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Sample records for earth pressure balance

  1. Rare earths and the balance problem

    OpenAIRE

    Binnemans, Koen; Jones , Peter Tom

    2015-01-01

    Maintaining the balance between the demand by the economic markets and the natural abundance of the rare-earth elements (REEs) in ores constitutes a major challenge for manufacturers of these elements. This is the so-called balance problem (or balancing problem). The ideal situation is a perfect match between the demand and (production) supply of REEs, so that there are no surpluses of any of the REEs. The balance problem implicates that the rare-earth industry has to either find new applicat...

  2. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    Two different analyses have been carried out in order to find the vertical earth pressure, or overburden pressure, at the crown of a tunnel going through a dike. Firstly, a hand calculation is performed using a simple dispersion of the stresses over depth. Secondly, the finite?element program...

  3. Rare-Earth Economics: The Balance Problem

    Science.gov (United States)

    Binnemans, K.; Jones, P. T.; Van Acker, K.; Blanpain, B.; Mishra, B.; Apelian, D.

    2013-07-01

    TMS has forged cooperative agreements with several carefully selected organizations that actively work to benefit the materials science community. In this occasional series, JOM will provide an update on the activities of these organizations. This installment, by the Center for Resource Recovery & Recycling (CR3), focuses on the importance of recycling of rare earths to mitigate the so-called Balance Problem. The CR3 is a research center established by Worcester Polytechnic Institute, Colorado School of Mines, and KU Leuven. Twenty-eight corporations and national laboratories along with support from the U.S. National Science Foundation's Industry University Cooperative Research Center (I/UCRC) program are sponsors of the center.

  4. Seismic induced earth pressures in buried vaults

    International Nuclear Information System (INIS)

    The magnitude and distribution of earth pressures acting on buried structures and induced by a seismic event are considered in this paper. A soil-structure-interaction analysis is performed for typical Department of Energy high level waste storage tanks using a lumped parameter model. The resulting soil pressure distributions are determined and compared with the static soil pressure to assess the design significance of the seismic induced soil pressures. It is found that seismic pressures do not control design unless the peak ground acceleration exceeds about 0.3 G. The effect of soil non linearities (resulting from local soil failure) are also found to have little effect on the predictions of the seismic response of the buried structure. The seismic induced pressures are found to be very similar to those predicted using the elastic model in ASCE 4-86

  5. Dynamic active earth pressure on retaining structures

    Indian Academy of Sciences (India)

    Deepankar Choudhury; Santiram Chatterjee

    2006-12-01

    Earth-retaining structures constitute an important topic of research in civil engineering, more so under earthquake conditions. For the analysis and design of retaining walls in earthquake-prone zones, accurate estimation of dynamic earth pressures is very important. Conventional methods either use pseudo-static approaches of analysis even for dynamic cases or a simple single-degree of freedom model for the retaining wall–soil system. In this paper, a simplified two-degree of freedom mass–spring–dashpot (2-DOF) dynamic model has been proposed to estimate the active earth pressure at the back of the retaining walls for translation modes of wall movement under seismic conditions. The horizontal zone of influence on dynamic earth force on the wall is estimated. Results in terms of displacement, velocity and acceleration-time history are presented for some typical cases, which show the final movement of the wall in terms of wall height, which is required for the design. The non-dimensional design chart proposed in the present study can be used to compute the total dynamic earth force on the wall under different input ground motion and backfill conditions. Finally, the results obtained have been compared with those of the available Scott model and the merits of the present results have been discussed.

  6. High pressure polymorphism of rare earth sulfideiodides

    International Nuclear Information System (INIS)

    High pressure transformations of rare earth sulfideiodides are reported. Compounds with the GdSI-type structure (GdSI to DySI) transform to the SmSI-type within the pressure range up to 40 kb. For GdSI itself an ?-CeSI-type arrangement can be achieved additionally in the higher pressure range. All compounds crystallizing in the SmSI-type at ambient pressures transform to the ?-CeSI-type under such conditions. We explain these structures briefly in terms of a topological description, and we offer a structure model for GdSI. Possible reaction mechanism are discussed in comparison with similar transformations in LnOCl and LnSF compounds. (author)

  7. Earth in the balance. Ecology and the human spirit

    International Nuclear Information System (INIS)

    This book is the translation of the original American edition ''earth in the balance''. When Earth in the Balance first came out, it caused quite a stir and for good reason. It convincingly makes the case that a crisis of epidemic proportions is nearly upon us and that if the world does not get its act together soon and agree to some kind of 'Global Marshall Plan' to protect the environment, we're all up a polluted creek without a paddle. Myriad plagues are upon us, but the worst include the loss of biodiversity, the depletion of the ozone layer, the slash-and-burn destruction of rain forests, and the onset of global warming. None of this is new, of course, nor was it new in 1992. But most environmentalists will still get a giddy feeling reading such a call to action as written by a prominent politician. The book is arranged into three sections: the first describes the plagues; the second looks at how we got ourselves into this mess; and the final chapters present ways out. Gore gets his points across in a serviceable way, though he could have benefited from a firmer editor's hand; at times the analogies are arcane and the pacing is odd kind of like a Gore speech that climaxes at weird points and then sinks just as the audience is about to clap. Still, at the end you understand what's been said. Gore believes that if we apply some American ingenuity, the twin engines of democracy and capitalism can be rigged to help us stabilize world population growth, spread social justice, boost education levels, create environmentally appropriate technologies, and negotiate international agreements to bring us back from the brink. For example, a worldwide shift to clean, renewable energy sources would create huge economic opportunities for companies large and small to design, build, and maintain solar panels, wind turbines, fuel cells, and other eco friendly innovations

  8. Pressure pressure-balanced pH sensing system for high temperature and high pressure water

    International Nuclear Information System (INIS)

    As for the pH measurement system for high temperature, high pressure water, there have been the circumstances that first the reference electrodes for monitoring corrosion potential were developed, and subsequently, it was developed for the purpose of maintaining the soundness of metallic materials in high temperature, high pressure water in nuclear power generation. In the process of developing the reference electrodes for high temperature water, it was clarified that the occurrence of stress corrosion cracking in BWRs is closely related to the corrosion potential determined by dissolved oxygen concentration. As the types of pH electrodes, there are metal-hydrogen electrodes, glass electrodes, ZrO2 diaphragm electrodes and TiO2 semiconductor electrodes. The principle of pH measurement using ZrO2 diaphragms is explained. The pH measuring system is composed of YSZ element, pressure-balanced type external reference electrode, pressure balancer and compressed air vessel. The stability and pH response of YSZ elements are reported. (K.I.)

  9. Rigidly framed earth retaining structures thermal soil structure interaction of buildings supporting unbalanced lateral earth pressures

    CERN Document Server

    Aboumoussa, Walid

    2014-01-01

    Structures placed on hillsides often present a number of challenges and a limited number of economical choices for site design. An option sometimes employed is to use the building frame as a retaining element, comprising a Rigidly Framed Earth Retaining Structure (RFERS). The relationship between temperature and earth pressure acting on RFERS, is explored in this monograph through a 4.5 year monitoring program of a heavily instrumented in service structure. The data indicated that the coefficient of earth pressure behind the monitored RFERS had a strong linear correlation with temperature. The study also revealed that thermal cycles, rather than lateral earth pressure, were the cause of failure in many structural elements. The book demonstrates that depending on the relative stiffness of the retained soil mass and that of the structural frame, the developed lateral earth pressure, during thermal expansion, can reach magnitudes several times larger than those determined using classical earth pressure theories....

  10. Journey to the Center of the Earth: Exploring High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Wendy

    2009-09-29

    The deeper we go into the Earth, the higher the pressure. At the pressures found within the center of our planet, minerals do not simply compress. Pressure dramatically alters all materials properties, in the process creating numerous novel phases not found on the surface. This lecture will describe how we simulate the conditions found in planetary interiors in the lab, what kinds of new behavior we find, and how these observations can explain what is going on within the Earth. High pressure explorations also lead to discoveries of novel materials with potential for practical applications in our low-pressure, environment.

  11. Earth pressures against- and stability of retaining structures

    OpenAIRE

    Sigurur Mr Valsson 1982

    2011-01-01

    The objective of the presented research is to investigate methods used to calculate earth pressures against- and the stability of retaining structures. The classical methods of calculating earth pressures are covered in detail. They are named after their creators Charles-Augustin de Coulomb and William John Macquorn Rankine. A special interest is taken in a variant of Rankine?s theory developed at Norges teknisk- naturvitenskapelige universitet (NTNU) that incorporates cohesive properties ...

  12. Pressure balance between a magnetized plasma and a low pressure neutral gas

    International Nuclear Information System (INIS)

    The steady state pressure balance between a plasma and a low pressure neutral gas is calculated by the continuum approach in order to predict the critical density of a neutral gas above which the plasma is drastically affected. The diffusion in the plasma-neutral gas boundary induces a large diamagnetic current which also induces the large pressure difference between a plasma and a neutral gas. This means that a plasma may be affected even by a low density neutral gas. (orig.)

  13. Reliability of Center of Pressure Measures During Dynamic Balance Performance

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Sanjary

    2011-12-01

    Full Text Available Background and Aim: Few studies have assessed the reliability of postural balance measures during dynamic balance performance that introduce additional challenging to postural control system. In addition sometimes in the static conditions some deficiencies of the postural control system may not be revealed obviously therefore the aim of this study was to assess the reliability of postural control parameters during functional performance on force plate in healthy subjects.Materials and Methods: Ten healthy male subjects (mean age: 25.4 years, weight: 68.2 kg height:176.9cm participated in this study. None of the subjects were involved in sport activities. Every subject performed three 15seconds trials of eyes open single leg stance on a force plate during dynamic balance task. Participants grasped object with hand at their waist level and release it at above shoulder level. The reproducibility of the center of pressure (COP deviations (average speed &length of path was assessed. All participants were tested on 2 sessions with an inter-measurement interval of 7 days. COP data was collected for each trial. The intraclass correlation coefficient (ICC was used as parameter of intra-session and inter-session (Test-Retest reliability.Results: The ICCs for intra-session reliability of average speed and length of COP path were 0.89 and 0.91 respectively. The ICCs for inter-session reliability were 0.95 and 0.96 respectively.Conclusion: The study showed high and very high reliability for center of pressure measures during dynamic balance task. Therefore this dynamic performance can be used as a balance pattern in postural control assessment. These can be used as reliable parameters in dynamic postural control assessment due to high reliability of average speed and length of COP path.

  14. Accurate determination of equilibrium state between two pressure balances using a pressure transducer

    Science.gov (United States)

    Kobata, Tokihiko; Olson, Douglas A.

    2005-12-01

    To determine an equilibrium state between two pressure balances accurately, the measurement method using a precise pressure transducer and two air-operated constant volume valves (CVV) is proposed in this paper. The advantages of the proposed method are as follows: (1) by the usage of two air-operated CVV, the pressure generated by the pressure balance can be connected and disconnected quickly to the transducer without volume change in the hydraulic circuit or heat transfer from the operator, (2) by managing the time intervals between measurements equally, the method proposed can compensate for the effect of the drift component in the successive values measured by the transducer used and (3) the short time stability of the pressure generated by each pressure balance used can be evaluated quantitatively at each pressure. From the measurement results, it was revealed that the equilibrium state could be determined accurately using the method proposed, and the differences between this method and the conventional fall-rate method were sufficiently small.

  15. Physical Limitations of Empirical Field Models: Force Balance and Plasma Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sorin Zaharia; C.Z. Cheng

    2002-06-18

    In this paper, we study whether the magnetic field of the T96 empirical model can be in force balance with an isotropic plasma pressure distribution. Using the field of T96, we obtain values for the pressure P by solving a Poisson-type equation {del}{sup 2}P = {del} {center_dot} (J x B) in the equatorial plane, and 1-D profiles on the Sun-Earth axis by integrating {del}P = J x B. We work in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials. Our results lead to the conclusion that the T96 model field cannot be in equilibrium with an isotropic pressure. We also analyze in detail the computation of Birkeland currents using the Vasyliunas relation and the T96 field, which yields unphysical results, again indicating the lack of force balance in the empirical model. The underlying reason for the force imbalance is likely the fact that the derivatives of the least-square fitted model B are not accurate predictions of the actual magnetospheric field derivatives. Finally, we discuss a possible solution to the problem of lack of force balance in empirical field models.

  16. Physical Limitations of Empirical Field Models: Force Balance and Plasma Pressure

    International Nuclear Information System (INIS)

    In this paper, we study whether the magnetic field of the T96 empirical model can be in force balance with an isotropic plasma pressure distribution. Using the field of T96, we obtain values for the pressure P by solving a Poisson-type equation (gradient)2P = (gradient) (J x B) in the equatorial plane, and 1-D profiles on the Sun-Earth axis by integrating (gradient)P = J x B. We work in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials. Our results lead to the conclusion that the T96 model field cannot be in equilibrium with an isotropic pressure. We also analyze in detail the computation of Birkeland currents using the Vasyliunas relation and the T96 field, which yields unphysical results, again indicating the lack of force balance in the empirical model. The underlying reason for the force imbalance is likely the fact that the derivatives of the least-square fitted model B are not accurate predictions of the actual magnetospheric field derivatives. Finally, we discuss a possible solution to the problem of lack of force balance in empirical field models

  17. High pressure ?SR studies: rare earths and related materials

    International Nuclear Information System (INIS)

    After a short introduction to ?SR with respect to the study of magnetic properties, followed by a brief outline of the principle of the high pressure-low temperature ?SR spectrometer installed at the Paul Scherrer Institute, we discuss some measurements on rare earth materials employing this instrument. They are concerned with: (1) The pressure dependence of the spin turning process in ferromagnetic Gd. (2) The volume dependence of the internal magnetic field in the heavy rare earth metals Gd, Dy, and Ho in their ordered magnetic states. (3) The response of the (first order) magnetic transition in the frustrated antiferromagnets of type RMn2 (R = Y,Gd) to pressure. (4) The variation of magnetic parameters with pressure in La2CuO4 (powder sample), the antiferromagnetic parent compound of the high TC superconductors of type La2-x(Sr, Ba)xCuO4. In conclusion a short outlook on further developments is given

  18. Elastic properties of alkaline earth oxides under high pressure

    International Nuclear Information System (INIS)

    A phenomenological theory has been developed to describe the elastic behavior of alkaline earth oxide solids under high pressure. The values of second order elastic constants, Cauchy's deviation and Zener anisotropy ratio at different pressures have been computed for MgO, CaO, SrO, and BaO. The results were found to be satisfactory and in agreement with available experimental and other theoretical results

  19. Risks of analyses with lateral earth pressure load.

    Czech Academy of Sciences Publication Activity Database

    Koudelka, Petr

    London : Taylor and Francis Group, 2011 - (Faber, M.; Kohler, J.; Nishijima, K.), s. 842-848 ISBN 978-0-415-66986-3. [IC on Application of statistics in civil engineering /11./. Zurich (CH), 01.08.2011-04.08.2011] Grant ostatn: GA?R(CZ) GAP105/11/1160 Institutional research plan: CEZ:AV0Z20710524 Keywords : earth pressure * active / passive pressure * EUROCODE 7-1 * design risk Subject RIV: BM - Solid Matter Physics ; Magnetism

  20. Measurement of pressures up to 7?MPa applying pressure balances for dielectric-constant gas thermometry

    Science.gov (United States)

    Zandt, Thorsten; Sabuga, Wladimir; Gaiser, Christof; Fellmuth, Bernd

    2015-10-01

    For the determination of the Boltzmann constant by dielectric-constant gas thermometry, the uncertainty of pressure measurements in helium up to 7?MPa has been decreased compared with previous achievements (Sabuga 2011 PTB-Mitt. 121 247-55). This was possible by performing comprehensive cross-float experiments with a system of six special pressure balances and the synchronization of their effective areas. It is now possible to measure a helium pressure of 7?MPa with a relative standard uncertainty of 1.0?ppm applying a 2?cm2 piston-cylinder unit, the calibration of which is traceable to the SI base units.

  1. Dual shell pressure balanced reactor vessel. Final project report

    International Nuclear Information System (INIS)

    The Department of Energy's Office of Energy Research (OER) has previously provided support for the development of several chemical processes, including supercritical water oxidation, liquefaction, and aqueous hazardous waste destruction, where chemical and phase transformations are conducted at high pressure and temperature. These and many other commercial processes require a pressure vessel capable of operating in a corrosive environment where safety and economy are important requirements. Pacific Northwest Laboratory (PNL) engineers have recently developed and patented (U.S. patent 5,167,930 December 1, 1992) a concept for a novel Dual Shell Pressure Balanced Vessel (DSPBV) which could solve a number of these problems. The technology could be immediately useful in continuing commercialization of an R ampersand D 100 award-winning technology, Sludge-to-oil Reactor System (STORS), originally developed through funding by OER. Innotek Corporation is a small business that would be one logical end-user of the DSPBV reactor technology. Innotek is working with several major U.S. engineering firms to evaluate the potential of this technology in the disposal of wastes from sewage treatment plants. PNL entered into a CRADA with Innotek to build a bench-scale demonstration reactor and test the system to advance the economic feasibility of a variety of high pressure chemical processes. Hydrothermal processing of corrosive substances on a large scale can now be made significantly safer and more economical through use of the DSPBV. Hydrothermal chemical reactions such as wet-air oxidation and supercritical water oxidation occur in a highly corrosive environment inside a pressure vessel. Average corrosion rates from 23 to 80 miles per year have been reported by Rice (1994) and Latanision (1993)

  2. Performance of earth pressure cell as grain pressure transducer in a model silo

    Directory of Open Access Journals (Sweden)

    J. Horabik

    2007-03-01

    Full Text Available Numerous methods have been proposed for determining the pressure exerted by grain at discrete locations in a storage structure, but few satisfactory solutions have been found. Earth pressure cells were tested as potential measurement devices for grain bins. Earth pressure cells are commercial transducers designed for geotechnical applications. Calibration of the earth pressure cell was performed in a pressurized chamber filled with wheat under normal load as well as shear load. The cell was tested in a model grain silo 1.83 m in diameter d with a height hc of 5.75 m. Vertical floor pressures and horizontal wall pressures were measured at different points in the model bin. The vertical floor pressure pvi was measured at two different radial locations and horizontal wall pressure ph was measured at four different wall heights. The vertical floor pressure obtained using the earth pressure cell was in good agreement with the mean floor pressure pv calculated using load cells that supported the entire floor or the bin. Considerable variation in the vertical floor pressure along the silo floor radius was observed. The variation of the lateral-to-vertical pressure ratio, K, was monitored during each fill-unload cycle of the model silo. In the case of the maximum h/d ratio of 2, K increased during filling and stabilized after reaching a grain h/d ratio of 1.3. At the onset of discharge, the pressure ratio immediately increased up to value of approximately 0.7, and remained stable during unloading down to a h/d ratio of approximately 0.65 when K decreased rapidly.

  3. Earth in the balance - ecology and the human spirit

    International Nuclear Information System (INIS)

    This book by Senator Albert Gore presents a global prospective on the environmental crisis facing the Earth. The chapters are framed in the twin ideas of the threat posed by human civilization to the global environment and the threat to human civilization posed by changes in the global environment. Gore first looks at evidence of risk in the environment: historical aspects of climate and civilization; ozone layer; water; land use; food supply; waste disposal. In Part II different aspects of our current approaches to the environment are described: politics; economics; technology; social problems; environmentalism of the human spirit. Finally in Part III, Gore presents his approach to the global environmental crisis, first presenting a section about a global sense of responsibility and purpose and then describing his ideas for A Global Marshal Plan. 169 refs., 4 figs

  4. Pressure-temperature Phase Diagram of the Earth

    CERN Document Server

    Jones, Eriita

    2010-01-01

    Based on a pressure-temperature (P-T) phase diagram model of the Earth, Jones & Lineweaver (2010) described uninhabited terrestrial liquid water. Our model represents the atmosphere, surface, oceans and interior of the Earth - allowing the range of P-T conditions in terrestrial environments to be compared to the phase regime of liquid water. Here we present an overview and additional results from the Earth model on the location of the deepest liquid water on Earth and the maximum possible extent of the terrestrial biosphere. The intersection of liquid water and terrestrial phase space indicates that the deepest liquid water environments in the lithosphere occur at a depth of ~ 75 km. 3.5 % of the volume of the Earth is above 75 km depth. Considering the 3.5 % of the volume of the Earth where liquid water exists, ~ 12% of this volume is inhabited by life while the remaining ~ 88% is uninhabited. This is distinct from the fraction of the volume of liquid water occupied by life. We find that at least 1% of t...

  5. EDITORIAL: The Earth radiation balance as driver of the global hydrological cycle

    Science.gov (United States)

    Wild, Martin; Liepert, Beate

    2010-06-01

    Variations in the intensity of the global hydrological cycle can have far-reaching effects on living conditions on our planet. While climate change discussions often revolve around possible consequences of future temperature changes, the adaptation to changes in the hydrological cycle may pose a bigger challenge to societies and ecosystems. Floods and droughts are already today amongst the most damaging natural hazards, with floods being globally the most significant disaster type in terms of loss of human life (Jonkman 2005). From an economic perspective, changes in the hydrological cycle can impose great pressures and damages on a variety of industrial sectors, such as water management, urban planning, agricultural production and tourism. Despite their obvious environmental and societal importance, our understanding of the causes and magnitude of the variations of the hydrological cycle is still unsatisfactory (e.g., Ramanathan et al 2001, Ohmura and Wild 2002, Allen and Ingram 2002, Allan 2007, Wild et al 2008, Liepert and Previdi 2009). The link between radiation balance and hydrological cycle Globally, precipitation can be approximated by surface evaporation, since the variability of the atmospheric moisture storage is negligible. This is the case because the fluxes are an order of magnitude larger than the atmospheric storage (423 x 1012 m3 year-1 versus 13 x 1012 m3 according to Baumgartner and Reichel (1975)), the latter being determined by temperature (Clausius-Clapeyron). Hence the residence time of evaporated water in the atmosphere is not more than a few days, before it condenses and falls back to Earth in the form of precipitation. Any change in the globally averaged surface evaporation therefore implies an equivalent change in precipitation, and thus in the intensity of the global hydrological cycle. The process of evaporation requires energy, which it obtains from the surface radiation balance (also known as surface net radiation), composed of the absorbed solar and net thermal radiative exchanges at the Earth's surface. Globally averaged, this surface radiation balance is positive, since radiative absorption, scattering and emission in the climate system act to generate an energy surplus at the surface and an energy deficit in the atmosphere (Liepert 2010). Evaporation, or more precisely its energy equivalent, the latent heat flux, is the main process that compensates for this imbalance between surface and atmosphere, since the latent heat dominates the convective energy flux over sensible heating. The radiative energy surplus at the surface is thus mainly consumed by evaporation and moist convection and subsequently released in the atmosphere through condensation. This implies that any alterations in the available radiative energy will induce changes in the water fluxes. Our focus in this editorial is therefore on the surface radiation balance as the principal driver of the global hydrological cycle. Note that this energetic view is in agreement with that of Richter and Xie (2008) who argue that the spatial and temporal behaviour of the process of evaporation is controlled by surface and atmospheric properties such as atmospheric stability, wind speed, moisture deficit and moisture availability. From radiation theory it is expected that with increasing radiative absorption due to abundance of anthropogenic greenhouse gases in the atmosphere and consequent warming, the emission of thermal energy from the atmosphere towards the surface is increasing (known as downward thermal radiation). This enhances the radiative energy surplus at the surface, and, where surface water is not limited, fuels evaporation besides warming the Earth's surface. The enhanced greenhouse effect therefore tends to accelerate the hydrological cycle, as also shown in many climate model simulations with increasing levels of greenhouse gases (e.g., IPCC 2007, but also see Yang et al 2003, Andrews et al 2009). We can assume that the increase in greenhouse gases since preindustrial times had already led to a substantial increase of downw

  6. Precariousness and hazard of lateral earth pressure theory.

    Czech Academy of Sciences Publication Activity Database

    Koudelka, Petr

    Reston : American Society of Civil Engineers, 2014 - ( Beer , M.; Au, S.; Hall, J.), s. 2765-2779 ISBN 978-0-7844-1360-9. [International Conference on vulnerability and risk analysis and management /2./. Liverpool (GB), 13.07.2014-16.07.2014] Institutional support: RVO:68378297 Keywords : earth pressure * EUROCODE 7-1 * soils Subject RIV: JM - Building Engineering http://ascelibrary.org/doi/abs/10.1061/9780784413609.279

  7. How reliable are latitudinal energy balance models for habitability calculations when using Earth's radiative properties?

    Science.gov (United States)

    Gilmore, James B.

    2014-05-01

    Exoplanet habitability studies are often performed using simple energy balance models (EBMs), which rely on an understanding of a planet's radiative properties. However, knowledge of these properties is currently limited. Here, I use Earth as a testbed for examining habitability and model uncertainty in a diffusive latitudinal EBM. Using an empirical approach, I parametrize Earth's radiative properties - top of atmosphere albedo and outgoing infrared radiation - as a function of surface temperature, using measurements from the NASA Clouds and Earth's Radiant Energy System instruments. When using surface temperature to construct these functions, a bias analysis shows only small global biases of 3 and - 0.3 W m-2 are introduced for the albedo and infrared functions, respectively. I also show there is a very fine balance between Earth's incoming solar and outgoing infrared radiation in the observational data, which is substantially smaller than previously assumed in this model. Using observationally derived radiative functions for an Earth-like planet, the snowball transition can be determined within a semimajor axis of 3 per cent, with a structural uncertainty of 2 per cent in the radiative function construction. This work shows that diffusive EBMs can be successfully used to identify habitable exo-Earths within 3 per cent if the radiative properties are known.

  8. Effect of revised high-heeled shoes on foot pressure and static balance during standing.

    Science.gov (United States)

    Bae, Young-Hyeon; Ko, Mansoo; Park, Young-Soul; Lee, Suk-Min

    2015-04-01

    [Purpose] The purpose of this study was to investigate the effects of revised high-heeled shoes on the foot pressure ratio and static balance during standing. [Subjects and Methods] A single-subject design was used, 15 healthy women wearing revised high-heeled shoes and general high-heeled shoes in a random order. The foot pressure ratio and static balance scores during standing were measured using a SpaceBalance 3D system. [Results] Forefoot and rearfoot pressures were significantly different between the 2 types of high-heeled shoes. Under the 3 conditions tested, the static balance score was higher for the revised high-heeled shoes than for the general high-heeled shoes, but this difference was not statistically significant. [Conclusion] Revised high-heeled shoes are preferable to general high-heeled shoes, as they result in normalization of normalized foot pressure and a positive effect on static balance. PMID:25995572

  9. THE HABITABLE ZONE OF EARTH-LIKE PLANETS WITH DIFFERENT LEVELS OF ATMOSPHERIC PRESSURE

    International Nuclear Information System (INIS)

    As a contribution to the study of the habitability of extrasolar planets, we implemented a one-dimensional energy balance model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply our EBM to investigate the surface habitability of planets with an Earth-like atmospheric composition but different levels of surface pressure. The habitability, defined as the mean fraction of the planet's surface on which liquid water could exist, is estimated from the pressure-dependent liquid water temperature range, taking into account seasonal and latitudinal variations of surface temperature. By running several thousands of EBM simulations we generated a map of the habitable zone (HZ) in the plane of the orbital semi-major axis, a, and surface pressure, p, for planets in circular orbits around a Sun-like star. As pressure increases, the HZ becomes broader, with an increase of 0.25 AU in its radial extent from p = 1/3 to 3 bar. At low pressure, the habitability is low and varies with a; at high pressure, the habitability is high and relatively constant inside the HZ. We interpret these results in terms of the pressure dependence of the greenhouse effect, the efficiency of horizontal heat transport, and the extent of the liquid water temperature range. Within the limits discussed in the paper, the results can be extended to planets in eccentric orbits around non-solar-type stars. The main characteristics of the pressure-dependent HZ are modestly affected by variations of planetary properties, particularly at high pressure.

  10. THE HABITABLE ZONE OF EARTH-LIKE PLANETS WITH DIFFERENT LEVELS OF ATMOSPHERIC PRESSURE

    Energy Technology Data Exchange (ETDEWEB)

    Vladilo, Giovanni; Murante, Giuseppe; Silva, Laura [INAF-Trieste Astronomical Observatory, Trieste (Italy); Provenzale, Antonello [Institute of Atmospheric Sciences and Climate-CNR, Torino (Italy); Ferri, Gaia; Ragazzini, Gregorio, E-mail: vladilo@oats.inaf.it [Department of Physics, University of Trieste, Trieste (Italy)

    2013-04-10

    As a contribution to the study of the habitability of extrasolar planets, we implemented a one-dimensional energy balance model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply our EBM to investigate the surface habitability of planets with an Earth-like atmospheric composition but different levels of surface pressure. The habitability, defined as the mean fraction of the planet's surface on which liquid water could exist, is estimated from the pressure-dependent liquid water temperature range, taking into account seasonal and latitudinal variations of surface temperature. By running several thousands of EBM simulations we generated a map of the habitable zone (HZ) in the plane of the orbital semi-major axis, a, and surface pressure, p, for planets in circular orbits around a Sun-like star. As pressure increases, the HZ becomes broader, with an increase of 0.25 AU in its radial extent from p = 1/3 to 3 bar. At low pressure, the habitability is low and varies with a; at high pressure, the habitability is high and relatively constant inside the HZ. We interpret these results in terms of the pressure dependence of the greenhouse effect, the efficiency of horizontal heat transport, and the extent of the liquid water temperature range. Within the limits discussed in the paper, the results can be extended to planets in eccentric orbits around non-solar-type stars. The main characteristics of the pressure-dependent HZ are modestly affected by variations of planetary properties, particularly at high pressure.

  11. The habitable zone of Earth-like planets with different levels of atmospheric pressure

    CERN Document Server

    Vladilo, Giovanni; Silva, Laura; Provenzale, Antonello; Ferri, Gaia; Ragazzini, Gregorio

    2013-01-01

    As a contribution to the study of the habitability of extrasolar planets, we implemented a 1-D Energy Balance Model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply our EBM to investigate the surface habitability of planets with an Earth-like atmospheric composition but different levels of surface pressure. The habitability, defined as the mean fraction of the planet's surface on which liquid water could exist, is estimated from the pressure-dependent liquid water temperature range, taking into account seasonal and latitudinal variations of surface temperature. By running several thousands of EBM simulations we generated a map of the habitable zone (HZ) in the plane of the orbital semi-major axis, a, and surface pressure, p, for planets in circular orbits around a Sun-like star. As pressure increases, the HZ becomes broader, with an increase of 0.25 AU in its radial extent from p=1/3 bar to p=3 bar. At low pressure, the habitability is...

  12. High pressure behaviour of heavy rare earth mono antimonides

    Energy Technology Data Exchange (ETDEWEB)

    Pagare, Gitanjali [Department of Physics, Govt. M.L.B. Girls P.G. College, Bhopal 462 002 (India); Sen, Deepti [Govt. Girls College, Raisen (India); Srivastava, Vipul; Sanyal, S P, E-mail: gita_pagare@yahoo.co.i [Condensed Matter Physics Lab, Department of Physics, Barkatullah University Bhopal 462 026 (India)

    2010-03-01

    We have investigated theoretically the high-pressure structural phase transition and cohesive properties of two heavy rare earth mono antimonides (RESb; RE = Dy and Lu) by using two body interionic potential with necessary modifications to include the effect of Coulomb screening by the delocalized 4f electrons of the RE ion. The peculiar properties of these compounds have been interpreted in terms of the hybridization of f electrons with the conduction band and strong mixing of f states of RE ion with the p orbital of neighboring pnictogen ion. These compounds exhibit first order crystallographic phase transition from their NaCl (B{sub 1}) phase to CsCl (B{sub 2}) phase at 23.6 GPa and 25.4 GPa respectively. The bulk modulii of RESb compounds are obtained from the P-V curve fitted by the Birch equation of state. We also calculated the RE-RE distance as a function of pressure. Elastic properties of these compounds have also been studied and their second order elastic constants are calculated.

  13. Regional earth-atmosphere energy balance estimates based on assimilations with a GCM

    Science.gov (United States)

    Alexander, Michael A.; Schubert, Siegfried D.

    1990-01-01

    The Oort and Vonder Haar (1976) column-budget technique is presently used to evaluate the physical consistency and accuracy of regional earth-atmosphere energy balance estimates for (1) atmospheric budget terms, (2) net radiation at the top of the atmosphere, and (3) time tendency and flux divergence of energy, for Special Observing Periods of the FGGE year. It is found that, during winter, the midlatitude oceans supply large quantities of energy to the overlying atmosphere, which then transports the energy to the continental heat-sinks; the energy flows in the opposite direction during summer.

  14. Seismic Earth Pressure Development in Sheet Pile Retaining Walls: A Numerical Study

    CERN Document Server

    Rajeev, P; Sivakugan, N

    2015-01-01

    The design of retaining walls requires the complete knowledge of the earth pressure distribution behind the wall. Due to the complex soil-structure effect, the estimation of earth pressure is not an easy task; even in the static case. The problem becomes even more complex for the dynamic (i.e., seismic) analysis and design of retaining walls. Several earth pressure models have been developed over the years to integrate the dynamic earth pressure with the static earth pressure and to improve the design of retaining wall in seismic regions. Among all the models, MononobeOkabe (M-O) method is commonly used to estimate the magnitude of seismic earth pressures in retaining walls and is adopted in design practices around the world (e.g., EuroCode and Australian Standards). However, the M-O method has several drawbacks and does not provide reliable estimate of the earth pressure in many instances. This study investigates the accuracy of the M-O method to predict the dynamic earth pressure in sheet pile wall. A 2D pl...

  15. Energy Balance and Power Performance Analysis for Satellite in Low Earth Orbit

    Science.gov (United States)

    Jang, Sung-Soo; Kim, Sung-Hoon; Lee, Sang-Ryool; Choi, Jaeho

    2010-09-01

    The electrical power system (EPS) of Korean satellites in low-earth-orbit is designed to achieve energy balance based on a one-orbit mission scenario. This means that the battery has to be fully charged at the end of a one-orbit mission. To provide the maximum solar array (SA) power generation, the peak power tracking (PPT) method has been developed for a spacecraft power system. The PPT is operated by a software algorithm, which tracks the peak power of the SA and ensures the battery is fully charged in one orbit. The EPS should be designed to avoid the stress of electronics in order to handle the main bus power from the SA power. This paper summarizes the results of energy balance to achieve optimal power sizing and the actual trend analysis of EPS performance in orbit. It describes the results of required power for the satellite operation in the worst power conditions at the end-of-life, the methods and input data used in the energy balance, and the case study of energy balance analyses for the normal operation in orbit. Both 10:35 AM and 10:50 AM crossing times are considered, so the power performance in each case is analyzed with the satellite roll maneuver according to the payload operation concept. In addition, the data transmission to the Korea Ground Station during eclipse is investigated at the local-time-ascending-node of 11:00 AM to assess the greatest battery depth-of-discharge in normal operation.

  16. Frequency domain mediolateral balance assessment using a center of pressure tracking task

    OpenAIRE

    Cofr Lizama, L Eduardo; Pijnappels, Mirjam; Reeves, N Peter; Verschueren, Sabine; van Dien, Jaap H

    2013-01-01

    Since impaired mediolateral balance can increase fall risk, especially in the elderly, its quantification and training might be a powerful preventive tool. We propose a visual tracking task (VTT) with increasing frequencies (.3-2.0Hz) and with center of pressure as visual feedback as an assessment method. This mediolateral balance assessment (MELBA) consists of two tasks, tracking a predictable target signal to determine physical capacity and tracking an unpredictable target signal to determi...

  17. Contact and pressure balance structures in two-fluid cosmic-ray hydrodynamics

    Science.gov (United States)

    Webb, G. M.; Brio, M.; Zank, G. P.; Story, T.

    1995-01-01

    The role of cosmic-ray-modified contact discontinuities and pressure balance structures in two-fluid cosmic-ray hydrodynamics in one Cartesian space dimension are investigated by means of analytic and numerical solution examples, as well as by weakly nonlinear asymptotics. The fundamental wave modes of the two-fluid cosmic-ray hydrodynamic equations in the long-wavelength limit consist of the backward and forward propagating cosmic-ray-modified sound waves, with sound speed dependent on both the cosmic-ray and thermal gas pressures; the contact discontinuity; and a pressure balance mode in which the sum ofthe cosmic ray and thermal gas pressure perturbations is zero. The pressure balance mode, like the contact discontinuity is advected with the background flow. The interaction of the pressure balance mode with the contact discontinuity is investigated by means of the method of multiple scales. The thermal gas and cosmic-ray pressure perturbations satisfy a linear diffusion equation, and entropy perturbations arising from nonisentropic initial conditions for the thermal gas are frozen into the fluid. The contact discontinuity and pressure balance eigenmodes both admit nonzero perturbations in the thermal gas, whereas the cosmic-ray-modified sound waves are isentropic. The total entropy perturbation is shared between the contact discontinuity and pressure balance eigenmodes, and examples are given in which there is a transfer of entropy between the two modes. In particular, N-wave type density disturbances are obtained which arise as a result of the entropy transfer between the two modes. A weakly nonlinear geometric optics perturbation expansion is used to study the long timescale evolution of the short-wavelength entropy wave and the thermal gas sound waves in a slowly varying, large-scale background flow. The weakly nonlinear geometric optics expansion is also used to generalize previous studies of squeezing instability for short-wavelength sound waves in the two fluid model, by including a weakly nonlinear wave steepening term that leads to shock formation, as well as the effect of long time and space dependence of the background flow. Implications of cosmic-ray-modified pressure balance structures and contact discontinuities in models of the interaction of traveling interplanetary shocks and compression and rarefraction waves with the solar wind termination shock are briefly discussed.

  18. Seismic response analysis of nuclear pressure vessel model with ADVENTRUE system on the earth simulator

    International Nuclear Information System (INIS)

    We have been developing an advanced general-purpose computational mechanics system, named ADVENTURE, which is designed to be able to analyze a three dimensional finite element model of arbitrary shape over 100 million Degrees Of Freedom (DOF) mesh. The one of main process modules for solid analysis, named ADVENTURE Solid, is based the hierarchical domain decomposition parallel algorithm and employs the balancing domain decomposition as a solution technique for linearized equations. The ADVENTURE Solid has been successfully implemented on a single PC, PC clusters and MPPs with high parallel performances. In order to realize a virtual demonstration test, the solid module is implemented on the Earth Simulator with minor modification for a vector processor and applied for an implicit dynamic elastic analysis such as seismic response of a precise nuclear pressure vessel model of 35 million DOF mesh with 128 nodes (1,024 Processing Elements), and succeeded in solving 300 unsteady steps in about 4.3 hours. Furthermore, the system is applied for a static elastic analysis of a nuclear pressure vessel model of 100 million DOF mesh in about 8.5 minutes on the 256 nodes (2,048 PEs), and archived 5.08 TFLOPS, which is 31.75% of the peak performance. (author)

  19. Earth radiation balance as observed and represented in CMIP5 models

    Science.gov (United States)

    Wild, Martin; Folini, Doris; Schr, Christoph; Loeb, Norman; Knig-Langlo, Gert

    2014-05-01

    The genesis and evolution of Earth's climate is largely regulated by the Earth radiation balance. Despite of its key role in the context of climate change, substantial uncertainties still exist in the quantification of the magnitudes of its different components, and its representation in climate models. While the net radiative energy flows in and out of the climate system at the top of atmosphere are now known with considerable accuracy from new satellite programs such as CERES and SORCE, the energy distribution within the climate system and at the Earth's surface is less well determined. Accordingly, the magnitudes of the components of the surface energy balance have recently been controversially disputed, and potential inconsistencies between the estimated magnitudes of the global energy and water cycle have been emphasized. Here we summarize this discussion as presented in Chapter 2.3 of the 5th IPCC assessment report (AR5). In this context we made an attempt to better constrain the magnitudes of the surface radiative components with largest uncertainties. In addition to satellite observations, we thereby made extensive use of the growing number of surface observations to constrain the radiation balance not only from space, but also from the surface. We combined these observations with the latest modeling efforts performed for AR5 (CMIP5) to infer best estimates for the global mean surface radiative components. Our analyses favor global mean values of downward surface solar and thermal radiation near 185 and 342 Wm-2, respectively, which are most compatible with surface observations (Wild et al. 2013). These estimates are on the order of 10 Wm-2 lower and higher, respectively, than in some of the previous global energy balance assessments, including those presented in previous IPCC reports. It is encouraging that these estimates, which make full use of the information contained in the surface networks, coincide within 2 Wm-2 with the latest satellite-derived estimates (Kato et al. 2013), which are completely independently determined. This enhances confidence in these recent surface flux estimates. IPCC AR5 further presents increasing evidence from direct observations that the surface radiative fluxes undergo significant changes on decadal timescales, not only in their thermal components as expected from the increasing greenhouse effect, but also in the amount of solar radiation that reaches the Earth surface. In the thermal range, surface observations suggest an overall increase of downward thermal radiation in line with latest projections from the CMIP5 models and expectations from an increasing greenhouse effect. On the other hand the strong decadal changes in surface solar radiation seen in the observations ("dimming/brightening") are not fully captured by current climate models. These decadal changes in surface solar radiation may largely affect various aspects of climate change. Selected related references: Hartmann, D.L., A.M.G. Klein Tank, M. Rusticucci, L. Alexander, S. Brnnimann, Y. Charabi, F. Dentener, E. Dlugokencky, D. Easterling, A. Kaplan, B. Soden, P. Thorne, M. Wild and P.M. Zhai, 2013: Observations: Atmosphere and Surface. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Kato, S., Loeb, N.G., Rose, F.G., Doelling, D.R., Rutan, D.A., Caldwell, T.E., Yu, L.S, and Weller, R.A., 2013: Surface irradiances consistent with CERES-derived top-of-atmosphere shortwave and longwave irradiances. Journal of Climate 26 (9):2719-2740. doi:Doi 10.1175/Jcli-D-12-00436.1 Wild, M., 2012: New Directions: A facelift for the picture of the global energy balance. Atmospheric Environment, 55, 366-367. Wild, M. 2012: Enlightening Global Dimming and Brightening. Bull. Amer. Meteor. Soc., 93, 27-37, d

  20. Mathematical model of the Lame' Problem for Simplified Elastic Theory applied to Controlled-Clearance Pressure Balances

    OpenAIRE

    Silvano, Saragosa

    2010-01-01

    In order to obtain more accurate measurements, the use of pressure balances with the controlled-clearance system is well known in the history of high pressures metrology. Furthermore, the introduction of assemblies with cylinders made up of two materials to the construction of controlled-clearance pressure balances, is one of the most important developments in the field of high pressure measurements. The use of some analytical procedures for the characterization of the press...

  1. Seismic earth pressures on flexible cantilever retaining walls with deformable inclusions

    OpenAIRE

    Ozgur L. Ertugrul; TRANDAFIR, Aurelian C.

    2014-01-01

    In this study, the results of 1-g shaking table tests performed on small-scale flexible cantilever wall models retaining composite backfill made of a deformable geofoam inclusion and granular cohesionless material were presented. Two different polystyrene materials were utilized as deformable inclusions. Lateral dynamic earth pressures and wall displacements at different elevations of the retaining wall model were monitored during the tests. The earth pressures and displacements of the retain...

  2. Pressure-induced changes in the compression mechanism of aluminous perovskite in the Earth's mantle

    Science.gov (United States)

    Brodholt

    2000-10-01

    Although aluminium is the fifth most abundant element in the Earth's mantle, its effect on the physical properties of perovskite, the main mineral phase in the lower mantle, has largely been ignored. It is becoming clear, however, that many properties of MgSiO3 perovskites are remarkably sensitive to small amounts of aluminium. In particular, perovskite with only 5 wt% Al2O3 has a bulk modulus 10% lower than that of the pure magnesian end-member. The increased compressibility may be due to the high concentrations of oxygen vacancies required to balance the charge of the aluminium; if so, this would have important consequences for the mantle, as aluminous perovskites could be weaker, have lower seismic velocities and be hosts for water. To test whether oxygen vacancies exist in aluminous perovskites, I have calculated the compressibility of end-member defect-bearing perovskites using ab initio methods. The results show that perovskites with oxygen vacancies do have significantly greater compressibilities than those without such vacancies. But the results also suggest that oxygen vacancies become unfavourable at high pressures, in which case only the physical properties of the shallow lower mantle would be affected by aluminium-with the deeper mantle retaining properties similar to those of aluminium-free perovskite. PMID:11034208

  3. Balancing

    Science.gov (United States)

    Harteveld, Casper

    At many occasions we are asked to achieve a balance in our lives: when it comes, for example, to work and food. Balancing is crucial in game design as well as many have pointed out. In games with a meaningful purpose, however, balancing is remarkably different. It involves the balancing of three different worlds, the worlds of Reality, Meaning, and Play. From the experience of designing Levee Patroller, I observed that different types of tensions can come into existence that require balancing. It is possible to conceive of within-worlds dilemmas, between-worlds dilemmas, and trilemmas. The first, the within-world dilemmas, only take place within one of the worlds. We can think, for example, of a user interface problem which just relates to the world of Play. The second, the between-worlds dilemmas, have to do with a tension in which two worlds are predominantly involved. Choosing between a cartoon or a realistic style concerns, for instance, a tension between Reality and Play. Finally, the trilemmas are those in which all three worlds play an important role. For each of the types of tensions, I will give in this level a concrete example from the development of Levee Patroller. Although these examples come from just one game, I think the examples can be exemplary for other game development projects as they may represent stereotypical tensions. Therefore, to achieve harmony in any of these forthcoming games, it is worthwhile to study the struggles we had to deal with.

  4. The energy balance of the material breaking under the action of the high pressure water jet

    OpenAIRE

    Dumitru, G.; Zgura, G.

    1994-01-01

    For a correct determination of the cutting process parameters by high pressure water jet, it is necessary to study the breaking mechanism of the material under the action of the water jet. From the analysis of the material behavior under high pressure water jet, moving at supersonic speed, it appears like a micro-erosive process. We study the energy balance of the micro-erosive breaking of the material taking into account the nucleation energy of the micro-cracking, the internal energy variat...

  5. Roles of Renal Proximal Tubule Transport in Acid/Base Balance and Blood Pressure Regulation

    OpenAIRE

    Motonobu Nakamura; Ayumi Shirai; Osamu Yamazaki; Nobuhiko Satoh; Masashi Suzuki; Shoko Horita; Hideomi Yamada; George Seki

    2014-01-01

    Sodium-coupled bicarbonate absorption from renal proximal tubules (PTs) plays a pivotal role in the maintenance of systemic acid/base balance. Indeed, mutations in the Na+-HCO3? cotransporter NBCe1, which mediates a majority of bicarbonate exit from PTs, cause severe proximal renal tubular acidosis associated with ocular and other extrarenal abnormalities. Sodium transport in PTs also plays an important role in the regulation of blood pressure. For example, PT transport stimulation by insulin...

  6. HII Regions in hydrostatic balance between gas pressure, radiation pressure and gravity

    Scientific Electronic Library Online (English)

    A. G., Raga; J., Cant; G., Mellema; A., Rodrguez-Gonzlez; A., Esquivel.

    Full Text Available Estudiamos las soluciones de una versin modificada de la ecuacin de Lane-Emden isotrmica, la cual incorpora el efecto de la presin de radiacin (dirigida hacia afuera) asociada a las fotoionizaciones. Estas soluciones son relevantes para regiones HII alrededor de un cmulo con ?500 estrellas O, [...] que puede fotoionizar el gas hasta distancias de ? 200 ?10 cm-3n0 pc (siendo n0 la densidad central del gas), donde son importantes los efectos tanto de la autogravedad como de la presin de radiacin. Encontramos que las soluciones tienen una transicin de un rgimen "dominado por gravedad" (en el que las soluciones convergen a radios grandes a la solucin de la esfera isotrmica autogravitante no singular) a uno "dominado por presin de radiacin" (en el que la densidad diverge a un radio finito) para regiones HII con densidades centrales mayores que n crit = 100 cm -3. Argumentamos que las soluciones con densidades centrales altas, dominadas por presin de radiacin, no ocurrirn en muchas de las situaciones astrofsicamente relevantes, dada la ausencia de un posible medio confinador de presin suficientemente alta. Abstract in english We study the solutions of a modified version of the isothermal Lane-Emden equation, which incorporates the effect of the (owtwards directed) radiation pressure resulting from photoionizations. These solutions are relevant for HII regions around a cluster with over ?500 O stars, which can photoionize [...] gas out to ? 200 ?10 cm-3n0 pc (where no is the central gas density), where the effects of the self-gravity and the radiation pressure become important. We find that the solutions have a transition from a "gravity dominated" regime (in which the solutions converge at large radii to the non-singular, isothermal sphere solution) to a "radiation pressure dominated" regime (in which the density diverges at a finite radius) for central HII region densities above n crit = 100 cm-3. We argue that the high central density, radiation pressure dominated solutions will not occur in most astrophysically relevant situations, because of the absence of a possible confining environment with a high enough pressure.

  7. A THEORY OF BIMODAL ACCELERATION OF PICKUP IONS BY COMPRESSIVE SOLAR WIND TURBULENCE UNDER PRESSURE BALANCE

    International Nuclear Information System (INIS)

    Recently, it was demonstrated that stochastic acceleration of particles going through a series of compressive plasma waves can be efficient and fast. It could be too fast so that the pressure built up by the accelerated particles may in turn modify the amplitude of waves to prevent the particles from having an exploding pressure. We call this condition pressure balance. In this paper, we take into account the fact that active acceleration of particles only occupies a limited volume of space due to a possible intermittent nature of plasma waves or turbulence. We develop a bimodal acceleration theory that treats the populations of particles in the active and inactive acceleration regions separately and allows the two populations to exchange particles efficiently. Under the requirement of the pressure balance condition, we show that the system automatically produces a solution of v 5 steady state distribution for the accelerated particles. It is found that the v 5 distribution is more robust and easier to achieve with a small volume of intense particle acceleration. These properties explain why the v 5 distribution is commonly observed in space. We apply our model to pickup ion propagation and acceleration throughout the entire heliosphere. Our results can reproduce various observations in some great detail. We also found that this mechanism could be responsible for producing anomalous cosmic rays deep in the heliosheath.

  8. Pressure-induced superconducting phase in rare-earth tritellurides (RTe3, R = Gd, Tb, Dy)

    International Nuclear Information System (INIS)

    It has recently been reported that the low-dimensional rare-earth tritellurides RTe3 (R=La-Nd,Sm,Gd-Tm) enter an unidirectional, incommensurate charge-density-wave (CDW) state when cooled below a temperature TCDW1? 450-250 K, which decreases with increasing rare earth atomic number, due to the effect of chemical pressure. For the heavier R (i. e.: Dy-Tm), a second CDW appears at TCDW2CDW1, orthogonal to the first one. We have recently found that the application of external pressure induces a superconducting (SC) state in GdTe3, TbTe3 and DyTe3 at low temperatures, coexisting or competing with the two CDWs and the local moment rare-earth magnetism. In this talk, we present the results of experiments we have performed on these materials at high pressure and low temperature, to help develop an understanding of the origin of the superconducting state.

  9. Seismic earth pressures on flexible cantilever retaining walls with deformable inclusions

    Directory of Open Access Journals (Sweden)

    Ozgur L. Ertugrul

    2014-10-01

    Full Text Available In this study, the results of 1-g shaking table tests performed on small-scale flexible cantilever wall models retaining composite backfill made of a deformable geofoam inclusion and granular cohesionless material were presented. Two different polystyrene materials were utilized as deformable inclusions. Lateral dynamic earth pressures and wall displacements at different elevations of the retaining wall model were monitored during the tests. The earth pressures and displacements of the retaining walls with deformable inclusions were compared with those of the models without geofoam inclusions. Comparisons indicated that geofoam panels of low stiffness installed against the retaining wall model affect displacement and dynamic lateral pressure profile along the wall height. Depending on the inclusion characteristics and the wall flexibility, up to 50% reduction in dynamic earth pressures was observed. The efficiency of load and displacement reduction decreased as the flexibility ratio of the wall model increased. On the other hand, dynamic load reduction efficiency of the deformable inclusion increased as the amplitude and frequency ratio of the seismic excitation increased. Relative flexibility of the deformable layer (the thickness and the elastic stiffness of the polystyrene material played an important role in the amount of load reduction. Dynamic earth pressure coefficients were compared with those calculated with an analytical approach. Pressure coefficients calculated with this method were found to be in good agreement with the results of the tests performed on the wall model having low flexibility ratio. It was observed that deformable inclusions reduce residual wall stresses observed at the end of seismic excitation thus contributing to the post-earthquake stability of the retaining wall. The graphs presented within this paper regarding the dynamic earth pressure coefficients versus the wall flexibility and inclusion characteristics may serve for the seismic design of full-scale retaining walls with deformable polystyrene inclusions.

  10. Pressure balanced type membrane covered polarographic oxygen detectors for use in high temperature-high pressure water, 2

    International Nuclear Information System (INIS)

    Performance tests of a pressure balanced type membrane covered polarographic oxygen detector were carried out in water at 2850C (BWR operating conditions) to determine the effects of environmental factors. Dependencies of detector current on pressure and sample water flow velocity were ascertained and response time of the detector was determined. Effects of H2 present in the water were also examined. The following conclusions were obtained: (1) The detector current increased in proportion to the 0.67th power of the flow velocity, but was independent of the pressure. (2) Response time was about 7s. (3) Hydrogen caused a decrease in the current at cathode potentials more positive than -0.75V against the Ag/AgCl electrode. However, at more negative potentials, the current was independent of H2 concentration and in proportion to O2 concentration. Oxygen concentrations in water containing H2 at 2850C could be determined by the detector under the measurement conditions of constant flow velocity and cathode potentials more negative than -0.75V. (author)

  11. Water balance in irrigation districts. Uncertainty in on-demand pressurized networks

    Science.gov (United States)

    Snchez-Calvo, Ral; Rodrguez-Sinobas, Leonor; Juana, Luis; Laguna, Francisco Vicente

    2015-04-01

    In on-demand pressurized irrigation distribution networks, applied water volume is usually controlled opening a valve during a calculated time interval, and assuming constant flow rate. In general, pressure regulating devices for controlling the discharged flow rate by irrigation units are needed due to the variability of pressure conditions. A pressure regulating valve PRV is the commonly used pressure regulating device in a hydrant, which, also, executes the open and close function. A hydrant feeds several irrigation units, requiring a wide range in flow rate. In addition, some flow meters are also available, one as a component of the hydrant and the rest are placed downstream. Every land owner has one flow meter for each group of field plots downstream the hydrant. Ideal PRV performance would maintain a constant downstream pressure. However, the true performance depends on both upstream pressure and the discharged flow rate. Theoretical flow rates values have been introduced into a PRV behavioral model, validated in laboratory, coupled with an on-demand irrigation district waterworks, composed by a distribution network and a multi-pump station. Variations on flow rate are simulated by taking into account the consequences of variations on climate conditions and also decisions in irrigation operation, such us duration and frequency application. The model comprises continuity, dynamic and energy equations of the components of both the PRV and the water distribution network. In this work the estimation of water balance terms during the irrigation events in an irrigation campaign has been simulated. The effect of demand concentration peaks has been estimated.

  12. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anch...

  13. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbll, Anette Susanne; Fuglsang, Leif D

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

  14. Effect of pressure on the coordination structure of acetate-rare earth complex in water

    International Nuclear Information System (INIS)

    Pressure-induced coordination structural changes of the acetate-rare earth complex in water (LnCl320H2OCH3COOLi) have been investigated using Raman spectroscopy. From the analysis of Raman CC stretching band of acetate ion, the integrated Raman intensity of polymeric chain structure decreases with increasing pressure throughout the rare-earth series. The monodentate ligand appears at around 0.6 GPa in the meddle-heavy rare earth region. We have determined the difference in the partial molar volume (PMV) (?V) among three coordination structures. The rank ordering of the PMV of three coordination structures is as follows: monodentate ligand Polymeric?Bidentate and ?VBidentate?Monodentate become larger with decreasing ionic radius of Ln3+ ion, and theses are probably due to the size effect of Ln3+ ion.

  15. A rightly balanced intellectual property rights regime as a mechanism to enhance commercial earth observation activities

    Science.gov (United States)

    Doldirina, Catherine

    2010-09-01

    Earth observation by satellites is one of the developing sectors of space activities with the growing involvement in private capital or actors. This leads to the question of how efficient legal rules governing this activity are. Copyright law is one of the key fields of law applicable to earth observation activities and is the subject of the present analysis. This paper describes the current state of copyright regulations in different jurisdictions. It also addresses the issue of defining earth observation data for the purpose of applying copyright protection to them. Finally, it analyses whether more or less copyright protection would be beneficial for the commercialisation of the earth observation activities, and the distribution and further use of data they produce. The paper is largely based on my current doctoral research. Draft chapter on file with the author.

