morton, Bruce; Dostaler, Suzanne

    2009-01-01

    Background: Physical aggression is an important issue in North American populations. The importance of students' social environments in the occurrence of physical aggression requires focused study. In this study, reports of physical aggression were examined in relation to social environment factors among national samples of students from Canada…

  20. The practice of active rest by workplace units improves personal relationships, mental health, and physical activity among workers.

    Science.gov (United States)

    Michishita, Ryoma; Jiang, Ying; Ariyoshi, Daisuke; Yoshida, Marie; Moriyama, Hideko; Yamato, Hiroshi

    2017-03-28

    This study was designed to clarify the effects of active rest, with a focus on the practice of short-time group exercise by workplace units, on personal relationships, mental health, physical activity, and work ability among workers. Fifty-nine white-collar workers (40 males and 19 females) performed our active rest (short-time exercise) program, which consists of warm-up, cognitive functional training, aerobic exercise, resistance training and cool-down for 10 minutes per day, 3 times per week during their lunch breaks for 10 weeks. Participants from a workplace unit were randomly allocated to the intervention (five workplaces, n=29) or control groups (six workplaces, n=30). The participants' anthropometric measurements, and their Profile of Mood States (POMS) 2, Brief Job Stress Questionnaire (BJSQ), physical activity levels and Work Ability Index were examined at the baseline and after the 10-week intervention. After 10 weeks, physical activity levels, especially the time spent in moderate and vigorous intensity, increased in the intervention group (pchange in "vigor-activity" in POMS 2 (r=0.467, p=0.011). These results suggest that the practice of active rest by workplace units is important for improving personal relationships, mental health, and physical activity among workers.

  1. Photoionization study of Ne-like K9+, Ca10+, Sc11+, Ti12+, V13+, Cr14+, Mn15+, and Fe16+ ions using the screening constant by unit nuclear charge method

    Science.gov (United States)

    Goyal, Arun; Khatri, Indu; Sow, Malick; Sakho, Ibrahima; Aggarwal, Sunny; Singh, A. K.; Mohan, Man

    2016-08-01

    Photoionization of the 2s22p6 (1S0) ground state of the Ne-like (Z=19-29) ions is presented in this paper. Resonance energies and total natural width of the 2s2p6np 1P series of the Ne-like K9+, Ca10+, Sc11+, Ti12+, V13+, Cr14+, Mn15+, and Fe16+are reported. All the calculations are made using the Screening constant by unit nuclear charge (SCUNC) formalism. New data for Ne-like K9+, Sc11+, Ti12+, V13+, Cr14+, and Mn15+ions are tabulated. Good agreements are found with available literature data.

  2. Particle Physics and Astronomy Research Council (PPARC) members, United Kingdom, visiting the ATLAS semiconductor tracker (SCT) module tests.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Photo 01: Mr Peter Warry, PPARC Chairman, Victrex Plc, United Kingdom visiting the ATLAS SCT module tests with Dr Joleen Pater, SCT (Manchester). Photo 02: PPARC Council Members, United Kingdom, visiting the ATLAS SCT module tests. L.t to r.: Mrs Judith Scott, Chief Executive, British Computer Society, Prof. George Efstathiou, Institute of Astronomy, University of Cambridge, Mr Peter Warry, PPARC Chairman, Victrex Plc, Prof. Martin Ward, Director X-Ray Astronomy, of Leicester, Prof. James Stirling, Director, Institute for Particle Physics Phenomenology, University of Durham and Prof. Brian Foster, University of Bristol.

  3. Ion exchange equilibrium constants

    CERN Document Server

    Marcus, Y

    2013-01-01

    Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and

  4. Musculoskeletal disorders in hemodialysis patients and its impact on physical function (Zagazig University Nephrology Unit, Egypt

    Directory of Open Access Journals (Sweden)

    Amany R El-Najjar

    2014-01-01

    Conclusion Musculoskeletal system involvement remains a common problem that limits the physical function of patients with renal failure, in particular, those treated with long-term maintenance dialysis.

  5. Proposal for inclusion of topics of particle physics integrated electric charge through a potentially meaningful teaching units

    OpenAIRE

    Lisiane Barcellos Calheiro; Isabel Krey Garcia

    2014-01-01

    In this article the results of the analysis of free and concept maps produced are presented from the application and evaluation of a Potentially Meaningful Teaching Units – PMTU, which is a teaching sequence based on various learning theories and seeks to promote meaningful student learning. Presents, in this work, part of a research Masters in Science Education which deals with the inclusion of topics of particle physics integrated with traditional content of the third year of hi...

  6. The practice of active rest by workplace units improves personal relationships, mental health, and physical activity among workers

    OpenAIRE

    Michishita, Ryoma; Jiang, Ying; Ariyoshi, Daisuke; Yoshida, Marie; Moriyama, Hideko; Yamato, Hiroshi

    2016-01-01

    Aim: This study was designed to clarify the effects of active rest, with a focus on the practice of short-time group exercise by workplace units, on personal relationships, mental health, physical activity, and work ability among workers. Methods: Fifty-nine white-collar workers (40 males and 19 females) performed our active rest (short-time exercise) program, which consists of warm-up, cognitive functional training, aerobic exercise, resistance training and cool-down for 10 minutes per day, ...

  7. Physics Education Research in the United States: A Summary of Its Rationale and Main Findings.

    Science.gov (United States)

    Gonzales-Espada, Wilson J.

    2003-01-01

    Recognizes how difficult it is for secondary and post-secondary students to make connections between physics and everyday phenomena, rationalize the use of a particular formula for a given problem, and go beyond algebraic substitutions to really make sense of physics in a meaningful way. Provides a rationale for physicists to become involved in…

  8. Fun and Creative Unit Assessment Ideas for All Students in Physical Education

    Science.gov (United States)

    Fencl, Matthew J.

    2014-01-01

    Although traditional methods of assessment--such as rubrics, checklists, skill tests, and quizzes--have long been viable methods of evaluation in physical education, they may at times seem boring or overwhelming. Yet, assessment can be as fun and interesting as the activities that are taught in physical education, and can help to increase…

  9. The Current Experiences of Physical Education Teachers at Schools for Blind Students in the United States

    Science.gov (United States)

    Haegele, Justin A.; Lieberman, Lauren J.

    2016-01-01

    Introduction: It has been well established that children with visual impairments tend to be less physically active and more delayed in motor skills than their sighted peers. As a result, there has been some research focusing on inclusive physical education for these children. However, there is a clear lack of research on the current status of…

  10. Content Analysis of Conceptually Based Physical Education in Southeastern United States Universities and Colleges

    Science.gov (United States)

    Williams, Suzanne Ellen; Greene, Leon; Satinsky, Sonya; Neuberger, John

    2016-01-01

    Purpose: The purposes of this study were to explore PE in higher education through the offering of traditional activity- and skills-based physical education (ASPE) and conceptually-based physical education (CPE) courses, and to conduct an exploratory content analysis on the CPE available to students in randomized colleges and universities in the…

  11. Physics Education Research in the United States: A Summary of Its Rationale and Main Findings.

    Science.gov (United States)

    Gonzales-Espada, Wilson J.

    2003-01-01

    Recognizes how difficult it is for secondary and post-secondary students to make connections between physics and everyday phenomena, rationalize the use of a particular formula for a given problem, and go beyond algebraic substitutions to really make sense of physics in a meaningful way. Provides a rationale for physicists to become involved in…

  12. Proposal for inclusion of topics of particle physics integrated electric charge through a potentially meaningful teaching units

    Directory of Open Access Journals (Sweden)

    Lisiane Barcellos Calheiro

    2014-03-01

    Full Text Available In this article the results of the analysis of free and concept maps produced are presented from the application and evaluation of a Potentially Meaningful Teaching Units – PMTU, which is a teaching sequence based on various learning theories and seeks to promote meaningful student learning. Presents, in this work, part of a research Masters in Science Education which deals with the inclusion of topics of particle physics integrated with traditional content of the third year of high school. It was implemented in a third grade high school class of a State School in Santa Maria, Rio Grande do Sul, and Brazil. The PMTU aimed to address in an integrated manner threads for Particle Physics and Electronics. A didactic sequence that integrated the topics of electric charge, atomic models, elementary particles, quantization and process electrification was applied. Such integration aimed at stimulating the interest on topics related to Modern and Contemporary Physics. It was developed using PMTU activities that aimed at promoting meaningful learning and knowledge construction in the classroom, Since the topics involved were quite complex, this made their integration a real challenge to the high school teachers, and resulted in changes in their teaching practices. Research showed that the inclusion of topics on physics of elementary particles the and electricity, through Potentially Meaningful Teaching Units, show satisfactory results in the students’ learning.

  13. Cosmological Constant, Fine Structure Constant and Beyond

    CERN Document Server

    Wei, Hao; Li, Hong-Yu; Xue, Dong-Ze

    2016-01-01

    In this work, we consider the cosmological constant model $\\Lambda\\propto\\alpha^{-6}$, which is well motivated from three independent approaches. As is well known, the evidence of varying fine structure constant $\\alpha$ was found in 1998. If $\\Lambda\\propto\\alpha^{-6}$ is right, it means that the cosmological constant $\\Lambda$ should be also varying. In this work, we try to develop a suitable framework to model this varying cosmological constant $\\Lambda\\propto\\alpha^{-6}$, in which we view it from an interacting vacuum energy perspective. We propose two types of models to describe the evolutions of $\\Lambda$ and $\\alpha$. Then, we consider the observational constraints on these models, by using the 293 $\\Delta\\alpha/\\alpha$ data from the absorption systems in the spectra of distant quasars, and the data of type Ia supernovae (SNIa), cosmic microwave background (CMB), baryon acoustic oscillation (BAO). We find that the model parameters can be tightly constrained to the narrow ranges of ${\\cal O}(10^{-5})$ t...

  14. Leisure-time physical activity among older adults. United States, 1990.

    Science.gov (United States)

    Yusuf, H R; Croft, J B; Giles, W H; Anda, R F; Casper, M L; Caspersen, C J; Jones, D A

    1996-06-24

    To investigate the prevalence and selected correlates of leisure-time physical activity in a nationally representative sample of persons aged 65 years or older. Data from 2783 older male and 5018 older female respondents to the 1990 National Health Interview Survey were used. Regular physical activity was defined as participation in leisure-time physical activities 3 times or more per week for 30 minutes or more during the previous 2 weeks. Odds ratios (ORs) were estimated from multivariate logistic regression analysis. Prevalence of regular physical activity was 37% among older men and 24% among older women. Correlates of regular physical activity included the perception of excellent to good health (men: OR, 1.5; 95% confidence interval [CI], 1.1-1.9; women: OR, 1.6; 95% CI, 1.3-1.9), correct exercise knowledge (men: OR, 2.4; 95% CI, 1.9-3.1; women: OR, 2.7; 95% CI, 2.2-3.4), no activity limitations (men: OR, 1.3; 95% CI, 1.0-1.6; women: OR, 1.7; 95% CI, 1.4-2.0) and not perceiving "a lot" of stress during the previous 2 weeks (men: OR, 1.7; 95% CI, 1.2-2.4; women: OR, 1.3; 95% CI, 1.0-1.6). Among those who had been told at least twice that they had high blood pressure, physician's advice to exercise was associated with regular physical activity (men: OR, 1.6; 95% CI, 1.2-2.3; women: OR, 1.5; 95% CI, 1.2-1.9). The 2 major activities among active older adults were walking (men, 69%; women, 75%) and gardening (men, 45%; women, 35%). Prevalence of regular physical activity is low among older Americans. Identifying the correlates of physical activity will help to formulate strategies to increase physical activity in this age group.

  15. A National Workshop in the United States to Prepare New Faculty in Physics and Astronomy

    Science.gov (United States)

    Krane, Kenneth S.

    2010-07-01

    Starting in 1996, newly hired college and university faculty in physics and astronomy from throughout the U.S. have been invited to attend a workshop to help them improve their teaching skills. More than 1000 faculty have participated, representing more than 25% of the new hires at all U. S. institutions that award a baccalaureate in physics or astronomy, from 4-year colleges through research universities. The workshops seek to improve physics teaching by introducing new faculty to instructional strategies and innovations that have been shown to be effective in a variety of contexts. Such a national mentoring workshop can effectively address a commonality of physics and astronomy teaching challenges that transcend institutional characters and types. Based on surveys of the participants (and their department chairs), we have found that a large fraction of the participants have become adopters of innovative teaching techniques and that they rate the workshops as the most significant cause of the improvements in their teaching.

  16. Association between Natural Resources for Outdoor Activities and Physical Inactivity: Results from the Contiguous United States

    Directory of Open Access Journals (Sweden)

    Yan Jiang

    2016-08-01

    Full Text Available Protected areas including national/state parks and recreational waters are excellent natural resources that promote physical activity and interaction with Nature, which can relieve stress and reduce disease risk. Despite their importance, however, their contribution to human health has not been properly quantified. This paper seeks to evaluate quantitatively how national/state parks and recreational waters are associated with human health and well-being, taking into account of the spatial dependence of environmental variables for the contiguous U.S., at the county level. First, we describe available natural resources for outdoor activities (ANROA, using national databases that include features from the Protected Areas Database, NAVSTREETS, and ATTAINSGEO 305(b Waters. We then use spatial regression techniques to explore the association of ANROA and socioeconomic status factors on physical inactivity rates. Finally, we use variance analysis to analyze ANROA’s influence on income-related health inequality. We found a significantly negative association between ANROA and the rate of physical inactivity: ANROA and the spatial effect explained 69%, nationwide, of the variation in physical inactivity. Physical inactivity rate showed a strong spatial dependence—influenced not only by its own in-county ANROA, but also by that of its neighbors ANROA. Furthermore, community groups at the same income level and with the highest ANROA, always had the lowest physical inactivity rate. This finding may help to guide future land use planning and community development that will benefit human health and well-being.

  17. Association between Natural Resources for Outdoor Activities and Physical Inactivity: Results from the Contiguous United States.

    Science.gov (United States)

    Jiang, Yan; Yuan, Yongping; Neale, Anne; Jackson, Laura; Mehaffey, Megan

    2016-08-17

    Protected areas including national/state parks and recreational waters are excellent natural resources that promote physical activity and interaction with Nature, which can relieve stress and reduce disease risk. Despite their importance, however, their contribution to human health has not been properly quantified. This paper seeks to evaluate quantitatively how national/state parks and recreational waters are associated with human health and well-being, taking into account of the spatial dependence of environmental variables for the contiguous U.S., at the county level. First, we describe available natural resources for outdoor activities (ANROA), using national databases that include features from the Protected Areas Database, NAVSTREETS, and ATTAINSGEO 305(b) Waters. We then use spatial regression techniques to explore the association of ANROA and socioeconomic status factors on physical inactivity rates. Finally, we use variance analysis to analyze ANROA's influence on income-related health inequality. We found a significantly negative association between ANROA and the rate of physical inactivity: ANROA and the spatial effect explained 69%, nationwide, of the variation in physical inactivity. Physical inactivity rate showed a strong spatial dependence-influenced not only by its own in-county ANROA, but also by that of its neighbors ANROA. Furthermore, community groups at the same income level and with the highest ANROA, always had the lowest physical inactivity rate. This finding may help to guide future land use planning and community development that will benefit human health and well-being.

  18. Intelligent Derivation Algorithm for Physical Units and Its Application%物理量单位的智能导出算法及其应用

    Institute of Scientific and Technical Information of China (English)

    陈鲤江; 郑云巧; 孙晓梦

    2013-01-01

    Derivation of units of physical quantities are important and indispensable part of the physics homework.An intelligent derivation algorithm for physical quantities units is proposed,that computer automatically derived units of unknown physical quantities from the arithmetic expression of known physical quantities.Convert division expressions to multiplication expressions by unit index symbol transform,uniform units of the same dimension through unit conversion,evaluate index algebraic sum for the same unit to get final derived units of unknown physical quantities.Performing unit conversion to the rest units toward the units with the largest number or SI units in the same dimension is auto-matically finished by database call technology.Experimental results on arithmetic expressions with numbers and units show that the operation results of the algorithm are correct with correct rate of 100%.%推导物理量的单位是物理作业中不可缺少的重要环节。提出一种物理量单位的智能导出算法,即计算机根据物理量的运算式自动推导出待求物理量的单位。实验结果表明,物理量单位导出及换算算法的结果正确,对算术运算式中的物理量单位导出及换算的正确率为100%,且物理量数值的运算正确。

  19. Physical rehabilitation of patients in the intensive care unit requiring extracorporeal membrane oxygenation: a small case series.

    Science.gov (United States)

    Rahimi, Rod A; Skrzat, Julie; Reddy, Dereddi Raja S; Zanni, Jennifer M; Fan, Eddy; Stephens, R Scott; Needham, Dale M

    2013-02-01

    Neuromuscular weakness and impaired physical function are common and long-lasting complications experienced by intensive care unit (ICU) survivors. There is growing evidence that implementing rehabilitation therapy shortly after ICU admission improves physical function and reduces health care utilization. Recently, there is increasing interest and utilization of extracorporeal membrane oxygenation (ECMO) to support patients with severe respiratory failure. Patients receiving ECMO are at great risk for significant physical impairments and pose unique challenges for delivering rehabilitation therapy. Consequently, there is a need for innovative examples of safely and feasibly delivering active rehabilitation to these patients. This case report describes 3 patients with respiratory failure requiring ECMO who received physical rehabilitation to illustrate and discuss relevant feasibility and safety issues. In case 1, sedation and femoral cannulation limited rehabilitation therapy while on ECMO. In the 2 subsequent cases, minimizing sedation and utilizing a single bicaval dual lumen ECMO cannula placed in the internal jugular vein allowed patients to be alert and participate in active physical therapy while on ECMO, illustrating feasible rehabilitation techniques for these patients. Although greater experience is needed to more fully evaluate the safety of rehabilitation on ECMO, these initial cases are encouraging. We recommend systematically and prospectively tracking safety events and patient outcomes during rehabilitation on ECMO to provide greater evidence in this area.

  20. Physical Activity and Reported Barriers to Activity Among Type 2 Diabetic Patients in the United Arab Emirates

    Science.gov (United States)

    Al-Kaabi, Juma; Al-Maskari, Fatma; Afandi, Bachar; Parkar, Hasratali; Nagelkerke, Nicolaas

    2009-01-01

    OBJECTIVES: This study was designed to assess the physical activity practice among type 2 diabetic patients in the United Arab Emirates (UAE). METHODS: This is a cross-sectional study of type 2 diabetic patients who participated in the outpatient clinics in Al-Ain District, during 2006. The patients completed an interviewer-administered questionnaire, and measurements of blood pressure, body mass index, body fat, abdominal circumference, glycemic control (HbA1c), and fasting lipid profile. RESULTS: Of the 390 patients recruited, only 25% reported an increase in their physical activity levels following the diagnosis of diabetes, and only 3% reported physical activity levels that meet the recommended guidelines. More than half of the study subjects had uncontrolled hypertension (53%) and unacceptable lipid profiles; 71% had a high low-density lipoprotein (LDL), 73% had low high-density lipoprotein (HDL), and 59% had hypertriglyceridemia. Forty-four percent were obese and a further 34% were overweight. Abdominal obesity was also common (59%). Only 32% had an acceptable glycemic control. CONCLUSIONS: The physical activity practice of type 2 diabetic patients in the UAE is largely inadequate to meet the recommended level necessary to prevent or ameliorate diabetic complications. Interventions aiming at overcoming the barriers to physical activity are urgently needed. PMID:20043039

  1. PHYSICS

    CERN Multimedia

    P. Sphicas

    There have been three physics meetings since the last CMS week: “physics days” on March 27-29, the Physics/ Trigger week on April 23-27 and the most recent physics days on May 22-24. The main purpose of the March physics days was to finalize the list of “2007 analyses”, i.e. the few topics that the physics groups will concentrate on for the rest of this calendar year. The idea is to carry out a full physics exercise, with CMSSW, for select physics channels which test key features of the physics objects, or represent potential “day 1” physics topics that need to be addressed in advance. The list of these analyses was indeed completed and presented in the plenary meetings. As always, a significant amount of time was also spent in reviewing the status of the physics objects (reconstruction) as well as their usage in the High-Level Trigger (HLT). The major event of the past three months was the first “Physics/Trigger week” in Apri...

  2. Frequency chain to measure the 2S-8S/8D transitions in atomic hydrogen: measurement of the Rydberg constant in frequency unit; Chaine de frequence optique pour mesurer les transitions 2S-8S/8D dans l'atome d'hydrogene: mesure de la constante de Rydberg en unite de frequence

    Energy Technology Data Exchange (ETDEWEB)

    Nez, F

    1993-10-15

    The aim of this thesis is to make a pure measurement of the frequency of the 2S-8S/8D two-photon transition in atomic hydrogen. In that purpose we have built a frequency chain in which hydrogen frequencies are compared with the difference of two optical standards, the methane stabilized He-Ne laser (3.39 {mu}m) and the iodine stabilized He-Ne laser (633 nm). The radiation from a home made Ti-sapphire laser (TS2) at 778 nm is mixed, in a LiIO{sub 3} crystal, with the one of a auxiliary He-Ne laser at 3.39 {mu}m to produce a synthesized radiation at 633 nm. The frequency of the Ti-sapphire (TS1) laser used for the two photon excitation is 89 GHz away from the one of TS2. To compare these two lasers, we have used a Schottky diode. The two lasers and a microwave radiation at 89 GHz, produced by a Gunn diode, are focused on the Schottky diode. The Gunn diode is phase locked on an ultra-stable quartz oscillator. In this way, we have linked an optical frequency of atomic hydrogen to the cesium clock without interferometry. From our measurements, we have deduced a new value of the Rydberg constant: R{sub {infinity}} equals 109737.3156834 (24) cm{sup -1} with an uncertainty of 2.2 10{sup -11}. Our uncertainty is near the one of the Q.E.D calculations giving the theoretical values of the energy levels. This value, which is currently the most precise available, is in good agreement with the recent result obtained from the 1S-2S and 2S-4D transitions. (author)

  3. Tables of physical and chemical constants

    CERN Document Server

    Kaye, George William C

    "It is now over ninety years since the first edition of Kaye and Laby's tables was published. Over that period a further fifteen editions were published at, roughly, five- to ten-year intervals. Following the launch of the sixteenth edition, the Editorial Board considered how the next edition should be prepared and what form it should take; should we propose a pocket version or a CD-ROM-based edition? We also explored publishing Kaye and Laby as a web-site. Above all, we felt, and our contributors agreed, that the tables were still extremely useful and that the tradition started by Kaye and Laby should be maintained. Our hope was that a paper version and a web-site could be launched together. However our publisher decided, for policy reasons, that he was not able to support the next edition of the book. The contract with the Editorial Board stipulated that, when the stocks of the sixteenth edition were exhausted, ownership of the rights to Kaye and Laby should pass to the Board. No alternative publisher wa...

  4. Prevalence of Physical Activity in the United States: Behavioral Risk Factor Surveillance System, 2001

    Directory of Open Access Journals (Sweden)

    Barbara E. Ainsworth, PhD, MPH

    2005-03-01

    Full Text Available Introduction The health benefits of regular cardiovascular exercise are well-known. Such exercise, however, has traditionally been defined as vigorous physical activity, such as jogging, swimming, or aerobic dance. Exercise of moderate intensity also promotes health, and many U.S. adults may be experiencing the health benefits of exercise through lifestyle activities of moderate intensity, such as yard work, housework, or walking for transportation. Until recently, public health surveillance systems have not included assessments of this type of physical activity, focusing on exercise of vigorous intensity. We used an enhanced surveillance tool to describe the prevalence and amount of both moderate-intensity and vigorous-intensity physical activity among U.S. adults. Methods We analyzed data from the 2001 Behavioral Risk Factor Surveillance System, a state-based, random-digit–dialed telephone survey administered to U.S. adults aged 18 years and older (n = 82,834 men and 120,286 women. Physical activity behavior was assessed using questions designed to quantify the frequency of participation in moderate- or vigorous-intensity physical activities performed during leisure time or for household chores and transportation. Results Overall, 45% of adults (48% of men and 43% of women were active at recommended levels during nonworking hours (at least 30 minutes five or more days per week in moderate-intensity activities, equivalent to brisk walking, or at least 20 minutes three or more days per week in vigorous activities, equivalent to running, heavy yard work, or aerobic dance. Less than 16% of adults (15% of men and 17% of women reported no moderate or vigorous activity in a usual week. Conclusion Integrating surveillance of lifestyle activities into national systems is possible, and doing so may provide a more accurate representation of the prevalence of recommended levels of physical activity. These results, however, suggest that the majority of U

  5. The association of ambient air pollution and physical inactivity in the United States.

    Directory of Open Access Journals (Sweden)

    Jennifer D Roberts

    Full Text Available BACKGROUND: Physical inactivity, ambient air pollution and obesity are modifiable risk factors for non-communicable diseases, with the first accounting for 10% of premature deaths worldwide. Although community level interventions may target each simultaneously, research on the relationship between these risk factors is lacking. OBJECTIVES: After comparing spatial interpolation methods to determine the best predictor for particulate matter (PM2.5; PM10 and ozone (O3 exposures throughout the U.S., we evaluated the cross-sectional association of ambient air pollution with leisure-time physical inactivity among adults. METHODS: In this cross-sectional study, we assessed leisure-time physical inactivity using individual self-reported survey data from the Centers for Disease Control and Prevention's 2011 Behavioral Risk Factor Surveillance System. These data were combined with county-level U.S. Environmental Protection Agency air pollution exposure estimates using two interpolation methods (Inverse Distance Weighting and Empirical Bayesian Kriging. Finally, we evaluated whether those exposed to higher levels of air pollution were less active by performing logistic regression, adjusting for demographic and behavioral risk factors, and after stratifying by body weight category. RESULTS: With Empirical Bayesian Kriging air pollution values, we estimated a statistically significant 16-35% relative increase in the odds of leisure-time physical inactivity per exposure class increase of PM2.5 in the fully adjusted model across the normal weight respondents (p-value<0.0001. Evidence suggested a relationship between the increasing dose of PM2.5 exposure and the increasing odds of physical inactivity. CONCLUSIONS: In a nationally representative, cross-sectional sample, increased community level air pollution is associated with reduced leisure-time physical activity particularly among the normal weight. Although our design precludes a causal inference, these

  6. The 1% concordance Hubble constant

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C. L.; Larson, D.; Weiland, J. L. [Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Hinshaw, G., E-mail: cbennett@jhu.edu [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

    2014-10-20

    The determination of the Hubble constant has been a central goal in observational astrophysics for nearly a hundred years. Extraordinary progress has occurred in recent years on two fronts: the cosmic distance ladder measurements at low redshift and cosmic microwave background (CMB) measurements at high redshift. The CMB is used to predict the current expansion rate through a best-fit cosmological model. Complementary progress has been made with baryon acoustic oscillation (BAO) measurements at relatively low redshifts. While BAO data do not independently determine a Hubble constant, they are important for constraints on possible solutions and checks on cosmic consistency. A precise determination of the Hubble constant is of great value, but it is more important to compare the high and low redshift measurements to test our cosmological model. Significant tension would suggest either uncertainties not accounted for in the experimental estimates or the discovery of new physics beyond the standard model of cosmology. In this paper we examine in detail the tension between the CMB, BAO, and cosmic distance ladder data sets. We find that these measurements are consistent within reasonable statistical expectations and we combine them to determine a best-fit Hubble constant of 69.6 ± 0.7 km s{sup –1} Mpc{sup –1}. This value is based upon WMAP9+SPT+ACT+6dFGS+BOSS/DR11+H {sub 0}/Riess; we explore alternate data combinations in the text. The combined data constrain the Hubble constant to 1%, with no compelling evidence for new physics.

  7. Participant report for National Physical Laboratory (United Kingdom) Hole Plate No. 137

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, Hans Nørgaard; Morace, Renate Erica

    International pour l’Etude Scientifique des Techniques de Production Mécanique (CIRP). In the project, 15 research laboratories have been involved from 9 countries: Belgium, Denmark, Germany, Italy, Poland, Spain, Switzerland, United Kingdom, USA. A total of 24 CMMs were used to measure an optomechanical hole...

  8. [Nursing interventions on the physical environment of Neonatal Intensive Care Units].

    Science.gov (United States)

    Miquel Capó Rn, I

    2016-01-01

    The objectives of this study are to analyse nursing interventions regarding noise and lighting that influence neurodevelopment of the preterm infant in the Neonatal Intensive Care Unit. A review of the literature was performed using the databases: Cuiden Plus, PubMed, IBECS and Cochrane Library Plus. The inclusion and exclusion criteria were established in accordance with the objectives and limits used in each database. Of the 35 articles used, most were descriptive quantitative studies based on the measurement of sound pressure levels and lighting in the Neonatal Intensive Care Units. The countries included in this study are Brazil and the United States, and the variables analysed were the recording the times of light and noise. Based on the high levels of light and noise recorded in the Neonatal Intensive Care Units, nursing interventions that should be carried out to reduce them are described. The evidence indicates that after the implementation of these interventions, the high levels of both environmental stimuli are reduced significantly. Despite the extensive literature published on this problem, the levels of light and noise continue to exceed the recommended limits. Therefore, nurses need to increase and enhance their efforts in this environment, in order to positively influence neurodevelopment of premature newborn. Copyright © 2016 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  9. Generalized Pickands constants

    NARCIS (Netherlands)

    Debicki, K.G.

    2001-01-01

    Pickands constants play an important role in the exact asymptotic of extreme values for Gaussian stochastic processes. By the {it generalized Pickands constant ${cal H_{eta$ we mean the limit begin{eqnarray* {cal H_{eta= lim_{T to inftyfrac{ {cal H_{eta(T){T, end{eqnarray* where ${cal H_{eta(T)= Exp

  10. Trends in No Leisure-Time Physical Activity--United States, 1988-2010

    Science.gov (United States)

    Moore, Latetia V.; Harris, Carmen D.; Carlson, Susan A.; Kruger, Judy; Fulton, Janet E.

    2012-01-01

    Purpose: The aim of this study was to examine trends in the prevalence of no leisure-time physical activity (LTPA) from 1988 to 2010. Method: Using the Behavioral Risk Factor Surveillance System data, 35 states and the District of Columbia reported information on no LTPA from 1988 to 1994; all states reported no LTPA from 1996 to 2010. Results: No…

  11. Purposeful Movement: The Integration of Physical Activity into a Mathematics Unit

    Science.gov (United States)

    Snyder, Kailey; Dinkel, Danae; Schaffer, Connie; Hiveley, Seth; Colpitts, Amanda

    2017-01-01

    Classroom physical activity (PA) has been linked to a multitude of health and academic benefits. However, due to barriers such as lack of time and resources many teachers are not implementing classroom PA to the degree they would like to. One innovative solution is to integrate classroom PA into academic concepts. Based on self-determination…

  12. School bullying among adolescents in the United States: physical, verbal, relational, and cyber.

    Science.gov (United States)

    Wang, Jing; Iannotti, Ronald J; Nansel, Tonja R

    2009-10-01

    Four forms of school bullying behaviors among US adolescents and their association with sociodemographic characteristics, parental support, and friends were examined. Data were obtained from the Health Behavior in School-Aged Children (HBSC) 2005 Survey, a nationally representative sample of grades 6-10 (N = 7,182). The revised Olweus Bully/Victim Questionnaire was used to measure physical, verbal, and relational forms of bullying. Two items were added using the same format to measure cyber bullying. For each form, four categories were created: bully, victim, bully-victim, and not involved. Multinomial logistic regressions were applied, with sociodemographic variables, parental support, and number of friends as predictors. Prevalence rates of having bullied others or having been bullied at school for at least once in the last 2 months were 20.8% physically, 53.6% verbally, 51.4% socially, or 13.6% electronically. Boys were more involved in physical or verbal bullying, whereas girls were more involved in relational bullying. Boys were more likely to be cyber bullies, whereas girls were more likely to be cyber victims. African-American adolescents were involved in more bullying (physical, verbal, or cyber) but less victimization (verbal or relational). Higher parental support was associated with less involvement across all forms and classifications of bullying. Having more friends was associated with more bullying and less victimization for physical, verbal, and relational forms but was not associated with cyber bullying. Parental support may protect adolescents from all four forms of bullying. Friends associate differentially with traditional and cyber bullying. Results indicate that cyber bullying is a distinct nature from that of traditional bullying.

  13. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  14. PHYSICS

    CERN Multimedia

    J. Incandela

    There have been numerous developments in the physics area since the September CMS week. The biggest single event was the Physics/Trigger week in the end of Octo¬ber, whereas in terms of ongoing activities the “2007 analyses” went into high gear. This was in parallel with participation in CSA07 by the physics groups. On the or¬ganizational side, the new conveners of the physics groups have been selected, and a new database for man¬aging physics analyses has been deployed. Physics/Trigger week The second Physics-Trigger week of 2007 took place during the week of October 22-26. The first half of the week was dedicated to working group meetings. The ple¬nary Joint Physics-Trigger meeting took place on Wednesday afternoon and focused on the activities of the new Trigger Studies Group (TSG) and trigger monitoring. Both the Physics and Trigger organizations are now focused on readiness for early data-taking. Thus, early trigger tables and preparations for calibr...

  15. PHYSICS

    CERN Multimedia

    P. Sphicas

    The CPT project came to an end in December 2006 and its original scope is now shared among three new areas, namely Computing, Offline and Physics. In the physics area the basic change with respect to the previous system (where the PRS groups were charged with detector and physics object reconstruction and physics analysis) was the split of the detector PRS groups (the old ECAL-egamma, HCAL-jetMET, Tracker-btau and Muons) into two groups each: a Detector Performance Group (DPG) and a Physics Object Group. The DPGs are now led by the Commissioning and Run Coordinator deputy (Darin Acosta) and will appear in the correspond¬ing column in CMS bulletins. On the physics side, the physics object groups are charged with the reconstruction of physics objects, the tuning of the simulation (in collaboration with the DPGs) to reproduce the data, the provision of code for the High-Level Trigger, the optimization of the algorithms involved for the different physics analyses (in collaboration with the analysis gr...

  16. The relationship between physical intimate partner violence and sexually transmitted infection among women in India and the United States.

