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1

Highly subcooled pool boiling heat transfer at various gravity levels Jungho Kim a,*, John F. Benton b  

E-print Network

Highly subcooled pool boiling heat transfer at various gravity levels Jungho Kim a,*, John F camera was used to provide subcooled pool boiling heat transfer measurements at gravity levels ranging- ronments, respectively. The data indicate that there is little effect of gravity on boiling heat transfer

Kim, Jungho

2

Effect of gravity level fluctuations for rotating fluids in high and low rotating speeds  

NASA Technical Reports Server (NTRS)

Time-dependent evolutions of the profile of the free surface (bubble shapes) for a cylindrical container partially filled with a Newtonian fluid of constant density, rotating about its axis of symmetry, have been studied. Numerical computations of the dynamics of bubble shapes have been carried out with sinusoidal-function vibration of the gravity environment at high and low cylinder speeds.

Hung, R. J.; Tsao, Y. D.; Hong, B. B.; Leslie, F. W.

1989-01-01

3

Preprocessing of gravity gradients at the GOCE high-level processing facility  

Microsoft Academic Search

One of the products derived from the gravity field and steady-state ocean circulation explorer (GOCE) observations are the\\u000a gravity gradients. These gravity gradients are provided in the gradiometer reference frame (GRF) and are calibrated in-flight\\u000a using satellite shaking and star sensor data. To use these gravity gradients for application in Earth scienes and gravity\\u000a field analysis, additional preprocessing needs to

Johannes Bouman; Sietse Rispens; Thomas Gruber; Radboud Koop; Ernst Schrama; Pieter Visser; Carl Christian Tscherning; Martin Veicherts

2009-01-01

4

Low gravity liquid level sensor rake  

NASA Technical Reports Server (NTRS)

The low gravity liquid level sensor rake measures the liquid surface height of propellant in a propellant tank used in launch and spacecraft vehicles. The device reduces the tendency of the liquid propellant to adhere to the sensor elements after the bulk liquid level has dropped below a given sensor element thereby reducing the probability of a false liquid level measurement. The liquid level sensor rake has a mast attached internal to a propellant tank with an end attached adjacent the tank outlet. Multiple sensor elements that have an arm and a sensor attached at a free end thereof are attached to the mast at locations selected for sensing the presence or absence of the liquid. The sensor elements when attached to the mast have a generally horizontal arm and a generally vertical sensor.

Grayson, Gary D. (Inventor); Craddock, Jeffrey C. (Inventor)

2003-01-01

5

Numerical simulation and flight experiment on oscillating lifted flames in coflow jets with gravity level variation  

SciTech Connect

Characteristics of oscillating lifted flames have been investigated numerically and experimentally by varying the gravity level in coflow jets with propane fuel highly diluted with nitrogen. The results showed that the oscillation amplitude and frequency increased with gravity level. As the gravity level decreased, the oscillation ceased and stationary lifted flames were stabilized when the gravity level became smaller than a critical value. A flame blowout occurred at high gravity levels. The reason for this limited range of oscillation has been analyzed by considering the local characteristics of the propagation speed of tribrachial (triple) flame and axial velocity at the edges of lifted flames. Considerations of the maximum and minimum values of these two components with gravity level during the flame edge oscillation could successfully explain the lower bounds of oscillation accounting for the influences of buoyancy and flame curvature. The blowout at high gravity levels can be explained by the effect of buoyancies on burnt gas and on propane fuel in such a way that the stoichiometric contour near the flame zone became detached from the contour near the nozzle. Finally, the experiments by varying gravity level through the parabolic flights of an aircraft substantiated the overall behavior of the oscillating lifted flames. (author)

Kim, J.; Kim, K.N.; Won, S.H.; Chung, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Fujita, O.; Takahashi, J. [Division of Mechanical Science, Hokkaido University, Sapporo 060-8628 (Japan)

2006-04-15

6

High-Resolution Gravity and Time-Varying Gravity Field Recovery using GRACE and CHAMP  

NASA Technical Reports Server (NTRS)

This progress report summarizes the research work conducted under NASA's Solid Earth and Natural Hazards Program 1998 (SENH98) entitled High Resolution Gravity and Time Varying Gravity Field Recovery Using GRACE (Gravity Recovery and Climate Experiment) and CHAMP (Challenging Mini-satellite Package for Geophysical Research and Applications), which included a no-cost extension time period. The investigation has conducted pilot studies to use the simulated GRACE and CHAMP data and other in situ and space geodetic observable, satellite altimeter data, and ocean mass variation data to study the dynamic processes of the Earth which affect climate change. Results from this investigation include: (1) a new method to use the energy approach for expressing gravity mission data as in situ measurements with the possibility to enhance the spatial resolution of the gravity signal; (2) the method was tested using CHAMP and validated with the development of a mean gravity field model using CHAMP data, (3) elaborate simulation to quantify errors of tides and atmosphere and to recover hydrological and oceanic signals using GRACE, results show that there are significant aliasing effect and errors being amplified in the GRACE resonant geopotential and it is not trivial to remove these errors, and (4) quantification of oceanic and ice sheet mass changes in a geophysical constraint study to assess their contributions to global sea level change, while the results improved significant over the use of previous studies using only the SLR (Satellite Laser Ranging)-determined zonal gravity change data, the constraint could be further improved with additional information on mantle rheology, PGR (Post-Glacial Rebound) and ice loading history. A list of relevant presentations and publications is attached, along with a summary of the SENH investigation generated in 2000.

Shum, C. K.

2002-01-01

7

The Gravity Model for High School Students  

ERIC Educational Resources Information Center

The authors suggest ways in which the gravity model can be used in high school geography classes. Based on Newton's Law of Molecular Gravitation, the law states that gravitation is in direct ratio to mass and inverse ratio to distance. One activity for students involves determination of zones of influence of cities of various sizes. (Author/AV)

Tribble, Paul; Mitchell, William A.

1977-01-01

8

A new method of gravity external correction for high precision gravity measurement  

NASA Astrophysics Data System (ADS)

There are a large number of simplifying assumptions in the external gravity correction methods in order to reduce the amount of calculation and improve the efficiency of operation. However, there are some problems caused by the simplifying assumptions, for example, errors in normal gravity caused by the confusion of ellipsoids, the indirect effect caused by the difference between the geoid surface and the ellipsoid surface, errors in the Bouguer correction caused by the improper selection of the density and destruction of structure caused by the Bouguer correction. In order to overcome this problem, we proposed a new method of gravity external correction for high precision gravity measurement. There are two steps in the correction method. The first one is to calculate the normal gravity of stations in any position with arbitrary latitude and geodetic height and then gravity anomaly is calculated by subtracting normal gravity from absolute gravity. The gravity anomaly to the position of station can be calculated instead of the gravity anomaly relative to the datum. Using some theoretical models and actual data in western China, we verified the gravity correction method proposed in the paper, and the result showed that the method can improve the accuracy and exploration effect of gravity exploration.

Luo, Di; Cai, Feng; Liu, Zhan

2014-10-01

9

Effects of continuous exposure to high gravity on gravity preference in rats.  

NASA Technical Reports Server (NTRS)

Rats were chronically centrifuged in excess of 2.0 g for 6 or 12 mo. They were given four 24-hr gravity-preference tests in a spiral centrifuge in which they could adjust the gravity level imposed by locomoting inward or outward radially along a track. Chronically centrifuged rats (Group CC) spent as much time at 2.0 g as at 1.0 g while normally raised controls (Group NC) selecdonly 1.0 g. Group CC initially selected 2.0 g and a preference for 1.0 g developed over the four test sessions. These results suggest that hypergravity is not necessarily an aversive stimulus and that gravity preference may depend initially upon the reference level involved. The ultimate selection of 1.0 g by chronically centrifuged animals suggests that a preference for a familiar gravity environment is replaced by a preference for low-gravity stimuli.

Mccoy, D. F.; Jankovich, J. P.

1972-01-01

10

Lignocellulosic ethanol production at high-gravity: challenges and perspectives.  

PubMed

In brewing and ethanol-based biofuel industries, high-gravity fermentation produces 10-15% (v/v) ethanol, resulting in improved overall productivity, reduced capital cost, and reduced energy input compared to processing at normal gravity. High-gravity technology ensures a successful implementation of cellulose to ethanol conversion as a cost-competitive process. Implementation of such technologies is possible if all process steps can be performed at high biomass concentrations. This review focuses on challenges and technological efforts in processing at high-gravity conditions and how these conditions influence the physiology and metabolism of fermenting microorganisms, the action of enzymes, and other process-related factors. Lignocellulosic materials add challenges compared to implemented processes due to high inhibitors content and the physical properties of these materials at high gravity. PMID:24231155

Koppram, Rakesh; Tomás-Pejó, Elia; Xiros, Charilaos; Olsson, Lisbeth

2014-01-01

11

Improved GOCE Gradiometer Level 1b Data Processing - Impact on Gravity Gradients and Gravity Field Models  

NASA Astrophysics Data System (ADS)

In the last year enhanced strategies for the GOCE gradiometer Level 1b processing have been developed, published and implemented within ESA's payload data ground segment. The novelties are (a) an improved method for the reconstruction of angular rates from gradiometer and star sensor data, (b) a new method for the determination of the inertial attitude quaternions, also based on a combination of gradiometer and star sensor data, (c) the use of all simultaneously available star sensor data and (d) an improved calibration of the gradiometer data that takes the time dependency of calibration parameters into account. At this point in time, the reprocessing of the gradiometer data is almost complete. In this paper, a quality assessment of the reprocessed gradiometer data is performed for two selected periods: 01/11/2009 - 31/12/2009 and 08/06/2011 - 23/08/2011. This allows on the one hand a comparison of the reprocessed and original (first released) data. The improved quality of reprocessed data is demonstrated on the level of gravity gradients as well as gravity field models. On the other hand, the analysis of the two periods allows a comparison of the quality of gravity gradients that were obtained under different aerodynamic drag conditions. Since the launch in 2009, aerodynamic drag experienced by the GOCE satellite has increased as the solar cycle advances towards maximum solar activity expected in 2013. In this way, the importance of the reprocessing is stressed not only for gradiometer data measured until today, but also in the future.

Siemes, C.; Stummer, C.; Fecher, T.; Rexer, M.; Haagmans, R.; Floberghagen, R.

2012-04-01

12

A high frequency resonance gravity gradiometer.  

PubMed

A new setup OGRAN--the large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare events--gravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS. PMID:24985859

Bagaev, S N; Bezrukov, L B; Kvashnin, N L; Krysanov, V A; Oreshkin, S I; Motylev, A M; Popov, S M; Rudenko, V N; Samoilenko, A A; Skvortsov, M N; Yudin, I S

2014-06-01

13

Gravity  

NASA Astrophysics Data System (ADS)

Preface; 1. Foundations of Newtonian gravity; 2. Structure of self-gravitating bodies; 3. Newtonian orbital dynamics; 4. Minkowski spacetime; 5. Curved spacetime; 6. Post-Minkowskian theory: formulation; 7. Post-Minkowskian theory: implementation; 8. Post-Newtonian theory: fundamentals; 9. Post-Newtonian theory: system of isolated bodies; 10. Post-Newtonian celestial mechanics, astrometry and navigation; 11. Gravitational waves; 12. Radiative losses and radiation reaction; 13. Alternative theories of gravity; References; Index.

Poisson, Eric; Will, Clifford M.

2014-05-01

14

High-resolution gravity survey: Investigation of subsurface structures at Poas volcano, Costa Rica  

E-print Network

High-resolution gravity survey: Investigation of subsurface structures at Poa´s volcano, Costa Rica July 2004; published 3 August 2004. [1] Bouguer gravity surveys have long been used to investigate sub correction. Here we describe a high- resolution gravity survey at Poa´s volcano, Costa Rica. Our gravity

Williams-Jones, Glyn

15

Nucleate pool boiling: High gravity to reduced gravity; liquid metals to cryogens  

NASA Technical Reports Server (NTRS)

Requirements for the proper functioning of equipment and personnel in reduced gravity associated with space platforms and future space station modules introduce unique problems in temperature control; power generation; energy dissipation; the storage, transfer, control and conditioning of fluids; and liquid-vapor separation. The phase change of boiling is significant in all of these. Although both pool and flow boiling would be involved, research results to date include only pool boiling because buoyancy effects are maximized for this case. The effective application of forced convection boiling heat transfer in the microgravity of space will require a well grounded and cogent understanding of the mechanisms involved. Experimental results are presented for pool boiling from a single geometrical configuration, a flat surface, covering a wide range of body forces from a/g = 20 to 1 to a/g = 0 to -1 for a cryogenic liquid, and from a/g = 20 to 1 for water and a liquid metal. Similarities in behavior are noted for these three fluids at the higher gravity levels, and may reasonably be expected to continue at reduced gravity levels.

Merte, Herman, Jr.

1988-01-01

16

in High Level Synthesis  

Microsoft Academic Search

This paper introduces hot potato high level synthesis transformation techniques. These techniques add deflection operations in the behavioral description of a computation in such a way that the requirements for two important components of the final implementation cost, the number of registers and the number of interconnects, are significantly reduced. Moreover, it is shown how hot potato techniques can be

Miodrag Potkonjak; Sujit Dey

17

Theory of high-temperature superconductivity and effective gravity  

SciTech Connect

We argue that an approach involving effective gravity could play a crucial role in elucidating the properties of the high-temperature superconducting materials. In particular we propose that the high critical temperature might be naturally explained in a framework constructed as a direct condensed-matter analog of the Randall-Sundrum approach to a geometrization of the hierarchy problem in high-energy physics.

Minic, Djordje; Heremans, J. J. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States)

2008-12-01

18

Water movement surveillance with high resolution surface gravity and GPS; a model study with field test results  

SciTech Connect

A unique method to monitor gas cap water movement in an Arctic environment has been developed and tested. The novel surveillance technique for monitoring the water movement had to be developed given the very limited number of wells that penetrate the gas cap. Conventional fluid monitoring techniques require drilling numerous observation wells to adequately monitor water movement. Modeling studies indicate that density changes associated with water replacing gas can be detected using high-resolution surface gravity measurements. Modeling gravity effects of water movement mass distribution, mass balance and water front detection are discussed. A test of the gravity meter and essential high precision station positioning under typical Arctic winter conditions is evaluated using the Global Positioning System (GPS). Modeling results have shown the general shape of the water front can be detected using surface gravity with {mu}Gal precision. With high precision gravity measurements, greater than 90% of the increased water can be accounted for in the resulting gravity anomaly. These estimates include reasonable assumptions concerning the noise level in the measurements of both the gravity data and the location data using the Global Positioning System (GPS). The average water front can be reliably detected within a producing well spacing (approximately 2000 ft (610 m)). Surface gravity and GPS were gathered over the Arctic Ocean in typical winter conditions (-44{degrees} F) accurately enough to monitor the water movement (surface gravity = (+-)5 {mu}Gals: GPS = {+-}1 cm elevation). In fact, this was the first high precision gravity survey using a GPS antenna as an integral part of the surface gravity meter housing.

Brady, J.L.; Wolcott, D.S.; Daggett, P.H. [and others

1995-12-31

19

Goce and Its Role in Combined Global High Resolution Gravity Field Determination  

NASA Astrophysics Data System (ADS)

Combined high-resolution gravity field models serve as a mandatory basis to describe static and dynamic processes in system Earth. Ocean dynamics can be modeled referring to a high-accurate geoid as reference surface, solid earth processes are initiated by the gravity field. Also geodetic disciplines such as height system determination depend on high-precise gravity field information. To fulfill the various requirements concerning resolution and accuracy, any kind of gravity field information, that means satellite as well as terrestrial and altimetric gravity field observations have to be included in one combination process. A key role is here reserved for GOCE observations, which contribute with its optimal signal content in the long to medium wavelength part and enable a more accurate gravity field determination than ever before especially in areas, where no high-accurate terrestrial gravity field observations are available, such as South America, Asia or Africa. For our contribution we prepare a combined high-resolution gravity field model up to d/o 720 based on full normal equation including recent GOCE, GRACE and terrestrial / altimetric data. For all data sets, normal equations are set up separately, relative weighted to each other in the combination step and solved. This procedure is computationally challenging and can only be performed using super computers. We put special emphasis on the combination process, for which we modified especially our procedure to include GOCE data optimally in the combination. Furthermore we modified our terrestrial/altimetric data sets, what should result in an improved outcome. With our model, in which we included the newest GOCE TIM4 gradiometry results, we can show how GOCE contributes to a combined gravity field solution especially in areas of poor terrestrial data coverage. The model is validated by independent GPS leveling data in selected regions as well as computation of the mean dynamic topography over the oceans. Further, we analyze the statistical error estimates derived from full covariance propagation and compare them with the absolute validation with independent data sets.

Fecher, T.; Pail, R.; Gruber, T.

2013-12-01

20

Investigating High Field Gravity using Astrophysical Techniques  

SciTech Connect

The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques. As the subject matter is vast, compromises are necessary in order to convey the central ideas to the reader. Many general references are included for those who want to learn more. The paragraphs below elaborate on the structure of these lectures. I hope this discussion will clarify my motivation and make the lectures easier to follow. The lectures begin with a brief review of more theoretical ideas. First, elements of general relativity are reviewed, concentrating on those aspects that are needed to understand compact stellar objects (white dwarf stars, neutron stars, and black holes). I then review the equations of state of these objects, concentrating on the simplest standard models from astrophysics. After these mathematical preliminaries, Sec. 2(c) discusses 'The End State of Stars'. Most of this section also uses the simplest standard models. However, as these lectures are for particle physicists, I also discuss some of the more recent approaches to the equation of state of very dense compact objects. These particle-physics-motivated equations of state can dramatically change how we view the formation of black holes. Section 3 focuses on the properties of the objects that we want to characterize and measure. X-ray binary systems and Active Galactic Nuclei (AGN) are stressed because the lectures center on understanding very dense stellar objects, black hole candidates (BHCs), and their accompanying high gravitational fields. The use of x-ray timing and gamma-ray experiments is also introduced in this section. Sections 4 and 5 review information from x-ray and gamma-ray experiments. These sections also discuss the current state of the art in x-ray and gamma-ray satellite experiments and plans for future experiments.

Bloom, Elliott D.; /SLAC

2008-02-01

21

Optical emission spectroscopic study for diagnostics in high gravity DC-plasma CVD diamond growth  

Microsoft Academic Search

The effect of gravity on materials processing is rather complicated, and a large number of considerably unexpected results\\u000a due to high gravity or sometimes centrifugation have been reported. The authors have been conducting high gravity diamond\\u000a thin film growth by the DC-plasma CVD method up to 100 G. The effects of high gravity appeared in the nucleation site density,\\u000a growth

Yoshiyuki Abe; Fabrizio Tappero; Yuki Tanaka; Yoshiki Takagi; Giovanni Maizza

2006-01-01

22

Gravity waves generated by convection during TWP-ICE: 2. High-frequency gravity waves  

NASA Astrophysics Data System (ADS)

High-frequency gravity waves are analyzed using radiosonde soundings taken during the Tropical Warm Pool-International Cloud Experiment (TWP-ICE). The intrinsic periods of these waves are estimated to be between 10 and 50 min. The high-frequency wave activity in the stratosphere, defined by mass-weighted variance of the vertical motion of the sonde, has a maximum following the afternoon local convection indicating that these waves are generated by local convection. The wave activity is the strongest in the lower stratosphere below 22 km and, during the suppressed monsoon period, is modulated with a 3-4 day period. The concentration of the wave activity in the lower stratosphere is consistent with the properties of the environment in which these waves propagate, whereas its 3-4 day modulation is explained by the variation of the convection activity in the TWP-ICE domain. For shallow convection, the wave activity has a weak tendency to increase as the rainfall intensity increases. The wave activity associated with deep convection, which typically occurs at high rainfall intensities, is larger and has more spread than that associated with shallow convection.

Hankinson, Mai C. N.; Reeder, M. J.; Lane, T. P.

2014-05-01

23

Bed topography of Store Glacier, Greenland from high-resolution airborne gravity data  

NASA Astrophysics Data System (ADS)

Store Glacier is a major west Greenland outlet tidewater glacier draining an area of 30,000 square km into Uummannaq Fjord, flowing at a speed of 4.8 km per year at the terminus. The bed topography of the glacier is poorly known and the fjord bathymetry has only been partially surveyed for the first time in 2012. In this study, we present a new approach on the modeling of glacier thickness and sea floor bathymetry based on high resolution gravity constrained with other observations. In August 2012, we acquired a 250m spacing grid of free-air gravity data at a speed of 50 knots with accuracy at sub-milligal level. We constrain the 3D inversion of these gravity data with ship-borne bathymetry near the glacier front and radar-derived ice thickness on grounded ice to derive a seamless map of bed topography of grounded ice and sea floor. Comparison of the new topography with prior maps reveals vast differences. Prior bathymetry (IBCAO3) has an ice front grounded at sea level whereas observations show a depth of 550m. On grounded ice, the data reveal the subglacial topography at an unprecedented level of spatial details. We discuss the impact of the results on the modeling of the glacier flow and the understanding of its interaction with ocean thermal forcing and surface mass balance.

An, L.; Rignot, E. J.

2013-12-01

24

Testing gravity at the second post-Newtonian level through gravitational deflection of massive particles  

SciTech Connect

Expression for second post-Newtonian level gravitational deflection angle of massive particles is obtained in a model independent framework. Comparison of theoretical values with the observationally constructed values of post-Newtonian parameters for massive particles offers the future possibility of testing at that level competing gravitational theories as well as the equivalence principle. Advantage of studying gravitational deflection of massive particles over that of massless particles in testing gravity is discussed.

Bhadra, A.; Sarkar, K.; Nandi, K. K. [High Energy and Cosmic Ray Research Centre, University of North Bengal, Siliguri, WB 734013 (India); Department of Mathematics, University of North Bengal, Siliguri, WB 734013 (India)

2007-06-15

25

Tethered gravity laboratories study  

NASA Technical Reports Server (NTRS)

The use is studied of tether systems to improve the lowest possible steady gravity level on the Space Station. Particular emphasis is placed by the microgravity community on the achievement of high quality microgravity conditions. The tether capability is explored for active control of the center of gravity and the analysis of possible tethered configurations.

Lucchetti, F.

1989-01-01

26

High pressure liquid level monitor  

DOEpatents

A liquid level monitor for tracking the level of a coal slurry in a high-pressure vessel including a toroidal-shaped float with magnetically permeable bands thereon disposed within the vessel, two pairs of magnetic field generators and detectors disposed outside the vessel adjacent the top and bottom thereof and magnetically coupled to the magnetically permeable bands on the float, and signal processing circuitry for combining signals from the top and bottom detectors for generating a monotonically increasing analog control signal which is a function of liquid level. The control signal may be utilized to operate high-pressure control valves associated with processes in which the high-pressure vessel is used.

Bean, Vern E. (Frederick, MD); Long, Frederick G. (Ijamsville, MD)

1984-01-01

27

High-Level Radioactive Waste.  

ERIC Educational Resources Information Center

Presents a method to calculate the amount of high-level radioactive waste by taking into consideration the following factors: the fission process that yields the waste, identification of the waste, the energy required to run a 1-GWe plant for one year, and the uranium mass required to produce that energy. Briefly discusses waste disposal and…

Hayden, Howard C.

1995-01-01

28

The CMS High Level Trigger  

E-print Network

The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a tradeoff between the complexity of the algorithms running on the available computing power, the sustainable output rate, and the selection efficiency. Here we will present the performance of the main triggers used during the 2012 data taking, ranging from simpler single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We will discuss the optimisation of the triggers and the specific techniques to cope with the increasing LHC pile-up, reducing its impact on the physics performance.

Valentina Gori

2014-03-06

29

The CMS High Level Trigger  

E-print Network

The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a tradeoff between the complexity of the algorithms running on the available computing power, the sustainable output rate, and the selection efficiency. Here we will present the performance of the main triggers used during the 2012 data taking, ranging from simpler single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We will discuss the optimisation of the triggers and the specific techniques to cope with the increasing LHC pile-up, reducing its impact on the physics performance.

Gori, Valentina

2014-01-01

30

Ocean contribution to seismic gravity changes: the sea level equation for seismic perturbations revisited  

NASA Astrophysics Data System (ADS)

During megathrust earthquakes, great ruptures are accompanied by large scale mass redistribution inside the solid Earth and by ocean mass redistribution due to bathymetry changes. These large scale mass displacements can be detected using the monthly gravity maps of the GRACE satellite mission. In recent years it has become increasingly common to use the long wavelength changes in the Earth's gravity field observed by GRACE to infer seismic source properties for large megathrust earthquakes. An important advantage of space gravimetry is that it is independent from the availability of land for its measurements. This is relevant for observation of megathrust earthquakes, which occur mostly offshore, such as the M_{text{w}} ˜ 9 2004 Sumatra-Andaman, 2010 Maule (Chile) and 2011 Tohoku-Oki (Japan) events. In Broerse et al., we examined the effect of the presence of an ocean above the rupture on long wavelength gravity changes and showed it to be of the first order. Here we revisit the implementation of an ocean layer through the sea level equation and compare the results with approximated methods that have been used in the literature. One of the simplifications usually lies in the assumption of a globally uniform ocean layer. We show that especially in the case of the 2010 Maule earthquake, due to the closeness of the South American continent, the uniform ocean assumption is not valid and causes errors up to 57 per cent for modelled peak geoid height changes (expressed at a spherical harmonic truncation degree of 40). In addition, we show that when a large amount of slip occurs close to the trench, horizontal motions of the ocean floor play a mayor role in the ocean contribution to gravity changes. Using a slip model of the 2011 Tohoku-Oki earthquake that places the majority of slip close to the surface, the peak value in geoid height change increases by 50 per cent due to horizontal ocean floor motion. Furthermore, we test the influence of the maximum spherical harmonic degree at which the sea level equation is performed for sea level changes occurring along coastlines, which shows to be important for relative sea level changes occurring along the shore. Finally, we demonstrate that ocean floor loading, self-gravitation of water and conservation of water mass are of second order importance for coseismic gravity changes. When GRACE observations are used to determine earthquake parameters such as seismic moment or source depth, the uniform ocean layer method introduces large biases, depending on the location of the rupture with respect to the continent. The same holds for interpreting shallow slip when horizontal motions are not properly accounted for in the ocean contribution. In both cases the depth at which slip occurs will be underestimated.

Broerse, Taco; Riva, Riccardo; Vermeersen, Bert

2014-11-01

31

Wireless optical diagnostic apparatus for analyzing diamond thin film CVD process under high gravity conditions  

Microsoft Academic Search

A wireless optical emission diagnostic apparatus has been developed for in-situ diagnosis of the high gravity (HG) plasma properties during diamond chemical vapor deposition using H2–CH4 gas mixture. Optical emission spectroscopy (OES) enabled us to identify the emitting chemical species and to qualitatively investigate the plasma composition changes as a function of process parameters, including gravity, up to 100 g.

F. Tappero; Y. Abe; Y. Takagi; Y. Tanaka; G. Maizza

2004-01-01

32

Effect of Gravity Level on the Particle Shape and Size During Zeolite Crystal Growth  

NASA Technical Reports Server (NTRS)

A microscopic diffusion model is developed to represent solute transport in the boundary layer of a growing zeolite crystal. This model is used to describe the effect of gravity on particle shape and solute distribution. Particle dynamics and crystal growth kinetics serve as the boundary conditions of flow and convection-diffusion equations. A statistical rate theory is used to obtain the rate of solute transport across the growing interface, which is expressed in terms of concentration and velocity of solute species. Microgravity can significantly decrease the solute velocity across the growing interface compared to its earth-based counterpart. The extent of this reduction highly depends on solute diffusion constant in solution. Under gravity, the flow towards the crystal enhances solute transport rate across the growing interface while the flow away from crystals reduces this rate, suggesting a non-uniform growth rate and thus an elliptic final shape. However, microgravity can significantly reduce the influence of flow and obtain a final product with perfect spherical shape. The model predictions compare favorably with the data of space experiment of zeolites grown in space.

Song, Hong-Wei; Ilebusi, Olusegun J.; Sacco, Albert, Jr.

