WorldWideScience

Sample records for earth pressure balance

  1. Pressure balance at the magnetopause: Experimental studies

    OpenAIRE

    Suvorova, A. V.; Dmitriev, A. V.

    2011-01-01

    The pressure balance at the magnetopause is formed by magnetic field and plasma in the magnetosheath, on one side, and inside the magnetosphere, on the other side. In the approach of dipole earth's magnetic field configuration and gas-dynamics solar wind flowing around the magnetosphere, the pressure balance predicts that the magnetopause distance R depends on solar wind dynamic pressure Pd as a power low R ~ Pd^alpha, where the exponent alpha=-1/6. In the real magnetosphere...

  2. Heat balance of the Earth

    Science.gov (United States)

    Budyko, M. I.; Berlyand, T. G.; Yefimova, N. A.; Zubenok, L. I.; Strokina, L. A.

    1980-01-01

    Results of improved calculations of the heat balance components of Earth's surface are reported for yearly average conditions. The technique used to determine the heat-balance components from land- and sea-based actinometric observations as well as from satellite data on the radiation balance of the Earth-atmosphere system is described, with special attention given to short-wavelength solar radiation on the continents, effective radiation from the land surface, the radiation balance of the ocean surface, heat expended by both evaporation from the ocean surface, and turbulent heat transfer between the ocean surface and the atmosphere. World maps of heat-balance components show yearly average values of total radiation, radiation balance, heat expended by evaporation, the turbulent heat flow between Earth's surface and atmosphere, and heat transfer between the ocean surface and underlying waters. The global surface heat balance is estimated along with global values of the various components and the heat-balance components for different latitude zones.

  3. Fluid pressure balanced seal

    Science.gov (United States)

    Marsh, H. W. (inventor)

    1966-01-01

    A seal which increases in effectiveness with increasing pressure is presented. The seal's functional capability throughout both static and dynamic operation makes it particularly useful for sealing ball valve ports. Other features of the seal include the ability to seal two opposed surfaces simultaneously, tolerance of small misalignments, tolerance of wide temperature ranges, ability to maintain positive sealing contact under conditions of internal or external pressurization, and ability to conform to slight irregularities in seal or surface contours.

  4. Rare earth luminescence under pressure

    International Nuclear Information System (INIS)

    The luminescence properties of different rare earth ions (RE3+ : Sm3+, Tb3+ and Er3+) in lithium fluoroborate glasses and oxyfluoride nanocrystalline glass-ceramics have been analyzed as a function of the pressure. The roles of the pressure-induced energy transfer between optically active ions, their host local structures and the energy trap centers in the quenching of the rare earth luminescence are discussed

  5. Earth Pressure on Tunnel Crown

    DEFF Research Database (Denmark)

    Andersen, Lars

    2008-01-01

    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 Plaxis is utilized to check the result.

  6. 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

  7. Modeling of the Earth’s Planetary Heat Balance with Electrical Circuit Analogy

    OpenAIRE

    Lapovok, Yevgeniy V.; Abdussamatov, Habibullo I.; Bogoyavlenskii, Alexander I.; Khankov, Sergey I.

    2010-01-01

    The integral heat model for the system of the Earth’s surface—the atmosphere—the open space based on the electrical circuit analogy is presented. Mathematical models of the heat balance for this system are proposed. Heat circuit which is analog of the electrical circuit for investigating the temperature dependencies on the key parameters in the clear form is presented.

  8. Earth's Energy Balance From Space: A 35 Year Perspective

    Science.gov (United States)

    Wielicki, B. A.

    2005-12-01

    The Earth's radiative energy balance is the most fundamental driver of long term climate. Changes of 1% or less are sufficient to cause major climate change. Earth orbiting satellites provide the optimal platform to observe this energy balance, and efforts began with Nimbus 3 in 1969. Prior to satellite missions, the Earths reflected and emitted radiation were estimated using earthshine from the moon, or by a radiative transfer calculation using surface observations of aerosol, cloud, temperature, humidity, and ozone. Observing the earths radiation balance from space is an 8-dimensional sampling problem, with a requirement for extremely high accuracy and stability to directly observe climate signals. The challenge is especially severe for decadal changes in aerosols and clouds. A perspective is given on the dramatic progress that has occurred in measuring radiation in space, from Nimbus 3 in 1969 to current CERES global and GERB geostationary observations. A vision for future advances in these observations as part of the global climate observing system is also given, including new ways to use the data in unscrambling the effects of aerosol indirect effects as well as cloud feedback in the climate system. These last two issues provide extraordinary challenges in climate forcing and climate sensitivity respectively.

  9. The energy balance of the earth' surface : a practical approach

    OpenAIRE

    De Bruin, H. A. R.

    1982-01-01

    This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This radiation originates partly from the sun, but an~ other fraction is coming from the atmosphere (= infra-red radiation emitted by clouds, water vapour and CO 2 ). From these gain terms the following...

  10. Earth in the Balance: Ecology and the Human Spirit

    Science.gov (United States)

    Lang, Valerie

    For concerned scientists frustrated by more than a decade of “business as usual” national economic and energy policy in the face of growing environmental consequences, Al Gore's book, Earth in the Balance: Ecology and the Human Spirit, can be viewed as a source for optimism.Twenty-five years of world travel and studies of the Earth's ecological problems led Gore to publish his conclusions on the environment during his campaign for vicepresident of the United States. As a member of a Congressional system that relies to a great extent on the news media, legislative staff, and second-hand reports as information sources, Gore is to be commended for devoting so much time to his personal study of the environment.

  11. 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 ze 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

  12. 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....

  13. Experimental investigation of the anode energy balance at reduced pressure

    International Nuclear Information System (INIS)

    The convective-radiative heat flux from the plasma to the anode is separated from the heat transported by the electrons with the aid of a calorimetric method. At pressures of 1--15 kPa in a high-current arc the convective--radiative heat flux is comparable to the electron flux. Negative values of the anode potential pump are obtained from the anode energy balance and from probe measurements

  14. Core makeup tanks with two pressure-balancing lines connected to the pressurizer

    International Nuclear Information System (INIS)

    In the AP600 plant [1], the core makeup tanks (CMTs) are connected to the pressurizer steam space and are therefore normally at RCS (reactor coolant system) operating pressure. They provide makeup at any RCS pressure and thus replace the high head safety injection pumps typically included in conventional plants. Differently from the original intention, however, since the inner pressure of the CMTs initially decreases due to the steam-water condensation, it is well known that water injection from the CMTs into a reactor coolant system is delayed. In this paper, a new conceptual design of the CMT is presented. A new CMT has two pressure-balancing lines connected to the top and bottom parts of a pressurizer and the pressure-balancing line is designed to have steam space under normal conditions. The top pressure-balancing line is small in diameter and the bottom one is large. Therefore, since the upper part of the CMT is initially filled up with hot water from the bottom part of the pressurizer and thus the steam-water condensation does not occur, water injection from the CMTs is not delayed. The proposed conceptual design was analyzed by MARS 1.4 code. (author)

  15. 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.

  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. 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.

  18. Earth pressures against- and stability of retaining structures

    OpenAIRE

    Sigurður Már 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 propertie...

  19. Numerical and comparative analysis of earth passive pressure acting.

    Czech Academy of Sciences Publication Activity Database

    Koudelka, Petr; Koudelka, T.

    Vol. 75. Amsterdam : IS SMGE/TC 28, 2005 - (Bakker, K.), s. 579-585 ISBN 0-415-39124-5. [IS Geotechnical aspects of Underground Construction in Soft Ground 2005 /5./. Amsterdam (NL), 15.06.2005-16.06.2005] R&D Projects: GA AV ?R(CZ) IAA2071302; GA ?R(CZ) GA103/05/2130 Institutional research plan: CEZ:AV0Z20710524 Keywords : passive earth pressure * pressure at rest * residual earth pressure Subject RIV: JN - Civil Engineering

  20. New weight-handling device for commercial oil pressure balances

    Science.gov (United States)

    Woo, S. Y.; Choi, I. M.; Kim, B. S.

    2005-12-01

    This paper presents a new device to automatically handle a large number of weights for the calibration of a pressure gauge. This newly invented weight-handling device is made for use in conjunction with a commercial oil pressure balance. Although the pressure balance is essential as a calibration tool, its use has been generally tedious and labour intensive for a long time. In particular, the process of loading a different combination of weights on the top of a piston requires repetitious manual handling for every new measurement. This inevitably leaves the operator fatigued, and sometimes causes damage to the weights due to careless handling. The newly invented automatic weight-handling device can eliminate such tedious, error-prone and wear-inducing manual weight manipulation. The device consists of a stepping motor, a drive belt, a solenoid valve, three weight-lifting assemblies and three linear-motion guide assemblies. The weight-lifting assembly is composed of a pneumatic actuator, a solid-state switch and a metal finger. It has many advantages compared with the commercial automatic weight-handling device. Firstly, it is not necessary to lift all the weights off the piston in the weight selection process, as it is in the case of the commercial device. Thus it can prevent a permanent deformation of the weight carrier. Secondly, this new device can handle a larger number of weights than the commercial one. This is because the new device adopts a different method in retaining the remaining weights in place. Another advantage of this new device is that there is no possibility of the fingers touching the surface of the weights due to the oscillation of weights. Moreover it uses the general technology of a stepping motor, and is also made up of components that are easily obtainable in the market, thereby being very economical.

  1. AN APPROXIMATION TO LATERAL EARTH PRESSURES FOR K0 CONDITION

    Directory of Open Access Journals (Sweden)

    M. Arslan TEK?NSOY

    1999-01-01

    Full Text Available In this study, the determination of lateral earth pressures of soils or Ko parameter is considered. For this effect, the deformation and the variations in the shear stresses of the soils placed in an oedometer set up were investigated. Based on this data, a general method which can be used in the calculation of lateral pressures of soils has been proposed. The study was carried out on a cohesive soil having two different group symbol and sandy soils with different relative densities. The lateral pressure values measured by thin wall oedometer technique are in very good agreement with those obtained by calculation. In conclusion, lateral earth pressures or the Ko values are depend upon the distribution of the samples, their relative density and consistancy, the magnitude of the pre-consolidation pressure. The proposed method is a simple and economic technique as regards to the approximation and experimentation.

  2. 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)

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

    OpenAIRE

    Rajeev, P.; Bui, Ha H.; 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 pressur...

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

    Science.gov (United States)

    Kalvius, G. M.; Schreier, E.; Ekström, M.; Hartmann, O.; Henneberger, S.; Kratzer, A.; Wäppling, R.; Martin, E.; Burghart, F. J.; Ballou, R.; Deportes, J.; Niedermayer, Ch.

    2000-11-01

    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.

  5. 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.

  6. 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 ostatní: 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

  7. Progress in development of controlled-clearance pressure balance in NMIJ

    International Nuclear Information System (INIS)

    A new controlled-clearance pressure balance is under development with the aim of improving the hydraulic high-pressure standard up to 1 GPa. This pressure balance consists of three parts: (i) a pressure generation device up to 1 GPa, (ii) a weight-loading unit which can load/unload weights automatically and independently, (iii) a controlled-clearance piston-cylinder which is designed to allow the jacket pressure to be applied independently. Some adjustments were made for loading heavy weights on/off the piston safely, keeping them in balance, then generating the pressure stably. Stability of the generated pressure was checked for several piston-cylinders, and it was found that pressure fluctuation was less than a few parts per million. The jacket pressure coefficient of a 500 MPa controlled-clearance piston-cylinder was precisely evaluated as a function of both the system pressure and the jacket pressure.

  8. Electron Heat Flux in Pressure Balance Structures at Ulysses

    Science.gov (United States)

    Yamauchi, Yohei; Suess, Steven T.; Sakurai, Takashi; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Pressure balance structures (PBSs) are a common feature in the high-latitude solar wind near solar minimum. Rom previous studies, PBSs are believed to be remnants of coronal plumes and be related to network activity such as magnetic reconnection in the photosphere. We investigated the magnetic structures of the PBSs, applying a minimum variance analysis to Ulysses/Magnetometer data. At 2001 AGU Spring meeting, we reported that PBSs have structures like current sheets or plasmoids, and suggested that they are associated with network activity at the base of polar plumes. In this paper, we have analyzed high-energy electron data at Ulysses/SWOOPS to see whether bi-directional electron flow exists and confirm the conclusions more precisely. As a result, although most events show a typical flux directed away from the Sun, we have obtained evidence that some PBSs show bi-directional electron flux and others show an isotropic distribution of electron pitch angles. The evidence shows that plasmoids are flowing away from the Sun, changing their flow direction dynamically in a way not caused by Alfven waves. From this, we have concluded that PBSs are generated due to network activity at the base of polar plumes and their magnetic structures axe current sheets or plasmoids.

  9. 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...

  10. The Effect of Displacement Mode of Rigid Retaining Walls on Shearing Bands by Active Earth Pressure

    OpenAIRE

    A. Sekkel; M. Meghachou

    2013-01-01

    This work treats the physical modeling of failure mechanisms by active earth pressure. This last is developed by retaining wall movement. A lot of research showed that wall displacement has a significant effect on active earth pressure. A good comprehension of active earth pressure phenomenon and its failure mechanisms help us to better conceive retaining walls. The conception of a small-scale model allowed the realization of active earth pressure tests, while displacing the mobile wall towar...

  11. 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

  12. High Pressure Behavior of Organic Materials and the Early Earth

    Science.gov (United States)

    Montgomery, W.; Crowhurst, J.; Zaug, J. M.; Jeanloz, R.

    2006-12-01

    Organic molecules observed in proto-planetary discs, such as cyanuric acid (H3C3N3O3), transform through currently unknown processes to the complex prebiotic compounds believed to have led to life on Earth. These processes could occur within the upper layers of the early Earth during the Hadean and Archaean. Laboratory experiments show that pressures of 1-10 GPa and temperatures of 300-600 K facilitate the formation of complex molecules from simple organic precursors. In particular, formic acid, another organic material associated with proto-planetary discs, undergoes irreversible reactions at pressures and temperatures above 2.5 GPa and 430 K with the products characterized by Raman peaks at 1349, 1520 and 1592 cm^{- 1}, close to peaks measured from interplanetary dust particle material. Cyanuric acid is of special interest because it has a structure similar to the carbon-nitrogen rings and helices incorporated in nucleosides and other key biological components. It appears to form N-H\\dotsO and C--O\\dotsH intramolecular bonds at pressures above 5.0 GPa, and forms complex macromolecular material at temperatures over 400K. If by emerging below the surface of a planet it can be protected from impact (including the late heavy bombardment) and other external threats, life may ultimately be initiated by conformational changes induced in pre-biotic molecules by pressure.

  13. 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

  14. Phase transitions in rare earth tellurides under pressure

    International Nuclear Information System (INIS)

    Using first-principles calculations we have studied the valence and structural transitions of the rare earth monotellurides RTe (R = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb) under pressure. The self-interaction corrected local spin-density approximation is used to establish the ground state valence configuration as a function of volume for the RTe in both the NaCl (B1) and CsCl (B2) structures. We find that in ambient conditions all the RTe are stabilized in the B1 structure. A trivalent (R3+) rare earth ground state is predicted for the majority of the RTe, with the exception of SmTe, EuTe, DyTe, TmTe and YbTe, where the fully localized divalent (R2+) rare earth configuration is found to be energetically most favourable. Under pressure, the trivalent RTe undergo structural transitions to the B2 structure without associated valence transition. The divalent RTe on the other hand are characterized by a competition between the structural and electronic degrees of freedom, and it is the degree of f-electron delocalization that determines the sequence of phase transitions. In EuTe and YbTe, where respectively the half-filled and filled shells result in a very stable divalent configuration, we find that it is the structural B1 ? B2 transition that occurs first, followed by the R2+ ? R3+ valence transition at even higher pressures. In SmTe, DyTe and TmTe, the electronic transition occurs prior to the structural transition. With the exception of YbTe, the calculated transition pressures are found to be in good agreement with experiment. (paper)

  15. 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.

  16. 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...

  17. Education for a Healthy Body Weight: Helping Adolescents Balance the Cultural Pressure for Thinness.

    Science.gov (United States)

    Collins, M. Elizabeth

    1988-01-01

    The article examines cultural pressure for extreme thinness in the United States and its impact as a possible predisposing factor for developing eating disorders among adolescent females. Preventive strategies are recommended to help adolescents balance this pressure and their own desire for attractiveness within the larger context of good health.…

  18. SEX DIFFERENCES IN SYMPATHETIC NEURAL-HEMODYNAMIC BALANCE: IMPLICATIONS FOR HUMAN BLOOD PRESSURE REGULATION

    OpenAIRE

    Hart, Emma C.; Charkoudian, Nisha; Wallin, B. Gunnar; Curry, Timothy B.; Eisenach, John H.; Joyner, Michael J.

    2009-01-01

    Among young normotensive men a reciprocal balance between cardiac output and sympathetic nerve activity is important in the regulation of arterial pressure. In young women, the balance among cardiac output, peripheral resistance and sympathetic nerve activity is unknown. Consequently, the aim of this study was to examine the relationship of cardiac output and total peripheral resistance to muscle sympathetic nerve activity in young women. Multi-unit peroneal recordings of muscle sympathetic n...

  19. Balancing food and predator pressure induces chronic stress in songbirds.

    OpenAIRE

    Clinchy, Michael; Zanette, Liana; Boonstra, Rudy; Wingfield, John C.; Smith, James N M

    2004-01-01

    The never-ending tension between finding food and avoiding predators may be the most universal natural stressor wild animals experience. The 'chronic stress' hypothesis predicts: (i) an animal's stress profile will be a simultaneous function of food and predator pressures given the aforesaid tension; and (ii) these inseparable effects on physiology will produce inseparable effects on demography because of the resulting adverse health effects. This hypothesis was originally proposed to explain...

  20. Balancing the books – a statistical theory of prospective budgets in Earth System science

    Directory of Open Access Journals (Sweden)

    J. P. O'Kane

    2003-01-01

    Full Text Available An honest declaration of the error in a mass, momentum or energy balance, ?, simply raises the question of its acceptability: 'At what value of ? is the attempted balance to be rejected?' Answering this question requires a reference quantity against which to compare ?. This quantity must be a mathematical function of all the data used in making the balance. To deliver this function, a theory grounded in a workable definition of acceptability is essential. A distinction must be drawn between a retrospective balance and a prospective budget in relation to any natural space-filling body. Balances look to the past; budgets look to the future. The theory is built on the application of classical sampling theory to the measurement and closure of a prospective budget. It satisfies R.A. Fisher's 'vital requirement that the actual and physical conduct of experiments should govern the statistical procedure of their interpretation'. It provides a test, which rejects, or fails to reject, the hypothesis that the closing error on the budget, when realised, was due to sampling error only. By increasing the number of measurements, the discrimination of the test can be improved, controlling both the precision and accuracy of the budget and its components. The cost-effective design of such measurement campaigns is discussed briefly. This analysis may also show when campaigns to close a budget on a particular space-filling body are not worth the effort for either scientific or economic reasons. Other approaches, such as those based on stochastic processes, lack this finality, because they fail to distinguish between different types of error in the mismatch between a set of realisations of the process and the measured data. Keywords: balance, budget, sampling, hypothesis test, closing error, Earth System

  1. 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...

  2. The annual variation in the global heat balance of the earth

    Science.gov (United States)

    Ellis, J. S.; Vonder Haar, T. H.; Levitus, S.; Oort, A. H.

    1978-01-01

    An annual variation with a range of 31 W/sq m is found in the global net radiation balance of the earth. The net radiation flux values measured from satellites and the changes in total heat content computed from independent sets of atmospheric and oceanic data show annual variations which are consistent with each other in both phase and magnitude. The net energy gain and loss by the planet within a year is stored and released within the system primarily by the oceans.

  3. 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)

  4. Effect of chemical pressure, misfit strain and hydrostatic pressure on structural and magnetic behaviors of rare-earth orthochromates

    International Nuclear Information System (INIS)

    First-principles calculations are performed to investigate structural and magnetic behaviors of rare-earth orthochromates as a function of ‘chemical’ pressure (that is, the rare-earth ionic radius), epitaxial misfit strain and hydrostatic pressure. From a structural point of view, (i) ‘chemical’ pressure significantly modifies antipolar displacements, Cr–O–Cr bond angles and the resulting oxygen octahedral tiltings; (ii) hydrostatic pressure mostly changes Cr–O bond lengths; and (iii) misfit strain affects all these quantities. The correlations between magnetic properties (Néel temperature and weak ferromagnetic moments) and unit cell volume are similar when varying the misfit strain or hydrostatic pressure, but differ from those associated with the ‘chemical’ pressure. Origins of such effects are also discussed. (paper)

  5. The energy balance and pressure in the solar transition zone for network and active region features

    Science.gov (United States)

    Nicolas, K. R.; Bartoe, J.-D. F.; Brueckner, G. E.; Vanhoosier, M. E.

    1979-01-01

    The electron pressure and energy balance in the solar transition zone are determined for about 125 network and active region features on the basis of high spectral and spatial resolution extreme ultraviolet spectra. Si III line intensity ratios obtained from the Naval Research Laboratory high-resolution telescope and spectrograph during a rocket flight are used as diagnostics of electron density and pressure for solar features near 3.5 x 10 to the 4th K. Observed ratios are compared with the calculated dependence of the 1301 A/1312 A and 1301 A/1296 A line intensity ratios on electron density, temperature and pressure. Electron densities ranging from 2 x 10 to the 10th/cu cm to 10 to the 12th/cu cm and active region pressures from 3 x 10 to the 15th to 10 to the 16th/cu cm K are obtained. Energy balance calculations reveal the balance of the divergence of the conductive flux and turbulent energy dissipation by radiative energy losses in a plane-parallel homogeneous transition zone (fill factor of 1), and an energy source requirement for a cylindrical zone geometry (fill factor less than 0.04).

  6. The Effect of Displacement Mode of Rigid Retaining Walls on Shearing Bands by Active Earth Pressure

    Directory of Open Access Journals (Sweden)

    A. Sekkel

    2013-10-01

    Full Text Available This work treats the physical modeling of failure mechanisms by active earth pressure. This last is developed by retaining wall movement. A lot of research showed that wall displacement has a significant effect on active earth pressure. A good comprehension of active earth pressure phenomenon and its failure mechanisms help us to better conceive retaining walls. The conception of a small-scale model allowed the realization of active earth pressure tests, while displacing the mobile wall toward the outside of the massif. The studied material is that of Schneebeli; light two-dimensional material made of cylindrical plastic rollers, simulating granular non-cohesive soil. The evolution of shearing zones under continuous and discontinuous displacement modes of mobile walls by correlation pictures allows the investigation of the localization of deformations and failure mechanisms.

  7. HII regions in hydrostatic balance between gas pressure, radiation pressure and gravity

    Science.gov (United States)

    Raga, A. C.; Cantó, J.; Mellema, G.; Rodríguez-González, A.; Esquivel, A.

    2015-04-01

    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 ??{10{cm}^{-3}/n_0}pc (where n_0 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.

  8. A novel pneumatic micropipette aspiration method using a balance pressure model

    Science.gov (United States)

    Zhao, Qili; Wu, Ming; Cui, Maosheng; Qin, Yanding; Yu, Jin; Sun, Mingzhu; Zhao, Xin; Feng, Xizeng

    2013-12-01

    This paper presents a novel micropipette aspiration (MA) method based on a common pneumatic micro-injection system. This method is the first to quantify the influence of capillary effect on aspiration pressure using a balance pressure model, and in return, uses the capillary effect to quantify the aspiration pressure. Subsequently, the seal between the cell and the micropipette is detected to judge and exclude the ineffective MA attempts. The rationality of the balance pressure model is validated by the designed micropipette-filling experiments. Through applied to elasticity-determination of the cells with different sizes, the feasibility and versatility of this MA method are proved. With abilities to quantify aspiration pressures and detect the seam between the cell and the micropipette, our method is expected to advance the application of the commercial pneumatic injector in the MA of cells. Moreover, with the quantified volume of the liquid entering into the micropipette during MA process, our method also has a potential applicability to the study of the permeability of the cell membrane in the future.

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

    OpenAIRE

    Leach, Julia M.; Martina Mancini; 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 labor...

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

    OpenAIRE

    Hemanta Hazarika

    2009-01-01

    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 int...

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

    Scientific Electronic Library Online (English)

    A. G., Raga; J., Cantó; G., Mellema; A., Rodríguez-González; A., Esquivel.

    Full Text Available Estudiamos las soluciones de una versión modificada de la ecuación de Lane-Emden isotérmica, la cual incorpora el efecto de la presión de radiación (dirigida hacia afuera) asociada a las fotoionizaciones. Estas soluciones son relevantes para regiones HII alrededor de un cúmulo 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 presión de radiación. Encontramos que las soluciones tienen una transición de un régimen "dominado por gravedad" (en el que las soluciones convergen a radios grandes a la solución de la esfera isotérmica autogravitante no singular) a uno "dominado por presión de radiación" (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 presión de radiación, no ocurrirán en muchas de las situaciones astrofísicamente relevantes, dada la ausencia de un posible medio confinador de presión 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.

  12. Comment of Conventional Access Inaccuracies and Advanced General Earth Pressure Model.

    Czech Academy of Sciences Publication Activity Database

    Koudelka, Petr

    Rotterdam : Balkema, 1999 - (Fujita, F.), s. 11-12 [IS Geotechnical Aspects of Underground Constru ction in Soft Ground. Tokyo (JP), 11.07.1999-13.07.1999] R&D Projects: GA ?R GA103/97/0702; GA ?R GA103/98/0632 Keywords : lateral (Earth) pressure * granular mass * extreme pressures (active, pasive) Subject RIV: JM - Building Engineering

  13. Salt balance: From space experiments to revolutionizing new clinical concepts on earth - A historical review

    Science.gov (United States)

    Gerzer, Rupert

    2014-11-01

    For a long time, sodium balance appeared to be a “done deal” and was thought to be well understood. However, experiments in preparation of space missions showed that the concept of osmotic sodium storage and close correlations of sodium with water balance are only part of the regulatory mechanisms of body salt. By now it has turned out that the human skin is an important storage place and regulator for sodium, that sodium storage involves macrophages which in turn salt-dependently co-regulate blood pressure, that body sodium also strongly influences bone and protein metabolism, and that immune functions are also strongly influenced by sodium. In addition, the aging process appears to lead to increased body sodium storage, which in turn might influence the aging process of the human body. The current review article summarizes the developments that have led to these revolutionizing new findings and concepts as well as consequences deriving from these findings. Therefore, it is not intended in this article to give a complete literature overview over the whole field but to focus on such key literature and considerations that led to the respective developments.

  14. Numerical Simulation of Earth Pressure on Head Chamber of Shield Machine with FEM

    International Nuclear Information System (INIS)

    Model parameters of conditioned soils in head chamber of shield machine are determined based on tree-axial compression tests in laboratory. The loads acting on tunneling face are estimated according to static earth pressure principle. Based on Duncan-Chang nonlinear elastic constitutive model, the earth pressures on head chamber of shield machine are simulated in different aperture ratio cases for rotating cutterhead of shield machine. Relationship between pressure transportation factor and aperture ratio of shield machine is proposed by using aggression analysis.

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

    Science.gov (United States)

    Sánchez-Calvo, Raúl; Rodríguez-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.

  16. High Pressure Earth Storable Rocket Technology Program: Basic Program

    Science.gov (United States)

    Chazen, M. L.; Sicher, D.; Huang, D.; Mueller, T.

    1995-01-01

    The HIPES Program was conducted for NASA-LeRC by TRW. The Basic Program consisted of system studies, design of testbed engine, fabrication and testing of engine. Studies of both pressure-fed and pump-fed systems were investigated for N2O4 and both MMH and N2H4 fuels with the result that N2H4 provides the maximum payload for all satellites over MMH. The higher pressure engine offers improved performance with smaller envelope and associated weight savings. Pump-fed systems offer maximum payload for large and medium weight satellites while pressure-fed systems offer maximum payload for small light weight satellites. The major benefits of HIPES are high performance within a confined length maximizing payload for lightsats which are length (volume) constrained. Three types of thrust chambers were evaluated -- Copper heatsink at 400, 500 and 600 psia chamber pressures for performance/thermal; water cooled to determine heat absorbed to predict rhenium engine operation; and rhenium to validate the concept. The HIPES engine demonstrated very high performance at 50 lbf thrust (epsilon = 150) and Pc = 500 psia with both fuels: Isp = 337 sec using N2O4-N2H4 and ISP = 327.5 sec using N2O4-MMH indicating combustion efficiencies greater than 98%. A powder metallurgy rhenium engine demonstrated operation with high performance at Pc = 500 psia which indicated the viability of the concept.

  17. Saturation vapor pressure in iron chloride-alkaline earth metal chlorides systems

    International Nuclear Information System (INIS)

    The boiling-point method was used to investigate the temperature and concentration dependence of the saturated vapour pressure in ferrous chloride systems with alkali earth metal chlorides at 10000K. Saturated vapour pressure isotherms were constructed for different solution ratios of these systems. In the FeCl2-MgCl2 system slight positive deviations from additivity were observed, while in ferrous chloride systems with calcium, strontium and barium chlorides there were negative deviations increasing on transition from calcium to barium, i.e. with increasing cationic radius of the alkali earth metal. The vapour composition of weakly interacting systems is discussed. (author)

  18. Nonlinear pressure effects in superconducting rare earth-iron-silicides

    International Nuclear Information System (INIS)

    The superconducting transition temperatures (Tsub(c)) of RE2Fe3Si5 (RE = Sc, Y, Lu) vary in a nonlinear fashion under hydrostatic pressure up to 20 kbar. For the Sc and Lu compounds Tsub(c) decreases at an average rate of -7x10-5K bar-1, while Tsub(c) of Y2Fe3Si5 increases rapidly (33x10-5K bar-1) and passes through a maximum whose value is twice that at ambient pressure. The results are compared with the effects of volume contraction across the series (Ysub(1-x)Lusub(x))2Fe3Si5 and (Ysub(1-x)Dysub(x))2Fe3Si5. (Auth.)

  19. High Pressure, Earth-storable Rocket Technology. Volume 1

    Science.gov (United States)

    Jassowski, D. M.

    1997-01-01

    The effect of elevated chamber pressure on combustion efficiency and heat transfer has been determined at the 100 lbf (445 N) thrust level for nitrogen tetroxide propellants. Measurements were made up to 500 psia (3.45 MPa) with testbed hardware; tests at 100 psia (0.690 MPa) and 250 psia (1.72 MPa) were made with radiation-cooled rhenium chambers. The first task of the program served to determine desirable thruster applications and operating conditions: high total impulse, i.e., communication satellite or spacecraft bus axial engines, at chamber pressures up to 250 psia (1.72 MPa) pressure-fed, or up to 500 psia (3.45 MPa) pump-fed. The hardware modifications and testing required to obtain the data were determined in Task 2, which included design-support hot fire tests; supplemental hardware, including a 250 psia (1.72 MPa) Pc rhenium chamber and a 20% fuel-film cooled platelet injector was fabricated in Task 3. Testing showed that satisfactory operation of Ir-Re radiation chambers is assured at pressures up to 250 psia and may be possible up to 500. The heat transfer data obtained show good correlation with throat Reynolds number and are generally under values given by the simplified Bartz equation; chambers equilibrium temperatures match predicted values. Preliminary optimization of trip configuration and mixture ratio were made; Isp performance from thrust measurements was within 1% of predicted values. Stability, compatibility, and front-end thermal management were determined to be satisfactory.

  20. High Pressure, Earth-storable Rocket Technology. Volume 2

    Science.gov (United States)

    Jassowski, D. M.

    1997-01-01

    The effect of elevated chamber pressure on combustion efficiency and heat transfer has been determined at the 100 lbf (445 N) thrust level for nitrogen tetroxide propellants. Measurements were made up to 500 psia (3.45 Mpa) with testbed hardware; tests at 100 psia (0.690 MPa) and 250 psia (1.72 MPa) were made with radiation-cooled rhenium chambers. The first task of the program served to determine desirable thruster applications and operating conditions: high total impulse, i.e. communication satellite or spacecraft bus axial engines, at chamber pressures up to 250 psia (1.72 MPa) pressure-fed, or up to 500 psia (3.45 MPa) pump-fed. The hardware modifications and testing required to obtain the data were determined in Task 2, which included design-support hot fire tests; supplemental hardware, including a 250 psia (1.72 MPa) Pc rhenium chamber and a 20% fuel-film cooled platelet injector was fabricated in Task 3. Testing showed that satisfactory operation of Ir-Re radiation chambers is assured at pressures up to 250 psia and may be possible up to 500. The heat transfer data obtained show good correlation with throat Reynolds number and are generally under values given by the simplified Bartz equation; chambers equilibrium temperatures match predicted values. Preliminary optimization of trip configuration and mixture ratio were made; Isp performance from thrust measurements was within 1% of predicted values. Stability, compatibility, and front-end thermal management were determined to be satisfactory.

  1. Advanced Pressure Coring System for Deep Earth Sampling (APRECOS)

    Science.gov (United States)

    Anders, E.; Rothfuss, M.; Müller, W. H.

    2009-04-01

    Nowadays the recovery of cores from boreholes is a standard operation. However, during that process the mechanical, physical, and chemical properties as well as living conditions for microorganisms are significantly altered. In-situ sampling is one approach to overcome the severe scientific limitations of conventional, depressurized core investigations by recovering, processing, and conducting experiments in the laboratory, while maintaining unchanged environmental parameters. The most successful equipment today is the suite of tools developed within the EU funded projects HYACE (Hydrate Autoclave Coring Equipment) and HYACINTH (Deployment of HYACE tools In New Tests on Hydrates) between 1997 and 2005. Within several DFG (German Research Foundation) projects the Technical University Berlin currently works on concepts to increase the present working pressure of 250 bar as well as to reduce logistical and financial expenses by merging redundant and analogous procedures and scaling down the considerable size of key components. It is also proposed to extend the range of applications for the wireline rotary pressure corer and the sub-sampling and transfer system to all types of soil conditions (soft to highly-consolidated). New modifications enable the tools to be used in other pressure related fields of research, such as unconventional gas exploration (coal-bed methane, tight gas, gas hydrate), CO2 sequestration, and microbiology of the deep biosphere. Expedient enhancement of an overall solution for pressure core retrieval, process and investigation will open the way for a complete on-site, all-purpose, in-situ equipment. The advanced assembly would allow for executing the whole operation sequences of coring, non-destructive measurement, sub-sampling and transfer into storage, measurement and transportation chambers, all in sterile, anaerobic conditions, and without depressurisation in quick succession. Extensive post-cruise handling and interim storage would be dispensable. The complete core processing and preparation of in-situ sample sections for worldwide shipping could be conducted within hours after retrieval.

  2. Spatiotemporal correlations in Earth's temperature field from fractional stochastic-diffusive energy balance models

    Science.gov (United States)

    Rypdal, Kristoffer; Rypdal, Martin; Fredriksen, Hege-Beate

    2015-04-01

    In the Earth temperature field, spatiotemporal long-range dependence is usually explained as a result of nonlinear cross-scale coupling and cascading. In this contribution we challenge that paradigm, demonstrating that the observed correlation structure can arise from simple, linear, conceptual models. A two-dimensional stochastic-diffusive energy balance model (EBM) formulated on a sphere by G. R. North et al., J. Climate, 24:5850-5862, 2011, is explored and generalized. We compute instantaneous and frequency-dependent spatial autocorrelation functions, and local temporal power spectral densities for local sites and for spatially averaged signal up to the global scale. On time scales up to the relaxation time scale given by the effective heat capacities of the ocean mixed layer and land surface, respectively, we obtain scaling features reminiscent of what can be derived from the observed temperature field. On longer time scales, however, the EBM predicts a transition to a white-noise scaling, which is not reflected in the observed records. We propose and explore a fractional generalization (FEBM), which can be considered as a spatiotemporal version of the zero-dimensional, long-memory EBM of M. Rypdal and K. Rypdal, J. Climate, 27:5240-5258, 2014. The fractional equation introduces a power-law (rather than exponential) impulse response representing the delayed action due to the slow heat exchange between the mixed layer and the deep ocean. It is demonstrated that this generalized model describes qualitatively the main spatiotemporal correlation characteristics of the temperature field derived from instrumental data and from a 500 yr control run of the Nor-ESM model. For instance, the FEBM implies temporal power-law spectra where the spectral exponent for globally averaged temperature is twice that of local temperatures, and spatial autocorrelation lengths increases with time scale, in good agreement with the Nor-ESM simulations. It also reproduces the long-time response to a step-function forcing in the Nor-ESM model.

  3. 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

  4. 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.

  5. Earth Observation Plan Looks Toward Balancing U.S. Federal Priorities

    Science.gov (United States)

    Showstack, Randy

    2014-08-01

    The U.S. federal government funds about 2.5 billion for Earth observation satellite systems and more than 1 billion for airborne, terrestrial (including freshwater), and marine networks and surveys among 11 departments and agencies. Combined, those Earth observation activities add about $30 billion to the U.S. economy each year.

  6. Novel high pressure modifications of rare earth trichlorides in the RhF3-type

    International Nuclear Information System (INIS)

    The results of high pressure investigations on rare earth trichlorides crystallizing with the AlCl3-type arrangement under normal conditions are reported. In addition to the PuBr3-type geometry, formed at higher pressures, a new structure type is found in a lower pressure range. This high pressure phase is isotypic with the RhF3-type arrangement, which so far has only been found with fluorides. It is packed more efficiently and shows a slightly higher primary coordination due to the higher symmetry of the coordination polyhedra compared with that of the original AlCl3-type structure. A model for the mechanism of transformation is presented. (author)

  7. Viscosity measurements on metal melts at high pressure and viscosity calculations for the earth's core

    International Nuclear Information System (INIS)

    A review is given of experimental and calculated data on the viscosity of iron-based melts on the melting curve. The interest in these data originates in the division of opinion on whether viscosity increases rather moderately or considerably in the high-pressure range. This disagreement is especially pronounced in the interpretation of the values of molten iron and its compounds in the environment of the earth's outer core. The conclusion on a substantial rise in viscosity mostly follows from the universal law, proposed by Brazhkin and Lyapin [1], of viscosity changing along the metal melting curve in the high-pressure range. The review analyzes available experimental and computational data, including the most recent ones. Data on viscosity of metals under shock wave compression in the megabar pressure range are also discussed. It is shown that data on viscosity of metal melts point to a small increase of viscosity on the melting curve. Specifics are discussed of the phase diagram of iron made more complex by the presence of several phase transitions and by the uncertainty in the position of the melting curve in the high-pressure range. Inaccuracies that arise in extrapolating the results of viscosity measurements to the pressure range corresponding to the earth's core environment are pointed out. (reviews of topical problems)

  8. 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

  9. 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.

  10. 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.

  11. Radiogenic heat production and the earth's heat balance. A source of arguments in geoscience

    International Nuclear Information System (INIS)

    The terrestrial heat flow into interstellar space amounts to approx. 32 TW on the basis of an average heat flow density of 63 mW per sq.m. of earth surface. The loss flow derives part of the energy from the residual heat of the nascent phase of the earth (approx. 40%) and the other part from the natural disintegration of longlived radionuclides, i.e. radiogenic heat production (roughly 60%). This concept met with broad consensus in the geosciences until the 1980s. In 1993, Pollack et al. concluded from the evaluation of recent measured data that heat loss via the oceanic crust of the earth was clearly higher, which raises the loss flow to a total of 44 TW. This is contradicted by Hoffmeister and Criss, who conclude from a modified geochemical model that the total heat loss of 31 TW is fully compensated by radiogenic heat production. In 2001, C. Herndon introduced a new idea into the discussion. According to his thesis, planetary differentiation caused a nuclear georeactor to be created in the center of the earth, whose continuous thermal power of approx. 3 TW contributes to compensating heat losses. Physicists and geoscientists hope to be able to derive new findings on this thesis and on the distribution of radiogenic heat production in the interior of the earth from the planned geo-neutrino experiment in Homestake, USA. (orig.)