    Science.gov (United States)

    Spiwak, Rae; Afifi, Tracie O; Halli, Shiva; Garcia-Moreno, Claudia; Sareen, Jitender

    2013-09-01

    To investigate the association between physical intimate partner violence (IPV) and sexually transmitted infection (STI) in two national samples. Data came from the National Epidemiologic Survey on Alcohol and Related Conditions Wave 2 (n=34,653) and the National Family Health Survey-3 (n=124 385). Ever-married women between the ages of 20 and 49 were asked if they had experienced physical violence by their partner in the past year. Outcomes were presence of doctor confirmed HIV and self-reported STI. Age at first intercourse was examined as a mediator of the relationship between IPV and STI. Logistic regression examined associations between IPV, age at first intercourse and STI. Compared to individuals with no physical IPV, risk for STI was higher for individuals who experienced past year IPV living in the United States and India, however once controlling for age at first intercourse, age, education, household wealth/income and past year sexual violence, the relationship between IPV, and STI was significant in the American sample [(AOR)=1.65, 95% (CI)=1.21-2.26], however not for individuals living in India [(AOR)=1.75, 95% (CI)=0.84-3.65]. Individuals with exposure to physical IPV are at increased odds for STI. Age at first intercourse although a marker of risk, may not be an accurate marker of risky sexual behavior in both samples.

  17. Plasticity, political economy, and physical growth status of Guatemala Maya children living in the United States.

    Science.gov (United States)

    Bogin, B; Loucky, J

    1997-01-01

    Migration of Maya refugees to the United States since the late 1970s affords the opportunity to study the consequences of life in a new environment on the growth of Maya children. The children of this study live in Indiantown, Florida, and Los Angeles, California. Maya children between 4 and 14 years old (n = 240) were measured for height, weight, fatness, and muscularity. Overall, compared with reference data for the United States, the Maya children are, on average, healthy and well nourished. They are taller and heavier and carry more fat and muscle mass than Maya children living in a village in Guatemala. However, they are shorter, on average, than children of black, Mexican-American, and white ethnicity living in Indiantown. Children of Maya immigrants born in the United States tend to be taller than immigrant children born in Guatemala or Mexico. Families that invest economic and social resources in their children have taller children. More economic successful families have taller children. Migration theory and political economy theory from the social sciences are combined with plasticity theory and life history theory (parental investment) from biology to interpret these data.

  18. Nicotine Content and Physical Properties of Large Cigars and Cigarillos in the United States.

    Science.gov (United States)

    Koszowski, Bartosz; Thanner, Meridith Hill; Pickworth, Wallace B; Taylor, Kenneth M; Hull, Lynn C; Schroeder, Megan J

    2017-03-04

    Cigars are combusted tobacco products consisting of filler, binder, and wrapper, which are derived from tobacco. Despite the abundance of literature on the composition of traditional combusted cigarettes, research is limited on the physical and chemical properties of cigars. Therefore, research on cigar properties may be useful to better understand their health impact. In this study, twenty large cigar and cigarillo products were characterized for physical properties (ie, weight, length, and diameter), filler nicotine content, and tobacco pH. Tobacco pH was used to calculate free nicotine content, free nicotine concentration, and percent free nicotine for all cigars using the Henderson-Hasselbach equation. An additional analysis was performed on a second batch of two large cigar and two cigarillo brands to determine within-brand consistency. All analyses were performed in triplicate. The initial analysis of the twenty cigars showed that cigars exhibited wide variation in product size and nicotine content, although tobacco pH was similar across cigars. Furthermore, in the two large cigar and cigarillo brands analyzed a second time, there was considerable within-brand variance in nicotine content and concentration between the first and second analyses. While only a small sample of commercially-available cigars was analyzed, our data suggest there is wide variability in nicotine content and some physical properties in the domestic cigar market. The data may help to inform potential future regulatory decisions related to these products. This study reveals some of the challenges to experimental cigar research and illustrates the need to characterize cigar products (eg, nicotine and tobacco content) before use in clinical studies. Additional studies and characterization of the physical and chemical properties of cigars may be useful to further understand these products' toxicity, abuse potential, and public health impact.

  19. Physical Dating Violence in Spain and the United Kingdom and the Importance of Relationship Quality.

    Science.gov (United States)

    Viejo, C; Monks, C P; Sánchez, V; Ortega-Ruiz, R

    2016-05-01

    Mixed-gender friendships, romantic relationships, and sexual behaviors increase during adolescence as a normal part of development. However, some studies have revealed potential risks to these types of social relationships. Different authors have indicated that dating violence among adolescents is an issue for concern. To date, there has been little research on this topic cross-nationally. This study examined and compared the prevalence and characteristics of physical dating violence among young people aged between 15 and 18 years in England and Spain (N = 200 in Spain, N = 199 in England), and how being involved (or not) in this violence relates to romantic relationship quality. Results indicated that approximately 23% of young people reported victimization and 30% reported perpetrating physical dating violence. In both countries, most of those involved in physical dating violence reported involvement in reciprocal violence (displaying both aggression and victimization). Those young people involved in dating violence reported higher levels on scales assessing negative aspects of relationship quality compared with those not involved, but there were no significant differences in positive aspects of relationship quality. Furthermore, different patterns appeared relating to the severity of violence and country. The findings are discussed in terms of their implications for theory and practice.

  20. On the Independent Determination of the Ultimate Density of Physical Vacuum

    Directory of Open Access Journals (Sweden)

    Belyakov A. V.

    2011-04-01

    Full Text Available In this paper, we attempt to present physical vacuum as a topologically non-unitary coherent surface. This representation follows with J. A. Wheeler's idea about fluctuating topology, and provides a possibility to express some parameters of the unit space element through the fundamental constants. As a result, we determined the ultimate density of physical vacuum without use of Hubble's constant.

  1. The International System of Units (SI) in Oceanography. Report of IAPSO Working Group on Symbols, Units and Nomenclature in Physical Oceanography (SUN). Unesco Technical Papers in Marine Science 45. IAPSO Publication Scientifique No. 32.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Marine Sciences.

    This report introduces oceanographers to the International System of Units (SI) in physical oceanography. The SI constitutes a universal language, designed to be understood by all scientists. It facilitates their mutual comprehension and exchange of views and results of their work. The first part of the report is devoted to physical quantities,…

  2. PHYSICS

    CERN Document Server

    Submitted by

    Physics Week: plenary meeting on physics groups plans for startup (14–15 May 2008) The Physics Objects (POG) and Physics Analysis (PAG) Groups presented their latest developments at the plenary meeting during the Physics Week. In the presentations particular attention was given to startup plans and readiness for data-taking. Many results based on the recent cosmic run were shown. A special Workshop on SUSY, described in a separate section, took place the day before the plenary. At the meeting, we had also two special DPG presentations on “Tracker and Muon alignment with CRAFT” (Ernesto Migliore) and “Calorimeter studies with CRAFT” (Chiara Rovelli). We had also a report from Offline (Andrea Rizzi) and Computing (Markus Klute) on the San Diego Workshop, described elsewhere in this bulletin. Tracking group (Boris Mangano). The level of sophistication of the tracking software increased significantly over the last few months: V0 (K0 and Λ) reconstr...

  3. A preliminary study of physical units teaching in the junior high school%初中物理“单位”教学初探

    Institute of Scientific and Technical Information of China (English)

    黄贵茹

    2016-01-01

    “单位”教学在整个物理教学中必须占有举足轻重的地位。因为如果只是数字而没有相应的物理量单位,则该数据就只能是一串阿拉伯数字,没有任何的物理意义。同时单位教学还可以在物理教学中起到承上启下、画龙点睛的作用。%The teaching of units should play an important role in physics teaching. If numbers go without corresponding physical units,they have no physical meanings. At the same time,the teaching of units is a connection link in physical teaching. It also adds add the finishing touch to the physical teaching.

  4. Time-Varying Fundamental Constants

    Science.gov (United States)

    Olive, Keith

    2003-04-01

    Recent data from quasar absorption systems can be interpreted as arising from a time variation in the fine-structure constant. However, there are numerous cosmological, astro-physical, and terrestrial bounds on any such variation. These includes bounds from Big Bang Nucleosynthesis (from the ^4He abundance), the Oklo reactor (from the resonant neutron capture cross-section of Sm), and from meteoretic lifetimes of heavy radioactive isotopes. The bounds on the variation of the fine-structure constant are significantly strengthened in models where all gauge and Yukawa couplings vary in a dependent manner, as would be expected in unified theories. Models which are consistent with all data are severly challenged when Equivalence Principle constraints are imposed.

  5. A physical function test for use in the intensive care unit: validity, responsiveness, and predictive utility of the physical function ICU test (scored).

    Science.gov (United States)

    Denehy, Linda; de Morton, Natalie A; Skinner, Elizabeth H; Edbrooke, Lara; Haines, Kimberley; Warrillow, Stephen; Berney, Sue

    2013-12-01

    Several tests have recently been developed to measure changes in patient strength and functional outcomes in the intensive care unit (ICU). The original Physical Function ICU Test (PFIT) demonstrates reliability and sensitivity. The aims of this study were to further develop the original PFIT, to derive an interval score (the PFIT-s), and to test the clinimetric properties of the PFIT-s. A nested cohort study was conducted. One hundred forty-four and 116 participants performed the PFIT at ICU admission and discharge, respectively. Original test components were modified using principal component analysis. Rasch analysis examined the unidimensionality of the PFIT, and an interval score was derived. Correlations tested validity, and multiple regression analyses investigated predictive ability. Responsiveness was assessed using the effect size index (ESI), and the minimal clinically important difference (MCID) was calculated. The shoulder lift component was removed. Unidimensionality of combined admission and discharge PFIT-s scores was confirmed. The PFIT-s displayed moderate convergent validity with the Timed "Up & Go" Test (r=-.60), the Six-Minute Walk Test (r=.41), and the Medical Research Council (MRC) sum score (rho=.49). The ESI of the PFIT-s was 0.82, and the MCID was 1.5 points (interval scale range=0-10). A higher admission PFIT-s score was predictive of: an MRC score of ≥48, increased likelihood of discharge home, reduced likelihood of discharge to inpatient rehabilitation, and reduced acute care hospital length of stay. Scoring of sit-to-stand assistance required is subjective, and cadence cutpoints used may not be generalizable. The PFIT-s is a safe and inexpensive test of physical function with high clinical utility. It is valid, responsive to change, and predictive of key outcomes. It is recommended that the PFIT-s be adopted to test physical function in the ICU.

  6. Unit of Analysis: Impact of Silverman and Solmon's Article on Field-Based Intervention Research in Physical Education in the U.S.A.

    Science.gov (United States)

    Li, Weidong; Chen, Yung-Ju; Xiang, Ping; Xie, Xiuge; Li, Yilin

    2017-01-01

    Purpose: The purposes of this study were to: (a) examine the impact of the Silverman and Solmon article (1998) on how researchers handle the unit of analysis issue in their field-based intervention research in physical education in the United States and summarize statistical approaches that have been used to analyze the data, and (b) provide…

  7. Physical attractiveness and reproductive success in humans: Evidence from the late 20 century United States.

    Science.gov (United States)

    Jokela, Markus

    2009-09-01

    Physical attractiveness has been associated with mating behavior, but its role in reproductive success of contemporary humans has received surprisingly little attention. In the Wisconsin Longitudinal Study (1244 women, 997 men born between 1937 and 1940) we examined whether attractiveness assessed from photographs taken at age ~18 predicted the number of biological children at age 53-56. In women, attractiveness predicted higher reproductive success in a nonlinear fashion, so that attractive (second highest quartile) women had 16% and very attractive (highest quartile) women 6% more children than their less attractive counterparts. In men, there was a threshold effect so that men in the lowest attractiveness quartile had 13% fewer children than others who did not differ from each other in the average number of children. These associations were partly but not completely accounted for by attractive participants' increased marriage probability. A linear regression analysis indicated relatively weak directional selection gradient for attractiveness (β=0.06 in women, β=0.07 in men). These findings indicate that physical attractiveness may be associated with reproductive success in humans living in industrialized settings.

  8. Development of monitoring unit for shaft generator set syetem with performances of variable speed and constant frequency%变速恒频轴带发电机组监控系统的研制

    Institute of Scientific and Technical Information of China (English)

    洪鹏鹏; 南余荣; 石健将

    2013-01-01

    Aiming at solving the problems of low efficiency, high pollution and complex monitoring in the traditional hybrid propulsion system on ship, the shaft generator set system with performances of variable speed and constant frequency was applied in the new hybrid propulsion system. A four-quadrant inverter was added between the shaft generator and the micro grid on ship, whose performances were researched in different working modes. A monitoring unit was developed to communicate with the controllers through CAN bus and the ship information management platform through Profibus. A TMS320F28335 was applied as the controller of the monitoring unit, while the LCD module was used as the displaying interface. The display of system state, working parameters, commands and data transferred were all completed by the monitoring unit. The experimental results indicate that the new hybrid propulsion system can work steadily in different working modes, while reducing the pollution and improving the efficiency of the system. At the same time, the monitoring unit is human friendly with flexiable operating performance and the communication is stable and reliable, which is fit for industrial application.%针对传统的船舶混合推进系统中存在效率低、污染高、工作模式单一、监控麻烦等问题,将变速恒频轴带发电机组系统应用于新型混合推进系统,在传统的轴带发电机和船舶微电网间添加了一个四象限变频器,对新型混合推进系统在不同工作模式下的系统性能进行了研究;同时设计了一个监控系统,采用TMS320F28335作为控制芯片,与底层控制器之间采用CAN总线通信,与上层的船舶综合信息管理平台之间采用Profibus总线通信,显示部分采用液晶模块,完成了系统实时控制、状态参数在线监测及命令数据传输等功能.实验结果表明,新型混合推进系统能够在不同模式工作下稳定工作,降低了燃油成本和污染,提高了系统

  9. Thermo-physical performance prediction of the KSC Ground Operation Demonstration Unit for liquid hydrogen

    Science.gov (United States)

    Baik, J. H.; Notardonato, W. U.; Karng, S. W.; Oh, I.

    2015-12-01

    NASA Kennedy Space Center (KSC) researchers have been working on enhanced and modernized cryogenic liquid propellant handling techniques to reduce life cycle costs of propellant management system for the unique KSC application. The KSC Ground Operation Demonstration Unit (GODU) for liquid hydrogen (LH2) plans to demonstrate integrated refrigeration, zero-loss flexible term storage of LH2, and densified hydrogen handling techniques. The Florida Solar Energy Center (FSEC) has partnered with the KSC researchers to develop thermal performance prediction model of the GODU for LH2. The model includes integrated refrigeration cooling performance, thermal losses in the tank and distribution lines, transient system characteristics during chilling and loading, and long term steady-state propellant storage. This paper will discuss recent experimental data of the GODU for LH2 system and modeling results.

  10. Participant report for National Physical Laboratory (United Kingdom) Hole Plate No. 137

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Hansen, Hans Nørgaard; Morace, Renate Erica

    International pour l’Etude Scientifique des Techniques de Production Mécanique (CIRP). In the project, 15 research laboratories have been involved from 9 countries: Belgium, Denmark, Germany, Italy, Poland, Spain, Switzerland, United Kingdom, USA. A total of 24 CMMs were used to measure an optomechanical hole...... procedure of own choice. In this report, the results of a single participant are analysed and compared with the reference values provided by DTU. The purpose of the report is to collect information from the participant and present the result of the data analysis. Furthermore, comments from the participant...... are expected by the organizer and the information will be used in the preparation of the final report....

  11. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.   Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish (we hoped) the readiness of CMS to do physics with the early collisions at the LHC. The agenda of the...

  12. PHYSICS

    CERN Multimedia

    D. Futyan

    A lot has transpired on the “Physics” front since the last CMS Bulletin. The summer was filled with preparations of new Monte Carlo samples based on CMSSW_3, the finalization of all the 10 TeV physics analyses [in total 50 analyses were approved] and the preparations for the Physics Week in Bologna. A couple weeks later, the “October Exercise” commenced and ran through an intense two-week period. The Physics Days in October were packed with a number of topics that are relevant to data taking, in a number of “mini-workshops”: the luminosity measurement, the determination of the beam spot and the measurement of the missing transverse energy (MET) were the three main topics.  Physics Week in Bologna The second physics week in 2009 took place in Bologna, Italy, on the week of Sep 7-11. The aim of the week was to review and establish how ready we are to do physics with the early collisions at the LHC. The agenda of the week was thus pac...

  13. The management in the sphere of physical culture and sport at the level of administrative and territorial units: traditions and innovations

    Directory of Open Access Journals (Sweden)

    Viktor Savchenko

    2016-02-01

    Full Text Available Purpose: to analyze the activity of subjects of management in the sphere of physical culture and sport at the level of territorial administrative units. Material & Methods: the legal analysis of a feature of management in the sphere of physical culture and sport of administrative and territorial units of the various level. Results: the main activities of administrative structures of the governmental authorities and the local governments are allocated. Conclusions: it is revealed that the sphere of physical culture and sport needs the improvement in the conditions of decentralization, offers on its reforming are considered.

  14. Variation of Fundamental Constants

    Science.gov (United States)

    Flambaum, V. V.

    2006-11-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. The spatial variation can explain a fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are consistent with our existence. We present a review of recent works devoted to the variation of the fine structure constant α, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra. Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance.

  15. OPERATOR-RELATED FORMULATION OF THE EIGENVALUE PROBLEM FOR THE BOUNDARY PROBLEM OF ANALYSIS OF A THREE-DIMENSIONAL STRUCTURE WITH PIECEWISE-CONSTANT PHYSICAL AND GEOMETRICAL PARAMETERS ALONGSIDE THE BASIC DIRECTION WITHIN THE FRAMEWORK OF THE DISCRETE-CON

    Directory of Open Access Journals (Sweden)

    Akimov Pavel Alekseevich

    2012-10-01

    Full Text Available The proposed paper covers the operator-related formulation of the eigenvalue problem of analysis of a three-dimensional structure that has piecewise-constant physical and geometrical parameters alongside the so-called basic direction within the framework of a discrete-continual approach (a discrete-continual finite element method, a discrete-continual variation method. Generally, discrete-continual formulations represent contemporary mathematical models that become available for computer implementation. They make it possible for a researcher to consider the boundary effects whenever particular components of the solution represent rapidly varying functions. Another feature of discrete-continual methods is the absence of any limitations imposed on lengths of structures. The three-dimensional problem of elasticity is used as the design model of a structure. In accordance with the so-called method of extended domain, the domain in question is embordered by an extended one of an arbitrary shape. At the stage of numerical implementation, relative key features of discrete-continual methods include convenient mathematical formulas, effective computational patterns and algorithms, simple data processing, etc. The authors present their formulation of the problem in question for an isotropic medium with allowance for supports restrained by elastic elements while standard boundary conditions are also taken into consideration.

  16. PHYSICS

    CERN Multimedia

    Joe Incandela

    There have been two plenary physics meetings since the December CMS week. The year started with two workshops, one on the measurements of the Standard Model necessary for “discovery physics” as well as one on the Physics Analysis Toolkit (PAT). Meanwhile the tail of the “2007 analyses” is going through the last steps of approval. It is expected that by the end of January all analyses will have converted to using the data from CSA07 – which include the effects of miscalibration and misalignment. January Physics Days The first Physics Days of 2008 took place on January 22-24. The first two days were devoted to comprehensive re¬ports from the Detector Performance Groups (DPG) and Physics Objects Groups (POG) on their planning and readiness for early data-taking followed by approvals of several recent studies. Highlights of POG presentations are included below while the activities of the DPGs are covered elsewhere in this bulletin. January 24th was devo...

  17. PHYSICS

    CERN Multimedia

    J. Incandela

    The all-plenary format of the CMS week in Cyprus gave the opportunity to the conveners of the physics groups to present the plans of each physics analysis group for tackling early physics analyses. The presentations were complete, so all are encouraged to browse through them on the Web. There is a wealth of information on what is going on, by whom and on what basis and priority. The CMS week was followed by two CMS “physics events”, the ICHEP08 days and the physics days in July. These were two weeks dedicated to either the approval of all the results that would be presented at ICHEP08, or to the review of all the other Monte-Carlo based analyses that were carried out in the context of our preparations for analysis with the early LHC data (the so-called “2008 analyses”). All this was planned in the context of the beginning of a ramp down of these Monte Carlo efforts, in anticipation of data.  The ICHEP days are described below (agenda and talks at: http://indic...

  18. Expressing oceanic turbulence parameters by atmospheric turbulence structure constant.

    Science.gov (United States)

    Baykal, Yahya

    2016-02-20

    The parameters composing oceanic turbulence are the wavelength, link length, rate of dissipation of kinetic energy per unit mass of fluid, rate of dissipation of mean-squared temperature, Kolmogorov microscale, and the ratio of temperature to salinity contributions to the refractive index spectrum. The required physical entities such as the average intensity and the scintillation index in the oceanic medium are formulated by using the power spectrum of oceanic turbulence, which is described by oceanic turbulence parameters. On the other hand, there exists a rich archive of formulations and results for the above-mentioned physical entities in atmospheric turbulence, where the parameters describing the turbulence are the wavelength, the link length, and the structure constant. In this paper, by equating the spherical wave scintillation index solutions in the oceanic and atmospheric turbulences, we have expressed the oceanic turbulence parameters by an equivalent structure constant used in turbulent atmosphere. Such equivalent structure constant will help ease reaching solutions of similar entities in an oceanic turbulent medium by employing the corresponding existing solutions, which are valid in an atmospheric turbulent medium.

  19. Physics

    CERN Document Server

    Cullen, Katherine

    2005-01-01

    Defined as the scientific study of matter and energy, physics explains how all matter behaves. Separated into modern and classical physics, the study attracts both experimental and theoretical physicists. From the discovery of the process of nuclear fission to an explanation of the nature of light, from the theory of special relativity to advancements made in particle physics, this volume profiles 10 pioneers who overcame tremendous odds to make significant breakthroughs in this heavily studied branch of science. Each chapter contains relevant information on the scientist''s childhood, research, discoveries, and lasting contributions to the field and concludes with a chronology and a list of print and Internet references specific to that individual.

  20. History and progress on accurate measurements of the Planck constant

    Science.gov (United States)

    Steiner, Richard

    2013-01-01

    The measurement of the Planck constant, h, is entering a new phase. The CODATA 2010 recommended value is 6.626 069 57 × 10-34 J s, but it has been a long road, and the trip is not over yet. Since its discovery as a fundamental physical constant to explain various effects in quantum theory, h has become especially important in defining standards for electrical measurements and soon, for mass determination. Measuring h in the International System of Units (SI) started as experimental attempts merely to prove its existence. Many decades passed while newer experiments measured physical effects that were the influence of h combined with other physical constants: elementary charge, e, and the Avogadro constant, NA. As experimental techniques improved, the precision of the value of h expanded. When the Josephson and quantum Hall theories led to new electronic devices, and a hundred year old experiment, the absolute ampere, was altered into a watt balance, h not only became vital in definitions for the volt and ohm units, but suddenly it could be measured directly and even more accurately. Finally, as measurement uncertainties now approach a few parts in 108 from the watt balance experiments and Avogadro determinations, its importance has been linked to a proposed redefinition of a kilogram unit of mass. The path to higher accuracy in measuring the value of h was not always an example of continuous progress. Since new measurements periodically led to changes in its accepted value and the corresponding SI units, it is helpful to see why there were bumps in the road and where the different branch lines of research joined in the effort. Recalling the bumps along this road will hopefully avoid their repetition in the upcoming SI redefinition debates. This paper begins with a brief history of the methods to measure a combination of fundamental constants, thus indirectly obtaining the Planck constant. The historical path is followed in the section describing how the improved

  1. Algorithm for structure constants

    CERN Document Server

    Paiva, F M

    2011-01-01

    In a $n$-dimensional Lie algebra, random numerical values are assigned by computer to $n(n-1)$ especially selected structure constants. An algorithm is then created, which calculates without ambiguity the remaining constants, obeying the Jacobi conditions. Differently from others, this algorithm is suitable even for poor personal computer. ------------- En $n$-dimensia algebro de Lie, hazardaj numeraj valoroj estas asignitaj per komputilo al $n(n-1)$ speciale elektitaj konstantoj de strukturo. Tiam algoritmo estas kreita, kalkulante senambigue la ceterajn konstantojn, obeante kondicxojn de Jacobi. Malsimile al aliaj algoritmoj, tiu cxi tauxgas ecx por malpotenca komputilo.

  2. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  3. The aliquot constant

    CERN Document Server

    Bosma, Wieb

    2009-01-01

    The average value of log s(n)/n taken over the first N even integers is shown to converge to a constant lambda when N tends to infinity; moreover, the value of this constant is approximated and proven to be less than 0. Here s(n) sums the divisors of n less than n. Thus the geometric mean of s(n)/n, the growth factor of the function s, in the long run tends to be less than 1. This could be interpreted as probabilistic evidence that aliquot sequences tend to remain bounded.

  4. Park availability and physical activity, TV time, and overweight and obesity among women: Findings from Australia and the United States.

    Science.gov (United States)

    Veitch, Jenny; Abbott, Gavin; Kaczynski, Andrew T; Wilhelm Stanis, Sonja A; Besenyi, Gina M; Lamb, Karen E

    2016-03-01

    This study examined relationships between three measures of park availability and self-reported physical activity (PA), television viewing (TV) time, and overweight/obesity among women from Australia and the United States. Having more parks near home was the only measure of park availability associated with an outcome. Australian women (n=1848) with more parks near home had higher odds of meeting PA recommendations and lower odds of being overweight/obese. In the US sample (n=489), women with more parks near home had lower odds of watching >4h TV per day. A greater number of parks near home was associated with lower BMI among both Australian and US women. Evidence across diverse contexts provides support to improve park availability to promote PA and other health behaviors.

  5. Determination of the gravitational constant G

    Institute of Scientific and Technical Information of China (English)

    HU Zhong-kun; LIU Qi; LUO Jun

    2006-01-01

    A precise knowledge of the Newtonian gravitational constant G has an important role in physics and is of considerable meteorological interest.Although G was the first physical constant to be introduced and measured in the history of science,it is still the least precisely determined of all the fundamental constants of nature.The 2002 CODATA recommended value for G,G=(6.6742±0.0010)×10-11m3·kg-1·s-2,has an uncertainty of 150 parts per million (ppm),much larger than that of all other fundamental constants.Reviewed here is the status of our knowledge of the absolute value of G,methods for determining G,and recent high precision experiments for determining G.

  6. PHYSICS

    CERN Multimedia

    Guenther Dissertori

    The time period between the last CMS week and this June was one of intense activity with numerous get-together targeted at addressing specific issues on the road to data-taking. The two series of workshops, namely the “En route to discoveries” series and the “Vertical Integration” meetings continued.   The first meeting of the “En route to discoveries” sequence (end 2007) had covered the measurements of the Standard Model signals as necessary prerequisite to any claim of signals beyond the Standard Model. The second meeting took place during the Feb CMS week and concentrated on the commissioning of the Physics Objects, whereas the third occurred during the April Physics Week – and this time the theme was the strategy for key new physics signatures. Both of these workshops are summarized below. The vertical integration meetings also continued, with two DPG-physics get-togethers on jets and missing ET and on electrons and photons. ...

  7. PHYSICS

    CERN Multimedia

    Chris Hill

    2012-01-01

    The months that have passed since the last CMS Bulletin have been a very busy and exciting time for CMS physics. We have gone from observing the very first 8TeV collisions produced by the LHC to collecting a dataset of the collisions that already exceeds that recorded in all of 2011. All in just a few months! Meanwhile, the analysis of the 2011 dataset and publication of the subsequent results has continued. These results come from all the PAGs in CMS, including searches for the Higgs boson and other new phenomena, that have set the most stringent limits on an ever increasing number of models of physics beyond the Standard Model including dark matter, Supersymmetry, and TeV-scale gravity scenarios, top-quark physics where CMS has overtaken the Tevatron in the precision of some measurements, and bottom-quark physics where CMS made its first discovery of a new particle, the Ξ*0b baryon (candidate event pictured below). Image 2:  A Ξ*0b candidate event At the same time POGs and PAGs...

  8. PHYSICS

    CERN Multimedia

    D. Acosta

    2011-01-01

    Since the last CMS Week, all physics groups have been extremely active on analyses based on the full 2010 dataset, with most aiming for a preliminary measurement in time for the winter conferences. Nearly 50 analyses were approved in a “marathon” of approval meetings during the first two weeks of March, and the total number of approved analyses reached 90. The diversity of topics is very broad, including precision QCD, Top, and electroweak measurements, the first observation of single Top production at the LHC, the first limits on Higgs production at the LHC including the di-tau final state, and comprehensive searches for new physics in a wide range of topologies (so far all with null results unfortunately). Most of the results are based on the full 2010 pp data sample, which corresponds to 36 pb-1 at √s = 7 TeV. This report can only give a few of the highlights of a very rich physics program, which is listed below by physics group...

  9. Compassion is a constant.

    Science.gov (United States)

    Scott, Tricia

    2015-11-01

    Compassion is a powerful word that describes an intense feeling of commiseration and a desire to help those struck by misfortune. Most people know intuitively how and when to offer compassion to relieve another person's suffering. In health care, compassion is a constant; it cannot be rationed because emergency nurses have limited time or resources to manage increasing demands.

  10. Patterns of physical activity in free-living adults in the Southern United States.

    Science.gov (United States)

    Buchowski, M S; Acra, S; Majchrzak, K M; Sun, M; Chen, K Y

    2004-05-01

    To examine the relationship between the amount and patterns of physical activity (PA), body fatness, and age in a heterogeneous adult population in the free living. Cross-sectional study of the amount of PA over a 1-week period. The amount of body movements during PA (PA counts*10(3)) and time spent on various PA intensity categories were calculated from a triaxial accelerometer and compared with subject characteristics, including body fat from hydrodensitometry. Adult healthy men (n=48) and women (n=72) were recruited from the Nashville, Tennessee area and their PA was monitored in their free-living environment. The average weekday PA counts (176.5+/-60.3, P=0.002, r(2)=0.294), PA counts day-to-day variability (47.3+/-32.7, P=0.002, r(2)=0.286), daily maximum PA counts (241.9+/-89.2, P=0.001, r(2)=0.327), minute-to-minute variability on weekdays (0.281+/-0.091, P=0.001, r(2)=0.362), and the difference between maximum and minimum daily PA counts (130.6+/-78.3, P=0.008, r(2)=0.243) were significantly and negatively correlated with body fatness. During awake time, both men and women spent 10-12 h on low intensity (1.0-2.9 metabolic equivalents (METs)) PA, approximately 1 h on moderate (3.0-5.9 MET), and less than 10 min on vigorous (>6.0 MET) PA each day. On weekends, men and women spent more time at rest (1 MET), less time on low-intensity PA, and men spent more time on moderate PA than on weekdays. In adults living in the Southern US the amount of free-living PA was negatively correlated with body fatness. Both men and women spent the majority of active time on low and moderate PA. PA patterns on weekends were different than on weekdays and were related to sex and age, but not to body fatness. National Institutes of Health, US.

  11. Trialogue on the number of fundamental constants

    CERN Document Server

    Duff, Michael J; Veneziano, Gabriele

    2002-01-01

    This paper consists of three separate articles on the number of fundamental dimensionful constants in physics. We started our debate in summer 1992 on the terrace of the famous CERN cafeteria. In the summer of 2001 we returned to the subject to find that our views still diverged and decided to explain our current positions. LBO develops the traditional approach with three constants, GV argues in favor of just two, while MJD advocates zero.

  12. Compact phase space, cosmological constant, discrete time

    CERN Document Server

    Rovelli, Carlo

    2015-01-01

    We study the quantization of geometry in the presence of a cosmological constant, using a discretiza- tion with constant-curvature simplices. Phase space turns out to be compact and the Hilbert space finite dimensional for each link. Not only the intrinsic, but also the extrinsic geometry turns out to be discrete, pointing to discreetness of time, in addition to space. We work in 2+1 dimensions, but these results may be relevant also for the physical 3+1 case.

  13. Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. (USDOE Pittsburgh Energy Technology Center, PA (USA). Coal Preparation Div.); Jacobsen, P.S. (Burns and Roe Services Corp., Pittsburgh, PA (USA))

    1991-02-01

    This report presents the washability and comprehensive characterization results of 184 raw coal channel samples, including anthracite, bituminous and lignite coals, collected from the Central Region of the United States. This is the second of a three volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in-depth characterization of each sample are presented alphabetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Central Region coals. Graphical summations are presented by state, section and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 35 figs., 5 tabs.

  14. Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. (USDOE Pittsburgh Energy Technology Center, PA (USA)); Jacobsen, P.S. (Burns and Roe Services Corp., Pittsburgh, PA (USA))

    1990-01-01

    This report presents the washability and comprehensive characterization results of 543 raw coal samples collected from the Eastern Region of the United States. This is the first volume of a three-volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in- depth characterization of each sample are presented alphbetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties, and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Eastern Region coals. Graphical summations are presented by state, section, and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 14 refs., 27 figs., 3 tabs.

  15. Cosmic Time Variation of the Gravitational Constant

    CERN Document Server

    Tomaschitz, R

    2000-01-01

    A pre-relativistic cosmological approach to electromagnetism and gravitation is explored that leads to a cosmic time variation of the fundamental constants. Space itself is supposed to have physical substance, which manifests by its permeability. The scale factors of the permeability tensor induce a time variation of the fundamental constants. Atomic radii, periods, and energy levels scale in cosmic time, which results in dispersionless redshifts without invoking a space expansion. Hubble constant and deceleration parameter are reviewed in this context. The time variation of the gravitational constant at the present epoch can be expressed in terms of these quantities. This provides a completely new way to restrain the deceleration parameter from laboratory bounds on the time variation of the gravitational constant. This variation also affects the redshift dependence of angular diameters and the surface brightness, and we study in some detail the redshift scaling of the linear sizes of radio sources. The effec...

  16. Feasibility and observed safety of interactive video games for physical rehabilitation in the intensive care unit: a case series.