  16. Earth Pressure at rest of Svind Marl a highly overconsolidated Eocene clay

    DEFF Research Database (Denmark)

    Grnbech, Gitte Lyng; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

    measured from in situ stresses to various stress levels to estimate continuous K0 development in this highly overconsolidated clay. The normally consolidated earth pressure at rest was found for two different sample ages of Svind Marl to be between 0.42 and 0.68. Results indicated the overconsolidated K0......The present study evaluated earth pressure at rest, K0, in highly overconsolidated Eocene clay called Svind Marl, which exhibits extremely high plasticity indices of up to 300%, a highly fissured structure, and preconsolidation stresses up to 6,800 kPa. Continuous Loading Oedometer (CLO) tests...... with a constant rate of strain were conducted on Svind Marl in the Danish Continuous Loading Oedometer Apparatus, which enables test water to be applied at 200 kPa, and measures the horizontal stresses via pressure gauges placed in a stiff oedometer ring. The horizontal and vertical stresses were...

  17. An Analytical Method for Static Earth Pressure Distribution against Rectangular Shallow Tunnels Using Lateral Deformation

    Directory of Open Access Journals (Sweden)

    Farzad Habibbeygi

    2015-10-01

    Full Text Available Analytical methods for computing the lateral earth pressure against tunnel is vastly used by engineers all over the world. Conventional analytical methods compute the lateral pressure in either active or passive state while the stress state usually falls between these two boundaries in many practical cases. Furthermore, using these boundary coefficients lead to either overestimated or underestimated results in design. Thus, a modified method based on the strain increment theory for calculating the lateral pressure against rectangular tunnels is presented herein to consider the amount of lateral deformation at each depth. First, the results for different values of overburden depth, friction angle and wall mobilized angle are investigated. Then comparative finite element analyses were performed to examine the effectiveness of the method. According to this study, the pressure pattern is completely nonlinear especially at the corners of tunnel lining. In fact, the pressure increases nonlinearly to about three times of the value at top. Lateral earth pressure decreases with the increase of friction angle which is in good agreement with finite element results. Overall, the pressure patterns derived by this method for shallow depths (less than tunnel height are almost the same as those computed by finite element method.

  18. Structural phase transitions of rare earth monophosphides with NaCl-type structure under high pressures

    International Nuclear Information System (INIS)

    Rare earth monophosphides REP (RE=La, Ce, Pr, Nd, Sm, Gd, Tb, Tm and Yb) crystallize in a NaCl-type structure at ambient pressure. Using synchrotron radiation X-ray diffractions of REP have been studied up to about 60 GPa at room temperature. All phosphides are found to undergo structural phase transitions at high pressures. The high pressure phases of LaP, PrP and NdP can be assigned to be a tetragonal structure, which can be seen as the distorted CsCl-type structure. The pressure-induced phase transitions of SmP, GdP, TbP, TmP and YbP occur at around 35, 40, 38, 53 and 51 GPa, respectively. The structure of the high pressure phases is unknown. X-ray diffraction patterns of the compounds with many f-electrons become more complex at high pressure. It is expected that 4f-electrons in rare earth atoms influence the structure of the high pressure phases. (author)

  19. Previously hidden low-energy ions: a better map of near-Earth space and the terrestrial mass balance

    Science.gov (United States)

    Andr, Mats

    2015-12-01

    This is a review of the mass balance of planet Earth, intended also for scientists not usually working with space physics or geophysics. The discussion includes both outflow of ions and neutrals from the ionosphere and upper atmosphere, and the inflow of meteoroids and larger objects. The focus is on ions with energies less than tens of eV originating from the ionosphere. Positive low-energy ions are complicated to detect onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of volts. We have invented a technique to observe low-energy ions based on the detection of the wake behind a charged spacecraft in a supersonic ion flow. We find that low-energy ions usually dominate the ion density and the outward flux in large volumes in the magnetosphere. The global outflow is of the order of 1026 ions s1. This is a significant fraction of the total number outflow of particles from Earth, and changes plasma processes in near-Earth space. We compare order of magnitude estimates of the mass outflow and inflow for planet Earth and find that they are similar, at around 1 kg s?1 (30 000 ton yr?1). We briefly discuss atmospheric and ionospheric outflow from other planets and the connection to evolution of extraterrestrial life.

  20. Measuring the initial earth pressure of granite using hydraulic fracturing test; Goseong and Yuseong areas

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byoung Yoon; Bae, Dae Seok; Kim, Chun Soo; Kim, Kyung Su; Koh, Young Kwon; Won, Kyung Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-02-01

    This report provides the initial earth pressure of granitic rocks obtained from Deep Core Drilling Program which is carried out as part of the assessment of deep geological environmental condition. These data are obtained by hydraulic fracturing test in three boreholes drilled up to 350{approx}500 m depth at the Yuseong and Goseong sites. These sites were selected based on the result of preliminary site evaluation study. The boreholes are NX-size (76 mm) and vertical. The procedure of hydraulic fracturing test is as follows: - Selecting the testing positions by preliminary investigation using BHTV logging. - Performing the hydraulic fracturing test at each selected position with depth.- Estimating the shut-in pressure by the bilinear pressure-decay-rate method. - Estimating the fracture reopening pressure from the pressure-time curves.- Estimating the horizontal principal stresses and the direction of principal stresses. 65 refs., 39 figs., 12 tabs. (Author)

  1. Center of pressure control for balance maintenance during lateral waist-pull perturbations in older adults.

    Science.gov (United States)

    Fujimoto, Masahiro; Bair, Woei-Nan; Rogers, Mark W

    2015-04-13

    When balance is disturbed, location of the center of pressure (COP) contributes to a person's ability to recover from a perturbation. This study investigated COP control prior to first step lift-off (FSLO) during lateral perturbations in older non-fallers and fallers. 38 non-fallers and 16 fallers received lateral waist-pulls at 5 different intensities. Crossover stepping responses at the intensity level where the largest number of subjects responded with crossover steps were analyzed. Whole-body center of mass (COM) and COP positions in the medio-lateral (ML) direction with respect to the base of support (BOS), and COP velocity were calculated. An inverted pendulum model was used to define the BOS stability boundary at FSLO, which was also adjusted using the COP position at FSLO (functional boundary). No significant differences were found in the COP velocities between fallers and non-fallers (p>.093). However, the COP positions for fallers were located significantly more medial at FSLO (p?.01), resulting in a significantly reduced functional boundary. Although the stability margins, measures of stability based on the BOS, were significantly larger than zero for fallers (p?.004), they were not significantly different from zero for the functional boundary, i.e., reaching the functional stability limit. Fallers had reduced functional limits of stability in the ML direction, which would predispose them to more precarious stability conditions than non-fallers. This could be a cause for taking more steps than non-fallers for balance recovery as we observed. The functional boundary estimation may be a more sensitive marker of balance instability than the BOS boundary. PMID:25728580

  2. A Plantar-pressure Based Tongue-placed Tactile Biofeedback System for Balance Improvement

    CERN Document Server

    Vuillerme, Nicolas; Pinsault, Nicolas; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    Maintaining an upright stance represents a complex task, which is achieved by integrating sensory information from the visual, vestibular and somatosensory systems. When one of these sensory inputs becomes unavailable and/or inaccurate and/or unreliable, postural control generally is degraded. One way to solve this problem is to supplement and/or substitute limited/altered/missing sensory information by providing additional sensory information to the central nervous system via an alternative sensory modality. Along these lines, we developed an original biofeedback system [1] whose underlying principle consists in supplying the user with supplementary sensory information related to foot sole pressure distribution through a tongue-placed output device (Tongue Display Unit, "TDU" [2]). The purpose of the present experiment was to assess its effectiveness in improving balance in young healthy adults.

  3. Smoothly waning, symmetrically expanding, cavity-pressure loads in earth materials

    International Nuclear Information System (INIS)

    An approximate solution for the pressure loading required to expand a spherical cavity in rock and soil targets is derived. A dual characterization of fracture and flow material model is used. Frictional resistance to flow is also included. Non-linear volumetric strain hardening is modeled with bi-linear curves and unloading is assumed to be non-dilative. Applications of this solution form to the prediction of pressure loading on slender, convex-nosed earth penetrators and on spherically-nosed water entry vehicles are discussed

  4. Iron under Earth's core conditions: Liquid-state thermodynamics and high-pressure melting curve

    OpenAIRE

    Alfe, D.; Price, G D; Gillan, M. J.

    2001-01-01

    {\\em Ab initio} techniques based on density functional theory in the projector-augmented-wave implementation are used to calculate the free energy and a range of other thermodynamic properties of liquid iron at high pressures and temperatures relevant to the Earth's core. The {\\em ab initio} free energy is obtained by using thermodynamic integration to calculate the change of free energy on going from a simple reference system to the {\\em ab initio} system, with thermal aver...

  5. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbll, Anette Susanne; Fuglsang, Leif D

    2006-01-01

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor level. The Finite element program PLAXIS is used and two material models are evaluated, the Mohr-Coulomb model and the Hardening Soil model. The differences between the two concern the deformation pro...

  6. Prediction of Seismic Active Earth Pressure Using Curved Failure Surface with Localized Strain

    Directory of Open Access Journals (Sweden)

    Hemanta Hazarika

    2009-01-01

    Full Text Available Problem statement: Correct evaluation of the earth pressure against retaining structure during earthquake is essential for the safe and economic design of geotechnical structures. Progressive deformation in the backfill and the assumed shape of failure wedge affect the calculated values of seismic earth pressures. However, no research until now is available that considers both of these two factors in an analysis. Approach: In this study, a new analytical methodology was proposed that took into the account the progressive failure of the backfill soil as well as the shape of the failure wedge. A new formulation was first established taking the failure plane as the combination of a curved lower part and a straight upper part. The localized deformation of the backfill was accounted for in the formulation by utilizing the mobilized friction angle and the peak friction angle depending on the locations along the failure surface. The proposed methodology was validated by comparing the calculated results with the established experimental results. Calculations were also performed for different types of wall with various backfill inclinations. Results: The developed methodology could predict the seismic active earth pressure against retaining structure with reasonable accuracy. It could also realistically predict the active failure domain in the backfill soil at the high excitation level, as compared to the pseudo-static solution provided by the well-known Mononobe-Okabe method. Conclusion/Recommendations: It was observed that the Mononobe-Okabe method underestimates the seismic active earth pressure and overestimates the domain of failure zone in the backfill, especially under intense seismic excitation. The proposed methodology, therefore, can contribute greatly towards the economic earthquake resistant design of geotechnical structures.

  7. Modeling long-term changes in forested landscapes and their relation to the Earth's energy balance

    Science.gov (United States)

    Shugart, H. H.; Emanuel, W. R.; Solomon, A. M.

    1984-01-01

    The dynamics of the forested parts of the Earth's surface on time scales from decades to centuries are discussed. A set of computer models developed at Oak Ridge National Laboratory and elsewhere are applied as tools. These models simulate a landscape by duplicating the dynamics of growth, death and birth of each tree living on a 0.10 ha element of the landscape. This spatial unit is generally referred to as a gap in the case of the forest models. The models were tested against and applied to a diverse array of forests and appear to provide a reasonable representation for investigating forest-cover dynamics. Because of the climate linkage, one important test is the reconstruction of paleo-landscapes. Detailed reconstructions of changes in vegetation in response to changes in climate are crucial to understanding the association of the Earth's vegetation and climate and the response of the vegetation to climate change.

  8. Digitalis-like activity in human plasma: Relation to blood pressure and sodium balance

    International Nuclear Information System (INIS)

    PURPOSE: On the assumption that renal tubular cells are more important as the target cells for a natriuretic factor than blood cells, we used a well-characterized cultured renal tubular cell line, Madin-Darby canine kidney (MDCK), cells to monitor the circulating digitalis-like factor in human plasma and examine its role in the regulation of blood pressure and sodium balance. SUBJECTS AND METHODS: We investigated the effects of plasma on binding of radioactive ouabain to monolayered MDCK cells in order to determine the level of a circulating digitalis-like factor. First, we measured specific 3H-ouabain binding to MDCK cells in the presence of plasma from 71 outpatients (34 normotensive subjects and 37 hypertensive patients) after incubation for 4 hours. Second, we measured specific 3H-ouabain binding after incubation of cells with plasma from 16 hospitalized subjects (eight normotensive subjects and eight hypertensive patients) receiving low and high sodium diets. RESULTS: In Study 1, ouabain binding was lower by 30% with plasma from hypertensive patients than with plasma from normotensive subjects (p less than 0.01). There was a significant negative correlation between individual subject's systolic or mean blood pressure and ouabain binding (r = -0.34, p less than 0.01 or r = -0.29, p less than 0.01). In Study 2, ouabain binding was also significantly reduced by 25% in the presence of plasma from hypertensive subjects as compared with plasma from normotensive subjects irrespective of sodium intake (p less than 0.01). A significant negative correlation was also found for all subjects between either systolic, diastolic, or mean blood pressure and ouabain binding (r = -0.58, p less than 0.01, r = -0.51, p less than 0.01, or r = -0.55, p less than 0.01, respectively)

  9. Novel Techniques for High Pressure Falling Sphere Viscosimetry under Simulated Earth's Mantle Conditions

    Science.gov (United States)

    Mueller, H. J.; Beckmann, F.; Dobson, D. P.; Hunt, S. A.; Secco, R.; Lauterjung, J.; Lathe, C.

    2014-12-01

    Viscosity data of melts measured under in situ high pressure conditions are crucial for the understanding of Earth's lower mantle and the interior of terrestrial and extrasolar Super-Earth planets. We report recent technical advances and techniques enabling falling sphere viscosity measurements in single- and double-stage DIA-type multi-anvil apparatus. For the experiments we used presses with a maximum load of 250 tons and 1750 tons. We anticipate that our system will enable viscosity measurements up to the maximum pressure for non-diamond anvils, i.e. pressures up to some 30 GPa. For the development of the new set ups the deformation of the cell assemblies were analyzed by X-ray absorption tomography at beamline W II at DESY/HASYLAB after the high pressure runs. These analysis gave considerable insights into strategies for improving the cell assembly with the result that the optimized assemblies could be used at much higher pressures without blow-outs. We think this approach is much faster and more beneficial than the classical way of trial and error. Additionally to prevent high pressure blow outs the task was to make the whole melting chamber accessible for the high pressure X-radiography system up to the maximum pressures. This way the accuracy and reliability of the measurements can be improved. For this goal we used X-ray transparent cBN-anvils at the single-stage DIA large volume press. Because this material is recently not available for the cube size of 32 mm this aproach did not work for the double-stage DIA. As a very useful and economical alternative we used slotted carbide anvils filled with fired pyrophyllite bars. To improve the frame quality of the platinum spheres taken by the CCD-camera the energy of the monochromatic X-rays had to be increased to 100 keV. The resulting ascent of scattered radiation required a new design of the X-radiography unit. Our results are demonstrated with viscosity measurements following Stokes law by evaluation of X-radiography sequences taken by a CCD-camera at pressures of 5 GPa as well as 10 GPa and temperatures of 1890 K. As the first result we could increase the maximum pressure range of published viscosity measurements with dacite melts by almost factor 1.5 (see Tinker et al., 2004).

  10. The Earth's core composition from high pressure density measurements of liquid iron alloys

    Science.gov (United States)

    Morard, G.; Siebert, J.; Andrault, D.; Guignot, N.; Garbarino, G.; Guyot, F.; Antonangeli, D.

    2013-07-01

    High-pressure, high-temperature in situ X-ray diffraction has been measured in liquid iron alloys (Fe-5 wt% Ni-12 wt% S and Fe-5 wt% Ni-15 wt% Si) up to 94 GPa and 3200 K in laser-heated diamond anvil cells. From the analysis of the X-ray diffuse scattering signal of the metallic liquids, we determined density and bulk modulus of the two liquid alloys. Comparison with a reference Earth model indicates that a core composition containing 6% of sulfur and 2% of silicon by weight would best match the geophysical data. Models with 2.5% of sulfur and 4-5% of silicon are still consistent with geophysical constraints whereas silicon only compositions are not. These results suggest only moderate depletion of sulfur in the bulk Earth.

  11. Earth Pressure at rest of Svind Marl a highly overconsolidated Eocene clay

    DEFF Research Database (Denmark)

    Grnbech, Gitte Lyng; Ibsen, Lars Bo

    2015-01-01

    The present study evaluated earth pressure at rest, K0, in highly overconsolidated Eocene clay called Svind Marl, which exhibits extremely high plasticity indices of up to 300%, a highly fissured structure, and preconsolidation stresses up to 6,800 kPa. Continuous Loading Oedometer (CLO) tests with a constant rate of strain were conducted on Svind Marl in the Danish Continuous Loading Oedometer Apparatus, which enables test water to be applied at 200 kPa, and measures the horizontal stresses via pressure gauges placed in a stiff oedometer ring. The horizontal and vertical stresses were measured from in situ stresses to various stress levels to estimate continuous K0 development in this highly overconsolidated clay. The normally consolidated earth pressure at rest was found for two different sample ages of Svind Marl to be between 0.42 and 0.68. Results indicated the overconsolidated K0 reached values as high as 6 to 8 in the in situ stress range. Meyerhofs (1976) reported correlation between K0(oc) and OCR was found inconsistent with K0(oc) development of in Svind Marl. However, the development of OCRlab dependent on previous test stresses, as an alternative to preconsolidation stresses, showed congruent results using ? = 1.05 independent of sample age.

  12. Modelling the rheology of MgO under Earth's mantle pressure, temperature and strain rates.

    Science.gov (United States)

    Cordier, Patrick; Amodeo, Jonathan; Carrez, Philippe

    2012-01-12

    Plate tectonics, which shapes the surface of Earth, is the result of solid-state convection in Earth's mantle over billions of years. Simply driven by buoyancy forces, mantle convection is complicated by the nature of the convecting materials, which are not fluids but polycrystalline rocks. Crystalline materials can flow as the result of the motion of defects--point defects, dislocations, grain boundaries and so on. Reproducing in the laboratory the extreme deformation conditions of the mantle is extremely challenging. In particular, experimental strain rates are at least six orders of magnitude larger than in nature. Here we show that the rheology of MgO at the pressure, temperature and strain rates of the mantle is accessible by multiscale numerical modelling starting from first principles and with no adjustable parameters. Our results demonstrate that extremely low strain rates counteract the influence of pressure. In the mantle, MgO deforms in the athermal regime and this leads to a very weak phase. It is only in the lowermost lower mantle that the pressure effect could dominate and that, under the influence of lattice friction, a viscosity of the order of 10(21)-10(22) pascal seconds can be defined for MgO. PMID:22237109

  13. Atmospheric pressure forced oceans and their effects on Earth's Rotation: a TOPEX data approach

    Science.gov (United States)

    Dey, N.; Dickman, S. R.

    2014-12-01

    Dey & Dickman [2010] showed (using a theoretical model) that the oceanic response to atmospheric pressure forcing depends on the frequency and spatial pattern of the forcing. We have developed an observational Green's function approach to determine the frequency- and spatially dependent sea-level response using satellite altimetric data. We applied it to 12 years of TOPEX sea-surface height (SSH) observations smoothed over a 4 8 grid at 3 day intervals and corrected for tides, winds, annual signals and secular trends. Wiener filtering, generalized for complex time series, was used to isolate pressure forced SSH within each gridbox. In most of the gridboxes, that SSH, after accounting for the forcing, showed a spatial and spectral dependence - a significant departure from the "inverted barometer" response. The oceanic currents associated with the response were calculated from a spherical harmonic relation between current velocities and SSH [Dickman 1991]. The rotational effects (polar motion and change in Earth's spin rate) of the pressure forced SSH & associated currents - with the pressure forcing accounted for, these are essentially Green's functions - were calculated at specific periods and interpolated to other periods. The rotational effects calculated here are dominated by the pressure-forced SSH and show a strong frequency dependence & significant departures from an inverted barometer excitation. The pressure forced SSH is effective in exciting both prograde & retrograde polar motion at periods of ~ 6 days, and prograde polar motion at periods of 10 - 15 days. Compared to the theoretical approach, our work finds that the prograde component shows higher amplitude and less spatial variability, whereas the other components are ~ similar in amplitude & spatial variability. When these Green's functions are combined with any time span of pressure data, they generate the total excitation for that time span. We will discuss the results for various spans of pressure data.

  14. Evolution of the Oxidation State of the Earth's Mantle: Challenges of High Pressure Quenching

    Science.gov (United States)

    Danielson, L. R.; Righter, K.; Keller, L.; Christoffersen, R.; Rahman, Z.

    2015-01-01

    The oxidation state of the Earth's mantle during formation remains an unresolved question, whether it was constant throughout planetary accretion, transitioned from reduced to oxidized, or from oxidized to reduced. We investigate the stability of Fe3+ at depth, in order to constrain processes (water, late accretion, dissociation of FeO) which may reduce or oxidize the Earth's mantle. Experiments of more mafic compositions and at higher pressures commonly form a polyphase quench intergrowth composed primarily of pyroxenes, with interstitial glass which hosts nearly all of the more volatile minor elements. In our previous experiments on shergottite compositions, variable fO2, T, and P is less than 4 GPa, Fe3+/TotFe decreased slightly with increasing P, similar to terrestrial basalt. For oxidizing experiments less than 7GPa, Fe3+/TotFe decreased as well, but it's unclear from previous modelling whether the deeper mantle could retain significant Fe3+. Our current experiments expand our pressure range deeper into the Earth's mantle and focus on compositions and conditions relevant to the early Earth. Experiments with Knippa basalt as the starting composition were conducted at 1-8 GPa and 1800 C, using a molybdenum capsule to set the fO2 near IW, by buffering with Mo-MoO3. TEM and EELS analyses revealed the run products from 7-8 GPa quenched to polycrystalline phases, with the major phase pyroxene containing approximately equal Fe3+/2+. A number of different approaches have been employed to produce glassy samples that can be measured by EELS and XANES. A more intermediate andesite was used in one experiment, and decompression during quenching was attempted after, but both resulted in a finer grained polyphase texture. Experiments are currently underway to test different capsule materials may affect quench texture. A preliminary experiment using liquid nitrogen to greatly enhance the rate of cooling of the assembly has also been attempted and this technique will be refined in further experiments.

  15. Pressure and strain effects of hexagonal rare-earth manganites: a first-principles study.

    Science.gov (United States)

    Tan, Hengxin; Xu, Changsong; Li, Menglei; Wang, Shanying; Gu, Bing-Lin; Duan, Wenhui

    2016-03-31

    We have investigated the structural, electrical and magnetic properties as well as the phonon modes of hexagonal rare-earth manganites (RMnO3, R  =  Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm and Lu) under chemical pressure, hydrostatic pressure and epitaxial strain by first-principles calculations. The magnetic ground state of RMnO3 is found to have [Formula: see text] magnetic configuration and to be stable under all considered external conditions. In contrast, the K 3 phonon mode, which is the primary order parameter and responsible for the 'improper ferroelectricity', is greatly influenced by pressure and epitaxial strain. Consequently, the electric polarization is enhanced by 56.7% when the chemical pressure increases from R  =  Pr to R  =  Lu. The hydrostatic pressure can also improve the polarization to a certain degree, e.g. by 14.7% from 0 GPa to 40 GPa in LuMnO3. Finally, the dependence of polarization on the epitaxial strain is also given, revealing that the compressive strain could promote the ferroelectricity while tensile strain will suppress it. PMID:26916139

  16. Reliability and Sex Differences in the Foot Pressure Load Balance Test and Its Relationship to Physical Characteristics in Preschool Children

    OpenAIRE

    Kosho Kasuga; Hiroki Sugiura; Shinichi Demura; Shigeki Matsuda

    2012-01-01

    This study aimed to examine the trial-to-trial reliability and sex differences in a foot pressure load balance test and its relationship to physical characteristics in 396 preschool children (201 boys and 195 girls). The subjects were asked to maintain an upright standing posture for 10 seconds three times on the Footview Clinic, an instrument designed to calculate the right-left and anterior-posterior ratios of foot pressure load. The ratios of the left and anterior foot pressure loads in ri...

  17. Pressure and energy balance of stagnating plasmas in z-pinch experiments: implications to current flow at stagnation.

    Science.gov (United States)

    Maron, Y; Starobinets, A; Fisher, V I; Kroupp, E; Osin, D; Fisher, A; Deeney, C; Coverdale, C A; Lepell, P D; Yu, E P; Jennings, C; Cuneo, M E; Herrmann, M C; Porter, J L; Mehlhorn, T A; Apruzese, J P

    2013-07-19

    Detailed spectroscopic diagnostics of the stagnating plasma in two disparate z pinches allow, for the first time, the examination of the plasma properties within a 1D shock wave picture, demonstrating a good agreement with this picture. The conclusion is that for a wide range of imploding-plasma masses and current amplitudes, in experiments optimizing non-Planckian hard radiation yields, contrary to previous descriptions the stagnating plasma pressure is balanced by the implosion pressure, and the radiation energy is provided by the imploding-plasma kinetic energy, rather than by the magnetic-field pressure and magnetic-field-energy dissipation, respectively. PMID:23909333

  18. Lateral Earth Pressure at Rest and Shear Modulus Measurements on Hanford Sludge Simulants

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Beric E.; Jenks, Jeromy WJ; Boeringa, Gregory K.; Bauman, Nathan N.; Guzman, Anthony D.; Arduino, P.; Keller, P. J.

    2010-09-30

    This report describes the equipment, techniques, and results of lateral earth pressure at rest and shear modulus measurements on kaolin clay as well as two chemical sludge simulants. The testing was performed in support of the problem of hydrogen gas retention and release encountered in the double- shell tanks (DSTs) at the Hanford Site near Richland, Washington. Wastes from single-shell tanks (SSTs) are being transferred to double-shell tanks (DSTs) for safety reasons (some SSTs are leaking or are in danger of leaking), but the available DST space is limited.

  19. Earth Pressure at rest of Svind Marl a highly overconsolidated Eocene clay

    DEFF Research Database (Denmark)

    Grnbech, Gitte Lyng; Ibsen, Lars Bo; Nielsen, Benjaminn Nordahl

    2015-01-01

    The present study evaluated earth pressure at rest, K0, in highly overconsolidated Eocene clay called Svind Marl, which exhibits extremely high plasticity indices of up to 300%, a highly fissured structure, and preconsolidation stresses up to 6,800 kPa. Continuous Loading Oedometer (CLO) tests with a constant rate of strain were conducted on Svind Marl in the Danish Continuous Loading Oedometer Apparatus, which enables test water to be applied at 200 kPa, and measures the horizontal stresses v...

  20. Satellite Earth observation data to identify anthropogenic pressures in selected protected areas

    Science.gov (United States)

    Nagendra, Harini; Mairota, Paola; Marangi, Carmela; Lucas, Richard; Dimopoulos, Panayotis; Honrado, Joo Pradinho; Niphadkar, Madhura; Mcher, Caspar A.; Tomaselli, Valeria; Panitsa, Maria; Tarantino, Cristina; Manakos, Ioannis; Blonda, Palma

    2015-05-01

    Protected areas are experiencing increased levels of human pressure. To enable appropriate conservation action, it is critical to map and monitor changes in the type and extent of land cover/use and habitat classes, which can be related to human pressures over time. Satellite Earth observation (EO) data and techniques offer the opportunity to detect such changes. Yet association with field information and expert interpretation by ecologists is required to interpret, qualify and link these changes to human pressure. There is thus an urgent need to harmonize the technical background of experts in the field of EO data analysis with the terminology of ecologists, protected area management authorities and policy makers in order to provide meaningful, context-specific value-added EO products. This paper builds on the DPSIR framework, providing a terminology to relate the concepts of state, pressures, and drivers with the application of EO analysis. The type of pressure can be inferred through the detection of changes in state (i.e. changes in land cover and/or habitat type and/or condition). Four broad categories of changes in state are identified, i.e. land cover/habitat conversion, land cover/habitat modification, habitat fragmentation and changes in landscape connectivity, and changes in plant community structure. These categories of change in state can be mapped through EO analyses, with the goal of using expert judgement to relate changes in state to causal direct anthropogenic pressures. Drawing on expert knowledge, a set of protected areas located in diverse socio-ecological contexts and subject to a variety of pressures are analysed to (a) link the four categories of changes in state of land cover/habitats to the drivers (anthropogenic pressure), as relevant to specific target land cover and habitat classes; (b) identify (for pressure mapping) the most appropriate spatial and temporal EO data sources as well as interpretations from ecologists and field data useful in connection with EO data analysis. We provide detailed examples for two protected areas, demonstrating the use of EO data for detection of land cover/habitat change, coupled with expert interpretation to relate such change to specific anthropogenic pressures. We conclude with a discussion of the limitations and feasibility of using EO data and techniques to identify anthropogenic pressures, suggesting additional research efforts required in this direction.

  1. Local structure around rare-earth ions in B2O3 glass at high pressure

    International Nuclear Information System (INIS)

    Melt quenching of B2O3 with less than 25 mol. % rare-earth oxide (RE2O3) at ambient pressure results in a milky white glass because of liquid-liquid phase separation into B2O3 and RE2O33B2O phases. In contrast, we have found that melt quenching under GPa-order pressure realizes a transparent RE-doped B2O3 glass. This study investigates the local structure around the RE ions in the B2O3 glass prepared at 3 GPa using optical measurements and electron-spin-echo envelope modulation spectroscopy. It is shown that the RE-rich microparticles disappear and the RE ions are isolated from each other in a highly symmetric crystal field formed by triangular and tetrahedral boron units. This result is consistent with that extrapolated from the data for RE-doped sodium borate glasses.

  2. Crystal structure, equation of state, and elasticity of phase H (MgSiO4H2) at Earths lower mantle pressures

    Science.gov (United States)

    Tsuchiya, Jun; Mookherjee, Mainak

    2015-10-01

    Dense hydrous magnesium silicate (DHMS) phases play a crucial role in transporting water in to the Earths interior. A newly discovered DHMS, phase H (MgSiO4H2), is stable at Earths lower mantle, i.e., at pressures greater than 30?GPa. Here we report the crystal structure and elasticity of phase H and its evolution upon compression. Using first principles simulations, we have explored the relative energetics of the candidate crystal structures with ordered and disordered configurations of magnesium and silicon atoms in the octahedral sites. At conditions relevant to Earths lower mantle, it is likely that phase H is able to incorporate a significant amount of aluminum, which may enhance the thermodynamic stability of phase H. The sound wave velocities of phase H are ~24% smaller than those of isostructural ?-AlOOH. The shear wave impedance contrast due to the transformation of phase D to a mixture of phase H and stishovite at pressures relevant to the upper part of the lower mantle could partly explain the geophysical observations. The calculated elastic wave velocities and anisotropies indicate that phase H can be a source of significant seismic anisotropy in the lower mantle.

  3. High Pressure Effects on the Superconductivity in Rare-Earth Doped CaFe2As2

    OpenAIRE

    Cargill, Dan; Uhoya, Walter; Krzysztof, Gofryk; Tsoi, Georgiy M.; Vohra, Yogesh K.; Sefat, Athena S; Weir, S. T.

    2013-01-01

    High-pressure superconductivity in a rare-earth doped Ca0.86Pr0.14Fe2As2 single crystalline sample has been studied up to 12 GPa and temperatures down to 11 K using designer diamond anvil cell under a quasi-hydrostatic pressure medium. The electrical resistance measurements were complemented by high pressure and low temperature x-ray diffraction studies at a synchrotron source. The electrical resistance measurements show an intriguing observation of superconductivity under p...

  4. Electron spin transition causing structure transformations of earth's interiors under high pressure

    Science.gov (United States)

    Yamanaka, T.; Kyono, A.; Kharlamova, S.; Alp, E.; Bi, W.; Mao, H.

    2012-12-01

    To elucidate the correlation between structure transitions and spin state is one of the crucial problems for understanding the geophysical properties of earth interiors under high pressure. High-pressure studies of iron bearing spinels attract extensive attention in order to understand strong electronic correlation such as the charge transfer, electron hopping, electron high-low spin transition, Jahn-Teller distortion and charge disproponation in the lower mantle or subduction zone [1]. Experiment Structure transitions of Fe3-xSixO4, Fe3-xTixO4 Fe3-xCrxO4 spinel solid solution have been investigated at high pressure up to 60 GPa by single crystal and powder diffraction studies using synchrotron radiation with diamond anvil cell. X-ray emission experiment (XES) at high pressure proved the spin transition of Fe-Kβ from high spin (HS) to intermediate spin state (IS) or low spin state (LS). Mössbauer experiment and Raman spectra study have been also conducted for deformation analysis of Fe site and confirmation of the configuration change of Fe atoms. Jahn-Teller effect A cubic-to-tetragonal transition under pressure was induced by Jahn-Teller effect of IVFe2+ (3d6) in the tetrahedral site of Fe2TiO4 and FeCr2O4, providing the transformation from 43m (Td) to 42m (D2d). Tetragonal phase is formed by the degeneracy of e orbital of Fe2+ ion. Their c/a ratios are c/aMine, S. Asogawa and Y. Nakamoto Physical Review B 80, 134120 (2009)

  5. Global mechanisms in atmosphere models and a balance of the Earth angle moment. Atmosphere radio-waveguides and teleconnection

    International Nuclear Information System (INIS)

    Complete text of publication follows. The satellite data and data of observing the radio-waveguide parameters (especially in the low troposphere layers) by means of radio-technical devices (in the ultra short-wave diapason) is the informative basis of the modern atmosphere long-termed forecasts. As any water quantities in atmosphere are formed on the basis of the cycle- and front-genesis (or in the convective non-stability lines) one can introduce the corresponding model on the basis of thermodynamics and hydro-mechanics of the corresponding processes [1,2]. For example, physics of these processes can coincide with the soliton mechanics, which has the long-periodical basis of the energy support. The action mechanics of such a soliton defines the key thermo-hydro-dynamical parameters of the atmosphere ultra-short-wave radio-waveguide. We present new approach to modeling a role of the atmosphere circulations forms in definition of the long-periodical processes in atmosphere, parameters of the troposphere ultra-short-wave radio-waveguides and the Earth angle momentum balance. We carried out a series of the computer experiments to provide new predictors for the long-termed and super long-termed forecasts of the low frequency atmospheric processes. Besides, we have adapted the modified theory of the macro-turbulence for possible using the atmosphere radio-waveguides as a special effective predictors in the long-termed plan.

  6. Present-day and future Antarctic ice sheet climate and surface mass balance in the Community Earth System Model

    Science.gov (United States)

    Lenaerts, Jan T. M.; Vizcaino, Miren; Fyke, Jeremy; van Kampenhout, Leo; van den Broeke, Michiel R.

    2016-02-01

    We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean-atmosphere-land Community Earth System Model (CESM) with a horizontal resolution of ˜1° in the past, present and future (1850-2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 {Gt year^{-1}} , which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 {Gt year^{-1}} per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet's edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content.

  7. X-ray absorption experiments on rare earth and uranium compounds under high pressure

    International Nuclear Information System (INIS)

    After an introduction into the phenomenon of the mixed valency and the method of measuring the microstructures by X-ray absorption spectroscopy in the area of the L edges under pressure, the results of investigations at selected substitutes of the chalcogenides and puictides of the rare earths and the uranium were given. Thus, pressure-induced valency transitions in YbS and YbTe, instabilities in valency and structural phase transitions in EUS and SmTe as well as the change in the electron structure in USb under pressure were investigated in order to answer questions of solid state physics (e.g. semiconductor-metal transitions, correlation between valency and structural phase transitions). Hybridization effects in LIII spectra of formally tetravalent Ca are analyzed at CeF4 and CeO2 (insulators) and the role of final state effects in the LIII spectra are analyzed at EuP2P2 and TmSe-TmTe (semiconductor systems). (RB)

  8. Impurity trapped exciton states related to rare earth ions in crystals under high hydrostatic pressure

    International Nuclear Information System (INIS)

    Emission related to rare earth ions in solids takes place usually due to 4fn ? 4fn and 4fn?15d1 ? 4fn internal transitions. In the case of band to band excitation the effective energy transfer from the host to optically active impurity is required. Among other processes one of the possibilities is capturing of the electron at excited state and hole at the ground state of impurity. Localization of electron or hole at the dopand site creates a long range Coulomb potential that attracts the second carrier which then occupies the localized Rydberg-like states. Such a system can be considered as impurity trapped exciton. Usually impurity trapped exciton is a short living phenomenon which decays non-radiatively leaving the impurity ion in the excited state. However, in several compounds doped with Eu2+ the impurity trapped exciton states become stable and contribute to the radiative processes though anomalous luminescence that appears apart of the 4f7 ? 4f7 and 4f75d1 ? 5f7 emission. In this contribution pressure effect on energies of the 4fn?15d1?5fn transitions in Ln doped oxides and fluorides as well as influence of pressure on the energy of impurity trapped exciton states is discussed. The latest results on high pressure investigations of luminescence related to Pr3+, and Eu2+ in different lattices are reviewed.

  9. Validating and calibrating the Nintendo Wii balance board to derive reliable center of pressure measures.

    Science.gov (United States)

    Leach, Julia M; Mancini, Martina; Peterka, Robert J; Hayes, Tamara L; Horak, Fay B

    2014-01-01

    The Nintendo Wii balance board (WBB) has generated significant interest in its application as a postural control measurement device in both the clinical and (basic, clinical, and rehabilitation) research domains. Although the WBB has been proposed as an alternative to the "gold standard" laboratory-grade force plate, additional research is necessary before the WBB can be considered a valid and reliable center of pressure (CoP) measurement device. In this study, we used the WBB and a laboratory-grade AMTI force plate (AFP) to simultaneously measure the CoP displacement of a controlled dynamic load, which has not been done before. A one-dimensional inverted pendulum was displaced at several different displacement angles and load heights to simulate a variety of postural sway amplitudes and frequencies (<1 Hz). Twelve WBBs were tested to address the issue of inter-device variability. There was a significant effect of sway amplitude, frequency, and direction on the WBB's CoP measurement error, with an increase in error as both sway amplitude and frequency increased and a significantly greater error in the mediolateral (ML) (compared to the anteroposterior (AP)) sway direction. There was no difference in error across the 12 WBB's, supporting low inter-device variability. A linear calibration procedure was then implemented to correct the WBB's CoP signals and reduce measurement error. There was a significant effect of calibration on the WBB's CoP signal accuracy, with a significant reduction in CoP measurement error (quantified by root-mean-squared error) from 2-6 mm (before calibration) to 0.5-2 mm (after calibration). WBB-based CoP signal calibration also significantly reduced the percent error in derived (time-domain) CoP sway measures, from -10.5% (before calibration) to -0.05% (after calibration) (percent errors averaged across all sway measures and in both sway directions). In this study, we characterized the WBB's CoP measurement error under controlled, dynamic conditions and implemented a linear calibration procedure for WBB CoP signals that is recommended to reduce CoP measurement error and provide more reliable estimates of time-domain CoP measures. Despite our promising results, additional work is necessary to understand how our findings translate to the clinical and rehabilitation research domains. Once the WBB's CoP measurement error is fully characterized in human postural sway (which differs from our simulated postural sway in both amplitude and frequency content), it may be used to measure CoP displacement in situations where lower accuracy and precision is acceptable. PMID:25268919

  10. Carbon content in the Earth's inner core from the elasticity of iron carbide at high pressure

    Science.gov (United States)

    Steinle-Neumann, G.; Mookherjee, M.

    2009-12-01

    Discrepancy between sound wave velocity of Fe-Ni alloys and seismological models indicate that Earths core is likely to contain lighter elements such as H, C, O, Si and S. Carbon is a plausible candidate because of its cosmic abundance and chemical affinity to iron at low pressures. Earlier it was thought that carbon, being volatile might have been lost during the accretionary stages of the planet. However, it is now known, that core formation likely took place from the deep magma ocean surrounded by solar-nebula type proto-atmosphere enriched in volatiles thus enabling incorporation of volatiles in to the molten core. Experimental studies conducted to study the phase diagram of Fe-C system revealed that volatility of carbon is only significant at pressures lower than 10-5 GPa. (Wood, 1993, EPSL, 117, 593) suggested that solid inner core might be composed of Fe3C. Recent experimental studies have extended the Fe-C phase diagram to considerably higher pressures (~70 GPa) and have found that Fe7C3 is the likely phase at the inner core conditions (Lord et al., 2009, EPSL, 284, 157). In this study we determine the elasticity of Fe7C3 using first principle methods. Results of compression for the ferromagnetic Fe7C3 is well represented by a third order Birch Murnaghan finite strain expression with K0~ 275 GPa, K?~2.5 and V0~ 182 3. Under compression magnetic moment gradually decreases and at ~69 GPa magnetic moment is instantaneously lost. Similar behavior has been reported for Fe3C at 60 GPa (Vocadlo et al., 2002, EPSL, 203, 567). The high-pressure non-magnetic phase has distinct elastic parameters with K0~ 228 GPa, K?~4.9 and V0~ 181 3. Calculated elastic constants also exhibit softening associated with the loss of magnetization. Similar anomalous behavior in thermoelastic parameter owing to loss of magnetization has been observed for Fe3C (Fiquet et al. 2009, PEPI, 172, 125) at 68 GPa. We will present full elastic tensor and sound wave velocity results for ferromagnetic and non-magnetic phase and infer about the carbon content of the inner core.

  11. A theoretical and experimental study of the deformation of the piston-cylinder unit of a metrological pressure balance

    Science.gov (United States)

    Soares Jnior, L.; da Silva Jnior, F. I.; Lamary, P.

    2015-10-01

    Pressure balance is a measuring system widely used in metrology as a reference standard. The common procedure is to estimate the pressure from an analytical formula involving a set of phenomenological parameters. These parameters are determined experimentally by calibration tests of the balance. In particular, the piston-cylinder deformation is taking into account by the use of a global distortion coefficient and by the use of an effective area of the piston. In order to analyze the possible influence of local deformation on the pressure estimation, a Finite Element (FE) model has been developed using OpenCavok FE code. For a given position of the piston in the cylinder chamber, for a given initial gap between of the cylinder and the chamber, a coupled fluid-structure calculation is carried out. From the local fields, mean values are calculated from which the effective area of the piston-cylinder unit. The analysis is conducted for several engagement lengths of the piston in the chamber and for several loads. The first results obtained show that the local deformation play a role and that FE models could help for precise calculation of the measured pressure.

  12. Towards the bulk carbon content of Earth; new metal carbide geobarometer in high pressure diamond.

    Science.gov (United States)

    Jones, A. P.; Dobson, D.; Milledge, H. J.

    2009-04-01

    Formation of the metallic core in Earth (and other terrestrial planets) is not thought to have completely removed metallic iron from the lower mantle, where metallic iron might therefore be expected to occur as a widespread minor component [1]. We provide a new interpretation of metallic carbide inclusions in some diamond, which support a very high pressure origin from the lower mantle. Unlike rare carbides reported from diamonds previously without silicon [2], some diamonds from Jagersfontein coexist with iron-rich carbides which do contain significant silicon and oxygen, including in some cases their partial exsolution products. Based on an experimental calibration for liquid iron coexisting with lower mantle perovskite [3], we are able to show that some carbides were likely derived from pressures of approximately 45 GPa, or depths of >1100 km. This potential geobarometer has not been corrected for the behaviour of carbon in the liquid iron system, which might be an important experimental goal. The recognition of this independent carbide geobarometer offers an important new tool to confirm the superdeep origin of some diamond. The carbide-bearing diamonds are from a group whose charcteristics have recently been described [5]. Their distinctive light carbon isotopic signature (13^C ~ 17 ) coupled with evidence for very low contents nitrogen which is nonetheless highly aggregated, might be interpreted as indicative of subducted carbon. However, we are also open to the possibility that the bulk carbon isotopic composition of the Earth might also be different from the normal mantle value (13^C ~ 6 ), in which case the potential 0.4 wt% C in the Earth's core could also be isotopically very light, as suggested by Grady et al [6]. References [1] Frost D et al, Nature 428, 409-412 (2004) [2] Jacob D E et al, Contrib. Mineral. Petrol., 146, 566-576 (2004) [3] Lin et al, Science, 295, 313-315 (2002) [4] Dubrovinsky L. et al, Nature 422, 58-61 (2003) [5] Jones A P et al, 9th Int Kimb Conf 9IKC-A-00360 (2008) [6] Grady et al, Int. J. Astrobiol. 3, 117-124 (2004)

  13. Validating and Calibrating the Nintendo Wii Balance Board to Derive Reliable Center of Pressure Measures

    Directory of Open Access Journals (Sweden)

    Julia M. Leach

    2014-09-01

    Full Text Available The Nintendo Wii balance board (WBB has generated significant interest in its application as a postural control measurement device in both the clinical and (basic, clinical, and rehabilitation research domains. Although the WBB has been proposed as an alternative to the gold standard laboratory-grade force plate, additional research is necessary before the WBB can be considered a valid and reliable center of pressure (CoP measurement device. In this study, we used the WBB and a laboratory-grade AMTI force plate (AFP to simultaneously measure the CoP displacement of a controlled dynamic load, which has not been done before. A one-dimensional inverted pendulum was displaced at several different displacement angles and load heights to simulate a variety of postural sway amplitudes and frequencies (<1 Hz. Twelve WBBs were tested to address the issue of inter-device variability. There was a significant effect of sway amplitude, frequency, and direction on the WBBs CoP measurement error, with an increase in error as both sway amplitude and frequency increased and a significantly greater error in the mediolateral (ML (compared to the anteroposterior (AP sway direction. There was no difference in error across the 12 WBBs, supporting low inter-device variability. A linear calibration procedure was then implemented to correct the WBBs CoP signals and reduce measurement error. There was a significant effect of calibration on the WBBs CoP signal accuracy, with a significant reduction in CoP measurement error (quantified by root-mean-squared error from 26 mm (before calibration to 0.52 mm (after calibration. WBB-based CoP signal calibration also significantly reduced the percent error in derived (time-domain CoP sway measures, from ?10.5% (before calibration to ?0.05% (after calibration (percent errors averaged across all sway measures and in both sway directions. In this study, we characterized the WBBs CoP measurement error under controlled, dynamic conditions and implemented a linear calibration procedure for WBB CoP signals that is recommended to reduce CoP measurement error and provide more reliable estimates of time-domain CoP measures. Despite our promising results, additional work is necessary to understand how our findings translate to the clinical and rehabilitation research domains. Once the WBBs CoP measurement error is fully characterized in human postural sway (which differs from our simulated postural sway in both amplitude and frequency content, it may be used to measure CoP displacement in situations where lower accuracy and precision is acceptable.

  14. Unusual pressure dependence of the crystallographic structure in RNiO{sub 3} perovskites (R = rare earth)

    Energy Technology Data Exchange (ETDEWEB)

    Medarde, M.; Mesot, J.; Rosenkranz, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Lacorre, P. [Lab. Fluorures, Le Mans (France); Marshall, W.; Loveday, J.S. [Edinburgh Univ. (United Kingdom); Klotz, S.; Hamel, G. [Paris-6 Univ., 75 (France)

    1997-09-01

    We report the first experimental observation of a pressure-induced structural phase transition in the RNiO{sub 3} series (R = rare earth). At {approx_equal} 40 kbar, the space group of NdNiO{sub 3} changes from Pbnm(orthorhombic) to the PrNiO{sub 3} indicating that the symmetry of the structure increases with pressure. (author) 1 fig., 7 refs.

  15. Study on passive earth pressure acting on the embedment of an earth retaining wall for braced excavation work in cohesive soil; Nenseido jiban ni okeru kussaku dodomeheki neirebu no judo doatsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H. [Pacific Consultants K.K., Tokyo (Japan); Hirashima, K. [Yamanashi University, Yamanashi (Japan). Faculty of Engineering

    1995-12-15

    Passive earth pressure exerts a great influence on the stress and deformation of earth retaining walls in braced excavation. To calculate this pressure, conventional ultimate earth pressure equation, or Rankine-Resals and Coulomb`s equation, are currently applied respectively to cohesive and sandy soil. However, these intentional equation to determine passive earth pressure do not adequately take into account the excavation width during work and the shearing resistance on the earth retaining wall surface. This paper deals with cohesive soil only, deriving a calculation equation for passive earth pressure, which takes into account excavation width and the shearing resistance of the earth retaining wall surface. Then, constants in this equation are determined using the calculation results obtained from the finite element method with blasts-plastic elements. The calculation results are also compared with measured values in the model test in order to check the applicability of the calculation equation for passive earth pressure thus obtained. Finally, this paper proposes a practicable calculation equation for passive earth pressure. 13 refs., 10 figs., 10 tabs.

  16. Establishment of a force balanced piston gauge for very low gauge and absolute pressure measurements at NPL, India

    International Nuclear Information System (INIS)

    National Physical Laboratory, the National Metrology Institute (NMI) of India is maintaining Primary standards of pressure that cover several decades of pressure, starting from 3.0E-06 Pa to 1.0 GPa. Among which a recent addition is a Force Balanced Piston Gauge, the non-rotating piston type, having better resolution and zero stability compared to any other primary pressure standards commercially available in the range 1.0 Pa to 15.0 kPa (abs and gauge). The characterization of this FPG is done against Ultrasonic Interferometer Manometer (UIM), the National Primary pressure standard, working in the range 1.0 Pa to 130.0 kPa (abs and diff) and Air Piston Gauge (APG), a Transfer Pressure Standard, working in the range 6.5 kPa to 360 kPa (abs and gauge), in their overlapping pressure regions covering both absolute and gauge pressures. As NPL being one of the signatories to the CIPM MRA, the Calibration and Measurement Capabilities (CMC) of both the reference standards (UIM and APG), are Peer reviewed and notified in the Key Comparison Data Base (KCDB) of BIPM. The estimated mean effective area of the Piston Cylinder assembly of this FPG against UIM (980.457 mm2) and APG (980.463 mm2) are well within 4 ppm and 10 ppm agreement respectively, with the manufacturer's reported value (980.453 mm2). The expanded uncertainty of this FPG, Q(0.012 Pa, 0.0025% of reading), evaluated against UIM as reference standard, is well within the reported value of the manufacturer, Q(0.008 Pa, 0.003% of reading) at k = 2. The results of the characterization along with experimental setup and measurement conditions (for gauge and absolute pressure measurements), uncertainty budget preparation and evaluation of measurement uncertainty are discussed in detail in this paper.

  17. Establishment of a force balanced piston gauge for very low gauge and absolute pressure measurements at NPL, India

    Science.gov (United States)

    Vijayakumar, D. Arun; Prakash, Om; Sharma, R. K.

    2012-11-01

    National Physical Laboratory, the National Metrology Institute (NMI) of India is maintaining Primary standards of pressure that cover several decades of pressure, starting from 3.0E-06 Pa to 1.0 GPa. Among which a recent addition is a Force Balanced Piston Gauge, the non-rotating piston type, having better resolution and zero stability compared to any other primary pressure standards commercially available in the range 1.0 Pa to 15.0 kPa (abs and gauge). The characterization of this FPG is done against Ultrasonic Interferometer Manometer (UIM), the National Primary pressure standard, working in the range 1.0 Pa to 130.0 kPa (abs and diff) and Air Piston Gauge (APG), a Transfer Pressure Standard, working in the range 6.5 kPa to 360 kPa (abs and gauge), in their overlapping pressure regions covering both absolute and gauge pressures. As NPL being one of the signatories to the CIPM MRA, the Calibration and Measurement Capabilities (CMC) of both the reference standards (UIM & APG), are Peer reviewed and notified in the Key Comparison Data Base (KCDB) of BIPM. The estimated mean effective area of the Piston Cylinder assembly of this FPG against UIM (980.457 mm2) and APG (980.463 mm2) are well within 4 ppm and 10 ppm agreement respectively, with the manufacturer's reported value (980.453 mm2). The expanded uncertainty of this FPG, Q(0.012 Pa, 0.0025% of reading), evaluated against UIM as reference standard, is well within the reported value of the manufacturer, Q(0.008 Pa, 0.003% of reading) at k = 2. The results of the characterization along with experimental setup & measurement conditions (for gauge and absolute pressure measurements), uncertainty budget preparation and evaluation of measurement uncertainty are discussed in detail in this paper.

  18. Total energy calculations using DFT+DMFT: Computing the pressure phase diagram of the rare earth nickelates

    Science.gov (United States)

    Park, Hyowon; Millis, Andrew J.; Marianetti, Chris A.

    2014-06-01

    A full implementation of the ab initio density functional plus dynamical mean field theory (DFT+DMFT) formalism to perform total energy calculations and structural relaxations is proposed and implemented. The method is applied to the structural and metal-insulator transitions of the rare earth nickelate perovskites as a function of rare earth ion, pressure, and temperature. In contrast to previous DFT and DFT+U theories, the present method accounts for the experimentally observed structure of LaNiO3 and the insulating nature of the other perovskites, and quantitatively reproduces the metal-insulator and structural phase diagram in the plane of pressure and rare earth element. The temperature dependence of the energetics of the phase transformation indicates that the thermal transition is driven by phonon entropy effects.

  19. Stress in highly demanding IT jobs: transformational leadership moderates the impact of time pressure on exhaustion and work-life balance.

    Science.gov (United States)

    Syrek, Christine J; Apostel, Ella; Antoni, Conny H

    2013-07-01

    The objective of this article is to investigate transformational leadership as a potential moderator of the negative relationship of time pressure to work-life balance and of the positive relationship between time pressure and exhaustion. Recent research regards time pressure as a challenge stressor; while being positively related to motivation and performance, time pressure also increases employee strain and decreases well-being. Building on the Job Demand-Resources model, we hypothesize that transformational leadership moderates the relationships between time pressure and both employees' exhaustion and work-life balance such that both relationships will be weaker when transformational leadership is higher. Of seven information technology organizations in Germany, 262 employees participated in the study. Established scales for time pressure, transformational leadership, work-life balance, and exhaustion were used, all showing good internal consistencies. The results support our assumptions. Specifically, we find that under high transformational leadership the impact of time pressure on exhaustion and work-life balance was less strong. The results of this study suggest that, particularly under high time pressure, transformational leadership is an important factor for both employees' work-life balance and exhaustion. PMID:23834443

  20. Systems Engineering of Chemical Hydrogen Storage, Pressure Vessel and Balance of Plant for Onboard Hydrogen Storage

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Kriston P.; Simmons, Kevin L.; Weimar, Mark R.

    2014-09-02

    This is the annual report for the Hydrogen Storage Engineering Center of Excellence project as required by DOE EERE's Fuel Cell Technologies Office. We have been provided with a specific format. It describes the work that was done with cryo-sorbent based and chemical-based hydrogen storage materials. Balance of plant components were developed, proof-of-concept testing performed, system costs estimated, and transient models validated as part of this work.

  1. Accuracy of force and center of pressure measures of the Wii Balance Board.

    Science.gov (United States)

    Bartlett, Harrison L; Ting, Lena H; Bingham, Jeffrey T

    2014-01-01

    The Nintendo Wii Balance Board (WBB) is increasingly used as an inexpensive force plate for assessment of postural control; however, no documentation of force and COP accuracy and reliability is publicly available. Therefore, we performed a standard measurement uncertainty analysis on 3 lightly and 6 heavily used WBBs to provide future users with information about the repeatability and accuracy of the WBB force and COP measurements. Across WBBs, we found the total uncertainty of force measurements to be within 9.1N, and of COP location within 4.1mm. However, repeatability of a single measurement within a board was better (4.5 N, 1.5mm), suggesting that the WBB is best used for relative measures using the same device, rather than absolute measurement across devices. Internally stored calibration values were comparable to those determined experimentally. Further, heavy wear did not significantly degrade performance. In combination with prior evaluation of WBB performance and published standards for measuring human balance, our study provides necessary information to evaluate the use of the WBB for analysis of human balance control. We suggest the WBB may be useful for low-resolution measurements, but should not be considered as a replacement for laboratory-grade force plates. PMID:23910725

  2. South Dakota Space Grant Consortium: Balancing Indigenous Earth System and Space Science with Western/Contemporary Science

    Science.gov (United States)

    Bolman, J.; Nall, J.