2003-01-01

33

Monitoring Earthquake Fault Slip from Space: Model Implications for a High Precision, High Resolution Dedicated Gravity Mission (Invited)  

NASA Astrophysics Data System (ADS)

Monitoring deformation produced by slip on earthquake faults can be carried out via GPS or InSAR measurements. Both of these types of observations have their advantages and disadvantages, in terms of cost, availability, and technical difficulty. It has been suggested that another method to accomplish many of the same objectives would be via a dedicated gravity mission. The GRACE mission has shown that it is possible to make detailed gravity measurements from space for climate dynamics and other purposes. An important question is what level of accuracy will be needed for precise estimation of fault slip in earthquakes of interest to researchers. To answer this question, we turn to numerical simulations of earthquake fault systems and use these to estimate gravity changes. Rundle (1978) considered the question of gravity changes from dilation sources and thrust faults, and found that gravity changes in these cases were free air anomaly (dilation) and Bouguer anomaly (thrust fault). Walsh and Rice (1978) computed these by a different method and found the same result. Okada (1991) listed gravity and potential Green functions for all possible sources for the general case. Hayes et al (2006) then took the Okada Greens functions and applied them computed from an earlier version of Virtual California earthquake fault system simulations. Those simulations only involved vertical strike slip faults. The current far more advanced generation of Virtual California simulations involves faults of any orientation, dip, and rake. In this talk, we discuss these computations and the implications they have for accuracies needed for a dedicated gravity monitoring mission. Preliminary results are in agreement with previous results from Hayes et al (2006). Computed gravity changes are in the range of tens to hundreds of microgals over distances of few to many tens of kilometers. These values are presumably well within the range of measurement for a modern gravity mission flown either at low altitudes, or via UAVs.

Rundle, J. B.; Sachs, M. K.; Tiampo, K. F.; Fernandez, J.; Turcotte, D. L.; Donnellan, A.; Heien, E. M.; Kellogg, L. H.

2013-12-01

34

Testing Plate Reconstructions For The High Arctic Using Crustal Thickness Mapping From Gravity Inversion  

NASA Astrophysics Data System (ADS)

The plate tectonic history of the Amerasia Basin (High Arctic) and its distribution of oceanic and continental lithosphere is poorly known. A new method of gravity inversion with an embedded lithosphere thermal gravity anomaly correction has been applied to the NGA (U) Arctic Gravity Project data to predict crustal thickness and to test different plate reconstructions within the Arctic region. Two end member plate reconstruction models have been tested: in one model the Mendeleev Ridge is rifted from the Canadian margin while in the other it is rifted from the Lomonosov Ridge. The inversion of gravity data to map crustal thickness variation within oceanic and rifted continental margin lithosphere requires the incorporation of a lithosphere thermal gravity anomaly correction for both oceanic and continental lithosphere. Oceanic lithosphere and stretched continental margin lithosphere produce a large negative residual thermal gravity anomaly (up to -380 mGal), for which a correction must be made in order to determine realistic Moho depth by gravity anomaly inversion. The lithosphere thermal model used to predict the lithosphere thermal gravity anomaly correction may be conditioned using plate reconstruction models to provide the age and location of oceanic lithosphere. Two end- member plate reconstruction models have been constructed for the opening of the Amerasia Basin and used to determine lithosphere thermal gravity anomaly corrections: in one model the (presumably) continental Mendeleev Ridge is rifted from the Canadian margin in the Jurassic while in the other it is rifted off the Lomonosov Ridge (Eurasia Basin) in the Late-Cretaceous. Crustal thickness predicted by gravity anomaly inversion for the two plate reconstructions is significantly different in the Makarov Basin because of their different lithosphere thermal gravity corrections. The plate reconstruction with younger Makarov Basin ages gives a crustal thickness of the order 6-8 km thinner than the older Makarov Basin model. A crustal thickness of approximately 20 km has been obtained from seismic refraction data (Lebedeva-Ivanova et al., 2006) which would imply a Late Mid-Cretaceous age for the Makarov Basin. In this case plume-related forces may have contributed to the opening of this basin, as regional plate tectonics predict compression and not extension in the Makarov Basin area at this time.

Alvey, A. D.; Gaina, C.; Kusznir, N. J.; Torsvik, T. H.

2006-12-01

35

Gravity Fountains  

NSDL National Science Digital Library

This activity (located on page 3 of the PDF) is a full inquiry investigation into the forces of gravity and air pressure. Groups of learners will construct a simple gravity fountain by making a hole near the bottom of a 2-liter bottle, filling it with water, then as the bottle empties, collecting measurements of the water levels and length of the stream, to make a graph for analysis. Relates to linked video, DragonflyTV GPS: Gravity Fountain.

Twin Cities Public Television, Inc.

2007-01-01

36

Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions  

NASA Technical Reports Server (NTRS)

The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

Wang, Y.; Gupta, A. K.

2001-01-01

37

A study of the effects of heater size, subcooling, and gravity level on pool boiling heat transfer  

E-print Network

A study of the effects of heater size, subcooling, and gravity level on pool boiling heat transfer Martin Hill, College Park, MD 20742, USA Abstract Pool boiling heat transfer measurements from different. Boiling on three heaters of different size (0.65, 2.62, 7.29 mm2 ) was studied. Control circuitry was used

Kim, Jungho

38

Venus gravity  

NASA Technical Reports Server (NTRS)

The anomalous gravity field of Venus shows high correlation with surface features revealed by radar. We extract gravity models from the Doppler tracking data from the Pioneer Venus Orbiter (PVO) by means of a two-step process. In the first step, we solve the nonlinear spacecraft state estimation problem using a Kalman filter-smoother. The Kalman filter was evaluated through simulations. This evaluation and some unusual features of the filter are discussed. In the second step, we perform a geophysical inversion using a linear Bayesian estimator. To allow an unbiased comparison between gravity and topography, we use a simulation technique to smooth and distort the radar topographic data so as to yield maps having the same characteristics as our gravity maps. The maps presented cover 2/3 of the surface of Venus and display the strong topography-gravity correlation previously reported. The topography-gravity scatter plots show two distinct trends.

Reasenberg, Robert D.

1993-01-01

39

High frequency atmospheric gravity-wave properties using Fe-lidar and OH-imager observations  

E-print Network

. [1] Simultaneous iron resonance lidar density profiles, OH intensity images and MF-radar wind the vertical component of the wave or the background wind is required. Lidars resonant with atoms or moleculesHigh frequency atmospheric gravity-wave properties using Fe-lidar and OH-imager observations J. C

Chu, Xinzhao

40

Isolation and characterization of brewer's yeast variants with improved fermentation performance under high-gravity conditions.  

PubMed

To save energy, space, and time, today's breweries make use of high-gravity brewing in which concentrated medium (wort) is fermented, resulting in a product with higher ethanol content. After fermentation, the product is diluted to obtain beer with the desired alcohol content. While economically desirable, the use of wort with an even higher sugar concentration is limited by the inability of brewer's yeast (Saccharomyces pastorianus) to efficiently ferment such concentrated medium. Here, we describe a successful strategy to obtain yeast variants with significantly improved fermentation capacity under high-gravity conditions. We isolated better-performing variants of the industrial lager strain CMBS33 by subjecting a pool of UV-induced variants to consecutive rounds of fermentation in very-high-gravity wort (>22 degrees Plato). Two variants (GT336 and GT344) showing faster fermentation rates and/or more-complete attenuation as well as improved viability under high ethanol conditions were identified. The variants displayed the same advantages in a pilot-scale stirred fermenter under high-gravity conditions at 11 degrees C. Microarray analysis identified several genes whose altered expression may be responsible for the superior performance of the variants. The role of some of these candidate genes was confirmed by genetic transformation. Our study shows that proper selection conditions allow the isolation of variants of commercial brewer's yeast with superior fermentation characteristics. Moreover, it is the first study to identify genes that affect fermentation performance under high-gravity conditions. The results are of interest to the beer and bioethanol industries, where the use of more-concentrated medium is economically advantageous. PMID:17158628

Blieck, Lies; Toye, Geert; Dumortier, Françoise; Verstrepen, Kevin J; Delvaux, Freddy R; Thevelein, Johan M; Van Dijck, Patrick

2007-02-01

41

Isolation and Characterization of Brewer's Yeast Variants with Improved Fermentation Performance under High-Gravity Conditions?  

PubMed Central

To save energy, space, and time, today's breweries make use of high-gravity brewing in which concentrated medium (wort) is fermented, resulting in a product with higher ethanol content. After fermentation, the product is diluted to obtain beer with the desired alcohol content. While economically desirable, the use of wort with an even higher sugar concentration is limited by the inability of brewer's yeast (Saccharomyces pastorianus) to efficiently ferment such concentrated medium. Here, we describe a successful strategy to obtain yeast variants with significantly improved fermentation capacity under high-gravity conditions. We isolated better-performing variants of the industrial lager strain CMBS33 by subjecting a pool of UV-induced variants to consecutive rounds of fermentation in very-high-gravity wort (>22° Plato). Two variants (GT336 and GT344) showing faster fermentation rates and/or more-complete attenuation as well as improved viability under high ethanol conditions were identified. The variants displayed the same advantages in a pilot-scale stirred fermenter under high-gravity conditions at 11°C. Microarray analysis identified several genes whose altered expression may be responsible for the superior performance of the variants. The role of some of these candidate genes was confirmed by genetic transformation. Our study shows that proper selection conditions allow the isolation of variants of commercial brewer's yeast with superior fermentation characteristics. Moreover, it is the first study to identify genes that affect fermentation performance under high-gravity conditions. The results are of interest to the beer and bioethanol industries, where the use of more-concentrated medium is economically advantageous. PMID:17158628

Blieck, Lies; Toye, Geert; Dumortier, Françoise; Verstrepen, Kevin J.; Delvaux, Freddy R.; Thevelein, Johan M.; Van Dijck, Patrick

2007-01-01

42

High temperature liquid level sensor  

DOEpatents

A length of metal sheathed metal oxide cable is perforated to permit liquid access to the insulation about a pair of conductors spaced close to one another. Changes in resistance across the conductors will be a function of liquid level, since the wetted insulation will have greater electrical conductivity than that of the dry insulation above the liquid elevation.

Tokarz, Richard D. (West Richland, WA)

1983-01-01

43

High temperature, high pressure water level sensor  

SciTech Connect

A sensor was developed to measure water level over a range of 750 mm with an uncertainty of +- 20 mm at a temperature from 20 to 250/sup 0/C and pressure up to 15.2 MPa. The sensor is type 304, flattened stainless steel rod. Its cross section is 1.6 x 3.2 mm, and its measured torsional transit time is a function of water density rho, level L, and temperature T. To minimize the influence of T, the extensional transit time is also measured in the same sensor. To interrogate the sensor with both modes, Joule and Wiedemann transducers are multiplexed in an alternating sequence. Experimental results, problems, and remedies are discussed.

Miller, G.N.; Anderson, R.L.; Lynnworth, L.C.

1980-01-01

44

High-Latitude Gravity Wave Measurements in Noctilucent Clouds and Polar Mesospheric Clouds  

Microsoft Academic Search

\\u000a Distinct wave forms traditionally observed in Noctilucent Cloud (NLC) photographs and most recently captured in high-resolution\\u000a panoramic images of Polar Mesospheric Clouds (PMC) provide an exceptionally rich resource for quantifying gravity wave activity\\u000a and properties in the high-latitude summer mesopause region. Using extensive image data on PMC structures obtained by the\\u000a Cloud Imaging and Particle Size (CIPS) ultraviolet instrument onboard

Michael J. Taylor; P.-D. Pautet; Y. Zhao; C. E. Randall; J. Lumpe; S. M. Bailey; J. Carstens; K. Nielsen; James M. Russell; J. Stegman

45

HIGH-LEVEL SCRIPTING AVATAR ANIMATION  

E-print Network

HIGH-LEVEL SCRIPTING AVATAR ANIMATION #12;ANIMATION SCRIPT Voice synthesizer Face muscle Control ) 3-D ARTICULATED AVATAR Avatar /"Machine" ­ level Instructions Story-level Instructions language for avatar animation · Highest level of abstraction: story-level description ­ constrained English

Petriu, Emil M.

46

Monitoring yeast physiology during very high gravity wort fermentations by frequent analysis of gene expression.  

PubMed

Brewer's yeast experiences constantly changing environmental conditions during wort fermentation. Cells can rapidly adapt to changing surroundings by transcriptional regulation. Changes in genomic expression can indicate the physiological condition of yeast in the brewing process. We monitored, using the transcript analysis with aid of affinity capture (TRAC) method, the expression of some 70 selected genes relevant to wort fermentation at high frequency through 9-10 day fermentations of very high gravity wort (25 degrees P) by an industrial lager strain. Rapid changes in expression occurred during the first hours of fermentations for several genes, e.g. genes involved in maltose metabolism, glycolysis and ergosterol synthesis were strongly upregulated 2-6 h after pitching. By the time yeast growth had stopped (72 h) and total sugars had dropped by about 50%, most selected genes had passed their highest expression levels and total mRNA was less than half the levels during growth. There was an unexpected upregulation of some genes of oxygen-requiring pathways during the final fermentation stages. For five genes, expression of both the Saccharomyces cerevisiae and S. bayanus components of the hybrid lager strain were determined. Expression profiles were either markedly different (ADH1, ERG3) or very similar (MALx1, ILV5, ATF1) between these two components. By frequent analysis of a chosen set of genes, TRAC provided a detailed and dynamic picture of the physiological state of the fermenting yeast. This approach offers a possible way to monitor and optimize the performance of yeast in a complex process environment. PMID:17605133

Rautio, Jari J; Huuskonen, Anne; Vuokko, Heikki; Vidgren, Virve; Londesborough, John

2007-09-01

47

High-resolution numerical modeling of wave-supported gravity-driven mudflows  

NASA Astrophysics Data System (ADS)

Wave-supported gravity-driven mudflow has been identified as a major offshore fine sediment transport mechanism of terrestrial sediment into the coastal ocean. This transport process essentially occurs within the wave boundary layer. In this study, wave-supported gravity-driven mudflow is investigated via a wave-phase-resolving high-resolution numerical model for fluid mud transport. The model results are verified with field observation of sediment concentration and near-bed flow velocities at Po prodelta. The characteristics of wave-supported gravity-driven mudflows are diagnosed by varying the bed erodibility, floc properties (fractal dimension), and rheological stresses in the numerical simulations. Model results for moderate concentration suggest that using an appropriately specified fractal dimension, the dynamics of wave-supported gravity-driven mudflow can be predicted without explicitly incorporating rheological stress. However, incorporating rheological stress makes the results less sensitive to prescribed fractal dimension. For high-concentration conditions, it is necessary to incorporate rheological stress in order to match observed intensity of downslope gravity-driven current. Model results are further analyzed to evaluate and calibrate simple parameterizations. Analysis suggests that when neglecting rheological stress, the drag coefficient decreases with increasing wave intensity and seems to follow a power law. However, when rheological stress is incorporated, the resulting drag coefficient is more or less constant (around 0.0013) for different wave intensities. Model results further suggest the bulk Richardson number has a magnitude smaller than 0.25 and is essentially determined by the amount of available soft mud (i.e., the erodibility), suggesting a supply limited condition for unconsolidated mud.

Hsu, Tian-Jian; Ozdemir, Celalettin E.; Traykovski, Peter A.

2009-05-01

48

Exploration of Anomalous Gravity Effects by rf-Pumped Magnetized High-T(c) Superconducting Oxides  

NASA Technical Reports Server (NTRS)

A number of anomalous gravitational effects have been reported in the scientific literature during recent years, but there has been no independent confirmation with regard to any of these claims. Therefore, the NASA Marshall Space Flight Center, in response to the propulsion challenges specified by NASA's Breakthrough Propulsion Physics (BPP) program, proposed to explore the possibility of observing anomalous gravitation behavior through the manipulation of Josephson junction effects in magnetized high-Tc superconducting oxides. The technical goal was to critically test this revolutionary physical claim and provide a rigorous, independent, empirical confirmation (or refutation) of anomalous effects related to the manipulation of gravity by radio frequency (rf)-pumped magnetized type-2 superconductors. Because the current empirical evidence for gravity modification is anecdotal, our objective was to design, construct, and meticulously implement a discriminating experiment, which would put these observations on a more firm footing within the scientific community. Our approach is unique in that we advocate the construction of an extremely sensitive torsion balance with which to measure gravity modification effects by rf-pumped type-2 superconductor test masses. This paper reviews the anecdotal evidence for anomalous gravity effects, describes the design and development of a simplified torsion balance experiment for empirically investigating these claims, and presents the results of preliminary experiments.

Robertson, Tony; Litchford, Ron; Peters, Randall; Thompson, Byran; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

49

Onset of Soret-driven convection of binary fluid in square cavity heated from above at different gravity levels  

NASA Astrophysics Data System (ADS)

The instability of incompressible viscous binary fluid with the Soret effect in square cavity heated from above is studied for different gravity levels. The no slip and zero mass flux conditions are imposed on all the boundaries. The horizontal boundaries are perfectly conductive, they are maintained at constant different temperatures and vertical boundaries are adiabatic. The calculations are performed for water - isopropanol mixture 90:10. Initial conditions correspond to the motionless state with uniform distribution of components and uniform temperature gradient directed upward. For binary fluid under consideration the separation parameter is negative therefore the Soret effect leads to the accumulation of heavy component in the upper part of cavity, moreover, the rate of accumulation is independent of the gravity level. The linear stability of the unsteady motionless state is studied numerically by solving linearized equations for small perturbations. To determine the time t* for the onset of instability, the criterion suggested in [1] is used. The dependence of t* on the gravity level is obtained. The work was done under financial support of Government of Perm Region, Russia (Contract C-26/212). 1. Shliomis M.I., Souhar M. Europhysics Letters. 2000. Vol. 49 (1), pp. 55-61.

Lyubimova, Tatyana; Zubova, Nadezhda

50

Fuel alcohol production: Optimization of temperature for efficient very-high-gravity fermentation  

SciTech Connect

The time required to end ferment wheat mash decreased as the temperature was increased from 17 to 33[degrees]C, but it increased as the concentration of dissolved solids was raised from 14.0 to 36.5 g/100 ml. Ethanol yield was not appreciably affected. Over the range of fermentation temperature tested, the addition of urea accelerated the rate of fermentation, decreased the time required to complete fermentation at all dissolved-solid concentrations, and stimulated the production of slightly more ethanol than was produced by the corresponding unsupplemented control mashes. The optimum temperature for maximum ethanol production in urea-supplemented very-high-gravity wheat mash was 27[degrees]C. These data are important for the industrial assessment of very-high-gravity fermentation technology. 19 refs., 2 figs.

Jones, A.M.; Ingledew, M.M. (Univ. of Saskatchewan, Saskatoon (Canada))

1994-03-01

51

Mass changes at different levels revealed by micro-gravity and deformation measurements at Kilauea Volcano, Hawai'i. (Invited)  

NASA Astrophysics Data System (ADS)

Using campaign micro-gravity measurements collected at Kilauea Volcano, Hawai'i (United States), between December 2009 and November 2012, we document significant mass variations at the summit of the volcano. These variations produce a maximum residual gravity change of +370 × 14 ?Gal near the east margin of Halema'uma'u Crater, within Kilauea's summit caldera, where in March 2008 a new eruptive vent opened. This vent has progressively enlarged through several collapses and now forms a 210x160 m elliptical cavity that is currently occupied by a lava lake whose surface fluctuates between 25 and 200 meters below the vent rim. Five micro-gravity surveys were performed using two Scintrex CG-5 gravimeters. Each survey was completed following a double-looping procedure, and each measurement was corrected for earth-tides, ocean loading, and instrument drift. Gravity changes at each station were then corrected for the free-air effect using vertical displacements calculated from combined ascending and descending InSAR measurements. InSAR data are from both the German Space Agency (DLR) TerraSAR-X satellite and the Italian Space Agency (ASI) Cosmo-SkyMed satellite-constellation. The spatial distribution of the gravity changes suggests that they are predominantly caused by the enlargement of the vent and variations in the height of the summit lava lake. The contribution to the gravity measurements caused by changes in lava level within the conduit feeding the lava lake is therefore estimated using a numerical model that takes into account its geometry, as inferred from visual and remotely sensed (LiDAR) observations, and lava height at the time of each gravity survey, determined from thermal camera data. These results can be used to make inferences on the density of the magma filling the lava lake, which we compare to values obtained using independent data from continuous gravimeters located near the campaign stations. Estimates of the lava level effect on the gravity allow us to compensate for it and assess changes measured across Kilauea's summit that may be due to mass variations caused by subsurface magma accumulation or withdrawal. We observe that a positive anomaly (which magnitude varies depending on the density of the material used for the fluid filling the lava lake) is still present after this correction in the 20-month-long period following the March 5-9, 2011, east rift zone (ERZ) fissure eruption. InSAR data spanning the same interval show that these positive changes are associated with uplift of the summit area, which we model as the inflation of a shallow magma reservoir at ~1.5 km depth. The contemporary increase in volume, inferred from the deformation data, and in mass, inferred from the micro-gravity measurement, suggest that, after the 2011 ERZ fissure eruption, magma has been accumulating beneath the summit of Kilauea.

Bagnardi, M.; Poland, M. P.; Battaglia, M.; Carbone, D.; Baker, S.; Amelung, F.

2013-12-01

52

Revealing the beneficial effect of protease supplementation to high gravity beer fermentations using "-omics" techniques  

PubMed Central

Background Addition of sugar syrups to the basic wort is a popular technique to achieve higher gravity in beer fermentations, but it results in dilution of the free amino nitrogen (FAN) content in the medium. The multicomponent protease enzyme Flavourzyme has beneficial effect on the brewer's yeast fermentation performance during high gravity fermentations as it increases the initial FAN value and results in higher FAN uptake, higher specific growth rate, higher ethanol yield and improved flavour profile. Results In the present study, transcriptome and metabolome analysis were used to elucidate the effect on the addition of the multicomponent protease enzyme Flavourzyme and its influence on the metabolism of the brewer's yeast strain Weihenstephan 34/70. The study underlines the importance of sufficient nitrogen availability during the course of beer fermentation. The applied metabolome and transcriptome analysis allowed mapping the effect of the wort sugar composition on the nitrogen uptake. Conclusion Both the transcriptome and the metabolome analysis revealed that there is a significantly higher impact of protease addition for maltose syrup supplemented fermentations, while addition of glucose syrup to increase the gravity in the wort resulted in increased glucose repression that lead to inhibition of amino acid uptake and hereby inhibited the effect of the protease addition. PMID:21513553

2011-01-01

53

Tutorial on high-level synthesis  

Microsoft Academic Search

High-level synthesis takes an abstract behavioral specification of a digital system and finds a register-transfer level structure that realizes the given behavior. In this tutorial we will examine the high-level synthesis task, showing how it can be decomposed into a number of distinct but not independent subtasks. Then we will present the techniques that have been developed for solving those

Michael C. McFarland; Alice C. Parker; Raul Carnposano

1988-01-01

54

Demystifying magic: high-level low-level programming  

Microsoft Academic Search

The power of high-level languages lies in their abstraction over hardware and software complexity, leading to greater security, bet- ter reliability, and lower development costs. However, opaque ab- stractions are often show-stoppers for systems programmers, forc- ing them to either break the abstraction, or more often, simply give up and use a different language. This paper addresses the challenge of

Daniel Frampton; Stephen M. Blackburn; Perry Cheng; Robin J. Garner; David Grove; J. Eliot B. Moss; Sergey I. Salishev

2009-01-01

55

Parallel Processing at the High School Level.  

ERIC Educational Resources Information Center

This study investigated the ability of high school students to cognitively understand and implement parallel processing. Data indicates that most parallel processing is being taught at the university level. Instructional modules on C, Linux, and the parallel processing language, P4, were designed to show that high school students are highly

Sheary, Kathryn Anne

56

A simulation for gravity fine structure recovery from high-low GRAVSAT SST data  

NASA Technical Reports Server (NTRS)

Covariance error analysis techniques were applied to investigate estimation strategies for the high-low SST mission for accurate local recovery of gravitational fine structure, considering the aliasing effects of unsolved for parameters. Surface density blocks of 5 deg x 5 deg and 2 1/2 deg x 2 1/2 deg resolution were utilized to represent the high order geopotential with the drag-free GRAVSAT configured in a nearly circular polar orbit at 250 km. altitude. GEOPAUSE and geosynchronous satellites were considered as high relay spacecraft. It is demonstrated that knowledge of gravitational fine structure can be significantly improved at 5 deg x 5 deg resolution using SST data from a high-low configuration with reasonably accurate orbits for the low GRAVSAT. The gravity fine structure recoverability of the high-low SST mission is compared with the low-low configuration and shown to be superior.

Estes, R. H.; Lancaster, E. R.

1976-01-01

57

Signatures of neutral gas gravity waves at high latitudes - EISCAT-radar ray simulations  

NASA Astrophysics Data System (ADS)

The present state of development of GIFTS (Graz Ionospheric Flux Tube Simulation), a numerical simulation model for the ionosphere at middle and high latitudes, is reviewed, and the first results of one-to-one comparisons between GIFTS model data and genuine EISCAT Common Program data are presented. First results are also reported on simulations of ionospheric signatures caused by the passage of neutral atmospheric gravity waves. The role of electric fields in the wave background is examined, and likely future applications of the GIFTS model are considered.

Kirchengast, G.; Leitinger, R.; Schlegel, K.

58

Techno-economic implications of improved high gravity corn mash fermentation  

Microsoft Academic Search

The performance of Saccharomyces cerevisiae MBG3964, a strain able to tolerate >18% v\\/v ethanol, was compared to leading industrial ethanol strain, Fermentis Ethanol Red, under high gravity corn mash fermentation conditions. Compared to the industrial ethanol strain, MBG3964 gave increased alcohol yield (140gL?1 vs. 126gL?1), lower residual sugar (4gL?1 vs. 32gL?1), and lower glycerol (11gL?1 vs. 12gL?1). After 72h fermentation,

Arthur Kollaras; John M. Kavanagh; Geoffrey L. Bell; Dragana Purkovic; Sophia Mandarakas; Psyche Arcenal; Woon Siew Ng; Kai S. Routledge; Drew H. Selwood; Paul Koutouridis; Ferdinand E. Paras; Peter Milic; Eduardo S. Tirado-Escobar; Michael J. B. Moore; Philip J. L. Bell; Paul V. Attfield

2011-01-01

59

Application of precise altimetry to the study of precise leveling of the sea surface, the Earth's gravity field, and the rotation of the Earth  

NASA Technical Reports Server (NTRS)

Our program includes five research items: (1) determination of a precision geoid and gravity anomaly field; (2) precise leveling and detection of tidal changes of the sea surface and study of the role of the tide in the global energy exchange; (3) oceanic effect on the Earth's rotation and polar motion; (4) geological and geophysical interpretation of the altimetry gravity field; and (5) evaluation of the effectiveness of local tracking of TOPEX/POSEIDON by use of a laser tracker.

Segawa, J.; Ganeko, Y.; Sasaki, M.; Mori, T.; Ooe, M.; Nakagawa, I.; Ishii, H.; Hagiwara, Y.

1991-01-01

60

High level indole signalling in Escherichia coli  

E-print Network

1 High level indole signalling in Escherichia coli Hannah Dorne Gaimster Girton College Department of Genetics A dissertation submitted for the degree of Doctor of Philosophy: April 2014 2 Title High level... indole signalling in Escherichia coli Abstract Indole is a small signalling molecule, produced by many species of bacteria, including Escherichia coli. It is made by the enzyme tryptophanase, which converts tryptophan into indole, pyruvate and ammonia...