    Science.gov (United States)

    Kho, Michelle E; Damluji, Abdulla; Zanni, Jennifer M; Needham, Dale M

    2012-04-01

    Early rehabilitation in the intensive care unit (ICU) improves patients' physical function. Despite reports of using commercially available interactive video game systems for rehabilitation, there are few data evaluating feasibility and safety as part of routine in-patient rehabilitation, particularly in the ICU. We conducted an observational study from September 1, 2009, to August 31, 2010, of adults admitted to a 16-bed medical ICU receiving video games as part of routine physical therapy (PT), evaluating use and indications and occurrence of 14 prospectively monitored safety events. Of 410 patients receiving PT in the medical ICU, 22 (5% of all patients; male, 64%; median age, 52 years) had 42 PT treatments with video games (median [interquartile range] per patient, 1.0 [1.0-2.0]). Main indications for video game therapy included balance (52%) and endurance (45%), and the most common activities included boxing (38%), bowling (24%), and balance board (21%). Of 42 treatments, 69% occurred while standing and 45% while mechanically ventilated. During 35 hours of PT treatment, 0 safety events occurred (95% upper confidence limit for safety event rate, 8.4%). Novel use of interactive video games as part of routine PT in critically ill patients is feasible and appears safe in our case series. Video game therapy may complement existing rehabilitation techniques for ICU patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. The Determination of the Strong Coupling Constant

    Science.gov (United States)

    Dissertori, Günther

    2016-10-01

    The strong coupling constant is one of the fundamental parameters of the Standard Theory of particle physics. In this review I will briefly summarise the theoretical framework, within which the strong coupling constant is defined and how it is connected to measurable observables. Then I will give an historical overview of its experimental determinations and discuss the current status and world average value. Among the many different techniques used to determine this coupling constant in the context of quantum chromodynamics, I will focus in particular on a number of measurements carried out at the Large Electron-Positron Collider (LEP) and the Large Hadron Collider (LHC) at CERN.

  18. PHYSICS

    CERN Multimedia

    the PAG conveners

    2011-01-01

    The delivered LHC integrated luminosity of more than 1 inverse femtobarn by summer and more than 5 by the end of 2011 has been a gold mine for the physics groups. With 2011 data, we have submitted or published 14 papers, 7 others are in collaboration-wide review, and 75 Physics Analysis Summaries have been approved already. They add to the 73 papers already published based on the 2010 and 2009 datasets. Highlights from each physics analysis group are described below. Heavy ions Many important results have been obtained from the first lead-ion collision run in 2010. The published measurements include the first ever indications of Υ excited state suppression (PRL synopsis), long-range correlation in PbPb, and track multiplicity over a wide η range. Preliminary results include the first ever measurement of isolated photons (showing no modification), J/ψ suppression including the separation of the non-prompt component, further study of jet fragmentation, nuclear modification factor...

  19. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      The period since the last CMS Bulletin has been historic for CMS Physics. The pinnacle of our physics programme was an observation of a new particle – a strong candidate for a Higgs boson – which has captured worldwide interest and made a profound impact on the very field of particle physics. At the time of the discovery announcement on 4 July, 2012, prominent signals were observed in the high-resolution H→γγ and H→ZZ(4l) modes. Corroborating excess was observed in the H→W+W– mode as well. The fermionic channel analyses (H→bb, H→ττ), however, yielded less than the Standard Model (SM) expectation. Collectively, the five channels established the signal with a significance of five standard deviations. With the exception of the diphoton channel, these analyses have all been updated in the last months and several new channels have been added. With improved analyses and more than twice the i...

  20. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    The Physics Groups are actively engaged on analyses of the first data from the LHC at 7 TeV, targeting many results for the ICHEP conference taking place in Paris this summer. The first large batch of physics approvals is scheduled for this CMS Week, to be followed by four more weeks of approvals and analysis updates leading to the start of the conference in July. Several high priority analysis areas were organized into task forces to ensure sufficient coverage from the relevant detector, object, and analysis groups in the preparation of these analyses. Already some results on charged particle correlations and multiplicities in 7 TeV minimum bias collisions have been approved. Only one small detail remains before ICHEP: further integrated luminosity delivered by the LHC! Beyond the Standard Model measurements that can be done with these data, the focus changes to the search for new physics at the TeV scale and for the Higgs boson in the period after ICHEP. Particle Flow The PFT group is focusing on the ...

  1. PHYSICS

    CERN Multimedia

    C. Hill

    2012-01-01

      2012 has started off as a very busy year for the CMS Physics Groups. Planning for the upcoming higher luminosity/higher energy (8 TeV) operation of the LHC and relatively early Rencontres de Moriond are the high-priority activities for the group at the moment. To be ready for the coming 8-TeV data, CMS has made a concerted effort to perform and publish analyses on the 5 fb−1 dataset recorded in 2011. This has resulted in the submission of 16 papers already, including nine on the search for the Higgs boson. In addition, a number of preliminary results on the 2011 dataset have been released to the public. The Exotica and SUSY groups approved several searches for new physics in January, such as searches for W′ and exotic highly ionising particles. These were highlighted at a CERN seminar given on 24th  January. Many more analyses, from all the PAGs, including the newly formed SMP (Standard Model Physics) and FSQ (Forward and Small-x QCD), were approved in February. The ...

  2. PHYSICS

    CERN Multimedia

    Darin Acosta

    2010-01-01

    The collisions last year at 900 GeV and 2.36 TeV provided the long anticipated collider data to the CMS physics groups. Quite a lot has been accomplished in a very short time. Although the delivered luminosity was small, CMS was able to publish its first physics paper (with several more in preparation), and commence the commissioning of physics objects for future analyses. Many new performance results have been approved in advance of this CMS Week. One remarkable outcome has been the amazing agreement between out-of-the-box data with simulation at these low energies so early in the commissioning of the experiment. All of this is testament to the hard work and preparation conducted beforehand by many people in CMS. These analyses could not have happened without the dedicated work of the full collaboration on building and commissioning the detector, computing, and software systems combined with the tireless work of many to collect, calibrate and understand the data and our detector. To facilitate the efficien...

  3. PHYSICS

    CERN Multimedia

    L. Demortier

    Physics-wise, the CMS week in December was dominated by discussions of the analyses that will be carried out in the “next six months”, i.e. while waiting for the first LHC collisions.  As presented in December, analysis approvals based on Monte Carlo simulation were re-opened, with the caveat that for this work to be helpful to the goals of CMS, it should be carried out using the new software (CMSSW_2_X) and associated samples.  By the end of the week, the goal for the physics groups was set to be the porting of our physics commissioning methods and plans, as well as the early analyses (based an integrated luminosity in the range 10-100pb-1) into this new software. Since December, the large data samples from CMSSW_2_1 were completed. A big effort by the production group gave a significant number of events over the end-of-year break – but also gave out the first samples with the fast simulation. Meanwhile, as mentioned in December, the arrival of 2_2 meant that ...

  4. On the radius constants for classes of analytic functions

    OpenAIRE

    Ali, Rosihan M.; Jain, Naveen; Ravichandran, V.

    2012-01-01

    Radius constants for several classes of analytic functions on the unit disk are obtained. These include the radius of starlikeness of a positive order, radius of parabolic starlikeness, radius of Bernoulli lemniscate starlikeness, and radius of uniform convexity. In the main, the radius constants obtained are sharp. Conjectures on the non-sharp constants are given.

  5. Variation of fundamental constants

    CERN Document Server

    Flambaum, V V

    2006-01-01

    We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and Oklo natural nuclear reactor data. A very promising method to search for the variation of the fundamental constants consists in comparison of different atomic clocks. Huge enhancement of the variation effects happens in transition between accidentally degenerate atomic and molecular energy levels. A new idea is to build a ``nuclear'' clock based on the ultraviolet transition between very low excited state and ground state in Thorium nucleus. This may allow to improve sensitivity to the variation up to 10 orders of magnitude! Huge enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feschbach resonance.

  6. Stepwise redefinition of the SI base units

    CERN Document Server

    Issaev, L K; Khruschov, V V

    2012-01-01

    The four SI base units are proposed to be redefined in two stages: first, the kilogram, mole and ampere should be defined, and then the kelvin. To realize the redefinition of a base unit of the SI in terms of fundamental physical constant (FPC), a principle of coincidence of their physical dimensions is put forward. Direct applying this principle will lead to the changing of the sets of base and derived units in the new SI. If we want to preserve the continuity of the division between base and derived units in the new and the current SI, the principle is to be generalized with the time dimension factor be included. The status of the mole as the base unit of measurement is considered in the current and new SI. It is proposed to redefine the kilogram using a fixed value of the Avogadro constant and then to redefine the kelvin, after the measurement accuracy of the Boltzmann constant has been increased and agreed with the values of other constants of molecular physics.

  7. Constant-pressure Blowers

    Science.gov (United States)

    Sorensen, E

    1940-01-01

    The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency.

  8. String Scale Cosmological Constant

    OpenAIRE

    Chalmers, Gordon

    2006-01-01

    The cosmological constant is an unexplained until now phenomena of nature that requires an explanation through string effects. The apparent discrepancy between theory and experiment is enourmous and has already been explained several times by the author including mechanisms. In this work the string theory theory of abolished string modes is documented and given perturbatively to all loop orders. The holographic underpinning is also exposed. The matching with the data of the LIGO and D0 experi...

  9. Universe of constant

    Science.gov (United States)

    Yongquan, Han

    2016-10-01

    The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan

  10. Fine-structure constant: Is it really a constant?

    Science.gov (United States)

    Bekenstein, Jacob D.

    1982-03-01

    It is often claimed that the fine-structure "constant" α is shown to be strictly constant in time by a variety of astronomical and geophysical results. These constrain its fractional rate of change α˙α to at least some orders of magnitude below the Hubble rate H0. We argue that the conclusion is not as straightforward as claimed since there are good physical reasons to expect α˙α<

  11. PHYSICS

    CERN Multimedia

    J. D'Hondt

    The Electroweak and Top Quark Workshop (16-17th of July) A Workshop on Electroweak and Top Quark Physics, dedicated on early measurements, took place on 16th-17th July. We had more than 40 presentations at the Workshop, which was an important milestone for 2007 physics analyses in the EWK and TOP areas. The Standard Model has been tested empirically by many previous experiments. Observables which are nowadays known with high precision will play a major role for data-based CMS calibrations. A typical example is the use of the Z to monitor electron and muon reconstruction in di-lepton inclusive samples. Another example is the use of the W mass as a constraint for di-jets in the kinematic fitting of top-quark events, providing information on the jet energy scale. The predictions of the Standard Model, for what concerns proton collisions at the LHC, are accurate to a level that the production of W/Z and top-quark events can be used as a powerful tool to commission our experiment. On the other hand the measure...

  12. PHYSICS

    CERN Multimedia

    C. Hill

    2013-01-01

    In the period since the last CMS Bulletin, the LHC – and CMS – have entered LS1. During this time, CMS Physics Analysis Groups have performed more than 40 new analyses, many of which are based on the complete 8 TeV dataset delivered by the LHC in 2012 (and in some cases on the full Run 1 dataset). These results were shown at, and well received by, several high-profile conferences in the spring of 2013, including the inaugural meeting of the Large Hadron Collider    Physics Conference (LHCP) in Barcelona, and the 26th International Symposium on Lepton Photon Interactions at High Energies (LP) in San Francisco. In parallel, there have been significant developments in preparations for Run 2 of the LHC and on “future physics” studies for both Phase 1 and Phase 2 upgrades of the CMS detector. The Higgs analysis group produced five new results for LHCP including a new H-to-bb search in VBF production (HIG-13-011), ttH with H to γ&ga...

  13. PHYSICS

    CERN Multimedia

    C. Hill

    2013-01-01

    The period since the last CMS bulletin has seen the end of proton collisions at a centre-of-mass energy 8 TeV, a successful proton-lead collision run at 5 TeV/nucleon, as well as a “reference” proton run at 2.76 TeV. With these final LHC Run 1 datasets in hand, CMS Physics Analysis Groups have been busy analysing these data in preparation for the winter conferences. Moreover, despite the fact that the pp run only concluded in mid-December (and there was consequently less time to complete data analyses), CMS again made a strong showing at the Rencontres de Moriond in La Thuile (EW and QCD) where nearly 40 new results were presented. The highlight of these preliminary results was the eagerly anticipated updated studies of the properties of the Higgs boson discovered in July of last year. Meanwhile, preparations for Run 2 and physics performance studies for Phase 1 and Phase 2 upgrade scenarios are ongoing. The Higgs analysis group produced updated analyses on the full Run 1 dataset (~25 f...

  14. PHYSICS

    CERN Multimedia

    Christopher Hill

    2013-01-01

    Since the last CMS Bulletin, the CMS Physics Analysis Groups have completed more than 70 new analyses, many of which are based on the complete Run 1 dataset. In parallel the Snowmass whitepaper on projected discovery potential of CMS for HL-LHC has been completed, while the ECFA HL-LHC future physics studies has been summarised in a report and nine published benchmark analyses. Run 1 summary studies on b-tag and jet identification, quark-gluon discrimination and boosted topologies have been documented in BTV-13-001 and JME-13-002/005/006, respectively. The new tracking alignment and performance papers are being prepared for submission as well. The Higgs analysis group produced several new results including the search for ttH with H decaying to ZZ, WW, ττ+bb (HIG-13-019/020) where an excess of ~2.5σ is observed in the like-sign di-muon channel, and new searches for high-mass Higgs bosons (HIG-13-022). Search for invisible Higgs decays have also been performed both using the associ...

  15. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  16. Search for Possible Variation of the Fine Structure Constant

    OpenAIRE

    2003-01-01

    Determination of the fine structure constant alpha and search for its possible variation are considered. We focus on a role of the fine structure constant in modern physics and discuss precision tests of quantum electrodynamics. Different methods of a search for possible variations of fundamental constants are compared and those related to optical measurements are considered in detail.

  17. Physical quantities and dimensional analysis: from mechanics to quantum gravity

    CERN Document Server

    Trancanelli, Diego

    2015-01-01

    Physical quantities and physical dimensions are among the first concepts encountered by students in their undergraduate career. In this pedagogical review, I will start from these concepts and, using the powerful tool of dimensional analysis, I will embark in a journey through various branches of physics, from basic mechanics to quantum gravity. I will also discuss a little bit about the fundamental constants of Nature, the so-called "cube of Physics", and the natural system of units.

  18. A new clinical unit for digital radiography based on a thick amorphous Selenium plate: Physical and psychophysical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Rivetti, Stefano; Lanconelli, Nico; Bertolini, Marco; Acchiappati, Domenico [Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna, Italy and S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy); Alma Mater Studiorum, Physics Department, University of Bologna, 40127 Bologna (Italy); Arcispedale Santa Maria Nuova, 42123 Reggio Emilia (Italy); S.C. di Fisica Sanitaria ' ' Azienda USL di Modena' ' 41100 Modena (Italy)

    2011-08-15

    Purpose: Here, we present a physical and psychophysical characterization of a new clinical unit (named AcSelerate) for digital radiography based on a thick a-Se layer. We also compared images acquired with and without a software filter (named CRF) developed for reducing sharpness and noise of the images and making them similar to images coming from traditional computed radiography systems. Methods: The characterization was achieved in terms of physical figures of merit [modulation transfer function (MTF), noise power spectra (NPS), detective quantum efficiency (DQE)], and psychophysical parameters (contrast-detail analysis with an automatic reading of CDRAD images). We accomplished measurements with four standard beam conditions: RAQ3, RQA5, RQA7, and RQA9. Results: The system shows an excellent MTF (about 50% at the Nyquist frequency). The DQE is about 55% at 0.5 lp/mm and above 20% at the Nyquist frequency and is almost independent from exposure. The contrast-detail curves are comparable to some of the best published data for other systems devoted to imaging in general radiography. The CRF filter influences both the MTF and NPS, but it does lead to very small changes on DQE. Also the visibility of CDRAD details is basically unaltered, when the filter is activated. Conclusions: As normally happens with detector based on direct conversion, the system presents an excellent MTF. The improved efficiency caused by the thick layer allows getting good noise characteristics and DQE results better (about 10% on average) than many of the computed radiography (CR) systems and comparable to those obtained by the best systems for digital radiography available on the market.

  19. Spaces of constant curvature

    CERN Document Server

    Wolf, Joseph A

    2010-01-01

    This book is the sixth edition of the classic Spaces of Constant Curvature, first published in 1967, with the previous (fifth) edition published in 1984. It illustrates the high degree of interplay between group theory and geometry. The reader will benefit from the very concise treatments of riemannian and pseudo-riemannian manifolds and their curvatures, of the representation theory of finite groups, and of indications of recent progress in discrete subgroups of Lie groups. Part I is a brief introduction to differentiable manifolds, covering spaces, and riemannian and pseudo-riemannian geomet

  20. New multitarget constant modulus array for CDMA systems

    Institute of Scientific and Technical Information of China (English)

    Zhang Jidong; Zheng Baoyu

    2006-01-01

    A new multitarget constant modulus array is proposed for CDMA systems based on least squares constant modulus algorithm. The new algorithm is called pre-despreading decision directed least squares constant modulus algorithm (DDDLSCMA). In the new algorithm, the pre-despreading is first applied for multitarget arrays to remove some multiple access signals, then the despreaded signal is processed by the algorithm which united the constant modulus algorithm and decision directed method. Simulation results illustrate the good performance for the proposed algorithm.

  1. Reviews Book: Sustainable Energy—Without the Hot Air Equipment: Doppler Effect Unit Book: The Physics of Rugby Book: Plastic Fantastic: How the Biggest Fraud in Physics Shook the Scientific World Equipment: Brunel Eyecam Equipment: 200x Digital Microscope Book: The Atom and the Apple: Twelve Tales from Contemporary Physics Book: Physics 2 for OCR Web Watch

    Science.gov (United States)

    2009-09-01

    WE RECOMMEND Sustainable Energy—Without the Hot Air This excellent book makes sense of energy facts and figures Doppler Effect Unit Another simple, effective piece of kit from SEP Plastic Fantastic: How the Biggest Fraud in Physics Shook the Scientific World Intriguing and unique write-up of an intellectual fraud case Brunel Eyecam An affordable digital eyepiece for your microscope 200x Digital Microscope An adjustable digital flexcam for classroom use The Atom and the Apple: Twelve Tales from Contemporary Physics A fascinating round-up of the recent history of physics WORTH A LOOK The Physics of Rugby Book uses sport analogy and context to teach physics concepts Physics 2 for OCR Essential textbook for the course but otherwise pointless WEB WATCH Some free teaching materials are better than those you'd pay for

  2. Toward a constructive physics

    Energy Technology Data Exchange (ETDEWEB)

    Noyes, H.P.; Gefwert, C.; Manthey, M.J.

    1983-06-01

    We argue that the discretization of physics which has occurred thanks to the advent of quantum mechanics has replaced the continuum standards of time, length and mass which brought physics to maturity by counting. The (arbitrary in the sense of conventional dimensional analysis) standards have been replaced by three dimensional constants: the limiting velocity c, the unit of action h, and either a reference mass (eg m/sub p/) or a coupling constant (eg G related to the mass scale by hc/(2..pi..Gm/sub p//sup 2/) approx. = 1.7 x 10/sup 38/). Once these physical and experimental reference standards are accepted, the conventional approach is to connect physics to mathematics by means of dimensionless ratios. But these standards now rest on counting rather than ratios, and allow us to think of a fourth dimensionless mathematical concept, which is counting integers. According to constructive mathematics, counting has to be understood before engaging in the practice of mathematics in order to avoid redundancy. In its strict form constructive mathematics allows no completed infinities, and must provide finite algorithms for the computation of any acceptable concept. This finite requirement in constructive mathematics is in keeping with the practice of physics when that practice is restricted to hypotheses which are testable in a finite time. In this paper we attempt to outline a program for physics which will meet these rigid criteria while preserving, in so far as possible, the successes that conventional physics has already achieved.

  3. PHYSICS

    CERN Multimedia

    V.Ciulli

    2011-01-01

    The main programme of the Physics Week held between 16th and 20th May was a series of topology-oriented workshops on di-leptons, di-photons, inclusive W, and all-hadronic final states. The goal of these workshops was to reach a common understanding for the set of objects (ID, cleaning...), the handling of pile-up, calibration, efficiency and purity determination, as well as to revisit critical common issues such as the trigger. Di-lepton workshop Most analysis groups use a di-lepton trigger or a combination of single and di-lepton triggers in 2011. Some groups need to collect leptons with as low PT as possible with strong isolation and identification requirements as for Higgs into WW at low mass, others with intermediate PT values as in Drell-Yan studies, or high PT as in the Exotica group. Electron and muon reconstruction, identification and isolation, was extensively described in the workshop. For electrons, VBTF selection cuts for low PT and HEEP cuts for high PT were discussed, as well as more complex d...

  4. Early publications about nonzero cosmological constant

    CERN Document Server

    Horvath, I

    2012-01-01

    In 2011 the Nobel Prize in Physics was awarded for the 1998 discovery of the nonzero cosmological constant. This discovery is very important and surely worth to receive the Nobel Prize. However, years earlier several papers had been published (Paal, Horvath, & Lukacs 1992; Holba et al. 1992, Holba et al. 1994) about a very similar discovery from observational data.

  5. Child Physical Abuse Prevalence, Characteristics, Predictors, and Beliefs about Parent-Child Violence in South Asian, Middle Eastern, East Asian, and Latina Women in the United States

    Science.gov (United States)

    Maker, Azmaira H.; Shah, Priti V.; Agha, Zia

    2005-01-01

    The present study examined the prevalence, characteristics, beliefs, and demographic predictors of parent-child physical violence among South Asian, Middle Eastern, East Asian, and Latina women in the United States. Two hundred fifty-one college-educated women from a middle to high SES (South Asian/Middle Eastern, n = 93; East Asian, n = 72;…

  6. Alignment between the Physics Content Standard and the Standardized Test: A Comparison among the United States-New York State, Singapore, and China-Jiangsu

    Science.gov (United States)

    Liu, Xiufeng; Zhang, Baohui; Liang, Ling L.; Fulmer, Gavin; Kim, Beaumie; Yuan, Haiquan

    2009-01-01

    Alignment between content standards and standardized tests is a significant issue to society, science pedagogy, and test validation. To better understand the issues related to alignment, this study compares the alignment in physics among three education systems: Jiangsu (China), New York State (United States), and Singapore. The same coding…

  7. The Hubble Constant

    Directory of Open Access Journals (Sweden)

    Jackson Neal

    2007-09-01

    Full Text Available I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. In the last 20 years, much progress has been made and estimates now range between 60 and 75 km s^-1 Mpc^-1, with most now between 70 and 75 km s^-1 Mpc^-1, a huge improvement over the factor-of-2 uncertainty which used to prevail. Further improvements which gave a generally agreed margin of error of a few percent rather than the current 10% would be vital input to much other interesting cosmology. There are several programmes which are likely to lead us to this point in the next 10 years.

  8. When constants are important

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1997-04-01

    In this paper the authors discuss several complexity aspects pertaining to neural networks, commonly known as the curse of dimensionality. The focus will be on: (1) size complexity and depth-size tradeoffs; (2) complexity of learning; and (3) precision and limited interconnectivity. Results have been obtained for each of these problems when dealt with separately, but few things are known as to the links among them. They start by presenting known results and try to establish connections between them. These show that they are facing very difficult problems--exponential growth in either space (i.e. precision and size) and/or time (i.e., learning and depth)--when resorting to neural networks for solving general problems. The paper will present a solution for lowering some constants, by playing on the depth-size tradeoff.

  9. Constant Proportion Portfolio Insurance

    DEFF Research Database (Denmark)

    Jessen, Cathrine

    2014-01-01

    Portfolio insurance, as practiced in 1987, consisted of trading between an underlying stock portfolio and cash, using option theory to place a floor on the value of the position, as if it included a protective put. Constant Proportion Portfolio Insurance (CPPI) is an option-free variation...... on the theme, originally proposed by Fischer Black. In CPPI, a financial institution guarantees a floor value for the “insured” portfolio and adjusts the stock/bond mix to produce a leveraged exposure to the risky assets, which depends on how far the portfolio value is above the floor. Plain-vanilla portfolio...... insurance largely died with the crash of 1987, but CPPI is still going strong. In the frictionless markets of finance theory, the issuer’s strategy to hedge its liability under the contract is clear, but in the real world with transactions costs and stochastic jump risk, the optimal strategy is less obvious...

  10. Decay constants in geochronology

    Institute of Scientific and Technical Information of China (English)

    IgorM.Villa; PaulR.Renne

    2005-01-01

    Geologic time is fundamental to the Earth Sciences, and progress in many disciplines depends critically on our ability to measure time with increasing accuracy and precision. Isotopic geochronology makes use of the decay of radioactive nuclides as a help to quantify the histories of rock, minerals, and other materials. Both accuracy and precision of radioisotopic ages are, at present, limited by those of radioactive decay constants. Modem mass spectrometers can measure isotope ratios with a precision of 10-4 or better. On the other hand, the uncertainties associated with direct half-life determinations are, in most cases, still at the percent level. The present short note briefly summarizes progress and problems that have been encountered during the Working Group's activity.

  11. Reconciling Planck constant determinations via watt balance and enriched-silicon measurements at NRC Canada

    Science.gov (United States)

    Steele, A. G.; Meija, J.; Sanchez, C. A.; Yang, L.; Wood, B. M.; Sturgeon, R. E.; Mester, Z.; Inglis, A. D.

    2012-02-01

    The next revision to the International System of Units will emphasize the relationship between the base units (kilogram, metre, second, ampere, kelvin, candela and mole) and fundamental constants of nature (the speed of light, c, the Planck constant, h, the elementary charge, e, the Boltzmann constant, kB, the Avogadro constant, NA, etc). The redefinition cannot proceed without consistency between two complementary metrological approaches to measuring h: a 'physics' approach, using watt balances and the equivalence principle between electrical and mechanical force, and a 'chemistry' approach that can be viewed as determining the mass of a single atom of silicon. We report the first high precision physics and chemistry results that agree within 12 parts per billion: h (watt balance) = 6.626 070 63(43) × 10-34 J s and h(silicon) = 6.626 070 55(21) × 10-34 J s. When combined with values determined by other metrology laboratories, this work helps to constrain our knowledge of h to 20 parts per billion, moving us closer to a redefinition of the metric system used around the world.

  12. Flexible alternatives to constant frequency systems

    Science.gov (United States)

    Stewart-Wilson, John

    The use of hybrid systems in which variable frequency is used as generated, with a proportion being converted to constant frequency by electronic conversion, is examined as a flexible alternative to constant frequency systems. Here, some practical solutions to the technical issues raised by adopting the more flexible approach to electrical system generation are presented. In particular, attention is given to the frequency ranges used, impact on aircraft equipment, motor-driven equipment, transformer rectifier units, lighting, and avionics. The discussion also covers fan-assisted galley ovens, system architecture, special airworthiness requirements, and power quality.

  13. RNA structure and scalar coupling constants

    Energy Technology Data Exchange (ETDEWEB)

    Tinoco, I. Jr.; Cai, Z.; Hines, J.V.; Landry, S.M.; SantaLucia, J. Jr.; Shen, L.X.; Varani, G. [Univ. of California, Berkeley, CA (United States)

    1994-12-01

    Signs and magnitudes of scalar coupling constants-spin-spin splittings-comprise a very large amount of data that can be used to establish the conformations of RNA molecules. Proton-proton and proton-phosphorus splittings have been used the most, but the availability of {sup 13}C-and {sup 15}N-labeled molecules allow many more coupling constants to be used for determining conformation. We will systematically consider the torsion angles that characterize a nucleotide unit and the coupling constants that depend on the values of these torsion angles. Karplus-type equations have been established relating many three-bond coupling constants to torsion angles. However, one- and two-bond coupling constants can also depend on conformation. Serianni and coworkers measured carbon-proton coupling constants in ribonucleosides and have calculated their values as a function of conformation. The signs of two-bond coupling can be very useful because it is easier to measure a sign than an accurate magnitude.

  14. Accelerometer Measured Level of Physical Activity Indoors and Outdoors During Preschool Time in Sweden and the United States

    DEFF Research Database (Denmark)

    Raustorp, A.; Pagels, P.; Boldemann, C.

    2012-01-01

    BACKGROUND: It is important to understand the correlates of physical activity in order to influence policy and create environments that promote physical activity among preschool children. We compared preschoolers' physical activity in Swedish and in US settings and objectively examined differences...

  15. Managing a Basic Unit Responsible for a Basic Discipline: The Physics Department at the Technical University, Aachen.

    Science.gov (United States)

    Felderhof, B. U.

    1983-01-01

    The administrative structure of the physics department in a major European technical university is described, particularly with regard to the organization of teaching and research functions. The department is subdivided into an institute of theoretical physics and several institutes of experimental physics, with a more important subdivision into…

  16. The Cosmological Constant Problem (2/2)

    CERN Document Server

    CERN. Geneva

    2015-01-01

    I will review the cosmological constant problem as a serious challenge to our notion of naturalness in Physics. Weinberg’s no go theorem is worked through in detail. I review a number of proposals possibly including Linde's universe multiplication, Coleman's wormholes, the fat graviton, and SLED, to name a few. Large distance modifications of gravity are also discussed, with causality considerations pointing towards a global modification as being the most sensible option. The global nature of the cosmological constant problem is also emphasized, and as a result, the sequestering scenario is reviewed in some detail, demonstrating the cancellation of the Standard Model vacuum energy through a global modification of General Relativity.

  17. The Cosmological Constant Problem (1/2)

    CERN Document Server

    CERN. Geneva

    2015-01-01

    I will review the cosmological constant problem as a serious challenge to our notion of naturalness in Physics. Weinberg’s no go theorem is worked through in detail. I review a number of proposals possibly including Linde's universe multiplication, Coleman's wormholes, the fat graviton, and SLED, to name a few. Large distance modifications of gravity are also discussed, with causality considerations pointing towards a global modification as being the most sensible option. The global nature of the cosmological constant problem is also emphasized, and as a result, the sequestering scenario is reviewed in some detail, demonstrating the cancellation of the Standard Model vacuum energy through a global modification of General Relativity.

  18. Degravitation of the Cosmological Constant in Bigravity

    CERN Document Server

    Platscher, Moritz

    2016-01-01

    In this article the phenomenon of degravitation of the cosmological constant is studied in the framework of bigravity. It is demonstrated that despite a sizable value of the cosmological constant its gravitational effect can be only mild. The bigravity framework is chosen for this demonstration as it leads to a consistent, ghost-free theory of massive gravity. We show that degravitation takes place in the limit where the physical graviton is dominantly a gauge invariant metric combination. We present and discuss several phenomenological consequences expected in this regime.

  19. The Interacting and Non-constant Cosmological Constant

    CERN Document Server

    Verma, Murli Manohar

    2009-01-01

    We propose a time-varying cosmological constant with a fixed equation of state, which evolves mainly through its interaction with the background during most of the long history of the universe. However, such interaction does not exist in the very early and the late-time universe and produces the acceleration during these eras when it becomes very nearly a constant. It is found that after the initial inflationary phase, the cosmological constant, that we call as lambda parameter, rolls down from a large constant value to another but very small constant value and further dominates the present epoch showing up in form of the dark energy driving the acceleration.

  20. Questioning the Universe concepts in physics

    CERN Document Server

    Sadoff, Ahren

    2008-01-01

    UNITS AND POWERS OF TEN PHYSICS AND ITS METHODOLOGY  What Is Physics? Methodology The First Scientist Why Do You Believe? Back to the Questions How Do We Answer theQuestions? The Need to BeQuantitative Theories Models AestheticJudgments  MOTION Relating the Variables of Motion Graphs of One-Dimensional Motion Constant Speed Constant Acceleration Two-Dimensional Motion FORCES The Fundamental Forces A Specific Force Law: Newtonian Gravity Weight How Does Force Affect Motion? Newton's SecondLaw Newton, the Apple, and the Moon Combining Two Laws The Mass of the Earth Newton's Firs

  1. Determination Instructions Efficiency of Teaching Methods in Teaching Physics in the Case of Teaching Unit "Viscosity. Newtonian and Stokes Law"

    Science.gov (United States)

    Radulovic, Branka; Stojanovic, Maja

    2015-01-01

    The use of different teaching methods has resulted in different quality and quantity of students' knowledge. For this reason, it is important to constantly review the teaching methods and applied most effectively. One way of determining instruction efficiency is by using cognitive load and student achievement. Cognitive load can be generally…

  2. The fine structure constant and numerical alchemy

    CERN Document Server

    Dattoli, Giuseppe

    2010-01-01

    We comment on past and more recent efforts to derive a formula yielding the fine structure constant in terms of integers and transcendent numbers. We analyse these "exoteric" attitudes and describe the myths regarding {\\alpha}, which seems to have very ancient roots, tracing back to Cabbala and to medieval alchemic conceptions. We discuss the obsession for this constant developed by Pauli and the cultural "environment" in which such an "obsession" grew. We also derive a simple formula for {\\alpha} in terms of two numbers {\\pi} and 137 only. The formula we propose reproduces the experimental values up to the last significant digit, it has not any physical motivation and is the result of an alchemic combination of numbers. We make a comparison with other existing formulae, discuss the relevant limits of validity by comparison with the experimental values and discuss a criterion to recover a physical meaning, if existing, from their mathematical properties.

  3. Mathematics and physics

    CERN Document Server

    Manin, Yu I

    1981-01-01

    A bird's eye view of mathematics ; physical quantities, dimensions and constants : the source of numbers in physics ; a drop of milk : observer, observation, observable and unobservable ; space-time as a physical system ; action and symmetry.

  4. Cosmological constant influence on cosmic string spacetime

    Science.gov (United States)

    Abbassi, Amir H.; Abbassi, Amir M.; Razmi, H.

    2003-05-01

    We investigate the line element of spacetime around a linear cosmic string in the presence of a cosmological constant. We obtain a static form of the metric and argue that it should be discarded because of asymptotic considerations. Then a time dependent and consistent form of the metric is obtained and its properties are discussed. This may be considered an example of a preferred frame in physics.