    2005-05-01

    The South Dakota Space Grant Consortium (SDSGC) was established March 1, 1991 by a NASA Capability Enhancement Grant. Since that time SDSGC has worked to provide earth system and space science education, outreach and services to all students across South Dakota. South Dakota has nine tribes and five Tribal Colleges. This has presented a tremendous opportunity to develop sustainable equitable partnerships and collaborations. SDSGC believes strongly in developing programs and activities that highlight and reinforce the balance of Indigenous science and ways of knowing with current findings in Western/Contemporary Science. This blending of science and culture creates a learning community where individuals especially students, can gain confidence and pride in their unique skills and abilities. Universities are also witnessing the accomplishments and achievements of students who are able to experience a tribal environment and then carry that experience to a college/university/workplace and significantly increase the learning achievement of all. The presentation will highlight current Tribal College and Tribal Community partnerships with the Rosebud Sioux Reservation (Sinte Gleska University), Pine Ridge Indian Reservation (Oglala Lakota College), Standing Rock Sioux Reservation (Sitting Bull College) and Cheyenne River Sioux Reservation (Si Tanka) amongst others. Programs and activities to be explained during the presentation include but not limited to: NASA Workforce Native Connections, Scientific Knowledge for Indian Learning and Leadership (SKILL), NSF "Bridges to Success" Summer Research Program, NSF "Fire Ecology" Summer Research Experience, as well as geospatial and space science programs for students and general community members. The presentation will also cover the current initiatives underway through NASA Workforce Development. These include: partnering with the Annual He Sapa Wacipi (Black Hills Pow Wow - attendance of 14,000 Natives) to host Native Space Days 2005 (October 2005), NASA research and internship programs, and the NASA Student Fellowship Summit. An overview of recent American Indian student success will conclude the presentation. The South Dakota School of Mines and Technology has struggled over many years to develop and implement sustainable successful initiatives with Tribal Colleges and Communities. The motivating philosophy is the betterment of all people in South Dakota and the nation through developing a worldview and understanding of the integrated nature of all things, especially earth system and space science. If people are provided equity and access, there is no limit to what they can accomplish. SDSM&T in the last three years has graduated nineteen Natives with degrees in engineering, many of those students Tribal College transfers. This is a significant increase, as only forty Natives had graduated from SDSM&T between the years of 1970 and 2000. SDSM&T has seen a number of "historical firsts" in the past five years. We see this as being a direct result of creating for students an educational philosophy and process where Indigenous understanding and connections become the foundation on which to build a STEM degree program. NASA's presence on the SDSM&T campus and in South Dakota has provided the necessary focus and encouragement for success to take place. We are building bridges in South Dakota and the builders are from Indian Country.

  3. Potassium modulates electrolyte balance and blood pressure through effects on distal cell voltage and chloride.

    Science.gov (United States)

    Terker, Andrew S; Zhang, Chong; McCormick, James A; Lazelle, Rebecca A; Zhang, Chengbiao; Meermeier, Nicholas P; Siler, Dominic A; Park, Hae J; Fu, Yi; Cohen, David M; Weinstein, Alan M; Wang, Wen-Hui; Yang, Chao-Ling; Ellison, David H

    2015-01-01

    Dietary potassium deficiency, common in modern diets, raises blood pressure and enhances salt sensitivity. Potassium homeostasis requires a molecular switch in the distal convoluted tubule (DCT), which fails in familial hyperkalemic hypertension (pseudohypoaldosteronism type 2), activating the thiazide-sensitive NaCl cotransporter, NCC. Here, we show that dietary potassium deficiency activates NCC, even in the setting of high salt intake, thereby causing sodium retention and a rise in blood pressure. The effect is dependent on plasma potassium, which modulates DCT cell membrane voltage and, in turn, intracellular chloride. Low intracellular chloride stimulates WNK kinases to activate NCC, limiting potassium losses, even at the expense of increased blood pressure. These data show that DCT cells, like adrenal cells, sense potassium via membrane voltage. In the DCT, hyperpolarization activates NCC via WNK kinases, whereas in the adrenal gland, it inhibits aldosterone secretion. These effects work in concert to maintain potassium homeostasis. PMID:25565204

  4. A Balancing Act in the Third Space: Graduate-Level Earth Science in an Urban Teacher-Residency Program

    Science.gov (United States)

    Zirakparvar, N. Alex

    2015-01-01

    This article describes a museum-based urban teacher-residency (UTR) program's approach to building subject-specific content knowledge and research experience in Earth Science teacher candidates. In the museum-based program, graduate-level science courses and research experiences are designed and implemented specifically for the UTR by active Earth

  5. Sodium-potassium balance in the regulation of high blood pressure

    Directory of Open Access Journals (Sweden)

    Luis Hernn Zrate Mndez

    2012-02-01

    Full Text Available The World Health Organization considers essential hypertension as a primary cause of death. Twenty-five percent of the population over 15 has high blood pressure (HBP, equivalent to a billion people. It has been predicted that this group will increase by 60%, lineal with age increase in the overall population. Unfortunately, detection, treatment and effective control of HBP, are deficient both in Chile and in the rest of the world, making it an unresolved health problem demanding urgent attention. The recently conducted Chilean National Health Survey (2009-2010 revealed a 26.9% prevalence of this condition in the population, sixty-five percent of individuals are aware of their condition, 37.6% are in treatment and only 16,49% are effectively controlled. Furthermore, the survey reveals unhealthy life-style markers, which explains the epidemic that besets the country as there are multiple risk factors at stake. This review focuses mainly on the importance of the sodium-potassium relationship in the regulation of high blood pressure. It must be pointed out that all of the studies underscore the importance of sodium in the genesis of hypertension because of its effects of blood pressure, especially in sensitive individuals, while little attention has been given to the manifold beneficial actions of potassium in the regulation of blood pressure.

  6. Pressure sensor-based tongue-placed electrotactile biofeedback for balance improvement - Biomedical application to prevent pressure sores formation and falls

    CERN Document Server

    Vuillerme, Nicolas; Pinsault, Nicolas; Moreau-Gaudry, Alexandre; Fleury, Anthony; Demongeot, Jacques; Payan, Yohan

    2007-01-01

    We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using artificial tongue-placed tactile biofeedback systems. Proposed applications are dealing with: (1) pressure sores prevention in case of spinal cord injuries (persons with paraplegia, or tetraplegia); and (2) balance control improvement to prevent fall in older and/or disabled adults. This paper describes the architecture and the functioning principle of these biofeedback systems and presents preliminary results of two feasibility studies performed on young healthy adults.

  7. Pressure effects on magnetic properties of R(Fe, M)12 single crystals (R = rare earth, M = Ti, Mi).

    Czech Academy of Sciences Publication Activity Database

    Kamard, Ji?; Garca-Landa, B.; Mikulina, Olga; Arnold, Zden?k; Ibarra, M. R.; Algarabel, P. A.

    226-230, - (2001), s. 1446-1448. ISSN 0304-8853. [International Conference on Magnetism. Recife, 06.08.2000-11.08.2000] R&D Projects: GA ?R GA202/99/0184; GA AV ?R IAA1010811 Institutional research plan: CEZ:AV0Z1010914 Keywords : magnetization * high pressure * rare-earth intermetallics * anisotropy * magnetocrystalline * magnetic transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.329, year: 2001

  8. Pressure and current balance conditions during electron beam injections from spacecraft

    Science.gov (United States)

    Hwang, K. S.; Singh, Nagendra

    1990-01-01

    Electrostatic charging level of a conducting surface in response to injections of electron beams into space plasma is investigated by means of one-dimensional Vlasov code. Injections of Maxwellian beams into a vacuum shows that the surface can charge up to an electric potential phi sub s greater than W sub b, where W sub b is the average electron beam energy. Since Maxwellian beams have extended trails with electrons having energies greater than W sub b, it is difficult to quantify the charging level in terms of the energies of the injected electrons. In order to quantitatively understand the charging in excess of W sub b, simulations were carried out for water-bag types of beam with velocity distribution functions described by f(V) = A for V sub min approx. less than V approx. less than V sub max and f(V) = O otherwise, where A is a constant making the normalized beam density unity. It is found that V sub max does not directly determine the charging level. The pressure distribution in the electron sheath determines the electric field distribution near the surface. The electric field in turn determines the electrostatic potential of the vehicle. The pressure distribution is determined by the beam parameters such as the average beam velocity and the velocity spread of the beam.

  9. Strength and Balance Exercises

    Science.gov (United States)

    ... Pressure High Blood Pressure Tools & Resources Stroke More Strength and Balance Exercises Updated:Jun 23,2015 If ... Be Safe While Being Active - Stretching & Flexibility Exercises - Strength & Balance Exercises - Problems & Solutions for Being Active - FAQs ...

  10. Contrasting effects of vasodilators on blood pressure and sodium balance in the hypertension of autonomic failure

    Science.gov (United States)

    Jordan, J.; Shannon, J. R.; Pohar, B.; Paranjape, S. Y.; Robertson, D.; Robertson, R. M.; Biaggioni, I.

    1999-01-01

    Supine hypertension, which is very common in patients with autonomic failure, limits the use of pressor agents and induces nighttime natriuresis. In 13 patients with severe orthostatic hypotension due to autonomic failure (7 women, 6 men, 72 +/- 3 yr) and supine hypertension, the effect of 30 mg nifedipine (n = 10) and 0.025 to 0.2 mg/h nitroglycerin patch (n = 11) on supine BP, renal sodium handling, and orthostatic tolerance was determined. Medications were given at 8 p.m.; patients stood up at 8 a.m. Nitroglycerin was removed at 6 a.m. Compared with placebo, nifedipine and nitroglycerin decreased systolic BP during the night by a maximum of 37 +/- 9 and 36 +/- 10 mmHg, respectively (P effective in controlling supine hypertension in patients with autonomic failure. However, nifedipine has a prolonged depressor effect and worsens orthostatic hypotension in the morning. The decrease in pressure natriuresis that would be expected with the substantial decrease in BP obtained with nitroglycerin and nifedipine may be offset by a direct effect of both drugs on renal sodium handling.

  11. Pressure and Ionization Balances in the Circum-Heliospheric Interstellar Medium and the Local Bubble

    CERN Document Server

    Jenkins, Edward B

    2008-01-01

    A disconcerting mismatch of thermal pressures for two media in contact with each other, (1) the warm, Circum-heliospheric Interstellar Medium (CHISM) and (2) the very hot material within a much larger region called the Local Bubble (LB), has troubled astronomers for over two decades. A possible resolution of this problem, at least in part, now seems possible. We now understand that earlier estimates for the average electron density in the very hot LB plasma were inflated by an unrecognized foreground contamination to the low energy diffuse X-ray background measurements. This foreground illumination arises from photons emitted by charge exchange reactions between solar wind ions and neutral atoms from the interstellar medium that enter into the heliosphere. However, with the resolution of this problem comes a new one. The high ionization fraction of helium in the CHISM, relative to that of hydrogen, could be understood in terms of the effects from a strong flux of EUV and X-ray radiation coming from both the L...

  12. Inclusion of electronic polarizability effect in high pressure structural properties of alloy of rare-earth antimonides

    International Nuclear Information System (INIS)

    In the present paper, we have investigated the high-pressure structural phase transition of rare-earth antimonides (NdSb and DySb). We studied theoretically the structural properties of alloy of these compounds (NdSb and DySb) by using the three-body potential model with the effect of electronic polarizability (TBIPEP). These compounds exhibit first order crystallographic phase transition from NaCl (B1) to CsCl (B2) phase at 17.8?GPa and 22.6?GPa respectively. The study has been extended to mixed crystals and the effect of composition on transition pressure and volume change is investigated. The phase transition pressures and associated volume collapse obtained from present potential model (TBIPEP) show a good agreement with available experimental data

  13. Inclusion of electronic polarizability effect in high pressure structural properties of alloy of rare-earth antimonides

    Energy Technology Data Exchange (ETDEWEB)

    Yaduvanshi, Namrata, E-mail: namrata-yaduvanshi@yahoo.com; Kapoor, Shilpa; Singh, Sadhna [High Pressure Research Lab. Department of Physics, Barkatullah University, Bhopal (M.P.) India-462026 (India)

    2015-05-15

    In the present paper, we have investigated the high-pressure structural phase transition of rare-earth antimonides (NdSb and DySb). We studied theoretically the structural properties of alloy of these compounds (NdSb and DySb) by using the three-body potential model with the effect of electronic polarizability (TBIPE{sub P}). These compounds exhibit first order crystallographic phase transition from NaCl (B{sub 1}) to CsCl (B{sub 2}) phase at 17.8?GPa and 22.6?GPa respectively. The study has been extended to mixed crystals and the effect of composition on transition pressure and volume change is investigated. The phase transition pressures and associated volume collapse obtained from present potential model (TBIPE{sub P}) show a good agreement with available experimental data.

  14. Jump conditions for pressure anisotropy and comparison with the Earth's bow shock

    Directory of Open Access Journals (Sweden)

    D. F. Vogl

    2001-01-01

    Full Text Available Taking into account the pressure anisotropy in the solar wind, we study the magnetic field and plasma parameters downstream of a fast shock, as functions of upstream parameters and downstream pressure anisotropy. In our theoretical approach, we model two cases: a the perpendicular shock and b the oblique shock. We use two threshold conditions of plasma instabilities as additional equations to bound the range of pressure anisotropy. The criterion of the mirror instability is used for pressure anisotropy p perp /pparrallel > 1. Analogously, the criterion of the fire-hose instability is taken into account for pressure anisotropy p perp /pparrallel < 1. We found that the variations of the parallel pressure, the parallel temperature, and the tangential component of the velocity are most sensitive to the pressure anisotropy downstream of the shock. Finally, we compare our theory with plasma and magnetic field parameters measured by the WIND spacecraft.

  15. SMALL-SCALE PRESSURE-BALANCED STRUCTURES DRIVEN BY OBLIQUE SLOW MODE WAVES MEASURED IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Yao Shuo [School of Geophysics and Information Technology, China University of Geosciences (Beijing), Beijing 100083 (China); He, J.-S.; Tu, C.-Y.; Wang, L.-H. [Department of Geophysics, Peking University, Beijing (China); Marsch, E., E-mail: yaoshuo@cugb.edu.cn [Christian Albrechts University at Kiel, Kiel (Germany)

    2013-09-01

    Recently, small-scale pressure-balanced structures (PBSs) were identified in the solar wind, but their formation mechanism remains unclear. This work aims to reveal the dependence of the properties of small-scale PBSs on the background magnetic field (B{sub 0}) direction and thus to corroborate the in situ mechanism that forms them. We analyze the plasma and magnetic field data obtained by WIND in the quiet solar wind at 1 AU. First, we use a developed moving-average method to obtain B{sub 0}(s, t) for every temporal scale (s) at each time moment (t). By wavelet cross-coherence analysis, we obtain the correlation coefficients between the thermal pressure P{sub th} and the magnetic pressure P{sub B}, distributing against the temporal scale and the angle {theta}{sub xB} between B{sub 0}(s, t) and Geocentric Solar Ecliptic coordinates (GSE)-x. We note that the angle coverage of a PBS decreases with shorter temporal scale, but the occurrence of the PBSs is independent of {theta}{sub xB}. Suspecting that the isolated small PBSs are formed by compressive waves in situ, we continue this study by testing the wave modes forming a small-scale PBS with B{sub 0}(s, t) quasi-parallel to GSE-x. As a result, we identify that the cross-helicity and the compressibility attain values for a slow mode from theoretical calculations. The wave vector is derived from minimum variance analysis. Besides, the proton temperatures obey T < T{sub Parallel-To} derived from the velocity distribution functions, excluding a mirror mode, which is the other candidate for the formation of PBSs in situ. Thus, a small-scale PBS is shown to be driven by oblique, slow-mode waves in the solar wind.

  16. Spin crossover and MottHubbard transition under high pressure and high temperature in the low mantle of the Earth

    Science.gov (United States)

    Ovchinnikov, S. G.; Ovchinnikova, T. M.; Plotkin, V. V.; Dyad'kov, P. G.

    2015-11-01

    Effect of high pressure induced spin crossover on the magnetic, electronic and structural properties of the minerals forming the Earth's low mantle is discussed. The low temperature P, T phase diagram of ferropericlase has the quantum phase transition point Pc = 56 GPa at T = 0 confirmed recently by the synchrotron Mssbauer spectroscopy. The LDA+GTB calculated phase diagram describes the experimental data. Its extension to the high temperature resulted earlier in prediction of the metallic properties of the Earth's mantle at the depth 1400 km electrical conductivity based on the percolation theory is given. We discuss also the thermodynamic properties and structural anomalies resulting from the spin crossover and metal-insulator transition and compare them with the experimental seismic and geomagnetic field data.

  17. The etching process of boron nitride by alkali and alkaline earth fluorides under high pressure and high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Guo, W., E-mail: guowei1982cry@163.com [College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); National Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China); Ma, H.A.; Jia, X. [National Key Lab of Superhard Materials, Jilin University, Changchun 130012 (China)

    2014-03-01

    Graphical abstract: - Highlights: Appropriate etch processes of hBN and cBN under HPHT are proposed. The degree of the crystallization of hBN was decreased. A special cBN growth mechanism with a triangular unit is proposed. Plate-shape cBN crystals with large ratio of length to thickness were obtained. A strategy provides useful guidance for controlling the cBN morphology. - Abstract: Some new etching processes of hexagonal boron nitride (hBN) and cubic boron nitride (cBN) under high pressure and high temperature in the presence of alkali and alkaline earth fluorides have been discussed. It is found that hBN is etched distinctly by alkali and alkaline earth fluorides and the morphology of hBN is significantly changed from plate-shape to spherical-shape. Based on the graphitization index values of hBN, the degree of the crystallization of hBN under high pressure and high temperature decreases in the sequence of LiF > CaF{sub 2} > MgF{sub 2}. This facilitates the formation of high-quality cBN single crystals. Different etch steps, pits, and islands are observed on cBN surface, showing the strong etching by alkali and alkaline earth fluorides and the tendency of layer-by-layer growth. A special layer growth mechanism of cBN with a triangular unit has been found. Furthermore, the morphologies of cBN crystals are apparently affected by a preferential surface etching of LiF, CaF{sub 2} and MgF{sub 2}. Respectively, the plate-shape and tetrahedral cBN crystals can be obtained in the presence of different alkali and alkaline earth fluorides.

  18. The etching process of boron nitride by alkali and alkaline earth fluorides under high pressure and high temperature

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: Appropriate etch processes of hBN and cBN under HPHT are proposed. The degree of the crystallization of hBN was decreased. A special cBN growth mechanism with a triangular unit is proposed. Plate-shape cBN crystals with large ratio of length to thickness were obtained. A strategy provides useful guidance for controlling the cBN morphology. - Abstract: Some new etching processes of hexagonal boron nitride (hBN) and cubic boron nitride (cBN) under high pressure and high temperature in the presence of alkali and alkaline earth fluorides have been discussed. It is found that hBN is etched distinctly by alkali and alkaline earth fluorides and the morphology of hBN is significantly changed from plate-shape to spherical-shape. Based on the graphitization index values of hBN, the degree of the crystallization of hBN under high pressure and high temperature decreases in the sequence of LiF > CaF2 > MgF2. This facilitates the formation of high-quality cBN single crystals. Different etch steps, pits, and islands are observed on cBN surface, showing the strong etching by alkali and alkaline earth fluorides and the tendency of layer-by-layer growth. A special layer growth mechanism of cBN with a triangular unit has been found. Furthermore, the morphologies of cBN crystals are apparently affected by a preferential surface etching of LiF, CaF2 and MgF2. Respectively, the plate-shape and tetrahedral cBN crystals can be obtained in the presence of different alkali and alkaline earth fluorides

  19. Cenosphere formation from heavy fuel oil: a numerical analysis accounting for the balance between porous shells and internal pressure

    KAUST Repository

    Vanteru, Mahendra Reddy

    2016-01-18

    Heavy fuel oil (HFO) as a fuel in industrial and power generation plants ensures the availability of energy at economy. Coke and cenosphere emissions from HFO combustion need to be controlled by particulate control equipment such as electrostatic precipitators, and collection effectiveness is impacted by the properties of these particulates. The cenosphere formation is a function of HFO composition, which varies depending on the source of the HFO. Numerical modelling of the cenosphere formation mechanism presented in this paper is an economical method of characterising cenosphere formation potential for HFO in comparison to experimental analysis of individual HFO samples, leading to better control and collection. In the present work, a novel numerical model is developed for understanding the global cenosphere formation mechanism. The critical diameter of the cenosphere is modelled based on the balance between two pressures developed in an HFO droplet. First is the pressure (Prpf) developed at the interface of the liquid surface and the inner surface of the accumulated coke due to the flow restriction of volatile components from the interior of the droplet. Second is the pressure due to the outer shell strength (PrC) gained from van der Walls energy of the coke layers and surface energy. In this present study it is considered that when PrC ≥ Prpf the outer shell starts to harden. The internal motion in the shell layer ceases and the outer diameter (DSOut) of the shell is then fixed. The entire process of cenosphere formation in this study is analysed in three phases: regression, shell formation and hardening, and post shell hardening. Variations in pressures during shell formation are analysed. Shell (cenosphere) dimensions are evaluated at the completion of droplet evaporation. The rate of fuel evaporation, rate of coke formation and coke accumulation are analysed. The model predicts shell outer diameters of 650, 860 and 1040 µm, and inner diameters are 360, 410 and 430 µm respectively, for 700, 900 and 1100 µm HFO droplets. The present numerical model is validated with experimental results available from the literature. Total variation between computational and experimental results is in the range of 3–7%.

  20. Topex data analysis to infer Earth's rotational fluctuations forced by the oceanic response to atmospheric pressure variations

    Science.gov (United States)

    Dey, Nirupam

    The oceanic response to atmospheric pressure variations is a dynamic response that depends on the frequency and spatial scale of the forcing. In this dissertation, the actual oceanic response is derived from TOPEX satellite altimeter sea-surface height (SSH) observations (1993--2004) on a 4 degree latitude, 8 degree longitude grid corrected for tides, winds and annual variations. The SSH data obtained from Jet Propulsion Laboratory (JPL) website is already corrected for tides. The wind correction values are from the ECCO model, which had been obtained from JPL. The wind correction has been modified by a "Darwin" correction to insure mass conservation. To eliminate the large annual signal, which might otherwise overwhelm the analysis, a sinusoid of annual period and a trend for 12 years have been removed at each grid location. Pressure data were downloaded from AER in spherical harmonic form. For each harmonic of forcing, a Wiener filter---generalized for complex time series---is used to isolate that portion of the sea-surface height within each gridbox location due to pressure forcing. The input to the Wiener filter was the corrected SSH time series at that location and the desired output was the pressure harmonic time series. Based on the reduction of the error between the desired and the actual output, this technique appears to be successful (mostly) in isolating that portion of SSH due to individual spherical harmonic pressure coefficients. This pressure-driven portion of the SSH has been used to calculate the associated oceanic currents. Then the combined effect of pressure forced SSH and associated currents on Earth's rotation---polar motion and change in Earth's spin rate---are calculated. The ocean's response showed a spatial and temporal dependence. The currents due to at least some harmonics of forcing showed higher velocities along East-West direction and seemed to be associated with sectorial harmonics. In contrast, the currents along North-South direction showed peak velocities for zonal harmonics. The rotational effects calculated here are mainly due to the pressure-forced SSH and shows frequency dependence. The excitation due to dynamic barometer shows significant departures from the excitation due to inverted barometer.

  1. Pressure-induced magnetic transition and sound velocities of Fe3C : implications for carbon in the earth's inner core

    International Nuclear Information System (INIS)

    We have carried out nuclear resonant scattering measurements on 57Fe-enriched Fe3C between 1 bar and 50 GPa at 300 K. Synchrotron Moessbauer spectra reveal a pressure-induced magnetic transition in Fe3C between 4.3 and 6.5 GPa. On the basis of our nuclear resonant inelastic X-ray scattering spectra and existing equation-of-state data, we have derived the compressional wave velocity Vp and shear wave velocity Vs for the high-pressure nonmagnetic phase, which can be expressed as functions of density (?): Vp (km/s) = -3.99 + 1.29?(g/cm3) and Vs (km/s) = 1.45 + 0.24?(g/cm3). The addition of carbon to iron-nickel alloy brings density, Vp and Vs closer to seismic observations, supporting carbon as a principal light element in the Earth's inner core

  2. Pressure-induced novel superconductivity and heavy fermion state in rare earth compounds

    International Nuclear Information System (INIS)

    We have carried out the electrical resistivity measurements under high pressures up to 24 GPa for CeTX3 (T: Co and Ir, X: Si and Ge), CePd5Al2 and YbIr2Zn20 in order to investigate quantum criticality and superconductivity. Antiferromagnets CeTX3 with the non-centrosymmetric tetragonal structure show superconductivity under high pressures and reveal a huge upper critical field for H? [001]. An antiferromagnet CePd5Al2, which is an isostructural family of a heavy fermion superconductor NpPd5Al2, also shows superconductivity under high pressures. In these compounds, superconductivity appears in the vicinity of quantum critical point. On the other hand, YbIr2Zn20 without magnetic ordering approaches to the quantum critical point with increasing pressure and exhibits a super-heavy fermion state exceeding 10 J/(K2 mol).

  3. Hydrogen and deuterium sorption by selected rare earth intermetallic compounds at pressures up to 1500 atm

    International Nuclear Information System (INIS)

    A limited survey was conducted of hydrogen and deuterium sorption by 13 selected ABsub(x) alloys (A equivalent to La, Ce, Pr, Er; B equivalent to Co, Ni). A structural analysis showed that AB5 hydrides share essentially the same structure, with a maximum of nine sites per AB5 unit available for hydrogen storage. To determine whether all nine sites could be filled at pressures higher than those previously studied, pressure-composition isotherms were obtained at 21 0C and up to 1500 atm for each of the alloys under study. The effect on the pressure-composition isotherm of substituting one A or B element for another (neodymium or manganese) was also explored. The pressure plateaus were usually shifted by these substitutions. (Auth.)

  4. The new-generation of solenoid injectors equipped with pressure-balanced pilot valves for energy saving and dynamic response improvement

    International Nuclear Information System (INIS)

    Highlights: Distinct pilot-valve setups, typical of modern Common Rail injectors, are compared. The analysis focuses on injector static leakages and the injector dynamic response. Experimental results are integrated or explained by means of simulation data. - Abstract: A numericalexperimental analysis on a new generation of hydraulically controlled servo solenoid injectors for Euro 6 Diesel engine applications has been carried out. The main innovation of these high-pressure injectors is the replacement of the standard pilot-valve configuration with a pressure-balanced layout. The new setup is aimed at reducing clearance leakages and at improving the dynamic response of the needle to the electrical command. A previously developed advanced one-dimensional code for the simulation of Common Rail injection systems has been adapted to simulate the innovative injectors. In particular, electromagnetic, hydraulic and mechanical submodels have been set up for the pressure-balanced pilot-valve simulation. The validated numerical model of the injector has been applied to investigate the mechanics of the pressure-balanced pilot-valve and the sensitivity of the dynamic response of the needle to some of the innovative pilot-valve layout design parameters. Furthermore, the developed simulation tool has been used to examine the real impact that the replacement of the standard pilot-valve layout with a pressure-balanced one could have on the injected flow-rate performance. The comparative investigation between the standard and the innovative pilot-valve has been completed with an analysis of their experimental static leakages. A comparison has also been made with static leakages measured for hydraulically-controlled servo piezoelectric injectors. Finally, a simple and accurate thermodynamic flow model has been developed to predict static leakages in indirect-acting solenoid and piezoelectric injectors. This model has pointed out the significant dependence of static leakages on temperature and pressure

  5. Comparison of Radiation Pressure Perturbations on Rocket Bodies and Debris at Geosynchronous Earth Orbit

    Science.gov (United States)

    Wetterer, C.; Hill, K.; Jah, M.

    2014-09-01

    Recent research has highlighted the need for physically consistent radiation pressure and Bidirectional Reflectance Distribution Function (BRDF) models. This paper seeks to evaluate the impact of BRDF-consistent radiation pressure models compared to changes in the other BRDF parameters. The differences in orbital position arising because of changes in the shape, attitude, angular rates, BRDF parameters, and radiation pressure model are plotted as a function of time for simulated rocket bodies and debris at geo-synchronous orbit (GEO). The initial position and velocity of the space object is kept fixed, and the orbital position difference between a baseline or-bit and the perturbed orbit are plotted as a function of time. This is similar to how the effects of perturbations have been visualized in the past in commonly used astrodynamics references.

  6. Luminescence of high pressure phases of Eu2+-activated alkaline earth borates and silicates

    International Nuclear Information System (INIS)

    High pressure phases of EuB2O4, MB2O4-Eu2+ (M=Ca, Sr), EuSiO3 and MSiO3-Eu2+ were synthesized at pressures of 30-150 kbar. The pressure-temperature phase diagram of EuB2O4 consists of the following four regions: phases I, III and IV, and a region of phase separation into EuB4O7 and Eu2B2O5. The band emissions of the high pressure phases of EuB2O4 and SrB2O4-Eu2+ are assigned to (4f)7-(4f)6(5d) transitions of the Eu2+ ions. The emission intensity increases on transformation into phase IV. In particular, the relative emission intensity of phase IV of SrB2O4-Eu2+ is about 100 times higher than that of phase I of the corresponding borate. This is firstly due to the fact that the Eu2+ ions in phase IV are effectively surrounded by BO4 tetrahedra of the three dimensional B3O6 network such that their interaction with neighbouring Eu2+ ions is restricted. Secondly, the phase transformation appears to reduce the lattice vibration of the borate network, thus decreasing non-radiative processes. The application of pressures of up to 150 kbar on EuSiO3 resulted in the formation of the new high pressure phases delta and delta'. The emission intensities of CaSiO3-Eu2+ and SrSiO3-Eu2+ also increased appreciably (by a factor of 20-40) when the host lattices transformed into delta-CaSiO3 and delta'-SrSiO3. (Auth.)

  7. From Science Reserves to Sustainable Multiple Uses beyond Earth orbit: Evaluating Issues on the Path towards Balanced Environmental Management on Planetary Bodies

    Science.gov (United States)

    Race, Margaret

    Over the past five decades, our understanding of space beyond Earth orbit has been shaped by a succession of mainly robotic missions whose technologies have enabled scientists to answer diverse science questions about celestial bodies across the solar system. For all that time, exploration has been guided by planetary protection policies and principles promulgated by COSPAR and based on provisions in Article IX of the Outer Space Treaty of 1967. Over time, implementation of the various COSPAR planetary protection policies have sought to avoid harmful forward and backward contamination in order to ensure the integrity of science findings, guide activities on different celestial bodies, and appropriately protect Earth whenever extraterrestrial materials have been returned. The recent increased interest in extending both human missions and commercial activities beyond Earth orbit have prompted discussions in various quarters about the need for updating policies and guidelines to ensure responsible, balanced space exploration and use by all parties, regardless whether activities are undertaken by governmental or non-governmental entities. Already, numerous researchers and workgroups have suggested a range of different ways to manage activities on celestial environments (e.g, wilderness parks, exclusion zones, special regions, claims, national research bases, environmental impact assessments, etc.). While the suggestions are useful in thinking about how to manage future space activities, they are not based on any systematically applied or commonly accepted criteria (scientific or otherwise). In addition, they are borrowed from terrestrial approaches for environmental protection, which may or may not have direct applications to space environments. As noted in a recent COSPAR-PEX workshop (GWU 2012), there are no clear definitions of issues such as harmful contamination, the environment to be protected, or what are considered reasonable activity or impacts for particular locationsand over what time frames. Likewise, there are no guidelines for how to deal with the potential conflict between economic viability for commercial space activity and the need for reasonable planetary protection measures and standards. Before creating guidelines for particular locations or developing a international environmental regime for blending space exploration and use, it is advisable to have at least have a cursory overview of what lies ahead in the technical, scientific, commercial, environmental and policy realms. To develop such an overview, I undertook a preliminary analysis of the proposed activities, stakeholders, timeframes, and potential environmental impacts anticipated in coming years for robotic and human missions, particularly for the Moon and Mars. Hopefully, this type of information will be useful as the international community works towards updating policies and guidelines for responsible, balanced space exploration and use by all parties.

  8. The temperature dependence of saturated vapor pressure over alkaline-earth metal pivaloyltrifluoroacetonate complexes

    Science.gov (United States)

    Efimova, Yu. A.; Abakumov, G. A.; Petrov, B. I.; Pochekutova, T. S.; Khamylov, V. K.

    2008-11-01

    The temperature dependences of saturated vapor pressure over M(PTA)2 15-crown-5, where M = Ca, Sr, or Ba and PTA is the pivaloyltrifluoroacetonate anion, were studied by the Knudsen effusion method, and the enthalpies of compound sublimation were calculated. Changes in volatility depending on the central metal atom were determined.

  9. A laboratory method for modeling synthesis of coesite in the earth's surface by combining local mechanical collision with shear stress and high static pressure.

    Science.gov (United States)

    Su, Wen-Hui; Liu, Shu-E.; Xu, Da-Peng; Wang, Wei-Ran; Liu, Xiao-Mei

    2006-03-01

    A laboratory method of combining the high-energy mechanical ball milling and high static pressure has been suggested for modeling synthesis of coesite in the earth's surface. A window of milling time, a mechanical collision-induced intermediate phase of ?-quartz and its condition of easily crystallizing into coesite induced by high static pressure 3.0 GPa, 923 K, static pressure in laboratory.

  10. Thermal and Pressure Characterization of a Wind Tunnel Force Balance Using the Single Vector System. Experimental Design and Analysis Approach to Model Pressure and Temperature Effects in Hypersonic Wind Tunnel Research

    Science.gov (United States)

    Lynn, Keith C.; Commo, Sean A.; Johnson, Thomas H.; Parker, Peter A,

    2011-01-01

    Wind tunnel research at NASA Langley Research Center s 31-inch Mach 10 hypersonic facility utilized a 5-component force balance, which provided a pressurized flow-thru capability to the test article. The goal of the research was to determine the interaction effects between the free-stream flow and the exit flow from the reaction control system on the Mars Science Laboratory aeroshell during planetary entry. In the wind tunnel, the balance was exposed to aerodynamic forces and moments, steady-state and transient thermal gradients, and various internal balance cavity pressures. Historically, these effects on force measurement accuracy have not been fully characterized due to limitations in the calibration apparatus. A statistically designed experiment was developed to adequately characterize the behavior of the balance over the expected wind tunnel operating ranges (forces/moments, temperatures, and pressures). The experimental design was based on a Taylor-series expansion in the seven factors for the mathematical models. Model inversion was required to calculate the aerodynamic forces and moments as a function of the strain-gage readings. Details regarding transducer on-board compensation techniques, experimental design development, mathematical modeling, and wind tunnel data reduction are included in this paper.

  11. Balance Disorders

    Science.gov (United States)

    ... rate and blood pressure, and fear, anxiety, or panic. Symptoms may come and go over short time ... the-counter medicine, such as aspirin, antihistamines, or sleep aids): Name of medicine: ... on balance disorders? Findings from animal studies may help researchers determine ...

  12. Elastic anisotropy in hcp metals at high pressure and the sound wave anisotropy of the Earth's inner core

    Science.gov (United States)

    Antonangeli, Daniele; Merkel, Sbastien; Farber, Daniel L.

    2006-12-01

    We compare the elastic anisotropy in hcp metals at high pressure obtained by radial diffraction measurements with those determined by other experiments and calculations. Our analysis demonstrates that in non-hydrostatically compressed hcp metals the assumption of a single uniform macroscopic stress applied to all grains in the polycrystal for the inversion of the lattice strain equations is violated due to plastic deformation. In addition, the derived apparent moduli and elastic anisotropy differ significantly from those derived from single crystals. We propose that for cobalt, rhenium and iron, the elastic anisotropy in the meridian plane is best described by a sigmoidal shape for the longitudinal velocity, with the fastest direction along the c-axis. Based on these results, we suggest that preferential alignment of the c-axis of iron crystallites along the Earth's rotation axis is the most plausible explanation for the observed P-wave travel time anomalies in the inner core.

  13. Effect of Intermittent Positive Pressure Ventilation (IPPV) on Acid-Base Balance and Plasma Electrolytes during Isoflurane Anaesthesia in Sulphur-Crested Cockatoos (Cacatua galerita galerita)

    OpenAIRE

    Saul Chemonges

    2012-01-01

    The objective of the study was to investigate the effect of Intermittent Positive Pressure Ventilation (IPPV) on acid-base balance and plasma electrolytes during isoflurane anaesthesia in sulphur-crested cockatoos (Cacatua galerita galerita) Anaesthesia was induced in six birds by mask using a T-piece with 3.0% isoflurane. Blood gases, plasma electrolytes, PCV and Total Protein (TP) were monitored for one hour during Spontaneous Ventilation (SV) and IPPV. IPPV was instituted by engaging the p...

  14. Earth in the balance. Ecology and the human spirit; Urgence Planete Terre. L'esprit humain face a la crise ecologique

    Energy Technology Data Exchange (ETDEWEB)

    Al Gore

    2007-07-01

    This book is the translation of the original American edition 'earth in the balance'. When Earth in the Balance first came out, it caused quite a stir and for good reason. It convincingly makes the case that a crisis of epidemic proportions is nearly upon us and that if the world does not get its act together soon and agree to some kind of 'Global Marshall Plan' to protect the environment, we're all up a polluted creek without a paddle. Myriad plagues are upon us, but the worst include the loss of biodiversity, the depletion of the ozone layer, the slash-and-burn destruction of rain forests, and the onset of global warming. None of this is new, of course, nor was it new in 1992. But most environmentalists will still get a giddy feeling reading such a call to action as written by a prominent politician. The book is arranged into three sections: the first describes the plagues; the second looks at how we got ourselves into this mess; and the final chapters present ways out. Gore gets his points across in a serviceable way, though he could have benefited from a firmer editor's hand; at times the analogies are arcane and the pacing is odd kind of like a Gore speech that climaxes at weird points and then sinks just as the audience is about to clap. Still, at the end you understand what's been said. Gore believes that if we apply some American ingenuity, the twin engines of democracy and capitalism can be rigged to help us stabilize world population growth, spread social justice, boost education levels, create environmentally appropriate technologies, and negotiate international agreements to bring us back from the brink. For example, a worldwide shift to clean, renewable energy sources would create huge economic opportunities for companies large and small to design, build, and maintain solar panels, wind turbines, fuel cells, and other eco friendly innovations.

  15. Metal-silicate partitioning of iodine at high pressures and temperatures: Implications for the Earth's core and 129*Xe budgets

    Science.gov (United States)

    Armytage, Rosalind M. G.; Jephcoat, Andrew P.; Bouhifd, M. A.; Porcelli, Donald

    2013-07-01

    The partition coefficients of iodine Dmet/sil between molten metal and molten silicate were investigated using a Laser Heated Diamond Anvil Cell (LHDAC) at pressures between 2 and 20 GPa and at ~2800 K. No pressure dependence of Dmet/sil was observed within this range, but the composition of the Fe-Ni alloy liquid phase was shown to have an effect. When the metallic liquid was alloyed with S, O and Si, there was an increase in iodine solubility in the metal. Iodine exhibited mildly siderophile behaviour across all the investigated conditions, with Dmet/sil=1.250.65 (2 s.d.) (Fe metal system) and Dmet/sil=4.331.41 (2 s.d.) (Fe-alloy). In conjunction with a revised bulk silicate Earth (BSE) concentration, it is calculated that the core could be a significant reservoir for iodine, with up to 82% of the bulk Earth's iodine budget in the core, depending on the light element content of the metal phase and the process of core formation. The composition of the metal phase appears to have a greater effect on the partitioning and sequestration of iodine than the style of core segregation. As the core likely formed while 129I was still extant, the core can also be a reservoir for radiogenic 129Xe from the decay system 129I-129Xe (T1/2=15.7 Myr). Preliminary modelling indicates that the decay of 129I in the core has the potential to generate radiogenic 129Xe concentrations that are at least two orders of magnitude greater than what has been estimated for the depleted mantle. While this may have a significant impact on the isotopic signatures of the overlying mantle, it is not yet clear how flux from the core fits within the overall picture of mantle noble gas evolution.

  16. Windsock memory conditioned RAM (Co-Ram) pressure effect: forced reconnection in the Earth's magnetotail

    CERN Document Server

    Vrs, Z; Khodachenko, M; Honkonen, I; Janhunen, P; Palmroth, M

    2014-01-01

    Magnetic reconnection (MR) is a key physical concept explaining the addition of magnetic flux to the magnetotail and closed flux lines back-motion to the dayside magnetosphere. This scenario elaborated by \\citet{dung63}, can explain many aspects of solar wind-magnetosphere interaction processes, including substorms. However, neither the Dungey model nor its numerous modifications were able to explain fully the onset conditions for MR in the tail. In this paper, we introduce new onset conditions for forced MR in the tail. We call our scenario the "windsock memory conditioned ram pressure effect". Our non-flux-transfer associated forcing is introduced by a combination of large-scale windsock motions exhibiting memory effects and solar wind dynamic pressure actions on the nightside magnetopause during northward oriented IMF. Using global MHD GUMICS-4 simulation results, upstream data from WIND, magnetosheath data from Cluster-1 and distant-tail data from the two-probe ARTEMIS mission, we show that the simultaneo...

  17. Noninvasive Intracranial Pressure and Tissue Oxygen Measurements for Space and Earth

    Science.gov (United States)

    Hargens, A. R.; Ballard, R. E.; Murthy, G.; Watenpaugh, D. E.

    1994-01-01

    The paper discusses the following: Increasing intracranial pressure in humans during simulated microgravity. and near-infrared monitoring of model chronic compartment syndrome in exercising skeletal muscle. Compared to upright-seated posture, 0 deg. supine, 6 deg. HDT, and 15 deg. HDT produced TMD changes of 317 +/- 112, 403 +/- 114, and 474 +/- 112 n1 (means +/- S.E.), respectively. Furthermore, postural transitions from 0 deg. supine to 6 deg. HDT and from 6 deg. to 15 deg. HDT generated significant TMD changes (p less than 0.05). There was no hysteresis when postural transitions to HDT were compared to reciprocal transitions toward upright seated posture. Currently, diagnosis of chronic compartment syndrome (CCS) depends on measurement of intramuscular pressure by invasive catheterization. We hypothesized that this syndrome can be detected noninvasively by near-infrared (NIR) spectroscopy, which tracks variations in muscle hemoglobin/myoglobin oxygen saturation. CCS was simulated in the tibialis anterior muscle of 7 male and 3 female subjects by gradual inflation of a cuff placed around the leg to 40 mmHg during 14 minutes of cyclic isokinetic dorsiflexion exercise. On a separate day, subjects underwent the identical exercise protocol with no external compression. In both cases, tissue oxygenation (T(sub O2) was measured in the tibialis anterior by NIR spectroscopy and normalized to a percentage scale between baseline and a T(sub O2) nadir reached during exercise to ischemic exhaustion. Over the course of exercise, T(sub O2) declined at a rate of 1.4 +/- 0.3% per minute with model CCS, yet did not decrease during control exercise. Post-exercise recovery of T(sub O2) was slower with model CCS (2.5 +/- 0.6 min) than in control (1.3 +/- 0.2 min). These results demonstrate that NIR spectroscopy can detect muscle deoxygenation caused by pathologically elevated intramuscular pressure in exercising skeletal muscle. Consequently, this technique shows promise as a noninvasive diagnostic tool for CCS.

  18. Experimental study on thermal-hydraulic behaviors of a pressure balanced coolant injection system for a passive safety light water reactor JPSR

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Takashi; Watanabe, Hironori; Araya, Fumimasa; Nakajima, Katsutoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Iwamura, Takamichi; Murao, Yoshio

    1998-02-01

    A conceptual design study of a passive safety light water reactor JPSR has been performed at Japan Atomic Energy Research Institute JAERI. A pressure balanced coolant injection experiment has been carried out, with an objective to understand thermal-hydraulic characteristics of a passive coolant injection system which has been considered to be adopted to JPSR. This report summarizes experimental results and data recorded in experiment run performed in FY. 1993 and 1994. Preliminary experiments previously performed are also briefly described. As the results of the experiment, it was found that an initiation of coolant injection was delayed with increase in a subcooling in the pressure balance line. By inserting a separation device which divides the inside of core make-up tank (CMT) into several small compartments, a diffusion of a high temperature region formed just under the water surface was restrained and then a steam condensation was suppressed. A time interval from an uncovery of the pressure balance line to the initiation of the coolant injection was not related by a linear function with a discharge flow rate simulating a loss-of-coolant accident (LOCA) condition. The coolant was injected intermittently by actuation of a trial fabricated passive valve actuated by pressure difference for the present experiment. It was also found that the trial passive valve had difficulties in setting an actuation set point and vibrations noises and some fraction of the coolant was remained in CMT without effective use. A modification was proposed for resolving these problems by introducing an anti-closing mechanism. (author)

  19. Study of the earth's deep interior and crystallography. X-ray and neutron diffraction experiments under high pressures

    International Nuclear Information System (INIS)

    History of the study of the Earth's deep interior was reviewed. In order to understand Earth's deep interior from the view point of materials science, X-ray diffraction under high pressure and high temperature played very important role. Use of synchrotron radiation dramatically advanced this experimental technique and it is now possible to make precise X-ray study under the P-T conditions corresponding even to the center of the Earth. In order to clarify the behavior of light elements such as hydrogen, however, studies using neutron diffraction are also required. A new neutron beam line dedicated for high-pressure science is constructed at J-PARC and is now ready for use. (author)

  20. Estudio experimental del empuje sobre estructuras de contencin en suelos reforzados con geomallas / Experimental study of the lateral earth pressure on retaining structures in soils reinforced with geogrids

    Scientific Electronic Library Online (English)

    Lissette, Ruiz-Tagle; Felipe, Villalobos.

    2011-12-01

    Full Text Available Este artculo presenta un estudio experimental de la variacin de las tensiones de empuje sobre una pared que soporta un suelo reforzado con geomallas. Para ello se utiliz un equipo diseado y construido especialmente para ejecutar ensayos de empuje bajo condiciones de deformacin plana. Se describ [...] e el equipo de ensayo y los instrumentos de medicin, as como el suelo y la preparacin de las muestras de arena y la geomalla utilizada. En la primera etapa de la investigacin se ensayan muestras sin reforzar y se comparan los resultados con aquellos provenientes de las teoras clsicas de empuje. Posteriormente se presentan los resultados de ensayos de empuje en suelo reforzado con una, dos, tres y cuatro geomallas. Se concluye que la incorporacin de geomallas como refuerzo en el suelo disminuye el empuje ejercido por el suelo sobre la estructura de contencin. Esta disminucin del empuje es de aproximadamente un 25% cuando se usa una geomalla, un 50% con dos o tres geomallas y de un 75% con cuatro geomallas para los espaciamientos, sobrecargas e incremento de desplazamientos usados. Result posible identificar que la distribucin de la tensin de empuje con la profundidad no slo no sigue la variacin triangular sino que se desarrollan arcos de tensiones en el suelo entre las geomallas. Abstract in english This article presents an experimental study on the variation with depth of the stresses due to lateral earth pressure on a wall retaining a soil reinforced with geogrids. To this end, an apparatus was designed and constructed especially tailored for performing lateral earth pressure tests under plai [...] n strain conditions. The experimental apparatus and the measurement instruments as well as the soil and the sample preparation and the geogrids used, are described. In a first stage of research, samples without reinforcing are tested and the results are compared with those from classic earth pressure theories. Subsequently, results from lateral earth pressure tests in soils reinforced with one, two, three and four geogrids are presented. It is concluded that the inclusion of geogrids as soil reinforcement reduces the earth pressure on the retaining structure. This lateral earth pressure reduction is approximately of 25% when one geogrid is used, 50% with two or three geogrids and 75% with four geogrids for the spacing, surcharges and displacement increments used. It was possible to identify that the lateral earth pressure distribution with depth not only does not follow a triangular variation, but it develops stress arching in the soil and between the geogrids.

  1. Effects of supplementing rare earth element cerium on rumen fermentation, nutrient digestibility, nitrogen balance and plasma biochemical parameters in beef cattle.

    Science.gov (United States)

    Lin, S X; Wei, C; Zhao, G Y; Zhang, T T; Yang, K

    2015-12-01

    The objectives of the trial were to investigate the effects of supplementing rare earth element (REE) cerium (Ce) on rumen fermentation, nutrient digestibility, methane (CH4 ) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged at 14months, with initial liveweight of 3558kg and fitted with permanent rumen cannulas, were used as experimental animals. The cattle were fed with a total mixed ration (TMR) composed of concentrate mixture and corn silage. Four levels of cerium chloride (CeCl3 7H2 O, purity 99.9%), that is 0, 80, 160 and 240mg CeCl3 /kg DM, were added to basal ration in a 4נ4 Latin square design. Each experimental period lasted 15days, of which the first 12days were for pre-treatment and the last 3days were for sampling. The results showed that supplementing CeCl3 at 160 or 240mg/kg DM increased neutral detergent fibre (NDF) digestibility (p<0.05) and tended to increased acid detergent fibre (ADF) digestibility (p=0.083). Supplementing CeCl3 at 80, 160 or 240mg/kg DM decreased the molar ratio of rumen acetate to propionate linearly (p<0.05). Supplementing CeCl3 at 160 or 240mg/kg DM decreased total N excretion, urinary N excretion and increased N retention (p<0.05), increased excretion of total urinary purine derivatives (PD) (p<0.05) and decreased CH4 /kg DMI (p<0.05). In conclusion, supplementing CeCl3 at 160 or 240mg/kg DM in the ration of beef cattle increased the digestibility of NDF, decreased the molar ratio of rumen acetate to propionate, increased N retention and microbial N flow and decreased CH4 /kg DMI. PMID:25787979

  2. X-ray Raman scattering study of MgSiO3 glass at high pressure: implication for triclustered MgSiO3 melt in Earth's mantle.

    Science.gov (United States)

    Lee, Sung Keun; Lin, Jung-Fu; Cai, Yong Q; Hiraoka, Nozomu; Eng, Peter J; Okuchi, Takuo; Mao, Ho-Kwang; Meng, Yue; Hu, Michael Y; Chow, Paul; Shu, Jinfu; Li, Baosheng; Fukui, Hiroshi; Lee, Bum Han; Kim, Hyun Na; Yoo, Choong-Shik

    2008-06-10

    Silicate melts at the top of the transition zone and the core-mantle boundary have significant influences on the dynamics and properties of Earth's interior. MgSiO3-rich silicate melts were among the primary components of the magma ocean and thus played essential roles in the chemical differentiation of the early Earth. Diverse macroscopic properties of silicate melts in Earth's interior, such as density, viscosity, and crystal-melt partitioning, depend on their electronic and short-range local structures at high pressures and temperatures. Despite essential roles of silicate melts in many geophysical and geodynamic problems, little is known about their nature under the conditions of Earth's interior, including the densification mechanisms and the atomistic origins of the macroscopic properties at high pressures. Here, we have probed local electronic structures of MgSiO3 glass (as a precursor to Mg-silicate melts), using high-pressure x-ray Raman spectroscopy up to 39 GPa, in which high-pressure oxygen K-edge features suggest the formation of tricluster oxygens (oxygen coordinated with three Si frameworks; 3O) between 12 and 20 GPa. Our results indicate that the densification in MgSiO3 melt is thus likely to be accompanied with the formation of triculster, in addition to a reduction in nonbridging oxygens. The pressure-induced increase in the fraction of oxygen triclusters >20 GPa would result in enhanced density, viscosity, and crystal-melt partitioning, and reduced element diffusivity in the MgSiO3 melt toward deeper part of the Earth's lower mantle. PMID:18535140

  3. 3-D Force-balanced Magnetospheric Configurations

    Energy Technology Data Exchange (ETDEWEB)

    Sorin Zaharia; C.Z. Cheng; K. Maezawa

    2003-02-10

    The knowledge of plasma pressure is essential for many physics applications in the magnetosphere, such as computing magnetospheric currents and deriving magnetosphere-ionosphere coupling. A thorough knowledge of the 3-D pressure distribution has however eluded the community, as most in-situ pressure observations are either in the ionosphere or the equatorial region of the magnetosphere. With the assumption of pressure isotropy there have been attempts to obtain the pressure at different locations by either (a) mapping observed data (e.g., in the ionosphere) along the field lines of an empirical magnetospheric field model or (b) computing a pressure profile in the equatorial plane (in 2-D) or along the Sun-Earth axis (in 1-D) that is in force balance with the magnetic stresses of an empirical model. However, the pressure distributions obtained through these methods are not in force balance with the empirical magnetic field at all locations. In order to find a global 3-D plasma pressure distribution in force balance with the magnetospheric magnetic field, we have developed the MAG-3D code, that solves the 3-D force balance equation J x B = (upside-down delta) P computationally. Our calculation is performed in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials as B = (upside-down delta) psi x (upside-down delta) alpha. The pressure distribution, P = P(psi,alpha), is prescribed in the equatorial plane and is based on satellite measurements. In addition, computational boundary conditions for y surfaces are imposed using empirical field models. Our results provide 3-D distributions of magnetic field and plasma pressure as well as parallel and transverse currents for both quiet-time and disturbed magnetospheric conditions.

  4. High-pressure rare earth silicates: Lanthanum silicate with barium phosphate structure, holmium silicate apatite, and lutetium disilicate type X

    International Nuclear Information System (INIS)

    The phase relations of a wide selection of rare earth disilicates have been investigated up to 10 GPa and 1700 deg. C using piston cylinder and multi-anvil equipment. Single-crystal X-ray structures have been obtained for the following high-pressure phases: (1) La2.67(SiO4)2: monoclinic, space group C2/m, Z=2, a=9.419(2), b=5.445(1), c=7.214(1) A, ?=115.71(3)o, R=0.042; disordered Ba3(PO4)2 structure type, with 3xb and 7xb superstructures identified. (2) Ho8.67(SiO4)6(OH)2: hexagonal, P63/m, Z=1, a=9.3221(4), c=6.7347(2) A, R=0.026; silicate hydroxyapatite. (3) Lu2Si2O7: tetragonal, P41212, Z=4, a=6.5620(2), c=11.9535(4) A, R=0.023; type X diorthosilicate structure, and the silicate analogue of tetragonal Er2Ge2O7

  5. Defect and intra-4f luminescence of rare earth doped group-III nitrides synthesized by high pressure high temperature method

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Sven; Vetter, Ulrich; Hofsaess, Hans [Georg-August-Universitaet Goettingen (Germany). II. Physikalisches Institut; Taniguchi, Takashi [National Institute for Materials Science, Namiki, Tsukuba, Ibaraki (Japan)

    2010-07-01

    Cubic boron nitride (c-BN) and AlN exhibit the largest band gaps among all group-III nitrides with 6.2 and 6.0 eV, respectively. Both materials posses the ability for optoelectonic building blocks which can operate at high temperatures, high power, high frequencies and under extreme chemical conditions. The intensive and narrow intra-4f luminescence of rare earth doped c-BN and AlN crystals could be employed for laser diodes or in optical communication technology. Rare earth doped c-BN and AlN crystals were synthesized via the high temperature high pressure method, with temperatures and pressures between 1450-1620 C and 4.5-6.3 GPa, respectively. Ba{sub 3}B{sub 2}N{sub 4} and Li{sub 3}AlN{sub 2} were used as solvents with addition of rare earth fluorides as source material for the synthesis of c-BN and AlN, respectively. The luminescence of rare earth doped c-BN and AlN is a superposition of different defect transitions of the host material and intra-4f transitions of the rare earth dopant ion. Intrinsic defects as well as impurity defect complexes serve as origin for various defect bands in c-BN and AlN.

  6. Postural balance in low back pain patients : Intra-session reliability of center of pressure on a portable force platform and of the one leg stand test

    DEFF Research Database (Denmark)

    Maribo, Thomas; Stengaard-Pedersen, Kristian

    2011-01-01

    Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (CoP) on a force platform. Portable force platforms might be of clinical relevance, but their reliability for LBP patients in a clinical setting has not been demonstrated. As LBP patients are more dependent on vision compared to healthy controls, the ratio of tests performed with eyes open and eyes closed (Romberg Ratio) might be of clinical interest. This study aimed to assess postural balance in LBP patients by analyzing intra-session reliability of CoP parameters on a portable force platform, the Romberg Ratio, and the OLST. Furthermore, we aimed to determine whether CoP parameters and OLST measure identical aspects of postural stability. We examined 49 LBP patients and found acceptable reliability of the CoP parameters' trace length and velocity, whereas reliability regarding C90 area, the Romberg Ratio, and the OLST was poor. Correlations between the CoP parameters and OLST were insignificant. Reliability of trace length and velocity is acceptable and can be used as parameters when assessing CoP in LBP patients.

  7. Effect of Horizontal Drain Length and Cutoff Wall on Seepage and Uplift Pressure in Heterogeneous Earth Dam with Numerical Simulation

    OpenAIRE

    Farzin Salmasi; Behnam Mansuri

    2013-01-01

    Design of earth dams and their problems are important during construction and after it,because of their potential hazards and failure for downstream population. This study focus on theeffectiveness of using horizontal drain and cutoff wall in reducing seepage flow from an assumedheterogeneous earth dam. For this purpose various horizontal drain lengths and cutoff wall depth examineunder the earth dam in different location of foundation. Seepage analysis, hydraulic gradient and upliftpressure,...