Gaimster, Hannah Dorne

2014-06-10

61

Finite volume numerical scheme for high-resolution gravity field modelling and its parallel implementation  

NASA Astrophysics Data System (ADS)

The paper discusses a numerical solution of the geodetic boundary value problem (GBVP) by the finite volume method (FVM). The FVM is a numerical method where numerical flux is conserved from one discretization cell to its neighbour, so it's very appropriate for solving GBVP with the Neumann and the Dirichlet BCs. Our numerical scheme is developed for 3D computational domain above an ellipsoid. It is shown that a refinement of the discretization in height's direction leads to more precise numerical results. In order to achieve high-resolution numerical results, parallel implementations of algorithms using the MPI procedures were developed and computations on parallel computers were successfully performed. This basis includes the splitting of all arrays in meridian's direction, usage of an implementation of the Bi-CGSTAB non-stationary iterative solver instead of the standard SOR and an optimization of communications on parallel computers with the NUMA architecture. This gives us higher speed up in comparison to standard approaches and enables us to develop an efficient tool for high-resolution global or regional gravity field modelling in huge areas. Numerical experiments present global modelling with the resolution comparable with EGM2008 and detailed regional modelling in the Pacific Ocean with the resolution 2x2 arc min. Input gravity disturbances are generated from the DTU10-GRAV gravity field model and the disturbing potential is computed from the GOCE_DIR2 satellite geopotential model up to degree 240. Finally, the obtained disturbing potential is used to evaluate the geopotential on the DTU10 mean sea surface and the achieved mean dynamic topography is compared with the ECCO oceanographic model.

Fašková, Z.; Macák, M.; ?underlík, R.; Mikula, K.

2012-04-01

62

High-resolution local gravity model of the south pole of the Moon from GRAIL extended mission data  

NASA Astrophysics Data System (ADS)

We estimated a high-resolution local gravity field model over the south pole of the Moon using data from the Gravity Recovery and Interior Laboratory's extended mission. Our solution consists of adjustments with respect to a global model expressed in spherical harmonics. The adjustments are expressed as gridded gravity anomalies with a resolution of 1/6° by 1/6° (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40°. The gravity anomalies have been estimated from a short-arc analysis using only Ka-band range-rate (KBRR) data over the area of interest. We apply a neighbor-smoothing constraint to our solution. Our local model removes striping present in the global model; it reduces the misfit to the KBRR data and improves correlations with topography to higher degrees than current global models.

Goossens, Sander; Sabaka, Terence J.; Nicholas, Joseph B.; Lemoine, Frank G.; Rowlands, David D.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

2014-05-01

63

Goose Bay radar observations of earth-reflected atmospheric gravity waves in the high-latitude ionosphere  

SciTech Connect

An HF backscatter radar at Goose Bay, Labrador made it possible to observe irregularities in the distribution of ionospheric ionization at E and F region altitudes (100 - 600 km) in the high-latitude (65 - 85 deg Lambda) ionosphere. Recently it has been established that the passage of atmospheric gravity waves perturbs the ionosphere in ways that are readily detected in returns that reflect off the ionospheric layers. The particular strength of the technique lies in the nearly instantaneous measurement of gravity wave effects over large areas ( 1 million sq. km). With this information the propagation of gravity waves can be accurately modelled. Generally gravity waves are observed during daylight hours propagating away from the auroral electrojets. The propagation mode involves penetration of wave energy through the lower atmosphere and subsequent reflection by the earth's surface. The frequencies associated with the waves lie in the 0.4 - 0.6 mHz range and the wavelengths vary from 300 to 500 km. The excitation sources appear to lie in the vicinity of the high-latitude electrojets. In this paper we outline the analysis of gravity wave effects on HF propagation and present an example of a modelled gravity wave event.

Ruohoniemi, J.M.; Greenwald, R.A.; Baker, K.B.; Samson, J.C.

1990-05-03

64

Effects of Varying Gravity Levels on fNIRS Headgear Performance and Signal Recovery  

NASA Technical Reports Server (NTRS)

This paper reviews the effects of varying gravitational levels on functional Near-Infrared Spectroscopy (fNIRS) headgear. The fNIRS systems quantify neural activations in the cortex by measuring hemoglobin concentration changes via optical intensity. Such activation measurement allows for the detection of cognitive state, which can be important for emotional stability, human performance and vigilance optimization, and the detection of hazardous operator state. The technique depends on coupling between the fNIRS probe and users skin. Such coupling may be highly susceptible to motion if probe-containing headgear designs are not adequately tested. The lack of reliable and self-applicable headgear robust to the influence of motion artifact currently inhibits its operational use in aerospace environments. Both NASAs Aviation Safety and Human Research Programs are interested in this technology as a method of monitoring cognitive state of pilots and crew.

Mackey, Jeffrey R.; Harrivel, Angela R.; Adamovsky, Grigory; Lewandowski, Beth E.; Gotti, Daniel J.; Tin, Padetha; Floyd, Bertram M.

2013-01-01

65

High-Level Application Framework for LCLS  

SciTech Connect

A framework for high level accelerator application software is being developed for the Linac Coherent Light Source (LCLS). The framework is based on plug-in technology developed by an open source project, Eclipse. Many existing functionalities provided by Eclipse are available to high-level applications written within this framework. The framework also contains static data storage configuration and dynamic data connectivity. Because the framework is Eclipse-based, it is highly compatible with any other Eclipse plug-ins. The entire infrastructure of the software framework will be presented. Planned applications and plug-ins based on the framework are also presented.

Chu, P; Chevtsov, S.; Fairley, D.; Larrieu, C.; Rock, J.; Rogind, D.; White, G.; Zalazny, M.; /SLAC

2008-04-22

66

Gravity and Crustal Structure in the Western Snake River Plain, Idaho  

Microsoft Academic Search

A gravity survey was made over the western Snake River Plain, Idaho. ; The data were reduced to sea level and expressed as simple Bouguer gravity ; anomalies for an assumed density of 2.67 g\\/cm³. Three elongated, ; northwesttrending, en echelon gravity highs were defined by the survey. The ; largest high is about 150 km long and 40 km

D. P. Hill

1963-01-01

67

Evaluation of an enhanced gravity-based fine-coal circuit for high-sulfur coal  

SciTech Connect

One of the main objectives of this study was to evaluate a fine-coal cleaning circuit using an enhanced gravity separator specifically for a high sulfur coal application. The evaluation not only included testing of individual unit operations used for fine-coal classification, cleaning and dewatering, but also included testing of the complete circuit simultaneously. At a scale of nearly 2 t/h, two alternative circuits were evaluated to clean a minus 0.6-mm coal stream utilizing a 150-mm-diameter classifying cyclone, a linear screen having a projected surface area of 0.5 m{sup 2}, an enhanced gravity separator having a bowl diameter of 250 mm and a screen-bowl centrifuge having a bowl diameter of 500 mm. The cleaning and dewatering components of both circuits were the same; however, one circuit used a classifying cyclone whereas the other used a linear screen as the classification device. An industrial size coal spiral was used to clean the 2- x 0.6-mm coal size fraction for each circuit to estimate the performance of a complete fine-coal circuit cleaning a minus 2-mm particle size coal stream. The 'linear screen + enhanced gravity separator + screen-bowl circuit' provided superior sulfur and ash-cleaning performance to the alternative circuit that used a classifying cyclone in place of the linear screen. Based on these test data, it was estimated that the use of the recommended circuit to treat 50 t/h of minus 2-mm size coal having feed ash and sulfur contents of 33.9% and 3.28%, respectively, may produce nearly 28.3 t/h of clean coal with product ash and sulfur contents of 9.15% and 1.61 %, respectively.

Mohanty, M.K.; Samal, A.R.; Palit, A. [South Illinois University, Carbondale, IL (United States). Dept. of Mining & Mineral Resources Engineering

2008-02-15

68

High-density particulate gravity currents and their internal density stratifications  

NASA Astrophysics Data System (ADS)

High-density particulate gravity currents exhibit internal density stratifications. In the basal part of these stratified flows, high-sediment concentrations cause rheological deviations from the Newtonian turbulent flow that dominates clear water and low density conditions. Previous studies have distinguished different types of basal layers on the basis of concentration dependent differences in grain interactions. Field studies have classically linked crude stratification bands, spaced laminations, and/or abundant internal erosion surfaces to high-density particulate gravity currents. Studies of the deposits of such flows have proposed various mechanisms for this variation in depositional characteristics; however, none of these propositions has been thoroughly tested by experiments or theory. This study presents experiments of high-density turbidity currents (varying in initial sediment concentration between 9-26 vol%) moving quasi steady on an inclined bed surface in a 4 x 0.5 x 0.07 m tank. Three distinct internal flow layers were distinguished on the basis of their observed behaviour as captured by a high-speed camera. Ultrasonic velocity profiler (UVP) probes were used to measure the overall velocity and turbulent intensity profiles of the flows, and the change therein as a result of different stacking patterns of internal flow layers. The relation between maximum velocity, shear stress and equilibrium slope for different types of high-density layers were investigated in the experiments. Velocity and camera data were combined to study the interactions between the different flow layers over time. Small-scale fluctuations (0.2-2 seconds) were observed to have a clear control on the depositional behaviour of the flow. However, the influence of these fluctuations gradually decreased with increasing sediment concentrations as function of the different types of basal flow layers. By combining these observations with theoretical grain size sorting mechanism previous experimental results, the different flow layers were linked to distinct depositional expressions known from the rock record.

Cartigny, Matthieu J. B.; Eggenhuisen, Joris T.; Hansen, Ernst W. M.; Postma, George

2013-04-01

69

High level performance estimate of relational queries  

SciTech Connect

Performance estimate of queries is a necessary part of any efficient database design methodology. A high-level performance estimator for relational queries is presented which is different from conventional evaluators such as SYSTEM R (Selinger, Proc. SIGMOD 79) in that performance is predicted without the details of the low-level constructs such as links and indices. Rather, abstractions and reasonable assumptions of these low-level constructs are used in a set of formulas to estimate the performance of a set of queries against a schema. The major results of the paper are the realization and motivation of the need of high-level performance estimators of this kind, and a fast way to estimate the cost of N-way joins. The second result is interesting in that the algorithm for N-way joins is found to be similar to matrix multiplication optimization, with straightforward extensions.

Wong, H.K.T.

1980-08-01

70

Brane-World Gravity  

NASA Astrophysics Data System (ADS)

The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+d-dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (˜TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity “leaks” into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies - the 5-dimensional Dvali-Gabadadze-Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.

Maartens, Roy; Koyama, Kazuya

2010-09-01

71

Cineradiographic analysis of mouse postural response to alteration of gravity and jerk (gravity deceleration rate).  

PubMed

The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6) were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and ? g (<0.001 g). Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%-200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of -0.3~-0.4 j (g/s) induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk. PMID:25370191

Hasegawa, Katsuya; de Campos, Priscila S; Zeredo, Jorge L; Kumei, Yasuhiro

2014-01-01

72

Cineradiographic Analysis of Mouse Postural Response to Alteration of Gravity and Jerk (Gravity Deceleration Rate)  

PubMed Central

The ability to maintain the body relative to the external environment is important for adaptation to altered gravity. However, the physiological limits for adaptation or the disruption of body orientation are not known. In this study, we analyzed postural changes in mice upon exposure to various low gravities. Male C57BL6/J mice (n = 6) were exposed to various gravity-deceleration conditions by customized parabolic flight-maneuvers targeting the partial-gravity levels of 0.60, 0.30, 0.15 and ? g (<0.001 g). Video recordings of postural responses were analyzed frame-by-frame by high-definition cineradiography and with exact instantaneous values of gravity and jerk. As a result, the coordinated extension of the neck, spine and hindlimbs was observed during the initial phase of gravity deceleration. Joint angles widened to 120%–200% of the reference g level, and the magnitude of the thoracic-curvature stretching was correlated with gravity and jerk, i.e., the gravity deceleration rate. A certain range of jerk facilitated mouse skeletal stretching efficiently, and a jerk of ?0.3~?0.4 j (g/s) induced the maximum extension of the thoracic-curvature. The postural response of animals to low gravity may undergo differential regulation by gravity and jerk.

Hasegawa, Katsuya; de Campos, Priscila S.; Zeredo, Jorge L.; Kumei, Yasuhiro

2014-01-01

73

Case hardenability at high carbon levels  

NASA Astrophysics Data System (ADS)

Loss of hardenability in the case was thought to be responsible for a lower than specified hardness found on a large carburized bushing. Pseudo Jominy testing on several high hardenability carburizing grades confirmed that hardenability fade was present at carbon levels above 0.65% and particularly for those steels containing molybdenum. Analysis of previous work provided a formula for calculating Jominy hardenability at various carbon levels. Again the results confirmed that the loss of hardenability was more severe in steels containing molybdenum.

Walton, H. W.

1995-02-01

74

A Software Architecture for High Level Applications  

SciTech Connect

A modular software platform for high level applications is under development at the National Synchrotron Light Source II project. This platform is based on client-server architecture, and the components of high level applications on this platform will be modular and distributed, and therefore reusable. An online model server is indispensable for model based control. Different accelerator facilities have different requirements for the online simulation. To supply various accelerator simulators, a set of narrow and general application programming interfaces is developed based on Tracy-3 and Elegant. This paper describes the system architecture for the modular high level applications, the design of narrow and general application programming interface for an online model server, and the prototype of online model server.

Shen,G.

2009-05-04

75

Exploring Quantum Gravity with Very-High-Energy Gamma-Ray Instruments - Prospects and Limitations  

SciTech Connect

Some models for quantum gravity (QG) violate Lorentz invariance and predict an energy dependence of the speed of light, leading to a dispersion of high-energy gamma-ray signals that travel over cosmological distances. Limits on the dispersion from short-duration substructures observed in gamma-rays emitted by gamma-ray bursts (GRBs) at cosmological distances have provided interesting bounds on Lorentz invariance violation (LIV). Recent observations of unprecedentedly fast flares in the very-high energy gamma-ray emission of the active galactic nuclei (AGNs) Mkn 501 in 2005 and PKS 2155-304 in 2006 resulted in the most constraining limits on LIV from light-travel observations, approaching the Planck mass scale, at which QG effects are assumed to become important. I review the current status of LIV searches using GRBs and AGN flare events, and discuss limitations of light-travel time analyses and prospects for future instruments in the gamma-ray domain.

Wagner, Robert [Max-Planck-Institut fuer Physik, D-80805 Muenchen (Germany)

2009-04-08

76

Local gravity disturbance estimation from multiple-high-single-low satellite-to-satellite tracking  

NASA Astrophysics Data System (ADS)

The idea of satellite-to-satellite tracking in the high-low mode has received renewed attention in light of the uncertain future of NASA's proposed low-low mission, Geopotential Research Mission (GRM). The principal disadvantage with a high-low system is the increased time interval required to obtain global coverage since the intersatellite visibility is often obscured by Earth. The U.S. Air Force has begun to investigate high-low satellite-to-satellite tracking between the Global Positioning System (GPS) of satellites (high component) and NASA's Space Transportation System (STS), the shuttle (low component). Because the GPS satellites form, or will form, a constellation enabling continuous three-dimensional tracking of a low-altitude orbiter, there will be no data gaps due to lack of intervisibility. Furthermore, all three components of the gravitation vector are estimable at altitude, a given grid of which gives a stronger estimate of gravity on Earth's surface than a similar grid of line-of-sight gravitation components. The proposed Air Force mission is STAGE (Shuttle-GPS Tracking for Anomalous Gravitation Estimation) and is designed for local gravity field determinations since the shuttle will likely not achieve polar orbits. The motivation for STAGE was the feasibility to obtain reasonable accuracies with absolutely minimal cost. Instead of simulating drag-free orbits, STAGE uses direct measurements of the nongravitational forces obtained by an inertial package onboard the shuttle. The sort of accuracies that would be achievable from STAGE vis-a-vis other satellite tracking missions such as GRM and European Space Agency's POPSAT-GRM are analyzed.

Jekeli, Christopher

1989-06-01

77

Local gravity disturbance estimation from multiple-high-single-low satellite-to-satellite tracking  

NASA Technical Reports Server (NTRS)

The idea of satellite-to-satellite tracking in the high-low mode has received renewed attention in light of the uncertain future of NASA's proposed low-low mission, Geopotential Research Mission (GRM). The principal disadvantage with a high-low system is the increased time interval required to obtain global coverage since the intersatellite visibility is often obscured by Earth. The U.S. Air Force has begun to investigate high-low satellite-to-satellite tracking between the Global Positioning System (GPS) of satellites (high component) and NASA's Space Transportation System (STS), the shuttle (low component). Because the GPS satellites form, or will form, a constellation enabling continuous three-dimensional tracking of a low-altitude orbiter, there will be no data gaps due to lack of intervisibility. Furthermore, all three components of the gravitation vector are estimable at altitude, a given grid of which gives a stronger estimate of gravity on Earth's surface than a similar grid of line-of-sight gravitation components. The proposed Air Force mission is STAGE (Shuttle-GPS Tracking for Anomalous Gravitation Estimation) and is designed for local gravity field determinations since the shuttle will likely not achieve polar orbits. The motivation for STAGE was the feasibility to obtain reasonable accuracies with absolutely minimal cost. Instead of simulating drag-free orbits, STAGE uses direct measurements of the nongravitational forces obtained by an inertial package onboard the shuttle. The sort of accuracies that would be achievable from STAGE vis-a-vis other satellite tracking missions such as GRM and European Space Agency's POPSAT-GRM are analyzed.

Jekeli, Christopher

1989-01-01

78

GOCE long-wavelength gravity field recovery from high-low satellite-to-satellite-tracking using the acceleration approach  

NASA Astrophysics Data System (ADS)

The restricted sensitivity of the GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometer instrument requires satellite gravity gradiometry to be supplemented by orbit analysis in order to resolve long-wavelength features of the geopotential. In this context, the energy conservation method gained particular interest to exploit GPS-based satellite-to-satellite tracking (SST) information. This method has been adopted within official ESA products. On the other hand, various investigations showed the energy conservation principle to be a sub-optimal choice. For this reason, we propose to estimate the low-frequency part of the gravity field by the acceleration approach, which proved to be an efficient and accurate tool in high-low-SST data analysis of former satellite data. This approach balances the gravitational vector with satellite accelerations by means of Newton's law of motion, and hence is characterized by (second-order) numerical differentiation of the kinematic orbit. However, the application of this method to GOCE-SST data, given with a 1s-sampling, showed that serious problems arise due to strong noise amplification of high frequency noise. In order to mitigate this problem, tailored processing strategies with regard to low-pass filtering, variance-covariance information handling, and robust parameter estimation have been adopted. By comparison of our GIWF (Geodetic Institute (GI), Space Research Institute (Institut für Weltraumforschung, IWF)) solutions and the official GOCE models with a state-of-the-art gravity field solution derived from GRACE (Gravity Recovery And Climate Experiment), we conclude that the acceleration approach is better suited for GOCE-only gravity field determination as opposed to the energy conservation method. Comparisons with solutions from other algorithms, e.g. the variational approach, show that the acceleration approach is able to estimate gravity fields of similar quality.

Reubelt, T.; Baur, O.; Weigelt, M.; Roth, M.; Sneeuw, N.

2012-04-01

79

High-level radioactive wastes. Supplement 1  

SciTech Connect

This bibliography contains information on high-level radioactive wastes included in the Department of Energy's Energy Data Base from August 1982 through December 1983. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. 1452 citations.

McLaren, L.H. (ed.)

1984-09-01

80

High-Level Waste Melter Review  

Microsoft Academic Search

The U.S. Department of Energy (DOE) is faced with a massive cleanup task in resolving the legacy of environmental problems from years of manufacturing nuclear weapons. One of the major activities within this task is the treatment and disposal of the extremely large amount of high-level radioactive (HLW) waste stored at the Hanford Site in Richland, Washington. The current planning

J. Ahearne; J. Gentilucci; L. D. Pye; T. Weber; F. Woolley; N. P. Machara; K. Gerdes; C. Cooley

2002-01-01

81

Applying simulated evolution to high level synthesis  

Microsoft Academic Search

A general optimization algorithm known as simulated evolution (SE) is applied to the tasks of scheduling and allocation in high level synthesis. Basically, SE-based synthesis explores the design space by repeatedly ripping up parts of a design in a probabilistic manner and reconstructing them using application-specific heuristics that combine rapid design iterations and probabilistic hill climbing to achieve effective design

Tai A. Ly; Jack T. Mowchenko

1993-01-01

82

Network-Based High Level Data Classification  

Microsoft Academic Search

Traditional supervised data classification considers only physical features (e.g., distance or similarity) of the input data. Here, this type of learning is called low level classification. On the other hand, the human (animal) brain performs both low and high orders of learning and it has facility in identifying patterns according to the semantic meaning of the input data. Data classification

Thiago Christiano Silva; Liang Zhao

2012-01-01

83

Physiological characterization of brewer's yeast in high-gravity beer fermentations with glucose or maltose syrups as adjuncts.  

PubMed

High-gravity brewing, which can decrease production costs by increasing brewery yields, has become an attractive alternative to traditional brewing methods. However, as higher sugar concentration is required, the yeast is exposed to various stresses during fermentation. We evaluated the influence of high-gravity brewing on the fermentation performance of the brewer's yeast under model brewing conditions. The lager brewer's strain Weihenstephan 34/70 strain was characterized at three different gravities by adding either glucose or maltose syrups to the basic wort. We observed that increased gravity resulted in a lower specific growth rate, a longer lag phase before initiation of ethanol production, incomplete sugar utilization, and an increase in the concentrations of ethyl acetate and isoamyl acetate in the final beer. Increasing the gravity by adding maltose syrup as opposed to glucose syrup resulted in more balanced fermentation performance in terms of higher cell numbers, respectively, higher wort fermentability and a more favorable flavor profile of the final beer. Our study underlines the effects of the various stress factors on brewer's yeast metabolism and the influence of the type of sugar syrups on the fermentation performance and the flavor profile of the final beer. PMID:19343343

Piddocke, Maya P; Kreisz, Stefan; Heldt-Hansen, Hans Peter; Nielsen, Kristian Fog; Olsson, Lisbeth

2009-09-01

84

TOPEX\\/POSEIDON, GRAVITY, AND THE EARTH'S ROTATION: INVESTIGATING MECHANISMS AND EFFECTS OF SEA LEVEL CHANGE  

Microsoft Academic Search

1. better describe, characterize, and understand the c auses of global-scale variations in sea level occurring on subseasonal to interannual time scales through the use of complementary oceanographic and geophysical data sets; 2. study the impact of sea level change upon global ge odynamic properties of the Earth such as its rotation and gravitational field and to thereby assess the

R. S. Gross; Y. Chao; S. L. Marcus; J. O. Dickey

85

Simultaneous dewatering and reconstitution in a high-gravity solid-bowl centrifuge  

SciTech Connect

The Pittsburgh Energy Technology Center has developed a dewatering and reconstitution process in which bitumen emulsion is added to a fine clean coal slurry ahead of the dewatering device. The process simultaneously improves dewatering efficiency and reduces dustiness of the fine coal product during subsequent handling. This paper describes the test results from dewatering and reconstitution of fine coal in a 500 lb. per hour continuous bench scale high-gravity solid-bowl centrifuge in PETC`s Coal Preparation Process Research Facility. Test results will be evaluated in terms of type and dosage of emulsion, product moisture and strength, and product handling and dust reduction efficiency. A preliminary cost analysis will also be included.

Wen, W.W.; Gray, M.L.; Killmeyer, R.P.; Finseth, D.H. [USDOE Pittsburgh Energy Technology Center, PA (United States)

1994-12-31

86

The long-term consequences of the exposure to increasing gravity levels on the muscular, vestibular and cognitive functions in adult mice.  

PubMed

Adult male mice C57Bl6/J were exposed to gravity levels between 1G and 4G during three weeks, and the long-term consequences on muscular, vestibular, emotional, and cognitive abilities were evaluated at the functional level to test the hypothesis of a continuum in the response to the increasing gravitational force. In agreement with the hypothesis, the growth of body mass slowed down in relation with the gravity level during the centrifugation, and weight recovery was inversely proportional. On the other hand, the long-term consequences on muscular, vestibular, emotional, and cognitive abilities did not fit the hypothesis of a continuum in the response to the gravity level. The hypergravity acted as endurance training on muscle force until 3G, then became deleterious at 4G. The vestibular reactions were not affected until 4G. Persistent emotional reactions appeared at 3G, and particularly 4G. The mice centrifuged at 3G and 4G showed an impaired spatial learning, probably in relation with the increased level of anxiety, but a greater difficulty was also observed in mice exposed at 2G, suggesting another cause for the impairment of spatial memory. The long-term response to the hypergravity was shown to depend on both the level of gravity and the duration of exposition, with different importance depending on the function considered. PMID:24509308

Bojados, Mickael; Jamon, Marc

2014-05-01

87

The CMS High-Level Trigger  

SciTech Connect

At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the 'High-Level Trigger'(HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, {tau} leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

Covarelli, R. [CERN, Geneva 1211 (Switzerland)

2009-12-17

88

Plants tolerant of high boron levels.  

PubMed

Reduced crop productivity due to soils containing toxic levels of boron (B) is a worldwide problem in food production. It is estimated that up to 17% of the barley yield losses in southern Australia are caused by B toxicity. We found that the expression of AtBOR4, an Arabidopsis paralog of BOR1, the first identified boron transporter gene, generates plants that are tolerant of high B levels. BOR4 is a polarly localized borate exporter that enhances B efflux from roots. The present study is a foundation for the improvement of crop productivity in soils containing excess B, which are distributed in arid areas of the world. PMID:18048682

Miwa, Kyoko; Takano, Junpei; Omori, Hiroyuki; Seki, Motoaki; Shinozaki, Kazuo; Fujiwara, Toru

2007-11-30

89

Complete Bouguer gravity map of the Nevada Test Site and vicinity, Nevada  

SciTech Connect

About 15,000 gravity stations were used to create the gravity map. Gravity studies at the Nevada Test Site were undertaken to help locate geologically favorable areas for underground nuclear tests and to help characterize potential high-level nuclear waste storage sites. 48 refs. (TEM)

Healey, D.L.; Harris, R.N.; Ponce, D.A.; Oliver, H.W.

1987-12-31

90

High-Level Integration of Data Systems  

NASA Astrophysics Data System (ADS)

One of the key capabilities required for data systems of the future is the integration of high-level systems and services into their design. Future systems need to provide users with integrated access to distributed and diverse scientific data holdings, models, services, and tools in order to increase the science and educational return from the data. These new capabilities go well beyond the garden variety "get me data" types of services and should be accomplished as part of a broader structure which ties together existing systems at the same time as introducing new capabilities. Here, we present the high-level integration of systems and services as the necessary pieces to accomplish this as well as some lessons learned. and http://sd-www.jhuapl.edu/SPDML/index.php

Weiss, M.; Morrison, D.; Daley, R.; Immer, E.; Hashemian, M.; Fortner, B.; Jen, J.; Holder, R.

2005-12-01

91

Immobilization of high level waste in Synroc  

Microsoft Academic Search

Synroc, a polyphase titanate ceramic, is being developed in Australia as a second generation waste from for the immobilization of high-level waste (HLW) from nuclear plants. The waste form, produced by reactive hot-pressing, has excellent resistance to leaching and there is good evidence that the long-term release rate of elements from Synroc will be of the order of 10\\/sup \\/minus\\/4\\/

A. Jostsons; K. D. Reeve

1988-01-01

92

The Grace Mission: The Challenges of Using Micron-Level Satellite-to-Satellite Ranging to Measure the Earth's Gravity Field  

NASA Technical Reports Server (NTRS)

The GRACE Mission, to be launched in mid-2001, will provide an unprecedented map of the Earth's gravity field every month. In this paper, we outline the challenges associated with this micron-level satellite-to-satellite ranging, the solutions used by the GRACE project, and the expected science applications of the data.

Watkins, M.; Bettadpur, S.