  5. Influence of Adult Knee Height, Age at First Birth, Migration, and Current Age on Adult Physical Function of Bangladeshi Mothers and Daughters in the United Kingdom and Bangladesh

    Directory of Open Access Journals (Sweden)

    Barry Bogin

    2014-01-01

    Full Text Available In the United Kingdom, Bangladeshi women have the lowest self-reported levels of physical activity and some of the highest levels of metabolic disease of all ethnic groups. To better understand these risks for poor health we employed life course and intergenerational hypotheses to predict lower body physical function in a sample of 121 Bangladeshi mothers (40–70 years old and one of their adult daughters (17–36 years old living in Bangladesh or in the UK. For the mothers, older age and shorter knee height predicted reduced lower body physical function. Knee height is a biomarker of nutrition and health status between birth and puberty. Age at first birth did not have a significant effect. For daughters, older age and migration to the UK predicted reduced lower body physical function. We controlled for total stature and fatness in all analyses. UK-born daughters were taller than BD-born daughters living in the UK, mostly due to differences in knee height. These new findings support previous research indicating that early life health and adequate nutritional status, along with appropriate adult physical activity and diet, may decrease risks for poor physical function, morbidity, and premature mortality.

  6. Constant load and constant volume response of municipal solid waste in simple shear.

    Science.gov (United States)

    Zekkos, Dimitrios; Fei, Xunchang

    2017-05-01

    Constant load and constant volume simple shear testing was conducted on relatively fresh municipal solid waste (MSW) from two landfills in the United States, one in Michigan and a second in Texas, at respective natural moisture content below field capacity. The results were assessed in terms of two failure strain criteria, at 10% and 30% shear strain, and two interpretations of effective friction angle. Overall, friction angle obtained assuming that the failure plane is horizontal and at 10% shear strain resulted in a conservative estimation of shear strength of MSW. Comparisons between constant volume and constant load simple shear testing results indicated significant differences in the shear response of MSW with the shear resistance in constant volume being lower than the shear resistance in constant load. The majority of specimens were nearly uncompacted during specimen preparation to reproduce the state of MSW in bioreactor landfills or in uncontrolled waste dumps. The specimens had identical percentage of waste. The results of these tests suggest the possibility of significantly lower shear strength of MSW in bioreactor landfills where waste is placed with low compaction effort and constant volume, i.e., "undrained", conditions may occur. Compacted MSW specimens resulted in shear strength parameters that are higher than uncompacted specimens and closer to values reported in the literature. However, the normalized undrained shear strength in simple shear for uncompacted and compacted MSW was still higher than the normalized undrained shear strength reported in the literature for clayey and silty soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Dr Julia King CBE FREng, Chief Executive Designate, Institute of Physics (United Kingdom), visiting the NA48 experiment.

    CERN Document Server

    Patrice Loïez

    2002-01-01

    Photo 02: Visiting the NA48 experiment, Dr Julia King, Chief Executive Designate, Institute of Physics (Britain and Ireland) (right) with A. Ceccucci and K. Peach. Photo 05: Visiting the NA48 experiment, Dr Julia King, Chief Executive Designate, Institute of Physics (Britain and Ireland) (centre) with A. Ceccucci and C. Lazzeroni. Photo 08: Visiting the NA48 experiment, Dr Julia King, Chief Executive Designate, Institute of Physics (Britain and Ireland) (second from left) with (left to right) R. Barlow, J. Wood, N. McCubbin, K. Peach, A. Ceccucci, C. Lazzeroni, M. Patel and D. Munday.

  8. Measuring Boltzmann's Constant with Carbon Dioxide

    Science.gov (United States)

    Ivanov, Dragia; Nikolov, Stefan

    2013-01-01

    In this paper we present two experiments to measure Boltzmann's constant--one of the fundamental constants of modern-day physics, which lies at the base of statistical mechanics and thermodynamics. The experiments use very basic theory, simple equipment and cheap and safe materials yet provide very precise results. They are very easy and…

  9. Measuring Boltzmann's Constant with Carbon Dioxide

    Science.gov (United States)

    Ivanov, Dragia; Nikolov, Stefan

    2013-01-01

    In this paper we present two experiments to measure Boltzmann's constant--one of the fundamental constants of modern-day physics, which lies at the base of statistical mechanics and thermodynamics. The experiments use very basic theory, simple equipment and cheap and safe materials yet provide very precise results. They are very easy and…

  10. Exploring the Relationship of Outdoor Recreational Resources to Physical Inactivity, Obesity and Diabetes for the Continental United States

    Science.gov (United States)

    Background: Access to outdoor recreational resources is important for promoting healthy behavior and physical activity, which may decrease the risk of disease. To date, no study has examined the relationship between access to outdoor recreational resources (including protected l...

  11. The course of development of school physical education in elementary and middle schools in the United States since the 19th century and inspirations therefrom%19世纪以来美国中小学体育发展历程及其启示

    Institute of Scientific and Technical Information of China (English)

    燕凌; 李京诚; 韩桂凤

    2015-01-01

    分析美国中小学体育的发展历程:19世纪是美国中小学体育在欧洲模式影响下,探索自身发展道路的阶段;20世纪上半叶,新体育思潮的出现促进了中小学体育政策法规的不断完善和师资培训的蓬勃发展;20世纪下半叶至今,通过中小学体育教育质量的全面提高,增强青少年体质、保障青少年接受体育教育的平等权利、解决青少年肥胖问题是这一时期的主要课题。美国中小学体育发展过程中,不断创新理念、完善政策法规建设、加强师资培训专业化,为我国学校体育发展提供了借鉴。%Based on methods such as literature research, the authors analyzed the course of development of school physical education in elementary and middle schools in the United States: the 19th century was a stage at which school physical education in elementary and middle schools in the United States explored its own way of develop-ment as influenced by the European mode; in the first half of the 20th century, the appearance of new physical edu-cation ideas boosted the constant perfection of policies and regulations on school physical education in elementary and middle schools and the booming of teacher training; from the second half of the 20th century up to this day, en-hancing teenager fitness, ensuring teenagers’ equal right to accept physical education, solving teenager obesity problem, through the comprehensive enhancement of the quality of school physical education in elementary and middle schools, were main topics in this period. In the course of development of school physical education in ele-mentary and middle schools in the United States, constantly innovating on new conceptions, perfecting policy and regulation construction, and strengthening teacher training professionalization, provide feasible reference for the development of school physical education in China.

  12. The relationship of prejudicial attitudes to psychological, social, and physical well-being within a sample of college students in the United States.

    Science.gov (United States)

    Dinh, Khanh T; Holmberg, Michelle D; Ho, Ivy K; Haynes, Michelle C

    2014-01-01

    This study examined the relationship of prejudicial attitudes to psychological, social, and physical well-being among 495 college students in the Northeast region of the United States. Prejudicial attitudes included racism, sexism, homophobia, physical disability bias, weight/body-size bias, and anti-immigrant sentiment. As a secondary objective, we examined the associations among the various forms of prejudice and their relationship to key demographic and personal characteristics. We also examined the associations between psychological, social, and physical well-being. The results indicated that specific forms of prejudice, especially racism and sexism, were negative correlates of psychological, social, and/or physical well-being. The results also indicated that there may exist a prejudicial syndrome, linking diverse forms of prejudice. Furthermore, poor functioning in one area of well-being (e.g., psychological health) is related to poor functioning in other areas of well-being (social and physical health). Overall, this study provides important implications for future research and prevention programs in the area of prejudice and well-being.

  13. Effect of aquatic physical therapy on pain and state of sleep and wakefulness among stable preterm newborns in neonatal intensive care units.

    Science.gov (United States)

    Vignochi, Carine Moraes; Teixeira, Patrícia P; Nader, Silvana S

    2010-01-01

    To evaluate the effects of aquatic physical therapy on pain and on the cycle of sleep and wakefulness among stable hospitalized premature infants. This study was characterized as an uncontrolled clinical trial on a time series and included 12 clinically stable newborns of gestational age less than 36 weeks who were hospitalized in a neonatal intensive care unit (NICU). After selection, the newborns were placed in a liquid medium for aquatic physical therapy lasting 10 minutes. Movements to stimulate flexor posture and postural organization were performed. The sleep-wakefulness cycle was assessed using the adapted Brazelton (1973)* scale and pain was assessed by the occurrence of signs of pain according to the Neonatal Facial Coding System (NFCS) scale; and physiological parameters. In relation to states of sleep and wakefulness, before the physical therapy, the newborns' behavior varied from fully awake with vigorous body movements to crying. After the physical therapy, the states of sleep ranged from light sleep with closed eyes to some body movement. These values presented statistically significant differences (paquatic physical therapy can be a simple and effective method for reducing pain and improving sleep quality among preterm infants in NICUs. Controlled studies with larger numbers of subjects are needed in order to generalize the results. Article registered of the Clinical Trials under the NCT00785837.

  14. A factors influencing applicant selection of entry-level physical therapist education programs in the United States.

    Science.gov (United States)

    Wilcox, Kim Curbow; Weber, Mark

    2005-01-01

    Physical therapist education programs must compete for qualified applicants due to a nationwide reduction in the applicant pool. To develop successful recruitment strategies, faculty members need information on factors influencing applicant selection of a program. The purpose of this study was to analyze factors influencing selection of an entry-level physical therapist education program. Survey subjects were students enrolled in the first professional year of an accredited entry-level physical therapist education program. A survey instrument was developed based on the literature and interviews with physical therapist students and faculty members. Results of pilot studies to determine face and content validity were acceptable. Stratified random cluster sampling was applied to select 66 entry-level physical therapy programs from an available population of 150 of the 199 accredited programs. Forty-nine programs were not included in the population for various reasons. Using a five-point Likert scale, subjects rated the influence of 51 items on their selection of a specific physical therapist education program. The overall return rate was 70.4% (1,250 surveys returned). Data were analyzed by response frequency. Four factors were selected as "very influential" by 50% or more of the subjects: degree offered, accreditation status, perception of educational quality, and program atmosphere. Additional factors selected by 45% or more of respondents as "very influential" were pass rate on licensing examination, marketability of degree, student/faculty ratio, and small class size. Factors rated "not influential" by 50% or more of subjects included ethnic, cultural, and gender issues. Since 1998, the physical therapy profession has experienced changes in entry-level degree requirements, practice requirements, and employment opportunities, resulting in increased competition for qualified applicants to education programs. The information gained in this study may assist faculty in

  15. Spectrophotometric determination of association constant

    DEFF Research Database (Denmark)

    2016-01-01

    Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charg...

  16. Constant-Pressure Hydraulic Pump

    Science.gov (United States)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  17. Spectrophotometric determination of association constant

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2016-01-01

    Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charge...

  18. A combined early cognitive and physical rehabilitation program for people who are critically ill: the activity and cognitive therapy in the intensive care unit (ACT-ICU) trial.

    Science.gov (United States)

    Brummel, Nathan E; Jackson, James C; Girard, Timothy D; Pandharipande, Pratik P; Schiro, Elena; Work, Brittany; Pun, Brenda T; Boehm, Leanne; Gill, Thomas M; Ely, E Wesley

    2012-12-01

    In the coming years, the number of survivors of critical illness is expected to increase. These survivors frequently develop newly acquired physical and cognitive impairments. Long-term cognitive impairment is common following critical illness and has dramatic effects on patients' abilities to function autonomously. Neuromuscular weakness affects similar proportions of patients and leads to equally profound life alterations. As knowledge of these short-term and long-term consequences of critical illness has come to light, interventions to prevent and rehabilitate these devastating consequences have been sought. Physical rehabilitation has been shown to improve functional outcomes in people who are critically ill, but subsequent studies of physical rehabilitation after hospital discharge have not. Post-hospital discharge cognitive rehabilitation is feasible in survivors of critical illness and is commonly used in people with other forms of acquired brain injury. The feasibility of early cognitive therapy in people who are critically ill remains unknown. The purpose of this novel protocol trial will be to determine the feasibility of early and sustained cognitive rehabilitation paired with physical rehabilitation in patients who are critically ill from medical and surgical intensive care units. This is a randomized controlled trial. The setting for this trial will be medical and surgical intensive care units of a large tertiary care referral center. The participants will be patients who are critically ill with respiratory failure or shock. Patients will be randomized to groups receiving usual care, physical rehabilitation, or cognitive rehabilitation plus physical rehabilitation. Twice-daily cognitive rehabilitation sessions will be performed with patients who are noncomatose and will consist of orientation, memory, and attention exercises (eg, forward and reverse digit spans, matrix puzzles, letter-number sequences, pattern recognition). Daily physical

  19. A Combined Early Cognitive and Physical Rehabilitation Program for People Who Are Critically Ill: The Activity and Cognitive Therapy in the Intensive Care Unit (ACT-ICU) Trial

    Science.gov (United States)

    Jackson, James C.; Girard, Timothy D.; Pandharipande, Pratik P.; Schiro, Elena; Work, Brittany; Pun, Brenda T.; Boehm, Leanne; Gill, Thomas M.; Ely, E. Wesley

    2012-01-01

    Background In the coming years, the number of survivors of critical illness is expected to increase. These survivors frequently develop newly acquired physical and cognitive impairments. Long-term cognitive impairment is common following critical illness and has dramatic effects on patients' abilities to function autonomously. Neuromuscular weakness affects similar proportions of patients and leads to equally profound life alterations. As knowledge of these short-term and long-term consequences of critical illness has come to light, interventions to prevent and rehabilitate these devastating consequences have been sought. Physical rehabilitation has been shown to improve functional outcomes in people who are critically ill, but subsequent studies of physical rehabilitation after hospital discharge have not. Post-hospital discharge cognitive rehabilitation is feasible in survivors of critical illness and is commonly used in people with other forms of acquired brain injury. The feasibility of early cognitive therapy in people who are critically ill remains unknown. Objective The purpose of this novel protocol trial will be to determine the feasibility of early and sustained cognitive rehabilitation paired with physical rehabilitation in patients who are critically ill from medical and surgical intensive care units. Design This is a randomized controlled trial. Setting The setting for this trial will be medical and surgical intensive care units of a large tertiary care referral center. Patients The participants will be patients who are critically ill with respiratory failure or shock. Intervention Patients will be randomized to groups receiving usual care, physical rehabilitation, or cognitive rehabilitation plus physical rehabilitation. Twice-daily cognitive rehabilitation sessions will be performed with patients who are noncomatose and will consist of orientation, memory, and attention exercises (eg, forward and reverse digit spans, matrix puzzles, letter

  20. On new definitions of SI base units. Why is the "atomic" kilogram preferable

    CERN Document Server

    Bronnikov, K A; Kalinin, M I; Khruschov, V V; Kononogov, S A; Melnikov, V N

    2014-01-01

    We discuss the role of fundamental constants and measurement data for the Planck, Avogadro and Boltzmann constants and the elementary electric charge in connection with the planned transition to new definitions of four base SI units (the kilogram, mole, ampere and kelvin) in terms of fixed values of these constants. It is proposed to choose a new definition of any base SI unit in terms of a particular fundamental physical constant using a number of criteria, or principles, such as succession relative to the current SI, a sufficient stability of the new unit standards, and concordance between physical dimensions of the unit and the corresponding fundamental constant. It is argued that a redefinition of the kilogram and mole by fixing the values of the atomic mass unit and the Avogadro constant satisfies all these criteria and bears some more advantages against the version with fixed Planck constant: a well founded approach to definition of the ampere and the opportunity to preserve the current relationship bet...

  1. Linear units improve articulation between social and physical constructs: An example from caregiver parameterization for children supported by complex medical technologies

    Science.gov (United States)

    Bezruczko, N.; Stanley, T.; Battle, M.; Latty, C.

    2016-11-01

    Despite broad sweeping pronouncements by international research organizations that social sciences are being integrated into global research programs, little attention has been directed toward obstacles blocking productive collaborations. In particular, social sciences routinely implement nonlinear, ordinal measures, which fundamentally inhibit integration with overarching scientific paradigms. The widely promoted general linear model in contemporary social science methods is largely based on untransformed scores and ratings, which are neither objective nor linear. This issue has historically separated physical and social sciences, which this report now asserts is unnecessary. In this research, nonlinear, subjective caregiver ratings of confidence to care for children supported by complex, medical technologies were transformed to an objective scale defined by logits (N=70). Transparent linear units from this transformation provided foundational insights into measurement properties of a social- humanistic caregiving construct, which clarified physical and social caregiver implications. Parameterized items and ratings were also subjected to multivariate hierarchical analysis, then decomposed to demonstrate theoretical coherence (R2 >.50), which provided further support for convergence of mathematical parameterization, physical expectations, and a social-humanistic construct. These results present substantial support for improving integration of social sciences with contemporary scientific research programs by emphasizing construction of common variables with objective, linear units.

  2. [Physical inactivity among adults and elderly living in areas covered by primary healthcare units with and without the Family Health Program in Pernambuco State, Brazil].

    Science.gov (United States)

    Alves, João Guilherme Bezerra; Siqueira, Fernando Vinholes; Figueiroa, José Natal; Facchini, Luiz Augusto; Silveira, Denise Silva da; Piccini, Roberto Xavier; Tomasi, Elaine; Thumé, Elaine; Hallal, Pedro C

    2010-03-01

    The epidemiological transition in Brazil has been explained partially by the low levels of physical activity. However, few studies have explored physical inactivity in low-income population groups. Within this context, primary healthcare units gain strategic importance. This article describes the prevalence of sedentary lifestyle and associated factors in a cross-sectional study, including 1,018 adults and 1,010 elderly adults in 10 cities in Pernambuco State. Prevalence of sedentary lifestyle was 37.8% (95%CI: 34.0-40.2) in adults and 68.3% (95%CI: 65.3-71.3) in the elderly. Identification of physical activity as the most important factor for good health was associated with sedentary lifestyle in elderly adults. A lower proportion of sedentary lifestyle among non-elderly adults was associated with good self-reported health status. We concluded that sedentary lifestyle prevalence is high in elderly and non-elderly people covered by primary healthcare units in Pernambuco State as compared to the South of Brazil.

  3. An Einstein-Cartan Fine Structure Constant Definition

    Directory of Open Access Journals (Sweden)

    Stone R. A. Jr.

    2010-01-01

    Full Text Available The fine structure constant definition given in Stone R.A. Jr. Progress in Physics, 2010, v.1, 11-13 is compared to an Einstein-Cartan fine structure constant definition. It is shown that the Einstein-Cartan definition produces the correct pure theory value, just not the measure value. To produce the measured value, the pure theory Einstein-Cartan fine structure constant requires only the new variables and spin coupling of the fine structure constant definition in [1].

  4. Planck intermediate results XXIV. Constraints on variations in fundamental constants

    DEFF Research Database (Denmark)

    Ade, P. A. R.; Aghanim, N.; Arnaud, M.;

    2015-01-01

    Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data...... of the electron, me, and in the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other...

  5. Ultrasonic physics

    CERN Document Server

    Richardson, E G

    1962-01-01

    Ultrasonic Physics, Second Edition, provides an introduction to the fundamental principles of ultrasonic physics. The book opens with a discussion of the sources of ultrasound. This is followed by separate chapters on the properties and detection of ultrasonic radiation; measurement of propagation constants, i.e., the velocity and absorption, of ultrasound; ultrasound propagation in gases, liquids, and solids; and ultrasound propagation in aerosols, suspensions, and emulsions. The final chapter covers miscellaneous physical and physico-chemical actions, including dispersion and coagulation of

  6. University physics

    CERN Document Server

    Arfken, George

    1984-01-01

    University Physics provides an authoritative treatment of physics. This book discusses the linear motion with constant acceleration; addition and subtraction of vectors; uniform circular motion and simple harmonic motion; and electrostatic energy of a charged capacitor. The behavior of materials in a non-uniform magnetic field; application of Kirchhoff's junction rule; Lorentz transformations; and Bernoulli's equation are also deliberated. This text likewise covers the speed of electromagnetic waves; origins of quantum physics; neutron activation analysis; and interference of light. This publi

  7. Bianchi Type-Ⅲ Cosmological Models with Gravitational Constant G and the Cosmological Constant Λ

    Institute of Scientific and Technical Information of China (English)

    J.P.Singh; R.K.Tiwari; Pratibha Shukla

    2007-01-01

    Einstein field equations with variable gravitational and cosmological constants are considered in the presence of perfect fluid for the Bianchi type-Ⅲ universe by assuming conservation law for the energy-momentum tensor.Exact solutions of the field equations are obtained by using the scalar of expansion proportional to the shear scalar θχσ,which leads to a relation between metric potential B=Cn,where n is a constant.The corresponding physical interpretation of the cosmological solutions are also discussed.

  8. Variation of the fine structure constant

    CERN Document Server

    Lipovka, Anton A

    2016-01-01

    In present paper we evaluate the fine structure constant variation which should take place as the Universe is expanded and its curvature is changed adiabatically. This changing of the fine structure constant is attributed to the energy lost by physical system (consist of baryonic component and electromagnetic field) due to expansion of our Universe. Obtained ratio (d alpha)/alpha = 1. 10{-18} (per second) is only five times smaller than actually reported experimental limit on this value. For this reason this variation can probably be measured within a couple of years. To argue the correctness of our approach we calculate the Planck constant as adiabatic invariant of electromagnetic field, from geometry of our Universe in the framework of the pseudo- Riemannian geometry. Finally we discuss the double clock experiment based on Al+ and Hg+ clocks carried out by T. Rosenband et al. (Science 2008). We show that in this particular case there is an error in method and this way the fine structure constant variation c...

  9. The New SI and the CODATA recommended values of the fundamental constants 2014 (arXiv:1507.07956)

    CERN Document Server

    Pavese, Franco

    2015-01-01

    This note's aim is to point out some standing features of the present CODATA method in the light of the recent CODATA table of the 2014 recommended values for the fundamental constants published on paper arXiv:1507.07956. A comprehensive discussion on this and related issues is becoming very important in view of the foreseen revision of the SI, presently planned for 2018. These features may raise doubts on a possible mixing of physical reasons of general validity in science with some needs specific of metrology concerning the base units of the International System (SI) of measurement units.

  10. Participation in School Physical Education and Selected Dietary Patterns among High School Students--United States, 1991.

    Science.gov (United States)

    Journal of School Health, 1992

    1992-01-01

    Examines the prevalence of self-reported enrollment, attendance, and participation in school physical education, noting dietary patterns among students in grades 9-12 from the Youth Risk Behavior Surveillance System. Percentages of students participating varied significantly. Males participated and exercised more than females. Very few students…

  11. Student Misconceptions during Two Invasion Game Units in Physical Education: A Qualitative Investigation of Student Thought Processing.

    Science.gov (United States)

    Hare, Molly K.; Graber, Kim C.

    2000-01-01

    Described misconceptions of elementary students participating in physical education, testing ways of recording and classifying types of misconceptions. Data from observations, videotapes, interviews, and document analysis indicated that misconceptions fell into categories representing motor skill execution and confusion over terminology, strategy,…

  12. Accelerometer measured level of physical activity indoors and outdoors during preschool time in Sweden and the United States

    DEFF Research Database (Denmark)

    Raustorp, Anders; Pagels, Peter; Boldemann, Cecilia

    2012-01-01

    It is important to understand the correlates of physical activity (PA) to influence policy and create environments that promote PA among preschool children. We compared preschoolers' PA in Swedish and in US settings and objectively examined differences boys' and girls' indoor and outdoor PA regar...

  13. Investigation of four problems on the units of material and its properties, energy with heat and temperature in the secondary school physics textbooks

    Science.gov (United States)

    Kavcar, Nevzat; Özen, Ali Ihsan

    2017-02-01

    In the present study, three units in textbooks in accordance with the 2013 Secondary School Physics Curriculum were analyzed in defined four problems, and some recommendations were made. The study carried out in the Spring semester of education year 2015-2016, within the scope of an undergraduate course. Method of the study is the descriptive model based on qualitative research technics. The data collection instruments were textbook evaluation reports prepared by the participants and pre-service teachers, and presentations reflecting teachers' and pre-service teachers' ideas on the textbooks. A document analysis was conducted by means of these data collection tools. It has been concluded that in the related units a significant shortcoming is not found regarding being student-centered, activity and contex-based approximations. However, some shortcomings were found in activity-gain concordance with measurement and evaluation applications. On the basis of the collected data, some recommendations for improving the textbooks have been presented.

  14. Investigation of four problems on the units of Force and Motion with Pressure and Buoyancy in the secondary school physics textbooks

    Science.gov (United States)

    Kavcar, Nevzat; Kaya, Uǧur

    2017-02-01

    In the study the four problems defined on three units in the textbooks in accordance with the 2013 Secondary School Physics Curriculum have been investigated. The study carried out in the Spring semester of education year 2015 - 2016, within the scope of an undergraduate course. Method of the study is the descriptive model based on qualitative research technics. The data collection instruments were textbook evaluation reports prepared by the participants and pre -service teachers, and presentations reflecting teachers' and pre-service teachers' ideas on the textbooks. A document analysis was conducted by means of these data collection tools. It has been concluded that in the related units a significant shortcoming is not found regarding being student-centered, activity-based and contex-based approximations. However, some shortcomings were found in activity-gain concordance with assessment and evaluation applications. On the basis of the collected data, some recommendations for improving the textbooks have been presented.

  15. Ringing in the new physics: The politics and technology of electron colliders in the United States, 1956--1972

    Science.gov (United States)

    Paris, Elizabeth

    The ``November Revolution'' of 1974 and the experiments that followed consolidated the place of the Standard Model in modern particle physics. Much of the evidence on which these conclusions depended was generated by a new type of tool: colliding beam storage rings, which had been considered physically unfeasible twenty years earlier. In 1956 a young experimentalist named Gerry O'Neill dedicated himself to demonstrating that such an apparatus could do useful physics. The storage ring movement encountered numerous obstacles before generating one of the standard machines for high energy research. In fact, it wasn't until 1970 that the U.S. finally broke ground on its first electron-positron collider. Drawing extensively on archival sources and supplementing them with the personal accounts of many of the individuals who took part, Ringing in the New Physics examines this instance of post-World War II techno-science and the new social, political and scientific tensions that characterize it. The motivations are twofold: first, that the chronicle of storage rings may take its place beside mathematical group theory, computer simulations, magnetic spark chambers, and the like as an important contributor to a view of matter and energy which has been the dominant model for the last twenty-five years. In addition, the account provides a case study for the integration of the personal, professional, institutional, and material worlds when examining an episode in the history or sociology of twentieth century science. The story behind the technological development of storage rings holds fascinating insights into the relationship between theory and experiment, collaboration and competition in the physics community, the way scientists obtain funding and their responsibilities to it, and the very nature of what constitutes ``successful'' science in the post- World War II era.

  16. Recent Temporal Trends in Parent-Reported Physical Activity in Children in the United States, 2009 to 2014.

    Science.gov (United States)

    Loprinzi, Paul D; Davis, Robert E

    2016-04-01

    The objective of this study was to provide recent temporal trends in parent-reported physical activity in children (6-11 years) between 2009 and 2014. Data from the 2009 to 2014 National Health and Nutrition Examination Survey were used. The analytic sample included 3946 children. Parent proxy of child physical activity at each of the 3 2-year cycles was assessed. For the entire sample, there was a quadratic trend, with the number of days children engaged in at least 60 min/d of physical activity increasing in the period 2011 to 2012 (6.12 days) when compared with the period 2009 to 2010 (5.96 days) and then decreasing in the period 2013 to 2014 (5.83 days). A similar quadratic trend was evident for boys, those above the poverty level, non-Hispanic whites (particularly boys), and those with less than the 85th body mass index-for-age percentile based on sex. A negative linear trend was observed for those above the poverty level and non-Hispanic whites (particularly girls). In conclusion, these findings provide suggestive evidence that over the past 6 years (1999-2014), parents report that children's physical activity has slightly decreased in the latest years, with this observation being most pronounced in boys, those above the poverty level, non-Hispanic whites, and those with less than the 85th body mass index-for-age and sex percentile. Encouragingly, however, across all evaluated subpopulations, most children (55%-82%), as determined by their parents, engaged in 60 min/d of physical activity (consistent with government recommendations).

  17. Personality disorders and physical comorbidities in adults from the United States: data from the National Epidemiologic Survey on Alcohol and Related Conditions.

    Science.gov (United States)

    Quirk, Shae E; El-Gabalawy, Renée; Brennan, Sharon L; Bolton, James M; Sareen, Jitender; Berk, Michael; Chanen, Andrew M; Pasco, Julie A; Williams, Lana J

    2015-05-01

    There is a paucity of research examining the relationship between personality disorders (PDs) and chronic physical comorbidities. Consequently, we investigated associations between individual PDs and PD Clusters, and various common disease groups [cardiovascular disease (CVD), diabetes, arthritis and gastrointestinal disease (GI)] in a nationally representative survey of adults from the United States. This study utilized pooled data (n = 34,653; ≥20 years) from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions. PDs were assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule- Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Physical conditions were based on self-reports of being diagnosed by a health professional. Unadjusted and adjusted logistic regressions examined the relationship between PDs and physical conditions. After adjustment (sociodemographic factors, past-year mood, anxiety and substance use disorders), Clusters A, B and C PDs were each associated with physical conditions (all p ≤ 0.01). Of the individual PDs, schizoid, schizotypal, narcissistic, borderline and obsessive-compulsive PDs were associated with CVD (all p ≤ 0.01) among younger adults. Paranoid, antisocial, borderline and avoidant PDs and younger adults with schizoid, schizotypal and obsessive-compulsive PDs were each associated with arthritis (all p ≤ 0.01). Significant associations were seen between paranoid, schizoid and schizotypal PDs and diabetes (all p ≤ 0.01). Finally, schizotypal, antisocial, borderline and narcissistic PDs were associated with GI conditions (all p ≤ 0.01). PDs were consistently associated with physical conditions. Investigation of PDs and their relationship with physical health outcomes warrant further research attention as these findings have important clinical implications.

  18. Fat Euclidean Gravity with Small Cosmological Constant

    CERN Document Server

    Sundrum, Raman

    2003-01-01

    The cosmological constant problem is usually considered an inevitable feature of any effective theory capturing well-tested gravitational and matter physics, without regard to the details of short-distance gravitational couplings. In this paper, a subtle effective description avoiding the problem is presented in a first quantized language, consistent with experiments and the Equivalence Principle. First quantization allows a minimal domain of validity to be carved out by cutting on the proper length of particle worldlines. This is facilitated by working in (locally) Euclidean spacetime, although considerations of unitarity are still addressed by analytic continuation from Lorentzian spacetime. The new effective description demonstrates that the cosmological constant problem {\\it is} sensitive to short-distance details of gravity, which can be probed experimentally. ``Fat Gravity'' toy models are presented, illustrating how gravity might shut off at short but testable distances, in a generally covariant manner...

  19. Lectures on the Cosmological Constant Problem

    CERN Document Server

    Padilla, Antonio

    2015-01-01

    These lectures on the cosmological constant problem were prepared for the X Mexican School on Gravitation and Mathematical Physics. The problem itself is explained in detail, emphasising the importance of radiative instability and the need to repeatedly fine tune as we change our effective description. Weinberg's no go theorem is worked through in detail. I review a number of proposals including Linde's universe multiplication, Coleman's wormholes, the fat graviton, and SLED, to name a few. Large distance modifications of gravity are also discussed, with causality considerations pointing towards a global modification as being the most sensible option. The global nature of the cosmological constant problem is also emphasized, and as a result, the sequestering scenario is reviewed in some detail, demonstrating the cancellation of the Standard Model vacuum energy through a global modification of General Relativity.

  20. DETERMINATION OF STABILITY CONSTANTS OF MANGANESE (II ...

    African Journals Online (AJOL)

    DR. AMINU

    Keywords: Amino acids, dissociation constant, potentiometry, stability constant. INTRODUCTION ... constants of manganese (II) amino acid complexes using potentiometer. .... Principles of Biochemistry Third Edition,. Worth publishers, 41 ...

  1. The introduction of individual treatment by resident physical therapists in primary care units - doi: 10.5020/18061230.2012.p261

    Directory of Open Access Journals (Sweden)

    Chandra da Silveira Langoni

    2012-11-01

    Full Text Available Objectives: To assess the effect on clinical indicators of the introduction of individual weekly physical therapy sessions in five Primary Health Care units in Porto Alegre, RS. Methods: The medical records from 59 patients were analyzed. They were treated between April 2010 and May 2011 by two physical therapists from the Multidisciplinary Residency Program in Family and Community Health at the Pontifical Catholic University of Rio Grande do Sul. Data was collected for the determination of the sociodemographic (gender, age, marital status and occupation and clinical profiles (medical diagnosis, medication intake, number of medications and the presence of pain, dyspnea, or urinary loss. Data was analyzed using Student’s t test, Mann Whitney, Chi-square and Fisher’s exact test; the odds ratio was used when a significant association has been identified. Results: Most participants were female (81.4%, adult (62%, who did not cohabitated (62.7%, domestic workers (35.6% with musculoskeletal and connective tissue disorders (86.4%. Thirty-two participants took medicine at the beginning of the intervention and, at the end, only five did so. After treatment, the amount of administered medications was also significantly reduced. The score of the Visual Analogue Scale (pain or dyspnea was significantly reduced at the end of an average of 7.7 ± 3.2 sessions. Those users who reported having followed the domiciliary advice had an 8.3 times greater chance of being discharged. Conclusions: The weekly physical therapy sessions carried out at Primary Care units reduced symptoms, the use and amount of medication taken by the users treated and achieved greater success among those who followed the domiciliary advice given by the resident physical therapists.

  2. Monitoring of physical health parameters for inpatients on a child and adolescent mental health unit receiving regular antipsychotic therapy.

