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Sample records for earth pressure balance

  1. Earth pressure balance control for EPB shield

    2009-01-01

    This paper mainly deals with the critical technology of earth pressure balance (EPB) control in shield tunneling. On the assumption that the conditioned soil in the working chamber of the shield is plasticized, a theoretical principle for EPB control is proposed. Dynamic equilibrium of intake volume and discharge volume generated by thrust and discharge is modeled theoretically to simulate the earth pressure variation during excavating. The thrust system and the screw conveyor system for earth pressure control are developed based on the electro-hydraulic technique. The control models of the thrust speed regulation of the cylinders and the rotating speed adjustment of the screw conveyor are also presented. Simulation for earth pressure control is conducted with software AMESim and MATLAB/Simulink to verify the models. Experiments are carried out with intake control in clay soil and discharge control in sandy gravel section, respectively. The experimental results show that the earth pressure variations in the working chamber can be kept at the expected value with a practically acceptable precision by means of real-time tuning the thrust speed or the revolving speed of discharge system.

  2. Feasibility study of tar sands conditioning for earth pressure balance tunnelling

    Martinelli, D; D. Peila; E. Campa

    2015-01-01

    This paper presents the results of laboratory test on the feasibility of soil conditioning for earth pressure balance (EPB) excavation in a tar sand, which is a natural material never studied in this respect. The laboratory test performed is based on a procedure and methods used in previous studies with different types of soils, but for this special complex material, additional tests are also conducted to verify particular properties of the tar sands, such as the tilt test and vane shear test...

  3. Feasibility study of tar sands conditioning for earth pressure balance tunnelling

    D. Martinelli

    2015-12-01

    Full Text Available This paper presents the results of laboratory test on the feasibility of soil conditioning for earth pressure balance (EPB excavation in a tar sand, which is a natural material never studied in this respect. The laboratory test performed is based on a procedure and methods used in previous studies with different types of soils, but for this special complex material, additional tests are also conducted to verify particular properties of the tar sands, such as the tilt test and vane shear test usually used in cohesive materials, and a direct shear test. The laboratory test proves that the test procedure is applicable also to this type of soil and the conditioned material can be considered suitable for EPB excavations, although it is necessary to use a certain percentage of fine elements (filler to create a material suitable to be mixed with foam. The test results show that the conditioned material fulfils the required standard for an EPB application.

  4. Pressure regulation for earth pressure balance control on shield tunneling machine by using adaptive robust control

    Xie, Haibo; Liu, Zhibin; Yang, Huayong

    2016-05-01

    Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control (ARC) are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve's dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.

  5. Pressure regulation for earth pressure balance control on shield tunneling machine by using adaptive robust control

    Xie, Haibo; Liu, Zhibin; Yang, Huayong

    2016-04-01

    Most current studies about shield tunneling machine focus on the construction safety and tunnel structure stability during the excavation. Behaviors of the machine itself are also studied, like some tracking control of the machine. Yet, few works concern about the hydraulic components, especially the pressure and flow rate regulation components. This research focuses on pressure control strategies by using proportional pressure relief valve, which is widely applied on typical shield tunneling machines. Modeling of a commercial pressure relief valve is done. The modeling centers on the main valve, because the dynamic performance is determined by the main valve. To validate such modeling, a frequency-experiment result of the pressure relief valve, whose bandwidth is about 3 Hz, is presented as comparison. The modeling and the frequency experimental result show that it is reasonable to regard the pressure relief valve as a second-order system with two low corner frequencies. PID control, dead band compensation control and adaptive robust control (ARC) are proposed and simulation results are presented. For the ARC, implements by using first order approximation and second order approximation are presented. The simulation results show that the second order approximation implement with ARC can track 4 Hz sine signal very well, and the two ARC simulation errors are within 0.2 MPa. Finally, experiment results of dead band compensation control and adaptive robust control are given. The results show that dead band compensation had about 30° phase lag and about 20% off of the amplitude attenuation. ARC is tracking with little phase lag and almost no amplitude attenuation. In this research, ARC has been tested on a pressure relief valve. It is able to improve the valve's dynamic performances greatly, and it is capable of the pressure control of shield machine excavation.

  6. Pressure balance at the magnetopause: Experimental studies

    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 the magnetic file...

  7. Rare earths and the balance problem

    Binnemans, Koen; Jones , Peter Tom

    2015-01-01

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

  8. Pressure balance at the magnetopause: Experimental studies

    Suvorova, 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 the magnetic filed is contributed by additional sources: Chapman-Ferraro current system, field-aligned currents, tail current, and storm-time ring current. Net contribution of those sources depends on particular magnetospheric region and varies with solar wind conditions and geomagnetic activity. As a result, the parameters of pressure balance, including power index alpha, depend on both the local position at the magnetopause and geomagnetic activity. In addition, the pressure balance can be affected by a non-linear transfer of the solar ...

  9. Pressure-Balance Consistency in Magnetospheric Modelling

    肖永登; 陈出新

    2003-01-01

    There have been many magnetic field models for geophysical and astrophysical bodies.These theoretical or empirical models represent the reality very well in some cases,but in other cases they may be far from reality.We argue that these models will become more reasonable if they are modified by some coordinate transformations.In order to demonstrate the transformation,we use this method to resolve the "pressure-balance inconsistency"problem that occurs when plasma transports from the outer plasma sheet of the Earth into the inner plasma sheet.

  10. Earth Pressure on Tunnel Crown

    Andersen, Lars

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

  11. Computerized Techniques for Calibrating Pressure Balances

    Simpson, D. I.

    1994-01-01

    Pressure balances are generally calibrated by the cross-floating technique, where the forces acting on two similar devices in hydrostatic equilibrium are compared. It is a skilled and time-consuming process which has not previously lent itself to significant automation; computers have mostly been used only to calculate results after measurements have been taken. The objective of the present work was to develop real-time computerized measurement techniques to ease the calibration task, which would fully integrate into a single package with versatile software for calculating and displaying results. The calibration process is now conducted by studying graphical computer displays which derive their inputs from differential-pressure transducers and capacitance or optical displacement sensors. The mass imbalance between oil-operated pressure balances is calculated by interpolating between changes in piston rate-of-fall. Differential-pressure transducers are used to estimate mass imbalances between gas-operated balances, and a quick in situ method for determining their sensitivity has been developed. The new techniques have been successfully applied to a variety of pressure balance designs and substantial reductions in calibration times have been achieved. Reduced levels of scatter have revealed small systematic differences between gauge and absolute modes of operation.

  12. Seismic induced earth pressures in buried vaults

    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

  13. Dynamic active earth pressure on retaining structures

    Deepankar Choudhury; Santiram Chatterjee

    2006-12-01

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

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

    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.

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

    Bruin, de, K.

    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...

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

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

    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....

  18. AN APPROXIMATION TO LATERAL EARTH PRESSURES FOR K0 CONDITION

    M. Arslan TEKİNSOY

    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.

  19. Stability of hydrocarbons at deep Earth pressures and temperatures

    Spanu, Leonardo; Donadio, Davide; Hohl, Detlef; Schwegler, Eric; Galli, Giulia

    2011-01-01

    Determining the thermochemical properties of hydrocarbons (HCs) at high pressure and temperature is a key step toward understanding carbon reservoirs and fluxes in the deep Earth. The stability of carbon-hydrogen systems at depths greater than a few thousand meters is poorly understood and the extent of abiogenic HCs in the Earth mantle remains controversial. We report ab initio molecular dynamics simulations and free energy calculations aimed at investigating the formation of higher HCs from...

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

    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

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

    Sorin Zaharia; C.Z. Cheng

    2002-06-18

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

  2. Economics as if the earth really mattered. Putting balance back on the balance sheet.

    Sherman, D

    1991-09-01

    Some of the thinking in the economic realm which affects the relationship between the economy and the environment is discussed. The standard economic model inherently conflicts with the environment. Humans as consumers have their needs met by maximizing production and efficiency in a free market economy, where an invisible hand guides to profit. The question is raised as to what the environmental impact is for economic growth. The need for clean air, water, and preservation of other living things is not met. It is argued that pollution is a necessary byproduct of production. Economic progress as measured by gross national product (GNP) cannot account for the degradation of nature, e.g., the Alaskan oil spill actually increased GNP. Traditional economics also tell little about the maldistribution of wealth. It is pointed out that Americans spend $5 billion a year on special diets while 400 million around the world are undernourished. Limits to natural resources are also not accounted for by economic theorists, or the value of the seemingly free life-sustaining services performed by a forest in purifying air, preventing erosion and flooding, regulating climate, and supporting biological diversity. It is pointed out that restructuring must occur if the capacity of the Earth to support life is classed in economic terms as an externality. Steady state economic models consider the cycles of production and consumption in the context of the surrounding ecosystem of waste and raw materials and try to achieve a state of equilibrium. Despite the 1972 President's Commission on Population Growth and the American Future's statement that population growth is not necessary for a vital economy, the mythology exists that the economy will collapse, personal income will drop, and business will decline without an ever-growing population. A summary on positive outcomes of zero population growth is given. The economist Julian Simon promotes the view that there is no environmental

  3. Earth Pressure Model with Curved Slip Surfaces by AIM

    Koudelka, Petr

    Rotterdam: A.A.Balkema, 1999 - ( Fujita , F.), s. 377-382 [Conf. of Geotechnical Aspects of Underground Construction in Soft Ground. Tokyo (JP), 07.07.1999-10.07.1999] R&D Projects: GA ČR GA103/98/0632 Keywords : Earth (lateral) pressure * apriori integration method * shear surface * slip surface * minimization Subject RIV: JM - Building Engineering

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

    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.

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

    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.

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

    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)

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

    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

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

    Wild, Martin; Liepert, Beate

    2010-06-01

    Variations in the intensity of the global hydrological cycle can have far-reaching effects on living conditions on our planet. While climate change discussions often revolve around possible consequences of future temperature changes, the adaptation to changes in the hydrological cycle may pose a bigger challenge to societies and ecosystems. Floods and droughts are already today amongst the most damaging natural hazards, with floods being globally the most significant disaster type in terms of loss of human life (Jonkman 2005). From an economic perspective, changes in the hydrological cycle can impose great pressures and damages on a variety of industrial sectors, such as water management, urban planning, agricultural production and tourism. Despite their obvious environmental and societal importance, our understanding of the causes and magnitude of the variations of the hydrological cycle is still unsatisfactory (e.g., Ramanathan et al 2001, Ohmura and Wild 2002, Allen and Ingram 2002, Allan 2007, Wild et al 2008, Liepert and Previdi 2009). The link between radiation balance and hydrological cycle Globally, precipitation can be approximated by surface evaporation, since the variability of the atmospheric moisture storage is negligible. This is the case because the fluxes are an order of magnitude larger than the atmospheric storage (423 x 1012 m3 year-1 versus 13 x 1012 m3 according to Baumgartner and Reichel (1975)), the latter being determined by temperature (Clausius-Clapeyron). Hence the residence time of evaporated water in the atmosphere is not more than a few days, before it condenses and falls back to Earth in the form of precipitation. Any change in the globally averaged surface evaporation therefore implies an equivalent change in precipitation, and thus in the intensity of the global hydrological cycle. The process of evaporation requires energy, which it obtains from the surface radiation balance (also known as surface net radiation), composed of the

  9. Precariousness and hazard of lateral earth pressure theory

    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

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

    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. Pressure-induced exotic states in rare earth hexaborides

    Sun, Liling; Wu, Qi

    2016-08-01

    Finding the exotic phenomena in strongly correlated electron systems (SCESs) and understanding the corresponding microphysics have long been the research frontiers of condensed matter physics. The remarkable examples for the intriguing phenomena discovered in past years include unconventional superconductivity, heavy Fermion behaviors, giant magneto-resistance and so on. A fascinating type of rare earth hexaboride RB6 (R  =  Sm, Yb, Eu and Ce) belongs to a strongly correlated electron system (SCES), but shows unusual ambient-pressure and high-pressure behaviors beyond the phenomena mentioned above. Particularly, the recent discovery of the coexistence of an unusual metallic surface state and an insulating bulk state in SmB6, known to be a Kondo insulator decades ago, by theoretical calculations and many experimental measurements creates new interest for the investigation of the RB6. This significant progress encourages people to revisit the RB6 with an attempt to establish a new physics that links the SCES and the unusual metallic surface state which is a common feature of a topological insulator (TI). It is well known that pressure has the capability of tuning the electronic structure and modifying the ground state of solids, or even inducing a quantum phase transition which is one of the kernel issues in studies of SCESs. In this brief review, we will describe the progress in high pressure studies on the RB6 based on our knowledge and research interests, mainly focusing on the pressure-induced phenomena in YbB6 and SmB6, especially on the quantum phase transitions and their connections with the valence state of the rare earth ions. Moreover, some related high-pressure results obtained from CeB6 and EuB6 are also included. Finally, a summary is given in the conclusions and perspectives section.

  12. Pressure-induced exotic states in rare earth hexaborides.

    Sun, Liling; Wu, Qi

    2016-08-01

    Finding the exotic phenomena in strongly correlated electron systems (SCESs) and understanding the corresponding microphysics have long been the research frontiers of condensed matter physics. The remarkable examples for the intriguing phenomena discovered in past years include unconventional superconductivity, heavy Fermion behaviors, giant magneto-resistance and so on. A fascinating type of rare earth hexaboride RB6 (R  =  Sm, Yb, Eu and Ce) belongs to a strongly correlated electron system (SCES), but shows unusual ambient-pressure and high-pressure behaviors beyond the phenomena mentioned above. Particularly, the recent discovery of the coexistence of an unusual metallic surface state and an insulating bulk state in SmB6, known to be a Kondo insulator decades ago, by theoretical calculations and many experimental measurements creates new interest for the investigation of the RB6. This significant progress encourages people to revisit the RB6 with an attempt to establish a new physics that links the SCES and the unusual metallic surface state which is a common feature of a topological insulator (TI). It is well known that pressure has the capability of tuning the electronic structure and modifying the ground state of solids, or even inducing a quantum phase transition which is one of the kernel issues in studies of SCESs. In this brief review, we will describe the progress in high pressure studies on the RB6 based on our knowledge and research interests, mainly focusing on the pressure-induced phenomena in YbB6 and SmB6, especially on the quantum phase transitions and their connections with the valence state of the rare earth ions. Moreover, some related high-pressure results obtained from CeB6 and EuB6 are also included. Finally, a summary is given in the conclusions and perspectives section. PMID:27376406

  13. Phase transitions in rare earth tellurides under pressure

    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)

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

    Kajikawa, H; Ide, K; Kobata, T, E-mail: kajikawa.hiroaki@aist.go.j [National Metrology Institute of Japan (NMIJ), AIST, Tsukuba, Ibaraki 305-8563 (Japan)

    2010-03-01

    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.

  15. Water-Energy balance in pressure irrigation systems

    Sánchez, Raúl; Rodríguez-Sinobas, Leonor; Juana, Luis; Laguna, Francisco V.; Castañón, Guillermo; Gil, María; Benitez, Javier

    2013-04-01

    Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure -sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. Automation techniques become easier after modernization, and operation management plays an important role in energy efficiency issues. Modern systems use to include elevated water reservoirs with enough capacity to irrigate during peak water demand period about 16 to 48 h. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems according to their management possibilities. Also is an objective to estimate the fraction of the water reservoirs available along the irrigation campaign for storing the energy from renewable sources during their availability periods. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity and new opportunities in the renewable energy field.

  16. INVESTIGATION INTO EFFECT OF SPRING PRESSURE ON PERFORMANCE OF BALANCED MECHANICAL SEALS

    SUN Jianjun; GU Boqin

    2007-01-01

    The loads acting on the sealing elements of balanced mechanical seals are analyzed. When the balance factor approaches the back pressure factor, the spring pressure will become main part of the face pressure. The leakage model of balanced mechanical seals is established on the base of M-B model for rough surface. Several GY-70 type balanced mechanical seals are tested. The influences of the spring pressure both on the leakage rate and on the friction characteristic of balanced mechanical seals are investigated. The research results indicate that as spring pressure increases, both the clearance between two end faces and the leakage rate will decrease, and the friction will be more serious because lubrication medium between the rotating ring and the stationary ring reduces, though the increase of the spring pressure may not be enough to change the face friction state of mechanical seals. There exists an optimum spring pressure for mechanical seal operation. Under this spring pressure, not only leakage rate is small, but also the seal end surfaces have a fine friction characteristic.Under different operating conditions, identical type mechanical seals may possess different spring pressure. Appropriate selection of spring pressure is valuable to realize long-period and small leakage rate operating of balanced mechanical seals.

  17. Statistical Behavior of Quasi-Steady Balanced Reconnection in Earth's Magnetosphere

    Kissinger, Jennifer Eileen

    2012-01-01

    Magnetic reconnection between Earth's magnetosphere and the solar wind results in several modes of response, including the impulsive substorm and the quasi-steady mode known as steady magnetospheric convection (SMC). SMC events are theorized to result from balancing the dayside and nightside reconnection rates. The reasons the magnetosphere responds with different modes are not fully known. This dissertation comprises statistical data analysis of the SMC mode to investigate the solar wind con...

  18. The effect of cloud type on Earth's energy balance - Global analysis

    Hartmann, Dennis L.; Ockert-Bell, Maureen E.; Michelsen, Marc L.

    1992-01-01

    The role of fractional area coverage by cloud types in the energy balance of the earth is investigated through joint use of International Satellite Cloud Climatology Project (ISCCP) C1 cloud data and Earth Radiation Budget Experiment (ERBE) broadband energy flux data for the one-year period March 1985 through February 1986. Multiple linear regression is used to relate the radiation budget data to the cloud data. Comparing cloud forcing estimates obtained from the ISCCP-ERBE regression with those derived from the ERBE scene identification shows generally good agreement except over snow, in tropical convective regions, and in regions that are either nearly cloudless or always overcast. It is suggested that a substantial fraction of the disagreement in longwave cloud forcing in tropical convective regions is associated with the fact that the ERBE scene identification does not take into account variations in upper-tropospheric water vapor. On a global average basis, low clouds make the largest contribution to the net energy balance of the Earth, because they cover such a large area and because their albedo effect dominates their effect on emitted thermal radiation. High, optically thick clouds can also very effectively reduce the energy balance, however, because their very high albedos overcome their low emission temperatures.

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

    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...

  20. A Mechanism of Solar Variability Effect on Radiative Balance of the Earth Atmosphere

    G. A. Zherebtsov; V.A. Kovalenko; S.I. Molodykh

    2005-01-01

    Possible mechanisms of solar-climatic connections, which may be of importance as over short and long time intervals, are discussed. The variations of energetic balance of Earth's climatic system for the last fifty years are estimated. It is ascertained that the disbalance between the flux of solar energy that comes to the Earth and radiates to space is of 0.1% for the last ten years. The suggested mechanism makes it possible to explain not only the observed variation of the enthalpy of the Earth's climatic system for the period 1910-1980, but also the climate anomalies during last thousand years: the climate optimum in 12 century, and"small glacial period" in 16-17 centuries.

  1. High pressure behaviour of heavy rare earth mono antimonides

    We have investigated theoretically the high-pressure structural phase transition and cohesive properties of two heavy rare earth mono antimonides (RESb; RE = Dy and Lu) by using two body interionic potential with necessary modifications to include the effect of Coulomb screening by the delocalized 4f electrons of the RE ion. The peculiar properties of these compounds have been interpreted in terms of the hybridization of f electrons with the conduction band and strong mixing of f states of RE ion with the p orbital of neighboring pnictogen ion. These compounds exhibit first order crystallographic phase transition from their NaCl (B1) phase to CsCl (B2) phase at 23.6 GPa and 25.4 GPa respectively. The bulk modulii of RESb compounds are obtained from the P-V curve fitted by the Birch equation of state. We also calculated the RE-RE distance as a function of pressure. Elastic properties of these compounds have also been studied and their second order elastic constants are calculated.

  2. Reliability and validity of center of pressure measures for balance assessment in older adults

    LI, ZHEN; Liang, Yan-Yi; Wang, Lei; Sheng, Jing; Ma, Shao-Jun

    2016-01-01

    [Purpose] This study was conducted to assess the reliability and validity of center of pressure-based parameters for balance assessment. [Subjects and Methods] Two hundred and forty older adults were evaluated using a force platform and the Berg Balance Scale at 1-week intervals. The intra-class correlation coefficient and the Pearson correlation coefficient were used to test reliability and validity respectively. [Results] The reliability of the 12 selected center of pressure measures was sa...

  3. Simulation of the Earth's gravitational field recovery from GRACE using the energy balance approach

    ZHENG Wei; LU Xiaolei; HSU Houtse; SHAO Chenggang; LUO Jun; WANG Nengchao

    2005-01-01

    Based on the measurement principles of GRACE satellites, the observation equations are set up using the energy balance approach. The Earth's gravitational field complete up to degree and order 120 is recovered applying the preconditioning conjugate gradient iterative approach by numerical simulation. Assuming an accuracy of 1?m/s in range-rate measurements of the K-band microwave ranging system, the matching relationships of accuracies of K-band microwave ranging system, SuperSTAR Accelerometer, position vector and velocity vector measurements are investigated.

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

    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.…

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

    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...

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

    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...

  7. Research on Earth's rotation and the effect of atmospheric pressure on vertical deformation and sea level variability

    Wahr, John

    1993-03-01

    The work done under NASA grant NAG5-485 included modelling the deformation of the earth caused by variations in atmospheric pressure. The amount of deformation near coasts is sensitive to the nature of the oceanic response to the pressure. The PSMSL (Permanent Service for Mean Sea Level) data suggest the response is inverted barometer at periods greater than a couple months. Green's functions were constructed to describe the perturbation of the geoid caused by atmospheric and oceanic loading and by the accompanying load-induced deformation. It was found that perturbation of up to 2 cm are possible. Ice mass balance data was used for continental glaciers to look at the glacial contributions to time-dependent changes in polar motion, the lod, the earth's gravitational field, the position of the earth's center-of-mass, and global sea level. It was found that there can be lateral, non-hydrostatic structure inside the fluid core caused by gravitational forcing from the mantle, from the inner core, or from topography at the core/mantle or inner core/outer core boundaries. The nutational and tidal response of a non-hydrostatic earth with a solid inner core was modeled. Monthly, global tide gauge data from PSMSL was used to look at the 18.6-year ocean tide, the 14-month pole tide, the oceanic response to pressure, the linear trend and inter-annual variability in the earth's gravity field, the global sea level rise, and the effects of post glacial rebound. The effects of mantle anelasticity on nutations, earth tides, and tidal variation in the lod was modeled. Results of this model can be used with Crustal Dynamics observations to look at the anelastic dissipation and dispersion at tidal periods. The effects of surface topography on various components of crustal deformation was also modeled, and numerical models were developed of post glacial rebound.

  8. Reliability and validity of center of pressure measures for balance assessment in older adults

    Li, Zhen; Liang, Yan-Yi; Wang, Lei; Sheng, Jing; Ma, Shao-Jun

    2016-01-01

    [Purpose] This study was conducted to assess the reliability and validity of center of pressure-based parameters for balance assessment. [Subjects and Methods] Two hundred and forty older adults were evaluated using a force platform and the Berg Balance Scale at 1-week intervals. The intra-class correlation coefficient and the Pearson correlation coefficient were used to test reliability and validity respectively. [Results] The reliability of the 12 selected center of pressure measures was satisfactory (intra-class correlation coefficient = 0.75–0.99) and the validity between the parameters and the Berg Balance Scale was moderate to good (r = −0.62 to −0.88). [Conclusion] Center of pressure-based parameters are reliable and valid measures in older adults.

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

    Silvano, Saragosa

    2010-01-01

    This paper is based on the original work of the master degree thesis [1] and also represents a revision of the models and the correlations with the analytical solutions given by other authors in the previous publications from 2003 to 2007. All the publications from 2003 to 2007 about simplified analytical methods applied to controlled-clearance pressure balances are not original re-elaborations (with some errors) of the thesis[1]. The analysis described in this paper starts with the mathematical model of thick-walled cylinder based on the solution of the Lame Equations applied to Mechanical theory of elastic equilibrium [5] for the formulation of the so called Simplified Elastic Theory that represents an analytical approach used in the study of the pressure balances. This analysis is well known as Lame problem. The solution of the Lame problem is used to determine the pressure distortion coefficient of controlled-clearance pressure balances. The analysis in this paper includes the case of pressure balances wi...

  10. Effect of impeller reflux balance holes on pressure and axial force of centrifugal pump

    CAO Wei-dong; DAI Xun; HU Qi-xiang

    2015-01-01

    The size of impeller reflux holes for centrifugal pump has influence on the pressure distribution of front and rear shrouds and rear pump chamber, as well as energy characteristics of whole pump and axial force. Low specific-speed centrifugal pump with Q=12.5 m3/h,H=60 m,n=2950 r/min was selected to be designed with eight axial reflux balance holes with 4.5 mm in diameter. The simulated Q-H curve and net positive suction head (NPSH) were in good agreement with experimental results, which illustrated that centrifugal pump with axial reflux balance holes was superior in the cavitation characteristic; however, it showed to little superiority in head and efficiency. The pressure in rear pump chamber at 0.6 times rate flow is 29.36% of pressure difference between outlet and inlet, which reduces to 29.10% at rate flow and 28.33% at 1.4 times rate flow. As the whole, the pressure distribution on front and rear shrouds from simulation results is not a standard parabola, and axial force decreases as flow rate increases. Radical reflux balance holes chosen to be 5.2 mm and 5.9 mm in diameter were further designed with other hydraulic parts unchanged. With structural grids adopted for total flow field, contrast numerical simulation on internal flow characteristics was conducted based on momentum equations and standard turbulence model (κ-ε). It is found that axial force of pump with radical reflux balance holes of 5.2 mm and 5.9 mm in diameter is significantly less than that with radical reflux balance holes of 4.5 mm in diameter. Better axial force balance is obtained as the ratio of area of reflux balance holes and area of sealing ring exceeds 6.

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

    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.

  12. Elements, Oxides, Silicates: High Pressure Phases With Implications for the Earth's Interior [Book Review

    Ahrens, Thomas J.

    1988-01-01

    A vitally important aspect of understanding the composition, structure, and processes acting within the solid Earth is obtaining a complete as possible knowledge of the fields of stability of the Earth's component minerals and their high-pressure polymorphs with respect to pressure and temperature. Liu and Bassett's book is the first effort which has focused on bringing together the available phase diagrams for the elements, oxides, and silicates that are relevant to the understanding of Eart...

  13. Lateral Earth Pressure behind Walls Rotating about Base considering Arching Effects

    Dong Li

    2014-01-01

    Full Text Available In field, the earth pressure on a retaining wall is the common effect of kinds of factors. To figure out how key factors act, it has taken into account the arching effects together with the contribution from the mode of displacement of a wall to calculate earth pressure in the proposed method. Based on Mohr circle, a conversion factor is introduced to determine the shear stresses between artificial slices in soil mass. In the light of this basis, a modified differential slices solution is presented for calculation of active earth pressure on a retaining wall. Comparisons show that the result of proposed method is identical to observations from model tests in prediction of lateral pressures for walls rotating about the base.

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

    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.

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

    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.

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

    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.

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

    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.

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

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

  19. Pressure dependence of the charge-density-wave gap in rare-earth tritellurides.

    Sacchetti, A; Arcangeletti, E; Perucchi, A; Baldassarre, L; Postorino, P; Lupi, S; Ru, N; Fisher, I R; Degiorgi, L

    2007-01-12

    We investigate the pressure dependence of the optical properties of CeTe3, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the midinfrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice compression removes the perfect nesting condition of the Fermi surface and therefore diminishes the impact of the CDW transition on the electronic properties of RTe3. PMID:17358625

  20. Pressure Dependence of the Charge-Density-Wave Gap in Rare-Earth Tri-Tellurides

    Sacchetti, A.; /Zurich, ETH; Arcangeletti, E.; Perucchi, A.; Baldassarre, L.; Postorino, P.; Lupi, S.; /Rome U.; Ru, N.; Fisher, I.R.; /Stanford U., Geballe Lab.; Degiorgi, L.; /Zurich, ETH

    2009-12-14

    We investigate the pressure dependence of the optical properties of CeTe{sub 3}, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the mid-infrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice compression removes the perfect nesting condition of the Fermi surface and therefore diminishes the impact of the CDW transition on the electronic properties of RTe{sub 3}.

  1. Pressure dependence of the charge-density-wave gap in rare-earth tri-tellurides

    A. Sacchetti; Arcangeletti, E.; Perucchi, A.; Baldassarre, L.; Postorino, P.; Lupi, S.; Ru, N.; Fisher, I. R.; Degiorgi, L.

    2006-01-01

    We investigate the pressure dependence of the optical properties of CeTe$_3$, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the mid-infrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice com...

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

    Ozgur L. Ertugrul; Aurelian C. Trandafir

    2014-01-01

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

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

    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 ČR GA103/97/0702; GA ČR GA103/98/0632 Keywords : lateral (Earth) pressure * granular mass * extreme pressures (active, pasive) Subject RIV: JM - Building Engineering

  4. Solar radiation pressure used for formation flying control around the Sun-Earth libration point

    Sheng-ping GONG; Jun-feng LI; He-xi BAOYIN

    2009-01-01

    Solar radiation pressure is used to control the formation flying around the L2 libration point in the Sun-Earth system. Formation flying control around a halo orbit requires a very small thrust that cannot be satisfied by the latest thrusters. The key contribution of this paper is that the continuous low thrust is produced by solar radiation pressure to achieve the tight formation flying around the libration point. However, only certain families of formation types can be controlled by solar radiation pressure since the direction of solar radiation pressure is restricted to a certain range. Two types of feasible formations using solar radiation pressure control are designed. The conditions of feasible formations are given analytically. Simulations are presented for each case, and the results show that the formations are well controlled by solar radiation pressure.

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

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

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

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

    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 anch...

  7. STUDY ON THE OVERALL PRESSURE BALANCE OF A DOWNFLOW CIRCULATING FLUIDIZED BED SYSTEM

    Hengzhi Chen; Dawei Yang; Hongzhong Li; Shiyu Tan

    2006-01-01

    A pressure balance model for a circulating fluidized bed unit that incorporates a downer has been proposed. The model predictions were validated with the experimental data obtained from a special cold-model circulating fluidized bed. Comparison of the operation stability between a CFB downer and a CFB riser has been carried out. Only one critical gas velocity exists in the CFB-riser for a given riser solids flux, while there can be many critical gas velocities for the operation of a CFB downer. Therefore, it is possible to achieve high solids concentration in a CFB downer if appropriate operating conditions are used.

  8. Current long-term negative average annual energy balance of the earth leads to the new little ice age

    Abdussamatov Habibullo

    2015-01-01

    Full Text Available The average annual decreasing rate of the total solar irradiance (TSI is increasing from the 22-nd to the 23-rd and 24-th cycles, because the Sun since the 1990 is in the phase decline of quasi-bicentennial variation. The portion of the solar energy absorbed by the Earth is decreasing. Decrease in the portion of TSI absorbed by the Earth since 1990 remains uncompensated by the Earth's radiation into space at the previous high level over a time interval determined by the thermal inertia of the Ocean. A long-term negative deviation of the Earth’s average annual energy balance from the equilibrium state is dictating corresponding variations in it’s the energy state. As a result, the Earth will have a negative average annual energy balance also in the future. This will lead to the beginning of the decreasing in the Earth's temperature and of the epoch of the Little Ice Age after the maximum phase of the 24-th solar cycle approximately since the end of 2014. The influence of the consecutive chain of the secondary feedback effects (the increase in the Bond albedo and the decrease in the concentration of greenhouse gases in the atmosphere due to cooling will lead to an additional reduction of the absorbed solar energy and reduce the greenhouse effect. The start of the TSI’s Grand Minimum is anticipated in the solar cycle 27±1 in 2043±11 and the beginning of the phase of deep cooling of the 19th Little Ice Age for the past 7,500 years around 2060±11.