  8. Anomalous pressure dependences of the superconducting transition temperature of dilute alloys of LaSn3 containing light rare earth impurities

    International Nuclear Information System (INIS)

    The initial depressions of the superconducting transition temperature T/sub c/ of LaSn3 by rare earth (RE) impurities are known to be anomalous. In an attempt to clarify this behavior, we have measured the pressure dependence of the T/sub c/ of (LaRE)Sn3 alloys (RE3 alloys containing RE impurities with partially filled 4f electron shells decreases monotonically with increasing RE atomic number. A general discussion of existing zero- and high-pressure data for various physical properties of (LaRE)Sn3 alloys demonstrates that the association of large pressure dependences of T/sub c/ with the occurrence of unstable impurity 4f shells (the Kondo effect) should be made with caution. The experimental high-pressure results are analyzed in terms of appropriate theoretical models for magnetic and nonmagnetic localized impurity states in superconductors

  9. Separation of rare earth, nuclear-fuel burn-up monitors in the 10-9 mole range by high-pressure liquid chromatography with UV-detection

    International Nuclear Information System (INIS)

    Anion-exchange chromatography of the rare earth (Sm, Nd, Pr, Ce) ions in methanol-nitric acid-water media is performed using high-pressure liquid chromatography. The separation method is especially designed for determination of 148Nd in nuclear fuel cycle in order to find precise burn-up values. While commonly used for rare earth separation at low pressure and hence low flow rate, this separation system has not been described using HPLC. The samples injected on the column contain typically 10 nmole of the nitrates of Sm, Nd, Pr and Ce. Furthermore, some experiments with a large excess of uranyl nitrate were carried out in order to simulate the conditions in solutions of irradiated nuclear fuel. After equilibration of the column to the desired elution composition, 20-25x?l of sample was injected. The sample concentration was typically 4x10-4 M for the ions of Sm, Pr, Nd and Ce. In the separations with added uranyl nitrate, the uranium concentrations were varied 1-125 times the concentrations of the individual rare earths. By adjusting the pressure between 300 and 600 psi, the flow rate was kept in the range 0.5-1.0 cm3/min. As no changes in the separation were observed as a result of this variation, 1.0 cm3/min was used throughout. The high-pressure liquid chromatography method presented here is very fast, gives high resolutions, and enables collection of selected fractions containing nmoles of rare earth by UV monitoring at 280 nm of the eluate. (T.G.)

  10. Shp2 signaling in POMC neurons is important for leptin's actions on blood pressure, energy balance, and glucose regulation

    OpenAIRE

    do Carmo, Jussara M; da Silva, Alexandre A.; Ebaady, Sabira E.; Sessums, Price O.; Abraham, Ralph S.; Elmquist, Joel K.; Lowell, Bradford B; Hall, John E

    2014-01-01

    Previous studies showed that Src homology-2 tyrosine phosphatase (Shp2) is an important regulator of body weight. In this study, we examined the impact of Shp2 deficiency specifically in proopiomelanocortin (POMC) neurons on metabolic and cardiovascular function and on chronic blood pressure (BP) and metabolic responses to leptin. Mice with Shp2 deleted in POMC neurons (Shp2/Pomc-cre) and control mice (Shp2flox/flox) were implanted with telemetry probes and venous catheters for measurement of...

  11. Immobilization-induced increases of systolic blood pressure and dysregulation of electrolyte balance in ethanol-treated rats.

    Science.gov (United States)

    Yasmin, Farzana; Haque, Zeba; Ikram, Huma; Haleem, Darakhshan Jabeen

    2015-07-01

    Clinical and experimental studies revealed that alcohol drinking and life event stresses are predisposing factors to hypertension. Intra and extra cellular levels of electrolytes may play important role in the pathogenesis and treatment of hypertension. Dietary intake of sodium, potassium, calcium and magnesium is suggested to have a role in the regulation of blood pressure. The present study was designed to monitor the effects of acute exposure to 2h immobilization stress and ethanol administration at a dose of 2.5g/kg body weight (i.p.) and combined effect of acute administration of ethanol and immobilization stress on systolic blood pressure (SBP), intraerythrocyte, serum and tissue electrolytes in rats. Results showed that acute exposure to 2h immobilization increased SBP, intraerythrocyte sodium and decreased intraerythrocyte potassium in water as well as in ethanol injected rats. The concentration of Na(+) and Ca(2+) increased while that of K(+) and Mg(2+) decreased in the heart and kidney tissue. Ethanol administration also increased Na(+) and Ca(2+)levelsand decreased K(+) and Mg(2+) levels in the heart and kidney tissue. Restraint stress decreased serum levels of Na(+), K(+), Ca(2+), P, and Cl(-) and increased serum Mg(2+), glucose and haematocrit. Ethanol administration also decreased serum levels of Na(+), K(+), Ca(2+), P, and Cl(-) and increased serum Mg(2+), glucose and haematocrit. The effects of ethanol and stress on the changes of blood and tissues electrolytes were additive and may be involved in the greater occurrence of hypertension in alcoholics. Our results suggested an important role of intra and extra cellular electrolytes in both stress and ethanol-induced hypertension. The findings may help to develop strategies for the treatment of hypertension in alcoholics. PMID:26142527

  12. Isolation of the oceanic response to atmospheric pressure forcing in satellite altimetry data using Wiener filtering, and its effects on Earth's rotation

    Science.gov (United States)

    Dey, N.; Dickman, S. R.

    2013-12-01

    The oceanic response to atmospheric pressure forcing is a dynamic one that depends on the frequency and spatial scale of the forcing (Dey & Dickman 2010 J. Geophys. Res.). In this work, the oceanic response is derived from TOPEX satellite altimeter observations (1993 - 2004) on a 4 latitude 8 longitude grid, corrected for the effects that tides, winds and an annual signal have on the sea-surface height (SSH). The wind correction values are from the ECCO model and were obtained from JPL. The wind correction has been modified by a Darwin correction term to insure ocean-wide mass conservation. For the annual signal, a sinusoid of annual period and the trend over 12 years have been removed at each grid location. Pressure data was downloaded from AER in spherical harmonic form. For each harmonic of forcing, a Wiener filter is used to isolate that portion of the SSH within each gridbox location due to pressure forcing. Wiener filters are designed (Robinson 1967 Multichannel Time Series Analysis) so that the input to the filter produces an 'actual output' which is as close as possible to a specified 'desired output'. The input to the Wiener filter in this work is the corrected SSH time series at each location, and the desired output is the pressure harmonic time series. Based on the reduction in the difference between desired and actual output, achieved by adjusting the filter properties, this technique appears to be successful in isolating that portion of SSH due to individual spherical harmonic pressure coefficients. The pressure-driven portion of the SSH within various frequency bands will be used to calculate the associated oceanic currents, and then the effects of the total response on Earth's rotation. Those effects will be compared with Earth rotation observations and results from other analyses.

  13. Earth materials and earth dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, K; Shankland, T. [and others

    2000-11-01

    In the project ''Earth Materials and Earth Dynamics'' we linked fundamental and exploratory, experimental, theoretical, and computational research programs to shed light on the current and past states of the dynamic Earth. Our objective was to combine different geological, geochemical, geophysical, and materials science analyses with numerical techniques to illuminate active processes in the Earth. These processes include fluid-rock interactions that form and modify the lithosphere, non-linear wave attenuations in rocks that drive plate tectonics and perturb the earth's surface, dynamic recrystallization of olivine that deforms the upper mantle, development of texture in high-pressure olivine polymorphs that create anisotropic velocity regions in the convecting upper mantle and transition zone, and the intense chemical reactions between the mantle and core. We measured physical properties such as texture and nonlinear elasticity, equation of states at simultaneous pressures and temperatures, magnetic spins and bonding, chemical permeability, and thermal-chemical feedback to better characterize earth materials. We artificially generated seismic waves, numerically modeled fluid flow and transport in rock systems and modified polycrystal plasticity theory to interpret measured physical properties and integrate them into our understanding of the Earth. This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  14. Experimental and Numerical Study of the Effect of PET Recycling Admixtures on Pore Water Pressure and Output Discharge in Homogeneous Earth Dams.

    Directory of Open Access Journals (Sweden)

    Reza Ahmad Zadeh Touri

    2015-01-01

    Full Text Available This study analytically and experimentally investigates the leakage in homogenous earth dam (clay reinforced by recycled PET. First, the effect of PET addition on permeability of clay in geotechnical laboratory is evaluated, according to the results of first step, a physical model of homogenous earth dam is prepared in laboratory flume, both in PETs or without PETs and measured the water height in dam body using piezometers installed on flume body and also leakage discharge was calculated. Third, phreatic line formed in the body of dam and the pore pressure of it was analyzed regarding the first and second phases. The impact of output discharge reduction on dam stability was also studied in software; PET addition impact on output discharge reduction was 23.14%. Discharge reduction lead to increase of dam stability.

  15. Effect of Horizontal Drain Length and Cutoff Wall on Seepage and Uplift Pressure in Heterogeneous Earth Dam with Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Farzin Salmasi

    2013-05-01

    Full Text Available Design of earth dams and their problems are important during construction and after it,because of their potential hazards and failure for downstream population. This study focus on theeffectiveness of using horizontal drain and cutoff wall in reducing seepage flow from an assumedheterogeneous earth dam. For this purpose various horizontal drain lengths and cutoff wall depth examineunder the earth dam in different location of foundation. Seepage analysis, hydraulic gradient and upliftpressure, are computing by numerical simulation, using Seep/w software. Results show that increasinghorizontal drain length, cause slightly in increasing seepage rate and increasing hydraulic gradient.Optimum location of cut off wall for reduction of seepage rate and piping is in the middle of damfoundation. By increasing in cut off wall depth, seepage from earth dam and its foundation is reducing.Different location of cut off wall in dam foundation has little effect on exit hydraulic gradient and always itis less than unity. Installation of cut off wall in middle of foundation, results 19.68 percent decreasing inhydraulic gradient respect to existent of cut off wall in upstream of dam.

  16. SPES-2, AP600 intergral system test S01007 2 inch CL to core make-up tank pressure balance line break

    Energy Technology Data Exchange (ETDEWEB)

    Bacchiani, M.; Medich, C.; Rigamonti, M. [SIET S.p.A. Piacenza (Italy)] [and others

    1995-09-01

    The SPES-2 is a full height, full pressure experimental test facility reproducing the Westinghouse AP600 reactor with a scaling factor of 1/395. The experimental plant, designed and operated by SIET in Piacenza, consists of a full simulation of the AP600 primary core cooling system including all the passive and active safety systems. In 1992, Westinghouse, in cooperation with ENEL (Ente Nazionale per l` Energia Elettrica), ENEA (Enter per le numove Technlogie, l` Energia e l` Ambient), Siet (Societa Informazioni Esperienze Termoidraulich) and ANSALDO developed an experimental program to test the integrated behaviour of the AP600 passive safety systems. The SPES-2 test matrix, concluded in November 1994, has examined the AP600 passive safety system response for a range of small break LOCAs at different locations on the primary system and on the passive system lines; single steam generator tube ruptures with passive and active safety systems and a main steam line break transient to demonstrate the boration capability of passive safety systems for rapid cooldown. Each of the tests has provided detailed experimental results for verification of the capability of the analysis methods to predict the integrated passive safety system behaviour. Cold and hot shakedown tests have been performed on the facility to check the characteristics of the plant before starting the experimental campaign. The paper first presents a description of the SPES-2 test facility then the main results of S01007 test {open_quotes}2{close_quotes} Cold Leg (CL) to Core Make-up Tank (CMT) pressure balance line break{close_quotes} are reported and compared with predictions performed using RELAP5/mod3/80 obtained by ANSALDO through agreement with U.S.N.R.C. (U.S. Nuclear Regulatory Commission). The SPES-2 nodalization and all the calculations here presented were performed by ANSALDO and sponsored by ENEL as a part of pre-test predictions for SPES-2.

  17. Postural balance in low back pain patients : criterion-related validity of centre of pressure assessed on a portable force platform

    DEFF Research Database (Denmark)

    Maribo, Thomas; Schittz-Christensen, Berit

    2012-01-01

    INTRODUCTION: Altered postural control has been observed in low back pain (LBP) patients. They seem to be more dependent on vision when standing. The objective of the study was to determine concurrent and predictive validity of measures of postural stability in LBP patients. MATERIALS AND METHODS: Centre of Pressure (CoP) measurements were tested against pain, fear of pain, and physical function. Velocity, anterior-posterior displacement, and the Romberg Ratio obtained on a portable force platform were used as measures of postural stability. RESULTS: Baseline and 12-week follow-up results of 97 LBP patients were evaluated. The correlations between CoP measurements and pain, fear of pain, and physical function were poor. There were no significant differences in CoP measurements between patients with no change or deterioration and patients with improvement in pain and back-specific function. CONCLUSION: This first study of concurrent and predictive validity of postural balance in LBP patients revealed no association between CoP measures and pain, fear of pain, and physical function.

  18. Quantifying the role of fire in the Earth system - Part 2: Impact on the net carbon balance of global terrestrial ecosystems for the 20th century

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fang; Bond-Lamberty, Benjamin; Levis, Samuel

    2014-03-07

    Fire is the primary terrestrial ecosystem disturbance agent on a global scale. It affects carbon balance of global terrestrial ecosystems by emitting carbon to atmosphere directly and immediately from biomass burning (i.e., fire direct effect), and by changing net ecosystem productivity and land-use carbon loss in post-fire regions due to biomass burning and fire-induced vegetation mortality (i.e., fire indirect effect). Here, we provide the first quantitative assessment about the impact of fire on the net carbon balance of global terrestrial ecosystems for the 20th century, and investigate the roles of fire direct and indirect effects. This study is done by quantifying the difference between the 20th century fire-on and fire-off simulations with NCAR community land model CLM4.5 as the model platform. Results show that fire decreases net carbon gain of the global terrestrial ecosystems by 1.0 Pg C yr-1 average across the 20th century, as a results of fire direct effect (1.9 Pg C yr-1) partly offset by indirect effect (-0.9 Pg C yr-1). Fire generally decreases the average carbon gains of terrestrial ecosystems in post-fire regions, which are significant over tropical savannas and part of forests in North America and the east of Asia. The general decrease of carbon gains in post-fire regions is because fire direct and indirect effects have similar spatial patterns and the former (to decrease carbon gain) is generally stronger. Moreover, the effect of fire on net carbon balance significantly declines prior to ~1970 with trend of 8 Tg C yr-1 due to increasing fire indirect effect and increases afterward with trend of 18 Tg C yr-1 due to increasing fire direct effect.

  19. Quantifying the role of fire in the Earth system - Part 2: Impact on the net carbon balance of global terrestrial ecosystems for the 20th century

    Science.gov (United States)

    Li, F.; Bond-Lamberty, B.; Levis, S.

    2014-03-01

    Fire is the primary form of terrestrial ecosystem disturbance on a global scale. It affects the net carbon balance of terrestrial ecosystems by emitting carbon directly and immediately into the atmosphere from biomass burning (the fire direct effect), and by changing net ecosystem productivity and land-use carbon loss in post-fire regions due to biomass burning and fire-induced vegetation mortality (the fire indirect effect). Here, we provide the first quantitative assessment of the impact of fire on the net carbon balance of global terrestrial ecosystems during the 20th century, and investigate the roles of fire's direct and indirect effects. This is done by quantifying the difference between the 20th century fire-on and fire-off simulations with the NCAR Community Land Model CLM4.5 (prescribed vegetation cover and uncoupled from the atmospheric model) as a model platform. Results show that fire decreases the net carbon gain of global terrestrial ecosystems by 1.0 Pg C yr-1 averaged across the 20th century, as a result of the fire direct effect (1.9 Pg C yr-1) partly offset by the indirect effect (-0.9 Pg C yr-1). Post-fire regions generally experience decreased carbon gains, which is significant over tropical savannas and some North American and East Asian forests. This decrease is due to the direct effect usually exceeding the indirect effect, while they have similar spatial patterns and opposite sign. The effect of fire on the net carbon balance significantly declines until ?1970 with a trend of 8 Tg C yr-1 due to an increasing indirect effect, and increases subsequently with a trend of 18 Tg C yr-1 due to an increasing direct effect. These results help constrain the global-scale dynamics of fire and the terrestrial carbon cycle.

  20. 3-D force-balanced magnetospheric configurations

    Directory of Open Access Journals (Sweden)

    S. Zaharia

    2004-01-01

    Full Text Available The knowledge of plasma pressure is essential for many physics applications in the magnetosphere, such as computing magnetospheric currents and deriving mag-netosphere-ionosphere coupling. A thorough knowledge of the 3-D pressure distribution has, however, eluded the community, as most in situ pressure observations are either in the ionosphere or the equatorial region of the magnetosphere. With the assumption of pressure isotropy there have been attempts to obtain the pressure at different locations,by either (a mapping observed data (e.g. in the ionosphere along the field lines of an empirical magnetospheric field model, or (b computing a pressure profile in the equatorial plane (in 2-D or along the Sun-Earth axis (in 1-D that is in force balance with the magnetic stresses of an empirical model. However, the pressure distributions obtained through these methods are not in force balance with the empirical magnetic field at all locations. In order to find a global 3-D plasma pressure distribution in force balance with the magnetospheric magnetic field, we have developed the MAG-3-D code that solves the 3-D force balance equation ${vec J} times {vec B} = nabla P$ computationally. Our calculation is performed in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials as ${vec B} = nabla psi times nabla alpha$. The pressure distribution, $P = P(psi, alpha$, is prescribed in the equatorial plane and is based on satellite measurements. In addition, computational boundary conditions for ? surfaces are imposed using empirical field models. Our results provide 3-D distributions of magnetic field, plasma pressure, as well as parallel and transverse currents for both quiet-time and disturbed magnetospheric conditions.

    Key words. Magnetospheric physics (magnetospheric configuration and dynamics; magnetotail; plasma sheet

  1. Structural, electronic, elastic and high-pressure properties of some alkaline-earth chalcogenides: An ab initio study

    International Nuclear Information System (INIS)

    The full-potential linearized augmented plane wave method (FP-LAPW) within the generalized gradient approximation (GGA) is used to calculate the electronic band structures and the total energies of BaS, CaSe and CaTe in NaCl and CsCl-type structures. The latter provide us with the ground states properties such as lattice parameter, bulk modulus and its pressure derivative, elastic constants and the structural phase stability of these compounds. The transition pressures at which these compounds undergo the structural phase transition from NaCl to CsCl phase are calculated. The energy band gaps and their volume dependence in NaCl and CsCl type-structures are investigated. The pressure and the volume at which band overlap metallization occurs are also determined. The ground state properties, the transition and metallization pressures (volumes) are found to agree with the experimental and other theoretical results. The elastic constants at equilibrium in both NaCl and CsCl structures are calculated and compared with the available theoretical results for CaSe, while for BaS and CaTe the elastic constants are not available

  2. Anlise da presso plantar e do equilbrio postural em diferentes fases da gestao / Analysis of plantar pressure and postural balance during different phases of pregnancy

    Scientific Electronic Library Online (English)

    SI, Ribas; ECO, Guirro.

    2007-10-01

    Full Text Available OBJETIVO: Analisar a presso plantar e o equilbrio postural nos trs trimestres de gravidez, bem como a correlao com as caractersticas antropomtricas. METODOLOGIA: 60 voluntrias com idade mdia de 23,3 5,5 anos, sendo 15 mulheres em cada grupo: no-gestantes (C), primeiro (1T), segundo (2T) [...] e terceiro trimestre (3T). A avaliao foi efetuada por meio de plataforma de presso na posio bipodal com os olhos abertos. As variveis analisadas nos ps direito e esquerdo foram: pico de presso em todo o p (PT), no antep (PA) e no retrop (PR); distncia entre a borda medial dos ps (largura da base de suporte); distncia do centro de fora ao limite anterior (CFF) e posterior (CFC) dos ps; deslocamento ntero-posterior (AP) e mdio--lateral (ML) do centro de fora; e rea de contato (AC). RESULTADOS: No houve diferena no pico de presso de contato e na distncia CFF e CFC entre os grupos. O deslocamento AP foi maior (p 0,05) entre os grupos para o deslocamento ML. Houve correlao positiva entre peso ganho durante a gestao com AC para o grupo 2T e com PT no p direito do grupo 1T. CONCLUSO: Os resultados demonstram a influncia das mudanas anatmicas e fisiolgicas inerentes gestao na presso plantar, alm de sugerir uma reduo do equilbrio postural no 3T, relacionada ao maior deslocamento AP nessa fase. Abstract in english OBJECTIVE: To analyze plantar pressure and postural balance during the three trimesters of pregnancy, and also to correlate these with anthropometric characteristics. METHOD: Sixty volunteers participated in this study, with a mean age of 23.3 5.5 years. There were 15 subjects in each group: non-p [...] regnant (C), first trimester (1T), second trimester (2T) and third trimester (3T). Evaluations were performed in bipedal stance with open eyes, using a pressure platform. The following variables were analyzed in the right and left feet: peak pressures in the whole foot (WFP), forefoot (FFP) and hindfoot (HFP); distance between the medial borders of the foot (width of support base); the distance from the center of force to the anterior (COF-A) and posterior (COF-P) limits of the foot; anteroposterior (AP) and mediolateral (ML) COF displacements; and the contact area (CA). RESULTS: There were no differences in peak contact pressures and COF-A and COF-P distances between the groups. The AP displacement was greater (p 0.05) between the groups regarding ML displacement. There was a positive correlation between weight gained during pregnancy and CA for the 2T group, and between weight gain and WFP in the right feet in the 1T group. CONCLUSION: The results demonstrate the influence of the anatomical and physiological changes inherent to pregnancy on plantar pressure. They also suggest that postural equilibrium decreases in the third trimester, associated with greater AP displacement during this phase.

  3. Anlise da presso plantar e do equilbrio postural em diferentes fases da gestao Analysis of plantar pressure and postural balance during different phases of pregnancy

    Directory of Open Access Journals (Sweden)

    SI Ribas

    2007-10-01

    Full Text Available OBJETIVO: Analisar a presso plantar e o equilbrio postural nos trs trimestres de gravidez, bem como a correlao com as caractersticas antropomtricas. METODOLOGIA: 60 voluntrias com idade mdia de 23,3 5,5 anos, sendo 15 mulheres em cada grupo: no-gestantes (C, primeiro (1T, segundo (2T e terceiro trimestre (3T. A avaliao foi efetuada por meio de plataforma de presso na posio bipodal com os olhos abertos. As variveis analisadas nos ps direito e esquerdo foram: pico de presso em todo o p (PT, no antep (PA e no retrop (PR; distncia entre a borda medial dos ps (largura da base de suporte; distncia do centro de fora ao limite anterior (CFF e posterior (CFC dos ps; deslocamento ntero-posterior (AP e mdio--lateral (ML do centro de fora; e rea de contato (AC. RESULTADOS: No houve diferena no pico de presso de contato e na distncia CFF e CFC entre os grupos. O deslocamento AP foi maior (p 0,05 entre os grupos para o deslocamento ML. Houve correlao positiva entre peso ganho durante a gestao com AC para o grupo 2T e com PT no p direito do grupo 1T. CONCLUSO: Os resultados demonstram a influncia das mudanas anatmicas e fisiolgicas inerentes gestao na presso plantar, alm de sugerir uma reduo do equilbrio postural no 3T, relacionada ao maior deslocamento AP nessa fase.OBJECTIVE: To analyze plantar pressure and postural balance during the three trimesters of pregnancy, and also to correlate these with anthropometric characteristics. METHOD: Sixty volunteers participated in this study, with a mean age of 23.3 5.5 years. There were 15 subjects in each group: non-pregnant (C, first trimester (1T, second trimester (2T and third trimester (3T. Evaluations were performed in bipedal stance with open eyes, using a pressure platform. The following variables were analyzed in the right and left feet: peak pressures in the whole foot (WFP, forefoot (FFP and hindfoot (HFP; distance between the medial borders of the foot (width of support base; the distance from the center of force to the anterior (COF-A and posterior (COF-P limits of the foot; anteroposterior (AP and mediolateral (ML COF displacements; and the contact area (CA. RESULTS: There were no differences in peak contact pressures and COF-A and COF-P distances between the groups. The AP displacement was greater (p 0.05 between the groups regarding ML displacement. There was a positive correlation between weight gained during pregnancy and CA for the 2T group, and between weight gain and WFP in the right feet in the 1T group. CONCLUSION: The results demonstrate the influence of the anatomical and physiological changes inherent to pregnancy on plantar pressure. They also suggest that postural equilibrium decreases in the third trimester, associated with greater AP displacement during this phase.

  4. Fault-related-folding structure and reflection seismic sections. Construction of earth model using balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 1. Balanced cross section wo mochiita chika model no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, T.; Tamagawa, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. The viscous matter flows and deforms for the formation of an anticline on the ramp. Such enables the reproduction of a fault-bend fold formation process, and helpful discussion may be furthered on the dynamic aspect of this simulation. 5 refs., 4 figs.

  5. Thermal conductivity of H2O-CH3OH mixtures at high pressures: Implications for the dynamics of icy super-Earths outer shells

    Science.gov (United States)

    Hsieh, Wen-Pin; Deschamps, Frdric

    2015-10-01

    Thermal conductivity of H2O-volatile mixtures at extreme pressure-temperature conditions is a key factor to determine the heat flux and profile of the interior temperature in icy bodies. We use time domain thermoreflectance and stimulated Brillouin scattering combined with diamond anvil cells to study the thermal conductivity and sound velocity of water (H2O)-methanol (CH3OH) mixtures to pressures as high as 12 GPa. Compared to pure H2O, the presence of 5-20 wt % CH3OH significantly reduces the thermal conductivity and sound velocity when the mixture becomes ice VI-CH3OH and ice VII-CH3OH phases at high pressures, indicating that the heat transfer is hindered within the icy body. We then apply these results to model the heat transfer through the icy mantles of super-Earths, assuming that these mantles are animated by thermal convection. Our calculations indicate that the decrease of thermal conductivity due to the presence of 10 wt % CH3OH induces a twofold decrease of the power transported by convection.

  6. The effect of compression on Individual Pressure Vessel Nickel/Hydrogen components. [for energy storage in low earth orbits

    Science.gov (United States)

    Manzo, Michelle A.; Perez-Davis, Marla E.

    1988-01-01

    Compression tests were performed on representative Individual Pressure Vessel (IPV) Nickel/Hydrogen cell components in an effort to better understand the effects of force on component compression and the interactions of components under compression. It appears that the separator is the most easily compressed of all of the stack components. It will typically partially compress before any of the other components begin to compress. The compression characteristics of the cell components in assembly differed considerably from what would be predicted based on individual compression characteristics. Component interactions played a significant role in the stack response to compression. The results of the compression tests were factored into the design and selection of Belleville washers added to the cell stack to accommodate nickel electrode expansion while keeping the pressure on the stack within a reasonable range of the original preset.

  7. Growth of Carnobacterium spp. from permafrost under low pressure, temperature, and anoxic atmosphere has implications for Earth microbes on Mars.

    Science.gov (United States)

    Nicholson, Wayne L; Krivushin, Kirill; Gilichinsky, David; Schuerger, Andrew C

    2013-01-01

    The ability of terrestrial microorganisms to grow in the near-surface environment of Mars is of importance to the search for life and protection of that planet from forward contamination by human and robotic exploration. Because most water on present-day Mars is frozen in the regolith, permafrosts are considered to be terrestrial analogs of the martian subsurface environment. Six bacterial isolates were obtained from a permafrost borehole in northeastern Siberia capable of growth under conditions of low temperature (0 C), low pressure (7 mbar), and a CO(2)-enriched anoxic atmosphere. By 16S ribosomal DNA analysis, all six permafrost isolates were identified as species of the genus Carnobacterium, most closely related to C. inhibens (five isolates) and C. viridans (one isolate). Quantitative growth assays demonstrated that the six permafrost isolates, as well as nine type species of Carnobacterium (C. alterfunditum, C. divergens, C. funditum, C. gallinarum, C. inhibens, C. maltaromaticum, C. mobile, C. pleistocenium, and C. viridans) were all capable of growth under cold, low-pressure, anoxic conditions, thus extending the low-pressure extreme at which life can function. PMID:23267097

  8. Effect of Intermittent Positive Pressure Ventilation (IPPV on Acid-Base Balance and Plasma Electrolytes during Isoflurane Anaesthesia in Sulphur-Crested Cockatoos (Cacatua galerita galerita

    Directory of Open Access Journals (Sweden)

    Saul Chemonges

    2012-12-01

    Full Text Available The objective of the study was to investigate the effect of Intermittent Positive Pressure Ventilation (IPPV on acid-base balance and plasma electrolytes during isoflurane anaesthesia in sulphur-crested cockatoos (Cacatua galerita galerita Anaesthesia was induced in six birds by mask using a T-piece with 3.0% isoflurane. Blood gases, plasma electrolytes, PCV and Total Protein (TP were monitored for one hour during Spontaneous Ventilation (SV and IPPV. IPPV was instituted by engaging the pop-off valve (IPPVa of the circle absorber or by squeezing the breathing bag (IPPVb. Results showed that during SV, pCO2, pO2, [HCO3-], BE, C+CO2 and PO4- increased significantly, while [Na+], [K+] and [Ca2+] did not change significantlyDuring IPPV, pCO2 and pO2 decreased, while C+CO2 CO2 increased during the initial 30 min. [HCO3-increased during IPPVa only in the first 30 min. BE increased only in the first 30 min of IPPV. There was a marginal increase and decrease in PO4- during SV and IPPV, respectively. [Na+], [K+] and [Ca2+] remained stable during both SV and IPPV. Subtle decreases were noted for [Cl-] TP and PCV during SV. It was concluded that mixed metabolic and respiratory acidosis occurs during SV in isoflurane-anaesthetised cockatoos. Metabolic acidosis that develops during isoflurane anaesthesia in spontaneously ventilating birds is reversible to some extent by IPPV, possibly through a mixed acidosis-alkalosis, respiratory alkalosis and a non-respiratory contribution to alkalosis mechanism. Reversal of Bohr Effect occurs during IPPV in isoflurane-anaesthetised cockatoos. Studies are indicated to understand the causes of decreased oxygen saturation in apparently alkalotic birds.

  9. Tunnel construction work under high earth pressure and springwater flouing condition. Construction details of a pioneer drift for Hida tunnel, Tokai-Hokuriku expressway

    International Nuclear Information System (INIS)

    Tunnels such as those planned for the International Linear Collider (ILC) Project are long and narrow structures under the ground. In the construction of these tunnels, various circumstances sometimes restrict the initial surveys from obtaining detailed geological information. In Japan, complicated geological structure composed of discontinuous plate tectonics can be found. Therefore, in order to ensure effective construction planning and execution, it is important that precise geological information be acquired through initial survey and then verified with investigation results during the construction. Hida Tunnel of Tokai Hokuriku Expressway, which is 10.7 km long and took more than 11 years to finish, is the second longest highway tunnel in Japan. The tunnel was constructed using the TBM method in the beginning. Later the method was replaced with NATM because of hostile construction conditions, which include existences of springwater and massive earth pressure due to more than 1000 m of earth loading on top, as well as weak zones consisted of active faults. This paper reports on the geological structure and construction details of a pioneer drift for Hida Tunnel, which was completed by overcoming complicated and poor geological conditions. At the same time, we will mention the ideal method of the geological survey in future ILC plan. (author)

  10. Indoor seismology by probing the Earth's interior by using sound velocity measurements at high pressures and temperatures

    International Nuclear Information System (INIS)

    The adiabatic bulk (K S) and shear (G) moduli of mantle materials at high pressure and temperature can be obtained directly by measuring compressional and shear wave velocities in the laboratory with experimental techniques based on physical acoustics. We present the application of the current state-of-the-art experimental techniques by using ultrasonic interferometry in conjunction with synchrotron x radiation to study the elasticity of olivine and pyroxenes and their high-pressure phases. By using these updated thermoelasticity data for these phases, velocity and density profiles for a pyrolite model are constructed and compared with radial seismic models. We conclude that pyrolite provides an adequate explanation of the major seismic discontinuities at 410- and 660-km depths, the gradient in the transition zone, as well as the velocities in the lower mantle, if the uncertainties in the modeling and the variations in different seismic models are considered. The characteristics of the seismic scaling factors in response to thermal anomalies suggest that anticorrelations between bulk sound and shear wave velocities, as well as the large positive density anomalies observed in the lower mantle, cannot be explained fully without invoking chemical variations

  11. Microstructual investigation of mixed rar earth iron boron processed vis melt-spinning and high-pressure gas-atomization for isotrophic bonded permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Buelow, Nicholas Lee

    2005-08-01

    A solid solution of three rare earths (RE) in the RE{sub 2}Fe{sub 14}B structure have been combined to create the novel mixed rare earth iron boron (MRE{sub 2}Fe{sub 14}B) alloy family. MRE{sub 2}Fe{sub 14}B exhibits reduced temperature dependent magnetic properties; remanence and coercivity. The desired form of MRE{sub 2}Fe{sub 14}B is a powder that can be blended with a polymer binder and compression or injection molded to form an isotropic polymer bonded permanent magnet (PBM). Commercially, Nd{sub 2}Fe{sub 14}B is the alloy of choice for PBMs. Powders of Nd{sub 2}Fe{sub 14}B are made via melt-spinning as can be MRE{sub 2}Fe{sub 14}B which allows for direct comparisons. MRE{sub 2}Fe{sub 14}B made using melt-spinning at high wheel speeds is overquenched and must be annealed to an optimal hard magnetic state. Due to the rare earth content in the MRE{sub 2}Fe{sub 14}B powders, they must be protected from the environment in which they operate. This protection is accomplished by using a modified fluidized bed process to grow a protective fluoride coating nominally 15nm thick, to reduce air oxidation. MRE{sub 2}Fe{sub 14}B has demonstrated reduced temperature dependent magnetic properties in ribbon and PBM form. The real challenge has been modifying alloy designs that were successfully melt-spun to be compatible with high-pressure gas-atomization (HPGA). The cooling rates in HPGA are lower than melt-spinning, as the powders are quenched via convective cooling, compared to melt-spinning, which quenches initially by conductive cooling. Early alloy designs, in gas atomized and melt-spun form, did not have similar phase compositions or microstructures. Alloy additions, such as the addition of zirconium as a nucleation catalyst, were successful in creating similar phases and microstructures in the HPGA powders and melt-spun ribbon of the same MRE{sub 2}Fe{sub 14}B composition.

  12. Balancing Work and Family: A Panel Analysis of the Impact of Part-Time Work on the Experience of Time Pressure

    Science.gov (United States)

    Laurijssen, Ilse; Glorieux, Ignace

    2013-01-01

    In this article we consider the consequences of work-family reconciliation, in terms of the extent to which the adjustment of the labour market career to family demands (by women) contributes to a better work-life balance. Using the Flemish SONAR-data, we analyse how changes in work and family conditions between the age of 26 and 29 are related to

  13. X-ray Raman scattering study of MgSiO3 glass at high pressure: Implication for triclustered MgSiO3 melt in Earth's mantle

    OpenAIRE

    Lee, Sung Keun; Lin, Jung-Fu; Cai, Yong Q.; Hiraoka, Nozomu; Eng, Peter J.; Okuchi, Takuo; Mao, Ho-kwang; Meng, Yue; Hu, Michael Y.; Chow, Paul; Shu, Jinfu; Li, Baosheng; FUKUI, HIROSHI; Lee, Bum Han; Kim, Hyun Na

    2008-01-01

    Silicate melts at the top of the transition zone and the core-mantle boundary have significant influences on the dynamics and properties of Earth's interior. MgSiO3-rich silicate melts were among the primary components of the magma ocean and thus played essential roles in the chemical differentiation of the early Earth. Diverse macroscopic properties of silicate melts in Earth's interior, such as density, viscosity, and crystal-melt partitioning, depend on their electronic and short-range loc...

  14. Microstructure and property evaluation of high-pressure die-cast MgLarare earth (Nd, Y or Gd) alloys

    International Nuclear Information System (INIS)

    Highlights: Different rare earth elements have remarkably different effects on Mg castability. For the addition of each RE element, the alloy castability follows a unique pattern. The effects of RE elements on the castability can be modelled. - Abstract: Microstructure, castability and tensile properties were investigated in high-pressure die-cast MgLaNd, MgLaY and MgLaGd alloy series, with a constant La concentration at approximately 2.5 wt.% and the concentrations of Nd, Y or Gd were varied. All three alloy series had a dendritic microstructure with a MgLa-rich eutectic with increasing Nd, Y or Gd content and containing a Mg12RE intermetallic phase. The morphology of the eutectic at ternary alloying additions of equal to or less than 1.0 wt.% was lamellar but became increasingly divorced at higher ternary concentrations. This was however more obvious in MgLaY and MgLaGd than MgLaNd alloys. The hot tearing susceptibility in all three alloy series increased markedly with even micro-alloying additions of Nd, Y or Gd, and began to decrease again in alloys with more than 0.5 wt.% Y or 1.0 wt.% Gd, but did not decrease significantly for MgLaNd. A model using the temperaturefraction solid curves as input parameters was used to estimate hot tearing susceptibility for MgLaNd alloys. Tensile testing at room temperature showed that MgLaNd alloy series had higher 0.2% proof stress and lower elongation to failure than either the MgLaY or the MgLaGd alloy series for Nd concentrations greater than 1 wt.% due to a greater effectiveness of grain boundary reinforcement

  15. Intra-session test-retest reliability of magnitude and structure of center of pressure from the Nintendo Wii Balance Board for a visually impaired and normally sighted population.

    Science.gov (United States)

    Jeter, Pamela E; Wang, Jiangxia; Gu, Jialiang; Barry, Michael P; Roach, Crystal; Corson, Marilyn; Yang, Lindsay; Dagnelie, Gislin

    2015-02-01

    Individuals with visual impairment (VI) have irreparable damage to one of the input streams contributing to postural stability. Here, we evaluated the intra-session test-retest reliability of the Wii Balance Board (WBB) for measuring Center of Pressure (COP) magnitude and structure, i.e. approximate entropy (ApEn) in fourteen legally blind participants and 21 participants with corrected-to-normal vision. Participants completed a validated balance protocol which included four sensory conditions: double-leg standing on a firm surface with eyes open (EO-firm); a firm surface with eyes closed (EC-firm); a foam surface with EO (EO-foam); and a foam surface with EC (EC-foam). Participants performed the full balance protocol twice during the session, separated by a period of 15min, to determine the intraclass correlation coefficient (ICC). Absolute reliability was determined by the standard error of measurement (SEM). The minimal difference (MD) was estimated to determine clinical significance for future studies. COP measures were derived from data sent by the WBB to a laptop via Bluetooth. COP scores increased with the difficulty of sensory condition indicating WBB sensitivity (all p<0.01). ICCs in the VI group ranged from 0.73 to 0.95, indicating high to very high correlations, and the normal group showed moderate to very high ICCs (0.62-0.94). The SEM was comparable between groups regardless of between-subject variability. The reliability of the WBB makes it practical to screen for balance impairment among VI persons. PMID:25555361

  16. Separation of the rare earths by high pressure liquid chromatography and the fission yield on sup(148m)Pm and sup(148g)Pm using thermal neutron induced fission of 233U and 239Pu

    International Nuclear Information System (INIS)

    This report is in two parts: in the first part, the method of high pressure liquid chromatography is described with particular reference to rare earth nuclei produced in nuclear reactions; in the second part, the results of a study of the fission yield of sup(148m)Pm and sup(148g)Pm from the thermal fission of 233U and 239Pu are presented. (G.T.H.)

  17. Balancing Risk

    DEFF Research Database (Denmark)

    Nygaard, Lene; Rossen, Camilla Blach; Buus, Niels

    2015-01-01

    This study explored how eight pregnant women diagnosed with depression managed the decision whether or not to take antidepressants during pregnancy. In total, 11 interviews were conducted and analysed by means of constructivist grounded theory. The major category constructed was Balancing risk...

  18. Production balance

    International Nuclear Information System (INIS)

    In terms of the environment, the year 2011 was balanced in the company Slovenske elektrarne. The trend of a high share of electricity production from nuclear and hydro power plants persisted; therefore, a greater part of electricity supplies (88.5%) was not loaded by emissions of harmful substances into the atmosphere. (author)

  19. New high pressure rare earth tantalates RExTa2O5+1.5x (RE=La, Eu, Yb)

    International Nuclear Information System (INIS)

    Rare earth tantalates La0.075Ta2O5.113, Eu0.089Ta2O5.134 and Yb0.051Ta2O5.077 have been prepared by solid state reaction at P=7.0 GPa and T=1050–1100 °C and studied by X-ray diffraction, thermal analysis and electron microscopy. Low hydrated amorphous tantalum, lanthanum, europium and ytterbium hydroxides were used as starting materials. Aqueous as well as anhydrous compounds were obtained. Title tantalates are crystallized in the structure type of F–Ta2O5 [Zibrov et al. Russ. J. Inorg. Chem. 48 (2003) 464–471] [5]. The structure was refined by the Rietveld method from X-ray powder diffractometer data: La0.075Ta2O5.113, a=10.5099(2), b=7.2679(1), c=6.9765(1) Å, V=532.90(1) Å3, Z=6, space group Ibam; Eu0.089Ta2O5.134, a=10.4182(3), b=7.2685(1), c=6.9832(1) Å, V=528.80(2) Å3, Z=6, space group Ibam; Yb0.051Ta2O5.077, a=10.4557(2), b=7.3853(1), c=6.8923(1) Å, V=532.21(1) Å3, Z=6, space group Ibam. RE atoms do not replace the tantalum in its positions but the only water in the channels of the structure. Highly charged cations RE+3 compress the unit cell so that its volume becomes less than that of F–Ta2O5. Significant decrease of the unit cell volume after water removal from the structure is possible due to the puckering of pentagonal bipyramid layers and change of the corrugation angle in the layer. - Graphical abstract: The structure of RExTa2O5+1.5x and its HRTEM image (“A” arrows show empty channel, “B” arrows show filled channel). - Highlights: • We synthesized new tantalates of RE under high pressure high temperature conditions. • RE atoms replace water molecules in the channels of the structure. • Aqueous as well as anhydrous tantalates were obtained. • Highly charged cations RE+3 compress the unit cell decreasing RE–O distances

  20. New high pressure rare earth tantalates RE{sub x}Ta{sub 2}O{sub 5+1.5x} (RE=La, Eu, Yb)

    Energy Technology Data Exchange (ETDEWEB)

    Zibrov, Igor P., E-mail: zibrov@mail.ru [Institute for High Pressure Physics, Russian Academy of Sciences, Kaluzhskoe Highway 14, Troitsk, Moscow 142190 (Russian Federation); Filonenko, Vladimir P., E-mail: filv@hppi.troitsk.ru [Institute for High Pressure Physics, Russian Academy of Sciences, Kaluzhskoe Highway 14, Troitsk, Moscow 142190 (Russian Federation); Zakharov, Nikolai D., E-mail: zakharov@mpi-halle.mpg.de [Max Planck Institute for Microstructure Physics, Weinberg 2, D-06120 Halle/Saale (Germany); Werner, Peter, E-mail: werner@mpi-halle.mpg.de [Max Planck Institute for Microstructure Physics, Weinberg 2, D-06120 Halle/Saale (Germany); Drobot, Dmitrii V., E-mail: dvdrobot@mail.ru [Lomonosov Moscow University of Fine Chemical Technology, Prospect Vernadskogo 86, Moscow 119571 (Russian Federation); Nikishina, Elena E.; Lebedeva, Elena N., E-mail: helena_nick@mail.ru [Lomonosov Moscow University of Fine Chemical Technology, Prospect Vernadskogo 86, Moscow 119571 (Russian Federation)

    2013-07-15

    Rare earth tantalates La{sub 0.075}Ta{sub 2}O{sub 5.113}, Eu{sub 0.089}Ta{sub 2}O{sub 5.134} and Yb{sub 0.051}Ta{sub 2}O{sub 5.077} have been prepared by solid state reaction at P=7.0 GPa and T=10501100 C and studied by X-ray diffraction, thermal analysis and electron microscopy. Low hydrated amorphous tantalum, lanthanum, europium and ytterbium hydroxides were used as starting materials. Aqueous as well as anhydrous compounds were obtained. Title tantalates are crystallized in the structure type of FTa{sub 2}O{sub 5} [Zibrov et al. Russ. J. Inorg. Chem. 48 (2003) 464471] [5]. The structure was refined by the Rietveld method from X-ray powder diffractometer data: La{sub 0.075}Ta{sub 2}O{sub 5.113}, a=10.5099(2), b=7.2679(1), c=6.9765(1) , V=532.90(1) {sup 3}, Z=6, space group Ibam; Eu{sub 0.089}Ta{sub 2}O{sub 5.134}, a=10.4182(3), b=7.2685(1), c=6.9832(1) , V=528.80(2) {sup 3}, Z=6, space group Ibam; Yb{sub 0.051}Ta{sub 2}O{sub 5.077}, a=10.4557(2), b=7.3853(1), c=6.8923(1) , V=532.21(1) {sup 3}, Z=6, space group Ibam. RE atoms do not replace the tantalum in its positions but the only water in the channels of the structure. Highly charged cations RE{sup +3} compress the unit cell so that its volume becomes less than that of FTa{sub 2}O{sub 5}. Significant decrease of the unit cell volume after water removal from the structure is possible due to the puckering of pentagonal bipyramid layers and change of the corrugation angle in the layer. - Graphical abstract: The structure of RE{sub x}Ta{sub 2}O{sub 5+1.5x} and its HRTEM image (A arrows show empty channel, B arrows show filled channel). - Highlights: We synthesized new tantalates of RE under high pressure high temperature conditions. RE atoms replace water molecules in the channels of the structure. Aqueous as well as anhydrous tantalates were obtained. Highly charged cations RE{sup +3} compress the unit cell decreasing REO distances.

  1. Chaotic behavior in a system simulating the pressure balanced injection system. Analysis of passive safety reactor behavior. JAERI's nuclear research promotion program, H12-012 (Contract research)

    Energy Technology Data Exchange (ETDEWEB)

    Madarame, Haruki; Okamoto, Koji; Tanaka, Gentaro; Morimoto, Yuichiro [Tokyo Univ., School of Engineering, Tokyo (Japan); Sato, Akira [Yamagata Univ., Faculty of Engineering, Yonezawa, Yamagata (Japan); Kondou, Masaya [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The pressure Balanced Injection System (PBIS) was proposed in a passive safety reactor. Pressurizing Line (PL) connects the Reactor Vessel (RV) and the gas area in the Contain Vessel (CV), and Injected Line (IL) connects two vessels at relatively lower position. In an accident, the two lines are passively opened. The vapor generated by the residual heat pressed downward the water level in the RV. When the level is lower than the inlet of the PL, vapor is ejected into the CV through the PL attaining the pressure balance between the vessels. Then boron water in the CV is injected into the RV through the IL by the static head. This process is repeated by the succeeding vapor generation. In an experiment, the oscillating system was replaced by water column in a U-shaped duct. The vapor generation was simulated by cover gas supply to one end of the duct, while the other end was open to the atmosphere. When the water level reached a certain level, electromagnetic valves opened and the cover gas was ejected. The gas pressure decreased rapidly, resulting in a surface rise. When the water level reached another level, the valves closed. The cover gas pressure increased again, thus, gas ejection occurred intermittently. The interval of the gas ejection was not constant but fluctuated widely. Mere stochastic noise could hardly explain the large amplitude. Then was expressed the system using a set of linear equations. Various types of piecewise linear model were developed to examine the cause of the fluctuation. There appeared tangential bifurcation, period-doubling bifurcation, period-adding bifurcation and so on. The calculated interval exhibited chaotic features. Thus the cause of the fluctuation can be attributed to chaotic features of the system having switching. Since the piecewise linear model was highly simplified the behavior, a quantitative comparison between the calculation and the experiment was difficult. Therefore, numerical simulation code considering nonlinear effect was developed to describe the system behavior in the case there was no stochastic noise. The comparison between the simulation and the experiment revealed that there are some bifurcation-like phenomena being not real bifurcations. Real bifurcations are discovered in the simulation as well as in the experiment. Confirmation of chaotic behavior of the system in the experiment is a subject for a future study. (author)

  2. Experimental and Numerical Study of the Effect of PET Recycling Admixtures on Pore Water Pressure and Output Discharge in Homogeneous Earth Dams.

    OpenAIRE

    Reza Ahmad Zadeh Touri; Somayyeh Pourbakhshian; Majid Pouraminian

    2015-01-01

    This study analytically and experimentally investigates the leakage in homogenous earth dam (clay) reinforced by recycled PET. First, the effect of PET addition on permeability of clay in geotechnical laboratory is evaluated, according to the results of first step, a physical model of homogenous earth dam is prepared in laboratory flume, both in PETs or without PETs and measured the water height in dam body using piezometers installed on flume body and also leakage discharge was calculated. T...

  3. Balancing Risk

    DEFF Research Database (Denmark)

    Nygaard, Lene; Rossen, Camilla Blach; Buus, Niels

    2015-01-01

    This study explored how eight pregnant women diagnosed with depression managed the decision whether or not to take antidepressants during pregnancy. In total, 11 interviews were conducted and analysed by means of constructivist grounded theory. The major category constructed was Balancing risk, with two minor categories: Assessing depression and antidepressants and Evaluating the impact of significant others. The participants tried to make the safest decision, taking all aspects of their life in...

  4. The balance of frictional heat production, thermal pressurization, and slip resistance on exhumed mid-crustal faults (Adamello batholith, Southern Italian Alps)

    Science.gov (United States)

    Griffith, W. A.; di Toro, G.; Pollard, D. D.

    2005-12-01

    Exhumed faults cutting the Adamello batholith (Italian Alps) were active ca. 30 Ma at seismogenic depths of 9-11 km. The faults "exploited preexisting joints and can be classified into three groups containing: (A) only cataclasite (a fault rock with no evidence of melting), (B) cataclasite and pseudotachylyte (solidified friction-induced melts produced during earthquakes), and (C) only pseudotachylyte. The majority of pseudotachylyte-bearing faults in this outcrop overprint pre-existing cataclasites (Type B), suggesting a transition between slip styles; however, some faults exhibiting pseudotachylyte and no cataclasite (Type C) display evidence of only one episode of slip. Faults of Type A never transitioned to frictional melting. We attempt to compare faults of type A, B, and C in terms of a simple one-dimensional thermo-mechanical model introduced by Lachenbruch (1980) describing the interaction between frictional heating, pore fluid pressure, and shear resistance during slip. The interaction of these three parameters influences how much elastic strain is relieved during an earthquake. For a conceptualized fault zone of finite thickness, the interplay between the shear resistance, heat production, and pore fluid pressure can be expressed as a non-linear partial differential equation relating these processes to the strain rate acting within a fault zone during a slip event. The behavior of fault zones in terms of these coupled processes during an earthquake depends on a number of parameters, such as thickness of the principal slipping zone, net coseismic slip, fault rock permeability and thermal diffusivity. Ideally, the governing equations should be testable on real fault zones if the requisite parameters can be measured or reasonably estimated. The model can be further simplified if the peak temperature reached during slip and the coseismic slip rate can be constrained. The contrasting nature of slip on the three Adamello fault types highlights (1) important differences between slip processes on cataclastic and melt-producing faults at depth and (2) some limitations of applicability of such models to real faults.

  5. Lesson "Balance in Nature

    Science.gov (United States)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human? nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  6. Earths Earliest Atmospheres

    OpenAIRE

    Zahnle, Kevin; Schaefer, Laura; Fegley, Bruce

    2010-01-01

    Earth is the one known example of an inhabited planet and to current knowledge the likeliest site of the one known origin of life. Here we discuss the origin of Earths atmosphere and ocean and some of the environmental conditions of the early Earth as they may relate to the origin of life. A key punctuating event in the narrative is the Moon-forming impact, partly because it made Earth for a short time absolutely uninhabitable, and partly because it sets the boundary conditions for Earths s...

  7. Chemical earth models

    Science.gov (United States)

    Javoy, Marc

    1999-10-01

    This article presents a critical review of method, concepts and prejudices used bv modelists of the Earth's chemical composition over approximate the last fifty years and of the resulting compositions. Brief descriptions are given of admitted accretion mechanisms, of the starting materials most often considered and of the major parameters and recurrent concepts: 'reduced" state, mantle homogeneity vs heterogeneity, 'low pressure' core formation, 'great impact', refractory, lithophile, siderophile, compatible, incompatible character of elements, depleted and degassed mantle, Urey ratio, as well as the description of a commonly-used instrument, possibly harmful to Iogic, the famous Ockham's razor. Differences between models are now restricted to the lower mantle composition:the 'primary' (before crust differentiation) upper mentle varies little from model to model and the idea of a 10-15% combined Si-O-S concentration as representing the necessary light elements in the core is gaining more and more ground. The dominant type of model derives more or less directly from the CI cabonaceous composition by complete devolatilization and reduction. Its mantle is homogeneous and convecting mainly in a one-level mode, in accordence with dominant geophysicists' views but in rather strong disagreement with geochemical data and models which insist on the strong decoupling between lower and upper mantle. Its low Si excess is generally supposed to have been absorbed by the core, whereas its high refractory lithophile element (RLE) content creates mass balance problems relative to presently observed mantle and crust concentrations. The alternative type is a two-lavel mantle with a Si and Fe-rich, RLE-poor, lower mantle, previously based mainly on seismic and mineral physics data, and now also on geochemical and cosmochemical arguments.

  8. First-Principles Studies of Pressure-Induced Structural and Insulator-To Transitions in Alkaline-Earth Dicarbides MC2 (M = Ca, Sr and Ba)

    Science.gov (United States)

    Jiang, Li-Na

    2013-12-01

    Pressure-induced phase transitions in MC2 (M = Ca, Sr and Ba) are investigated by using the first-principles plane wave pseudopotential method within the generalized gradient approximation. The first-order phase transition from tetragonal phase (CaC2-type, space group I4/mmm) to rhombohedral (CsCl-type, space group R/line{3}m) structure is predicted to occur at 22.2, 10.0 and 3.6 GPa, respectively, and transition pressure point of BaC2 agrees well with recent theoretical works. Based on the electronic analysis, the ionic Ca-C bond character becomes stronger with increasing pressure in both I4/mmm and R/line{3}m phases. In particular, there will occur a transition from insulator to metal with increasing pressure due to the reason that the calculated band gap gets narrower and finally closes at some high pressure.

  9. Development of high temperature reference electrodes for in-pile application: Part I. Feasibility study of the external pressure balanced Ag/AgCl reference electrode (EPBRE) and the cathodically charged Palladium hydrogen electrode

    International Nuclear Information System (INIS)

    The main problems connected with corrosion potential measurements at elevated temperatures and pressures are related to the stability and lifetime of the reference electrode and the correct estimation of the potential related to the Standard Hydrogen Scale (SHE). Under Pressurised Water Reactor (PWR) conditions of 300 degrees Celsius and 150 bar, the choice of materials is also a limiting factor due to the influence of radiation. Investigations on two reference electrodes that can be used under PWR conditions are reported: the cathodically charged palladium hydrogen electrode, and the external pressure balanced silver/silver chloride electrode. Preliminary investigations with the Pd-electrode were focused on the calculation of the required charging time and the influence of dissolved oxygen. High temperature applications are discussed on the basis of results reported in the literature. Investigations with the silver/silver chloride reference electrode mainly dealt with the salt bridge which is necessary to connect the reference electrode with the testing solution. It is shown that the thermal junction potential is independent of the length of the salt bridge. In addition, the high temperature contributes to an increase of the conductivity of the solution, which is beneficial for the salt bridge connection

  10. Development of high temperature reference electrodes for in-pile application: Part I. Feasibility study of the external pressure balanced Ag/AgCl reference electrode (EPBRE) and the cathodically charged Palladium hydrogen electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, R.W.; Van Nieuwenhove, R

    1998-10-01

    The main problems connected with corrosion potential measurements at elevated temperatures and pressures are related to the stability and lifetime of the reference electrode and the correct estimation of the potential related to the Standard Hydrogen Scale (SHE). Under Pressurised Water Reactor (PWR) conditions of 300 degrees Celsius and 150 bar, the choice of materials is also a limiting factor due to the influence of radiation. Investigations on two reference electrodes that can be used under PWR conditions are reported: the cathodically charged palladium hydrogen electrode, and the external pressure balanced silver/silver chloride electrode. Preliminary investigations with the Pd-electrode were focused on the calculation of the required charging time and the influence of dissolved oxygen. High temperature applications are discussed on the basis of results reported in the literature. Investigations with the silver/silver chloride reference electrode mainly dealt with the salt bridge which is necessary to connect the reference electrode with the testing solution. It is shown that the thermal junction potential is independent of the length of the salt bridge. In addition, the high temperature contributes to an increase of the conductivity of the solution, which is beneficial for the salt bridge connection.

  11. Ballet Balance Strategies

    DEFF Research Database (Denmark)

    Pedersen, Camilla; Erleben, Kenny

    2006-01-01

    Animating physically realistic human characters is challenging, since human observers are highly tuned to recognize human cues such as emotion and gender from motion patterns. The main contribution of this paper is a new model firmly based on biomechanics, which is used to animate balance and basic movements of a ballet dancers. It is supported by computer simulated experiments and it is in good agreement with biomechanical measurements of real-life dancers. Our results questions the previous approaches in dynamic animation, which only uses the center of gravity strategy, and instead demonstrate the viability of the center of pressure strategy.