2000-01-01

93

Crustal Structure of the High Lava Plains of the Pacific Northwest - Source Seismic and Gravity Modeling  

NASA Astrophysics Data System (ADS)

This study uses data from the High Lava Plains (HLP) experiment collected in September 2008. A total of 2612 Texan short-period seismic recorders and 120 RT-130 recorders were spaced across the HLP of eastern Oregon and adjacent parts of Nevada and Idaho to record 15 seismic sources thanks to the help of the 67 scientists, students, and 6 staff members from the PASSCAL/Earthscope Instrument Center who deployed. The purpose of this study is to integrate the seismic and gravity data to create 2D crustal scale P-wave seismic velocity and density models across the NW-SE and N-S transecting profiles. These models provide a better understanding of the crustal structure and upper mantle beneath the path of volcanism that dotted the High Lava Plains during the past 16 Ma, in addition to the extension experienced in the region since 35 Ma. Our results show that the crustal structure across the HLP region is similar to that of the northern Basin and Range. However, a thick cover (5-7 km) of sediments and volcanics covers most of the area in addition to the Harney Basin. Based on the gravity data, denser material underlies the southern part of the Harney Basin which might be mafic material based on its close proximity to Diamond Craters. This might also support the assertion that there is a caldera system underlying the HLP. The crust thickens (34km -37km) and increases in density (2.8-2.85 gm/cc) from west to eat across eastern Oregon in close proximity to the interpreted position of the 0.706 Sr isotope line. There is thin layer of relatively high velocities (7.2-7.4 km/s) and densities of (2.95 gm/cc) in the lowermost crust suggest underplating. Also, the average crustal velocity is somewhat higher that in the adjacent Basin and Range suggesting some magmatic modification in the lower crust but not as much as might be expected given the voluminous surface volcanism.

Cox, C.; Keller, G. R.

2010-12-01

94

Regulation of high density lipoprotein levels  

SciTech Connect

An increasing awareness of the physiologic and pathologic importance of serum high density lipoproteins (HDL) has led to a large number of observations regarding factors which influence their concentrations. HDL consists of a heterogeneous collection of macromolecules with diverse physical properties and chemical constituents. While laboratory techniques have made it possible to measure HDL and their individual components, there are as yet large gaps in our knowledge of the biochemical mechanisms and clinical significance of changes in these laboratory parameters. In this review, current concepts of the structure and metabolism of HDL will be briefly summarized, and the factors influencing their levels in humans will be surveyed. 313 references.

Krauss, R.M.

1982-03-01

95

Chiral Gravity, Log Gravity and Extremal CFT  

E-print Network

We show that the linearization of all exact solutions of classical chiral gravity around the AdS3 vacuum have positive energy. Non-chiral and negative-energy solutions of the linearized equations are infrared divergent at second order, and so are removed from the spectrum. In other words, chirality is confined and the equations of motion have linearization instabilities. We prove that the only stationary, axially symmetric solutions of chiral gravity are BTZ black holes, which have positive energy. It is further shown that classical log gravity-- the theory with logarithmically relaxed boundary conditions --has finite asymptotic symmetry generators but is not chiral and hence may be dual at the quantum level to a logarithmic CFT. Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We normally evaluate the Euclidean sum over geometries of chiral gravity and show that it gives precisely the holomorphic extremal CFT partition function. The modular invariance and integrality of the expansion coefficients of this partition function are consistent with the existence of an exact quantum theory of chiral gravity. We argue that the problem of quantizing chiral gravity is the holographic dual of the problem of constructing an extremal CFT, while quantizing log gravity is dual to the problem of constructing a logarithmic extremal CFT.

Alexander Maloney; Wei Song; Andrew Strominger

2009-03-26

96

Technetium Chemistry in High-Level Waste  

SciTech Connect

Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry.

Hess, Nancy J.

2006-06-01

97

Gravity effects on stability and flickering motion of diffusion flames  

SciTech Connect

Effects of gravity level on the flame stability and flickering motion were experimentally investigated for the propane jet diffusion flames. A spin tester was used to form the high gravity fields. Flames were observed under the various conditions of injection Reynolds number of the fuel jet and gravity level which were controlled independently. Regions of stable flame, flickering flame, and lifting flame were mapped with the gravity level and injection Reynolds number. Then, it could be pointed out that the onset of flame lifting was strongly affected by the gravity compared with the onset of flickering. Flickering frequency increased with an increase of gravity level. Gravity effect on the wavelength and wave velocity were also investigated to clarify the reason for the change of frequency. It was found that the increase of flickering frequency with the rise of gravity level was caused by the increase of wave velocity and the decrease of wavelength. Flickering frequencies obtained here could be summarized using Strouhal number and Froude number, and in a relation of St {proportional_to} Fr{sup 0.57}. This result showed a good agreement with the previous results of Hamins obtained from normal gravity experiments.

Arai, M.; Sato, H.; Amagai, K. [Gunma Univ., Kiryu (Japan). Dept. of Mechanical System Engineering] [Gunma Univ., Kiryu (Japan). Dept. of Mechanical System Engineering

1999-07-01

98

Assimilation of TOPEX Sea Level Measurements with a Reduced-Gravity, Shallow Water Model of the Tropical Pacific Ocean  

NASA Technical Reports Server (NTRS)

Sea surface height variability measured by TOPEX is analyzed in the tropical Pacific Ocean by way of assimilation into a wind-driven, reduced-gravity, shallow water model using an approximate Kalman filter and smoother. The analysis results in an optimal fit of the dynamic model to the observations, providing it dynamically consistent interpolation of sea level and estimation of the circulation. Nearly 80% of the expected signal variance is accounted for by the model within 20 deg of the equator, and estimation uncertainty is substantially reduced by the voluminous observation. Notable features resolved by the analysis include seasonal changes associated with the North Equatorial Countercurrent and equatorial Kelvin and Rossby waves. Significant discrepancies are also found between the estimate and TOPEX measurements, especially near the eastern boundary. Improvements in the estimate made by the assimilation are validated by comparisons with independent tide gauge and current meter observations. The employed filter and smoother are based on approximately computed estimation error covariance matrices, utilizing a spatial transformation and an symptotic approximation. The analysis demonstrates the practical utility of a quasi-optimal filter and smoother.

Fukumori, Ichiro

1995-01-01

99

Beam size measurement at high radiation levels  

SciTech Connect

At the end of the Stanford Linear Accelerator the high energy electron and positron beams are quite small. Beam sizes below 100 {mu}m ({sigma}) as well as the transverse distribution, especially tails, have to be determined. Fluorescent screens observed by TV cameras provide a quick two-dimensional picture, which can be analyzed by digitization. For running the SLAC Linear Collider (SLC) with low backgrounds at the interaction point, collimators are installed at the end of the linac. This causes a high radiation level so that the nearby cameras die within two weeks and so-called radiation hard'' cameras within two months. Therefore an optical system has been built, which guides a 5 mm wide picture with a resolution of about 30 {mu}m over a distance of 12 m to an accessible region. The overall resolution is limited by the screen thickness, optical diffraction and the line resolution of the camera. Vibration, chromatic effects or air fluctuations play a much less important role. The pictures are colored to get fast information about the beam current, size and tails. Beside the emittance, more information about the tail size and betatron phase is obtained by using four screens. This will help to develop tail compensation schemes to decrease the emittance growth in the linac at high currents. 4 refs., 2 figs.

Decker, F.J.

1991-05-01

100

The significance of GPS/leveling points for the high precision geoid computation  

NASA Astrophysics Data System (ADS)

The computation of a local geoid can be done by several methods. Collocation as one of the possible tools has the big advantage that observations representing different functionals of the disturbing potential can be combined. Therefore also GPS/leveling points can be used as observation values. The present work discusses the significance of GPS/leveling data in the collocation process as well as the overall importance of this kind of data in the field of the high precision geoid computation. Several basic principles are discussed. Is the combination of GPS/leveling data with the other gravity field observations in one step better than performing the widely used two step procedure? The two step procedure means combining gravity anomalies and deflections of the vertical in a first step, followed by the fitting of the geoidal surface to the GPS/leveling benchmarks by a transformation surface. The present work also focuses on the modeling of the transformation surface by radial base functions. An adapted version of the Greedy algorithm is used to find the minimum number of GPS/leveling points that are necessary to fix the transformation surface with a given accuracy. Finally the principle of a possible validation of the GPS/leveling points by a combined leave one out cross validation is discussed.

Kühtreiber, N.; Pock, C.

2012-04-01

101

Detection Method and Observed Data of High-energy Gamma Rays under the Influence of Quantum Gravity  

NASA Astrophysics Data System (ADS)

The interaction of high-energy particles affected by quantum gravity is argued from the experimental viewpoint of raising a question, ``our detection method for high-energy ?-rays supplies trustworthy observation data and we are now seeing the true image of the universe through high-energy ?-rays?" The modified dispersion relation (MDR) for particles' energy and momentum is applied to the equation of energy-momentum conservation in particle reactions, to study the restriction imposed on the kinematic state of high-energy particles by the Lorentz invariance violation (LIV) due to quantum gravity, as a function of the incident particle energy of the reaction. The result suggests that the interaction utilized for ?-ray detection is not free from the effect of quantum gravity when ?-ray energy is higher than 1013 ~ 1017 eV depending on models of MDR. Discussion is presented on the prospect of finding clear evidence of the LIV effect from ?-ray observations, as well as on the radiation and propagation mechanism of ?-rays under the influence of the LIV effect.

Kifune, T.

2014-05-01

102

Normalization to specific gravity prior to analysis improves information recovery from high resolution mass spectrometry metabolomic profiles of human urine.  

PubMed

Extraction of meaningful biological information from urinary metabolomic profiles obtained by liquid-chromatography coupled to mass spectrometry (MS) necessitates the control of unwanted sources of variability associated with large differences in urine sample concentrations. Different methods of normalization either before analysis (preacquisition normalization) through dilution of urine samples to the lowest specific gravity measured by refractometry, or after analysis (postacquisition normalization) to urine volume, specific gravity and median fold change are compared for their capacity to recover lead metabolites for a potential future use as dietary biomarkers. Twenty-four urine samples of 19 subjects from the European Prospective Investigation into Cancer and nutrition (EPIC) cohort were selected based on their high and low/nonconsumption of six polyphenol-rich foods as assessed with a 24 h dietary recall. MS features selected on the basis of minimum discriminant selection criteria were related to each dietary item by means of orthogonal partial least-squares discriminant analysis models. Normalization methods ranked in the following decreasing order when comparing the number of total discriminant MS features recovered to that obtained in the absence of normalization: preacquisition normalization to specific gravity (4.2-fold), postacquisition normalization to specific gravity (2.3-fold), postacquisition median fold change normalization (1.8-fold increase), postacquisition normalization to urinary volume (0.79-fold). A preventative preacquisition normalization based on urine specific gravity was found to be superior to all curative postacquisition normalization methods tested for discovery of MS features discriminant of dietary intake in these urinary metabolomic datasets. PMID:25285402

Edmands, William M B; Ferrari, Pietro; Scalbert, Augustin

2014-11-01

103

Fast fabrication of W-Cu functionally graded material by high-gravity combustion synthesis and melt-infiltration  

NASA Astrophysics Data System (ADS)

W-Cu functionally graded material (FGM, 75 wt% W + 25 wt% Cu—40 wt% W + 60 wt% Cu) has been prepared by a method of high-gravity combustion synthesis and melt-infiltration in a short time (˜5 min). The infiltration mechanism in the high-gravity field was investigated. The W-Cu FGM showed an overall relative density of ˜97% and gradually-varying properties in terms of density, micro hardness, coefficient of thermal expansion. Especially, the W-Cu FGM exhibited a coefficient of thermal expansion between those of W and Cu, and thus could be used as a transition layer between W and Cu to relax the thermal stresses.

Zhao, P.; Guo, S. B.; Liu, G. H.; Chen, Y. X.; Li, J. T.

2014-02-01

104

Feeling Gravity's Pull: Gravity Modeling. The Gravity Field of Mars  

NASA Technical Reports Server (NTRS)

Most people take the constant presence of gravitys pull for granted. However, the Earth's gravitational strength actually varies from location to location. This variation occurs because mass, which influences an object's gravitational pull, is not evenly distributed within the planet. Changes in topography, such as glacial movement, an earthquake, or a rise in the ocean level, can subtly affect the gravity field. An accurate measurement of the Earth's gravity field helps us understand the distribution of mass beneath the surface. This insight can assist us in locating petroleum, mineral deposits, ground water, and other valuable substances. Gravity mapping can also help notice or verify changes in sea surface height and other ocean characteristics. Such changes may indicate climate change from polar ice melting and other phenomena. In addition, gravity mapping can indicate how land moves under the surface after earthquakes and other plate tectonic processes. Finally, changes in the Earth's gravity field might indicate a shift in water distribution that could affect agriculture, water supplies for population centers, and long-term weather prediction. Scientists can map out the Earth's gravity field by watching satellite orbits. When a satellite shifts in vertical position, it might be passing over an area where gravity changes in strength. Gravity is only one factor that may shape a satellite's orbital path. To derive a gravity measurement from satellite movement, scientists must remove other factors that might affect a satellite's position: 1. Drag from atmospheric friction. 2. Pressure from solar radiation as it heads toward Earth and. as it is reflected off the surface of the Earth 3. Gravitational pull from the Sun, the Moon, and other planets in the Solar System. 4. The effect of tides. 5. Relativistic effects. Scientists must also correct for the satellite tracking process. For example, the tracking signal must be corrected for refraction through the atmosphere of the Earth. Supercomputers can calculate the effect of gravity for specific locations in space following a mathematical process known as spherical harmonics, which quantifies the gravity field of a planetary body. The process is based on Laplace's fundamental differential equation of gravity. The accuracy of a spherical harmonic solution is rated by its degree and order. Minute variations in gravity are measured against the geoid, a surface of constant gravity acceleration at mean sea level. The geoid reference gravity model strength includes the central body gravitational attraction (9.8 m/sq s) and a geopotential variation in latitude partially caused by the rotation of the Earth. The rotational effect modifies the shape of the geoid to be more like an ellipsoid, rather than a perfect, circle. Variations of gravity strength from the ellipsoidal reference model are measured in units called milli-Galileos (mGals). One mGal equals 10(exp -5) m/sq s. Research projects have also measured the gravity fields of other planetary bodies, as noted in the user profile that follows. From this information, we may make inferences about our own planet's internal structure and evolution. Moreover, mapping the gravity fields of other planets can help scientists plot the most fuel-efficient course for spacecraft expeditions to those planets.

Lemoine, Frank; Smith, David; Rowlands, David; Zuber, Maria; Neumann, G.; Chinn, Douglas; Pavlis, D.

2000-01-01

105

Gravity effects obtained from global hydrology models in comparison with high precision gravimetric time series  

NASA Astrophysics Data System (ADS)

Water mass changes are a major source of variations in residual gravimetric time series obtained from the combination of observations with superconducting and absolute gravimeters. Changes in the local water storage are the main influence, but global variations contribute to the signal significantly. For three European gravity stations, Bad Homburg, Wettzell and Medicina, different global hydrology models are compared. The influence of topographic effects is discussed and due to the long-term stability of the combined gravity time series, inter-annual signals in model data and gravimetric observations are compared. Two sources of influence are discriminated, i.e., the effect of a local zone with an extent of a few kilometers around the gravimetric station and the global contribution beyond 50km. Considering their coarse resolution and uncertainties, local effects calculated from global hydrological models are compared with the in-situ gravity observations and, for the station Wettzell, with local hydrological monitoring data.

Wziontek, Hartmut; Wilmes, Herbert; Güntner, Andreas; Creutzfeldt, Benjamin

2010-05-01

106

Reflection surveys conducted on the western side of the mid-continental gravity high  

SciTech Connect

The few spatially isolated deeper drill holes available on the western side of the mid-continental gravity high have established elevation changes in the Sioux quartzite that exceed 500m within a few hundred kilometers. Thirteen, 12-fold, CMP, reflection surveys were conducted within this area to supplement the limited drilling data. These surveys used an elastic wave generator as the energy source and a digital 24 channel IFP system for recording. The survey locations were selected to best supplement the existing drill hole data. Phone spacings and near offsets were selected on the basis of walk-out surveys conducted at each reflection site. No velocity control was available and the stacking velocities were selected based on graded velocity stacks. Interval velocities, constrained by general stratigraphic considerations, were calculated from the stacking velocities. For the near surface, interval velocities were extracted from the first arrivals. The lack of velocity control did not appear to seriously degrade the interpretation of gross structural features. Both the Sioux quartzite and a deeper interface, assumed to be the top of igneous basement, were reliably mapped. The two-way times of the basement reflector varied from 400m sec to 200m sec, approximately 500m to 300m respectively. The two-way times to the top of the quartzite varied from 300 m secs to 135m secs, approximately 350m to 160m respectively. The results suggest a major northeast, southwest trending basement fault with displacements exceeding 100m. The structure of both the basement and the quartzite appear to be a faulted anticline or dome. The reflection surveys provided a cost effective method for reconnaissance studies required to establish gross structural features.

Taylor, R.W.; Fromm, A.J. (Fromm Applied Technology, Mequon, WI (United States)); Okita, P. (PHP Minerals, Herndon, VA (United States))

1992-01-01

107

Climate scenarios of sea level rise for the northeast Atlantic Ocean: a study including the effects of ocean dynamics and gravity changes induced by ice melt  

Microsoft Academic Search

Here we present a set of regional climate scenarios of sea level rise for the northeast Atlantic Ocean. In this study, the\\u000a latest observations and results obtained with state-of-the-art climate models are combined. In addition, regional effects\\u000a due to ocean dynamics and changes in the Earth’s gravity field induced by melting of land-based ice masses have been taken\\u000a into account.

Caroline A. Katsman; Wilco Hazeleger; Sybren S. Drijfhout; Geert Jan van Oldenborgh; Gerrit J. H. Burgers

2008-01-01

108

Effect of Melt Convection at Various Gravity Levels and Orientations on the Forces Acting on a Large Spherical Particle in the Vicinity of a Solidification Interface  

NASA Technical Reports Server (NTRS)

Numerical modeling was Undertaken to analyze the influence of both radial and axial thermal gradients on convection patterns and velocities claiming solidification of pure Al and an Al-4 wt% Cu alloy. The objective of the numerical task was to predict the influence of convective velocity on an insoluble particle near a solid/liquid (s/l) interface. These predictions were then be used to define the minimum gravity level (q) required to investigate the fundamental physics of interactions between a particle and a s/l interface. This is an ongoing NASA founded flight experiment entitled "particle engulfment and pushing by solidifying interfaces (PEP)". Steady-state calculations were performed for different gravity levels and orientations with respect to the gravity vector The furnace configuration used in this analysis is the quench module insert (QMI-1) proposed for the Material Science Research Facility (MSRF) on board the International Space Station (ISS). The general model of binary alloy solidification was based on the finite element code FIDAP. At a low g level of 10(exp -4) g(sub o) (g(sub o) = 9.8 m/square s) maximum melt convection was obtained for an orientation of 90 deg. Calculations showed that even for this worst case orientation the dominant forces acting on the particle are the fundamental drag and interfacial forces.

Bune, Andris V.; Sen, Subhayu; Mukherjee, Sundeep; Catalina, Adrian; Stefanescu, Doru M.

2000-01-01

109

Evaluation of the fermentation of high gravity thick sugar beet juice worts for efficient bioethanol production  

PubMed Central

Background Sugar beet and intermediates of sugar beet processing are considered to be very attractive feedstock for ethanol production due to their content of fermentable sugars. In particular, the processing of the intermediates into ethanol is considerably facilitated because it does not require pretreatment or enzymatic treatment in contrast to production from starch raw materials. Moreover, the advantage of thick juice is high solid substance and saccharose content which eliminates problems with the storability of this feedstock. Results The objective of this study were to investigate bioethanol production from thick juice worts and the effects of their concentration, the type of mineral supplement, as well as the dose of yeast inoculum on fermentation dynamics and ethanol yield. The obtained results show that to ensure efficient ethanolic fermentation of high gravity thick juice worts, one needs to use a yeast strain with high ethanol tolerance and a large amount of inoculum. The highest ethanol yield (94.9?±?2.8% of the theoretical yield) and sugars intake of 96.5?±?2.9% were obtained after the fermentation of wort with an extract content of 250 g/kg supplemented with diammonium hydrogen phosphate (0.3 g/L of wort) and inoculated with 2 g of Ethanol Red dry yeast per L of wort. An increase in extract content in the fermentation medium from 250 g/L to 280 g/kg resulted in decreased efficiency of the process. Also the distillates originating from worts with an extract content of 250 g/kg were characterized by lower acetaldehyde concentration than those obtained from worts with an extract content of 280 g/kg. Conclusions Under the favorable conditions determined in our experiments, 38.9?±?1.2 L of 100% (v/v) ethyl alcohol can be produced from 100 kg of thick juice. The obtained results show that the selection of process conditions and the yeast for the fermentation of worts with a higher sugar content can improve the economic performance of the alcohol-distilling industry due to more efficient ethanol production, reduced consumption of cooling water, and energy for ethanol distillation, as well as a decreased volume of fermentation stillage. PMID:24206573

2013-01-01

110

DEFENSE HIGH LEVEL WASTE GLASS DEGRADATION  

SciTech Connect

The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to provide models and parameter values that can be used to calculate the dissolution rates for the different modes of water contact. The analyses were conducted to identify key aspects of the mechanistic model for glass dissolution to be included in the abstracted models used for PA calculations, evaluate how the models can be used to calculate bounding values of the glass dissolution rates under anticipated water contact modes in the disposal. system, and determine model parameter values for the range of potential waste glass compositions and anticipated environmental conditions. The analysis of a bounding rate also considered the effects of the buildup of glass corrosion products in the solution contacting the glass and potential effects of alteration phase formation. Note that application of the models and model parameter values is constrained to the anticipated range of HLW glass compositions and environmental conditions. The effects of processes inherent to exposure to humid air and dripping water were not modeled explicitly. Instead, the impacts of these processes on the degradation rate were taken into account by using empirically measured parameter values. These include the rates at which water sorbs onto the glass, drips onto the glass, and drips off of the glass. The dissolution rates of glasses that were exposed to humid air and dripping water measured in laboratory tests are used to estimate model parameter values for contact by humid air and dripping water in the disposal system.

W. Ebert

2001-09-20

111

High frequency limit for gravitational perturbations of cosmological models in modified gravity theories  

E-print Network

In general relativity, it has been shown that the effective gravitational stress-energy tensor for short-wavelength metric perturbations acts just like that for a radiation fluid, and thus, in particular, cannot provide any effects that mimic dark energy. However, it is far from obvious if this property of the effective gravitational stress-energy tensor is a specific nature held only in the Einstein gravity, or holds also in other theories of gravity. In particular, when considering modified gravity theories that involve higher order derivative terms, one may expect to have some non-negligible effects arising from higher order derivatives of short-wavelength perturbations. In this paper, we argue this is not the case at least in the cosmological context. We show that when the background, or coarse-grained metric averaged over several wavelengths has FLRW symmetry, the effective gravitational stress-energy tensor for metric perturbations of a cosmological model in a simple class of f(R) gravity theories, as w...

Saito, Keiki

2012-01-01

112

Coordinated Parallelizing Compiler Optimizations and High-Level Synthesis  

Microsoft Academic Search

We present a framework for high-level synthesis that enables the designer to explore the best choice of source level and low level parallelizing transformations for improved synthesis. Within this framework, we implemented a methodology that applies a set of parallelizing code transfor- mations, both at the source level and during scheduling. A designer can use these transformations to optimize high-level

SUMIT GUPTA; Alex Nicolau; Rajesh Gupta

2002-01-01

113

Equilibrium Tides Along with surface gravity waves, the predictable rise and fall of sea level at the coast are  

E-print Network

want to find a semidiurnal tidal component due to the moon (called the M2 tide), we would use a model-squares method) to our available data of sea level to obtain the amplitude, M2, and phase, , of the lunar, and the phase is 45 degrees, then to find when high tide occurs we write M 2 t + / 4 = 2 since high tide

Thompson, LuAnne

114

Influence of gravity on self-propagating high-temperature thermite reactions: the case of Cu 2O-Al and Cu 2O-Cu-Al systems  

NASA Astrophysics Data System (ADS)

The effect of gravity on self-propagating reactions is investigated for the case of the thermite systems Cu 2O-Al and Cu 2O-Cu-Al. It is found that the gravitational overload influences wave velocity, degree of expulsion, sample shrinkage as well as product microstructure. The mechanism of structure formation under different gravity levels is also examined and the corresponding transformation zones are identified.

Rogachev, A. S.; Sanin, V. N.; Sytschev, A. E.; Yukhvid, V. I.; Medda, E.; Orrù, R.; Cao, G.

115

Application of low-cost algal nitrogen source feeding in fuel ethanol production using high gravity sweet potato medium.  

PubMed

Protein-rich bloom algae biomass was employed as nitrogen source in fuel ethanol fermentation using high gravity sweet potato medium containing 210.0 g l(-1) glucose. In batch mode, the fermentation could not accomplish even in 120 h without any feeding of nitrogen source. While, the feeding of acid-hydrolyzed bloom algae powder (AHBAP) notably promoted fermentation process but untreated bloom algae powder (UBAP) was less effective than AHBAP. The fermentation times were reduced to 96, 72, and 72 h if 5.0, 10.0, and 20.0 g l(-1) AHBAP were added into medium, respectively, and the ethanol yields and productivities increased with increasing amount of feeding AHBAP. The continuous fermentations were performed in a three-stage reactor system. Final concentrations of ethanol up to 103.2 and 104.3 g l(-1) with 4.4 and 5.3 g l(-1) residual glucose were obtained using the previously mentioned medium feeding with 20.0 and 30.0 g l(-1) AHBAP, at dilution rate of 0.02 h(-1). Notably, only 78.5 g l(-1) ethanol and 41.6 g l(-1) residual glucose were obtained in the comparative test without any nitrogen source feeding. Amino acids analysis showed that approximately 67% of the protein in the algal biomass was hydrolyzed and released into the medium, serving as the available nitrogen nutrition for yeast growth and metabolism. Both batch and continuous fermentations showed similar fermentation parameters when 20.0 and 30.0 g l(-1) AHBAP were fed, indicating that the level of available nitrogen in the medium should be limited, and an algal nitrogen source feeding amount higher than 20.0 g l(-1) did not further improve the fermentation performance. PMID:22387426

Shen, Yu; Guo, Jin-Song; Chen, You-Peng; Zhang, Hai-Dong; Zheng, Xu-Xu; Zhang, Xian-Ming; Bai, Feng-Wu

2012-08-31

116

Goose Bay radar observations of Earth-reflected, atmospheric gravity waves in the high-latitude ionosphere  

SciTech Connect

In the late fall and early winter, The Johns Hopkins University HF radar at Goose Bay, Labrador, observes the effects of atmospheric gravity waves on radar transmissions that are obliquely reflected from the ionosphere and subsequently backscattered from the Earth's surface. The waves exist under a wide variety of geomagnetic conditions; however, they are particularly noticeable under quiet conditions (O {le} Kp {le} 1 +). The clearest signatures of the waves are spatially localized enhancements in the backscattered power and quasi-periodic fluctuations in the backscatter powers, Doppler velocities, and reflection heights. The waves are generally observed during daylight hours and propagate equatorward from regions of high-latitude ionospheric backscatter that are located near the ionospheric convection reversal boundary. The gravity waves appear to be generated just equatorward of the dayside flow-reversal boundary in the vicinity of the auroral electrojet at altitudes of 115 to 135 km and propagate approximately perpendicular to the boundary along azimuths ranging from 156{degree} to 180{degree}. The waves propagate obliquely downward through the lower atmosphere until they are reflected by the Earth's surface back into the upper atmosphere. The frequencies associated with these gravity waves cover the range of 0.3 to 0.6 mHz, with wavelengths of 300 to 500 km, and with average phase velocities of 110 to 180 m/s. The maximum phase speeds are 270 to 300 m/s, which is slightly less than the speed of sound in the lower atmosphere. Poleward-propagating gravity waves are sometimes observed under disturbed conditions when the polar cap and convection reversal boundary have expanded equatorward.