  9. Education for healthy body weight: helping adolescents balance the cultural pressure for thinness.

    Collins, M E

    1988-08-01

    Though education for healthy body weight traditionally has focused on obesity, the increased incidence of anorexia nervosa and bulimia among young women suggests education also is needed to address the opposite end of the spectrum. Anorexia nervosa and bulimia are complex and multidimensional disorders associated with individual, family, and sociocultural factors. This article examines the cultural pressure for dieting and thinness currently experienced in America and its impact as a possible predisposing factor for developing eating disorders among adolescent females. Literature is reviewed related to the changing American standard of attractiveness for females reflected by 20th century mass media and its subsequent influence on adolescent concerns for dieting and thinness. Preventive strategies are recommended to help adolescents balance the cultural pressure for thinness and their own desires for attractiveness within the larger context of overall good health. PMID:3216626

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

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

    2002-02-01

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

  11. Break the electron- hole balance and pressure induced superconductivity in Tungsten Ditelluride

    Song, Fengqi; Pan, Xing-Chen

    Tungsten ditelluride has garnered immense interest due to the recent discovery of titanic unsaturated magnetoresistance up to 60 Tesla and its possible topological metal nature. The titanic unsaturated magnetoresistance is attributed to the perfect compensation between the opposite carriers in this material. Motivated by the small and sensitive Fermi surface of 5d electronic orbitals, we break the electron-hole balance by the application of high pressure. Superconductivity sharply appears at the pressure of 2.5 GPa, quickly reaching a maximum critical temperature of 7 K at around 16.8 GPa, and followed by a monotonic decrease in Tc with increasing pressure exhibiting the typical dome-shaped superconducting phase. What's more, linear magnetoresistance dominates the transport behavior under high pressure instead of semi-classical parabolic magnetoresistance, like in other topological metals. Refence: Nature Commun. 6, 7805 (2015), arXiv 1505, 07968. The authors would like to thank the National Key Projects for Basic Research in China, the National Natural Science Foundation of China , the NSF of Jiangsu Province, the PAPD project, and the Fundamental Research Funds for the Central Universities.

  12. Highly balanced single-layer high-temperature superconductor SQUID gradiometer freely movable within the Earth's magnetic field

    We developed a gradiometer system based on a single-layer high-temperature superconductor dc superconducting quantum interference device (SQUID), which can be freely moved within the Earth's magnetic field during measurement. The problem of circumferential shielding currents in the parallel gradiometer pick-up loop is solved by the use of an appropriately designed magnetometer SQUID integrated on the gradiometer chip. The magnetometer's feedback coil of the flux-locked loop is laid out as a small Helmholtz coil pair, thus keeping the homogeneous magnetic field constant for both the magnetometer and the gradiometer. Therefore, the balance of the directly coupled gradiometer SQUID is enhanced from 100 up to 3800. The noise limited magnetic field gradient resolution of 45 pT m-1 Hz-1/2 is preserved down to frequencies of several Hz even after strong motion in the Earth's magnetic field

  13. High-pressure phase transitions in rare earth metal thulium to 195 GPa

    We have performed image plate x-ray diffraction studies on a heavy rare earth metal, thulium (Tm), in a diamond anvil cell to a pressure of 195 GPa and volume compression V/Vo = 0.38 at room temperature. The rare earth crystal structure sequence, hcp → Sm-type → dhcp → fcc → distorted fcc, is observed in Tm below 70 GPa with the exception of a pure fcc phase. The focus of our study is on the ultrahigh-pressure phase transition and Rietveld refinement of crystal structures in the pressure range between 70 and 195 GPa. The hexagonal hR- 24 phase is seen to describe the distorted fcc phase between 70 and 124 GPa. Above 124 ± 4 GPa, a structural transformation from hR 24 phase to a monoclinic C 2/m phase is observed with a volume change of - 1.5%. The equation of state data shows rapid stiffening above the phase transition at 124 GPa and is indicative of participation of f-electrons in bonding. We compare the behavior of Tm to other heavy rare-earths and heavy actinide metals under extreme conditions of pressure.

  14. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Cheng, Xi; Pinsky, Peter M

    2015-01-01

    The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK) equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea. PMID:26719894

  15. The Balance of Fluid and Osmotic Pressures across Active Biological Membranes with Application to the Corneal Endothelium.

    Xi Cheng

    Full Text Available The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Katchalsky (KK equations is proposed to describe fluxes of water and solutes across biological membranes, and is applied to analyze the relationship between fluid and osmotic pressures, accounting for active transport mechanisms that propel substances against their concentration gradients and for fixed charges that alter ionic distributions in separated environments. The equilibrium analysis demonstrates that the proposed theory recovers the Donnan osmotic pressure and can predict the correct fluid pressure difference across membranes, a result which cannot be achieved by existing KK theories due to the neglect of fixed charges. The steady-state analysis on active membranes suggests a new pressure mechanism which balances the fluid pressure together with the osmotic pressure. The source of this pressure arises from active ionic fluxes and from interactions between solvent and solutes in membrane transport. We apply the proposed theory to study the transendothelial fluid pressure in the in vivo cornea, which is a crucial factor maintaining the hydration and transparency of the tissue. The results show the importance of the proposed pressure mechanism in mediating stromal fluid pressure and provide a new interpretation of the pressure modulation mechanism in the in vivo cornea.

  16. Dualistic Chemical Evolution to the Stabilization of the Energy-Balance: A Hypothesis on the Origin of Life on the Earth

    Matsuda, Genji

    2004-01-01

    A hypothesis of the dualistic chemical evolution to the stabilization of the energy-balance is proposed and explained in connection with the origin of life on the earth. From author's viewpoint, the existence of all things and all phenomena in the universe are closely related to the stabilization of the energy-balance and life is not an exceptional case in this matter. It is presumed that the first life on the earth was formed as the process towards the stabilization of the energy-balance by ...

  17. Effect of seawater immersion on plasma osmotic pressure and electrolyte balance following open chest trauma

    李辉; 鹿尔驯; 虞积耀; 王大鹏; 马聪

    2002-01-01

    To explore the effect of seawater immersion on serum osmotic pressure and electrolytes balance following chest trauma in dogs. Methods: Twenty-five healthy adult dogs were used in the experiment. A canine model of right open pneumothorax was established by chest puncturing on all animals. Animals were divided into three groups: a control group (n = 10) with chest trauma without any immersion;a seawater group ( n = 10) immersed in seawater after chest trauma and a normal saline group ( n = 5 ) immersed in normal saline solution following chest trauma. Blood samples were taken at different time intervals to determine plasma osmotic pressure and electrolytes. The hemodynamic changes were also recorded. Results: Mortality in the seawater group was much higher than that of the control group and the normal saline group. The mean survival time in the seawater group lasted only 45 minutes, while in the control group and the normal saline group the average survival time was more than 4 hours (P < 0.01 ). One of the most important causes of death was hypernatremia and high osmolality. Severe electrolytes imbalance was observed in seawater group.Hypernatremia and high osmolality were the most significant factors of high mortality in the seawater group. Conclusions: Seawater immersion after chest trauma appears to be associated with severe electrolyte imbalance as well as high osmotic pressure, These may be the risk factors leading to fatal outcome.

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

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

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

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

    2016-01-01

    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...

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

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

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

  1. Experimental and Numerical Modeling of Seismic Earth Pressures on Retaining Walls with Cohesive Backfills

    CANDIA, GABRIEL ALFONSO

    2013-01-01

    Observations from recent earthquakes show that all types of retaining structures with non-liquefiable backfills perform very well and there is limited evidence of damage or failures related to seismic earth pressures. Even retaining structures designed only for static loading have performed well during strong ground motions suggesting that special seismic design provisions may not be required in some cases. The objective of this study was to characterize the seismic interaction of backfill-wa...

  2. Seismic Earth Pressures of Retaining Wall from Large Shaking Table Tests

    Changwei Yang

    2015-01-01

    Full Text Available To ascertain seismic response of retaining wall in the Wenchuan earthquake, large shaking table tests are performed and an acceleration record is acted in 3 directions. In the tests, acceleration time history recorded at Wolong station in the Wenchuan earthquake is used to excite the model wall. Results from the tests show that the location of dynamic resultant earth pressure is 0.35–0.49 H from toe of the wall for road shoulder retaining wall on rock foundation, 0.33–0.42 H for embankment retaining wall on rock foundation, and 0.46–0.77 H for road shoulder retaining wall on soil foundation. Besides, dynamic earth pressure increases with the increase of ground shaking from 0.1 g to 0.9 g and the relationship is nonlinear. The distribution is closed to for PGA less than 0.4 g but larger for PGA larger than and equal to 0.4 g, especially on the soil foundation. After the comparison of measured earth pressures and theoretical results by pseudodynamic method and pseudostatic method, results of the former are consistent with those of the shaking table test, but results of the latter method are smaller than measured.

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

    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

    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. Three-Month Test-Retest Reliability of Center of Pressure Motion During Standing Balance in Individuals with Multiple Sclerosis

    Wajda, Douglas A.; Motl, Robert W.; Sosnoff, Jacob J.

    2016-01-01

    Background: Balance impairment and an increased rate of falls are commonly reported in individuals with multiple sclerosis (MS). Force platform–generated center of pressure (COP) metrics have previously been recommended as an outcome measure to quantify balance deficits and distinguish between fallers and nonfallers in MS. Information is limited regarding the preservation of postural control in individuals with MS over extended time frames in the absence of an intervention. This report examin...

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

    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

  7. Test re-test reliability of centre of pressure measures during standing balance in individuals with knee osteoarthritis.

    Takacs, Judit; Carpenter, Mark G; Garland, S Jayne; Hunt, Michael A

    2014-01-01

    Assessment of changes in standing balance following an intervention requires accurate measurement of balance parameters. The reliability of centre of pressure measures of balance during single-leg standing has not been reported in individuals with knee osteoarthritis. The purpose of this study was to assess the test re-test reliability of force platform centre of pressure measures during single-leg standing in older adults with knee osteoarthritis. Twenty-five adults with radiographic evidence of knee osteoarthritis performed single-leg standing balance trials on a laboratory-grade force platform on two occasions, no more than 14 days apart. Participants were asked to stand on their more symptomatic limb for three, ten second trials. Centre of pressure measures collected included: standard deviation in the mediolateral and anteroposterior directions, mean path length, velocity, and area. The mean of the three trials was calculated. Intraclass correlation coefficients, standard error of measurement, Bland and Altman plots and the minimum detectable change were calculated. Intraclass correlation coefficients ranged from 0.54 to 0.87, suggesting mixed reliability of measures. Reliability was lowest for the centre of pressure area (intraclass correlation coefficient=0.54), and highest for centre of pressure velocity and path length (intraclass correlation coefficient=0.87 for both). Standard error of measurement values were low for standard deviation in the mediolateral direction and high for centre of pressure area. These results suggest that centre of pressure values, in particular path length and velocity, are appropriate for assessment of standing balance in people with medial knee osteoarthritis. PMID:24746407

  8. Moderate pressure synthesis of rare earth nickelate with metal-insulator transition using polymeric precursors

    Napierala, C.; Lepoittevin, C.; Edely, M.; Sauques, L.; Giovanelli, F.; Laffez, P.; VanTedeloo, G.

    2010-07-01

    Rare earth nickelates exhibit a reversible metal-semiconductor phase transition that is, in the infrared range, responsible for a thermo-optical contrast. The state of the art synthesis of these compounds usually requires high oxygen pressure to stabilize Ni in the oxidation state 3 +. In this work, using polymeric precursor associated with moderate pressure annealing, we show that it is possible to obtain fully oxidized rare earth nickelate with metal-insulator transition. Using thermogravimetric analysis, X-ray diffraction and transmission electronic microscopy we compare different samples synthesized at different oxygen pressures and demonstrate their structural similarity. Thermo-optical properties were measured, in the infrared range, using reflectance measurements and confirmed the metal-insulator transition at 60 °C in both samples.TEM observations lead to the conclusion that the structure commonly obtained at 175 bar is perfectly observed in the 20 bar sample without major structural defects. The two samples exhibit a thermochromic behavior and thermo-optical properties of the two samples are equivalent.

  9. Moderate pressure synthesis of rare earth nickelate with metal-insulator transition using polymeric precursors

    Rare earth nickelates exhibit a reversible metal-semiconductor phase transition that is, in the infrared range, responsible for a thermo-optical contrast. The state of the art synthesis of these compounds usually requires high oxygen pressure to stabilize Ni in the oxidation state 3+. In this work, using polymeric precursor associated with moderate pressure annealing, we show that it is possible to obtain fully oxidized rare earth nickelate with metal-insulator transition. Using thermogravimetric analysis, X-ray diffraction and transmission electronic microscopy we compare different samples synthesized at different oxygen pressures and demonstrate their structural similarity. Thermo-optical properties were measured, in the infrared range, using reflectance measurements and confirmed the metal-insulator transition at 60 oC in both samples.TEM observations lead to the conclusion that the structure commonly obtained at 175 bar is perfectly observed in the 20 bar sample without major structural defects. The two samples exhibit a thermochromic behavior and thermo-optical properties of the two samples are equivalent. - Graphical Abstract: Thermochromic behavior of Nd0.3Sm0.7NiO3 samples annealed under 20 and 175 bar at 278 and 373 K.

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

    Cheng-Wei Huang; Pei-Der Sue; Maysam F. Abbod; Jiang, Bernard C.; Jiann-Shing Shieh

    2013-01-01

    Copyright @ 2013 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/). 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 pr...

  11. Pressure-induced valence change in the rare earth metals:The case of Praseodymium

    Tateiwa, Naoyuki; Nakagawa, Akitoshi; Fujio, Kazuhiko; Kawae, Tatsuya; Takeda, Kazuyoshi

    2005-01-01

    The rare earth metal praseodymium (Pr) transforms from the d-fcc crystal structure (Pr-III) to {$\\alpha$}-U one (Pr-IV) at 20 GPa with a large volume collapse (${\\rm\\Delta} V/V$ = 0.16), which is associated with the valence change of the Pr ion. The two 4{\\it f} electrons in the Pr ion is supposed to be itinerant in the Pr-IV phase. In order to investigate the electronic state of the phase IV, we performed the high pressure electrical resistance measurement using the diamond anvil cell up to ...

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

    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.

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

    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.

  14. Numerical investigation of the real and ideal gap profiles in the calculation of the pressure distortion coefficient and piston fall rate of an LNE 200 MPa pressure balance

    Wongthep, Padipat; RABAULT, Thierry; Noguera, Ricardo; SARRAF, Christophe

    2013-01-01

    This paper aims to investigate, by means of numerical simulation, the effect of gap profiles on the calculation of the pressure distortion coefficient (λ) and the piston fall rate (vf) of two piston-cylinder units used in a Laboratoire National de Métrologie et d'Essais (LNE) 200 MPa pressure balance. The ideal mean gap width between the piston and the cylinder was obtained after measuring the piston fall rate at a low pressure, while the piston radius was obtained from the cross-float experi...

  15. THE INFLUENCE OF PRESSURE-DEPENDENT VISCOSITY ON THE THERMAL EVOLUTION OF SUPER-EARTHS

    We study the thermal evolution of super-Earths with a one-dimensional (1D) parameterized convection model that has been adopted to account for a strong pressure dependence of the viscosity. A comparison with a 2D spherical convection model shows that the derived parameterization satisfactorily represents the main characteristics of the thermal evolution of massive rocky planets. We find that the pressure dependence of the viscosity strongly influences the thermal evolution of super-Earths—resulting in a highly sluggish convection regime in the lower mantles of those planets. Depending on the effective activation volume and for cooler initial conditions, we observe with growing planetary mass even the formation of a conductive lid above the core-mantle boundary (CMB), a so-called CMB-lid. For initially molten planets our results suggest no CMB-lids but instead a hot lower mantle and core as well as sluggish lower mantle convection. This implies that the initial interior temperatures, especially in the lower mantle, become crucial for the thermal evolution—the thermostat effect suggested to regulate the interior temperatures in terrestrial planets does not work for massive planets if the viscosity is strongly pressure dependent. The sluggish convection and the potential formation of the CMB-lid reduce the convective vigor throughout the mantle, thereby affecting convective stresses, lithospheric thicknesses, and heat fluxes. The pressure dependence of the viscosity may therefore also strongly affect the propensity of plate tectonics, volcanic activity, and the generation of a magnetic field of super-Earths.

  16. First-principles modelling of Earth and planetary materials at high pressures and temperatures

    Atomic-scale materials modelling based on first-principles quantum mechanics is playing an important role in the science of the Earth and the other planets. We outline the basic theory of this kind of modelling and explain how it can be applied in a variety of different ways to probe the thermodynamics, structure and transport properties of both solids and liquids under extreme conditions. After a summary of the density functional formulation of quantum mechanics and its practical implementation through pseudopotentials, we outline the simplest way of applying first-principles modelling, namely static zero-temperature calculations. We show how calculations of this kind can be compared with static compression experiments to demonstrate the accuracy of first-principles modelling at pressures reached in planetary interiors. Noting that virtually all problems concerning planetary interiors require an understanding of materials at high temperatures as well as high pressures, we then describe how first-principles lattice dynamics gives a powerful way of investigating solids at temperatures not too close to the melting line. We show how such calculations have contributed to important progress, including the recent discovery of the post-perovskite phase of MgSiO3 in the D'' layer at the base of the Earth's mantle. A range of applications of first-principles molecular dynamics are then reviewed, including the properties of metallic hydrogen in Jupiter and Saturn, of water, ammonia and methane in Uranus and Neptune, and of oxides and silicates and solid and liquid iron and its alloys in the Earth's deep interior. Recognizing the importance of phase equilibria throughout the planetary sciences, we review recently developed techniques for the first-principles calculation of solid and liquid free energies, melting curves and chemical potentials of alloys. We show how such calculations have contributed to an improved understanding of the temperature distribution and the chemical

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

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

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

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

    2016-02-01

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

  19. Three-Month Test-Retest Reliability of Center of Pressure Motion During Standing Balance in Individuals with Multiple Sclerosis

    Wajda, Douglas A.; Motl, Robert W.

    2016-01-01

    Background: Balance impairment and an increased rate of falls are commonly reported in individuals with multiple sclerosis (MS). Force platform–generated center of pressure (COP) metrics have previously been recommended as an outcome measure to quantify balance deficits and distinguish between fallers and nonfallers in MS. Information is limited regarding the preservation of postural control in individuals with MS over extended time frames in the absence of an intervention. This report examines the test-retest reliability and magnitude of change of COP motion during standing balance over 3 months. Methods: Twenty individuals with MS and a history of falling underwent testing on two occasions 3 months apart in the absence of an intervention. On both occasions, participants completed two 30-second trials of three conditions: eyes open, eyes closed, and eyes open with concurrent cognitive challenge (dual task). Measures of COP area, velocity, and temporal structure were calculated and included in the reliability analysis. Results: The COP metrics displayed fair-to-excellent reliability over 3 months without an intervention. Reliability was maintained across the three commonly used balance conditions. Conclusions: These results offer insight into the reliability of COP measures over a 3-month period in MS and can inform the use of COP metrics for future study design (eg, sample size estimates) and balance outcome assessment during randomized controlled trials and fall-prevention studies in individuals with MS. PMID:27134578

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

    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.

  1. Three-dimensional numerical simulation and earth pressure analysis on double-row piles with consideration of spatial effects

    Zi-han WANG; Jian ZHOU

    2011-01-01

    As a new kind of technology in retaining structures,the characteristics of double-row piles are significantly affected by spatial effects.In this paper,double-row piles as a retaining structure are simulated numerically in three-dimension by finite element software PLAXIS 3D FOUNDATION.The behavior differences of piles in different positions around the foundation pit are analyzed.By changing the parameters,including the length-width ratio,the excavation depth,the distance between rows and the diameter of piles,the variations of the lateral deformation,the bending moment and the earth pressure around the piles are determined.The reasonable values of parameters and some suggestions with consideration of earth pressure are proposed for the design of double-row piles as a retaining structure.The results show that the lateral deformation and bending moment are the largest in the middle of long side of the foundation pit,which is identified as the most unfavorable position.It is indicated that the earth pressure between rows above pit bottom is close to active earth pressure,while the earth pressure between rows under pit bottom is close to static earth pressure.It is suggested that 1/2-2/3 of pile length,0.6-1.2 m,3d-6d,and 2d-2.5d be chosen as embedded depth of piles,diameter of piles,distance between rows,and distance between piles,respectively,where d is the pile diameter.

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

    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

  3. The high-pressure phase of alumina and implications for Earth's D″ layer

    Oganov, Artem R.; Ono, Shigeaki

    2005-01-01

    Using ab initio simulations and high-pressure experiments in a diamond anvil cell, we show that alumina (Al2O3) adopts the CaIrO3-type structure above 130 GPa. This finding substantially changes the picture of high-pressure behavior of alumina; in particular, we find that perovskite structure is never stable for Al2O3 at zero Kelvin. The CaIrO3-type phase suggests a reinterpretation of previous shock-wave experiments and has important implications for the use of alumina as a window material in shock-wave experiments. In particular, the conditions of the stability of this phase correspond to those at which shock-wave experiments indicated an increase of the electrical conductivity. If this increase is caused by high ionic mobility in the CaIrO3-type phase of Al2O3, similar effect can be expected in the isostructural postperovskite phase of MgSiO3 (which is the dominant mineral phase in the Earth's D″ layer). The effect of the incorporation of Al on the perovskite/postperovskite transition of MgSiO3 is discussed. PMID:16040809

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

    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.

  5. 力平衡法测量大气压强%Atmospheric pressure measurement based on force balance principle

    钟寿仙; 杨自强; 任团结; 夏亚康; 胡家晨; 林春丹

    2014-01-01

    依据力平衡法原理,重新构思、设计了测量大气压强的实验方案及装置,力学传感器的使用,提高了大气压强测量中的关键物理量的测量精度;采用最小二乘法,实现了大气压强的巧妙测量。%Based on the force balance principle ,the experimental scheme and apparatus were rede-signed to measure the atmospheric pressure .By using mechanical sensor and least square method ,the atmospheric pressure had been measured ingeniously ,and the measurement accuracies of atmospheric pressure and the relevant key physical quantities were improved .

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

    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

  7. Miniaturization techniques for obtaining static pressures comparable to the pressure at the center of the earth: X-ray diffraction at 416 GPa

    X-ray diffraction studies on tungsten and molybdenum were performed, using a 4-μm-diam x-ray beam, to very high pressures, with the pressures being obtained from the measured lattice parameters and isothermal equations of state of tungsten and molybdenum deduced from shock data. The bcc structure persists to the highest pressure, 378 GPa in tungsten, and 416 GPa in molybdenum. The static pressures generated and measured here exceed the pressure of 361 GPa at the center of the earth, the first time that this has been achieved and measured with a calibrated pressure scale. The details of the pressure profile at 335 GPa are shown and are of great use in designing anvils for future research. It is noted that the maximum pressures attained by x-ray diffraction with beveled anvils varies linearly with D-1/2 where D is the diameter of the flat suggesting that, perhaps, even higher pressures are possible with further miniaturization. A scaling law is used to calculate the minimum correction due to the presence of nonhydrostatic stress

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

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

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

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

    2012-11-01

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

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

    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

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

    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.

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

    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

  13. Resource constrained flux balance analysis predicts selective pressure on the global structure of metabolic networks

    Abedpour, Nima; Kollmann, Markus

    2015-01-01

    Background A universal feature of metabolic networks is their hourglass or bow-tie structure on cellular level. This architecture reflects the conversion of multiple input nutrients into multiple biomass components via a small set of precursor metabolites. However, it is yet unclear to what extent this structural feature is the result of natural selection. Results We extend flux balance analysis to account for limited cellular resources. Using this model, optimal structure of metabolic networ...

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

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

    2014-01-01

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

  15. Measuring center of pressure signals to quantify human balance using multivariate multiscale entropy by designing a force platform.

    Huang, Cheng-Wei; Sue, Pei-Der; Abbod, Maysam F; Jiang, Bernard C; Shieh, Jiann-Shing

    2013-01-01

    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. PMID:23966184

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

    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.

  17. Effects on the location of the centre of gravity and the foot pressure contribution to standing balance associated with ageing.

    Tanaka, T; Takeda, H; Izumi, T; Ino, S; Ifukube, T

    1999-07-01

    The aim was to analyse the limitation of the head and lumbar movements in relation to the centre of gravity which is needed to maintain standing balance with ageing. The participants of the study were 25 healthy volunteers divided into two age categories, the young group (mean 22.4 +/- 2.7 years) and the elderly group (mean 71.2 +/- 3.6 years). The instruments for measuring the movements of the lumbar region and head and the centre of pressure (COP) were a 3-D motion analysis system and a force plate. In addition, the peak foot pressure was measured during standing using the F-Scan system. The participants were first asked to stand relaxed for 10 s. They then shifted from the starting position to the four directions of sway: anterior, posterior, right and left. They were asked to maintain standing balance at the maximal distance position for each sway as much as possible for 10 s. Analysis of parameters was performed by measuring the average maximal linear displacement (cm) of the head and lumbar markers, the COP (cm), and the peak foot pressure (% of body weight per cm2) in each participant. The data of the young group for lumbar maximal displacement were greater than those of the elderly group in the anterior, posterior and lateral sways. A significant difference between the young and elderly data was found in the posterior sway. According to the data of the head's maximal displacement, the elderly group's data were greater than the young group's data in all sways, except for the anterior side. For the data of peak foot pressure in the posterior sway, the elderly group's data was greater than the young group's data. The forefoot area data of the young group was significantly greater than that of the elderly group, and the heel area data of the elderly was significantly greater than that of the young group in the right sway. The results suggest that the maximal displacement of head and lumbar positions and the toe's muscle activity in the forefoot are important

  18. The “Stick-Slip” Phenomenon During the Active Earth Pressure Failure of a Granular Soil of Analogical Material

    S. M. Daoud

    2014-02-01

    Full Text Available The aim of this paper is to highlight the "stick-slip" phenomenon in the mechanisms of failure related to active earth pressure of an analogical material simulating a granular medium. For this, a two-dimensional small-scale model was used and a phenomenological analysis of these mechanisms was conducted employing measurements of the fields of deformations using the method of digital image correlation. It was noted that a fluctuation in the response of the material occurs during the equal increments of displacements imposed on the mobile wall. This incremental response of the medium during the failure process related to active earth pressure explains the "stick-slip" phenomenon

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

    V.S. Korovkin

    2013-01-01

    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 di...

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

    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.

  1. Turbulent kinetic energy balance measurements in the wake of a low-pressure turbine blade

    Sideridis, A. [Laboratory of Fluid Mechanics and Turbomachinery, Department of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Yakinthos, K., E-mail: kyros@eng.auth.g [Laboratory of Fluid Mechanics and Turbomachinery, Department of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Goulas, A. [Laboratory of Fluid Mechanics and Turbomachinery, Department of Mechanical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2011-02-15

    The turbulent kinetic energy budget in the wake generated by a high lift, low-pressure two-dimensional blade cascade of the T106 profile was investigated experimentally using hot-wire anemometry. The purpose of this study is to examine the transport mechanism of the turbulent kinetic energy and provide validation data for turbulence modeling. Point measurements were conducted on a high spatial resolution, two-dimensional grid that allowed precise derivative calculations. Positioning of the probe was achieved using a high accuracy traversing mechanism. The turbulent kinetic energy (TKE) convection, production, viscous diffusion and turbulent diffusion were all obtained directly from experimental measurements. Dissipation and pressure diffusion were calculated indirectly using techniques presented and validated by previous investigators. Results for all terms of the turbulent kinetic energy budget are presented and discussed in detail in the present work.

  2. The temperature structure and pressure balance of magnetic loops in active regions. [in solar atmosphere

    Foukal, P.

    1975-01-01

    EUV observations show many active region loops in lines formed at temperatures between 10,000 and 2,000,000 K. The brightest loops are associated with flux tubes leading to the umbrae of sunspots. It is shown that the high visibility of certain loops in transition region lines is due principally to a sharp radial decrease of temperature to chromospheric values toward the loop axis. The plasma density of these cool loops is not significantly greater than in the hot gas immediately surrounding it. Consequently, the internal gas pressure of the cool material is clearly lower. The hot material immediately surrounding the cool loops is generally denser than the external corona by a factor 3-4. When the active region is examined in coronal lines, this hot high pressure plasma shows up as loops that are generally parallel to the cool loops but significantly displaced laterally.

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

    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.

  4. High pressure effects on the superconductivity in rare-earth-doped CaFe2As2

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

    2014-01-01

    High pressure superconductivity in a rare-earth-doped Ca0.86Pr0.14Fe2As2 single-crystalline sample has been studied up to 12 GPa and temperatures down to 11 K using the designer diamond anvil cell under a quasi-hydrostatic pressure medium. The electrical resistance measurements were complemented by high pressure and low-temperature X-ray diffraction studies at a synchrotron source. The electrical resistance measurements show an intriguing observation of superconductivity under pressure, with Tc as high as ∼51 K at 1.9 GPa, presenting the highest Tc reported in the intermetallic class of 122 iron-based superconductors. The resistive transition observed suggests a possible existence of two superconducting phases at low pressures of 0.5 GPa: one phase starting at Tc1 ∼ 48 K and the other starts at Tc2 ∼ 16 K. The two superconducting transitions show distinct variations with increasing pressure. High pressure and low-temperature structural studies indicate that the superconducting phase is a collapsed tetragonal ThCr2Si2-type (122) crystal structure.

  5. Origin of “memory glass” effect in pressure-amorphized rare-earth molybdate single crystals

    The memory glass effect (MGE) describes the ability of some materials to recover the initial structure and crystallographic orientation after pressure-induced amorphization (PIA). In spite of numerous studies the nature and underlying mechanisms of this phenomenon are still not clear. Here we report investigations of MGE in β′-Eu2(MoO4)3 single crystal samples subjected to high pressure amorphization. Using the XRD and TEM techniques we carried out detailed analysis of the structural state of high pressure treated single crystal samples as well as structural transformations due to subsequent annealing at atmospheric pressure. The structure of the sample has been found to be complex, mainly amorphous, however, the amorphous medium contains evenly distributed nanosize inclusions of a paracrystalline phase. The inclusions are highly correlated in orientation and act as “memory units” in the MGE. - Graphical abstract: Schematic representation of pressure-induced amorphization and “memory glass” effect in rare-earth molybdate single crystals. The XRD and TEM measurements have revealed the presence of the residual identically oriented paracrystalline nanodomains in the pressure-amorphized state. These domains preserve the information about initial structure and orientation of the sample. They act as memory units and crystalline seeds during transformation of the amorphous phase back to the starting single crystalline one. - Highlights: • Pressure-amorphized Eu2(MoO4)3 single crystals were studied ex-situ by XRD and TEM. • Tiny residual crystalline inclusions were found in amorphous matrix of sample. • The inclusions keep in memory the parent crystal structure and orientation. • The inclusions account for “memory glass” effect in rare-earth molibdates

  6. Chaotic behavior of water column oscillator simulating pressure balanced injection system in passive safety reactor

    Japan Atomic Energy Research Institute (JAERI) proposed a passive safety reactor called the System-integrated Pressurized Water Reactor (SPWR). In a loss of coolant accident, the Pressurizing Line (PL) and the Injection Line (IL) are passively opened. Vapor generated by residual heat pushes down the water level in the Reactor Vessel (RV). When the level is lower than the inlet of the PL, the vapor is ejected into the Containment Vessel (CV) through the PL. Then boronized water in the CV is injected into the RV through the IL by the static head. In an experiment using a simple apparatus, gas ejection and water injection were found to occur alternately under certain conditions. The gas ejection interval was observed to fluctuate considerably. Though stochastic noise affected the interval, the experimental results suggested that the large fluctuation was produced by an inherent character in the system. A set of piecewise linear differential equations was derived to describe the experimental result. The large fluctuation was reproduced in the analytical solution. Thus it was shown to occur even in a deterministic system without any source of stochastic noise. Though the derived equations simulated the experiment well, they had ten independent parameters governing the behavior of the solution. There appeared chaotic features and bifurcation, but the analytical model was too complicated to examine the features and mechanism of bifurcation. In this study, a new simple model is proposed which consists of a set of piecewise linear ordinary differential equations with only four independent parameters. (authors)

  7. Earth Inner Core Periodic Motion due to Pressure Difference Induced by Tidal Acceleration

    Wolf, M

    2013-01-01

    The inner structure of the earth is still a topic of discussion. Seismic measurements showed a structure of solid, liquid, solid which describes the mantle, outer core and inner core with the inner core in the center. The analysis of waveform doublets suggests now that the inner core is out of center and even of faster rotation than the mantel and crust. From the sum of Buoyancy and Gravity on the earth inner core, the position energy is plotted and together with the tangential tidal acceleration, it is derived that Earth Inner Core cannot be in a center position without additional force. The Earth Core System is explained as Hydrodynamic Bearing. The Eccentricities out of nutation due to the effects from the sun and moon are calculated as an approximation.