  12. Anthropogenic and natural exergy losses (exergy balance of the Earth's surface and atmosphere)

    International Nuclear Information System (INIS)

    Natural exergy losses connected with the absorption of solar radiation by the Earth have been calculated. The exergy income caused by the radiation exchange between the Earth and the cosmic space has also been considered. The exergy losses occurring near the Earth's surface have been distinguished because they represent the most accessible natural resources of exergy. The term 'natural losses of utilizable exergy' has been proposed. These losses have been compared with the anthropogenic ones caused by the activity of humankind. The positive impact of the natural exergy losses has been pointed out: they were a main cause of the formation of the terrestrial natural environment, of the non-renewable natural resources of fuels, and of the generation of stable dissipative structures in form of living beings

  13. 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).

  14. Engineering kinematic theory of the contact earth pressure and its application to the static calculation of thin quay walls

    Directory of Open Access Journals (Sweden)

    V.S. Korovkin

    2013-10-01

    Full Text Available Construction of deep-water thrust berthing structures requires using new and more perfect methods of calculation containing fewer assumptions. A version of the engineering kinematic theory of contact earth pressure in the application to the water-transport and offshore structures was suggested in the article. A dimensionless static “compression – tension” diagram of the soil, presented by curvilinear function, was used in the method. In this case, the displacement of the limit point of the diagram is determined with the account of the plastic deformation modulus in the earth contact point. Practical application of engineering theory was implemented in the proposed method of the mirroring with respect to anchored thin walls. In this method different lateral pressure profiles depending on the rated scheme were used. This method consists in three steps’ loading of anchored wall. The first stage – the normal calculation of the wall in the form of beam loaded by active earth pressure and bearing on the anchor pole and partly on the base ground. The second stage – the anchor reaction and the foundation earth reactive pressure are mirrored in the form of external loads acting on the part of the water area on the beam bearing on the backfill and foundation soil. Third stage – repeating the first external load in the form of the earth pressure profile behind the wall derived in the second calculation step. Suggested calculation as distinct from existing methods, which are using active earth pressure, defines more exactly the strains in retaining wall upward or downward.

  15. Differential velocity between solar wind protons and alpha particles in pressure balance structures

    Science.gov (United States)

    Yamauchi, Yohei; Suess, Steven T.; Steinberg, John T.; Sakurai, Takashi

    2004-03-01

    Pressure balance structures (PBSs) are a common high-plasma beta feature in high-latitude, high-speed solar wind. They have been proposed as remnants of coronal plumes. If true, they should reflect the observation that plumes are rooted in unipolar magnetic flux concentrations in the photosphere and are heated as oppositely directed flux is advected into and reconnects with the flux concentration. A minimum variance analysis (MVA) of magnetic discontinuities in PBSs showed there is a larger proportion of tangential discontinuities than in the surrounding high-speed wind, supporting the hypothesis that plasmoids or extended current sheets are formed during reconnection at the base of plumes. To further evaluate the character of magnetic field discontinuities in PBSs, differential streaming between alpha particles and protons is analyzed here for the same sample of PBSs used in the MVA. Alpha particles in high-speed wind generally have a higher radial flow speed than protons. However, if the magnetic field is folded back on itself, as in a large-amplitude Alfvén wave, alpha particles will locally have a radial flow speed less than protons. This characteristic is used here to distinguish between folded back magnetic fields (which would contain rotational discontinuities) and tangential discontinuities using Ulysses high-latitude, high-speed solar wind data. The analysis indicates that almost all reversals in the radial magnetic field in PBSs are folded back field lines. This is found to also be true outside PBSs, supporting existing results for typical high-speed, high-latitude wind. There remains a small number of cases that appear not to be folds in the magnetic field and which may be flux tubes with both ends rooted in the Sun. The distinct difference in MVA results inside and outside PBSs remains unexplained.

  16. Prediction of Satellite Motion under the Effects of the Earth’s Gravity, Drag Force and Solar Radiation Pressure in terms of the KS-regularized Variables

    Directory of Open Access Journals (Sweden)

    Hany R. Dwidar

    2014-06-01

    Full Text Available This paper is concerned with an orbit prediction using one of the best regular theories (KS-regularized variables. Perturbations due to the Earth’s gravitational field with axial symmetry up to the fourth order zonal harmonic, atmospheric drag (variation in density model with height and solar radiation pressure are considered. Applications of the problem with a comparison between the perturbations effect will be illustrated by numerical and graphical example.

  17. 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.

  18. Earth Pressure at rest of Søvind Marl – a highly overconsolidated Eocene clay

    DEFF Research Database (Denmark)

    GrØnbech, Gitte Lyng; Ibsen, Lars Bo

    2015-01-01

    The present study evaluated earth pressure at rest, K0, in highly overconsolidated Eocene clay called Søvind 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 Søvind 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 Søvind 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. Meyerhof’s (1976) reported correlation between K0(oc) and OCR was found inconsistent with K0(oc) development of in Søvind 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.

  19. Pressure dependence of viscosity, or is the earth's mantle a glass?

    International Nuclear Information System (INIS)

    Little is known about the real conditions in the earth's interior because direct sampling is not feasible. The propagation of seismic waves is the only instrument for investigating the mantle. Therefore, viscosity ? is of prime importance. Experimental data indicate that mantle viscosity is about 1022 Pa s. At such a high viscosity even molten materials behave like solids. The aim of the present paper is to demonstrate that, due to the extreme pressure, viscosity increases sharply. In this way the glass transition temperature increases faster than the melting point, so an important part of the mantle could be in a glassy state, although being molten

  20. High Pressure Earth Storable Rocket Technology Program-Hipes Options 1/2 Report

    Science.gov (United States)

    Chazen, M. L.; Sicher, D.; Calvignac, J.; Ono, D.

    1999-01-01

    Under the High Pressure Earth Storable Rocket Technology (HIPES) Program, TRW successfully completed testing of two 100 lbf thrust class rhenium chambers using N204-MMH. The first chamber was successfully fired for 4789 seconds of operating time with a maximum duration of 700 seconds. This chamber had been previously fired for 5230 seconds with N2O4-N2H4. The second chamber was successfully fired for 8085 seconds with a maximum firing duration of 1200 seconds. The Isp (specific impulse) for both chambers ranged from 323 lbf-sec/lbm to 330 lbf-sec/lbm.

  1. 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.

  2. 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, João Pradinho; Niphadkar, Madhura; Mücher, 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.

  3. The Coupled Effects of Pressure and Mineralogy on the Dynamics of Axisymmetric Thermochemical Plumes in the Earth's Lower Mantle

    Science.gov (United States)

    Samuel, H.; Bercovici, D.

    2005-12-01

    Mass balance considerations based on chondrites compositions as well as the observed anticorrelation between bulk sound and shear wave velocities suggest that a significant part of the deep mantle is enriched in Si and Fe, relative to the bulk mantle composition. Several numerical studies and laboratory experiments have shown that the presence of these compositional heterogeneities may have a first order impact on the dynamics of ascending mantle plumes, through their induced chemical density contrast ? ??/? with respect to the surrounding mantle. However, using mineral physics data and thermodynamic considerations, we first show that contrary to what was assumed in previous geodynamic studies, ? ??/? may significantly vary with pressure in the lower mantle (up to 200% variation), depending on the Si and Fe content of the chemically distinct material. We therefore investigate the coupled effects of mineralogy and pressure on the dynamics of axisymmetric thermochemical plumes in the Earth's lower mantle, using both high resolution numerical experiments and analytical theory. Our results show that the effect of mineralogy is considerable: (1) For relatively low Si enrichment, an oscillatory behavior of the plume head is observed, similar to previous laboratory experiments [Davaille, Nature, 402, 756-760, (1999)] but without the need of large volume of chemically distinct material. (2) For Si-enriched compositions with respect to a reference pyrolitic mantle, the chemical density excess increases with decreasing depth, leading to the stagnation of large plume heads at various depths in the lower mantle. As a consequence, these thermochemical plumes may display broad (~ 1200 km wide and more) negative seismic velocity anomalies at various lower mantle depths, which may not necessarily be associated with upwelling currents. In addition, the coupling between mineralogy and dynamics may provide an efficient mechanism for the long term survival of compositional heterogeneity in the lower mantle, as suggested by geophysical observations and geochemical record.

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

    Science.gov (United States)

    Funabiki, Fuji; Matsuishi, Satoru; Hosono, Hideo

    2013-06-01

    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 RE2O3.3B2O 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.

  5. Decadal variations of Earth's oblateness and surface mass balance in polar ice sheets from 1979 to 2012

    Science.gov (United States)

    Seo, K. W.; Wilson, C. R.; Chen, J.; Lee, C. K.

    2014-12-01

    Gravity variations associated with Earth's oblateness (J2) have been observed by satellite laser ranging (SLR) since 1976. More than three-decades long satellite observation of J2 has been useful to understand dynamical process of Earth from mantle to atmosphere. However, causes of decadal J2 variations were still uncertain while ice mass change in polar region was generally believed to be one of the driving forces. In this study, we use anomalous surface mass balance (SMB) in Antarctica and Greenland as a proxy of past anomalous ice mass variation in both ice sheets and quantify their contribution to J2. The SMB contribution in polar ice sheets depicts decadal J2 variations, which agree well with those of SLR observations from 1979 to 2012. This result also suggests an important implication that SMB variations have been important contributors to polar ice mass changes along with ice dynamics. There are still unknown J2 variations with about 10-year periods, and its cause is probably due to limitation of numerical models to depict climate variations associated with solar activity.

  6. 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

  7. Solubility of silicon in liquid metal at high pressure: implications for the composition of the Earth's core

    OpenAIRE

    Gessmann, Ck; Wood, Bj; Rubie, Dc; Kilburn, MR

    2001-01-01

    Silicon solubility in liquid Fe-rich metal was measured experimentally as a function of pressure, temperature and oxygen fugacity to determine if silicon could be a major light element in the Earth's core. At the P, T, fO2 conditions of the experiments, Si solubility in liquid metal increases with increasing pressure, increasing temperature and decreasing oxygen fugacity. Evaluating single-stage core formation scenarios, the experimental results show that if the core segregated at low pressur...

  8. 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

  9. Earth's variable oblateness: Implications of space geodesy for glacial mass balance

    Science.gov (United States)

    Marcus, S.; Dickey, J.; de Viron, O.

    2003-04-01

    Satellite and ancient eclipse data show that the Earth's dynamic oblateness (J2) has been steadily decreasing since the last Ice Age, due to post-glacial rebound (PGR). Recently, however, Cox and Chao used a multi-satellite solution to show that J2 began to increase in 1997-98, reflecting an equatorward mass transport large enough to offset the ongoing PGR. Dickey et al. subsequently showed that changes in oceanic mass distribution as computed by the ECCO model, along with plausible melting scenarios for sub-polar glaciers based on analyses by the (U.S.) National Snow and Ice Data Center, can explain the observed trend reversal in J2. Here we provide a more detailed examination of the glacial contribution to recent J2 variations, in light of the melting scenarios employed by Dickey et al. and other determinations of J2. The relation of these glacial anomalies to recent climate fluctuations, such as the 1997-98 ENSO, will also be considered.

  10. 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)

  11. 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 valustandard, 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.

  12. 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 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.

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

    OpenAIRE

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

    2013-01-01

    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 experimental...

  14. Petrography and alteration of Chehelkureh copper deposit: Mass balance of elements and behavior of rare earth elements

    International Nuclear Information System (INIS)

    Chehelkureh copper deposit is located in Kuh-e-Lunka area, 120 km Northwest of Zahedan (Southeast of Iran). The host rocks of mineralization are intercalated Eocene turbiditic greywackes, siltstones, and shales (flysch). They are folded with N-S trend and the eastern limb of this fold has been drag folded. Several stocks and dykes of granodiorite to quartz monzodiorite and granite compositions intruded the turbidites, converting them locally to hornfels. These intrusions are oriented parallel to the major Northwest-Southeast fault set. The Chehelkureh are field comprises numerous irregular lenses and veins. The ore field extends for 1500 meters in N23degW direction, and is displaced by late brittle faults striking roughly East-West. The fault and fracture filling ores include quartz, dolomite, ankerite, siderite, calcite, and lesser amounts of pyrrhotite, arsenopyrite, pyrite, chalcopyrite, sphalerite, galena, Se-rich galena, marcasite, molybdenite, ilmenite, and rutile. Assay data from 39 drill holes show high contents of base metals, with an average of 1.48% Cu, 1.77% Zn, 0.85% Pb (4.1% Cu + Zn + Pb), and silver (average 22 ppm in 45 samples). The ores are not so enriched in gold (0.14 ppm on average in 45 samples). A composite sample of least-altered greywackes and shales (host rocks) is used for comparison with mineralized samples. Mass-balance calculations were carried out to quantify chemical changes resulting from different alteration episs resulting from different alteration episodes. With the low solubility and low variance of Al (Al2O3) in moderately altered sedimentary country rocks compared with many other immobile trace components, Al2O3 is used as an immobile component for mass-balance calculations. There is a net mass increase in Fe2O3T, and Mg O and a net mass decrease in Na2O, Ca O, K2O, and, SiO2 with chloritization. Carbonatization shows Fe2O3T. and Mg O enrichment and SiO2 and Na2O depletion, implying that ankerite, siderite and dolomite are predominant phases. SiO2 is enriched in silicified samples and depleted in other alteration types. There is no mass change in Cu, Pb and Zn with kaolinization, but these elements are enriched in other alteration types. Hg is enriched in all alteration types except kaolinization, which may even show a slight depletion. Samples from gossan with siIicifcation showedanincrease in SiO2, Fe2O3T, Cu, Pb, Hg, and Znandadecrease in Mg O, Na2O,Ca O, and K2O. Sometraceandmajor elements have high variance in different alterations and are more complicated to interpret, such as P2O5, Mn O, Ni, CO, and Rb. The rare earth element contents of the composite host rock sample are enriched in the LREE relative to the HREE and moderately depleted in Eu and Ho. As a whole, samples with kaolinization and carbonatization (ankerite and siderite) have been enriched in rare earth element contents and other wallrock alteration, including chloritization, dolomitization, kaolinization, minor sericitization, and silicification, are depleted in rare earth element. SEM-EDS evidence indicates that enrichment of rare earth element-bearing phosphates, such as monazite, occurred with carbonatization and kaolinization assemblages

  15. Energy balance in the solar transition region. II - Effects of pressure and energy input on hydrostatic models

    Science.gov (United States)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1991-01-01

    The radiation of energy by hydrogen lines and continua in hydrostatic energy-balance models of the transition region between the solar chromosphere and corona is studied using models which assume that mechanical or magnetic energy is dissipated in the hot corona and is then transported toward the chromosphere down the steep temperature gradient of the transition region. These models explain the average quiet sun and also the entire range of variability of the Ly-alpha lines. The relations between the downward energy flux, the pressure of the transition region, and the different hydrogen emission are described.

  16. Analysis of ground tests of a microwave, earth-occultation, pressure-reference-level system.

    Science.gov (United States)

    Ungar, S. G.; Lusignan, B. B.

    1973-01-01

    A two-satellite, microwave, earth-occultation system can supplement an infrared sensor by providing an accurate altitude reference that will serve to fix, as a function of height, the derived temperature profile of the infrared sounder. The results of ground tests made in Hawaii to estimate the likely effects of scintillation and fading on an occultation system are described. It was found that the microwave signal suffered periods of intense fading; extensive computer analyses of the data were performed in which aircraft-generated refractivity profiles were subjected to ray tracing. Results of these analyses indicate that the probable cause of the observed fading was multipath, a low-altitude phenomenon usually attributed to water vapor inhomogeneities. It is maintained that multipath will therefore have minimal effect on the pressure-reference microwave occultation system, which would operate at a relatively high closest-approach altitude (about 8 km).

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

    DEFF Research Database (Denmark)

    KrogsbØll, 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 properties. Generally good agreement was observed between physical and numerical models. The HS-model showed the right behaviour in pre-failure as well as failure for both flexible and stiff walls, whereas the MC-model showed some shortcomings when stiff walls were modelled.

  18. Barometric pressure, dry bulb temperature and vapor pressure at the lowest terrestrial site on earth, Dead Sea basin, Neve Zohar, Israel

    Science.gov (United States)

    Kudish, A. I.; Evseev, E. G.

    2006-03-01

    The Dead Sea basin is located at the lowest terrestrial site on the earth and, thereby, has the tallest atmospheric air column above its surface. Consequently, the Dead Sea basin is expected, a priori, to have the highest terrestrial barometric pressure and, thereby, the highest molecular oxygen density on the earth. The barometric pressure and dry bulb temperature have been monitored continuously at Neve Zohar, located on the western shore of the Dead Sea, since January 1995. The monthly average daily barometric pressure values exceed normal atmospheric pressure by a maximum of 4.83 hPa (4.77%) and a minimum of 33.1 hPa (3.26%) for December and July, respectively. This increase in barometric pressure can serve as a simple way to improve arterial oxygenation in hypoxemic patients. As a result, a number of research projects have been initiated on the treatment of patients suffering from pulmonary and cardiac diseases at the Dead Sea basin. The hourly barometric pressure data with regard to both its diurnal and monthly variation and the correlation between barometric pressure and dry bulb temperature will be analyzed.

  19. Structure and Stability of High-Pressure Dolomite with Implications for the Earth's Deep Carbon Cycle

    Science.gov (United States)

    Solomatova, N. V.; Asimow, P. D.

    2014-12-01

    Carbon is subducted into the mantle primarily in the form of metasomatically calcium-enriched basaltic rock, calcified serpentinites and carbonaceous ooze. The fate of these carbonates in subduction zones is not well understood. End-member CaMg(CO3)2 dolomite typically breaks down into two carbonates at 2-7 GPa, which may further decompose to oxides and CO2-bearing fluid. However, high-pressure X-ray diffraction experiments have recently shown that the presence of iron may be sufficient to stabilize dolomite I to high pressures, allowing the transformation to dolomite II at 17 GPa and subsequently to dolomite III at 35 GPa [1][2]. Such phases may be a principal host for deeply subducted carbon. The structure and equation of state of these high-pressure phases is debated and the effect of varying concentrations of iron is unknown, creating a need for theoretical calculations. Here we compare calculated dolomite structures to experimentally observed phases. Using the Vienna ab-initio simulation package (VASP) interfaced with a genetic algorithm that predicts crystal structures (USPEX), a monoclinic phase with space group 5 ("dolomite sg5") was found for pure end-member dolomite. Dolomite sg5 has a lower energy than reported dolomite structures and an equation of state that resembles that of dolomite III. It is possible that dolomite sg5 is not achieved experimentally due to a large energy barrier and a correspondingly large required volume drop, resulting in the transformation to metastable dolomite II. Due to the complex energy landscape for candidate high-pressure dolomite structures, it is likely that several competing polymorphs exist. Determining the behavior of high-pressure Ca-Mg-Fe(-Mn) dolomite phases in subduction environments is critical for our understanding of the Earth's deep carbon cycle and supercell calculations with Fe substitution are in progress. [1] Mao, Z., Armentrout, M., Rainey, E., Manning, C. E., Dera, P., Prakapenka, V. B., and Kavner, A. (2011). Dolomite III: A new candidate lower mantle carbonate. Geophy. Res. Lett., 38(22). [2] Merlini, M., Crichton, W. A., Hanfland, M., Gemmi, M., Müller, H., Kupenko, I., and Dubrovinsky, L. (2012). Structures of dolomite at ultrahigh pressure and their influence on the deep carbon cycle. Proc. Nat. Acad. Sci., 109(34), 13509-13514.

  20. 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.

  1. Vapor pressure and activity of components of melts formed by manganese chloride and chlorides of alkaline-earth metals

    International Nuclear Information System (INIS)

    The boiling points of melts were measured at different pressures over the melts for certain concentrations of components of the liquid phase in binary systems constituted by manganese chloride and chlorides of alkaline-earth metals. The temperature dependences of the saturated vapor pressure, normal boiling points, and enthalpies of evaporation were calculated. The concentration dependences of the thermodynamic activities of the components of four binary systems MnCl2-MCl2 (M=Mg, Ca, Sr, Ba) were analyzed

  2. 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.

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

    OpenAIRE

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

    2013-01-01

    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 measure...

  4. Measuring Center of Pressure Signals to Quantify Human Balance Using Multivariate Multiscale Entropy by Designing a Force Platform

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Huang

    2013-08-01

    Full Text Available To assess the improvement of human body balance, a low cost and portable measuring device of center of pressure (COP, known as center of pressure and complexity monitoring system (CPCMS, has been developed for data logging and analysis. In order to prove that the system can estimate the different magnitude of different sways in comparison with the commercial Advanced Mechanical Technology Incorporation (AMTI system, four sway tests have been developed (i.e., eyes open, eyes closed, eyes open with water pad, and eyes closed with water pad to produce different sway displacements. Firstly, static and dynamic tests were conducted to investigate the feasibility of the system. Then, correlation tests of the CPCMS and AMTI systems have been compared with four sway tests. The results are within the acceptable range. Furthermore, multivariate empirical mode decomposition (MEMD and enhanced multivariate multiscale entropy (MMSE analysis methods have been used to analyze COP data reported by the CPCMS and compare it with the AMTI system. The improvements of the CPCMS are 35% to 70% (open eyes test and 60% to 70% (eyes closed test with and without water pad. The AMTI system has shown an improvement of 40% to 80% (open eyes test and 65% to 75% (closed eyes test. The results indicate that the CPCMS system can achieve similar results to the commercial product so it can determine the balance.

  5. Pressure dependence of the magnetic properties of some rare earth intermetallic systems

    International Nuclear Information System (INIS)

    The magnetization and susceptibility of several rare earth intermetallic compounds have been measured under hydrostatic pressure, P, up to 10 kbar and in magnetic fields, H, up to 60 kG. For all the materials studied the magnetic properties are strongly influenced by crystalline electric field (CEF) effects. For the Pr-monochalcogenides and TmAl3 the low temperature van Vleck-like susceptibility, chi, decreases with increasing P. This is consistent with an increase of the CEF interaction as the lattice constant is reduced. This trend is also observed for the CEF level structure of dilute Tb in superconducting LaAl2 (where the impurity pairbreaking is reduced with increasing P). However, for the Pr- and Tm- monopnictides chi increases with increasing P. The pressure dependence of the magnetic ordering temperatures for singlet ground state TbSb, Pr3Tl and TmS is also reported. The effect of P is very strong on the low temperature magnetic anomalies of TmSe; the transition fields increase with increasing P at a rate of +1.7 kG/kbar, and these results are discussed in terms of the mixed-valence nature of TmSe

  6. Electronic and structural properties of Lu under pressure: Relation to structural phases of the rare-earth metals

    International Nuclear Information System (INIS)

    Ground-state electronic and structural properties of Lu under pressure are investigated with use of the self-consistent all-electron total-energy linear muffin-tin orbital band-structure method within a local-density-functional approximation. Pressure-induced structural transitions are found to occur in the following sequence: hcp--(Sm-type)--dhcp--fcc, which is the same as that observed in the crystal structures of the trivalent rare-earth metals with decreasing atomic number. This structural transition is correlated with the increase in the number of d electrons under pressure

  7. 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.

  8. Changes in body core temperatures and heat balance after an abrupt release of lower body negative pressure in humans

    Science.gov (United States)

    Tanabe, Minoru; Shido, Osamu

    1994-03-01

    Changes in body core temperature ( T cor) and heat balance after an abrupt release of lower body negative pressure (LBNP) were investigated in 5 volunteers under the following conditions: (1) an ambient temperature ( T a) of 20 °C or (2) 35 °C, and (3) T a of 25 °C with a leg skin temperature of 30°C or (4) 35°C. The leg skin temperature was controlled with water perfusion devices wound around the legs. Rectal ( T re), tympanic ( T ty) and esophageal ( T es) temperatures, skin temperatures (7 sites) and oxygen consumption were measured. The intensity of LBNP was adjusted so that the amount of blood pooled in the legs was the same under all conditions. When a thermal balance was attained during LBNP, application of LBNP was suddenly halted. The skin temperatures increased significantly after the release of LBNP under all conditions, while oxygen consumption hardly changed. The release of LBNP caused significant falls in T cor s under conditions (1) and (3), but lowered T cor s very slightly under conditions (2) and (4). The changes in T es were always more rapid and greater than those of T ty and T re. The falls in T ty and T re appeared to be explained by changes in heat balance, whereas the sharp drop of T es could not be explained especially during the first 8 min after the release of LBNP. The results suggest that a fall in T cor after a release of LBNP is attributed to an increase in heat loss due to reflexive skin vasodilation and is dependent on the temperature of venous blood returning from the lower body. It is presumed that T es may not be an appropriate indicator for T cor when venous return changes rapidly.

  9. 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.

  10. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles

    Directory of Open Access Journals (Sweden)

    Papadakis Stamatios A

    2007-09-01

    Full Text Available Abstract Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i without brace, ii with brace and 30 kPa application pressure and iii with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris activation onset. Results The results showed that overall balance (total stability parameter was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately stimulated by the brace application and therefore are not able to alter the balance control strategy of the CNS, or that they play a less important role in the control of single limb balance. Further research is needed in this area with more dynamic and functional measurements, before the safe use of ankle bracing can be widely recommended.

  11. Development of the Kawai-type Multi-anvil Apparatus (KMA) and Its Application to High Pressure Earth Science

    International Nuclear Information System (INIS)

    Since Birch's prediction on the structure of the Earth's interior high pressure Earth science has rapidly been grown by the Kawai-type multi-anvil apparatus (KMA) and the diamond anvil cell (DAC). An important advantage of the KMA is its large specimen volume which makes it possible to conduct experiments under precisely controlled P-T conditions. A typical application of the KMA to the Earth science might be determination of the post-spinel phase equilibria in the system Mg2SiO4-Fe2SiO4. By adopting sintered diamond (SD) as the anvil material accessible pressure of the KMA has substantially increased. Melting experiments of mantle materials up to 35 GPa opened a new paradigm on the mantle fractionation in early Earth. Combining the KMA equipped with SD anvils with the synchrotron radiation phase equilibria of Fe GaN and Fe2O3 were determined by means of in situ X-ray diffraction. Special attention was paid to define the phase boundaries between perovskite and post-perovskite in MgGeO3 and MnGeO3 as analogues of MgSiO3. We also observed the spin transition of Fe2+ in (Mg0.87Fe0.17)O at 300 and 700 K. Recently the maximum attainable pressure is reaching 100 GPa and high P-T experiments up to 90 GPa are our ordinary jobs. In order to produce still higher pressure however innovation of SD such as NPD is indispensable. is indispensable.

  12. Development of the Kawai-type Multi-anvil Apparatus (KMA) and Its Application to High Pressure Earth Science

    Science.gov (United States)

    Ito, E.

    2012-07-01

    Since Birch's prediction on the structure of the Earth's interior high pressure Earth science has rapidly been grown by the Kawai-type multi-anvil apparatus (KMA) and the diamond anvil cell (DAC). An important advantage of the KMA is its large specimen volume which makes it possible to conduct experiments under precisely controlled P-T conditions. A typical application of the KMA to the Earth science might be determination of the post-spinel phase equilibria in the system Mg2SiO4-Fe2SiO4. By adopting sintered diamond (SD) as the anvil material accessible pressure of the KMA has substantially increased. Melting experiments of mantle materials up to 35 GPa opened a new paradigm on the mantle fractionation in early Earth. Combining the KMA equipped with SD anvils with the synchrotron radiation phase equilibria of Fe GaN and Fe2O3 were determined by means of in situ X-ray diffraction. Special attention was paid to define the phase boundaries between perovskite and post-perovskite in MgGeO3 and MnGeO3 as analogues of MgSiO3. We also observed the spin transition of Fe2+ in (Mg0.87Fe0.17)O at 300 and 700 K. Recently the maximum attainable pressure is reaching 100 GPa and high P-T experiments up to 90 GPa are our ordinary jobs. In order to produce still higher pressure however innovation of SD such as NPD is indispensable.

  13. Heliotropic orbits at oblate asteroids: balancing solar radiation pressure and J2 perturbations

    Science.gov (United States)

    Lantukh, Demyan; Russell, Ryan P.; Broschart, Stephen

    2015-02-01

    The combined effect of significant solar radiation pressure and perturbations on spacecraft orbits is investigated using both singly and doubly-averaged disturbing potentials with the Lagrange Planetary Equations. The resulting dynamics are applied to a spacecraft around an oblate asteroid. Several Sun-frozen families of orbits are identified using the singly-averaged potential, including two new families of orbits and a previously-discovered equatorial heliotropic orbit family. Families of both stable and unstable Sun-frozen orbits are mapped and characterized in the singly-averaged case. In addition, a heliotropic constraint is implemented to locate heliotropic orbits out of the equatorial plane using a constrained, doubly-averaged potential. Dynamic bounds for these 3D heliotropic orbits are shown to have an inclination limit of approximately 46 degrees for oblate bodies, and this limit is independent of the value of and radiation parameters. The resulting heliotropic and related periodic families of orbits are good candidates to consider for low-altitude science orbits around small oblate bodies with low or near-180 degree obliquity like Bennu, the target for the OSIRIS-REx mission.

  14. 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...

  15. The high-pressure phase diagram of Fe(0.94)O - A possible constituent of the earth's core

    Science.gov (United States)

    Knittle, Elise; Jeanloz, Raymond

    1991-01-01

    Electrical resistivity measurements to pressures of 83 GPa and temperatures ranging from 300 K to 4300 K confirm the presence of both crystalline and liquid metallic phases of FeO at pressures above 60-70 GPa and temperatures above 1000 K. By experimentally determinig the melting temperature of FeO to 100 GPa and of a model-core composition at 83 GPa, it is found that the solid-melt equilibria can be described by complete solid solution across the Fe-FeO system at pressures above 70 GPa. The results indicate that oxygen is a viable and likely candidate for the major light alloying element of the earth's liquid outer core. The data suggest that the temperature at the core-mantle boundary is close to 4800 K and that heat lost out of the core accounts for more than 20 percent of the heat flux observed at the surface.

  16. Analytical Analysis of the Effect of the Radiation Pressure on Planetary Exospheres: Application to Earth, Mars, Titan and Hot Jupiters

    Science.gov (United States)

    Beth, A.; Garnier, P.; Toublanc, D.; Dandouras, I. S.; Mazelle, C. X.

    2014-12-01

    Because of rare collisions, the motion of light species (H, H2) in the planetary exospheres is essentially determined by the external forces: the gravitation from the planet and the radiation pressure, ... Currently, the only analytical model used to model exospheric neutral density profiles is the well-known Chamberlain model which takes into account only the gravity. In this work and in the same way as Chamberlain, we solve rigorously and analytically, based on the Hamiltonian mechanics and Liouville theorem, the additional effect of the radiation pressure in particular for hydrogen (the model works for any species sensitive to the radiation pressure) on the structure of the exosphere and on the density profiles of ballistic particles. This approach was initially developed by Bishop and Chamberlain (1989) only in the Sun-planet direction. We extend it here to the whole exosphere with a 2D model. Also, we determine analytically the escape flux on the dayside at SZA=0, which can be compared with the Jeans' escape flux. We thus show that the radiation pressure induces : strong density asymmetries at high altitudes in the planetary exospheres, leading to the phenomenon of geotail at Earth for example the natural existence of an external limit (or exopause) for the exosphere, whose location is analytically determined an increase of the exospheric densities compared with Chamberlain profiles without radiation pressure (e.g. up to +150% at 5 Martian radius) a significant increase of the thermal escape flux (up to 30/35% for Earth/Mars today), until a «blow-off » regime with a constant escape flux for an extreme radiation pressure. The influence of the radiation pressure on the escape flux may thus bring conditions on the size of primary atmospheres, because of a strong radiation pressure in the Sun's young years. Finally, we show that this model may be applied to exoplanets, in particular to the hot Jupiters that are also subject to additional effects: centrifugal force and stellar gravity. We show the influence of the radiation pressure on the equipotentials of the Circular Restricted Three Body Problem. We also demonstrate that the hot Jupiter HD 209458b is actually in a blow-off regime induced by the radiation pressure, which allows us to propose an alternative scenario for the evolution of its atmosphere.

  17. Analysis of the effect of the radiation pressure on planetary exospheres : application to Earth, Mars, Titan and hot Jupiters

    Science.gov (United States)

    Beth, Arnaud; Garnier, Philippe; Toublanc, Dominique; Mazelle, Christian; Dandouras, Iannis

    2015-04-01

    Because of rare collisions, the motion of light species (H, H2) in the planetary exospheres is essentially determined by the external forces: the gravitation from the planet and the radiation pressure, ... Currently, the only analytical model used to model exospheric neutral density profiles is the well-known Chamberlain model which takes into account only the gravity. In this work and in the same way as Chamberlain, we solve rigorously and analytically, based on the Hamiltonian mechanics and Liouville theorem, the additional effect of the radiation pressure in particular for hydrogen (the model works for any species sensitive to the radiation pressure) on the structure of the exosphere and on the density profiles of ballistic particles. This approach was initially developed by Bishop and Chamberlain (1989) only in the Sun-planet direction. We extend it here to the whole exosphere with a 2D model. Also, we determine analytically the escape flux on the dayside at SZA=0, which can be compared with the Jeans' escape flux. We thus show that the radiation pressure induces : 1. strong density asymmetries at high altitudes in the planetary exospheres, leading to the phenomenon of geotail at Earth for example 2. the natural existence of an external limit (or exopause) for the exosphere, whose location is analytically determined 3. an increase of the exospheric densities compared with Chamberlain profiles without radiation pressure (e.g. up to +150% at 5 Martian radius) 4. a significant increase of the thermal escape flux (up to 30/35% for Earth/Mars today), until a «blow-off » regime with a constant escape flux for an extreme radiation pressure. The influence of the radiation pressure on the escape flux may thus bring conditions on the size of primary atmospheres, because of a strong radiation pressure in the Sun's young years. Finally, we show that this model may be applied to exoplanets, in particular to the hot Jupiters that are also subject to additional effects: centrifugal force and stellar gravity. We show the influence of the radiation pressure on the equipotentials of the Circular Restricted Three Body Problem. We also demonstrate that the hot Jupiter HD 209458b is actually in a blow-off regime induced by the radiation pressure, which allows us to propose an alternative scenario for the evolution of its atmosphere.

  18. Dynamic balance improvement program

    Science.gov (United States)

    Butner, M. F.

    1983-01-01

    The reduction of residual unbalance in the space shuttle main engine (SSME) high pressure turbopump rotors was addressed. Elastic rotor response to unbalance and balancing requirements, multiplane and in housing balancing, and balance related rotor design considerations were assessed. Recommendations are made for near term improvement of the SSME balancing and for future study and development efforts.

  19. 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.

  20. 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

  1. 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.

  2. BLOOD PRESSURE, HEART RATE AND MELATONIN CYCLES SYNCHRONIZATION WITH THE SEASON, EARTH MAGNETISM AND SOLAR FLARES.

    Science.gov (United States)

    Cornélissen, G; Halberg, F; Sothern, R B; Hillman, D C; Siegelová, J

    2010-01-01

    Three spectral components with periods of about (~) 0.41, ~0.5 and ~1.0 year had been found with serially independent sampling in human circulating melatonin. The time series consisted of around-the-clock samples collected for 24 hours at 4-hour intervals from different patients over several years. Some of these components had been found to be circadian stage-dependent, the daytime measurements following mostly a circannual variation, whereas a half-year characterized the nighttime samples. The latter were incorporated into a circasemiannual map. The relative brevity of the series prevented a check for the coexistence of all three spectral components, even if each component seemed to have a raison d'être. In time series of transdisciplinary data, a 1.00-year synchronized component is interpreted as representing the seasons. The half-year may qualify the circannual waveform, but it is also a signature of geomagnetics. An ~0.41-year (~5-month) component is the signature of solar flares. It has been called a cis-half-year (cis = on this side of a half-year) and may be detected only intermittently. Charles L. Wolff predicted the existence, among others, of ~0.42- and ~0.56-year components as beat periods of rotations at different solar latitudes.The multiple components characterizing circulating melatonin could also be found in a (to our knowledge unique) data set of a clinically healthy scientist (RBS). Herein, we focus on vascular data self-measured by RBS as he aged from ~20 to ~60 years. A multi-component model consisting of cosine curves with periods of 0.41, 0.50 and 1.00 year was fitted to weekly means of systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) collected ~5 times a day over 39 years by RBS. All three components can coexist for a while, although all of them are nonstationary in their characteristics and come and go by the criterion of statistical significance.Intermittently, BP and HR are synchronized selectively with one or the other aspect of RBS' physical environment, namely the seasons (at ~1.0 year), earth magnetism (at ~0.5 year) and/or solar flares (at ~0.42 year). Cosmic-biotic transfer of information, albeit hardly of energy (the biospheric amplitudes are very small) may be mediated in this set of frequency windows. As found earlier, RBS' circulation is also frequency-trapped environmentally in multidecadal windows, HR being locked into the transtridecadal Brückner, or rather Brückner-Egeson-Lockyer, BEL sunspot and terrestrial weather cycle, while his BP follows Hale's didecadal cycle in the changing polarity of sunspots.The ~0.41-year HR cycle may be associated with changes in solar flares, the cis-half-year amplitude of HR showing a cross-correlation coefficient of 0.79 with the total solar flare index (from both solar hemispheres) at a lag of ~3.2 years. The superposed time courses of these two variables indicate the presence of a shared Horrebow-Arago-Schwabe sunspot cycle of ~11 years, the cis-half-year in HR being more prominent after the total solar flare index reaches its ~11-year peak. Differences in the time-varying behavior of BP vs. HR are also described. PMID:21566725

  3. 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

  4. 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...

  5. Direct qualitative and quantitative determination of rare earths after separation by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    The rare earths from lanthanum to erbium can be separated by means of HPLC in an eluent system containing di-isopropylether/tetrahydrofuran/nitric acid (100:30:3), and they are determined qualitatively and quantitatively after calibration. Fluorescence quenching of THF at break-through of the single elements serves as indication method. This quenching is proportional to the concentration. The calibration curve is linear within 0.2 to 0.02 moles input. Standards, ores (monazites, cerite earths, yttriae) and technical products were analysed qualitatively and quantitatively. The results obtained are in good agreement with analytical values from different methods. The relative standard deviation is 1.8-3% (N = 10). The procedure takes 50 min from dissolution of the analytical sample. (orig.)

  6. 3-D Force-balanced Magnetospheric Configurations

    International Nuclear Information System (INIS)

    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

  7. Raman scattering of rare earth sesquioxide Ho?O?: A pressure and temperature dependent study

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Sugandha Dogra; Samanta, K.; Singh, Jasveer; Sharma, Nita Dilawar; Bandyopadhyay, A. K. [Pressure and Vacuum Standards, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

    2014-10-07

    Pressure and temperature dependent Raman scattering studies on Ho?O? have been carried out to investigate the structural transition and the anharmonic behavior of the phonons. Ho?O? undergoes a transition from cubic to monoclinic phase above 15.5 GPa, which is partially reversible on decompression. The anharmonic behavior of the phonon modes of Ho?O? from 80 K to 440 K has been investigated. We find an anomalous line-width change with temperature. The mode Grüneisen parameter of bulk Ho?O? was estimated from high pressure Raman investigation up to 29 GPa. Furthermore, the anharmonic components were calculated from the temperature dependent Raman scattering.