Samson, J.C.; Greenwald, R.A.; Ruohoniemi, J.M.; Frey, A.; Baker, K.B. (Johns Hopkins Univ., Laurel, MD (USA))

1990-06-01

117

The Current Status of the Space Station Biological Research Project: a Core Facility Enabling Multi-Generational Studies under Slectable Gravity Levels  

NASA Astrophysics Data System (ADS)

The Space Station Biological Research Project (SSBRP) has developed a new plan which greatly reduces the development costs required to complete the facility. This new plan retains core capabilities while allowing for future growth. The most important piece of equipment required for quality biological research, the 2.5 meter diameter centrifuge capable of accommodating research specimen habitats at simulated gravity levels ranging from microgravity to 2.0 g, is being developed by NASDA, the Japanese space agency, for the SSBRP. This is scheduled for flight to the ISS in 2007. The project is also developing a multi-purpose incubator, an automated cell culture unit, and two microgravity habitat holding racks, currently scheduled for launch in 2005. In addition the Canadian Space Agency is developing for the project an insect habitat, which houses Drosophila melanogaster, and provides an internal centrifuge for 1 g controls. NASDA is also developing for the project a glovebox for the contained manipulation and analysis of biological specimens, scheduled for launch in 2006. This core facility will allow for experimentation on small plants (Arabidopsis species), nematode worms (C. elegans), fruit flies (Drosophila melanogaster), and a variety of microorganisms, bacteria, yeast, and mammalian cells. We propose a plan for early utilization which focuses on surveys of changes in gene expression and protein structure due to the space flight environment. In the future, the project is looking to continue development of a rodent habitat and a plant habitat that can be accommodated on the 2.5 meter centrifuge. By utilizing the early phases of the ISS to broadly answer what changes occur at the genetic and protein level of cells and organisms exposed to the ISS low earth orbit environment, we can generate interest for future experiments when the ISS capabilities allow for direct manipulation and intervention of experiments. The ISS continues to hold promise for high quality, long term, multi-generational biological studies with large sample sizes and appropriate controls.

Santos, O.

2002-01-01

118

Integration of P- and SH-wave high-resolution seismic reflection and micro-gravity techniques to improve interpretation of shallow subsurface structure: New Madrid seismic zone  

USGS Publications Warehouse

Shallow high-resolution seismic reflection surveys have traditionally been restricted to either compressional (P) or horizontally polarized shear (SH) waves in order to produce 2-D images of subsurface structure. The northernmost Mississippi embayment and coincident New Madrid seismic zone (NMSZ) provide an ideal laboratory to study the experimental use of integrating P- and SH-wave seismic profiles, integrated, where practicable, with micro-gravity data. In this area, the relation between "deeper" deformation of Paleozoic bedrock associated with the formation of the Reelfoot rift and NMSZ seismicity and "shallower" deformation of overlying sediments has remained elusive, but could be revealed using integrated P- and SH-wave reflection. Surface expressions of deformation are almost non-existent in this region, which makes seismic reflection surveying the only means of detecting structures that are possibly pertinent to seismic hazard assessment. Since P- and SH-waves respond differently to the rock and fluid properties and travel at dissimilar speeds, the resulting seismic profiles provide complementary views of the subsurface based on different levels of resolution and imaging capability. P-wave profiles acquired in southwestern Illinois and western Kentucky (USA) detect faulting of deep, Paleozoic bedrock and Cretaceous reflectors while coincident SH-wave surveys show that this deformation propagates higher into overlying Tertiary and Quaternary strata. Forward modeling of micro-gravity data acquired along one of the seismic profiles further supports an interpretation of faulting of bedrock and Cretaceous strata. The integration of the two seismic and the micro-gravity methods therefore increases the scope for investigating the relation between the older and younger deformation in an area of critical seismic hazard. ?? 2006 Elsevier B.V. All rights reserved.

Bexfield, C.E.; McBride, J.H.; Pugin, A.J.M.; Ravat, D.; Biswas, S.; Nelson, W.J.; Larson, T.H.; Sargent, S.L.; Fillerup, M.A.; Tingey, B.E.; Wald, L.; Northcott, M.L.; South, J.V.; Okure, M.S.; Chandler, M.R.

2006-01-01

119

High Resolution Mapping of the Gravity Field in Coastal Areas: a New Airborne Planar Gradiometer Concept  

NASA Astrophysics Data System (ADS)

Recent space missions such as CHAMP, GRACE and GOCE have contributed to considerably improve the accuracy of global gravity field models down to a resolution of 90 km. Albeit the use of these new data has been very beneficial to many fields of geosciences, many geodetic and geophysical issues require higher resolution models. This is all the more true in coastal areas where the gravity field is poorly covered by current measurement systems. Here we put forward airborne gravity gradiometry as a convenient way to address these limitations. In this respect, we present a new airborne acceleration gradiometer, GREMLIT, which permits along with ancillary measurements to determine the horizontal gradients of the horizontal components of the gravitational field in the instrumental frame. GREMLIT is composed of a compact assembly of 4 planar electrostatic accelerometers based on ONERA recognized expertise in the field of inertial sensors. The 4 accelerometers are mounted on a controlled platform. With an expected accuracy below 1E for the acceleration gradients, we discuss the possibility to recover the local geoid in coastal areas with a precision better than 1cm. For that, our approach follows 2 steps. First we theoretically determine the necessary conditions to fulfill in order to meet the objective. Conversely, assuming that the latter conditions are met, we test in a second phase if the use of GREMLIT in an airborne survey enables to determine a 1cm accuracy geoid. To do so, we design numerical simulations in 2 case studies and compute the total error budget on the gravity gradients in the instrumental frame. Solutions to increase the signal to noise ratio are presented.

Douch, K.; Panet, I.; Foulon, B.; Christophe, B.; Diament, M.; Métivier-Pajot, G.

2013-12-01

120

Statistics of high-level scene context  

PubMed Central

Context is critical for recognizing environments and for searching for objects within them: contextual associations have been shown to modulate reaction time and object recognition accuracy, as well as influence the distribution of eye movements and patterns of brain activations. However, we have not yet systematically quantified the relationships between objects and their scene environments. Here I seek to fill this gap by providing descriptive statistics of object-scene relationships. A total of 48, 167 objects were hand-labeled in 3499 scenes using the LabelMe tool (Russell et al., 2008). From these data, I computed a variety of descriptive statistics at three different levels of analysis: the ensemble statistics that describe the density and spatial distribution of unnamed “things” in the scene; the bag of words level where scenes are described by the list of objects contained within them; and the structural level where the spatial distribution and relationships between the objects are measured. The utility of each level of description for scene categorization was assessed through the use of linear classifiers, and the plausibility of each level for modeling human scene categorization is discussed. Of the three levels, ensemble statistics were found to be the most informative (per feature), and also best explained human patterns of categorization errors. Although a bag of words classifier had similar performance to human observers, it had a markedly different pattern of errors. However, certain objects are more useful than others, and ceiling classification performance could be achieved using only the 64 most informative objects. As object location tends not to vary as a function of category, structural information provided little additional information. Additionally, these data provide valuable information on natural scene redundancy that can be exploited for machine vision, and can help the visual cognition community to design experiments guided by statistics rather than intuition. PMID:24194723

Greene, Michelle R.

2013-01-01

121

Generation of Acoustic Gravity Waves by Periodic Radio Transmissions from a High-Power Ionospheric Heater  

NASA Astrophysics Data System (ADS)

The Radiophysical Research Institute (Nizhny Novgorod, Russia) and Kharkiv V. N. Karazin National University (Kharkiv, Ukraine) have studied opportunities for the effective generation of acoustic gravity waves (AGWs) in 3 - 180-min period range. The excitation of such waves was conducted for the last several years using the SURA heating facility (Nizhny Novgorod). The detection of the HF-induced AGWs was carried out in the Radiophysical Observatory located near Kharkiv City at a distance of about 960 km from the SURA. A coherent radar for vertical sounding, an ionosonde, and magnetometer chains were used in our measurements. The main results are the following (see [1-5]): 1. Infrasound oscillation trains with a period of 6 min are detected during periodic SURA heater turn-on and -off. Similar oscillation trains are detected after long time pumping, during periodic transmissions with a period of 20 s, as well as after pumping turn-off. The train recordings begin 28 - 54 min after the heater turn-on or -off, and the train propagation speeds are about 300 - 570 m/s, the value of which is close to the sound speed at upper atmospheric altitudes. The amplitude of the Doppler shift frequency is of 10 - 40 mHz, which fits to the 0.1 - 0.3% electron density disturbances at ionospheric altitudes. The amplitude of the infrasound oscillations depends on the SURA mode of operation and the state of the upper atmosphere and ionosphere. 2. High-power radio transmissions stimulate the generation (or enhancement) of waves at ionospheric altitudes in the range of internal gravity wave periods. The HF-induced waves propagate with speeds of 360 - 460 m/s and produce changes in electron density with amplitudes of 2 - 3%. The generation of such periodic perturbations is more preferable with periods of 10 - 60 minutes. Their features depend significantly on the heater mode of operation. It should be stressed that perturbation intensity increases when a pumping wave frequency approaches the F _{_2} layer critical frequency. High-power periodic radio transmissions are capable of enhancing/damping natural wave perturbations generated by the solar terminator. 3. The study has demonstrated that the generation and propagation of AGWs with periods close to the natural oscillation periods of the atmosphere is possible. The duration of AGW oscillation trains does not dependent on the duration of turn-on/-off trains, but it is determined by changes in the current state of the atmosphere-ionosphere-magnetosphere system in general. The period of the AGW oscillation trains is determined by the period or semi-period of the pumping. It means that the mechanism of AGW generation in this case is distinct from the agreed-upon mechanism developed earlier. The AGWs, whose periods are 5 - 10% greater than the Brunt-Vaisala period, exhibit group velocities less than the speed of sound that is of about 80 - 160 m/s. They induce electron density perturbations of about 1.1 - 1.5%. The AGW generation has the following features. When the effective radiated power (ERP) is 50 MW or less, AGWs are not detected; they are reliably observed when the ERP is equal or larger than about 100 MW. Geomagnetic storms play a dual role in the AGW generation because they: (i) increase amplitudes of AGWs with 4 - 6-min and 8 - 12-min periods and (ii) yet enhance background oscillations. The latter hampers the identification of the HF-induced oscillations. Moderate magnetic storms do not markedly exert an influence on the amplitudes of oscillations with 13 - 17-min periods. 4. The quasi-periodic variations in the horizontal components of the geomagnetic field with 8 - 12-min periods become observable near Kharkiv 35 - 45 min after the beginning of pumping. Their speeds are 355 - 460 m/s, and they form trains 40 - 90 min in duration when the [5-min on, 5-min off] or [10-min on, 10-min off] heater timing is used. The 12 - 18-min period variations become observable 35 - 45 min after the beginning of pumping. Their speeds are 355 - 460 m/s, and they form trains 55 - 90 min in duration when the

Frolov, Vladimir; Chernogor, Leonid; Rozumenko, Victor

122

40 CFR 227.30 - High-level radioactive waste.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

2011-07-01

123

40 CFR 227.30 - High-level radioactive waste.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

2013-07-01

124

40 CFR 227.30 - High-level radioactive waste.  

...2014-07-01 2014-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

2014-07-01

125

40 CFR 227.30 - High-level radioactive waste.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2011-07-01 true High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

2012-07-01

126

HIGH LEVEL AMINOGLYCOSIDE RESISTANCE IN ENTEROCOCCAL BLOOD CULTURE ISOLATES  

Microsoft Academic Search

Enterococci may display high level resistance to aminoglycosides, in which case synergy with cell-wall active antibiotics will be lost. All enterococcal blood culture isolates at Royal Brisbane Hospital have been screened by agar dilution for high level resistance to gentamicin and strepto- mycin since 1989. Of 110 isolates of Enterococcus faecalis, 16% displayed high level resistance to gentamicin and 10%

David Paterson; Janet Bodman; Mee Len Thong

127

Network congestion analysis of gravity generated models  

NASA Astrophysics Data System (ADS)

The network topology has lately proved to be critical to the appearance of traffic congestion, with scale-free networks being the less affected at high volumes of traffic. Here, the congestion dynamics are investigated for a class of networks that has experienced a resurgence of interest, the networks based on the gravity model. In addition, supplementary to the standard paradigm of uniform traffic volumes between randomly interacting node pairs, more realistic gravity traffic patterns are used to simulate the flows in the network. Results indicate that depending on the traffic pattern, the networks have different tolerance to congestion. Experiment simulation shows that the topologies created on the basis of the gravity model suffer less from congestion than the random, the scale-free or the Jackson-Rogers ones under both random and gravity traffic patterns. The congestion level is found to be approximately correlated with the network clustering coefficient in the case of random traffic, whereas in the case of gravity traffic such a correlation is not a trivial one. Other basic network properties such as the average shortest path and the diameter are seen to correlate fairly well with the congestion level. Further investigation on the adjustment of the gravity model parameters indicates particular sensitivity to network congestion. This work may have practical implications for designing traffic networks with both reasonable budget and good performance.

Maniadakis, Dimitris; Varoutas, Dimitris

2014-07-01

128

Electricity from Gravity  

NASA Astrophysics Data System (ADS)

Einstein's cosmological constant as gravity, will unify quantum mechanics to general relativity and link gravity to electromagnetism. Then, an electromagnetic vacuum engine driven by the force that spins, moves, and sustains mass at the subatomic level, will do free, what generators cannot. Flowing outward-bound sinusoidally from its source, this gravity force assumes a three-dimensional spherical universe. Lines of force intersect, spinning into gyroscopic particles and passes as time-present, with a compression gravity of space-time curvature continuum unifying all mass. The spaces between approaching masses suffer a decrease of right-angled vacuum energy, increasing external pressures, pushing them together. Ubiquitous gravity now interacts electromagnetically with mass. Gravity's ``heat energy'' operates below absolute zero and squeezes mass into thermonuclear ignition of stars. Creation needs a gravity field for the propagation of light that will make sense of its wave/particle behavior. Creation from a white hole recycles down through a black one, into new beginnings of galaxies. ``Vacuum energy'' will light cities and factories; faster than light spacecraft will raise silently from the ground utilizing the very gravity it defies, propelling us to the stars.

Masters, Roy

2007-03-01

129

Progress in high-level exploratory vision  

NASA Astrophysics Data System (ADS)

We have been exploring the hypothesis that vision is an explanatory process, in which causal and functional reasoning about potential motion plays an intimate role in mediating the activity of low-level visual processes. In particular, we have explored two of the consequences of this view for the construction of purposeful vision systems: Causal and design knowledge can be used to (1) drive focus of attention, and (2) choose between ambiguous image interpretations. An important result of visual understanding is an explanation of the scene's causal structure: How action is originated, constrained, and prevented, and what will happen in the immediate future. In everyday visual experience, most action takes the form of motion, and most causal analysis takes the form of dynamical analysis. This is even true of static scenes, where much of a scene's interest lies in how possible motions are arrested. This paper describes our progress in developing domain theories and visual processes for the understanding of various kinds of structured scenes, including structures built out of children's constructive toys and simple mechanical devices.

Brand, Matthew

1993-08-01

130

Feeling Gravity's Pull: Gravity Modeling. The Gravity Field of Mars  

Microsoft Academic Search

Most people take the constant presence of gravitys pull for granted. However, the Earth's gravitational strength actually varies from location to location. This variation occurs because mass, which influences an object's gravitational pull, is not evenly distributed within the planet. Changes in topography, such as glacial movement, an earthquake, or a rise in the ocean level, can subtly affect the

Frank Lemoine; David Smith; David Rowlands; Maria Zuber; G. Neumann; Douglas Chinn; D. Pavlis

2000-01-01

131

Increased expression of the yeast multidrug resistance ABC transporter Pdr18 leads to increased ethanol tolerance and ethanol production in high gravity alcoholic fermentation  

PubMed Central

Background The understanding of the molecular basis of yeast tolerance to ethanol may guide the design of rational strategies to increase process performance in industrial alcoholic fermentations. A set of 21 genes encoding multidrug transporters from the ATP-Binding Cassette (ABC) Superfamily and Major Facilitator Superfamily (MFS) in S. cerevisiae were scrutinized for a role in ethanol stress resistance. Results A yeast multidrug resistance ABC transporter encoded by the PDR18 gene, proposed to play a role in the incorporation of ergosterol in the yeast plasma membrane, was found to confer resistance to growth inhibitory concentrations of ethanol. PDR18 expression was seen to contribute to decreased 3?H-ethanol intracellular concentrations and decreased plasma membrane permeabilization of yeast cells challenged with inhibitory ethanol concentrations. Given the increased tolerance to ethanol of cells expressing PDR18, the final concentration of ethanol produced during high gravity alcoholic fermentation by yeast cells devoid of PDR18 was lower than the final ethanol concentration produced by the corresponding parental strain. Moreover, an engineered yeast strain in which the PDR18 promoter was replaced in the genome by the stronger PDR5 promoter, leading to increased PDR18 mRNA levels during alcoholic fermentation, was able to attain a 6?% higher ethanol concentration and a 17?% higher ethanol production yield than the parental strain. The improved fermentative performance of yeast cells over-expressing PDR18 was found to correlate with their increased ethanol tolerance and ability to restrain plasma membrane permeabilization induced throughout high gravity fermentation. Conclusions PDR18 gene over-expression increases yeast ethanol tolerance and fermentation performance leading to the production of highly inhibitory concentrations of ethanol. PDR18 overexpression in industrial yeast strains appears to be a promising approach to improve alcoholic fermentation performance for sustainable bio-ethanol production. PMID:22839110

2012-01-01

132

High Level Programming, Arun Chauhan, Rochester 2009-11-30 Higher Level Programming on Parallel  

E-print Network

High Level Programming, Arun Chauhan, Rochester 2009-11-30 Higher Level Programming on Parallel Computers: Sweetening the Deal for Programmers (and Making Compilers Work Harder) Arun Chauhan, Indiana University University of Rochester, Nov 30, 2009 #12;High Level Programming, Arun Chauhan, Rochester 2009

Chauhan, Arun

133

Clear and Measurable Signature of Modified Gravity in the Galaxy Velocity Field  

NASA Astrophysics Data System (ADS)

The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution v12 are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion ?12(r) is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations, we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon f(R) gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from general relativity at the (5-10)? level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity.

Hellwing, Wojciech A.; Barreira, Alexandre; Frenk, Carlos S.; Li, Baojiu; Cole, Shaun

2014-06-01

134

A clear and measurable signature of modified gravity in the galaxy velocity field  

E-print Network

The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution, $v_{12}$, are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion, $\\sigma_{12}(r)$, is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon $f(R)$ gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses exhibit deviations from General Relativity at the 5 to 10 $\\sigma$ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a smoking gun for modified gravity.

Hellwing, Wojciech A; Frenk, Carlos S; Li, Baojiu; Cole, Shaun

2014-01-01

135

Clear and measurable signature of modified gravity in the galaxy velocity field.  

PubMed

The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution v_{12} are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion ?_{12}(r) is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations, we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon f(R) gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from general relativity at the (5-10)? level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity. PMID:24949751

Hellwing, Wojciech A; Barreira, Alexandre; Frenk, Carlos S; Li, Baojiu; Cole, Shaun

2014-06-01

136

Turbulence Investigations With High-Resolution Simulations of Dilute Suspension Particle-Laden Gravity Currents  

NASA Astrophysics Data System (ADS)

Gravity currents are very common in nature, either in atmosphere (due to sea-breeze fronts), in mountain avalanches (in airborne snow or debris flow), or in the ocean due to turbidity currents or river plumes (Simpson, 1982). In this numerical study, we focus on particle-laden hyperpycnal flows (negative-buoyancy), where the dynamics play a central role in the formation of hydrocarbon reservoirs (Meiburg & Kneller, 2009). Moreover, these particle-driven gravity currents are often extremely dangerous for the stability of submarine structures placed near the sea-floor (like pipelines or submarines cables). It is clear that the understanding of the physical mechanism associated with these currents and the correct prediction of their main features are of great importance for practical as well as theoretical purposes. For this numerical work, we are interested in the prediction of a mono-disperse dilute suspension particle-laden flow in the typical lock-exchange configuration. We consider only flat surfaces using DNS (Direct Numerical Simulation). Our approach takes into account the possibility of particles deposition but ignores erosion and/or re-suspension. Previous results for this kind of flows were obtained in laboratory experiments with Reynolds numbers up to 10400 (De Rooij & Dalziel, 2001), or by numerical simulations at moderate Reynolds numbers, up to 5000 for a 2D case (Nasr-Azadani, Hall & Meiburg, 2011) and up to 2236 for a 3D (Necker, Härtel, Kleiser & Meiburg, 2002) case with a Reynolds number based on the buoyancy velocity. It was shown that boundary conditions, initial lock configuration and different particle sizes can have a strong influence on the main characteristics of this kind of flows. The main objective of this numerical study is to undertake unprecedented simulations in order to focus on the turbulence and to investigate the effect of the Reynolds number in such flows. We want to investigate the turbulent mechanism in gravity currents such as local production and dissipation and their relationships with the main features of the flow for different Reynolds numbers, ranging from 2236 to 10000 for 2D and 3D cases. The main features of the flow will be related to the temporal evolution of the front location, sedimentation rate and the resulting streamwise deposit profiles. In particular, we will investigate the flow energy budget where the balance between kinetic and potential energy with dissipation (due to convective fluid motion and Stokes flow around particles) will be analysed in detail, using comparisons with previous experimental and numerical works.

Espath, L.; Pinto, L.; Laizet, S.; Silvestrini, J.; Scientific Team of DNS on Gravity Currents

2013-05-01

137

Exploring medium gravity icy planetary bodies: an opportunity in the Inner System by landing at Ceres high latitudes  

NASA Astrophysics Data System (ADS)

With potentially up to 25% of its mass as H2O and current indications of a differentiated morphology, 950km-wide "dwarf planet" Ceres is holding the promise to be our closest significant icy planetary body. Ceres is within easier reach than the icy moons, allowing for the use of solar arrays and not lying inside the deep gravity well of a giant planet. As such, it would represent an ideal step stone for future in-situ exploration of other airless icy bodies of major interest such as Europa or Enceladus. But when NASA's Dawn orbits Ceres and maps it in 2015, will we be ready to undertake the next logical step: landing? Ceres' gravity at its poles, at about one fifth of the Moon's gravity, is too large for rendezvous-like asteroid landing techniques to apply. Instead, we are there fully in the application domain of soft precision landing techniques such as the ones being developed for ESA's MoonNext mission. These latter require a spacecraft architecture akin to robotic lunar Landers or NASA's Phoenix, and differing from missions to comets and asteroids. If Dawn confirms the icy nature of Ceres under its regolith-covered surface, the potential presence of some ice spots on the surface would call for specific attention. Such spots would indeed be highly interesting landing sites. They are more likely to lie close to the poles of Ceres where cold temperatures should prevent exposed ice from sublimating and/or may limit the thickness of the regolith layer. Also the science and instruments suite should be fitted to study a large body that has probably been or may still be geologically active: its non-negligible gravity field combined with its high volatile mass fraction would then bring Ceres closer in morphology and history to an "Enceladus" or a frozen or near-frozen "Europa" than to a rubble-pile-structured asteroid or a comet nucleus. Thales Alenia Space and the "Laboratoire de Planétologie et Géodynamique" of the University of Nantes have carried out a preliminary assessment of a mission to Ceres high latitudes. We present here why we think an in-situ mission to the polar areas of Ceres should be of interest in the near future. We dwell on the environmental factors and challenges for a Lander, both as specificities of Ceres and as a consequence of the high latitude targeted. Factors such as day duration, fine regolith, terrain hazards, optical contrasts, thermal gradients, planetary contamination... are reviewed. We then assess how the soft precision landing technologies being developed for other missions would apply in such an environment. We present a preliminary mission analysis and a concept for the Lander, with preliminary evaluation of mass and power resources for a fixed payload or for a mini-rover. The resulting mission design combines technological maturity and a launch mass that is found compatible with the moderate cost of a Soyuz launcher. Finally we conclude that a Ceres Polar Lander mission should be feasible, covered by automatic missions to the Moon in terms of difficulty of landing and by Dawn for the cruise. Lander missions to medium gravity bodies such as Ceres, Enceladus, Europa, Ganymede, Callisto, Iapetus, Triton… in the [0.01-0.15g] range should be accounted for in the development roadmaps of landing techniques and be considered in their return on investment. The synergies with the soft landing missions to come on Mars and Moon should then make a Ceres lander affordable for the agencies within the end of the next decade and pave the way for in-situ missions to more distant icy bodies.

Poncy, J.; Grasset, O.; Martinot, V.; Tobie, G.

2009-04-01

138

On the influence of the ground track on the gravity field recovery from high-low satellite-to-satellite tracking missions: CHAMP monthly gravity field recovery using the energy balance approach revisited  

NASA Astrophysics Data System (ADS)

In this paper, the influence of the ground track coverage on the quality of a monthly gravity field solution is investigated for the scenario of a high-low satellite- to-satellite tracking mission. Data from the CHAllenging Minisatellite Payload ( champ) mission collected in the period April 2002 to February 2004 has been used to recover the gravity field to degree and order 70 on a monthly basis. The quality is primarily restricted by the accuracy of the instruments. Besides, champ passed through a 31/2 repeat mode three times during the period of interest resulting in an insufficient spatial sampling and a degraded solution. Contrary to the rule of thumb by Colombo (The global mapping of gravity with two satellites, Publications on Geodesy, vol 7(3), Netherlands Geodetic Commission, The Netherlands, 263 pp, 1984), see also Wagner (J Geod 80(2): 94-103, 2006), we found that the monthly solutions themselves could be recovered to about degree 30, not 15. In order to improve the monthly gravity solutions, two strategies have been developed: the restriction to a low degree, and the densification of the sampling by the introduction of additional sensitive measurements from contemporaneous satellite missions. The latter method is tested by combining the champ measurements with data from the Gravity Recovery And Climate Experiment ( grace). Note that the two grace satellites are considered independent here, i.e. no use is made of the K-band ranging data. This way, we are able to almost entirely remove the influence of the ground track leaving the accuracy of the instruments as the primary restriction on the quality of a monthly solution. These findings are especially interesting for the upcoming swarm-mission since it will consist of a similar configuration as the combined champ and ( grace) missions.

Weigelt, Matthias; Sideris, Michael G.; Sneeuw, Nico

2009-12-01

139

Changes in water levels and storage in the High Plains Aquifer, predevelopment to 2009  

USGS Publications Warehouse

The High Plains aquifer underlies 111.8 million acres (175,000 square miles) in parts of eight States - Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The area overlying the High Plains aquifer is one of the primary agricultural regions in the Nation. Water-level declines began in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater from the aquifer (about 1950 and termed "predevelopment" in this fact sheet). By 1980, water levels in the High Plains aquifer in parts of Texas, Oklahoma, and southwestern Kansas had declined more than 100 feet (ft) (Luckey and others, 1981). In 1987, in response to declining water levels, Congress directed the U.S. Geological Survey (USGS), in collaboration with numerous Federal, State, and local water-resources entities, to assess and track water-level changes in the aquifer. This fact sheet summarizes changes in water levels and drainable water in storage in the High Plains aquifer from predevelopment to 2009. Drainable water in storage is the fraction of water in the aquifer that will drain by gravity and can be withdrawn by wells. The remaining water in the aquifer is held to the aquifer material by capillary forces and generally cannot be withdrawn by wells. Drainable water in storage is termed "water in storage" in this report. A companion USGS report presents more detailed and technical information about water-level and storage changes in the High Plains aquifer during this period (McGuire, 2011).

McGuire, V.L.

2011-01-01

140

A Framework for Translating a High Level Security Policy into Low Level Security Mechanisms  

NASA Astrophysics Data System (ADS)

Security policies have different components; firewall, active directory, and IDS are some examples of these components. Enforcement of network security policies to low level security mechanisms faces some essential difficulties. Consistency, verification, and maintenance are the major ones of these difficulties. One approach to overcome these difficulties is to automate the process of translation of high level security policy into low level security mechanisms. This paper introduces a framework of an automation process that translates a high level security policy into low level security mechanisms. The framework is described in terms of three phases; in the first phase all network assets are categorized according to their roles in the network security and relations between them are identified to constitute the network security model. This proposed model is based on organization based access control (OrBAC). However, the proposed model extend the OrBAC model to include not only access control policy but also some other administrative security policies like auditing policy. Besides, the proposed model enables matching of each rule of the high level security policy with the corresponding ones of the low level security policy. Through the second phase of the proposed framework, the high level security policy is mapped into the network security model. The second phase could be considered as a translation of the high level security policy into an intermediate model level. Finally, the intermediate model level is translated automatically into low level security mechanism. The paper illustrates the applicability of proposed approach through an application example.