    Science.gov (United States)

    Pasha, Nida; Saeed, Shoaib; Drewek, Katherine

    2015-01-01

    Physical health monitoring of patients receiving antipsychotics is vital. Overall it is estimated that individuals suffering with conditions like schizophrenia have a 20% shorter life expectancy than the average population, moreover antipsychotic use has been linked to a number of conditions including diabetes, obesity, and cardiovascular disease.[1-4] The severity of possible adverse effects to antipsychotics in adults has raised awareness of the importance of monitoring physical health in this population. However, there is little literature available as to the adverse effects of these medications in the child and adolescent community, which make physical health monitoring in this predominantly antipsychotic naïve population even more important. An expert group meeting in the UK has laid down recommendations in regards to screening and management of adult patients receiving antipsychotics, however no specific guidelines have been put in place for the child and adolescent age group.[5] The aim of this audit was to establish whether in-patients receiving antipsychotics had the following investigations pre-treatment and 12 weeks after treatment initiation: body mass index, hip-waist circumference, blood pressure, ECG, urea and electrolytes, full blood count, lipid profile, random glucose level, liver function test, and prolactin. This is in addition to a pre-treatment VTE risk assessment. These standards were derived from local trust guidelines, NICE guidelines on schizophrenia [6] and The Maudsley Prescribing Guidelines.[7] We retrospectively reviewed 39 electronic case notes in total, of which 24 cases were post intervention. Intervention included the use of a prompting tool. This tool was filed in the physical health files of all patients receiving antipsychotics which was intended as a reminder to doctors regarding their patient's need for physical health monitoring. Professionals involved in the monitoring of such parameters were educated in the importance and

  3. Ruzsa's Constant on Additive Functions

    Institute of Scientific and Technical Information of China (English)

    Jin Hui FANG; Yong Gao CHEN

    2013-01-01

    A function f:N → R is called additive if f(mn) =f(m)+f(n) for all m,n with (m,n) =1.Let μ(x) =maxn≤x(f(n)-f(n + 1)) and v(x) =maxn≤x(f(n + 1)-f(n)).In 1979,Ruzsa proved that there exists a constant c such that for any additive function f,μ(x) ≤ cv(x2) + cf,where cf is a constant depending only on f.Denote by Raf the least such constant c.We call Raf Ruzsa's constant on additive functions.In this paper,we prove that Raf ≤ 20.

  4. Naturally Time Dependent Cosmological Constant

    CERN Document Server

    Gregori, A

    2004-01-01

    In the light of the proposal of hep-th/0207195, we discuss in detail the issue of the cosmological constant, explaining how can string theory naturally predict the value which is experimentally observed, without low-energy supersymmetry.

  5. Physical functional outcome assessment of patients with major burns admitted to a UK Burn Intensive Care Unit.

    Science.gov (United States)

    Smailes, Sarah T; Engelsman, Kayleen; Dziewulski, Peter

    2013-02-01

    Determining the discharge outcome of burn patients can be challenging and therefore a validated objective measure of functional independence would assist with this process. We developed the Functional Assessment for Burns (FAB) score to measure burn patients' functional independence. FAB scores were taken on discharge from ICU (FAB 1) and on discharge from inpatient burn care (FAB 2) in 56 patients meeting the American Burn Association criteria for major burn. We retrospectively analysed prospectively collected data to measure the progress of patients' physical functional outcomes and to evaluate the predictive validity of the FAB score for discharge outcome. Mean age was 38.6 years and median burn size 35%. Significant improvements were made in the physical functional outcomes between FAB 1 and FAB 2 scores (ppatients were discharged home, 8 of these with social care. 8 patients were transferred to another hospital for further inpatient rehabilitation. FAB 1 score (≤ 9) is strongly associated with discharge outcome (pburn patients.

  6. Inflation and the cosmological constant

    Directory of Open Access Journals (Sweden)

    FENG Chaojun

    2014-08-01

    Full Text Available By assuming the cosmological “constant” is no longer a constant during the inflation epoch,it is found that the cosmological constant fine-tuning problem is solved.In the meanwhile,inflation models could predict a large tensor-to-scalar ratio,correct power spectral index and a larger running of it.Furthermore,the e-folding number is large enough to overcome the horizon,flatness problems in the Big Bang cosmology.

  7. Dr Kathryn Beers, Assistant Director Physical Sciences and Engineering, Office of Science and Technology Policy Executive Office of the President United States of America visit the CMS experiment at point 5.

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    Dr Kathryn Beers, Assistant Director Physical Sciences and Engineering, Office of Science and Technology Policy Executive Office of the President United States of America visit the CMS experiment at point 5.

  8. Professor Tony F. Chan Assistant Director for Mathematics and Physical Sciences National Science Foundation United States of America on 23rd May 2007. Here visiting ATLAS experiment with P. Jenni and M. Tuts.

    CERN Multimedia

    Maximilien Brice

    2007-01-01

    Professor Tony F. Chan Assistant Director for Mathematics and Physical Sciences National Science Foundation United States of America on 23rd May 2007. Here visiting ATLAS experiment with P. Jenni and M. Tuts.

  9. Operational health physics training

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-06-01

    The initial four sections treat basic information concerning atomic structure and other useful physical quantities, natural radioactivity, the properties of {alpha}, {beta}, {gamma}, x rays and neutrons, and the concepts and units of radiation dosimetry (including SI units). Section 5 deals with biological effects and the risks associated with radiation exposure. Background radiation and man-made sources are discussed next. The basic recommendations of the ICRP concerning dose limitations: justification, optimization (ALARA concepts and applications) and dose limits are covered in Section seven. Section eight is an expanded version of shielding, and the internal dosimetry discussion has been extensively revised to reflect the concepts contained in the MIRD methodology and ICRP 30. The remaining sections discuss the operational health physics approach to monitoring radiation. Individual sections include radiation detection principles, instrument operation and counting statistics, health physics instruments and personnel monitoring devices. The last five sections deal with the nature of, operation principles of, health physics aspects of, and monitoring approaches to air sampling, reactors, nuclear safety, gloveboxes and hot cells, accelerators and x ray sources. Decontamination, waste disposal and transportation of radionuclides are added topics. Several appendices containing constants, symbols, selected mathematical topics, and the Chart of the Nuclides, and an index have been included.

  10. The Fine Structure Constant and Habitable Planets

    CERN Document Server

    Sandora, McCullen

    2016-01-01

    We use the existence of habitable planets to impose anthropic requirements on the fine structure constant, $\\alpha$. To this effect, we present two considerations that restrict its value to be very near the one observed. The first, that the end product of stellar fusion is iron and not one of its neighboring elements, restricts $\\alpha^{-1}$ to be $145\\pm 50$. The second, that radiogenic heat in the Earth's interior remains adequately productive for billions of years, restricts it to be $145\\pm9$. A connection with the grand unified theory window is discussed, effectively providing a route to probe ultra-high energy physics with upcoming advances in planetary science.

  11. The fine structure constant and habitable planets

    Science.gov (United States)

    Sandora, McCullen

    2016-08-01

    We use the existence of habitable planets to impose anthropic requirements on the fine structure constant, α. To this effect, we present two considerations that restrict its value to be very near the one observed. The first, that the end product of stellar fusion is iron and not one of its neighboring elements, restricts α-1 to be 145± 50. The second, that radiogenic heat in the Earth's interior remains adequately productive for billions of years, restricts it to be 145±9. A connection with the grand unified theory window is discussed, effectively providing a route to probe ultra-high energy physics with upcoming advances in planetary science.

  12. [Effects of physics on development of optometry in the United States from the late 19th to the mid 20th century].

    Science.gov (United States)

    Kim, Dal-Young

    2014-08-01

    In this paper, it was studied how physics affected development of optometry in the United States, from aspects of formation and academization of optometry. It was also revealed that history of optometry was analogous to history of engineering. Optics in the 19th century was divided into electromagnetic study of light and visual optics. Development of the visual optics promoted professionalization of ophthalmology that had already started in the 18th century. The visual optics also stimulated formation of optometry and optometrists body in the late 19th century of the United States. The American optometrists body were originated from opticians who had studied visual optics. Publication of several English academic textbooks on visual optics induced appearance of educated opticians (and jewelers). They acquired a right to do the eye examination in the early 20th century after C. F. Prentice's trial in 1897, evolving into optometrists. The opticians could be considered as craftsmen, and they were divided into (dispensing) opticians and optometrists. Such history of American optometrists body is analogous to that of engineers body in the viewpoints of craftsmen origin and separation from craftsmen. Engineers were also originated from educated craftsmen, but were separated from craftsmen when engineering was built up. Education system and academization of optometry was strongly influenced by physics, too. When college education of optometry started at American universities, it was not belonged to medical school but to physics department. Physics and optics were of great importance in curriculum, and early faculty members were mostly physicists. Optometry was academized in the 1920s by the college education, standardization of curriculum, and formation of the American Academy of Optometry. This is also analogous to history of engineering, which was academized by natural sciences, especially by mathematics and physics. The reason why optometry was academized not by

  13. United States Adolescents' Television, Computer, Videogame, Smartphone, and Tablet Use: Associations with Sugary Drinks, Sleep, Physical Activity, and Obesity.

    Science.gov (United States)

    Kenney, Erica L; Gortmaker, Steven L

    2017-03-01

    To quantify the relationships between youth use of television (TV) and other screen devices, including smartphones and tablets, and obesity risk factors. TV and other screen device use, including smartphones, tablets, computers, and/or videogames, was self-reported by a nationally representative, cross-sectional sample of 24 800 US high school students (2013-2015 Youth Risk Behavior Surveys). Students also reported on health behaviors including sugar-sweetened beverage (SSB) intake, physical activity, sleep, and weight and height. Sex-stratified logistic regression models, adjusting for the sampling design, estimated associations between TV and other screen device use and SSB intake, physical activity, sleep, and obesity. Approximately 20% of participants used other screen devices for ≥5 hours daily. Watching TV ≥5 hours daily was associated with daily SSB consumption (aOR = 2.72, 95% CI: 2.23, 3.32) and obesity (aOR = 1.78, 95% CI: 1.40, 2.27). Using other screen devices ≥5 hours daily was associated with daily SSB consumption (aOR = 1.98, 95% CI: 1.69, 2.32), inadequate physical activity (aOR = 1.94, 95% CI: 1.69, 2.25), and inadequate sleep (aOR = 1.79, 95% CI: 1.54, 2.08). Using smartphones, tablets, computers, and videogames is associated with several obesity risk factors. Although further study is needed, families should be encouraged to limit both TV viewing and newer screen devices. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Learning Read-constant Polynomials of Constant Degree modulo Composites

    DEFF Research Database (Denmark)

    Chattopadhyay, Arkadev; Gavaldá, Richard; Hansen, Kristoffer Arnsfelt;

    2011-01-01

    Boolean functions that have constant degree polynomial representation over a fixed finite ring form a natural and strict subclass of the complexity class \\textACC0ACC0. They are also precisely the functions computable efficiently by programs over fixed and finite nilpotent groups. This class...... is not known to be learnable in any reasonable learning model. In this paper, we provide a deterministic polynomial time algorithm for learning Boolean functions represented by polynomials of constant degree over arbitrary finite rings from membership queries, with the additional constraint that each variable...

  15. Effective cosmological constant induced by stochastic fluctuations of Newton's constant

    Science.gov (United States)

    de Cesare, Marco; Lizzi, Fedele; Sakellariadou, Mairi

    2016-09-01

    We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered as a macroscopic effective dynamical quantity. Consistency with Riemannian geometry entails the presence of a time-dependent dark energy term in the modified field equations, which can be expressed in terms of the dynamical gravitational constant. We suggest that the late-time accelerated expansion of the Universe may be ascribed to quantum fluctuations in the geometry of spacetime rather than the vacuum energy from the matter sector.

  16. Effective cosmological constant induced by stochastic fluctuations of Newton's constant

    CERN Document Server

    de Cesare, Marco; Sakellariadou, Mairi

    2016-01-01

    We consider implications of the microscopic dynamics of spacetime for the evolution of cosmological models. We argue that quantum geometry effects may lead to stochastic fluctuations of the gravitational constant, which is thus considered as a macroscopic effective dynamical quantity. Consistency with Riemannian geometry entails the presence of a time-dependent dark energy term in the modified field equations, which can be expressed in terms of the dynamical gravitational constant. We suggest that the late-time accelerated expansion of the Universe may be ascribed to quantum fluctuations in the geometry of spacetime rather than the vacuum energy from the matter sector.

  17. Physical characterization and in vitro evaluation of some generic medications available in pharma market of United Arab Emirates (UAE)

    OpenAIRE

    Abdul Rasool, Bazigha K; Khan, Saeed A.; Shamsueldin, Eiman; Sadik, Raghad

    2011-01-01

    This study is the first attempt in UAE to prove the trustworthiness of the in vitro evaluation to assess the reliability of the generic medications comparing to the brand name. Five generic medicines, two Local (codes: L1, L2), three Arabic (codes: A1, A2 and A3) and the International brand (code: I1) of diclofenac sodium (DS) sustained release tablets, as a model product, was collected randomly from the UAE pharma market. The products were characterized by physical parameters including weigh...

  18. Dimensionless constants, cosmology and other dark matters

    CERN Document Server

    Tegmark, M; Rees, M; Wilczek, F; Tegmark, Max; Aguirre, Anthony; Rees, Martin; Wilczek, Frank

    2006-01-01

    We identify 31 dimensionless physical constants required by particle physics and cosmology, and emphasize that both microphysical constraints and selection effects might help elucidate their origin. Axion cosmology provides an instructive example, in which these two kinds of arguments must both be taken into account, and work well together. If a Peccei-Quinn phase transition occurred before or during inflation, then the axion dark matter density will vary from place to place with a probability distribution. By calculating the net dark matter halo formation rate as a function of all four relevant cosmological parameters and assessing other constraints, we find that this probability distribution, computed at stable solar systems, is arguably peaked near the observed dark matter density. If cosmologically relevant WIMP dark matter is discovered, then one naturally expects comparable densities of WIMPs and axions, making it important to follow up with precision measurements to determine whether WIMPs account for ...

  19. Effect of culturally relevant pedagogy on Latino students' engagement and content mastery on states of matter unit in physical science

    Science.gov (United States)

    Cao, Jennifer

    This research, in response to the lack of empirical evidence of the impact of culturally relevant pedagogy (CRP) on Latino students in science education, examined the effect CRP on Latino students' engagement and content mastery. Quantitative research was conducted with a treatment group that received an intervention unit on states of matter with CRP approaches and a comparison group that did not receive the intervention. The sample comprised approximately 189 eighth-grade students from a Southern Californian middle school. The research findings reveal that CRP approaches had a statistically significant positive effect on student engagement of all ethnic groups in this study, particularly Latino students, while CRP approaches had a statistically significant negative effect on Latino students' content mastery. Three recommendations result from this study, including professional development of CRP for educators, professional development of CRP for educational leaders, and using CRP to address multiculturalism.

  20. From the Rydberg constant to the fundamental constants metrology; De la constante de Rydberg a la metrologie des constantes fondamentales

    Energy Technology Data Exchange (ETDEWEB)

    Nez, F

    2005-06-15

    This document reviews the theoretical and experimental achievements of the author since the beginning of his scientific career. This document is dedicated to the spectroscopy of hydrogen, deuterium and helium atoms. The first part is divided into 6 sub-sections: 1) the principles of hydrogen spectroscopy, 2) the measurement of the 2S-nS/nD transitions, 3) other optical frequency measurements, 4) our contribution to the determination of the Rydberg constant, 5) our current experiment on the 1S-3S transition, 6) the spectroscopy of the muonic hydrogen. Our experiments have improved the accuracy of the Rydberg Constant by a factor 25 in 15 years and we have achieved the first absolute optical frequency measurement of a transition in hydrogen. The second part is dedicated to the measurement of the fine structure constant and the last part deals with helium spectroscopy and the search for optical references in the near infrared range. (A.C.)

  1. Physical physics

    CERN Multimedia

    Schulman, Mark

    2006-01-01

    "Protons, electrons, positrons, quarks, gluons, muons, shmuons! I should have paid better attention to my high scholl physics teacher. If I had, maybe I could have understood even a fration of what Israeli particle physicist Giora Mikenberg was talking about when explaining his work on the world's largest science experiment." (2 pages)

  2. Emergent gravity in spaces of constant curvature

    Science.gov (United States)

    Alvarez, Orlando; Haddad, Matthew

    2017-03-01

    In physical theories where the energy (action) is localized near a submanifold of a constant curvature space, there is a universal expression for the energy (or the action). We derive a multipole expansion for the energy that has a finite number of terms, and depends on intrinsic geometric invariants of the submanifold and extrinsic invariants of the embedding of the submanifold. This is the second of a pair of articles in which we try to develop a theory of emergent gravity arising from the embedding of a submanifold into an ambient space equipped with a quantum field theory. Our theoretical method requires a generalization of a formula due to by Hermann Weyl. While the first paper discussed the framework in Euclidean (Minkowski) space, here we discuss how this framework generalizes to spaces of constant sectional curvature. We focus primarily on anti de Sitter space. We then discuss how such a theory can give rise to a cosmological constant and Planck mass that are within reasonable bounds of the experimental values.

  3. Participating in politics resembles physical activity: general action patterns in international archives, United States archives, and experiments.

    Science.gov (United States)

    Noguchi, Kenji; Handley, Ian M; Albarracín, Dolores

    2011-02-01

    A series of studies examined whether political participation can emerge from general patterns of indiscriminate activity. In the first two studies, general action tendencies were measured by combining national and state-level indicators of high activity (e.g., impulsiveness, pace of life, and physical activity) from international and U.S. data. This action-tendency index positively correlated with a measure of political participation that consisted of voting behaviors and participation in political demonstrations. The following two experimental studies indicated that participants exposed to action words (e.g., go, move) had stronger intentions to vote in an upcoming election and volunteered more time to make phone calls on behalf of a university policy than participants exposed to inaction words did (e.g., relax, stop). These studies suggest that political participation can be predicted from general tendencies toward activity present at the national and state levels, as well as from verbal prompts suggestive of activity.

  4. Mirror QCD and Cosmological Constant

    CERN Document Server

    Pasechnik, Roman; Teryaev, Oleg

    2016-01-01

    An analog of Quantum Chromo Dynamics (QCD) sector known as mirror QCD (mQCD) can affect the cosmological evolution and help in resolving the Cosmological Constant problem. In this work, we explore an intriguing possibility for a compensation of the negative QCD vacuum contribution to the ground state energy density of the universe by means of a positive contribution from the chromomagnetic gluon condensate in mQCD. The trace anomaly compensation condition and the form of the mQCD coupling constant in the infrared limit have been proposed by analysing a partial non-perturbative solution of the Einstein--Yang-Mills equations of motion.

  5. Spatial Variations of Fundamental Constants

    CERN Document Server

    Barrow, John D; Barrow, John D.; Toole, Chris O'

    1999-01-01

    We show that observational limits on the possible time variation of constants of Nature are significantly affected by allowing for both space and time variation. Bekenstein's generalisation of Maxwell's equations to allow for cosmological variation of $alpha$ is investigated in a universe containing spherically symmetric inhomogeneities. The time variation of $alpha$ is determined by the local matter density and hence limits obtained in high-density geophysical enviroments are far more constraining than those obtained at high redshift. This new feature is expected to be a property of a wide class of theories for the variation of constants.

  6. Bouncing universes with varying constants

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, John D [DAMTP, Centre for Mathematical Sciences, Cambridge University, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Kimberly, Dagny [Theoretical Physics, Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ (United Kingdom); Magueijo, Joao [Theoretical Physics, Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BZ (United Kingdom)

    2004-09-21

    We investigate the behaviour of exact closed bouncing Friedmann universes in theories with varying constants. We show that the simplest BSBM varying alpha theory leads to a bouncing universe. The value of alpha increases monotonically, remaining approximately constant during most of each cycle, but increasing significantly around each bounce. When dissipation is introduced we show that in each new cycle the universe expands for longer and to a larger size. We find a similar effect for closed bouncing universes in Brans-Dicke theory, where G also varies monotonically in time from cycle to cycle. Similar behaviour occurs also in varying speed of light theories.

  7. Bouncing Universes with Varying Constants

    CERN Document Server

    Barrow, J D; Magueijo, J; Barrow, John D.; Kimberly, Dagny; Magueijo, Joao

    2004-01-01

    We investigate the behaviour of exact closed bouncing Friedmann universes in theories with varying constants. We show that the simplest BSBM varying-alpha theory leads to a bouncing universe. The value of alpha increases monotonically, remaining approximately constant during most of each cycle, but increasing significantly around each bounce. When dissipation is introduced we show that in each new cycle the universe expands for longer and to a larger size. We find a similar effect for closed bouncing universes in Brans-Dicke theory, where $G$ also varies monotonically in time from cycle to cycle. Similar behaviour occurs also in varying speed of light theories.

  8. Gravitational Instantons and Cosmological Constant

    CERN Document Server

    Cyriac, Josily

    2015-01-01

    The cosmological dynamics of an otherwise empty universe in the presence of vacuum fields is considered. Quantum fluctuations at the Planck scale leads to a dynamical topology of space-time at very small length scales, which is dominated by compact gravitational instantons. The Planck scale vacuum energy acts as a source for the curvature of the these compact gravitational instantons and decouples from the large scale energy momentum tensor of the universe, thus making the observable cosmological constant vanish. However, a Euclidean functional integral over all possible topologies of the gravitational instantons generates a small non-zero value for the large scale cosmological constant, which agrees with the present observations.

  9. Quantum metrology foundation of units and measurements

    CERN Document Server

    Goebel, Ernst O

    2015-01-01

    The International System of Units (SI) is the world's most widely used system of measurement, used every day in commerce and science, and is the modern form of the metric system. It currently comprises the meter (m), the kilogram (kg), the second (s), the ampere (A), the kelvin (K), the candela (cd) and the mole (mol)). The system is changing though, units and unit definitions are modified through international agreements as the technology of measurement progresses, and as the precision of measurements improves. The SI is now being redefined based on constants of nature and their realization by quantum standards. Therefore, the underlying physics and technologies will receive increasing interest, and not only in the metrology community but in all fields of science. This book introduces and explains the applications of modern physics concepts to metrology, the science and the applications of measurements. A special focus is made on the use of quantum standards for the realization of the forthcoming new SI (the...

  10. Effects of Model Resolution and Subgrid-Scale Physics on the Simulation of Daily Precipitation in the Continental United States

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, P B; Iorio, J P; Govindasamy, B; Thompson, S L; Khairoutdinov, M; Randall, D

    2004-07-28

    We analyze simulations of the global climate performed at a range of spatial resolutions to assess the effects of horizontal spatial resolution on the ability to simulate precipitation in the continental United States. The model investigated is the CCM3 general circulation model. We also preliminarily assess the effect of replacing cloud and convective parameterizations in a coarse-resolution (T42) model with an embedded cloud-system resolving model (CSRM). We examine both spatial patterns of seasonal-mean precipitation and daily-timescale temporal variability of precipitation in the continental United States. For DJF and SON, high-resolution simulations produce spatial patterns of seasonal-mean precipitation that agree more closely with observed precipitation patterns than do results from the same model (CCM3) at coarse resolution. However, in JJA and MAM, there is little improvement in spatial patterns of seasonal-mean precipitation with increasing resolution, particularly in the Southeast. This is owed to the dominance of convective (i.e., parameterized) precipitation in these two seasons. We further find that higher-resolution simulations have more realistic daily precipitation statistics. In particular, the well-known tendency at coarse resolution to have too many days with weak precipitation and not enough intense precipitation is partially eliminated in higher-resolution simulations. However, even at the highest resolution examined here (T239), the simulated intensity of the mean and of high-percentile daily precipitation amounts is too low. This is especially true in the Southeast, where the most extreme events occur. A new GCM, in which a cloud-resolving model (CSRM) is embedded in each grid cell and replaces convective and stratiform cloud parameterizations, solves this problem, and actually produces too much precipitation in the form of extreme events. However, in contrast to high-resolution versions of CCM3, this model produces little improvement in

  11. The Physical Design of Special Chain Pumping Unit%特种链条抽油机结构设计

    Institute of Scientific and Technical Information of China (English)

    王集思; 刘兴德; 卢伟宏

    2016-01-01

    设计一种长冲程、大泵径、低冲次,适合稠油、高粘、多砂等作业工况的特种链条抽油机。该机采用特殊链条结构可实现链节的无油自润滑传动;采用无游梁式换向机构,通过特种销轴和特种链节,实现换向无冲击和换向无受力死点。%Design a kind of special chain pumping unit with the characteristics of long stroke,large pump diameter and low speed,suitable for heavy oil,high viscosity,sand etc.operating mode.This machine USES the special chain structure can realize self-lubrication chain transmission;Adopting no-beam steering,through special pin and special link,achieve the reversing no impact and the reversing no dead point.

  12. Effects of radiant exposure and wavelength spectrum of light-curing units on chemical and physical properties of resin cements

    Directory of Open Access Journals (Sweden)

    Adriano Fonseca Lima

    2016-11-01

    Full Text Available Objectives In this study, we evaluated the influence of different radiant exposures provided by single-peak and polywave light-curing units (LCUs on the degree of conversion (DC and the mechanical properties of resin cements. Materials and Methods Six experimental groups were established for each cement (RelyX ARC, 3M ESPE; LuxaCore Dual, Ivoclar Vivadent; Variolink, DMG, according to the different radiant exposures (5, 10, and 20 J/cm2 and two LCUs (single-peak and polywave. The specimens were made (7 mm in length × 2 mm in width × 1 mm in height using silicone molds. After 24 hours of preparation, DC measurement was performed using Fourier transform infrared spectrometry. The same specimens were used for the evaluation of mechanical properties (flexural strength, FS; elastic modulus, E by a three-point bending test. Data were assessed for normality, after which two-way analysis of variance (ANOVA and post hoc Tukey's test were performed. Results No properties of the Variolink cement were influenced by any of the considered experimental conditions. In the case of the RelyX ARC cement, DC was higher when polywave LCU was used; FS and E were not influenced by the conditions evaluated. The LuxaCore cement showed greater sensitivity to the different protocols. Conclusions On the basis of these results, both the spectrum of light emitted and the radiant exposure used could affect the properties of resin cements. However, the influence was material-dependent.

  13. Decay Constants of Vector Mesons

    Institute of Scientific and Technical Information of China (English)

    LI Heng-Mei; WAN Shao-Long

    2008-01-01

    @@ The light vector mesons are studied within the framework of the Bethe-Salpeter equation with the vector-vectortype flat-bottom potential The Bethe-Salpeter wavefunctions and the decay constants of the vector mesons are obtained. All the obtained results, fρ, fφ, and fΚ* , are in agreement with the experimental values, respectively.

  14. Diet and Physical Activity in Rural vs Urban Children and Adolescents in the United States: A Narrative Review.

    Science.gov (United States)

    McCormack, Lacey Arneson; Meendering, Jessica

    2016-03-01

    Current research suggests that the prevalence of obesity is higher among rural youth than urban youth. Due to the health implications that are associated with child and adolescent obesity, it is critical to understand systematic differences in diet and physical activity (PA) behaviors that may be contributing to this disparity in weight. However, varying definitions of rural and inconsistencies in study tools and methodologies may limit the generalizability of findings from research in this area. The objective of this narrative review was to synthesize and critically evaluate existing literature comparing diet and PA behaviors between rural and urban children and adolescents, providing recommendations for future research. Only five studies were found that reported on measures of diet in rural vs urban youth, whereas 16 were found that reported on measures of PA. Dietary assessment tools were generally standard and acceptable; however, differences existed in how dietary outcomes were defined. Few studies used assessment tools that objectively measured PA, and definitions for meeting PA recommendations varied among studies. Very few studies defined rural using the same criteria. Future research on the rural youth obesity disparity should focus on including a high-quality assessment of both diet and PA (as opposed to one or the other) and on using an appropriate and consistent definition of rural.

  15. Variation of fundamental constants: theory

    Science.gov (United States)

    Flambaum, Victor

    2008-05-01

    Theories unifying gravity with other interactions suggest temporal and spatial variation of the fundamental ``constants'' in expanding Universe. There are some hints for the variation of different fundamental constants in quasar absorption spectra and Big Bang nucleosynthesis data. A large number of publications (including atomic clocks) report limits on the variations. We want to study the variation of the main dimensionless parameters of the Standard Model: 1. Fine structure constant alpha (combination of speed of light, electron charge and Plank constant). 2. Ratio of the strong interaction scale (LambdaQCD) to a fundamental mass like electron mass or quark mass which are proportional to Higgs vacuum expectation value. The proton mass is propotional to LambdaQCD, therefore, the proton-to-electron mass ratio comes into this second category. We performed necessary atomic, nuclear and QCD calculations needed to study variation of the fundamental constants using the Big Bang Nucleosynthsis, quasar spectra, Oklo natural nuclear reactor and atomic clock data. The relative effects of the variation may be enhanced in transitions between narrow close levels in atoms, molecules and nuclei. If one will study an enhanced effect, the relative value of systematic effects (which are not enhanced) may be much smaller. Note also that the absolute magnitude of the variation effects in nuclei (e.g. in very narrow 7 eV transition in 229Th) may be 5 orders of magnitude larger than in atoms. A different possibility of enhancement comes from the inversion transitions in molecules where splitting between the levels is due to the quantum tunneling amplitude which has strong, exponential dependence on the electron to proton mass ratio. Our study of NH3 quasar spectra has already given the best limit on the variation of electron to proton mass ratio.

  16. Varying Fine-Structure Constant and the Cosmological Constant Problem

    CERN Document Server

    Fujii, Y

    2003-01-01

    We start with a brief account of the latest analysis of the Oklo phenomenon providing the still most stringent constraint on time-variability of the fine- structure constant $\\alpha$. Comparing this with the recent result from the measurement of distant QSO's appears to indicate a non-uniform time-dependence, which we argue to be related to another recent finding of the accelerating universe. This view is implemented in terms of the scalar-tensor theory, applied specifically to the small but nonzero cosmological constant. Our detailed calculation shows that these two phenomena can be understood in terms of a common origin, a particular behavior of the scalar field, dilaton. We also sketch how this theoretical approach makes it appropriate to revisit non- Newtonian gravity featuring small violation of Weak Equivalence Principle at medium distances.

  17. Varying Fine-Structure Constant and the Cosmological Constant Problem

    Science.gov (United States)

    Fujii, Yasunori

    We start with a brief account of the latest analysis of the Oklo phenomenon providing the still most stringent constraint on time variability of the fine-structure constant α. Comparing this with the recent result from the measurement of distant QSO's appears to indicate a non-uniform time-dependence, which we argue to be related to another recent finding of the accelerating universe. This view is implemented in terms of the scalar-tensor theory, applied specifically to the small but nonzero cosmological constant. Our detailed calculation shows that these two phenomena can be understood in terms of a common origin, a particular behavior of the scalar field, dilaton. We also sketch how this theoretical approach makes it appropriate to revisit non-Newtonian gravity featuring small violation of Weak Equivalence Principle at medium distances.

  18. Cosmological Constant Implementing Mach Principle in General Relativity

    CERN Document Server

    Namavarian, Nadereh

    2016-01-01

    We consider the fact that noticing on the operational meaning of the physical concepts played an impetus role in the appearance of general relativity (GR). Thus, we have paid more attention to the operational definition of the gravitational coupling constant in this theory as a dimensional constant which is gained through an experiment. However, as all available experiments just provide the value of this constant locally, this coupling constant can operationally be meaningful only in a local area. Regarding this point, to obtain an extension of GR for the large scale, we replace it by a conformal invariant model and then, reduce this model to a theory for the cosmological scale via breaking down the conformal symmetry through singling out a specific conformal frame which is characterized by the large scale characteristics of the universe. Finally, we come to the same field equations that historically were proposed by Einstein for the cosmological scale (GR plus the cosmological constant) as the result of his ...

  19. Constant-bandwidth constant-temperature hot-wire anemometer.

    Science.gov (United States)

    Ligeza, P

    2007-07-01

    A constant-temperature anemometer (CTA) enables the measurement of fast-changing velocity fluctuations. In the classical solution of CTA, the transmission band is a function of flow velocity. This is a minor drawback when the mean flow velocity does not significantly change, though it might lead to dynamic errors when flow velocity varies over a considerable range. A modification is outlined, whereby an adaptive controller is incorporated in the CTA system such that the anemometer's transmission band remains constant in the function of flow velocity. For that purpose, a second feedback loop is provided, and the output signal from the anemometer will regulate the controller's parameters such that the transmission bandwidth remains constant. The mathematical model of a CTA that has been developed and model testing data allow a through evaluation of the proposed solution. A modified anemometer can be used in measurements of high-frequency variable flows in a wide range of velocities. The proposed modification allows the minimization of dynamic measurement errors.

  20. (Photo)physical Properties of New Molecular Glasses End-Capped with Thiophene Rings Composed of Diimide and Imine Units

    Science.gov (United States)

    2014-01-01

    New symmetrical arylene bisimide derivatives formed by using electron-donating–electron-accepting systems were synthesized. They consist of a phthalic diimide or naphthalenediimide core and imine linkages and are end-capped with thiophene, bithiophene, and (ethylenedioxy)thiophene units. Moreover, polymers were obtained from a new diamine, N,N′-bis(5-aminonaphthalenyl)naphthalene-1,4,5,8-dicarboximide and 2,5-thiophenedicarboxaldehyde or 2,2′-bithiophene-5,5′-dicarboxaldehyde. The prepared azomethine diimides exhibited glass-forming properties. The obtained compounds emitted blue light with the emission maximum at 470 nm. The value of the absorption coefficient was determined as a function of the photon energy using spectroscopic ellipsometry. All compounds are electrochemically active and undergo reversible electrochemical reduction and irreversible oxidation processes as was found in cyclic voltammetry and differential pulse voltammetry (DPV) studies. They exhibited a low electrochemically (DPV) calculated energy band gap (Eg) from 1.14 to 1.70 eV. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels and Eg were additionally calculated theoretically by density functional theory at the B3LYP/6-31G(d,p) level. The photovoltaic properties of two model compounds as the active layer in organic solar cells in the configuration indium tin oxide/poly(3,4-(ethylenedioxy)thiophene):poly(styrenesulfonate)/active layer/Al under an illumination of 1.3 mW/cm2 were studied. The device comprising poly(3-hexylthiophene) with the compound end-capped with bithiophene rings showed the highest value of Voc (above 1 V). The conversion efficiency of the fabricated solar cell was in the range of 0.69–0.90%. PMID:24966893

  1. How does Planck’s constant influence the macroscopic world?

    Science.gov (United States)

    Yang, Pao-Keng

    2016-09-01

    In physics, Planck’s constant is a fundamental physical constant accounting for the energy-quantization phenomenon in the microscopic world. The value of Planck’s constant also determines in which length scale the quantum phenomenon will become conspicuous. Some students think that if Planck’s constant were to have a larger value than it has now, the quantum effect would only become observable in a world with a larger size, whereas the macroscopic world might remain almost unchanged. After reasoning from some basic physical principles and theories, we found that doubling Planck’s constant might result in a radical change on the geometric sizes and apparent colors of macroscopic objects, the solar spectrum and luminosity, the climate and gravity on Earth, as well as energy conversion between light and materials such as the efficiency of solar cells and light-emitting diodes. From the discussions in this paper, students can appreciate how Planck’s constant affects various aspects of the world in which we are living now.