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

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

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

    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

  10. Earth's air pressure 2.7 billion years ago constrained to less than half of modern levels

    Som, Sanjoy M.; Buick, Roger; Hagadorn, James W.; Blake, Tim S.; Perreault, John M.; Harnmeijer, Jelte P.; Catling, David C.

    2016-06-01

    How the Earth stayed warm several billion years ago when the Sun was considerably fainter is the long-standing problem of the `faint young Sun paradox'. Because of negligible O2 and only moderate CO2 levels in the Archaean atmosphere, methane has been invoked as an auxiliary greenhouse gas. Alternatively, pressure broadening in a thicker atmosphere with a N2 partial pressure around 1.6-2.4 bar could have enhanced the greenhouse effect. But fossilized raindrop imprints indicate that air pressure 2.7 billion years ago (Gyr) was below twice modern levels and probably below 1.1 bar, precluding such pressure enhancement. This result is supported by nitrogen and argon isotope studies of fluid inclusions in 3.0-3.5 Gyr rocks. Here, we calculate absolute Archaean barometric pressure using the size distribution of gas bubbles in basaltic lava flows that solidified at sea level ~2.7 Gyr in the Pilbara Craton, Australia. Our data indicate a surprisingly low surface atmospheric pressure of Patm = 0.23 +/- 0.23 (2σ) bar, and combined with previous studies suggests ~0.5 bar as an upper limit to late Archaean Patm. The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that Patm fluctuated over geologic time to a previously unrecognized extent.

  11. Electron pressure balance in the SOL through the transition to detachment

    McLean, A.G., E-mail: mclean@fusion.gat.com [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Leonard, A.W.; Makowski, M.A. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Groth, M. [Aalto University, Espoo 02150 (Finland); Allen, S.L. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Boedo, J.A. [University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Bray, B.D. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Briesemeister, A.R. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Carlstrom, T.N. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Eldon, D. [University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Fenstermacher, M.E.; Hill, D.N.; Lasnier, C.J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Liu, C.; Osborne, T.H.; Petrie, T.W. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Soukhanovskii, V.A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Stangeby, P.C.; Tsui, C. [University of Toronto Institute for Aerospace Studies, Toronto M3H 5T6 (Canada); Unterberg, E.A. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); and others

    2015-08-15

    Upgrades to core and divertor Thomson scattering (DTS) diagnostics at DIII-D have provided measurements of electron pressure profiles in the lower divertor from attached- to fully-detached divertor plasma conditions. Detailed, multistep sequences of discharges with increasing line-averaged density were run at several levels of P{sub inj}. Strike point sweeping allowed 2D divertor characterization using DTS optimized to measure T{sub e} down to 0.5 eV. The ionization front at the onset of detachment is found to move upwards in a controlled manner consistent with the indication that scrape-off layer parallel power flux is converted from conducted to convective heat transport. Measurements of n{sub e}, T{sub e} and p{sub e} in the divertor versus L{sub parallel} demonstrate a rapid transition from T{sub e} ⩾ 15 eV to ⩽3 eV occurring both at the outer strike point and upstream of the X-point. These observations provide a strong benchmark for ongoing modeling of divertor detachment for existing and future tokamak devices.

  12. Electron pressure balance in the SOL through the transition to detachment

    McLean, A. G.; Leonard, A. W.; Makowski, M. A.; Groth, M.; Allen, S. L.; Boedo, J. A.; Bray, B. D.; Briesemeister, A. R.; Carlstrom, T. N.; Eldon, D.; Fenstermacher, M. E.; Hill, D. N.; Lasnier, C. J.; Liu, C.; Osborne, T. H.; Petrie, T. W.; Soukhanovskii, V. A.; Stangeby, P. C.; Tsui, C.; Unterberg, E. A.; Watkins, J. G.

    2015-08-01

    Upgrades to core and divertor Thomson scattering (DTS) diagnostics at DIII-D have provided measurements of electron pressure profiles in the lower divertor from attached- to fully-detached divertor plasma conditions. Detailed, multistep sequences of discharges with increasing line-averaged density were run at several levels of Pinj. Strike point sweeping allowed 2D divertor characterization using DTS optimized to measure Te down to 0.5 eV. The ionization front at the onset of detachment is found to move upwards in a controlled manner consistent with the indication that scrape-off layer parallel power flux is converted from conducted to convective heat transport. Measurements of ne, Te and pe in the divertor versus Lparallel demonstrate a rapid transition from Te ⩾ 15 eV to ⩽3 eV occurring both at the outer strike point and upstream of the X-point. These observations provide a strong benchmark for ongoing modeling of divertor detachment for existing and future tokamak devices.

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

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

    2013-09-01

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

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

    Recently, small-scale pressure-balanced structures (PBSs) were identified in the solar wind, but their formation mechanism remains unclear. This work aims to reveal the dependence of the properties of small-scale PBSs on the background magnetic field (B0) direction and thus to corroborate the in situ mechanism that forms them. We analyze the plasma and magnetic field data obtained by WIND in the quiet solar wind at 1 AU. First, we use a developed moving-average method to obtain B0(s, t) for every temporal scale (s) at each time moment (t). By wavelet cross-coherence analysis, we obtain the correlation coefficients between the thermal pressure Pth and the magnetic pressure PB, distributing against the temporal scale and the angle θxB between B0(s, t) and Geocentric Solar Ecliptic coordinates (GSE)-x. We note that the angle coverage of a PBS decreases with shorter temporal scale, but the occurrence of the PBSs is independent of θxB. Suspecting that the isolated small PBSs are formed by compressive waves in situ, we continue this study by testing the wave modes forming a small-scale PBS with B0(s, t) quasi-parallel to GSE-x. As a result, we identify that the cross-helicity and the compressibility attain values for a slow mode from theoretical calculations. The wave vector is derived from minimum variance analysis. Besides, the proton temperatures obey T ∥ derived from the velocity distribution functions, excluding a mirror mode, which is the other candidate for the formation of PBSs in situ. Thus, a small-scale PBS is shown to be driven by oblique, slow-mode waves in the solar wind

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

    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.

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

    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

  17. Pressure effects on hydrogen atoms near the metal plane in the HCP phase of rare-earth metal trihydrides

    Tunghathaithip, N.; Pakornchote, T.; Phaisangittisakul, N.; Bovornratanaraks, T.; Pinsook, U.

    2016-04-01

    Rare-earth metal trihydrides, REH3 (RE=Sc, Y, La), in the hcp phase were investigated under high pressure by the ab initio method. We concentrated on the behavior of hydrogen atoms which is affected by pressure. Two-thirds of the hydrogen atoms near the metal plane (Hm) were found to displace away from the metal plane as pressure increases. The trajectory of these squeezed hydrogen atoms is from a site near the metal plane, and moves past the plane of the tetragonal sites, and heads toward the nearest octahedral site. However, the rate of displacement depends on the local environment. LaH3 exhibits the least impediment on the Hm displacement while YH3 and ScH3 exhibit stronger impediment. Furthermore, our calculated Raman and IR active modes are in general agreement with the experimental data. The displacement of Hm can be used to explain the behavior of the Ov peak in Raman spectra, where it exists at low pressure and disappears at higher pressure in YH3 and ScH3.

  18. Cycle studies: material balance estimation in the domain of pressurized water and boiling water reactors. Experimental qualification

    This study is concerned with the physics of the fuel cycle the aim being to develop and make recommendations concerning schemes for calculating the neutronics of light water reactor fuel cycles. A preliminary study carried out using the old fuel cycle calculation scheme APOLLO1- KAFKA and the library SERMA79 has shown that for the compositions of totally dissolved assemblies from Pressurized Water Reactors (type 17*17) and also for the first time, for Boiling Water Reactor assemblies (type 8*8), the differences between calculation and measurement are large and must be reduced. The integration of the APOLLO2 neutronics code into the fuel cycle calculation scheme improves the results because it can model the situation more precisely. A comparison between APOLLO1 and APOLLO2 using the same options, demonstrated the consistency of the two methods for PWR and BWR geometries. Following this comparison, we developed an optimised scheme for PWR applications using the library CEA86 and the code APOLLO2. Depending on whether the information required is the detailed distribution of the composition of the irradiated fuel or the average composition (estimation of the total material balance of the fuel assembly), the physics options recommended are different. We show that the use of APOLLO2 and the library CEA86 improves the results and especially the estimation of the Pu239 content. Concerning the Boiling Water Reactor, we have highlighted the need to treat several axial sections of the fuel assembly (variation of the void-fraction, heterogeneity of composition). A scheme using Sn transport theory, permits one to obtain a better coherence between the consumption of U235, the production of plutonium and burnup, and a better estimation of the material balance. (author)

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

    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 (ρ): Vp (km/s) = -3.99 + 1.29ρ(g/cm3) and Vs (km/s) = 1.45 + 0.24ρ(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

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

    Reddy, Vanteru M.; Rahman, Mustafa M.; Gandi, Appala N.; Elbaz, Ayman M.; Schrecengost, Robert A.; Roberts, William L.

    2016-01-01

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

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

    Vanteru, Mahendra Reddy

    2016-01-18

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

  2. Chemical pressure and hidden one-dimensional behavior in rare earth tri-telluride

    Sacchetti, A.; Degiorgi, L.; /Zurich, ETH; Giamarchi, T.; /Geneva U.; Ru, N.; Fisher, I.R.; /Stanford U., Geballe Lab.

    2009-12-14

    We report on the first optical measurements of the rare-earth tri-telluride charge-density-wave systems. Our data, collected over an extremely broad spectral range, allow us to observe both the Drude component and the single-particle peak, ascribed to the contributions due to the free charge carriers and to the charge-density-wave gap excitation, respectively. The data analysis displays a diminishing impact of the charge-density-wave condensate on the electronic properties with decreasing lattice constant across the rare-earth series. We propose a possible mechanism describing this behavior and we suggest the presence of a one-dimensional character in these two-dimensional compounds. We also envisage that interactions and umklapp processes might play a relevant role in the formation of the charge-density-wave state in these compounds.

  3. High-pressure high-temperature crystal growth of equiatomic rare earth stannides RENiSn and REPdSn

    Heymann, Gunter; Heying, Birgit; Rodewald, Ute Ch.; Janka, Oliver; Huppertz, Hubert; Pöttgen, Rainer

    2016-04-01

    The two series of equiatomic rare earth (RE) stannides RENiSn and REPdSn were systematically studied with respect to high-pressure modifications. The normal-pressure (NP) low-temperature (LT) modifications were synthesized by arc-melting and subsequently treated under high-pressure (Pmax=11.5 GPa) and high-temperature (Tmax=1570 K) conditions in a Walker-type multi-anvil press. The pressure and temperature conditions were systematically varied in order to improve the crystallization conditions. The new ZrNiAl-type high-pressure modifications HP-RENiSn (RE=Sc, Y, La, Gd-Lu) and HP-REPdSn (RE=Y, Sm-Dy) were obtained in 80 mg quantities, several of them in X-ray pure form. Some of the REPdSn stannides with the heavy rare earth elements show high-temperature (HT) modifications. The structures of HP-ScNiSn, HP-GdNiSn, HP-DyNiSn (both ZrNiAl-type), NP-YbNiSn, and HT-ErPdSn (both TiNiSi-type) were refined from single crystal diffractometer data, indicating full ordering of the transition metal and tin sites. TiNiSi-type NP-EuPdSn transforms to MgZn2-type HP-EuPdSn: P63/mmc, a=588.5(2), c=917.0(3) pm, wR2=0.0769, 211 F2 values, 11 variables. The structure refinement indicated statistical occupancy of the palladium and tin sites on the tetrahedral network. The X-ray pure high-pressure phases were studied with respect to their magnetic properties. HP-YPdSn is a Pauli paramagnet. The susceptibility data of HP-TbNiSn, HP-DyNiSn, HP-GdPdSn, and HP-TbPdSn show experimental magnetic moments close to the free ion values of RE3+ and antiferromagnetic ordering at low temperature with the highest Néel temperature of 15.8 K for HP-TbPdSn. HP-SmPdSn shows the typical Van Vleck type behavior along with antiferromagnetic ordering at TN=5.1 K. HP-EuPdSn shows divalent europium and antiferromagnetic ordering at 8.9 K followed by a spin reorientation at 5.7 K.

  4. The high-pressure phase of alumina and implications for Earth's D″ layer

    Artem R. Oganov; Ono, Shigeaki

    2005-01-01

    Using ab initio simulations and high-pressure experiments in a diamond anvil cell, we show that alumina (Al2O3) adopts the CaIrO3-type structure above 130 GPa. This finding substantially changes the picture of high-pressure behavior of alumina; in particular, we find that perovskite structure is never stable for Al2O3 at zero Kelvin. The CaIrO3-type phase suggests a reinterpretation of previous shock-wave experiments and has important implications for the use of alumina as a window material i...

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

    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

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

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

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

    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

  8. [Research on Adaptive Balance Reaction for Gait Slippery Instability Events on Level Walk Based on Plantar Pressure and Gait Parameter Analysis].

    Li, Yang; Zhang, Junxia; Si, Ying

    2015-12-01

    Nowadays, for gait instability phenomenon, many researches have been carried out at home and abroad. However, the relationship between plantar pressure and gait parameters in the process of balance adjustment is still unclear. This study describes the human body adaptive balance reaction during slip events on slippery level walk by plantar pressure and gait analysis. Ten healthy male subjects walked on a level path wearing shoes with two contrastive contaminants (dry, oil). The study collected and analyzed the change rule of spatiotemporal parameters, plantar pressure parameters, vertical ground reaction force (VGRF), etc. The results showed that the human body adaptive balance reaction during slip events on slippery level walk mainly included lighter touch at the heel strikes, tighter grip at the toe offs, a lower velocity, a shorter stride length and longer support time. These changes are used to maintain or recover body balance. These results would be able to explore new ideas and provide reference value for slip injury prevention, walking rehabilitation training design, research and development of walking assistive equipments, etc. PMID:27079090

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

    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 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.

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

    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.

  11. Improved determination of dynamic balance using the centre of mass and centre of pressure inclination variables in a complete golf swing cycle.

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2016-01-01

    Golf requires proper dynamic balance to accurately control the club head through a harmonious coordination of each human segment and joint. In this study, we evaluated the ability for dynamic balance during a golf swing by using the centre of mass (COM)-centre of pressure (COP) inclination variables. Twelve professional, 13 amateur and 10 novice golfers participated in this study. Six infrared cameras, two force platforms and SB-Clinic software were used to measure the net COM and COP trajectories. In order to evaluate dynamic balance ability, the COM-COP inclination angle, COM-COP inclination angular velocity and normalised COM-COP inclination angular jerk were used. Professional golfer group revealed a smaller COM-COP inclination angle and angular velocity than novice golfer group in the lead/trail direction (P < 0.01). In the normalised COM-COP inclination angular jerk, the professional golfer group showed a lower value than the other two groups in all directions. Professional golfers tend to exhibit improved dynamic balance, and this can be attributed to the neuromusculoskeletal system that maintains balance with proper postural control. This study has the potential to allow for an evaluation of the dynamic balance mechanism and will provide useful basic information for swing training and prevention of golf injuries. PMID:26264189

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

    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...

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

    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

  14. 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

    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.

  15. Comparison of Regression Methods to Compute Atmospheric Pressure and Earth Tidal Coefficients in Water Level Associated with Wenchuan Earthquake of 12 May 2008

    He, Anhua; Singh, Ramesh P.; Sun, Zhaohua; Ye, Qing; Zhao, Gang

    2016-07-01

    The earth tide, atmospheric pressure, precipitation and earthquake fluctuations, especially earthquake greatly impacts water well levels, thus anomalous co-seismic changes in ground water levels have been observed. In this paper, we have used four different models, simple linear regression (SLR), multiple linear regression (MLR), principal component analysis (PCA) and partial least squares (PLS) to compute the atmospheric pressure and earth tidal effects on water level. Furthermore, we have used the Akaike information criterion (AIC) to study the performance of various models. Based on the lowest AIC and sum of squares for error values, the best estimate of the effects of atmospheric pressure and earth tide on water level is found using the MLR model. However, MLR model does not provide multicollinearity between inputs, as a result the atmospheric pressure and earth tidal response coefficients fail to reflect the mechanisms associated with the groundwater level fluctuations. On the premise of solving serious multicollinearity of inputs, PLS model shows the minimum AIC value. The atmospheric pressure and earth tidal response coefficients show close response with the observation using PLS model. The atmospheric pressure and the earth tidal response coefficients are found to be sensitive to the stress-strain state using the observed data for the period 1 April-8 June 2008 of Chuan 03# well. The transient enhancement of porosity of rock mass around Chuan 03# well associated with the Wenchuan earthquake (Mw = 7.9 of 12 May 2008) that has taken its original pre-seismic level after 13 days indicates that the co-seismic sharp rise of water well could be induced by static stress change, rather than development of new fractures.

  16. Comparison of Regression Methods to Compute Atmospheric Pressure and Earth Tidal Coefficients in Water Level Associated with Wenchuan Earthquake of 12 May 2008

    He, Anhua; Singh, Ramesh P.; Sun, Zhaohua; Ye, Qing; Zhao, Gang

    2016-05-01

    The earth tide, atmospheric pressure, precipitation and earthquake fluctuations, especially earthquake greatly impacts water well levels, thus anomalous co-seismic changes in ground water levels have been observed. In this paper, we have used four different models, simple linear regression (SLR), multiple linear regression (MLR), principal component analysis (PCA) and partial least squares (PLS) to compute the atmospheric pressure and earth tidal effects on water level. Furthermore, we have used the Akaike information criterion (AIC) to study the performance of various models. Based on the lowest AIC and sum of squares for error values, the best estimate of the effects of atmospheric pressure and earth tide on water level is found using the MLR model. However, MLR model does not provide multicollinearity between inputs, as a result the atmospheric pressure and earth tidal response coefficients fail to reflect the mechanisms associated with the groundwater level fluctuations. On the premise of solving serious multicollinearity of inputs, PLS model shows the minimum AIC value. The atmospheric pressure and earth tidal response coefficients show close response with the observation using PLS model. The atmospheric pressure and the earth tidal response coefficients are found to be sensitive to the stress-strain state using the observed data for the period 1 April-8 June 2008 of Chuan 03# well. The transient enhancement of porosity of rock mass around Chuan 03# well associated with the Wenchuan earthquake (Mw = 7.9 of 12 May 2008) that has taken its original pre-seismic level after 13 days indicates that the co-seismic sharp rise of water well could be induced by static stress change, rather than development of new fractures.

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

    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.

  18. Evaluation of earth pressure on triple multi-face shield tunnel based on centrifuge model tests; Enshin mokei jikken ni yoru yoko sanren shield tunnel no doatsu hyoka

    Sugihara, Y.; Igarashi, H.; Fujisaki, K. [Kajima Corp., Tokyo (Japan)

    1995-12-20

    Recently, various needs for the utilization of underground space in urban areas, i.e., those for utilizing underground spaces with complicated cross-section shapes, have been encouraging the research and development of new shield methods. There have been considerations of building many tunnels with various cross-section shapes, such as horizontal double multi-face, horizontal triple multi-face, vertical double multi-face, MMST (multi-micro shield tunnel), and large-section tunnels with combinations of those shapes. The horizontal triple multi-face shield method is a new technique applied to underground railway stations with respect to construction period and safety. Since the horizontal triple multi-face shield tunnel has a laterally flatter shape than the former one circle shield tunnel, it is necessary to verify the validity of design using a usual method of evaluating earth pressure mainly for circle cross-sections. Therefore, the force on segments and deformation of surrounding soil were measured by using a centrifuge model equipment. Consequently, it was found that the earth pressure on horizontal triple multi-face shield segments in sandy ground is between earth pressure as evaluated by Terzaghi`s method and full earth pressure. 5 refs., 14 figs., 3 tabs.

  19. High-Pressure Rare Earth Disilicates REE2Si 2O 7( REE=Nd, Sm, Eu, Gd): Type K

    Fleet, Michael E.; Liu, Xiaoyang

    2001-10-01

    A new structure type (K) is reported for the disilicates of Nd, Sm, Eu, and Gd made at high pressure. Crystals of type K were synthesized at 10 GPa, 1600-1700°C in an MA6/8 superpress and used for single-crystal X-ray structure study by Kappa CCD diffractometry at room temperature. Crystal data are: monoclinic, space group P21/n, Z=4; Nd2Si2O7-a=6.6658(2), b=6.7234(3), c=12.3975(6) Å, β=102.147(3)°, V=543.2 Å3, R=0.029, and Dx=5.584 g/cm3; Sm2Si2O7-a=6.6039(3), b=6.6849(3), c=12.3069(5) Å, β=102.489(3)°, V=530.4 Å3, R=0.038, and Dx=5.871 g/cm3; Eu2Si2O7-a=6.5777(3), b=6.6652(4), c=12.2668(8) Å, β=102.671(4)°, V=524.7 Å3, R=0.030, and Dx=5.976 g/cm3; Gd2Si2O7-a=6.5558(4), b=6.6469(4), c=12.2394(6) Å, β=102.844(3)°, V=520.0 Å3, R=0.026, and Dx=6.166 g/cm3. The type K structure is built from a diorthosilicate group [Si2O7] interconnected by REE3+ cations in eightfold coordination with oxygen. The bridging oxygen (Si-O-Si) bond angle of the diorthosilicate group of rare earth disilicates stable at 1 bar (types A to G) is related to spatial accommodation of the REE3+ cation and ranges from 130 to 135° in the light rare earth disilicates (types A, F, G) to 180° in Lu2Si2O7 (type C). Volume reduction in the high-pressure type K structure is achieved largely by closure of the Si-O-Si bond angle to 122.7-124.4°, through rigid body rotation of the two SiO4 tetrahedra. This also permits a marginal increase in the average coordination of the REE3+ cation.

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

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

  1. Discover Earth

    Steele, Colleen

    1998-01-01

    Discover Earth is a NASA-sponsored project for teachers of grades 5-12, designed to: (1) enhance understanding of the Earth as an integrated system; (2) enhance the interdisciplinary approach to science instruction; and (3) provide classroom materials that focus on those goals. Discover Earth is conducted by the Institute for Global Environmental Strategies in collaboration with Dr. Eric Barron, Director, Earth System Science Center, The Pennsylvania State University; and Dr. Robert Hudson, Chair, the Department of Meteorology, University of Maryland at College Park. The enclosed materials: (1) represent only part of the Discover Earth materials; (2) were developed by classroom teachers who are participating in the Discover Earth project; (3) utilize an investigative approach and on-line data; and (4) can be effectively adjusted to classrooms with greater/without technology access. The Discover Earth classroom materials focus on the Earth system and key issues of global climate change including topics such as the greenhouse effect, clouds and Earth's radiation balance, surface hydrology and land cover, and volcanoes and climate change. All the materials developed to date are available on line at (http://www.strategies.org) You are encouraged to submit comments and recommendations about these materials to the Discover Earth project manager, contact information is listed below. You are welcome to duplicate all these materials.

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

    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, β=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

  3. Novel high-pressure structures of MgCO3, CaCO3 and CO2 and their role in Earth's lower mantle

    Oganov, Artem R.; Ono, Shigeaki; Ma, Yanming; Glass, Colin W.; Garcia, Alberto

    2008-08-01

    Most of the oxidized carbon in the Earth's lower mantle is believed to be stored in the high-pressure forms of MgCO3 and/or CaCO3 or possibly even CO2. Recently, through ab initio evolutionary simulations and high-pressure experiments, a complete picture of phase transformations of CaCO3 at mantle pressures was obtained. Here, using the same approach, we investigate the high-pressure structures of MgCO3. Two new structure types were predicted to be stable in the relevant pressure range: one at 82-138 GPa and the other above 138 GPa. Both phases contain rings of corner-sharing CO4-tetrahedra. These predictions were largely confirmed by the experiments presented here. A number of structurally very different, but energetically competitive metastable polymorphs were found and reveal complex high-pressure chemistry of MgCO3, in contrast to CaCO3. For CO2, from 19 GPa to at least 150 GPa, we find β-cristobalite structure to be stable. Differences between high-pressure tetrahedral carbonates and low-pressure silicates are discussed in terms of rigidity of the T-O-T angles (flexible when T = Si and stiff when T = C). We show that through most of the P-T conditions of the mantle, MgCO3 is the major host of oxidized carbon in the Earth. We discuss the possibility of CO2 release at the very bottom of the mantle, which could enhance partial melting of rocks and explain the geodynamical differences between the Earth and Venus.

  4. 3-D Force-balanced Magnetospheric Configurations

    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

  5. High-pressure syntheses and characterization of the rare-earth fluoride borates RE2(BO3)F3 (RE = Tb, Dy, Ho)

    The new rare-earth fluoride borates RE2(BO3)F3 (RE = Tb, Dy, Ho) were synthesized under high-pressure/high-temperature conditions of 1.5 GPa/1200 C for Tb2(BO3)F3 and 3.0 GPa/900 C for Dy2(BO3)F3 and Ho2(BO3)F3 in a Walker-type multianvil apparatus from the corresponding rare-earth sesquioxides, rare-earth fluorides, and boron oxide. The single-crystal structure determinations revealed that the new compounds are isotypic to the known rare-earth fluoride borate Gd2(BO3)F3. The new rare-earth fluoride borates crystallize in the monoclinic space group P21/c (Z = 8) with the lattice parameters a = 16.296(3), b = 6.197(2), c = 8.338(2) A, β = 93.58(3) for Tb2(BO3)F3, a = 16.225(3), b = 6.160(2), c = 8.307(2) A, β = 93.64(3) for Dy2(BO3)F3, and a = 16.189(3), b = 6.124(2), c = 8.282(2) A, β = 93.69(3) for Ho2(BO3)F3. The four crystallographically different rare-earth cations (CN = 9) are surrounded by oxygen and fluoride anions. All boron atoms form isolated trigonal-planar [BO3]3- groups. The six crystallographically different fluoride anions are in a nearly planar coordination by three rare-earth cations. (orig.)

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

    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. (paper)

  7. Earth materials and earth dynamics

    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).

  8. Effect of hydrostatic pressure on the elastic properties of some rare earth-iron Laves phase compounds

    The pressure dependence of the Young's and shear moduli of RFe2(R=Sm, Gd, Tb, Dy, Ho and Er) has been determined at room temperature in the pressure range between 0 and 1 GPa. The elastic moduli of GdFe2, DyFe2, HoFe2 and ErFe2 show a moderate increase with increasing hydrostatic pressure. However, the elastic moduli of SmFe2 and TbFe2 exhibit an initially drastic increase followed by a high, and linear, pressure dependence. From the pressure and temperature derivatives of the elastic moduli of these RFe2 Laves phase compounds the equations of state and the Grueneisen parameters have been derived. The variation of the elastic properties with hydrostatic pressure is compared with the effect of magnetic fields. The anomalous behavior of SmFe2 and TbFe2 is discussed. (author)

  9. Features and regularities in behavior of thermoelectric properties of rare-earth, transition, and other metals under high pressure up to 20 GPa

    We report results of systematic investigations of the thermoelectric properties of a number of rare-earth metals, transition metals, and other metals under high pressure up to 20 GPa at room temperature. We studied an effect of applied pressure on the Seebeck effect of scandium (Sc), yttrium (Y), lanthanum (La), europium (Eu), ytterbium (Yb), iron (Fe), manganese (Mn), chromium (Cr), gold (Au), tin (Sn), and CeNi alloy. We found that the high-pressure behavior of the thermopower of three rare-earth metals, namely, Sc, Y, and La, follows a general trend that has been established earlier in lanthanides, and addressed to a s → d electron transfer. Europium and ytterbium, on the contrary, showed a peculiar high-pressure behavior of the thermopower with peaks at near 0.7–1 GPa for Eu and 1.7–2.5 GPa for Yb. Chromium, manganese, and tin demonstrated a gradual and pronounced lowering of the absolute value of the thermopower with pressure. Above 9–11 GPa, the Seebeck coefficients of Mn and Sn were inverted, from n- to p-type for Mn and from p- to n-type for Sn. The Seebeck effect in iron was rather high as ∼16 μV/K and weakly varied with pressure up to ∼11 GPa. Above ∼11 GPa, it started to drop dramatically with pressure to highest pressure achieved 18 GPa. Upon decompression cycle the thermopower of iron returned to the original high values but demonstrated a wide hysteresis loop. We related this behavior in iron to the known bcc (α-Fe) → hcp (ε-Fe) phase transition, and proposed that the thermoelectricity of the α-Fe phase is mainly contributed by the spin Seebeck effect, likewise, the thermoelectricity of the ε-Fe phase—by the conventional diffusion thermopower. We compare the pressure dependencies of the thermopower for different groups of metals and figure out some general trends in the thermoelectricity of metals under applied stress

  10. Features and regularities in behavior of thermoelectric properties of rare-earth, transition, and other metals under high pressure up to 20 GPa

    Morozova, Natalia V.; Shchennikov, Vladimir V. [M. N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 18 S. Kovalevskaya Str., Yekaterinburg 620137 (Russian Federation); Ovsyannikov, Sergey V., E-mail: sergey.ovsyannikov@uni-bayreuth.de, E-mail: sergey2503@gmail.com [Bayerisches Geoinstitut, Universität Bayreuth, Universitätsstrasse 30, Bayreuth D-95447 (Germany); Institute for Solid State Chemistry of Ural Branch of Russian Academy of Sciences, 91 Pervomayskaya Str., Yekaterinburg 620990 (Russian Federation)

    2015-12-14

    We report results of systematic investigations of the thermoelectric properties of a number of rare-earth metals, transition metals, and other metals under high pressure up to 20 GPa at room temperature. We studied an effect of applied pressure on the Seebeck effect of scandium (Sc), yttrium (Y), lanthanum (La), europium (Eu), ytterbium (Yb), iron (Fe), manganese (Mn), chromium (Cr), gold (Au), tin (Sn), and CeNi alloy. We found that the high-pressure behavior of the thermopower of three rare-earth metals, namely, Sc, Y, and La, follows a general trend that has been established earlier in lanthanides, and addressed to a s → d electron transfer. Europium and ytterbium, on the contrary, showed a peculiar high-pressure behavior of the thermopower with peaks at near 0.7–1 GPa for Eu and 1.7–2.5 GPa for Yb. Chromium, manganese, and tin demonstrated a gradual and pronounced lowering of the absolute value of the thermopower with pressure. Above 9–11 GPa, the Seebeck coefficients of Mn and Sn were inverted, from n- to p-type for Mn and from p- to n-type for Sn. The Seebeck effect in iron was rather high as ∼16 μV/K and weakly varied with pressure up to ∼11 GPa. Above ∼11 GPa, it started to drop dramatically with pressure to highest pressure achieved 18 GPa. Upon decompression cycle the thermopower of iron returned to the original high values but demonstrated a wide hysteresis loop. We related this behavior in iron to the known bcc (α-Fe) → hcp (ε-Fe) phase transition, and proposed that the thermoelectricity of the α-Fe phase is mainly contributed by the spin Seebeck effect, likewise, the thermoelectricity of the ε-Fe phase—by the conventional diffusion thermopower. We compare the pressure dependencies of the thermopower for different groups of metals and figure out some general trends in the thermoelectricity of metals under applied stress.