Hassan, Ahmed A.; Bahgat, Waleed M.

2010-01-01

141

Gravity Waves  

article title:  Gravity Waves Ripple over Marine Stratocumulus Clouds ... Imaging SpectroRadiometer (MISR), a fingerprint-like gravity wave feature occurs over a deck of marine stratocumulus clouds. Similar ... Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82° north ...

2013-04-19

142

Preliminary results of absolute and high-precision gravity measurements at the Nevada Test Site and vicinity, Nevada  

NASA Astrophysics Data System (ADS)

Absolute gravity measurements were made at 4 sites in southern Nevada using the absolute gravity free-fall apparatus. Three of the sites are located on the Nevada Test Site at Mercury, Yucca Pass, and in northern Jackass Flats. The fourth site is at Kyle Canyon ranger station near Charleston Park where observed gravity is 216.19 mGal lower than at Mercury. Although there is an uncertainty of about 0.02 mGal in the absolute measured values, their gravity differences are considered accurate to about 0.03 mGal. Therefore, the absolute measurements should provide local control for the calibration of gravity meters between Mercury and Kyle Canyon ranger station to about 1 to 2 parts in 10,000. The average gravity differences between Mercury and Kyle Canyon obtained using LaCoste and Romberg gravity meters is 216.13 mGal, 0.06 mGal lower, or 3 parts in 10,000 lower than using the absolute gravity meter. Because of the discrepancy between the comparison of the absolute and relative gravity meters, more absolute and relative gravity control in southern Nevada, as well as the Mt. Hamilton area where the LaCoste and Romberg instruments were calibrated, is needed. Multiple gravity meter ties were also made between each of the four absolute stations to nearby base stations located on bedrock. These stations were established to help monitor possible real changes in gravity at the absolute sites that could result from seasonal variations in the depth to the water table.

Zumberge, M. A.; Harris, R. N.; Oliver, H. W.; Sasagawa, G. S.; Ponce, D. A.

143

MEMORY AWARE HIGH-LEVEL SYNTHESIS FOR EMBEDDED SYSTEMS  

E-print Network

MEMORY AWARE HIGH-LEVEL SYNTHESIS FOR EMBEDDED SYSTEMS Gwenole Corre, Eric Senn, Nathalie Julien to take into account the memory architecture and the memory mapping in the High- Level Synthesis of Real-Time embedded systems. We formalize the memory mapping as a set of constraints for the synthesis, and defined

Paris-Sud XI, Université de

144

Gravity model studies of Newberry Volcano, Oregon  

SciTech Connect

Newberry, Volcano, a large Quaternary volcano located about 60 km east of the axis of the High Cascades volcanoes in central Oregon, has a coincident positive residual gravity anomaly of about 12 mGals. Model calculations of the gravity anomaly field suggest that the volcano is underlain by an intrusive complex of mafic composition of about 20-km diameter and 2-km thickness, at depths above 4 km below sea level. However, uplifted basement in a northwest trending ridge may form part of the underlying excess mass, thus reducing the volume of the subvolcanic intrusive. A ring dike of mafic composition is inferred to intrude to near-surface levels along the caldera ring fractures, and low-density fill of the caldera floor probably has a thickness of 0.7--0.9 km. The gravity anomaly attributable to the volcano is reduced to the east across a north-northwest trending gravity anomaly gradient through Newberry caldera and suggests that normal, perhaps extensional, faulting has occurred subsequent to caldera formation and may have controlled the location of some late-stage basaltic and rhyolitic eruptions. Significant amounts of felsic intrusive material may exist above the mafic intrusive zone but cannot be resolved by the gravity data.

Gettings, M.E.; Griscom, A.

1988-09-10

145

Interactions between Artificial Gravity, the Affected Physiological Systems, and Nutrition  

NASA Technical Reports Server (NTRS)

Malnutrition, either by insufficient supply of some nutrients or by overfeeding, has a profound effect on the health of an organism. Therefore, optimal nutrition is a necessity in normal gravity on Earth, in microgravity, and when applying artificial gravity to the human system. Reduced physical activity, such as observed in microgravity or bed rest, has an effect on many physiological systems, such as the cardiovascular, musculoskeletal, immune, and body fluids regulation systems. There is currently no countermeasure that is effective to counteract both the cardiovascular and musculoskeletal deconditioning when applied for a short duration (see Chapter 1). Artificial gravity therefore seems the simplest physiological approach to keep these systems intact. The application of intermittent daily dose of artificial gravity by means of centrifugation has often been proposed as a potential countermeasure against the physiological deconditioning induced by spaceflight. However, neither the optimal gravity level, nor its optimal duration of exposure have been enough studied to recommend a validated, effective, and efficient artificial gravity application. As discussed in previous chapters, artificial gravity has a very high potential to counteract any changes caused by reduced physical activity. The nutrient supply, which ideally should match the actual needs, will interact with these changes and therefore has also to be taken into account. This chapter reviews the potential interactions between these nutrients (energy intake, vitamins, minerals) and the other physiological systems affected by artificial gravity generated by an on-board short-radius centrifuge.

Heer, Martina; Baecker, Nathalie; Zwart, Sara; Smith, Scott

2006-01-01

146

Numerical Simulations of Bubble Dynamics and Heat Transfer in Pool Boiling---Including the Effects of Conjugate Conduction, Level of Gravity, and Noncondensable Gas Dissolved in the Liquid  

NASA Astrophysics Data System (ADS)

Due to the complex nature of the subprocesses involved in nucleate boiling, it has not been possible to develop comprehensive models or correlations despite decades of accumulated data and analysis. Complications such as the presence of dissolved gas in the liquid further confound attempts at modeling nucleate boiling. Moreover, existing empirical correlations may not be suitable for new applications, especially with regards to varying gravity level. More recently, numerical simulations of the boiling process have proven to be capable of reliably predicting bubble dynamics and associated heat transfer by showing excellent agreement with experimental data. However, most simulations decouple the solid substrate by assuming constant wall temperature. In the present study complete numerical simulations of the boiling process are performed---including conjugate transient conduction in the solid substrate and the effects of dissolved gas in the liquid at different levels of gravity. Finite difference schemes are used to discretize the governing equations in the liquid, vapor, and solid phases. The interface between liquid and vapor phases is tracked by a level set method. An iterative procedure is used at the interface between the solid and fluid phases. Near the three-phase contact line, temperatures in the solid are observed to fluctuate significantly over short periods. The results show good agreement with the data available in the literature. The results also show that waiting and growth periods can be related directly to wall superheat. The functional relationship between waiting period and wall superheat is found to agree well with empirical correlations reported in the literature. For the case of a single bubble in subcooled nucleate boiling, the presence of dissolved gas in the liquid is found to cause noncondensables to accumulate at the top of the bubble where most condensation occurs. This results in reduced local saturation temperature and condensation rates. The numerical predictions show reasonable agreement with the results from experiments performed at microgravity. For nucleate boiling at microgravity the simulations predict a drastic change in vapor removal pattern when compared to Earth normal gravity. The predictions match well with experimental results. However, simulated heat transfer rates were significantly under-predicted.

Aktinol, Eduardo

147

Cascading gravity is ghost free  

SciTech Connect

We perform a full perturbative stability analysis of the 6D cascading gravity model in the presence of 3-brane tension. We demonstrate that for sufficiently large tension on the (flat) 3-brane, there are no ghosts at the perturbative level, consistent with results that had previously only been obtained in a specific 5D decoupling limit. These results establish the cascading gravity framework as a consistent infrared modification of gravity.

Rham, Claudia de [Departement de Physique Theorique, Universite de Geneve, 24 Quai E. Ansermet, CH-1211 Geneve (Switzerland); Khoury, Justin [Center for Particle Cosmology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6395 (United States); Tolley, Andrew J. [Perimeter Institute for Theoretical Physics, 31 Caroline St. N., Waterloo, ON, N2L 2Y5 (Canada)

2010-06-15

148

Fusing high- and low-level features for speaker recognition  

Microsoft Academic Search

The area of automatic speaker recognition has been dominated by systems using only short-term, low-level acoustic information, such as cepstral features. While these systems have produced low error rates, they ignore higher levels of information beyond low-level acoustics that convey speaker information. Recently published works have demonstrated that such high-level information can be used successfully in automatic speaker recognition systems

Joseph P. Campbell; Douglas A. Reynolds; Robert B. Dunn

2003-01-01

149

Effects of Body Orientation and Retinal Image Pitch on the Perception of Gravity-Referenced Eye Level (GREL)  

NASA Technical Reports Server (NTRS)

It has been asserted that the pitch orientation of a visual array and of an observer's body jointly determine the perception of GREL. The current study formally tests this assertion over an extended range with multiple combinations of visual and body pitch orientations. Ten subjects were individually secured in a Circolectric bed surrounded by a room (pitchroom) with walls that could be pitched at various angles with respect to gravity. The bed and the walls of the room were independently adjusted to each of five positions relative to gravitational vertical: -15, -7.5, 0, +7.5, and +15 degrees, yielding 25 combinations of body x room pitch angles, and retinal image pitch (RIP) conditions ranging from -30 to +30 degrees. Each subject set a target to apparent GREL while viewing it against a background of two electroluminescent strips on the outer edges of the far wall of the room. As determined by ANOVA, the orientation of the room, and its interaction with that of the observer, significantly altered GREL (p less than 0.01). Regression analysis showed that GREL was best described as a linear summation of the weighted independent contributions from a body-referenced mechanism (B) and a visual mechanism given by the orientation of the background array on the retina (RIP). The equation for this relationship is: GREL = .74 (B) +.64 (RIP) - 1.42; r-squared = .994.

Cohen, Malcolm M.; Guzy, Larry T.; Wade, Charles E. (Technical Monitor)

1994-01-01

150

High-gravity-assisted pulsed laser ablation system for the fabrication of functionally graded material thin film.  

PubMed

This paper describes a novel method for the fabrication of a thin film deposited on an appropriate substrate having a continuous composition gradient. The composition gradient was achieved by a combination of pulsed laser ablation (PLA) of the target material with a very strong acceleration field generated on a moving disk rotating at a very high speed. The PLA process was used to produce a cloud of high-energy particles of the target material that will be deposited on a substrate placed on the rotating disk. After deposition, the particles will diffuse on the surface of the thin film under a strong acceleration field. The high energy of the particles and their diffusion on the substrate surface in a high-vacuum environment produces a macroscopic composition distribution in the thin film. We have constructed an experimental apparatus consisting of a vacuum chamber in which a circular disk made of titanium is driven by a high-frequency inductive motor. An acceleration field of up to 10,000 G can be generated by this apparatus. Functionally graded material thin films of FeSi(2) with a continuous concentration gradient were successfully fabricated by this method under a gravity field of 5400 G. A significant advantage of this method is that it allows us to fabricate graded thin films with a very smooth surface covered by few droplets. PMID:19334931

Nishiyama, T; Morinaga, S; Nagayama, K

2009-03-01

151

High temperature testing of the EDCON borehole gravity housing system conducted at Los Alamos National Laboratories, January 12-18, 1986  

SciTech Connect

A series of tests were conducted on the EDCON borehole gravity meter (BHGM) high temperature sonde. The tests were conducted to determine the suitability of this sonde for logging operations in the Department of Energy Salton Trough test well. 1 ref., 3 figs., 4 tabs.

Not Available

1986-01-01

152

Gravity brake  

DOEpatents

A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

Lujan, Richard E. (Santa Fe, NM)

2001-01-01

153

Engineering chloroplasts for high-level foreign protein expression.  

PubMed

Expression of transgenes from the plastid genome offers a number of attractions to biotechnologists, with the potential to attain very high protein accumulation levels arguably being the most attractive one. High-level transgene expression is of particular importance in resistance engineering (e.g., via expression of insecticidal proteins) and molecular farming. Over the past years, the production of many commercially valuable proteins in chloroplast-transgenic (transplastomic) plants has been attempted, including pharmaceutical proteins (such as subunit vaccines and protein antibiotics) and industrial enzymes. Although, in some cases, spectacularly high foreign protein accumulation levels have been obtained, expression levels were disappointingly poor in other cases. In this review, I summarize our current knowledge about the factors influencing the efficiency of plastid transgene expression and highlight possible optimization strategies to alleviate problems with poor expression levels. PMID:24599848

Bock, Ralph

2014-01-01

154

Consistently high urine specific gravity in adolescent American football players and the impact of an acute drinking strategy.  

PubMed

The purpose of this study was to determine whether high-school football players showed risks of fluid deficits during two-a-day training (Part 1), and whether implementing a drinking strategy could acutely improve the markers of hydration (Part 2). In Part 1, pre-training urine specific gravity (USG) and pre- and post-training body weight were measured at the morning session for 5 consecutive days of two-a-day practices to monitor the hydration status of 13 varsity players. The mean pre-training body weight was consistently lower (mean decrease of 0.5 kg, p<0.05) following the first day of measurement. Pre-training USG values remained consistently high each day (range for daily means: 1.022+/-0.003 to 1.024+/-0.005). Part 2 consisted of assessing hydration status in 46 varsity and junior varsity players prior to morning training during two-a-day training before and following implementing a drinking strategy. In association with the strategy, mean body weight increased 0.5 kg (p<0.01) and mean USG decreased from 1.021 to 1.016 (p<0.01) following the drinking protocol. The slight decline in body weight and consistently high USG (Part 1) suggested that standard fluid replacement strategies were less than optimal for a majority of the players. Implementing a drinking strategy appeared to improve hydration status based on changes in body weight and USG (Part 2). PMID:16572377

Stover, E A; Zachwieja, J; Stofan, J; Murray, R; Horswill, C A

2006-04-01

155

Neptunium estimation in dissolver and high-level-waste solutions  

SciTech Connect

This papers deals with the optimization of the experimental conditions for the estimation of {sup 237}Np in spent-fuel dissolver/high-level waste solutions using thenoyltrifluoroacetone as the extractant. (authors)

Pathak, P.N.; Prabhu, D.R.; Kanekar, A.S.; Manchanda, V.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

2008-07-01

156

Transportation system modeling using the High Level Architecture  

E-print Network

This dissertation investigates the High Level Architecture (HLA) as a possible distributed simulation framework for transportation systems. The HLA is an object-oriented approach to distributed simulations developed by the Department of Defense (Do...

Melouk, Sharif

2004-09-30

157

HIGH-LEVEL OZONE DISINFECTION OF MUNICIPAL WASTEWATER EFFLUENTS  

EPA Science Inventory

A 20 month operating experimental program was conducted at Marlborough, Massachusetts to evaluate the feasibility, engineering, and economic aspects of achieving high levels of effluent disinfection with ozone. The ozone research pilot facility was designed to operate at a consta...

158

Evolving Automatically High-Level Music Descriptors from Acoustic Signals  

Microsoft Academic Search

High-Level music descriptors are key ingredients fo r music information retrieval systems. Although there is a long tradition in extracting information from acoustic signals, the field of mus ic information extraction is largely heuristic in nature. We present here a heur istic-based generic approach for extracting automatically high-level music descr iptors from acoustic signals. This approach is based on Genetic

François Pachet; Aymeric Zils

2003-01-01

159

Adaptive Simulated Annealer for high level synthesis design space exploration  

Microsoft Academic Search

This paper presents a microarchitectural design space exploration tool called cwbexplorer based on an Adaptive Simulated Annealer Exploration Algorithm (ASA-ExpA) for behavioral descriptions written in untimed C or SystemC. Cwbexplorer automatically generates a series of designs given a set of constraints (area and latency) from an untimed high level language description. A commercial high level synthesis tool (Cy- berWorkBench) is

Benjamin Carrion Schafer; Takashi Takenaka; Kazutoshi Wakabayashi

2009-01-01

160

Dynamic Communicating Automata and Branching High-Level MSCs  

E-print Network

Communicating Automata · Branching High-Level MSCs ... x := new(s,x) x ? comx ! req(y) #12;Outline · Dynamic Communicating Automata · Branching High-Level MSCs ... x y x y req(y) x y com com x := new(s,x) x ? comx ! req com x := new(s,x) x ? comx ! req(y) implementable? #12;Outline · Dynamic Communicating Automata

Bollig, Benedikt

161

High-Level Waste System Process Interface Description  

SciTech Connect

The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment.

d'Entremont, P.D.

1999-01-14

162

Discovery of high-level tasks in the operating room.  

PubMed

Recognizing and understanding surgical high-level tasks from sensor readings is important for surgical workflow analysis. Surgical high-level task recognition is also a challenging task in ubiquitous computing because of the inherent uncertainty of sensor data and the complexity of the operating room environment. In this paper, we present a framework for recognizing high-level tasks from low-level noisy sensor data. Specifically, we present a Markov-based approach for inferring high-level tasks from a set of low-level sensor data. We also propose to clean the noisy sensor data using a Bayesian approach. Preliminary results on a noise-free dataset of ten surgical procedures show that it is possible to recognize surgical high-level tasks with detection accuracies up to 90%. Introducing missed and ghost errors to the sensor data results in a significant decrease of the recognition accuracy. This supports our claim to use a cleaning algorithm before the training step. Finally, we highlight exciting research directions in this area. PMID:20060495

Bouarfa, L; Jonker, P P; Dankelman, J

2011-06-01

163

Reasoning about High-Level Tree Update and its Low-Level Implementation  

E-print Network

- ifying properties about arbitrary structured data up- date such as XML update. Since then, we have had requiring addi- tional pointer surgery. Tying up the high-level and low-level reasoning is therefore rather identifiers and lists of children which may vary in length. This simple structure gives the essence of XML

Gardner, Philippa

164

Activity in high-level brain regions reflects visibility of low-level stimuli.  

PubMed

Stimulus visibility is associated with neural signals in multiple brain regions, ranging from visual cortex to prefrontal regions. Here we used functional magnetic resonance imaging (fMRI) to investigate to which extent the perceived visibility of a "low-level" grating stimulus is reflected in the brain activity in high-level brain regions. Oriented grating stimuli were presented under varying visibility conditions created by backward masking. Visibility was manipulated using four different stimulus onset asynchronies (SOAs), which created a continuum from invisible to highly visible target stimuli. Brain activity in early visual areas, high-level visual brain regions (fusiform gyrus), as well as parietal and prefrontal brain regions was significantly correlated with subjects' psychometric visibility functions. In addition, increased stimulus visibility was reflected in the functional coupling between low and high-level visual areas. Specifically, neuroimaging signals in the middle occipital gyrus were significantly more correlated with signals in the inferior temporal gyrus when subjects successfully perceived the target stimulus than when they did not. These results provide evidence that not only low-level visual but also high-level brain regions reflect visibility of low-level grating stimuli and that changes in functional connectivity reflect perceived stimulus visibility. PMID:25175537

Imamoglu, F; Heinzle, J; Imfeld, A; Haynes, J-D

2014-11-15

165

Regeneration of eye tissues is modulated by altered levels of gravity at 1g, 2g, and in microgravity during spaceflight  

NASA Astrophysics Data System (ADS)

The pursuit of human space exploration requires detailed knowledge of microgravity-related changes in fundamental biological processes, and their effects on health. Normal regeneration of organs and tissues is one such fundamental process that allows maintenance of vitality and function of living organisms. Animal models of tissue regeneration include the newt (Pleurodeles waltl, Urodela) eye, which has been extensively used by our team in Russian Bion and Foton microgravity experiments since 1985, and in recent NASA 2.5 meter diameter centrifuge hypergravity experiments. In total, these experiments allow us to draw several broad conclusions: Newt lens regeneration is significantly altered in microgravity and hypergravity relative to 1g controls. Lenses formed in microgravity are larger and more developed than those regenerated in 1g controls; Microgravity alterations of lens regeneration can persist after spaceflight, and continue to affect repeated removal and regeneration of the lens after return to 1g; Microgravity increases the numbers of early stage regenerative proliferating BrdU-labeled cells in dorsal iris progenitors and in the lens regenerate. Regeneration under hypergravity conditions at 2g inhibits lens regeneration, and often causes retinal detachment. Molecular mechanisms regulating lens regeneration rate include FGF2 signaling, (a key pathway for eye tissue development and regeneration), and an expression of stress-related proteins - HSPs. In conclusion, regeneration of lens and other eye tissues in the newt is sensitive to, and regulated by the level of gravity mechanotransduction and developmental signaling pathways, with microgravity favoring stem cell progenitor proliferation, and gravity at 1g promoting terminal differentiation, while hypergravity at 2g often causes damage of delicate regenerating tissues.

Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

166

High-Level Synthesis of Software Function Calls  

NASA Astrophysics Data System (ADS)

This letter presents a novel framework in high-level synthesis where hardware modules synthesized from functions in a given ANSI-C program can call the other software functions in the program. This enables high-level synthesis from C programs that contains calls to hard-to-synthesize functions, such as dynamic memory management, I/O request, or very large and complex functions. A single-thread implementation scheme is shown, whose correctness has been verified through register transfer level simulation.

Nishimura, Masanari; Ishiura, Nagisa; Ishimori, Yoshiyuki; Kanbara, Hiroyuki; Tomiyama, Hiroyuki

167

Characterization of very high gravity ethanol fermentation of corn mash. Effect of glucoamylase dosage, pre-saccharification and yeast strain.  

PubMed

Ethanol was produced from very high gravity mashes of dry milled corn (35% w/w total dry matter) under simultaneous saccharification and fermentation conditions. The effects of glucoamylase dosage, pre-saccharification and Saccharomyces cerevisiae strain on the growth characteristics such as the ethanol yield and volumetric and specific productivity were determined. It was shown that higher glucoamylase doses and/or pre-saccharification accelerated the simultaneous saccharification and fermentation process and increased the final ethanol concentration from 106 to 126 g/kg although the maximal specific growth rate was decreased. Ethanol production was not only growth related, as more than half of the total saccharides were consumed and more than half of the ethanol was produced during the stationary phase. Furthermore, a high stress tolerance of the applied yeast strain was found to be crucial for the outcome of the fermentation process, both with regard to residual saccharides and final ethanol concentration. The increased formation of cell mass when a well-suited strain was applied increased the final ethanol concentration, since a more complete fermentation was achieved. PMID:15678305

Devantier, Rasmus; Pedersen, Sven; Olsson, Lisbeth

2005-09-01

168

Retrieving mesospheric winds and gravity waves using high resolution radar measurements of polar mesospheric summer echoes with MAARSY  

NASA Astrophysics Data System (ADS)

The Middle Atmosphere Alomar Radar System (MAARSY) located at the northern Norwegian island of Andøya (69.3 ° N, 16° E) observes polar mesosphere summer echoes (PMSE) on a regular basis. This backscatter turned out to be an ideal tracer of atmospheric dynamics and to investigate the wind field at the mesosphere/lower thermosphere (MLT) at high spatial and temporal scales. MAARSY is dedicated to explore the polar mesosphere at such high resolution and employs an active phased array antenna with the capability to steer the beam on a pulse-to-pulse basis, which permits to perform systematic scanning of PMSE and to investigate the horizontal structure of the backscatter. The radar also uses a 16 channel receiver system for interferometric applications e.g. mean angle of arrival analysis or coherent radar imaging. Here we present measurements using these features of MAARSY to study the wind field at the MLT applying sophisticated wind analysis algorithms such as velocity azimuth display or volume velocity processing to derive gravity wave parameters such as horizontal wave length, phase speed and propagation direction. Further, we compare the interferometrically corrected and uncorrected wind measurements to emphasize the importance to account for likely edge effects using PMSE as tracer of the dynamics. The observations indicate huge deviations from the nominal beam pointing direction at the upper and lower edges of the PMSE altering the wind analysis.

Stober, G.; Sommer, S.; Schult, C.; Chau, J. L.; Latteck, R.

2013-12-01

169

Water borne transport of high level nuclear waste in very deep borehole disposal of high level nuclear waste  

E-print Network

The purpose of this report is to examine the feasibility of the very deep borehole experiment and to determine if it is a reasonable method of storing high level nuclear waste for an extended period of time. The objective ...

Cabeche, Dion Tunick

2011-01-01

170

A Testing Instrument for High School Arabic, Level III.  

ERIC Educational Resources Information Center

The Arabic language examination was designed for Jewish immigrants from Syria wishing to satisfy New York State language requirements for high school graduation by indicating their proficiency in Arabic. The test is essentially a translation of a state test of Hebrew, and is intended to test Arabic at the third-year high school level. The…

Wolowelsky, Joel B.

171

MPGS: a high-level language for microprogram generating system  

Microsoft Academic Search

A high level microprogramming language MPGS is described.MPGS programs consist of three parts; the machine description part, the function part , and the microprogram part. In an MPGS program a microprogrammer can write micro-instructions in any symbolic language defined by himself. By means of control statements in the function part, a high efficiency object code can be obtained. The language

Mitsuhiro Hattori; Michiko Yano; Kiichi Fujino

1972-01-01

172

Neuropsychological divergence of high-level autism and severe dyslexia  

Microsoft Academic Search

The relationship between cognitive deficits in high-level autism and those in learning disabilities has received little attention. To determine whether high-functioning autistic patients and individuals with severe dyslexia display different cognitive characteristics, 10 nonretarded men (mean age 26 years) with infantile autism, residual state, were compared with 15 severely dyslexic men (mean age 22 years) and 25 matched controls on

Judith M. Rumsey; Susan D. Hamburger

1990-01-01

173

Gravity and the hydrosphere: new frontier  

Microsoft Academic Search

Satellite gravity measurements expected in the next few years will provide unprecedented views of the Earth's gravity field and, given sufficient duration, its changes with time. Gravity changes directly reflect changes in the masses of the ocean (thus allowing the separation of steric (heat induced) and non-steric contributions to sea-level rise), the Greenland and Antarctic ice sheets, and the water

JEAN O. DICKEY; CHARLES R. BENTLEY; ROGER BILHAM; JAMES A. CARTON; RICHARD J. EANES; THOMAS A. HERRING; WILLIAM M. KAULA; GARY S. E. LAGERLOEF; STUART ROJSTACZER; WALTER H. F. SMITH; HUGO M. VAN DEN DOOL; JOHN M. WAHR; MARIA T. ZUBER

1999-01-01

174

A comparison of high level synthesis and register transfer level design techniques for custom computing machines  

Microsoft Academic Search

The most expensive component in the process of building a custom computing machine is the time consuming and highly qualified work of hardware designers. This hinders the wide proliferation of CCMs and pushes this innovative technology into a niche market of research applications. A potential solution to the problem is behavioural or high level synthesis (HLS) which promises the compilation

Adam Postula; David Abramsont; Ziping Fang; P. Logathetis

1998-01-01

175

Energy Performance and Comfort Level in High Rise and Highly Glazed Office Buildings  

E-print Network

Thermal and visual comfort in buildings play a significant role on occupants' performance but on the other hand achieving energy savings and high comfort levels can be a quite difficult task especially in high rise buildings with highly glazed...

Bayraktar, M.; Perino, M.; Yilmaz, A. Z.

2010-01-01

176

Analogue Gravity  

E-print Network

Analogue gravity is a research programme which investigates analogues of general relativistic gravitational fields within other physical systems, typically but not exclusively condensed matter systems, with the aim of gaining new insights into their corresponding problems. Analogue models of (and for) gravity have a long and distinguished history dating back to the earliest years of general relativity. In this review article we will discuss the history, aims, results, and future prospects for the various analogue models. We start the discussion by presenting a particularly simple example of an analogue model, before exploring the rich history and complex tapestry of models discussed in the literature. The last decade in particular has seen a remarkable and sustained development of analogue gravity ideas, leading to some hundreds of published articles, a workshop, two books, and this review article. Future prospects for the analogue gravity programme also look promising, both on the experimental front (where technology is rapidly advancing) and on the theoretical front (where variants of analogue models can be used as a springboard for radical attacks on the problem of quantum gravity).