  8. The effect of temperature and pressure on the elastic behaviour of rare-earth phosphate glasses

    International Nuclear Information System (INIS)

    The longitudinal and shear wave velocities propagated in phosphate glasses containing samarium, euporium, neodynium and lantanum have been studied for the first time using the ultrasonic technique from 4.2 to 300 K. The elastic behaviour changes with temperature in an anomalous fashion due to anharmonic vibrational, thermally activated relaxations and the present of two-level system especially at low temperature. The pressure variation of the elastic constants has also been measured and has been used to calculate the elastic Grueneisen parameter for these glasses. For each of these vitreous materials, except the lanthanum phosphates, the bulk and shear moduli decrease under hydrostatic pressure; an indication of acoustic modes softening

  9. Correlation between sway parameters of center of pressure in quiet standing with eyes open and eyes closed, functional balance tests and symmetry index in chronic hemiparesis patients

    Directory of Open Access Journals (Sweden)

    Dorsa Hamedi

    2013-11-01

    Full Text Available Abstract Background and Aim: Proprioceptive problems, visuospatial deficits and muscle weakness are the main causes of weight bearing asymmetry and postural control impairment in chronic hemiparesis patients. The aim of this study was to investigate the correlation between center of pressure parameters in quiet standing with eyes open and closed and functional balance tests and symmetry index in these patients. Materials and Methods: In this correlation study, 16 stroke patients (mean age: 52.937±10.109 years, were selected by simple non-probability sapling. Force plate, Functional Reach and Timed Up and Go tests and scales were used in order to investigate postural sway parameters in quiet standing, functional balance and symmetry index, respectively. Results: Moderate to high significant correlation was obtained between Timed Up and Go test and symmetry index and most of the postural sway parameters in eyes closed condition, while Functional Reach test had only moderate significant correlation with standard deviation of velocity (anterior-posterior and phase plane total. Also symmetry index showed moderate correlation with most of the postural sway parameters. Conclusion: Current study demonstrates the role of vision and task in correlation between center of pressure parameters, balance tests and symmetry index. Key words: Correlation, Symmetric weight bearing, Postural sway, Functional Reach, Timed Up and Go, Force plate, Quiet standing

  10. 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 locations—and 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.

  11. Development of in situ Brillouin spectroscopy at high pressure and high temperature with synchrotron radiation and infrared laser heating system: Application to the Earth's deep interior

    Science.gov (United States)

    Murakami, Motohiko; Asahara, Yuki; Ohishi, Yasuo; Hirao, Naohisa; Hirose, Kei

    2009-05-01

    Seismic wave velocity profiles in the Earth provide one of the strongest constraints on structure, mineralogy and elastic properties of the Earth's deep interior. Accurate sound velocity data of deep Earth materials under relevant high-pressure and high-temperature conditions, therefore, are essential for interpretation of seismic data. Such information can be directly obtained from Brillouin scattering measurement. Here we describe an in situ Brillouin scattering system for measurements at high pressure and high temperature using a laser heated diamond anvil cell and synchrotron radiation for sample characterization. The system has been used with single-crystal and polycrystalline materials, and with glass and fluid phase. It provided high quality sound velocity and elastic data with X-ray diffraction data at high pressure and/or high temperature. Those combined techniques can potentially offer the essential information for resolving many remaining issues in mineral physics.

  12. Unusual phases in rare-earth oxide thin films: evidence for acoustic pressure wave generation during electron microscopy observations

    International Nuclear Information System (INIS)

    Rare earth oxide thin films treated under the beam in the electron microscope yield several unusual phases, some of them difficult to identify, others apparently out of thermodynamic equilibrium in the microscope conditions, especially the ROx non-stoechiometric phases (R=Ce, Pr, Tb) and the B-R2O3 phases (R=Pr, Nd). The role of impurities, notably water, is demonstrated. The presence of high pressure phases suggests that their occurrence is due to the generation of acoustic waves, possibly shock-waves, in the process of the phase formation under electron beam heating, a phenomenon which may be impurity (water) enhanced. A comparison is drawn with laser-beam impact studies on materials

  13. Raman scattering of rare earth sesquioxide Ho2O3: A pressure and temperature dependent study

    International Nuclear Information System (INIS)

    Pressure and temperature dependent Raman scattering studies on Ho2O3 have been carried out to investigate the structural transition and the anharmonic behavior of the phonons. Ho2O3 undergoes a transition from cubic to monoclinic phase above 15.5?GPa, which is partially reversible on decompression. The anharmonic behavior of the phonon modes of Ho2O3 from 80?K to 440?K has been investigated. We find an anomalous line-width change with temperature. The mode Grüneisen parameter of bulk Ho2O3 was estimated from high pressure Raman investigation up to 29?GPa. Furthermore, the anharmonic components were calculated from the temperature dependent Raman scattering.

  14. High Pressure, Earth-Storable Rocket Technology. Volume 3; Appendices C and D

    Science.gov (United States)

    Jassowski, D. M.

    1997-01-01

    The effect of elevated chamber pressure on combustion efficiency and heat transfer has been determined at the 100 lbf (445 N) thrust level for nitrogen tetroxide propellants. Measurements were made up to 500 psia (3.45 MPa) with testbed hardware; tests at 100 psia (0.690 MPa) and 250 psia (1.72 MPa) were made with radiation-cooled rhenium chambers. The first task of the program served to determine desirable thruster applications and operating conditions: high total impulse, i.e. communication satellite or spacecraft bus axial engines, at chamber pressures up to 250 psia (1.72 MPa) pressure-fed, or up to 500 psia (3.45 MPa) pump-fed. The hardware modifications and testing required to obtain the data were determined in Task 2, which included design-support hot fire tests; supplemental hardware, including a 250 psia (1.72 MPa) Pc rhenium chamber and a 20% fuel-film cooled platelet injector was fabricated in Task 3. Testing showed that satisfactory operation of Ir-Re radiation chambers is assured at pressures up to 250 psia and may be possible up to 500. The heat transfer data obtained show good correlation with throat Reynolds number and are generally under values given by the simplified Bartz equation; chambers equilibrium temperatures match predicted values. Preliminary optimization of trip configuration and mixture ratio were made; Isp performance from thrust measurements was within 1% of predicted values. Stability, compatibility, and front-end thermal management were determined to be satisfactory.

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

    CERN Document Server

    Vörös, 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...

  16. 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.

  17. Quantifying Uncertainty in the Predictions of the SimSphere Land Biosphere Model in Simulating Key Parameters Characterising Earth's Energy Balance

    Science.gov (United States)

    North, Matthew; Petropoulos, George

    2014-05-01

    Soil Vegetation Atmosphere Transfer (SVAT) models are becoming the preferred scientific tool to assess land surface energy fluxes due to their computational efficiency, accuracy and ability to provide results at fine temporal scales. An all-inclusive validation of those models is a fundamental step before those can be confidently used for any practical application or research purpose alike. SimSphere is an example of a SVAT model, simulating a large array of parameters characterising various land surface interactions over a 24 hour cycle at a 1-D vertical profile. Being able to appreciate the uncertainty of SimSphere predictions, is of vital importance towards increasing confidence in the models' overall use and ability to represent accurate land surface interactions. This is particularly important, given that its use either as a stand-alone tool or synergistically with Earth Observation (EO) data is currently expanding worldwide. In the present study, uncertainty in the SimSphere's predictions is evaluated at seven European sites, representative of a range of ecosystem conditions and biomes types for which in-situ data from the CarboEurope IP operational network acquired during 2011 were available. Selected sites are characterised by varying topographical characteristics, which further allow developing a comprehensive understanding on how topography can affect the models' ability to reproduce the variables which are evaluated. Model simulations are compared to in-situ data collected on cloud free days and on days with high Energy Balance Ratio. We focused here specifically on evaluating SimSphere capability in predicting selected variables of the energy balance, namely the Latent Heat (LE), Sensible heat (H) and Net Radiation (Rn) fluxes. An evaluation of the uncertainty in the model predictions was evaluated on the basis of extensive statistical analysis that was carried out by computing a series of relevant statistical measures. Results obtained confirmed the correspondence of the model structure to real conditions for which it had been parameterised, evidencing its ability to reproduce reasonably satisfactory the examined parameters, particularly so over flat terrain sites and specific land cover types. Given the very small number of SimSphere validation studies, our work contributes decisively towards obtaining a better understanding of the model structure and correspondence to a real world system. The latter, not only provides very important information to future model users but also is of potential key value to efforts ongoing at present by different Space Agencies examining the use of SimSphere synergistically with Earth Observation data in developing operational products at a global scale. KEYWORDS: SimSphere, Latent Heat flux, Sensible Heat fulx, Net Radiation, SVAT; Land Surface Interactions, CarboEurope.

  18. 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.

  19. Effect of chemical and hydrostatic pressures on structural and magnetic properties of rare-earth orthoferrites: a first-principles study

    International Nuclear Information System (INIS)

    The dependence of structural and magnetic properties of rare-earth orthoferrites (in their Pbnm ground state) on the rare-earth ionic radius is systematically investigated from first principles. The effects of this ‘chemical pressure’ on lattice constants, Fe–O bond lengths, Fe–O–Fe bond angles and Fe–O bond length splittings are all well reproduced by these ab initio calculations. The simulations also offer novel predictions (on tiltings of FeO6 octahedra, cation antipolar displacements and weak magnetization) to be experimentally checked. In particular, the weak ferromagnetic moment of rare-earth orthoferrites is predicted to be a linear function of the rare-earth ionic radius. Finally, the effects of applying hydrostatic pressure on structural and magnetic behavior of SmFeO3 is also studied. It is found that, unlike previously assumed, hydrostatic pressure typically generates changes in physical properties that are quantitatively and even qualitatively different from those associated with the chemical pressure. (paper)

  20. Effects of chemical and hydrostatic pressures on structural, magnetic, and electronic properties of R2NiMn O6 (R =rare -earth ion ) double perovskites

    Science.gov (United States)

    Zhao, Hong Jian; Liu, Xiao Qiang; Chen, Xiang Ming; Bellaiche, L.

    2014-11-01

    The effects of chemical and hydrostatic pressures on structural, magnetic, and electronic properties of R2NiMn O6 double perovskites, with R being a rare-earth ion, have been systematically studied by using specific first-principles calculations. These latter reproduce well the correlation between several properties (e.g., lattice parameters, Ni-O-Mn bond angles, magnetic Curie temperature, and electronic band gap) and the rare-earth ionic radius (i.e., the chemical pressure). They also provide novel predictions awaiting experimental confirmation, such as (i) that many physical quantities respond in dramatically different manners to chemical versus hydrostatic pressure, unlike as commonly thought for perovskites containing rare-earth ions, and (ii) a dependence of antipolar displacements on chemical and hydrostatic pressures, which would further explain why the recently predicted electrical polarization of L a2NiMn O6/R2NiMn O6 superlattices [H. J. Zhao, W. Ren, Y. Yang, J. Íñiguez, X. M. Chen, and L. Bellaiche, Nat. Commun. 5, 4021 (2014), 10.1038/ncomms5021] can be created and controlled by playing with the rare-earth element.

  1. The melting points of some rare-earth metal nitrides as a function of nitrogen pressure

    International Nuclear Information System (INIS)

    The melting points of LaN, CeN, PrN, NdN, and GdN were determined in an autoclave in the pressure range 10-2 to 102 atm by means of the Pirani-Alterthum technique consisting of heating compact nitride rods until melting occurs. A narrow borehole extending to the centre of the rod served as the blackbody cavity. To check the results a second method was used in which a small amount of nitride powder was placed in the apex of a V-shaped tungsten ribbon and the ribbon was heated resistively until melting was observed. Although blackbody conditions were here absent, the results obtained by the two methods were in good agreement. The nitrides were subjected to X-ray and chemical analysis before and after melting. (author)

  2. 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.

  3. 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.

  4. Estudio experimental del empuje sobre estructuras de contención 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 artículo presenta un estudio experimental de la variación de las tensiones de empuje sobre una pared que soporta un suelo reforzado con geomallas. Para ello se utilizó un equipo diseñado y construido especialmente para ejecutar ensayos de empuje bajo condiciones de deformación plana. Se describ [...] e el equipo de ensayo y los instrumentos de medición, así como el suelo y la preparación de las muestras de arena y la geomalla utilizada. En la primera etapa de la investigación se ensayan muestras sin reforzar y se comparan los resultados con aquellos provenientes de las teorías clásicas 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 incorporación de geomallas como refuerzo en el suelo disminuye el empuje ejercido por el suelo sobre la estructura de contención. Esta disminución 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. Resultó posible identificar que la distribución de la tensión de empuje con la profundidad no sólo no sigue la variación 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.

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

    Directory of Open Access Journals (Sweden)

    Lissette Ruiz-Tagle

    2011-12-01

    Full Text Available Este artículo presenta un estudio experimental de la variación de las tensiones de empuje sobre una pared que soporta un suelo reforzado con geomallas. Para ello se utilizó un equipo diseñado y construido especialmente para ejecutar ensayos de empuje bajo condiciones de deformación plana. Se describe el equipo de ensayo y los instrumentos de medición, así como el suelo y la preparación de las muestras de arena y la geomalla utilizada. En la primera etapa de la investigación se ensayan muestras sin reforzar y se comparan los resultados con aquellos provenientes de las teorías clásicas 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 incorporación de geomallas como refuerzo en el suelo disminuye el empuje ejercido por el suelo sobre la estructura de contención. Esta disminución 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. Resultó posible identificar que la distribución de la tensión de empuje con la profundidad no sólo no sigue la variación triangular sino que se desarrollan arcos de tensiones en el suelo entre las geomallas.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 plain 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.

  6. 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

  7. In-situ sound velocity measurements at high pressure and high temperature using Brillouin spectroscopy with synchrotron radiation and infrared laser heating system. Application to the deep earth science

    International Nuclear Information System (INIS)

    Average composition and structure of the Earth's deep interior can be approached by comparing observed seismic velocities to appropriate laboratory sound velocity data collected for candidate minerals under relevant pressure and temperature conditions. Simultaneous measurement of sound velocities and densities also enable us to construct a primary pressure scale, which can independently determine the pressure. Our newly developed high-pressure and high-temperature sound velocity measurement system using Brillouin spectroscopy with synchrotron radiation and infrared laser heating techniques has proven to be highly suitable for establishments of Earth's mineralogical model and the primary pressure scale. (author)

  8. 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,...

  9. Predicted pressure-induced spin and electronic transition in double perovskite R2CoMnO6 (R = rare-earth ion)

    Science.gov (United States)

    Zhao, Hong Jian; Zhou, Haiyang; Chen, Xiang Ming; Bellaiche, L.

    2015-06-01

    Specific first-principles calculations are performed to predict structural, magnetic and electronic properties of seven double perovskite R2CoMnO6 materials, with R being a rare-earth ion, under hydrostatic pressure. All these compounds are found to undergo a first-order transition from a high spin (HS) to low spin (LS) state at a critical pressure (whose value is dependent on the R ion). Such transition not only results in a significant volume collapse but also yields a dramatic change in electronic structure. More precisely, the HS-to-LS transition is accompanied by a transition from an insulator to a half-metallic state in the R2CoMnO6 compounds having the largest rare-earth ionic radius (i.e., Nd, Sm, Gd and Tb) while it induces a change from an insulator to a semiconductor having a narrow band gap for the smallest rare-earth ions (i.e., R = Dy, Ho and Er). Experiments are called for to confirm these predictions.

  10. Pr4B10O21: A new composition of rare-earth borates by high-pressure/high-temperature synthesis

    International Nuclear Information System (INIS)

    High-pressure chemistry led to the synthesis of the rare-earth borate Pr4B10O21 using a Walker-type multianvil apparatus at 3.5 GPa and 1050 deg. C. The tetra-praseodymium(III)-decaborate crystallizes monoclinicly with four formula units in the space group P21/n and lattice parameters of a=710.2(2), b=1948.8(4), c=951.6(2) pm, and ?=93.27(3)o. The boron-oxygen network consists of [BO4]5- tetrahedra and [BO3]3- groups; however, the [BO4]5- groups represent the major part (80%) due to the high-pressure conditions during the synthesis. The praseodymium ions are coordinated by 10 and 12 oxygen atoms. Along with a detailed description of the crystal structure, temperature programmed X-ray powder diffraction data are shown, demonstrating the metastable character of this compound. - Graphical abstract: Synthesis of Pr4B10O21 via the multianvil high-pressure/high-temperature technique representing a new composition of rare-earth borates

  11. Análise da pressão plantar e do equilíbrio postural em diferentes fases da gestação 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 pressão plantar e o equilíbrio postural nos três trimestres de gravidez, bem como a correlação com as características antropométricas. METODOLOGIA: 60 voluntárias com idade média de 23,3 ± 5,5 anos, sendo 15 mulheres em cada grupo: não-gestantes (C, primeiro (1T, segundo (2T e terceiro trimestre (3T. A avaliação foi efetuada por meio de plataforma de pressão na posição bipodal com os olhos abertos. As variáveis analisadas nos pés direito e esquerdo foram: pico de pressão em todo o pé (PT, no antepé (PA e no retropé (PR; distância entre a borda medial dos pés (largura da base de suporte; distância do centro de força ao limite anterior (CFF e posterior (CFC dos pés; deslocamento ântero-posterior (AP e médio--lateral (ML do centro de força; e área de contato (AC. RESULTADOS: Não houve diferença no pico de pressão de contato e na distância CFF e CFC entre os grupos. O deslocamento AP foi maior (p 0,05 entre os grupos para o deslocamento ML. Houve correlação positiva entre peso ganho durante a gestação com AC para o grupo 2T e com PT no pé direito do grupo 1T. CONCLUSÃO: Os resultados demonstram a influência das mudanças anatômicas e fisiológicas inerentes à gestação na pressão plantar, além de sugerir uma redução do equilíbrio 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.

  12. Análise da pressão plantar e do equilíbrio postural em diferentes fases da gestação / 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 pressão plantar e o equilíbrio postural nos três trimestres de gravidez, bem como a correlação com as características antropométricas. METODOLOGIA: 60 voluntárias com idade média de 23,3 ± 5,5 anos, sendo 15 mulheres em cada grupo: não-gestantes (C), primeiro (1T), segundo (2T) [...] e terceiro trimestre (3T). A avaliação foi efetuada por meio de plataforma de pressão na posição bipodal com os olhos abertos. As variáveis analisadas nos pés direito e esquerdo foram: pico de pressão em todo o pé (PT), no antepé (PA) e no retropé (PR); distância entre a borda medial dos pés (largura da base de suporte); distância do centro de força ao limite anterior (CFF) e posterior (CFC) dos pés; deslocamento ântero-posterior (AP) e médio--lateral (ML) do centro de força; e área de contato (AC). RESULTADOS: Não houve diferença no pico de pressão de contato e na distância CFF e CFC entre os grupos. O deslocamento AP foi maior (p 0,05) entre os grupos para o deslocamento ML. Houve correlação positiva entre peso ganho durante a gestação com AC para o grupo 2T e com PT no pé direito do grupo 1T. CONCLUSÃO: Os resultados demonstram a influência das mudanças anatômicas e fisiológicas inerentes à gestação na pressão plantar, além de sugerir uma redução do equilíbrio 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.

  13. High Pressure Melting, Phase Diagrams, and Equations of State in the Fe-FeSi System with Application to Earth's Core

    Science.gov (United States)

    Fischer, R. A.; Campbell, A. J.; Reaman, D. M.; Heinz, D. L.; Dera, P. K.; Prakapenka, V.

    2012-12-01

    The Earth's core is comprised mostly of iron, with some nickel and several weight percent of one or more light elements. The light element(s) dictate phase relations, structure, and dynamic behaviour, so it is crucial to evaluate various candidates at conditions of planetary interiors. We present results on high P-T phase diagrams and equations of state in the Fe-FeSi system with application to the structure and composition of Earth's core. X-ray diffraction measurements were performed on stoichiometric FeSi and on Fe-Si alloys containing 9 and 16 wt% silicon in a laser-heated diamond anvil cell at the APS, NSLS, and ALS. Pressures were determined from the lattice parameter of KBr. We have investigated the phase diagram of Fe-9Si to 100 GPa and over 3000 K. Our melting curve agrees with previous results on similar alloys [1,2], as demonstrated using multiple methods of detecting melting. Our subsolidus results are similar to those of Lin et al. [3], though we find the B2 structure instead of bcc, and a shallower slope for the hcp+B2 to fcc+B2 boundary. We studied phase relations of Fe-16Si to over 135 GPa, finding agreement with previous melting curves [2,4]. Below 45 GPa, this alloy has the D0_3 structure. At high pressures, Fe-16Si breaks down into a mixture of B2 and hcp phases, with this mixture stable to pressures of the Earth's outer core. This is the first study on the B2 phase of FeSi with in situ X-ray diffraction at high pressures and temperatures. We report a wide B2+B20 two-phase field in FeSi, with complete conversion to the B2 structure by ~42 GPa. A melting experiment on FeSi agrees with the results of Lord et al. [5]. We have synthesized our results with previous studies to construct T-X and P-X phase diagrams, and we have determined thermal equations of state of each alloy. Our measured densities can be used to constrain the maximum amount of silicon in the Earth's outer core by comparison to the equation of state of hcp-Fe [6] and the seismologically-determined density. Assuming a core-mantle boundary (CMB) temperature of 4000 +/- 500 K and a 1-2% density decrease upon melting, the amount of silicon in the outer core required to match PREM at the CMB is 11.3 +/- 1.5 weight percent, under the simplifying assumption of a purely Fe-Ni-Si outer core. The minimum temperature of an Fe-Si outer core is 4380 K, based on the eutectic melting point of Fe-FeSi alloys, and silicon is shown not to significantly depress the melting point of iron at core conditions. At the highest pressures reached, only the hcp and B2 structures are seen in the Fe-FeSi system. We predict that alloys containing more than ~4-8 wt% Si will convert to an hcp+B2 mixture and later to the hcp structure with increasing pressure, and that an iron-silicon alloy in the Earth's inner core would most likely be a mixture of hcp and B2 phases. [1] Kuwayama and Hirose (2004) Am Mineral 89, 273-276 [2] Morard et al. (2011) PCM 38, 767-776 [3] Lin et al (2002) Science 295, 313-315 [4] Asanuma et al. (2010) PCM 37, 353-359 [5] Lord et al. (2010) JGR 115, B06208 [6] Dewaele et al. (2006) PRL 97, 215504

  14. 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).

  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. Ab initio MD simulations of Mg2SiO4 liquid at high pressures and temperatures relevant to the Earth's mantle

    Science.gov (United States)

    Martin, G. B.; Kirtman, B.; Spera, F. J.

    2010-12-01

    Computational studies implementing Density Functional Theory (DFT) methods have become very popular in the Materials Sciences in recent years. DFT codes are now used routinely to simulate properties of geomaterials—mainly silicates and geochemically important metals such as Fe. These materials are ubiquitous in the Earth’s mantle and core and in terrestrial exoplanets. Because of computational limitations, most First Principles Molecular Dynamics (FPMD) calculations are done on systems of only 100 atoms for a few picoseconds. While this approach can be useful for calculating physical quantities related to crystal structure, vibrational frequency, and other lattice-scale properties (especially in crystals), it would be useful to be able to compute larger systems especially for extracting transport properties and coordination statistics. Previous studies have used codes such as VASP where CPU time increases as N2, making calculations on systems of more than 100 atoms computationally very taxing. SIESTA (Soler, et al. 2002) is a an order-N (linear-scaling) DFT code that enables electronic structure and MD computations on larger systems (N 1000) by making approximations such as localized numerical orbitals. Here we test the applicability of SIESTA to simulate geosilicates in the liquid and glass state. We have used SIESTA for MD simulations of liquid Mg2SiO4 at various state points pertinent to the Earth’s mantle and congruous with those calculated in a previous DFT study using the VASP code (DeKoker, et al. 2008). The core electronic wave functions of Mg, Si, and O were approximated using pseudopotentials with a core cutoff radius of 1.38, 1.0, and 0.61 Angstroms respectively. The Ceperly-Alder parameterization of the Local Density Approximation (LDA) was used as the exchange-correlation functional. Known systematic overbinding of LDA was corrected with the addition of a pressure term, P 1.6 GPa, which is the pressure calculated by SIESTA at the experimental zero-pressure volume of forsterite under static conditions (Stixrude and Lithgow-Bertollini 2005). Results are reported here that show SIESTA calculations of T and P on densities in the range of 2.7 - 5.0 g/cc of liquid Mg2SiO4 are similar to the VASP calculations of DeKoker et al. (2008), which used the same functional. This opens the possibility of conducting fast /emph{ab initio} MD simulations of geomaterials with a hundreds of atoms.

  17. 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.

  18. Anorthite: Thermal equation of state to high pressures. [for comparison with Earth interior and cratering properties of lunar surface

    Science.gov (United States)

    Jeanloz, R.; Ahrens, T. J.

    1979-01-01

    The shock wave (Hugoniot) data on single crystal and porous anorthite (CaAl2Si208) to pressures of 120 GPa are presented. These data are inverted to yield high pressure values of the Grueneisen parameter, adiabatic bulk modulus, and coefficient of thermal expansion over a broad range of pressures and temperatures which in turn are used to reduce the raw Hugoniot data and construct an experimentally based, high pressure thermal equation of state for anorthite. The hypothesis that higher order anharmonic contributions to the thermal properties decrease more rapidly upon compression than the lowest order anharmonicities is supported. The properties of anorthite corrected to lower mantle conditions show that although the density of anorthite is comparable to that of the lower most mantle, its bulk modulus is considerably less, hence making enrichment in the mantle implausible except perhaps near its base.

  19. Pressure-induced valence and structure change in some anti-Th3P4 structure rare earth compounds

    International Nuclear Information System (INIS)

    The anti-Th3P4 structure compounds Yb4Bi3 and Yb4Sb3 have been investigated to 350 kbar by high pressure X-ray diffraction, using the diamond anvil cell. From the P-V data it is found that Yb4Bi3 and Yb4Sb3 are much more compressible, compared to Sm4Bi3 before the valence transition. This suggests that a continuous change in the valence state of Yb takes place with pressure in the two compounds and that they may be in the mixed valent state already at ambient pressure. The ''collapsed'' anti-Th3P4 structure becomes unstable in Yb4Bi3 and Yb4Sb3 and new lines appear at high pressure, that fit the NaCl structure. The latter structure change seems to occur also in the electronically collapsed Sm4Bi3. The results are presented and discussed. (Auth.)

  20. Coupled orbit-attitude dynamics of high area-to-mass ratio (HAMR) objects: influence of solar radiation pressure, Earth's shadow and the visibility in light curves

    Science.gov (United States)

    Früh, Carolin; Kelecy, Thomas M.; Jah, Moriba K.

    2013-12-01

    The orbital and attitude dynamics of uncontrolled Earth orbiting objects are perturbed by a variety of sources. In research, emphasis has been put on operational space vehicles. Operational satellites typically have a relatively compact shape, and hence, a low area-to-mass ratio (AMR), and are in most cases actively or passively attitude stabilized. This enables one to treat the orbit and attitude propagation as decoupled problems, and in many cases the attitude dynamics can be neglected completely. The situation is different for space debris objects, which are in an uncontrolled attitude state. Furthermore, the assumption that a steady-state attitude motion can be averaged over data reduction intervals may no longer be valid. Additionally, a subset of the debris objects have significantly high area-to-mass ratio (HAMR) values, resulting in highly perturbed orbits, e.g. by solar radiation pressure, even if a stable AMR value is assumed. Note, this assumption implies a steady-state attitude such that the average cross-sectional area exposed to the sun is close to constant. Time-varying solar radiation pressure accelerations due to attitude variations will result in un-modeled errors in the state propagation. This work investigates the evolution of the coupled attitude and orbit motion of HAMR objects. Standardized pieces of multilayer insulation (MLI) are simulated in a near geosynchronous orbits. It is assumed that the objects are rigid bodies and are in uncontrolled attitude states. The integrated effects of the Earth gravitational field and solar radiation pressure on the attitude motion are investigated. The light curves that represent the observed brightness variations over time in a specific viewing direction are extracted. A sensor model is utilized to generate light curves with visibility constraints and magnitude uncertainties as observed by a standard ground based telescope. The photometric models will be needed when combining photometric and astrometric observations for estimation of orbit and attitude dynamics of non-resolved space objects.

  1. Orbital dynamics of high area-to-mass ratio spacecraft with J2 and solar radiation pressure for novel Earth observation and communication services

    Science.gov (United States)

    Colombo, Camilla; Lücking, Charlotte; McInnes, Colin R.

    2012-12-01

    This paper investigates the effect of planetary oblateness and solar radiation pressure on the orbits of high area-to-mass spacecraft. A planar Hamiltonian model shows the existence of equilibrium orbits with the orbit apogee pointing towards or away from the Sun. These solutions are numerically continued to non-zero inclinations and considering the obliquity of the ecliptic plane relative to the equator. Quasi-frozen orbits are identified in eccentricity, inclination and the angle between the Sun-line and the orbit perigee. The long-term evolution of these orbits is then verified through numerical integration. A set of 'heliotropic' orbits with apogee pointing in the direction of the Sun is proposed for enhancing imaging and telecommunication on the day side of the Earth. The effects of J2 and solar radiation pressure are exploited to obtain a passive rotation of the apsides line following the Sun; moreover the effect of solar radiation pressure enables such orbits at higher eccentricities with respect to the J2 only case.

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

    Science.gov (United States)

    Khenata, R.; Sahnoun, M.; Baltache, H.; Rérat, M.; Rached, D.; Driz, M.; Bouhafs, B.

    2006-01-01

    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.

  3. 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

  4. The analytical modeling of planetary exospheres: a) the satellite particles at Earth, Titan and Mars, b) the influence of the radiation pressure on the ballistic and escaping particles density profiles

    Science.gov (United States)

    Beth, A.; Garnier, P.; Toublanc, D.; Dandouras, I. S.; Mazelle, C. X.

    2013-12-01

    a) The planetary exospheres are poorly known in their outer parts, since the neutral densities are low compared with the instruments detection capabilities. The exospheric models are thus often the main source of information at such high altitudes. We revisit here the importance of a specific exospheric population, i.e. the satellite particles, which is usually neglected in the models (see also Beth et al., Icarus, accepted). These particles are indeed produced through rare collisions in the exospheres, and may either be negligible or dominate the exospheres of all planets with dense atmospheres in our solar system, depending on the balance between their sources and losses. Richter et al. (1979) were the first to propose, beyond the Chamberlain's (Chamberlain (1963)) rough approximation, a rigorous approach for these particles by using the Boltzmann equation in the Earth exosphere below 3000 km altitude. We here further investigate this approach and determine the contribution of satellite populations to the densities of light elements at Titan (H2 species) and Mars (H species). The results confirm that the Chamberlain approximation overestimates the satellite particles densities at high altitudes, but that there may be enough collisions to produce a significant amount of satellite particles in some conditions, up to more than 50% of the contributions due to ballistic and escaping populations (i.e. those considered in the collisionless models) in the case of Mars or even 36% at Titan. This suggests that considering collisionless exospheric profiles for light species can lead to an underestimation of the total densities at high altitudes. b) We also present a new analytical approach to understand the structure of the exospheres submitted to the radiation pressure and determine the densities of others populations, i.e. ballistic and escaping particles, using the Liouville theorem and Hamiltonian mechanics. Our modeling work will in particular enable to better understand the future observations by the MAVEN mission at Mars, planned to be launched in November 2013.

  5. Low pressure ion chromatography with a low cost paired emitter-detector diode based detector for the determination of alkaline earth metals in water samples

    International Nuclear Information System (INIS)

    The use of a low pressure ion chromatograph based upon short (25 mm x 4.6 mm) surfactant coated monolithic columns and a low cost paired emitter-detector diode (PEDD) based detector, for the determination of alkaline earth metals in aqueous matrices is presented. The system was applied to the separation of magnesium, calcium, strontium and barium in less than 7 min using a 0.15 M KCl mobile phase at pH 3, with post-column reaction detection at 570 nm using o-cresolphthalein complexone. A comparison of the performance of the PEDD detector with a standard laboratory absorbance detector is shown, with limits of detection for magnesium and calcium using the low cost PEDD detector equal to 0.16 and 0.23 mg L-1, respectively. Finally, the developed system was used for the determination of calcium and magnesium in a commercial spring water sample

  6. High-Pressure High-Temperature Equation of State of B1 Cobalt Oxide and Implications for Redox Relations in the Earth's Lower Mantle

    Science.gov (United States)

    Kavner, A.; Armentrout, M. M.

    2012-12-01

    First row transition metals play important roles in the Earth's mantle by influencing minerals' phase stability, density and elastic properties, and helping to govern defect-mediated behavior including electrical and thermal conductivity, and rheology. Since transition metals are also somewhat siderophile, geochemical measurements of absolute and relative abundances of transition metals in mantle-derived rocks helps constrain the evolution of the core/mantle system, including initial segregation and continuing reactions. Interpreting the geochemical record in terms of partitioning of transition metals among oxide and metal phases requires measurements of thermoelastic properties of the oxide and metal phases at the high pressure and temperature conditions of the Earth's interior. The high pressure and temperature equation of state of rocksalt-structured cobalt oxide was measured up to 65 GPa and 2600 K using synchrotron X-ray diffraction in conjunction with the laser heated diamond anvil cell. We determine the best fit equation of state parameters to be V0=77.4 (fixed) Å3, K0T=190 (1) GPa, dK/dP =3.49 (4), ?0=1.54 (4), q=2.87 (15), and ?0=517.8 (fixed), using a Mie-Gruneisen-Debye parameterization. We use these values in conjunction with existing measurements of the cobalt metal equation of state to calculate chemical free energy differences between the cobalt oxide and cobalt metal phases as a function of pressure and temperature. A comparison of the Co/CoO with Ni/NiO system energetics (Campbell et al. 2009) predicts a crossing point at 55 GPa and 2000 K. This energy crossing point in energy can be mapped as a crossing point in electrochemical potential of the two metal ions, suggesting that the Ni becomes more siderophile than Co as pressure and temperature increases. This result is in good agreement with existing measurements of Ni and Co partition coefficients between mantle and core materials (O'Neill et al. 1998; Bouhifd and Jephcoat 2011).

  7. 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.

  8. 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)

  9. Number Balance

    Science.gov (United States)

    This activity promotes algebraic thinking of equivalency as well as giving children practice in addition and subtraction. Students see weights on each side of a balance, and are asked to find ways they can hang a weight or two weights to balance the bar. An interactive balance allows student to explore the different ways weights can be added to balance or equalize the bars. A more challenging problem,"Getting the Balance" is cataloged separately. The Teachers' Notes page offers rationale, suggestions for implementation, discussion questions, ideas for extension and support.

  10. 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.

  11. Potassium-bearing Iron-Nickel Sulfides in Nature and High-Pressure Experiments: Geochemical Consequences of Potassium in the Earth's Core

    Science.gov (United States)

    Keshav, S.; Corgne, A.; McDonough, W. F.; Fei, Y.

    2005-01-01

    Introduction: Potassium (K) as a large ion lithophile element has dominantly been concentrated in the Earth s crust and the mantle through differentiation, and in the form of K-40 contributes to the planet s heat budget. However, whether or not K also enters core-forming phases, has been debated for over three decades. Arguments favoring entry of K in the core are based on: (1) K-sulfide (with Fe, Ni, Cu, Na, and Cl; djerfisherite) found in highly reduced enstatite chondrites (or aubrites, enstatite achondrites); (2) demonstration that K, owing to an s-d electronic switch at high-pressure, exhibits transition- element like character, (3) solubility of measurable K in Fe-Ni-S liquids at high pressure, temperature conditions, and (4) models of cooling of the core that seem to require, besides convection, some form of radioactivity, and thus lending support to the experimental work. In this contribution, we assess the effect of sequestering K in the core, as it is perhaps an element that is a key to reconciling geochemistry, paleomagnetism, accretion, and thermal evolution models for the planet.

  12. Ce2B8O15. High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new 'Fundamental Building Block'

    International Nuclear Information System (INIS)

    The new cerium polyborate Ce2B8O15 was synthesized under high-pressure/high-temperature conditions of 6 GPa and 1050 C in a Walker-type multianvil apparatus. The single-crystal structure determination revealed that the new compound crystallizes in the space group P2/c with the lattice parameters a = 916.6(2), b = 421.0(1), c = 1248.9(3) pm, ? = 116.7(1) , V = 0.4303(2) nm3, R1 = 0.0356, and wR2 = 0.0504. The crystal structure of Ce2B8O15 exhibits a new fundamental building block (FBB) in borate chemistry that consists of four BO4 tetrahedra and can be written as 4?: [?] left angle 3? right angle vertical stroke ? vertical stroke. These FBB are interconnected via common corners, forming a complex threedimensional network that contains the Ce3+ cations. Ce2B8O15 represents the most boron rich rare-earth borate synthesized under high-pressure/high-temperature conditions so far. We report about the synthetic conditions, structural details, thermal behaviour, and the IR/Raman spectra of Ce2B8O15. (orig.)

  13. 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.

  14. 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

  15. Coupled Orbit-Attitude Dynamics of High Area-to-Mass Ratio (HAMR) Objects: Influence of Solar Radiation Pressure, Earth's Shadow and the Visibility in Light Curves

    CERN Document Server

    Frueh, Carolin; Kelecy, Thomas

    2013-01-01

    The orbital and attitude dynamics of uncontrolled Earth orbiting objects are perturbed by a variety of sources. In research, emphasis has been put on operational space vehicles. Operational satellites typically have a relatively compact shape, and hence, a low area-to-mass ratio (AMR), and are in most cases actively or passively attitude stabilized. This enables one to treat the orbit and attitude propagation as decoupled problems, and in many cases the attitude dynamics can be neglected completely. The situation is different for space debris objects, which are in an uncontrolled attitude state. Furthermore, the assumption that a steady-state attitude motion can be averaged over data reduction intervals may no longer be valid. Additionally, a subset of the debris objects have significantly high area-to-mass ratio values, resulting in highly perturbed orbits, e.g. by solar radiation pressure, even if a stable AMR value is assumed. This assumption implies a steady-state attitude such that the average cross-sect...

  16. Estudo da sinterização da zircônia dopada com óxidos de terras raras a 5 GPa de pressão / Sintering of rare earth-doped zirconia under 5 GPa pressure

    Scientific Electronic Library Online (English)

    C., Kuranaga; F. S. de Azevedo, Ribeiro; M., Filgueira.

    2005-06-01

    Full Text Available A zircônia (ZrO2) tem mostrado grande destaque entre as cerâmicas avançadas, atraindo muito o interesse de pesquisadores em seus vários campos de atuação. A zircônia apresenta elevada resistência quando na fase tetragonal, mas a fase estável a temperatura ambiente é a monoclínica, sendo necessário o [...] uso de estabilizantes para a fase tetragonal. Neste trabalho propomos a sinterização rápida da zircônia parcialmente estabilizada com óxidos de terras raras (ZrO2-OTR), mediante o emprego da alta pressão de 5 GPa. As condições de sinterização realizadas neste trabalho são inovadoras, haja visto que utilizou-se de tecnologia alternativa para processar a ZrO2-OTR, chamada de altas temperaturas e altas pressões (HPHT). Foi utilizada uma pressão de 5 GPa, temperaturas de 1100, 1200 e 1300 ºC nos tempos de 2 e 5 min. O melhor resultado foi obtido nas amostras sinterizadas a 5 GPa/1300 ºC/5 min, onde apresentaram microdureza média de 488,73 kgf/mm², para uma tenacidade à fratura de 5,33 MPa.m½, as quais apresentaram densidade da ordem de 97,88% da teórica, e 88% em volume de fase tetragonal retida à temperatura ambiente. Abstract in english Zirconia (ZrO2) has shown great projection among the advanced ceramics, attracting the interest of researchers in its various fields of application. Tetragonal zirconia presents high mechanical strength, but the room temperature stable phase is the monoclinic, being necessary the use of stabilizers [...] for obtaining the tetragonal phase. In this work the rapid sintering of zirconia partially stabilized with rare earth oxides (ZrO2-OTR), via 5 GPa high pressure is proposed. The sintering conditions employed in this work are innovative, due to the use of an alternative technology to process ZrO2-OTR, so called high temperature - high pressure (HPHT). A pressure of 5 GPa and temperatures of 1100, 1200 and 1300 ºC for times of 2 and 5 min were used. The best results were obtained for samples sintered at 5 GPa at 1300 ºC/5 min., where a micro-hardness of 488,73 kgf/mm², a fracture toughness of 5,33 MPa.m½, a density of 97,88%, and a 88vol.% of tetragonal phase retained at room temperature were achieved.