  11. UNIFIED METHOD OF SEPARATE AND COMBINED CALCULATION OF WATER AND EARTH PRESSURES%水土压力分算与合算的统一算法

    王洪新

    2011-01-01

    Applying combined calculation of water and earth pressures for clay leads to a result which is more close to the field measurement value, however, obviously violates the principle of effective stress. Based on characteristics of the pore water in soil, it is assumed that the bound water absorbed by the clay particles in the soil offsets part of soil pore, and finally physical parameters such as void ratio, boundary water content, particle analysis, etc. are introduced to calculation of water and earth pressures on retaining structures to propose a coefficient ξ which can be calculated through physical parameters of soil and to provide the method of measuring the value of ξ through permeability tests. With the coefficient ξ, the effective stress intensity index and total stress intensity index are integrated in one strength formula. A new calculation method to unify the separate calculation and combined calculation of water and earth pressures is proposed to carry out the transition between results of the two conventional calculation methods and provide a new idea for solving the jump problem between the two results. According to the theory analysis of this paper, the measured permeability coefficient-void ratio curve will have a translational move in a forward direction along e-axis. The more clay particles that soil contains will have the larger translation, which has been verified by experimental data of related literatures. Separate calculation of water and earth pressures is too conventional for sand soil containing clay particles while combined calculation of water and earth pressures for clay with high void ratio can't guarantee the safety. Water and earth pressures on retaining structure are related not only to the soil categories, but also the void ratio.%以土中孔隙水特征为基础,假定土体中的黏性土颗粒吸附的结合水会抵消一部分土中孔隙,最终把土的孔隙比、界限含水量、颗粒分析等物理参数引入土水

  12. Education and Outreach Programs Offered by the Center for High Pressure Research and the Consortium for Materials Properties Research in Earth Sciences

    Richard, G. A.

    2003-12-01

    Major research facilities and organizations provide an effective venue for developing partnerships with educational organizations in order to offer a wide variety of educational programs, because they constitute a base where the culture of scientific investigation can flourish. The Consortium for Materials Properties Research in Earth Sciences (COMPRES) conducts education and outreach programs through the Earth Science Educational Resource Center (ESERC), in partnership with other groups that offer research and education programs. ESERC initiated its development of education programs in 1994 under the administration of the Center for High Pressure Research (CHiPR), which was funded as a National Science Foundation Science and Technology Center from 1991 to 2002. Programs developed during ESERC's association with CHiPR and COMPRES have targeted a wide range of audiences, including pre-K, K-12 students and teachers, undergraduates, and graduate students. Since 1995, ESERC has offered inquiry-based programs to Project WISE (Women in Science and Engineering) students at a high school and undergraduate level. Activities have included projects that investigated earthquakes, high pressure mineral physics, and local geology. Through a practicum known as Project Java, undergraduate computer science students have developed interactive instructional tools for several of these activities. For K-12 teachers, a course on Long Island geology is offered each fall, which includes an examination of the role that processes in the Earth's interior have played in the geologic history of the region. ESERC has worked with Stony Brook's Department of Geosciences faculty to offer courses on natural hazards, computer modeling, and field geology to undergraduate students, and on computer programming for graduate students. Each summer, a four-week residential college-level environmental geology course is offered to rising tenth graders from the Brentwood, New York schools in partnership with

  13. Experimental investigation of anaerobic nitrogen fixation rates with varying pressure, temperature and metal concentration with application to the atmospheric evolution of early Earth and Mars.

    Gupta, Prateek

    2012-07-01

    The atmosphere of the early Earth is thought to have been significantly different than the modern composition of 21% O2 and 78% N2, yet the planet has been clearly established as hosting microbial life as far back as 3.8 billion years ago. As such, constraining the atmospheric composition of the early Earth is fundamental to establishing a database of habitable atmospheric compositions. A similar argument can be made for the planet Mars, where nitrates have been hypothesized to exist in the subsurface. During the early period on Mars when liquid water was likely more abundant, life may have developed to take advantage of available nitrates and a biologically-driven Martian nitrogen cycle could have evolved. Early Earth atmospheric composition has been investigated numerically, but only recently has the common assumption of a pN2 different than modern been investigated. Nonetheless, these latest attempts fail to take into account a key atmospheric parameter: life. On modern Earth, nitrogen is cycled vigorously by biology. The nitrogen cycle likely operated on the early Earth, but probably differed in the metabolic processes responsible, dominantly due to the lack of abundant oxygen which stabilizes oxidized forms of N that drive de-nitrification today. Recent advances in evolutionary genomics suggest that microbial pathways that are relatively uncommon today (i.e. vanadium and iron-based nitrogen fixation) probably played important roles in the early N cycle. We quantitatively investigate in the laboratory the effects of variable pressure, temperature and metal concentration on the rates of anoxic nitrogen fixation, as possible inputs for future models investigating atmospheric evolution, and better understand the evolution of the nitrogen cycle on Earth. A common anaerobic methanogenic archaeal species with i) a fully sequenced genome, ii) all three nitrogenases (molybdenum, vanadium and iron-based) and iii) the ability to be genetically manipulated will be used as

  14. Separation of rare earths from uranium by anion exchange with pre-exclusion of loading solution under pressure and determination by ICP-MS

    An intermittently pressurized anion exchange column is used for separation of trace rare earth elements (REES) from uranium before ICP-MS measurements. The whole separation can be completed within 20 min. The recoveries for all REES are in the range of 96%-106%. Comparing with previous methods, this technique consumes less chemicals and produces less waste. The applicability and reliability of this procedure is demonstrated by the good accordance between results determined by this method and the recommended values for REES in a standard reference material (GBW04207). It is proved that this method would be useful for analysis of trace REES impurities in uranium metal and its oxides

  15. Universal behavior of chalcogenides of rare-earth metals in the transition to a state with intermediate valence at high pressures

    Tsiok, O. B.; Khvostantsev, L. G.; Brazhkin, V. V., E-mail: brazhkin@hppi.troitsk.ru [Russian Academy of Sciences, Vereshchagin Institute of High-Pressure Physics (Russian Federation)

    2015-06-15

    Precision measurements of resistivity, thermopower, and volume are performed for TmS, TmSe, and TmTe under a hydrostatic pressure up to 8 GPa. Comparison of the transport properties and volume of TmTe and SmTe in the valence transition region demonstrates a complete analogy up to quantitative coincidence. It is shown that the thermopower of all thulium and samarium chalcogenides in the lattice collapse region and in subsequent rearrangement of the electron spectrum in a wide range of pressures follow a universal dependence corresponding the passage of the Fermi level through the peak of the density of states (DOS). The results are considered in the context of ideas about the exciton nature of the intermediate valence in chalcogenides of rare-earth metals.

  16. Universal behavior of chalcogenides of rare-earth metals in the transition to a state with intermediate valence at high pressures

    Tsiok, O. B.; Khvostantsev, L. G.; Brazhkin, V. V.

    2015-06-01

    Precision measurements of resistivity, thermopower, and volume are performed for TmS, TmSe, and TmTe under a hydrostatic pressure up to 8 GPa. Comparison of the transport properties and volume of TmTe and SmTe in the valence transition region demonstrates a complete analogy up to quantitative coincidence. It is shown that the thermopower of all thulium and samarium chalcogenides in the lattice collapse region and in subsequent rearrangement of the electron spectrum in a wide range of pressures follow a universal dependence corresponding the passage of the Fermi level through the peak of the density of states (DOS). The results are considered in the context of ideas about the exciton nature of the intermediate valence in chalcogenides of rare-earth metals.

  17. Carbonate stability in the earth's mantle - A vibrational spectroscopic study of aragonite and dolomite at high pressures and temperatures

    Kraft, Susan; Knittle, Elise; Williams, Quentin

    1991-01-01

    The structural changes of aragonite and dolomite taking place at high pressures and temperatures were investigated by measuring the Raman spectra of these materials to pressures of 23 and 28 GPa (generated in a diamond anvil cell), respectively; in addition, the IR spectra of aragonite were measured to 40 GPa. The spectroscopic data demonstrated that, at 300 K, dolomite and aragonite samples were stable to pressures of 28 and 41 GPa, respectively. No phase transitions were observed following heating of aragonite and dolomite to temperatures of 2000 K and 800 K, respectively. The mode Grueneisen parameters indicate that the carbonate group in these two minerals is relatively insensitive to pressure, with the dominant compaction mechanism being the compression of the Ca and Mg polyhedra.

  18. Unified solution of Coulomb's active earth pressure for unsaturated soils%非饱和土库仑主动土压力统一解

    赵均海; 梁文彪; 张常光; 李艳

    2013-01-01

    基于非饱和土双应力状态变量抗剪强度统一解,合理考虑中间主应力效应,建立了非饱和土库仑主动土压力统一解,并对其进行可比性分析,将其计算结果与非饱和土朗肯主动土压力统一解进行对比,得出各因素的影响特性.研究结果表明,中间主应力和基质吸力对库仑主动土压力的影响显著,随统一强度理论参数和基质吸力的增加,库仑主动土压力不断减小直至为0,证明了考虑中间主应力可以充分发挥材料的自承载能力和强度潜能,具有可观的经济效益;库仑主动土压力随墙背倾角与填土倾角的增大而增大,随有效内摩擦角和基质吸力角的增大而减小,外摩擦角的影响不显著.非饱和土库仑主动土压力统一解具有更广泛的适用性,朗肯主动土压力统一解为其特例,其结果对边坡、基坑等工程的土压力确定和支挡结构设计有很好的借鉴作用.%Based on the unified solution of shear strength in terms of two stress state variables for unsaturated soils, the unified solution of Coulomb's active earth pressure for unsaturated soils is proposed which considers the effect of the intermediate principal stress rationally. Moreover, the comparability of this unified solution is analyzed. Influential characteristic of each factor is discussed by comparing with the unified solution of Rankine active earth pressure. The result shows that: the effects of intermediate principal stress and matric suction are significant; the Coulomb's active earth pressure decreases until zero with the increase of the unified strength theory parameter and matric suction, which indicates that the consideration of the intermediate principal stress effect can make materials give full play to their self-bearing capacities and strength potential, bringing obvious economic benefits to the project; the Coulomb's active earth pressure increases with the increase of the grading angle of retaining wall

  19. Magnesite formation from MgO and CO2 at the pressures and temperatures of Earth's mantle

    Scott, Henry P.; Doczy, Vincent M.; Frank, Mark R.; Hasan, Maggie; Lin, Jung-Fu; Yang, Jing [NIU; (Indiana); (Texas)

    2013-08-02

    Magnesite (MgCO3) is an important phase for the carbon cycle in and out of the Earth’s mantle. Its comparably large P-T stability has been inferred for several years based on the absence of its decomposition in experiments. Here we report the first experimental evidence for synthesis of magnesite out of its oxide components (MgO and CO2) at P-T conditions relevant to the Earth’s mantle. Magnesite formation was observed in situ using synchrotron X-ray diffraction, coupled with laser-heated diamond-anvil cells (DACs), at pressures and temperatures of Earth’s mantle. Despite the existence of multiple high-pressure CO2 polymorphs, the magnesite-forming reaction was observed to proceed at pressures ranging from 5 to 40 GPa and temperatures between 1400 and 1800 K. No other pressure-quenchable materials were observed to form via the MgO + CO2 = MgCO3 reaction. This work further strengthens the notion that magnesite may indeed be the primary host phase for oxidized carbon in the deep Earth.

  20. New high-pressure and high-temperature metal/silicate partitioning of U and Pb: Implications for the cores of the Earth and Mars

    In order to quantify possible fractionation of U and Pb into a metallic core, we have performed piston cylinder and multi-anvil press experiments at high pressure (up to 20 GPa) and high temperature (up to 2400 degrees C) and obtained the distribution coefficient D(metal-silicate) and the exchange partition coefficient K(metal-silicate) for these elements between metal and silicates (mineral or liquid). DPb(metal-silicate) and DU(metal-silicate) depend strongly on the S content of the metallic phase, and also on the oxygen fugacity, in agreement with an effective valence state of 4 for U in silicates and 2 for Pb in silicates. KdPb( metal-silicate) and KdU(metal-silicate) show no discernable pressure and temperature trend. U remains lithophile even at high pressure and high temperature but its lithophile nature decreases at very low oxygen fugacity. From our experimental data, it was possible to calculate the U and Pb contents of the cores of Mars and Earth under core-mantle equilibrium conditions at high pressure and high temperature. From the D(metal-silicate) of the present study, we obtained that: 0.008 ppm ≤ Pb (in the core) ≤ 4.4 ppm, and 0.0003 ppb ≤ U (in the core) ≤ 0.63 ppb, depending on whether the metal is S-free or S-saturated respectively, and if the mantle was molten or solid during the segregation process of the Earth's core around ΔIW-2. For Mars, based on a core segregation process around ΔIW-1, we obtained that: 0.005 ppm ≤ Pb (in the core) ≤ 3 ppm, and 0.00002 ppb ≤ U (in the core) < 0.05 ppb, depending on the metallic composition: S-free or S-saturated respectively. Our results suggest that the low concentration of Pb in the terrestrial mantle could not be explained by an early Pb sequestration in the Earth's core even if S is the dominant light element of the core. If we assume a magma ocean scenario, U might produced a maximum value of 1.5% of the total heat budget of the core with a segregation occurring below ΔIW-3. The

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

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

    1995-09-01

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

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

    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. Anti-overturning stability analysis of cement-soil gravity retaining wall under different earth pressure modes%考虑不同土压力模式的水泥土重力式围护墙抗倾覆稳定性分析

    毛明强; 熊巨华

    2014-01-01

    墙前开挖区土压力和墙后土压力模式的确定是水泥土重力式挡土墙抗倾覆稳定性验算的关键,不同土压力模式下抗倾覆系数曲线形态有一定的差异。根据墙体竖向力的平衡确定抗倾覆验算点位置,根据墙体的变形特征,同时考虑由于基坑开挖引起的上覆有效土压力变化引入修正系数α修正墙前后土压力,推导了修正土压力模式下墙体的抗倾覆稳定计算公式,对比分析三种不同土压力模式下Kq曲线的形态特征及其影响因素,结果表明墙前后土压力修正模式更能反映实际状态下墙的倾覆失稳形态,其抗倾覆稳定系数也更加合理。%The mode of earth pressures acting on the front wall and behind the wall plays a key role in checking the anti-overturning stability of cement-soil gravity retaining wall after excavation. The curve of anti-overturning safety factor somewhat varies under different earth pressure modes. The turning point can be determined according to the balance of vertical force. In order to consider the characteristics of wall deformation and the change of effective vertical earth pressure, a coefficient is introduced to modify the earth pressure on the wall, meanwhile a formula for calculating the safety factor is proposed under the new mode. Through analysis of the morphological characteristics of the curve and the influencing factor under three different earth pressure modes, the calculated results show that the anti-overturning safety factor is more reasonable, and the modified method can better reveal the real state of wall overturning.

  4. 3-D force-balanced magnetospheric configurations

    S. Zaharia

    2004-01-01

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

  5. 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

    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.

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

    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)

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

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

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

    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.

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

    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, β = 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□: [Φ] 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.)

  10. Rare—Earth Element Geochemistry of Elogites from the Ultra—High Pressure Metamorphic Belt in Central China

    黄智龙; 刘丛强; 等

    2000-01-01

    Based on their REE contents and REE patterns,eclogites from the ultra-high pressure metamorphic belt in central China may be roughly divided into xis types including LREE-rich.LREE-rich+positive Eu anomaly,LREE-rich+negative Eu anomaly,REE pattern-smooth,MREE-rich and HREE-rich.The LREE_rich,LREE-rich+positive Eu anomaly and LREE-rich+negative Eu anomaly types of eclogites are dominant .REE types of eclogites in different areas can be compared and the REE feactures of the same REE type of eclogites in different areas are similar.The results of reconstruction of the primary rocks show that the primary rocks of eclogites possibly are dominated by continental tholeiites which are the product of partial melting of relatively fertile mantle and the rocks of tholeiite crystallization-differentiation.There is perfect evolution relationship among the primary rocks of the LREE-rich, LREE-rich+positive Eu anomaly and LREE-rich+negative Eu anomaly types of eclogites and among those of the REE pattern smooth and MREE-rich types of eclogites,the former three types were deried from continental settings and the latter two from nearly oceanic settings.Meanwhile,it is concluded that the mantle sources of primary rocks of the eclogites are inhomogeneous and the primary rocks of eclogites in this area appear to have undergone varying degree of crustal contamination.

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

    Buelow, Nicholas Lee

    2005-08-01

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

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

    Lee, Sung Keun; Lin, Jung-Fu; Cai, Yong Q.; Hiraoka, Nozomu; Eng, Peter J.; Okuchi, Takuo; Mao, Ho-kwang; Meng, Yue; Hu, Michael Y.; Chow, Paul; Shu, Jinfu; Li, Baosheng; Fukui, Hiroshi; Lee, Bum Han; Kim, Hyun Na; Yoo, Choong-Shik [SNU; (LLNL); (NSRRC); (Okayama); (UC); (CIW); (Wash State U); (Nagoya); (SBU)

    2015-02-09

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

  13. 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

    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...

  14. Geophysics: Earth's core problem

    Dobson, David

    2016-06-01

    Measurements of the electrical resistance and thermal conductivity of iron at extreme pressures and temperatures cast fresh light on controversial numerical simulations of the properties of Earth's outer core. See Letters p.95 & 99

  15. Temperature of Earth's core constrained from melting of Fe and Fe0.9Ni0.1 at high pressures

    Zhang, Dongzhou; Jackson, Jennifer M.; Zhao, Jiyong; Sturhahn, Wolfgang; Alp, E. Ercan; Hu, Michael Y.; Toellner, Thomas S.; Murphy, Caitlin A.; Prakapenka, Vitali B.

    2016-08-01

    The melting points of fcc- and hcp-structured Fe0.9Ni0.1 and Fe are measured up to 125 GPa using laser heated diamond anvil cells, synchrotron Mössbauer spectroscopy, and a recently developed fast temperature readout spectrometer. The onset of melting is detected by a characteristic drop in the time-integrated synchrotron Mössbauer signal which is sensitive to atomic motion. The thermal pressure experienced by the samples is constrained by X-ray diffraction measurements under high pressures and temperatures. The obtained best-fit melting curves of fcc-structured Fe and Fe0.9Ni0.1 fall within the wide region bounded by previous studies. We are able to derive the γ-ɛ-l triple point of Fe and the quasi triple point of Fe0.9Ni0.1 to be 110 ± 5GPa, 3345 ± 120K and 116 ± 5GPa, 3260 ± 120K, respectively. The measured melting temperatures of Fe at similar pressure are slightly higher than those of Fe0.9Ni0.1 while their one sigma uncertainties overlap. Using previously measured phonon density of states of hcp-Fe, we calculate melting curves of hcp-structured Fe and Fe0.9Ni0.1 using our (quasi) triple points as anchors. The extrapolated Fe0.9Ni0.1 melting curve provides an estimate for the upper bound of Earth's inner core-outer core boundary temperature of 5500 ± 200K. The temperature within the liquid outer core is then approximated with an adiabatic model, which constrains the upper bound of the temperature at the core side of the core-mantle boundary to be 4000 ± 200K. We discuss a potential melting point depression caused by light elements and the implications of the presented core-mantle boundary temperature bounds on phase relations in the lowermost part of the mantle.

  16. Balanced Scorecard

    Ahonen, Tiina

    2015-01-01

    Tasapainotetun tuloskortin eli Balanced Scorecardin avulla organisaatiolla on mahdollisuus saada toiminnasta perinteisiä taloudellisia raportteja parempi kuva. Balanced Scorecard huomioi taloudellisten tunnuslukujen lisäksi myös asiakkaiden, sisäisten prosessien sekä oppimisen ja kasvun näkökulman. Tämän opinnäytetyön tavoitteena oli suunnitella suoritusmittaristo pk-yritykselle. Tutkimuksella haettiin Balance Scorecardin kautta vahvistusta ja tukea kohdeyrityksen sisäiseen laskentaan ja ...

  17. On the radial force balance in the quiet time magnetotail current sheet

    Artemyev, A. V.; Angelopoulos, V.; Runov, A.

    2016-05-01

    Using Time History of Events and Macroscale Interactions spacecraft observations of the quite magnetotail current sheet within the r∈[9,35]RE region (r is the radial distance from Earth and RE is Earth's radius), we investigate the thermal plasma pressure distribution along the magnetotail. Taking advantage of flapping motions of an ensemble of current sheets at various distances, we estimate the current density magnitude jy (in GSM coordinates). Comparing the tension force jyBz (Bz is the magnetic field component) with the radial gradient of the plasma pressure demonstrates that this gradient is only a small fraction, ˜10-15%, of the Ampere force exerted on the cross-tail current, in the r > 15RE region. We also estimate the contribution of the electron temperature anisotropy to the pressure balance: in the r > 15RE region the corresponding force can balance only 10-15% of the observed tension force jyBz. Thus, we conclude that about 70% of the tension force is not balanced by the combination of isotropic radial pressure gradient or the electron anisotropy. We discuss mechanisms that could be responsible for balancing the magnetotail current sheet.

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

    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

  19. A fluid model for the edge pressure pedestal height and width in tokamaks based on the transport constraint of particle, energy, and momentum balance

    Stacey, W. M.

    2016-06-01

    A fluid model for the tokamak edge pressure profile required by the conservation of particles, momentum and energy in the presence of specified heating and fueling sources and electromagnetic and geometric parameters has been developed. Kinetics effects of ion orbit loss are incorporated into the model. The use of this model as a "transport" constraint together with a "Peeling-Ballooning (P-B)" instability constraint to achieve a prediction of edge pressure pedestal heights and widths in future tokamaks is discussed.

  20. Formulation of high-precision volume-of-fluid method establishing appropriate balance between pressure and surface tension and its application to gas entrainment phenomena in fast breeder reactors

    To evaluate directly gas entrainment (GE) phenomena in fast reactors, a numerical simulation method based on a high-precision volume-of-fluid (VOF) methodology have been studied. Unstructured meshes to subdivide simulation domains have been employed because exact modeling of complicated geometries is necessary for GE simulations. In this note, formulations of each calculation procedure in the high-precision VOF methodology on unstructured meshes are briefly presented. Calculation procedures of surface tension forces are also presented. In addition, unphysical behaviors of velocity distributions near gas-liquid interface induced by inappropriate formulation of pressure gradient are addressed and an appropriate formulation is presented considering proper balance conditions between pressure and surface tension forces. Finally, the improved simulation method is applied to the basic GE experiment. The simulation results show that the GE phenomena occur in the same mechanism with the experimental results. (author)

  1. High-pressure syntheses and characterization of the rare-earth fluoride borates RE{sub 2}(BO{sub 3})F{sub 3} (RE = Tb, Dy, Ho)

    Hinteregger, Ernst; Pitscheider, Almut; Wurst, Klaus; Heymann, Gunter; Huppertz, Hubert [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie; Enders, Michael [Innsbruck Univ. (Austria). Inst. fuer Pharmazie

    2013-11-15

    The new rare-earth fluoride borates RE{sub 2}(BO{sub 3})F{sub 3} (RE = Tb, Dy, Ho) were synthesized under high-pressure/high-temperature conditions of 1.5 GPa/1200 C for Tb{sub 2}(BO{sub 3})F{sub 3} and 3.0 GPa/900 C for Dy{sub 2}(BO{sub 3})F{sub 3} and Ho{sub 2}(BO{sub 3})F{sub 3} in a Walker-type multianvil apparatus from the corresponding rare-earth sesquioxides, rare-earth fluorides, and boron oxide. The single-crystal structure determinations revealed that the new compounds are isotypic to the known rare-earth fluoride borate Gd{sub 2}(BO{sub 3})F{sub 3}. The new rare-earth fluoride borates crystallize in the monoclinic space group P2{sub 1}/c (Z = 8) with the lattice parameters a = 16.296(3), b = 6.197(2), c = 8.338(2) A, {beta} = 93.58(3) for Tb{sub 2}(BO{sub 3})F{sub 3}, a = 16.225(3), b = 6.160(2), c = 8.307(2) A, {beta} = 93.64(3) for Dy{sub 2}(BO{sub 3})F{sub 3}, and a = 16.189(3), b = 6.124(2), c = 8.282(2) A, {beta} = 93.69(3) for Ho{sub 2}(BO{sub 3})F{sub 3}. The four crystallographically different rare-earth cations (CN = 9) are surrounded by oxygen and fluoride anions. All boron atoms form isolated trigonal-planar [BO{sub 3}]{sup 3-} groups. The six crystallographically different fluoride anions are in a nearly planar coordination by three rare-earth cations. (orig.)

  2. 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.

    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

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

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

  4. 滑裂面形状对挡土墙主动土压力的影响%Effect of slip surface shape on active earth pressure upon retaining wall

    徐杨; 阎长虹; 姜玉平; 许宝田

    2015-01-01

    滑裂面的准确选取对挡土墙稳定性分析有重要影响。基于塑性极限分析理论,分别推导了直线和对数螺旋线滑移模式下挡土墙主动土压力的计算公式,通过算例对比分析研究了平面滑裂面和对数螺旋滑裂面主动土压力的特点。研究结果表明:直线滑裂面为对数螺旋滑裂面的一种特例,随着滑裂面曲率增大,主动土压力合力作用点逐渐上移,主动土压力合力略有增加,但对墙趾的弯矩显著增加,不利于挡土墙稳定性;挡土墙各参数对直线滑裂面主动土压力合力作用点有不同影响,随着填土内摩擦角、挡墙倾角、填土倾角的增大而上移,随着墙土间摩擦角、黏聚力与容重挡土墙高度的乘积之比的增大而下移,合力作用点位置大致在0.2~0.4倍墙高处,说明主动土压力的非线性分布。研究结果对准确选取滑裂面形状计算挡土墙主动土压力有实际工程应用价值。%Based on the plastic limit analysis theory, the calculation formulas of active earth pressure for retaining wall were derived at the linear and logarithmic spiral slip pattern respectively. And the features of active earth pressure between the plane slip surface and logarithmic spiral slip surface were also compared through the calcula-tion examples. The linear slip surface is considered as a special case of the logarithmic spiral slip surface the point of resultant force of active earth pressure for linear slip surface was determined by the combination of the two cal-culation formulas. With the increase of slip surface curvature, the point of resultant force of active earth pressure gradually moves up, the value of active earth pressure slightly increases but there is significant increase in the moment of the wall toe. The parameters of the retaining wall were analyzed to study its influence on the point of resultant force of active earth pressure for linear slip surface. The

  5. Balance System

    1988-01-01

    TherEx Inc.'s AT-1 Computerized Ataxiameter precisely evaluates posture and balance disturbances that commonly accompany neurological and musculoskeletal disorders. Complete system includes two-strain gauged footplates, signal conditioning circuitry, a computer monitor, printer and a stand-alone tiltable balance platform. AT-1 serves as assessment tool, treatment monitor, and rehabilitation training device. It allows clinician to document quantitatively the outcome of treatment and analyze data over time to develop outcome standards for several classifications of patients. It can evaluate specifically the effects of surgery, drug treatment, physical therapy or prosthetic devices.

  6. 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)

    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

  7. Balance (or Vestibular) Rehabilitation

    ... for the Public / Hearing and Balance Balance (or Vestibular) Rehabilitation Audiologic (hearing), balance, and medical diagnostic tests help indicate whether you are a candidate for vestibular (balance) rehabilitation. Vestibular rehabilitation is an individualized balance ...

  8. Does sympathetic overactivation feature all hypertensives? Differences of sympathovagal balance according to night/day blood pressure ratio in patients with essential hypertension.

    Di Raimondo, Domenico; Miceli, Giuseppe; Casuccio, Alessandra; Tuttolomondo, Antonino; Buttà, Carmelo; Zappulla, Valentina; Schimmenti, Caterina; Musiari, Gaia; Pinto, Antonio

    2016-06-01

    When evaluating the 'night/day BP ratio', both hypertensives and normotensives can be arbitrarily classified into four groups: extreme dippers (ratio ⩽0.8), dippers (0.8SNS); however, the HRV behavior in extreme dippers is still controversial. The goal of this study was to compare HRV indexes of extreme vs. reverse dipper essential hypertensives measured on the basis of time domains. We enrolled 125 hypertensive subjects, divided in 4 quartiles according to day/night blood pressure (BP) ratios. The upper and lower quartiles (31 subjects per quartile) were compared; 30 normotensive subjects were enrolled as a control group. Time domain HRV parameters of the three groups revealed a higher degree of sympathetic activation in the lower quartile (reverse dipper) vs. the upper quartile (extreme) and normotensive controls. HRV parameters related to parasympathetic tone did not show any significant variations among the three groups. Contrary to common belief, not all hypertensives have SNS overactivation. PMID:26865002

  9. Lesson "Balance in Nature

    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

  10. Pressure fluctuation performance of low specific-speed centrifugal pump with radial reflux balance hole/%采用径向回流平衡孔的低比速离心泵压力脉动特性

    曹卫东; 张晓娣; 施卫东

    2011-01-01

    采用Relizablek~ε模型对具有径向回流平衡孔以及传统轴向回流平衡孔和无平衡孔结构的低比速离心泵进行全流场非定常数值模拟,并进行时域分析和频域分析.研究结果表明:平衡孔采用径向回流方式、传统轴向回流方式以及无平衡孔结构这3种方案时,离心泵的叶轮进口、蜗壳出口以及蜗壳隔舌处的流体均随时间呈周期性波动,脉动频率以叶片通过频率为主;具有径向回流平衡孔的低比速离心泵与其他2种结构形式的低比速离心泵相比,能够有效地改善蜗壳隔舌处的压力脉动情况.%By means of the k-ε model, numerical simulation of unsteady full flow fields of low specific-speed centrifugal pump with three different structures, that is, radial reflux balance hole, traditional axial reflux balance hole and no balance hole, was carried out. The time domain and frequency domain were analyzed. The results show that for the above three kinds of structures, the fluid at the inlet of the impeller, outlet and tongue of the volute exhibits cyclic fluctuation with the time, and the fluctuating frequency is mainly the passing frequency of the blade. Compared with that with the other two structures, the low specific-speed centrifugal pump with radial reflux balance hole will effectively improve the pressure fluctuation at the tongue of the volute.

  11. Formation of high-precision volume-of-fluid method establishing appropriate balance between pressure and surface tension and its application to gas entrainment phenomena in fast breeder reactors

    To evaluate directly gas entrainment (GE) phenomena in fast breeders, we have been studied a numerical simulation method based on a high-precision volume-of-fluid (VOF) methodology. In addition, we have been employed unstructured meshes to subdivide simulation domains because exact modeling of complicated geometries in each simulation domain is a key to simulate gas entrainment phenomena accurately. Therefore, as important parts of our study, formulations of each calculation procedure in the high-precision VOF methodology on unstructured meshes are conducted in this paper. In concrete terms, calculation procedures for 1) interfacial gradient vectors, 2) interface reconstructions, 3) fluxes of volume fraction on each mesh cell face are formulated on unstructured meshes. Calculation procedures of Surface tension forces are also formulated in this paper. Then, unphysical behaviors of velocity distributions near gas-liquid interface induced by inappropriate formulation of pressure gradient are discussed and an appropriate formulation is derived considering proper balance conditions between pressure and surface tension forces. It is confirmed that this new formulation reduces the unphysical behaviors in a numerical simulation of a rising gas bubble in liquid. Finally, the basic GE experiment is simulated using our numerical simulation method. The simulation results shows that the GE phenomena occurs in the same mechanism with the experimental results. (author)

  12. 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

    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.

  13. 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

    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

  14. Balancing Risk

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

    2015-01-01

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

  15. Social Balance Theory

    Hokky Situngkir; Deni Khanafiah

    2004-01-01

    We construct a model based on social balance theory proposed by Fritz Heider to analyze the interpersonal network among social agents. The model of social balance theory provides us an interesting tool to see how a social group evolves to the possible balance state. We introduce the balance index that can be used to measure social balance in macro structure level (global balance index) or in micro structure (local balance index) to see how the local balance index influences the global balance...