  12. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    Science.gov (United States)

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  13. Mars, earth, and ice

    International Nuclear Information System (INIS)

    Possible mechanisms to explain the global ice covering of Mars, and previous ice ages on the earth, are considered. Evidence for the Milankovitch effect is found in the close correspondence of earth's past climate with its orbital variations, as recorded principally in ocean sediments, and the role of CO2 is discussed. Mars' range of obliquity, 10 times that of the earth, and orbital eccentricity, fluctuating over a range 2 1/2 times that of the earth, could produce an important climate-driving cycle. Mathematical models of the Martian surface and atmosphere based on Viking data suggest that escaped CO2 could create a surface pressure of 1-3 bars. Other factors such as the effect of continental drift, the increased brightness of the sun, and planetary reversals of magnetic field polarity are discussed, and the questions of where Martian water and CO2 have gone are considered

  14. Estudio experimental y numrico del desplazamiento y rotacin de suelo reforzado con geomallas bajo empuje activo Experimental and numerical study of the displacement and rotation of geogrid reinforced soil under active lateral earth pressure

    Directory of Open Access Journals (Sweden)

    Lissette Ruiz-Tagle

    2011-01-01

    Full Text Available Se presenta un estudio experimentaly numrico de desplazamiento y rotacin de suelo sin y con refuerzo de geomallas bajo la accin del empuje activo. Para ello se ha usado la tcnica de medicin PIV con la cual se procesan imgenes digitales para la obtencin de campos de desplazamiento y rotacin. El equipo de ensayo de empuje posee una ventana transparente que permite registrar el movimiento del suelo. Los resultados medidos de movimiento del suelo permiten determinar reas de suelo que fluyen y no fluyen debido a la accin del empuje activo. De esta manera se puede determinar la posicin y geometra de la superficie de falla, la cual se puede comparar con la definida por la teora de la plasticidad de empuje activo de Rankine. Esta comparacin resulta solo posible para el caso sin geomallas, dado que con geomallas la zona de suelo en fluencia cambia significativamente. La presencia de geomallas puede reducir hasta dos veces el volumen de suelo que entra en fluencia debido al empuje activo. Esta conclusin relacionada con la deformacin del suelo est en directa relacin con la disminucin de la tensin de empuje activo al utilizar geomallas como elementos de refuerzo. Tambin se presenta un anlisis numrico usando el programa computacional Plaxis para estimar los desplazamientos horizontales. Los resultados numricos entregan estimaciones que se aproximan a los resultados medidos de desplazamientos horizontales en trminos de la forma de la zona de suelo en fluencia. Sin embargo, no son capaces de reproducir en detalle la geometra de la superficie de falla.An experimental and numerical study is presented related to displacement and rotation of soil with and without geogrid reinforcement under the application of active lateral earth pressure. To this end, the measurement technique PIV has been used, with which digital images are processed to obtain displacement and rotation fields. The experimental earth pressure equipment has a transparent window which allows the recording of soil movements. Through the process and analysis of the measured soil movement, soil areas which yielded and did not yield due to the active earth pressure, were defined. In this form, the position and geometry of the failure surface can be determined and compared with the defined by the plasticity theory of active Rankine states. This comparison is only possible for the case without geogrids since the presence of geogrids change significantly the zone of soil yielding. Geogrids can reduce up to twice the volume of soil yielding due to the active lateral earth pressure. This conclusion related with the soil deformation is in direct relation with the active lateral earth pressure reduction when geogrids are used as reinforced elements. In addition, a numerical analysis using the computational program Plaxis is presented to estimate horizontal displacements. The numerical results estimate reasonably well the horizontal displacements measured in terms of the shape of the soil yielding area. However, they do not reproduce in detail the geometry of the failure surface.

  15. Burnup of UO2-Gd2O3 nuclear fuel elements. Separation of gadolinium from rare earths by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    In the framework of a research project on burnable poisons, a technique to separate gadolinium from irradiated samples of (U-Gd)O2+x has been developed in order to determine the burnup of mixed oxides fuel elements. The separation of Gd from the other rare earths (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) has been carried out by HPLC after uranium extraction with TBP. The procedure can be applied as a step to determine the burnup of spent nuclear fuels

  16. Earth\\'s Mass Variability

    OpenAIRE

    Mawad, Ramy

    2014-01-01

    The perturbation of the Earth caused by variability of mass of Earth as additional reason with gravity of celestial bodies and shape of the Earth. The Earth eating and collecting matters from space and loss or eject matters to space through its flying in the space around the Sun. The source of the rising in the global sea level is not closed in global warming and icebergs, but the outer space is the additional important source for this rising. The Earth eats waters from space in unknown mecha...

  17. Melting relations in the iron-sulfur system at ultra-high pressures - Implications for the thermal state of the earth

    Science.gov (United States)

    Williams, Quentin; Jeanloz, Raymond

    1990-01-01

    The melting temperatures of FeS-troilite and of a 10-wt-pct sulfur iron alloy have been measured to pressures of 120 and 90 GPa, respectively. The results document that FeS melts at a temperature of 4100 (+ or - 300) K at the pressure of the core-mantle boundary. Eutecticlike behavior persists in the iron-sulfur system to the highest pressures of measurements, in marked contrast to the solid-solutionlike behavior observed at high pressures in the iron-iron oxide system. Iron with 10-wt-pct sulfur melts at a similar temperature as FeS at core-mantle boundary conditions. If the sole alloying elements of iron within the core are sulfur and oxygen and the outer core is entirely liquid, the minimum temperature at the top of the outer core is 4900 (+ or - 400) K. Calculations of mantle geotherms dictate that there must be a temperature increase of between 1000 and 2000 K across thermal boundary layers within the mantle. If D-double-prime is compositionally stratified, it could accommodate the bulk of this temperature jump.

  18. Changes of arterial blood pressure, heart rate, internal body temperature, and blood acido-basic balance in the unanaesthetized rabbit following whole-body gamma irradiation at a mean absorbed dose of 250 rads

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, R.; Court, L.

    1973-09-01

    The general effects of whole-body gamma -irradiation at a mean absorbed dose of 250 rads were studied simultaneously in the unanaesthetized rabbit for 48 hours. They occurred early, with the following characteristics: arterial blood pressure decreased steadily as early as the 2nd hour and reached its minimum value on the 5th hour with a decrease of about 14%; it remained low during the following two days. Heart rate increased during the first hour, was the highest by the end of the second hour, and resumed normal value on the 24th hour. Internal body temperature increased during the 1st hour and was maximum by the end of the 2nd hour, with a mean increase of 1.2 deg C; hyperthermia steadily decreased between the 4th and the 6th hours and had completely disappeared by the 24th hour. Respiratory alkalosis is shown in the acido-basic balance by a raise of pH, a decrease of PCO/sub 2/ and arterial blood bicarbonates. These various changes seem to indicate a double origin, both central and peripheral. (FR)

  19. Postural balance in low back pain patients

    DEFF Research Database (Denmark)

    Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk; Andersen, Niels Trolle; Schiøttz-Christensen, Berit

    2011-01-01

    Low back pain (LBP) patients have poorer postural control compared to healthy controls, and the importance of assessing and addressing balance is a matter of debate. In the clinic, balance is often tested by means of the one leg stand test (OLST) while research often employs center of pressure (Co...

  20. Effects of diving on hearing and balance

    OpenAIRE

    Goplen, Frederik Kragerud

    2011-01-01

    Diving has profound effects on the human body including the inner ear, which contains the organs of hearing and balance. Ear injury is the most common medical problem in diving. The aim of this work was to explore the short and long-term effects of diving on hearing and balance through a simulated deep saturation dive and two epidemiological studies on commercial divers. The first study explored short-term effects of absolute pressure on the body. The high-pressure neurologi...

  1. A hypothesis of earth quake

    CERN Document Server

    Tsai, Yeong-Shyeong

    2008-01-01

    Without a model, it is impossible for a geophysicist to study the possibility of forecasting earth quakes. In order to make a simple model, we make a hypothesis of earth quakes. The hypothesis is: (i) There are two kinds of earth quakes, one is the triggered breaking (earth quake), the other is spontaneous breaking (earth quake). (ii) Most major quakes in continental plates Eurasian Plate, North America Plate, South America Plate, Africa Plate and Australia Plate are triggered breaking. (iii) These triggered quakes are triggered by the movements of high pressure centers and low pressure centers of the atmosphere on continental plates. (iv) How can the movements of the high pressure centers trigger a quake? It depends on the extent of the high pressure center and the speed of the movement. Here, we stress high pressure center instead of low pressure center because it is dominated by high pressure center mostly. Of course, the boundary of the plates must have stored enough energy to have quakes, that is, near t...

  2. Indicator system provides complete data of engine cylinder pressure variation

    Science.gov (United States)

    Mc Jones, R. W.; Morgan, N. E.

    1966-01-01

    Varying reference pressure used together with a balanced pressure pickup /a diaphragm switch/ to switch the electric output of the pressure transducer in a reference pressure line obtains precise engine cylinder pressure data from a high speed internal combustion engine.

  3. High-pressure densified solid solutions of alkaline earth hexaborides (Ca/Sr, Ca/Ba, Sr/Ba) and their high-temperature thermoelectric properties

    Science.gov (United States)

    Grsoy, M.; Takeda, M.; Albert, B.

    2015-01-01

    Solid solutions of alkaline earth hexaborides were synthesized and densified by spark plasma sintering at 100 MPa. The high-temperature thermoelectric properties (Seebeck coefficients, electrical and thermal diffusivities, heat capacities) were measured between room temperature and 1073 K. CaB6, SrB6, BaB6 and the ternary hexaborides CaxSr1-xB6, CaxBa1-xB6, SrxBa1-xB6 (x = 0.25, 0.5, 0.75) are n-type conducting compounds over the whole compositional and thermal ranges. The values of the figure of merit ZT for CaB6 (ca. 0.3 at 1073 K) were found to be significantly increased compared to earlier investigations which is attributed to the densification process.

  4. Earth\\'s Mass Variability

    CERN Document Server

    Mawad, Ramy

    2014-01-01

    The perturbation of the Earth caused by variability of mass of Earth as additional reason with gravity of celestial bodies and shape of the Earth. The Earth eating and collecting matters from space and loss or eject matters to space through its flying in the space around the Sun. The source of the rising in the global sea level is not closed in global warming and icebergs, but the outer space is the additional important source for this rising. The Earth eats waters from space in unknown mechanism. The mass of the Earth become greater in November i.e. before transit apoapsis two months, and become latter in February i.e. after transit apoapsis to two months.

  5. Balanced Mind Foundation

    Science.gov (United States)

    ... Parent Network: Our Mission Get Started eNews Balanced Mind Updates Jul. 21, 2014 July eUpdate: DBSA Webinars ... Introducing the DBSA Young Adult Council Follow Balanced Mind Parent Network Updates: Balanced Mind Parent Network Updates ...

  6. Human Balance System

    Science.gov (United States)

    ... product or service advertised on this site. The Human Balance System Good balance is often taken for ... support. 1 A properly functioning balance system allows humans to see clearly while moving, identify orientation with ...

  7. Momentum balance in wall jets

    Science.gov (United States)

    Johansson, T. Gunnar; Mehdi, Faraz; Naughton, Jonathan W.

    2012-11-01

    A plane wall jet experiment has been done to study its momentum balance. Two component laser Doppler anemometry was used to simultaneously measure the axial and wall-normal velocity components in 6 axial positions (x/H= 25, 50, 75, 100, 125 and 150) spanning from the wall all the way well into the ambient stagnant area. In this way not only the mean velocity components and Reynolds normal and shear stresses but also all their spatial derivatives were determined. In addition the wall shear stress was measured in all six axial positions using oil film interferometry. From these data all terms in the x-momentum equation, except the pressure term, could be evaluated. Later also the pressure was measured in the same profiles, and thereby also the pressure term was included in the balance. Contrary to common belief it was found that the pressure was not constant in the wall jet. The complete momentum balance is discussed and used to evaluate the roles played by the different contributing terms in different regions of the flow field in an effort to improve on our understanding of the mechanics of wall jets.

  8. Effect of mass disorder on the lattice thermal conductivity of MgO periclase under pressure

    OpenAIRE

    Douglas Allen Dalton; Wen-Pin Hsieh; Gregory T. Hohensee; David G. Cahill; Goncharov, Alexander F.

    2013-01-01

    Thermal conductivity of mantle materials controlling the heat balance and thermal evolution of the Earth remains poorly constrained as the available experimental and theoretical techniques are limited in probing minerals under the relevant conditions. We report measurements of thermal conductivity of MgO at high pressure up to 60?GPa and 300?K via diamond anvil cells using the time-domain thermoreflectance technique. These measurements are complemented by model calculations which take into ac...

  9. Rare earths

    International Nuclear Information System (INIS)

    For conventional applications, there is limited demand for rare earth elements as well as yttrium and scandium. But the emergence of new high technology applications such as supermagnets, lasers, and superconductors should result in significant demand for some of these elements. This article examines the anticipated applications and demands for rare earth elements over the next decade. It also looks at the implications on the use of available resources. In the context of a growing demand, process methods are reviewed for the recovery of rare earth elements from conventional and unconventional resources. And the article also discusses the challenges facing the mining industry in meeting this opportunity

  10. Rare earths

    International Nuclear Information System (INIS)

    The conference was held from September 12 to 13, 1984 in Jetrichovice, Czechoslovakia. The participants heard 16 papers of which 4 were inputted in INIS. These papers dealt with industrial separation processes of rare earths, the use of chemical methods of separation from the concentrate of apatite and bastnesite, the effect of the relative permittivity of solvents in the elution of rare earth elements from a cation exchanger, and the determination of the content of different rare earth elements using X-ray fluorescence analysis and atomic absorption spectroscopy. (E.S.)

  11. Re-entry dynamics of high area-to-mass ratio objects in eccentric Earth orbits considering drag and solar radiation pressure

    International Nuclear Information System (INIS)

    The discovery of a new population of objects with high area-to-mass ratios (HAMR) in orbits near the geostationary ring has motivated recent research seeking to understand the behaviour of those debris under the influence of certain types of disturbances, such as solar radiation pressure and atmospheric drag. Based on a series of selection criteria, it was made from the NORAD catalogue a list of potential candidates for study. As we developed an orbital propagator that takes into account the major disturbances, it was possible to study the behaviour and variation of orbital parameters during decay of the HAMR objects. The results obtained for two cases studied exhibit the dynamic behaviour of all orbital parameters and show good agreement with the observed decay times

  12. New high pressure rare earth tantalates RExTa2O5+1.5x (RE=La, Eu, Yb)

    Science.gov (United States)

    Zibrov, Igor P.; Filonenko, Vladimir P.; Zakharov, Nikolai D.; Werner, Peter; Drobot, Dmitrii V.; Nikishina, Elena E.; Lebedeva, Elena N.

    2013-07-01

    Rare earth tantalates La0.075Ta2O5.113, Eu0.089Ta2O5.134 and Yb0.051Ta2O5.077 have been prepared by solid state reaction at P=7.0 GPa and T=1050-1100 C and studied by X-ray diffraction, thermal analysis and electron microscopy. Low hydrated amorphous tantalum, lanthanum, europium and ytterbium hydroxides were used as starting materials. Aqueous as well as anhydrous compounds were obtained. Title tantalates are crystallized in the structure type of F-Ta2O5 [Zibrov et al. Russ. J. Inorg. Chem. 48 (2003) 464-471] [5]. The structure was refined by the Rietveld method from X-ray powder diffractometer data: La0.075Ta2O5.113, a=10.5099(2), b=7.2679(1), c=6.9765(1) , V=532.90(1) 3, Z=6, space group Ibam; Eu0.089Ta2O5.134, a=10.4182(3), b=7.2685(1), c=6.9832(1) , V=528.80(2) 3, Z=6, space group Ibam; Yb0.051Ta2O5.077, a=10.4557(2), b=7.3853(1), c=6.8923(1) , V=532.21(1) 3, Z=6, space group Ibam. RE atoms do not replace the tantalum in its positions but the only water in the channels of the structure. Highly charged cations RE+3 compress the unit cell so that its volume becomes less than that of F-Ta2O5. Significant decrease of the unit cell volume after water removal from the structure is possible due to the puckering of pentagonal bipyramid layers and change of the corrugation angle in the layer.

  13. A Balancing Act: A Quantitative Analysis of the Influence of Work/Life Balance and Work Atmosphere on Personal and Professional Success of Women Scientists

    Science.gov (United States)

    Archie, T.; Laursen, S. L.; Kogan, M.

    2012-12-01

    Despite an increase in advanced degrees awarded to women in the geosciences, scientific leaders in academia remain dominantly male. Women are underrepresented in tenure-track positions in Earth science departments at research universities and are less likely to have more senior positions within their academic institutions. Our empirical study analyzes factors that influence personal and professional success for women scientists. Prior research has shown that women are subjected to unintended and unrecognized biases that can have an ultimate impact on their productivity, advancement, and success. We used an electronic survey to collect data from 662 early-career geoscientists who are members of the Earth Science Women's Network and/or the network's Earth Science Jobs list. We asked respondents to self-report their perceptions of work/life balance, professional atmosphere and other variables indicative and/or predictive of personal and professional success. In a previous analysis (Kogan & Laursen, 2011) we found that women consistently rated the professional atmosphere in their departments and their interactions with colleagues less favorably than men. Women indicated lower rates of collaboration with colleagues in their unit compared to their male peers. We also found work/life balance is of particular concern to early-career scientists, especially since tenure clock and the biological clock function on similar timetables. Women reported more caregiving responsibilities than men, further complicating the balance between work and personal life. We hypothesize that the work life balance and professional atmosphere influences productivity, advancement, and career/job satisfaction. We now investigate how work/life balance, atmosphere within the work unit, and mentoring influence productivity, job and career satisfaction, and career advancement. We introduce a structural equation model that seeks to explain how these relationships vary dependent upon gender, career level, caretaking responsibilities, and other variables. Our data indicate strong positive correlations between professional climate and job satisfaction, and between work/life balance and productivity. Our results suggest that the uneven pressures experienced by women influence their ability to achieve personal and professional success. However, our model implies that positive changes in women's work/life balance and professional atmosphere have the potential to help them become more successful both professionally and personally.

  14. Earth, atmosphere

    Science.gov (United States)

    Levine, Joel S.

    1991-01-01

    Present understanding of the earth's atmosphere is briefly reviewed. The structure and composition of the atmosphere are described. The origin of the atmosphere and the factors involved in global atmospheric change are addressed.

  15. Greenland ice sheet mass balance: a review

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Aschwanden, Andy; Bjrk, Anders A.; Wahr, John; Kjeldsen, Kristian K.; Kjr, Kurt H.

    2015-01-01

    Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance and to ...

  16. Toroidal and poloidal Alfvn waves with arbitrary azimuthal wavenumbers in a finite pressure plasma in the Earth's magnetosphere

    Directory of Open Access Journals (Sweden)

    D. Yu. Klimushkin

    2004-01-01

    Full Text Available In this paper, in terms of an axisymmetric model of the magnetosphere, we formulate the criteria for which the Alfvn waves in the magnetosphere can be toroidally and poloidally polarized (the disturbed magnetic field vector oscillates azimuthally and radially, respectively. The obvious condition of equality of the wave frequency ? to the toroidal (poloidal eigenfrequency ?TN (?PN is a necessary and sufficient one for the toroidal polarization of the mode and only a necessary one for the poloidal mode. In the latter case we must also add to it a significantly stronger condition ??TN?PN?/?TN ? m1 where m is the azimuthal wave number, and N is the longitudinal wave number. In cold plasma (the plasma to magnetic pressure ratio ? = 0 the left-hand side of this inequality is too small for the routinely recorded (in the magnetosphere second harmonic of radially polarized waves, therefore these waves must have nonrealistically large values of m. By studying several models of the magnetosphere differing by the level of disturbance, we found that the left-hand part of the poloidality criterion can be satisfied by taking into account finite plasma pressure for the observed values of m ? 50 100 (and in some cases, for even smaller values of the azimuthal wave numbers. When the poloidality condition is satisfied, the existence of two types of radially polarized Alfvn waves is possible. In magnetospheric regions, where the function ?PN is a monotonic one, the mode is poloidally polarized in a part of its region of localization. It propagates slowly across magnetic shells and changes its polarization from poloidal to toroidal. The other type of radially polarized waves can exist in those regions where this function reaches its extreme values (ring current, plasmapause. These waves are standing waves across magnetic shells, having a poloidal polarization throughout the region of its existence. Waves of this type are likely to be exemplified by giant pulsations. If the poloidality condition is not satisfied, then the mode is toroidally polarized throughout the region of its existence. Furthermore, it has a resonance peak near the magnetic shell, the toroidal eigenfrequency of which equals the frequency of the wave.

    Key words. Magnetospheric physics (plasmasphere; MHD waves and instabilities Space plasma physics (kinetic and MHD theory

  17. Balance Disorders (For Parents)

    Science.gov (United States)

    ... What's in this article? How Balance Works Symptoms Types of Balance Disorders Causes Diagnosis Treatment When to See a Doctor When you think about balance, the role that ears play might not come to mind. But ears are crucial to maintaining balance thanks ...

  18. High-pressure, temperature elasticity of Fe- and Al-bearing MgSiO3: implications for the Earth's lower mantle

    CERN Document Server

    Zhang, Shuai; Liu, Tao; Stackhouse, Stephen; Militzer, Burkhard

    2015-01-01

    Fe and Al are two of the most important rock-forming elements other than Mg, Si, and O. Their presence in the lower mantle's most abundant minerals, MgSiO_3 bridgmanite, MgSiO_3 post-perovskite and MgO periclase, alters their elastic properties. However, knowledge on the thermoelasticity of Fe- and Al-bearing MgSiO_3 bridgmanite, and post-perovskite is scarce. In this study, we perform ab initio molecular dynamics to calculate the elastic and seismic properties of pure, Fe^{3+}- and Fe^{2+}-, and Al^{3+}-bearing MgSiO_3 perovskite and post-perovskite, over a wide range of pressures, temperatures, and Fe/Al compositions. Our results show that a mineral assemblage resembling pyrolite fits a 1D seismological model well, down to, at least, a few hundred kilometers above the core-mantle boundary, i.e. the top of the D'' region. In D'', a similar composition is still an excellent fit to the average velocities and fairly approximate to the density. We also implement polycrystal plasticity with a geodynamic model to ...

  19. High-pressure, temperature elasticity of Fe- and Al-bearing MgSiO3: Implications for the Earth's lower mantle

    Science.gov (United States)

    Zhang, Shuai; Cottaar, Sanne; Liu, Tao; Stackhouse, Stephen; Militzer, Burkhard

    2016-01-01

    Fe and Al are two of the most important rock-forming elements other than Mg, Si, and O. Their presence in the lower mantle's most abundant minerals, MgSiO3 bridgmanite, MgSiO3 post-perovskite and MgO periclase, alters their elastic properties. However, knowledge on the thermoelasticity of Fe- and Al-bearing MgSiO3 bridgmanite, and post-perovskite is scarce. In this study, we perform ab initio molecular dynamics to calculate the elastic and seismic properties of pure, Fe3+- and Fe2+-, and Al3+-bearing MgSiO3 perovskite and post-perovskite, over a wide range of pressures, temperatures, and Fe/Al compositions. Our results show that a mineral assemblage resembling pyrolite fits a 1D seismological model well, down to, at least, a few hundred kilometers above the core-mantle boundary, i.e. the top of the D? region. In D?, a similar composition is still an excellent fit to the average velocities and fairly approximate to the density. We also implement polycrystal plasticity with a geodynamic model to predict resulting seismic anisotropy, and find post-perovskite with predominant (001) slip across all compositions agrees best with seismic observations in the D?.

  20. THE COSMIC-RAY INTENSITY NEAR THE ARCHEAN EARTH

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, O.; Drake, J. J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Kota, J. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092 (United States)

    2012-11-20

    We employ three-dimensional state-of-the-art magnetohydrodynamic models of the early solar wind and heliosphere and a two-dimensional model for cosmic-ray transport to investigate the cosmic-ray spectrum and flux near the Archean Earth. We assess how sensitive the cosmic-ray spectrum is to changes in the sunspot placement and magnetic field strength, the large-scale dipole magnetic field strength, the wind ram pressure, and the Sun's rotation period. Overall, our results confirm earlier work that suggested the Archean Earth would have experienced a greatly reduced cosmic-ray flux than is the case today. The cosmic-ray reduction for the early Sun is mainly due to the shorter solar rotation period and tighter winding of the Parker spiral, and to the different surface distribution of the more active solar magnetic field. These effects lead to a global reduction of the cosmic-ray flux at 1 AU by up to two orders of magnitude or more. Variations in the sunspot magnetic field have more effect on the flux than variations in the dipole field component. The wind ram pressure affects the cosmic-ray flux through its influence on the size of the heliosphere via the pressure balance with the ambient interstellar medium. Variations in the interstellar medium pressure experienced by the solar system in orbit through the Galaxy could lead to order of magnitude changes in the cosmic-ray flux at Earth on timescales of a few million years.

  1. Tracking Earths global energy (Invited)

    Science.gov (United States)

    Trenberth, K. E.

    2009-12-01

    With global mean temperatures in 2008 the lowest since 2000, but carbon dioxide increasing apace, where has global warming gone? We use available observations to estimate contributions to changes in the Earths radiation imbalance from changes in ocean heat content, sea level, sea ice, land ice, land heat, and atmospheric temperatures. Sea level rise slowed somewhat with the double La Nia in 2007-2008-2009 but not as much as the rise in ocean content appears to have, and the difference seems to be made up from increased melting of land ice (Greenland and Antarctica). However, such a change in the main contributions to sea level rise does not satisfy the energy budget, as a gain factor of about 50 is achieved by putting energy into melting land ice vs ocean expansion. Changes in the sun have contributed at the 12% level. CERES observations suggest an increase in absorbed energy, the opposite of what is required to balance the energy budget. If we can not understand what is happening in recent times, what business have we in considering geoengineering?

  2. Social Balance Theory

    CERN Document Server

    Khanafiah, D; Khanafiah, Deni; Situngkir, Hokky

    2004-01-01

    We construct a model based on social balance theory proposed by Fritz Heider to analyze the interpersonal network among social agents. The model of social balance theory provides us an interesting tool to see how a social group evolves to the possible balance state. We introduce the balance index that can be used to measure social balance in macro structure level (global balance index) or in micro structure (local balance index) to see how the local balance index influences the global balance structure. Several experiments are done and we discover how the social group can form separation of subgroups in a group or strengthening a social group while emphasizing the structure theorem and social mitosis previously introduced.

  3. Titan's Greenhouse Effect And Climate: Lessons From The Earth's Cooler Cousin

    Science.gov (United States)

    Nixon, Conor A.; Titan Climate White Paper Proposal Team

    2009-12-01

    We argue that continuing scientific study of Earth's `distant cousin Titan can provide a greater understanding and insight into the energy balance of our own planet's atmosphere. Titan's Earth-like properties have been recognized for some time, from the discovery of its atmosphere in 1907, through the Voyager 1 encounter in 1980 that showed Titan's atmosphere is mostly nitrogen gas with a surface pressure within a factor of two of terrestrial. Calculation shows that Titan's atmosphere causes `greenhouse warming of the surface, an effect similar to that seen on the Earth, Mars, and Venus. In the 1990s, direct imaging from the Earth by adaptive optics revealed that Titan's ubiquitous haze layer is slowly changing in apparent response to the seasons that occur due to the Saturn system's obliquity. The NASA Cassini mission that arrived in Saturnian orbit in 2004, and the ESA Huygens Titan probe of 2005, have returned a flood of new data regarding this intriguing world. For the first time, we are building a detailed picture of weather in the lower atmosphere, where condensable methane takes on the role played by water in the Earth's atmosphere, leading to methane rainfall, rivers and lakes. We examine parallels between the atmospheres of Earth and of Titan, including the possibilities for dramatic climate change. Extending the duration of the Cassini spacecraft mission during the next decade will provide part of the needed picture, but in addition we urge planning for a future new mission focused on Titan's climate, and other measures.

  4. Digital Earth - A sustainable Earth

    Science.gov (United States)

    Mahavir

    2014-02-01

    All life, particularly human, cannot be sustainable, unless complimented with shelter, poverty reduction, provision of basic infrastructure and services, equal opportunities and social justice. Yet, in the context of cities, it is believed that they can accommodate more and more people, endlessly, regardless to their carrying capacity and increasing ecological footprint. The 'inclusion', for bringing more and more people in the purview of development is often limited to social and economic inclusion rather than spatial and ecological inclusion. Economic investment decisions are also not always supported with spatial planning decisions. Most planning for a sustainable Earth, be at a level of rural settlement, city, region, national or Global, fail on the capacity and capability fronts. In India, for example, out of some 8,000 towns and cities, Master Plans exist for only about 1,800. A chapter on sustainability or environment is neither statutorily compulsory nor a norm for these Master Plans. Geospatial technologies including Remote Sensing, GIS, Indian National Spatial Data Infrastructure (NSDI), Indian National Urban Information Systems (NUIS), Indian Environmental Information System (ENVIS), and Indian National GIS (NGIS), etc. have potential to map, analyse, visualize and take sustainable developmental decisions based on participatory social, economic and social inclusion. Sustainable Earth, at all scales, is a logical and natural outcome of a digitally mapped, conceived and planned Earth. Digital Earth, in fact, itself offers a platform to dovetail the ecological, social and economic considerations in transforming it into a sustainable Earth.

  5. Rare earths

    Science.gov (United States)

    Gambogi, J.

    2013-01-01

    Global mine production of rare earths was estimated to have declined slightly in 2012 relative to 2011 (Fig. 1). Production in China was estimated to have decreased to 95 from 105 kt (104,700 from 115,700 st) in 2011, while new mine production in the United States and Australia increased.

  6. Random walk and balancing

    CERN Document Server

    Borg, F G

    2004-01-01

    Presents a minireview of topics concerned with balancing in quiet (bipedal) standing, and balancing of a stick. In the focus is the apparent stochastic nature of the swaying of the human inverted pendulum.

  7. Polarization-balanced beamsplitter

    International Nuclear Information System (INIS)

    A beamsplitter assembly is disclosed that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting. 10 figs

  8. Magnetospheric plasma pressures in the midnight meridian: Observations from 2.5 to 35 RE

    International Nuclear Information System (INIS)

    Plasma pressure data from the ISEE 2 fast plasma experiment (FPE) were statistically analyzed to determine the plasma sheet pressure versus distance in the midnight local time sector of the near-earth (12-35 RE) magnetotail plasma sheet. The observed plasma pressure, assumed isotropic, was mapped along model magnetic field flux tubes (obtained from the Tsyganenko and Usmanov (1982) model) to the magnetic equator, sorted according to magnetic activity, and binned according to the mapped equatorial location. In regions (L approx-gt 12 RE) where the bulk of the plasma pressure was contributed by particles in the energy range of the FPE (70 eV to 40 keV for ions), the statistically determined peak plasma pressures vary with distance similarly to previously determined lobe magnetic pressures (i.e., in a time-averaged sense, pressure balance normal to the magnetotail magnetic equator in the midnight meridian is maintained between lobe magnetic and plasma sheet plasma pressures). Additional plasma pressure data obtained in the inner magnetosphere (2.5 E), where the magnetic field topology changes rapidly from a dipolar to a tail-like configuration, are compared with the observed pressure profiles. The quiet time transition region pressure estimates, obtained previously from inversions of empirical magnetic field models, bridge observations both interior to and exterior to the transition region in a reasonable manner. Quiet time observations and estimates are combined to provide profiles of the equatorial plasma pressure along the midnight meridian between 2.5 and 35 RE

  9. Balance control impairment in obese individuals is caused by larger balance motor commands variability.

    Science.gov (United States)

    Simoneau, Martin; Teasdale, Normand

    2015-01-01

    It is acknowledged that various factors impaired balance control. Among them, heavy body weight is associated with poor balance control because the location of the center of mass is further away from the ankle joint. Thus, a larger active ankle torque is required to counter the greater gravitational torque. Because balance motor commands have signal-dependent noise whose standard deviation increases with the absolute value of the neural control signal, it was hypothesized that faster center of pressure speed observed in obese individuals would be related to larger balance motor commands variability. A feedback-control model and parametric system identification technique was used to estimate the variability in the balance motor commands and neural controller parameters based on previously published experimental data. Results of the neuromechanical model confirmed that the balance motor commands of obese individuals are more variable than that of lean individuals. PMID:25455209

  10. Performance of balanced bellows safety relief valves

    International Nuclear Information System (INIS)

    By the nature of its design, the set point and lift of a conventional spring loaded safety relief valve are sensitive to back pressure. One way to reduce the adverse effects of the back pressure on the safety relief valve function is to install a balanced bellows in a safety relief valve. The metallic bellows has a rather wide range of manufacturing tolerance which makes the design of the bellows safety relief valve very complicated. The state-of-the-art balanced bellows safety relief valve can only substantially minimize, but cannot totally eliminate the back pressure effects on its set point and relieving capacity. Set point change is a linear function of the back pressure to the set pressure ratio. Depending on the valve design, the set point correction factor can be either greater or smaller than unity. There exists an allowable back pressure and critical back pressure for each safety relief valve. When total back pressure exceeds the Ra, the relieving capacity will be reduced mainly resulting from the valve lift being reduced by the back pressure and the capacity reduction factor should be applied in valve sizing. Once the Rc is exceeded, the safety relief valve becomes unstable and loses its over pressure protection capability. The capacity reduction factor is a function of system overpressure, but their relationship is non-linear in nature. (orig.)

  11. Preparation process of an yttrium (or one rare earth), one alkaline earth metal, copper and oxygen superconductive compound

    International Nuclear Information System (INIS)

    The present invention describes the fabrication at atmospheric pressure of a compound based on yttrium (or a rare earth), one alkaline earth metal, copper, and oxygen so as to get a high-tc superconductor material. 2 refs

  12. ISLSCP II Earth Radiation Budget Experiment (ERBE) Monthly Albedo, 1986-1990

    Data.gov (United States)

    National Aeronautics and Space Administration The goals of the Earth Radiation Budget Experiment (ERBE) are (1) to understand the radiation balance between the Sun, Earth, atmosphere, and space and (2) to...

  13. ISLSCP II Earth Radiation Budget Experiment (ERBE) Monthly Albedo, 1986-1990

    Data.gov (United States)

    National Aeronautics and Space Administration ABSTRACT: The goals of the Earth Radiation Budget Experiment (ERBE) are (1) to understand the radiation balance between the Sun, Earth, atmosphere, and space and...

  14. Objective assessment of postural balance through use of the variable resistance balance board.

    Science.gov (United States)

    Mechling, R W

    1986-05-01

    The purpose of this study was to evaluate postural balance with a practical clinical assessment tool. I evaluated eight men and eight women in their 20s, using a variable resistance balance board, to determine the deviation of their average center of pressure in the anterior-posterior plane during stance. The resulting data were compared with the average center of pressure deviation of eight men in their 20s as measured by Murray et al with a force platform. The difference between the two men's groups was not statistically significant (p less than .05). These findings suggest that physical therapists may determine average center of pressure data and may assign progressive balance tasks that match any patient's level of center of pressure control. PMID:3703933

  15. A seismologically consistent compositional model of Earths core

    Science.gov (United States)

    Badro, James; Ct, Alexander S.; Brodholt, John P.

    2014-01-01

    Earths core is less dense than iron, and therefore it must contain light elements, such as S, Si, O, or C. We use ab initio molecular dynamics to calculate the density and bulk sound velocity in liquid metal alloys at the pressure and temperature conditions of Earth's outer core. We compare the velocity and density for any composition in the (FeNi, C, O, Si, S) system to radial seismological models and find a range of compositional models that fit the seismological data. We find no oxygen-free composition that fits the seismological data, and therefore our results indicate that oxygen is always required in the outer core. An oxygen-rich core is a strong indication of high-pressure and high-temperature conditions of core differentiation in a deep magma ocean with an FeO concentration (oxygen fugacity) higher than that of the present-day mantle. PMID:24821817

  16. Future Satellite Gravimetry and Earth Dynamics

    CERN Document Server

    Flury, Jakob

    2005-01-01

    Currently, a first generation of dedicated satellite missions for the precise mapping of the Earths gravity field is in orbit (CHAMP, GRACE, and soon GOCE). The gravity data from these satellite missions provide us with very new information on the dynamics of planet Earth. In particular, on the mass distribution in the Earths interior, the entire water cycle (ocean circulation, ice mass balance, continental water masses, and atmosphere), and on changes in the mass distribution. The results are fascinating, but still rough with respect to spatial and temporal resolution. Technical progress in satellite-to-satellite tracking and in gravity gradiometry will allow more detailed results in the future. In this special issue, Earth scientists develop visions of future applications based on follow-on high-precision satellite gravimetry missions.

  17. Space vehicle with artificial gravity and earth-like environment

    Science.gov (United States)

    Gray, V. H. (inventor)

    1973-01-01

    A space vehicle adapted to provide an artificial gravity and earthlike atmospheric environment for occupants is disclosed. The vehicle comprises a cylindrically shaped, hollow pressure-tight body, one end of which is tapered from the largest diameter of the body, the other end is flat and transparent to sunlight. The vehicle is provided with thrust means which rotates the body about its longitudinal axis, generating an artificial gravity effect upon the interior walls of the body due to centrifugal forces. The walls of the tapered end of the body are maintained at a temperature below the dew point of water vapor in the body and lower than the temperature near the transparent end of the body. The controlled environment and sunlight permits an earth like environment to be maintained wherein the CO2/O2 is balanced, and food for the travelers is supplied through a natural system of plant life grown on spacecraft walls where soil is located.

  18. The Genesis of the Earth's Moon

    OpenAIRE

    De Aquino, Fran

    2015-01-01

    Here we show how in the early Earth, a matter column, which extended from the Earth's surface down to near the upper boundary of the outer core, it was vaporized due to a suddenly increase of temperature greater than 8,367C, and after ejected of the Earth by the enormous pressure at the bottom of the mantle (~136 GPa), forming posteriorly the Moon.

  19. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Sren

    2010-01-01

    The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust and...... trust and control made the problem of finding a balance between trust and control a once and for all decision the process perspective introduced here implies that balancing trust and control is an ongoing process of balancing and rebalancing. The implication for management is that the problem of...... balancing trust and control becomes an issue that deserve ongoing attention. This paper adds to the discussion on the relation between trust and control by showing that the process perspective reframes the problem of balancing trust and control. More generally, by demonstrating the importance of the process...

  20. Medical Devices Assess, Treat Balance Disorders

    Science.gov (United States)

    2009-01-01

    You may have heard the phrase as difficult as walking and chewing gum as a joking way of referring to something that is not difficult at all. Just walking, however, is not all that simple physiologically speaking. Even standing upright is an undertaking requiring the complex cooperation of multiple motor and sensory systems including vision, the inner ear, somatosensation (sensation from the skin), and proprioception (the sense of the body s parts in relation to each other). The compromised performance of any of these elements can lead to a balance disorder, which in some form affects nearly half of Americans at least once in their lifetimes, from the elderly, to those with neurological or vestibular (inner ear) dysfunction, to athletes with musculoskeletal injuries, to astronauts returning from space. Readjusting to Earth s gravity has a significant impact on an astronaut s ability to balance, a result of the brain switching to a different "model" for interpreting sensory input in normal gravity versus weightlessness. While acclimating, astronauts can experience headaches, motion sickness, and problems with perception. To help ease the transition and study the effects of weightlessness on the body, NASA has conducted many investigations into post-flight balance control, realizing this research can help treat patients with balance disorders on Earth as well. In the 1960s, the NASA-sponsored Man Vehicle Laboratory at the Massachusetts Institute of Technology (MIT) studied the effects of prolonged space flight on astronauts. The lab s work intrigued MIT doctoral candidate Lewis Nashner, who began conducting NASA-funded research on human movement and balance under the supervision of Dr. Larry Young in the MIT Department of Aeronautics and Astronautics. In 1982, Nashner s work resulted in a noninvasive clinical technique for assessing the cooperative systems that allow the body to balance, commonly referred to as computerized dynamic posturography (CDP). CDP employs a series of dynamic protocols to isolate and assess balance function deficiencies. The technology was based on Nashner s novel, engineering-inspired concept of balance as an adaptable collaboration between multiple sensory and motor systems. CDP proved useful not only for examining astronauts, but for anyone suffering from balance problems. Today, CDP is the standard medical tool for objectively evaluating balance control.

  1. A safety analysis of warhead balancing

    Energy Technology Data Exchange (ETDEWEB)

    Bott, T.F.

    1998-12-01

    Reentry vehicles (RVs) carrying warheads from ballistic missiles must be carefully balanced with the warhead in situ to prevent wobble as the RVs enter the earth`s atmosphere to prevent inaccuracy or loss of the warhead. This balancing is performed on a dynamic balancing machine that rotates the RV at significant angular velocities. Seizure of the spindle shaft of the machine could result in rapid deceleration of the rotating assembly, which could over-stress and shear bolts or other structures that attach the RV to the balancing machine. This could result in undesired motions of the RV and impact of the RV on equipment or structures in the work area. This potential safety problem has long been recognized in a general way, but no systematic investigation of the possible accident sequences had been performed. The purpose of this paper is to describe an integrated set of systems analysis techniques that worked well in developing a set of accident sequences that describe the motions of the RV following a spindle-shaft seizure event.

  2. Keeping Earth at work: Using thermodynamics to develop a holistic theory of the Earth system

    Science.gov (United States)

    Kleidon, Axel

    2010-05-01

    The Earth system is unique among terrestrial planets in that it is maintained in a state far from thermodynamic equilibrium. Practically all processes are irreversible in their nature, thereby producing entropy, and these would act to destroy this state of disequilibrium. In order to maintain disequilibrium in steady state, driving forces are required that perform the work to maintain the Earth system in a state far from equilibrium. To characterize the functioning of the Earth system and the interactions among its subsystems we need to consider all terms of the first and second law of thermodynamics. While the global energy balance is well established in climatology, the global entropy and work balances receive little, if any, attention. Here I will present first steps in developing a holistic theory of the Earth system including quantifications of the relevant terms that is based on the first and second laws of thermodynamics. This theory allows us to compare the significance of different processes in driving and maintaining disequilibrium, allows us to explore interactions by investigating the role of power transfer among processes, and specifically illustrate the significance of life in driving planetary disequilibrium. Furthermore, the global work balance demonstrates the significant impact of human activity and it provides an estimate for the availability of renewable sources of free energy within the Earth system. Hence, I conclude that a holistic thermodynamic theory of the Earth system is not just some academic exercise of marginal use, but essential for a profound understanding of the Earth system and its response to change.

  3. Identifying Balance in a Balanced Scorecard System

    Science.gov (United States)

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of

  4. Conclusion: The balanced company

    DEFF Research Database (Denmark)

    Scheuer, John Damm; Jensen, Inger

    This concluding chapter brings together the various research findings of the book "The balanced company - organizing for the 21st Century" and develops a general overview of their implications for our understanding of the balancing processes unfolding in companies and organizations....

  5. Leadership: A Balancing Act

    Science.gov (United States)

    Hines, Thomas E.

    2011-01-01

    Maintaining balance in leadership can be difficult because balance is affected by the personality, strengths, and attitudes of the leader as well as the complicated environment within and outside the community college itself. This article explores what being a leader at the community college means, what the threats are to effective leadership, and

  6. The EarthCARE Power System

    Science.gov (United States)

    Ruf, Daniel; Beaufils, Gilles

    2011-10-01

    This paper describes the Electrical Power System of the EarthCARE satellite. EarthCARE is an Earth-observation mission aiming to improve the understanding of the Earth's radiation balance. It will fly in a specifically low polar Earth orbit with an altitude of around 400 km. The satellite with an orbit average power demand of about 1700 W is supplied by an unregulated 28 V power bus. Electrical power is generated by a deployable, rotating solar array with an active area of 21.5 m2. Energy is stored by a Li-Ion battery with a capacity of 326 Ah. The central Power Conditioning and Control Unit controls the solar array power by maximum power point tracking. It distributes protected power supply lines to the electrical units, heaters and release initiators.

  7. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, Sren

    This paper focuses on the leadership challenge of balancing trust and control. The relation between trust and control has for a long time been a puzzling issue for management researchers. In the paper I first show that there has been a dramatic change in the way the relation between trust and...... control has been conceptualized in trust research. While the relation between trust and control earlier was conceptualized as a more or less stable balance between trust and control, more recent research conceptualizes the relation between trust and control more as a dynamical process that involves an...... ongoing process of balancing the relation between trust and control. Second, taking the departure in the recent conceptualization of the balance between trust and control as an interactive process I discuss the challenges for management in handling this more subtle balancing of trust and control. The...

  8. Earth Observation Plan Focuses on User Needs and Measurements

    Science.gov (United States)

    Showstack, Randy

    2014-09-01

    The White House's new U.S. National Plan for Civil Earth Observations focuses on user needs and measurements while defining a framework for constructing a balanced portfolio of Earth observations and observing systems, officials with the White House Office of Science and Technology Policy (OSTP) said at a 4 September forum about the plan.

  9. Procedure for Balancing an Air Distribution System with Decentralised Fan

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Gran; Vorre, Anders; Afshari, Alireza; Bergse, Niels Christian

    2015-01-01

    This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally introduce pressure drops in the duct system thus nominal airflows are achieved throughout the ductwork within specified tolerances. However, introduction of pressure drops will increase energy requirement ...

  10. Errors in potassium balance

    International Nuclear Information System (INIS)

    Six overweight adult subjects given a low calorie diet containing adequate amounts of nitrogen but subnormal amounts of potassium (K) were observed on the Clinical Research Center for periods of 29 to 40 days. Metabolic balance of potassium was measured together with frequent assays of total body K by 40K counting. Metabolic K balance underestimated body K losses by 11 to 87% (average 43%): the intersubject variability is such as to preclude the use of a single correction value for unmeasured losses in K balance studies

  11. Near-earth Thin Current Sheets and Birkeland Currents during Substorm Growth Phase

    International Nuclear Information System (INIS)

    Two important phenomena observed during the magnetospheric substorm growth phase are modeled: the formation of a near-Earth (|X| ? 9 RE) thin cross-tail current sheet, as well as the equatorward shift of the ionospheric Birkeland currents. Our study is performed by solving the 3-D force-balance equation with realistic boundary conditions and pressure distributions. The results show a cross-tail current sheet with large current (J? ? 10 nA/m2) and very high plasma ? (? ? 40) between 7 and 10 RE. The obtained region-1 and region-2 Birkeland currents, formed on closed field lines due to pressure gradients, move equatorward and become more intense (Jparallelmax ? 3 (micro)A/m2) compared to quiet times. Both results are in agreement with substorm growth phase observations. Our results also predict that the cross-tail current sheet maps into the ionosphere in the transition region between the region-1 and region-2 currents

  12. Rotating Balances Used for Fluid Pump Testing

    Science.gov (United States)

    Skelley, Stephen; Mulder, Andrew

    2014-01-01

    Marshall Space Flight Center has developed and demonstrated two direct read force and moment balances for sensing and resolving the hydrodynamic loads on rotating fluid machinery. These rotating balances consist of a series of stainless steel flexures instrumented with semiconductor type, unidirectional strain gauges arranged into six bridges, then sealed and waterproofed, for use fully submerged in degassed water at rotational speeds up to six thousand revolutions per minute. The balances are used to measure the forces and moments due to the onset and presence of cavitation or other hydrodynamic phenomena on subscale replicas of rocket engine turbomachinery, principally axial pumps (inducers) designed specifically to operate in a cavitating environment. The balances are inserted into the drive assembly with power to and signal from the sensors routed through the drive shaft and out through an air-cooled twenty-channel slip ring. High frequency data - balance forces and moments as well as extensive, flush-mounted pressures around the rotating component periphery - are acquired via a high-speed analog to digital data acquisition system while the test rig conditions are varied continuously. The data acquisition and correction process is described, including the in-situ verifications that are performed to quantify and correct for known system effects such as mechanical imbalance, "added mass," buoyancy, mechanical resonance, and electrical bias. Examples of four types of cavitation oscillations for two typical inducers are described in the laboratory (pressure) and rotating (force) frames: 1) attached, symmetric cavitation, 2) rotating cavitation, 3) attached, asymmetric cavitation, and 4) cavitation surge. Rotating and asymmetric cavitation generate a corresponding unbalanced radial force on the rotating assembly while cavitation surge generates an axial force. Attached, symmetric cavitation induces no measurable force. The frequency of the forces can be determined a priori from the pressure environment while the magnitude of the hydrodynamic force is proportional to the pressure unsteadiness.

  13. Diasporic Trauma in Unaccustomed Earth

    Directory of Open Access Journals (Sweden)

    Ling YUN

    2014-04-01

    Full Text Available Jhumpa Lahiri is a famous Indian American author whose works consistently deal with the themes like diaspora, dislocation and belonging. She explores the trauma of diaspora in her third book Unaccustomed Earth in which the characters suffer from the loss of a traditional culture, death of a family member, the sense of rootlessness, double consciousness and generation conflicts. This paper argues that only by renegotiating the relationship between the past and present, keeping the balance between memories and forgetting, can characters in the novel gradually work through their trauma and reconstruct a new identity.

  14. Dizziness and Balance

    Science.gov (United States)

    ... Complaints of vertigo or dizziness Audiology Information Series © ASHA 2015 10802 • Balance dysfunction • Difficulty walking • Suspected disease ... certified by the American Speech-Language-Hearing Association (ASHA), call the ASHA Action Center at 800-638- ...

  15. National Energy Balance - 1984

    International Nuclear Information System (INIS)

    The National Energy Balance - 1984 shows energy fluxes of several primary and secondary energy sources, since the productions to final consumption in the main economic sectors, since 1973 to 1983. (E.G.)

  16. National Energy Balance - 1985

    International Nuclear Information System (INIS)

    The National Energy Balance - 1985 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1974 to 1984 (E.G.)

  17. National Energy Balance-1987

    International Nuclear Information System (INIS)

    The National Energy Balance - 1987 showns energy fluxes of several primary and secondary energy sources, since the production to final consumption in the main economic sectors, since 1971 to 1986. (E.G.)

  18. Energy balances 2000

    International Nuclear Information System (INIS)

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 2000 are presented for comparison. (EHS)

  19. The Balanced Literacy Diet.

    Science.gov (United States)

    Willows, Dale

    2002-01-01

    Describes professional development program in Ontario school district to improve student reading and writing skills. Program used food-pyramid concepts to help teacher learn to provide a balanced and flexible approach to literacy instruction based on student needs. (PKP)

  20. Solar influence on Earths climate

    Science.gov (United States)

    Thiblemont, Rmi; Matthes, Katja

    2015-08-01

    Understanding the influence of solar variability on the Earths climate requires knowledge of solar variability, solar-terrestrial interactions and observations, as well as mechanisms determining the response of the Earths climate system. A summary of our current understanding from observational and modeling studies will be presented with special focus on the top-down stratospheric UV and the bottom-up air-sea coupling mechanisms to discuss the influence of the solar forcing on climate natural variability.

  1. Balancing beyond the horizon?

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    2011-01-01

    The present article seeks to make sense of recent European Union (EU) naval capability changes by applying neo-realist theory to the EU as a collective actor in the global balance of power. The paper compares two different strands of neorealist theory by deducing key predictions about the expected......-term balancing strategy aimed at bolstering the autonomy and international influence of the Union vis-a`-vis other major powers, including the USA....

  2. Bruhat and balanced graphs

    OpenAIRE

    Ehrenborg, Richard; Readdy, Margaret A.

    2013-01-01

    We generalize chain enumeration in graded partially ordered sets by relaxing the graded, poset and Eulerian requirements. The resulting balanced digraphs, which include the classical Eulerian posets having an R-labeling, implies the existence of the (non-homogeneous) cd-index, a key invariant for studying inequalities for the flag vector of polytopes. Mirroring Alexander duality for Eulerian posets, we show an analogue of Alexander duality for balanced digraphs. For Bruhat graphs of Coxeter g...

  3. Procedure for Balancing an Air Distribution System with Decentralised Fan

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Gran

    2015-01-01

    This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally introduce pressure drops in the duct system thus nominal airflows are achieved throughout the ductwork within specified tolerances. However, introduction of pressure drops will increase energy requirement for the ventilation system and in addition, balancing a duct system is a time consuming task and often flawed. This paper presents a new procedure for balancing of CAV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan pressure requirements the fan was dimensioned for the branch with the least pressure resistance. The decentralised fans then provided sufficient pressure to overcome the exact resistance in the corresponding branch. The results show that by using decentralised fans in duct systems instead of dampers there is a potential for energy saving. In this study the calculated saving in the power consumption for the main fan was found to be 40%. The results also show that when dampers are replaced with decentralised fans with the same efficiency the overall power saving potential was 16%. In the study a mock-up of the calculated ventilation system was tested. Results from the calculations and the measurements showed a good correlation and the balancing procedure was acceptable

  4. Thermodynamics of the Earth

    International Nuclear Information System (INIS)

    Applications of elementary thermodynamic principles to the dynamics of the Earth lead to robust, quantitative conclusions about the tectonic effects that arise from convection. The grand pattern of motion conveys deep heat to the surface, generating mechanical energy with a thermodynamic efficiency corresponding to that of a Carnot engine operating over the adiabatic temperature gradient between the heat source and sink. Referred to the total heat flux derived from the Earth's silicate mantle, the efficiency is 24% and the power generated, 7.7 x 1012 W, causes all the material deformation apparent as plate tectonics and the consequent geological processes. About 3.5% of this is released in seismic zones but little more than 0.2% as seismic waves. Even major earthquakes are only localized hiccups in this motion. Complications that arise from mineral phase transitions can be used to illuminate details of the motion. There are two superimposed patterns of convection, plate subduction and deep mantle plumes, driven by sources of buoyancy, negative and positive respectively, at the top and bottom of the mantle. The patterns of motion are controlled by the viscosity contrasts (>104 : 1) at these boundaries and are self-selected as the least dissipative mechanisms of heat transfer for convection in a body with very strong viscosity variation. Both are subjects of the thermodynamic efficiency argument. Convection also drives the motion in the fluid outer core that generates the geomagnetic field, although in that case there is an important energy contribution by compositional separation, as light solute is rejected by the solidifying inner core and mixed into the outer core, a process referred to as compositional convection. Uncertainty persists over the core energy balance because thermal conduction is a drain on core energy that has been a subject of diverse estimates, with attendant debate over the need for radiogenic heat in the core. The geophysical approach to thermal physics, especially thermal expansion and the Grueneisen parameter, invokes insights that have disappeared from view in 'mainstream' physics.

  5. Balances instruments, manufacturers, history

    CERN Document Server

    Robens, Erich; Kiefer, Susanne

    2014-01-01

    The book deals mainly with direct mass determination by means of a conventional balances. It covers the history of the balance from the beginnings in Egypt earlier than 3000 BC to recent developments. All balance types are described with emphasis on scientific balances. Methods of indirect mass determination, which are applied to very light objects like molecules and the basic particles of matter and celestial bodies, are included.  As additional guidance, today’s manufacturers are listed and the profile of important companies is reviewed. Several hundred photographs, reproductions and drawings show instruments and their uses. This book includes commercial weighing instruments for merchandise and raw materials in workshops as well as symbolic weighing in the ancient Egyptian’s ceremony of ‘Weighing of the Heart’, the Greek fate balance, the Roman  Justitia, Juno Moneta and Middle Ages scenes of the Last Judgement with Jesus or St. Michael and of modern balances. The photographs are selected from the...

  6. Free oscillation of the Earth

    Directory of Open Access Journals (Sweden)

    Y. Abedini

    2000-06-01

    Full Text Available This work is a study of the Earths free oscillations considering a merge of solid and liquid model. At the turn of 19th century Geophysicists presented the theory of the free oscillations for a self-gravitating, isotropic and compressible sphere. Assuming a steel structure for an Earth size sphere, they predicted a period of oscillation of about 1 hour. About 50 years later, the free oscillations of stars was studied by Cowling and others. They classified the oscillation modes of the stars into acoustic and gravity modes on the basis of their driving forces. These are pressure and buoyancy forces respectively. The earliest measurements for the period of the free oscillations of the Earth was made by Benyove from a study of Kamchathca earthquake. Since then, the Geophysicists have been trying to provide a theoretical basis for these measurements. Recently, the theory concerning oscillations of celestial fluids is extended by Sobouti to include the possible oscillations of the Earthlike bodies. Using the same technique, we study the free oscillations of a spherically symmetric, non-rotating and elastic model for the Earth. We used the actual data of the Earths interior structure in our numerical calculations. Numerical results show that there exist three distinct oscillation modes namely acoustic, gravity and toroidal modes. These modes are driven by pressure, buoyancy and shear forces respectively. The shear force is due to the elastic properties of the solid part of the Earth. Our numerical results are consistent with the seismic data recorded from earthquake measurements.