  17. Balance Checklist

    Science.gov (United States)

    ... Clinical Exercise Specialist CSU FallPROOF Balance & Mobility Specialist Pilates Institute of America Exercise Director, Parkinson Association of ... be improved with abdominal and back exercises or Pilates mat work. Lower body and ankle flexibility, which ...

  18. 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)

  19. Microstructure and property evaluation of high-pressure die-cast Mg–La–rare 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 Mg–La–Nd, Mg–La–Y and Mg–La–Gd 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 Mg–La-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 Mg–La–Y and Mg–La–Gd than Mg–La–Nd 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 Mg–La–Nd. A model using the temperature–fraction solid curves as input parameters was used to estimate hot tearing susceptibility for Mg–La–Nd alloys. Tensile testing at room temperature showed that Mg–La–Nd alloy series had higher 0.2% proof stress and lower elongation to failure than either the Mg–La–Y or the Mg–La–Gd alloy series for Nd concentrations greater than 1 wt.% due to a greater effectiveness of grain boundary reinforcement

  20. Microstructure and property evaluation of high-pressure die-cast Mg–La–rare earth (Nd, Y or Gd) alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gavras, Serge, E-mail: serge.gavras@monash.edu [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Easton, Mark A. [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia); Gibson, Mark A. [CAST CRC, CSIRO Process Science and Engineering, Clayton South 3168 (Australia); Zhu, Suming; Nie, Jian-Feng [CAST CRC, Department of Materials Engineering, Monash University, Victoria 3800 (Australia)

    2014-06-01

    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 Mg–La–Nd, Mg–La–Y and Mg–La–Gd 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 Mg–La-rich eutectic with increasing Nd, Y or Gd content and containing a Mg{sub 12}RE 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 Mg–La–Y and Mg–La–Gd than Mg–La–Nd 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 Mg–La–Nd. A model using the temperature–fraction solid curves as input parameters was used to estimate hot tearing susceptibility for Mg–La–Nd alloys. Tensile testing at room temperature showed that Mg–La–Nd alloy series had higher 0.2% proof stress and lower elongation to failure than either the Mg–La–Y or the Mg–La–Gd alloy series for Nd concentrations greater than 1 wt.% due to a greater effectiveness of grain boundary reinforcement.

  1. Investigation of electron parallel pressure balance in the scrape-off layer of deuterium-based radiative divertor discharges IN DIII-D

    International Nuclear Information System (INIS)

    Electron density, temperature, and parallel pressure measurements at several locations along field lines connecting the midplane scrapeoff layer (SOL) with the outer divertor are presented for both attached and partially-detached divertor cases: Ip = 1.4 MA, q95 = 4.2, and Pinput ? 6.7 MW under ELMing H-mode conditions. At the onset of the Partially Detached Divertor (PDD), a high density, low temperature plasma forms in the divertor SOL (divertor MARFE). The electron pressure drops by a factor of ? 2 between the midplane separatrix and the X-point, and then an additional ?3--5 times between the X-point and the outboard separatrix strike point. These results are in contrast to the attached (non-PDD) case, where electron pressure in the SOL is reduced by, at most, a factor of two between the midplane and the divertor target. Divertor MARFEs generally have only marginal adverse impact on important H-mode characteristics, such as confinement time. In fact, PDD discharges at low input power maintains good H-mode characteristics until a high density, low temperature plasma abruptly forms inside the separatrix near the X-point (X-point MARFE). Concurrent with the appearance of this X-point MARFE is a degradation in both energy confinement and the plasma fueling rate, and an increase in the carbon impurity concentration inside the core plasma. The formation of the X-point MARFE is consistent with a thermal instability resulting from the temperature dependence of the carbon radiative cooling rate in the range ? 7--30 eV

  2. Uniqueness of Herndon's Georeactor: Energy Source and Production Mechanism for Earth's Magnetic Field

    CERN Document Server

    Herndon, J Marvin

    2009-01-01

    Herndon's georeactor at the center of Earth is immune to meltdown, which is not the case for recently published copy-cat georeactors, which would necessarily be subject to hot nuclear fuel, prevailing high temperature environments, and high confining pressures. Herndon's georeactor uniquely is expected to be self-regulating through establishing a balance between heat production and actinide settling out. The seven decade old idea of convection in the Earth's fluid core is refuted because thermal expansion cannot overcome the 23 percent higher density at the core's bottom than at its top. Some implications of geomagnetic field production within Herndon's georeactor are briefly described.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. Air Pressure, Height and Temperature

    Science.gov (United States)

    John Nielsen-Gammon

    1996-01-01

    This undergraduate meteorology tutorial uses the balancing of gravity/centrifugal forces and the vertical pressure gradient with the ideal gas law to explain how pressure, temperature, and height are related in the atmosphere.

  8. 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.

  9. Automated pressure regulator

    International Nuclear Information System (INIS)

    A pressure regulator has been constructed that automatically nulls a sensitive differential pressure indicator of the type used in high-quality PVT experiments, thus permitting at least partial automation of such experiments. Distinguishing features are: high resolution, sufficient rigidity for operation in a pressure range up to 100 MPa, and a control logic that permits nulling of the pressure transducer, even if the initial state is very far from balance

  10. Number Balance

    Science.gov (United States)

    Dan Bunker

    2005-01-01

    This open-ended interactive Flash applet helps students develop operation and number sense, facility with number facts, and understanding of equations. Users designate single-digit whole numbers or integers and operations on both sides of an equation and test for balance. Users can enter numbers by using the keyboard or arrow buttons or by dragging number tiles. Each element can be hidden and a seesaw may be toggled on/off. Teachers may use this applet to lead instruction, or students may use it independently to perform specific investigations or explore freely. Supplementary documents include Objectives, containing teaching suggestions, and a student recording sheet.

  11. Social Balance Theory

    OpenAIRE

    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 ...

  12. Dynamical balance in the Indonesian Seas circulation

    Science.gov (United States)

    Burnett, William H.; Kamenkovich, Vladimir M.; Jaffe, David A.; Gordon, Arnold L.; Mellor, George L.

    2000-09-01

    A high resolution, four-open port, non-linear, barotropic ocean model (2D POM) is used to analyze the Indonesian Seas circulation. Both local and overall momentum balances are studied. It is shown that geostrophy holds over most of the area and that the Pacific-Indian Ocean pressure difference is essentially balanced by the resultant of pressure forces acting on the bottom.

  13. Optical absorption and determination of band offset in strain-balanced GaInP/InAsP multiple quantum wells grown by low-pressure metalorganic vapour phase epitaxy

    Science.gov (United States)

    Ababou, Y.; Desjardins, P.; Chennouf, A.; Masut, R. A.; Yelon, A.; Beaudoin, M.; Bensaada, A.; Leonelli, R.; L'Espérance, G.

    1997-05-01

    We report on optical absorption of the interband transitions in zero-net strained 0268-1242/12/5/006/img12 multiple quantum wells (MQW) grown by low-pressure metalorganic vapour phase epitaxy (LP-MOVPE), using tertiarybutylarsine as a group V source. Sharp interfaces are obtained using a growth interruption procedure. Analysis of this procedure with different interruption times leads to the same optimal times as those obtained for InP/InAsP superlattices grown in the same reactor. We have achieved the growth of modulation-free strain-balanced heterostructures, as indicated by cross-sectional transmission electron microscopy. High-resolution x-ray diffraction and optical absorption analysis demonstrate the high crystallographic and optical quality of these structures. The absorption spectrum of an x = 0.06, y = 0.14 sample was accurately fitted using the Bastard/Marzin model, and a strained conduction band offset of 0268-1242/12/5/006/img13 was deduced. This corresponds to about 0268-1242/12/5/006/img14 of the total strained bandgap difference.

  14. Estudio experimental y numérico del desplazamiento y rotación 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

    Scientific Electronic Library Online (English)

    Lissette, Ruiz-Tagle; Felipe, Villalobos.

    Full Text Available Se presenta un estudio experimentaly numérico de desplazamiento y rotación de suelo sin y con refuerzo de geomallas bajo la acción del empuje activo. Para ello se ha usado la técnica de medición PIV con la cual se procesan imágenes digitales para la obtención de campos de desplazamiento y rotación. [...] 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 áreas de suelo que fluyen y no fluyen debido a la acción del empuje activo. De esta manera se puede determinar la posición y geometría de la superficie de falla, la cual se puede comparar con la definida por la teoría de la plasticidad de empuje activo de Rankine. Esta comparación 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 conclusión relacionada con la deformación del suelo está en directa relación con la disminución de la tensión de empuje activo al utilizar geomallas como elementos de refuerzo. También se presenta un análisis numérico usando el programa computacional Plaxis para estimar los desplazamientos horizontales. Los resultados numéricos entregan estimaciones que se aproximan a los resultados medidos de desplazamientos horizontales en términos de la forma de la zona de suelo en fluencia. Sin embargo, no son capaces de reproducir en detalle la geometría de la superficie de falla. Abstract in english 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 dis [...] placement 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. Estudio experimental y numérico del desplazamiento y rotación 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 numérico de desplazamiento y rotación de suelo sin y con refuerzo de geomallas bajo la acción del empuje activo. Para ello se ha usado la t?cnica de medición PIV con la cual se procesan imágenes digitales para la obtención de campos de desplazamiento y rotación. 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 áreas de suelo que fluyen y no fluyen debido a la acción del empuje activo. De esta manera se puede determinar la posición y geometría de la superficie de falla, la cual se puede comparar con la definida por la teoría de la plasticidad de empuje activo de Rankine. Esta comparación 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 conclusión relacionada con la deformación del suelo está en directa relación con la disminución de la tensión de empuje activo al utilizar geomallas como elementos de refuerzo. También se presenta un análisis numérico usando el programa computacional Plaxis para estimar los desplazamientos horizontales. Los resultados numéricos entregan estimaciones que se aproximan a los resultados medidos de desplazamientos horizontales en términos de la forma de la zona de suelo en fluencia. Sin embargo, no son capaces de reproducir en detalle la geometría 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.

  16. The monosulfid solid solution in the Fe?Ni?S system: relationship to the earth's core on the basis of experimental high-pressure investigations

    Science.gov (United States)

    Kraft, A.; Stiller, H.; Vollstädt, H.

    1982-01-01

    Experimental high-pressure results on phase stability, electrical conductivity and compression behavior up to 5 and 21 GPa respectively are used to calculate an isothermal equation of state for a monosulfid solid solution (MSS-composition) in the Fe?Ni?S system. The high-pressure relations in the range 1-8 GPa are very complex. A continuous electrical transition, from semiconducting to metallic, takes place at high pressures and temperatures and results in anomalous compression behavior at pressures in this region. No polymorphic transition from the NiAs-structure to another type could be observed; however, density increases by as much as 8.8%. Using compression values for pressure greater than 10 GPa, the bulk modulus, a zero-pressure density and a core density were calculated. Extrapolation for the conditions of the outer core yields a difference in the density of up to 20%, relative to seismological models. In a composition model with (Fe, Ni)+MSS, a MSS-content must be assumed to be in the range of 30-35 wt% at the core-mantle boundary (CMB) and 13-17 wt% at the inner-core boundary (ICB). That corresponds to a sulfur content of 10.8-13.3 wt% (CMB) and 4.9-6.5 wt% (ICB), respectively, the values increasing with increasing Ni content of the MSS-phase.

  17. 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.

  18. Coupled Orbit-Attitude Dynamics of High Area-to-Mass Ratio (HAMR) Objects: Influence of Solar Radiation Pressure, Earth's Shadow and the Visibility in Light Curves

    OpenAIRE

    Frueh, Carolin; Jah, Moriba; Kelecy, Thomas

    2013-01-01

    The orbital and attitude dynamics of uncontrolled Earth orbiting objects are perturbed by a variety of sources. In research, emphasis has been put on operational space vehicles. Operational satellites typically have a relatively compact shape, and hence, a low area-to-mass ratio (AMR), and are in most cases actively or passively attitude stabilized. This enables one to treat the orbit and attitude propagation as decoupled problems, and in many cases the attitude dynamics can...

  19. Bulk Earth carbon and its isotopic value

    Science.gov (United States)

    Jones, A. P.; Mikhail, S.; Basugupta, S.

    2012-12-01

    The carbon isotope distribution in the Earth today is the net product of several primary processes, including planetary accretion, segregation of the core, the Moon-forming giant impact, magma oceans, crustal recycling, and biological processes. Therefore carbon isotope fractionation under mantle pressure and temperature conditions is one of the most important factors in deciphering the messages recorded in mantle samples and will assist towards the greater understanding the geodynamic carbon system. The largest and most powerful geochemical differentiation event during Earth's geologic history was core formation. The behaviour of 13C during this process is little constrained and needs to be investigated to understand the potential effects that it may have had on the carbon isotope composition of the silicate Earth. Isotopic fractionation of carbon at mantle pressure and temperatures in laboratory experiments and for natural terrestrial and extra-terrestrial samples between coexisting elemental carbon and carbides (reducing conditions) are higher than other systems previously investigated and can exceed 12 ‰ in the cores of celestial bodies and observed in Fe-meteorites (Deines and Wickman, 1975; Mikhail et al., 2010). First we review the mean values for carbon in ordinary chondrites and other solar system meteorites (from Mars, Vesta and the Moon) with a value of ?13C ? -20 +/- 4 ‰ (Grady et al 2004). Then we review the notion that the bulk Earth ?13C is around -5 ‰ similar to enstatite and carbonaceous chondrites and reflected in the majority of peridotitic mantle materials. Our modelling demonstrates that in order to understand the core/mantle carbon ratio we need to constrain the bulk Earth's initial ?13C value. We can constrain the relative proportion of carbon in the core/mantle by using simple isotopic mass balance and produce a range of carbon contents for the Earth then apply this to the maximum and minimums for the core using geophysical constraints. The mantle dominates the terrestrial carbon reservoir from an initial ?13C value of -5 ‰, but is dwarfed by the core with an initial ?13C value of -20 ‰. REFERENCES: S. Mikhail 2010 AGU U21A-001 abstract; Deines, P., Wickman, F.E., 1975. A contribution to the stable carbon isotope geochemistry of iron meteorites. Geochimica Et Cosmochimica Acta 39, 547-557. Grady, M. Verchovsky A, Wright, I. 2004 Magmatic carbon in Martian meteorites: attempts to constrain the carbon cycle on Mars. Int. J. Astrobiol. 2004;3:117-124.

  20. Balance equations for a relativistic plasma. Pt. 1

    International Nuclear Information System (INIS)

    Relativistic power moments of the four-momentum are decomposed according to a macroscopic four-velocity. The thus obtained quantities are identified as relativistic generalization of the nonrelativistic orthogonal moments, e.g. diffusion flow, heat flow, pressure, etc. From the relativistic Boltzmann equation we then derive balance equations for these quantities. Explicit expressions for the relativistic mass conservation, energy balance, pressure balance, heat flow balance are presented. The weak relativistic limit is discussed. The derivation of higher order balance equations is sketched. (orig.)

  1. The albedo of Earth

    Science.gov (United States)

    Stephens, Graeme L.; O'Brien, Denis; Webster, Peter J.; Pilewski, Peter; Kato, Seiji; Li, Jui-lin

    2015-03-01

    The fraction of the incoming solar energy scattered by Earth back to space is referred to as the planetary albedo. This reflected energy is a fundamental component of the Earth's energy balance, and the processes that govern its magnitude, distribution, and variability shape Earth's climate and climate change. We review our understanding of Earth's albedo as it has progressed to the current time and provide a global perspective of our understanding of the processes that define it. Joint analyses of surface solar flux data that are a complicated mix of measurements and model calculations with top-of-atmosphere (TOA) flux measurements from current orbiting satellites yield a number of surprising results including (i) the Northern and Southern Hemispheres (NH, SH) reflect the same amount of sunlight within ~ 0.2 W m-2. This symmetry is achieved by increased reflection from SH clouds offsetting precisely the greater reflection from the NH land masses. (ii) The albedo of Earth appears to be highly buffered on hemispheric and global scales as highlighted by both the hemispheric symmetry and a remarkably small interannual variability of reflected solar flux (~0.2% of the annual mean flux). We show how clouds provide the necessary degrees of freedom to modulate the Earth's albedo setting the hemispheric symmetry. We also show that current climate models lack this same degree of hemispheric symmetry and regulation by clouds. The relevance of this hemispheric symmetry to the heat transport across the equator is discussed.

  2. 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 ...

  3. Persistence of oceans on Earth-like planets

    Science.gov (United States)

    Schaefer, Laura; Sasselov, Dimitar D.

    2015-01-01

    The habitable zone is an orbital region around a star in which an Earth-like planet can maintain liquid water on its surface given a variety of atmospheric compositions. However, the abundance of water on the Earth's surface is not controlled by the atmosphere, but rather by the deep water/silicate cycle. On the Earth, volcanic outgassing of water from the mantle is balanced by loss of water to the mantle through subduction of water-rich oceanic seafloor. Much of this water is released immediately back to the surface through shallow, water-induced volcanism. However, a small but significant fraction of the water can be transported to deeper levels of the mantle. Mantle convection has therefore played an important role in controlling the size of Earth's surface oceans over the planet's lifetime.The deep water cycle of Earth has been studied with parameterized convection models incorporating a water-dependent viscosity. The abundance of water in the mantle, which lowers the convective viscosity, evolves along with the mantle temperature. Here we present results from a parameterized convection model extended to high pressures to study the deep water cycles of super-Earths. Assuming compositions similar to the Earth, our models indicate that ocean formation will be delayed on 5 MEarth planets by ~1 Gyr after planet formation. Although ocean mass on these planets increases with time, the oceans remain much shallower than for smaller planets, consistent with previous studies. Intermediate mass planets (2-4 MEarth) have immediate, but gradual outgassing and persistent oceans. Small terrestrial planets (? 1 MEarth) have rapid initial outgassing, but will gradually lose a significant fraction of their surface oceans due to mantle sequestration over their lifetimes.

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF MICROBIOLOGICAL AND PARTICULATE CONTAMINANTS IN DRINKING WATER : SEPARMATIC? FLUID SYSTEMS DIATOMACEOUS EARTH PRESSURE TYPE FILTER SYSTEM MODEL 12P-2

    Science.gov (United States)

    The verification test of the SeparmaticTM DE Pressure Type Filter System Model 12P-2 was conducted at the UNH Water Treatment Technology Assistance Center (WTTAC) in Durham, New Hampshire. The source water was finished water from the Arthur Rollins Treatment Plant that was pretr...

  5. 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

  6. Water and sodium balance in space

    DEFF Research Database (Denmark)

    Drummer, C; Norsk, P

    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 water balance, are generally diminished during space flight compared with conditions on Earth. Nevertheless, cumulative water balance and total body water content are stable during flight if hydration, nutritional energy supply, and protection of muscle mass are at an acceptable level. Recent water balance data disclose that the phenomenon of an absolute water loss during space flight, which has often been reported in the past, is not a consequence of the variable microG. The handling of sodium, however, is considerably affected by microG. Sodium-retaining endocrine systems, such as renin-aldosterone and catecholamines, are much more activated during microG than on Earth. Despite a comparable oral sodium supply, urinary sodium excretion is diminished and a considerable amount of sodium is retained-without accumulating in the intravascular space. An enormous storage capacity for sodium in the extravascular space and a mechanism that allows the dissociation between water and sodium handling likely contribute to the fluid balance adaptation in weightlessness.

  7. Delamination in super-Earths extrapolated from the Earth model

    Science.gov (United States)

    Shoji, D.; Kurita, K.

    2015-05-01

    It is suggested that the delamination process, in which the mantle lithosphere is peeled into the asthenosphere, contributes to the topographies and magmatism of the Earth. We investigated the vigorousness of the delamination in super-Earths by applying the Earth model to planets of heavy mass. Delamination is induced in planets of mass 5M? by the negative buoyancy of the mantle lithosphere. However, assuming pressure dependent rheology, the thermal Rayleigh number decreases due to the high pressure in super-Earths and thus the magnitude of convection in the Moho decreases. Because reduced convection in the Moho weakens the peeling of the mantle lithosphere, the delaminated area is narrower. The magnitude of the heat flux caused by the delamination process is also reduced in planets large in size compared with Earth. Although further work is needed, our model indicates that delamination can transfer more heat than the conduction of the lithosphere if the planet's mass is less than 5M?.

  8. Multianvil high-pressure/high-temperature synthesis, crystal structure, and thermal behaviour of the rare-earth borogermanate Ce6(BO4)2Ge9O22

    International Nuclear Information System (INIS)

    The new monoclinic cerium borogermanate Ce6(BO4)2Ge9O22 was synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 10.5GPa and 1200 deg. C. Ce6(BO4)2Ge9O22 crystallizes with two formula units in the space group P21/n with lattice parameters a=877.0(2), b=1079.4(2), c=1079.1(2) pm, and ?=95.94(3)o. As the parameter pressure favours the formation of compounds with cations possessing high coordination numbers, it was possible to produce simultaneously BO4-tetrahedra and GeO6-octahedra in one and the same borogermanate for the first time. Furthermore, the cerium atoms show high coordination numbers (C.N.: 9 and 11), and one oxygen site bridges one boron and two germanium atoms (O[3]), which is observed here for the first time. Besides a structural discussion, temperature-dependent X-ray powder diffraction data are presented, demonstrating the metastable character of this high-pressure phase

  9. Determining Atmospheric Pressure Using a Water Barometer

    Science.gov (United States)

    Lohrengel, C. Frederick, II; Larson, Paul R.

    2012-01-01

    The atmosphere is an envelope of compressible gases that surrounds Earth. Because of its compressibility and nonuniform heating by the Sun, it is in constant motion. The atmosphere exerts pressure on Earth's surface, but that pressure is in constant flux. This experiment allows students to directly measure atmospheric pressure by measuring the…

  10. Google Earth

    Science.gov (United States)

    2009-01-01

    Google Earth has gone underwater with this latest iteration of their popular Earth-roaming application. Along with traveling the usual roads provided by previous versions of Google Earth, visitors can now visit the bottom of the Mariana Trench, learn about ocean observations, and even discover new places to surf and dive. On the Google Earth homepage, visitors can take a guided tour of all these new features. This version is compatible with all operating systems.

  11. 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)

    Gürsoy, 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.

  12. Earth Flow

    Science.gov (United States)

    Wiley

    This Flash animation with accompanying audio exhibits the different stages involved in the formation of an earth flow. A step-like scarp forms along with a flowage zone at the toe of the earth flow. The sequence concludes with the stabilization of the earth flow with vegetation. Expect long loading times.

  13. The Balancing Act

    Science.gov (United States)

    AMPS GK-12 Program,

    Students visualize and interact with concepts already learned, specifically algebraic equations and solving for unknown variables. They construct a balancing seesaw system (LEGO® Balance Scale) made from LEGO MINDSTORMS® parts and digital components to mimic a balancing scale. They are given example algebraic equation problems to analyze, configure onto the balance scale, and evaluate by manipulating LEGO pieces and gram masses that represent terms of an equation such as unknown variables, coefficients and integers. Digital light sensors, built into the LEGO Balance Scale, detect any balance or imbalances displayed on the balancing scale. The LEGO Balance Scale interactively issues a digital indication of balance or imbalance within the system. If unbalanced, students continue using the LEGO Balance Scale until they are confident in their understanding of solving algebraic equations. The goal is for students to become confident in solving algebraic equations by fundamentally understanding the basics of algebra and real-world algebraic applications.

  14. A New Carbonate Chemistry in the Earth's Lower Mantle

    Science.gov (United States)

    Boulard, E.; Gloter, A.; Corgne, A.; Antonangeli, D.; Auzende, A.; Perrillat, J.; Guyot, F. J.; Fiquet, G.

    2010-12-01

    The global geochemical carbon cycle involves exchange between the Earth’s mantle and the surface. Carbon (C) is recycled into the mantle via subduction and released to the atmosphere via volcanic outgassing. Carbonates are the main C-bearing minerals that are transported deep in the Earth’s mantle via subduction of the oceanic lithosphere [1]. The way C is recycled and its contribution to the lower mantle reservoir is however largely unknown [ e.g 2, 3]. In this respect, it is important to assess if carbonates can be preserved in the deep mantle, or if decarbonatation, melting or reduction play a role in the deep carbon cycle. To clarify the fate of carbonates in the deep mantle, we carried out high-pressure and high-temperature experiments up to 105 GPa and 2850 K. Natural Fe-Mg carbonates or oxide mixtures of (Mg,Fe)O + CO2 were loaded into laser heated diamond anvil cells. In situ characterizations were done by X-ray Diffraction (XRD) using synchrotron radiation at the high-pressure beamline ID27 of the European Synchrotron Radiation Facility. A focused ion beam technique was then used to prepare the recovered samples for electron energy loss spectroscopy in a dedicated scanning transmission electron microscope (EELS-STEM) and scanning transmission X-ray microscopy (STXM). In situ XRD clearly shows the transformation of the initial carbonate phase into a new Mg-Fe high pressure carbonate phase at lower mantle conditions. We also provide direct evidence for recombination of CO2 with (Mg,Fe)O to form this new carbonate structure. In addition, subsequent EELS-STEM and STXM spectroscopies carried out on recovered samples yields C K-edge and stoechiometry characteristic to this new carbonate structure. This new high pressure phase concentrates a large amount of Fe(III), as a result of redox reactions within the siderite-rich carbonate. The oxidation of iron is balanced by partial reduction of carbon into CO groups and/or diamond. These reactions may provide an explanation for the coexistence of oxidized and reduced C species observed on natural samples [4, 5], but also a new diamond formation mechanism at lower mantle conditions. [1] Sleep, N. H., and K. Zahnle (2001) J. Geophys. Res.-Planets 106(E1), 1373-1399. [2] Javoy, M. (1997) Geophys. Res. Lett. 24(2), 177-180. [3] Lecuyer et al. (2000) Earth Planet. Sci. Lett. 181(1-2), 33-40. [4] Brenker et al. (2007) Earth Planet. Sci. Lett. 260(1-2), 1-9. [5] Stachel et al. (2000) Contrib. Mineral. Petrol. 140(1), 16-27.

  15. Balancing Vanguard Satellites

    Science.gov (United States)

    Simkovich, A.; Baumann, Robert C.

    1961-01-01

    The Vanguard satellites and component parts were balanced within the specified limits by using a Gisholt Type-S balancer in combination with a portable International Research and Development vibration analyzer and filter, with low-frequency pickups. Equipment and procedures used for balancing are described; and the determination of residual imbalance is accomplished by two methods: calculation, and graphical interpretation. Between-the-bearings balancing is recommended for future balancing of payloads.

  16. Entropy of balance - some recent results

    OpenAIRE

    Laxåback Gerd; Borg Frank G

    2010-01-01

    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...

  17. 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 spac...

  18. 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.)

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

    Science.gov (United States)

    Bauer Espitia, E.; Schulz, W.

    2013-10-01

    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.

  20. 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

  1. Visible Earth

    Science.gov (United States)

    NASA's Visible Earth is a searchable directory of images, visualizations, and animations of the Earth. The images are also listed under the following categories: agriculture, atmosphere, biosphere, cryosphere, human dimensions, hydrosphere, land surface, oceans, radiance or imagery, solid earth, locations, and satellites. Accompanying each image are credits, data about the image, the satellite it was taken from, a description of what is shown, and a high-resolution viewable image.

  2. Earth's Interior

    Science.gov (United States)

    John Louie

    This website contains class notes from a Geology 101 (physical geology) course. It discusses the composition and structure of the Earth's interior. Each layer, the inner core, outer core, mantle, and crust, is covered. Details about each layer explain their composition, temperature, depth, and state. Also covered is how scientists discovered what the interior of the Earth is made of through the use of seismic waves, plate tectonics, and the Earth's magnetic field.

  3. Earth Force

    Science.gov (United States)

    "Earth Force engages young people as active citizens who improve the environment and their communities now and in the future." Educators can learn about Earth Force's three programs: Community Action and Problem solving (CAPS), the Global Rivers Environmental Education Network (GREEN), and Earth Force After School. Users can discover students' many accomplishments such as creating reusable fabric grocery bags, recycling cell phones and ink cartridges to earn money, and cleaning up litter. The Tools for Teachers section offers evaluation results, a quality rubric, and a description of the six-step Earth Force community action and problem-solving process.

  4. Rare earths

    International Nuclear Information System (INIS)

    Rare earth elements are commonly extracted from the minerals monazite, bastnaesite, and xenotine. New uses for these elements are constantly developing; they have found applications in glass polishing, television tube phosphors, high-strength low-alloy steels, magnets, catalysts, refractory ceramics, and hydrogen sponge alloys. In Canada, rare earths have been produced as byproducts of the uranium mining industry, but there was no production of rare earths in 1978 or 1979. The world sources of and markets for the rare earth elements are discussed

  5. 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 ...

  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. 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.

  8. Isotope composition and volume of Earth´s early oceans

    DEFF Research Database (Denmark)

    Pope, Emily Catherine; Bird, Dennis K.

    2012-01-01

    Oxygen and hydrogen isotope compositions of Earth´s 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 hydrogen´s was not, as it can escape to space. Isotopic properties of serpentine from the approximately 3.8 Ga Isua Supracrustal Belt in West Greenland are used to characterize hydrogen and oxygen isotope compositions of ancient seawater. Archaean oceans were depleted in deuterium [expressed as δD relative to Vienna standard mean ocean water (VSMOW)] by at most 25± 5‰, but oxygen isotope ratios were comparable to modern oceans. Mass balance of the global hydrogen budget constrains the contribution of continental growth and planetary hydrogen loss to the secular evolution of hydrogen isotope ratios in Earth´s 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.

  9. Low-Hysteresis Flow-Through Wind-Tunnel Balance

    Science.gov (United States)

    Kunz, N.; Luna, P. M.; Roberts, A. C.; Smith, R. C.; Horne, W. L.; Smith, K. M.

    1992-01-01

    Improved flow-through wind-tunnel balance includes features minimizing both spurious force readings caused by internal pressurized flow and mechanical hysteresis. Symmetrical forces caused by internal flow cancelled.

  10. 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

  11. Functional balance tests

    Directory of Open Access Journals (Sweden)

    Parvin Raji

    2012-12-01

    Full Text Available Background and Aim: All activities of daily living need to balance control in static and dynamic movements. In recent years, a numerous increase can be seen in the functional balance assessment tools. Functional balance tests emphasize on static and dynamic balance, balance in weight transfer, the equilibrium response to the imbalances, and functional mobility. These standardized and available tests assess performance and require minimal or no equipment and short time to run. Functional balance is prerequisite for the most static and dynamic activities in daily life and needs sufficient interaction between sensory and motor systems. According to the critical role of balance in everyday life, and wide application of functional balance tests in the diagnosis and assessment of patients, a review of the functional balance tests was performed.Methods: The Google Scholar, PubMed, Science Direct, Scopus, Magiran, Iran Medex, and IranDoc databases were reviewed and the reliable and valid tests which were mostly used by Iranian researchers were assessed.Conclusion: It seems that Berg balance scale (BBS have been studied by Iranian and foreign researches more than the other tests. This test has high reliability and validity in elderly and in the most neurological disorders.

  12. Rare earths

    International Nuclear Information System (INIS)

    There has been no Canadian production of the rare earth oxides since 1977. World production in 1978, the last year for which figures are available, is estimated to have been about 41000 tonnes, mostly from Australia and the United States. The United States Bureau of Mines estimates that world reserves contain about 7 million tonnes of rare earth oxides and 35 million tonnes of yttrium. The largest yttrium reserves are in India, while China is believed to have the world's largest reserves of rare earth oxides. World consumption of rare aarths increased slightly in 1980, but is still only a small fraction of known reserves. Rare earths are used mainly in high-strength magnets, automobile exhaust systems, fluorescent tube and television screen phosphors, metallurgical applications, petroleum cracking catalysts, and glass polishing

  13. Earth Day

    Science.gov (United States)

    The State University of New York at Buffalo presents this History of Earth Day website. The goal of the site is that teachers and students can better understand the development and purpose of Earth Day. In addition to the history, SUNY-Buffalo has compiled a series of websites complete with projects associated with Earth Day, appropriate for children, high school students, and college undergrads. Furthermore, the legal aspect of Earth Day - environmental legislation, EPA standards, and Global Climate Change legislation - are also discussed on the site. A list of further sites is also provided if users want more information on this national effort to help solve environmental issues such as pollution, overpopulation, and global warming. Teachers will find this website both informative and helpful in developing appropriate teaching curricula connected to this holiday, while students can have fun learning and creating projects of their own that contribute to preserving the environment.

  14. 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.

  15. Earth Sciences

    International Nuclear Information System (INIS)

    The following papers were presented at the earth science session: earth science developments in support of water isolation; development of models and parameters for ground-water flow in fractured rock masses; isotope geochemistry as a tool for determining regional ground-water flow; natural analogs of radionuclide migration; nuclide retardation data: its use in the NWTS program; and ground-water geochemistry and interaction with basalt at Hanford

  16. A climatic thermostat making Earth habitable

    OpenAIRE

    Ditlevsen, Peter D.

    2005-01-01

    The mean surface temperature on Earth and other planets with atmospheres is determined by the radiative balance between the non-reflected incoming solar radiation and the outgoing long-wave black-body radiation from the atmosphere. The surface temperature is higher than the black-body temperature due to the greenhouse warming. Balancing the ice-albedo cooling and the greenhouse warming gives rise to two stable climate states. A cold climate state with a completelyice-covered...

  17. 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 Earth’s 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 Earth’s 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.

  18. 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...

  19. Unsteady response of flow system around balance piston in a rocket pump

    Science.gov (United States)

    Kawasaki, S.; Shimura, T.; Uchiumi, M.; Hayashi, M.; Matsui, J.

    2013-03-01

    In the rocket engine turbopump, a self-balancing type of axial thrust balancing system using a balance piston is often applied. In this study, the balancing system in liquid-hydrogen (LH2) rocket pump was modeled combining the mechanical structure and the flow system, and the unsteady response of the balance piston was investigated. The axial vibration characteristics of the balance piston with a large amplitude were determined, sweeping the frequency of the pressure fluctuation on the inlet of the balance piston. This vibration was significantly affected by the compressibility of LH2.

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

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran

    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

  1. 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

  2. Geoelectromagnetic investigation of the earth’s crust and mantle

    CERN Document Server

    Rokityansky, Igor I

    1982-01-01

    Electrical conductivity is a parameter which characterizes composition and physical state of the Earth's interior. Studies of the state equations of solids at high temperature and pressure indicate that there is a close relation be­ tween the electrical conductivity of rocks and temperature. Therefore, measurements of deep conductivity can provide knowledge of the present state and temperature of the Earth's crust and upper mantle matter. Infor­ mation about the temperature of the Earth's interior in the remote past is derived from heat flow data. Experimental investigation of water-containing rocks has revealed a pronounced increase of electrical conductivity in the temperature range D from 500 to 700 DC which may be attributed to the beginning of fractional melting. Hence, anomalies of electrical conductivity may be helpful in identitying zones of melting and dehydration. The studies of these zones are perspective in the scientific research of the mobile areas of the Earth's crust and upper mantle where t...

  3. Pan Balance-Shapes

    Science.gov (United States)

    2011-01-01

    This Java applet allows children to explore a balancing tool and thus build their algebraic thinking about equivalency. By placing shapes on each side of the balance and finding equivalent sets of weights, students discover the weight of each shape in one of six built-in sets or a random set.

  4. Numerical Results of Earth's Core Accumulation 3-D Modelling

    Science.gov (United States)

    Khachay, Yurie; Anfilogov, Vsevolod

    2013-04-01

    For a long time as a most convenient had been the model of mega impact in which the early forming of the Earth's core and mantle had been the consequence of formed protoplanet collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,3] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone. Only after the increasing of the gravitational radius, the growing area of the future core can save also the silicate envelope fragments. All existing dynamical accumulation models are constructed by using a spherical-symmetrical model. Hence for understanding the further planet evolution it is significant to trace the origin and evolution of heterogeneities, which occur on the planet accumulation stage. In that paper we are modeling distributions of temperature, pressure, velocity of matter flowing in a block of 3D- spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach. The numerical algorithm of the problem solution in velocity-pressure variables is constructed on the base of the splitting method. The velocity field and pressure field we obtain using the checkerboard grid. The occurring and evolution of the initial heterogeneities in the growing planets is caused by heterogeneous distribution of falling accumulated bodies. 1.V.N. Anfilogov and Yu.V.Khachai A Possible Scenario of Material Differentiation at the Ini-tial Stage of the Earth's Formation // Doklady Earth Sciences. V. 403 A.N 6. 2005. 954-957 Transl. from Doklady Akademii Nauk.v.403.N 6.2005.803-806. 2.Khachay Yu., Anfilogov V. VARIANTS OF TEMPERATURE DISTRIBUTIONS IN THE EARTH ON ITS ACCUMULATION // Proc. of the 6th Orlov Conf. "The study of the Earth as a planet by methods of geophysics, geodesy and astronomy" K.: Akad. 2010.197-202. 3.V.N. Anfilogov and Yu.V.Khachay Differentiation of the mantle matter during the process of the Earth's accumulation and early crust formation // Litosphere, 2012, N6, 3-15.

  5. 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.

  6. 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.

  7. Momentum balance and flux conservation in model magnetospheric magnetic fields

    International Nuclear Information System (INIS)

    We have tested four recent quantitative magnetospheric magnetic field models to determine whether the magnetic field configuration is consistent with a balance of forces between the J x B force and the gradient of the pressure. A necessary condition for the models to be consistent with an isotropic pressure distribution is that curl (J x B) vanish. None of the models (Olson-Pfitzer, Tsyganenko, Hedgecock-Thomas, and Beard) meet this requirement: Our analysis indicates that the models are intrinsically inconsistent with momentum balance with any isotropic pressure distribution. We have also, for purposes of comparison, examined delxB. In certain models this can be nonzero

  8. Balance Evaluation Systems

    Science.gov (United States)

    1996-01-01

    NeuroCom's Balance Master is a system to assess and then retrain patients with balance and mobility problems and is used in several medical centers. NeuroCom received assistance in research and funding from NASA, and incorporated technology from testing mechanisms for astronauts after shuttle flights. The EquiTest and Balance Master Systems are computerized posturography machines that measure patient responses to movement of a platform on which the subject is standing or sitting, then provide assessments of the patient's postural alignment and stability.

  9. Social Balance Explanation

    Science.gov (United States)

    A triad of attitudinal relationships is considered balanced if all three relationships are positive, or if one is positive and two are negative. Balance theory has been extended to apply to larger interpersonal groups (Situngkir & Khanafiah, 2004), perceptions of groups such as the US Supreme Court (Pilialoha & Brewer, 2006), matchmaking (Chapdelaine, Kenny, & LaFontana, 1994), the connection between voters and their political parties (Ray, 1999), bargaining (Kette, 1986), and developing a comprehensive theory of self-esteem, self-concept, implicit attitudes and stereotyping (Greenwald, Banaji, Rudman, Farnham, Nosek, & Mellot, 2002). This page describes a study that can be used to illustrate balance theory.