  16. 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

    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 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.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

  17. Earth\\'s Mass Variability

    Mawad, Ramy

    2014-01-01

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

  18. A hypothesis of earth quake

    Tsai, Yeong-Shyeong

    2008-01-01

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

  19. Relevance of balance measurement tools and balance training for fall prevention in older adults

    Majumi M. Noohu, MPTh

    2014-06-01

    Full Text Available Approximately one in three older people fall each year owing to gait/balance disorder/weakness, the second leading cause of falls in older adults. This review evaluates the capability of different balance measurement tools to predict falls in the elderly, which are used routinely for assessing balance impairment. Balance measurement tools reviewed are the Timed Up and Go test, Berg Balance Scale, Tinetti Performance Oriented Mobility Assessment, Functional Reach Test, Clinical Test of Sensory Integration for Balance, and the postural sway measurements or center of pressure. The effect of balance training on the postural control mechanism and its efficacy in fall prevention in older adults were also reviewed. The current evidence is not conclusive enough to favor existing balance measurement tools and balance training implemented for fall prevention in older adults.

  20. Phase states of hydrous-hydrocarbon fluids at elevated and high temperatures and pressures: Study of the forms and maximal depths of oil occurrence in the Earth's interior

    Balitsky, V. S.; Penteley, S. V.; Pironon, J.; Barres, O.; Balitskaya, L. V.; Setkova, T. V.

    2016-02-01

    Based on synthetic fluid inclusions in quartz grown at 240-490°C and 7-150 MPa in aqueous-oil solutions, the behavior, composition, and phase states of liquid, gaseous, and solid hydrocarbons (HC) were studied. Investigations were performed using common and fluorescent microscopy, microthermometry, local common and high-temperature IR Fourier spectroscopy, Raman spectroscopy, chromatography, and X-ray and microprobe analysis. The data obtained allowed us to understand the influence of thermobaric conditions and volume proportions of the oil, aqueous, and gaseous phases on the composition, phase state, and behavior of hydrous-hydrocarbon fluids and estimate the forms and probable maximal depths of the origin of oil in the Earth's interior.

  1. Balanced Scorecard

    Kytka, Roman

    2008-01-01

    V současnosti se podniky setkávají s řadou přístupů k řízení společností a velmi častými pojícími prvky bývají zejména náklady, efektivita a výkonnost. Z nepřeberné řady nástrojů k řízení společností určených tato práce blíže seznamuje s metodikou Balanced Scorecard (BSC), koncepčním rámcem ITIL a metodikou Cobit. Jednotlivě zde jsou představeny dílčí metodiky a rámce. Míra tohoto seznámení je úměrná potřebám práce, tzn. není cílem představit ITIL či Cobit úplně detailně. Naopak zde jsou podc...

  2. Earth\\'s Mass Variability

    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.

  3. Earth Wisdom.

    Van Matre, Steve

    1985-01-01

    In our human-centered ignorance and arrogance we are rapidly destroying the earth. We must start helping people understand the big picture of ecological concepts. What these concepts mean for our own lives and how we must begin to change our lifestyles in order to live more harmoniously with the earth. (JHZ)

  4. The Global Challenge: A Matter of Balance.

    Mulford, Bill

    2002-01-01

    Argues that global challenge created by the pressure for change requires educators to understand the balance between continuity and constant change dependence and independence, individualism and community, homogeneity and heterogeneity. To achieve balanced learning and development, education should place greater emphasis on continuity,…

  5. Hydrogeochemistry in soils and sediments in the area of the Lagoa Campestre lake (Salitre, MG, Brazil) : chemical balances of major and trace elements and dynamics of rare earth elements

    Sondag, Francis; Soubiès, François; Fortune, J.P.; B. Dupré; Magat, P.; Melfi, A. (collab.)

    1997-01-01

    Study of the sediments filling the Lagoa Campestre peaty lake (Minas Gerais, Brazil) showed a high rare earth elements (REE) content, especially in phosphatic bottom beds (authigenic phosphates), whose fluctuations could be related to variations in the erosion conditions and the nature of the plant cover. In order to understand better the mode of complexation and transport of trace elements in this environment, a geochemical survey was undertaken of the waters of the area, both in surface str...

  6. Mineral solubilities in aqueous fluids at high pressures and temperatures: New thermodynamic model and implications for mass transfer in the Earth's crust and mantle

    Dolejš, David; Manning, Craig E.

    2010-05-01

    Aqueous fluids are produced by metamorphic devolatilization and magmatic activity in a variety of settings including continental orogens, subduction zones with magmatic arcs as well as oceanic ridges and sea floor. They are responsible for mobility and transport of inorganic and organic solutes as manifested by alteration or veining, distinct element depletion-enrichment patterns or isotopic disturbances. The impact of many fluid-mediated processes is promoted by high time-integrated fluid fluxes, 101-106 m3 m-2, inferred for diffuse and focused fluid flow through lithosphere. Previous approaches to aqueous speciation have almost exclusively been based on the Helgeson-Kirkham-Flowers equation of state, which, however, suffers from inaccuracies in the vicinity of critical point of water and cannot be extrapolated to very high temperatures and pressures due to the lack of experimental data on dielectric constant of H2O. We propose a new thermodynamic model for dissolution of minerals in aqueous fluids at high temperatures and pressures, which is derived from individual energetic contributions to lattice breakdown, solute hydration and compression of the hydration shell. The thermodynamic properties depend on temperature and H2O density only and are calculated using three to five model parameters calibrated by experimental data. Our formulation of the density dependence has the advantage of behaving as a smooth function at the critical point of H2O, it closely corresponds to the generalized Krichevskii parameter, and it linearly correlates with the Born electrostatic energy. Solubilities of quartz, corundum, rutile, calcite, apatite, fluorite, and portlandite monotonously increase for a given phase by 4-5 orders of magnitude as temperature rises from 200 to 1100 oC along typical geotherms. At constant pressure, however, mineral solubilities initially increase with rising temperature, but subsequently drop. This effect results from a reversal in isobaric expansivity of

  7. Automatic calibration system for pressure transducers

    1968-01-01

    Fifty-channel automatic pressure transducer calibration system increases quantity and accuracy for test evaluation calibration. The pressure transducers are installed in an environmental tests chamber and manifolded to connect them to a pressure balance which is uniform.

  8. Momentum balance in wall jets

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

    2012-11-01

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

  9. Origin of the change of the electrical and optical properties in shocked Al2O3 and prediction of an increase in electrical conductivity in MgSiO3 at pressure-temperature conditions of the Earth's D'' layer

    He, L.; Tang, M. J.; Fang, Y.; Jing, F. Q.

    2008-08-01

    Shock-wave experiments of Al2O3 indicated the onset of an increase in electrical conductivity and observed the optical transparency loss at ~130 GPa. Here, based on first-principles calculations, we determine the pressure dependence of the band gap of perfect Al2O3 to 220 GPa, and investigate the optical absorption of Al2O3 without and with oxygen and aluminum vacancies within 220 GPa. Our results indicate that: 1) the onset of the conductivity increase is attributed to a band-gap decrease due to the Rh2O3(II)-CaIrO3 transition at ~130 GPa and ~1500 K; 2) this transition is not responsible for the transparency loss, but heterogeneous absorption in the visible-light region, induced by the +2 charge oxygen vacancy, should be a source of this phenomenon. The calculations of perfect MgSiO3, a material analogous to Al2O3, suggest that a perovskite to post-povskite transition in MgSiO3 at ~125 GPa and ~2500 K also yields a band-gap reduction. This causes an increase in electrical conductivity in MgSiO3 at pressure-temperature conditions of the Earth's D'' layer.

  10. Balanced Permutation Codes

    Gabrys, Ryan; Milenkovic, Olgica

    2016-01-01

    Motivated by charge balancing constraints for rank modulation schemes, we introduce the notion of balanced permutations and derive the capacity of balanced permutation codes. We also describe simple interleaving methods for permutation code constructions and show that they approach capacity

  11. Dizziness and Balance

    AUDIOLOGY Dizziness and Balance Inform ation Seri es Our balance system helps us walk, run, and move ... known as nystagmus) • Complaints of vertigo or dizziness Audiology Information Series © ASHA 2015 10802 • Balance dysfunction • Difficulty ...

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

    D. Yu. Klimushkin

    2004-01-01

    Full Text Available In this paper, in terms of an axisymmetric model of the magnetosphere, we formulate the criteria for which the Alfvén waves in the magnetosphere can be toroidally and poloidally polarized (the disturbed magnetic field vector oscillates azimuthally and radially, respectively. The obvious condition of equality of the wave frequency ω to the toroidal (poloidal eigenfrequency ΩTNPN is a necessary and sufficient one for the toroidal polarization of the mode and only a necessary one for the poloidal mode. In the latter case we must also add to it a significantly stronger condition ∣ΩTN–ΩPN∣/ΩTNm–1 where m is the azimuthal wave number, and N is the longitudinal wave number. In cold plasma (the plasma to magnetic pressure ratio β = 0 the left-hand side of this inequality is too small for the routinely recorded (in the magnetosphere second harmonic of radially polarized waves, therefore these waves must have nonrealistically large values of m. By studying several models of the magnetosphere differing by the level of disturbance, we found that the left-hand part of the poloidality criterion can be satisfied by taking into account finite plasma pressure for the observed values of m ∼ 50 – 100 (and in some cases, for even smaller values of the azimuthal wave numbers. When the poloidality condition is satisfied, the existence of two types of radially polarized Alfvén waves is possible. In magnetospheric regions, where the function ΩPN is a monotonic one, the mode is poloidally polarized in a part of its region of localization. It propagates slowly across magnetic shells and changes its polarization from poloidal to toroidal. The other type of radially polarized waves can exist in those regions where this function reaches its extreme values (ring current

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

    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 ...

  14. 土石坝心墙填土恒压吸湿变形试验研究%EXPERIMENTAL STUDY ON THE WETTING DEFORMATION OF THE SOIL USED IN THE CORE WALL OF EARTH-ROCK DAM UNDER CONSTANT PRESSURE

    郭冲; 邱秀梅; 赵晓龙; 卞汉兵

    2013-01-01

    通过一维固结试验分析了各级压力下非饱和重塑土在加水饱和过程中的变形特征,结果显示不同压力下试件饱和过程的变形呈现出不同特征.试验结果如下:50 kPa压力下呈现出膨胀特征;100 kPa、150 kPa和200kPa压力下,呈现出先膨胀后压缩的特征,而且最终变形与加水前相比也各有不同;300kPa和400kPa压力下,试件压缩变形量明显增大.此种变形特征可能会导致土石坝心墙在蓄水过程中形成裂缝,从而为土石坝心墙发生水力劈裂破坏提供条件.%By using the conventional oedometer consolidation test, the deformation characteristics of unsaturated remolded soil under constant compression stresses subjected to wetting process were analyzed. The test result indicates that the deformation characteristics were different under different constant compression stresses. The test result is as follows; under the pressure of 50kPa the specimen was expansive; under the pressure of lOOkPa, 150kPa and 200kPa, the deformations had a transition from expansion to compression, and the final total deformations were respectively different from the deformations compared with prior to the saturation process; and under the pressure of 300kPa and 400kPa, the collapse was observed. The deformation characteristics may lead to cracks in the core of earth - rock fill dam which cause the hydraulic fracture.

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

    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

  16. Water and sodium balance in space

    Drummer, C; Norsk, P; Heer, M

    2001-01-01

    We have previously shown that fluid balances and body fluid regulation in microgravity (microG) differ from those on Earth (Drummer et al, Eur J Physiol 441:R66-R72, 2000). Arriving in microG leads to a redistribution of body fluid-composed of a shift of fluid to the upper part of the body and an...

  17. Digital Earth - A sustainable Earth

    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.

  18. A reconciled estimate of ice-sheet mass balance

    Shepherd, Andrew; Ivins, Erik R; A, Geruo;

    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 agre...

  19. Hydrogen Escape from early Earth and Mars

    Zugger, M. E.; Ramirez, R. M.; Kasting, J. F.

    2012-12-01

    A controversy regarding hydrodynamic escape rates arose when Tian et al. (2005) published transonic escape rates for an atmosphere composed of pure H2. Tian et al. concluded that the hydrogen escape rate from early Earth would have been a factor of 20 or more slower than the diffusion limit, even if the solar EUV (extreme ultraviolet) flux was enhanced by a factor of 5 relative to today. This conclusion was challenged by Catling (2006), who pointed out that solar EUV fluxes could have been much higher than this so that plenty of energy should have been available to power escape. This controversy has remained unresolved to date. Hydrogen escape from early Mars is also of interest. As discussed in this session in a complementary paper by Ramirez et al., collision-induced absorption by molecular hydrogen could have helped to warm early Mars, perhaps explaining the formation of valleys and valley networks. Ramirez et al. have shown that a mixture of 90% CO2 and 10% H2 is capable raising early Mars' surface temperature above the freezing point of water, for surface pressures exceeding ~3 bar. However, we need to understand whether H2 mixing ratios of 10% are physically plausible. The H2 partial pressure in Mars' early atmosphere would have been determined by the balance between volcanic outgassing and escape to space. The 10% mixing ratio is high compared to the value of ~10-3 typically assumed for early Earth. But Mars' early atmosphere may have been more reduced than Earth's (Wadwha, 2001); if the hydrogen escape rate on Mars was also slower than on Earth, then additional increases in atmospheric hydrogen concentration are possible. To answer these questions about the early atmospheres of Earth and Mars, we have modified an existing model of hydrodynamic escape, developed by F. Tian, J. Kasting, and others, to converge for atmospheres with a wide range of hydrogen mixing ratios. The model finds subsonic solutions to the hydrodynamic equations; these can be shown to

  20. Effect of Aquatic Immersion on Static Balance

    Louder, Talin J.

    2013-01-01

    Objective To quantitatively assess measures of static balance and limits of stability (LOS) in an aquatic environment compared to on land. Methods Fifteen healthy, young adults (23 + or - 2 years) performed 90 s static balance trials on land and aquatic immersion at two different depths (greater trochanter, xiphoid process). Measures of 95% ellipse area and center of pressure (CoP) mean velocity were computed from the force data. Additionally, participants completed a visual analog scale (VAS...

  1. Human Balance System

    ... Rated Nonprofit! Volunteer. Donate. Review. The Human Balance System Good balance is often taken for granted. Good ... soft, slippery, or uneven). Input from the vestibular system Sensory information about motion, equilibrium, and spatial orientation ...

  2. Random walk and balancing

    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.

  3. Skylab water balance analysis

    Leonard, J. I.

    1977-01-01

    The water balance of the Skylab crew was analyzed. Evaporative water loss using a whole body input/output balance equation, water, body tissue, and energy balance was analyzed. The approach utilizes the results of several major Skylab medical experiments. Subsystems were designed for the use of the software necessary for the analysis. A partitional water balance that graphically depicts the changes due to water intake is presented. The energy balance analysis determines the net available energy to the individual crewman during any period. The balances produce a visual description of the total change of a particular body component during the course of the mission. The information is salvaged from metabolic balance data if certain techniques are used to reduce errors inherent in the balance method.

  4. Polarization-balanced beamsplitter

    Decker, D.E.

    1998-02-17

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

  5. A climatic thermostat making Earth habitable

    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 planet, called Sn...

  6. Coaching for Balance.

    Larson, Bonnie

    2001-01-01

    Discusses coaching for balance the integration of the whole self: physical (body), intellectual (mind), spiritual (soul), and emotional (heart). Offers four ways to identify problems and tell whether someone is out of balance and four coaching techniques for creating balance. (Contains 11 references.) (JOW)

  7. Performance of balanced bellows safety relief valves

    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.)

  8. Mass balance, meteorological, and runoff measurements at South Cascade Glacier, Washington, 1992 balance year

    Krimmel, R.M.

    1993-01-01

    Values of winter snow accumulation and summer snow, firn, and ice ablation were measured at South Cascade Glacier, WA, to determine the winter and net balance for the 1992 balance year. The 1992 winter balance, averaged over the glacier, was 1.91 m, and the net balance was -2.01 m. This extremely negative balance continued a trend of negative balance years beginning in 1977. Air temperature (at 1,615 m and 1,867 m), barometric pressure, precipitation, and runoff from this glacier basin and an adjacent non-glacierized basin were also continuously measured. This report makes all these data, in tabular, graphical, and machine-readable forms, available to users.

  9. Using Multi-threading for the Automatic Load Balancing of 2D Adaptive Finite Element Meshes

    Heber, Gerd; Biswas, Rupak; Thulasiraman, Parimala; Gao, Guang R.; Saini, Subhash (Technical Monitor)

    1998-01-01

    In this paper, we present a multi-threaded approach for the automatic load balancing of adaptive finite element (FE) meshes The platform of our choice is the EARTH multi-threaded system which offers sufficient capabilities to tackle this problem. We implement the adaption phase of FE applications oil triangular meshes and exploit the EARTH token mechanism to automatically balance the resulting irregular and highly nonuniform workload. We discuss the results of our experiments oil EARTH-SP2, on implementation of EARTH on the IBM SP2 with different load balancing strategies that are built into the runtime system.

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

    Gray, V. H. (Inventor)

    1973-01-01

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

  11. Rare earths

    General mineralogical-geochemical and analytical characteristics of (lanthanides and yttrium) are presented. It is pointed out that individual RE in complex chemical composition samples are successfully determined by physical methods of the analysis (emission spectral method, spark mass spectrometry method, neutron + activation analysis). RE sum determination is performed by spectrophotometric titrimetric or gravimetric methods. Principal methods of RE separation and concentration, methods of analytical samples dissolution are considered. Detailed descriptions of some specific techniques of determining rare earths in rocks, ores and minerals are presented

  12. The Genesis of the Earth's Moon

    De Aquino, Fran

    2015-01-01

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

  13. Accounting on Material Balance of Hydroprocessing Unit by Solubility Equilibrium in High Pressure Separator%利用高分溶解平衡核算加氢装置物料平衡的探索

    牛世坤; 李士才; 徐大海

    2013-01-01

    针对目前实验室测定装置物料平衡方法中存在的高分各种低分子烃类溶解度不同对物料平衡的影响,改变测定装置物料平衡的流程,利用反应物料在高分溶解后废氢中低分子烃类含量,结合 HYSYS 软件中Adjust功能,较为准确核算装置物料平衡,还原加氢反应本身的反应结果。%In view of the effects of different solubility of low molecular hydrocarbons in HP separator on the material balance in the unit material balance measuring method of the current lab, the material balance measuring process was changed, using the low molecular hydrocarbon concentration in the waste H2 after HP solubility and combining with the Adjust function in HYSYS software could account the unit material balance more accurately and restore hydrogenation reaction results.

  14. DYMAC digital electronic balance

    The Dynamic Materials Accountability (DYMAC) System at LASL integrates nondestructive assay (NDA) instruments with interactive data-processing equipment to provide near-real-time accountability of the nuclear material in the LASL Plutonium Processing Facility. The most widely used NDA instrument in the system is the DYMAC digital electronic balance. The DYMAC balance is a commercial instrument that has been modified at LASL for weighing material in gloveboxes and for transmitting the weight data directly to a central computer. This manual describes the balance components, details the LASL modifications, reviews a DYMAC measurement control program that monitors balance performance, and provides instructions for balance operation and maintenance

  15. The Balanced Company

    involved in both the creation and recreation of balanced relationships. Chapters in The Balanced Company ask and provide answers to questions about corporately responsible and ethically driven balanced decision making, such as: • How can a company and its stakeholders identify what should be taken into...... changes in their environments. Communication specialists need to make balanced decisions which take the different value systems and assumptions of stakeholders into consideration. Change specialists need to balance the need for continuity and change. Managers need to make balanced decisions about whether...... in consumers' and other stakeholder's eyes. Leaders also have to acknowledge that there are times when organizations have to be taken out of balance, since it is necessary to 'unfreeze' existing relationships in organizations during change. Therefore, there are decision and organizing processes...

  16. Sulfur Earth

    de Jong, B. H.

    2007-12-01

    Variations in surface tension affect the buoyancy of objects floating in a liquid. Thus an object floating in water will sink deeper in the presence of dishwater fluid. This is a very minor but measurable effect. It causes for instance ducks to drown in aqueous solutions with added surfactant. The surface tension of liquid iron is very strongly affected by the presence of sulfur which acts as a surfactant in this system varying between 1.9 and 0.4 N/m at 10 mass percent Sulfur (Lee & Morita (2002), This last value is inferred to be the maximum value for Sulfur inferred to be present in the liquid outer core. Venting of Sulfur from the liquid core manifests itself on the Earth surface by the 105 to 106 ton of sulfur vented into the atmosphere annually (Wedepohl, 1984). Inspection of surface Sulfur emission indicates that venting is non-homogeneously distributed over the Earth's surface. The implication of such large variation in surface tension in the liquid outer core are that at locally low Sulfur concentration, the liquid outer core does not wet the predominantly MgSiO3 matrix with which it is in contact. However at a local high in Sulfur, the liquid outer core wets this matrix which in the fluid state has a surface tension of 0.4 N/m (Bansal & Doremus, 1986), couples with it, and causes it to sink. This differential and diapiric movement is transmitted through the essentially brittle mantle (1024 Pa.s, Lambeck & Johnson, 1998; the maximum value for ice being about 1030 Pa.s at 0 K, in all likely hood representing an upper bound of viscosity for all materials) and manifests itself on the surface by the roughly 20 km differentiation, about 0.1 % of the total mantle thickness, between topographical heights and lows with concomitant lateral movement in the crust and upper mantle resulting in thin skin tectonics. The brittle nature of the medium though which this movement is transmitted suggests that the extremes in topography of the D" layer are similar in range to

  17. Synthetic Investigations in Rare-Earth Borates, Gallates, Oxides, and Gallium Oxonitrides at Extreme Conditions

    Hering, Stefanie Alexandra

    2010-01-01

    The present phD thesis concerns synthetic investigations under extreme conditions of high-temperature and high-pressure. The high-temperature / high-pressure experiments, performed using a multianvil high-pressure device, led to the first single crystals of various rare-earth gallates, rare-earth borates, rare-earth oxides and gallium oxonitrides.

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

    Kleidon, Axel

    2010-05-01

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

  19. A method to estimate the composition of the bulk silicate Earth in the presence of a hidden geochemical reservoir

    Korenaga, Jun

    2009-11-01

    The possibility of a hidden geochemical reservoir in the deep mantle has long been debated in geophysics and geochemistry, because of its bearings on the structure of the core-mantle boundary region, the origin of hotspots, the style of mantle convection, the history of the geomagnetic field, and the thermal evolution of Earth. The presence of such hidden reservoir, however, may invalidate existing models for the composition of the bulk silicate Earth because these models invariably assume that major chemical differentiation in the mantle follows the compositional trend exhibited by upper-mantle rocks. This article presents a new method to estimate the composition of the bulk silicate Earth by explicitly taking into account the possibility of a hidden reservoir. This geochemical inference is formulated as a nonlinear inverse problem, for which an efficient Markov chain Monte Carlo algorithm is developed. Inversion results indicate that the formation of a hidden reservoir, if any, took place at low pressures probably within the first 10 Myr of the history of the solar system and was subsequently lost from the Earth by impact erosion. The global mass balance of the bulk silicate Earth is revisited with the inversion results, and the depletion of highly incompatible elements in the present-day Earth is suggested to be moderate.

  20. Cyclical budget balance measurement

    C. AUDENIS; C. PROST

    2000-01-01

    Government balances are often adjusted for changes in economic activity in order to draw a clearer picture of the underlying fiscal situation and to use this as a guide to fiscal policy analysis. International organisations estimate the cyclical component of economic activity by the current level of the output gap. Using elasticities of tax and public expenditures to GDP, they compute the cyclical part of budget balance. The structural budget balance is defined as the remainder. Our approach ...

  1. Inevitability of Balance Restoration

    Oh, Man S.

    2010-01-01

    Prolonged imbalance between input and output of any element in a living organism is incompatible with life. The duration of imbalance varies, but eventually balance is achieved. This rule applies to any quantifiable element in a compartment of finite capacity. Transient discrepancies occur regularly, but given sufficient time, balance is always achieved, because permanent imbalance is impossible, and the mechanism for eventual restoration of balance is foolproof. The kidney is a central playe...

  2. Medical Devices Assess, Treat Balance Disorders

    2009-01-01

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

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

    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

  4. The Effect of Balance Acupuncture on“Jiangtang point”for the Blood Pressure of Patients with Type 2 Diabetes Mellitus%针刺降糖穴对2型糖尿病血压的影响研究

    王文远; 马忠立; 张利芳

    2014-01-01

    Objective :To observe the clinical efficacy of balance acupuncture on “Jiangtang point”for blood pressure and heart rate of patients with type 2 diabetes mellitus .Methods :60 patients with type 2 diabetes mellitus were acu‐punctured on“Jiangtang point”for 3 weeks .During the treatment ,we recorded the level change of blood glucose ,urine glucose and the clinical symptoms as well as the systolic pressure ,diastolic pressure ,heart rate and pulse and so on .Sta‐tistical analysis was performed with the use of CHISS software .Results:The treatment of balance acupuncture on“Jian‐gtang point”can not only reduce the level of blood glucose ,urine glucose and the clinical symptoms but also the systolic pressure ,diastolic pressure ,heart rate and pulse of the patients during the treatment for 3 weeks (P<0 .001) .Conclu‐sion:The treatment of balance acupuncture on“Jiangtang point”has an effective improvement on the hypertension while reducing the level of blood glucose ,urine glucose for the patients with type 2 diabetes mellitus .%目的:观察平衡针灸降糖穴对2型糖尿病患者的血压和心率的影响。方法:对60例2型糖尿病患者针刺降糖穴治疗3周,对其血糖、尿糖及其临床症状变化记录的同时,记录收缩压、舒张压、心率和脉搏等变化,采取CHISS统计软件进行统计分析。结果:针刺降糖穴不仅能够降低2型糖尿病患者血糖、尿糖和改善临床症状,同时可以降低收缩压、舒张压和心率,治疗3周前、后有明显差异( P<0.001)。结论:平衡针灸降糖穴对2型糖尿病血糖、尿糖降低的同时对高血压有明显改善。

  5. Identifying Balance in a Balanced Scorecard System

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

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

  6. The oxygen and carbon dioxide balance in the earth's atmosphere

    Johnson, F. S.

    1975-01-01

    The oxygen-carbon dioxide cycle is described in detail, and steps which are sensitive to perturbation or instability are identified. About half of the carbon dioxide consumption each year in photosynthesis occurs in the oceans. Phytoplankton, which are the primary producers, have been shown to assimilate insecticides and herbicides. The impact of such materials on phytoplankton photosynthesis, both direct and as the indirect result of detrimental effects higher up in the food chain, cannot be assessed. Net oxygen production is very small in comparison with the total production and occurs almost exclusively in a few ocean areas with anoxic bottom conditions and in peat-forming marshes which are sensitive to anthropogenic disturbances. The carbon dioxide content of the atmosphere is increasing at a relatively rapid rate as the result of fossil fuel combustion. Increases in photosynthesis as the result of the hothouse effect may in turn reduce the carbon dioxide content of the atmosphere, leading to global cooling.

  7. Repetitive sit-to-stand training with the step-foot position on the non-paretic side, and its effects on the balance and foot pressure of chronic stroke subjects

    Kim, Kyung; Kim, Young Mi; Kang, Dong Yeon

    2015-01-01

    [Purpose] This study aimed to improve the asymmetrical weight-bearing ratio by applying repetitive sit-to-stand training methods that feature a step-foot position to the paretic-side foot of hemiplegic patients; it sought also to provide the information needed to apply weight-bearing and balance training to hemiplegic patients. [Subjects and Methods] The subjects were divided into two groups: a spontaneous group and a step group. They all performed repetitive sit-to-stand training five times ...

  8. Conclusion: The balanced company

    Scheuer, John Damm; Jensen, Inger

    2013-01-01

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

  9. Balancing Trust and Control

    Jagd, Søren

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

  10. Mass balance myths

    In the event of an oil spill at sea, remediation technologies rely on oil spill monitoring and mass balance calculations. The types of oil spills that require knowledge of mass-balance include weathering studies, dispersant-effectiveness testing, measurement of response effectiveness and damage assessment. Non-destructive and non-interfering measuring methods are needed to find components of the mass balance equation such as temporal and spatial distribution of the oil thickness, and the temporal and spatial distribution of oil concentration in the sub-surface plume. The main challenge is the variation in the size scale of laboratory and open ocean measurements. Most large scale oil-spill experiments do not have scientific credibility because there are few situations in which all the oil in the system is accounted for. While some components are accurately accounted for, others ignore mass balance, or the range of measurements is not sufficient to allow for computation of mass balance. 48 refs

  11. Synchrotron radiation - Applications in the earth sciences

    Bassett, W. A.; Brown, G. E., Jr.

    Synchrotron-radiation sources and their characteristics are overviewed along with recent synchrotron-based research on earth materials and future earth-science applications utilizing the next generation of synchrotron-radiation sources presently under construction. Focus is placed on X-ray scattering studies of earth materials (crystalline and noncrystalline) under ambient conditions, diffraction studies of earth materials at high pressures and/or temperatures, spectroscopic studies, primarily X-ray absorption spectroscopy, and spatially resolved X-ray fluorescence studies of compositional variations in earth materials. It is noted that other synchrotron-based methods, such as X-ray tomography and topography may become important in characterizing earth materials, while soft X-ray/vacuum ultraviolet radiation from synchrotron sources can be applied to problems involving the structural environments of low-atomic-number elements and the characterization of surface reactions of minerals with liquids and gases.

  12. Early Earth differentiation [rapid communication

    Walter, Michael J.; Trønnes, Reidar G.

    2004-09-01

    The birth and infancy of Earth was a time of profound differentiation involving massive internal reorganization into core, mantle and proto-crust, all within a few hundred million years of solar system formation ( t0). Physical and isotopic evidence indicate that the formation of iron-rich cores generally occurred very early in planetesimals, the building blocks of proto-Earth, within about 3 million years of t0. The final stages of terrestrial planetary accretion involved violent and tremendously energetic giant impacts among core-segregated Mercury- to Mars-sized objects and planetary embryos. As a consequence of impact heating, the early Earth was at times partially or wholly molten, increasing the likelihood for high-pressure and high-temperature equilibration among core- and mantle-forming materials. The Earth's silicate mantle harmoniously possesses abundance levels of the siderophile elements Ni and Co that can be reconciled by equilibration between iron alloy and silicate at conditions comparable to those expected for a deep magma ocean. Solidification of a deep magma ocean possibly involved crystal-melt segregation at high pressures, but subsequent convective stirring of the mantle could have largely erased nascent layering. However, primitive upper mantle rocks apparently have some nonchondritic major and trace element refractory lithophile element ratios that can be plausibly linked to early mantle differentiation of ultra-high-pressure mantle phases. The geochemical effects of crystal fractionation in a deep magma ocean are partly constrained by high-pressure experimentation. Comparison between compositional models for the primitive convecting mantle and bulk silicate Earth generally allows, and possibly favors, 10-15% total fractionation of a deep mantle assemblage comprised predominantly of Mg-perovskite and with minor but geochemically important amounts of Ca-perovskite and ferropericlase. Long-term isolation of such a crystal pile is generally

  13. Models of the Earth's Core.

    Stevenson, D J

    1981-11-01

    Combined inferences from seismology, high-pressure experiment and theory, geomagnetism, fluid dynamics, and current views of terrestrial planetary evolution lead to models of the earth's core with the following properties. Core formation was contemporaneous with earth accretion; the core is not in chemical equilibrium with the mantle; the outer core is a fluid iron alloy containing significant quantities of lighter elements and is probably almost adiabatic and compositionally uniform; the more iron-rich inner solid core is a consequence of partial freezing of the outer core, and the energy release from this process sustains the earth's magnetic field; and the thermodynamic properties of the core are well constrained by the application of liquid-state theory to seismic and laboratory data. PMID:17839632

  14. Thermodynamics of the Earth

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

  15. Active balance system and vibration balanced machine

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  16. Rare Earth Market Review

    2008-01-01

    @@ Oversupply of rare earths led to the significant price drop of rare earth mineral products and separated products in Chinese domestic market. To stabilize the price, prevent waste of resources, further improve regulation capability on domestic rare earth market and rare earth price and maintain sustaining and healthy development of rare earth industry, partial rare earth producers in Baotou and Jiangxi province projected to cease the production for one month.