  7. The Effects of Virtual Reality-based Balance Training on Balance of the Elderly.

    Science.gov (United States)

    Cho, Gyeong Hee; Hwangbo, Gak; Shin, Hyung Soo

    2014-04-01

    [Purpose] The objective of this study was to determine the effects of virtual reality-based balance training on balance of the elderly. [Methods] The subjects were 32 healthy elderly people aged between 65 and 80, who were divided into a VR (virtual reality) training group (n=17) and a control group (n=15). The VR training group engaged in a 30-minute exercise session using Wii Fit three times a week for eight weeks, while the control group received no intervention. The balance of the two groups was measured before and after the intervention. [Results] According to the Romberg Test conducted to examine the effects of the training on balance, both the area covered by the body's center of pressure movement, and movement distances per unit area of the body's center of pressure envelope significantly decreased in the VR training group. Moreover, the two groups showed significant differences in balance. [Conclusion] Virtual reality training is effective at improving the balance of the healthy elderly. Thus, virtual reality training can be proposed as a form of fall prevention exercise for the elderly. PMID:24764645

  8. Assessment of the Hf-N, Zr-N and Ti-N phase diagrams at high pressures and temperatures: balancing between MN and M3N4 (M = Hf, Zr, Ti)

    International Nuclear Information System (INIS)

    We study the nitrogen-rich part of the phase diagram Hf-N, Zr-N and Ti-N, employing first-principle calculations for an assessment of energy and enthalpy as a function of pressure. At zero pressure the novel cubic Th3P4-type structures are metastable modifications of M3N4 (M = Hf,Zr). The lowest energy configuration of both compounds is an orthorhombic Zr3N4-type. This orthorhombic structure will transform into the Th3P4-type at 9 and 6 GPa, for Hf3N4 and Zr3N4, respectively. The lowest energy configuration of Ti3N4 is a CaTi2O4-type structure. It will first transform into the orthorhombic Zr3N4-type at 3.8 GPa, then further transform into the cubic Th3P4-type at 15 GPa. The spinel type is metastable throughout the phase diagram for all three systems. The phase boundary between mononitrides MN and the M3N4-phases is accessed as a function of pressure. We include the entropy of gaseous nitrogen from tabulated data to estimate the free enthalpy ?G of the nitride phases. The orthorhombic modification of Hf3N4 turns out to be thermodynamically stable with respect to a decomposition into the mononitrides and nitrogen for temperatures up to about 1000 deg. C. The stability of Zr3N4 is in question; within the estimated error no final conclusion can be drawn. Ti3N4, on the other hand, will only be metastable. At higher pressures, however, the free energy of nitrogen is substantially reduced and the 3:4 compositions become more stable. We reproduce the experimental requirements (18 GPa and 2800 K) for the synthesis of the novel Hf3N4. At 2800 K the pressures needed to synthesize cubic phases of Zr3N4 and Ti3N4 are estimated to be 40 and 100 GPa, respectively

  9. Watt and joule balances

    Science.gov (United States)

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated prior to a decision on redefinition. The CCM had already recognized that agreement was close and has set in place a process whereby redefinition can take place by 2018. The final decision will be in the hands of the Conférence Générale des Poids et Mesures (CGPM) but the results reported here should aid a positive decision. Figure 1. Figure 1. Results from recent measurements of the Planck constant. The reference for the results h 90 is derived from the conventional values of the Josephson constant K J-90 and the von Klitzing constant R K-90. The factor of ten improvement in uncertainty of the NRC watt balance result, over that achieved by the same apparatus at NPL a few years earlier, can be understood as a factor of five improvement arising from the elimination of an effect discovered at NPL that could not be eliminated before shipment to Canada and a factor of two arising from the considerable improvements made by NRC. Once the kilogram has been redefined, the watt and joule balances will complete their transitions from instruments that are primarily of interest to the electrical community for determining the SI electrical units from the mechanical units, to the principal methods by which an individual National Measurement Institute (NMI) can make an independent determination of the SI unit of mass and thereby contribute to the maintenance of national and international mass scales. This special issue gives an introduction to the diversity of techniques which are required for the operation of watt and joule balances. However it does not contain a review of existing balances; this was a deliberate decision, as a number of such review papers have been published in the past five years [3-7] and it was felt that it was not yet time for another. The first technique considered is that of gravimetry; the watt balance measures the weight Mg of a mass M , and to convert the measured weight into a mass, the value of the acceleration due to gravity g must be known, at the time of the weighing and at the centre of gravity of the mass. The paper by Liard and his co-authors at NRC describes how they have made this essential measurement. The accuracy of the watt balance may also depend on the alignment of the apparatus. Two papers deal with this important issue. The first, by Sanchez and his co-authors at NRC, shows that their balance is insensitive to a range of alignments and concentrates on the essential alignments that contribute directly to the overall uncertainty of the apparatus. Thomas and his co-authors at LNE describe their technique for reducing uncertainties in their watt balance by aligning its coil in the field of the magnet to minimize both horizontal forces and torques about horizontal axes. The search for discrepancies between the results from watt balances has encouraged researchers to consider possible error mechanisms arising from the secondary electrical interactions between the coil of a watt balance and other parts of the apparatus. Researchers from INRIM have two such papers: one considering magnetic interactions and the other considering electrostatic interactions. It is essential that such investigations are carried out: both to prove that the problems are understood and for the guidance of those building the next generation of watt and joule balances. The next four papers describe aspects of the construction of watt balances. The BIPM watt balance group describe the principles behind their simultaneous measurement scheme for a watt balance. The balance that they are constructing can also be used in the conventional two-phase mode and their paper describes the relative advantages and disadvantages of the two modes of operation. In a watt balance there are some advantages to precise vertical movement of the coil. The METAS group describe the two mechanisms that they have tested to achieve such motion and give the reasons for the choice of mechanism for use in the balance that they are constructing. The KRISS watt balance group are in the initial phases of the design and construction of a watt balance and their paper provides valuable information on the design that they are building. The design of the main magnet of a watt balance is critical to its successful operation, and an important assumption of watt balance operation is that the field of the magnet in moving mode is equivalent to that in weighing mode. Sutton and Clarkson from MSL describe a novel magnet which is designed to address this issue. The international prototype of the kilogram is kept in air but, after redefinition, the best realizations of the mass unit will be in vacuum. In their paper Berry and Davidson from NPL describe progress in techniques which relate mass measured in vacuum to that measured in air. Such techniques will be essential for making the results of watt and joule balance measurements available to science and industry. Both the NIST and NPL Mark II (NRC) watt balances use knife edges to act as the pivots for the beam. Knife edges suffer from hysteresis which can produce systematic offsets during weighing. In their paper Choi (KRISS) and Robinson (NPL) describe the analysis of this problem using both finite element (FEM) techniques and a stand-alone balance designed for testing knife edges. The last two papers deal with the possible future of the watt balance technique. The BIPM simultaneous measurement scheme for the watt balance was originally conceived for operation at cryogenic temperatures with a superconducting coil. In their paper de Mirandes and her co-authors describe initial work on the principles of this superconducting variant of the BIPM watt balance and concentrate on the characteristics of the superconducting coil in comparison with those of a normal coil. The final paper is a good example of serendipity in which Kibble (Independent Consultant) was designing novel watt balances based on seismometer suspensions and Robinson (NPL) had derived a set of general expressions, which are required for a watt balance to be immune to a range of common misalignments but also lead to the design of watt balances with a range of coil motions. The combination of these techniques has led to the novel watt balance designs which are described. Finally I would like to thank: the editor of Metrologia and the editorial staff of IOP Publishing, the referees who have responded rapidly to requests and have kept the issue on schedule, and the authors who have taken the time to provide a range of papers showing the breadth of the work required to build and operate watt or joule balances. References [1] Andreas B et al 2011 Determination of the Avogadro constant by counting the atoms in a 28Si crystal Phys. Rev. Lett. 106 030801 [2] BIPM 2013 Report of the 14th Meeting of the CCM Sèvres pp 34-7 [3] Steiner R 2013 History and progress on accurate measurements of the Planck constant Rep. Prog. Phys. 76 016101 [4] Stock M 2013 Watt balance experiments for the determination of the Planck constant and the redefinition of the kilogram Metrologia 50 R1-16 [5] Li S, Han B, Li Z and Lan J 2012 Precisely measuring the Planck constant by electromechanical balances Measurement 45 1-13 [6] Eichenberger A, Genevès G and Gournay P 2009 Determination of the Planck constant by means of a watt balance Eur. Phys. J. Spec. Top. 172 363-83 [7] Robinson I A 2009 Toward the redefinition of the kilogram: measurements of Planck's constant using watt balances IEEE Trans. Instrum. Meas. 58 942-8

  10. Cloud radiation interaction and the Earth's climate: Relevance to the climate of the Arctic

    International Nuclear Information System (INIS)

    The influence on the energy balance of the earth's climate system is reviewed and is based on recent satellite observations of the Earth's Radiation Budget (ERB) and other satellite-derived cloud information. The special difficulties that polar cloudiness poses in analysis of ERB data are discussed. The role of arctic cloudiness on the snow-ice albedo feedback is examined and the possible influence of this feedback to global cloudiness and thus to the radiation balance on the earth are explored

  11. Pressure vessel for a nuclear power station

    International Nuclear Information System (INIS)

    This proposal concerns the temperature balance inside a pressure vessel of reinforced concrete which is provided with a certain number of caverns covered with a metallic layer. In the center is a gas cooled high temperature nuclear reactor. Inside the pressure vessel there is a closed loop system where a cooling medium transports heat from places with high temperature to places with lower temperature. This ensures the temperature balance for avoiding thermal stresses in the pressure vessel walls. (UWI)

  12. Systems' optimization: Achieving the balance

    Science.gov (United States)

    Kraus, Peter

    1994-04-01

    Fuel cells for stationary power generation applications are being pursued on a large scale worldwide in an effort to achieve commercialization before the turn of the century. Some aspects of system optimization are discussed illustrating the influence of basic system design possibilities. Design variants investigated include alternatives for anode and cathode gas supply and gas recycling, methods to achieve self-sufficiency on water for the reforming of natural gas, and recovery of unspent fuel from the anode exhaust. Especially in small systems for decentralized applications, e.g., industrial cogeneration, system simplification is decisive to bring down the capital cost of the balance-of-plant. Trade-offs between system complexity and efficiency are possible to optimize the economy. In large plants, high-temperature fuel cell can be supplemented with bottoming cycles for best fuel utilization. Gas turbines and steam turbines can be evaluated, having strong influence on the system design pressures and, therefore, system cost.

  13. Balanced articulated manipulator

    International Nuclear Information System (INIS)

    The description is given of a manipulator of the type comprising a master arm and a slave arm, capable of working in a containment restricted by a wall fitted with an aperture to introduce the slave arm into the containment. According to the invention this manipulator is permanently balanced irrespective of its distortions when it is secured to the wall of the containment in which it is desired to work. The entire manipulator is also balanced when being set up and when moved outside the containment, in relation to a supporting axle. This result is achieved in a simplified manner by giving homothetic shapes to the various component parts of the slave and master arms, the master arm having at least one balancing weight

  14. The Balanced Company

    DEFF Research Database (Denmark)

    Controlling the sustainability of production processes and ethical employment of the work force in suppliers' production facilities far away from the home country has resulted in new challenges for managers. They now have to consider how important it is for customers, investors and employees to see...... that a company is respected in wider society and behaves according to ethical standards. Strategists and Leaders need to make balanced choices about long-term goals and the allocation of resources. They need to analyse, understand and adjust strategies to market, political, value and technology related...... to achieve goals through control or trust. Human resource specialists need to make balanced decisions about how to design tasks and jobs in order to make them attractive as well as motivating. Marketers need to make balanced decisions about how to market products in the light of what is now important...

  15. Why Earth Science?

    Science.gov (United States)

    Smith, Michael J.

    2004-01-01

    This article briefly describes Earth science. The study of Earth science provides the foundation for an understanding of the Earth, its processes, its resources, and its environment. Earth science is the study of the planet in its entirety, how its lithosphere, atmosphere, hydrosphere, and biosphere work together as systems and how they affect

  16. In the balance

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    The present paper seeks to make sense of recent EU naval capability changes by applying neo-realist theory on the EU as an international actor in the global balance of power. The paper compares three different strands of Neo-realist theory by deducting key predictions about the expected defense...... posture of the Union and the expected changes in naval capabilities. The predictions are subsequently held up against recent data on naval military build-up in the EU. The paper argues that the observed patterns are best explained not as bandwagoning with the United States, but as a long-term balancing...

  17. Multidimensional spectral load balancing

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, B.; Leland, R.

    1993-01-01

    We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.

  18. Finding Your Balance

    CERN Document Server

    (CCL), Center for Creative Leadership; Patterson, Gordon

    2011-01-01

    Balance isn't an issue of time, but an issue of choice. It's about living your values by aligning your behavior with what you believe is really important. Aligning your behavior with your values is much like any other developmental experience; the basic process involves assessment, challenge, and support. You need to determine where you are, define where you want to go, and then put into place the tools you need to get there.Balance is about more than how you spend your time. It's about how you live your life. It's about recognizing that you have control over the choices you make and aligning

  19. Getting the balance right

    International Nuclear Information System (INIS)

    This 8 page leaflet is published by the Nuclear Electricity Information Group (NEIG) which is made up of eight different bodies working within the nuclear industry. It aims to present a balanced outline of the facts needed to form an opinion about energy policy in the UK. It looks at the price of electricity, other sources of electricity, (oil and coal, solar power, wind power, water power), safety in the nuclear industry, nuclear waste disposal and risks from radiation. The NEIG is in favour of a balanced energy programme with nuclear energy being only a part of the overall scheme. (U.K.)

  20. The Earth's atmosphere its physics and dynamics

    CERN Document Server

    Saha, Kshudiram

    2008-01-01

    The book entitled ""Atmospheric science and Global Warming"" covers a wide area of the atmospheric science, focusing particularly on those physical and dynamical aspects of our environment which tend to create heat sources and sinks in the earth-atmosphere system and which it seeks to balance through circulation at different time and space scales. The processes of heat transfer in the atmosphere and ocean by general circulation and by waves and oscillations are discussed in detail. The heat balance of the atmosphere is discussed after taking into consideration the role of various types of gree

  1. Water and sodium balance in space

    DEFF Research Database (Denmark)

    Drummer, C; Norsk, P; Heer, M

    2001-01-01

    We have previously shown that fluid balances and body fluid regulation in microgravity (microG) differ from those on Earth (Drummer et al, Eur J Physiol 441:R66-R72, 2000). Arriving in microG leads to a redistribution of body fluid-composed of a shift of fluid to the upper part of the body and an exaggerated extravasation very early in-flight. The mechanisms for the increased vascular permeability are not known. Evaporation, oral hydration, and urinary fluid excretion, the major components of wa...

  2. Power balance limit in collective ion acceleration

    International Nuclear Information System (INIS)

    The power balance limit to the IREB beam front propagation velocity, as first applied to the problem of collective ion acceleration by Olson in 1973, is investigated in view of recent data of Ecker and Putnam. The beam front velocity ?/sub f/c as a function of IREB impedance Z is given, showing the dependence on the power balance limit, the ionization front velocity, and the runaway cutoff. The Olson theory predictions, with no fitted parameters, are shown to be in agreement with the data. Further comparisons of ?/sub f/ with respect to the IREB electron energy, the IREB current, and the neutral gas pressure are given. Various forms for the power balance limit are discussed; it is shown that inclusion of the secondary electron power loss term results in an essentially negligible correction to ?/sub f/ for typical data parameters. The power balance limit used by Ecker and Putnam is shown to be simply a 3-parameter curve fit, wherein the fitted parameters must exceed their allowed physical values to obtain a reasonable fit for ?/sub f/ vs Z. Further, it is shown that this curve fitting leads to serious disagreements with other aspects of the data. It is concluded that the original Olson theory adequately accounts for the data, and that the power balance limit for IREB/gas data is typically not significant except for very small values of Z

  3. High-pressure neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongwu [Los Alamos National Laboratory

    2011-01-10

    This lecture will cover progress and prospect of applications of high-pressure neutron diffraction techniques to Earth and materials sciences. I will first introduce general high-pressure research topics and available in-situ high-pressure techniques. Then I'll talk about high-pressure neutron diffraction techniques using two types of pressure cells: fluid-driven and anvil-type cells. Lastly, I will give several case studies using these techniques, particularly, those on hydrogen-bearing materials and magnetic transitions.

  4. Application of Pascal Principle in Earth Science

    Science.gov (United States)

    Samimi Namin, M.

    2009-12-01

    The Pascal experiment is interpreted and the chamber is roughly defined. Pascal experiment in relation to Pascal principle compared with a chamber in the earth crust. It is conclude that: 1: The pressure (P) inside the Pascal's cylinder is the combination of two pressure; the external pressure (P1) and the hydraulic pressure (P2). Pc=P1+P2 The direction of the force is from top to bottom. In the case of the chamber the pressure is Pch=P1-P2 and its positive direction is regarded to be from bottom to top. P1 is the external pressure, and is the maximum pressure applied to chamber .The external pressure creates a constant internal pressure throughout the chamber .The magnitude of the constant pressure is based on the litho static pressure of the bottom of the chamber; because it is the maximum pressure that the chamber is connected. P1=?1gH+?2gh Where H is the overburden thickness, h is the highness of the chamber, ?1 is the density of the overburden and ?2 is density of country rock. The hydrostatic pressure within the chamber is P2=?3gh. Also ?3 is the density of the chamber. So the pressure inside the chamber would be: Pch=P1-P2 then Pch=?1gH+(?2-?3)gh. The equation above means that, the chamber pressure equals to the overburden pressure plus Archimedes pressure. 2: The word squeezing which is a vulgar word has an important physical meaning that is ((Pascal principle driving movement)).In another word, almost all movements, related to chambers, within the earth are a squeezing event which's, driving force is the steady constant pressure mentioned above. Any change in this pressure depends on the rupturing of the chamber and the behavior of the movement of the chamber matter. 3: If we provide a safety valve on piston of the Pascal's cylinder and increase the load we see the safety valve bursts and the matter inside the cylinder squeeze out .The pressure is from top to bottom but the movement is from bottom to top. The direction of force has changed 180 degree. This is Pascal's miracle and displays the all movements that pierce the earth surface and let the matter squeeze out.

  5. Plasma pressure and anisotropy inferred from the Tsyganenkomagnetic field model

    Directory of Open Access Journals (Sweden)

    F. Cao

    Full Text Available A numerical procedure has been developed to deduce the plasma pressure and anisotropy from the Tsyganenko magnetic field model. The Tsyganenko empirical field model, which is based on vast satellite field data, provides a realistic description of magnetic field configuration in the magnetosphere. When the force balance under the static condition is assumed, the electromagnetic JB force from the Tsyganenko field model can be used to infer the plasma pressure and anisotropy distributions consistent with the field model. It is found that the JB force obtained from the Tsyganenko field model is not curl-free. The curl-free part of the JB force in an empirical field model can be balanced by the gradient of the isotropic pressure, while the nonzero curl of the JB force can only be associated with the pressure anisotropy. The plasma pressure and anisotropy in the near-Earth plasma sheet are numerically calculated to obtain a static equilibrium consistent with the Tsyganenko field model both in the noon-midnight meridian and in the equatorial plane. The plasma pressure distribution deduced from the Tsyganenko 1989 field model is highly anisotropic and shows this feature early in the substorm growth phase. The pressure anisotropy parameter ?P, defined as ?P=1-PVertP, is typically ~0.3 at x ? -4.5RE and gradually decreases to a small negative value with an increasing tailward distance. The pressure anisotropy from the Tsyganenko 1989 model accounts for 50% of the cross-tail current at maximum and only in a highly localized region near xsim-10RE. In comparison, the plasma pressure anisotropy inferred from the Tsyganenko 1987 model is much smaller. We also find that the boundary conditions have significant effects on the plasma pressure distributions and have to be considered carefully.

  6. Monitoring Earth's Climate with Shortwave Hyperspectral Reflectance

    Science.gov (United States)

    Pilewskie, Peter

    The Sun provides nearly all the energy that fuels the dynamical, chemical, and biological processes in the Earth system. Absorbed solar radiation, the difference between incoming and reflected sunlight, defines Earths equilibrium temperature and, along with the emitted infrared radiation, determines the climate state of the planet. The transfer of solar radiation through the atmosphere is modulated by wavelength-specific interactions that are unique for given surface types and the intervening atmospheric gases and condensed species. Reflected radiation that exits the Earths atmosphere carries with it the complex fingerprint of the Earth system state. How this signal varies temporally, spatially, and spectrally is a measure of those processes within the Earth system that affect climate change. Despite its importance to the basic energy balance between Earth and the solar-terrestrial environment in which it resides, a precise record of the nature of reflected solar spectral radiation over all climate-relevant time scales remains elusive. A primary goal of a climate observing system is to obtain climate benchmark data records with sufficient accuracy for identifying climate variability on decadal time scales and longer, and with sufficient information content to attribute change to underlying causes. Until recently, detecting climate change signatures in reflected solar radiance has been hindered by instrument accuracy and stability, insufficient spectral coverage and resolution, and inherent sampling limitations from low-Earth orbit observations. This talk will discuss the challenges to monitoring the shortwave energy budget from space. I will present new studies on methods to separate the various contributions in the top-of-atmosphere outgoing shortwave radiance using existing satellite (SCIAMACHY) data and explore methods to enhance trend detection in hyperspectral reflectance time series. Finally, I look ahead to the requirements for a climate observing system for monitoring shortwave hyperspectral reflectance, the Earth Climate Hyperspectral Observatory (ECHO).

  7. Strategic Balanced Scorecard Simulation

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    The purpose of this article is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The case companys BSC model includes five perspectives and a number of...

  8. Ballet Balance Strategies

    DEFF Research Database (Denmark)

    Pedersen, Camilla; Erleben, Kenny; Sporring, Jon

    2006-01-01

    Animating physically realistic human characters is challenging, since human observers are highly tuned to recognize human cues such as emotion and gender from motion patterns. The main contribution of this paper is a new model firmly based on biomechanics, which is used to animate balance and basic...

  9. Frihed, anerkendelse og balance

    DEFF Research Database (Denmark)

    Anker, Thomas Boysen

    Artiklen argumenterer for, at selv ikke den absolut mest familievenlige arbejdsplads vil kunne lse det psykologiske problem med at skabe balance mellem familie og arbejdsliv, fordi ubalancen grundlggende handler om en anerkendelseskonflikt, som individet ikke altid selv er interesseret i at komme...

  10. Yin-Yang Balancing

    DEFF Research Database (Denmark)

    Li, Peter Ping

    The potential contribution of the Eastern frame of Yin-Yang Balancing lies in the mindset of "either/and", in contrast to Aristotle's either/or logic and Hegel's "both/or". Implications of this either/and thinking for science and management will be explored....

  11. Lives in the Balance.

    Science.gov (United States)

    Our Children, 1997

    1997-01-01

    Changes in the workplace that would provide flexibility for working parents are slowly developing and receiving government, business, and societal attention. A sidebar, "Mother, Professional, Volunteer: One Woman's Balancing Act," presents an account of how one woman rearranged her professional life to enable her to do full-time parenting. (SM)

  12. National Energy Balance - 1981

    International Nuclear Information System (INIS)

    The National Energy Balance - 1981, shows a new metodology and information in level of several economic sectors, as well as a separation of primary and secondary energy sources, its energy fluxes, i.e. production, imports, exports, consumption, etc...(E.G.)

  13. National energy balance - 1977

    International Nuclear Information System (INIS)

    The national energy balance of the 1976 shows several modifications in relation to the last year. The historical serie is based in more confiable information, from several energy companies. The most greater modifications are on energy source of hard control, such as lignite and charcoal for non-siderurgic uses. (E.G.)

  14. National energy balance - 1978

    International Nuclear Information System (INIS)

    The national energy balance of 1978 shows some modifications in relation to the last year. New tables were included aiming to show the brazilian energy situation, such as the hydraulic potential and the non-renewable energy resources. (E.G.)

  15. Maintaining an Environmental Balance

    Science.gov (United States)

    Environmental Science and Technology, 1976

    1976-01-01

    A recent conference of the National Environmental Development Association focused on the concepts of environment, energy and economy and underscored the necessity for balancing the critical needs embodied in these issues. Topics discussed included: nuclear energy and wastes, water pollution control, federal regulations, environmental technology

  16. 1992 provisional energy balance

    International Nuclear Information System (INIS)

    This paper gives a provisional energy balance in France in 1992. After a brief study of economical and energy context in world wide, this paper gives informations about energy dependence ratio and evolutions of energy sources (electric power, coal, petroleum, natural gas), evolution of energy consumption. 1 fig,. 4 tab

  17. National Energy Balance - 1986

    International Nuclear Information System (INIS)

    The National Energy Balance - 1986 shows energy fluxes of several primary and secondary energy sources, since the production to the final consumption in the main economic sectors, since 1970 to 1985. The incorporation of a new brazilian information is done. (E.G.)

  18. Martian Atmospheric Pressure Static Charge Elimination Tool

    Science.gov (United States)

    Johansen, Michael R.

    2014-01-01

    A Martian pressure static charge elimination tool is currently in development in the Electrostatics and Surface Physics Laboratory (ESPL) at NASA's Kennedy Space Center. In standard Earth atmosphere conditions, static charge can be neutralized from an insulating surface using air ionizers. These air ionizers generate ions through corona breakdown. The Martian atmosphere is 7 Torr of mostly carbon dioxide, which makes it inherently difficult to use similar methods as those used for standard atmosphere static elimination tools. An initial prototype has been developed to show feasibility of static charge elimination at low pressure, using corona discharge. A needle point and thin wire loop are used as the corona generating electrodes. A photo of the test apparatus is shown below. Positive and negative high voltage pulses are sent to the needle point. This creates positive and negative ions that can be used for static charge neutralization. In a preliminary test, a floating metal plate was charged to approximately 600 volts under Martian atmospheric conditions. The static elimination tool was enabled and the voltage on the metal plate dropped rapidly to -100 volts. This test data is displayed below. Optimization is necessary to improve the electrostatic balance of the static elimination tool.

  19. On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earths Radiant Energy Balance

    OpenAIRE

    Roy W. Spencer; William D. Braswell

    2011-01-01

    The sensitivity of the climate system to an imposed radiative imbalance remains the largest source of uncertainty in projections of future anthropogenic climate change. Here we present further evidence that this uncertainty from an observational perspective is largely due to the masking of the radiative feedback signal by internal radiative forcing, probably due to natural cloud variations. That these internal radiative forcings exist and likely corrupt feedback diagnosis is demonstrated with...

  20. Seasonal contributions of precipitation to recharge: Completely different estimates from water budget and stable isotope balance

    International Nuclear Information System (INIS)

    The seasonal recharge into a karstified aquifer system of the Franconian Alb, southern Germany, was determined for 1995 and 1996 by balancing stable isotope composition of precipitation with that of ground water and by water balancing applying the empirical formula of Haude which introduces climatic parameters like mean daily temperature, humidity, and precipitation as well as the natural features of earth's surface

  1. Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

    Science.gov (United States)

    Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

    2012-01-01

    Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/ sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain s ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable providing imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles.

  2. The Lifeworld Earth and a Modelled Earth

    Science.gov (United States)

    Juuti, Kalle

    2014-01-01

    The goal of this paper is to study the question of whether a phenomenological view of the Earth could be empirically endorsed. The phenomenological way of thinking considers the Earth as a material entity, but not as an object as viewed in science. In the learning science tradition, tracking the process of the conceptual change of the shape of the

  3. Earth magnetism and the economic behavior

    OpenAIRE

    Melo, L

    2010-01-01

    This paper provides an analysis of how the current economic crisis and the changes in the earth magnetism can be an opportunity to develop an economic system based on more balanced economic relationships. Consciousness is fundamental to achieve this. A practical example, examined in the article, to understand how consciousness and the belief systems affect the observed reality, is associated with the effect that the credibility of economic authorities and individuals expectations have on the...

  4. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W; Heymsfield, S B; Thomas, D; Srensen, T I A; Speakman, J R; Jeansonne, M; Allison, D B

    2015-01-01

    infancy, it is unacceptable to use decidedly inaccurate instruments, which may misguide health-care policies, future research and clinical judgment. The scientific and medical communities should discontinue reliance on self-reported EI and PAEE. Researchers and sponsors should develop objective measures......Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance are in their...

  5. Pressure Dome for High-Pressure Electrolyzer

    Science.gov (United States)

    Norman, Timothy; Schmitt, Edwin

    2012-01-01

    A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom segment and is trapped by the flange on the top dome segment when these components are bolted together with high-strength bolts. The pressure dome has several unique features. It is made (to ASME Pressure Vessel guidelines) in a high-strength aluminum alloy with the strength of stainless steel and the weight benefits of aluminum. The flange of the upper dome portion contains specially machined flats for mounting the dome, and other flats dedicated to the special feedthroughs for electrical connections. A pressure dome can be increased in length to house larger stacks (more cells) of the same diameter with the simple addition of a cylindrical segment. To aid in dome assembly, two stainless steel rings are employed. One is used beneath the heads of the high-strength bolts in lieu of individual hardened washers, and another is used instead of individual nuts. Like electrolyzers could be operated at low or high pressures simply by operating the electrolyzer outside or inside a pressurized dome.

  6. National energy balance - 1976

    International Nuclear Information System (INIS)

    Based on available data from IBGE, CNP/Petrobras, Eletrobras, Nuclebras and other governmental enterprises the National Energy Balance was done. This publication covers since 1965 to 1975. In conformity to the international rules, the energy resources used for non-energy purposes were excluded. The energy production and consumption for the next ten years were forecasted, considering the actual brazilian energy policy. (E.G.)

  7. An ideal balance?

    OpenAIRE

    Mair, Jane

    2013-01-01

    Considers the intersection between employment policy and family law, and the changes in work and family regarding traditional gender roles. Examines UK and EU policy initiatives aimed at achieving a better work/life balance for employees with children. Argues that many of the policy aspirations are predicated on an equal opportunities employment model that may not exist in practice and also fail to reflect the realities of family life.

  8. Balancing beyond the horizon?

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    2011-01-01

    The present article seeks to make sense of recent European Union (EU) naval capability changes by applying neo-realist theory to the EU as a collective actor in the global balance of power. The paper compares two different strands of neorealist theory by deducing key predictions about the expected naval posture of the Union and the corresponding expected changes in capabilities. These predictions are subsequently held up against post-cold war data on naval acquisitions in the EU. The paper concl...

  9. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W; Heymsfield, S B; Thomas, D; Srensen, T I A; Speakman, J R; Jeansonne, M; Allison, D B

    2014-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific re...

  10. Balance-bot

    OpenAIRE

    Abreu, Victor Vicente

    2009-01-01

    Research on inverted pendulum has gained momentum over the last decade on a number of robotic laboratories over the world; due to its unstable proprieties is a good example for control engineers to verify a control theory. To verify that the pendulum can balance we can make some simulations using a closed-loop controller method such as the linear quadratic regulator or the proportionalintegralderivative method. Also the idea of robotic teleoperation is gaining ground. Control...

  11. Kin Selection - Mutation Balance

    DEFF Research Database (Denmark)

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamiltons rule is satisfie...

  12. Explosive Target Balances

    OpenAIRE

    Potrafke, Niklas; Reischmann, Markus

    2013-01-01

    Using the new unit root test by Phillips et al. (2011) we show that the Target balances of the German Bundesbank have been exploding from the beginning of 2009 to the beginning of 2013. By implementing a full-allotment policy and reducing the required minimum quality of collaterals in October 2008, the European Central Bank (ECB) refinanced credits in the GIIPS countries to a large extent. Private capital flowed out of the GIIPS countries (Greece, Italy, Ireland, Portugal and Spain), and the ...

  13. Simple Cell Balance Circuit

    Science.gov (United States)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  14. NASA Earth Exchange (NEX)

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Earth Exchange (NEX) represents a new platform for the Earth science community that provides a mechanism for scientific collaboration and knowledge...

  15. EarthKAM

    Data.gov (United States)

    National Aeronautics and Space Administration — Sponsored by NASA, EarthKAM (Earth Knowledge Acquired by Middle School Students) is an educational outreach program allowing middle school students to take pictures...

  16. Rigidly rotating dust with magnetic pressure in general relativity

    International Nuclear Information System (INIS)

    Rigidly rotating pressure-free matter interacting with an electromagnetic field is studied under the assumption that in the co-rotating frame the gravitational attraction is balanced by the centrifugal force and by magnetic pressure. (author)

  17. The fate of Earths ocean

    Directory of Open Access Journals (Sweden)

    C. Bounama

    2001-01-01

    Full Text Available Questions of how water arrived on the Earths surface, how much water is contained in the Earth system as a whole, and how much water will be available in the future in the surface reservoirs are of central importance to our understanding of the Earth. To answer the question about the fate of the Earths ocean, one has to study the global water cycle under conditions of internal and external forcing processes. Modern estimates suggest that the transport of water to the surface is five times smaller than water movement to the mantle, so that the Earth will lose all its sea-water in one billion years from now. This straightforward extrapolation of subduction-zone fluxes into the future seems doubtful. Using a geophysical modelling approach it was found that only 27% of the modern ocean will be subducted in one billion years. Internal feedbacks will not be the cause of the ocean drying out. Instead, the drying up of surface reservoirs in the future will be due to the increase in temperature caused by a maturing Sun connected to hydrogen escape to outer space. Keywords: Surface water reservoir, water fluxes, regassing, degassing, global water cycle

  18. The balanced scorecard: sustainable performance assessment for forensic laboratories.

    Science.gov (United States)

    Houck, Max; Speaker, Paul J; Fleming, Arron Scott; Riley, Richard A

    2012-12-01

    The purpose of this article is to introduce the concept of the balanced scorecard into the laboratory management environment. The balanced scorecard is a performance measurement matrix designed to capture financial and non-financial metrics that provide insight into the critical success factors for an organization, effectively aligning organization strategy to key performance objectives. The scorecard helps organizational leaders by providing balance from two perspectives. First, it ensures an appropriate mix of performance metrics from across the organization to achieve operational excellence; thereby the balanced scorecard ensures that no single or limited group of metrics dominates the assessment process, possibly leading to long-term inferior performance. Second, the balanced scorecard helps leaders offset short term performance pressures by giving recognition and weight to long-term laboratory needs that, if not properly addressed, might jeopardize future laboratory performance. PMID:23068771

  19. Rare earth elements

    International Nuclear Information System (INIS)

    Present article is devoted to content of rare earth elements in fluorite. The data on content of rare earth elements in fluorite was systematized and generalized. The 446 analysis results were used. The rare earth elements content in fluorite of geologic deposits of various mineralogical and genetic type was defined.

  20. Binary rare earth oxides

    CERN Document Server

    Adachi, G; Kang, ZC

    2006-01-01

    Introduces the unique characteristics of the binary rare earth oxides with their chemistry, physics and applicationsProvides a comprehensive review of all the characteristics of rare earth oxides, essential for scientists and engineers involved with rare earths, oxides, inorganic materials, ceramics, and structures

  1. Statistics of pressure and of pressure-velocity correlations in isotropic turbulence

    OpenAIRE

    Biferale, L.; Gualtieri, P; Toschi, F.

    2000-01-01

    Some pressure and pressure-velocity correlation in a direct numerical simulations of a three-dimensional turbulent flow at moderate Reynolds numbers have been analyzed. We have identified a set of pressure-velocity correlations which posseses a good scaling behaviour. Such a class of pressure-velocity correlations are determined by looking at the energy-balance across any sub-volume of the flow. According to our analysis, pressure scaling is determined by the dimensional ass...

  2. Balancing mechanism status: May 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for May 2009. (J.S.)

  3. Balancing mechanism status: January 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for January 2009. (J.S.)

  4. Balancing mechanism status: April 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for April 2009. (J.S.)

  5. Balancing mechanism status: February 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for February 2009. (J.S.)

  6. Balancing mechanism status: August 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for August 2009. (J.S.)

  7. Balancing mechanism status: July 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for July 2009. (J.S.)

  8. Balancing mechanism status: October 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for October 2009. (J.S.)

  9. Balancing mechanism status: December 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for December 2009. (J.S.)

  10. Balancing mechanism status: November 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for November 2009. (J.S.)

  11. Balancing mechanism status: September 2009

    International Nuclear Information System (INIS)

    RTE ensures the real-time balance between production and consumption and deals with congestion on the French electricity system. The Balancing Mechanism assists in the accomplishment of this task. As in many countries, and after extensive dialogue with representatives from the market's various players, RTE proposes a Balancing Mechanism in the form of a permanent and transparent system of calls for tender. The system is open to everyone and provides a real-time reserve of power that can be used for balancing either upward or downward. RTE takes advantage of these offers according to economic precedence, taking into account the system's operating conditions. It pays for them at the offer price. There are two types of offer: - Upward offer: increase in production, decrease in consumption, imports, - Downward offer: decrease in production, increase in consumption, exports. For a Balancing Entity, an offer systematically consists of: a balancing direction (upward/downward), a time period, a price that may vary according to six time slots. RTE publishes each month a Balancing Mechanism Report. which includes the following information: - energy volumes activated to ensure the balance of the system and to resolve congestion; - minimum and maximum prices of offers activated to balance the system; - daily trends calculated according to the predominant value of the overall upward or downward trend; - balancing shares by technology (nuclear, thermal, hydraulic); - characteristics of the five most activated balancing entities; - balances/imbalances accounts and production/consumption overcharge; - congestion curbing costs on the French electricity system; - energy volumes activated to ensure the balance of the system according to contracts between RTE and other Balance Responsible entities (UK, Belgium, Italy, Germany, Switzerland); - reliability of the provisional data supplied by RTE about the balancing trend; - availability of RTE's information services (planning, balancing mechanism, block exchange notification, market indicators). This report presents the above information for September 2009. (J.S.)

  12. A Simple Approach to Dynamic Material Balance in Gas-Condensate Reservoirs

    OpenAIRE

    Heidari Sureshjani M.; Gerami S.; Emadi M.A.

    2013-01-01

    In traditional material balance calculations, shut-in well pressure data are used to determine average reservoir pressure while recent techniques do not require the well to be shut-in and use instead flowing well pressure-rate data. These methods, which are known as dynamic material balance, are developed for single-phase flow (oil or gas) in reservoirs. However, utilization of such methods for gas-condensate reservoirs may create ...

  13. Wind-Tunnel Balance Characterization for Hypersonic Research Applications

    Science.gov (United States)

    Lynn, Keith C.; Commo, Sean A.; Parker, Peter A.

    2012-01-01

    Wind-tunnel research was recently conducted at the NASA Langley Research Center s 31-Inch Mach 10 Hypersonic Facility in support of the Mars Science Laboratory s aerodynamic program. Researchers were interested in understanding the interaction between the freestream flow and the reaction control system onboard the entry vehicle. A five-component balance, designed for hypersonic testing with pressurized flow-through capability, was used. In addition to the aerodynamic forces, the balance was exposed to both thermal gradients and varying internal cavity pressures. Historically, the effect of these environmental conditions on the response of the balance have not been fully characterized due to the limitations in the calibration facilities. Through statistical design of experiments, thermal and pressure effects were strategically and efficiently integrated into the calibration of the balance. As a result of this new approach, researchers were able to use the balance continuously throughout the wide range of temperatures and pressures and obtain real-time results. Although this work focused on a specific application, the methodology shown can be applied more generally to any force measurement system calibration.

  14. Modeling the Surface Temperature of Earth-like Planets

    Science.gov (United States)

    Vladilo, Giovanni; Silva, Laura; Murante, Giuseppe; Filippi, Luca; Provenzale, Antonello

    2015-05-01

    We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial-temporal distribution of planetary surface temperatures. The ESTM adopts a surface energy balance model (EBM) complemented by: radiative-convective atmospheric column calculations, a set of physically based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (? ? 45{}^\\circ ). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ? 5 K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5? {? }/{{{? }}\\oplus }? 2, 0.75? S/{{S}\\circ }? 1.25, 0.3? p/(1 bar)? 10, and 0.5? R/{{R}\\oplus }? 2, respectively. The ESTM has an extremely low computational cost and can be used when the planetary parameters are scarcely known (as for most exoplanets) and/or whenever many runs for different parameter configurations are needed. Model simulations of a test-case exoplanet (Kepler-62e) indicate that an uncertainty in surface pressure within the range expected for terrestrial planets may impact the mean temperature by 60 K. Within the limits of validity of the ESTM, the impact of surface pressure is larger than that predicted by uncertainties in rotation rate, axis obliquity, and ocean fractions. We discuss the possibility of performing a statistical ranking of planetary habitability taking advantage of the flexibility of the ESTM.

  15. Capturing Near Earth Objects

    OpenAIRE

    Baoyin, Hexi; Chen, Yang; Li, Junfeng

    2011-01-01

    Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting ob...

  16. Blood pressure

    Science.gov (United States)

    ... blood pressure is considered to be a systolic blood pressure of 115 millimeters of mercury a diastolic pressure of 70 millimeters of mercury (stated as "115 over 70"). If an individual were to have a consistent blood pressure reading of 140 over 90, he would ...

  17. LINE BALANCING IN SERVICES

    Directory of Open Access Journals (Sweden)

    Hadi GKEN

    2002-01-01

    Full Text Available This paper investigates how the Assembly Line Balancing (ALB methods known for the production systems can be applied in service systems. For this purpose, an application study is done in a Physical therapy and rehabilitation clinic. Each standart service provided to patients is taken into consideration as a product, and problem is solved as a mixed model ALB problem. In conclusion, it is seen that the ALB methods developed for the production systems are also applicable in service systems. So, it is possible to do similar studies at hospitals, tax offices, driving licence and passport offices, fast food restaurants, etc.

  18. Balancing innovation and evidence.

    Science.gov (United States)

    Pilcher, Jobeth W

    2015-01-01

    Nurse educators are encouraged to use evidence to guide their teaching strategies. However, evidence is not always available. How can educators make decisions regarding strategies when data are limited or absent? Where do innovation and creativity fit? How can innovation be balanced with evidence? This article provides a discussion regarding other sources of evidence, such as extrapolations, theories and principles, and collective expertise. Readers are encouraged to review the options and then analyze how they might be applied to innovation in education. PMID:25790361

  19. Finding the right balance

    DEFF Research Database (Denmark)

    Christensen, Toke Haunstrup

    2011-01-01

    Like in other countries, the number of people living in one-person households is growing in Denmark. From 1981 to 2006 solo-living increased from 16% to 23%. Studies on family life and intimate relations in (late) modernity suggest different explanations for this increase, including the historica...... individual independence while at the same time sharing the daily life with their partner. In order to secure the right balance, they consider different strategies such as having ones own room in the shared dwelling or living-apart-together as a permanent solution....

  20. Earth Science Information Center

    Science.gov (United States)

    U.S. Geological Survey

    1991-01-01

    An ESIC? An Earth Science Information Center. Don't spell it. Say it. ESIC. It rhymes with seasick. You can find information in an information center, of course, and you'll find earth science information in an ESIC. That means information about the land that is the Earth, the land that is below the Earth, and in some instances, the space surrounding the Earth. The U.S. Geological Survey (USGS) operates a network of Earth Science Information Centers that sell earth science products and data. There are more than 75 ESIC's. Some are operated by the USGS, but most are in other State or Federal agencies. Each ESIC responds to requests for information received by telephone, letter, or personal visit. Your personal visit.

  1. Investigating of relationship between balance parameters and balance lost of elite gymnastics on balance beam

    OpenAIRE

    Ayşe Oya Erkut Atılgan; Manolya Akın; Ufuk Alpkaya; Salih Pınar

    2012-01-01

    The aim of this study was to investigate the relationship between balance lost on balance beam during the series performed by women gymnasts at International Bosphorus Gymnastics Tournament with anthropometric characteristics and static-dynamic balance test scores. 19 female gymnasts (ages 14,53±2,20, training years9,0±3) participated in this research voluntarily. Before the competition, the static and dynamic balance score and anthropometrics values were taken by experienced researchers. In ...

  2. Investigating of relationship between balance parameters and balance lost of elite gymnastics on balance beam

    OpenAIRE

    Salih P?nar; Ufuk Alpkaya; Manolya Ak?n; Ay?e Oya Erkut At?lgan

    2012-01-01

    The aim of this study was to investigate the relationship between balance lost on balance beam during the series performed by women gymnasts at International Bosphorus Gymnastics Tournament with anthropometric characteristics and static-dynamic balance test scores.19 female gymnasts (ages 14,532,20, training years9,03) participated in this research voluntarily. Before the competition, the static and dynamic balance score and anthropometrics values were taken by experienced researchers. In o...

  3. Canopy edge flow: A momentum balance analysis

    Science.gov (United States)

    Moltchanov, Sharon; Bohbot-Raviv, Yardena; Duman, Tomer; Shavit, Uri

    2015-04-01

    Canopy flow models are often dedicated to ideal, infinite, homogenous systems. However, real canopy systems have physical boundaries, where the flow enters and leaves patches of vegetation, generating a complex pressure field and velocity variations. Here we focus our study on the canopy entry region by examining the terms involved in the double (space and time) averaged momentum equations and their relative contribution to the total momentum balance. The estimation of each term is made possible by particle image velocimetry (PIV) measurements in a model canopy constructed of randomly distributed thin glass plates. The instantaneous velocity fields were used to calculate the mean velocities, pressure, drag, Reynolds stresses, and dispersive stresses. It was found that within the entry region, the pressure gradient, the drag forces, and dispersive stresses are the three most significant terms that affect the balance in the streamwise momentum equation. In the vertical direction, the dispersive stresses are also significant and their contribution to the total momentum cannot be ignored. The study shows that dispersive stresses are initially formed around canopy edges; at both the entry region and the canopy top boundary. They start as a sink term, extracting momentum from the flow, and then become a source term that contributes momentum to the flow until they eventually decay at some short penetration distance into the canopy. These results reveal a new understanding on the evolution of momentum within the entry region, necessary in any closure modeling of flow in real canopies.

  4. Entropy of balance - some recent results

    Directory of Open Access Journals (Sweden)

    Laxback Gerd

    2010-07-01

    Full Text Available Abstract Background Entropy when applied to biological signals is expected to reflect the state of the biological system. However the physiological interpretation of the entropy is not always straightforward. When should high entropy be interpreted as a healthy sign, and when as marker of deteriorating health? We address this question for the particular case of human standing balance and the Center of Pressure data. Methods We have measured and analyzed balance data of 136 participants (young, n = 45; elderly, n = 91 comprising in all 1085 trials, and calculated the Sample Entropy (SampEn for medio-lateral (M/L and anterior-posterior (A/P Center of Pressure (COP together with the Hurst self-similariy (ss exponent ? using Detrended Fluctuation Analysis (DFA. The COP was measured with a force plate in eight 30 seconds trials with eyes closed, eyes open, foam, self-perturbation and nudge conditions. Results 1 There is a significant difference in SampEn for the A/P-direction between the elderly and the younger groups Old > young. 2 For the elderly we have in general A/P > M/L. 3 For the younger group there was no significant A/P-M/L difference with the exception for the nudge trials where we had the reverse situation, A/P Eyes Open. 5 In case of the Hurst ss-exponent we have for the elderly, M/L > A/P. Conclusions These results seem to be require some modifications of the more or less established attention-constraint interpretation of entropy. This holds that higher entropy correlates with a more automatic and a less constrained mode of balance control, and that a higher entropy reflects, in this sense, a more efficient balancing.

  5. Thermal balance in infants.

    Science.gov (United States)

    Bolton, D P; Nelson, E A; Taylor, B J; Weatherall, I L

    1996-06-01

    A theoretical model of heat balance is presented that could clarify the matching of babies' wrapping with their environments. Best estimates of metabolic heat input and heat loss by all known routes are defined for 22 parts of the body surface. The variation of these with core temperature, posture, skin vasodilatation, and the onset of sweating are calculated: first, by using presumed skin temperatures and second, by following iterative calculation of the skin temperature and the consequent total heat losses. Calculation of the highest tolerable ambient temperature (HTAT) for a given set of clothes, underbedding, and covers shows that a well-wrapped baby lying face down could have an HTAT 10 degrees C lower than if he/she were lying supine. Representative values for highest and lowest tolerable temperatures (defined in text) are presented for the first 6 mo of life. Retrospective estimation of thermal balance from death-scene data on clothing and bedding can permit assessment of hyperthermia or hypothermia as a contributing cause of death. Recommendations are made on the avoidance of hyperthermia. PMID:8806935

  6. Resource Balancing Control Allocation

    Science.gov (United States)

    Frost, Susan A.; Bodson, Marc

    2010-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the control effort. The paper discusses the alternative choice of using the l1 norm for minimization of the tracking error and a normalized l(infinity) norm, or sup norm, for minimization of the control effort. The algorithm computes the norm of the actuator deflections scaled by the actuator limits. Minimization of the control effort then translates into the minimization of the maximum actuator deflection as a percentage of its range of motion. The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are investigated through examples. In particular, the min-max criterion results in a type of resource balancing, where the resources are the control surfaces and the algorithm balances these resources to achieve the desired command. A study of the sensitivity of the algorithms to the data is presented, which shows that the normalized l(infinity) algorithm has the lowest sensitivity, although high sensitivities are observed whenever the limits of performance are reached.

  7. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates i...

  8. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30September and/or 31December, leave will automatically be transferred from one account to another on the relevant dates in or...

  9. Physical and Geochemical Conditions Required for the Initiation of Snowball Earth

    Science.gov (United States)

    Tajika, E.

    2001-03-01

    Condition for initiation of snowball Earth phenomena is studied by using a one-dimensional energy balance climate model and carbon geochemical cycle model. Critical condition for pCO2 to cause climate instability will be discussed.

  10. Balance ability and athletic performance.

    Science.gov (United States)

    Hrysomallis, Con

    2011-03-01

    The relationship between balance ability and sport injury risk has been established in many cases, but the relationship between balance ability and athletic performance is less clear. This review compares the balance ability of athletes from different sports, determines if there is a difference in balance ability of athletes at different levels of competition within the same sport, determines the relationship of balance ability with performance measures and examines the influence of balance training on sport performance or motor skills. Based on the available data from cross-sectional studies, gymnasts tended to have the best balance ability, followed by soccer players, swimmers, active control subjects and then basketball players. Surprisingly, no studies were found that compared the balance ability of rifle shooters with other athletes. There were some sports, such as rifle shooting, soccer and golf, where elite athletes were found to have superior balance ability compared with their less proficient counterparts, but this was not found to be the case for alpine skiing, surfing and judo. Balance ability was shown to be significantly related to rifle shooting accuracy, archery shooting accuracy, ice hockey maximum skating speed and simulated luge start speed, but not for baseball pitching accuracy or snowboarding ranking points. Prospective studies have shown that the addition of a balance training component to the activities of recreationally active subjects or physical education students has resulted in improvements in vertical jump, agility, shuttle run and downhill slalom skiing. A proposed mechanism for the enhancement in motor skills from balance training is an increase in the rate of force development. There are limited data on the influence of balance training on motor skills of elite athletes. When the effectiveness of balance training was compared with resistance training, it was found that resistance training produced superior performance results for jump height and sprint time. Balance ability was related to competition level for some sports, with the more proficient athletes displaying greater balance ability. There were significant relationships between balance ability and a number of performance measures. Evidence from prospective studies supports the notion that balance training can be a worthwhile adjunct to the usual training of non-elite athletes to enhance certain motor skills, but not in place of other conditioning such as resistance training. More research is required to determine the influence of balance training on the motor skills of elite athletes. PMID:21395364

  11. Nuclear reactor pressure vessels

    International Nuclear Information System (INIS)

    Reference is made to gas cooled reactors having pre-stressed concrete pressure vessels. Such pressure vessels entail the use of high grade thermal insulation, capable of satisfactory use in high pressure gas environments, in order to combat the sensitivity of concrete to high temperature. Temperature limitations both in regard to absolute temperature and allowable gradients through the vessel walls require the use of a protective thermal barrier on the inside of the pressure vessel wall to separate the gas coolant from the concrete. This barrier must also be designed to withstand, or be isolated from, the intense noise arising from the gas circulators. In the arrangement described the thermal barrier system comprises a metal liner to which is fixed an impervious inner metal membrane having flexible corrugated thinner metal portions. Heat resistant ilsultation is held between the metal liner and the inner membrane, and fitted vents are located between the insulation and the interior of the vessel for balancing the the pressure within the insulation and to provide controlled maximum pressure differential porting. The studs fixing the inner metal membrane to the metal liner may be hollow and act as the filter vents. (U.K.)

  12. Optimized balance rehabilitation training strategy for the elderly through an evaluation of balance characteristics in response to dynamic motions

    Science.gov (United States)

    Jung, HoHyun; Chun, Keyoung Jin; Hong, Jaesoo; Lim, Dohyung

    2015-01-01

    Balance is important in daily activities and essential for maintaining an independent lifestyle in the elderly. Recent studies have shown that balance rehabilitation training can improve the balance ability of the elderly, and diverse balance rehabilitation training equipment has been developed. However, there has been little research into optimized strategies for balance rehabilitation training. To provide an optimized strategy, we analyzed the balance characteristics of participants in response to the rotation of a base plate on multiple axes. Seven male adults with no musculoskeletal or nervous system-related diseases (age: 25.51.7 years; height: 173.96.4 cm; body mass: 71.36.5 kg; body mass index: 23.62.4 kg/m2) were selected to investigate the balance rehabilitation training using customized rehabilitation equipment. Rotation of the base plate of the equipment was controlled to induce dynamic rotation of participants in the anteriorposterior, right-diagonal, mediallateral, and left-diagonal directions. We used a three-dimensional motion capture system employing infrared cameras and the Pedar Flexible Insoles System to characterize the major lower-extremity joint angles, center of body mass, and center of pressure. We found statistically significant differences between the changes in joint angles in the lower extremities in response to dynamic rotation of the participants (P0.05). These results indicate that optimizing rotation control of the base plate of balance rehabilitation training equipment to induce anteriorposterior and mediallateral dynamic rotation preferentially can lead to effective balance training. Additional tests with varied speeds and ranges of angles of base plate rotation are expected to be useful as well as an analysis of the balance characteristics considering a balance index that reflects the muscle activity and cooperative characteristics. PMID:26508847

  13. A Reconciled Estimate of Ice-Sheet Mass Balance

    Science.gov (United States)

    Shepherd, Andrew; Ivins, Erik R.; A, Geruo; Barletta, Valentina R.; Bentley, Mike J.; Bettadpur, Srinivas; Briggs, Kate H.; Bromwich, David H.; Forsberg, Ren; Galin, Natalia; Horwath, Martin; Jacobs, Stan; Joughin, Ian; King, Matt A.; Lenaerts, Jan T. M.; Li, Jilu; Ligtenberg, Stefan R. M.; Luckman, Adrian; Luthcke, Scott B.; McMillan, Malcolm; Meister, Rakia; Milne, Glenn; Mouginot, Jeremie; Muir, Alan; Nicolas, Julien P.; Paden, John; Payne, Antony J.; Pritchard, Hamish; Rignot, Eric; Rott, Helmut; Srensen, Louise Sandberg; Scambos, Ted A.; Scheuchl, Bernd; Schrama, Ernst J. O.; Smith, Ben; Sundal, Aud V.; van Angelen, Jan H.; van de Berg, Willem J.; van den Broeke, Michiel R.; Vaughan, David G.; Velicogna, Isabella; Wahr, John; Whitehouse, Pippa L.; Wingham, Duncan J.; Yi, Donghui; Young, Duncan; Zwally, H. Jay

    2012-11-01

    We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earths polar ice sheets. We find that there is good agreement between different satellite methodsespecially in Greenland and West Antarcticaand that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by -142 49, +14 43, -65 26, and -20 14 gigatonnes year-1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 0.20 millimeter year-1 to the rate of global sea-level rise.

  14. balance del 2007

    Directory of Open Access Journals (Sweden)

    Emilio lvarez Icaza

    2008-01-01

    Full Text Available La Comisin de Derechos Humanos del Distrito Federal (CDHDF, en el presente artculo, busca realizar un balance de los principales avances, problemticas y retos que en el mbito de los derechos humanos se enfrentaron en el 2007. Enmarcados en un hecho sin precedente en el mbito estatal, se puso en marcha el proceso de construccin del Diagnstico y Programa de Derechos Humanos del Distrito Federal, esfuerzo que constituye un punto de partida comn para instancias pblicas, acadmicas y organismos de la sociedad civil en el DF, que favorecer directamente a todas las personas que habitan y transitan esta ciudad, y que sin duda constituye una experiencia indita e innovadora que aspira a convertirse en referente local, nacional e internacional.