  10. BIOCHEMISTRY: Balancing Cellular Energy

    Science.gov (United States)

    D. Grahame Hardie (University of Dundee; Division of Molecular Physiology)

    2007-03-23

    Access to the article is free, however registration and sign-in are required. The structure of the core of an enzyme complex that senses and responds to changes in the cell's energy balance has been solved. Adenosine monophosphate-activated protein kinase (AMPK) complex regulates cellular energy balance. On page 1726 of this issue, Townley and Shapiro (2) describe crystal structures for the core of the AMPK complex from fission yeast. The study provides insights into binding of AMP and adenosine triphosphate (ATP), which may be very helpful in the design of new drugs that might treat disorders of energy balance (i.e. obesity and type-2 diabetes).

  11. Global analysis of river systems: from Earth system controls to Anthropocene syndromes.

    Science.gov (United States)

    Meybeck, Michel

    2003-12-29

    Continental aquatic systems from rivers to the coastal zone are considered within two perspectives: (i) as a major link between the atmosphere, pedosphere, biosphere and oceans within the Earth system with its Holocene dynamics, and (ii) as water and aquatic biota resources progressively used and transformed by humans. Human pressures have now reached a state where the continental aquatic systems can no longer be considered as being controlled by only Earth system processes, thus defining a new era, the Anthropocene. Riverine changes, now observed at the global scale, are described through a first set of syndromes (flood regulation, fragmentation, sediment imbalance, neo-arheism, salinization, chemical contamination, acidification, eutrophication and microbial contamination) with their related causes and symptoms. These syndromes have direct influences on water uses, either positive or negative. They also modify some Earth system key functions such as sediment, water, nutrient and carbon balances, greenhouse gas emissions and aquatic biodiversity. Evolution of river syndromes over the past 2000 years is complex: it depends upon the stages of regional human development and on natural conditions, as illustrated here for the chemical contamination syndrome. River damming, eutrophication and generalized decrease of river flow due to irrigation are some of the other global features of river changes. Future management of river systems should also consider these long-term impacts on the Earth system. PMID:14728790

  12. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... with each other -- kind of organized by the brain -- to help us maintain our balance, or, another ... balance nerve then sends the stimulation to the brain centers for balance. Another leg of the stool ...

  13. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... people are discussing a problem common to many older adults -- a problem with balance. Balance problems can have a serious impact on an older person's life. In fact, balance problems are one ...

  14. Power balance in highly loaded fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Lister, G G [Osram Sylvania, 71 Cherry Hill Drive, Beverly, MA 01915 (United States); Curry, J J [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8422 (United States); Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2004-11-21

    Discrepancies reported in the literature between numerical predictions and experimental measurements in low-pressure Hg discharges at high current densities are considered. Elements of a one-dimensional fluid model and recent spectroscopic and Langmuir probe measurements are combined in a semi-empirical way to individually examine components of the positive column power balance and the discharge conductivity. At a Hg vapour pressure of 0.81 Pa (6.1 mTorr) and a current density of 300 mA cm{sup -2}, previous discrepancies in the power balance and discharge conductivity are simultaneously resolved by assuming a higher electron density than that obtained from the Langmuir probe measurements. This conclusion is supported by independent measurements of ion density reported in a companion paper. The importance of radial cataphoresis under these conditions, particularly with regard to radiation transport, is highlighted. This work is of particular interest for the design of fluorescent lamps operating at high current densities.

  15. 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...

  16. 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.)

  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. 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.)

  20. Characteristic of VHF plasma produced by balanced power feeding

    International Nuclear Information System (INIS)

    The characteristics of a VHF hydrogen plasma produced by a balanced power feeding method were examined using a two-dimensional hybrid model. The simulation results showed that the electron density peaks at a certain pressure inside the discharge electrodes and significantly decreases outside the electrodes for high gas pressure. In addition, the power absorption efficiency inside the electrodes was improved by increasing the gas pressure. On the other hand, the plasma was produced within the electrodes for low applied voltages.

  1. Balanced Flow Metering and Conditioning: Technology for Fluid Systems

    Science.gov (United States)

    Kelley, Anthony R.

    2006-01-01

    Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

  2. Breathing Earth

    Science.gov (United States)

    Bleja, David

    Visual simulation and representation programs and applications have been popping up online in greater numbers, and this recent find is one that will pique the interest of scientists, policy makers, and others who are concerned about carbon dioxide emission rates across the Earth. The Breathing Earth site was created by David Bleja, and he draws on a number of resources (such as the World Factbook and the United Nations) for the data that is utilized to create this site. Visitors can scroll over different countries to learn about their population, their emissions, and their birth and death rate. This interactive map and educational resource also contains a legend in the right-hand corner which explains the various symbols in use here.

  3. Earth Observatory

    Science.gov (United States)

    2011-01-01

    This Web site includes shares the images, stories and discoveries that emerge from NASA Earth science research, including its satellite missions, in-the-field research and climate models. View global maps of NASA data, check out the Image of the Day and images of current events, and read feature articles and blogs. Also includes special collections of NASA images, including the World of Change series, which documents how our planet’s land, oceans, atmosphere and Sun are changing over time.

  4. Impact Earth

    Science.gov (United States)

    This 24 minute planetarium show teaches about meteors, meteorites, asteroids, and comets. The show was created for fulldome theaters, but is also available on DVD to be shown in flat version for TVs and computer monitors, and can be freely viewed online. It shows the effects of the Chixulub and Tungusta events, plus the Pallasite impact that resulted in the Brenham meteorite fall, and describes ways that asteroid hunters seek new objects in the solar system, and how ground penetrating radar is used to find meteorites that have survived to the Earth's surface. Narrated by astronaut Tom Jones, it also discusses ways that humans might try to deflect an asteroid or comet that is on a collision course with Earth. The show was created for informal science venues (digital planetariums); it is also useful as supplemental material for middle school science. Impact Earth is available for free if presented directly from the Space Update site (widescreen or fisheye views linked from YouTube). Otherwise, a DVD of the show can be purchased for $10.

  5. Balanced Integrated Regulatory Oversight

    International Nuclear Information System (INIS)

    Reactor safety, protecting the public health and safety, and protecting the environment must always be the nuclear regulator's top priorities. Enabling the use of nuclear power for the benefit of society, while protecting the public and the environment requires the regulator to balance many factors. In addition, the regulator is only one part of the overall government that must consider many factors as it carries out its societal responsibilities. Some of the factors that must be balanced and the practical impacts on how the regulator carries out its responsibilities will be addressed. The first International Conference on Effective Regulatory Systems, held in Moscow, Russian Federation, in 2006, focused on safety and security challenges with a goal of improving regulatory effectiveness through cooperation and sharing of information and best practices. The challenge of meeting both safety and security objectives is one example of potentially competing programmes that must be balanced. Other balances that must be evaluated include the benefits of safety improvements compared to the cost of implementation, the use of deterministic and probabilistic approaches, communication openness balanced with the protection of information that could be used for detrimental purposes, and timeliness of regulatory decision making balanced with the need to perform quality work in support of oversight responsibilities. A balanced and integrated approach to regulatory oversight is vital tpproach to regulatory oversight is vital to ensuring that the regulatory body remains effective in its mission to enable the use of nuclear power while protecting the public and the environment. This concept is applicable to nations beginning a nuclear programme as well as established and experienced regulatory bodies. (author)

  6. Thermal structure and energy balance of Uranus

    Science.gov (United States)

    Conrath, B. J.; Pearl, J. C.; Appleby, J. F.; Lindal, G. F.; Orton, G. S.; Bezard, B.

    1991-01-01

    The present study determines the basic properties of the atmospheric temperature field of Uranus through a combination of earth-based and Voyager measurements. Stellar occultation observations indicate both spatial and temporal variability at microbar pressure levels. The tropospheric and stratospheric vertical structure are established via Voyager radio occultation and infrared measurements as well as earth-based full-disk infrared observations. It is found that the measured lapse rate at pressures greater than about 600 microbar exceeds that for fully equilibrated ortho and para hydrogen. The latitude dependence of the upper tropospheric temperatures is determined from Voyager infrared measurements; remarkably little contrast is found. The weak horizontal structure is consistent with tropospheric zonal winds which decay with height and are directed prograde at midlatitudes but retrograde at low latitudes.

  7. Field dependence and body balance.

    Science.gov (United States)

    Kitamura, F; Matsunaga, K

    1990-12-01

    This study reports four points about the portable Rod and Frame Test performance of 30 Japanese women in terms of body balance. The primary findings using a stabilometer are: (a) field dependence correlated negatively with increased sway path within 1 min. both while a dot pattern as a visual stimulus was stationary and while it was moving. (b) Field dependence correlated positively with the difference in sway path between the two following phases, in one of which the subjects watched the horizontal visual movement to the right and in the other movement to the left. (c) Motion aftereffect had no direct and immediate influence on sway path, but rather a latent and long-term effect. And on a pedograph which measures the distribution of foot pressure and the shape of the sole, (d) field dependence correlated negatively with anterior positions of the center of foot pressure and with the proportion of the front part to the rear of the sole. Over-all, field dependence measured by the Rod and Frame Test seems to be associated with body posture when dot patterns are viewed. PMID:2293175

  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 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.

  9. Evapotranspiration Estimation with Remote Sensing and Various Surface Energy Balance Algorithms—A Review

    OpenAIRE

    Yuei-An Liou; Sanjib Kumar Kar

    2014-01-01

    With the advent of new satellite technology, the radiative energy exchanges between Sun, Earth, and space may now be quantified accurately. Nevertheless, much less is known about the magnitude of the energy flows within the climate system and at the Earth’s surface, which cannot be directly measured by satellites. This review surveys the basic theories, observational methods, and different surface energy balance algorithms for estimating evapotranspiration (ET) from landscapes and regions w...

  10. Toward an internally consistent pressure scale

    OpenAIRE

    Fei, Yingwei; Ricolleau, Angele; Frank, Mark; Mibe, Kenji; Shen, Guoyin; Prakapenka, Vitali

    2007-01-01

    Our ability to interpret seismic observations including the seismic discontinuities and the density and velocity profiles in the earth's interior is critically dependent on the accuracy of pressure measurements up to 364 GPa at high temperature. Pressure scales based on the reduced shock-wave equations of state alone may predict pressure variations up to 7% in the megabar pressure range at room temperature and even higher percentage at high temperature, leading to large uncertainties in under...

  11. 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.)

  12. 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

  13. Pressure Sores

    Science.gov (United States)

    ... skin and tissue. They usually are caused by sitting or lying in one position for too long. This puts pressure on certain ... pressure sores? Pressure sores usually are caused by sitting or lying in one position for too long. This puts pressure on certain ...

  14. Thermal Evolution and Habitability of Super-Earths

    Science.gov (United States)

    Stamenkovic, V.; Breuer, D.

    2012-09-01

    The recent discovery of super-Earths has increased the interest to better understand the thermal state and the habitability of such worlds. The major question is if super-Earths are simply scaled-up versions of Earth or if they are actually very different from our home planet. The planet's habitability, in especially the planet's ability to form an atmosphere, have a magnetic field and plate tectonics, is controlled by the planet's interior thermal evolution, which is ultimately determined by high-pressure and high-temperature solid state physics. The pressure at the Earth's core-mantle boundary (CMB) is about 135 GPa, pressures at the base of the mantles of extra-terrestrial rocky planets - if these are at all differentiated into mantles and cores - may reach, however, Tera Pascals. These high pressures might lead to very different interior energy transport mechanisms in comparison to Earth - and hence super-Earths might significantly differ from Earth. In this talk, we present newest results from highpressure physics ([4]), which control the interior thermal properties of super-Earths, and show how the thermal evolution of those planets can be described by a 1D model ([5]). We demonstrate that the mantles of super-Earths can be partially stagnant or highly sluggish and hot, strongly depending on the planet's initial interior thermal state. We additionally find that the duration of volcanism and outgassing, as well as the ability to generate magnetic fields on super- Earths is reduced in comparison to less massive planets.

  15. 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.

  16. 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.)

  17. Social Balance Experiment

    Science.gov (United States)

    This is the entry page for participation in the Social Balance Experiment. In this experiment, participants are asked to imagine that they are in a situation in which they have one of five feelings (love, like, neutral, dislike or hate) toward another person named Bill.

  18. Balancing through episodic learning

    DEFF Research Database (Denmark)

    Scheuer, John Damm

    2013-01-01

    Peter Jarvis’s theory about learning suggests that human beings learn and change as a result of hearing, seeing, smelling, tasting, touching, and feeling. They change and learn by interacting with other humans, things, and events in certain time-space contexts and by reflecting upon these, as well as upon wished-for future states or past experiences, knowledge, and history, and upon what these experiences mean to one’s own self and identity. This chapter explores how female top managers have to reflect and find a balance in their work-family lives on the basis of interaction with, and inputs from, all these human and nonhuman elements. It shows how they have to overcome relational inertia related to all of them in order to succeed in obtaining such a balance. If a certain degree of balance between elements is achieved at work, as well as on the home front, the female top manager may experience being in a state of balance.

  19. 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.)

  20. 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.)

  1. 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.)

  2. Gain in strength and muscular balance after balance training.

    Science.gov (United States)

    Heitkamp, H C; Horstmann, T; Mayer, F; Weller, J; Dickhuth, H H

    2001-05-01

    The isolated effect of balance training on muscle strength of the flexors and extensors of the knee, without accompanying strength training, has not been addressed in the past. Effects of a balance training program alone were compared to a strength training program. Balance and strength training were performed by 15 persons each for 6 weeks including 12 training units of 25 min. Balance training was performed on instability training devices such as rolling board, mini trampoline and large rubber ball. The 15 persons of the strength training group trained on machines for leg curls and on leg presses for 25 min per unit. Measurements for balance were performed with one-leg balance on a narrow edge and a tilting stabilometer for 30 s; maximum isometric strength was measured using an isokinetic device for each leg separately. The muscular balance between dominant and non-dominant leg was calculated. Strength gain was similar for the flexors and extensors in both groups. One-leg balance improved after balance training (Pstabilometer test for each person in the balance (P < 0.01), but not in the strength training group. In the balance group the initial difference between right and left diminished. The results indicate balance training to be effective for gain in muscular strength, and secondly, in contrast to strength training, equalisation of muscular imbalances may be achieved after balance training. PMID:11414672

  3. Earth-Sun Geometry - Earth Revolution Animation

    Science.gov (United States)

    Dr. Michael Pidwirny

    The representation is an animation of the Earth revolving around the sun. The Earth is shown as a solid green sphere with the equator and arctic circle marked with black lines and the dark side of the Earth shaded. The Earth's axis is shown with a red line. As the Earth revolves around the sun, the axis is shown to always be pointing in the same direction. The positions of Earth at the winter solstice, vernal equinox, summer solstice, and autumnal equinox are labeled.

  4. Earth Pulse

    Science.gov (United States)

    2007-12-12

    Earth Pulse is the National Geographic site for conservation. It features a set of links to National Geographic sites with a variety of conservation themes such as oceans, climate, energy, fresh water, and others. Many of these pages feature interactive tours or videos. Virtual Worlds is a set of interactive tours of various environments, from the rain forest at night to a new urbanist neighborhood. There is also a collection of Sights and Sounds interactive pages on a variety of ecosystems, in which users can click on a map and see information on wildlife that inhabits the selected region. There are also links to news articles and online expeditions in which users can follow actual expeditions as they were conducted by explorers-in-residence.

  5. 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

  6. Slackline training for balance and strength promotion.

    Science.gov (United States)

    Granacher, U; Iten, N; Roth, R; Gollhofer, A

    2010-10-01

    The prevalence of sustaining a sport injury is high in adults. Deficits in postural control/muscle strength represent important injury-risk factors. Thus, the purpose of this study was to investigate the impact of a specific type of balance training, i.?e. slackline training, followed by detraining on balance and strength performance. Twenty-seven adults participated in this study and were assigned to an intervention (age 22.8±3.3 yrs) or a control group (age 23.9±4.4 yrs). The intervention group participated in 4 weeks of slackline training on nylon webbings. Detraining lasted 4 weeks. Tests included the measurement of (A) total centre of pressure displacements during one-legged standing on a balance platform and during the compensation of a perturbation impulse, (B) maximal torque and rate of force development (RFD) of the plantar flexors on an isokinetic device, and (C) jumping height on a force platform. After training, no significant interaction effects were observed for variables of static/dynamic postural control, maximal torque, and jumping height. Training-induced improvements were found for RFD. After the withdrawal of the training stimulus, RFD slightly decreased. Given that the promotion of balance and strength is important for injury prevention, changes in RFD only might not be sufficient to produce an injury-preventive effect. PMID:20677124

  7. Rough wall skin friction measurements using a high resolution surface balance

    International Nuclear Information System (INIS)

    This paper describes the design of a floating element friction balance which is based upon a commercially available micro force balance. The balance has a perfectly linear calibration function and was successfully applied to rough wall flows in a channel and a diffusor. Extrapolation of the turbulent shear stress measured by two component LDA to the wall matched very well the shear stress measured using the friction balance. Also, the wall shear stress obtained from the balance in the fully developed channel flow agreed with the stress that could be derived from the pressure gradient to within 3%.

  8. Spreadsheet eases heat balance, payback calculations

    International Nuclear Information System (INIS)

    This paper reports that a generalized Lotus type spreadsheet program has been developed to perform the heat balance and simple payback calculations for various turbine-generator (TG) inlet steam pressures. It can be used for potential plant expansions or new cogeneration installations. The program performs the basic heat balance calculations that are associated with turbine-generator, feedwater heating process steam requirements and desuperheating. The printout, shows the basic data and formulation used in the calculations. The turbine efficiency data used are applicable for automatic extraction turbine-generators in the 30-80 MW range. Simple payback calculations are for chemical recovery boilers and power boilers used in the pulp and paper industry. However, the program will also accommodate boilers common to other industries

  9. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... They thought I was getting senile because the vertigos -- it upset my balance completely. Narrator: These people ... person with a balance disorder might have are vertigo -- or a feeling as if you or the ...

  10. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... vertigos -- it upset my balance completely. Narrator: These people are discussing a problem common to many older ... can have a serious impact on an older person's life. In fact, balance problems are one reason ...

  11. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... activities of daily living. Narrator: Our body's balance system is what allows us to move, stand erect, ... maintain balance with the help of our vestibular system, which is located in the inner ear. A. ...

  12. NASA Earth Exchange (NEX)

    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...

  13. Energy balances 2001

    International Nuclear Information System (INIS)

    Denmark's consumption of energy increased 1,6 % from 2000 to 2001, primarily due to the year 2001 being colder than the year 2000. The production of petroleum decreased from 2000 to 2001, the reason being an accident at the Gorm oil field. The production of renewable energy and natural gas, however, increased. The energy balances is an account of production, import and export, and consumption of energy. The consumption is presented for households and industry. In the energy balances the energy consumption is accounted as physical amounts as well as gross consumption. Also an account is made of the costs of energy in basis prices and in market prices, including calculation of excises on energy, CO2 and SO2. (ln)

  14. 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.

  15. 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.)

  16. 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 proportional–integral–derivative method. Also the idea of robotic teleoperation is gaining ground. Control...

  17. Modeling your Water Balance

    Science.gov (United States)

    Students create a physical model illustrating soil water balance using drinking glasses to represent the soil column, and explain how the model can be used to interpret data and form predictions. Using data from the GLOBE Data Server, they calculate the potential evapotranspiration, average monthly temperatures and precipitation for their model. This is a learning activity associated with the GLOBE hydrology investigations and is supported by the Hydrology chapter of the GLOBE Teacher's Guide.

  18. 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.

  19. Balancing Software Product Investments

    OpenAIRE

    Barney, Sebastian; Wohlin, Claes; Aurum, Aybu?ke

    2009-01-01

    The long-term sustainability of a software product depends on more than developing features. Priorities are placed on aspects that support the development of software, like software product quality (eg. ISO 9126), project constraints -- time and cost, and even the development of intellectual capital (IC). A greater focus on any one aspect takes priority from another, but as each aspects delivers a different type of value managers have trouble comparing and balancing th...

  20. Entropy of balance - some recent results

    Directory of Open Access Journals (Sweden)

    Laxåback 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.

  1. 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 ...

  2. Pressure ulcers

    OpenAIRE

    Grey, Joseph E.; Harding, Keith G.; Enoch, Stuart

    2008-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers, which affect up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease.

  3. Rotating Torsion Balance Tests of the Equivalence Principle

    Science.gov (United States)

    Wagner, Todd; Schlamminger, Stephan; Gundlach, Jens

    2010-02-01

    We present current results from tests of the equivalence principle using a rotating torsion balance. Test bodies made from different materials are arranged in a composition dipole and installed on a torsion pendulum. The torsion pendulum is mounted on a turntable that rotates with constant angular velocity. Test body pairs of Be-Ti, Be-Al and test bodies that mimic the earth's and moon's compositions were used. Results are presented with limits using the earth and astrophysical objects as sources for a hypothetical equivalence principle violation. )

  4. 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.

  5. On the near surface momentum balance in the Yucatán Channel

    Directory of Open Access Journals (Sweden)

    A. Badan

    2008-11-01

    Full Text Available The horizontal momentum balance in the upper layers of the Yucatán Channel is examined for a period of 22 months, from September 1999 to June 2001, using subsurface currents from ADCP measurements at eight moorings across the channel, pressure measurements from coastal pressure sensors on both sides of the channel, QuickSCAT winds and AVISO altimetry data. The averaged balance between Isla Mujeres, México, and Cabo San Antonio, Cuba, (across-channel axis is basically geostrophic, but with contributions from ageostrophic terms, particularly friction against lower layers and to a lesser degree, the surface Ekman drift. Both the advective and the local acceleration terms appear unimportant in the side-to-side averaged balance. Interestingly, the averaged balance in along-channel axis is also mainly geostrophic; linear friction, Ekman drift, local acceleration and advective terms remain unimportant. An analysis of the balance from mooring to mooring across the channel indicates that in the region where the Yucatán current meanders, the advective terms with across-channel derivatives contribute significantly. The EOF modes of sea level anomalies from altimetry and the along-channel flow in the upper 90 m surface layer are correlated. Their two first modes are seemingly related to the transport fluctuations through the channel, but also to the along-channel pressure gradient and to the meandering of the Yucatán Current core, suggesting the presence of appreciable eddy-current interactions in the Channel.

  6. Price pressures

    OpenAIRE

    Hendershott, Terrence; Menkveld, Albert J.

    2010-01-01

    We study price pressures in stock prices—price deviations from fundamental value due to a risk-averse intermediary supplying liquidity to asynchronously arriving investors. Empirically, twelve years of daily New York Stock Exchange intermediary data reveal economically large price pressures. A $100,000 inventory shock causes an average price pressure of 0.28% with a half-life of 0.92 days. Price pressure causes average transitory volatility in daily stock returns of 0.49%. Price pressure ef...

  7. 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 t...

  8. Analysis of radionuclides in two rare earth products

    International Nuclear Information System (INIS)

    This paper describes a study on radioactivity change of rare-earth products after hydrometallurgy technology, using HPGe gamma spectrometer to analyze two rare earth products (LaCl3 and YCl). The results show that in the two samples exist natural radionuclides of thorium series and actinium-uranium series as well as other natural radionuclides 138La and 176Lu. In the sample of lanthanum chloride the radioactivity of actinium-uranium series and thorium series has not reached balance, the contents of their main progenies 226Ra and 227Th obviously changes with the time, reaching balance 60 days later, while YCl3 keeps stability. (authors)

  9. Twelve weeks of BodyBalance® training improved balance and functional task performance in middle-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 55 years.Participants and methods: A total of 28 healthy, active adults aged 66±5 years completed the randomized controlled trial. Balance, functional task performance, fear of falling, and self-reported quality of life were assessed at baseline and after 12 weeks. Participants either undertook two sessions of BodyBalance per week for 12 weeks (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

  10. Laser techniques in high-pressure geophysics

    Science.gov (United States)

    Hemley, R. J.; Bell, P. M.; Mao, H. K.

    1987-01-01

    Laser techniques in conjunction with the diamond-anvil cell can be used to study high-pressure properties of materials important to a wide range of problems in earth and planetary science. Spontaneous Raman scattering of crystalline and amorphous solids at high pressure demonstrates that dramatic changes in structure and bonding occur on compression. High-pressure Brillouin scattering is sensitive to the pressure variations of single-crystal elastic moduli and acoustic velocities. Laser heating techniques with the diamond-anvil cell can be used to study phase transitions, including melting, under deep-earth conditions. Finally, laser-induced ruby fluorescence has been essential for the development of techniques for generating the maximum pressures now possible with the diamond-anvil cell, and currently provides a calibrated in situ measure of pressure well above 100 gigapascals.

  11. The effects of load carriage and bracing on the balance of schoolgirls with adolescent idiopathic scoliosis

    OpenAIRE

    Chow, Daniel H K; Leung, Dawn S. S.; Holmes, Andrew D.

    2007-01-01

    The balance function of children is known to be affected by carriage of a school backpack. Children with adolescent idiopathic scoliosis (AIS) tend to show poorer balance performance, and are typically treated by bracing, which further affects balance. The objective of this study is to examine the combined effects of school backpack carriage and bracing on girls with AIS. A force platform was used to record center of pressure (COP) motion in 20 schoolgirls undergoing thoraco-lumbar-sacral ort...

  12. Deuterium inventory in Tore Supra: Coupled carbon–deuterium balance

    Energy Technology Data Exchange (ETDEWEB)

    Pégourié, B., E-mail: bernard.pegourie@cea.fr [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Panayotis, S. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Languille, P.; Martin, C. [Laboratoire PIIM, Aix-Marseille Université, CNRS UMR 7345, 13397 Marseille (France); Dittmar, T. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Center for Energy Research, Univ. of California – San Diego, San Diego (United States); Gauthier, E.; Hatchressian, J.-C.; Pascal, J.-Y. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Roubin, P.; Ruffe, R. [Laboratoire PIIM, Aix-Marseille Université, CNRS UMR 7345, 13397 Marseille (France); Tsitrone, E.; Vartanian, S. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Wang, H. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Beauté, A.; Bouvet, J.; Brosset, C.; Bucalossi, J. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); Cabié, M. [Aix-Marseille Univ., CP2M, Marseille (France); Caprin, E.; Courtois, X. [CEA, IRFM, 13108 Saint-Paul-lez-Durance (France); and others

    2013-07-15

    This paper presents an analysis of the carbon–deuterium circulation and the resulting balance in Tore Supra over the period 2002–2007. Carbon balance combines the estimation of carbon gross erosion from spectroscopy, net erosion and deposition using confocal microscopy, lock-in thermography and SEM, and a measure of the amount of deposits collected in the vacuum chamber. Fuel retention is determined from post-mortem (PM) analyses and gas balance (GB) measurements. Special attention was paid to the deuterium outgassed during the nights and weekends of the experimental campaign (vessel under vacuum, Plasma Facing Components at 120 °C) and during vents (vessel at atmospheric pressure, PFCs at room temperature). It is shown that this outgassing is the main process reconciling the PM and GB estimations of fuel retention, closing the coupled carbon–deuterium balance. In particular, it explains why the deuterium concentration in deposits decreases with increasing depth.

  13. Pressure vessel

    International Nuclear Information System (INIS)

    In a pressure vessel comprising a cylindrical main body of a pressure vessel, a plurality of pump shaft-penetration holes, and an end plate having nozzles for mounting pumps disposed at the outer side thereof corresponding to the pump shaft penetration holes, in which the circumferential edge of the end plate is joined to the end of the main body of the pressure vessel such that nozzles situate at the outer side of the main body of the pressure vessel, in order to prevent displacement of the center line of the nozzle due to the deformation of the pressure vessel, the end plate is shaped as a partially spherical shell concaved toward the nozzle, and the ratio of the wall thickness between the end of the main body of the pressure vessel and the circumferential portion of the end plate is properly adjusted while considering the inner radius of the main body of the pressure vessel, the inner radius of the end plate, the Young's coefficient of the main body of the pressure vessel, a Young's coefficient of the end plate, the Poisson's ratio of the main body of the pressure vessel, the Poisson's ratio of the end plate. As a result, the amount of deformation of the main body of the pressure vessel, and the amount of displacement of the joined portion between the main body of the pressure vessel and the end plate are made substantially equal, to prevent the displacement of the center line of the nozzle due to deformation of the main body of the pressure vessel and the end platdy of the pressure vessel and the end plate. (N.H.)

  14. Energy balances 2002

    International Nuclear Information System (INIS)

    Denmark's consumption of energy decreased almost 2% from 2001 to 2002, primarily due to the year 2002 being warmer than the year 2001. The total production of petroleum, natural gas, and renewable energy increased almost 6%. The production of petroleum increased 7%, the natural gas production was unchanged, and the production of wind energy increased 13%. The energy balances is an account of production, import and export, and consumption of energy. The consumption is accounted as physical amounts as well as gross consumption. Also an account is made of the costs of energy in basis prices and in market prices, including calculation of excises on energy, CO2 and SO2. (LN)

  15. Energy balances 2005

    International Nuclear Information System (INIS)

    Denmark's energy consumption was 800 PJ in 2005 when corrected for the fuel consumption used for producing electricity for export. The consumption is 0,5 % higher than in 2004. Since 1975, the energy consumption has been on the same level with minor fluctuations which are mainly due to the climate. The energy balances is an account of production, import and export, and consumption of energy. The consumption is accounted as physical amounts as well as gross consumption. Also, accounts are presented of the costs of energy in basis prices and in market prices, including excises on energy, CO2, and SO2. (LN)

  16. Body-Centered Cubic Iron-Nickel Alloy in Earth’s Core

    Science.gov (United States)

    Dubrovinsky, L.; Dubrovinskaia, N.; Narygina, O.; Kantor, I.; Kuznetzov, A.; Prakapenka, V. B.; Vitos, L.; Johansson, B.; Mikhaylushkin, A. S.; Simak, S. I.; Abrikosov, I. A.

    2007-06-01

    Cosmochemical, geochemical, and geophysical studies provide evidence that Earth’s core contains iron with substantial (5 to 15%) amounts of nickel. The iron-nickel alloy Fe0.9Ni0.1 has been studied in situ by means of angle-dispersive x-ray diffraction in internally heated diamond anvil cells (DACs), and its resistance has been measured as a function of pressure and temperature. At pressures above 225 gigapascals and temperatures over 3400 kelvin, Fe0.9Ni0.1 adopts a body-centered cubic structure. Our experimental and theoretical results not only support the interpretation of shockwave data on pure iron as showing a solid-solid phase transition above about 200 gigapascals, but also suggest that iron alloys with geochemically reasonable compositions (that is, with substantial nickel, sulfur, or silicon content) adopt the bcc structure in Earth’s inner core.

  17. Earth and Moon Viewer

    Science.gov (United States)

    Walker, John.

    Developed by John Walker, the Earth and Moon Viewer supplies updated, interactive maps for the World. Visitors can observe the Earth's Cloud cover, topography, Water Vapor, land and sea temperatures, and more. These maps can simulate views of Earth from the Sun, Moon, and satellites in Earth's orbit. Visitors will also find maps presenting the day and night regions at the moment. Anyone looking for visual interpretations of the earth and its atmosphere should visit this fascinating Web site.

  18. Earth Observatory Glossary

    Science.gov (United States)

    The Earth Observatory Glossary defines words from space science, ecology and Earth science. It is part of the NASA Earth Observatory site, which provides new satellite imagery and scientific information about Earth with a focus on climate and environmental change. The new glossary mode allows users to browse the Earth Observatory site with special terms highlighted that, when selected, will take you to the appropriate entry in the glossary.

  19. Study of the atmospheric pressure loading signal in VLBI observations

    OpenAIRE

    Petrov, Leonid; Boy, Jean-Paul

    2003-01-01

    Redistribution of air masses due to atmospheric circulation causes loading deformation of the Earth's crust which can be as large as 20 mm for the vertical component and 3 mm for horizontal components. Rigorous computation of site displacements caused by pressure loading requires knowledge of the surface pressure field over the entire Earth surface. A procedure for computing 3-D displacements of geodetic sites of interest using a 6-hourly pressure field from the NCEP numeric...

  20. 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

  1. Structural behaviour of YGa under high pressure

    International Nuclear Information System (INIS)

    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 Bo = 60 ± 3 GPa, Bo' = 4.6 ± 1.5

  2. 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)

  3. Lattice thermal conductivity of MgO at conditions of Earth’s interior

    OpenAIRE

    Tang, Xiaoli; Dong, Jianjun

    2010-01-01

    Thermal conductivity of the Earth’s lower mantle greatly impacts the mantle convection style and affects the heat conduction from the core to the mantle. Direct laboratory measurement of thermal conductivity of mantle minerals remains a technical challenge at the pressure-temperature (P-T) conditions relevant to the lower mantle, and previously estimated values are extrapolated from low P-T data based on simple empirical thermal transport models. By using a numerical technique that combines...

  4. 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 in or...

  5. 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 1Â 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. Â 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 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  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. Earth, Earth's Moon and Mars Balloons

    Science.gov (United States)

    2013-04-03

    This is an activity about planetary sizes and distances. Learners will construct a scale model of the Earth, Earth’s Moon and Mars in relation to each other using balloons. They will use this model to predict distances and reflect on how scientists use models to construct explanations through the scientific process. The lesson models scientific inquiry using the 5E instructional model and includes teacher notesand vocabulary.

  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. Data needs for nutrient balances

    DEFF Research Database (Denmark)

    Vinther, Finn Pilgaard

    2011-01-01

    One of the tools for evaluating the results of environmental action plans or EU directives related to nutrients in the agricultural sector is to follow the development of annually estimated nitrogen (N) and phosphorus (P) balances and surplus. Unlike greenhouse gas and ammonia emissions, countries are not required to report N and P balances for agriculture as part of any international conventions. As a consequence, there is no organisation equivalent to the Intergovernmental Panel on Climate Change (IPCC) or United Nations Economic Commission for Europe (UNECE) who has responsibility for standardising and improving the methodology to calculate such balances. However, Eurostat and OECD have jointly established a standard for using a gross N balances, and the soil N balance calculated by the CAPRI model has gained acceptance in European policymaking. It can be mentioned that the Task Force on Reactive Nitrogen (TFRN), established under Convention on Long-Range Transboundary Pollution (CLRTP), is currently establishing national N balances that include agriculture.

  10. 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

    2014-09-15

    Abstract 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

  11. 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...

  12. Balancing Costs for Wind Power

    OpenAIRE

    Larssen, Marit

    2007-01-01

    Nordel is the organisation for the Nordel synchronous system, held by the Nordic Transmission System Operators. In their work to harmonise the Nordic electricity markets they have agreed upon harmonising the Nordic balance management. This will imply three large changes, firstly the settlement of the production balance will be done by a 2-price settlement, (instead of the 1-price settlement in Norway), and secondly there will be a new intraday market for settling the balances after 12- ...

  13. Balancing Trust and Control

    DEFF Research Database (Denmark)

    Jagd, SØren

    Dette papir fokuserer på ledelsesudfordringerne med at afbalancere tillid og kontrol. Forholdet mellem tillid og kontrol har i lang tid været en problem for ledelsesforskere. I papiret vises først at der har været en ændring i den måde, hvorpå forholdet mellem tillid og kontrol er blevet konceptualiseret i tillidsforskningen. Mens forholdet mellem tillid og kontrol tidligere blev set som et mere eller mindre stabil balance mellem tillid og kontrol, anskuer nyere forskning forholdet mellem tillid og kontrol som en dynamisk proces, der involverer en løbende afbalancering af forholdet mellem tillid og kontrol. For det andet, med udgangspunkt i en konceptualisering af balancen mellem tillid og kontrol som en interaktiv proces, drøftes udfordringerne for ledelsen i at håndtere denne mere subtile afbalancering af tillid og kontrol. Papiret konkluderer med at illustrere, hvordan denne mere detaljerede forståelse af samspillet mellem tillid og kontrol er nyttige for forståelsen af samspillet mellem tillid, kontrol ogselvkontrol i nye organisationsformer.

  14. 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 company’s 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.

  15. Recent Changes in the Dynamic Oblateness (J2) of the Earth: Contributions from the Earth's Subsystems and Their Implications

    Science.gov (United States)

    Dickey, J. O.; Marcus, S. L.; Quinn, K. J.; de Viron, O.; Fukumori, I.; Dyurgerov, M. B.

    2004-12-01

    Earth's dynamic oblateness (J2) has been decreasing due to post-glacial rebound (PGR). However, an increase began in 1997 (Cox and Chao, Science, 2002) indicating a pronounced change in the global-scale mass redistribution process. Dickey et al. (Science, 2002) have determined that the observed increases in J2 were caused primarily by a surge in sub-polar glacial melting and mass shifts in the Southern Pacific, and Indian Oceans. Recently, the geodetic J2 series has been decreasing rather than increasing, which motivates the further study. Data series have been extended, in particular ocean loading derived from ECCO bottom pressures and hydrology (Milly, pers. comm.). Both glacial and oceanic sources had enhanced upward trends around 1998. The sums of the glacial, oceanic, atmospheric and continental hydrological contributions to J2 are compared with geodetic observations (Cox and Chao, 2002; Cox, pers. comm., 2003). The modeled excitation captures the rise of J2 in the late 1990's as well as its subsequent decrease, even though J2 contributions due to glacial melting maintain a positive slope. Thus it is not necessary for the glaciers to switch to a net positive mass-balance, in order to match the decrease in the observed J2. Special emphasis will be placed on the recent glacier results.

  16. 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.

  17. Pressure gauge

    International Nuclear Information System (INIS)

    A hollow probe made of a material exhibiting magnetostriction is placed inside the enclosure where the pressure is to be determined. A coil to measure the probe's magnetic permeability is placed outside the enclosure, as near as possible to the probe. A second identical coil is placed elsewhere. A comparison between both coil currents gives the pressure in the enclosure. High sensitiviteis (0.07 at) are reported over a wide range (0-35 at). The instrument is ideal in situations where no electrical or mechanical signal transmission device is allowed through to be fitted into the pressure container, as is the case in fuel bundles in nuclear reactors, for example. (RW)

  18. Measuring Pressure

    Science.gov (United States)

    AMPS GK-12 Program,

    Students learn first-hand the relationship between force, area and pressure. They use a force sensor built from a LEGO® MINDSTORMS® NXT kit to measure the force required to break through a paper napkin. An interchangeable top at the end of the force sensor enables testing of different-sized areas upon which to apply pressure. Measuring the force, and knowing the area, students compute the pressure. This leads to a concluding discussion on how these concepts are found and used in engineering and nature.

  19. Earth System Science

    Science.gov (United States)

    Erin Bardar

    Understanding climate requires understanding that Earth is a holistic system of dynamic, interacting components. Furthermore, understanding how the Earth system works is essential for making informed decisions about how to manage, protect, and sustain our planet and its natural resources. This EarthLabs module helps students understand their world as an interconnected living system. Students learn to identify the parts of the Earth system and the processes that connect them, starting locally and gradually expanding their view to regional and global scales.