Carlos Barcelo; Stefano Liberati; Matt Visser

2005-05-13

177

Highly efficient and flexible electrospun carbon-silica nanofibrous membrane for ultrafast gravity-driven oil-water separation.  

PubMed

A novel free-standing and flexible electrospun carbon-silica composite nanofibrous membrane is newly introduced. The characterization results suggest that the electrospun composite nanofibers are constructed by carbon chains interpenetrated through a linear network of 3-dimensional SiO2. Thermogravimetric analysis indicates that the presence of insulating silica further improve the thermal resistance of the membrane. Additionally, the mechanical strength test shows that the membrane's toughness and flexibility can be enhanced if the concentration of SiO2 is maintained below 2.7 wt %. Thermal and chemical stability test show that the membrane's wettability properties can be sustained at an elevated temperature up to 300 °C and no discernible change in wettability was observed under highly acidic and basic conditions. After surface-coating with silicone oil for 30 mins, the composite membrane exhibits ultra-hydrophobic and superoleophilic properties with water and oil contact angles being 144.2 ± 1.2° and 0°, respectively. The enhanced flexibility and selective wetting property enables the membrane to serve as an effective substrate for separating free oil from water. Lab-scale oil-water separation test indicates that the membrane possesses excellent oil-water separation efficiency. In addition, its inherent property of high porosity allows oil-water separation to be performed in a gravity-driven process with high-flux. We anticipate that this study will open up a new avenue for fabrication of free-standing carbonaceous composite membrane with tunable flexibility for energy efficient and high-throughput production of clean water. PMID:24867399

Tai, Ming Hang; Gao, Peng; Tan, Benny Yong Liang; Sun, Darren D; Leckie, James O

2014-06-25

178

Gravity field of the Western Weddell Sea: Comparison of airborne gravity and Geosat derived gravity  

NASA Technical Reports Server (NTRS)

Marine gravity surveying in polar regions was typically difficult and costly, requiring expensive long range research vessels and ice-breakers. Satellite altimetry can recover the gravity field in these regions where it is feasible to survey with a surface vessel. Unfortunately, the data collected by the first global altimetry mission, Seasat, was collected only during the austral winter, producing a very poor quality gravitational filed for the southern oceans, particularly in the circum-Antarctic regions. The advent of high quality airborne gravity (Brozena, 1984; Brozena and Peters, 1988; Bell, 1988) and the availability of satellite altimetry data during the austral summer (Sandwell and McAdoo, 1988) has allowed the recovery of a free air gravity field for most of the Weddell Sea. The derivation of the gravity field from both aircraft and satellite measurements are briefly reviewed, before presenting along track comparisons and shaded relief maps of the Weddell Sea gravity field based on these two data sets.

Bell, R. E.; Brozena, J. M.; Haxby, W. F.; Labrecque, J. L.

1989-01-01

179

Converting gravity bins to spherical harmonic coefficients  

NASA Technical Reports Server (NTRS)

The gravity bin technique as originally formulated recovers the local gravity field from the bin parameters by finite differencing. The spherical harmonic coefficients of the gravity field are then computed by an orthogonal transformation of the local gravity field. The result differs from that of the traditional method. This paper discusses the difference and proposes a new algorithm to convert the bin parameters to spherical harmonic coefficients. It is shown that the new method produces the same gravity field as the traditional method and maintains the high computational efficiency of the basic gravity bin technique.

Wu, J. T.; Bertiger, W. I.; Wu, S. C.

1990-01-01

180

Satellite-to-satellite tracking in the high-low mode: Line-of-sight acceleration in a residual gravity field  

NASA Astrophysics Data System (ADS)

The residual line-of-sight acceleration for a general satellite configuration is developed that is rigorous to within the first-order differentials. In addition to the usual 'basic term' treated in geophysical literature, two kinds of corrective terms are derived: the term c sub 1 (related to satellite velocities) and the combined term c(sub 2)+c(sub 3)+c(sub 4) (related to satellite positions). Subsequently, the general formulation is specialized for a high-low configuration. The outcome of computer simulations performed for this configuration confirms the first-order formulation. In all cases examined (two arcs of up to three minutes in duration, three different reference gravity fields), the first-order results agree with the known 'true' values to within 0.00001 mgal. These results clearly indicate that the basic term lacks the accuracy to represent alone a valid mathematical model. However, when this term is corrected by c(sub 1), its accuracy improves significantly, attaining the level of 0.01 mgal or better. The practical significance of this finding, as well as a possibility to exploit it efficiently in the future, are indicated.

Blaha, Georges

1991-07-01

181

Mars - Crustal structure inferred from Bouguer gravity anomalies.  

NASA Technical Reports Server (NTRS)

Bouguer gravity has been computed for the equatorial region of Mars by differencing free air gravity and the gravity predicted from topographic variations. The free air gravity was generated from an eighth-order set of spherical harmonic coefficients. The gravity from topographic variations was generated by integrating a two-dimensional Green's function over each contour level. The Bouguer gravity indicates crustal inhomogeneities on Mars that are postulated to be variations in crustal thickness. The Tharsis ridge is a region of thick continental type crust. The gravity data, structural patterns, topography, and surface geology of this region lead to the interpretation of the Tharsis topographic high as a broad crustal upwarp possibly associated with local formation of lower-density crustal material and subsequent rise of a thicker crust. The Amazonis region is one of several basins of relatively thin crust, analogous to terrestrial ocean basins. The Libya and Hellas basins, which are probable impact features, are also underlain by thin crust and are possible regions of mantle upwelling.

Phillips, R. J.; Saunders, R. S.; Conel, J. E.

1973-01-01

182

Novel type of cryogenic liquid level sensor with high sensitivity  

NASA Astrophysics Data System (ADS)

The results of experiments carried out during the investigation of the thermoelectric force of different high Tc superconductors led to the development of a cryogenic liquid level indicator. These sensors can be easily realized using high temperature superconductors based on different high Tc compounds, such as compounds of the Y-Ba-Cu-O 123, iron doped 123, 124, and 5611 and Bi-(Pb)-Ca-Sr-Cu-O systems in both bulk ceramic and thick film form. The measuring equipment designed in the study is suitable for examination of different high Tc materials to be used as cryogenic liquid level indicators. An example demonstrates the method of selection of the proper high Tc material, the sensitivity of the material, and the simplicity of the application.

Immonen, E.; Uusimaki, A.; Hagberg, J.; Leppavuori, S.; Porjesz, T.

183

High-level language debugging for concurrent programs  

Microsoft Academic Search

An integrated system design for debugging distributed programs written in concurrent high-level languages is described. A variety of user-interface, monitoring, and analysis tools integrated around a uniform process model are provided. Because the tools are language-based, the user does not have to deal with low-level implementation details of distribution and concurrency, and instead can focus on the logic of the

German S. Goldszmidt; Shaula Yemini; Shmuel Katz

1990-01-01

184

High-level test generation using physically-induced faults  

Microsoft Academic Search

A high-level fault modeling and testing philosophy is proposed which is aimed at ensuring full detection of low- level, physical faults, as well as the industry-standard sin- gle stuck-line (SSL) faults. A set of independent functional faults and the corresponding functional tests are derived (induced) from the circuit under test; of particular interest are SSL-induced functional faults or SIFs. We

Mark C. Hansen; John P. Hayes

1995-01-01

185

Algorithms, performance, development of the ATLAS High-Level trigger  

NASA Astrophysics Data System (ADS)

The ATLAS trigger system has been used for the online event selection for three years of LHC data-taking and is preparing for the next run. The trigger system consists of a hardware level-1 and a software high-level trigger (HLT) which is implemented in a region-of-interest based level-2 stage and a event filter operating after event building with offline-like software. During the past three years, the luminosity and pile-up (number of collisions per beam crossing) has increased significantly placing escalating demands on the rejection and timing performance. The HLT algorithms advanced during this period to maintain and even improve performance. Also discussed is the work towards the merging of the two HLT levels in to a single level HLT.

Nagano, Kunihiro; Atlas Collaboration

2014-06-01

186

High level radioactive waste management facility design criteria  

SciTech Connect

This paper discusses the engineering systems for the structural design of the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS). At the DWPF, high level radioactive liquids will be mixed with glass particles and heated in a melter. This molten glass will then be poured into stainless steel canisters where it will harden. This process will transform the high level waste into a more stable, manageable substance. This paper discuss the structural design requirements for this unique one of a kind facility. A special emphasis will be concentrated on the design criteria pertaining to earthquake, wind and tornado, and flooding.

Sheikh, N.A.; Salaymeh, S.R.

1993-10-01

187

High Level Waste (HLW) Feed Process Control Strategy  

SciTech Connect

The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system.

STAEHR, T.W.

2000-06-14

188

High Power MPD Nuclear Electric Propulsion (NEP) for Artificial Gravity HOPE Missions to Callisto  

NASA Technical Reports Server (NTRS)

This documents the results of a one-year multi-center NASA study on the prospect of sending humans to Jupiter's moon, Callisto, using an all Nuclear Electric Propulsion (NEP) space transportation system architecture with magnetoplasmadynamic (MPD) thrusters. The fission reactor system utilizes high temperature uranium dioxide (UO2) in tungsten (W) metal matrix cermet fuel and electricity is generated using advanced dynamic Brayton power conversion technology. The mission timeframe assumes on-going human Moon and Mars missions and existing space infrastructure to support launch of cargo and crewed spacecraft to Jupiter in 2041 and 2045, respectively.

McGuire, Melissa L.; Borowski, Stanley K.; Mason, Lee M.; Gilland, James

2003-01-01

189

Preliminary results of gravity investigations at Yucca Mountain and vicinity, Southern Nye County, Nevada  

NASA Astrophysics Data System (ADS)

Exploration for a high level nuclear waste-repository site in the Yucca Mountain area, Nevada, resulted in the addition of 423 new gravity stations during the past 2 years to the 934 existing stations to form the data base of this study. Surface rock samples, borehold gamma-gamma logs, and a borehold gravity study provide density control. A linear increase in density of 0.26 g/cm(3) per km is indicated in the tuff sequences makes the density contract across the basal contact of the tuff the only strong source of gravity fluctuations. The resulting residual gravity plot shows significant gravity anomalies that correlate closely with the structures inferred from drill hole and surface geologic studies. Gravity highs over the three Paleozoic rock outcrops within the study area served as reference points for the gravity models. At least 3000 m of tuff fills a large steep sided depression in the prevolcanic rocks beneath Yucca Mountain and Crater Flat. The gravity low and thick tuff section probably lie within a large collapse area comprising the Crater Flat Timber Mountain Silent Canyon caldera complexes. Gravity lows in Crater Flat itself are thought to coincide with the source areas of the Prow Pass Member, the Bullfrog Member, and the unnamed member of the Crater Flat Tuff.

Snyder, D. B.; Carr, W. J.

190

First Test of High Frequency Gravity Waves from Inflation using ADVANCED LIGO  

E-print Network

Inflation models ending in a first order phase transition produce gravitational waves (GW) via bubble collisions of the true vacuum phase. We demonstrate that these bubble collisions can leave an observable signature in Advanced LIGO, an upcoming ground-based GW experiment. These GW are dependent on two parameters of the inflationary model: $\\varepsilon$ represents the energy difference between the false vacuum and the true vacuum of the inflaton potential, and $\\chi$ measures how fast the phase transition ends ($\\chi \\sim$ the number of e-folds during the actual phase transition). Advanced LIGO will be able to test the validity of single-phase transition models within the parameter space $10^7 \\rm{GeV}\\lesssim \\varepsilon^{1/4} \\lesssim 10^{10} \\rm{GeV}$ and $0.19 \\lesssim \\chi \\lesssim 1$. If inflation occurred through a first order phase transition, then Advanced LIGO could be the first to discover high frequency GW from inflation.

Alejandro López-Suárez; Katherine Freese

2013-05-24

191

Consistency of spherical, gravity-dominated dynamics with quasar high-ionization emission-line profiles  

NASA Technical Reports Server (NTRS)

Line profile data are used to test a simple kinematic model - spherically symmetric gravitational free fall - in which the number of free parameters is limited by requiring physical self-consistency. The predictions of this model are fitted to high-resolution spectra of the stronger rest-frame UV emission lines in 12 quasars with z of about 2. It is found that if all the lines are radiated predominantly from the illuminated faces of the emission-line clouds, the profiles of Ly-alpha, N V 1240 A, and C IV 1549 A can be simultaneously well fitted with very similar parameters for all 12 quasars. It is concluded that spherically symmetric gravitational free fall does not correctly describe the dynamics of quasar broad emission-line regions.

Kallman, T. R.; Wilkes, B. J.; Krolik, J. H.; Green, Richard

1993-01-01

192

High levels of fluctuating asymmetry in isolated stickleback populations  

PubMed Central

Background Fluctuating asymmetry (FA), defined as small random deviations from the ideal bilateral symmetry, has been hypothesized to increase in response to both genetic and environmental stress experienced by a population. We compared levels of FA in 12 bilateral meristic traits (viz. lateral-line system neuromasts and lateral plates), and heterozygosity in 23 microsatellite loci, among four marine (high piscine predation risk) and four pond (zero piscine predation risk) populations of nine-spined sticklebacks (Pungitius pungitius). Results Pond sticklebacks had on average three times higher levels of FA than marine fish and this difference was highly significant. Heterozygosity in microsatellite markers was on average two times lower in pond (HE ? 0.3) than in marine (HE ? 0.6) populations, and levels of FA and heterozygosity were negatively correlated across populations. However, after controlling for habitat effect on heterozygosity, levels of FA and heterozygosity were uncorrelated. Conclusions The fact that levels of FA in traits likely to be important in the context of predator evasion were elevated in ponds compared to marine populations suggests that relaxed selection for homeostasis in ponds lacking predatory fish may be responsible for the observed habitat difference in levels of FA. This inference also aligns with the observation that the levels of genetic variability across the populations did not explain population differences in levels of FA after correcting for habitat effect. Hence, while differences in strength of selection, rather than in the degree of genetic stress could be argued to explain habitat differences in levels of FA, the hypothesis that increased FA in ponds is caused by genetic stress cannot be rejected. PMID:22788717

2012-01-01

193

Nonlocal Effects in Quantum Gravity  

E-print Network

It is shown explicitly that in the framework of Bohmian quantum gravity, the equations of motion of the space-time metric are Einstein's equations plus some quantum corrections. It is observed that these corrections are not covariant. So that in the framework of Bohmian quantum gravity the general covariance principle breaks down at the individual level. This principle is restored at the statistical level.

Ali Shojai; Fatimah Shojai; Mehdi Golshani

1999-03-13

194

Simulating Gravity  

ERIC Educational Resources Information Center

This article describes one classroom activity in which the author simulates the Newtonian gravity, and employs the Euclidean Geometry with the use of new technologies (NT). The prerequisites for this activity were some knowledge of the formulae for a particle free fall in Physics and most certainly, a good understanding of the notion of similarity…

Pipinos, Savas

2010-01-01

195

Real-time monitoring of high-gravity corn mash fermentation using in situ raman spectroscopy.  

PubMed

In situ Raman spectroscopy was employed for real-time monitoring of simultaneous saccharification and fermentation (SSF) of corn mash by an industrial strain of Saccharomyces cerevisiae. An accurate univariate calibration model for ethanol was developed based on the very strong 883?cm(-1) C-C stretching band. Multivariate partial least squares (PLS) calibration models for total starch, dextrins, maltotriose, maltose, glucose, and ethanol were developed using data from eight batch fermentations and validated using predictions for a separate batch. The starch, ethanol, and dextrins models showed significant prediction improvement when the calibration data were divided into separate high- and low-concentration sets. Collinearity between the ethanol and starch models was avoided by excluding regions containing strong ethanol peaks from the starch model and, conversely, excluding regions containing strong saccharide peaks from the ethanol model. The two-set calibration models for starch (R(2) ?=?0.998, percent error?=?2.5%) and ethanol (R(2) ?=?0.999, percent error?=?2.1%) provide more accurate predictions than any previously published spectroscopic models. Glucose, maltose, and maltotriose are modeled to accuracy comparable to previous work on less complex fermentation processes. Our results demonstrate that Raman spectroscopy is capable of real time in situ monitoring of a complex industrial biomass fermentation. To our knowledge, this is the first PLS-based chemometric modeling of corn mash fermentation under typical industrial conditions, and the first Raman-based monitoring of a fermentation process with glucose, oligosaccharides and polysaccharides present. PMID:23334886

Gray, Steven R; Peretti, Steven W; Lamb, H Henry

2013-06-01

196

Sensorimotor aspects of high-speed artificial gravity: I. Sensory conflict in vestibular adaptation  

NASA Technical Reports Server (NTRS)

Short-radius centrifugation offers a promising and affordable countermeasure to the adverse effects of prolonged weightlessness. However, head movements made in a fast rotating environment elicit Coriolis effects, which seriously compromise sensory and motor processes. We found that participants can adapt to these Coriolis effects when exposed intermittently to high rotation rates and, at the same time, can maintain their perceptual-motor coordination in stationary environments. In this paper, we explore the role of inter-sensory conflict in this adaptation process. Different measures (vertical nystagmus, illusory body tilt, motion sickness) react differently to visual-vestibular conflict and adapt differently. In particular, proprioceptive-vestibular conflict sufficed to adapt subjective parameters and the time constant of nystagmus decay, while retinal slip was required for VOR gain adaptation. A simple correlation between the strength of intersensory conflict and the efficacy of adaptation fails to explain the data. Implications of these findings, which differ from existing data for low rotation rates, are discussed.

Brown, Erika L.; Hecht, Heiko; Young, Laurence R.

2002-01-01

197

Leadership Retreats for Middle Level and Senior High School Students.  

ERIC Educational Resources Information Center

Student leadership is a critical aspect of all middle level and senior high school experiences. Involving students in the workings of the school can mean the difference for them between a mediocre school experience and an exceptional one. This retreat manual is a resource guide for student advisors who wish to develop retreat programs in their…

Stevens, Kelly

198

A Preview of High School Level Economic Software.  

ERIC Educational Resources Information Center

The purpose of this study was to locate and evaluate high-school-level economic software compatible with an Apple II or IIe computer. To identify software, computer searches were run, bibliographies were scanned, and reviews were collected. Only software that was recommended by some outside source was included in the evaluation. The following…

Kincade, Jeannine H.

199

Multigame — A Very High Level Language for Describing Board Games  

Microsoft Academic Search

Languages with implicit parallelism are easier to program in than those wit h explicit par- allelism, but finding and efficiently exploiting parallelism in general-p urpose programming languages by parallelizing compilers is hard. A compiler for a Very High Level Language, de- signed for a specific application domain, has more knowledge about its application domain and may use this knowledge to

John Romein; Henri Bal; Dick Grune

200

High levels of genetic variability in west African Dwarf Crocodiles  

E-print Network

High levels of genetic variability in west African Dwarf Crocodiles Osteolaemus tetraspis getraspis Crocodile (Osteolaemus) has been a long-standing problem for crocodilian systematists. Previously divided, to which the dwarf African crocodile belongs, is generally considered the sister taxon to the genus

Ray, David

201

Box Calculus with High-Level Buffers Ccile Bui Thanh  

E-print Network

Box Calculus with High-Level Buffers Cécile Bui Thanh LACL, Université Paris 12 61 avenue du: Process algebra, handshake/buffered commu- nication, structured operational semantics, coloured Petri nets both handshake and buffered communication. This allows a sim- ple and compositional expression

Paris-Sud XI, Université de

202

High-Level waste process and product data annotated bibliography  

SciTech Connect

The objective of this document is to provide information on available issued documents that will assist interested parties in finding available data on high-level waste and transuranic waste feed compositions, properties, behavior in candidate processing operations, and behavior on candidate product glasses made from those wastes. This initial compilation is only a partial list of available references.

Stegen, G.E.

1996-02-13

203

PROGRAMMING AT A HIGH-LEVEL ON MULTI-CORES  

E-print Network

PROGRAMMING AT A HIGH- LEVEL ON MULTI-CORES What is a compiler to do? Arun Chauhan Indiana University #12;Arun Chauhan, Indiana University HP Research, July 29, 2008 The Multi-core crisis · Physical limitations Transistor sizes Clock skew · Power consumption ·"Moore's Law" #12;Arun Chauhan, Indiana

Chauhan, Arun

204

Effect of high-level content organizers on hypertext learning  

Microsoft Academic Search

This study investigates the cognitive abilities involved in hypertext learning and design approaches that can help users. We examined the effects of two types of high-level content organizers – a graphic spatial map and an alphabetical list – on readers’ memory for hypertext structure. In the control condition, a simple “home” page with no navigational aid was offered. Subjects were

Zsofia Vörös; Jean-François Rouet; Csaba Pléh

2011-01-01

205

46 CFR 119.530 - Bilge high level alarms.  

Code of Federal Regulations, 2010 CFR

(a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the following normally unmanned spaces: (1) A space with a through-hull fitting below the deepest load waterline, such as a...

2010-10-01

206

A Behavioral Intermediate Format For High Level Synthesis  

E-print Network

#12; BIF: A Behavioral Intermediate Format For High Level Synthesis BY Nikil D. Dutt Tedd Hadley Daniel D. Gajski Technical Report 89­03 (Revised 9/19/89) Information and Computer Science University of California at Irvine Irvine, CA 92717 Abstract BIF is a new intermediate format for behavioral synthesis

California at Irvine, University of

207

High?level radioactive waste management in the USA  

Microsoft Academic Search

High?level radioactive waste (HLW) disposal policy in the USA since 1987 has focused on a site in volcanic tuffs 305 meters beneath Yucca Mountain, Nevada, with current plans calling for the repository to be opened in 2017 subject to approval by the Obama Administration. Yet the offsite radiation release standards of the US Environmental Protection Agency are still being finalized,

Barry D. Solomon

2009-01-01

208

Computational Modeling of High-Level Cognition and Brain Function  

E-print Network

Computational Modeling of High-Level Cognition and Brain Function Marcel Adam Just,* Patricia A. Carpenter, and Sashank Varma Center for Cognitive Brain Imaging, Carnegie Mellon University, Pittsburgh key properties of cortical function into the design of the modeling system. Hum. Brain Mapping 8

209

THE XAL INFRASTRUCTURE FOR HIGH LEVEL CONTROL ROOM APPLICATIONS  

SciTech Connect

XAL is a Java programming framework for building high-level control applications related to accelerator physics. The structure, details of implementation, and interaction between components, auxiliary XAL packages, and the latest modifications are discussed. A general overview of XAL applications created for the SNS project is presented.

Shishlo, Andrei P [ORNL] [ORNL; Allen, Christopher K [ORNL] [ORNL; Chu, Paul [Stanford University] [Stanford University; Galambos, John D [ORNL] [ORNL; Pelaia II, Tom [ORNL] [ORNL

2009-01-01

210

High-level manpower movement and Japan's foreign aid.  

PubMed

"Japan's technical assistance programs to Asian countries are summarized. Movements of high-level manpower accompanying direct foreign investments by private enterprise are also reviewed. Proposals for increased human resources development include education and training of foreigners in Japan as well as the training of Japanese aid experts and the development of networks for information exchange." PMID:12285771

Furuya, K

1992-01-01

211

Truck cask design for shipping Defense High Level Waste  

Microsoft Academic Search

The Defense High Level Waste (DHLW) cask is a Type B packaging currently under development by the US Department of Energy (DOE). This truck cask has been designed to initially transport borosilicate glass waste from the Defense Waste Processing Facility (DWPF) to the Waste Isolation Pilot Plant (WIPP). Specific program activities include designing, testing, certifying, and fabricating a prototype legal-weight

M. M. Madsen; A. Zimmer

1985-01-01

212

HighLevel Execution Time Analysis Farn Wang 1  

E-print Network

High�Level Execution Time Analysis Farn Wang 1 Institute of Information Science, Academia Sinica Nankang, Taipei, Taiwan 115, R.O.C. +886�2�7883799 ext. 1717 FAX : +886�2�7824814 farn@iis.sinica.edu.tw 1 Supported by National Science Council, Taiwan, ROC under grant NSC 86�2213�E�001�009 #12; High

Chen, Sheng-Wei

213

The Estuary Guide. Level 3: High School. Draft.  

ERIC Educational Resources Information Center

Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

Alexander, Glen; And Others

214

Extending Java for High-Level Web Service Construction  

Microsoft Academic Search

We incorporate innovations from the project into the Java language to provide high- level features for Web service programming. The resulting language, JWIG, contains an advanced session model and a flexible mechanism for dynamic construction of XML documents, in particular XHTML. To support program development we provide a suite of program analyses that at compile- time verify for a

Aske Simon Christensen; Anders Mller; Michael I. Schwartzbach

215

Extending Java for high-level Web service construction  

Microsoft Academic Search

We incorporate innovations from the project into the Java language to provide high-level features for Web service programming. The resulting language, JWIG, contains an advanced session model and a flexible mechanism for dynamic construction of XML documents, in particular XHTML. To support program development we provide a suite of program analyses that at compile time verify for a given program

Aske Simon Christensen; Anders Møller; Michael I. Schwartzbach

2003-01-01

216

High-Level Languages and Floating-Point  

E-print Network

for the entire design process. CFD is currently used only at some design steps, and wind tunnel tests are stillHigh-Level Languages and Floating-Point Arithmetic for FPGA- Based CFD Simulations Diego Sanchez Universidad Autonoma de Madrid Francisco Palacios Stanford University COMPUTATIONAL FLUID DYNAMICS (CFD) plays

Alonso, Juan J.

217

Structuring Peer Interaction To Promote High-Level Cognitive Processing.  

ERIC Educational Resources Information Center

Examines the kind of peer learning that demands high-level cognitive processing, discussing how peer interaction influences cognitive processes (structuring peer interaction and using guided reciprocal peer questioning); how to promote cognitive processing (knowledge construction and integration and socio- cognitive conflict); metacognition; and…

King, Alison

2002-01-01

218

MIXING PROCESSES IN HIGH-LEVEL WASTE TANKS  

EPA Science Inventory

Flammable gases can be generated in DOE high-level waste tanks, including radiolytic hydrogen, and during cesium precipitation from salt solutions, benzene. Under normal operating conditions the potential for deflagration or detonation from these gases is precluded by purging and...

219

Hot Potato T e chniques in High Level Synthesis  

Microsoft Academic Search

This paper introduces hot potato high level synthesis transformation techniques. These techniques add deflection operations in the behavioral description of a computation in such a way that the requirements for two important components of the final implementation cost, the number of registers and the number of interconnects, are significantly reduced. Moreover, it is shown how hot potato techniques can be

Miodrag Potkonjak; Sujit Dey

220

Selection of artificial gravity by animals during suborbital rocket flights  

NASA Technical Reports Server (NTRS)

White rats selected preferred artificial gravity levels by locomotion in centrifuges consisting of two runways mounted in the nose of sounding rockets. Roll rate of the Aerobee 150A rocket was designed to produce an angular velocity of 45 rpm during 5 min of free-fall, providing a gravity range from 0.3 to 1.5 G depending on a subject's runway position. One animal was released at the high and one at the low gravity position in each flight. Animal positions were continuously recorded. Locomotion patterns during these flights were similar. All four animals explored the entire available G-range. One rat settled at 0.4 G after 2 min; the others crossed the 1-G location in progressively narrower excursions and were near earth gravity at the end of the test period. Tentatively, the data suggest that normal earth-reared rats select earth gravity when available magnitudes include values above and below 1 G. Modification of gravity preference by prolonged exposure to higher or lower levels remains a possibility.

Lange, K. O.; Belleville, R. E.; Clark, F. C.

1975-01-01

221

Review of high-level waste form properties  

NASA Astrophysics Data System (ADS)

Waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle are reviewed. Proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, either glass of crystalline materials have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort is applied to the development of glass and calcine waste forms. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer advantages.

Rusin, J. M.