  17. Load Balancing Scientific Applications

    Pearce, Olga Tkachyshyn [Texas A & M Univ., College Station, TX (United States)

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  18. Energy balance measurement

    Dhurandhar, N V; Schoeller, D; Brown, A W;

    2015-01-01

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

  19. Rotating Balances Used for Fluid Pump Testing

    Skelley, Stephen; Mulder, Andrew

    2014-01-01

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

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

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

  1. Keeping Your Balance

    ... or problems with balance. Sometimes your doctor or physical therapist can reposition the crystals in your ear and ... Adherence Calcium/Vitamin D Nutrition Overall Health Fractures/Fall Prevention Exercise/Safe Movement Safe Movement & Exercise Videos ...

  2. National Energy Balance - 1984

    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.)

  3. National Energy Balance - 1985

    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.)

  4. National Energy Balance-1987

    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.)

  5. Detailed balance and entanglement

    We study a connection between quantum detailed balance, which is a concept of importance in statistical mechanics, and entanglement. We also explore how this connection fits into thermofield dynamics. (paper)

  6. Balance Disorders (For Parents)

    ... usually used on infants and young children. electronystagmogram (ENG). To assess balance, electrodes are placed around the ... videonystagmography (VNG). This test is similar to an ENG, only the child has to focus on the ...

  7. Balance costs for windpower

    Skaflestad, Stig

    2009-01-01

    Wind power scheduling is subject to high forecast uncertainty compared to the dominant Norwegian energy source, hydro power. The regulating market, also known as the balance market, is a market solution for optimal operation of the Nordic power system, putting a price on schedule deviations. Schedules, or production/consumption plans, are collected daily, 12 hours prior to delivery by the system operator Statnett. Wind power is especially vulnerable to balance costs due to the relatively high...

  8. Selectively Balancing Unit Vectors

    Blokhuis, Aart; Chen, Hao

    2016-01-01

    A set $U$ of unit vectors is selectively balancing if one can find two disjoint subsets $U^+$ and $U^-$, not both empty, such that the Euclidean distance between the sum of $U^+$ and the sum of $U^-$ is smaller than $1$. We prove that, to guarantee a selectively balancing set, $n \\log n$ unit vectors suffice for sufficiently large $n$, but $\\tfrac{1}{23} n \\log n$ unit vectors won't be enough for infinitely many $n$.

  9. Greenland Ice Sheet Mass Balance

    Reeh, N.

    1984-01-01

    Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

  10. Balances instruments, manufacturers, history

    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...

  11. Blood pressure

    ... the walls of the arteries is called blood pressure. Blood pressure is measured both as the heart contracts, which ... as it relaxes, which is called diastole. Normal blood pressure is considered to be a systolic blood pressure ...

  12. Development of the NTF-117S Semi-Span Balance

    Lynn, Keith C.

    2010-01-01

    A new high-capacity semi-span force and moment balance has recently been developed for use at the National Transonic Facility at the NASA Langley Research Center. This new semi-span balance provides the NTF a new measurement capability that will support testing of semi-span test models at transonic high-lift testing regimes. Future testing utilizing this new balance capability will include active circulation control and propulsion simulation testing of semi-span transonic wing models. The NTF has recently implemented a new highpressure air delivery station that will provide both high and low mass flow pressure lines that are routed out to the semi-span models via a set high/low pressure bellows that are indirectly linked to the metric end of the NTF-117S balance. A new check-load stand is currently being developed to provide the NTF with an in-house capability that will allow for performing check-loads on the NTF-117S balance in order to determine the pressure tare affects on the overall performance of the balance. An experimental design is being developed that will allow for experimentally assessing the static pressure tare affects on the balance performance.

  13. Near Earth Objects

    Wolff, Stefan

    2006-01-01

    , Near Earth Objects: Asteroids and comets following paths that bring them near the Earth. NEOs have collided with the Earth since its formation, some causing local devastation, some causing global climate changes, yet the threat from a collision with a near Earth object has only recently been recognised...

  14. Why Earth Science?

    Smith, Michael J.

    2004-01-01

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

  15. Rare Earth Resolution

    Mei Xinyu

    2012-01-01

    BEFORE the early 1970s, China had no rare earth exports, and the world rare earth market was dominated by the United States, Europe and Japan. In the 1970s, China began to enter the world rare earth market and its share has picked up sharply in the following decades. Today, having the monopoly over global rare earth production, China must improve the benefits from rare earth production, not only from producing individual rare earth products, but also from mastering the intensive processing of rare earth products.

  16. Watt and joule balances

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

  17. EarthLabs - Investigating Hurricanes: Earth's Meteorological Monsters

    McDaris, J. R.; Dahlman, L.; Barstow, D.

    2007-12-01

    which students investigate the different interactions involved in hurricane generation, steering, and intensification. Students analyze a variety of visualization resources looking for patterns in occurrence and to develop an understanding of hurricane structure. They download archived data about past hurricanes and produce temporal and spatial plots to discover patterns in hurricane life cycles. They investigate the relationship between hurricane wind speed and factors such as barometric pressure and sea surface temperature by conducting spreadsheet analyses on archived data. They also conduct hands-on laboratory experiments in order to understand the physical processes that underpin energy transfer in convection, condensation, and latent heat. These activities highlight Earth science as a vital, rich, invigorating course, employing state-of-the-art technologies and in-depth labs with high relevance for our daily lives and the future.

  18. Chromatographic separation and analysis of rare earths

    It is shown that difficult inorganic separation problems can be solved by a simple and inexpensive method. Examples: 1. Separation of rare earths by means of thin-layer chromatography in analyses of minerals, highest grade materials, and fission products within a fuel element; 2. Separation and quantitative determination of rare earths by means of high-pressure liquid chromatography in analyses of monazite sands, cerium composition metals, and fission products. (RB)

  19. Balanced Integrated Regulatory Oversight

    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 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)

  20. Postural balance in low back pain patients

    Maribo, Thomas; Stengaard-Pedersen, Kristian; Jensen, Lone Donbæk;

    2011-01-01

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

  1. Analyzing hydrological sustainability through water balance.

    Menció, Anna; Folch, Albert; Mas-Pla, Josep

    2010-05-01

    The objective of the Water Framework Directive (2000/60/EC) is to assist in the development of management plans that will lead to the sustainable use of water resources in all EU member states. However, defining the degree of sustainability aimed at is not a straightforward task. It requires detailed knowledge of the hydrogeological characteristics of the basin in question, its environmental needs, the amount of human water demand, and the opportunity to construct a proper water balance that describes the behavior of the hydrological system and estimates available water resources. An analysis of the water balance in the Selva basin (Girona, NE Spain) points to the importance of regional groundwater fluxes in satisfying current exploitation rates, and shows that regional scale approaches are often necessary to evaluate water availability. In addition, we discuss the pressures on water resources, and analyze potential actions, based on the water balance results, directed towards achieving sustainable water management in the basin. PMID:20229067

  2. The Earth's atmosphere its physics and dynamics

    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

  3. Automatic force balance calibration system

    Ferris, Alice T.

    1995-05-01

    A system for automatically calibrating force balances is provided. The invention uses a reference balance aligned with the balance being calibrated to provide superior accuracy while minimizing the time required to complete the calibration. The reference balance and the test balance are rigidly attached together with closely aligned moment centers. Loads placed on the system equally effect each balance, and the differences in the readings of the two balances can be used to generate the calibration matrix for the test balance. Since the accuracy of the test calibration is determined by the accuracy of the reference balance and current technology allows for reference balances to be calibrated to within +/-0.05% the entire system has an accuracy of +/-0.2%. The entire apparatus is relatively small and can be mounted on a movable base for easy transport between test locations. The system can also accept a wide variety of reference balances, thus allowing calibration under diverse load and size requirements.

  4. Power balance in highly loaded fluorescent lamps

    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.

  5. The cryogenic balance design and balance calibration methods

    Ewald, B.; Polanski, L.; Graewe, E.

    1992-07-01

    The current status of a program aimed at the development of a cryogenic balance for the European Transonic Wind Tunnel is reviewed. In particular, attention is given to the cryogenic balance design philosophy, mechanical balance design, reliability and accuracy, cryogenic balance calibration concept, and the concept of an automatic calibration machine. It is shown that the use of the automatic calibration machine will improve the accuracy of calibration while reducing the man power and time required for balance calibration.

  6. Finding Your Balance

    (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

  7. Getting the balance right

    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.)

  8. Aplikace Balanced Scorecard

    Jaroměřská, Martina

    2015-01-01

    This master's thesis deals with application of the Balanced Scorecard method to Němcova selská mlékárna Radonice, spol. s.r.o. The goal is to analyse the strategic position of the company and propose a new company strategy. Further, the strategic goals defined by the strategy are converted to a strategic map to clearly show causality relationships between the goals of the four perspectives of the Balanced Scoreboard method. The strategic goals are assigned measures and target values and initi...

  9. A balanced team generating model

    van de Water, Tara; van de Water, Henny; Bukman, Cock

    2007-01-01

    This paper introduces a general team balancing model. It first summarizes existing balancing methods. It is shown that for these methods it is difficult to meet all the conditions posed by Belbin on balanced teams. This mainly is caused by the complexity of the balancing problem. A mathematical mode

  10. The Lifeworld Earth and a Modelled Earth

    Juuti, Kalle

    2014-01-01

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

  11. Thermodynamics of the Earth

    Stacey, Frank D.

    2010-04-01

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

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

    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.

  13. Toward Balance in Translation.

    Costello, Nancy A.

    A study compared translations of biblical passages into different languages in Papua New Guinea. The study looked for evidence of balance between literal and free interpretation in translation style in the gospel of Mark, which is narrative and didactic material, in 12 languages, and the mainly hortatory genre in translations of 4 epistles:…

  14. National energy balance - 1977

    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.)

  15. Yin-Yang Balancing

    Li, Peter Ping

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

  16. National energy balance - 1978

    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.)

  17. National Energy Balance - 1986

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

  18. National Energy Balance - 1981

    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.)

  19. Lives in the Balance.

    Our Children, 1997

    1997-01-01

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

  20. Regulation of Energy Balance.

    Bray, George A.

    1985-01-01

    Explains relationships between energy intake and expenditure focusing on the cellular, chemical and neural mechanisms involved in regulation of energy balance. Information is referenced specifically to conditions of obesity. (Physicians may earn continuing education credit by completing an appended test). (ML)

  1. Earth's changeable atmosphere

    2016-06-01

    Billions of years ago, high atmospheric greenhouse gas concentrations were vital to life's tenuous foothold on Earth. Despite new constraints, the composition and evolution of Earth's early atmosphere remains hazy.

  2. EarthKAM

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

  3. 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...

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

    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.

  5. Numerical Simulation on Piston Buffering Characteristics of Pressure-balanced Underwater Torpedo Launch System%液压平衡式水下鱼雷发射系统活塞缓冲特性数值仿真

    张孝芳; 胡坤; 由文立

    2011-01-01

    For researching the shock vibration resulted from the water cylinder piston buffering of the underwater torpedo launch system, computational fluid dynamics ( CFD) simulation is conducted to study the piston buffering characteristics. One-dimensional and CFD methods are combined in the simulation.The thermodynamic models of air bottle and cylinder, and the kinetic model of piston and weapon are described by using ordinary differential equations ( ODE ) , and they are solved by using four-order RungeKutta method. The seawater flows in cylinder, launch chamber and launch tube are solved by using CFD method. The applied force and velocity of the torpedo are used as coupling variables to account for the interaction between fluid and solids. The simulation results show that, at the end of the launch process, the pressure surges in piston buffering mechanism will generate shocks to submarine structure. To reduce the shock vibration and noise of underwater torpedo launch, the buffering mechanism should be redesigned optimally.%为研究水下鱼雷发射系统水缸活塞缓冲阶段对系统造成的冲击振动影响,采用计算流体力学(CFD)仿真对其缓冲机构特性进行研究.仿真中采用一维仿真与CFD仿真相结合的方法.气瓶与气缸热力学模型、活塞及鱼雷动力学模型均用一维常微分方程(ODE)描述,采用四阶龙格库塔法求解;包括水缸、发射水舱和发射管的整个海水区域的流体流动采用CFD方法求解.一维模型和流体计算模型之间用活塞与鱼雷的受力和运动速度作为中间变量相联系,从而实现流体与固体之间的耦合.仿真结果表明,发射结束时缓冲座内海水瞬时压力过高会对潜艇结构造成较大冲击,为降低鱼雷发射冲击振动与噪声必须对活塞缓冲机构进行优化.

  6. Setting the Pressure at Which to Conduct a Distillation.

    Barduhn, Allen J.

    1984-01-01

    Discusses how pressure setting is determined for distillation columns, examining factors which must be considered when optimizing design for economical balance. Also discusses the basics of heat exchangers and cites a common problem with pressure differences. (JM)

  7. NASA ESTO: Preparing the Future of Earth Science Observation Technology

    Mlynczak, M. G.; Johnson, D. G.; Hogue, H. H.

    2007-12-01

    NASA's Earth-Sun System Technology Office (ESTO) is investing in passive remote sensing technologies that will provide revolutionary advances in our knowledge of the Earth system. We will focus specifically on two Instrument Incubator Program (IIP) projects, the Far-Infrared Spectroscopy of the Troposphere (FIRST) instrument already developed and the In-situ Net Flux within the Atmosphere of the Earth (INFLAME) instruments presently in development. Both of these sensors provide measurements of the Earth's radiation balance presently not available in any other sensors. ESTO is also investing in detector technologies for future Earth science missions through the Far-Infrared Detector Technology Advancement Partnership (FIDTAP), a joint effort concurrently supported by NASA Langley and DRS Technologies, Inc. These sensors and technologies will position NASA to implement missions spelled out in the recent National Research Council's Decadal Survey for Earth Sciences.

  8. Using balance program for energy balance analysis

    Belong with development of the economy, the energy consumption will be increased very high in the future. Vietnam has a broad range of mineral resources. There is considerable energy potential on form of coal, oil and gas, hydropower and fuel wood, Recently, Vietnam is an exporter of energy. But in next two decades, the energy sources will be enough to meet requirement? The model BALANCE was used to solve energy planning problem. The objective of this model is analyzing energy system and built an energy development strategy in long term. After using model, the results are: total coal consumption will be 17.440 Mtoe in 2020 and 32 Mtoe in 2030. the biggest coal consumer is electricity sector. Total oil production consumption will be more than 30 Mtoe in 2020 and more than 50 Mtoe in 2030. If we have 4 refinery factories from now to 2030, total oil products import will be 11 Mtoe in 2020 and 25 Mtoe in 2030. The amount of gas supply in 2030 will be 20 billions m3 (18 Mtoe). Vietnam needs to import 8.3 Mtoe more, Vietnam will become an energy importer in next 15 years. In previous years, the economy of Vietnam was mainly based on agricultural production. But Vietnam is moving rapidly from an agricultural to an industrial economy. Belong with the development of the economy, energy consumption increases very fast. So which energy sources should be used first and when it will be use...are questions need to be answered. Vietnam has a broad range of mineral resources. There is considerable energy potential on form of coal, oil and gas, hydropower and fuel wood. Recently, Vietnam is energy exporter, but in near future Vietnam has enough energy to meet demand or we need to import from outside? It should be studied carefully to answer. (author)

  9. Earth - Pacific Ocean

    1990-01-01

    This color image of the Earth was obtained by the Galileo spacecraft early Dec. 12, 1990, when the spacecraft was about 1.6 million miles from the Earth. The color composite used images taken through the red, green and violet filters. The Pacific Ocean covers virtually all of the visible disk of the Earth in this picture. The glint of the Sun reflected from smooth water is near the center. This is a frame of the Galileo Earth spin movie, a 500-frame time-lapse motion picture showing a 25-hour period of Earths rotation and atmospheric dynamics.

  10. Energy balances 2001

    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)

  11. Modeling the Surface Temperature of Earth-like Planets

    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 (ɛ ≲ 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≲ {Ω }/{{{Ω }}\\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.

  12. France's energy balances

    Several terminological definitions of words and concepts used for the establishment of France's energy balance (i.e. the supply and utilization of energy) are presented, taken from the Energy dictionary, published in 1992 by the world Energy Council: primary, secondary, final and useful energy. Statistics concerning energy production, importation and exportation, consumption, and costs are discussed, showing the market share evolution of the different energy types; the France's energy independence ratio has increased from 22% in 1973 to 51% in 1995

  13. An ideal balance?

    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.

  14. Balance-bot

    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...

  15. Ballet Balance Strategies

    Pedersen, Camilla; Erleben, Kenny; Sporring, Jon

    2006-01-01

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

  16. National energy balance - 1976

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

  17. Finance and Balanced Growth

    Trew, Alex

    2010-01-01

    We study the relationships between various concepts of financial development and balanced economic growth. A model of endogenous growth that incorporates roles for both financial efficiency and access to financial services permits a better understanding of the relationship between the size of the financial sector (value added) and growth. Higher financial value added results from some, but not all, kinds of finance-driven growth. If greater access rather than greater efficiency generates high...

  18. In the balance

    Kluth, Michael Friederich; Pilegaard, Jess

    The present paper seeks to make sense of recent EU naval capability changes by applying neo-realist theory on the EU as an international actor in the global balance of power. The paper compares three different strands of Neo-realist theory by deducting key predictions about the expected defense...... strategy aimed at bolstering the autonomy and international influence of the Union, vis-à-vis other major powers, including the United States....

  19. Thinking About Competitive Balance

    Allen R. Sanderson; John J. Siegfried

    2003-01-01

    Simon Rottenberg long ago noted that the nature of sports is such that competitors must be of approximately equal ability if any are to be financially successful. In recent years, sports commentators and fans, Major League Baseball itself, and even some economists have expressed growing concern about the widening disparities among team expenditures and the growing concentrations of postseason contenders and championships. In this article we compare different concepts of competitive balance, r...

  20. Simple Cell Balance Circuit

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

    2012-01-01

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

  1. Gait and balance disorders.

    Masdeu, Joseph C

    2016-01-01

    This chapter focuses on one of the most common types of neurologic disorders: altered walking. Walking impairment often reflects disease of the neurologic structures mediating gait, balance or, most often, both. These structures are distributed along the neuraxis. For this reason, this chapter is introduced by a brief description of the neurobiologic underpinning of walking, stressing information that is critical for imaging, namely, the anatomic representation of gait and balance mechanisms. This background is essential not only in order to direct the relevant imaging tools to the regions more likely to be affected but also to interpret correctly imaging findings that may not be related to the walking deficit object of clinical study. The chapter closes with a discussion on how to image some of the most frequent etiologies causing gait or balance impairment. However, it focuses on syndromes not already discussed in other chapters of this volume, such as Parkinson's disease and other movement disorders, already discussed in Chapter 48, or cerebellar ataxia, in Chapter 23, in the previous volume. As regards vascular disease, the spastic hemiplegia most characteristic of brain disease needs little discussion, while the less well-understood effects of microvascular disease are extensively reviewed here, together with the imaging approach. PMID:27430451

  2. Geochemistry: Hydrogen and oxygen in the deep Earth

    Yagi, Takehiko

    2016-06-01

    The finding that an unusual iron oxide forms at extremely high pressures suggests that hydrogen and oxygen -- two elements that strongly influence Earth's evolution -- are generated in the mantle. See Letter p.241

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

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

    2012-12-01

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

  4. Effects of insoles contact on static balance

    Shin, Ju Yong; Ryu, Young Uk; Yi, Chae Woo

    2016-01-01

    [Purpose] This study examined the effect of the degree of the contact area between the insoles and soles on static balance. [Subjects and Methods] Thirteen healthy male and female adults voluntarily participated. All of the subjects wore three different types of insoles (no orthotic insole, partial contact, full contact) in the present experiment. The subjects were instructed to place both feet parallel to each other and maintain static balance for 30 seconds. Center of pressure parameters (range, total distance, and mean velocity) were analyzed. [Results] The results show that the anteroposterior range and mediolateral (ML) total distance and velocity decreased when orthotic insoles with partial contact or full contact were used in comparison to when a flat insole (no orthotic insole) was used. Also, the ML range and total distance were lower with full contact than in the other two conditions. These results indicate that static balance improves as the degree of contact between the soles and insoles increases. [Conclusion] The results of this study suggests that using insoles with increased sole contact area would improve static balance ability.

  5. Balanced skills among nascent entrepreneurs

    Stuetzer, Michael; Obschonka, Martin; Schmitt-Rodermund, Eva

    2012-01-01

    This paper examines the effects and origins of balanced skills among nascent entrepreneurs. In a first step we apply Lazear’s jack-of-all-trades theory to investigate performance effects of a balanced skill set. Second, we investigate potential sources of balanced skills, thereby testing the investment hypothesis against the endowment hypothesis. Analyzing data on high-potential nascent projects, we find support for the notion that balanced skills are important for making progress in the vent...

  6. Wind-Tunnel Balance Characterization for Hypersonic Research Applications

    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.

  7. Digital Earth – A sustainable Earth

    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

  8. Balancing innovation and evidence.

    Pilcher, Jobeth W

    2015-01-01

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

  9. Watt and joule balances

    Robinson, Ian A.

    2014-04-01

    The time is fast approaching when the SI unit of mass will cease to be based on a single material artefact and will instead be based upon the defined value of a fundamental constant—the Planck constant—h . This change requires that techniques exist both to determine the appropriate value to be assigned to the constant, and to measure mass in terms of the redefined unit. It is important to ensure that these techniques are accurate and reliable to allow full advantage to be taken of the stability and universality provided by the new definition and to guarantee the continuity of the world's mass measurements, which can affect the measurement of many other quantities such as energy and force. Up to now, efforts to provide the basis for such a redefinition of the kilogram were mainly concerned with resolving the discrepancies between individual implementations of the two principal techniques: the x-ray crystal density (XRCD) method [1] and the watt and joule balance methods which are the subject of this special issue. The first three papers report results from the NRC and NIST watt balance groups and the NIM joule balance group. The result from the NRC (formerly the NPL Mk II) watt balance is the first to be reported with a relative standard uncertainty below 2 × 10-8 and the NIST result has a relative standard uncertainty below 5 × 10-8. Both results are shown in figure 1 along with some previous results; the result from the NIM group is not shown on the plot but has a relative uncertainty of 8.9 × 10-6 and is consistent with all the results shown. The Consultative Committee for Mass and Related Quantities (CCM) in its meeting in 2013 produced a resolution [2] which set out the requirements for the number, type and quality of results intended to support the redefinition of the kilogram and required that there should be agreement between them. These results from NRC, NIST and the IAC may be considered to meet these requirements and are likely to be widely debated

  10. Die Balance der Verantwortung

    Abt, Andreas

    2006-01-01

    Die Balance der Verantwortung Ein Modell der Pädagogik zur Entwicklung von Verantwortungsfähigkeit Diese Arbeit befasst sich mit dem Begriff der Verantwortung, der in der Gesellschaft häufig verwendet wird und dort in der Regel positiv belegt ist. Neben der Vorstellung einer modernen Begriffsinterpretation lege ich die Bedeutung des Themas Verantwortung für die menschliche Existenz und damit auch für die Themen Erziehung und Bildung dar. Ausgehend von der Frage, warum Menschen in der d...

  11. Entropy of balance - some recent results

    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 α 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.

  12. Earth - India and Australia

    1990-01-01

    This color image of the Earth was obtained by the Galileo spacecraft on Dec. 11, 1990, when the spacecraft was about 1.5 million miles from the Earth. The color composite used images taken through the red, green and violet filters. India is near the top of the picture, and Australia is to the right of center. The white, sunlit continent of Antarctica is below. Picturesque weather fronts are visible in the South Pacific, lower right. This is a frame of the Galileo Earth spin movie, a 500-frame time-lapse motion picture showing a 25-hour period of Earth's rotation and atmospheric dynamics.

  13. Capturing near-Earth asteroids around Earth

    Hasnain, Zaki; Lamb, Christopher A.; Ross, Shane D.

    2012-12-01

    The list of detected near-Earth asteroids (NEAs) is constantly growing. NEAs are likely targets for resources to support space industrialization, as they may be the least expensive source of certain needed raw materials. The limited supply of precious metals and semiconducting elements on Earth may be supplemented or even replaced by the reserves floating in the form of asteroids around the solar system. Precious metals make up a significant fraction NEAs by mass, and even one metallic asteroid of ˜1km size and fair enrichment in platinum-group metals would contain twice the tonnage of such metals already harvested on Earth. There are ˜1000 NEAs with a diameter of greater than 1 km. Capturing these asteroids around the Earth would expand the mining industry into an entirely new dimension. Having such resources within easy reach in Earth's orbit could provide an off-world environmentally friendly remedy for impending terrestrial shortages, especially given the need for raw materials in developing nations. In this paper, we develop and implement a conceptually simple algorithm to determine trajectory characteristics necessary to move NEAs into capture orbits around the Earth. Altered trajectories of asteroids are calculated using an ephemeris model. Only asteroids of eccentricity less than 0.1 have been studied and the model is restricted to the ecliptic plane for simplicity. We constrain the time of retrieval to be 10 years or less, based on considerations of the time to return on investment. For the heliocentric phase, constant acceleration is assumed. The acceleration required for transporting these asteroids from their undisturbed orbits to the sphere of influence of the Earth is the primary output, along with the impulse or acceleration necessary to effect capture to a bound orbit once the Earth's sphere of influence is reached. The initial guess for the constant acceleration is provided by a new estimation method, similar in spirit to Edelbaum's. Based on the

  14. Balance of multi-wavelets

    MAO Yibo

    2003-01-01

    The discrete scalar data need prefiltering when transformed by discrete multi-wavelet, but prefiltering will make some properties of multi-wavelets lost. Balanced multi-wavelets can avoid prefiltering. The sufficient and necessary condition of p-order balance for multi-wavelets in time domain, the interrelation between balance order and approximation order and the sampling property of balanced multi-wavelets are investigated. The algorithms of 1-0rder and 2-0rder balancing for multi-wavelets are obtained. The two algorithms both preserve the orthogonal relation between multi-scaling function and multi-wavelets. More importantly, balancing operation doesn't increase the length of filters, which suggests that a relatively short balanced multiwavelet can be constructed from an existing unbalanced multi-wavelet as short as possible.

  15. Modeling the surface temperature of Earth-like planets

    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...

  16. Negative leave balances

    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...

  17. Negative leave balances

    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...

  18. Pressure Sores

    ... pressure sore include the following: Thick yellow or green pus A bad smell from the sore Redness ... spots, color changes or other signs of sores. Pay special attention to the pressure points where sores ...

  19. Pressure ulcers.

    O'Byrne, Deborah

    2016-04-13

    My nursing experience is in acute care. Acute medical nurses are well placed to assess skin integrity, identify patients at risk of pressure ulcer development, and commence appropriate interventions to prevent or treat pressure ulcers. PMID:27073966

  20. Peer Pressure

    ... How Can I Help a Friend Who Cuts? Peer Pressure KidsHealth > For Teens > Peer Pressure Print A A A Text Size What's in ... She'd just had a big dose of peer pressure. Who Are Your Peers? When you were a ...

  1. GRACE卫星太阳光照与地球反照辐射压力模型的效果分析%Analysis of Solar and Earth Albedo Radiation Pressure Models for GRACE on Their Performance

    陈润静; 彭碧波; 高凡; 范城城

    2013-01-01

    应用GRACE产品说明书中的宏模参数,将模型计算结果与加速度计在径向与法向的非保守力实测值进行比较,结果显示两者之间具有较好的吻合性.通过改变卫星侧面的镜面反射以及漫反射系数,观察模型计算结果与实测数据之间的吻合度变化情况,发现宏模给出的反射系数可能较真实情况偏大.直接使用宏模参数并将其应用于动力学定轨试验,结果表明,本文采用的光照辐射压力模型满足动力学定轨的精度需要,且较传统Knocke地球反照辐射模型在效果上有了较大的改进.%Accurate model of radiation pressure is essential in determining the variations of the thermospheric density and the winds from accelerometer aboard the GRACE. In order to analyse the radiation model we employed in the paper, modeled radiation acceleration is compared with observed value from accelerometer in radial and cross-track components, which shows that they coincide with each other well. By changing the specular and diffusive reflectivity coefficients in Starboard panel, we observe the change in agreement between modeled acceleration and actual measurement, finding that the reflectivity coefficients in macro-model may be overestimated. By implementing the radiation pressure model inorbit determination with raw macro-model coefficients, the result indicates that the model meets the precision requirement of dynamical orbit determination, making considerable improvement in performance when compared with traditional Knocke model.

  2. Lunar origin from impact on the Earth

    Stevenson, D. J.

    1984-01-01

    All theories of lunar origin involve events or processes which seemingly have low efficiencies or low probabilities or both. An impact-triggered fission lunar origin is presented. If the impact ejecta (a mixture of target and projectile) leave the impact site ballistically and are subsequently acted upon only by the gravity field of a spherical Earth, then the ejecta either reimpacts the Earth or escapes on a hyperbolic trajectory. Hence the need for a second burn. Three possible resolutions are considered: pressure gradient acceleration, non-central gravity, and viscous spreading.

  3. Temperature response of Earth to the annual solar irradiance cycle

    We directly determine the sensitivity and time delay of Earth's surface temperature response to annual solar irradiance variations from 60 years of data. A two-layer energy balance model is developed to interpret the results. Explaining both the resulting low sensitivity and time delay of 1-2 months requires negative feedback

  4. Pressurized SOFC systems for stationary applications

    Leucht, Florian; Seidler, Stephanie; Henke, Moritz; Bessler, Wolfgang G.; Kallo, Josef; Friedrich, K. Andreas

    2009-01-01

    Solid oxide fuel cell (SOFC) systems show very high electrical efficiencies even at small sizes. DLR applies a multidisciplinary and multiscale approach to designing and optimizing pressurized SOFC systems for hybrid power plants. A large Simulink model library was developed featuring balance-of-plant components as well as fuel cell models. Recently a pressurized cell test rig was taken into operation.

  5. Earth System Science Project

    Rutherford, Sandra; Coffman, Margaret

    2004-01-01

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

  6. Evolution and Earth's Entropy

    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.

  7. The Earth Charter

    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…

  8. Kin Selection - Mutation Balance

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

    2011-01-01

    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin...... selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...... lineages are transient and do not invade. Instead, cheating lineages are eliminated by kin selection but are constantly reintroduced by mutation, maintaining a stable equilibrium frequency of cheaters. The presence of cheaters at equilibrium creates a "cheater load" that selects for mechanisms of cheater...

  9. Energy balance climate models

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

    1981-01-01

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

  10. A Balancing Act?

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

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

  11. The balanced mind

    Allen, Micah; Smallwood, Jonathan; Christensen, Joanna;

    2013-01-01

    Self-generated thoughts unrelated to ongoing activities, also known as "mind-wandering," make up a substantial portion of our daily lives. Reports of such task-unrelated thoughts (TUTs) predict both poor performance on demanding cognitive tasks and blood-oxygen-level-dependent (BOLD) activity in......-wandering on response inhibition and monitoring, using the Error Awareness Task (EAT). We expected to replicate links between TUT and reduced inhibition, and explored whether variance in TUT would predict improved error monitoring, reflecting a capacity to balance between internal and external cognition. By...... during error awareness, supporting a link between monitoring and TUTs. Altogether our results suggest that although TUT is detrimental to task performance, fluctuations in attention between self-generated and external task-related thought is a characteristic of individuals with greater metacognitive...

  12. Balancing Trust and Control

    Jagd, Søren

    2010-01-01

    The purpose of this paper is to show that conceptualizing trust and control as interactively related processes, as opposed to more static conceptualizations of the two concepts and the relations between them, adds importantly towards understanding the challenges involved in balancing of trust and...... control in organizations. The paper examines recent literature on the conceptualization of the relation between trust and control in and between organizations. The literature review shows that trust and control has been conceptualized as either substituting or complementing each other. Further, it is...... found that the complementary/substitution debate calls for an explicit conceptualization of the relation between trust and control as an interactive process, in contrast to earlier conceptualizations of trust and control as two relatively static and isolated concepts. While the static perspective on...