  2. High precision fundamental constants at the TeV scale

    CERN Document Server

    Moch, S; Alekhin, S; Blumlein, J; de la Cruz, L; Dittmaier, S; Dowling, M; Erler, J; Espinosa, J R; Fuster, J; Tormo, X Garcia i; Hoang, A H; Huss, A; Kluth, S; Mulders, M; Papanastasiou, A S; Piclum, J; Rabbertz, K; Schwinn, C; Schulze, M; Shintani, E; Uwer, P; Zerf, N

    2014-01-01

    This report summarizes the proceedings of the 2014 Mainz Institute for Theoretical Physics (MITP) scientific program on "High precision fundamental constants at the TeV scale". The two outstanding parameters in the Standard Model dealt with during the MITP scientific program are the strong coupling constant $\\alpha_s$ and the top-quark mass $m_t$. Lacking knowledge on the value of those fundamental constants is often the limiting factor in the accuracy of theoretical predictions. The current status on $\\alpha_s$ and $m_t$ has been reviewed and directions for future research have been identified.

  3. Socioeconomic and Demographic Factors for Spousal Resemblance in Obesity Status and Habitual Physical Activity in the United States

    Directory of Open Access Journals (Sweden)

    Hsin-Jen Chen

    2014-01-01

    Full Text Available Studies suggested that the married population has an increased risk of obesity and assimilation between spouses’ body weight. We examined what factors may affect married spouses’ resemblance in weight status and habitual physical activity (HPA and the association of obesity/HPA with spouses’ sociodemoeconomic characteristics and lifestyles. Medical Expenditure Panel Survey data of 11,403 adult married couples in the US during years 2006–2008 were used. Absolute-scale difference and relative-scale resemblance indices (correlation and kappa coefficients in body mass index (BMI and HPA were estimated by couples’ socioeconomic and demographic characteristics. We found that spousal difference in BMI was smaller for couples with a lower household income, for who were both unemployed, and for older spouses. Correlation coefficient between spouses’ BMI was 0.24, differing by race/ethnicity and family size. Kappa coefficient for weight status (obesity: BMI ≥ 30, overweight: 30 > BMI ≥ 25 was 0.11 and 0.35 for HPA. Never-working women’s husbands had lower odds of obesity than employed women’s husbands (OR = 0.69 (95% CI = 0.53–0.89. Men’s unemployment status was associated with wives’ greater odds of obesity (OR = 1.31 (95% CI = 1.01–1.71. HPA was associated with men’s employment status and income level, but not with women’s. The population representative survey showed that spousal resemblance in weight status and HPA varied with socioeconomic and demographic factors.

  4. Three pion nucleon coupling constants

    CERN Document Server

    Arriola, E Ruiz; Perez, R Navarro

    2016-01-01

    There exist four pion nucleon coupling constants, $f_{\\pi^0, pp}$, $-f_{\\pi^0, nn}$, $f_{\\pi^+, pn} /\\sqrt{2}$ and $ f_{\\pi^-, np} /\\sqrt{2}$ which coincide when up and down quark masses are identical and the electron charge is zero. While there is no reason why the pion-nucleon-nucleon coupling constants should be identical in the real world, one expects that the small differences might be pinned down from a sufficiently large number of independent and mutually consistent data. Our discussion provides a rationale for our recent determination $$f_p^2 = 0.0759(4) \\, , \\quad f_{0}^2 = 0.079(1) \\,, \\quad f_{c}^2 = 0.0763(6) \\, , $$ based on a partial wave analysis of the $3\\sigma$ self-consistent nucleon-nucleon Granada-2013 database comprising 6713 published data in the period 1950-2013.

  5. The Borderlands - A region of physical and cultural diversity: Chapter 2 in United States-Mexican Borderlands: Facing tomorrow's challenges through USGS science

    Science.gov (United States)

    Parcher, Jean W.; Papoulias, Diana M.; Woodward, Dennis G.; Durall, Roger A.

    2013-01-01

    The area surrounding the United States–Mexican border is very physically and culturally diverse and cannot be generalized by any single description. To assist in an accurate appraisal and understanding of this remarkable region, the Borderlands team has divided it into eight subareas based on the watershed subareas of the U.S. Geological Survey Border Environmental Health Initiative (http://borderhealth.cr.usgs.gov) (fig. 2–1), the boundaries of which are defined primarily by surface-water drainage basins. The drainage basins directly adjacent to or crossing the international boundary were automatically included in the defined border region, as were those basins that contain unconsolidated aquifers that extend to or cross the international boundary. Also, “protected areas” adjacent to included basins were selectively added to the defined border region. Though some geographic features are entirely within the Borderlands, many features—deserts, mountain ranges, rivers, etc.— extend beyond the region boundaries but are still influential to Borderlands environments (fig. 2–2). In some cases, the authors of the following chapters have made fine adjustments to the Borderlands boundaries, and they have described those alterations where necessary. By describing and studying these subareas individually and comparing them to one another, we can emphasize the physical and cultural diversity that makes the Borderlands such an important geographic area.

  6. Statistical Modelling of the Soil Dielectric Constant

    Science.gov (United States)

    Usowicz, Boguslaw; Marczewski, Wojciech; Bogdan Usowicz, Jerzy; Lipiec, Jerzy

    2010-05-01

    The dielectric constant of soil is the physical property being very sensitive on water content. It funds several electrical measurement techniques for determining the water content by means of direct (TDR, FDR, and others related to effects of electrical conductance and/or capacitance) and indirect RS (Remote Sensing) methods. The work is devoted to a particular statistical manner of modelling the dielectric constant as the property accounting a wide range of specific soil composition, porosity, and mass density, within the unsaturated water content. Usually, similar models are determined for few particular soil types, and changing the soil type one needs switching the model on another type or to adjust it by parametrization of soil compounds. Therefore, it is difficult comparing and referring results between models. The presented model was developed for a generic representation of soil being a hypothetical mixture of spheres, each representing a soil fraction, in its proper phase state. The model generates a serial-parallel mesh of conductive and capacitive paths, which is analysed for a total conductive or capacitive property. The model was firstly developed to determine the thermal conductivity property, and now it is extended on the dielectric constant by analysing the capacitive mesh. The analysis is provided by statistical means obeying physical laws related to the serial-parallel branching of the representative electrical mesh. Physical relevance of the analysis is established electrically, but the definition of the electrical mesh is controlled statistically by parametrization of compound fractions, by determining the number of representative spheres per unitary volume per fraction, and by determining the number of fractions. That way the model is capable covering properties of nearly all possible soil types, all phase states within recognition of the Lorenz and Knudsen conditions. In effect the model allows on generating a hypothetical representative of

  7. Assessment of Diet and Physical Activity in Paediatric Non-Alcoholic Fatty Liver Disease Patients: A United Kingdom Case Control Study

    Directory of Open Access Journals (Sweden)

    Philippa S. Gibson

    2015-11-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD is the most common cause of chronic liver disease in children, with prevalence rising alongside childhood obesity rates. This study aimed to characterise the habitual diet and activity behaviours of children with NAFLD compared to obese children without liver disease in the United Kingdom (UK. Twenty-four biopsy-proven paediatric NAFLD cases and eight obese controls without biochemical or radiological evidence of NAFLD completed a 24-h dietary recall, a Physical Activity Questionnaire (PAQ, a Dutch Eating Behavior Questionnaire (DEBQ and a 7-day food and activity diary (FAD, in conjunction with wearing a pedometer. Groups were well matched for age and gender. Obese children had higher BMI z-scores (p = 0.006 and BMI centiles (p = 0.002 than participants with NAFLD. After adjusting for multiple hypotheses testing and controlling for differences in BMI, no differences in macro- or micronutrient intake were observed as assessed using either 24-h recall or 7-day FAD (p > 0.001. Under-reporting was prevalent (NAFLD 75%, Obese Control 87%: p = 0.15. Restrained eating behaviours were significantly higher in the NAFLD group (p = 0.005, who also recorded more steps per day than the obese controls (p = 0.01. In conclusion, this is the first study to assess dietary and activity patterns in a UK paediatric NAFLD population. Only a minority of cases and controls were meeting current dietary and physical activity recommendations. Our findings do not support development of specific dietary/ physical activity guidelines for children with NAFLD; promoting adherence with current general paediatric recommendations for health should remain the focus of clinical management.

  8. Assessment of Diet and Physical Activity in Paediatric Non-Alcoholic Fatty Liver Disease Patients: A United Kingdom Case Control Study.

    Science.gov (United States)

    Gibson, Philippa S; Lang, Sarah; Gilbert, Marianne; Kamat, Deepa; Bansal, Sanjay; Ford-Adams, Martha E; Desai, Ashish P; Dhawan, Anil; Fitzpatrick, Emer; Moore, J Bernadette; Hart, Kathryn H

    2015-11-26

    Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children, with prevalence rising alongside childhood obesity rates. This study aimed to characterise the habitual diet and activity behaviours of children with NAFLD compared to obese children without liver disease in the United Kingdom (UK). Twenty-four biopsy-proven paediatric NAFLD cases and eight obese controls without biochemical or radiological evidence of NAFLD completed a 24-h dietary recall, a Physical Activity Questionnaire (PAQ), a Dutch Eating Behavior Questionnaire (DEBQ) and a 7-day food and activity diary (FAD), in conjunction with wearing a pedometer. Groups were well matched for age and gender. Obese children had higher BMI z-scores (p = 0.006) and BMI centiles (p = 0.002) than participants with NAFLD. After adjusting for multiple hypotheses testing and controlling for differences in BMI, no differences in macro- or micronutrient intake were observed as assessed using either 24-h recall or 7-day FAD (p > 0.001). Under-reporting was prevalent (NAFLD 75%, Obese Control 87%: p = 0.15). Restrained eating behaviours were significantly higher in the NAFLD group (p = 0.005), who also recorded more steps per day than the obese controls (p = 0.01). In conclusion, this is the first study to assess dietary and activity patterns in a UK paediatric NAFLD population. Only a minority of cases and controls were meeting current dietary and physical activity recommendations. Our findings do not support development of specific dietary/ physical activity guidelines for children with NAFLD; promoting adherence with current general paediatric recommendations for health should remain the focus of clinical management.

  9. Why isn't the solar constant a constant?

    CERN Document Server

    Li, K J; Xu, J C; Gao, P X; Yang, L H; Liang, H F; Zhan, L S

    2012-01-01

    In order to probe the mechanism of variations of the Solar Constant on the inter-solar-cycle scale, total solar irradiance (TSI, the so-called Solar Constant) in the time interval of 7 November 1978 to 20 September 2010 is decomposed into three components through the empirical mode decomposition and time-frequency analyses. The first component is the rotation signal, counting up to 42.31% of the total variation of TSI, which is understood to be mainly caused by large magnetic structures, including sunspot groups. The second is an annual-variation signal, counting up to 15.17% of the total variation, the origin of which is not known at this point in time. Finally, the third is the inter-solar-cycle signal, counting up to 42.52%, which are inferred to be caused by the network magnetic elements in quiet regions, whose magnetic flux ranges from $(4.27-38.01)\\times10^{19}$ Mx.

  10. Low uncertainty Boltzmann constant determinations and the kelvin redefinition.

    Science.gov (United States)

    Fischer, J

    2016-03-28

    At its 25th meeting, the General Conference on Weights and Measures (CGPM) approved Resolution 1 'On the future revision of the International System of Units, the SI', which sets the path towards redefinition of four base units at the next CGPM in 2018. This constitutes a decisive advance towards the formal adoption of the new SI and its implementation. Kilogram, ampere, kelvin and mole will be defined in terms of fixed numerical values of the Planck constant, elementary charge, Boltzmann constant and Avogadro constant, respectively. The effect of the new definition of the kelvin referenced to the value of the Boltzmann constant k is that the kelvin is equal to the change of thermodynamic temperature T that results in a change of thermal energy kT by 1.380 65×10(-23) J. A value of the Boltzmann constant suitable for defining the kelvin is determined by fundamentally different primary thermometers such as acoustic gas thermometers, dielectric constant gas thermometers, noise thermometers and the Doppler broadening technique. Progress to date of the measurements and further perspectives are reported. Necessary conditions to be met before proceeding with changing the definition are given. The consequences of the new definition of the kelvin on temperature measurement are briefly outlined. © 2016 The Author(s).

  11. Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; And Others

    1988-01-01

    Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

  12. Localized (super)gravity and cosmological constant

    Science.gov (United States)

    Kakushadze, Zurab

    2000-11-01

    We consider localization of gravity in domain wall solutions of Einstein's gravity coupled to a scalar field with a generic potential. We discuss conditions on the scalar potential such that domain wall solutions are non-singular. Such solutions even exist for appropriate potentials which have no minima at all and are unbounded below. Domain walls of this type have infinite tension, while usual kink type of solutions interpolating between two AdS minima have finite tension. In the latter case the cosmological constant on the domain wall is necessarily vanishing, while in the former case it can be zero or negative. Positive cosmological constant is allowed for singular domain walls. We discuss non-trivial conditions for physically allowed singularities arising from the requirement that truncating the space at the singularities be consistent. Non-singular domain walls with infinite tension might a priori avoid recent "no-go" theorems indicating impossibility of supersymmetric embedding of kink type of domain walls in gauged supergravity. We argue that (non-singular) domain walls are stable even if they have infinite tension. This is essentially due to the fact that localization of gravity in smooth domain walls is a Higgs mechanism corresponding to a spontaneous breakdown of translational invariance. As to discontinuous domain walls arising in the presence of δ-function "brane" sources, they explicitly break translational invariance. Such solutions cannot therefore be thought of as limits of smooth domain walls. We point out that if the scalar potential has no minima and approaches finite negative values at infinity, then higher derivative terms are under control, and do not affect the cosmological constant which is vanishing for such backgrounds. Nonetheless, we also point out that higher curvature terms generically delocalize gravity, so that the desired lower-dimensional Newton's law is no longer reproduced.

  13. Positive Cosmological Constant and Quantum Theory

    Directory of Open Access Journals (Sweden)

    Felix M. Lev

    2010-11-01

    Full Text Available We argue that quantum theory should proceed not from a spacetime background but from a Lie algebra, which is treated as a symmetry algebra. Then the fact that the cosmological constant is positive means not that the spacetime background is curved but that the de Sitter (dS algebra as the symmetry algebra is more relevant than the Poincare or anti de Sitter ones. The physical interpretation of irreducible representations (IRs of the dS algebra is considerably different from that for the other two algebras. One IR of the dS algebra splits into independent IRs for a particle and its antiparticle only when Poincare approximation works with a high accuracy. Only in this case additive quantum numbers such as electric, baryon and lepton charges are conserved, while at early stages of the Universe they could not be conserved. Another property of IRs of the dS algebra is that only fermions can be elementary and there can be no neutral elementary particles. The cosmological repulsion is a simple kinematical consequence of dS symmetry on quantum level when quasiclassical approximation is valid. Therefore the cosmological constant problem does not exist and there is no need to involve dark energy or other fields for explaining this phenomenon (in agreement with a similar conclusion by Bianchi and Rovelli.

  14. Variation of fundamental constants: theory and observations

    CERN Document Server

    Flambaum, V V

    2007-01-01

    Review of recent works devoted to the variation of the fundamental constants is presented including atomic clocks, quasar absorption spectra, and Oklo natural nuclear reactor data. Assuming linear variation with time we can compare different results. From the quasar absorption spectra: $\\dot{\\mu}/\\mu=(1 \\pm 3) \\times 10^{-16}$ yr$^{-1}$. A combination of this result and the atomic clock results gives the best limt on variation of $\\alpha$: $\\dot{\\alpha}/\\alpha=(-0.8 \\pm 0.8) \\times 10^{-16}$ yr$^{-1}$. The Oklo natural reactor gives the best limit on the variation of $m_s/\\Lambda_{QCD}$ where $m_s$ is the strange quark mass. Huge enhancement of the relative variation effects happens in transitions between close atomic, molecular and nuclear energy levels. We suggest several new cases where the levels are very narrow. Large enhancement of the variation effects is also possible in cold atomic and molecular collisions near Feshbach resonance. Massive bodies (stars or galaxies) can also affect physical constants....

  15. Local constants of motion imply information propagation

    Science.gov (United States)

    Friesdorf, M.; Werner, A. H.; Goihl, M.; Eisert, J.; Brown, W.

    2015-11-01

    Interacting quantum many-body systems are expected to thermalize, in the sense that the evolution of local expectation values approaches a stationary value resembling a thermal ensemble. This intuition is notably contradicted in systems exhibiting many-body localisation (MBL). In stark contrast to the non-interacting case of Anderson localisation, the entanglement of states grows without limit over time, albeit slowly. In this work, we establish a novel link between quantum information theory and notions of condensed matter physics, capturing this phenomenon in the Heisenberg picture. We show that the mere existence of local constants of motion, often taken as the defining property of MBL, together with a generic spectrum of the Hamiltonian, is already sufficient to rigorously prove information propagation: these systems can be used to send a classical bit over arbitrary distances, in that the impact of a local perturbation can be detected arbitrarily far away. This counterintuitive result is compatible with and further corroborates the intuition of a slow entanglement growth following global quenches in MBL systems. We perform a detailed perturbation analysis of quasi-local constants of motion and also show that they indeed can be used to construct efficient spectral tensor networks, as recently suggested. Our results provide a detailed and at the same time model-independent picture of information propagation in MBL systems.

  16. Local Pain Dynamics during Constant Exhaustive Exercise.

    Science.gov (United States)

    Slapsinskaite, Agne; Razon, Selen; Balagué Serre, Natàlia; Hristovski, Robert; Tenenbaum, Gershon

    2015-01-01

    The purpose of this study was to delineate the topological dynamics of pain and discomfort during constant exercise performed until volitional exhaustion. Eleven physical education students were tested while cycling and running at a "hard" intensity level (e.g., corresponding to Borg's RPE (6-20) = 15). During the tests, participants reported their discomfort and pain on a body map every 15s. "Time on task" for each participant was divided into five equal non-overlapping temporal windows within which their ratings were considered for analysis. The analyses revealed that the number of body locations with perceived pain and discomfort increased throughout the five temporal windows until reaching the mean (± SE) values of 4.2 ± 0.7 and 4.1 ± 0.6 in cycling and running, respectively. The dominant locations included the quadriceps and hamstrings during cycling and quadriceps and chest during running. In conclusion, pain seemed to spread throughout the body during constant cycling and running performed up to volitional exhaustion with differences between cycling and running in the upper body but not in the lower body dynamics.

  17. Local Pain Dynamics during Constant Exhaustive Exercise.

    Directory of Open Access Journals (Sweden)

    Agne Slapsinskaite

    Full Text Available The purpose of this study was to delineate the topological dynamics of pain and discomfort during constant exercise performed until volitional exhaustion. Eleven physical education students were tested while cycling and running at a "hard" intensity level (e.g., corresponding to Borg's RPE (6-20 = 15. During the tests, participants reported their discomfort and pain on a body map every 15s. "Time on task" for each participant was divided into five equal non-overlapping temporal windows within which their ratings were considered for analysis. The analyses revealed that the number of body locations with perceived pain and discomfort increased throughout the five temporal windows until reaching the mean (± SE values of 4.2 ± 0.7 and 4.1 ± 0.6 in cycling and running, respectively. The dominant locations included the quadriceps and hamstrings during cycling and quadriceps and chest during running. In conclusion, pain seemed to spread throughout the body during constant cycling and running performed up to volitional exhaustion with differences between cycling and running in the upper body but not in the lower body dynamics.

  18. Gravitational domain walls and the dynamics of the gravitational constant G

    Science.gov (United States)

    Bunster, Claudio; Gomberoff, Andrés

    2017-07-01

    From the point of view of elementary particle physics, the gravitational constant G is extraordinarily small. This has led to asking whether it could have decayed to its present value from an initial one commensurate with microscopical units. A mechanism that leads to such a decay is proposed herein. It is based on assuming that G may take different values within regions of the universe separated by a novel kind of domain wall, a "G -wall." The idea is implemented by introducing a gauge potential Aμ ν ρ, and its conjugate D , which determines the value of G as an integration constant rather than a fundamental constant. The value of G jumps when one goes through a G -wall. The procedure extends one previously developed for the cosmological constant, but the generalization is far from straightforward: (i) The intrinsic geometry of a G -wall is not the same as seen from its two sides because the second law of black hole thermodynamics mandates that the jump in G must cause a discontinuity in the scale of length. (ii) The size of the decay step in G is controlled by a function G (D ) which may be chosen so as to diminish the value of G towards the asymptote G =0 . It is shown that: (i) The dynamics of the gravitational field with G treated as a dynamical variable, coupled to G -walls and matter, follows from an action principle, which is given. (ii) A particle that impinges on a G -wall may be refracted or reflected. (iii) The various forces between two particles change when a G -wall is inserted in between them. (iv) G -walls may be nucleated trough tunneling and thermal effects, whose semiclassical probabilities are evaluated. (v) If the action principle is constructed properly, the entropy of a black hole increases when the value of the gravitational constant is changed through the absorption of a G-wall by the hole.

  19. Cryptography in constant parallel time

    CERN Document Server

    Applebaum, Benny

    2013-01-01

    Locally computable (NC0) functions are 'simple' functions for which every bit of the output can be computed by reading a small number of bits of their input. The study of locally computable cryptography attempts to construct cryptographic functions that achieve this strong notion of simplicity and simultaneously provide a high level of security. Such constructions are highly parallelizable and they can be realized by Boolean circuits of constant depth.This book establishes, for the first time, the possibility of local implementations for many basic cryptographic primitives such as one-way func

  20. Henry's law constants of polyols

    Directory of Open Access Journals (Sweden)

    S. Compernolle

    2014-05-01

    Full Text Available Henry's law constants (HLC are derived for several polyols bearing between 2 and 6 hydroxyl groups, based on literature data for water activity, vapour pressure and/or solubility. Depending on the case, infinite dilution activity coefficients (IDACs, solid state pressures or activity coefficient ratios are obtained as intermediary results. For most compounds, these are the first values reported, while others compare favourably with literature data in most cases. Using these values and those from a previous work (Compernolle and Müller, 2014, an assessment is made on the partitioning of polyols, diacids and hydroxy acids to droplet and aqueous aerosol.

  1. Exact constants in approximation theory

    CERN Document Server

    Korneichuk, N

    1991-01-01

    This book is intended as a self-contained introduction for non-specialists, or as a reference work for experts, to the particular area of approximation theory that is concerned with exact constants. The results apply mainly to extremal problems in approximation theory, which in turn are closely related to numerical analysis and optimization. The book encompasses a wide range of questions and problems: best approximation by polynomials and splines; linear approximation methods, such as spline-approximation; optimal reconstruction of functions and linear functionals. Many of the results are base

  2. Low Redundancy in Static Dictionaries with Constant Query Time

    DEFF Research Database (Denmark)

    Pagh, Rasmus

    2001-01-01

    A static dictionary is a data structure for storing subsets of a finite universe U, so that membership queries can be answered efficiently. We study this problem in a unit cost RAM model with word size Ω(log |U|), and show that for n-element subsets, constant worst case query time can be obtained...

  3. Kepler's Constant and WDS Orbit

    CERN Document Server

    Siregar, S

    2012-01-01

    The aim of this work are to find a Kepler's constant by using polynomial regression of the angular separation \\rho = \\rho(t) and the position angle \\theta = \\theta(t). The Kepler's constant obtained is used to derive the element of orbit. As a case study the angular separation and the position angle of the WDS 00063 +5826 and the WDS 04403-5857 were investigated. For calculating the element of orbit the Thiele-Innes van den Bos method is used. The rough data of the angular separation \\rho(t) and the position angle \\theta(t) are taken from the US Naval Observatory, Washington. This work also presents the masses and absolute bolometric magnitudes of each star.These stars include into the main-sequence stars with the spectral class G5V for WDS04403-5857and the type of spectrum G3V for WDS 00063+5826. The life time of the primary star and the secondary star of WDS 04403-5857 nearly equal to 20 Gyr. The life time of the primary star and the secondary star of WDS 00063+5826 are 20 Gyr and 19 Gyr, respectively.

  4. Fields of rational constants of cyclic factorizable derivations

    Directory of Open Access Journals (Sweden)

    Janusz Zielinski

    2015-12-01

    Full Text Available We describe all rational constants of a large family of four-variable cyclic factorizable derivations. Thus, we determine all rational first integrals of their corresponding systems of differential equations. Moreover, we give a characteristic of all four-variable Lotka-Volterra derivations with a nontrivial rational constant. All considerations are over an arbitrary field of characteristic zero. Our main tool is the investigation of the cofactors of strict Darboux polynomials. Factorizable derivations are important in derivation theory. Namely, we may associate the factorizable derivation with any given derivation of a polynomial ring and that construction helps to determine rational constants of arbitrary derivations. Besides, Lotka-Volterra systems play a significant role in population biology, laser physics and plasma physics.

  5. Perfil de fisioterapeutas brasileiros que atuam em unidades de terapia intensiva A profile of Brazilian physical therapists in intensive care units

    Directory of Open Access Journals (Sweden)

    Emilia Nozawa

    2008-01-01

    Full Text Available Este estudo visou investigar o perfil dos fisioterapeutas que atuam nas unidades de terapia intensiva (UTIs no Brasil, focalizando a direção do serviço, técnicas fisioterapêuticas empregadas e nível de autonomia em relação à ventilação mecânica invasiva e não-invasiva. Questionários foram enviados aos chefes dos serviços de fisioterapia de 1.192 hospitais registrados na Associação Médica de Terapia Intensiva, com retorno de 461 (39% UTIs. Em 88% destas, os serviços são chefiados por fisioterapeutas; em 78%, compostos por até oito fisioterapeutas; 44,4% dos fisioterapeutas trabalham em regime de 30 horas semanais e 46,1% têm contrato de trabalho. Há assistência fisioterapêutica durante 24 horas em 33,6% das UTIs; 88% delas mantêm assistência nos finais de semana. Quanto às técnicas fisioterapêuticas, todos realizam mobilização, posicionamento e aspiração; 91,5% atuam na ventilação não-invasiva, sendo que 43% trabalham com total autonomia. Em relação à ventilação mecânica invasiva, 80% realizam extubação; 79,2% realizam regulagem e desmame do ventilador; entretanto, só 22% têm total autonomia (78% necessitam de protocolo ou opinião da equipe médica. Os fisioterapeutas brasileiros atuam, em sua maioria, em instituições privadas e assistenciais, cujos serviços são chefiados por fisioterapeutas. Têm relativa autonomia quanto às técnicas fisioterapêuticas e o manuseio da ventilação mecânica não-invasiva mas, no caso da invasiva, atuam sob diretiva da equipe médica.The purpose of this study was to outline a profile of physical therapists who work in intensive care units (ICU in Brazil, focusing on service management, techniques used, and the degree of therapists' autonomy regarding invasive and non-invasive mechanical ventilation. Questionnaires were sent to the heads of physical therapy (PT services of 1,192 hospitals registered at the Brazilian Intensive Care Medicine Association and 461

  6. Some Debye temperatures from single-crystal elastic constant data

    Science.gov (United States)

    Robie, R.A.; Edwards, J.L.

    1966-01-01

    The mean velocity of sound has been calculated for 14 crystalline solids by using the best recent values of their single-crystal elastic stiffness constants. These mean sound velocities have been used to obtain the elastic Debye temperatures ??De for these materials. Models of the three wave velocity surfaces for calcite are illustrated. ?? 1966 The American Institute of Physics.

  7. Using synthetic tracers as a proxy for summertime PM2.5 air quality over the Northeastern United States in physical climate models

    Science.gov (United States)

    Fang, Yuanyuan; Fiore, Arlene M.; Lamarque, Jean-FrançOis; Horowitz, Larry W.; Lin, Meiyun

    2013-02-01

    Fine particulate matter (PM2.5) is a criteria pollutant. Its sensitivity to meteorology implies its distribution will likely change with climate shifts. Limited availability of global climate models with full chemistry complicates efforts to assess rigorously the uncertainties in the PM2.5 response to a warming climate. We evaluate the potential for PM2.5 distributions in a chemistry-climate model under current-day and warmer climate conditions over the Northeastern United States to be represented by a Synthetic Aerosol tracer (SAt). The SAt implemented into the Geophysical Fluid Dynamics Laboratory chemistry-climate model (AM3) follows the protocol of a recent multimodel community effort (HTAP), with CO emissions, 25-day chemical lifetime, and wet deposition rate of sulfate. Over the Northeastern United States, the summer daily time series of SAt correlates strongly with that of PM2.5, with similar cumulative density functions under both present and future climate conditions. With a linear regression model derived from PM2.5 and SAt in the current-day simulation, we reconstruct both the current-day and future PM2.5 daily time series from the simulated SAt. This reconstruction captures the summer mean PM2.5, the incidence of days above the 24-h mean PM2.5 NAAQS, and PM2.5 responses to climate change. This reconstruction also works over other polluted Northern Hemispheric regions and in spring. Our proof-of-concept study demonstrates that simple tracers can be developed to mimic PM2.5, including its response to climate change, as an easy-to-implement and low-cost addition to physical climate models that should help air quality managers to reap the benefits of climate models that have no chemistry.

  8. Graphs with constant μ and μ

    NARCIS (Netherlands)

    van Dam, E.R.; Haemers, W.H.

    1995-01-01

    A graph G has constant u = u(G) if any two vertices that are not adjacent have u common neighbours. G has constant u and u if G has constant u = u(G), and its complement G has constant u = u(G). If such a graph is regular, then it is strongly regular, otherwise precisely two vertex degrees occur. We

  9. Cosmological constant and curved 5D geometry

    CERN Document Server

    Ito, M

    2002-01-01

    We study the value of cosmological constant in de Sitter brane embedded in five dimensions with positive, vanishing and negative bulk cosmological constant. In the case of negative bulk cosmological constant, we show that not zero but tiny four-dimensional cosmological constant can be realized by tiny deviation from bulk curvature of the Randall-Sundrum model.

  10. Stability constant estimator user`s guide

    Energy Technology Data Exchange (ETDEWEB)

    Hay, B.P.; Castleton, K.J.; Rustad, J.R.

    1996-12-01

    The purpose of the Stability Constant Estimator (SCE) program is to estimate aqueous stability constants for 1:1 complexes of metal ions with ligands by using trends in existing stability constant data. Such estimates are useful to fill gaps in existing thermodynamic databases and to corroborate the accuracy of reported stability constant values.

  11. (Krauss) at constant high temperatures

    African Journals Online (AJOL)

    the various physical and chemical factors that may affect freshwater snails. However ... order to assess the effect of temperature on the organism, it is essential to ..... of snails by parasites is of cardinal importance to shed light on the population ...

  12. Larson-Miller Constant of Heat-Resistant Steel

    Science.gov (United States)

    Tamura, Manabu; Abe, Fujio; Shiba, Kiyoyuki; Sakasegawa, Hideo; Tanigawa, Hiroyasu

    2013-06-01

    Long-term rupture data for 79 types of heat-resistant steels including carbon steel, low-alloy steel, high-alloy steel, austenitic stainless steel, and superalloy were analyzed, and a constant for the Larson-Miller (LM) parameter was obtained in the current study for each material. The calculated LM constant, C, is approximately 20 for heat-resistant steels and alloys except for high-alloy martensitic steels with high creep resistance, for which C ≈ 30 . The apparent activation energy was also calculated, and the LM constant was found to be proportional to the apparent activation energy with a high correlation coefficient, which suggests that the LM constant is a material constant possessing intrinsic physical meaning. The contribution of the entropy change to the LM constant is not small, especially for several martensitic steels with large values of C. Deformation of such martensitic steels should accompany a large entropy change of 10 times the gas constant at least, besides the entropy change due to self-diffusion.

  13. Constant training in direct ophthalmoscopy

    Directory of Open Access Journals (Sweden)

    Younan HC

    2017-08-01

    Full Text Available Helen-Cara Younan, Rishi Iyer, Janaki Natasha DesaiFaculty of Medicine, Imperial College London, London, UKWe read with great interest the review by Ricci and Ferraz on the advances in training and practice in ophthalmoscopy simulation.1As final year medical students, we have recently experienced direct ophthalmoscopy teaching and agree with the authors that “simulation is a helpful tool in ophthalmoscopy training”.1 Indeed, in our experience, simulation is useful in teaching a wide variety of clinical skills including venepuncture, intravenous cannulation, and catheterization. We were taught all of these clinical skills in our first clinical year of study through use of simulation models. With regards to our direct ophthalmoscopy teaching, we were first taught to recognize the normal retina and different retinal pathologies using images, before practicing our technique and recognition of those images in a model similar to the THELMA (The Human Eye Learning Model Assistant described by the authors.1However, we feel that the use of simulation models alone is not enough to provide confidence and competency in direct ophthalmoscopy among medical students. The authors conclude that “constant training is a well-known strategy for skill enhancement”,1 and we have found that a lack of constant training in direct ophthalmoscopy is evident. After learning venepuncture, cannulation, and catheterization on the simulation models, we were able to observe doctors performing these skills before performing them on patients either in the wards or in theatre. These are skills that we are constantly trained in across a wide variety of medical and surgical attachments. However, opportunities to observe and practice ophthalmoscopy during our attachments are more limited, and thus we are not continuing to use the skills we learn.Authors' replyLucas Holderegger Ricci,1 Caroline Amaral Ferraz21Department of Ophthalmology, School of Medicine, Laureate

  14. Physics the Google Way

    Science.gov (United States)

    Ward, David W.

    2005-09-01

    Are we smarter now than Socrates was in his time? Society as a whole certainly enjoys a higher degree of education, but humans as a species probably don't get intrinsically smarter with time. Our knowledge base, however, continues to grow at an unprecedented rate, so how then do we keep up? The printing press was one of the earliest technological advances that expanded our memory and made possible our present intellectual capacity. We are now faced with a new technological advance of the same magnitude, the Internet, but how do we use it effectively? A new tool is available on Google™ (http://www.google.com)that allows a user not only to numerically evaluate equations but also to automatically perform unit analysis and conversion, with most of the fundamental physical constants built in. This paper describes some of its capabilities.