  20. Pressure correction schemes for compressible flows

    International Nuclear Information System (INIS)

    This thesis is concerned with the development of semi-implicit fractional step schemes, for the compressible Navier-Stokes equations; these schemes are part of the class of the pressure correction methods. The chosen spatial discretization is staggered: non conforming mixed finite elements (Crouzeix-Raviart or Rannacher-Turek) or the classic MA C scheme. An upwind finite volume discretization of the mass balance guarantees the positivity of the density. The positivity of the internal energy is obtained by discretizing the internal energy balance by an upwind finite volume scheme and b y coupling the discrete internal energy balance with the pressure correction step. A special finite volume discretization on dual cells is performed for the convection term in the momentum balance equation, and a renormalisation step for the pressure is added to the algorithm; this ensures the control in time of the integral of the total energy over the domain. All these a priori estimates imply the existence of a discrete solution by a topological degree argument. The application of this scheme to Euler equations raises an additional difficulty. Indeed, obtaining correct shocks requires the scheme to be consistent with the total energy balance, property which we obtain as follows. First of all, a local discrete kinetic energy balance is established; it contains source terms winch we somehow compensate in the internal energy balance. The kinetic and internal energy equations are associated with the dual and primal meshes respectively, and thus cannot be added to obtain a total energy balance; its continuous counterpart is however recovered at the limit: if we suppose that a sequence of discrete solutions converges when the space and time steps tend to 0, we indeed show, in 1D at least, that the limit satisfies a weak form of the equation. These theoretical results are comforted by numerical tests. Similar results are obtained for the baro-tropic Navier-Stokes equations. (author)

  1. Sun-Earth Viewer

    Science.gov (United States)

    The Sun-Earth Viewer is an experimental Flash-based viewer that allows visitors to zoom and pan live NASA solar and Earth images. In addition, it features video interviews with scientists and detailed scientific animations, extensive interactive sun-earth illustrations, and live interactive solar and aurora images.

  2. 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

  3. Earth science space missions in the 21st century

    Science.gov (United States)

    Grofic, B.

    In 2007, the National Research Council (NRC) published “ Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, 2007” , commonly known as the “ Decadal Survey” . This report called for a balanced set of Earth Science Missions across the Earth Science research spectrum. In response, in February 2008, NASA's Earth Science Division reorganized into two program offices: The Earth Systematic Missions Program Office (ESM PO) at Goddard Space Flight Center which includes satellites making continuous measurements of the Earth's climate, and the Earth System Science Pathfinder Program Office (ESSP PO) at Langley Research Center which develops pathfinder missions through Announcements of Opportunity. In June 2010 NASA published its plan to achieve the goals of the Decadal Survey, “ Responding to the Challenge of Climate and Environmental Change: NASA's Plan for a Climate-Centric Architecture for Earth Observations and Applications from Space.” This plan includes support for the Decadal Survey missions as well as a set of “ climate continuity missions” to address the scientific need for data continuity of key climate observations. In 2011 the NRC revisited the Decadal Survey report and published “ Earth Science and Applications from Space: A Midterm Assessment of NASA's Implementation of the Decadal Survey” . This report notes that progress on the Decadal Survey plan has been slower than planned due to budget shortfalls and launch vehicle failures, and stresses that the goals of the Decadal Survey are as important as ever and must still yield a scientifically-balanced program. This paper will discuss the current status of the mission/mission study portfolios of the ESMP Program and the Earth Venture solicitations of the ESSP Program and how the Programs support the goals established and reiterated by the NRC, and will discuss the risks and challenges faced by t- e Programs as together they strive to meet these goals.

  4. 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

  5. US Government Balances Budget

    Science.gov (United States)

    de Nie, Michael Willem.

    1998-01-01

    This week's In the News discusses the recent announcement that the US government has effectively balanced the budget for the first time in 30 years. The eleven resources discussed offer a variety of information on this topic. The Congressional Budget Office (CBO) recently issued revised projections showing that the federal budget is effectively in the black and should remain that way in the coming decade. The 1998 deficit was once forecast as high as $120 billion, but the new report shows that it will be only $5 billion, a very small amount compared to the overall annual federal budget of $1.7 trillion. If the economy continues to grow at the same steady pace, lawmakers can expect the last vestiges of the deficit to disappear by 2001 and see surpluses as large as $138 billion by 2008. Despite warnings that the economy could slow down and concerns over spending money we do not yet have, lawmakers and the White House are already contemplating ways to spend this expected windfall. Both parties favor some sort of tax cut, with Republicans calling for a larger and more immediate cut than Democrats. The president and many Democrats have declared their support for smaller tax cuts along with expansion of Medicare, child care and other programs. Speaker Newt Gingrich also has called for more spending for defense, highways and scientific research in the event of a surplus.

  6. 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

  7. 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.)

  8. 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...

  9. 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...

  10. The Balanced Development of Basic Education in the Context of Globalization

    Science.gov (United States)

    Sun, Qi-lin; Kong, Kai

    2006-01-01

    Basic education is not only an essential means for eliminating stratification and differences in society but also one of the main reasons for the enlargement of the gap between the rich and the poor. Because it faces pressure in the context of globalization, a balanced development of basic education would be a good way to relieve this pressure.…

  11. Independent effects of adding weight and inertia on balance during quiet standing

    Directory of Open Access Journals (Sweden)

    Costello Kerry

    2012-04-01

    Full Text Available Abstract Background Human balance during quiet standing is influenced by adding mass to the body with a backpack, with symmetrically-applied loads to the trunk, or with obesity. Adding mass to the body increases both the weight and inertia of the body, which theoretically could provide counteracting effects on body dynamics and balance. Understanding the independent effects of adding weight and inertia on balance may provide additional insight into human balance that could lead to novel advancements in balance training and rehabilitation. Therefore, the purpose of this study was to investigate the independent effects of adding weight and inertia on balance during quiet standing. Methods Sixteen normal-weight young adult participants stood as still as possible on a custom-built backboard apparatus under four experimental conditions: baseline, added inertia only, added weight only, and added inertia and weight. Results Adding inertia by itself had no measurable effect on center of pressure movement or backboard movement. Adding weight by itself increased center of pressure movement (indicated greater effort by the postural control system to stand as still as possible and backboard movement (indicating a poorer ability of the body to stand as still as possible. Adding inertia and weight at the same time increased center of pressure movement but did not increase backboard movement compared to the baseline condition. Conclusions Adding inertia and adding weight had different effects on balance. Adding inertia by itself had no effect on balance. Adding weight by itself had a negative effect on balance. When adding inertia and weight at the same time, the added inertia appeared to lessen (but did not eliminate the negative effect of adding weight on balance. These results improve our fundamental understanding of how added mass influences human balance.

  12. 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

  13. 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.

  14. Thermal History of Planetary Objects: From Asteroids to super-Earths, from plate-tectonics to life (Runcorn-Florensky Medal Lecture)

    Science.gov (United States)

    Spohn, Tilman

    2013-04-01

    Convection in the interiors of planetesimals (asteroids), planets, and satellites is driving the thermal and chemical evolution of these bodies including the generation of possible magnetic fields. The wide size range induces a wide of range of time scales from hundreds of thousands of years for small planetesimals to a few tens of Gigayears for massive super-Earths. Evolution calculations are often based on energy (and entropy) balances parameterizing the transport properties of the interior in suitable ways. These thereby allow incorporating (in parameterized forms) interesting physical processes that depend in one way or another on the transport properties of the interior. The interior will usually be chemically layered in mantles and cores and include ice layers if icy satellites are considered. In addition to magnetic field generation calculated via energy balances of the core and using semi-empirical dynamo strength relations, processes that can be considered include sintering and compaction for small bodies and mantle (or ice) melting, differentiation and even continental growth for full-scaled terrestrial planets. The rheology of the interior is considered temperature and pressure dependent and the concentration of volatiles can be important. For super-Earths, probably the most critical consideration is how the mantle rheology would vary with pressure and thus with depth. It is possible that the increasing pressure will frustrate deep mantle convection thereby reducing the vigor of mantle convection. Possibly, the generation of a magnetic field in a putative iron-rich core will be impossible, if super-Earths at all have earth-like cores. On a much smaller scale, the decay of short-lived radioactives suffices to heat and melt planetesimals, the melting being helped by the low thermal conductivity of the initially porous body. This allows planets to form from pre-differentiated planetesimals thus helping to differentiate and form cores rapidly. On active planets - like the Earth - the volatile budget matters for the interior evolution. With plate tectonics, large-scale volatile cycles are invoked. On the Earth, even the biosphere is speculated to interact with the interior. It has been argued (e.g., Rosing et al. 2006; Sleep et al, 2012) that the formation of continents could be a consequence of bioactivity harvesting solar energy through photosynthesis to help build the continents and that the mantle should carry a chemical biosignature. A model is presented that includes mantle convection, mantle water vapor degassing at mid-oceanic ridges and regassing through subduction zones, continental crust formation and erosion and water storage and transport in a porous oceanic crust that includes hydrous mineral phases. The biosphere enters the model through its effect on continental erosion and through a reduction of the activation barrier to metamorphic reactions (e.g., Kim et al., 2004) in sediment layers. An abiotic world is found to have a much drier mantle than the present Earth but may have a similar surface coverage by continents. The reduced rate of continental crust production on the abiotic world would be balanced by a reduced rate of continent erosion. Through the effect of water on the mantle rheology, the biotic world would tend to be tectonically more active and have a more rapid long-term carbon-silicate cycle. J. Kim, H. Dong, J. Seabaugh, S. W. Newell, D. D. Eberl, Science 303, 830-832, 2004 N. H. Sleep, D. K. Bird, E. Pope, Annu. Rev. Earth Planet. Sci. 40, 277-300, 2012 M. T. Rosing, D. K. Bird, N. H. Sleep, W. Glassley, F. Albarede, Paleo3 232, 90-113, 2006

  15. Projectile penetration of earth media

    International Nuclear Information System (INIS)

    Penetration of a projectile into earth is a function of parameters which describe the impact velocity, size, shape, weight, and material properties of the missile, and the unconfined compressive strength of the earth material. Increased velocity, weight, and hardness of the missile material increase the penetration. A sharper nose also leads to deeper penetration, but stronger earth reduces it. The formula for depth of penetration takes into consideration all the important parameters which influence this penetration. The earth can be rock or soil. The soil can be uniform or layered, for which an averaging technique is used. The water table may vary. Results predicted by the proposed formula have been compared with full-scale test results. In the tests, the missile and soil characteristics varied widely. The soil varied from competent rock to very soft clay. The impact velocities of the projectiles were in both the subsonic and supersonic regions. Though the penetrations varied from a few feet to several hundred feet, the differences between the predicted and full-scale test results were within three percent of each other. Formulas are given for the determination of the deceleration and velocity time histories of the penetrating projectile. These easy-to-use formulas are developed considering the phenomenon of contact pressure between colliding bodies. Predicted results compare well with the results obtained by other analytical methods. The proposed method has been ext methods. The proposed method has been extended to missile impact on concrete barriers. Comparisons between predicted and test results for impact on concrete barriers show very good correlation

  16. SiCOI pressure sensors radiation response

    International Nuclear Information System (INIS)

    Radiation tests of SiC-based pressure sensors were carried out. The measured bridge dis-balance voltage deviations from the initial values did not exceed 2% after dose rate 5 x 1010 rad(Si)/s, total dose 106 rad(Si)/s and neutron flux 1013 n/cm2 irradiation. (authors)

  17. CFD application for coal/air balancing in power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vijiapurapu, S.; Cui, J.; Munukutla, S. [Tennessee Technological University, Cookeville, TN (United States). Dept. for Engineering Mechanics

    2006-09-15

    Unbalanced coal/air flow in the pipe systems of coal-fired power plants will lead to non-uniform combustion in the furnace, and hence a overall lower efficiency of the boiler. A common solution to this problem is to put orifices in the pipe systems to balance the flow. It is well known that if the orifices are sized to balance clean air flow to individual burners connected to a pulverizer, the coal/air flow would still be unbalanced and vice versa. However, the current power industry practice throughout the world is to size orifices for balancing the clean air flow and accept the resulting imbalance in coal/air flow. Field tests are mostly conducted to verify a balanced clean air flow. It is now proposed to size the orifices for balancing the coal/air flow and then calculate the unbalanced clean air flow distribution to be known as the 'tailored clean air flow'. Commercially available Computational Fluid Dynamics (CFD) code CFX was used to simulate the complex flows in the piping systems in a power plant. The two-phase modelling technique was employed to estimate the pressure drop coefficients with both clean air and coal/air flows in order to size the orifices. The results indicate that the pressure drop is strongly dependent on the piping system geometry. With this proposed method, field tests can be conducted to correspond with the tailored clean air flow, and the coal/air flow balancing would be achieved.

  18. Análise de fases por difração de raios X de WC-10%Co dopado com terras-raras obtido sob alta pressão / 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 também denominado de metal duro é um material de grande importância tecnológica produzido por metalurgia do pó através de sinterização por fase líquida, partindo-se da mistura dos pós de carbeto de tungstênio (WC) e de cobalto (Co) em moinho convencional. Entretanto, para o [...] btenção de metal duro com maior capacidade (produtividade, vida útil, etc.), uma nova rota alternativa de metalurgia do pó denominada de altas pressões e altas temperaturas vem sendo utilizada para produção destes materiais com resultados promissores. O presente trabalho tem como objetivo principal a análise de fases de WC-10Co dopado com terras-raras (La2O3, CeO2e Y2O3) preparadas sob condições de alta pressão. Esta liga de metal duro é um exemplo de material compósito largamente utilizado como ferramenta de corte e operações de usinagem em geral. Foram preparadas diversas misturas de WC-10Co contendo até 2 % em peso de terra-rara (La2O3, CeO2e Y2O3) da fase cobalto. Os pós previamente misturados foram compactados numa matriz cilíndrica (? = 7 mm) a uma pressão de 800 MPa e sinterizados a 1400 ºC durante 40 s sob alta pressão de 5,5 GPa. Os compósitos produzidos foram caracterizados por difração de raios X para identificação de fases cristalinas presentes. Além disso, foi feita análise comparativa entre o carbeto isento de terra-rara (amostras de referência) e carbetos dopados com elementos de terra-rara (La2O3, CeO2, e Y2O3). Para as condições estudadas os resultados mostraram que durante o processo de sinterização ocorreu à formação, mesmo que em pequenas quantidades, das fases Co3W3C2 e ? (carbeto tipo ?) nas peças 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 1400ºC 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.

  19. 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 thermal 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 high-energy 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 signficiant improvement in plant efficiency as the electrical power multiplication factor and steam cycle efficiency increases

  20. Older Adults and Balance Problems

    Medline Plus

    Full Text Available ... way of looking at it, our orientation in space. The inner ear organ of balance is the ... have receptors telling you where you are in space. Narrator: Some of the symptoms a person with ...

  1. 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)

  2. 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)

  3. Exercise to Improve Your Balance

    Science.gov (United States)

    ... number of lower-body exercises – especially those that strengthen your legs and ankles – also can help improve your balance. These include the back leg raise, side leg raise, knee curl, and toe stand exercises, which can be ...

  4. 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...

  5. Uncontrolled hypertension and orthostatic hypotension in relation to standing balance in elderly hypertensive patients

    Science.gov (United States)

    Shen, Shanshan; He, Ting; Chu, Jiaojiao; He, Jin; Chen, Xujiao

    2015-01-01

    Objective To investigate the associations among uncontrolled hypertension, orthostatic hypotension (OH), and standing balance impairment in the elderly hypertensive patients referred to comprehensive geriatric assessment (CGA). Methods In a cross-sectional study, a total of 176 elderly hypertensive patients who underwent CGA were divided into OH group (n=36) and non-OH group (n=140) according to blood pressure measurement in the supine position, after immediate standing up, and after 1 minute and 3 minutes of standing position. Uncontrolled hypertension was defined as blood pressure of ?140/90 mmHg if accompanied by diabetes mellitus (DM) or chronic kidney disease (CKD), or ?150/90 mmHg if no DM and no CKD. Standing balance, including immediate standing balance and prolonged standing balance, was assessed in side-by-side and tandem stance. Results Neither uncontrolled hypertension nor OH was associated with prolonged standing balance impairment in elderly hypertensive patients (P>0.05). Blood pressure decrease after postural change was significantly associated with immediate standing balance impairment in side-by-side and tandem stance (Ppressure decrease after postural change were associated with immediate standing balance impairment, and therefore, a better understanding of the underlying associations might have major clinical value.

  6. 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

  7. 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 firm's assets. 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 the deg...

  8. Sodium Balance in Maintenance Hemodialysis

    OpenAIRE

    Lee, Seoung Woo

    2012-01-01

    Sodium is the principal solute in the extracellular compartment and the major component of serum osmolality. In normal persons in the steady state, sodium homeostasis is achieved by a balance between the dietary intake and the urinary output of sodium, whereas in intermittent hemodialysis patients, sodium balance depends on dietary intake and sodium removal during hemodialysis. Thus, the main goal of hemodialysis is to remove precisely the amount of sodium that has accumulated during the inte...

  9. Compositional Balancing Before Moon Formation

    Science.gov (United States)

    Taylor, G. J.

    2008-02-01

    A striking feature in the compositions of the Earth and Moon is their identical abundances of oxygen isotopes. Most planetary scientists agree that the Moon formed as the result of a giant impact with the proto-Earth. It explains some important characteristics about the Earth and Moon, such as why the Moon has a small metallic iron core, but planetary formation models suggest that the Moon ought to have a different oxygen isotopic composition than the Earth. Why is it the same? Kaveh Pahlevan and David Stevenson (Caltech) suggest that after the giant impact and before the Moon formed, Earth exchanged materials with the disk of magma and gas surrounding it, ironing out differences in their isotopic compositions. The process would take a couple of hundred years, about the time (100 to 1000 years) the disk would last before coalescing into the Moon. This interesting idea is far from proven, but it will undoubtedly lead to additional work because it has such great implication s for the compositions of the Earth and Moon, when Earth received its water, and how planets accreted from the cloud of gas and dust surrounding the primitive Sun.

  10. Interannual-Decadal Changes in the Earth's Dynamic Oblateness: Isolation of the Cryospheric Contribution

    Science.gov (United States)

    Dickey, J. O.; Marcus, S. L.; Dyurgerov, M. B.; Quinn, K. J.; Viron, O. D.; Fukumori, I.

    2005-12-01

    Recent changes in the Earths dynamic oblateness (J2) have shown evidence of pronounced variability on interannual-decadal time scales. In particular, a marked anomaly commencing in 1997 showed an increase in J2 strong enough to temporarily reverse the secular decrease due to post-glacial rebound (Cox and Chao, 2002), indicating an anomalous global mass flux from high to low latitudes. Dickey et al. (2002) showed that glacier melting and oceanic bottom pressure changes made substantial contributions to this anomaly. Data series have since been extended, in particular ocean loading derived from ECCO bottom pressures and the hydrology (Milly, pers. comm.). In our updated results, we show that changes in the oceanic and continental hydrological contributions account for a large portion of the J2 changes on interannual time scales. The changes in the mass balance of small (mountain and sub-polar) glaciers explain the larger and longer-term residual changes in J2. Since J2 has its strongest weighting at the poles, contributions from glacial melting at high latitudes account for most of this signal. We note that the temperate-latitude glaciers, for example in Asia, make a large mass change contribution; however, their contribution to J2 changes is small because of their proximity to the J2 nodal latitude, especially near the Himalayas. The polar ice sheets may also be contributing to oblateness variations; due to the many competing geophysical processes and the large areas involved, however, their net mass balance and gravity changes on interannual-decadal time scales cannot yet be accurately assessed.

  11. Near Earth Objects

    OpenAIRE

    Wolff, Stefan

    2008-01-01

    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 ...

  12. The Earth's Magnetic Field

    OpenAIRE

    Edda Lína Gunnarsdóttir 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...

  13. Balanced Flow Measurement and Conditioning Technology (Balanced Orifice Plate 7,051,765 B1) for NASA Inventions and Contributions Board Invention of the Year Evaluation

    Science.gov (United States)

    Kelley, Anthony R.

    2008-01-01

    This viewgraph document reviews the Balanced Flow Measurement (BFM) and Conditioning Technology, and makes the case for this as the NASA Invention of the Year. The BFM technology makes use of a thin, multi-hole orifice plate with holes sized and placed per a unique set of equations. It produces mass flow, volumetric flow,kinelic energy,or momentum BALANCE across the face of the plate. The flow is proportional.to the square root of upstream to downstream differential pressure. Multiple holes lead to smoother pressure measurement. Measures and conditions or can limit fluid flow. This innovation has many uses in and out of NASA.

  14. Conclusions drawn of tritium balance in light water reactors

    International Nuclear Information System (INIS)

    In the tritium balance of pressurized water reactors, using boric acid and lithium in the cooling water, contribution of the tritium produced by fission, diffusing through the zircalloy of the fuel cladding estimated to 0.1%, was not in agreement with quantities measured in reactors. It is still difficult to estimate what percentage is represented by the tritium formed by fission in the fuel, owing to diffusion through cladding. The tritium balance in different working nuclear power stations is consequently of interest. The tritium balance method in the water of the cooling circuit of PWR is fast and experimentally simple. It is less sensitive to errors originating from fission yields than balance of tritium produced by fission in the fuel. A tritium balance in the water of the cooling circuit of Biblis-A, with a specific burn-up of 18000 MWd/t gives a better precision. Diffusion rate of tritium produced by fission was less than 0.2%. So low a contribution is a justification to the use of lithium with an isotopic purity of 99.9% of lithium 7 to limit at a low value the residual lithium 6

  15. Pressure polymerization of polyester

    Science.gov (United States)

    Maurer, Charles J. (Matthews, NC); Shaw, Gordon (Charlotte, NC); Smith, Vicky S. (Greer, SC); Buelow, Steven J. (Los Alamos, NM); Tumas, William (Los Alamos, NM); Contreras, Veronica (San Antonio, TX); Martinez, Ronald J. (Santa Cruz, NM)

    2000-08-29

    A process is disclosed for the preparation of a polyester polymer or polyester copolymer under superatmospheric pressure conditions in a pipe or tubular reaction under turbannular flow conditions. Reaction material having a glycol equivalents to carboxylic acid equivalents mole ratio of from 1.0:1 to 1.2:1, together with a superatmospheric dense gaseous medium are fed co-currently to the reactor. Dicarboxylic acid and/or diol raw materials may be injected into any of the reaction zones in the process during operation to achieve the overall desired mole ratio balance. The process operates at temperatures of from about 220.degree. C. to about 320.degree. C., with turbannular flow achieved before the polymer product and gas exit the reactor process. The pressure in the reaction zones can be in the range from 15 psia to 2500 psia. A polymer product having a DP of a greater than 40, more preferably at least about 70, is achieved by the transfer of water from the reacting material polymer melt to the gaseous medium in the reactor.

  16. Ecological Elements of Water Balance

    Science.gov (United States)

    Dong, X.; Fisher, S. G.; Grimm, N. B.

    2011-12-01

    In simplest terms, "water balance" can refer to the water budget in a bounded system within a specified time frame. While this mass-balance approach is important, a broader concept that includes ecological notions of balance, stability, and feedbacks is useful, especially when management goals extend to maintenance of ecological health and ecosystem integrity concomitant with water delivery. Here, we propose three ecological elements to enrich the concept of hydrologic balance. (1) A spatially explicit perspective of water and nutrient balance replaces the holistic view. For example, in fluvial landscapes, routing of water generates hydrologic connectivity via flowpaths and creates a hydrologic network. Important patches in the network include hillslopes, floodplains, riparian areas, surface channels, and hyporheic zones, each of which is characterized by unique biogeochemical processes. Different hydrologic network structures have different nutrient-removal capacities, which depend upon how their flowpaths intersect patch-specific processing. The connectivity among these patches is an important variable influencing nutrient-retention capacity of landscapes, and thereby the resulting water quality in receiving systems. (2) Temporal regime is an important component of balance. Organisms in a fluvial landscape reflect the inherent time schedule of the system, as a result of long-term interactions and adaptation to the environment. In aridland streams, the drying and flood cycle select flora whose life cycles and activities fit the hydrological regime. The existence of particular species relies on the temporal distribution of water-the input regime-more than the integral input and output balance. The match of organism life cycle and hydrologic regime is the basis for biodiversity and ecosystem functions. (3) Ecosystems are self-organized systems based on feedbacks among organisms and between organisms and the abiotic environment. They do not simply respond to hydrology passively and predictably. While both the amount and the spatial-temporal regime of water can be easily quantified, the consequences for ecosystems are harder to predict. Many ecological responses are nonlinear and state changes are observed in many systems. The return of a former hydrological regime may not take the system back to its previous state. In summary, while water is an important factor in ecosystems, a focus on hydrological balance or even ecological balance is insufficient. A new, broader perspective, which considers the self-organizing nature of ecosystems and nonlinear feedbacks between hydrogeomorphology and ecology, and a conceptual shift from water balance to spatiotemporal ecohydrologic dynamics, will enhance understanding.

  17. The relationship of abdominal muscles balance and body balance.

    Science.gov (United States)

    Seo, Dong-Kwon; Kim, Ji-Seon; Lee, Dong-Yeop; Kwon, Oh-Sung; Lee, Sang-Sook; Kim, Jee-Hee

    2013-07-01

    This study aimed to identify what impact the thickness differences between the leftside and rightside transversus abdominis (TrA), internal obliquus (IO) and external obliquus (EO) have on balance ability in the abdominal drawing-in maneuver (ADIM) and resting postures. [Subjects and Methods] In this study, 41 young adults were asked to adopt a resting posture and to perform ADIM. The thicknesses of the abdominal muscles (TrA, IO, EO) were measured using ultrasound imaging, Then balance ability was measured, so that a comparative analysis could be carried out. [Results] According to the results, the thicknesses of TrA and IO very significantly increased when ADIM was performed. The changes in thickness of the muscles on the left and right sides showed no significant correlations with balance ability. [Conclusion] According to the study results, the difference in thickness between the left and right side muscles in a normal person is small (symmetric), and the differences in the thickness of TrA and IO on the left and right side reduced when the ADIM, which is a re-education method for abdominal muscles was performed. Therefore, we consider that the ADIM should be used in future clinical trials to induce symmetric contraction of the abdominal muscles. Also, the correlation results of muscle balance and body balance can be used as empirical data. PMID:24259848

  18. Solar energy resources not accounted in Brazilian National Energy Balance

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Paulo Cesar da Costa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica], Emails: pinheiro@netuno.Lcc.ufmg.br, pinheiro@demec.ufmg.br

    2009-07-01

    The main development vector of a society is the energy. The solar energy is the main energy source on the planet earth. Brazil is a tropical country, and the incident solar energy on its soil (15 trillion MWh/year) is 20,000 times its annual oil production. Several uses of solar energy are part of our lives in a so natural way that it despised in the consumption and use energy balance. In Brazil, solar energy is used directly in many activities and not accounted for in Energy Balance (BEN 2007), consisting of a virtual power generation. This work aims to make a preliminary assessment of solar energy used in different segments of the Brazilian economy. (author)

  19. A reconciled estimate of ice-sheet mass balance.

    DEFF Research Database (Denmark)

    Shepherd, Andrew; Ivins, Erik R

    2012-01-01

    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 Earth's polar ice sheets. We find that there is good agreement between different satellite methods--especially in Greenland and West Antarctica--and 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.

  20. Equilibrium and power balance constraints on a quasi-static Ohmically heated field-reversed configuration (FRC)

    International Nuclear Information System (INIS)

    Zero-dimensional power balance calculations are performed for a quasi-static, purely Ohmically heated field-reversed configuration. Without compression, the constraint imposed by radial pressure balance limits the power input. Estimates of the energy loss from impurity line radiation as well as from classical and anomalous transport are given. Effects of cold puff gas injection are also investigated. (author)

  1. High Poisson's ratio of Earth's inner core explained by carbon alloying

    Science.gov (United States)

    Prescher, C.; Dubrovinsky, L.; Bykova, E.; Kupenko, I.; Glazyrin, K.; Kantor, A.; McCammon, C.; Mookherjee, M.; Nakajima, Y.; Miyajima, N.; Sinmyo, R.; Cerantola, V.; Dubrovinskaia, N.; Prakapenka, V.; Rüffer, R.; Chumakov, A.; Hanfland, M.

    2015-03-01

    Geochemical, cosmochemical, geophysical, and mineral physics data suggest that iron (or iron-nickel alloy) is the main component of the Earth’s core. The inconsistency between the density of pure iron at pressure and temperature conditions of the Earth’s core and seismological observations can be explained by the presence of light elements. However, the low shear wave velocity and high Poisson’s ratio of the Earth’s core remain enigmatic. Here we experimentally investigate the effect of carbon on the elastic properties of iron at high pressures and temperatures and report a high-pressure orthorhombic phase of iron carbide, Fe7C3. We determined the crystal structure of the material at ambient conditions and investigated its stability and behaviour at pressures up to 205 GPa and temperatures above 3,700 K using single-crystal and powder X-ray diffraction, Mössbauer spectroscopy, and nuclear inelastic scattering. Estimated shear wave and compressional wave velocities show that Fe7C3 exhibits a lower shear wave velocity than pure iron and a Poisson’s ratio similar to that of the Earth’s inner core. We suggest that carbon alloying significantly modifies the properties of iron at extreme conditions to approach the elastic behaviour of rubber. Thus, the presence of carbon may explain the anomalous elastic properties of the Earth’s core.

  2. 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...

  3. Blood pressure measurement

    Science.gov (United States)

    Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... or your health care provider will wrap the blood pressure cuff snugly around your upper arm. The ...

  4. 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 aretor 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)

  5. Production of Freshwater and Energy from Earth’s Atmosphere

    Directory of Open Access Journals (Sweden)

    Alexander Bolonkin

    2011-05-01

    Full Text Available The author offers a new, cheap method for the extraction of freshwater from the Earth’s atmosphere. The suggested method is fundamentally dictinct from all existing methods that extract freshwater from air. All other industrial methods extract water from a saline water source (in most cases from seawater. This new method may be used at any point in the Earth except the Polar Zones. It does not require long-distance freshwater transportation. If seawater is not utilized for increasing its productivity, this inexpensive new method is very environmentally-friendly. The author’s method has two working versions: 1 In the first variant warm (or hot atmospheric air is lifted by the inflatable tube in a high altitude and atmospheric water vapor is condensed into freshwater: 2 in the second version, the warm air is pumped 20-30 meters under the sea-surface. In the first version, wind and solar heating of air are used for causing air flow. In version 2 wind and fans are used for causing air movment. The first method does not need energy, the second needs a small amount. Moreover, in variant 1 the freshwater has a high pressure (> 30 or more atm and can be used for production of energy such as electricity and in that way the freshwater cost is lower. For increasing the productivity the seawater is injected into air and a solar air heater may be used. The solar air heater produces a huge amount of electricity as a very powerful electrical generation plant. The offered electricity installation is 100 - 200 times cheaper than any common electric plant of equivalent output.

  6. Closing the balance (Louis Agassiz Medal Lecture)

    Science.gov (United States)

    van den Broeke, Michiel

    2015-04-01

    The 4000 Gt of ice that has been lost since 2003 by the ice sheets of Greenland and West Antarctica accounts for about 1/3 of recent global mean sea level rise. Especially the Greenland ice sheet is far out of balance: each year, 30% more mass leaves the ice sheet than is gained by snowfall at its surface; in Antarctica, this imbalance is currently less than 10%. To make matters worse, the mass loss is accelerating: each year it increases by about 10%, making it likely that the ice sheets will soon become the main source of global mean sea level rise. Given their huge volumes, they could remain so for centuries to come. Thirty years ago, the concept of rapid melting of the large ice sheets was purely theoretical. But since that time, the evolution of remote sensing techniques (altimetry, gravimetry and interferometry), in situ observations (automatic weather stations, mass balance and ice velocity measurements) and climate models has revealed a surprising diversity of mass loss mechanisms. This ranges from the relatively steady acceleration of large West-Antarctic ice streams to the highly variable (in space and time) flow speed of outlet glaciers in Greenland. Moreover, both ice sheets experience large interannual fluctuations in snowfall and melt, temporarily masking or accentuating the mass loss. In spite of all the technological developments, there is still room for exciting discoveries. In April 2011, a reservoir of liquid water twice the size of the Netherlands was discovered in the firn in southeast Greenland. In July 2012, an extreme melt event affected the entire Greenland ice sheet, with meltwater runoff destroying infrastructure in west Greenland that had been in place since the 1950's. And in 2014, two separate studies concluded that the mass loss in West Antarctica appears to be irreversible. When will it be possible to model and robustly predict the fully coupled system of atmosphere, ocean, sea ice and ice sheets? To start answering that question, we explore possibilities and outstanding challenges in the application of Earth System Models to ice sheet mass balance on one hand, and the use of very-high-resolution regional models to individual glacier basins and fjord systems on the other. These models need observations! We show a newly developed suitcase automatic weather station (iWS) for easy deployment in remote, glaciated regions, without compromising measurement accuracy.

  7. 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.

  8. 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…

  9. 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.

  10. Earth and Universe

    International Nuclear Information System (INIS)

    Rocks, the age of which according to certain data exceeds considerably the recognized age of the Earth and approximates the age of the Universe, have been detected on the Earth. There is a necessity to coordinate the geological data with cosmological structures

  11. 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…

  12. An Improved Hadoop Data Load Balancing Algorithm

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2013-12-01

    Full Text Available Data load balancing is one of the key problems of big data technology. As a big data application, Hadoop has had many successful applications. HDFS is Hadoop Distributed File System and has the load balancing procedure which can balance the storage load on each machine. However, this method cannot balance the overload rack preferentially, and so it is likely to cause the breakdown of overload machines. In this paper, we focus on the overload machines and propose an improved algorithm for balancing the overload racks preferentially. The improved method constructs Prior Balance List list which includes overload machines, For Balance List list and NextForBalanceList list by many factors and balances among the racks selected from these lists firstly. Experiments show that the improved method can balance the overload racks in time and reduce the possibility of breakdown of these racks

  13. 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.)

  14. Introduction to Google Earth

    Science.gov (United States)

    Liane Stevens

    This assignment is a geologically-oriented Google Earth tutorial that is used in preparation for a course project in which students create Google Earth content summarizing the geology of features of interest on campus. This tutorial addresses navigation, layers and featured content, and creation and modification of placemarks, paths, and polygons. Students are expected to be proficient in the use of Google Earth at the completion of the tutorial. Proficiency with Google Earth allows students to complete geologically advanced projects that require, or benefit from, geographic display of information. Further, non-science majors are introduced to the exploration of Earth using this fascinating application, and are able to find applications for the program in their daily lives.

  15. Rare earth containing magnets

    International Nuclear Information System (INIS)

    This patent describes a rare earth-ferromagnetic metal alloy permanent magnet. Produced by the method comprising the steps of: mixing a particular additive material selected from the group consisting of refractory oxides, carbides, and nitrides, in an amount which provides about 0.1 percent to about 2 percent by weight additive material in the mixture, with a major amount of a particulate rare earth-ferromagnetic metal, and a minor amount of a particulate rate earth-ferromagnetic metal sintering aid alloy; aligning magnetic domains of the mixture in a magnetic field; compacting the aligned mixture to form a shape; sintering the compacted shape; and wherein the method produces a magnet composition containing a major phase amount of the particulate rare earth-ferromagnetic metal alloy, a minor phase amount of the particulate rare earth-ferromagnetic metal sintering aid alloy, and added oxide, carbide or nitride from the particulate additive

  16. Asteroid Challenge, Target: Earth

    Science.gov (United States)

    This interactive multimedia feature introduces students to asteroids. Topics include what they are, where they occur, and the probability that a large asteroid might strike the Earth. There is a discussion of Near-Earth Asteroids (NEAs) and particularly the asteroid Apophis, an asteroid over a thousand feet wide that is expected to pass very close to Earth in 2036. There is also discussion of possible ways to alter the orbits of NEAs so that they will not hit the Earth. After each segment, which consists of narrated videos and illustrations featuring Dr. Neil deGrasse Tyson, director of New York City's Hayden Planetarium, students complete a quiz to move on to the next section. The feature concludes with virtual labs in which students match spectrograms of asteroids with compositions of known substances such as water, carbon, and iron, and compute the trajectory of an asteroid to see if it will hit the Earth.

  17. Realization of thermal Convection into the initial Earth's Core on the Stage of planetary Accumulation

    Science.gov (United States)

    Professor Khachay, Yurie

    2015-04-01

    Convection in the Earth's core is not only the main mechanism of heat-mass transfer, but the significant component of the MHD mechanism of geomagnetic field generation. However the research of different convection forms on the Earth's accumulation stage had been so far not produced. Regarding the convection realization into the initial core of the growing proto planet we can distinguish some qualitative different stages. The earliest from them for the area of the planets of the Earth's group had been realized in to the pre planetary bodies, when the energy dissipation by the decay of the short living radioactive, first of all 26Al, provided the melted state of the inner areas of the proto planet. By that the masses and relative velocities of body's impacts during the process of accumulation had been small. That stipulated the low temperature values of the growing proto planetary surface [1] and the background of Raleigh heat convection realization. On the next stage of the planetary accumulation the contribution of short living isotopes to the energetic process during the decay 26Al decreased, but the energy contribution from the body's impact increased. The balance of the energy on the surface of the proto planet leaded to the melted state of the upper envelope and to the inelastic character of the impact. Further during the increase of the proto planetary mass, increase of the pressure and the melting temperature with the depth and decrease of the intensity of the dissipate energy by the body's impact, which became more elastic because of the silicate part, the background of the Raleigh heat convection can be realized [2]. However the falling of accumulated bodies can lead to the random distribution of the heat anomalies, which we could research only in the frame of the 3-D model [3-4]. For researching of the MHD mechanism of geomagnetic field generation developing yet on the stage of Earth's accumulation in that paper are presented the results of numerical modeling of PT- conditions and revealed the conditions, when the random distribution of 3D thermal heterogeneities does not destroy the thermal convection into the forming outer Earth's core. Reference 1Anfilogov V.N.,Khachay Y.V.DAN (2005) ,V 403, N 6, 803-806. 2 Anfilogov V.N.,Khachay Y.V.Litosphere (2012), N6, 3-1 3.Khachay Y.V. Magnetohydrodynamics. ( 2013), 49 N 1-3, 81-86 4.Khachay Y., Antipin A.Ural'skij geofiziceskij vestnik (2014), N1,81-85

  18. On the near surface momentum balance in the Yucatán Channel

    Scientific Electronic Library Online (English)

    M, Marín; J, Candela; J, Sheinbaum; J, Ochoa; A, Badan.

    2008-03-01

    Full Text Available Se analizó el balance horizontal de momento en la capa superior de Canal de Yucatán para un periodo de 22 meses de septiembre de 1999 a junio de 2001, usando datos de corrientes superficiales de mediciones de ADCPs de ocho anclajes localizados a través del canal, datos de presión de mediciones de se [...] nsores de presión a ambos lados del canal, vientos de QUICKSCAT y datos de altimetría de AVISO. El balance promedio entre Isla Mujeres, México, y Cabo San Antonio, Cuba, (a través del canal) es básicamente geostrófico con contribuciones de los términos ageostroficos, en particular de la fricción contra la capa inferior y en menor grado el flujo de Ekman en la superficie. Los términos advectivos así como el término de la aceleración local parecen no tener importancia en el balance promediado de lado a lado del canal. Es interesante notar que a lo largo del canal el balance promedio es principalmente geostrófico mientras que la fricción lineal, el flujo de Ekman, así como los términos de aceleración local y advectivos permanecen sin importancia. Realizando un análisis del balance de anclaje a anclaje a través del canal se encontró que en la zona donde la corriente de Yucatán oscila, los términos advectivos con derivadas en la dirección a través del canal si contribuyen significativamente al balance dinámico. Se obtuvieron FEOs de las anomalías del nivel del mar de altimetría y de los primeros 90 metros del flujo a lo largo del canal encontrando que existe relación entre ellos donde los primero modos (altimetría y flujo) parecen estar relacionados con la variabilidad del transporte a través del canal y también están asociados con el gradiente de presión a lo largo del canal y la oscilación del núcleo de la corriente, sugiriendo que existe una considerable interacción de remolinos con la corriente en el Canal. Abstract in english The horizontal momentum balance in the upper layers of the Yucatán Channel is examined for a period of 22 months, from September 1999 to June 2001, using subsurface currents from ADCP measurements at eight moorings across the channel, pressure measurements from coastal pressure sensors on both sides [...] of the channel, QuickSCAT winds and AVISO altimetry data. The averaged balance between Isla Mujeres, México, and Cabo San Antonio, Cuba, (across-channel axis) is basically geostrophic, but with contributions from ageostrophic terms, particularly friction against lower layers and to a lesser degree, the surface Ekman drift. Both the advective and the local acceleration terms appear unimportant in the side-to-side averaged balance. Interestingly, the averaged balance in along-channel axis is also mainly geostrophic; linear friction, Ekman drift, local acceleration and advective terms remain unimportant. An analysis of the balance from mooring to mooring across the channel indicates that in the region where the Yucatán current meanders, the advective terms with across-channel derivatives contribute significantly. The EOF modes of sea level anomalies from altimetry and the along-channel flow in the upper 90 m surface layer are correlated. Their two first modes are seemingly related to the transport fluctuations through the channel, but also to the along-channel pressure gradient and to the meandering of the Yucatán Current core, suggesting the presence of appreciable eddy-current interactions in the Channel.