  13. Gravity in the balance

    Although Einstein's theories of relativity showed that Newton's ideas about gravity, space and time were approximations, general relativity still predicts that the gravitational force between two point objects will obey an inverse-square law in the limit of low velocities and weak gravitational fields. Of course, we know that general relativity is probably an approximation as well and that some grander theory - possibly involving extra dimensions of space - will unify gravity with the other fundamental forces. Many of these theories predict that the inverse-square law will break down at distances that are becoming accessible to (relatively small) experiments with torsion balances. As researchers from the Eoet-Wash group in Seattle report 'Testing the gravitational inverse-square law', the inverse-square law has survived all tests so far, but its days are surely numbered. (U.K.)

  14. A Balancing Act?

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

    efficiency moderates the effect of market attention on new product development. The paper therefore concludes that product innovation and energy efficiency is a balancing act, focusing on one will have detrimental effects on the other! These findings point to the conclusion that researchers and practitioners....... Logistic regression analysis demonstrates that while market attention is important for new product development, green aspects of innovation and efficiency considerations for innovation are important for the energy efficiency of the production companies. Combining these models highlights that energy...... in innovation management have to take the specificities and interactions of different types of eco-innovation more carefully in consideration than so far and to formulate new managerial practices combining energy efficiency and product innovation....

  15. Earth Science Informatics - Overview

    Ramapriyan, H. K.

    2015-01-01

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

  16. Well balanced finite volume methods for nearly hydrostatic flows

    In numerical approximations of nearly hydrostatic flows, a proper representation of the dominant hydrostatic balance is of crucial importance: unbalanced truncation errors can induce unacceptable spurious motions, e.g., in dynamical cores of models for numerical weather prediction (NWP) in particular near steep topography. In this paper we develop a new strategy for the construction of discretizations that are 'well-balanced' with respect to dominant hydrostatics. The classical idea of formulating the momentum balance in terms of deviations of pressure from a balanced background distribution is realized here through local, time dependent hydrostatic reconstructions. Balanced discretizations of the pressure gradient and of the gravitation source term are achieved through a 'discrete Archimedes' buoyancy principle'. This strategy is applied to extend an explicit standard finite volume Godunov-type scheme for compressible flows with minimal modifications. The resulting method has the following features: (i) It inherits its conservation properties from the underlying base scheme. (ii) It is exactly balanced, even on curvilinear grids, for a large class of near-hydrostatic flows. (iii) It solves the full compressible flow equations without reference to a background state that is defined for an entire vertical column of air. (iv) It is robust with respect to details of the implementation, such as the choice of slope limiting functions, or the particularities of boundary condition discretizations

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

    Cahalan, Robert F.

    2004-01-01

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

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

    Monteiro-Junior, Renato Sobral; Ferreira, Arthur Sá; Puell, Vivian Neiva; Lattari, Eduardo; Machado, Sérgio; Otero Vaghetti, César Augusto; da Silva, Elirez Bezerra

    2015-01-01

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

  19. Neural Networks Based Component Content Soft-Sensor in Countercurrent Rare-Earth Extraction

    杨辉; 谭明皓; 柴天佑

    2003-01-01

    The equilibrium model for multicomponent rare earth extraction is developed using neural networks, which combined with the material balance model could give online prediction of component content in countercurrent rare earth extraction production. Simulation experiments with industrial operation data prove the effect iveness of the hybrid soft- sensor.

  20. Variance approximation under balanced sampling

    Deville, Jean-Claude; Tillé, Yves

    2016-01-01

    A balanced sampling design has the interesting property that Horvitz–Thompson estimators of totals for a set of balancing variables are equal to the totals we want to estimate, therefore the variance of Horvitz–Thompson estimators of variables of interest are reduced in function of their correlations with the balancing variables. Since it is hard to derive an analytic expression for the joint inclusion probabilities, we derive a general approximation of variance based on a residual technique....

  1. Designing Multinational Electricity Balancing Markets

    Van der Veen, R.A.C.

    2012-01-01

    In today’s unbundled electricity markets, the balancing market is an intricate institutional arrangement that makes sure that the balance between electricity supply and demand is maintained. In the light of the development of a single electricity market in Europe, harmonization and integration of currently national balancing markets have received an increasing attention from governments, system operators, and regulators. This dissertation provides a systematic overview of the possibilities an...

  2. Psychology of the nuclear balance

    Sonntag, P.

    1981-10-01

    The balance of military forces is meant to prevent war. But it is a very precarious balance, which becomes all the more dubious when the deterrent is no longer psychologically effective: when the country attacked is deterred from striking back with nuclear weapons. A unilateral disarmament above the overkill level would be possible without endangering the balance. It would improve the climate for mutual disarmament.

  3. Radar channel balancing with commutation

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

    2014-02-01

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

  4. A volume-balance model for flow on porous media

    Malaga, Carlos; Mandujano, Francisco; Becerra, Julian

    2015-11-01

    Volume-balance models are used by petroleum engineers for simulating multiphase and multicomponent flow phenomena in porous media and the extraction process in oil reservoirs. In these models, mass conservation equations and Darcy's law are supplemented by a balance condition for the pore and fluid volumes. This provides a pressure equation suitable for simulating a compressible flow within a compressible solid matrix. Here we present an alternative interpretation of the volume-balance condition that includes the advective transport within a consolidated porous media. We obtain a modified equation for the time evolution of the pressure field. Numerical tests for phase separation under gravity are presented for multiphase three dimensional flow in heterogeneous porous media. The authors acknowledge funding from Fondo Sectorial CONACYT-SENER grant number 42536 (DGAJ-SPI-34-170412-217).

  5. People, poverty and the Earth Summit.

    Wheeler, J

    1992-01-01

    UNCED is about human beings managing their affairs so that all can achieve a reasonably good life without destroying the life-supporting environment. Currently human activities are approaching an upset of environmental balance through production of greenhouse gases, depletion of the ozone layer, and reduction of natural resources. Equity is the right to a decent life for the current human population of 5.5 billion and the future 10 billion expected within the next 50 years. A minimum use of environmental space/person is required. The Earth Summit will be a broad statement of environmental policy. Agenda 21 includes 115 action programs within 40 chapters. Separate conventions will be held on climate and biodiversity. The secretariat of UNCED has been working primarily with Agenda 21. Population issues are emphasized in Chapter 5 ("Demographic Dynamics and Sustainability") of the first section in Agenda 21 on Social and Economic Dimensions. The program areas include 1) research on the links between population, the environment, and development; 2) formulation by governments of integrated national policies on environment and development, which account for demographic trends, and promotion of population literacy; and 3) implementation of local level programs to ensure access to education and information and services in order to plan families freely and responsibly. Increases in funding for the population program are anticipated to be US $9 billion by the year 2000 and about US $7 billion/year until then. The year 2000 will bring with it a doubling of urban population in developing countries. There are challenges and opportunities to expand private sector job creation, education, clean water, and family health services. In addition to managing human settlements, there is also management of fragile ecosystems, which means relieving the pressure on these lands through urban migration or relocation to richer agricultural areas. The goal for agriculture is to triple food

  6. Balancing on a narrow ridge : biomechanics and control

    Otten, Ellen

    1999-01-01

    The balance of standing humans is usually explained by the inverted pendulum model. The subject invokes a horizontal ground-reaction force in this model and controls it by changing the location of the centre of pressure under the foot or feet. In experiments I showed that humans are able to stand on

  7. Greenland ice sheet mass balance: a review

    Khan, Shfaqat Abbas; Aschwanden, Andy; Bjørk, Anders A.;

    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...... 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...

  8. Energy Balance Models and Planetary Dynamics

    Domagal-Goldman, Shawn

    2012-01-01

    We know that planetary dynamics can have a significant affect on the climate of planets. Planetary dynamics dominate the glacial-interglacial periods on Earth, leaving a significant imprint on the geological record. They have also been demonstrated to have a driving influence on the climates of other planets in our solar system. We should therefore expect th.ere to be similar relationships on extrasolar planets. Here we describe a simple energy balance model that can predict the growth and thickness of glaciers, and their feedbacks on climate. We will also describe model changes that we have made to include planetary dynamics effects. This is the model we will use at the start of our collaboration to handle the influence of dynamics on climate.

  9. Rare earth industries: Upstream business

    Evidently, many factors contribute to the rush to invest in the unprecedented revival of rare earths. One major reason has to do with the rapidly growing world demand. The other reason relates to the attractive price of rare earths which is projected to stay strong in the coming years. This is because supply is predicted to have difficulty keeping pace with demand. Experts believe a major driver of global rare earths demand is the forecasted expansion in the green economy. Climate change is a major driver of the green economy. With climate change, there is concern that the uncontrolled emission of the greenhouse gases, especially carbon dioxide, can lead to catastrophic consequences for the world. This has been documented in countless studies and reports. Another important driver of the green economy is the growing shortfall in many resources. The world is now experiencing declines in key resources to meet a growing global demand. With more than 6 billion people now in the world and growing, the pressure exerted on global resources including energy, water and food is a major concern. Recent demand surge in China and India has dented the supply position of major world resources. The much quoted Stern Report from the UK has warned that, unless immediate steps are taken to reduce greenhouse gas emissions, it may be a costly exercise to undertake the corrections later. Since energy use, especially fossil fuels, is a major contributor to climate change, greener options are being sought. Add to that the fact that the fossil energy resources of the world are declining, the need to seek alternatives becomes even more urgent. One option is to change to renewable energy sources. These include such potentials as solar, wind and biomass. Rare earths have somehow become a critical feature of the technologies in such renewable. Another option is to improve the efficient use of energy in transport, buildings and all the other energy intensive industries. Again the technologies in

  10. Stable isotope composition of Earth's large lakes

    Jasechko, S.; Gibson, J. J.; YI, Y.; Birks, S. J.; Sharp, Z. D.

    2011-12-01

    Lakes cover about three percent of Earth's continental area. Large lakes can significantly influence lake shore and regional climates by increasing specific humidity during evaporation and by moderating air temperatures. Stable isotopes of oxygen and hydrogen can be used to quantify lake evaporation, providing a supplementary and often cost-advantageous alternative to conventional hydrologic approaches that require over lake monitoring. Further, stable isotopes in lake sediments are an established tool in paleolimnology; however, interpreting changes to a lake's past isotope composition requires a comprehensive understanding of contemporary controls. Here, δ18O and δ2H values of water in modern lakes exceeding roughly five hundred square kilometres are compiled (n > 35). Voluminous and seasonally mixed lakes - such as the North American Great Lakes - have the most homogenous stable isotope compositions, while perennially-stratified and shallow lakes show greater variability. A rudimentary stable isotope mass balance is used to assess evaporation fluxes from large lakes on Earth. The approach taken simultaneously constrains evaporation outputs for both oxygen and hydrogen stable isotopes by accounting for lake effects on the overlying atmosphere. Model development highlights important considerations such as isotopic stratification (Tanganyika), disequilibrium isotopic mass balances (Baikal), and non-steady hydrologic balances. Further, the isotope composition of Earth's continental surface water reservoir is calculated. This value - weighted to volume - is δ18O = -7.5±1.7 per mille relative to standard mean ocean water. The compiled data may be a useful tracer of continental evaporate in global atmospheric water cycle studies and could be coupled to climate models capable of incorporating oxygen-18 and deuterium tracers to improve or validate calculations of lake effects on regional water cycling.

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

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

    2010-03-01

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

  12. Earth from Above

    Parkinson, Claire L.

    Earth from Above provides an easy introduction to understanding and interpreting satellite images, using illustrative examples to instruct on the fantastically informative new global data sets. Beginning with two short chapters on visible satellite images and radiation, the book then covers six key Earth-atmosphere variables on such environmentally important topics as the Antarctic ozone hole, El Nino, deforestation, the missing carbon dilemma, and the effects of sea ice, snow cover, and volcanoes on atmospheric temperatures. A final chapter broadens the discussion to consider satellite Earth observations in general.

  13. Project Earth Science

    Holt, Geoff

    2011-01-01

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

  14. The Earth's Magnetic Interior

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

    2011-01-01

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

  15. Axions from the Earth

    The possibility of axion production in the Earth's interior due to natural radioactive decay is considered. Axions, or axion-like particles, could be created in nuclear disintegrations and deexitations of natural radionuclides present in the Earth's crust and mantle, as well as due to photon to axion conversion of the emitted gamma rays via the Primakoff effect. The estimated geo-axion production rates and fluxes on the Earth's surface are given along with the axion coupling to ordinary matter in the frame of the simple axion models as well as for axion-like particles with stronger couplings

  16. Future Satellite Gravimetry and Earth Dynamics

    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.

  17. Digital Earth reloaded - Beyond the next generation

    Ehlers, M.; Woodgate, P.; Annoni, A.; Schade, S.

    2014-02-01

    Digital replicas (or 'mirror worlds') of complex entities and systems are now routine in many fields such as aerospace engineering; archaeology; medicine; or even fashion design. The Digital Earth (DE) concept as a digital replica of the entire planet occurs in Al Gore's 1992 book Earth in the Balance and was popularized in his speech at the California Science Center in January 1998. It played a pivotal role in stimulating the development of a first generation of virtual globes, typified by Google Earth that achieved many elements of this vision. Almost 15 years after Al Gore's speech, the concept of DE needs to be re-evaluated in the light of the many scientific and technical developments in the fields of information technology, data infrastructures, citizen?s participation, and earth observation that have taken place since. This paper intends to look beyond the next generation predominantly based on the developments of fields outside the spatial sciences, where concepts, software, and hardware with strong relationships to DE are being developed without referring to this term. It also presents a number of guiding criteria for future DE developments.

  18. Paul Collier : Balancing beams

    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...

  19. Interim balance: Ecology

    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.)

  20. Balancing safety and economics

    The safety requirements of NPPs have always aimed at limiting societal risks. This risk approach initially resulted in deterministic design criteria and concepts. In the 1980s the paradigm 'safety at all costs' arose and often led to questionable backfitting measures. Conflicts between new requirements, classical design concepts and operational demands were often ignored. The design requirements for advanced reactors ensure enhanced protection against severe accidents. Still, it is questionable whether the 'no-damage-outside-the-fence' criteria can be achieved deterministically and at competitive costs. Market deregulation and utility privatisation call for a balance between safety and costs, without jeopardising basic safety concepts. An ideal approach must be risk-based and imply modern PSAs and new methods for cost-benefit and ALARA analyses, embed nuclear risks in a wider risk spectrum, but also make benefits transparent within the context of a broader life experience. Governments should define basic requirements, minimum standards and consistent comparison criteria, and strengthen operator responsibility. Internationally sufficient and binding safety requirements must be established and nuclear technology transfer handled in a responsible way, while existing plants, with their continuous backfitting investments, should receive particular attention. (orig.)

  1. Par Pond water balance

    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

  2. Balancing "we" and "me".

    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

  3. The right balance

    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...

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

    Gaol, F. L.

    2016-02-01

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

  5. Whole-Earth Decompression Dynamics

    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 rebounding. The i...

  6. High-pressure optical studies

    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

  7. Combined CFD/Population Balance Model for Gas Hydrate Particle Size Prediction in Turbulent Pipeline Flow

    Balakin, Boris V.; Hoffmann, Alex C.; Kosinski, Pawel; Istomin, Vladimir A.; Chuvilin, Evgeny M.

    2010-09-01

    A combined computational fluid dynamics/population balance model (CFD-PBM) is developed for gas hydrate particle size prediction in turbulent pipeline flow. The model is based on a one-moment population balance technique, which is coupled with flow field parameters computed using commercial CFD software. The model is calibrated with a five-moment, off-line population balance model and validated with experimental data produced in a low-pressure multiphase flow loop.

  8. Adaptive Load Balancing of Parallel Applications with Multi-Agent Reinforcement Learning on Heterogeneous Systems

    Johan Parent; Katja Verbeeck; Jan Lemeire; Ann Nowe; Kris Steenhaut; Erik Dirkx

    2004-01-01

    We report on the improvements that can be achieved by applying machine learning techniques, in particular reinforcement learning, for the dynamic load balancing of parallel applications. The applications being considered in this paper are coarse grain data intensive applications. Such applications put high pressure on the interconnect of the hardware. Synchronization and load balancing in complex, heterogeneous networks need fast, flexible, adaptive load balancing algorithms. Viewing a parall...

  9. Earth Sciences Today

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

  10. Gambling with the earth

    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).

  11. Jupiter and planet Earth

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included

  12. Observing earth from Skylab

    1975-01-01

    Skylab technology and observations of earth resources are discussed. Special attention was given to application of Skylab data to mapmaking, geology/geodesy, water resources, oceanography, meteorology, and geography/ecology.

  13. Vocabulary related to earth sciences through etymology

    DileepKumar, M.

    and roots of numerous technical terms that occur in a disparate fashion in different disciplines related to earth sciences, namely, biology, chemistry, geology?geo- physics?geography, meteorology, ocean- ography (and limnology), and physics. Where... pressure (Grede baros) and diurnal radia- tion (Grede helios, sun) respectively. Isot- ropy (Grede isos, same) is the condition when physical properties, e.g. magnetic susceptibility or elastic constants, are the same in all directions; in anisotropy...

  14. Extremophiles: Link between earth and astrobiology

    Stojanović Dejan B.; Fojkar Oliver; Drobac-Čik Aleksandra V.; Čajko Kristina O.; Dulić Tamara I.; Svirčev 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...

  15. Optimal allocation in balanced sampling

    Tillé, Yves; Favre, Anne-Catherine

    2016-01-01

    The development of new sampling methods allows the selection of large balanced samples. In this paper we propose a method for computing optimal inclusion probabilities for balanced samples. Next, we show that the optimal Neyman allocation is a particular case of this method.

  16. A balancing act for renewables

    Elliott, David

    2016-01-01

    Energy storage will play a key role in increasing the use of variable energy sources. Nonetheless, storage is not the only balancing option and the overall design of power systems will incorporate a range of flexible generation, storage and grid-balancing options of different types and scales.

  17. H∞ Balancing for Nonlinear Systems

    Scherpen, Jacquelien M.A.

    1996-01-01

    In previously obtained balancing methods for nonlinear systems a past and a future energy function are used to bring the nonlinear system in balanced form. By considering a different pair of past and future energy functions that are related to the H∞ control problem for nonlinear systems we define H

  18. When Do States Balance Power?

    Hariri, Jacob Gerner; Wivel, Anders

    2010-01-01

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

  19. NASA Earth science missions

    Neeck, Steven P.; Volz, Stephen M.

    2013-10-01

    NASA's Earth Science Division (ESD) conducts pioneering work in Earth system science, the interdisciplinary view of Earth that explores the interaction among the atmosphere, oceans, ice sheets, land surface interior, and life itself that has enabled scientists to measure global and climate changes and to inform decisions by governments, organizations, and people in the United States and around the world. The ESD makes the data collected and results generated by its space missions accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster management, agricultural yield projections, and aviation safety. Through partnerships with national and international agencies, NASA enables the application of this understanding. The ESD's Flight Program provides the spacebased observing systems and supporting ground segment infrastructure for mission operations and scientific data processing and distribution that support NASA's Earth system science research and modeling activities. The Flight Program currently has 15 operating Earth observing space missions, including the recently launched Landsat-8/Landsat Data Continuity Mission (LDCM). The ESD has 16 more missions planned for launch over the next decade. These include first and second tier missions from the 2007 Earth Science Decadal Survey, Climate Continuity missions to assure availability of key data sets needed for climate science and applications, and small-sized competitively selected orbital missions and instrument missions of opportunity utilizing rideshares that are part of the Earth Venture (EV) Program. The recently selected Cyclone Global Navigation Satellite System (CYGNSS) microsatellite constellation and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument are examples. In addition, the International Space Station (ISS) is being increasingly used to host NASA Earth observing science instruments. An overview of plans

  20. EARTH ROADS ARE EASY

    David O. Whitten (ed.)

    2000-01-01

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

  1. Fuller's earth (montmorillonite) pneumoconiosis.

    Gibbs, A R; Pooley, F D

    1994-01-01

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

  2. Mathematics of Planet Earth

    Željka Tutek

    2013-01-01

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

  3. Afganistan and rare earths

    Emilian M. Dobrescu; Edith Mihaela Dobre

    2013-01-01

    On our planet, over a quarter of new technologies for the economic production of industrial goods, are using rare earths, which are also called critical minerals and industries that rely on these precious items being worth of an estimated nearly five trillion dollars, or 5 percent of world gross domestic product. In the near future, competition will increase for the control of rare earth minerals embedded in high-tech products. Rare minerals are in the twenty-first century what oil accounted ...

  4. Toward other Earths

    Hatzes, Artie P.

    2016-04-01

    How common are habitable Earth-like planets? This is a key question that drives much of current research in exoplanets. To date, we have discovered over one thousand exoplanets, mostly through the transit method. Among these are Earth-size planets, but these orbit very close to the star (semi-major axis approximately 0.01 Astronomical Units). Potentially rocky planets have also been discovered in a star's habitable zone, but these have approximately twice the radius of the Earth. These certainly do not qualify as Earth "twins". Several hundreds of multi-planet systems have also been discovered, but these are mostly ultra-compact systems with up to seven planets all with orbital distances less than that of Mercury in our solar system. The detection of a planetary system that is the direct analog of our solar system still eludes us. After an overview of the current status of exoplanet discoveries I will discuss the prospects and challenges of finding such Earth analogs from the ground and from future space missions like PLATO. After over two decades of searching, we may well be on the brink of finding other Earths.

  5. Data needs for nutrient balances

    Vinther, Finn Pilgaard

    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...

  6. The Solubility of Rock in Steam Atmospheres of the Early Earth and Hot Rocky Exoplanets

    Fegley, Bruce

    2016-07-01

    Extensive experimental studies show all major rock-forming elements (e.g., Si, Mg, Fe, Ca, Al, Na, K) dissolve in steam to a greater or lesser extent. We use these results to compute chemical equilibrium abundances of rocky element - bearing gases in steam atmospheres equilibrated with silicate magma oceans. Rocky elements partition into steam atmospheres as volatile hydroxide gases (e.g., Si(OH)4, Mg(OH)2, Fe(OH)2, Ni(OH)2, Al(OH)3, Ca(OH)2, NaOH, KOH) and via reaction with HF and HCl as volatile halide gases (e.g., NaCl, KCl, CaFOH, CaClOH, FAl(OH)2) in much larger amounts than expected from their vapor pressures over volatile-free solid or molten rock at high temperatures expected for steam atmospheres on the early Earth and hot rocky exoplanets. We quantitatively compute the extent of fractional vaporization by defining gas/magma distribution coefficients and show Earth's sub-solar Si/Mg ratio may be due to loss of a primordial steam atmosphere. We conclude hot rocky exoplanets that are undergoing or have undergone escape of steam-bearing atmospheres may experience fractional vaporization and loss of Si, Mg, Fe, Ni, Al, Ca, Na, and K. This loss can modify their bulk composition, density, heat balance, and interior structure. This work was supported by NSF Astronomy Program Grant AST-1412175.

  7. Diversity of burial rates in convergent settings decreased as Earth aged.

    Nicoli, Gautier; Moyen, Jean-François; Stevens, Gary

    2016-01-01

    The evolution and the growth of the continental crust is inextricably linked to the evolution of Earth's geodynamic processes. The detrital zircon record within the continental crust, as well as the isotopic composition of this crust, indicates that the amount of juvenile felsic material decreased with time and that in geologically recent times, the generation of new crust is balanced by recycling of the crust back into the mantle within subduction zones. However it cannot always have been so; yet the nature of the crust and the processes of crustal reworking in the Precambrian Earth are not well constrained. Here we use both detrital zircon ages and metamorphic pressure-temperature-time (P-T-t) information from metasedimentary units deposited in proposed convergent settings from Archaean, Proterozoic and Phanerozoic terrains to characterize the evolution of minimum estimates of burial rate (km.Ma(-1)) as a function of the age of the rocks. The demonstrated decrease in burial rate correlates positively with a progressive decrease in the production of juvenile felsic crust in the Archaean and Proterozoic. Burial rates are also more diverse in the Archaean than in modern times. We interpret these features to reflect a progressive decrease in the diversity of tectonic processes from Archaean to present, coupled with the emergence of the uniquely Phanerozoic modern-style collision. PMID:27216133

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

    Chambers, Lin; Bethea, Katie

    2013-01-01

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

  9. Field reversing magnetotail current sheets: earth, Venus, and Comet Giacobini-Zinner

    McComas, D.J.

    1986-09-01

    This dissertation examines the field reversing magnetotail current sheets at the earth, Venus, and Comet Giacobini-Zinner. In the near earth study a new analysis technique is developed to calculate the detailed current density distributions within the cross tail current sheet for the first time. This technique removes the effects of a variable sheet velocity by inverting intersatellite timings between the co-orbiting satellites ISEE-1 and -2. Case studies of three relatively geomagnetically quiet crossings are made; sheet thicknesses and peak current densities are approx.1-5 x 10/sup 4/ km and approx.5-50 nA/m/sup 2/. Current density distributions reveal a high density central region, lower density shoulders, and considerable fine structure throughout. In the Venus study another new analysis technique is developed to reconstruct the average tail configuration from a correlation between field magnitude and draping angle in a large statistical data set. In the comet study, high resolution magnetic field and plasma electron data from the ICE traversal of Giacobini-Zinner are combined for the first time to determine the tail/current sheet geometry and calculate certain important but unmeasured local ion and upstream properties. Pressure balance across the tail gives ion temperatures and betas of approx.1.2 x 10/sup 5/ K and approx.40 in the center of the current sheet to approx.1 x 10/sup 6/ K and approx.3 in the outer lobes. Axial stress balance shows that the velocity shear upstream near the nucleus is >6 (approx.1 at ICE), and that a region of strongly enhanced mass loading (ion source rate approx.24 times that upstream from lobes) exists upstream from the current sheet. The integrated downtail mass flux is approx.2.6 x 10/sup 26/ H/sub 2/O+/sec, which is only approx.1% of the independently determined total cometary efflux. 79 refs., 37 figs.

  10. Global Images of Earth

    1997-01-01

    Global images of Earth from Galileo. In each frame, the continent of Antarctica is visible at the bottom of the globe. South America may be seen in the first frame (top left), the great Pacific Ocean in the second (bottom left), India at the top and Australia to the right in the third (top right), and Africa in the fourth (bottom right). Taken at six-hour intervals on December 11, 1990, at a range of between 2 and 2.7 million kilometers (1.2 to 1.7 million miles). P-37630These images were taken during Galileo's first Earth flyby. This gravity assist increased Galileo's speed around the Sun by about 5.2 kilometers per second (or 11,600 miles per hour) and substantially redirected Galileo as required for its flybys of the asteroid Gaspra in October 1991 and Earth in 1992. Galileo's closest approach (960 kilometers, or 597 miles, above the Earth's surface) to the Earth was on December 8, 1990, 3 days before these pictures were taken.Each of these images is a color composite, made up using images taken through red, green, and violet filters. The four images are part of the Galileo Earth spin movie, a 256-frame time-lapse motion picture that shows a 25-hour period of Earth's rotation and atmospheric dynamics. The movie gives scientists a unique overall view of global weather patterns, as opposed to the limited view of weather satellite images.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA'is Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  11. Pressure transducers

    Strain gauges pressure transducers types are presented. Models, characteristics and calibration procedures were also analysed. Initially, a theoretical study was accomplished to evaluate metallic alloys behavior on sensing elements manufacturing, and diaphragm was used as deflecting elements. Electrical models for potenciometric transducers were proposed at the beginning and subsequently comproved according our experiments. Concerning bridge transducers, existing models confirmed the conditions of linearity and sensitivity related to the electrical signal. All the work done was of help on the calibration field and pressure measurements employing unbounded strain gauge pressure transducers

  12. A new program in earth system science education

    Huntress, Wesley; Kalb, Michael W.; Johnson, Donald R.

    1990-01-01

    A program aimed at accelerating the development of earth system science curricula at the undergraduate level and at seeding the establishment of university-based mechanisms for cooperative research and education among universities and NASA has been initiated by the Universities Space Research Association (USRA) in conjunction with NASA. Proposals were submitted by 100 U.S. research universities which were selected as candidates to participate in a three-year pilot program to develop undergraduate curricula in earth system science. Universities were then selected based upon peer review and considerations of overall scientific balance among proposed programs. The program will also aim to integrate a number of universities with evolving earth system programs, linking them with a cooperative curriculum, shared faculty, and NASA scientists in order to establish a stronger base for earth systems related education and interdisciplinary research collaboration.

  13. Atmospheres and evolution. [of microbial life on earth

    Margulis, L.; Lovelock, J. E.

    1981-01-01

    Studies concerning the regulation of the earth atmosphere and the relation of atmospheric changes to the evolution of microbial life are reviewed. The improbable nature of the composition of the earth atmosphere in light of the atmospheric compositions of Mars and Venus and equilibrium considerations is pointed out, and evidence for the existence of microbial (procaryotic) life on earth as far back as 3.5 billion years ago is presented. The emergence of eucaryotic life in the Phanerozoic due to evolving symbioses between different procaryotic species is discussed with examples given of present-day symbiotic relationships between bacteria and eucaryotes. The idea that atmospheric gases are kept in balance mainly by the actions of bacterial cells is then considered, and it is argued that species diversity is necessary for the maintenance and origin of life on earth in its present form.

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

    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.

  15. [Individual pressure tolerance--a "target" pressure?].

    Bogdănici, C; Vancea, P P

    1999-01-01

    In literature there are many meanings for the limit between normal and pathological intraocular pressure: "normative pressure", "critic pressure", "individual tolerance pressure" and "target pressure". The aim of this paper is to demonstrate that these terms are synonymous. PMID:10756882

  16. The earth's hydrological cycle

    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 ...

  17. Modeling the earth system

    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.

  18. Crescent Earth and Moon

    1977-01-01

    This picture of a crescent-shaped Earth and Moon -- the first of its kind ever taken by a spacecraft -- was recorded Sept. 18, 1977, by NASA's Voyager 1 when it was 7.25 million miles (11.66 million kilometers) from Earth. The Moon is at the top of the picture and beyond the Earth as viewed by Voyager. In the picture are eastern Asia, the western Pacific Ocean and part of the Arctic. Voyager 1 was directly above Mt. Everest (on the night side of the planet at 25 degrees north latitude) when the picture was taken. The photo was made from three images taken through color filters, then processed by the Jet Propulsion Laboratory's Image Processing Lab. Because the Earth is many times brighter than the Moon, the Moon was artificially brightened by a factor of three relative to the Earth by computer enhancement so that both bodies would show clearly in the print. Voyager 2 was launched Aug. 20, 1977, followed by Voyager 1 on Sept. 5, 1977, en route to encounters at Jupiter in 1979 and Saturn in 1980 and 1981. JPL manages the Voyager mission for NASA's Office of Space Science.

  19. Earth and planetary sciences

    The earth is a dynamic body. The major surface manifestation of this dynamism has been fragmentation of the earth's outer shell and subsequent relative movement of the pieces on a large scale. Evidence for continental movement came from studies of geomagnetism. As the sea floor spreads and new crust is formed, it is magnetized with the polarity of the field at the time of its formation. The plate tectonics model explains the history, nature, and topography of the oceanic crust. When a lithospheric plate surmounted by continental crust collides with an oceanic lithosphere, it is the denser oceanic lithosphere that is subducted. Hence the ancient oceans have vanished and the knowledge of ancient earth will require deciphering the complex continental geological record. Geochemical investigation shows that the source region of continental rocks is not simply the depleted mantle that is characteristic of the source region of basalts produced at the oceanic ridges. The driving force of plate tectonics is convection within the earth, but much remains to be learned about the convection and interior of the earth. A brief discussion of planetary exploration is given

  20. The Sun and Earth

    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.

  1. Monitoring the Earth

    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.