  15. Physics the google way

    CERN Document Server

    Ward, D W

    2004-01-01

    Are we smarter now than Socrates was in his time? Society as a whole certainly enjoys a higher degree of education, but humans as a species probably don't get intrinsically smarter with time. Our knowledge base, however, continues to grow at an unprecedented rate, so how then do we keep up? The printing press was one of the earliest technological advances that expanded our memory and made possible our present intellectual capacity. We are now faced with a new technological advance of the same magnitude--the internet--but how do we use it effectively? A new tool is available on Google (http://www.google.com) that allows a user not only to numerically evaluate equations, but to automatically perform unit analysis and conversion as well, with most of the fundamental physical constants built in.

  16. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  17. Coupling constant in dispersive model

    Indian Academy of Sciences (India)

    R Saleh-Moghaddam; M E Zomorrodian

    2013-11-01

    The average of the moments for event shapes in + - → hadrons within the context of next-to-leading order (NLO) perturbative QCD prediction in dispersive model is studied. Moments used in this article are $\\langle 1 - T \\rangle, \\langle ρ \\rangle, \\langle B_{T} \\rangle$ and $\\langle B_{W} \\rangle$. We extract , the coupling constant in perturbative theory and α0 in the non-perturbative theory using the dispersive model. By fitting the experimental data, the values of $(M_{Z^{°}})$ = 0.1171 ± 0.00229 and 0 ($_{I} = 2{\\text{GeV}}$) = 0.5068 ± 0.0440 are found. Our results are consistent with the above model. Our results are also consistent with those obtained from other experiments at different energies. All these features are explained in this paper.

  18. Constant Proportion Debt Obligations (CPDOs)

    DEFF Research Database (Denmark)

    Cont, Rama; Jessen, Cathrine

    2012-01-01

    be made arbitrarily small—and thus the credit rating arbitrarily high—by increasing leverage, but the ratings obtained strongly depend on assumptions on the credit environment (high spread or low spread). More importantly, CPDO loss distributions are found to exhibit a wide range of tail risk measures......Constant Proportion Debt Obligations (CPDOs) are structured credit derivatives that generate high coupon payments by dynamically leveraging a position in an underlying portfolio of investment-grade index default swaps. CPDO coupons and principal notes received high initial credit ratings from...... the major rating agencies, based on complex models for the joint transition of ratings and spreads for all names in the underlying portfolio. We propose a parsimonious model for analysing the performance of CPDO strategies using a top-down approach that captures the essential risk factors of the CPDO. Our...

  19. Henry's law constants of polyols

    Directory of Open Access Journals (Sweden)

    S. Compernolle

    2014-12-01

    Full Text Available Henry's law constants (HLC are derived for several polyols bearing between 2 and 6 hydroxyl groups, based on literature data for water activity, vapour pressure and/or solubility. While deriving HLC and depending on the case, also infinite dilution activity coefficients (IDACs, solid state vapour pressures or activity coefficient ratios are obtained as intermediate results. An error analysis on the intermediate quantities and the obtained HLC is included. For most compounds, these are the first values reported, while others compare favourably with literature data in most cases. Using these values and those from a previous work (Compernolle and Müller, 2014, an assessment is made on the partitioning of polyols, diacids and hydroxy acids to droplet and aqueous aerosol.

  20. Omnidirectional antenna having constant phase

    Energy Technology Data Exchange (ETDEWEB)

    Sena, Matthew

    2017-04-04

    Various technologies presented herein relate to constructing and/or operating an antenna having an omnidirectional electrical field of constant phase. The antenna comprises an upper plate made up of multiple conductive rings, a lower ground-plane plate, a plurality of grounding posts, a conical feed, and a radio frequency (RF) feed connector. The upper plate has a multi-ring configuration comprising a large outer ring and several smaller rings of equal size located within the outer ring. The large outer ring and the four smaller rings have the same cross-section. The grounding posts ground the upper plate to the lower plate while maintaining a required spacing/parallelism therebetween.

  1. Type Ia Supernovae and the Hubble Constant

    CERN Document Server

    Branch, D

    1998-01-01

    The focus of this review is the work that has been done during the 1990s on using Type Ia supernovae (SNe Ia) to measure the Hubble constant ($H_0$). SNe Ia are well suited for measuring $H_0$. A straightforward maximum-light color criterion can weed out the minority of observed events that are either intrinsically subluminous or substantially extinguished by dust, leaving a majority subsample that has observational absolute-magnitude dispersions of less than $\\sigma_{obs}(M_B) \\simeq \\sigma_{obs}(M_V) \\simeq 0.3$ mag. Correlations between absolute magnitude and one or more distance-independent SN Ia or parent-galaxy observables can be used to further standardize the absolute magnitudes to better than 0.2 mag. The absolute magnitudes can be calibrated in two independent ways --- empirically, using Cepheid-based distances to parent galaxies of SNe Ia, and physically, by light curve and spectrum fitting. At present the empirical and physical calibrations are in agreement at $M_B \\simeq M_V \\simeq -19.4$ or -19....

  2. Is There a Cosmological Constant?

    Science.gov (United States)

    Kochanek, Christopher

    2002-07-01

    The grant contributed to the publication of 18 refereed papers and 5 conference proceedings. The primary uses of the funding have been for page charges, travel for invited talks related to the grant research, and the support of a graduate student, Charles Keeton. The refereed papers address four of the primary goals of the proposal: (1) the statistics of radio lenses as a probe of the cosmological model (#1), (2) the role of spiral galaxies as lenses (#3), (3) the effects of dust on statistics of lenses (#7, #8), and (4) the role of groups and clusters as lenses (#2, #6, #10, #13, #15, #16). Four papers (#4, #5, #11, #12) address general issues of lens models, calibrations, and the relationship between lens galaxies and nearby galaxies. One considered cosmological effects in lensing X-ray sources (#9), and two addressed issues related to the overall power spectrum and theories of gravity (#17, #18). Our theoretical studies combined with the explosion in the number of lenses and the quality of the data obtained for them is greatly increasing our ability to characterize and understand the lens population. We can now firmly conclude both from our study of the statistics of radio lenses and our survey of extinctions in individual lenses that the statistics of optically selected quasars were significantly affected by extinction. However, the limits on the cosmological constant remain at lambda sigma confidence level, which is in mild conflict with the results of the Type la supernova surveys. We continue to find that neither spiral galaxies nor groups and clusters contribute significantly to the production of gravitational lenses. The lack of group and cluster lenses is strong evidence for the role of baryonic cooling in increasing the efficiency of galaxies as lenses compared to groups and clusters of higher mass but lower central density. Unfortunately for the ultimate objective of the proposal, improved constraints on the cosmological constant, the next large survey

  3. Is There a Cosmological Constant?

    Science.gov (United States)

    Kochanek, Christopher; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The grant contributed to the publication of 18 refereed papers and 5 conference proceedings. The primary uses of the funding have been for page charges, travel for invited talks related to the grant research, and the support of a graduate student, Charles Keeton. The refereed papers address four of the primary goals of the proposal: (1) the statistics of radio lenses as a probe of the cosmological model (#1), (2) the role of spiral galaxies as lenses (#3), (3) the effects of dust on statistics of lenses (#7, #8), and (4) the role of groups and clusters as lenses (#2, #6, #10, #13, #15, #16). Four papers (#4, #5, #11, #12) address general issues of lens models, calibrations, and the relationship between lens galaxies and nearby galaxies. One considered cosmological effects in lensing X-ray sources (#9), and two addressed issues related to the overall power spectrum and theories of gravity (#17, #18). Our theoretical studies combined with the explosion in the number of lenses and the quality of the data obtained for them is greatly increasing our ability to characterize and understand the lens population. We can now firmly conclude both from our study of the statistics of radio lenses and our survey of extinctions in individual lenses that the statistics of optically selected quasars were significantly affected by extinction. However, the limits on the cosmological constant remain at lambda Labor and Munoz).

  4. A Variant of Davenport's Constant

    Indian Academy of Sciences (India)

    R Thangadurai

    2007-05-01

    Let be a prime number. Let be a finite abelian -group of exponent (written additively) and be a non-empty subset of $]n[:=\\{1,2,\\ldots,n\\}$ such that elements of are incongruent modulo and non-zero modulo . Let $k ≥ D(G)/|A|$ be any integer where () denotes the well-known Davenport’s constant. In this article, we prove that for any sequence $g_1,g_2,\\ldots,g_k$ (not necessarily distinct) in , one can always extract a subsequence $g_{i_1},g_{i_2},\\ldots,g_{i_l}$ with $1 ≤ l ≤ k$ such that $$\\sum\\limits_{j=1}^l a_j g_{i_j}=0 \\text{in} G,$$ where $a_j\\in A$ for all . We provide examples where this bound cannot be improved. Furthermore, for the cyclic groups, we prove some sharp results in this direction. In the last section, we explore the relation between this problem and a similar problem with prescribed length. The proof of Theorem 1 uses group-algebra techniques, while for the other theorems, we use elementary number theory techniques.

  5. Higgs inflation and the cosmological constant

    Energy Technology Data Exchange (ETDEWEB)

    Jegerlehner, Fred [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2014-02-15

    The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density. SM running couplings not only allow us to extrapolate SM physics up to the Planck scale, but equally important they are triggering the Higgs mechanism. This is possible by the fact that the bare mass term in the Higgs potential changes sign at about μ{sub 0}≅1.40 x 10{sup 16} GeV and in the symmetric phase is enhanced by quadratic terms in the Planck mass. Such a huge Higgs mass term is able to play a key role in triggering inflation in the early universe. In this article we extend our previous investigation by working out the details of a Higgs inflation scenario. We show how different terms contributing to the Higgs Lagrangian are affecting inflation. Given the SM and its extrapolation to scales μ>μ{sub 0} we find a calculable cosmological constant V(0) which is weakly scale dependent and actually remains large during inflation. This is different to the Higgs fluctuation field dependent ΔV(φ), which decays exponentially during inflation, and actually would not provide a sufficient amount of inflation. The fluctuation field has a different effective mass which shifts the bare Higgs transition point to a lower value μ'{sub 0} ≅7.7 x 10{sup 14} GeV. The vacuum energy V(0) being proportional to M{sub Pl}{sup 4} has a coefficient which vanishes near the Higgs transition point, such that the bare and the renormalized cosmological constant match at this point. The role of the Higgs in reheating and baryogenesis is emphasized.

  6. Einstein Manifolds, Abelian Instantons, Bundle Reduction, and the Cosmological Constant

    CERN Document Server

    Soo, C P

    2001-01-01

    The anti-self-dual projection of the spin connections of certain four-dimensional Einstein manifolds can be Abelian in nature. These configurations signify bundle reductions. By a theorem of Kobayashi and Nomizu such a process is predicated on the existence of a covariantly constant field. It turns out that even without fundamental Higgs fields and other physical matter, gravitational self-interactions can generate this mechanism if the cosmological constant is non-vanishing. This article identifies the order parameter, and clarifies how these Abelian instanton solutions are associated with a Higgs triplet which causes the bundle reduction from SO(3) gauge group to U(1).

  7. Planck intermediate results. XXIV. Constraints on variation of fundamental constants

    CERN Document Server

    Ade, P A R; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A.J.; Barreiro, R.B.; Battaner, E.; Benabed, K.; Benoit-Levy, A.; Bernard, J.P.; Bersanelli, M.; Bielewicz, P.; Bond, J.R.; Borrill, J.; Bouchet, F.R.; Burigana, C.; Butler, R.C.; Calabrese, E.; Chamballu, A.; Chiang, H.C.; Christensen, P.R.; Clements, D.L.; Colombo, L.P.L.; Couchot, F.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R.D.; Davis, R.J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Diego, J.M.; Dole, H.; Dore, O.; Dupac, X.; Ensslin, T.A.; Eriksen, H.K.; Fabre, O.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Gonzalez-Nuevo, J.; Gorski, K.M.; Gregorio, A.; Gruppuso, A.; Hansen, F.K.; Hanson, D.; Harrison, D.L.; Henrot-Versille, S.; Hernandez-Monteagudo, C.; Herranz, D.; Hildebrandt, S.R.; Hivon, E.; Hobson, M.; Holmes, W.A.; Hornstrup, A.; Hovest, W.; Huffenberger, K.M.; Jaffe, A.H.; Jones, W.C.; Keihanen, E.; Keskitalo, R.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lamarre, J.M.; Lasenby, A.; Lawrence, C.R.; Leonardi, R.; Lesgourgues, J.; Liguori, M.; Lilje, P.B.; Linden-Vornle, M.; Lopez-Caniego, M.; Lubin, P.M.; Macias-Perez, J.F.; Mandolesi, N.; Maris, M.; Martin, P.G.; Martinez-Gonzalez, E.; Masi, S.; Matarrese, S.; Mazzotta, P.; Meinhold, P.R.; Melchiorri, A.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Miville-Deschenes, M.A.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Munshi, D.; Murphy, J.A.; Naselsky, P.; Nati, F.; Natoli, P.; Norgaard-Nielsen, H.U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C.A.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Pratt, G.W.; Prunet, S.; Rachen, J.P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Ristorcelli, I.; Rocha, G.; Roudier, G.; Rusholme, B.; Sandri, M.; Savini, G.; Scott, D.; Spencer, L.D.; Stolyarov, V.; Sudiwala, R.; Sutton, D.; Suur-Uski, A.S.; Sygnet, J.F.; Tauber, J.A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Uzan, J.P.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L.A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2015-01-01

    Any variation of the fundamental physical constants, and more particularly of the fine structure constant, $\\alpha$, or of the mass of the electron, $m_e$, would affect the recombination history of the Universe and cause an imprint on the cosmic microwave background angular power spectra. We show that the Planck data allow one to improve the constraint on the time variation of the fine structure constant at redshift $z\\sim 10^3$ by about a factor of 5 compared to WMAP data, as well as to break the degeneracy with the Hubble constant, $H_0$. In addition to $\\alpha$, we can set a constraint on the variation of the mass of the electron, $m_{\\rm e}$, and on the simultaneous variation of the two constants. We examine in detail the degeneracies between fundamental constants and the cosmological parameters, in order to compare the limits obtained from Planck and WMAP and to determine the constraining power gained by including other cosmological probes. We conclude that independent time variations of the fine structu...

  8. Contribution of Disclination Lines to Free Energy of Liquid Crystals in Single-Elastic Constant Approximation

    Institute of Scientific and Technical Information of China (English)

    YANGGuo-Hong; WANGYu-Sheng; DUANYi-Shi

    2004-01-01

    In the light of C-mapping method and topological current theory, the contribution of disclination lines to free energy density of liquid crystals is studied in the single-elastic constant approximation. It is pointed out that the total free energy density can be divided into two parts. One is the usual distorted energy density of director field around the disclination lines. The other is the free energy density of disclination lines themselves, which is shown to be centralized at the disclination lines and to be topologically quantized in the unit of kn/2. The topological quantum numbers are determined by the Hopf indices and Brouwer degrees of the director l~eld at the disclination lines, i.e. the disclination strengths. From the Lagrange's method of multipliers, the equilibrium equation and the molecular field ofliquid crystals are also obtained. The physical meaning of the Lagrangian multiplier is just the distorted energy density.

  9. Contribution of Disclination Lines to Free Energy of Liquid Crystals in Single-Elastic Constant Approximation

    Institute of Scientific and Technical Information of China (English)

    YANG Guo-Hong; WANG Yu-Sheng; DUAN Yi-Shi

    2004-01-01

    In the light of φ-mapping method and topological current theory, the contribution of disclination lines to free energy density of liquid crystals is studied in the single-elastic constant approximation. It is pointed out that the total free energy density can be divided into two parts. One is the usual distorted energy density of director field around the disclination lines. The other is the free energy density of disclination lines themselves, which is shown to be centralized at the disclination lines and to be topologically quantized in the unit of kπ /2. The topological quantum numbers are determined by the Hopf indices and Brouwer degrees of the director field at the disclination lines, i.e. the disclination strengths. From the Lagrange's method of multipliers, the equilibrium equation and the molecular field of liquid crystals are also obtained. The physical meaning of the Lagrangian multiplier is just the distorted energy density.

  10. Determining the value of the fine-structure constant from a current balance: getting acquainted with some upcoming changes to the SI

    CERN Document Server

    Davis, Richard S

    2016-01-01

    The revised International System of Units (SI), expected to be approved late in 2018, has implications for physics pedagogy; the ampere definition which dates from 1948 will be replaced by a definition that fixes the numerical value of the elementary charge, e, in coulombs. The kilogram definition which dates from 1889 will be replaced by a definition that fixes the numerical value of the Planck constant, h, in joule seconds. Existing SI equations are completely unaffected. However, there will be a largely-negligible, but nevertheless necessary, change to published numerical factors relating SI electrical units to their corresponding units in the Gaussian and other CGS systems of units. The implications of the revised SI for electrical metrology are neatly illustrated by considering the interpretation of results obtained from a current balance in the present SI and in the revised SI.

  11. The fundamental constants and quantum electrodynamics

    CERN Document Server

    Taylor, Barry N; Langenberg, D N

    1969-01-01

    Introduction ; review of experimental data ; least-squares adjustment to obtain values of the constants without QED theory ; implications for quantum electrodynamics ; final recommended set of fundamental constants ; summary and conclusions.

  12. Temporal variation of coupling constants and nucleosynthesis

    CERN Document Server

    Oberhummer, Heinz; Fairbairn, M; Schlattl, H; Sharma, M M

    2003-01-01

    We investigate the triple-alpha process and the Oklo phenomenon to obtain constraints on possible cosmological time variations of fundamental constants. Specifically we study cosmological temporal constraints for the fine structure constant and nucleon and meson masses.

  13. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  14. Temporal variation of coupling constants and nucleosynthesis

    Science.gov (United States)

    Oberhummer, H.; Csótó, A.; Fairbairn, M.; Schlattl, H.; Sharma, M. M.

    2003-05-01

    We investigate the triple-alpha process and the Oklo phenomenon to obtain constraints on possible cosmological time variations of fundamental constants. Specifically we study cosmological temporal constraints for the fine structure constant and nucleon and meson masses.

  15. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  16. 中美体育教育专业人才培养模式比较研究%The physical education professional personnel training mode in China and the United States

    Institute of Scientific and Technical Information of China (English)

    王海星; 陈晨

    2015-01-01

    University physical education professional education should train primary and secondary school physical education teachers and social sports workers, relationship with our country physical education the improvement of teaching level and social physical education development. Higher education in the United States in the world advanced level, by the United States and China physical education professional training objectives, curriculum setting and practice system of three aspects of the contrast, can make us more clear understanding to our country physical education professional personnel training mode of defects, and puts forward the optimization strategy.%高校体育教育专业承担着培养中小学体育教师及社会体育工作者的重任,关系着我国体育师资水平的提高及社会体育事业的发展。美国高等教育在世界上处于先进水平,通过对中美两国体育教育专业培养目标、课程设置、实习体系三大方面的对比,可以使我们更加清醒地认识到我国体育教育专业人才培养模式存在的缺陷,并有针对性地提出优化策略。

  17. Critical survey of stability constants of EDTA complexes critical evaluation of equilibrium constants in solution stability constants of metal complexes

    CERN Document Server

    Anderegg, G

    2013-01-01

    Critical Survey of Stability Constants of EDTA Complexes focuses on the computations, values, and characteristics of stability constants. The book emphasizes that for a critical discussion of experimentally determined stability constants, it is important to consider the precision of the values that manifests the self-consistency of the constant, taking into consideration the random errors. The publication reviews the stability constants of metal complexes. The numerical calculations affirm the reactions and transformations of metal ions when exposed to varying conditions. The text also present

  18. A brief history of the unit of mass: continuity of successive definitions of the kilogram

    Science.gov (United States)

    Davis, Richard S.; Barat, Pauline; Stock, Michael

    2016-10-01

    The very first definition of the kilogram was in terms of a constant of nature, although this idea could not be fully realized at the end of the 18th century. Instead the kilogram was defined by an artefact whose mass was made to approximate as closely as possible a physical constant with unit kg m-3—the maximum density of distilled water at atmospheric pressure. For the next two centuries, mass comparators improved greatly as did the materials from which artefacts could be constructed. These improvements put tighter constraints on the realization of a non-artefact definition of the kilogram. However, it is now expected that the goal of redefining the kilogram in terms of fundamental constants will be achieved in 2018. We present a history of the kilogram with emphasis on continuity of this unit of mass each time it has been redefined and the stability of a unit defined by the mass of an artefact.

  19. Untangling Fixed Effects and Constant Regressors

    NARCIS (Netherlands)

    Klaassen, F.; Teulings, R.

    2015-01-01

    Fixed effects (FE) in panel data models overlap each other and prohibit the identification of the impact of "constant" regressors. Think of regressors that are constant across countries in a country-time panel with time FE. The traditional approach is to drop some FE and constant regressors by

  20. Searching for Kaprekar's constants: algorithms and results

    Directory of Open Access Journals (Sweden)

    Byron L. Walden

    2005-01-01

    Full Text Available We examine some new results on Kaprekar's constants, specifically establishing the unique 7-digit (in base 4 and 9-digit (in base 5 Kaprekar's constants and showing that there are no 15-, 21-, 27-, or 33-digit Kaprekar's constants.

  1. Untangling Fixed Effects and Constant Regressors

    NARCIS (Netherlands)

    Klaassen, F.; Teulings, R.

    2015-01-01

    Fixed effects (FE) in panel data models overlap each other and prohibit the identification of the impact of "constant" regressors. Think of regressors that are constant across countries in a country-time panel with time FE. The traditional approach is to drop some FE and constant regressors by norma

  2. William Wales and the 1769 Transit of Venus: Puzzle Solving and the Determination of the Astronomical Unit

    Science.gov (United States)

    Metz, Don

    2009-01-01

    According to Thomas Kuhn, a significant part of "normal science" is the fact gathering, empirical work which is intended to illustrate an existing paradigm. Some of this effort focuses on the determination of physical constants such as the astronomical unit (AU). For Kuhn, normal science is also what prepares students for membership in a…

  3. The Cosmological Constant Problem from a Brane-World Perspective

    CERN Document Server

    Förste, S; Lavignac, Stephane; Nilles, Hans Peter; Forste, Stefan; Lalak, Zygmunt; Lavignac, St\\'ephane; Nilles, Hans Peter

    2000-01-01

    We point out several subtleties arising in brane-world scenarios of cosmological constant cancellation. We show that solutions with curvature singularities are inconsistent, unless the contribution to the effective four-dimentional cosmological constant of the physics that resolves the singularities is fine-tuned. This holds for both flat and curved branes. Irrespective of this problem, we then study an isolated class of flat solutions in models where a bulk scalar field with a vanishing potential couples to a 3-brane. We give an example where the introduction of a bulk scalar potential results in a nonzero cosmological constant. Finally we comment on the stability of classical solutions of the brane system with respect to quantum corrections.

  4. Accurate lineshape spectroscopy and the Boltzmann constant.

    Science.gov (United States)

    Truong, G-W; Anstie, J D; May, E F; Stace, T M; Luiten, A N

    2015-10-14

    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here, we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a very accurate measurement of the excited-state (6P1/2) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity dispersion of the Cs vapour with an uncertainty of 35 p.p.m. within an hour. This allows us to determine a value for Boltzmann's constant with a precision of 6 p.p.m., and an uncertainty of 71 p.p.m.

  5. Expanding Taylor bubble under constant heat flux

    Science.gov (United States)

    Voirand, Antoine; Benselama, Adel M.; Ayel, Vincent; Bertin, Yves

    2016-09-01

    Modelization of non-isothermal bubbles expanding in a capillary, as a contribution to the understanding of the physical phenomena taking place in Pulsating Heat Pipes (PHPs), is the scope of this paper. The liquid film problem is simplified and solved, while the thermal problem takes into account a constant heat flux density applied at the capillary tube wall, exchanging with the liquid film surrounding the bubble and also with the capillary tube outside medium. The liquid slug dynamics is solved using the Lucas-Washburn equation. Mass and energy balance on the vapor phase allow governing equations of bubble expansion to be written. The liquid and vapor phases are coupled only through the saturation temperature associated with the vapor pressure, assumed to be uniform throughout the bubble. Results show an over-heating of the vapor phase, although the particular thermal boundary condition used here always ensures an evaporative mass flux at the liquid-vapor interface. Global heat exchange is also investigated, showing a strong decreasing of the PHP performance to convey heat by phase change means for large meniscus velocities.

  6. Enhancement of the dielectric constant near a percolation threshold

    Science.gov (United States)

    Wilkinson, David; Langer, J. S.; Sen, Pabitra N.

    1983-07-01

    When one of the components of a mixture of two materials is a conductor, geometrical effects can lead to a dielectric constant for the mixture which is much greater than that of either constituent. Here we illustrate a simple example of this effect in a two-dimensional network consisting of randomly placed conductors and capacitors. The dielectric enhancement is obtained as a function of frequency and the concentration of conductors. The calculational technique used is the position-space renormalization group in which smaller units are combined iteratively to form larger units.

  7. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  8. $\\bar{\\psi} \\psi$-condensate in constant magnetic fields

    CERN Document Server

    Anguiano-Galicia, M de J; Raya, A

    2007-01-01

    We solve Dirac equation in the presence of a constant magnetic field in (3+1)- and (2+1)-dimensions. Quantizing the fermion field, we calculate $\\bar{\\psi} \\psi$-condensate from first principles for parity conserving and violating Lagrangians for arbitrary field strength. We make comparison with the results already known in the literature for some particular cases and point out the relevance of our work for possible physical applications.

  9. Large scale-small scale duality and cosmological constant

    CERN Document Server

    Darabi, F

    1999-01-01

    We study a model of quantum cosmology originating from a classical model of gravitation where a self interacting scalar field is coupled to gravity with the metric undergoing a signature transition. We show that there are dual classical signature changing solutions, one at large scales and the other at small scales. It is possible to fine-tune the physics in both scales with an infinitesimal effective cosmological constant.

  10. Ferroelectric metal-organic framework with a high dielectric constant.

    Science.gov (United States)

    Ye, Qiong; Song, Yu-Mei; Wang, Guo-Xi; Chen, Kai; Fu, Da-Wei; Chan, Philip Wai Hong; Zhu, Jin-Song; Huang, Songping D; Xiong, Ren-Gen

    2006-05-24

    Hydrothermal reaction of (l)-N-(4'-cyanobenzy)-(S)-proline with CdCl2 as a Lewis acid catalyst and NaN3 gives colorless block compound 1, in which 1 displays a complicated 3D framework. Ferroelectric and dielectric property measurements reveal that 1 exhibits physical properties comparable to that of a typical ferroelectric compound with a dipole relaxation process and a dielectric constant of ca. 38.6 that makes it, by definition, a high dielectric material.

  11. The cosmological constant and the time of its dominance

    OpenAIRE

    Garriga Torres, Jaume; Livio, Mario; Vilenkin, A.

    1999-01-01

    We explore a model in which the cosmological constant $\\Lambda$ and the density contrast at the time of recombination $\\sigma_{rec}$ are random variables, whose range and {\\it a priori} probabilities are determined by the laws of physics. (Such models arise naturally in the framework of inflationary cosmology.) Based on the assumption that we are typical observers, we show that the order of magnitude coincidence among the three timescales: the time of galaxy formation, the time when the cosmo...

  12. Bayesian Approach to the Best Estimate of the Hubble Constant

    Institute of Scientific and Technical Information of China (English)

    王晓峰; 陈黎; 李宗伟

    2001-01-01

    A Bayesian approach is used to derive the probability distribution (PD) of the Hubble constant H0 from recent measurements including supernovae Ia, the Tully-Fisher relation, population Ⅱ and physical methods. The discrepancies among these PDs are briefly discussed. The combined value of all the measurements is obtained,with a 95% confidence interval of 58.7 < Ho < 67.3 (km·s-1.Mpc-1).

  13. Fluorescence decay-time constants in organic liquid scintillators.

    Science.gov (United States)

    Marrodán Undagoitia, T; von Feilitzsch, F; Oberauer, L; Potzel, W; Ulrich, A; Winter, J; Wurm, M

    2009-04-01

    The fluorescence decay-time constants have been measured for several scintillator mixtures based on phenyl-o-xylylethane (PXE) and linear alkylbenzene (LAB) solvents. The resulting values are of relevance for the physics performance of the proposed large-volume liquid scintillator detector Low Energy Neutrino Astronomy (LENA). In particular, the impact of the measured values to the search for proton decay via p-->K(+)nu is evaluated in this work.

  14. Dimensionless Units in the SI

    CERN Document Server

    Mohr, Peter J

    2014-01-01

    The International System of Units (SI) is supposed to be coherent. That is, when a combination of units is replaced by an equivalent unit, there is no additional numerical factor. Here we consider dimensionless units as defined in the SI, {\\it e.g.} angular units like radians or steradians and counting units like radioactive decays or molecules. We show that an incoherence may arise when different units of this type are replaced by a single dimensionless unit, the unit "one", and suggest how to properly include such units into the SI in order to remove the incoherence. In particular, we argue that the radian is the appropriate coherent unit for angles and that hertz is not a coherent unit in the SI. We also discuss how including angular and counting units affects the fundamental constants.

  15. Cosmological constant implementing Mach principle in general relativity

    Science.gov (United States)

    Namavarian, Nadereh; Farhoudi, Mehrdad

    2016-10-01

    We consider the fact that noticing on the operational meaning of the physical concepts played an impetus role in the appearance of general relativity (GR). Thus, we have paid more attention to the operational definition of the gravitational coupling constant in this theory as a dimensional constant which is gained through an experiment. However, as all available experiments just provide the value of this constant locally, this coupling constant can operationally be meaningful only in a local area. Regarding this point, to obtain an extension of GR for the large scale, we replace it by a conformal invariant model and then, reduce this model to a theory for the cosmological scale via breaking down the conformal symmetry through singling out a specific conformal frame which is characterized by the large scale characteristics of the universe. Finally, we come to the same field equations that historically were proposed by Einstein for the cosmological scale (GR plus the cosmological constant) as the result of his endeavor for making GR consistent with the Mach principle. However, we declare that the obtained field equations in this alternative approach do not carry the problem of the field equations proposed by Einstein for being consistent with Mach's principle (i.e., the existence of de Sitter solution), and can also be considered compatible with this principle in the Sciama view.

  16. Does the measured value of the Planck constant depend on the energy of measurements?

    CERN Document Server

    Massa, Enrico; Jentschel, Michael

    2011-01-01

    The measurement of the Avogadro constant opened the way to a comparison of the watt-balance measurements of the Planck constant with the values calculated from the quotients of the Planck constant and the mass of a particle or an atom. Since the energy scales of these measurements span nine energy decades, these data provide insight into the consistency of our understanding of physics.

  17. The Scales of Time, Length, Mass, Energy, and Other Fundamental Physical Quantities in the Atomic World and the Use of Atomic Units in Quantum Mechanical Calculations

    Science.gov (United States)

    Teo, Boon K.; Li, Wai-Kee

    2011-01-01

    This article is divided into two parts. In the first part, the atomic unit (au) system is introduced and the scales of time, space (length), and speed, as well as those of mass and energy, in the atomic world are discussed. In the second part, the utility of atomic units in quantum mechanical and spectroscopic calculations is illustrated with…

  18. Proposal of a New SI Base Unit for Value. An Hedonic Estimation of the Physical Purchasing Power (PhPP) of Money.

    Science.gov (United States)

    Defilla, Steivan

    2006-03-01

    Hitherto, the purchasing power of money, i.e. its transaction value, has been measured in terms of inflation index numbers and consumer baskets. Consumer baskets are variable phenomena and their use as measurement units for value confuses the measuring with the measurand. We propose an invariant numeraire, or value unit, based on the market value of a Planck energy (1956 MJ). Planck units form a natural system of units independent of any civilization. The hedonic estimation of the PhPP of a currency differentiates energy by product as well as by thermodynamic quality (exergy). Following SI rules, we propose to name the value unit walras (Wal) in honour of the economist Leon Walras (1834 - 1910). One Wal can also be interpreted as the minimum cost of physiological life of a reference person during one year. The study uses official disaggregated Swiss Producer and Consumer Price Index data and estimates the PhPP of the Swiss franc in 2003.

  19. Non-Relativistic Spacetimes with Cosmological Constant

    OpenAIRE

    Aldrovandi, R.; Barbosa, A. L.; Crispino, L.C.B.; Pereira, J. G.

    1998-01-01

    Recent data on supernovae favor high values of the cosmological constant. Spacetimes with a cosmological constant have non-relativistic kinematics quite different from Galilean kinematics. De Sitter spacetimes, vacuum solutions of Einstein's equations with a cosmological constant, reduce in the non-relativistic limit to Newton-Hooke spacetimes, which are non-metric homogeneous spacetimes with non-vanishing curvature. The whole non-relativistic kinematics would then be modified, with possible ...

  20. Cosmological constant and Brane New World

    CERN Document Server

    Nojiri, S; Odintsov, S D; Nojiri, Shin'ichi; Obregon, Octavio; Odintsov, Sergei D.

    2001-01-01

    The estimation of the cosmological constant in inflationary Brane New World models is done. It is shown that basically it is quite large, of the same order as in anomaly-driven inflation. However, for some fine-tuning of bulk gravitational constant and AdS scale parameter $l^2$ it may be reduced to sufficiently small value. Bulk higher derivative AdS gravity with quantum brane matter may also serve as the model where small positive cosmological constant occurs.

  1. Singularities in universes with negative cosmological constant

    Energy Technology Data Exchange (ETDEWEB)

    Tipler, F.J.

    1976-10-01

    It is well known that many universes with negative cosmological constant contain singularities. We shall generalize this result by proving that all closed universes with negative cosmological constant are both future and past timelike geodesically incomplete if the strong energy condition holds. No global causality conditions or restrictions on the initial data are used in the proof. Furthermore, we shall show that all open universes with a Cauchy surface and a negative cosmological constant are singular if the strong energy condition holds. (AIP)

  2. Coasting cosmologies with time dependent cosmological constant

    CERN Document Server

    Pimentel, L O; Pimentel, Luis O.