  19. Balancing on tightropes and slacklines.

    Science.gov (United States)

    Paoletti, P; Mahadevan, L

    2012-09-01

    Balancing on a tightrope or a slackline is an example of a neuromechanical task where the whole body both drives and responds to the dynamics of the external environment, often on multiple timescales. Motivated by a range of neurophysiological observations, here we formulate a minimal model for this system and use optimal control theory to design a strategy for maintaining an upright position. Our analysis of the open and closed-loop dynamics shows the existence of an optimal rope sag where balancing requires minimal effort, consistent with qualitative observations and suggestive of strategies for optimizing balancing performance while standing and walking. Our consideration of the effects of nonlinearities, potential parameter coupling and delays on the overall performance shows that although these factors change the results quantitatively, the existence of an optimal strategy persists. PMID:22513724

  20. Variable pressure ionization detector for gas chromatography

    Science.gov (United States)

    Buchanan, Michelle V. (Knoxville, TN); Wise, Marcus B. (Oak Ridge, TN)

    1988-01-01

    Method and apparatus for differentiating organic compounds based on their electron affinity. An electron capture detector cell (ECD) is operated at pressures ranging from atmospheric to less than 1 torr. Through variation of the pressure within the ECD cell, the organic compounds are induced to either capture or emit electrons. Differentiation of isomeric compounds can be obtianed when, at a given pressure, one isomer is in the emission mode and the other is in the capture mode. Output of the ECD is recorded by chromatogram. The invention also includes a method for obtaining the zero-crossing pressure of a compound, defined as the pressure at which the competing emission and capture reactions are balanced and which may be correlated to the electron affinity of a compound.

  1. Redox balance in cystic fibrosis.

    Science.gov (United States)

    Ziady, Assem G; Hansen, Jason

    2014-07-01

    The homeostatic balance between oxidants and antioxidants in biological systems is known as redox balance, and is regulated by complex processes. Redox balance regulates many of the known cellular pathways and disease processes. The dysregulation of redox balance can lead to acute or long-term oxidative or reductive stresses that are associated with many of the abnormalities observed in cystic fibrosis (CF). Over the past 5 decades researchers have examined contributors to redox dysregulation, their molecular products, and their impact on ion transport, cell proliferation, inflammation, bacterial killing, and the metabolism of nucleic acids, proteins, and lipids in CF. CF patients exhibit elevated markers of oxidative stress when compared to non-CF healthy controls; however, whether the reported redox imbalance is sufficient to produce pathology has been controversial. In addition, comparisons between CF and non-CF disease controls have been lacking. To better understand the mechanisms which mediate the generation of oxidants and antioxidants in CF and the importance of their balance in effecting oxidative or reductive stress, we will review the determinants of redox balance in the blood, lumen, and cellular compartments. From the perspective of methodological application, we will focus on the approaches most often used to study oxidant and antioxidants in CF, including biochemical, proteomic, metabolomic, and lipidomic studies, with a discussion of the few transcriptomic analyses that predict changes in the expression of regulators of redox. Finally, we will discuss the utility of oxidants and antioxidants as biomarkers of disease and the use of antioxidant therapy in CF. PMID:24657650

  2. The Moon and the Earth

    Science.gov (United States)

    Carrie Benson

    2012-01-06

    How does the moon affect the Earth? Read the information on the following websites to help you learn about the moon and the earth. Easy Moon/Earth info Easy Moon Info Moon Information Moon Photos Moon Phases ...

  3. Heider balance in human networks

    Science.gov (United States)

    Gawro?ski, P.; Ku?akowski, K.

    2005-07-01

    Recently, a continuous dynamics was proposed to simulate dynamics of interpersonal relations in a society represented by a fully connected graph. The final state of such a society was found to be identical with the so-called Heider balance (HB), where the society is divided into two mutually hostile groups. In the continuous model, a polarization of opinions was found in HB. Here we demonstrate that the polarization occurs also in Barabási-Albert networks, where the Heider balance is not necessarily present. In the second part of this work we demonstrate the results of our formalism, when applied to reference examples: the Southern women and the Zachary club.

  4. Balanced Unemployment in Polish Economy

    Directory of Open Access Journals (Sweden)

    Kamila Szyma?ska

    2009-06-01

    Full Text Available The article deals with the problem of balanced unemployment in relation to the Polish economy. This issue with its variety considerations and economic, social and political implications is today one of the most important matter. Author analyses this problem together with its reasons and refer it to the Polish economy. In first and second part of the text there are presented basic assumptions of natural unemployment theory and Non-Accelerating Inflation Rate of Unemployment. Third part is an analysis of balanced unemployment in the Polish economy

  5. 25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

    Science.gov (United States)

    Packard, Edward

    2008-01-01

    Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The ESA Large Space Simulator Mechanical Ground Support Equipment for Spacecraft Testing; Temperature Stability and Control Requirements for Thermal Vacuum/Thermal Balance Testing of the Aquarius Radiometer; The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System; Return to Mercury: A Comparison of Solar Simulation and Flight Data for the MESSENGER Spacecraft; Floating Pressure Conversion and Equipment Upgrades of Two 3.5kw, 20k, Helium Refrigerators; Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load; Special ISO Class 6 Cleanroom for the Lunar Reconnaissance Orbiter (LRO) Project; A State-of-the-Art Contamination Effects Research and Test Facility Martian Dust Simulator; Cleanroom Design Practices and Their Influence on Particle Counts; Extra Terrestrial Environmental Chamber Design; Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability; SES and Acoustics at GSFC; HST Super Lightweight Interchangeable Carrier (SLIC) Static Test; Virtual Shaker Testing: Simulation Technology Improves Vibration Test Performance; Estimating Shock Spectra: Extensions beyond GEVS; Structural Dynamic Analysis of a Spacecraft Multi-DOF Shaker Table; Direct Field Acoustic Testing; Manufacture of Cryoshroud Surfaces for Space Simulation Chambers; The New LOTIS Test Facility; Thermal Vacuum Control Systems Options for Test Facilities; Extremely High Vacuum Chamber for Low Outgassing Processing at NASA Goddard; Precision Cleaning - Path to Premier; The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT; Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar; Thermal (Silicon Diode) Data Acquisition System; Aquarius's Instrument Science Data System (ISDS) Automated to Acquire, Process, Trend Data and Produce Radiometric System Assessment Reports; Exhaustive Thresholds and Resistance Checkpoints; Reconfigurable HIL Testing of Earth Satellites; FPGA Control System for the Automated Test of MicroShutters; Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM; Operationally Responsive Space Standard Bus Battery Thermal Balance Testing and Heat Dissipation Analysis; Galileo - The Serial-Production AIT Challenge; The Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Simulated Reentry Heating by Torching; Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum; High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber; The Planning and Implementation of Test Facility Improvements; and Development of a Silicon Carbide Molecular Beam Nozzle for Simulation Planetary Flybys and Low-Earth Orbit.

  6. Greenland ice sheet mass balance: a review

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Aschwanden, Andy

    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 photographs and gravimetry data sets together with modelling studies. We revisit the mass loss of different sectors and show that theymanifest quite different sensitivities to atmospheric and oceanic forcing. In addition, we discuss recent progress in constructing coupled ice-ocean-atmosphere models required to project realistic future sea-level changes.

  7. Greenland ice sheet mass balance: a review

    Science.gov (United States)

    Khan, Shfaqat A.; Aschwanden, Andy; Bjørk, Anders A.; Wahr, John; Kjeldsen, Kristian K.; Kjær, Kurt H.

    2015-04-01

    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 photographs and gravimetry data sets together with modelling studies. We revisit the mass loss of different sectors and show that they manifest quite different sensitivities to atmospheric and oceanic forcing. In addition, we discuss recent progress in constructing coupled ice-ocean-atmosphere models required to project realistic future sea-level changes.

  8. 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...

  9. SAVER: digital computer code to determine pressure drops

    International Nuclear Information System (INIS)

    The SAVER code calculates the steady-state flow and pressure drop in all paths of an arbitrary flow network. SAVER calculates elevation and momentum recoverable pressure drops and the types of unrecoverable pressure drops encountered most often. The pressure drop in each path is the sum of the elevation, momentum, and unrecoverable pressure drops. The momentum and unrecoverable pressure drops are expressed as R x W2, where R is the resistance to flow and W is the flow rate. The elevation pressure drop is not a function of flow rate. The elevation pressure drop and the resistances to flow are calculated using the B and W standard methods. A set of flow and pressure drop equations is written using these values. First, N-1 flow balance equations are written, where N is the number of flow path junctions in the network. Then, all the unique pressure drop balance equations are written, considering that the pressure drop across each path through the network must equal the pressure drop imposed by the boundary conditions. These equations are then solved for the flow rate in each path. (auth)

  10. Studies on extraction of rare earth elements from apatite Kola

    International Nuclear Information System (INIS)

    Studies were carried out on precipitation of phosphates of rare earth elements by the method consisting in heating of aqueous solutions, obtained by dissolution of Kola apatite concentrate in HNO3, in an autoclave to the temperature 200-2100C under pressure of 20 atm, subsequent freezing off the excess of Ca(NO3)2x4H2O and partial defluorization. Precipitation in the autoclave makes possible getting rare earth elements from solutions of low concentrations. Studies were also carried out on precipitating elements of rare earths from extractive phosphoric acid. (author)

  11. Balance retraining after stroke using force platform biofeedback.

    Science.gov (United States)

    Nichols, D S

    1997-05-01

    Balance is a somewhat ambiguous term used to describe the ability to maintain or move within a weight-bearing posture without falling. Balance can further be broken down into three aspects: steadiness, symmetry, and dynamic stability. Steadiness refers to the ability to maintain a given posture with minimal extraneous movement (sway). The term symmetry is used to describe equal weight distribution between the weight-bearing components (eg, the feet in a standing position, the buttocks in a sitting position), and dynamic stability is the ability to move within a given posture without loss of balance. All of these components of balance (steadiness, symmetry, and dynamic stability) have been found to be disturbed following stroke. Balance testing of patients with hemiparesis secondary to stroke has revealed a greater amount of postural sway during static stance, asymmetry with greater weight on the nonparetic leg, and a decreased ability to move within a weight-bearing posture without loss of balance. Furthermore, research has demonstrated moderate relationships between balance function and gait speed (r = -.67 and .42, respectively), independence (r = .62), appearance (defined as "significantly abnormal," "slightly abnormal," and "nearly normal") (r = .50), dressing (r.55-.69), wheelchair mobility (r = .51), and reaching (r = .49-.78). Thus, a principal construct within physical therapy practice is the reestablishment of balance function in patients following stroke. Recent advances in technology have resulted in the commercial availability of numerous force platform systems for the retraining of balance function in patient populations, including patients with stroke. These systems are designed to provide visual or auditory biofeedback to patients regarding the locus of their center of force (COF) or center of pressure (COP), as well as training protocols to enhance stance symmetry, steadiness, and dynamic stability. Typical force platform biofeedback systems consist of at least two force plates to allow the weight on each foot to be determined, a computer and monitor to allow visualization of the COF or COP, and software that provides training protocols and data analysis capabilities. Some units allow auditory feedback in addition to the visual feedback in response to errors in performance. PMID:9149764

  12. Increasing cognitive load with increasing balance challenge: recipe for catastrophe.

    Science.gov (United States)

    Barra, Julien; Bray, Adam; Sahni, Vishal; Golding, John F; Gresty, Michael A

    2006-10-01

    The variety of sometimes contradictory results of studies of the impact of secondary cognitive tasks on postural balance may be attributed to the heterogeneity of balance challenges and tasks deployed and frequent lack of quantitative comparability of tasks. We deployed a wide range of quantitatively graded difficulties of both balance challenge and cognitive tasking to obtain an overview of the spectrum of their interactions in a multi-tasking situation. A differential comparison of the effects of verbally versus spatially loaded tasks, balanced for difficulty, was made and unlike any other study, we contrived to incorporate falls as an experimental variable. In the first study subjects stood in tandem on beams of either 2, 3 and 6 cm or 3, 6 and 8 cm width (according to 'best performance' ability) while performing mental verbal or spatial 'Stroop' tasks. The design was a between groups (sixteen subjects each) comparison (to reduce learning effect) of sway, fall rate and task error, balanced for order. Measurements were taken of centre of pressure, sway velocity at the hip and head displacement. For any beam width there were no within-subject correlations between sway magnitudes and frequency of falls. Spatial task errors increased with balance challenge (hence with magnitude of sway) but verbal performance was maintained independently of balance challenge. The results of the first study provided statistical power estimates for the design of the second focussed experiment which made a within group (twenty four subjects) comparison of the impact of spatial versus verbal tasks on balancing on the hardest beam. The spatial task significantly elevated the incidence of falls whereas the verbal task had no effect on fall rate. The spatial task raised the incidence of falling by 50% (P = 0.0008) in comparison with 'no task'. The verbal task had no effect (P = 0.07). We conclude that sway magnitude is a poor index of multi-task load. Multi-tasking can increase the chance of falling and spatial processing may have a specific impact on balance. The significant elevation of fall frequency during cognitive tasking shows that the 'posture first' principal can be transgressed although the necessary condition for transgression may be that the subject is willing to take risks believing that he can arrest any fall. PMID:16721607

  13. The Earth Clouds and Radiation Explorer (EarthCARE) Mission and DSCOVR

    Science.gov (United States)

    Donovan, D. P.; EarthCARE joint mission advisory Group

    2011-12-01

    The Earth Clouds and Radiation Explorer (EarthCARE) mission is a combined ESA, JAXA mission to be flown in late 2015. It will be a polar sun-synchronous orbiting satellite with an orbit altitude of about 400 km and an equator crossing time of 13:45. EarthCARE's main focus is on providing data for better understanding the Earth's radiative balance. In order to do this, EarthCARE will carry four instruments: -A High Spectral resolution 355nm cloud/aerosol lidar(ATLID) -A 35 GHz cloud radar (CPR) -A multi-spectral imager (MSI) [0.67, 0.86, 1.65, 2.21, 8.8, 10.8, 12.0 um] -A long- and short-wave 3 view Broad-Band Radiometer (BBR) EarthCARE has been designed from the ground-up with the ideas of sensor-synergy playing a major role. For example, variational based retrievals are being developed which combine ATLID, CPR and MSI measurements in order to obtain `best-estimates' of 3-D cloud and aerosol properties on the 1-km scale. These fields will then be used as input to radiative transfer codes in order to predict TOA radiances and fluxes on the 10km scale. The predicted radiances will the then be compared against the actual BBR measurements. So far, the development of synergetic algorithms and data products has been limited to the EarthCARE instruments themselves. However, during the period of mission overlap between DISCOVR and EarthCARE, several useful opportunities for inter-platform synergy exist. The unique viewing geometry of DISCOVR means that data from any daytime EarthCARE orbit can be matched to DISCOVR observations. This opens up, for example, the possibility of both platforms benefiting from sharing of different broad-band radiance views. The lidar and radar measurements of cloud and aerosol vertical structure will also be a valuable source of data which can be used to evaluate the passive measurements of cloud height and optical thickness made by DSCOVR. In this presentation an overview of EarthCARE will be given. As well some preliminary ideas regarding how EartrhCARE and DSCOVR can usefully interact will be presented.

  14. Rare earth oxychalcogenides

    International Nuclear Information System (INIS)

    Considered are oxychalcogenides of rare earth elements: their nomenclature, general physico-chemical characteristics, methods of preparation. Considered in detail are chemistry and crystal chemistry of oxychalcogenides of Ln2O2S, Ln2O2Se, Ln4O4Se3, Ln2O2Te types, where Ln=La-Lu. Given are parameters of crystal lattices, elementary cells, interatomic distances and dependences of lattice periods on ion radii of rare earth elements. Described are the prospects of the practical application of rare-earth element oxychalcogenides as various luminophores

  15. Dimensions of the Earth

    Science.gov (United States)

    Medina, Philip

    This unit consists of a variety of materials that explain the shape of the Earth and how it is measured. There is a set of 'proofs' that the Earth is round, an account of how Greek geographer and mathematician Eratosthenes deduced that Earth's surface was curved, and explanations of how roundness, latitude, and longitude are measured. There is also information on time zones, contour (isoline) maps, topograpic profiles, and map projections. A vocabulary list and downloadable, printable worksheets for each major topic are provided.

  16. Rare earth phosphates

    International Nuclear Information System (INIS)

    Data on synthesis, monocrystals growth, structure, crystal chemistry and some properties of rare earth phosphates, including yttrium phosphates and double alkali metal phosphates are generalized. Analysis of rare earth phosphate structure is given, their systematization by the type of phosphorus-oxygen radical is conducted. Physico-chemical conditions for producing phosphates and glasses on their base are investigated, basic regularities condensed phosphate crystallization in four-component systems are revealed, data on rare earth phosphate crystal and glass properties are generalized, promising spheres of application are shown. 312 refs.; 130 figs.; 66 tabs

  17. The earth's gravitational field

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    2007-01-01

    at the centre of the Earth, but for very precise work the direction can also vary slightly because the Earth is not a perfectly uniform sphere. Latitude Gravity is weaker at lower latitudes (nearer the equator), for two reasons. The first is that in a... objects at the poles. Because the force due to gravitational attraction between two bodies (the Earth and the object being weighed) varies inversely with the square of the distance between them, objects at the equator experience a weaker gravitational...

  18. Pressure, Chaotic Magnetic Fields and MHD Equilibria

    Energy Technology Data Exchange (ETDEWEB)

    S.R. Hudson & N. Nakajima

    2010-05-12

    Analyzes of plasma behavior often begin with a description of the ideal magnetohydrodynamic equilibrium, this being the simplest model capable of approximating macroscopic force balance. Ideal force balance is when the pressure gradient is supported by the Lorentz force, ?p = j x B. We discuss the implications of allowing for a chaotic magnetic field on the solutions to this equation. We argue that the solutions are pathological and not suitable for numerical calculations. If the pressure and magnetic Field are continuous, the only non-trivial solutions have an uncountable infinity of discontinuities in the pressure gradient and current. The problems arise from the arbitrarily small length scales in the structure of the field, and the consequence of ideal force balance that the pressure is constant along the Field-lines, B • ?p = 0. A simple method to ameliorate the singularities is to include a small but Finite perpendicular diffusion. A self-consistent set of equilibrium equations is described and some algorithmic approaches aimed at solving these equations are discussed.

  19. Photosynthesis Respiration Balance of Lakes

    Science.gov (United States)

    Dubois, K. D.; Veizer, J.; Carignan, R.

    2004-05-01

    Growing concern about global climate change necessitates an improved understanding of carbon cycling in aquatic systems. Aquatic ecosystems are net autotrophic and act as sinks for CO2 if photosynthesis exceeds respiration. When respiration exceeds photosynthesis they are net heterotrophic and act as sources of CO2 to the atmosphere. The relative importance of net primary productivity over community respiration in both marine and freshwater ecosystems has been a highly debated subject for many years. While some work has shown respiration to exceed photosynthesis in all but the most eutrophic ecosystems, others have found that photosynthesis is greater than respiration in even oligotrophic systems. Independent of these studies is the observation that most lakes are continually supersaturated with respect to CO2. Previous work has shown stable isotopes of oxygen are an effective means of tracing the photosynthesis respiration balance of aquatic ecosystems. In an attempt to resolve the P:R balance of lakes we have applied this stable isotope technique to twenty-one lakes in Quebec with varying physiochemical properties. The lakes were examined on a monthly basis between May and October 2003 and the metabolic balance determined. Preliminary results indicate the P:R balance of the ice-free period to be near equilibrium, despite near continual supersaturation in CO2.

  20. [Assessment of perioperative fluid balance].

    Science.gov (United States)

    Sindeli?, R; Vlajkovi?, G; Markovi?, D; Bumbasirevi?, V

    2009-01-01

    Careful assessment of the fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient's outcome. Haemodynamic monitoring allows understanding the physiology of the circulation and changes of fluid balance in the perioperative period. This is diagnostic aid and guide for fluid replacement therapy. Patient's volume status is frequently assessed by different haemodynamic variables that could be targeted as the endpoints for fluid therapy and resuscitation. Fluid balance is the crucial factor in the maintenance of haemodynamic stability, tissue oxygenation and organ function. When the haemodynamic monitoring is applied in a rigorous and consistent manner, it reduces mortality and length of stay as well as costs incurred. There are a number of tests which describe the effectiveness of the invasive haemodynamic monitoring procedures usage. Since the pulmonary artery catheter (PAC) had been introduced into clinical practice it was considered as a golden standard for cardiac output measurements, haemodynamic and fluid balance assessment. Nevertheless, in previous 10 years new minimally invasive and noninvasive simple techniques for haemodynamic monitoring and patient's hydroelectricity status evaluation have been developed. They can replace PAC under different clinical circumstances and some of these techniques PMID:19504992

  1. Assessment of perioperative fluid balance

    Directory of Open Access Journals (Sweden)

    Bumbaširevi? V.

    2009-01-01

    Full Text Available Careful assessment of the fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient's outcome. Haemodynamic monitoring allows understanding the physiology of the circulation and changes of fluid balance in the perioperative period. This is diagnostic aid and guide for fluid replacement therapy. Patient's volume status is frequently assessed by different haemodynamic variables that could be targeted as the endpoints for fluid therapy and resuscitation. Fluid balance is the crucial factor in the maintenance of haemodynamic stability, tissue oxygenation and organ function. When the haemodynamic monitoring is applied in a rigorous and consistent manner, it reduces mortality and length of stay as well as costs incurred. There are a number of tests which describe the effectiveness of the invasive haemodynamic monitoring procedures usage. Since the pulmonary artery catheter (PAC had been introduced into clinical practice it was considered as a golden standard for cardiac output measurements, haemodynamic and fluid balance assessment. Nevertheless, in previous 10 years new minimally invasive and noninvasive simple techniques for haemodynamic monitoring and patient's hydroelectricity status evaluation have been developed. They can replace PAC under different clinical circumstances and some of these techniques additionally allow a more refined perioperative fluid assessment. The aim of this article is to describe actually technique of haemodynamic measurement and assessment of fluid status and therapy in perioperative period.

  2. Galactic Cosmic Rays - Clouds Effect and Bifurcation Model of the Earth Global Climate. Part 2. Comparison of Theory with Experiment

    CERN Document Server

    Rusov, V; Vaschenko, V; Mihalys, O; Kosenko, S; Mavrodiev, S; Vachev, B

    2008-01-01

    The solution of the energy-balance model of the Earth's global climate proposed in Ref. [1] is compared with well-known experimental data on the palaeotemperature evolution of Earth's surface over past 420 kyr and 740 kyr obtained in the framework of Antarctic projects the EPICA Dome C and Vostok. The Solar-Earth mechanism of anomalous temperature jumps observed in the EPICA Dome C and Vostok experiments and its relation with the "order-chaos" transitions in convection evolution in the liquid Earth core responsible to the mechanism of the Earth magnetic field inversions was discussed. The stabilizing role of the slow nuclear burning on the boundary of the liquid and solid phases of the Earth's core (georeactor with power of 30 TW) for convection evolution in the liquid Earth's core and hence in the Earth's magnetic field evolution is pointed out.

  3. Synchrotron facilities and the study of the Earth's deep interior

    International Nuclear Information System (INIS)

    The combination of synchrotron x-ray facilities with high-pressure methods provides new experimental tools for addressing geophysical problems relevant to understanding the interior of the Earth and other planets. Among the important geophysical questions related to the Earth's silicate mantle are the origin of seismic discontinuities in the upper mantle, the rheological properties of mantle minerals and their influence on dynamic flow in the Earth, and the nature of the core-mantle boundary region. In the case of the Earth's core, key questions are centred on the identity of the light elements of the core and their effect on energetics and thermodynamic properties, the melting curve of iron and its alloys and the origin of seismic anisotropy in the inner core. Both new and established high-pressure synchrotron methods applied to the diamond anvil cell and large-volume apparatus are surveyed. Advances in synchrotron capabilities have been accompanied by new innovations in high-pressure technology. X-ray diffraction techniques are mature but continued improvements are leading to expanded pressure-temperature coverage and better ability to recover crystallographic details. Diffraction and absorption studies of the properties of liquids of silicate and iron alloy composition have expanded in response to new capabilities. Recently, methods for inelastic scattering and nuclear resonance probes have been developed at high pressures and these provide constraints on vibrationand these provide constraints on vibrational, electronic and magnetic properties, which were previously unattainable

  4. PREFACE: The 2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014)

    Science.gov (United States)

    Lumban Gaol, Ford; Soewito, Benfano

    2015-01-01

    The 2nd International Conference on Geological, Geographical, Aerospace and Earth Sciences 2014 (AeroEarth 2014), was held at Discovery Kartika Plaza Hotel, Kuta, Bali, Indonesia during 11 - 12 October 2014. The AeroEarth 2014 conference aims to bring together researchers and engineers from around the world. 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. 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 98 papers and after rigorous review, 17 papers were accepted. The participants come from eight countries. There are four Parallel Sessions and two invited 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 contributions. 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 2014. The Editors of the AeroEarth 2014 Proceedings Dr. Ford Lumban Gaol Dr. Benfano Soewito

  5. Stable Xenon Nitride at High Pressures

    Science.gov (United States)

    Zhang, Yunwei; Peng, Feng; Ma, Yanming

    2015-03-01

    Nitrogen is the most abundant element on Earth and exists as inert N2 molecules in the atmosphere. Noble gas nitrides are missing in nature because N2 molecules do not interact with noble gases at ambient conditions, greatly impeding the understanding of physics and chemistry of such nitrides. We report here a pressure-induced chemical reaction of N2 with xenon predicted using a swarm-structure searching calculation as implemented in the CALYPSO code. This reaction leads to the formation of a hitherto unexpected Xe nitride at megabar pressure accessible to high-pressure experiments. The high-pressure phase with a hypervalent state of Xe by accepting unprecedented Xe-N covalent bonds appears to be the most stable stoichiometry. The Xe bonding situation in this new phase is substantially different from earlier high-pressure examples of ionic Xe bonding or van der Waals interactions.

  6. Engineering redox balance through cofactor systems.

    Science.gov (United States)

    Chen, Xiulai; Li, Shubo; Liu, Liming

    2014-06-01

    Redox balance plays an important role in the production of enzymes, pharmaceuticals, and chemicals. To meet the demands of industrial production, it is desirable that microbes maintain a maximal carbon flux towards target metabolites with no fluctuations in redox. This requires functional cofactor systems that support dynamic homeostasis between different redox states or functional stability in a given redox state. Redox balance can be achieved by improving the self-balance of a cofactor system, regulating the substrate balance of a cofactor system, and engineering the synthetic balance of a cofactor system. This review summarizes how cofactor systems can be manipulated to improve redox balance in microbes. PMID:24794722

  7. 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.

  8. 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).

  9. Climate Stability of Habitable Earth-like Planets

    OpenAIRE

    Menou, Kristen

    2014-01-01

    The carbon-silicate cycle regulates the atmospheric $CO_2$ content of terrestrial planets on geological timescales through a balance between the rates of $CO_2$ volcanic outgassing and planetary intake from rock weathering. It is thought to act as an efficient climatic thermostat on Earth and, by extension, on other habitable planets. If, however, the weathering rate increases with the atmospheric $CO_2$ content, as expected on planets lacking land vascular plants, the carbo...

  10. Time-of-day influences postural balance in older adults

    DEFF Research Database (Denmark)

    Jorgensen, M G; Rathleff, M S

    2012-01-01

    BACKGROUND: Postural balance assessments are performed in both clinical and basic research settings on a daily basis. During a 24-h time span our physiology and physical performance undergo radical changes as we are influenced by the circadian rhythm. The time-of-day interaction on postural balance is unknown in older adults. The aim of this study was to investigate the time-of-day effect on postural balance in older adults. METHODS: Center of pressure (CoP) excursion was measured (100Hz) by force plate analysis in 34 older adults during 30s of narrow quiet bilateral stance. Measurements were performed around 9a.m., 12.30p.m. and 4p.m. on the same day. Postural balance was quantified by velocity-moment, confidence ellipse area, total sway area and total sway length. RESULTS: An overall significant time-of-day (between 9a.m. and 4p.m.) effect was observed for velocity-moment (mm(2)/s) 57±27-65±29 (p=0.001), confidence ellipse area (mm(2)) 36±16-44±19 (p

  11. Biasable, Balanced, Fundamental Submillimeter Monolithic Membrane Mixer

    Science.gov (United States)

    Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Gill, John; Velebir, James; Tsang, Raymond; Dengler, Robert; Lin, Robert

    2010-01-01

    This device is a biasable, submillimeter-wave, balanced mixer fabricated using JPL s monolithic membrane process a simplified version of planar membrane technology. The primary target application is instrumentation used for analysis of atmospheric constituents, pressure, temperature, winds, and other physical and chemical properties of the atmospheres of planets and comets. Other applications include high-sensitivity gas detection and analysis. This innovation uses a balanced configuration of two diodes allowing the radio frequency (RF) signal and local oscillator (LO) inputs to be separated. This removes the need for external diplexers that are inherently narrowband, bulky, and require mechanical tuning to change frequency. Additionally, this mixer uses DC bias-ability to improve its performance and versatility. In order to solve problems relating to circuit size, the GaAs membrane process was created. As much of the circuitry as possible is fabricated on-chip, making the circuit monolithic. The remainder of the circuitry is precision-machined into a waveguide block that holds the GaAs circuit. The most critical alignments are performed using micron-scale semiconductor technology, enabling wide bandwidth and high operating frequencies. The balanced mixer gets superior performance with less than 2 mW of LO power. This can be provided by a simple two-stage multiplier chain following an amplifier at around 90 GHz. Further, the diodes are arranged so that they can be biased. Biasing pushes the diodes closer to their switching voltage, so that less LO power is required to switch the diodes on and off. In the photo, the diodes are at the right end of the circuit. The LO comes from the waveguide at the right into a reduced-height section containing the diodes. Because the diodes are in series to the LO signal, they are both turned on and off simultaneously once per LO cycle. Conversely, the RF signal is picked up from the RF waveguide by the probe at the left, and flows rightward to the diodes. Because the RF is in a quasi- TEM (suspended, microstrip-like) mode, it impinges on the diodes in an anti-parallel mode that does not couple to the waveguide mode. This isolates the LO and RF signals. This operation is similar to a cross-bar mixer used at low frequencies, except the RF signal enters through the back-short end of the waveguide rather than through the side. The RF probe also conveys the down-converted intermediate frequency (IF) signal out to an off-chip circuit board through a simple LC low-pass filter to the left as indicated. The bias is brought to the diodes through a bypass capacitor at the top.

  12. Looking At Earth

    Science.gov (United States)

    This home page for Gallery 110 of the National Air And Space Museum shows visitors how satellite imagery and aerial photography views of our planet have helped us to better understand the Earth. This remote sensing is used for urban planning, geology, archaeology, military reconnaissance, environmental monitoring and natural disaster assessment. There is a gallery tour and map, and a section on the artifacts and technology that made views of Earth from space possible.

  13. Mantle Dynamics in Super-Earths: Post-Perovskite Rheology and Self-Regulation of Viscosity

    CERN Document Server

    Tackley, Paul J; Brodholt, John P; Dobson, David P; Valencia, Diana

    2012-01-01

    Simple scalings suggest that super-Earths are more likely than an equivalent Earth-sized planet to be undergoing plate tectonics. Generally, viscosity and thermal conductivity increase with pressure while thermal expansivity decreases, resulting in lower convective vigor in the deep mantle. According to conventional thinking, this might result in no convection in a super-Earth's deep mantle. Here we evaluate this. First, we here extend the density functional theory (DFT) calculations of post-perovskite activation enthalpy of to a pressure of 1 TPa. The activation volume for diffusion creep becomes very low at very high pressure, but nevertheless for the largest super-Earths the viscosity along an adiabat may approach 1030 Pa s in the deep mantle. Second, we use these calculated values in numerical simulations of mantle convection and lithosphere dynamics of planets with up to ten Earth masses. The models assume a compressible mantle including depth-dependence of material properties and plastic yielding induce...

  14. The Relationship of Abdominal Muscles Balance and Body Balance

    OpenAIRE

    Seo, Dong-kwon; Kim, Ji-seon; Lee, Dong-yeop; Kwon, Oh-sung; Lee, Sang-sook; Kim, Jee-hee

    2013-01-01

    This study aimed to identify what impact the thickness differences between the leftside and rightside transversus abdominis (TrA), internal obliquus (IO) and external obliquus (EO) have on balance ability in the abdominal drawing-in maneuver (ADIM) and resting postures. [Subjects and Methods] In this study, 41 young adults were asked to adopt a resting posture and to perform ADIM. The thicknesses of the abdominal muscles (TrA, IO, EO) were measured using ultrasound imaging, The...

  15. How far is complex balancing from detailed balancing?

    OpenAIRE

    Dickenstein, Alicia; Millan, Mercedes Perez

    2010-01-01

    The aim of this article is to build on the use of tools from computational algebra initiated in Craciun, Dickenstein, Shiu, Sturmfels (JSC, 2009), for the study of general kinetic systems, which have a wide range of applications in chemistry and biology. We clarify the relation between the algebraic conditions that must be satisfied by the reaction constants in general (mass action) kinetics systems for the existence of detailed or complex balancing equilibria. The main prop...

  16. The Geostationary Earth Radiation Budget data record

    Science.gov (United States)

    Russell, Jacqueline; Harries, John; Kellock, Stephen; Bantges, Richard; Murray, Jon; Rufus, James

    The Geostationary Earth Radiation Budget data record Accurate observations of the Earth's radiation balance can provide us with unique information on the climate and allow us to monitor how it might be changing. However such observations need to achieve demanding absolute accuracy targets and maintain calibration stability over many years if they are to meet the needs of the user community. Achieving and validating this requires a variety of approaches and, particularly for the broadband shortwave measurement, presents some unique challenges. The first Geostationary Earth Radiation Budget (GERB) instrument was launched on ME-TEOSAT 8 in 2002 and provided operational observations of the reflected solar and emitted thermal energy at 15 minute temporal resolution from March 2004 to May 2007. Since then the record has been continued by the second GERB instrument on METEOSAT 9. Two further in-struments have been built and calibrated and will fly on METEOSAT-10 and -11. The ultimate aim is to produce a single seamless climate record covering from the four GERB instruments which will operate over the period 2004 -2016. This paper discusses the challenges of this task, it will address ground calibration and the problem of monitoring and maintaining calibration stability in orbit. Validation, stability and inter-comparison results from the GERB instruments on METEOSAT-8 and 9 will be presented and the particular issues of combing such geostationary data highlighted.

  17. Galactic Cosmic Rays - Clouds Effect and Bifurcation Model of the Earth Global Climate. Part 1. Theory

    CERN Document Server

    Rusov, V; Vaschenko, V; Mihalys, O; Kosenko, S; Mavrodiev, S; Vachev, B

    2008-01-01

    The possible physical linkage between galactic cosmic rays intensity and the Earth's cloud cover is discussed using the analysis of the first indirect aerosol effect (Twomey effect) and its experimental representation as the dependence of average cloud droplet effective radius on aerosol index characterizing the aerosol concentration in the atmospheric air column of unit section. It is shown that the basic kinetic equation of the Earth's climate energy-balance model is described by the bifurcation equation (with respect to the temperature of the Earth's surface) in the form of fold catastrophe with two governing parameters defining the variations of insolation and Earth's magnetic field (or galactic cosmic rays intensity in the atmosphere), respectively. The principle of hierarchical climatic models construction, which consists in the structural invariance of balance equations of these models evolving on the different time scales, is described. It means that if the system of equations of multizonal weather mo...

  18. 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...

  19. 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.

  20. Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations

    Science.gov (United States)

    Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura

    2008-01-01

    Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system.

  1. Computational searches for iron carbide in the Earth's inner core

    Science.gov (United States)

    Weerasinghe, Gihan L.; Needs, R. J.; Pickard, Chris J.

    2011-11-01

    We have used density-functional-theory methods together with a structure searching algorithm to determine stable structures and stoichiometries of mixtures of iron and carbon at high pressures and zero temperature. The most favorable stoichiometries at Earth's inner-core pressures (˜350 GPa) are those with between about 20% and 35% carbon atoms. The most stable stoichiometries were found to be (Fe and C), Fe3C, Fe7C3, and Fe2C. The latter has not to our knowledge been discussed previously in relation to the Earth's core. The stoichiometries Fe4C and Fe5C2 were found to be close to stability at Earth's inner-core pressures. We find that Fe7C3 is unstable to decomposition into Fe3C + 2Fe2C at pressures greater than ˜330 GPa. At 150 GPa only Fe, C, Fe3C, and Fe7C3 are stable. Formation of Fe/C compounds is energetically more favorable at 350 GPa than at 150 GPa. We also report a new phase for Fe3C with Cmcm symmetry to be more stable than the well-known cementite phase at 350 GPa. A number of pressure-induced phase transitions are identified in Fe3C, Fe3C2, FeC, Fe8C, and FeC2. The lowest enthalpy Fe/C phases were found to be metallic at the pressures studied.

  2. The energy balance of the solar transition region

    Science.gov (United States)

    Jordan, C.

    1980-01-01

    It is shown how the observed distribution of the emission measure with temperature can be used to limit the range of energy deposition functions suitable for heating the solar transition region and inner corona. The minimum energy loss solution is considered in view of the work by Hearn (1975) in order to establish further scaling laws between the transition region pressure, the maximum coronal temperature and the parameter giving the absolute value of the emission measure. Also discussed is the absence of a static energy balance at the base of the transition region in terms of measurable atmospheric parameters, and the condition for a static energy balance is given. In addition, the possible role of the emission from He II in stabilizing the atmosphere by providing enhanced radiation loss is considered.

  3. Load Balancing in IP/MPLS Networks: A Survey

    Directory of Open Access Journals (Sweden)

    Kanak Saxena

    2012-05-01

    Full Text Available The present era has witnessed tremendous growth of the Internet and various applications that are supported by it. There is an enormous pressure on Internet Service Providers (ISPs to make available adequate services for the traffics like VoIP and Video on demand. Since the resources like computing power, bandwidth etc. are limited, the traffic needs to be engineered to properly exploit them. Due to these limitations, terms like Traffic Engineering, Quality of Service (QoS came into existence. Traffic Engineering broadly includes techniques like multipath routing & traffic splitting to balance the load among different paths. In this document, we survey various techniques proposed for load balancing that are available on the Internet. We here try not to be exhaustive but analyze the important techniques in the literature. Present survey would help to give a new direction to the research in this realm.

  4. Laterally transferred elements and high pressure adaptation in Photobacterium profundum strains

    OpenAIRE

    Malacrida Giorgio; Cestaro Alessandro; Simonato Francesca; D'Angelo Michela; Lauro Federico M; Vitulo Nicola; Vezzi Alessandro; Campanaro Stefano; Bertoloni Giulio; Valle Giorgio; Bartlett Douglas H

    2005-01-01

    Abstract Background Oceans cover approximately 70% of the Earth's surface with an average depth of 3800 m and a pressure of 38 MPa, thus a large part of the biosphere is occupied by high pressure environments. Piezophilic (pressure-loving) organisms are adapted to deep-sea life and grow optimally at pressures higher than 0.1 MPa. To better understand high pressure adaptation from a genomic point of view three different Photobacterium profundum strains were compared. Using the sequenced piezop...