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

    Jung HH

    2015-10-01

    Full Text Available HoHyun Jung,1 Keyoung Jin Chun,2 Jaesoo Hong,2 Dohyung Lim1 1Department of Mechanical Engineering, Sejong University, Seoul, Republic of Korea; 2Smart Welfare Technology Research Group, Korea Institute of Industrial Technology, Cheonan, Republic of Korea Abstract: Balance is important in daily activities and essential for maintaining an independent lifestyle in the elderly. Recent studies have shown that balance rehabilitation training can improve the balance ability of the elderly, and diverse balance rehabilitation training equipment has been developed. However, there has been little research into optimized strategies for balance rehabilitation training. To provide an optimized strategy, we analyzed the balance characteristics of participants in response to the rotation of a base plate on multiple axes. Seven male adults with no musculoskeletal or nervous system-related diseases (age: 25.5±1.7 years; height: 173.9±6.4 cm; body mass: 71.3±6.5 kg; body mass index: 23.6±2.4 kg/m2 were selected to investigate the balance rehabilitation training using customized rehabilitation equipment. Rotation of the base plate of the equipment was controlled to induce dynamic rotation of participants in the anterior–posterior, right-diagonal, medial–lateral, and left-diagonal directions. We used a three-dimensional motion capture system employing infrared cameras and the Pedar Flexible Insoles System to characterize the major lower-extremity joint angles, center of body mass, and center of pressure. We found statistically significant differences between the changes in joint angles in the lower extremities in response to dynamic rotation of the participants (P<0.05. The maximum was greater with anterior–posterior and medial–lateral dynamic rotation than with that in other directions (P<0.05. However, there were no statistically significant differences in the frequency of center of body mass deviations from the base of support (P>0.05. These results

  3. Solar activity and earth's climate

    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.

  4. Pressure Drop

    Lawson, Mike

    2010-01-01

    Mike Lawson briefly discussed pressure drop for aerospace applications and presented short stories about adventures experienced while working at NASA and General Dynamics, including exposure to technologies like the Crew and Equipment Translation Aid (CETA) cart and the SWME.

  5. Pressure sensor

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

    2015-09-29

    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  6. Pressure losses in pneumatic transport

    Ottjes, J.A.

    1982-01-01

    A model is derived to calculate the pressure losses originating from the dilute phase pneumatic transport of coarse particles in the horizontal stationary flow regime. The model is based on the balance of drag forces and frictional forces acting on the particles during pneumatic transport. The particles are characterized by the particle terminal velocity, the particle âwall sliding friction coefficient and the coefficient of restitution between particles and wall. The influence of the inhomog...

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

    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

  8. Better Than Earth

    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.

  9. Better Than Earth

    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.

  10. Dagik Earth and IUGONET

    Ebisawa, K.; Koyama, Y.; Saito, A.; Sakamoto, S.; Ishii, M.; Kumano, Y.; Hazumi, Y.

    2015-09-01

    In this paper we introduce two independent projects in progress in Japan. Dagik Earth is a visualization project of the Earth and planets on a spherical screen using only a standard PC and a projector. Surface images of the Earth or planets (or whatever having spherical shape) in the equirectangular (plate carre) projection are projected on a spherical screen in the orthographic projection. As a result, the spherical screen becomes a virtual digital globe, which can be rotated using mouse or remote controller. Inter-university Upper atmosphere Global Observation NETwork (IUGONET) is a collaboration of five Japanese institutes to build a comprehensive database system for the metadata of the upper-atmospheric data taken by these institutes. We explain the IUGONET metadata database and iUgonet Data Analysis Software (UDAS) for upper atmospheric research.

  11. Experimental petrology: a new insight into the deep Earth composition

    Ciazela, Jakub

    2012-01-01

    Meteorites remain the main data source for inferring deep Earth composition (McDonough 2003; Palme, O’Neill 2003) whereas seismic waves give fundamental information on the structure of our planet (Bina 2003; McDonough 2003). However, the constant development of high pressure methods in recent decades has allowed us to simulate core and mantle conditions on the surface of the Earth. As a consequence, we can examine the mineralogical composition, crystal structure and physical st...

  12. Electronic structure and properties of rare earth and actinide intermetallics

    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.)

  13. High-pressure phases of alumina

    Lyle, Matthew; Pickard, Chris; Needs, Richard

    2014-03-01

    Alumina (Al2O3) has been widely used as a pressure standard in static diamond anvil cell experiments and is a major chemical component of the Earth. So a detailed knowledge of its high-pressure stability is of great importance in both materials science and deep Earth science. A phase transition is known to occur at roughly 80-100 GPa between corundum and the Rh2O3 (II) structure. A second phase transition to the CaIrO3 structure occurs at even higher pressures. Here we present a computational structure search to reveal three additional structures which are competitive at these pressures but hitherto unknown to be stable in high-pressure alumina.

  14. How Big is Earth?

    Thurber, Bonnie B.

    2015-08-01

    How Big is Earth celebrates the Year of Light. Using only the sunlight striking the Earth and a wooden dowel, students meet each other and then measure the circumference of the earth. Eratosthenes did it over 2,000 years ago. In Cosmos, Carl Sagan shared the process by which Eratosthenes measured the angle of the shadow cast at local noon when sunlight strikes a stick positioned perpendicular to the ground. By comparing his measurement to another made a distance away, Eratosthenes was able to calculate the circumference of the earth. How Big is Earth provides an online learning environment where students do science the same way Eratosthenes did. A notable project in which this was done was The Eratosthenes Project, conducted in 2005 as part of the World Year of Physics; in fact, we will be drawing on the teacher's guide developed by that project.How Big Is Earth? expands on the Eratosthenes project by providing an online learning environment provided by the iCollaboratory, www.icollaboratory.org, where teachers and students from Sweden, China, Nepal, Russia, Morocco, and the United States collaborate, share data, and reflect on their learning of science and astronomy. They are sharing their information and discussing their ideas/brainstorming the solutions in a discussion forum. There is an ongoing database of student measurements and another database to collect data on both teacher and student learning from surveys, discussions, and self-reflection done online.We will share our research about the kinds of learning that takes place only in global collaborations.The entrance address for the iCollaboratory is http://www.icollaboratory.org.

  15. Google Earth Engine

    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

  16. Geoneutrino and Hydridic Earth model

    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. How Our Balance System Works

    ... from your eyes, the inner ear, and the sensory systems of the body (such as the skin, muscles, ... function? How are vision, the inner ear, and sensory systems impacting functional balance? Some of the tests of ...

  18. Cautions Concerning Electronic Analytical Balances.

    Johnson, Bruce B.; Wells, John D.

    1986-01-01

    Cautions chemists to be wary of ferromagnetic samples (especially magnetized samples), stray electromagnetic radiation, dusty environments, and changing weather conditions. These and other conditions may alter readings obtained from electronic analytical balances. (JN)

  19. Skylab water balance error analysis

    Leonard, J. I.

    1977-01-01

    Estimates of the precision of the net water balance were obtained for the entire Skylab preflight and inflight phases as well as for the first two weeks of flight. Quantitative estimates of both total sampling errors and instrumentation errors were obtained. It was shown that measurement error is minimal in comparison to biological variability and little can be gained from improvement in analytical accuracy. In addition, a propagation of error analysis demonstrated that total water balance error could be accounted for almost entirely by the errors associated with body mass changes. Errors due to interaction between terms in the water balance equation (covariances) represented less than 10% of the total error. Overall, the analysis provides evidence that daily measurements of body water changes obtained from the indirect balance technique are reasonable, precise, and relaible. The method is not biased toward net retention or loss.

  20. An Oscillating Magnet Watt Balance

    Ahmedov, H

    2015-01-01

    We establish the principles for a new generation of simplified and accurate watt balances in which an oscillating magnet generates Faraday's voltage in a stationary coil. A force measuring system and a mechanism providing vertical movements of the magnet are completely independent in an oscillating magnet watt balance. This remarkable feature allows to establish the link between the Planck constant and a macroscopic mass by a one single experiment. Weak dependence on variations of environmental and experimental conditions, weak sensitivity to ground vibrations and temperature changes, simple force measuring procedure, small sizes and other useful features offered by the novel approach considerably reduce the complexity of the experimental setup. We formulate the oscillating magnet watt balance principle and establish the measurement procedure for the Planck constant. We discuss the nature of oscillating magnet watt balance uncertainties and give a brief description of the National Metrology Institute (UME) wa...

  1. Laboratory Workhorse: The Analytical Balance.

    Clark, Douglas W.

    1979-01-01

    This report explains the importance of various analytical balances in the water or wastewater laboratory. Stressed is the proper procedure for utilizing the equipment as well as the mechanics involved in its operation. (CS)

  2. Teaching earth science

    Alpha, Tau Rho, (Edited By); Diggles, M.F.

    1998-01-01

    This CD-ROM contains 17 teaching tools: 16 interactive HyperCard 'stacks' and a printable model. They are separated into the following categories: Geologic Processes, Earthquakes and Faulting, and Map Projections and Globes. A 'navigation' stack, Earth Science, is provided as a 'launching' place from which to access all of the other stacks. You can also open the HyperCard Stacks folder and launch any of the 16 stacks yourself. In addition, a 17th tool, Earth and Tectonic Globes, is provided as a printable document. Each of the tools can be copied onto a 1.4-MB floppy disk and distributed freely.

  3. Rare (Earth Elements [score

    Camilo Méndez

    2014-12-01

    Full Text Available Rare (Earth Elements is a cycle of works for solo piano. The cycle was inspired by James Dillon’s Book of Elements (Vol. I-V. The complete cycle will consist of 14 pieces; one for each selected rare (earth element. The chosen elements are Neodymium, Erbium, Tellurium, Hafnium, Tantalum, Technetium, Indium, Dysprosium, Lanthanium, Cerium, Europium, Terbium, Yttrium and Darmstadtium. These elements were selected due to their special atomic properties that in many cases make them extremely valuable for the development of new technologies, and also because of their scarcity. To date, only 4 works have been completed Yttrium, Technetium, Indium and Tellurium.

  4. Quantizing Earth surface deformations

    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.

  5. Hatha yoga on body balance

    Erick Tadeu Prado; Vagner Raso; Renata Coelho Scharlach; Cristiane Akemi Kasse

    2014-01-01

    Background: A good body balance requires a proper function of vestibular, visual, and somatosensory systems which can be reach with exercise practice and/or yoga. Aim: To determine the effects of a 5-month hatha yoga training program on body balance in young adults. Materials and Methods: This study used a controlled, nonrandomized design, where the experimental group underwent a 5-month training program and were then compared with the control group that had a sedentary lifestyle. A c...

  6. Risk, Balanced Skills and Entrepreneurship

    Hsieh, C.; Parker, S.C.; Praag, van, B.

    2011-01-01

    This paper proposes that risk aversion encourages individuals to invest in balanced skill profiles, making them more likely to become entrepreneurs. By not having taken this possible linkage into account, previous research has underestimated the impacts both of risk aversion and balanced skills on the likelihood individuals choose entrepreneurship. Data on Dutch university graduates provides evidence which supports this contention. It thereby raises the possibility that even risk-averse peopl...

  7. Balancing local budgets in Romania

    Attila GYÖRGY

    2014-01-01

    Local budgets in Romania are balanced with revenues transferred from state budget according to the criterions laid down in the Local Public Finance Act. These criterions are focusing on the financial capacity, population and surface, each local budget getting balancing amounts inversely with the administrative unit’s wellness and directly to size. The repartition algorithm is used for more than a decade, but periodically it was revised in order to be better folded to fiscal policy and economi...

  8. Electric power balance sheet 2012

    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

  9. Financial intermediary balance sheet management

    Adrian,Tobias; Shin, Hyun Song

    2011-01-01

    Conventional discussions of balance sheet management by nonfinancial firms take the set of positive net present value (NPV) projects as given, which in turn determines the size of the assets of the firm. The focus is on the composition of equity and debt in funding such assets. In contrast, the balance sheet management of financial intermediaries reveals that it is equity that behaves like the predetermined variable, and the asset size of the bank or financial intermediary is determined by th...

  10. VALUE BALANCE IN CONSUMER PROTECTION

    Dahsan Hasan

    2015-01-01

    This research aims to describe how the realization of ' Balance ' in the Consumer Protection Act, describes how the responsibility of the parties (consumers, businessmen and the Government) so that it can realize the value of the balance in the protection of consumer, Research conducted in the framework of the preparation of this dissertation is to type the socio-juridical, in addition to researching the secondary legal materials in the form of legal regulations, manual and electronic law lib...

  11. Balancer effects in opinion dynamics

    Cheon, Taksu

    2016-01-01

    We introduce a novel type of contrarian agent, the balancer, to Galam model of opinion dynamics, in order to account for the skepticism over one-sidedness and for the sense of fairness. We find that the inclusion of balancers along with floaters and inflexibles brings about a critical point on parametric plane of the dynamical system, which results in the new kind of stable final states of the opinion dynamics, that seem to capture several intriguing features found often in mature democracies.

  12. Assessment of perioperative fluid balance

    Bumbaširević V.; Marković D.; Vlajković G.; Sinđelić R.

    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 ther...

  13. Earth science framework research based on the digital earth platform

    Liu, Rui; Kong, Xiangsheng; Miao, Fang; Ye, Chengming

    2007-06-01

    This paper explains the basic points of earth science research, reviews the notion of digital earth and suggests the basic concept of digital earth platform. Taking the theory of digital earth as an essence point and the framework of digital earth platform as a main clue, we mainly discuss: the basic theories of digital earth platform, a comparatively flawless model of earth science research framework based on the digital earth platform. The discussing issues involves the unified coordinate projecting, data updating, data transferring, data processing and analyzing and data displaying and a series of researches relating to energy sources, eco-system and disasters monitoring and forecasting with a combination of the suggested model of earth science research framework.

  14. Form 6 - gas balancing agreement

    In 1988, a special Committee of the Rocky Mountain Mineral Law Foundation undertook a project to draft a model from gas balancing agreement. This project was initiated at the request of a number of Foundation members who felt that a model form gas balancing agreement would facilitate the negotiation of operating agreement, since gas balancing issues had become sticking points in the process. The Committee was composed of attorneys representing a wide cross-section of the oil and gas industry including both major and independent oil companies, production companies with interstate pipeline affiliates, and private practitioners. The Committee attempted to address the more controversial issues in gas balancing with optional provisions in the Form. To facilitate the negotiation process, the number of optional provisions was minimized. This form may be used as an Appendix to the new A.A.P.L. Form 610-1989 Model Form Operating Agreement. This book includes provision of this Form which are: Ownership of gas production; Balancing of production accounts; Cash balancing upon depletion; Deliverability tests; Nominations; Statements; Payment of taxes; Operating expenses; Overproducing allowable; Payment of leasehold burdens; Operator's liability; Successors and assigns; Audits; Arbitration; and Operator's fees

  15. Field Measurements and Pullout Tests of Reinforced Earth Retaining Wall

    陈群; 何昌荣; 朱分清

    2004-01-01

    In this paper, field measurements and pullout tests of a new type of reinforced earth retaining wall, which is reinforced by trapezoid concrete blocks connected by steel bar, are described. Field measurements included settlements of the earth fill, tensile forces in the ties and earth pressures on the facing panels during the construction and at completion. Based on the measurements, the following statements can be made: ( 1 ) the tensile forces in the ties increased with the height of backfill above the tie and there is a tensile force crest in most ties; (2) at completion, the measured earth pressures along the wall face were between the values of the active earth pressures and the pressures at rest; (3) larger settlements occurred near the face of the wall where a zone of drainage sand and gravel was not compacted properly and smaller settlements occurred in the well-compacted backfill. The results of field pullout tests indicated that the magnitudes of pullout resistances as well as tensile forces induced in the ties were strongly influenced by the relative displacements between the ties and the backfill, and pullout resistances increased with the height of backfill above the ties and the length of ties.

  16. Seismic rehabilitation and analysis of Chaohe earth dam

    Lei Fu; Xiangwu Zeng

    2005-01-01

    Stability of earth dams during earthquakes has been a major concern for geotechnical engineers in seismic active regions. Liquefaction induced slope failure occurred at the upstream slope of a major earth dam in the suburb of Beijing, China, during the 1976 Tangshan Earthquake. The gravelly soil with loose initial condition liquefied under relatively small ground vibration. In recent years, a major seismic rehabilitation project was carried out on a similar earth dam nearby using dumped quarry stone. Seismic stability analysis was carried out using model test, finite element simulation, and pseudostatic slope stability program after taking into account the influence of excess pore pressure.

  17. Earth System Science Education Modules

    Hall, C.; Kaufman, C.; Humphreys, R. R.; Colgan, M. W.

    2009-12-01

    The College of Charleston is developing several new geoscience-based education modules for integration into the Earth System Science Education Alliance (ESSEA). These three new modules provide opportunities for science and pre-service education students to participate in inquiry-based, data-driven experiences. The three new modules will be discussed in this session. Coastal Crisis is a module that analyzes rapidly changing coastlines and uses technology - remotely sensed data and geographic information systems (GIS) to delineate, understand and monitor changes in coastal environments. The beaches near Charleston, SC are undergoing erosion and therefore are used as examples of rapidly changing coastlines. Students will use real data from NASA, NOAA and other federal agencies in the classroom to study coastal change. Through this case study, learners will acquire remotely sensed images and GIS data sets from online sources, utilize those data sets within Google Earth or other visualization programs, and understand what the data is telling them. Analyzing the data will allow learners to contemplate and make predictions on the impact associated with changing environmental conditions, within the context of a coastal setting. To Drill or Not To Drill is a multidisciplinary problem based module to increase students’ knowledge of problems associated with nonrenewable resource extraction. The controversial topic of drilling in the Arctic National Wildlife Refuge (ANWR) examines whether the economic benefit of the oil extracted from ANWR is worth the social cost of the environmental damage that such extraction may inflict. By attempting to answer this question, learners must balance the interests of preservation with the economic need for oil. The learners are exposed to the difficulties associated with a real world problem that requires trade-off between environmental trust and economic well-being. The Citizen Science module challenges students to translate scientific

  18. Exploring the Earth's Past

    Lindaman, Arnold D.; And Others

    1972-01-01

    Describes three approaches to a study of the earth's past: (1) development of a time line of the ages; (2) a study of rocks and how each was formed; and (3) a study of fossils as found in certain kinds of stone. (Editor)

  19. Earth's City Lights

    2002-01-01

    This image of Earth's city lights was created with data from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). Originally designed to view clouds by moonlight, the OLS is also used to map the locations of permanent lights on the Earth's surface. The brightest areas of the Earth are the most urbanized, but not necessarily the most populated. (Compare western Europe with China and India.) Cities tend to grow along coastlines and transportation networks. Even without the underlying map, the outlines of many continents would still be visible. The United States interstate highway system appears as a lattice connecting the brighter dots of city centers. In Russia, the Trans-Siberian railroad is a thin line stretching from Moscow through the center of Asia to Vladivostok. The Nile River, from the Aswan Dam to the Mediterranean Sea, is another bright thread through an otherwise dark region. Even more than 100 years after the invention of the electric light, some regions remain thinly populated and unlit. Antarctica is entirely dark. The interior jungles of Africa and South America are mostly dark, but lights are beginning to appear there. Deserts in Africa, Arabia, Australia, Mongolia, and the United States are poorly lit as well (except along the coast), along with the boreal forests of Canada and Russia, and the great mountains of the Himalaya. The Earth Observatory article Bright Lights, Big City describes how NASA scientists use city light data to map urbanization. Image by Craig Mayhew and Robert Simmon, NASA GSFC, based on DMSP data

  20. Between Earth and Sky

    Carter, Adrian

    2009-01-01

    able to rescue architecture from the sterile impasse of late-modernism. In his works the basic elements of lived space become present: the earth, the sky and the `between` of human existence." Jørn Utzon's architecture ranges from the modest to the monumental; from the Kingo courtyard houses, the...

  1. Citizens of Planet Earth

    Frisk, Kristian

    2015-01-01

    The inability of the nation-state system to handle contemporary environmental issues comprehensively has spurred greater cooperation between religious and secular civil society actors. An empirical analysis of the Alliance of Religions and Conservation (ARC) contributes to knowledge about this pr...... (2010a) have termed Terrapolitan Earth Religion....

  2. Magnetic rare earth superlattices

    Majkrzak, C.F.; Kwo, J.; Hong, M.;

    1991-01-01

    Advances in molecular beam epitaxy deposition techniques have recently made it possible to grow, an atomic plane at a time, single crystalline superlattices composed of alternating layers of a magnetic rare earth, such as Gd, Dy, Ho, or Er, and metallic Y, which has an identical chemical structure...

  3. Artificial earth satellites

    V. R. Thiruvenkatachar

    1958-10-01

    Full Text Available A general discussion is given of the scientific and technological problems involved in the launching of earth satellites, covering various aspects such as the dynamical relationships involved, the propulsion and guidance systems, tracking and data transmission etc. The possible uses of satellites for scientific research as well as some of the likely future developments are also briefly indicated.

  4. The earths innermost core

    A new earth model is advanced with a solid innermost core at the centre of the Earth where elements heavier than iron, over and above what can be retained in solution in the iron core, are collected. The innermost core is separated from the solid iron-nickel core by a shell of liquid copper. The innermost core has a natural vibration measured on the earth's surface as the long period 26 seconds microseisms. The earth was formed initially as a liquid sphere with a relatively thin solid crust above the Byerly discontinuity. The trace elements that entered the innermost core amounted to only 0.925 ppm of the molten mass. Gravitational differentiation must have led to the separation of an explosive thickness of pure 235U causing a fission explosion that could expel beyond the Roche limit a crustal scab which would form the centre piece of the moon. A reservoir of helium floats on the liquid copper. A small proportion of helium-3, a relic of the ancient fission explosion present there will spell the exciting magnetic field. The field is stable for thousands of years because of the presence of large quantity of helium-4 which accounts for most of the gaseous collisions that will not disturb the atomic spin of helium-3 atoms. This field is prone to sudden reversals after long periods of stability. (author). 14 refs

  5. How life shaped Earth.

    Gross, Michael

    2015-10-01

    Earth is much more complex than all the other solar system objects that we know. Thanks to its rich and diverse geology, our planet can offer habitats to a wide range of living species. Emerging insights suggest that this is not just a happy coincidence, but that life itself has in many ways helped to shape the planet. PMID:26726334

  6. The Earth and Moon

    1990-01-01

    During its flight, the Galileo spacecraft returned images of the Earth and Moon. Separate images of the Earth and Moon were combined to generate this view. The Galileo spacecraft took the images in 1992 on its way to explore the Jupiter system in 1995-97. The image shows a partial view of the Earth centered on the Pacific Ocean about latitude 20 degrees south. The west coast of South America can be observed as well as the Caribbean; swirling white cloud patterns indicate storms in the southeast Pacific. The distinct bright ray crater at the bottom of the Moon is the Tycho impact basin. The lunar dark areas are lava rock filled impact basins. This picture contains same scale and relative color/albedo images of the Earth and Moon. False colors via use of the 1-micron filter as red, 727-nm filter as green, and violet filter as blue. The Galileo project is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory.

  7. The Earth & Moon

    1990-01-01

    During its flight, the Galileo spacecraft returned images of the Earth and Moon. Separate images of the Earth and Moon were combined to generate this view. The Galileo spacecraft took the images in 1992 on its way to explore the Jupiter system in 1995-97. The image shows a partial view of the Earth centered on the Pacific Ocean about latitude 20 degrees south. The west coast of South America can be observed as well as the Caribbean; swirling white cloud patterns indicate storms in the southeast Pacific. The distinct bright ray crater at the bottom of the Moon is the Tycho impact basin. The lunar dark areas are lava rock filled impact basins. This picture contains same scale and relative color/albedo images of the Earth and Moon. False colors via use of the 1-micron filter as red, 727-nm filter as green, and violet filter as blue. The Galileo project is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory.

  8. Earth's Reflection: Albedo

    Gillette, Brandon; Hamilton, Cheri

    2011-01-01

    When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word "albedo" is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is…

  9. "Galileo Calling Earth..."

    National Aeronautics and Space Administration, Washington, DC.

    This guide presents an activity for helping students understand how data from the Galileo spacecraft is sent to scientists on earth. Students are asked to learn about the concepts of bit-rate and resolution and apply them to the interpretation of images from the Galileo Orbiter. (WRM)

  10. Modeling Earth's Climate

    Pallant, Amy; Lee, Hee-Sun; Pryputniewicz, Sara

    2012-01-01

    Systems thinking suggests that one can best understand a complex system by studying the interrelationships of its component parts rather than looking at the individual parts in isolation. With ongoing concern about the effects of climate change, using innovative materials to help students understand how Earth's systems connect with each other is…

  11. Understanding Earth's Albedo Effect

    Fidler, Chuck

    2012-01-01

    Earth and space science in the middle school classroom are composed of intricately intertwined sets of conceptual systems (AAAS 1993; NRC 1996). Some systems of study, such as the water and rock cycles, are quite explicit and often found as stand-alone middle school science units. Other phenomena are not so apparent, yet they play an extremely…

  12. Google Earth Science

    Baird, William H.; Padgett, Clifford W.; Secrest, Jeffery A.

    2015-01-01

    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…

  13. Earth as art 4

    U.S. Geological Survey

    2016-01-01

    Landsat 8 is the latest addition to the long-running series of Earth-observing satellites in the Landsat program that began in 1972. The images featured in this fourth installment of the Earth As Art collection were all acquired by Landsat 8. They show our planet’s diverse landscapes with remarkable clarity.Landsat satellites see the Earth as no human can. Not only do they acquire images from the vantage point of space, but their sensors record infrared as well as visible wavelengths of light. The resulting images often reveal “hidden” details of the Earth’s land surface, making them invaluable for scientific research.As with previous Earth As Art exhibits, these Landsat images were selected solely for their aesthetic appeal. Many of the images have been manipulated to enhance color variations or details. They are not intended for scientific interpretation—only for your viewing pleasure. What do you see in these unique glimpses of the Earth’s continents, islands, and coastlines?

  14. Balancing wobbles in the body sodium.

    Titze, Jens; Rakova, Natalia; Kopp, Christoph; Dahlmann, Anke; Jantsch, Jonathan; Luft, Friedrich C

    2016-07-01

    Sodium balance is achieved within a matter of days and everything that enters should come out; sodium stores are of questionable relevance and sodium accumulation is accompanied by weight gain. Careful balance studies oftentimes conflicted with this view, and long-term studies suggested that total body sodium (TBNa) fluctuates independent of intake or body weight. We recently performed the opposite experiment in that we fixed sodium intake for weeks at three levels of sodium intake and collected all urine made. We found weekly (circaseptan) patterns in sodium excretion that were inversely related to aldosterone and directly related to cortisol. TBNa was not dependent on sodium intake, but instead exhibited far longer (greater than or equal to monthly) infradian rhythms independent of extracellular water, body weight or blood pressure. To discern the mechanisms further, we delved into sodium magnetic resonance imaging (Na-MRI) to identify sodium storage clinically. We found that sodium stores are greater in men than in women, increase with age and are higher in hypertensive than normotensive persons. We have suggestive evidence that these sodium stores can be mobilized, also in dialysis patients. The observations are in accordance with our findings that immune cells regulate a hypertonic interface in the skin interstitium that could serve as a protective barrier. Returning to our balance studies, we found that due to biological variability in 24-h sodium excretion, collecting urine for a day could not separate 12, 9 or 6 g/day sodium intakes with the precision of tossing a coin. Every other daily urine sampling correctly classified a 3-g difference in salt intake less than half the time, making the gold standard 24-h urine collection of little value in predicting salt intake. We suggest that wobbles in expected outcomes can lead to novel clinical insights even with respect to banal salt questions. PMID:26410883

  15. Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1).

    Angel, Roger

    2006-11-14

    If it were to become apparent that dangerous changes in global climate were inevitable, despite greenhouse gas controls, active methods to cool the Earth on an emergency basis might be desirable. The concept considered here is to block 1.8% of the solar flux with a space sunshade orbited near the inner Lagrange point (L1), in-line between the Earth and sun. Following the work of J. Early [Early, JT (1989) J Br Interplanet Soc 42:567-569], transparent material would be used to deflect the sunlight, rather than to absorb it, to minimize the shift in balance out from L1 caused by radiation pressure. Three advances aimed at practical implementation are presented. First is an optical design for a very thin refractive screen with low reflectivity, leading to a total sunshade mass of approximately 20 million tons. Second is a concept aimed at reducing transportation cost to 50 dollars/kg by using electromagnetic acceleration to escape Earth's gravity, followed by ion propulsion. Third is an implementation of the sunshade as a cloud of many spacecraft, autonomously stabilized by modulating solar radiation pressure. These meter-sized "flyers" would be assembled completely before launch, avoiding any need for construction or unfolding in space. They would weigh a gram each, be launched in stacks of 800,000, and remain for a projected lifetime of 50 years within a 100,000-km-long cloud. The concept builds on existing technologies. It seems feasible that it could be developed and deployed in approximately 25 years at a cost of a few trillion dollars, <0.5% of world gross domestic product (GDP) over that time. PMID:17085589

  16. Mechanism of Rare Earth Incorporation and Crystal Growth of Rare Earth Containing Type-I Clathrates

    2015-01-01

    Type-I clathrates possess extremely low thermal conductivities, a property that makes them promising materials for thermoelectric applications. The incorporation of cerium into one such clathrate has recently been shown to lead to a drastic enhancement of the thermopower, another property determining the thermoelectric efficiency. Here we explore the mechanism of the incorporation of rare earth elements into type-I clathrates. Our investigation of the crystal growth and the composition of the phase Ba8–xRExTMySi46–y (RE = rare earth element; TM = Au, Pd, Pt) reveals that the RE content x is mainly governed by two factors, the free cage space and the electron balance. PMID:26823658

  17. Whole-Earth Decompression Dynamics

    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...

  18. Relationships between fear of falling, balance confidence, and control of balance, gait, and reactive stepping in individuals with sub-acute stroke.

    Schinkel-Ivy, Alison; Inness, Elizabeth L; Mansfield, Avril

    2016-01-01

    Fear of falling is common in individuals with stroke; however, the associations between fear of falling, balance confidence, and the control of balance and gait are not well understood for this population. This study aimed to determine whether, at the time of admission to in-patient rehabilitation, specific features of balance and gait differed between individuals with stroke who did and did not report fear of falling, and whether these features were related to balance confidence. Individuals with stroke entering in-patient rehabilitation were asked if they were afraid of falling, and completed the Activities-Specific Balance Confidence Scale. Participants performed quiet standing, gait, and reactive stepping tasks, and specific measures were extracted for each (quiet standing: centre of pressure amplitude, between-limb synchronization, and Romberg quotients; gait: walking velocity, double support time, and variability measures; reactive stepping: number of steps, frequency of grasp reactions, and frequency of assists). No significant differences were identified between individuals with and without fear of falling. Balance confidence was negatively related to centre of pressure amplitude, double support time, and step time variability, and positively related to walking velocity. Low balance confidence was related to poor quiet standing balance control and cautious behavior when walking in individuals with sub-acute stroke. While the causal relationship between balance confidence and the control of balance and gait is unclear from the current work, these findings suggest there may be a role for interventions to increase balance confidence among individuals with stroke, in order to improve functional mobility. PMID:26482234

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

    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

  20. VALUE BALANCE IN CONSUMER PROTECTION

    Dahsan Hasan

    2015-07-01

    Full Text Available This research aims to describe how the realization of ' Balance ' in the Consumer Protection Act, describes how the responsibility of the parties (consumers, businessmen and the Government so that it can realize the value of the balance in the protection of consumer, Research conducted in the framework of the preparation of this dissertation is to type the socio-juridical, in addition to researching the secondary legal materials in the form of legal regulations, manual and electronic law library, relevant research results in the field of law of particular problems in the field of consumer protection and other written materials, as well as researching various legal facts about consumer protection which occur in the field as well as its impact on the general public. The results showed that: 1 a form of value balance in consumer protection legislation lies in the synergy between the rights and obligations the rights and obligations of consumers, businessmen, as well as the duties and responsibilities of the Government, the supporters of both public institutions and private consumers are dispute resolution Efforts, and the use of contract oversight of overall indicators are assessed if merged between the assessment of consumers and businessmen, as well as assessment of the Government then obtained 32 indicators of where the total number of indicators corresponding to the value of the balance of a total of 10 indicators, while the total number of which is not in accordance with the value of the balance as much as 21 indicators and only one indicator that his judgment balanced. So that the efforts made in the framework of the fulfilment of the rights and obligations of consumers and businessmen as well as maximize the task and responsibility of the Government is still having a lot of obstacles or not be able to realize the value of balance