    1999-01-01

    The effect of a time dependent cosmological constant is considered in a family of scalar tensor theories. Friedmann-Robertson-Walker cosmological models for vacumm and perfect fluid matter are found. They have a linear expansion factor, the so called coasting cosmology, the gravitational "constant" decreace inversely with time; this model satisfy the Dirac hipotesis. The cosmological "constant" decreace inversely with the square of time, therefore we can have a very small value for it at present time.

  3. On a time varying fine structure constant

    CERN Document Server

    Berman, M S; Berman, Marcelo S.; Trevisan, Luis A.

    2001-01-01

    By employing Dirac LNH, and a further generalization by Berman (GLNH), we estimate how should vary the total number of nucleons, the energy density, Newton Gravitational constant, the cosmological constant, the magnetic permeability and electric permitivity, of the Universe,in order to account for the experimentally observed time variation of the fine structure constant. As a bonus,we find an acceptable value for the deceleration parameter of the present Universe, compatible with the Supernovae observations.

  4. Electronic measurement of the Boltzmann constant with a quantum-voltage-calibrated Johnson-noise thermometer

    NARCIS (Netherlands)

    Benz, Samuel; White, D. Rod; Qu, JiFeng; Rogalla, Horst; Tew, Weston

    2010-01-01

    Currently, the CODATA value of the Boltzmann constant is dominated by a single gas-based thermometry measurement with a relative standard uncertainty of 1.8×10−6 [P.J. Mohr, B.N. Taylor, D.B. Newell, CODATA recommended values of the fundamental physical constants: 2006, Rev. Mod. Phys. 80 (2008)

  5. A natural cosmological constant from chameleons

    Directory of Open Access Journals (Sweden)

    Horatiu Nastase

    2015-07-01

    Full Text Available We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why Λ is so small, yet nonzero and the coincidence problem (why Λ is comparable to the matter density now.

  6. A natural cosmological constant from chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Nastase, Horatiu, E-mail: nastase@ift.unesp.br [Instituto de Física Teórica, UNESP-Universidade Estadual Paulista, R. Dr. Bento T. Ferraz 271, Bl. II, Sao Paulo 01140-070, SP (Brazil); Weltman, Amanda, E-mail: amanda.weltman@uct.ac.za [Astrophysics, Cosmology & Gravity Center, Department of Mathematics and Applied Mathematics, University of Cape Town, Private Bag, Rondebosch 7700 (South Africa)

    2015-07-30

    We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density, patches of approximately constant scalar field potential cluster around regions of matter with density above a certain value, generating the effect of a cosmological constant on large scales. This construction addresses both the cosmological constant problem (why Λ is so small, yet nonzero) and the coincidence problem (why Λ is comparable to the matter density now)

  7. Modeling for Hydraulic Permeability and Kozeny-Carman Constant of Porous Nanofibers Using a Fractal Approach

    Science.gov (United States)

    Xiao, Boqi; Tu, Xing; Ren, Wen; Wang, Zongchi

    2015-06-01

    In this study, the analytical expressions for the hydraulic permeability and Kozeny-Carman (KC) constant of porous nanofibers are derived based on fractal theory. In the present approach, the permeability is explicitly related to the porosity and the area fractal dimensions of porous nanofibers. The proposed fractal models for KC constant is also found to be a function of the microstructural parameters (porosity, area fractal dimensions). Besides, the present model clearly indicates that KC constant is not a constant and increases with porosity. However, KC constant is close to a constant value which is 18 for ϕ > 0.8. Every parameter of the proposed formulas of calculating permeability and KC constant has clear physical meaning. The model predictions are compared with the existing experimental data, and fair agreement between the model predictions and experimental data is found for different porosities.

  8. Sedentary and physically active behavior patterns among low-income African-American and white adults living in the southeastern United States.

    Directory of Open Access Journals (Sweden)

    Sarah S Cohen

    Full Text Available Increased sedentary behavior and lack of physical activity are associated with increased risk for many chronic diseases. Differences in leisure-time physical activity between African American and white adults have been suggested to partially explain racial disparities in chronic disease outcomes, but expanding the definition of physical activity to include household and occupational activities may reduce or even eliminate racial differences in total physical activity. The objective of this study was to describe patterns of active and sedentary behaviors in black and white adults and to examine these behaviors across demographic measures. Sedentary and physically active behaviors were obtained from a validated physical activity questionnaire in 23,021 black men, 9,899 white men, 32,214 black women, and 15,425 white women (age 40-79 at enrollment into the Southern Community Cohort Study. Descriptive statistics for sedentary time; light, moderate, and vigorous household/occupational activity; sports/exercise; total activity; and meeting current physical activity recommendations via sports/exercise were examined for each race-sex group. Adjusted means were calculated using multiple linear regression models across demographic measures. Study participants spent approximately 60% of waking time in sedentary behaviors. Blacks reported more television viewing time than whites (45 minutes for females, 15 minutes for males, but when sitting time was expressed as a proportion of overall awake time, minimal racial differences were found. Patterns of light, moderate, and vigorous household/occupational activity were similar in all race/sex groups. 2008 Physical Activity Guidelines for Americans were followed by 16% of women and 25% of men independent of race. Overall, black and white men and women in this study spent the majority of their daily time in sedentary behaviors and less than one-fourth followed current guidelines for physical activity. These

  9. FOREWORD: International Workshop on the Avogadro Constant and the Representation of the Silicon Mole

    Science.gov (United States)

    Basile, Giuseppe; Garfagnini, Raffaello; Mana, Giovanni; Peuto, Anna; Zosi, Gianfranco

    1994-01-01

    work on the set of consistent values of the fundamental physical constants and on the definition of the mass unit. Dr T Quinn, Director of the Bureau International des Poids et Mesures, chaired the final discussion, drawing attention to the message of the workshop and its contribution to mass metrology. Grateful thanks are addressed to all lecturers and participants and to the guest editors and reviewers of the papers for their contribution to the success of the workshop.

  10. Physical therapists' guideline adherence on early mobilization and intensity of practice at dutch acute stroke units: a country-wide survey

    NARCIS (Netherlands)

    Otterman, N.M.; Wees, P.J. van der; Bernhardt, J.; Kwakkel, G.

    2012-01-01

    BACKGROUND AND PURPOSE: Clinical practice guidelines for patients with stroke recommend early stroke rehabilitation at acute hospital stroke units. The present study aimed to (1) explore the organization of early stroke rehabilitation; (2) investigate current practice with respect to early

  11. Elementary particle physics in early physics education

    CERN Document Server

    Wiener, Gerfried

    2017-01-01

    Current physics education research is faced with the important question of how best to introduce elementary particle physics in the classroom early on. Therefore, a learning unit on the subatomic structure of matter was developed, which aims to introduce 12-year-olds to elementary particles and fundamental interactions. This unit was iteratively evaluated and developed by means of a design-based research project with grade-6 students. In addition, dedicated professional development programmes were set up to instruct high school teachers about the learning unit and enable them to investigate its didactical feasibility. Overall, the doctoral research project led to successful results and showed the topic of elementary particle physics to be a viable candidate for introducing modern physics in the classroom. Furthermore, thanks to the design-based research methodology, the respective findings have implications for both physics education and physics education research, which will be presented during the PhD defen...

  12. Constant Width Planar Computation Characterizes ACC0

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt

    2006-01-01

    We obtain a characterization of ACC0 in terms of a natural class of constant width circuits, namely in terms of constant width polynomial size planar circuits. This is shown via a characterization of the class of acyclic digraphs which can be embedded on a cylinder surface in such a way that all...

  13. Constant Width Planar Computation Characterizes ACC0

    DEFF Research Database (Denmark)

    Hansen, K.A.

    2004-01-01

    We obtain a characterization of ACC 0 in terms of a natural class of constant width circuits, namely in terms of constant width polynomial size planar circuits. This is shown via a characterization of the class of acyclic digraphs which can be embedded on a cylinder surface in such a way that all...

  14. Chiral Corrections to Vector Meson Decay Constants

    CERN Document Server

    Bijnens, J; Talavera, P; Bijnens, Johan; Gosdzinsky, Peter; Talavera, Pere

    1998-01-01

    We calculate the leading quark mass corrections of order $m_q\\log(m_q)$, $m_q$ and $m_q^{3/2}$ to the vector meson decay constants within Heavy Vector Meson Chiral Perturbation Theory. We discuss the issue of electromagnetic gauge invariance and the heavy mass expansion. Reasonably good fits to the observed decay constants are obtained.

  15. Constant Angle Surfaces in the Heisenberg Group

    Institute of Scientific and Technical Information of China (English)

    Johan FASTENAKELS; Marian Ioan MUNTEANU; Joeri VAN DER VEKEN

    2011-01-01

    In this article we extend the notion of constant angle surfaces in S2 × R and H2 × R to general Bianchi-Cartan-Vranceanu spaces. We show that these surfaces have constant Gaussian curvature and we give a complete local classification in the Heisenberg group.

  16. The time constant of the somatogravic illusion.

    Science.gov (United States)

    Correia Grácio, B J; de Winkel, K N; Groen, E L; Wentink, M; Bos, J E

    2013-02-01

    Without visual feedback, humans perceive tilt when experiencing a sustained linear acceleration. This tilt illusion is commonly referred to as the somatogravic illusion. Although the physiological basis of the illusion seems to be well understood, the dynamic behavior is still subject to discussion. In this study, the dynamic behavior of the illusion was measured experimentally for three motion profiles with different frequency content. Subjects were exposed to pure centripetal accelerations in the lateral direction and were asked to indicate their tilt percept by means of a joystick. Variable-radius centrifugation during constant angular rotation was used to generate these motion profiles. Two self-motion perception models were fitted to the experimental data and were used to obtain the time constant of the somatogravic illusion. Results showed that the time constant of the somatogravic illusion was on the order of two seconds, in contrast to the higher time constant found in fixed-radius centrifugation studies. Furthermore, the time constant was significantly affected by the frequency content of the motion profiles. Motion profiles with higher frequency content revealed shorter time constants which cannot be explained by self-motion perception models that assume a fixed time constant. Therefore, these models need to be improved with a mechanism that deals with this variable time constant. Apart from the fundamental importance, these results also have practical consequences for the simulation of sustained accelerations in motion simulators.

  17. Decay constants from twisted mass QCD

    CERN Document Server

    Dimopoulos, P; Michael, C; Simula, S; Urbach, C

    2008-01-01

    We present results for chiral extrapolations of the mass and decay constants of the rho meson. The data sets used are the nf=2 unquenched gauge configurations generated with twisted mass fermions by the European Twisted Mass Collaboration. We describe a calculation of three decay constants in charmonium and explain why they are required.

  18. String theory, cosmology and varying constants

    Science.gov (United States)

    Damour, Thibault

    In string theory the coupling `constants' appearing in the low-energy effective Lagrangian are determined by the vacuum expectation values of some (a priori) massless scalar fields (dilaton, moduli). This naturally leads one to expect a correlated variation of all the coupling constants, and an associated violation of the equivalence principle. We review some string-inspired theoretical models which incorporate such a spacetime variation of coupling constants while remaining naturally compatible both with phenomenological constraints coming from geochemical data (Oklo; Rhenium decay) and with present equivalence principle tests. Barring a very unnatural fine-tuning of parameters, a variation of the fine-structure constant as large as that recently `observed' by Webb et al. in quasar absorption spectra appears to be incompatible with these phenomenological constraints. Independently of any model, it is emphasized that the best experimental probe of varying constants are high-precision tests of the universality of free fall, such as MICROSCOPE and STEP.

  19. String theory, cosmology and varying constants

    CERN Document Server

    Damour, Thibault Marie Alban Guillaume

    2002-01-01

    In string theory the coupling ``constants'' appearing in the low-energy effective Lagrangian are determined by the vacuum expectation values of some (a priori) massless scalar fields (dilaton, moduli). This naturally leads one to expect a correlated variation of all the coupling constants, and an associated violation of the equivalence principle. We review some string-inspired theoretical models which incorporate such a spacetime variation of coupling constants while remaining naturally compatible both with phenomenological constraints coming from geochemical data (Oklo; Rhenium decay) and with present equivalence principle tests. Barring a very unnatural fine-tuning of parameters, a variation of the fine-structure constant as large as that recently ``observed'' by Webb et al. in quasar absorption spectra appears to be incompatible with these phenomenological constraints. Independently of any model, it is emphasized that the best experimental probe of varying constants are high-precision tests of the universa...

  20. General Relativity, Cosmological Constant and Modular Forms

    CERN Document Server

    Kraniotis, G V

    2001-01-01

    Strong field (exact) solutions of the gravitational field equations of General Relativity in the presence of a Cosmological Constant are investigated. In particular, a full exact solution is derived within the inhomogeneous Szekeres-Szafron family of space-time line element with a nonzero Cosmological Constant. The resulting solution connects, in an intrinsic way, General Relativity with the theory of modular forms and elliptic curves and thus to the theory of Taniyama-Shimura.The homogeneous FLRW limit of the above space-time elements is recovered and we solve exactly the resulting Friedmann Robertson field equation with the appropriate matter density for generic values of the Cosmological Constant $ \\Lambda $ and curvature constant $K$. A formal expression for the Hubble constant is derived. The cosmological implications of the resulting non-linear solutions are systematically investigated. Two particularly interesting solutions i) the case of a flat universe $K=0,\\Lambda \

  1. Acute effects of constant torque and constant angle stretching on the muscle and tendon tissue properties.

    Science.gov (United States)

    Konrad, Andreas; Budini, Francesco; Tilp, Markus

    2017-08-01

    Static stretching induces acute structural changes of the muscle-tendon unit (MTU) that are related to the intensity or duration of stretching. It has been reported that stretching with a constant torque (CT) leads to greater joint range of motion changes than stretching with a constant angle (CA). Whether or not this difference is due to different structural changes of the MTUs of the lower leg and ankle plantar flexors is not known. Therefore, the purpose of this study was to compare the acute effects of single CA and CT stretching on various muscle and tendon mechanical properties. Seventeen young, healthy volunteers were tested on two separate days using either CT or CA stretching (4 × 30 s each). Before and after stretching, dorsiflexion range of motion (RoM), passive resistive torque (PRT), and maximum voluntary contraction (MVC) were measured with a dynamometer. Ultrasonography of the medial gastrocnemius (GM) muscle-tendon junction (MTJ) displacement allowed us to determine the length changes in the tendon and muscle, respectively, and hence to calculate their stiffness. Maximum dorsiflexion increased while PRT, muscle-tendon stiffness, and muscle stiffness decreased following both CA and CT stretching. There was a greater increase in RoM following CT stretching compared to CA stretching. Moreover, the decline in PRT was greater during CT stretching compared to CA stretching. As expected, several functional adaptations (RoM, PRT) were different between CT and CA stretching due to the higher intensity of CT stretching. However, no structural differences in the adaptations to the stretching modalities could be detected. We suggest that the different functional adaptations between CA and CT stretching are the consequence of different adaptations in the perception of stretch and pain.

  2. Prof. John Wood, Chief Executive Designate, Dr Gordon Walker, Directorate, Chief Executive, Prof. Ken J. Peach, Head of the Particle Physics Department, CLRC Rutherford Appleton Laboratory, United Kingdom

    CERN Document Server

    Patrice Loïez

    2001-01-01

    L. to. r.: Dr. Ian Wilson, CLIC Deputy Study Leader, Prof. Ken J. Peach, Head of the Particle Physics Department, Prof. John Wood, Chief Executive Designate, Dr. Gordon Walker, Directorate, Chief Executive

  3. 美国物理治疗职业发展%The Development of Profession of Physical Therapy in the United States

    Institute of Scientific and Technical Information of China (English)

    Patricia S.Hodson; Denis Brunt

    2008-01-01

    This article described the historical development, related occupations, jobs and employment characteristics of physical therapy, education system for the professionals, and put forward future trends in physical therapy education and practice.%本文探讨了物理治疗行业的历史发展、相关的职业、工作和就业特征,专业教育体系并对未来的发展进行了展望.

  4. Understanding the complex interplay of barriers to physical activity amongst black and minority ethnic groups in the United Kingdom:a qualitative synthesis using meta-ethnography

    OpenAIRE

    Koshoedo, Sejlo A.; Paul-Ebhohimhen, Virginia A; Jepson, Ruth G.; Watson, Margaret C

    2015-01-01

    Background To conduct a meta-ethnographic analysis of qualitative studies to identify barriers to Black and Minority Ethnic (BME) individuals engaging in physical activity in the UK context. Methods A qualitative synthesis using meta-ethnographic methods to synthesis studies of barriers to engaging in physical activity among BME groups in the UK. A comprehensive search strategy of multiple databases was employed to identify qualitative research studies published up to October 2012. The eleven...

  5. IAU 2015 Resolution B3 on Recommended Nominal Conversion Constants for Selected Solar and Planetary Properties

    CERN Document Server

    Mamajek, E E; Torres, G; Harmanec, P; Asplund, M; Bennett, P D; Capitaine, N; Christensen-Dalsgaard, J; Depagne, E; Folkner, W M; Haberreiter, M; Hekker, S; Hilton, J L; Kostov, V; Kurtz, D W; Laskar, J; Mason, B D; Milone, E F; Montgomery, M M; Richards, M T; Schou, J; Stewart, S G

    2015-01-01

    Astronomers commonly quote the properties of celestial objects in units of parameters for the Sun, Jupiter, or the Earth. The resolution presented here was proposed by the IAU Inter-Division Working Group on Nominal Units for Stellar and Planetary Astronomy and passed by the XXIXth IAU General Assembly in Honolulu. IAU 2015 Resolution B3 adopts a set of nominal solar, terrestrial, and jovian conversion constants for stellar and (exo)planetary astronomy which are defined to be exact SI values. While the nominal constants are based on current best estimates (CBEs; which have uncertainties, are not secularly constant, and are updated regularly using new observations), they should be interpreted as standard values and not as CBEs. IAU 2015 Resolution B3 adopts five solar conversion constants (nominal solar radius, nominal total solar irradiance, nominal solar luminosity, nominal solar effective temperature, and nominal solar mass parameter) and six planetary conversion constants (nominal terrestrial equatorial ra...

  6. Associations of Physical Activity, Sedentary Time, and Screen Time With Cardiovascular Fitness in United States Adolescents: Results from the NHANES National Youth Fitness Survey (NNYFS).

    Science.gov (United States)

    Porter, Anna K; Matthews, Krystin J; Salvo, Deborah; Kohl, Harold W

    2017-03-14

    Background Most US adolescents do not meet guidelines of at least 60 daily minutes of moderate- to vigorous-intensity physical activity. Additionally, sedentary behaviors among this age group are of increasing concern. This study examined the association of movement behaviors with cardiovascular fitness among US adolescents. Methods Data from the 2012 NHANES National Youth Fitness Survey were used to assess the association of movement behaviors (physical activity, sedentary time, screen time) with cardiovascular fitness among adolescent males and females. Multiple logistic regressions were used to test the independent and interactive effects of movement behaviors on cardiovascular fitness. Results Among females, physical activity was directly associated with cardiovascular fitness; no significant association was observed between sedentary behaviors and CVF. Among males, sedentary time moderated the relationship between physical activity and cardiovascular fitness, such that a significant, direct association was only observed among those with high sedentary time (OR: 5.01, 95% CI: 1.60, 15.70). Conclusions Results from this cross-sectional analysis suggest that among female US adolescents, physical activity, but not sedentary behavior, is associated with cardiovascular fitness. Among males, the interaction between physical activity and sedentary time seems to be important for cardiovascular fitness. Longitudinal studies are warranted to confirm these findings.

  7. Mobility Status as a Predictor of Obesity, Physical Activity, and Screen Time Use among Children Aged 5-11 Years in the United States.

    Science.gov (United States)

    Wilson, Patrick B; Haegele, Justin A; Zhu, Xihe

    2016-09-01

    To examine physical activity participation, screen time habits, and the prevalence of overweight/obesity among children in the general population with mobility limitations and those enrolled in special education services. An observational, cross-sectional analysis of the 2011-2014 National Health and Nutrition Examination Survey, a representative sample of the US population. Mobility limitations, special education services utilization, proxy-reported physical activity and screen time, and overweight/obesity status were assessed in children aged 5-11 years. Boys with mobility limitations were less likely to meet physical activity guidelines (≥60 minutes daily) compared with those with no limitations (58.1% vs 74.4%, adjusted F = 4.61, P = .04). In a logistic regression model, boys with mobility limitations had significantly lower odds (0.42, 95% CI 0.20-0.86) of meeting physical activity guidelines. The prevalence of children meeting screen time recommendations (≤2 hours daily) among those receiving special education services (42.4%) was lower than children not receiving services (53.2%; adjusted F = 8.87, P obesity were found. Clear differences were present in physical activity between boys with and without mobility limitations. Furthermore, children receiving special education services demonstrated a lower likelihood of meeting screen time recommendations. Children with disabilities may benefit from targeted interventions aimed at increasing physical activity while decreasing screen time. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Determination of the dissociation constants of polyepoxysuccinic acid

    Institute of Scientific and Technical Information of China (English)

    Lihua ZHANG; Zhiliang ZHU; Yanling QIU; Ronghua ZHANG; Jianfu ZHAO

    2008-01-01

    The dissociation constants of polyepoxysucci-nic acid (PESA) were investigated in this study. Based on the potentiometric titration and the BEST program, the dissociation constants of PESA were determined. Considering the complexity of the dissociation of PESA in aqueous solution, several models were constructed to simulate the dissociation process of PESA. By compar-ison, the dissociation constants of PESA were obtained with model 4. The species distribution of PESA in aque-ous solution as a function of pH was also presented according to the experimental and calculation results. It showed that the H2L model with five basic structure units to describe the dissociation of PESA was reasonable, and the relevant constants had less error and better matching between the experimental and calculation data. The cor-responding values of pKai were 4.68 and 4.92, respectively, for H2L at 35℃ with ionic strength of 0.1 mol/L.

  9. The historical evolution and stage-specific characteristics of college physical education in the United States%美国大学体育的历史沿革及阶段性特征

    Institute of Scientific and Technical Information of China (English)

    边宇; 刘明; 吕红芳

    2013-01-01

    By generalizing, analyzing and systemizing literature data about the history of physical education in the United States, the authors concluded that the historical evolution of college physical education in the United States can be divided into three stages, namely, formation stage, localization stage and diversification stage. The character-istics of the formation stage were scientized, diversified, and de-religion;the characteristic of the localization stage was the legalization of “Americanized” fundamental appeals, systemized philosophical foundations and sports competitions;the characteristics of the diversification stage were repeated and government dominated. The source of power for the historical evolution of college physical education in the United States was the changing of physical education ideology;the overall trend of stage-specific characteristics was the evolution from instrumental values to ontological values.%  通过对美国体育史文献的归纳、分析与整理,认为美国大学体育的历史沿革可分为形成、本土化和多元化3个阶段。形成阶段的特征是科学化、多样化和去宗教化;本土化阶段的特征是“美国化”根本诉求、系统化的哲学基础和体育竞赛的法制化;多元化阶段的特征是反复化和政府化。美国大学体育历史沿革的动力来源是体育思想的转变,阶段性特征的整体趋势是从工具价值到本体价值的演进。

  10. Charge of the Electron, and the Constants of Radiation According to J. A. Wheeler's Geometrodynamic Model

    Directory of Open Access Journals (Sweden)

    Belyakov A. V.

    2010-10-01

    Full Text Available This study suggests a mechanical interpretation of Wheeler's model of the charge. According to the suggested interpretation, the oppositely charged particles are connected through the vortical lines of the current thus create a close contour "input-output" whose parameters determine the properties of the charge and spin. Depending on the energetic state of the system, the contour can be structurized into the units of the second and third order (photons. It is found that, in the framework of this interpretation, the charge is equivalent to the momentum. The numerical value of the unit charge has also been calculated proceeding from this basis. A system of the relations, connecting the charge to the constants of radiation (the Boltzmann, Wien, and Stefan-Boltzmann constants, and the fine structure constant has been obtained: this give a possibility for calculating all these constants through the unit charge.

  11. Charge of the Electron, and the Constants of Radiation According to J. A. Wheeler's Geometrodynamic Model

    Directory of Open Access Journals (Sweden)

    Belyakov A. V.

    2010-10-01

    Full Text Available This study suggests a mechanical interpretation of Wheller’s model of the charge. Ac- cording to the suggested interpretation, the oppositely charged particles are connected through the vortical lines of the current thus create a close contour “input-output” whose parameters determine the properties of the charge and spin. Depending on the energetic state of the system, the contour can be structurized into the units of the second and thirs order (photons. It is found that, in the framework of this interpretation, the charge is equivalent to the momentum. The numerical value of the unit charge has also been cal- culated proceeding from this basis. A system of the relations, connecting the charge to the constants of radiation (the Boltzmann, Wien, and Stefan-Boltzmann constants, and the fine structure constant has been obtained: this give a possibility for calculating all these constants through the unit charge.

  12. Scrutinizing the cosmological constant problem and a possible resolution

    Science.gov (United States)

    Bernard, Denis; LeClair, André

    2013-03-01

    We suggest a new perspective on the cosmological constant problem by scrutinizing its standard formulation. In classical and quantum mechanics without gravity, there is no definition of the zero point of energy. Furthermore, the Casimir effect only measures how the vacuum energy changes as one varies a geometric modulus. This leads us to propose that the physical vacuum energy in a Friedmann-Lemaître-Robertson-Walker expanding universe only depends on the time variation of the scale factor a(t). Equivalently, requiring that empty Minkowski space is gravitationally stable is a principle that fixes the ambiguity in the zero-point energy. On the other hand, if there is a meaningful bare cosmological constant, this prescription should be viewed as a fine-tuning. We describe two different choices of vacuum, one of which is consistent with the current universe consisting only of matter and vacuum energy. The resulting vacuum energy density ρvac is constant in time and approximately kc2H02, where kc is a momentum cutoff and H0 is the current Hubble constant; for a cutoff close to the Planck scale, values of ρvac in agreement with astrophysical measurements are obtained. Another choice of vacuum is more relevant to the early universe consisting of only radiation and vacuum energy, and we suggest it as a possible model of inflation.

  13. Comparison of availability and offer of controlled physical activities for pupils with disability in selected regions of Czech Republic and United Kingdom

    Directory of Open Access Journals (Sweden)

    Zuzana Kornatovská

    2016-11-01

    Full Text Available Background: The European Union and other countries of the world need quality research data, without which it cannot assess how the overall situation of persons with disabilities develops. Objective: The aim of this paper is to compare the availability of controlled physical activities for pupils with mental disabilities, hearing or visual disabilities in selected regions of the Czech Republic and Great Britain (region of South Bohemia and the region West Midlands. Partial aim is to analyse an offer of the controlled physical activities for this population of pupils. Methods: We used analytical investigative methods (Investigative pentagram. The survey was based on explanation, exploration and direct observation. Another method was a tool "ArcGIS" evaluating the distance of polygons and "packaging zones" by driving times for the EU - Index of availability. After that it was determined the availability of controlled physical activities for pupils with the observed types of disability and evaluated the hypothesis H1. In surveyed regions were also examined ways of organizing a range of offers of controlled physical activities for pupils with disabilities. Results: The range of controlled physical activities was verified higher in the West Midlands region compared to the South Bohemian region. It was found that the British region unlike the South Bohemian region accentuated non-confrontational character of the controlled physical activities with health preventive impact (yoga, swimming and social integration (dancing, walking and hiking. Conclusions: It was verified the hypothesis H1, assuming that the availability of controlled physical activities for pupils with mental disabilities, hearing, visual is significantly higher in the surveyed region of the UK compared to the surveyed region in the Czech Republic.

  14. X-rays, radiometers and skin unit dose. The development of measuring methods and measuring units for X radiation in medical physics from the beginning until the international standardization; X-Strahlen, Radiometer und Hauteinheitsdosis. Die Entwicklung der Messverfahren und Masseinheiten fuer Roentgenstrahlung in der medizinischen Physik von den Anfaengen bis zur internationalen Standardisierung

    Energy Technology Data Exchange (ETDEWEB)

    Glessmer-Junike, Simone

    2015-01-22

    international standardization began. This fourth stage continues arguably to the present day, since by now not only units, but also standards for both measurement of these units and quality assurance, are developed in international cooperation. This study presents how present-day knowledge of fundamental physical laws, of potential measurement errors and of shortcomings of methods contribute to a better understanding of the historical process of the development portrayed here. When applying scientific discoveries to medicine and technology, this historical knowledge is an essential prerequisite for successful communication in a globalized world, which depends on international standards for manufacturing and application of measurement devices.

  15. VMATc: VMAT with constant gantry speed and dose rate

    Science.gov (United States)

    Peng, Fei; Jiang, Steve B.; Romeijn, H. Edwin; Epelman, Marina A.

    2015-04-01

    This article considers the treatment plan optimization problem for Volumetric Modulated Arc Therapy (VMAT) with constant gantry speed and dose rate (VMATc). In particular, we consider the simultaneous optimization of multi-leaf collimator leaf positions and a constant gantry speed and dose rate. We propose a heuristic framework for (approximately) solving this optimization problem that is based on hierarchical decomposition. Specifically, an iterative algorithm is used to heuristically optimize dose rate and gantry speed selection, where at every iteration a leaf position optimization subproblem is solved, also heuristically, to find a high-quality plan corresponding to a given dose rate and gantry speed. We apply our framework to clinical patient cases, and compare the resulting VMATc plans to idealized IMRT, as well as full VMAT plans. Our results suggest that VMATc is capable of producing treatment plans of comparable quality to VMAT, albeit at the expense of long computation time and generally higher total monitor units.

  16. Physical property of basic unit and database in machine tool lightweight design%机床轻量化设计基本单元物理性能与数据库的研究

    Institute of Scientific and Technical Information of China (English)

    董惠敏; 邢俏芳; 王德胜; 姜怀胜; 王德伦; 申会鹏; 孙颖

    2012-01-01

    To provide the scientific basis for mac.hine tool structure lightweight design, the machine tool lightweight unit design technology is explored. The structure performance of panel-type unit is investigated. The basic unit database for the machine tool lightweight design is constructed. Through researching the internal structure feature of machine tool components in practical engineering application, the concept of lightweight panel-type unit is proposed. Seven kinds of plane-type basic units are abstracted, and the plane-type basic unit spectrum is established. Based on ANSYS finite element analysis method, the seven kinds of parametric physical models with plane-type basic unit are built. In the situation of basic unit with same dimension parameters or same mass, the static and dynamic performances of seven kinds of plane-type basic units are studied respectively. The static property of each kind of basic unit in pull, press, bend and twist, as well as the dynamic base frequency distribution rule are obtained, which provides the data sources for the machine tool lightweight database.%探讨机床轻量化单元设计技术,研究壁板类单元的结构性能,构建机床轻量化设计基本单元数据库,为机床支承件轻量化设计提供科学依据.通过研究实际工程应用中机床支承件的内部结构特征,提出机床轻量化壁板类单元概念,抽象出7种壁板类基本单元,建立壁板类基本单元型谱.基于AN-SYS有限元分析方法,建立7种壁板类基本单元的参数化物理模型.在基本单元尺度参数和质量相同情况下,分别研究了7种壁板类基本单元的静动态性能.得到各种基本单元的拉、压、弯、扭静态性能,以及动态基频分布规律,为机床轻量化数据库提供数据来源.

  17. Some Zero-Sum Constants with Weights

    Indian Academy of Sciences (India)

    S D Adhikari; R Balasubramanian; F Pappalardi; P Rath

    2008-05-01

    For an abelian group , the Davenport constant () is defined to be the smallest natural number such that any sequence of elements in has a non-empty subsequence whose sum is zero (the identity element). Motivated by some recent developments around the notion of Davenport constant with weights, we study them in some basic cases. We also define a new combinatorial invariant related to $(\\mathbb{Z}/n\\mathbb{Z})^d$, more in the spirit of some constants considered by Harborth and others and obtain its exact value in the case of $(\\mathbb{Z}/n\\mathbb{Z})^2$ where is an odd integer.

  18. EFFECTS OF CONSTANT EXCITATION ON LOCAL BIFURCATION

    Institute of Scientific and Technical Information of China (English)

    WU Zhi-qiang; CHEN Yu-shu

    2006-01-01

    The effects of the constant excitation on the local bifurcation of the periodic solutions in the 1:2 internal resonant systems were analyzed based on the singularity theory. It is shown that the constant excitation make influence only when there exist some nonlinear terms, in the oscillator with lower frequency. Besides acting as main bifurcation parameter, the constant excitation, together with coefficients of some nonlinear terms,may change the values of unfolding parameters and the type of the bifurcation. Under the non-degenerate cases, the effect of the third order terms can be neglected.

  19. On the constants for some Sobolev imbeddings

    Directory of Open Access Journals (Sweden)

    Pizzocchero Livio

    2001-01-01

    Full Text Available We consider the imbedding inequality is the Sobolev space (or Bessel potential space of type and (integer or fractional order . We write down upper bounds for the constants , using an argument previously applied in the literature in particular cases. We prove that the upper bounds computed in this way are in fact the sharp constants if , , and exhibit the maximising functions. Furthermore, using convenient trial functions, we derive lower bounds on for in many cases these are close to the previous upper bounds, as illustrated by a number of examples, thus characterizing the sharp constants with little uncertainty.

  20. The cosmological constant and the time of its dominance

    CERN Document Server

    Garriga, J; Vilenkin, A; Garriga, Jaume; Livio, Mario; Vilenkin, Alexander

    2000-01-01

    We explore a model in which the cosmological constant $\\Lambda$ and the density contrast at the time of recombination $\\sigma_{rec}$ are random variables, whose range and {\\it a priori} probabilities are determined by the laws of physics. (Such models arise naturally in the framework of inflationary cosmology.) Based on the assumption that we are typical observers, we show that the order of magnitude coincidence among the three timescales: the time of galaxy formation, the time when the cosmological constant starts to dominate the cosmic energy density, and the present age of the universe, finds a natural explanation. We also discuss the probability distribution for $\\sigma_{rec}$, and find that it is peaked near the observationally suggested values, for a wide class of {\\it a priori} distributions.