  5. [Striking the work-life balance].

    Science.gov (United States)

    Dumas, Marc

    2014-11-01

    Solutions for finding a satisfactory balance between home life and work lie in the organisation of work and the work environment. Line managers in particular have a key role to play in helping their staff maintain this balance. PMID:25619100

  6. A finite element algorithm of a nonlinear diffusive climate energy balance model

    OpenAIRE

    Di?az Di?az, Jesu?s Ildefonso; Bermejo, R.; Carpio, Jaime; Gala?n Del Sastre, Pedro

    2008-01-01

    We present a finite element algorithm of a climate diagnostic model that takes as a climate indicator the atmospheric sea-level temperature. This model belongs to the category of energy balance models introduced independently by the climatologists M.I. Budyko and W. D. Sellers in 1969 to study the influence of certain geophysical mechanisms on the Earth climate. The energy balance model we are dealing with consists of a two-dimensional nonlinear parabolic problem on the 2-sphere with the albe...

  7. LOAD BALANCING WITH NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Nada M. Al Sallami

    2013-11-01

    Full Text Available This paper discusses a proposed load balance technique based on artificial neural network. It distributes workload equally across all the nodes by using back propagation learning algorithm to train feed forward Artificial Neural Network (ANN. The proposed technique is simple and it can work efficiently when effective training sets are used. ANN predicts the demand and thus allocates resources according to that demand. Thus, it always maintains the active servers according to current demand, which results in low energy consumption than the conservative approach of over-provisioning. Furthermore, high utilization of server results in more power consumption, server running at higher utilization can process more workload with similar power usage. Finally the existing load balancing techniques in cloud computing are discussed and compared with the proposed technique based on various parameters like performance, scalability, associated overhead... etc. In addition energy consumption and carbon emission perspective are also considered to satisfy green computing.

  8. Universally Balanced Combinatorial Optimization Games

    Directory of Open Access Journals (Sweden)

    Xiaotie Deng

    2010-09-01

    Full Text Available This article surveys studies on universally balanced properties of cooperative games defined in a succinct form. In particular, we focus on combinatorial optimization games in which the values to coalitions are defined through linear optimization programs, possibly combinatorial, that is subject to integer constraints. In economic settings, the integer requirement reflects some forms of indivisibility. We are interested in the classes of games that guarantee a non-empty core no matter what are the admissible values assigned to the parameters defining these programs. We call such classes universally balanced. We present characterization and complexity results on the universally balancedness property for some classes of interesting combinatorial optimization games. In particular, we focus on the algorithmic properties for identifying universally balancedness for the games under discussion.

  9. Balancing energy flexibilities through aggregation

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja

    2014-01-01

    One of the main goals of recent developments in the Smart Grid area is to increase the use of renewable energy sources. These sources are characterized by energy fluctuations that might lead to energy imbalances and congestions in the electricity grid. Exploiting inherent flexibilities, which exist 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.

  10. Double-yoke balanced compressor

    International Nuclear Information System (INIS)

    A double-yoke balanced compressor for a cryogenic cooler that has only linear motion imparted to balanced piston and cylinder masses. A piston yoke is driven in the linear stroke direction by a piston axially offset crankshaft cam and a cylinder yoke is driven linearly by a cylinder axially offset crankshaft cam that is exactly offset 1800 from the other cam. A large circular bushing in the compressor housing covers the entire outer cylinder head during linear operation to prevent blow by and to guide the cylinder linearly. The lower portion of the piston and cylinder connecting rods fit into linear guides that are further comprised of low molecular weight gas filled cavities to provide additional air bearing smoothness to the linear motion of the piston and cylinder

  11. The Pseudo Radiation Energy Amplifier (PREA) and the mean earth s ground temperature

    CERN Document Server

    Boucenna, Ahmed

    2008-01-01

    From the radiation balance diagram illustrating the IPCC reports one can estimate the power received by Earth from the sun at Pin = 342 W/m2 and the power consumed, remitted and reflected by the earth and its atmosphere at Pout = 599 kW/m2. It seems that the earth emits more power than it receives. The earth s ground mean temperature is estimated at 15 C. A calculation based on the black body radiation theory gives an earth s ground mean temperature of the order of -18 C which is much lower than 15 C. The important gap between these calculated and estimated temperature mean values requires an explanation. Here we show that a gray body separated from vacuum by an interface and submitted to outside incident radiation can behave like a Pseudo Radiation Energy Amplifier. The Earth which is a gray body separated from the space by an interface, behaves like a Pseudo Radiation Energy Amplifier. The balance of the energy exchanged between Earth and outer space is reconsidered and the 15 C Earth s ground temperature m...

  12. All lives seek balance : intro to homeostasis

    Science.gov (United States)

    2005-01-01

    The study of homeostasis reveals that balance within living systems is not peaceful, nor quiet, is filled with change, but does harmonize the interior environment with the exterior environment. Call it dynamic equilibrium, a continuous circle dance of adjustment and correction. Maintaining this balance between a living system's internal conditions and fluctuating environmental (external) conditions is called homeostasis. Illusrates and describes feedback loops. Contins links to Balance in Natural Communities and Balancing the Planet: Gaia Theory.

  13. Structural change and generalized balanced growth

    OpenAIRE

    Meckl, Jürgen

    1999-01-01

    This paper addresses the criticism that balanced growth models are inconsistent with the dynamics of structural change typical for the process of economic growth. Using a sectoral disaggregated version of a researchdriven growth model, we develop the concept of a generalized balanced growth path (GBGP). The GBGP preserves decisive properties of the balanced growth path analyzed in aggregated growth models. Along a GBGP, aggregate variables grow at constant rates (balanced growth) while disagg...

  14. The balance principle in scientific research

    OpenAIRE

    Liang-ping Hu

    2012-01-01

    The principles of balance, randomization, control and repetition, which are closely related, constitute the four principles of scientific research. The balance principle is the kernel of the four principles which runs through the other three. However, in scientific research, the balance principle is always overlooked. If the balance principle is not well performed, the research conclusion is easy to be denied, which may lead to the failure of the whole research. Therefore, it is essential to ...

  15. Magnetic Field Generation on Super-Earths and Sub-Earths

    Science.gov (United States)

    Stamenkovic, Vlada; Breuer, Doris

    2010-05-01

    The last 15 years of astronomical observation have revealed a universe filled with planets. The observational techniques still limit the possibility to detect smaller, Earth-sized planets. New missions such as Kepler and Corot, next generation telescopes such as Darwin and TPF, and improved techniques in radial velocity measurements will lower this limit and make it possible to even detect Earth-sized planets in the near future. We study the ability of planets with different masses to generate a magnetic dynamo. For this we [1] investigate the thermal evolution and convection of planets with Earth-like composition and structure of sizes ranging from 0.1 to 10 Earth masses (Mearth). Important is that we include the pressure dependence of viscosity into our parameterized 1D boundary layer and spherical 2D/3D models, with the scope to understand how the pressure-viscosity coupling changes the convection in the mantles of Super-Earths, and less massive planets, which we termed Sub-Earths. We then look how this influences magnetic dynamos on those planets. We observe that the pressure dependence of viscosity becomes an important factor for the mantle convection of planets with masses larger than 1Mearth - resulting in a sluggish convection regime in the lower mantle for Earth-sized planets. Depending on activation volume we observe with growing planetary mass the formation of a conductive lid over the core mantle boundary (CMB), termed low-lid, where convection velocities cease and where heat transport is only due to conduction. The sluggish convection and the formation of the low-lid reduce the convective vigour throughout the mantle. This leads to much lower core cooling in comparison to non-pressure-dependent viscosity models. We find using our parameterized 1D convection models that the low-lid insulates the core and thus affects the potential growth of an inner core and the ratio of CMB heat flux to critical heat flux. This on the other hand influences the generation of a magnetic dynamo, thermally and compositionally. The results, in particular for the compositional dynamo, depend on the melting curve, which can differ strongly in magnitude if different approaches are followed ([2], [3]). But we can show that thermodynamic constraints lead to the exclusion of [2] and therefore leave [3] as the most reliable melting curve at high pressures. In our model the scaling of thermodynamic core properties is tightly connected to the Grüneisen parameter. Assuming an initially molten core as the consequence of accretion and core formation, we find that in the early evolution the low-lid reduces strongly the heat flow through the core-mantle-boundary, even though the melting temperatures (and thus the initial core temperatures), can be very high - up to 20'000K for 10-Earth-mass planets with pressures above 1200 GPa. Our results show that the thermally induced magnetic field generation is highly suppressed on Super-Earths, for plate tectonics and stagnant lid planets, as critical heat fluxes grow much faster that effective CMB heat fluxes. Compositional dynamos might also be suppressed as the inner core growth rate might become only very small, and the associated power is possibly even not strong enough to overcome ohmic dissipation thus inducing only small surface magnetic fields or no fields at all. We show that the mass-richer the planet, the more difficult it is to generate strong magnetic fields. References [1] Stamenkovic, V., L. Noack, T. Spohn and D. Breuer (2010), to be submitted to EPSL [2] Boehler, R. (1993) Nature, 363, 534-536 [3] Stacey, F.D and Davies, P.M. (2004) PEPI, 142, 137-184

  16. 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.

  17. Electric power balance sheet 2013

    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 2013: stabilisation of the electricity consumption in France, high level of hydropower generation, fast evolution of the European power network, electricity markets in a transition situation, adaptation of RTE's network to the evolutions of the energy system

  18. Balancing on tightropes and slacklines

    OpenAIRE

    Paoletti, P.; Mahadevan, L.

    2012-01-01

    Balancing on a tightrope or a slackline is an example of a neuromechanical task where the whole body both drives and responds to the dynamics of the external environment, often on multiple timescales. Motivated by a range of neurophysiological observations, here we formulate a minimal model for this system and use optimal control theory to design a strategy for maintaining an upright position. Our analysis of the open and closed-loop dynamics shows the existence of an optimal rope sag where b...

  19. Mean as the Balance Point

    Science.gov (United States)

    Dedra L. Wright

    2010-01-01

    In this 3 minute video, Dedra Wright demonstrates how to teach students about the mean as a balance point. She models this concept using a number line and blocks which are manipulated throughout the activity. In the video, two data sets are shown as models and then connected to the written algorithm. A companion video, Introduction to the Concept of the Mean: Mean as Fair Share, is cataloged separately as a related resource.

  20. Cell phone based balance trainer

    OpenAIRE

    Lee Beom-Chan; Kim Jeonghee; Chen Shu; Sienko Kathleen H

    2012-01-01

    Abstract Background In their current laboratory-based form, existing vibrotactile sensory augmentation technologies that provide cues of body motion are impractical for home-based rehabilitation use due to their size, weight, complexity, calibration procedures, cost, and fragility. Methods We have designed and developed a cell phone based vibrotactile feedback system for potential use in balance rehabilitation training in clinical and home environments. It comprises an iPhone with an embedded...

  1. Hypothalamic lipophagy and energetic balance

    OpenAIRE

    Singh, Rajat

    2011-01-01

    Autophagy is a conserved cellular turnover process that degrades unwanted cytoplasmic material within lysosomes. Through “in bulk” degradation of cytoplasmic proteins and organelles, including lipid droplets, autophagy helps provide an alternative fuel source, in particular, when nutrients are scarce. Recent work demonstrates a role for autophagy in hypothalamic agouti-related peptide (AgRP) neurons in regulation of food intake and energy balance. The induction of autophagy in hypothalami...

  2. Energy balance of a vehicle

    OpenAIRE

    Gourdeau, Sarah

    2012-01-01

    Simulation has become a very useful tool to predict the characteristics of a system and perform analysis of parameters without having to run too many tests. The advanced system engineering team of Continental Automotive uses a 0D simulation program, AMESim, to realize simulations of vehicle models. These simulations are used e.g. to predict the fuel consumption and CO2 emissions. A tool has been developed over the course of previous internships to realize the energy balance of AMESim vehicle ...

  3. Age-Related Differences in the Sympathetic-Hemodynamic Balance in Men

    OpenAIRE

    Hart, Emma C.; Joyner, Michael J.; Wallin, B. Gunnar; Johnson, Christopher P.; Curry, Timothy B.; Eisenach, John H.; Charkoudian, Nisha

    2009-01-01

    As humans age, the tonic level of activity in sympathetic vasoconstrictor nerves increases and may contribute to age-related increases in blood pressure. In previous studies in normotensive young men with varying levels of resting sympathetic nerve activity, we observed a balance among factors contributing to blood pressure regulation, such that higher sympathetic activity was associated with lower cardiac output and lesser vascular responsiveness to ?-adrenergic agonists, which limited the ...

  4. Pitfalls in Using the Balanced Scorecard

    DEFF Research Database (Denmark)

    NØrreklit, Hanne; Jakobsen, Morten

    2008-01-01

    The balanced scorecard has quickly become a leading management tool. But business performance measurement is notoriously difficult, so any system, including the balanced scorecard, is likely to have unanticipated and often dysfunctional consequences. This article briefly reviews the main attractions of the balanced scorecard and then shows how these apparent advantages might lead to problems.

  5. Balanced binary trees in the Tamari lattice

    CERN Document Server

    Giraudo, Samuele

    2010-01-01

    We show that the set of balanced binary trees is closed by interval in the Tamari lattice. We establish that the intervals [T0, T1] where T0 and T1 are balanced trees are isomorphic as posets to a hypercube. We introduce tree patterns and synchronous grammars to get a functional equation of the generating series enumerating balanced tree intervals.

  6. Pressure measurements in magnetic-fusion devices

    International Nuclear Information System (INIS)

    Accurate pressure measurements are important in magnetic fusion devices for: (1) plasma diagnostic measurements of particle balance and ion temperature; (2) discharge cleaning optimization; (3) vacuum system performance; and (4) tritium accountability. This paper reviews the application, required accuracy, and suitable instrumentation for these measurements. Demonstrated uses of ionization-type and capacitance-diaphragm gauges for various pressure and gas-flow measurements in tokamaks are presented, with specific reference to the effects of magnetic fields on gauge performance and the problems associated with gauge calibration

  7. On output measurements via radiation pressure

    DEFF Research Database (Denmark)

    Leeman, S.; Healey, A.J.

    1990-01-01

    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 calorimetric methods relate to wave energy. Measurements with some typical ultrasound fields are performed with a novel type of hydrophone, and these allow an estimate to be made of the magnitude of the discrepancy to be expected between the two types of output measurement in a typical case.

  8. Climate Stability of Habitable Earth-like Planets

    CERN Document Server

    Menou, Kristen

    2014-01-01

    The carbon-silicate cycle regulates the atmospheric $CO_2$ content of terrestrial planets on geological timescales through a balance between the rates of $CO_2$ volcanic outgassing and planetary intake from rock weathering. It is thought to act as an efficient climatic thermostat on Earth and, by extension, on other habitable planets. If, however, the weathering rate increases with the atmospheric $CO_2$ content, as expected on planets lacking land vascular plants, the carbon-silicate cycle feedback can become severely limited. Here we show that Earth-like planets receiving less sunlight than current Earth may no longer possess a stable warm climate but instead repeatedly cycle between unstable glaciated and deglaciated climatic states. This has implications for the search for life on exoplanets in the habitable zone of nearby stars.

  9. The Earth System Model

    Science.gov (United States)

    Schoeberl, Mark; Rood, Richard B.; Hildebrand, Peter; Raymond, Carol

    2003-01-01

    The Earth System Model is the natural evolution of current climate models and will be the ultimate embodiment of our geophysical understanding of the planet. These models are constructed from components - atmosphere, ocean, ice, land, chemistry, solid earth, etc. models and merged together through a coupling program which is responsible for the exchange of data from the components. Climate models and future earth system models will have standardized modules, and these standards are now being developed by the ESMF project funded by NASA. The Earth System Model will have a variety of uses beyond climate prediction. The model can be used to build climate data records making it the core of an assimilation system, and it can be used in OSSE experiments to evaluate. The computing and storage requirements for the ESM appear to be daunting. However, the Japanese ES theoretical computing capability is already within 20% of the minimum requirements needed for some 2010 climate model applications. Thus it seems very possible that a focused effort to build an Earth System Model will achieve succcss.

  10. 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.

  11. 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.

  12. 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 ...

  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. Bizarre Life Forms Thrive Beneath Earth's Surface

    Science.gov (United States)

    In the classic tale, "A Journey to the Center of the Earth," Jules Verne imagined elaborate worlds in a hollow, miles beneath our feet. More modern science-fiction novelists have dreamed of spheres in outer space where earthling astronauts encounter alien life forms. Now these two ideas are being fused in a bubbling witches' cauldron: deep within the planet may be the best place to find new life forms on our planet--and glean clues to possible life on others. Vaporous hot pools far beneath Earth's surface support microbes conducting the business of life at extreme temperatures and pressures. The microbes, some of which are bacteria, are all called extremophiles, and their potentially far-reaching domain is called the subsurface biosphere.

  15. Effect of Selected Balance Exercises on the Dynamic Balance of Children with Visual Impairments

    Science.gov (United States)

    Jazi, Shirin Davarpanah; Purrajabi, Fatemeh; Movahedi, Ahmadreza; Jalali, Shahin

    2012-01-01

    Introduction: Maintaining balance while walking is of utmost importance for individuals with visual impairments because deficits in dynamic balance have been associated with a high risk of falling. Thus, the primary aim of the study presented here was to determine whether balance training effects the dynamic balance of children with visual…

  16. Predicting the earth's future

    Science.gov (United States)

    Dutton, J. A.

    1986-01-01

    The development of earth system models that will simulate the past and present and provide predictions of future conditions is essential now that human activities have the potential to induce changes in the planetary environment. Critical aspects of global change include its pervasiveness and ubiquity, its distribution in several distinct time-scale bands, and the interactions between the atmosphere, ocean, land surface, and the terrestrial and marine biospheres. A model of the earth system on the scale of decades to centuries, developed by the Earth System Science Committee (NASA) with the strategy of dividing by time scale rather than discipline, is presented and the requirements for observations to support the implementation of the model are reviewed.

  17. Better Than Earth

    Science.gov (United States)

    Heller, René

    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.

  18. Better Than Earth

    CERN Document Server

    Heller, René

    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.

  19. The key to a balanced lifestyle.

    Science.gov (United States)

    Weinstein, Sharon

    2015-01-28

    WORK-LIFE BALANCE is a barometer for wellbeing: personal, professional, family and community wellbeing. To maintain this balance, you must be empowered to act on your own behalf. Yet, how? We think: 'A new year, a new me: I'll get it together when…' but 'when' never comes around. We get caught up in a balancing act, unable to do it all. We are only as good as we are balanced, but we have a chance to balance our lives whenever we prepare our new year resolutions. PMID:25629335

  20. Whole-Earth Decompression Dynamics

    CERN Document Server

    Herndon, J M

    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 rebounding. The initial whole-Earth decompression is expected to result in a global system of major primary decompression cracks appearing in the rigid crust which persist as the basalt feeders for the global, mid-oceanic ridge system. As the Earth subsequently decompresses, the area of the Earth's surface increases by the formation of secondary decompression cracks, often located near the continental margins, presently identified as oceanic trenches. These secondary decompression cracks are subsequently in-filled with basalt, extruded fr...

  1. Google Earth Engine

    Science.gov (United States)

    Gorelick, Noel

    2013-04-01

    The Google Earth Engine platform is a system designed to enable petabyte-scale, scientific analysis and visualization of geospatial datasets. Earth Engine provides a consolidated environment including a massive data catalog co-located with thousands of computers for analysis. The user-friendly front-end provides a workbench environment to allow interactive data and algorithm development and exploration and provides a convenient mechanism for scientists to share data, visualizations and analytic algorithms via URLs. The Earth Engine data catalog contains a wide variety of popular, curated datasets, including the world's largest online collection of Landsat scenes (> 2.0M), numerous MODIS collections, and many vector-based data sets. The platform provides a uniform access mechanism to a variety of data types, independent of their bands, projection, bit-depth, resolution, etc..., facilitating easy multi-sensor analysis. Additionally, a user is able to add and curate their own data and collections. Using a just-in-time, distributed computation model, Earth Engine can rapidly process enormous quantities of geo-spatial data. All computation is performed lazily; nothing is computed until it's required either for output or as input to another step. This model allows real-time feedback and preview during algorithm development, supporting a rapid algorithm development, test, and improvement cycle that scales seamlessly to large-scale production data processing. Through integration with a variety of other services, Earth Engine is able to bring to bear considerable analytic and technical firepower in a transparent fashion, including: AI-based classification via integration with Google's machine learning infrastructure, publishing and distribution at Google scale through integration with the Google Maps API, Maps Engine and Google Earth, and support for in-the-field activities such as validation, ground-truthing, crowd-sourcing and citizen science though the Android Open Data Kit.

  2. 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.

  3. In Brief: Earth TV

    Science.gov (United States)

    Showstack, Randy

    2008-11-01

    The British Broadcasting Corporation (BBC) is seeking participation from primary investigators working on science projects in geology, geomorphology, climate, and history for a new series, ``How Earth Made Us.'' According to the BBC, the aim of this follow-up to the 2007 program ``Earth: Power of the Planet'' is to reveal the influence of planetary forces (geology, climate, and geomorphology) in shaping human history over the past 10,000 years. The BBC anticipates producing a series focusing on cutting-edge science and dramatic locations that have been rarely filmed.

  4. Visible Earth: Coastal Processes

    Science.gov (United States)

    Kevin Ward

    This web page is part of Visible Earth, the National Atmospheric and Space Agency (NASA) web site, a searchable directory of images, visualizations, and animations of the Earth. Subtopics of Oceans: Coastal Processes are: Barrier Islands, Coral Reefs, Deltas, Estuaries, Fjords, Lagoons, Sea Level Rise, Sea Surface Height, Sediment Transport, Sedimentation, and Shoreline Displacement. At the time of cataloging, most items were images. For the Advanced search, users may search by Sensor (usually a satellite), Location, Other terms, or by Dates; they may also set retrieval for animations only. This database solicits additional material from users.

  5. Quantizing Earth surface deformations

    Directory of Open Access Journals (Sweden)

    C. O. Bowin

    2015-03-01

    Full Text Available The global analysis of Bowin (2010 used the global 14 absolute Euler pole set (62 Myr history from Gripp and Gordon (1990 and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003 52 present-day Euler pole set (relative to a fixed Pacific plate for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

  6. Song of the Earth

    Science.gov (United States)

    This PBS Web site is the online companion to the Nature documentary "Song of the Earth," hosted by David Attenborough. The program explores the elemental purpose of music and offers a fascinating look at the connection between animal sounds and human music. The site includes two detailed lesson plans that integrate science and language arts, designed for grades 9-12. Learning objectives include conducting research on animal behavior, applying scientific methodology, synthesizing information to create presentations, and more. The main Song of the Earth Web site has other features -- such as a list of related links and a photo essay of animal music -- that would make excellent additions to classroom activities.

  7. Quantizing Earth surface deformations

    Science.gov (United States)

    Bowin, C. O.; Yi, W.; Rosson, R. D.; Bolmer, T. S.; Sass, W. J.

    2015-03-01

    The global analysis of Bowin (2010) used the global 14 absolute Euler pole set (62 Myr history) from Gripp and Gordon (1990) and demonstrated that plate tectonics conserves angular momentum. We herein extend that analysis using the more detailed Bird (2003) 52 present-day Euler pole set (relative to a fixed Pacific plate) for the Earth's surface, after conversion to absolute Euler poles. Additionally, new analytical results now provide new details on upper mantle mass anomalies in the outer 200 km of the Earth, as well as an initial quantizing of surface deformations.

  8. Earth as an Exoplanet: Lessons in Recognizing Planetary Habitability

    Science.gov (United States)

    Meadows, Victoria; Robinson, Tyler; Misra, Amit; Ennico, Kimberly; Sparks, William B.; Claire, Mark; Crisp, David; Schwieterman, Edward; Bussey, D. Ben J.; Breiner, Jonathan

    2015-01-01

    Earth will always be our best-studied example of a habitable world. While extrasolar planets are unlikely to look exactly like Earth, they may share key characteristics, such as oceans, clouds and surface inhomogeneity. Earth's globally-averaged characteristics can therefore help us to recognize planetary habitability in data-limited exoplanet observations. One of the most straightforward ways to detect habitability will be via detection of 'glint', specular reflectance from an ocean (Robinson et al., 2010). Other methods include undertaking a census of atmospheric greenhouse gases, or attempting to measure planetary surface temperature and pressure, to determine if liquid water would be feasible on the planetary surface. Here we present recent research on detecting planetary habitability, led by the NASA Astrobiology Institute's Virtual Planetary Laboratory Team. This work includes a collaboration with the NASA Lunar Science Institute on the detection of ocean glint and ozone absorption using Lunar Crater Observation and Sensing Satellite (LCROSS) Earth observations (Robinson et al., 2014). This data/model comparison provides the first observational test of a technique that could be used to determine exoplanet habitability from disk-integrated observations at visible and near-infrared wavelengths. We find that the VPL spectral Earth model is in excellent agreement with the LCROSS Earth data, and can be used to reliably predict Earth's appearance at a range of phases relevant to exoplanet observations. Determining atmospheric surface pressure and temperature directly for a potentially habitable planet will be challenging due to the lack of spatial-resolution, presence of clouds, and difficulty in spectrally detecting many bulk constituents of terrestrial atmospheres. Additionally, Rayleigh scattering can be masked by absorbing gases and absorption from the underlying surface. However, new techniques using molecular dimers of oxygen (Misra et al., 2014) and nitrogen (Schwieterman et al., 2014) may provide an alternative means to determine terrestrial atmospheric pressure for both transit transmission and direct imaging observations.

  9. RITD - Adapting Mars Entry, Descent and Landing System for Earth

    Science.gov (United States)

    Heilimo, Jyri; Aleksashkin, Sergey; Martynov, Maxim; Schmidt, Walter; Harri, Ari-Matti; Vsevolod Koryanov, D.; Kazakovtcev, Victor; Haukka, Harri; Arruego, Ignacio; Finchenko, Valery; Ostresko, Boris; Ponomarenko, Andrei; Martin, Susanna; Siili, Tero

    Abstract A new generation of inflatable Entry, Descent and Landing System (EDLS) or Mars has been developed. It is used in both the initial atmospheric entry and atmospheric descent before the semi-hard impact of the penetrator into Martian surface. The EDLS applicability to Earth’s atmosphere is studied by the EU/RITD [1] project. Project focuses to the analysis and tests of the transonic behaviour of this compact and light weight payload entry system at the Earth re-entry 1. EDLS for Earth The dynamical stability of the craft is analysed, concentrating on the most critical part of the atmospheric re-entry, the transonic phase. In Martian atmosphere the MetNet vehicle stability during the transonic phase is understood. However, in the more dense Earth’s atmosphere, the transonic phase is shorter and turbulence more violent. Therefore, the EDLS has to be sufficiently dynamically stable to overcome the forces tending to deflect the craft from its nominal trajectory and attitude. The preliminary design of the inflatable EDLS for Earth will be commenced once the scaling of the re-entry system and the dynamical stability analysis have been performed. The RITD-project concentrates on mission and applications achievable with the current MetNet-type (i.e. “Mini-1” category) of lander, and on requirements posed by other type Earth re-entry concepts. 2. Entry Angle Determination for Mini-1 - lander For successful Earth landing, the suitable re-entry angle and velocity with specific descent vehicle (DV) mass and heat flux parameters need to be determined. These key parameters in determining the Earth re-entry for DV are: - qmax (kW/m2): maximal specific heat flux, - Q (MJ/m2): specific integral heat flux to DV front shield, - m (kg): descent vehicle (DV) mass, - V (m/s): re-entry velocity and - theta(deg.): flight-path angle at Earth re-entry For Earth re-entry, the calculation results in the optimal value of entry velocity for MetNet (“Mini-1” category) -type lander, with mass of 22kg, being VSOL = 5268 m/s. Using the basic pre-defined parameters for MetNet-type of lander in Earth atmosphere, we get the optimal angle of = -3.06 degrees for Earth re-entry. 3. Payload Mass for Earth Entry DV One of the key elements in Earth entry lander is the amount of available payload mass. The payload mass depends on, e.g., the lander size, landing type (soil or water), heat shield durability and additional landing gear. The payload mass will have an impact to the center of gravity of the lander. The payload with a “low” CoG (compared the the lander structure) has a larger tolerance than the payload with “high” CoG. In cases where payload CoG causes instability, the extra balance mass can be used to adjust CoG. This balance mass will reduce the available payload mass. A major limitation for payload mass is the heat shielding. Acknowledgements The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 263255. References [1] http://ritd.fmi.fi

  10. Pressure control device in a BWR type reactor

    International Nuclear Information System (INIS)

    Purpose: To perform an adequate pressure control with no erroneous scram operation even when the balance of pressure is lost between main steam pipelines. Constitution: Pressure detectors are disposed respectively to a plurality of main steam pipelines and pressure detection values therefrom are inputted into a higher value preference circuit to select a higher value. The deviation between the higher pressure value signal and an aimed value is calculated in an addition circuit and the calculated deviation is inputted to a succeeding higher value preference circuit by way of a servo mechanism as an output from an electronic main steam pressure controller. The above output and the output from another mechanical main steam pressure controller are compared in this circuit to issue a higher value signal to a governer to control the degree of a steam control valve by way of the governor and the servo mechanism. The deviation hereinafter is converged through the same procedures into an aimed predetermined value. (Sekiya, K.)

  11. Iron in the Earth's Lower Mantle and Core

    Science.gov (United States)

    Lin, J.

    2006-12-01

    Iron is the most abundant transition metal in the Earth's interior. The multiple electronic configurations of iron with different oxidation and spin states give rise to complex physical and chemical properties of the Earth's interior. Knowledge of the spin and oxidation states as well as sound velocities of iron and iron-containing minerals at high pressures and temperatures can provide new insights into the geophysics and geochemistry of the Earth's mantle and core. Electronic spin-pairing transitions of iron in magnesiowuestite-(Mg,Fe)O and silicate persovkite- (Mg,Fe)SiO3, the most abundant mineral assemblage in the lower mantle, have been recently reported experimentally and theoretically. Here I will address the spin states of iron in these minerals as well as potential effects of the transitions on their properties, namely sound velocities, under lower mantle pressure- temperature conditions. In particular, recent high pressure-temperature studies indicate that the electronic spin-pairing transition in (Mg,Fe)O should occur over an extended pressure range at high temperatures. Considering the spin crossover in magnesiowuestite and possibly in silicate perovskite in the lower mantle, it is likely that the effects of the spin transitions on the physical and transport properties of the mantle minerals will be reduced significantly; though, it remains to be seen how future results at high pressures and temperatures will influence geophysical, geochemical, and geodynamic modeling of the lower mantle. Sound velocities of iron and iron-containing mantle oxide and silicate under high pressures and high temperatures have been used to relate seismic observations in the Earth's core and mantle and to constrain their mineralogy and chemistry. Recently, sound velocities of hcp-Fe, the most abundant constitute of the Earth's core, and magnesiowuestite, the second most abundant mineral in the lower mantle, have been measured with nuclear inelastic X-ray scattering in a laser-heated diamond cell. The temperature effect on the sound velocities of iron metal and iron-containing oxide will be discussed. It is found that the compressional (VP) and shear wave velocities (VS) of hcp-Fe decrease significantly with increasing temperature under moderate high pressures, indicating that the linear sound velocity-density relation, Birch's law, should be corrected to lower velocities in extrapolations to inner core conditions. These new results at simultaneous high temperature-pressure conditions affect our current understanding of the role of iron in the geophysics and geochemistry of the Earth's interior. This work was performed under the auspices of the U.S. DOE by UC/LLNL under Contract W-7405-Eng-48.

  12. Work to live, don’t live to work! : A cross-sectional study of the work-life balance of higher managers

    OpenAIRE

    Korpunen, Pa?ivi; Na?pravni?kova?, Andrea

    2007-01-01

    The work-life balance is currently in vogue among governments, organizations as well as researchers. Higher managers in organizations all over the world are exposed to significant pressures in their jobs, which further influence the balance between their work and private lives, job satisfaction and overall well-being. In this thesis, we apply a different perspective on the topic of work-life balance than most of the previous scientific research. We have focused on the governmental, organizati...

  13. Flow resistivity instrument in the earth

    Science.gov (United States)

    Zuckerwar, Allan J. (Inventor)

    1984-01-01

    Method and apparatus for making in-situ measurements of flow resistivity on the Earth's ground surface. The novel feature of the invention is two concentric cylinders, 22 and 23, inserted into the ground surface 24 with a measured pressure 21 applied to the surface inside the inner cylinder 22. The outer cylinder 23 vents a plane B-B beneath the surface to the atmosphere through an air space 28. The flow to the inner cylinder is measured (16) thereby indicating the flow from the surface to the plane beneath the surface.

  14. The rotational feedback on linear-momentum balance in glacial isostatic adjustment

    Science.gov (United States)

    Martinec, Zdenek; Hagedoorn, Jan

    2015-04-01

    The influence of changes in surface ice-mass redistribution and associated viscoelastic response of the Earth, known as glacial-isostatic adjustment (GIA), on the Earth's rotational dynamics has long been known. Equally important is the effect of the changes in the rotational dynamics on the viscoelastic deformation of the Earth. This signal, known as the rotational feedback, or more precisely, the rotational feedback on the sea-level equation, has been mathematically described by the sea-level equation extended for the term that is proportional to perturbation in the centrifugal potential and the second-degree tidal Love number. The perturbation in the centrifugal force due to changes in the Earth's rotational dynamics enters not only into the sea-level equation, but also into the conservation law of linear momentum such that the internal viscoelastic force, the perturbation in the gravitational force and the perturbation in the centrifugal force are in balance. Adding the centrifugal-force perturbation to the linear-momentum balance creates an additional rotational feedback on the viscoelastic deformations of the Earth. We term this feedback mechanism as the rotational feedback on the linear-momentum balance. We extend both the time-domain method for modelling the GIA response of laterally heterogeneous earth models and the traditional Laplace-domain method for modelling the GIA-induced rotational response to surface loading by considering the rotational feedback on linear-momentum balance. The correctness of the mathematical extensions of the methods is validated numerically by comparing the polar motion response to the GIA process and the rotationally-induced degree 2 and order 1 spherical harmonic component of the surface vertical displacement and gravity field. We present the difference between the case where the rotational feedback on linear-momentum balance is considered against that where it is not. Numerical simulations show that the resulting difference in radial displacement and sea-level change between these situations since the Last Glacial Maximum reaches values of ± 25 m and ± 1.8 m, respectively. Furthermore, the surface deformation pattern is modified by up to 10% in areas of former or ongoing glaciation, but by up to 50% at the bottom of the southern Indian ocean. This also results in the movement of coastlines during the last deglaciation to differ between the two cases due to the difference in the ocean loading, which is seen for instance in the area around Hudson Bay, Canada, and along the Chinese, Australian, or Argentinian coastlines.

  15. Energy balances for power plants

    International Nuclear Information System (INIS)

    An important aspect of a power plant is its energy balance, i.e. the electrical energy produced by the plant over its overall operation period, compared to the amount of non-renewable energy used to create and build the plant. Tense discussions took place in the past between criticizers and promotors of a given technology, some technologies even being accused of having a negative energy balance. Mostly based on built examples the present study aims at giving objective data for the represented technologies, as follows: a 64 MW hydro power plant in the Alps, with seasonal water storage in a lake; a 60 MW run-of-river high-head hydro power plant in the Alps; two run-of-river low-head hydro power plants in the Swiss Midlands (14 MW and 25 MW respectively); a small 30 kW wind power generator located near the Simplon Pass at 2000 m over sea level, in the Alps; a 3 kW photovoltaic generator in the roof of a single-family house; a 500 kW photovoltaic power plant in the Jura, at 1000 m over sea level; a 0.9 MWel/8.8 MWtherm fossil-fuel co-generation plant near Zuerich; a 200 MW natural-gas-fired gas/vapour turbine power plant; a 300 MW heavy-fuel-fired power plant; a 500 MW coal-fired power plant; and the Leibstadt 990 MW nuclear power plant. The best energy balances are obtained for the hydro power plants, the worst for the Leibstadt nuclear power plant. In between the photovoltaic plants and the fossil-fuel-fired plants are found. The figures differ by d plants are found. The figures differ by more than two orders of magnitude

  16. PRIORITIZING HIGHER EDUCATION BALANCED SCORECARD PERFORMANCE INDICATORS USING FUZZY APPROACH IN AN IRANIAN CONTEXT

    Directory of Open Access Journals (Sweden)

    Daryush Farid

    2008-10-01

    Full Text Available Higher education institutes are facing new challenges in order to improve the quality of education. There is a pressure for restructuring and reforming higher education in order to provide quality education and bring up graduates who become fruitful members of their societies. In higher education as in business there are acceptable conventions of measuring excellence. As a result, the implementation of Balanced Scorecard in higher education has been a target of interest in recent years. However, rather than emphasizing on financial performance, higher education has emphasized on academic measures in its Balanced Scorecard. This paper aims to prioritize performance indicators within the higher education balanced scorecard using fuzzy TOPSIS technique.Because Fuzzy Theory is a better approach in comparison to Logical Theory in case of measuring linguistic terms, therefore this paper tries to apply a fuzzy approach in prioritizing the performance indicators introduced by Balanced Scorecard.

  17. On the existence of another source of heat production for the earth and planets, and its connection with gravitomagnetism

    OpenAIRE

    Elbeze, Alexandre Chaloum

    2013-01-01

    Recent revised estimates of the Earth’s surface heat flux are in the order of 47 TW. Given that its internal radiogenic (mantle and crust) heat production is estimated to be around 20 TW, the Earth has a thermal deficit of around 27 TW. This article will try to show that the action of the gravitational field of the Sun on the rotating masses of the Earth is probably the source of another heat production in order of 54TW, which would satisfy the thermal balance of our celestial body and prob...

  18. The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes

    OpenAIRE

    Su, Z

    2002-01-01

    A Surface Energy Balance System (SEBS) is proposed for the estimation of atmospheric turbulent fluxes and evaporative fraction using satellite earth observation data, in combination with meteorological information at proper scales. SEBS consists of: a set of tools for the determination of the land surface physical parameters, such as albedo, emissivity, temperature, vegetation coverage etc., from spectral reflectance and radiance measurements; a model for the determination of the roughness le...

  19. Balancing oil and environment... responsibly.

    Energy Technology Data Exchange (ETDEWEB)

    Weimer, Walter C.; Teske, Lisa

    2007-01-25

    Balancing Oil and Environment…Responsibly As the price of oil continues to skyrocket and global oil production nears the brink, pursuing unconventional oil supplies, such as oil shale, oil sands, heavy oils, and oils from biomass and coal has become increasingly attractive. Of particular significance to the American way is that our continent has significant quantities of these resources. Tapping into these new resources, however, requires cutting-edge technologies for identification, production, processing and environmental management. This job needs a super hero or two for a job of this size and proportion…

  20. Densities for random balanced sampling

    OpenAIRE

    Bubenik, Peter; Holbrook, John

    2006-01-01

    A random balanced sample (RBS) is a multivariate distribution with n components X_1,...,X_n, each uniformly distributed on [-1, 1], such that the sum of these components is precisely 0. The corresponding vectors X lie in an (n-1)-dimensional polytope M(n). We present new methods for the construction of such RBS via densities over M(n) and these apply for arbitrary n. While simple densities had been known previously for small values of n (namely 2,3 and 4), for larger n the k...