  15. A Balancing Act?

    DEFF Research Database (Denmark)

    Gerstlberger, Wolfgang; Stampe, Ian; Knudsen, Mette Præst

    2009 European Manufacturing Survey for the Danish sub-sample including 335 manufacturing firms. Through factor analysis, the paper confirms three main focus areas of new product development in relation to production facilities: efficiency considerations, market attention and greening of innovation....... Logistic regression analysis demonstrates that while market attention is important for new product development, green aspects of innovation and efficiency considerations for innovation are important for the energy efficiency of the production companies. Combining these models highlights that energy...... efficiency moderates the effect of market attention on new product development. The paper therefore concludes that product innovation and energy efficiency is a balancing act, focusing on one will have detrimental effects on the other! These findings point to the conclusion that researchers and practitioners...

  16. A Balancing Act?

    DEFF Research Database (Denmark)

    Gerstlberger, Wolfgang; Knudsen, Mette Præst; Stampe, Ian

    With an undifferentiated catchword ‘eco-innovation’ is a largely understudied area, but of high relevance to the society and companies given the strong focus especially by governments on grand challenges like climate change, green technologies and environmental challenges. The paper utilizes the...... efficiency moderates the effect of market attention on new product development. The paper therefore concludes that product innovation and energy efficiency is a balancing act, focusing on one will have detrimental effects on the other! These findings point to the conclusion that researchers and practitioners...... 2009 European Manufacturing Survey for the Danish sub-sample including 335 manufacturing firms. Through factor analysis, the paper confirms three main focus areas of new product development in relation to production facilities: efficiency considerations, market attention and greening of innovation...

  17. Work-life balance

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Pat

    2011-03-15

    Gay Renouf has opted for a work/life balance; with a chemistry degree she joined the Saskatchewan Research Council out of graduate school in 1986. She first worked on understanding surfactants in emulsions and then dealt more with petroleum engineering issues like pipeline specifications. She is looking at waterfloods in heavy and medium gravity pools and has discovered factors helping to produce heavy oil waterfloods. But all Renouf's life is not devoted to her work: she has been working part-time, spending her free time being a parent, training for marathons and being a running coach. Renouf believes that her passion for running is consistent with her work as a scientist.

  18. Strategic Balanced Scorecard Simulation

    DEFF Research Database (Denmark)

    Nielsen, Steen; Nielsen, Erland Hejn

    2012-01-01

    The purpose of this article is to show how a System Dynamics Modelling approach can be integrated into the Balanced Scorecard (BSC) for a case company with special focus on the handling of causality in a dynamic perspective. The case companys BSC model includes five perspectives and a number of financial and non-financial measures. The overall idea of BSC is to make the strategy operational, as proposed by Kaplan and Norton (1992; 1996; 2007) and to use the strategy for simulation. Our results indicate that a company may gain great learning insight from such simulation studies. The whole article will be published in a coming issue of Journal of Business and Systems Research.

  19. Energy balance climate models

    Science.gov (United States)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1981-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  20. Virtual Acts of Balance!

    DEFF Research Database (Denmark)

    Madsen, Anders Koed

    2013-01-01

    Construction of Technology' and it shows how the framing of the portals and the concrete digital choices taken in relation to the infrastructure are influenced by the social intentions of relevant social groups as well as by the technical limitations on computers abilities to process semantic data. It is...... especially emphasized how technical web-ontologies implicitly carries with them deeper philosophical ontologies about phanomena such as 'politic', 'scientific intentionality' and 'freedom'. The compromise between these technical influences and the social intentions is described as a 'virtual act of balance......This paper presents an analysis of official documents and white papers pertaining to the two web-portals The Policy Grid Project and FEED that are launched by the UK and the EU respectively. The aim of the portals is to filter and synthesize information relevant for policy discussions and thereby...

  1. Rare earth separation process

    International Nuclear Information System (INIS)

    Light rare earths including yttrium (i.e. Z<63) are separated from other rare earths by contacting an aqueous solution with an organic solution containing an extracting agent, which is a mixture of a carboxylic acid (water-insoluble and comprising more than 6 carbon atoms) and a neutral organic phosphorus compound or an alcohol with more than 6 carbon atoms. Heavy rare earths are re-extracted with an aqueous acid solution

  2. Near Earth Objects

    OpenAIRE

    Wolff, Stefan

    2006-01-01

    The word planet comes from Greek planetes, wanderers, because the planets appear to wander across the celestial sphere, contrary to the fixed stars. This thesis presents several methods for using this motion to distinguish between stars and solar system objects in order to detect and track NEOs, Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global clim...

  3. The Earth's Magnetic Field

    OpenAIRE

    Edda Lna Gunnarsdttir 1988

    2012-01-01

    The Earth's magnetic field is essential for life on Earth, as we know it, to exist. It forms a magnetic shield around the planet, protecting it from high energy particles and radiation from the Sun, which can cause damage to life, power systems, orbiting satellites, astronauts and spacecrafts. This report contains a general overview of the Earth's magnetic field. The different sources that contribute to the total magnetic field are presented and the diverse variations in the field are describ...

  4. Earth observing system implementation

    Science.gov (United States)

    Donohoe, M. J.; Walton, B. A.; Vane, D.

    1985-01-01

    The Earth Observing System (EOS) is a planned major earth science program initiative using the Polar Platforms of the Space Station. The Polar Platform resource capabilities will allow a multi-disciplinary, long term mission life approach to future earth science measurements. The EOS will be the subject of an Announcement of Opportunity (AO) in 1986. The EOS concept and the planned implementation approach is outlined.

  5. Modeling the surface temperature of Earth-like planets

    CERN Document Server

    Vladilo, G; Murante, G; Filippi, L; Provenzale, A

    2015-01-01

    We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial-temporal distribution of planetary surface temperatures. The ESTM adopts a surface Energy Balance Model complemented by: radiative-convective atmospheric column calculations, a set of physically-based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (epsilon >= 45^o). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ~5K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5 <= Omega/Omega_o <= 2, 0.75 <= S/S_o <= 1.25, 0.3 <= p/(1 bar) <= 10, and 0.5 <= R/R_o <= 2, respectively. The ESTM has an extremely l...

  6. The early Earth

    CERN Document Server

    Badro, James

    2015-01-01

    The Early Earth: Accretion and Differentiation provides a multidisciplinary overview of the state of the art in understanding the formation and primordial evolution of the Earth. The fundamental structure of the Earth as we know it today was inherited from the initial conditions 4.56 billion years ago as a consequence of planetesimal accretion, large impacts among planetary objects, and planetary-scale differentiation. The evolution of the Earth from a molten ball of metal and magma to the tectonically active, dynamic, habitable planet that we know today is unique among the terrestrial plane

  7. Rare earths; Seltene Erden

    Energy Technology Data Exchange (ETDEWEB)

    Liedtke, Maren; Elsner, Harald [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany). Fachbereich Wirtschaftsgeologie der mineralischen Rohstoffe

    2010-03-15

    Because of their user in high tech products rare earths have attracted considerable economic interest in recent years. PR China produces over 95% of the mined output of rare earths. Increasing demand and possible further tightening of the trade restrictions on rare earths by PR China could lead to bottlenecks in supply. Mining projects which will probably lead to production in the near future, are currently at an advanced planning stage in particular Australia, the USA and Canada. Two important rare earth deposits are known in Europe. (orig.)

  8. The Earth: Present Scenario

    OpenAIRE

    Nishad Gopal Deshpande

    2009-01-01

    In this article, the present scenario of our motherly loved planet Earth is presented. We are living in one of the most developed phases of the Earths life cycle. The choices we make today will determine the life on the Earth, tomorrow. Problems that are been created by us and the consequences we are going to face are discussed in length. Some statistical data is provided to get a brief idea. Measure/prevention(s) to combat the upcoming problems have been putforth.

  9. Peer Pressure

    Science.gov (United States)

    ... She'd just had a big dose of peer pressure. Who Are Your Peers? When you were a ... adults parents, teachers, guidance counselors, etc. talk about peer pressure more than the benefits of belonging to a ...

  10. Pressure Sores

    Science.gov (United States)

    Pressure sores are areas of damaged skin caused by staying in one position for too long. They commonly ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which are ...

  11. Energy Balance, Climate, and Life - Work of M. Budyko

    Science.gov (United States)

    Cahalan, Robert F.

    2004-01-01

    This talk will review the work of Mikhail I. Budyko, author of "Climate and Life" and many other works, who died recently at age 81, in St Petersburg, Russia. He directed the Division for Climate Change Research at the State Hydrological Institute. We will explore Budyko's work in clarifying the role of energy balance in determining planetary climate, and the role of climate in regulating Earth s biosphere.

  12. Human domination of earth`s ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Vitousek, P.M.; Mooney, H.A.; Lubchenko, J.; Melillo, J.M. [Stanford University, Stanford, CA (United States). Dept. of Biological Sciences

    1997-07-25

    Human alteration of Earth is substantial and growing. Between one-third and one-half of the land surface has been transformed by human action; the carbon dioxide concentration in the atmosphere has increased by nearly 30% since the beginning of the Industrial Revolution; more atmospheric nitrogen is fixed by humanity than by all natural terrestrial sources combined; more than half of all accessible surface fresh water is put to use by humanity; and about one-quarter of the bird species on Earth have been driven to extinction. By these and other standards, it is clear that we live on a human-dominated planet. 58 refs., 4 figs.

  13. Rare earths production and marketing opportunities

    International Nuclear Information System (INIS)

    The rare earths (RE) market is relatively small. The total production during 1968 was only 10000 tons (REO) which rose to 27000 tons (REO) during 1985. The three major areas of application, which are volume market for ceric rare earths are catalysts, glass ceramics and metallurgy. Among the other uses of rare earths, the permanent magnets, lamp phosphors and fine ceramics have registered significant growth in RE consumption. Monazite and bastnasite are the main natural source for rare earths and processing of these for one of the rare earths in high demand leads to over production of some others not in demand, thus creating a balance problem. The growth in RE market has always been influenced by the technology shifts and product substitution. For example, the RE consumption during 1974/76 for desulfurization of steel had substantially decreased due to the usage of calcium. Similarly, 1985 had witnessed a drastic cut in the use of REs in fluid cracking due to the introduction of stabilized zeolites which contain less REO. Thus, the overall compound growth rate of demand was only 3.9 % per year during the period 1970-1985. At present, 37 % of the rare earths production goes to the glass/ceramics industry, 33 % for catalyst and 25 % to metallurgy. The price of REs constantly shows a downward trend. This trend coupled with the rapid changes taking place in the various technological fields, demands greater flexibility and high marketing skills from the RE producers. The key factor for future expansion of RE market will be the development of 'high volume' application of ceric rare earths. (author) 2 figs., 8 tabs

  14. Wii Balance Board: Reliability and Clinical Use in Assessment of Balance in Healthy Elderly Women.

    Science.gov (United States)

    Monteiro-Junior, Renato Sobral; Ferreira, Arthur S; Puell, Vivian Neiva; Lattari, Eduardo; Machado, Srgio; Otero Vaghetti, Csar Augusto; da Silva, Elirez Bezerra

    2015-01-01

    Force plate is considered gold standard tool to assess body balance. However the Wii Balance Board (WBB) platform is a trustworthy equipment to assess stabilometric components in young people. Thus, we aim to examine the reliability of measures of center of pressure with WBB in healthy elderly women. Twenty one healthy and physically active women were enrolled in the study (age: 64 7 years; body mass index: 29 5 kg/m2. The WBB was used to assess the center of pressure measures in the individuals. Pressure was linearly applied to different points to test the platform precision. Three assessments were performed, with two of them being held on the same day at a 5- to 10-minute interval, and the third one was performed 48 h later. A linear regression analysis was used to find out linearity, while the intraclass correlation coefficient was used to assess reliability. The platform precision was adequate (R2 = 0.997, P = 0.01). Center of pressure measures showed an excellent reliability (all intraclass correlation coefficient values were > 0.90; p < 0.01). The WBB is a precise and reliable tool of body stability quantitative measure in healthy active elderly women and its use should be encouraged in clinical settings. PMID:26556091

  15. Pressure ulcer

    Science.gov (United States)

    Bedsore; Decubitus ulcer ... form. You are more likely to get a pressure ulcer if you: Use a wheelchair or stay in ... Symptoms of a pressure ulcer are: Red skin that gets worse over time The area forms a blister, then an open sore Pressure sores ...

  16. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  17. Dynamic load balancing of applications

    Science.gov (United States)

    Wheat, Stephen R. (Albuquerque, NM)

    1997-01-01

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated.

  18. Greenland ice sheet mass balance: a review

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Aschwanden, Andy; Bjrk, Anders A.; Wahr, John; Kjeldsen, Kristian K.; Kjr, Kurt H.

    2015-01-01

    Over the past quarter of a century the Arctic has warmed more than any other region on Earth, causing a profound impact on the Greenland ice sheet (GrIS) and its contribution to the rise in global sea level. The loss of ice can be partitioned into processes related to surface mass balance and to...... ice discharge, which are forced by internal or external (atmospheric/oceanic/basal) fluctuations. Regardless of the measurement method, observations over the last two decades show an increase in ice loss rate, associated with speeding up of glaciers and enhanced melting. However, both ice discharge...... and melt-induced mass losses exhibit rapid short-term fluctuations that, when extrapolated into the future, could yield erroneous long-term trends. In this paper we review the GrIS mass loss over more than a century by combining satellite altimetry, airborne altimetry, interferometry, aerial...

  19. On output measurements via radiation pressure

    DEFF Research Database (Denmark)

    Leeman, S.; Healey, A.J.; Forsberg, F.; Jensen, J.A.

    It is shown, by simple physical argument, that measurements of intensity with a radiation pressure balance should not agree with those based on calorimetric techniques. The conclusion is ultimately a consequence of the circumstance that radiation pressure measurements relate to wave momentum, while...

  20. Twelve weeks of BodyBalance training improved balance and functional task performance inmiddle-aged and older adults

    Directory of Open Access Journals (Sweden)

    Nicholson VP

    2014-11-01

    Full Text Available Vaughan P Nicholson, Mark R McKean, Brendan J Burkett School of Health and Sport Sciences, University of the Sunshine Coast, Sunshine Coast, QLD, Australia Purpose: The purpose of the study was to evaluate the effect of BodyBalance training on balance, functional task performance, fear of falling, and health-related quality of life in adults aged over 55years.Participants and methods: A total of 28healthy, active adults aged 665years completed the randomized controlled trial. Balance, functional task performance, fear of falling, and self-reported quality of life were assessed at baseline and after 12weeks. Participants either undertook two sessions of BodyBalance per week for 12weeks (n=15 or continued with their normal activities (n=13.Results: Significant group-by-time interactions were found for the timed up and go (P=0.038, 30-second chair stand (P=0.037, and mediolateral center-of-pressure range in narrow stance with eyes closed (P=0.017. There were no significant effects on fear of falling or self-reported quality of life.Conclusion: Twelve weeks of BodyBalance training is effective at improving certain balance and functional based tasks in healthy older adults. Keywords: postural control, yoga, tai chi, center of pressure, exercise

  1. Validity and reliability of the Nintendo Wii Balance Board for assessment of standing balance.

    Science.gov (United States)

    Clark, Ross A; Bryant, Adam L; Pua, Yonghao; McCrory, Paul; Bennell, Kim; Hunt, Michael

    2010-03-01

    Impaired standing balance has a detrimental effect on a person's functional ability and increases their risk of falling. There is currently no validated system which can precisely quantify center of pressure (COP), an important component of standing balance, while being inexpensive, portable and widely available. The Wii Balance Board (WBB) fits these criteria, and we examined its validity in comparison with the 'gold standard'-a laboratory-grade force platform (FP). Thirty subjects without lower limb pathology performed a combination of single and double leg standing balance tests with eyes open or closed on two separate occasions. Data from the WBB were acquired using a laptop computer. The test-retest reliability for COP path length for each of the testing devices, including a comparison of the WBB and FP data, was examined using intraclass correlation coefficients (ICC), Bland-Altman plots (BAP) and minimum detectable change (MDC). Both devices exhibited good to excellent COP path length test-retest reliability within-device (ICC=0.66-0.94) and between-device (ICC=0.77-0.89) on all testing protocols. Examination of the BAP revealed no relationship between the difference and the mean in any test, however the MDC values for the WBB did exceed those of the FP in three of the four tests. These findings suggest that the WBB is a valid tool for assessing standing balance. Given that the WBB is portable, widely available and a fraction of the cost of a FP, it could provide the average clinician with a standing balance assessment tool suitable for the clinical setting. PMID:20005112

  2. The Earth Charter

    Science.gov (United States)

    Journal of Education for Sustainable Development, 2010

    2010-01-01

    Humanity is part of a vast evolving universe. Earth is alive with a unique community of life. The forces of nature make existence a demanding and uncertain adventure, but Earth has provided the conditions essential to life's evolution. The resilience of the community of life and the well-being of humanity depend upon preserving a healthy biosphere

  3. Evolution and Earth's Entropy

    OpenAIRE

    Klauber, Robert D.

    2010-01-01

    Entropy decreases on the Earth due to day/night temperature differences. This decrease exceeds the decrease in entropy on the Earth related to evolution by many orders of magnitude. Claims by creationists that science is somehow inconsistent with regard to evolution are thus show to be baseless.

  4. Earth Flyby Anomalies

    OpenAIRE

    Nieto, Michael Martin; Anderson, John D.

    2009-01-01

    In a reference frame fixed to the solar system's center of mass, a satellite's energy will change as it is deflected by a planet. But a number of satellites flying by Earth have also experienced energy changes in the Earth-centered frame -- and that's a mystery.

  5. Earth System Science Project

    Science.gov (United States)

    Rutherford, Sandra; Coffman, Margaret

    2004-01-01

    For several decades, science teachers have used bottles for classroom projects designed to teach students about biology. Bottle projects do not have to just focus on biology, however. These projects can also be used to engage students in Earth science topics. This article describes the Earth System Science Project, which was adapted and developed

  6. Is the Earth Expanding ?

    Science.gov (United States)

    Shen, W.; Chen, W.; Li, J.

    2007-12-01

    Whether the Earth is expanding or contracting is an interesting problem in geoscience. The information of the secular change of the Earth's gravity field supports the conclusion that the Earth is expanding at least in recent years. The gravitational potential could be expressed as a spherical harmonic series outside the Earth. In practical applications, it could be approximately realized by a truncated series, e.g., EGM96 (the Earth Gravity Model 96), EIGEN-GL04C, etc. The principal moments of inertia of the Earth are related to the second-order coeffients of the spherical harmonic series. Based on EGM96 as well as EIGEN-GL04C, the principal moments of inertia and especially their temporal variations are determined. All the three principal moments of inertia are gradually increasing at almost the same rate in recent 10 years, which might be due to the following three causes: 1) the rise of the sea level; 2) the increase of the total mass of the Earth; 3) the expansion of the Earth in the general sense. Calculations show that the rise of the sea level has too week influence on the variation of the principal moments of inertia comparing with the actual observations, and consequently the cause 1) could be given up. As to the increase of the total mass of the Earth, there does not exist any definite evidence, especially, it has not been found that the geocentric constant GM (where G and M are gravitational constant and the total mass of the Earth respectively) varies with time by various satellite approaches. Hence, it is reasonable to assume that the increase of the principal moments of inertia is caused by the expansion of the interior of the Earth or at least the whole mantle. This clearly demonstrates that the Earth is expanding at least in recent 10 years. Preliminary numerical calculations show that the Earth is expanding at the rate around 0.6 mm/yr at least in recent 10 years. Taking into account the Dirac's large number postulate, it could be concluded that the Earth expansion has and will have happened continuously in a long geological history.

  7. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  8. Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

    Science.gov (United States)

    Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

    2012-01-01

    Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain's ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable and provides imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles. SR using imperceptible stochastic electrical stimulation of the vestibular system (stochastic vestibular stimulation, SVS) applied to normal subjects has shown to improve the degree of association between the weak input periodic signals introduced via venous blood pressure receptors and the heart-rate responses. Also, application of SVS over 24 hours improves the long-term heart-rate dynamics and motor responsiveness as indicated by daytime trunk activity measurements in patients with multi-system atrophy, Parkinson s disease, or both, including patients who were unresponsive to standard therapy for Parkinson s disease. Recent studies conducted at the NASA JSC Neurosciences Laboratories showed that imperceptible SVS, when applied to normal young healthy subjects, leads to significantly improved balance performance during postural disturbances on unstable compliant surfaces. These studies have shown the benefit of SR noise characteristic optimization with imperceptible SVS in the frequency range of 0-30 Hz, and amplitudes of stimulation have ranged from 100 to 400 microamperes.

  9. Distributed Selfish Load Balancing

    CERN Document Server

    Berenbrink, P; Goldberg, L A; Goldberg, P; Hu, Z; Martin, R; Berenbrink, Petra; Friedetzky, Tom; Goldberg, Leslie Ann; Goldberg, Paul; Hu, Zengjian; Martin, Russell

    2005-01-01

    Suppose that a set of m tasks are to be shared as equally as possible amongst a set of n resources. A game-theoretic mechanism to find a suitable allocation is to associate each task with a ``selfish agent'', and require each agent to select a resource, with the cost of a resource being the number of agents to select it. Agents would then be expected to migrate from overloaded to underloaded resources, until the allocation becomes balanced. Recent work has studied the question of how this can take place within a distributed setting in which agents migrate selfishly without any centralized control. In this paper we discuss a natural protocol for the agents which combines the following desirable features: It can be implemented in a strongly distributed setting, uses no central control, and has good convergence properties. We show using a martingale technique that the process converges in expected time O(\\log\\log m + n^4). We also give a lower bound of \\Omega(\\max{\\log\\log m, n}) for the convergence time, as wel...

  10. Paul Collier : Balancing beams

    CERN Multimedia

    2009-01-01

    As former head of AB Operations, Paul Collier and his group were in the ‘cockpit’ for the LHC’s maiden voyage - piloting the first beam around the ring. But now, as Head of the Beams Department, he will need his feet firmly on the ground in order to balance all the beam activities at CERN. "As Department Head, I’ll have less direct contact with the machines," Collier says with a hint of regret. "I’ll still obviously be very involved, but they won’t actually let me loose in front of the keyboard anymore!" As the new Head of the BE Department, Collier will be in charge of nearly 400 people, and will oversee all the beam activities, including the preparations for the longest period of beam operation in the history of CERN. In the new organization, the BE, TE and EN Departments have been grouped together in the Accelerator and Technology Sector. "‘Partnership’ is a key word for the three departments," says Collier. "The n...

  11. Balancing Bounded Treewidth Circuits

    Science.gov (United States)

    Jansen, Maurice; Sarma M. N., Jayalal

    We use algorithmic tools for graphs of small treewidth to address questions in complexity theory. For both arithmetic and Boolean circuits, we show that any circuit of size n O(1) and treewidth O(log i n) can be simulated by a circuit of width O(log i + 1 n) and size n c , where c = O(1), if i = 0, and c = O(loglogn) otherwise. For our main construction, we prove that multiplicatively disjoint arithmetic circuits of size n O(1) and treewidth k can be simulated by bounded fan-in arithmetic formulas of depth O(k 2logn). From this we derive an analogous statement for syntactically multilinear arithmetic circuits, which strengthens the central theorem of [14]. As another application, we derive that constant width arithmetic circuits of size n O(1) can be balanced to depth O(logn), provided certain restrictions are made on the use of iterated multiplication. Also from our main construction, we derive that Boolean bounded fan-in circuits of size n O(1) and treewidth k can be simulated by bounded fan-in formulas of depth O(k 2logn). This strengthens in the non-uniform setting the known inclusion that SC0 ? NC1. Finally, we apply our construction to show that Reachability and Circuit Value Problem for some treewidth restricted cases can be solved in LogDCFL.

  12. Balancing Bounded Treewidth Circuits

    CERN Document Server

    Jansen, Maurice

    2009-01-01

    Algorithmic tools for graphs of small treewidth are used to address questions in complexity theory. For both arithmetic and Boolean circuits, it is shown that any circuit of size $n^{O(1)}$ and treewidth $O(\\log^i n)$ can be simulated by a circuit of width $O(\\log^{i+1} n)$ and size $n^c$, where $c = O(1)$, if $i=0$, and $c=O(\\log \\log n)$ otherwise. For our main construction, we prove that multiplicatively disjoint arithmetic circuits of size $n^{O(1)}$ and treewidth $k$ can be simulated by bounded fan-in arithmetic formulas of depth $O(k^2\\log n)$. From this we derive the analogous statement for syntactically multilinear arithmetic circuits, which strengthens a theorem of Mahajan and Rao. As another application, we derive that constant width arithmetic circuits of size $n^{O(1)}$ can be balanced to depth $O(\\log n)$, provided certain restrictions are made on the use of iterated multiplication. Also from our main construction, we derive that Boolean bounded fan-in circuits of size $n^{O(1)}$ and treewidth $k...

  13. Par Pond water balance

    International Nuclear Information System (INIS)

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

  14. Balancing "we" and "me".

    Science.gov (United States)

    Congdon, Christine; Flynn, Donna; Redman, Melanie

    2014-10-01

    The open office is the dominant form of workspace design for good reason: It fosters collaboration, promotes learning, and nurtures strong culture. But what most companies fail to realize is that collaboration has a natural rhythm that requires both interaction and private contemplation. Companies have been trying for decades to find the balance between public and private workspace that best supports collaboration. In 1980 52% of U.S. employees lacked workspaces where they could concentrate without distraction. In response, high-walled cubicles took over the corporate landscape. By the late 1990s, the tide had turned, and only 23% of employees wanted more privacy, and 50% wanted more access to other people. Ever since, firms have been beefing up spaces that support collaboration and shrinking areas for individual work. But the pendulum seems to have swung too far: Once again, people feel a pressing need for privacy, not only to do heads-down work but to cope with the intensity of work today. To address these needs, according to the authors, we have to rethink our assumptions about privacy. Traditionally defined in physical terms, privacy is now about the individual's ability to control information and stimulation. In this article, the authors examine workspace design through the new lens of privacy and offer insights on how to foster teamwork and solitude. PMID:25509575

  15. Interim balance: Ecology

    International Nuclear Information System (INIS)

    Subjects: The ecology problem - world wide. Sectoral balances: The examples of energy, transportation, chemistry, agriculture and food industry, water supply. Destruction of nature and human discord. Conservatives in our political parties and their views on environmental protection. Alliance between reds and 'greens', integration between reds and greens. The Rhine initiative. Lead respects no borders, experiences of citizens' action groups in Lothringia and the Saar district. International airport Munich-II/comments by a protestant. 'Give priority to life'/A hearing on environmental protection. 4:96 - 'greens' in the Bremen Senate. Policy in a hard-hearing world/psychology of citizens' action groups. Critical ecological research and scientific establishment. Full productivity and ecology. The deluge to follow/Hints on how to build an ark. Symbiosis is more than coexistence/Ecologists' social theory. Throwing in two hundred elementary particles/on the way to an ecological concept of science. Scientific journals. Alternative literature. Teaching model for a teaching subject 'ecology'. (orig.)

  16. The right balance

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Over the course of her career as a physicist, Felicitas Pauss, currently responsible for CERN's External Relations, has often been the sole woman in an environment dominated by men. While she freely admits that being a woman physicist can have as many advantages as disadvantages, she thinks the best strategy is to maintain the right balance.   From a very early age, Felicitas Pauss always wanted to be involved in projects that interested and fascinated her. That's how she came to study physics. When she was a first-year university student in Austria in 1970, it was still fairly uncommon for women to go into physics research. "I grew up in Salzburg with a background in music. At that time, it was certainly considered more ‘normal’ for a woman to study music than to do research in physics. But already in high school I was interested in physics and technical instruments and wanted to know how things work and what they are made of”. At the beginning of her care...

  17. Earth Science Informatics - Overview

    Science.gov (United States)

    Ramapriyan, H. K.

    2015-01-01

    Over the last 10-15 years, significant advances have been made in information management, there are an increasing number of individuals entering the field of information management as it applies to Geoscience and Remote Sensing data, and the field of informatics has come to its own. Informatics is the science and technology of applying computers and computational methods to the systematic analysis, management, interchange, and representation of science data, information, and knowledge. Informatics also includes the use of computers and computational methods to support decision making and applications. Earth Science Informatics (ESI, a.k.a. geoinformatics) is the application of informatics in the Earth science domain. ESI is a rapidly developing discipline integrating computer science, information science, and Earth science. Major national and international research and infrastructure projects in ESI have been carried out or are on-going. Notable among these are: the Global Earth Observation System of Systems (GEOSS), the European Commissions INSPIRE, the U.S. NSDI and Geospatial One-Stop, the NASA EOSDIS, and the NSF DataONE, EarthCube and Cyberinfrastructure for Geoinformatics. More than 18 departments and agencies in the U.S. federal government have been active in Earth science informatics. All major space agencies in the world, have been involved in ESI research and application activities. In the United States, the Federation of Earth Science Information Partners (ESIP), whose membership includes nearly 150 organizations (government, academic and commercial) dedicated to managing, delivering and applying Earth science data, has been working on many ESI topics since 1998. The Committee on Earth Observation Satellites (CEOS)s Working Group on Information Systems and Services (WGISS) has been actively coordinating the ESI activities among the space agencies. Remote Sensing; Earth Science Informatics, Data Systems; Data Services; Metadata

  18. A Distributed Model for Mountain Climate and Glacier mass Balance

    Science.gov (United States)

    Arrell, K. E.; Evans, I.; Donoghue, D.

    2006-12-01

    The cryosphere has responded to recent climatic variability and change but the precise causes of glacier mass balance changes remain elusive. Predicting the response of relatively small glaciers and ice caps to future climate variability and change is particularly important, since these have contributed more water to eustatic sea level rise in the last 100 years than the larger ice sheets, and are likely to do so for the next 100 years (Arendt et al.2002; Raper and Braithwaite, 2006). Recent research has shown that accurate sea level rise predictions require a greater understanding of glacier response to rising air temperatures and changes in precipitation receipt (Raper and Braithwaite, 2006). The continued shrinkage of relatively small glaciers also has important impacts on the local hydrology and ecology of glacier-fed streams and for water resource management. A regional scale mass balance model based on energy balance at the Earth's surface was developed to calculate accumulation areas in the Jotunheimen, Norway. Spatially distributed modelling used simulated local climate and energy balance data to drive monthly mass balance calculations. Our mass balance model uses spatially distributed climate data derived from 30 year normals (for air temperature, wind speed, cloudiness, albedo and precipitation) with a local energy balance model to predict spatially distributed accumulation and ablation at a 100 m spatial resolution and monthly temporal resolution. The modelled spatial distribution of snow-cover showed good agreement (up to 86 % accuracy) for topographically constrained glaciers in the Jotunheimen, Norway, where aspect, gradient and altitude impose dominant controls on snow and ice accumulation. Melt within accumulation areas was found to be most sensitive to air temperature, especially spring temperatures and cloud cover. A key conclusion identifies several topographic controls on local climate and accumulation as critical for predicting observed spatial variability in glacier mass balance.

  19. A contribution to the validation of the Wii Balance Board for the assessment of standing balance.

    Science.gov (United States)

    Pavan, Piero; Cardaioli, Matteo; Ferri, Ilaria; Gobbi, Erica; Carraro, Attilio

    2015-10-01

    Valid and reliable accessible measures of balance are required in a health-related fitness test battery, both in the general population and in groups with special needs. For this purpose, the capability of the Wii Balance Board (WBB) in evaluating standing balance was analysed and compared with a laboratory-graded force platform (FP). A 30-s double limb standing test with open and closed eyes was performed by 28 individuals (12 male and 16 female, mean age = 23.8, SD = 2.7 years). A simple method of acquisition of the centre of pressure (CoP) over time was applied to compare WBB and FP simultaneously on the same signal. User-defined software was developed to obtain the CoP from WBB over time and the resulting related measures and graphical representations. The comparison of measures, such as sway path and maximum oscillations along the anterior-posterior and medial-lateral direction, obtained with the FP and the WBB shows that the latter, in conjunction with the user-defined developed software, can be appropriate, considering prescribed limits, and an easy-to-use tool for evaluating standing balance. PMID:25222558

  20. When Do States Balance Power?

    DEFF Research Database (Denmark)

    Hariri, Jacob Gerner; Wivel, Anders

    2010-01-01

    This paper explores the logic of balancing in structural realist theory. Arguably, the durability of the unipolar moment is a challenge to the logic of balancing. The paper uses the tools of microeconomics to build a mathematical model of structural realism. The simple model reiterates the...

  1. The origin of the moon and the early history of the earth - a chemical model. Part 2: The earth

    International Nuclear Information System (INIS)

    The geochemical implications for the earth of a giant impact model for the origin of the earth-moon system are discussed, using a mass balance between three components: the proto-earth, the Impactor, and a late veneer. It is argued that the proto-earth accretes from material resembling a high temperature condensate from the solar nebula. Core formation takes place under very reducing conditions, resulting in the mantle of the proto-earth being completely stripped of all elements more siderophile than Fe, and partly depleted in the barely siderophile elements V, Cr, and perhaps Si. The Impactor then collides with the proto-earth, causing vaporisation of both the Impactor and a substantial portion of the earth's mantle. Most of this material recondenses to the earth, but some forms the moon. The Impactor adds most of the complement of the siderophile elements of the present mantle in an oxidized form. The oxidation state of the mantle is set near to its present, oxidized level. Finally, the addition of a late veneer, of composition similar to that of the H-group ordinary chondrites, accounts for the complement of the highly siderophile elements of the present mantle. The model accounts at least semi-quantitatively for the siderophile element abundances of the present mantle. Implications for the composition of the earth's core are discussed; the model predicts that neither S, O, nor Si should be present in sufficient quantities to provide the required light element in the core, whose identity, therefore, remains enigmatic

  2. A question of balance: Kinetic balance for electrons and positrons

    International Nuclear Information System (INIS)

    Graphical abstract: Kinetic balance for both electrons and positrons is achieved by applying the correct relation for positive and negative energy states separately and then using the electron and positron eigensolutions from the separate diagonalizations of the Hamiltonian as a dual basis. Highlights: ? Kinetic balance for electrons and positrons is achieved in a dual atomic basis. ? Dual atomic balance alleviates, but does not eliminate, energy prolapse. ? Positron affinities converge quicker with basis set size with dual atomic balance. - Abstract: The kinetic balance criterion used in current relativistic basis set codes is satisfied by the electron solutions of the Dirac equation, but not the positron solutions. A proposal for applying kinetic balance to both sets of solutions is presented. The method is applied along with normal kinetic balance to one-electron systems, to investigate its possible relation to prolapse, and to the positron affinity of F?, to investigate the kinetic energy deficiency for positron solutions. The new method reduces but does not eliminate prolapse for energy-optimized basis sets, and provides faster and smoother convergence with basis set size for the positron affinity.

  3. Rare earth industries: Upstream business

    International Nuclear Information System (INIS)

    Evidently, many factors contribute to the rush to invest in the unprecedented revival of rare earths. One major reason has to do with the rapidly growing world demand. The other reason relates to the attractive price of rare earths which is projected to stay strong in the coming years. This is because supply is predicted to have difficulty keeping pace with demand. Experts believe a major driver of global rare earths demand is the forecasted expansion in the green economy. Climate change is a major driver of the green economy. With climate change, there is concern that the uncontrolled emission of the greenhouse gases, especially carbon dioxide, can lead to catastrophic consequences for the world. This has been documented in countless studies and reports. Another important driver of the green economy is the growing shortfall in many resources. The world is now experiencing declines in key resources to meet a growing global demand. With more than 6 billion people now in the world and growing, the pressure exerted on global resources including energy, water and food is a major concern. Recent demand surge in China and India has dented the supply position of major world resources. The much quoted Stern Report from the UK has warned that, unless immediate steps are taken to reduce greenhouse gas emissions, it may be a costly exercise to undertake the corrections later. Since energy use, especially fossil fuels, is a major contributor to climate change, greener options are being sought. Add to that the fact that the fossil energy resources of the world are declining, the need to seek alternatives becomes even more urgent. One option is to change to renewable energy sources. These include such potentials as solar, wind and biomass. Rare earths have somehow become a critical feature of the technologies in such renewable. Another option is to improve the efficient use of energy in transport, buildings and all the other energy intensive industries. Again the technologies in energy efficiency rely a lot on the use of rare earths. These include applications in energy efficient lighting, new and more reliable energy storage batteries as well as more efficient energy distribution mechanism. The growing demand for more efficient communication systems, not only in the world of business but also in defence and the military, is another significant driver of the global demand for rare earths. Mobility and miniaturisation, which feature prominently in the current specifications for telecommunications equipment's, rely a lot on the deployment of powerful and efficient magnetic technology. And rare earths have become a much sought after material in the latest magnets used in mobile phones, defence equipment's and computer hardware's. With the rise in the global investments in smart cities and intelligent communities, the demand for such communication products is destined to witness equally prolific expansion. This would inadvertently translate into a rising demand for rare earths. (author)

  4. Pressure sensor

    International Nuclear Information System (INIS)

    The pressure sensor will be used for pressure measurement in high-temperature liquids, in particular for Na or K during fast breeder operation. It has a soft membrane which is unshielded at the pressure medium side and can actuate a rigid membrane an the other side by means of a botton element. The displacement of the rigid membrane is proportional to the difference between the liquid pressure and a reference gas pressure. The displacement can be measured by means of a capacity displacement measuring instrument, using a fixed plate as reference. Absolute calibration is performed by admitting pressurized gas into the zone between the membranes and into the zone between rigid membrane and fixed plate. The coupling between the soft and the rigid membrane is thus interrupted. (DG)

  5. Pressure transmitter

    International Nuclear Information System (INIS)

    An isolator or the like for nuclear power stations employed to separate two fluids or two pressures or other sensing instruments from the containment or elsewhere includes first and second fluid filled bellows having a fluid connection in between and which together provide a pressure transfer mechanism. Excessive travel of the bellows is prevented by overrange valves, one of which closes the pathway on application of high pressure. (author)

  6. Energetics and dynamics of the earth's thermosphere

    International Nuclear Information System (INIS)

    An overview of current (1983-1986) research on the energetics and dynamics of the earth's thermosphere is presented. The global mean radiative and thermal balance in the thermosphere is examined, and the results of experimental investigations for the low-latitude, mid-latitude, and high-latitude upper thermosphere regions are discussed. Consideration is also given to research done in the lower thermosphere, including investigations of tidal and gravity wave processes. In addition, various thermospheric models are discussed together with the results obtained by the analysis of the thermosphere's energetics and dynamics

  7. Earths, Super-Earths, and Jupiters

    Science.gov (United States)

    Chiang, Eugene; Lee, Eve J.

    2015-12-01

    We review and add to the theory of how planets acquire atmospheres from parent circumstellar disks. We derive (in real time) a simple and general analytic expression for how a planet's atmosphere grows with time, as a function of the underlying core mass and nebular conditions, including the gas metallicity. Planets accrete as much gas as can cool: an atmosphere's doubling time is given by its Kelvin-Helmholtz time. The theory can be applied in any number of settings --- gas-rich vs. gas-poor nebulae; dusty vs. dust-free atmospheres; close-in vs. far-out distances --- and is confirmed against detailed numerical models for objects ranging in mass from Mars (0.1 Mearth) to the most extreme super Earths (10--20 Mearth). We explain why heating from planetesimal accretion, commonly invoked in models of core accretion, is irrelevant. This talk sets the stage for another presentation, "Breeding Super-Earths and Birthing Super-Puffs".

  8. Earth's background free oscillations

    Science.gov (United States)

    Suda; Nawa; Fukao

    1998-03-27

    Earth's free oscillations were considered to be transient phenomena occurring after large earthquakes. An analysis of records of the IDA (International Deployment of Accelerometers) gravimeter network shows that Earth is freely oscillating at an observable level even in seismically inactive periods. The observed oscillations are the fundamental spheroidal modes at frequencies between 2 and 7 millihertz. Numerical modeling indicates that these incessant excitations cannot be explained by stacked effects of a large number of small earthquakes. The observed "background" free oscillations represent some unknown dynamic process of Earth. PMID:9516105

  9. Project Earth Science

    CERN Document Server

    Holt, Geoff

    2011-01-01

    Project Earth Science: Astronomy, Revised 2nd Edition, involves students in activities that focus on Earth's position in our solar system. How do we measure astronomical distances? How can we look back in time as we gaze across vast distances in space? How would our planet be different without its particular atmosphere and distance to our star? What are the geometries among Earth, the Moon, and the Sun that yield lunar phases and seasons? Students explore these concepts and others in 11 teacher-tested activities.

  10. The Earth's Magnetic Interior

    CERN Document Server

    Petrovsky, Eduard; Harinarayana, T; Herrero-Bervera, Emilio

    2011-01-01

    This volume combines review and solicited contributions, related to scientific studies of Division I of IAGA presented recently at its Scientific Assembly in Sopron in 2009. The book is aimed at intermediate to advanced readers dealing with the Earth's magnetic field generation, its historical records in rocks and geological formations - including links to geodynamics and magnetic dating, with magnetic carriers in earth materials, electromagnetic induction and conductivity studies of the Earth interior with environmental applications of rock magnetism and electromagnetism. The aim of the book

  11. Wringing out the earth

    Science.gov (United States)

    van Loon, A. J.

    2000-03-01

    The increase in global energy consumption urges the exploitation of known energy resources in the most efficient way. The oil and gas industry seems well capable, but politics may hamper optimum recovery, even though politicians advocate that the laws and regulations laid upon the industry are meant to promote a sustainable society and to diminish environmental pollution. Lack of geological insight sometimes plays a role, which implies that an attitude of effectively wringing out the Earth is not sufficient: more attention for earth-scientific education may turn out to be even more important. This does not affect, however, the need for ever more effective technologies for wringing out the Earth.

  12. Snowball Earth: A thin-ice solution with flowing sea glaciers

    Science.gov (United States)

    Pollard, David; Kasting, James F.

    2005-07-01

    The late Neoproterozoic era, 600-800 Myr ago, was marked by at least two intervals of widespread cold that left glacial deposits at low paleolatitudes. Both "Snowball" solutions with global ice cover and "Slushball" solutions with ice-free tropical oceans have been proposed to explain the paleomagnetic data. The Snowball model is best able to explain the auxiliary geological evidence, particularly the existence of cap carbonates, but it implies drastic survival pressure on the photosynthetic biota if the ice cover was everywhere thick enough to prevent sunlight from reaching the underlying ocean. A "thin ice" solution that avoids this problem has been proposed but is thought to be inconsistent with realistic optical properties of sea ice and with the equatorward flow of sea glaciers. Here we use a coupled energy-balance climate/sea-glacier model to argue that these apparent difficulties can be overcome and that thin tropical ice may have prevailed during these remarkable glacial episodes. We also suggest that (1) some processes beyond the scope of zonal mean energy-balance models may significantly affect the solutions and (2) thin ice could have prevailed on low-latitude seas (or large lakes) protected from large-scale sea-glacier flow by surrounding land even if most of the Earth was in a "hard Snowball" state.

  13. PREFACE: 3rd International Conference on Geological, Geographical, Aerospace and Earth Science 2015 (AeroEarth 2015)

    Science.gov (United States)

    Gaol, F. L.

    2016-02-01

    The 3rd International Conferences on Geological, Geographical, Aerospaces and Earth Sciences 2015 (AeroEarth 2015), was held at The DoubleTree Hilton, Jakarta, Indonesia during 26 - 27 September 2015. The 1st AeoroEarth was held succefully in Jakarta in 2013. The success continued to The 2nd AeroEarth 2014 that was held in Kuta Bali, Indonesia. The publications were published by EES IOP in http://iopscience.iop.org/1755-1315/19/1 and http://iopscience.iop.org/1755-1315/23/1 respectively. The AeroEarth 2015 conference aims to bring together researchers, engineers and scientists from around the world. Through research and development, Earth's scientists have the power to preserve the planet's different resource domains by providing expert opinion and information about the forces which make life possible on Earth. The theme of AeroEarth 2015 is ''Earth and Aerospace Sciences : Challenges and Opportunities'' Earth provides resources and the exact conditions to make life possible. However, with the advent of technology and industrialization, the Earth's resources are being pushed to the brink of depletion. Non-sustainable industrial practices are not only endangering the supply of the Earth's natural resources, but are also putting burden on life itself by bringing about pollution and climate change. A major role of earth science scholars is to examine the delicate balance between the Earth's resources and the growing demands of industrialization. Through research and development, earth scientists have the power to preserve the planet's different resource domains by providing expert opinion and information about the forces which make life possible on Earth. We would like to express our sincere gratitude to all in the Technical Program Committee who have reviewed the papers and developed a very interesting Conference Program as well as the invited and plenary speakers. This year, we received 78 papers and after rigorous review, 18 papers were accepted. The participants come from 8 countries. There are 4 (four) Parallel Sessions and 3 (Three) Keynote Speakers. It is an honour to present this volume of IOP Conference Series: Earth and Environmental Science (EES) and we deeply thank the authors for their enthusiastic and high-grade contribution. Finally, we would like to thank the conference chairmen, the members of the steering committee, the organizing committee, the organizing secretariat and the financial support from the conference sponsors that allowed the success of AeroEarth 2015.

  14. High-pressure optical studies

    International Nuclear Information System (INIS)

    High pressure experimentation may concern intrinsically high pressure phenomena, or it may be used to gain a better understanding of states or processes at one atmosphere. The latter application is probably more prevelant in condensed matter physics. Under this second rubric one may either use high pressure to perturb various electronic energy levels and from this pressure tuning characterize states or processes, or one can use pressure to change a macroscopic parameter in a controlled way, then measure the effect on some molecular property. In this paper, the pressure tuning aspect is emphasized, with a lesser discussion of macroscopic - molecular relationships. In rare earth chelates the efficiency of 4f-4f emission of the rare earth is controlled by the feeding from the singlet and triplet levels of the organic ligand. These ligand levels can be strongly shifted by pressure. A study of the effect of pressure on the emission efficiency permits one to understand the effect of ligand modification at one atmosphere. Photochromic crystals change color upon irradiation due to occupation of a metastable ground state. In thermochromic crystals, raising the temperature accomplishes the same results. For a group of molecular crystals (anils) at high pressure, the metastable state can be occupied at room temperature. The relative displacement of the energy levels at high pressure also inhibits the optical process. Effects on luminescence intensity are shown to be consistent. In the area of microscopic - molecular relationships, the effect of viscosity and dielectric properties on rates of non-radiative (thermal) and radiative emission, and on peak energy for luminescence is demonstrated. For systems which can emit from either of two excited states depending on the interaction with the environment, the effect of rigidity of the medium on the rate of rearrangement of the excited state is shown

  15. Whole-Earth Decompression Dynamics

    OpenAIRE

    Herndon, J. Marvin

    2005-01-01

    The principles of Whole-Earth Decompression Dynamics are disclosed leading to a new way to interpret whole-Earth dynamics. Whole-Earth Decompression Dynamics incorporates elements of and unifies the two seemingly divergent dominant theories of continential displacement, plate tectonics theory and Earth expansion theory. Whole-Earth decompression is the consequence of Earth formation from within a Jupiter-like protoplanet with subsequent loss of gases and ices and concomitant...

  16. Hydration study of rare earth trivalent ions

    International Nuclear Information System (INIS)

    In this work we confirm the fact that in the case of rare earth ions, the hydration process has an electrostatic character. We calculate with our theoretical model the local electrostatic field which is equivalent to an electrostriction pressure. The local density around an Ln3+ ions is obtained from the state equation of pure water at high pressure. The hydration numbers obtained by this model agree with the experimental results and show a progressive diminution of one molecule of water from La3+ to Lu3+

  17. Investigation of hot Flow Anomaly structure observed near the Earth's bow shock

    Science.gov (United States)

    Shestakov, A. Yu.; Vaisberg, O. L.

    2012-02-01

    The work is dedicated to investigation of Hot Flow Anomaly (HFA), formed at the front of Earth's bows hock. Using Interball-Tail data we estimated orientation of the current sheet that was a cause of the anomaly. From the ion energy-time spectrogram we divided the anomaly into several regions. The motional electric fields near the HFA were estimated with 3D model of Earth's bow shock. In accordance with previous investigations of HFA's formation conditions these fields were directed towards the current sheet on both sides of it. We also provided the picture of HFA's motion along the bow shock and calculated its speed. Analyzing ions' bulk velocities within the HFA we found that the anomaly is expanding. This conclusion was supported by estimation of thermal and magnetic pressure balance. Ion energy-time spectrogram shows that anomaly is a complicated structure consisting of two partsleading and trailing. Comparison of ion velocity distributions, magnetic field data and ion energy-time spectrogram provides better understanding of the phenomena and indicated the region that is the source of thermal and convective energy inside HFA.

  18. Gambling with the earth

    CERN Multimedia

    Muir, H

    2000-01-01

    The probability that dangerous Earth-devouring particles will be born at a new accelerator in the US may be tiny, but scientists have played down the devastating potential costs in their risk assessments according to a physicist (1 page).

  19. Earth Science Programs

    Science.gov (United States)

    Freeman, Tony; Im, Eastwood

    2007-01-01

    This slide presentation reviews the JPL missions that enabling Earth Sciences, past, present and future. Included is a list of the National Academy of Sciences Space Studies Board of the recommended missions that are of interest to JPL.

  20. Earth rotation and geodynamics

    Science.gov (United States)

    Bogusz, Janusz; Brzezinski, Aleksander; Kosek, Wieslaw; Nastula, Jolanta

    2015-12-01

    This paper presents the summary of research activities carried out in Poland in 2011-2014 in the field of Earth rotation and geodynamics by several Polish research institutions. It contains a summary of works on Earth rotation, including evaluation and prediction of its parameters and analysis of the related excitation data as well as research on associated geodynamic phenomena such as geocentre motion, global sea level change and hydrological processes. The second part of the paper deals with monitoring of geodynamic phenomena. It contains analysis of geodynamic networks of local, and regional scale using space (GNSS and SLR) techniques, Earth tides monitoring with gravimeters and water-tube hydrostatic clinometer, and the determination of secular variation of the Earth' magnetic field.

  1. Hemimelitates of rare earths

    International Nuclear Information System (INIS)

    The conditions of formation of rare earth complexes with hemimelitic acid were studied. The compositions of lanthanons and yttrium hemimelitates were determined. The properties of obtained complexes were also investigated. (Z.R.)

  2. Down to earth relativity

    Science.gov (United States)

    Shapiro, I. I.

    1978-01-01

    The basic concepts of the special and general theories of relativity are described. Simple examples are given to illustrate the effect of relativity on measurements of time and frequency in the near-earth environment.

  3. Near Earth Objects

    DEFF Research Database (Denmark)

    Wolff, Stefan

    2006-01-01

    The word planet comes from Greek planetes, wanderers, because the planets appear to wander across the celestial sphere, contrary to the fixed stars. This thesis presents several methods for using this motion to distinguish between stars and solar system objects in order to detect and track NEOs......, Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...... and accepted. The European Space Agency mission Gaia is a proposed space observatory, designed to perform a highly accurate census of our galaxy, the Milky Way, and beyond. Through accurate measurement of star positions, Gaia is expected to discover thousands of extra-solar planets and follow the...

  4. Earth study from space

    Science.gov (United States)

    Sidorenko, A. V.

    1981-01-01

    The significance that space studies are making to all Earth sciences in the areas of geography, geodesy, cartography, geology, meteorology, oceanology, agronomy, and ecology is discussed. It is predicted that cosmonautics will result in a revolution in science and technology.

  5. Earth Sciences Today

    International Nuclear Information System (INIS)

    This book intents to present a sample of some aspects of the Earth sciences that are studied at the moment in Mexico. In the context of the International research. The first chapter describes some of the aspects of seismology, considering the study of natural and artificial seismic waves. The more important applications in Mexico are also discussed. The risk associated with the earthquakes and the structures that govern the transmission of seismic signals. In later chapters other signs of the internal dynamic of Earth and other planets are described, such as volcanism, which allow a comparative analysis. This discussions are complemented with three chapters that synthesize aspects of the internal composition of the Earth and the nature and consequences of the magnetic field fluctuations. In the last chapters, the Earth sciences are related with the ecology, by means of the study of that one fragile layer, the soil. (Author)

  6. WorkLife Balance: History, Costs, and Budgeting for Balance

    OpenAIRE

    Raja, Siva; Stein, Sharon L.

    2014-01-01

    The concept and difficulties of worklife balance are not unique to surgeons, but professional responsibilities make maintaining a worklife balance difficult. Consequences of being exclusively career focused include burn out, physical, and mental ailments. In addition, physician burn out may hinder optimal patient care and incur significant costs on health care in general. Assessing current uses of time, allocating goals catered to an individual surgeon, and continual self-assessment may hel...

  7. Anlise de fases por difrao de raios X de WC-10%Co dopado com terras-raras obtido sob alta presso / Phase analysis by x-ray diffraction on the WC-10Co doped with rare-earth elements obtained under high pressure

    Scientific Electronic Library Online (English)

    C. M. F. G., Marques; G. S., Bobrovnitchii; J. N. F., Holanda.

    Full Text Available O carbeto cementado WC-Co tambm denominado de metal duro um material de grande importncia tecnolgica produzido por metalurgia do p atravs de sinterizao por fase lquida, partindo-se da mistura dos ps de carbeto de tungstnio (WC) e de cobalto (Co) em moinho convencional. Entretanto, para o [...] bteno de metal duro com maior capacidade (produtividade, vida til, etc.), uma nova rota alternativa de metalurgia do p denominada de altas presses e altas temperaturas vem sendo utilizada para produo destes materiais com resultados promissores. O presente trabalho tem como objetivo principal a anlise de fases de WC-10Co dopado com terras-raras (La2O3, CeO2e Y2O3) preparadas sob condies de alta presso. Esta liga de metal duro um exemplo de material compsito largamente utilizado como ferramenta de corte e operaes de usinagem em geral. Foram preparadas diversas misturas de WC-10Co contendo at 2 % em peso de terra-rara (La2O3, CeO2e Y2O3) da fase cobalto. Os ps previamente misturados foram compactados numa matriz cilndrica (? = 7 mm) a uma presso de 800 MPa e sinterizados a 1400 C durante 40 s sob alta presso de 5,5 GPa. Os compsitos produzidos foram caracterizados por difrao de raios X para identificao de fases cristalinas presentes. Alm disso, foi feita anlise comparativa entre o carbeto isento de terra-rara (amostras de referncia) e carbetos dopados com elementos de terra-rara (La2O3, CeO2, e Y2O3). Para as condies estudadas os resultados mostraram que durante o processo de sinterizao ocorreu formao, mesmo que em pequenas quantidades, das fases Co3W3C2 e ? (carbeto tipo ?) nas peas de metal duro estudadas. Abstract in english The WC-Co cemented carbide also called hardmetal is a material of great technological importance, currently produced by powder metallurgy by liquid phase sintering, starting from the mixture of powdered tungsten carbide (WC) and cobalt (Co) using conventional mill. Seeking to obtain materials with h [...] igher capacity (productivity, life, etc.), an alternative route for powder metallurgy called High Pressure High Temperature (HPHT) has been used for the production of these materials with promising results. The main aim of this work is the phases analysis of the WC-10Co doped with rare-earths (La2O3, CeO2,and Y2O3) obtained under high pressure. This hardmetal alloy is an example of the composite material widely used as cutting tool and machining processes in general. Several WC-10Co mixtures containing up to 2 wt % La2O3,CeO2and Y2O3 of the cobalt phase were prepared. The mixed powders were pressed at 800 MPa in a cylindrical matrix (? = 7 mm) and sintered at 1400C during 40 s under high pressure (5.5 GPa). The identification of the crystalline phases was done by X-ray diffraction. In addition, comparative analysis between the free rare-earth and doped with rare-earths elements (La2O3, CeO2 and Y2O3) carbides was done. The results showed that, within the conditions studied during the sintering process, formation, even, small amounts, of the phases Co3W3C2 and ? (? carbide type) were observed in the carbide pieces studied.

  8. Extremophiles: Link between earth and astrobiology

    OpenAIRE

    Stojanovi? Dejan B.; Fojkar Oliver; Drobac-?ik Aleksandra V.; ?ajko Kristina O.; Duli? Tamara I.; Svir?ev Zorica B.

    2008-01-01

    Astrobiology studies the origin, evolution, distribution and future of life in the universe. The most promising worlds in Solar system, beyond Earth, which may harbor life are Mars and Jovian moon Europa. Extremophiles are organisms that thrive on the edge of temperature, hypersalinity, pH extremes, pressure, dryness and so on. In this paper, some extremophile cyanobacteria have been discussed as possible life forms in a scale of astrobiology. Samples were taken from solenetz and solonchak ty...

  9. Balancing with Noise and Delay

    CERN Document Server

    Hosaka, T; Luciani, C; Cabrera, J L; Milton, J G; Hosaka, Tadaaki; Ohira, Toru; Luciani, Christian; Cabrera, Juan Luis; Milton, John G.

    2006-01-01

    Motivated by recent studies in human balance control, we study a delayed random walk with an unstable fixed point. It is observed that the random walker moves away from the unstable fixed point more slowly than is observed in the absence of delay. It is shown that, for given a noise level, there exists an optimal delay to achieve the longest first passage time. Our observations support recent demonstrations that noise has a beneficial role for balance control and emphasize that predicitive strategies are not necessary to transiently control balance.

  10. Calibration and Data Analysis of the MC-130 Air Balance

    Science.gov (United States)

    Booth, Dennis; Ulbrich, N.

    2012-01-01

    Design, calibration, calibration analysis, and intended use of the MC-130 air balance are discussed. The MC-130 balance is an 8.0 inch diameter force balance that has two separate internal air flow systems and one external bellows system. The manual calibration of the balance consisted of a total of 1854 data points with both unpressurized and pressurized air flowing through the balance. A subset of 1160 data points was chosen for the calibration data analysis. The regression analysis of the subset was performed using two fundamentally different analysis approaches. First, the data analysis was performed using a recently developed extension of the Iterative Method. This approach fits gage outputs as a function of both applied balance loads and bellows pressures while still allowing the application of the iteration scheme that is used with the Iterative Method. Then, for comparison, the axial force was also analyzed using the Non-Iterative Method. This alternate approach directly fits loads as a function of measured gage outputs and bellows pressures and does not require a load iteration. The regression models used by both the extended Iterative and Non-Iterative Method were constructed such that they met a set of widely accepted statistical quality requirements. These requirements lead to reliable regression models and prevent overfitting of data because they ensure that no hidden near-linear dependencies between regression model terms exist and that only statistically significant terms are included. Finally, a comparison of the axial force residuals was performed. Overall, axial force estimates obtained from both methods show excellent agreement as the differences of the standard deviation of the axial force residuals are on the order of 0.001 % of the axial force capacity.

  11. Earth construction: bird teaching

    OpenAIRE

    B Silva; Correia, J.; Nunes, F.; Tavares, P.; Varum, H.; Pinto, J

    2009-01-01

    The paradigm of earth being a traditional and a modern building material has been related to the fact that it is natural, ecological, recycled, abundant and economic. Among the traditional Portuguese building techniques, earth construction was always one very common. The construction built with these techniques must be preserved. In this context, the main objective of this research work is to give a contribution on the material properties characterization and, in particular, for t...

  12. Mathematics of Planet Earth

    OpenAIRE

    eljka Tutek

    2013-01-01

    At the beginning of the December 2013, it was announced that the successful year-long world-wide project Mathematics of Planet Earth 2013 (MPE2013) under the patronage of UNESCO will continue as Mathematics of Planet Earth (MPE)! The idea of Christiane Rousseau, the past president of the Canadian Mathematical Society, about uniting the worlds mathematicians in an effort to bring awareness to global issues has been worked out far beyond what she could have hoped.

  13. Earth's surface heat flux

    OpenAIRE

    Davies, J. H.; Davies, D.R.

    2010-01-01

    We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by ...

  14. Earth's surface heat flux

    OpenAIRE

    Davies, J. H.; Davies, D.R.

    2009-01-01

    We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by ...

  15. Life After Earth

    OpenAIRE

    Marzban, Caren; Viswanathan, Raju; Yurtsever, Ulvi

    2013-01-01

    A recent study reported that there is evidence life may have originated prior to the formation of the Earth. That conclusion was based on a regression analysis of a certain data set involving evolution of functional genome size across major phyla. Here it is shown that if measurement errors and "confidence" intervals are taken into account, then the regression analysis of the same data set leads to conclusions that allow for life to have appeared after the formation of the Earth.

  16. Earth rotation and geodynamics

    OpenAIRE

    Bogusz Janusz; Brzezinski Aleksander; Kosek Wieslaw; Nastula Jolanta

    2015-01-01

    This paper presents the summary of research activities carried out in Poland in 2011-2014 in the field of Earth rotation and geodynamics by several Polish research institutions. It contains a summary of works on Earth rotation, including evaluation and prediction of its parameters and analysis of the related excitation data as well as research on associated geodynamic phenomena such as geocentre motion, global sea level change and hydrological processes. The second part of the paper deals wit...

  17. Gravity and expanding Earth

    OpenAIRE

    Scalera, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia

    2003-01-01

    The analysis of different clues indicating a variation of the local gravity (g) through geological time is performed. The examined data come from Astrogeodesy (PM and TPW), Paleogeography, Tidal torques, J2 variation, and paleogravity data from Geology. It is shown that a joint reasoning about all these data can constrain the possible variation rate of G, g and M (Earths mass). The result is that, albeit in the past great theoretical and experimental efforts were made in propo...

  18. EARTH ROADS ARE EASY

    OpenAIRE

    David O. Whitten

    2000-01-01

    The earliest European immigrants in America traveled on waterways and on pathways worn into the earth by animals and Native Americans. Once their communities began to thrive, settlers widened paths and cleared new roads and streets then began experimenting with inexpensive surfacing to reduce dust in dry weather and mud in wet. Earth Roads Are Easy investigates materials and techniques used to maintain primitive thoroughfares with a minimum of effort and expense. The options range from the ...

  19. Fuller's earth (montmorillonite) pneumoconiosis.

    OpenAIRE

    Gibbs, A R; Pooley, F.D.

    1994-01-01

    A fuller's earth worker developed signs of pneumoconiosis. Pathological examination of the lung tissues showed interstitial collections of dust laden macrophages associated with mild fibrosis. Mineralogical analysis showed a high content of montmorillonite. This study shows that a pneumoconiosis can result from prolonged heavy exposure to calcium montmorillonite (fuller's earth) in the absence of quartz. The disease is relatively mild and associated with little clinical disability.

  20. Energy Budget: Earth's Most Important and Least Appreciated Planetary Attribute

    Science.gov (United States)

    Chambers, Lin; Bethea, Katie

    2013-01-01

    The energy budget involves more than one kind of energy. People can sense this energy in different ways, depending on what type of energy it is. We see visible light using our eyes. We feel infrared energy using our skin (such as around a campfire). We know some species of animals can see ultraviolet light and portions of the infrared spectrum. NASA satellites use instruments that can "see" different parts of the electromagnetic spectrum to observe various processes in the Earth system, including the energy budget. The Sun is a very hot ball of plasma emitting large amounts of energy. By the time it reaches Earth, this energy amounts to about 340 Watts for every square meter of Earth on average. That's almost 6 60-Watt light bulbs for every square meter of Earth! With all of that energy shining down on the Earth, how does our planet maintain a comfortable balance that allows a complex ecosystem, including humans, to thrive? The key thing to remember is the Sun - hot though it is - is a tiny part of Earth's environment. Earth's energy budget is a critical but little understood aspect of our planetary home. NASA is actively studying this important Earth system feature, and sharing data and knowledge about it with the education community.

  1. Simulations of micrometeoroid interactions with the Earth atmosphere

    CERN Document Server

    Briani, G; Shore, S N; Pupillo, G; Passaro, A; Aiello, S

    2013-01-01

    Micrometeoroids (cosmic dust with size between a few $\\mu$m and $\\sim$1 mm) dominate the annual extraterrestrial mass flux to the Earth. We investigate the range of physical processes occurring when micrometeoroids traverse the atmosphere. We compute the time (and altitude) dependent mass loss, energy balance, and dynamics to identify which processes determine their survival for a range of entry conditions. We develop a general numerical model for the micrometeoroid-atmosphere interaction. The equations of motion, energy, and mass balance are simultaneously solved for different entry conditions (e.g. initial radii, incident speeds and angles). Several different physical processes are taken into account in the equation of energy and in the mass balance, in order to understand their relative roles and evolution during the micrometeoroid-atmosphere interaction. In particular, to analyze the micrometeoroid thermal history we include in the energy balance: collisions with atmospheric particles, micrometeoroid radi...

  2. Optimized balance rehabilitation training strategy for the elderly through an evaluation of balance characteristics in response to dynamic motions

    Directory of Open Access Journals (Sweden)

    Jung HH

    2015-10-01

    Full Text Available HoHyun Jung,1 Keyoung Jin Chun,2 Jaesoo Hong,2 Dohyung Lim1 1Department of Mechanical Engineering, Sejong University, Seoul, Republic of Korea; 2Smart Welfare Technology Research Group, Korea Institute of Industrial Technology, Cheonan, Republic of Korea Abstract: Balance is important in daily activities and essential for maintaining an independent lifestyle in the elderly. Recent studies have shown that balance rehabilitation training can improve the balance ability of the elderly, and diverse balance rehabilitation training equipment has been developed. However, there has been little research into optimized strategies for balance rehabilitation training. To provide an optimized strategy, we analyzed the balance characteristics of participants in response to the rotation of a base plate on multiple axes. Seven male adults with no musculoskeletal or nervous system-related diseases (age: 25.51.7 years; height: 173.96.4cm; body mass: 71.36.5 kg; body mass index: 23.62.4 kg/m2 were selected to investigate the balance rehabilitation training using customized rehabilitation equipment. Rotation of the base plate of the equipment was controlled to induce dynamic rotation of participants in the anteriorposterior, right-diagonal, mediallateral, and left-diagonal directions. We used a three-dimensional motion capture system employing infrared cameras and the Pedar Flexible Insoles System to characterize the major lower-extremity joint angles, center of body mass, and center of pressure. We found statistically significant differences between the changes in joint angles in the lower extremities in response to dynamic rotation of the participants (P<0.05. The maximum was greater with anteriorposterior and mediallateral dynamic rotation than with that in other directions (P<0.05. However, there were no statistically significant differences in the frequency of center of body mass deviations from the base of support (P>0.05. These results indicate that optimizing rotation control of the base plate of balance rehabilitation training equipment to induce anteriorposterior and mediallateral dynamic rotation preferentially can lead to effective balance training. Additional tests with varied speeds and ranges of angles of base plate rotation are expected to be useful as well as an analysis of the balance characteristics considering a balance index that reflects the muscle activity and cooperative characteristics. Keywords: optimized strategy, balance rehabilitation training, balance characteristics, maximum deviation, deviation frequency

  3. Structural behaviour of YGa under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sekar, M., E-mail: sekarm@igcar.gov.in; Shekar, N. V. Chandra, E-mail: sekarm@igcar.gov.in; Sahu, P. Ch., E-mail: sekarm@igcar.gov.in [Condensed Matter Physics Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam- 603 102 Tamil Nadu (India); Babu, R. [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam- 603 102 Tamil Nadu (India)

    2014-04-24

    High pressure X-ray diffraction studies on rare-earth gallide YGa was carried up to a pressure of ? 33 GPa using rotating anode x-ray source in an angle dispersive mode. YGa exhibits CrB (B33) type orthorhombic structure (space group Cmcm) at ambient pressure. It undergoes a reversible structural phase transition from orthorhombic to tetragonal structure at ? 8.8 GPa. Both the phases coexist up to the highest pressure studied. The zero pressure bulk modulus and its derivative for parent phase have been estimated to be B{sub o} = 60 3 GPa, B{sub o}' = 4.6 1.5.

  4. Field reversing magnetotail current sheets: earth, Venus, and Comet Giacobini-Zinner

    International Nuclear Information System (INIS)

    This dissertation examines the field reversing magnetotail current sheets at the earth, Venus, and Comet Giacobini-Zinner. In the near earth study a new analysis technique is developed to calculate the detailed current density distributions within the cross tail current sheet for the first time. This technique removes the effects of a variable sheet velocity by inverting intersatellite timings between the co-orbiting satellites ISEE-1 and -2. Case studies of three relatively geomagnetically quiet crossings are made; sheet thicknesses and peak current densities are ?1-5 x 104 km and ?5-50 nA/m2. Current density distributions reveal a high density central region, lower density shoulders, and considerable fine structure throughout. In the Venus study another new analysis technique is developed to reconstruct the average tail configuration from a correlation between field magnitude and draping angle in a large statistical data set. In the comet study, high resolution magnetic field and plasma electron data from the ICE traversal of Giacobini-Zinner are combined for the first time to determine the tail/current sheet geometry and calculate certain important but unmeasured local ion and upstream properties. Pressure balance across the tail gives ion temperatures and betas of ?1.2 x 105 K and ?40 in the center of the current sheet to ?1 x 106 K and ?3 in the outer lobes. Axial stress balance shows that the velocity shear upstream near the nucleus is >6 (?1 at ICE), and that a region of strongly enhanced mass loading (ion source rate ?24 times that upstream from lobes) exists upstream from the current sheet. The integrated downtail mass flux is ?2.6 x 1026 H2O+/sec, which is only ?1% of the independently determined total cometary efflux. 79 refs., 37 figs

  5. Field reversing magnetotail current sheets: earth, Venus, and Comet Giacobini-Zinner

    Energy Technology Data Exchange (ETDEWEB)

    McComas, D.J.

    1986-09-01

    This dissertation examines the field reversing magnetotail current sheets at the earth, Venus, and Comet Giacobini-Zinner. In the near earth study a new analysis technique is developed to calculate the detailed current density distributions within the cross tail current sheet for the first time. This technique removes the effects of a variable sheet velocity by inverting intersatellite timings between the co-orbiting satellites ISEE-1 and -2. Case studies of three relatively geomagnetically quiet crossings are made; sheet thicknesses and peak current densities are approx.1-5 x 10/sup 4/ km and approx.5-50 nA/m/sup 2/. Current density distributions reveal a high density central region, lower density shoulders, and considerable fine structure throughout. In the Venus study another new analysis technique is developed to reconstruct the average tail configuration from a correlation between field magnitude and draping angle in a large statistical data set. In the comet study, high resolution magnetic field and plasma electron data from the ICE traversal of Giacobini-Zinner are combined for the first time to determine the tail/current sheet geometry and calculate certain important but unmeasured local ion and upstream properties. Pressure balance across the tail gives ion temperatures and betas of approx.1.2 x 10/sup 5/ K and approx.40 in the center of the current sheet to approx.1 x 10/sup 6/ K and approx.3 in the outer lobes. Axial stress balance shows that the velocity shear upstream near the nucleus is >6 (approx.1 at ICE), and that a region of strongly enhanced mass loading (ion source rate approx.24 times that upstream from lobes) exists upstream from the current sheet. The integrated downtail mass flux is approx.2.6 x 10/sup 26/ H/sub 2/O+/sec, which is only approx.1% of the independently determined total cometary efflux. 79 refs., 37 figs.

  6. Thermal balance testing of MSAT 2 spacecraft

    Science.gov (United States)

    Samson, Serge; Choueiry, Elie

    1994-11-01

    The present work reports on the recently completed infrared thermal balance/thermal vacuum testing of a MSAT satellite, the first satellite to provide mobile communications service for all of continental North America. MSAT is a two spacecraft program, using a three-axis stabilized Hughes HS-601 series Bus as the vehicle for the Canadian designed Payload. The thermal tests which were performed at the Canadian Space Agency's David Florida Laboratory in Ottawa, Canada, lasted approximately 35 days. The infrared (IR) heating rig was designed to provide radiant heat inputs into seven spacecraft zones during Thermal Vacuum (TV) testing. The TV test was divided into multiple phases. It began with a thermal balance cold phase, followed by a thermal cold cycle and a hot balance phase, complemented by a thermal hot cycle to finish with a thermal cycle with continuous monitoring of the Bus and Payload. The spacecraft's external heat fluxes were provided by IR lamp sources. To ensure flux uniformity, highly reflective baffles and IR East and West faces; the Earth facing (Nadir); and the inside of the thrust cylinder. The aft-end panel heat fluxes were provided by a heated LN2 shroud. The radiation flux intensity on the spacecraft zones from the various rig elements was measured using Monitored Background Radiometers (MBR's) and compared with direct calculations and with pretest predictions. The temperature measurement system was based on Uniform Temperature References (UTR's) located inside the chamber such that all feedthroughs were copper-copper. This system was devised to achieve a temperature measurement accuracy of plus/minus 0.5 C for over 850 thermocouples used in the test. A PC-(QNX-based) based real-time data acquisition system was utilized to provide continuous monitoring of all channels based on a 30-second time scan. In addition, the data acquisition system was able to retrieve telemetry stream from the Satellite Test Equipments (STE) station for real-time data manipulation. Preliminary results showed the test to be successful from both the thermal balance side and the electrical testing side.

  7. An Oscillating Magnet Watt Balance

    CERN Document Server

    Ahmedov, H

    2015-01-01

    We establish the principles for a new generation of simplified and accurate watt balances in which an oscillating magnet generates Faraday's voltage in a stationary coil. A force measuring system and a mechanism providing vertical movements of the magnet are completely independent in an oscillating magnet watt balance. This remarkable feature allows to establish the link between the Planck constant and a macroscopic mass by a one single experiment. Weak dependence on variations of environmental and experimental conditions, weak sensitivity to ground vibrations and temperature changes, simple force measuring procedure, small sizes and other useful features offered by the novel approach considerably reduce the complexity of the experimental setup. We formulate the oscillating magnet watt balance principle and establish the measurement procedure for the Planck constant. We discuss the nature of oscillating magnet watt balance uncertainties and give a brief description of the National Metrology Institute (UME) wa...

  8. Aging: Balancing regeneration and cancer

    Energy Technology Data Exchange (ETDEWEB)

    Beausejour, Christian M.; Campisi, Judith

    2006-08-24

    The proliferation of cells must balance the longevity assured by tissue renewal against the risk of developing cancer. The tumor-suppressor protein p16{sup INK4a} seems to act at the pivot of this delicate equilibrium.

  9. Exercise to Improve Your Balance

    Science.gov (United States)

    ... the Go4Life website. As you progress in your exercise routine, try adding the following challenges to help ... steady on your feet, try doing the balance exercises with your eyes closed. Quick Tip In the ...

  10. Energy balances 1997 and 1998

    International Nuclear Information System (INIS)

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 1998 are presented for comparison. (EHS)

  11. Energy balances 1998 and 1999

    International Nuclear Information System (INIS)

    The energy balances of the Danish Statistical Office are the designation of the goods balances, which are tabulated for each energy article in both physical entities (quantities) and in base rates (values). The balance concept is connected to the definition supply = use, which is the basis for the construction of the system. The supply is determined as the sum of two items: import and production while the total use is the sum of 138 items: export, waste and transmission loss, stock increase, input in lack of the 130 industries, and private consumption divided into 5 consumption groups. The statistical analysis is performed yearly in both quantities and values for 35 energy articles. Values are computed for base rates, profits, taxes, VAT and market prices (buyer's price), respectively. The energy balances from 1975 to 1998 are presented for comparison. (EHS)

  12. Pre-onset Azimuthal Pressure Gradient and Associated Auroral Intensifications Related to Dipolarization Fronts

    Science.gov (United States)

    Xing, X.; Lyons, L. R.; Angelopoulos, V.; Zhou, X.; Donovan, E.; Larson, D. E.; Carlson, C. W.; Auster, U.

    2011-12-01

    The plasma pressure spatial distribution and the magnetic field in force balance with it determine the distribution of the Field-Aligned Current (FAC) in the quasi-static near-Earth plasma sheet. The time evolution of the azimuthal plasma pressure gradient during undisturbed periods is of particular importance in leading to the evolution of FACs, which strongly affect the ionospheric current circulation and the aurora formation before dynamical processes strike, e.g., substorms. Xing et al. (2011) demonstrated by case study that the plasma sheet pressure gradient at ~11 RE near the substorm onset meridian undergoes a substantial duskward enhancement shortly before the onset as identified from the auroral poleward expansion. The increased upward FAC driven by this pressure gradient enhancement leads to the thin onset arc intensification from which the poleward expansion initiates. The mechanism of the formation of such a transient duskward pressure gradient is still an open question. In the present study, we employ the multi-THEMIS spacecraft in azimuthal conjunction -at ~-11 RE and examine the ion flux and distributions during the period of pressure gradient enhancement. Strong field-aligned ion flux enhancements covering the energy range from several KeV to above 25KeV were observed by the spacecraft identifying the higher pressure increase, while at the same time the ion distributions show substantial field-aligned, mushroom-like shift in velocity space. These resemble the ion acceleration ahead of earthward moving dipolarization fronts in a highly stretched magnetic field during the late growth phase. The local plasma develops strong transient parallel anisotropy due to the ion acceleration. On the other hand, the spacecraft observing the lower pressure increase found weaker or no ion flux enhancements and had nearly isotropic distributions. Due to these spatial differences, similar transient pressure gradient enhancements in the dawnward direction were also found for some events. These suggest that the transient azimuthal pressure gradient enhancement near the onset meridian could result from the azimuthal difference of the ion acceleration caused by the localized dipolarization fronts that reach the near-Earth plasma sheet at the onset meridian. The associated transient upward FAC enhancement, which leads to the thin onset arc intensification, would thus be related to the current pair generated in the plasma compression region ahead of the dipolarization front. Thus the earthward penetrating plasma flow channels could play a dominant role in leading to substorm onset.

  13. Balancing energy flexibilities through aggregation

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    in both energy production and consumption, is the key to solving these problems. Flexibilities can be expressed as flex-offers, which due to their high number need to be aggregated to reduce the complexity of energy scheduling. In this paper, we discuss balance aggregation techniques that already...... during aggregation aim at balancing flexibilities in production and consumption to reduce the probability of congestions and reduce the complexity of scheduling. We present results of our extensive experiments....

  14. Balancer effects in opinion dynamics

    CERN Document Server

    Cheon, Taksu

    2015-01-01

    We introduce a novel type of contrarian agent, the balancer, to Galam model of opinion dynamics, in order to account for the skepticism over one-sidedness and for the sense of fairness. We find that the inclusion of balancers along with floaters and inflexibles brings about a critical point on parametric plane of the dynamical system, which results in the new kind of stable final states of the opinion dynamics, that seem to capture several intriguing features found often in mature democracies.

  15. Electric power balance sheet 2012

    International Nuclear Information System (INIS)

    The mission of RTE, the French electricity Transportation grid, a public service assignment, is to balance the electricity supply and demand in real time. This report presents RTE's technical results for the year 2012: strong seasonal contrast of power consumption, rise of the renewable energies contribution in meeting the electricity demand, slight decay of the nuclear and thermal power generation, decrease of the export balance and change in trades structure, adaptation of RTE's network to the evolutions of the energy system

  16. Balanced Scorecard for Olvi Plc

    OpenAIRE

    Tarpio, Monica

    2013-01-01

    Company performance measurement is the most important factor of any business. Earlier the emphasis was on the financial factor, but nowadays the nonfinancial factors have emerged more. Balanced Scorecard is used to monitor business operations, because it has four different perspec-tives that originate from critical success factors. The thesis is divided into two parts. The first part includes the theory of Balanced Scorecard and other examples. The second part is a case study and it inclu...

  17. Balancing with Noise and Delay

    OpenAIRE

    Hosaka, Tadaaki; Ohira, Toru; Luciani, Christian; Cabrera, Juan Luis; Milton, John G.

    2006-01-01

    Motivated by recent studies in human balance control, we study a delayed random walk with an unstable fixed point. It is observed that the random walker moves away from the unstable fixed point more slowly than is observed in the absence of delay. It is shown that, for given a noise level, there exists an optimal delay to achieve the longest first passage time. Our observations support recent demonstrations that noise has a beneficial role for balance control and emphasize t...

  18. Financial intermediary balance sheet management

    OpenAIRE

    Adrian, Tobias; Shin, Hyun Song

    2011-01-01

    Conventional discussions of balance sheet management by nonfinancial firms take the set of positive net present value (NPV) projects as given, which in turn determines the size of the assets of the firm. The focus is on the composition of equity and debt in funding such assets. In contrast, the balance sheet management of financial intermediaries reveals that it is equity that behaves like the predetermined variable, and the asset size of the bank or financial intermediary is determined by th...

  19. A new program in earth system science education

    Science.gov (United States)

    Huntress, Wesley; Kalb, Michael W.; Johnson, Donald R.

    1990-01-01

    A program aimed at accelerating the development of earth system science curricula at the undergraduate level and at seeding the establishment of university-based mechanisms for cooperative research and education among universities and NASA has been initiated by the Universities Space Research Association (USRA) in conjunction with NASA. Proposals were submitted by 100 U.S. research universities which were selected as candidates to participate in a three-year pilot program to develop undergraduate curricula in earth system science. Universities were then selected based upon peer review and considerations of overall scientific balance among proposed programs. The program will also aim to integrate a number of universities with evolving earth system programs, linking them with a cooperative curriculum, shared faculty, and NASA scientists in order to establish a stronger base for earth systems related education and interdisciplinary research collaboration.

  20. Reproducibility of calibration results by 0-A-0 pressurization procedures for hydraulic pressure transducers

    Science.gov (United States)

    Kajikawa, Hiroaki; Kobata, Tokihiko

    2014-01-01

    This paper focuses on 0-A-0 pressurization for the calibration of electromechanical pressure gauges in order to obtain reproducible results by various procedures. In 0-A-0 pressurization, pressure is released to atmospheric pressure after finishing each measurement at each calibration pressure, and the output reading at atmospheric pressure is used for offset correction. Pressure gauges are calibrated under various pressure sequence and time interval conditions in the pressure range of 10 MPa to 100 MPa using a fully automated calibration system that uses a pressure balance as the standard device. Results for a quartz Bourdon-type pressure transducer are mainly reported. The hysteresis obtained by 0-A-0 pressurization is found to be nearly one-tenth of that obtained by stepwise pressurization. The effect of the previously applied pressure is less than 10 parts per million even for a random pressure sequence. Key points for calibration procedures are proposed from the calibration results for different time intervals. When the appropriate procedure is used, 0-A-0 pressurization largely reduces the effect of pressurization history, thus yielding highly reproducible calibration results.

  1. Isotope composition and volume of Earths early oceans

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Bird, Dennis K.; Rosing, Minik Thorleif

    2012-01-01

    Oxygen and hydrogen isotope compositions of Earths seawater are controlled by volatile fluxes among mantle, lithospheric (oceanic and continental crust), and atmospheric reservoirs. Throughout geologic time the oxygen mass budget was likely conserved within these Earth system reservoirs, but...... in Earths oceans. Our calculations predict that the oceans of early Earth were up to 26% more voluminous, and atmospheric CH4 and CO2 concentrations determined from limits on hydrogen escape to space are consistent with clement conditions on Archaean Earth....

  2. Form 6 - gas balancing agreement

    International Nuclear Information System (INIS)

    In 1988, a special Committee of the Rocky Mountain Mineral Law Foundation undertook a project to draft a model from gas balancing agreement. This project was initiated at the request of a number of Foundation members who felt that a model form gas balancing agreement would facilitate the negotiation of operating agreement, since gas balancing issues had become sticking points in the process. The Committee was composed of attorneys representing a wide cross-section of the oil and gas industry including both major and independent oil companies, production companies with interstate pipeline affiliates, and private practitioners. The Committee attempted to address the more controversial issues in gas balancing with optional provisions in the Form. To facilitate the negotiation process, the number of optional provisions was minimized. This form may be used as an Appendix to the new A.A.P.L. Form 610-1989 Model Form Operating Agreement. This book includes provision of this Form which are: Ownership of gas production; Balancing of production accounts; Cash balancing upon depletion; Deliverability tests; Nominations; Statements; Payment of taxes; Operating expenses; Overproducing allowable; Payment of leasehold burdens; Operator's liability; Successors and assigns; Audits; Arbitration; and Operator's fees

  3. Checks and balances of a helium pipe line system

    Energy Technology Data Exchange (ETDEWEB)

    Tacquard, A.H.

    1969-02-01

    A pipe line system balance is a means for detecting possible pipeline leaks, inaccuracies in measurement, and trends or changes of the pipeline material balance. A balance determination may be made for any period of time, an hour, a day, a month, or a year. The U.S. Bureau of Mines Helium Activity crude helium pipeline system, designed for 1,800 psi maximum operation pressure, consists of 3, 4, and 8-in.-diam pipe. Helium is delivered into the pipeline at pressures ranging from 860 to 1,200 psia which provide transportation and injection into Cliffside gas field at about 850 psia without further compression. The system has automatic pneumatic valves at approx. 10-mile intervals along the pipeline that will close in the event of a rapid drop in pressure, to prevent excessive losses of helium should a pipeline break occur. A telemetering system is used to transmit flow data (including pressure, helium content, gross flow rate, cumulative gross volume, and cumulative contained helium volume) to a central control room. These data are updated every hour.

  4. Comparison of Static Balance and the Role of Vision in Elite Athletes

    OpenAIRE

    Hammami Raouf; Behm David G; Chtara Mokhtar; Othman Aymen Ben; Chaouachi Anis

    2014-01-01

    When prescribing balance exercises to athletes in different sports, it may be important to recognize performance variations. Indeed, how athletes from different sports perform on balance tests is not well understood. The goal of the present study was to compare static balance and the role of vision among elite sprinters, jumpers and rugby players. The modified clinical test of sensory interaction on balance (mCTSIB) was used to assess the velocity of the center-of-pressure (CoP) on a force pl...

  5. Measuring the Earths Magnetic Field from Space

    DEFF Research Database (Denmark)

    Olsen, Nils; Hulot, G.; Sabaka, T. J.

    2010-01-01

    Observations of the Earths magnetic field from low-Earth orbiting (LEO) satellites started very early on, more than 50 years ago. Continuous such observations, relying on more advanced technology and mission concepts, have however only been available since 1999. The unprecedented time-space coverage of this recent data set opened revolutionary new possibilities for monitoring, understanding and exploring the Earths magnetic field. In the near future, the three-satellite Swarm constellation con...

  6. Time variable Earths gravity field from SLR satellites

    OpenAIRE

    Sosnica, Krzysztof Jakub; Jggi, Adrian; Meyer, Ulrich; Thaller, Daniela; Beutler, Gerhard; Arnold, Daniel; Dach, Rolf

    2015-01-01

    The time variable Earths gravity field contains information about the mass transport within the system Earth, i.e., the relationship between mass variations in the atmosphere, oceans, land hydrology, and ice sheets. For many years, satellite laser ranging (SLR) observations to geodetic satellites have provided valuable information of the low-degree coefficients of the Earths gravity field. Today, the Gravity Recovery and Climate Experiment (GRACE) mission is the major source of information ...

  7. Alkaline earth- and rare earth-transition metal complexes

    OpenAIRE

    Blake, Matthew Paul; Mountford, Philip

    2013-01-01

    This Thesis describes the synthesis and characterisation of new alkaline earth- and rare earth-transition metal complexes. Experimental and computational studies were performed to investigate the structure and bonding in these complexes. Their reactivity was also studied. Chapter 1 introduces metal-metal bonded complexes and current alkaline earth- and rare earth-transition metal bonded complexes. Chapter 2 describes experimental and computational studies of new alkaline earth- and la...

  8. Pressure sensor

    Science.gov (United States)

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

    2015-09-29

    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  9. Venus, Earth, Xenon

    Science.gov (United States)

    Zahnle, K. J.

    2013-12-01

    Xenon has been regarded as an important goal of many proposed missions to Venus. This talk is intended to explain why. Despite its being the heaviest gas found in natural planetary atmospheres, there is more evidence that Xe escaped from Earth than for any element apart from helium: (i) Atmospheric Xe is very strongly mass fractionated (at about 4% per amu) from any known solar system source. This suggests fractionating escape that preferentially left the heavy Xe isotopes behind. (ii) Xe is underabundant compared to Kr, a lighter noble gas that is not strongly mass fractionated in air. (iii) Radiogenic Xe is strongly depleted by factors of several to ~100 compared to the quantities expected from radioactive decay of primordial solar system materials. In these respects Xe on Mars is similar to Xe on Earth, but with one key difference: Xe on Mars is readily explained by a simple process like hydrodynamic escape that acts on an initially solar or meteoritic Xe. This is not so for Earth. Earth's Xe cannot be derived by an uncontrived mass fractionating process acting on any known type of Solar System Xe. Earth is a stranger, made from different stuff than any known meteorite or Mars or even the Sun. Who else is in Earth's family? Comets? We know nothing. Father Zeus? Data from Jupiter are good enough to show that jovian Xe is not strongly mass-fractionated but not good enough to determine whether Jupiter resembles the Earth or the Sun. Sister Venus? Noble gas data from Venus are incomplete, with Kr uncertain and Xe unmeasured. Krypton was measured by several instruments on several spacecraft. The reported Kr abundances are discrepant and were once highly controversial. These discrepancies appear to have been not so much resolved as forgotten. Xenon was not detected on Venus. Upper limits were reported for the two most abundant xenon isotopes 129Xe and 132Xe. From the limited data it is not possible to tell whether Venus's affinities lie with the solar wind, or with the chondrites, with Earth, or with none of the above. Modern spacecraft mass spectrometers are at least 100-fold more sensitive to noble gases. Sending such an instrument to Venus may be the last best hope for decrypting what Earth's noble gases have been trying to tell us.

  10. Google Earth and Map Projections

    OpenAIRE

    Nedjeljko Fran?ula

    2010-01-01

    By starting Google Earth, the screen shows Earth from a great distance, e.g. from a satellite rotating around the Earth (Fig. 1). The graticule is drawn by using the Grid function from the View menu. Google Earth is a virtual globe which can be rotated in all directions using a mouse.

  11. Solar activity and earth's climate

    CERN Document Server

    Benestad, Rasmus E

    2006-01-01

    Introduces the subject of solar activity and the connection with Earth''s climate. This book commences with a review of the historical progress on the understanding of the solar-terrestrial connection and moves on to an objective scrutiny of the various hypothesis. It focuses on how knowledge about the solar cycle and Earth''s climate is obtained.

  12. The Sun and Earth

    Science.gov (United States)

    Gopalswamy, Natchimuthuk

    2012-01-01

    Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

  13. Modeling the earth system

    Energy Technology Data Exchange (ETDEWEB)

    Ojima, D. [ed.

    1992-12-31

    The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.

  14. Earth - Moon Conjunction

    Science.gov (United States)

    1992-01-01

    On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990.

  15. Monitoring the Earth

    Science.gov (United States)

    Vita-Finzi, Claudio

    2003-02-01

    Monitoring the Earth is the first book to review the recent advances in satellite technology, computing and mass spectrometry that are opening up completely new avenues of enquiry to Earth scientists. Among the geological changes that were previously considered too slow or too extensive for direct measurements and that can now be monitored directly are continental displacements, mountain uplift, the growth and decay of icesheets and glaciers, the faulting and folding of rocks, the progress of weathering and sedimentation, and the growth of coral reefs. In addition to these developments, the book assesses progress in fields not normally considered part of physical geology, such as the shape and orbit of the gravity and the terrestrial magnetic field. The results from the new findings are already helping Earth scientists analyze and explain the underlying mechanisms, notably with regard to the storage and release of strain during earthquakes and the interaction of glacial history with the Earth's rate of rotation. The outcoe is a foretaste of the physical geology of the space age.^Fully illustrated with line drawings and photographs, and with a bibliography that encompasses the scattered and disparate litarature, Monitoring the Earth is intended for undergraduates in geology, geomorphology, geomatic engineering and planetary science, but it should also be of interest to astronomers and historians of science.

  16. Earth and planetary sciences

    International Nuclear Information System (INIS)

    The earth is a dynamic body. The major surface manifestation of this dynamism has been fragmentation of the earth's outer shell and subsequent relative movement of the pieces on a large scale. Evidence for continental movement came from studies of geomagnetism. As the sea floor spreads and new crust is formed, it is magnetized with the polarity of the field at the time of its formation. The plate tectonics model explains the history, nature, and topography of the oceanic crust. When a lithospheric plate surmounted by continental crust collides with an oceanic lithosphere, it is the denser oceanic lithosphere that is subducted. Hence the ancient oceans have vanished and the knowledge of ancient earth will require deciphering the complex continental geological record. Geochemical investigation shows that the source region of continental rocks is not simply the depleted mantle that is characteristic of the source region of basalts produced at the oceanic ridges. The driving force of plate tectonics is convection within the earth, but much remains to be learned about the convection and interior of the earth. A brief discussion of planetary exploration is given

  17. Rare earths and actinides

    International Nuclear Information System (INIS)

    This paper reviews the different properties of rare-earths and actinides, either as pure metals or as in alloys or compounds. Three different cases are considered: (i) First, in the case of 'normal' rare-earths which are characterized by a valence of 3, we discuss essentially the magnetic ordering, the coexistence between superconductivity and magnetism and the properties of amorphous rare-earth systems. (ii) Second, in the case of 'anomalous' rare-earths, we distinguish between either 'intermediate-valence' systems or 'Kondo' systems. Special emphasis is given to the problems of the 'Kondo lattice' (for compounds such as CeAl2,CeAl3 or CeB6) or the 'Anderson lattice' (for compounds such as TmSe). The problem of neutron diffraction in these systems is also discussed. (iii) Third, in the case of actinides, we can separate between the d-f hybridized and almost magnetic metals at the beginning of the series and the rare-earth like the metals after americium. (orig.)

  18. The earth's hydrological cycle

    CERN Document Server

    Bonnet, R-M; Calisto, M; Destouni, G; Gurney, R; Johannessen, J; Kerr, Y; Lahoz, WA; Rast, M

    2014-01-01

    This book gives a comprehensive presentation of our present understanding of the Earth's Hydrological cycle and the problems, consequences and impacts that go with this topic. Water is a central component in the Earth's system. It is indispensable for life on Earth in its present form and influences virtually every aspect of our planet's life support system. On relatively short time scales, atmospheric water vapor interacts with the atmospheric circulation and is crucial in forming the Earth's climate zones. Water vapor is the most powerful of the greenhouse gases and serves to enhance the tropospheric temperature. The dominant part of available water on Earth resides in the oceans. Parts are locked up in the land ice on Greenland and Antarctica and a smaller part is estimated to exist as groundwater. If all the ice over the land and all the glaciers were to melt, the sea level would rise by some 80 m. In comparison, the total amount of water vapor in the atmosphere is small; it amounts to ~ 25 kg/m2, or the ...

  19. Pressure Alopecia

    OpenAIRE

    Davies, Kate E; Yesudian, PD

    2012-01-01

    Postoperative or pressure alopecia (PA) is an infrequently reported group of scarring and non-scarring alopecias. It has been reported after immobilization of the head during surgery and following prolonged stays on intensive care units, and may be analogous to a healed pressure ulcer. This review presents a summary of cases published in pediatrics and after cardiac, gynecological, abdominal and facial surgeries. PA may manifest as swelling, tenderness, and ulceration of the scalp in the firs...

  20. Earth Global Reference Atmospheric Model 2007 (Earth-GRAM07) Applications for the NASA Constellation Program

    Science.gov (United States)

    Leslie, Fred W.; Justus, C. G.

    2008-01-01

    Engineering models of the atmosphere are used extensively by the aerospace community for design issues related to vehicle ascent and descent. The Earth Global Reference Atmosphere Model version 2007 (Earth-GRAM07) is the latest in this series and includes a number of new features. Like previous versions, Earth-GRAM07 provides both mean values and perturbations for density, temperature, pressure, and winds, as well as monthly- and geographically-varying trace constituent concentrations. From 0 km to 27 km, thermodynamics and winds are based on the National Oceanic and Atmospheric Administration Global Upper Air Climatic Atlas (GUACA) climatology. For altitudes between 20 km and 120 km, the model uses data from the Middle Atmosphere Program (MAP). Above 120 km, EarthGRAM07 now provides users with a choice of three thermosphere models: the Marshall Engineering Thermosphere (MET-2007) model; the Jacchia-Bowman 2006 thermosphere model (JB2006); and the Naval Research Labs Mass Spectrometer, Incoherent Scatter Radar Extended Model (NRL MSIS E-OO) with the associated Harmonic Wind Model (HWM-93). In place of these datasets, Earth-GRAM07 has the option of using the new 2006 revised Range Reference Atmosphere (RRA) data, the earlier (1983) RRA data, or the user may also provide their own data as an auxiliary profile. Refinements of the perturbation model are also discussed which include wind shears more similar to those observed at the Kennedy Space Center than the previous version Earth-GRAM99.

  1. Tandem Mirror Reactor power balance studies

    International Nuclear Information System (INIS)

    A Tandem Mirror Reactor (TMR) power plant balance model has been developed and is now being used as a computer aid for performing parametric studies. End-cell power injection into the plasma and the physics plasma Q are used to determine the fusion power. About 80% of the fusion power is transferred by high-energy neutrons to the blanket modules and structures. The other 20% of the fusion power in the highenergy alpha particles is used to heat the deuterium-tritium (D-T) plasma. Most of the plasma-ionized particles transfer their energy to the halo dumps and direct converters. The plant efficiency is calculated for three different system cycles: (1) the pressurized water/saturated steam cycle, (2) the superheated steam cycle, and (3) the more complex superheat/reheat cycle. There is a significant improvement in plant efficiency as the electrical power multiplication factor and steam cycle efficiency increases

  2. Electronic structure and properties of rare earth and actinide intermetallics

    International Nuclear Information System (INIS)

    There are 188 contributions, experimental and theoretical, a few on rare earth and actinide elements but mostly on rare earth and actinide intermetallic compounds and alloys. The properties dealt with include 1) crystal structure, 2) magnetic properties and magnetic structure, 3) magnetic phase transformations and valence fluctuations, 4) electrical properties and superconductivity and their temperature, pressure and magnetic field dependence. A few papers deal with crystal growth and novel measuring methods. (G.Q.)

  3. Better Than Earth

    Science.gov (United States)

    Heller, Ren

    2015-01-01

    Do we inhabit the best of all possible worlds? German mathematician Gottfried Leibniz thought so, writing in 1710 that our planet, warts and all, must be the most optimal one imaginable. Leibniz's idea was roundly scorned as unscientific wishful thinking, most notably by French author Voltaire in his magnum opus, Candide. Yet Leibniz might find sympathy from at least one group of scientists - the astronomers who have for decades treated Earth as a golden standard as they search for worlds beyond our own solar system. Because earthlings still know of just one living world - our own - it makes some sense to use Earth as a template in the search for life elsewhere, such as in the most Earth-like regions of Mars or Jupiter's watery moon Europa. Now, however, discoveries of potentially habitable planets orbiting stars other than our sun - exoplanets, that is - are challenging that geocentric approach.

  4. Dagik Earth and IUGONET

    Science.gov (United States)

    Ebisawa, K.; Koyama, Y.; Saito, A.; Sakamoto, S.; Ishii, M.; Kumano, Y.; Hazumi, Y.

    2015-09-01

    In this paper we introduce two independent projects in progress in Japan. Dagik Earth is a visualization project of the Earth and planets on a spherical screen using only a standard PC and a projector. Surface images of the Earth or planets (or whatever having spherical shape) in the equirectangular (plate carre) projection are projected on a spherical screen in the orthographic projection. As a result, the spherical screen becomes a virtual digital globe, which can be rotated using mouse or remote controller. Inter-university Upper atmosphere Global Observation NETwork (IUGONET) is a collaboration of five Japanese institutes to build a comprehensive database system for the metadata of the upper-atmospheric data taken by these institutes. We explain the IUGONET metadata database and iUgonet Data Analysis Software (UDAS) for upper atmospheric research.

  5. Better Than Earth

    CERN Document Server

    Heller, Ren

    2015-01-01

    Do We Inhabit The Best O All Possible Worlds? German mathematician Gottfried Leibniz thought so, writing in 1710 that our planet, warts and all, must be the most optimal one imaginable. Leibniz's idea was roundly scorned as unscientific wishful thinking, most notably by French author Voltaire in his magnum opus, Candide. Yet Leibniz might find sympathy from at least one group of scientists - the astronomers who have for decades treated Earth as a golden standard as they search for worlds beyond our own solar system. Because earthlings still know of just one living world - our own - it makes some sense to use Earth as a template in the search for life elsewhere, such as in the most Earth-like regions of Mars or Jupiter's watery moon Europa. Now, however, discoveries of potentially habitable planets orbiting stars other than our sun - exoplanets, that is - are challenging that geocentric approach.

  6. Near-earth Thin Current Sheets and Birkeland Currents during Substorm Growth Phase

    Energy Technology Data Exchange (ETDEWEB)

    Sorin Zaharia; C.Z. Cheng

    2003-04-30

    Two important phenomena observed during the magnetospheric substorm growth phase are modeled: the formation of a near-Earth (|X| {approx} 9 R{sub E}) thin cross-tail current sheet, as well as the equatorward shift of the ionospheric Birkeland currents. Our study is performed by solving the 3-D force-balance equation with realistic boundary conditions and pressure distributions. The results show a cross-tail current sheet with large current (J{sub {phi}} {approx} 10 nA/m{sup 2}) and very high plasma {beta} ({beta} {approx} 40) between 7 and 10 R{sub E}. The obtained region-1 and region-2 Birkeland currents, formed on closed field lines due to pressure gradients, move equatorward and become more intense (J{sub {parallel}max} {approx} 3 {micro}A/m{sup 2}) compared to quiet times. Both results are in agreement with substorm growth phase observations. Our results also predict that the cross-tail current sheet maps into the ionosphere in the transition region between the region-1 and region-2 currents.

  7. Geoneutrino and Hydridic Earth model

    CERN Document Server

    Bezrukov, Leonid

    2013-01-01

    Uranium, Thorium and Potassium-40 abundances in the Earth were calculated in the frame of Hydridic Earth model. Terrestrial heat producton from U, Th and K40 decays was calculated also. We must admit the existance of Earth expansion process to understand the obtained large value of terrestrial heat producton. The geoneutrino detector with volume more than 5 kT (LENA type) must be constructed to definitely separate between Bulk Silicat Earth model and Hydridic Earth model.

  8. A hypothesis of earth quake

    OpenAIRE

    Tsai, Yeong-Shyeong

    2008-01-01

    Without a model, it is impossible for a geophysicist to study the possibility of forecasting earth quakes. We will define a quantity, the event-degree, in the paper. This quantity plays an important role in the model of quakes forecasting. In order to make a simple model, we make a hypothesis of earth quakes. The hypothesis is: "(i) There are two kinds of earth quakes, one is the triggered breaking (earth quake), the other is spontaneous breaking (earth quake). (ii) Most maj...

  9. Human stick balancing: Tuning Lvy flights to improve balance control

    Science.gov (United States)

    Cabrera, Juan Luis; Milton, John G.

    2004-09-01

    State-dependent, or parametric, noise is an essential component of the neural control mechanism for stick balancing at the fingertip. High-speed motion analysis in three dimensions demonstrates that the controlling movements made by the fingertip during stick balancing can be described by a Lvy flight. The Lvy index, ?, is approximately 0.9; a value close to optimal for a random search. With increased skill, the index ? does not change. However, the tails of the Lvy distribution become broader. These observations suggest a Lvy flight that is truncated by the properties of the nervous and musculoskeletal system; the truncation decreasing as skill level increases. Measurements of the cross-correlation between the position of the tip of the stick and the fingertip demonstrate that the role of closed-loop feedback changes with increased skill. Moreover, estimation of the neural latencies for stick balancing show that for a given stick length, the latency increases with skill level. It is suggested that the neural control for stick balancing involves a mechanism in which brief intervals of consciously generated, corrective movements alternate with longer intervals of prediction-free control. With learning the truncation of the Lvy flight becomes better optimized for balance control and hence the time between successive conscious corrections increases. These observations provide the first evidence that changes in a Lvy flight may have functional significance for the nervous system. This work has implications for the control of balancing problems ranging from falling in the elderly to the design of two-legged robots and earthquake proof buildings.

  10. How Big is Earth?

    Science.gov (United States)

    Thurber, Bonnie B.

    2015-08-01

    How Big is Earth celebrates the Year of Light. Using only the sunlight striking the Earth and a wooden dowel, students meet each other and then measure the circumference of the earth. Eratosthenes did it over 2,000 years ago. In Cosmos, Carl Sagan shared the process by which Eratosthenes measured the angle of the shadow cast at local noon when sunlight strikes a stick positioned perpendicular to the ground. By comparing his measurement to another made a distance away, Eratosthenes was able to calculate the circumference of the earth. How Big is Earth provides an online learning environment where students do science the same way Eratosthenes did. A notable project in which this was done was The Eratosthenes Project, conducted in 2005 as part of the World Year of Physics; in fact, we will be drawing on the teacher's guide developed by that project.How Big Is Earth? expands on the Eratosthenes project by providing an online learning environment provided by the iCollaboratory, www.icollaboratory.org, where teachers and students from Sweden, China, Nepal, Russia, Morocco, and the United States collaborate, share data, and reflect on their learning of science and astronomy. They are sharing their information and discussing their ideas/brainstorming the solutions in a discussion forum. There is an ongoing database of student measurements and another database to collect data on both teacher and student learning from surveys, discussions, and self-reflection done online.We will share our research about the kinds of learning that takes place only in global collaborations.The entrance address for the iCollaboratory is http://www.icollaboratory.org.

  11. Google Earth science

    Science.gov (United States)

    Baird, William H.; Padgett, Clifford W.; Secrest, Jeffery A.

    2015-03-01

    Google Earth has made a wealth of aerial imagery available online at no cost to users. We examine some of the potential uses of that data in illustrating basic physics and astronomy, such as finding the local magnetic declination, using landmarks such as the Washington Monument and Luxor Obelisk as gnomons, and showing how airport runways get their numbers. Close inspection of the images provided by Google Earth reveals that most of them are actually obtained via camera-equipped planes rather than satellites.

  12. Alkaline earth metal thiogallates

    International Nuclear Information System (INIS)

    Alkaline rare-earth metal thiogallates of the MGa2S4 composition (M - Ca, Sr, Ba) are synthesized by interaction of alkaline rare-earth metal oxogallates and hydrogen sulphide upon heating. Investigations of the compounds by the method of X-ray diffraction analysis have shown that calcium and strontium compounds are crystallized in a rhombic structure, while barium compounds - in a cubic structure. The parameters of a unit cell and the number of atomic units in the formula have been determined. Thiogallates of the M3Ga2S6 composition have been synthesized, and their individual nature is demonstrated

  13. Rubidium and cesium in the earth and the moon

    Science.gov (United States)

    Jones, John H.; Drake, Michael J.

    1993-01-01

    The purpose of the study is to provide an alternative perspective on both the mass balance issue and on the issue of secular change in the Rb-Cs ratio in the earth mantle. In particular, it is argued that the apparent secular change in the Rb/Cs ratio may be simply an artifact of alteration of older rocks through weathering and/or metamorphism subsequent to formation. It is also shown that there is not necessarily a need for a hidden, undepleted reservoir, and the consistency of this result with other mass calculations is explored. New methods for estimating the Rb/Cs ratio of the bulk silicate earth are suggested.

  14. Connections between the bulk composition, geodynamics and habitability of Earth

    Science.gov (United States)

    Jellinek, A. M.; Jackson, M. G.

    2015-08-01

    The bulk composition of the silicate part of Earth has long been linked to chondritic meteorites. Ordinary chondrites -- the most abundant meteorite class -- are thought to represent planetary building materials. However, a landmark discovery showed that the 142Nd/144Nd ratio of the accessible parts of the modern terrestrial mantle on Earth is greater than that of ordinary chondrites. If Earth was derived from these precursors, mass balance requires that a missing reservoir with 142Nd/144Nd lower than ordinary chondrites was isolated from the accessible mantle within 20 to 30 million years of accretion. This reservoir would host the equivalent of the modern continents' budget of radioactive heat-producing elements (uranium, thorium and potassium), yet has not been discovered. We argue that this reservoir could have been lost to space by ablation from early impactors. If so, Earth's radiogenic heat generation is between 18 and 45% lower than estimates based on a chondritic composition. Calculations of Earth's thermal history that incorporate such reduced radiogenic heating are consistent with a transition to the current plate tectonic mode in the past 2.5 billion years or so, a late onset of the dynamo and an evolving rate of volcanic outgassing consistent with Earth's long-term habitable climate. Reduced heat production compared with Venus and Mars could also explain aspects of the differences between the current climatic regimes of these planets and Earth.

  15. On the Skill of Balancing While Riding a Bicycle

    Science.gov (United States)

    Cain, Stephen M.; Ashton-Miller, James A.; Perkins, Noel C.

    2016-01-01

    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements. PMID:26910774

  16. Conceptual radiometer design studies for Earth observations from low Earth orbit

    Science.gov (United States)

    Harrington, Richard F.

    1994-01-01

    A conceptual radiometer design study was performed to determine the optimum design approach for spaceborne radiometers in low Earth orbit. Radiometric system configurations which included total power radiometers, unbalanced Dicke radiometers, and balanced Dicke, or as known as noise injection, radiometers were studied. Radiometer receiver configurations which were analyzed included the direct detection radiometer receiver, the double sideband homodyne radiometer receiver, and the single sideband heterodyne radiometer receiver. Radiometer system performance was also studied. This included radiometric sensitivity analysis of the three different radiometer system configurations studied. Both external and internal calibration techniques were analyzed. An accuracy analysis with and without mismatch losses was performed. It was determined that the balanced Dicke radiometer system configuration with direct detection receivers and external calibrations was optimum where frequent calibration such as once per minute were not feasible.

  17. Comparison of Empirical Models of the Earth's Inner Magnetosphere

    Science.gov (United States)

    Verkhoglyadova, O. P.; Panchenko, M. G.

    Comparison of empirical models of the magnetospheric magnetic field elaborated by Ostapenko and by Tsyganenko for the inner magnetosphere is made. Under conditions of weak disturbance, both models show good coincidence near the Earth's magnetic dipole equator plane for geocentric distances from 4 to 10 Earth radii (RE). The Ostapenko model predicts stronger fields up to the ring current region (8 RE), and the Tsyganenko model gives stronger fields outside the region. The models diverge in the subsolar region and near the Earth as the solar wind pressure increases.

  18. Venus as a more Earth-like planet.

    OpenAIRE

    Svedhem, H.; Titov, DV; Taylor, FW; Witasse, O.

    2007-01-01

    Venus is Earth's near twin in mass and radius, and our nearest planetary neighbour, yet conditions there are very different in many respects. Its atmosphere, mostly composed of carbon dioxide, has a surface temperature and pressure far higher than those of Earth. Only traces of water are found, although it is likely that there was much more present in the past, possibly forming Earth-like oceans. Here we discuss how the first year of observations by Venus Express brings into focus the evoluti...

  19. Estimating Flow-Through Balance Momentum Tares with CFD

    Science.gov (United States)

    Melton, John E.; James, Kevin D.; Long, Kurtis R.; Flamm, Jeffrey D.

    2016-01-01

    This paper describes the process used for estimating flow-through balance momentum tares. The interaction of jet engine exhausts on the BOEINGERA Hybrid Wing Body (HWB) was simulated in the NFAC 40x80 wind tunnel at NASA Ames using a pair of turbine powered simulators (TPS). High-pressure air was passed through a flow-through balance and manifold before being delivered to the TPS units. The force and moment tares that result from the internal shear and pressure distribution were estimated using CFD. Validation of the CFD simulations for these complex internal flows is a challenge, given limited experimental data due to the complications of the internal geometry. Two CFD validation efforts are documented, and comparisons with experimental data from the final model installation are provided.

  20. Earth System Science Education Modules

    Science.gov (United States)

    Hall, C.; Kaufman, C.; Humphreys, R. R.; Colgan, M. W.

    2009-12-01

    The College of Charleston is developing several new geoscience-based education modules for integration into the Earth System Science Education Alliance (ESSEA). These three new modules provide opportunities for science and pre-service education students to participate in inquiry-based, data-driven experiences. The three new modules will be discussed in this session. Coastal Crisis is a module that analyzes rapidly changing coastlines and uses technology - remotely sensed data and geographic information systems (GIS) to delineate, understand and monitor changes in coastal environments. The beaches near Charleston, SC are undergoing erosion and therefore are used as examples of rapidly changing coastlines. Students will use real data from NASA, NOAA and other federal agencies in the classroom to study coastal change. Through this case study, learners will acquire remotely sensed images and GIS data sets from online sources, utilize those data sets within Google Earth or other visualization programs, and understand what the data is telling them. Analyzing the data will allow learners to contemplate and make predictions on the impact associated with changing environmental conditions, within the context of a coastal setting. To Drill or Not To Drill is a multidisciplinary problem based module to increase students knowledge of problems associated with nonrenewable resource extraction. The controversial topic of drilling in the Arctic National Wildlife Refuge (ANWR) examines whether the economic benefit of the oil extracted from ANWR is worth the social cost of the environmental damage that such extraction may inflict. By attempting to answer this question, learners must balance the interests of preservation with the economic need for oil. The learners are exposed to the difficulties associated with a real world problem that requires trade-off between environmental trust and economic well-being. The Citizen Science module challenges students to translate scientific information into words that are understandable and useful for policy makers and other stakeholders. The inability of scientists to effectively communicate with the public has been highlighted as a major reason for the anti-science attitude of a large segment of the public. This module, unlike other ESSEA modules, addresses this problem by first, investigating a global change environmental problem using Earth System Science methodologies, then developing several solutions to that problem, and finally writing a position paper for the policy makers to use. These three hands-on, real-world modules that engage students in authentic research share similar goals: 1) to use global change data sets to examine controversial environmental problems; 2) to use an earth system science approach to understand the complexity of global problems; and 3) to help students understand the political complexity of environmental problems where there is a clash between economic and ecological problems. The curriculum will meet National Standards in science, geography, math, etc.