1980-12-01

222

High-Level Waste Vitrification Facility Feasibility Study  

SciTech Connect

A ''Settlement Agreement'' between the Department of Energy and the State of Idaho mandates that all radioactive high-level waste now stored at the Idaho Nuclear Technology and Engineering Center will be treated so that it is ready to be moved out of Idaho for disposal by a compliance date of 2035. This report investigates vitrification treatment of the high-level waste in a High-Level Waste Vitrification Facility based on the assumption that no more New Waste Calcining Facility campaigns will be conducted after June 2000. Under this option, the sodium-bearing waste remaining in the Idaho Nuclear Technology and Engineering Center Tank Farm, and newly generated liquid waste produced between now and the start of 2013, will be processed using a different option, such as a Cesium Ion Exchange Facility. The cesium-saturated waste from this other option will be sent to the Calcine Solids Storage Facilities to be mixed with existing calcine. The calcine and cesium-saturated waste will be processed in the High-Level Waste Vitrification Facility by the end of calendar year 2035. In addition, the High-Level Waste Vitrification Facility will process all newly-generated liquid waste produced between 2013 and the end of 2035. Vitrification of this waste is an acceptable treatment method for complying with the Settlement Agreement. This method involves vitrifying the waste and pouring it into stainless-steel canisters that will be ready for shipment out of Idaho to a disposal facility by 2035. These canisters will be stored at the Idaho National Engineering and Environmental Laboratory until they are sent to a national geologic repository. The operating period for vitrification treatment will be from the end of 2015 through 2035.

D. A. Lopez

1999-08-01

223

Extremely high urine arsenic level after remote seafood ingestion.  

PubMed

Urine testing for heavy metal concentrations is increasingly performed in the outpatient setting as a part of laboratory evaluation for neuropathy. Abnormal urine arsenic levels due to dietary intake of organic arsenic can lead to unnecessary chelation therapy. A 54-year-old man underwent a 24-hour urine collection for heavy metal concentrations in evaluation of paresthesia of the right foot. The total arsenic level was 8880 ?g/d with concentrations of 4749 ?g/L and 3769 ?g/g creatinine. He was urgently referred to the toxicology clinic for consideration of chelation therapy. History revealed consumption of 2 lobster tails 5 days before the testing. Speciation was then performed on the original urine specimen and revealed an organic arsenic concentration of 4332 ?g/L. No inorganic or methylated arsenic was detected. Repeat testing after abstaining from seafood demonstrated a total arsenic level of 50 ?g/d with concentrations of 30 ?g/L and 21 ?g/g creatinine. Our patient demonstrates the highest level of arsenobetaine reported in the literature, and this level is higher than expected for a person who had not consumed seafood for 5 days before testing. The high levels may be due to consumption of food that he did not recognize as containing arsenobetaine or that his clearance of arsenobetaine from the ingested lobster is slower than published ranges. This case demonstrates the importance of speciation when measuring urine arsenic levels to avoid unnecessary chelation therapy. PMID:22407195

Nañagas, Kristine A; Tormoehlen, Laura M

2014-01-01

224

Spatial and seasonal variability of medium- and high-frequency gravity waves in the lower atmosphere revealed by US radiosonde data  

NASA Astrophysics Data System (ADS)

We extended the broad spectral method proposed by Zhang et al. (2013) for the extraction of medium- and high-frequency gravity waves (MHGWs). This method was applied to 11 years (1998-2008) of radiosonde data from 92 stations in the Northern Hemisphere to investigate latitudinal, continuous vertical and seasonal variability of MHGW parameters in the lower atmosphere (2-25 km). The latitudinal and vertical distributions of the wave energy density and horizontal momentum fluxes as well as their seasonal variations exhibit considerable consistency with those of inertial gravity waves. Despite the consistency, the MHGWs have much larger energy density, horizontal momentum fluxes and wave force, indicating the more important role of MHGWs in energy and momentum transportation and acceleration of the background. For the observed MHGWs, the vertical wavelengths are usually larger than 8 km; the horizontal wavelengths peak in the middle troposphere at middle-high latitudes. These characteristics are obviously different from inertial gravity waves. The energy density and horizontal momentum fluxes have similar latitude-dependent seasonality: both of them are dominated by a semiannual variation at low latitudes and an annual variation at middle latitudes; however at high latitudes, they often exhibit more than two peaks per year in the troposphere. Compared with the inertial GWs, the derived intrinsic frequencies are more sensitive to the spatiotemporal variation of the buoyancy frequency, and at all latitudinal regions they are higher in summer. The wavelengths have a weaker seasonal variation; an evident annual cycle can be observed only at middle latitudes.

Zhang, S. D.; Huang, C. M.; Huang, K. M.; Yi, F.; Zhang, Y. H.; Gong, Y.; Gan, Q.

2014-09-01

225

Global grids of gravity anomalies and vertical gravity gradients at 10 km altitude from GOCE gradient data 2009-2011 and polar gravity.  

NASA Astrophysics Data System (ADS)

The GOCE satellite measures gravity gradients which are filtered and transformed to gradients into an Earth-referenced frame by the GOCE High Level processing Facility. More than 80000000 data with 6 components are available from the period 2009-2011. IAG Arctic gravity was used north of 83 deg., while data at the Antarctic was not used due to bureaucratic restrictions by the data-holders. Subsets of the data have been used to produce gridded values at 10 km altitude of gravity anomalies and vertical gravity gradients in 20 deg. x 20 deg. blocks with 10' spacing. Various combinations and densities of data were used to obtain values in areas with known gravity anomalies. The (marginally) best choice was vertical gravity gradients selected with an approximately 0.125 deg spacing. Using Least-Squares Collocation, error-estimates were computed and compared to the difference between the GOCE-grids and grids derived from EGM2008 to deg. 512. In general a good agreement was found, however with some inconsistencies in certain areas. The computation time on a usual server with 24 processors was typically 100 minutes for a block with generally 40000 GOCE vertical gradients as input. The computations will be updated with new Wiener-filtered data in the near future.

Tscherning, Carl Christian; Arabelos, Dimitrios; Reguzzoni, Mirko

2013-04-01

226

A controlled-source seismic and gravity study of the High Lava Plains (HLP) of Eastern Oregon  

NASA Astrophysics Data System (ADS)

This study employs data collected during the High Lava Plains (HLP) controlled-source seismic experiment conducted in September 2008. In this experiment, 2612 short-period seismic recorders and 120 3-component recorders were deployed across eastern Oregon and adjacent parts of Nevada and Idaho to record 15 seismic sources. Seismic and gravity data were integrated to create 2-D crustal scale P-wave velocity and density models for the ˜400 km long NW-SE and N-S profiles to provide a better understanding of the crustal and upper mantle structure and ultimately the magmatic and tectonic evolution of the region. These models are the first high-resolution images beneath the path of migratory, bi-modal volcanism that dotted the High Lava Plains beginning at 16 Ma. Our models show that the crustal structure across the HLP region is similar to that of the northern Basin and Range which has experienced extension since ˜35 Ma but with moderate magmatic modification of the crust. A thick layer (5-7 km) of sediments and volcanics extends over most of the area and is thickest in the Harney Basin area. We interpret denser/faster material in the lower to middle crust under the southern Harney Basin area to be mafic intraplating. We have also identified a region of denser/faster material in the upper crust in the vicinity of Oregon-Idaho border. The crust thickens from 34 to 37 km, and the lower crust increases in density (2.8-2.85 g/cm3), from west to east across eastern Oregon in close proximity to the interpreted position of the 0.706 Sr isotope line, suggesting a decrease in extension. In the lowermost crust below the southeastern HLP, there is relatively high velocity (7.2-7.4 km/s) and density (2.95 g/cm3) that suggests the presence of underplating. The HLP region has undergone moderate extension, and the average crustal velocity is somewhat higher than in the adjacent Basin and Range, suggesting some magmatic modification in the lower crust, but not as much as might be expected given the voluminous surface volcanism.

Cox, Catherine; Keller, G. Randy; Harder, Steven H.

2013-12-01

227

Integrating a Gravity Simulation and Groundwater Modeling on the Calibration of Specific Yield for Choshui Alluvial Fan  

NASA Astrophysics Data System (ADS)

For sustainable management, accurate estimation of recharge can provide critical information. The accuracy of estimation is highly related to uncertainty of specific yield (Sy). Because Sy value is traditionally obtained by a multi-well pumping test, the available Sy values are usually limited due to high installation cost. Therefore, this information insufficiency of Sy may cause high uncertainty for recharge estimation. Because gravity is a function of a material mass and the inverse square of the distance, gravity measurement can assist to obtain the mass variation of a shallow groundwater system. Thus, the groundwater level observation data and gravity measurements are used for the calibration of Sy for a groundwater model. The calibration procedure includes four steps. First, gravity variations of three groundwater-monitoring wells, Si-jhou, Tu-ku and Ke-cuo, are observed in May, August and November 2012. To obtain the gravity caused by groundwater variation, this study filters the noises from other sources, such as ocean tide and land subsidence, in the collected data The refined data, which are data without noises, are named gravity residual. Second, this study develops a groundwater model using MODFLOW 2005 to simulate the water mass variation of the groundwater system. Third, we use Newton gravity integral to simulate the gravity variation caused by the simulated water mass variation during each of the observation periods. Fourth, comparing the ratio of the gravity variation between the two data sets, which are observed gravity residuals and simulated gravities. The values of Sy is continuously modified until the gravity variation ratios of the two data sets are the same. The Sy value of Si-jhou is 0.216, which is obtained by the multi-well pumping test. This Sy value is assigned to the simulation model. The simulation results show that the simulated gravity can well fit the observed gravity residual without parameter calibration. This result indicates that the proposed approach is correct and reasonable. In Tu-ku and Ke-cuo, the ratios of the gravity variation between observed gravity residuals and simulated gravities are approximate 1.8 and 50, respectively. The Sy values of these two stations are modified 1.8 and 50 times the original values. These modified Sy values are assigned to the groundwater morel. After the parameter re-assignment, the simulated gravities meet the gravity residuals in these two stations. In conclusion, the study results show that the proposed approach has the potential to identify Sy without installing wells. Therefore, the proposed approach can be used to increase the spatial density of Sy and can conduct the recharge estimation with low uncertainty.

Chang, Liang Cheng; Tsai, Jui pin; Chen, Yu Wen; Way Hwang, Chein; Chung Cheng, Ching; Chiang, Chung Jung

2014-05-01

228

Heat and Momentum Transfer Studies in High Reynolds Number Wavy Films at Normal and Reduced Gravity Conditions  

NASA Technical Reports Server (NTRS)

We examined the effect of the gas flow on the liquid film when the gas flows in the countercurrent direction in a vertical pipe at normal gravity conditions. The most dramatic effect of the simultaneous flow of gas and liquid in pipes is the greatly increased transport rates of heat, mass, and momentum. In practical situations this enhancement can be a benefit or it can result in serious operational problems. For example, gas-liquid flow always results in substantially higher pressure drop and this is usually undesirable. However, much higher heat transfer coefficients can be expected and this can obviously be of benefit for purposes of design. Unfortunately, designers know so little of the behavior of such two phase systems and as a result these advantages are not utilized. Due to the complexity of the second order boundary model as well as the fact that the pressure variation across the film is small compared to the imposed gas phase pressure, the countercurrent gas flow affect was studied for the standard boundary layer model. A different stream function that can compensate the shear stress affect was developed and this stream function also can predict periodic solutions. The discretized model equations were transformed to a traveling wave coordinate system. A stability analysis of these sets of equations showed the presence of a Hopf bifurcation for certain values of the traveling wave velocity and the shear stress. The Hopf celerity was increased due to the countercurrent shear. For low flow rate the increases of celerity are more than for the high flow rate, which was also observed in experiments. Numerical integration of a traveling wave simplification of the model also predicts the existence of chaotic large amplitude, nonperiodic waves as observed in the experiments. The film thickness was increased by the shear.

Balakotaiah, V.

1996-01-01

229

High-accurate optical fiber liquid level sensor  

NASA Astrophysics Data System (ADS)

A highly accurate optical fiber liquid level sensor is presented. The single-chip microcomputer is used to process and control the signal. This kind of sensor is characterized by self-security and is explosion-proof, so it can be applied in any liquid level detecting areas, especially in the oil and chemical industries. The theories and experiments about how to improve the measurement accuracy are described. The relative error for detecting the measurement range 10 m is up to 0.01%.

Sun, Dexing; Chen, Shouliu; Pan, Chao; Jin, Henghuan

1991-08-01

230

Gravity quantized: Loop quantum gravity with a scalar field  

SciTech Connect

...''but we do not have quantum gravity.'' This phrase is often used when analysis of a physical problem enters the regime in which quantum gravity effects should be taken into account. In fact, there are several models of the gravitational field coupled to (scalar) fields for which the quantization procedure can be completed using loop quantum gravity techniques. The model we present in this paper consists of the gravitational field coupled to a scalar field. The result has similar structure to the loop quantum cosmology models, except that it involves all the local degrees of freedom of the gravitational field because no symmetry reduction has been performed at the classical level.

Domagala, Marcin; Kaminski, Wojciech [Instytut Fizyki Teoretycznej, Uniwersytet Warszawski, ul. Hoza 69, 00-681 Warszawa (Warsaw), Polska (Poland) (Poland); Giesel, Kristina [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstrasse 2, 85748 Garching (Germany); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Lewandowski, Jerzy [Instytut Fizyki Teoretycznej, Uniwersytet Warszawski, ul. Hoza 69, 00-681 Warszawa (Warsaw), Polska (Poland) (Poland); Institute for Gravitation and the Cosmos, Physics Department, Penn State, University Park, Pennsylvania 16802 (United States)

2010-11-15

231

Gravity quantized: Loop quantum gravity with a scalar field  

NASA Astrophysics Data System (ADS)

…“but we do not have quantum gravity.” This phrase is often used when analysis of a physical problem enters the regime in which quantum gravity effects should be taken into account. In fact, there are several models of the gravitational field coupled to (scalar) fields for which the quantization procedure can be completed using loop quantum gravity techniques. The model we present in this paper consists of the gravitational field coupled to a scalar field. The result has similar structure to the loop quantum cosmology models, except that it involves all the local degrees of freedom of the gravitational field because no symmetry reduction has been performed at the classical level.

Domaga?a, Marcin; Giesel, Kristina; Kami?ski, Wojciech; Lewandowski, Jerzy

2010-11-01

232

Oil gravity segregation in the Monterey formation, California  

SciTech Connect

The Monterey Formation is a fractured siliceous shale that is the principal reservoir and source rock for oil fields in the Santa Maria basin and the western Santa Barbara Channel. Monterey crudes in producing offshore fields are high-sulfur oils that range from 10[degrees] to 35[degrees] API. The oils in Monterey fractured reservoirs display a systematic increase in API gravity with increasing height above the oil-water contact. The rate of change in API gravity with depth in Monterey oil fields generally ranges from 0.5[degrees] to 1.2[degrees] API/100 ft. The oil-water contact usually occurs at an oil gravity of 10[degrees] API (the gravity at which the density of the oil and the water is equal). The maximum API gravity in a Monterey oil field is related to the level of thermal exposure experienced by the formation in the adjacent depocenter. Monterey oils are sourced by high-sulfur kerogens that generate heavy oils at low levels of thermal exposure, but generate progressively higher gravity oils at higher levels of thermal maturity. Comparison of the maximum API gravity found in 33 Monterey-sourced oil fields with the maximum temperature experienced by the Monterey Formation within three miles of the field (the most likely migration distance) suggests that a temperature of 260[degrees]F (127[degrees]C) is required to generate 20[degrees] API oil, and a temperature of 330[degrees]F (166[degrees]C) is required to generate 30[degrees] API oil.

Hornafius, J.S. (Mobil Exploration and Producing, Bakersfield, CA (United States))

1994-04-01

233

Cohomological gravity  

SciTech Connect

In the present work, the authors construct a theory of cohomological gravity in arbitrary dimensions based upon a local vector supersymmetry algebra. The observables in this theory are polynomial, but generally non-local operators, and have a natural interpretation in terms of a universal bundle for gravity. As such, their correlation functions correspond to cohomology classes on moduli spaces of Riemannian connections. In this uniformization approach, different moduli spaces are obtained by introducing curvature singularities on codimension two submanifolds via a puncture operator. This puncture operator is constructed from a naturally occurring differential form of co-degree two in the theory, and the authors are led to speculate on connections between this continuum quantum field theory, and the discrete Regge calculus. 16 refs.

Birmingham, D. (CERN, Geneva (Switzerland)); Rakowski, M. (Johannes-Gutenberg Universitaet, Mainz (Germany))

1993-07-01

234

Measuring the effects of high CO? levels in Caenorhabditis elegans.  

PubMed

Carbon dioxide (CO2) is an important molecule in cell metabolism. It is also a byproduct of many physiological processes. In humans, impaired lung function and lung diseases disrupt the body's ability to dispose of CO2 and elevate its levels in the body (hypercapnia). Animal models allow further understanding of how CO2 is sensed in the body and what are the physiological responses to high CO2 levels. This information can provide new strategies in the battle against the detrimental effects of CO2 accumulation in lung diseases. The nematode Caenorhabditis elegans provides us with such a model animal due to its natural ability to sense and navigate through varying concentrations of CO2, as well as the fact that it can be genetically manipulated with ease. Here we describe the different methods used to measure the effects elevated levels of CO2 have on the molecular sensing mechanism and physiology of C. elegans. PMID:24650565

Zuela, Noam; Friedman, Nurit; Zaslaver, Alon; Gruenbaum, Yosef

2014-08-01

235

The SuperSID project: exploiting high-level information for high-accuracy speaker recognition  

Microsoft Academic Search

The area of automatic speaker recognition has been dominated by systems using only short-term, low-level acoustic information, such as cepstral features. While these systems have indeed produced very low error rates, they ignore other levels of information beyond low-level acoustics that convey speaker information. Recently published work has shown examples that such high-level information can be used successfully in automatic

Douglas Reynolds; Walter Andrews; Joseph Campbell; Jiri Navratil; Barbara Peskin; Andre Adami; Qin Jin; David Klusacek; Joy Abramson; Radu Mihaescu; Jack Godfrey; Doug Jones; Bing Xiang

2003-01-01

236

Airborne Gravity Gradiometry Resolves a Full Range of Gravity Frequencies  

NASA Astrophysics Data System (ADS)

Airborne Full Tensor Gradiometry (Air\\-FTGR) was flown at high altitude coincident with Airborne Gravity (AG) flown in 2003 in West Arnhem Land, Australia. A preliminary analysis of two data sets indicates that the Air\\-FTGR system has the capability of resolving intermediate to long wavelengths features that may be associated with relatively deeper geological structures. A comparison of frequency filtered slices and power spectral density (PSD) for both data sets using the short (> 5 km), intermediate (10 km) and long (20 km) wavelengths reveals that high altitude Air\\-FTGR data show greater response in high frequency anomalies than a conventional Airborne Gravity and matches well with the AG even at the longest wavelengths anomalies. The effect of line spacing and target resolution was examined between the two data sets. Reprocessed gradient and AG data at 2, 4 and 6 km line spacing suggest that Air\\-FTGR could be effectively flown at a comparatively wider line spacing to resolve similar targets the AG would resolve with tighter line spacing. Introduction Airborne Full Tensor Gradiometry (Air\\-FTGR) data have been available to the mining industry since 2002 and their use for geologic applications is well established. However, Air\\-FTGR data has been mostly considered and used in mapping and delineation of near surface geological targets. This is due to the fact that gravity gradiometer measurements are well suited to capture the high frequency signal associated with near\\-surface targets ( Li, 2001). This is possible because the gradiometer signal strength falls off with the cube of the distance to the target. Nonetheless, in recent years there has been an increasing demand from the mining, oil, and gas industry in utilizing Full Tensor Gravity Gradiometer as a mapping tool for both regional and prospect level surveys. Air\\-FTGR as a Regional Mapping Tool Several, relatively low altitude surveys have been successfully flown in Brazil, Canada and Australia mostly targeting large, regional\\- scale crustal structures as well as regional mapping of both lithology and regolith. Air\\-FTGR mapping is especially effective in areas of thick lateritic and/or clay cover where other geophysical methods such as airborne magnetics or electromagnetics become less effective. For instance, an Air\\-FTGR survey was successfully flown in Brazil in the Province of Minas Gerais, where several crustal\\-scale structures associated with iron oxide mineralization were identified ( Mataragio et. al., 2006). In addition, in 2006 Air\\-FTGR had good success in the regional mapping of structures associated with Iron Oxide Copper Gold (IOCG) and uranium mineralization in the Wernecke Mountains in the Yukon, and Northwest Territories, Canada. On the basis of these successful surveys, Bell Geospace has initiated a number of high altitude test surveys aiming at evaluating the performance of the Air\\-FTGR system in capturing low frequency signal that may be associated with regional\\-scale, deeper structures. One of the test surveys was conducted in December of 2006 in Australia, where the performance of Air\\-FTGR and the conventional Airborne Gravity were evaluated. Airborne gravity is currently considered well suited for capturing low frequency signal.

Mataragio, J.; Brewster, J.; Mims, J.

2007-12-01

237

High-level waste management technology program plan  

SciTech Connect

The purpose of this plan is to document the integrated technology program plan for the Savannah River Site (SRS) High-Level Waste (HLW) Management System. The mission of the SRS HLW System is to receive and store SRS high-level wastes in a see and environmentally sound, and to convert these wastes into forms suitable for final disposal. These final disposal forms are borosilicate glass to be sent to the Federal Repository, Saltstone grout to be disposed of on site, and treated waste water to be released to the environment via a permitted outfall. Thus, the technology development activities described herein are those activities required to enable successful accomplishment of this mission. The technology program is based on specific needs of the SRS HLW System and organized following the systems engineering level 3 functions. Technology needs for each level 3 function are listed as reference, enhancements, and alternatives. Finally, FY-95 funding, deliverables, and schedules are s in Chapter IV with details on the specific tasks that are funded in FY-95 provided in Appendix A. The information in this report represents the vision of activities as defined at the beginning of the fiscal year. Depending on emergent issues, funding changes, and other factors, programs and milestones may be adjusted during the fiscal year. The FY-95 SRS HLW technology program strongly emphasizes startup support for the Defense Waste Processing Facility and In-Tank Precipitation. Closure of technical issues associated with these operations has been given highest priority. Consequently, efforts on longer term enhancements and alternatives are receiving minimal funding. However, High-Level Waste Management is committed to participation in the national Radioactive Waste Tank Remediation Technology Focus Area. 4 refs., 5 figs., 9 tabs.

Harmon, H.D.

1995-01-01

238

Radioactive high level waste insight modelling for geological disposal facilities  

NASA Astrophysics Data System (ADS)

Within this paper we present a simplified analytical model to provide insight into the key performance measures of a generic disposal system for high level waste within a geological disposal facility. The model assumes a low solubility waste matrix within a corrosion resistant disposal container surrounded by a low permeability buffer. Radionuclides migrate from the disposal area through a porous geosphere to the biosphere and give a radiological dose to a receptor. The system of equations describing the migration is transformed into Laplace space and an approximation used to determine peak values for the radionuclide mass transfer rate entering the biosphere. Results from the model are compared with those from more detailed numerical models for key radionuclides in the UK high level waste inventory. Such an insight model can provide a valuable second line of argument to assist in confirming the results of more detailed models and build confidence in the safety case for a geological disposal facility.

Carter, Alexander; Kelly, Martin; Bailey, Lucy

239

Evaluation and selection of candidate high-level waste forms  

SciTech Connect

Seven candidate waste forms being developed under the direction of the Department of Energy's National High-Level Waste (HLW) Technology Program, were evaluated as potential media for the immobilization and geologic disposal of high-level nuclear wastes. The evaluation combined preliminary waste form evaluations conducted at DOE defense waste-sites and independent laboratories, peer review assessments, a product performance evaluation, and a processability analysis. Based on the combined results of these four inputs, two of the seven forms, borosilicate glass and a titanate based ceramic, SYNROC, were selected as the reference and alternative forms for continued development and evaluation in the National HLW Program. Both the glass and ceramic forms are viable candidates for use at each of the DOE defense waste-sites; they are also potential candidates for immobilization of commercial reprocessing wastes. This report describes the waste form screening process, and discusses each of the four major inputs considered in the selection of the two forms.

None

1982-03-01

240

FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL  

SciTech Connect

Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. provided by organic additives such as sugar or coal, to reduce NOX in the off-gas to N2 to meet Clean Air Act (CAA) standards during processing. Thus, organics will be present during the waste form stabilization process regardless of the GNEP processes utilized and exists in some of the high level radioactive waste tanks at Savannah River Site and Hanford Tank Farms, e.g. organics in the feed or organics used for nitrate destruction. Waste streams containing high organic concentrations cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by pretreatment. The alternative waste stabilization pretreatment process of Fluidized Bed Steam Reforming (FBSR) operates at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). The FBSR process has been demonstrated on GNEP simulated waste and radioactive waste containing high organics from Tank 48H to convert organics to CAA compliant gases, create no secondary liquid waste streams and create a stable mineral waste form.

Williams, M

2008-05-09

241

Security Mechanisms in High-Level Network Protocols  

Microsoft Academic Search

The implications of adding security mechanisms to high-level network protocols operating in an open-system environment are analyzed. First the threats to security that may arise in such an environment are described, and then a set of goals for communications security measures is established. This is followed by a brief description of the two basic approaches to communications security, link-oriented measures

Victor L. Voydock; Stephen T. Kent

1983-01-01

242

High Level System Design and Analysis Using Abstract State Machines  

Microsoft Academic Search

We provide an introduction to a practical method for rigorous system development which has been used successfully, under industrial\\u000a constraints, for design and analysis of complex hardware\\/software systems. The method allows one to start system development\\u000a with a trustworthy high level system specification and to link such a “ground model” in a well documented and inspectable\\u000a way through intermediate design

Egon Börger

1998-01-01

243

[Corrosion testing of high level radioactive waste. Final report  

SciTech Connect

Alloys under consideration as candidates for the high level nuclear waste containers at Yucca Mountain were exposed to a range of corrosion conditions and their performance measured. The alloys tested were Incoloy 825, 70/30 Copper-Nickel, Monel 400, Hastelloy C- 22, and low carbon steel. The test conditions varied were: temperature, concentration, agitation, and crevice simulation. Only in the case of carbon steel was significant attack noted. This attack appeared to be transport limited.

NONE

1996-06-01

244

Expanding Gravity  

NASA Astrophysics Data System (ADS)

Newton's gravitational constant Gn and Laws of Gravity are based upon observations in our solar system. Mysteries appear when they are used far outside our solar system Apparently, Newton's gravitational constant can not be applied at large distances. Dark matter was needed to explain the observed flat rotational velocity curves of spiral galaxies (Rubin), and of groups of remote galaxies (Zwicky). Our expansion of Newton's gravitational constant Gn as a power series in distance r, is sufficient to explain these observations without using dark matter. This is different from the MOND theory of Milgrom involving acceleration. Also, our Expanded Gravitational Constant (EGC) can show the correct use of the red shift. In addition to the Doppler contribution, there are three other contributions and these depend only upon gravity. Thus, velocity observations only based on the red shift can not be used to support the concept of the expanding universe, the accelerating expansion, or dark energy. Our expanded gravity constant can predict and explain Olbers' paradox (dark sky), and the temperature of the CMB (cosmic microwave background). Thus, CMB may not support the big bang and inflation.

Aisenberg, Sol

2005-04-01

245

Handbook of high-level radioactive waste transportation  

SciTech Connect

The High-Level Radioactive Waste Transportation Handbook serves as a reference to which state officials and members of the general public may turn for information on radioactive waste transportation and on the federal government`s system for transporting this waste under the Civilian Radioactive Waste Management Program. The Handbook condenses and updates information contained in the Midwestern High-Level Radioactive Waste Transportation Primer. It is intended primarily to assist legislators who, in the future, may be called upon to enact legislation pertaining to the transportation of radioactive waste through their jurisdictions. The Handbook is divided into two sections. The first section places the federal government`s program for transporting radioactive waste in context. It provides background information on nuclear waste production in the United States and traces the emergence of federal policy for disposing of radioactive waste. The second section covers the history of radioactive waste transportation; summarizes major pieces of legislation pertaining to the transportation of radioactive waste; and provides an overview of the radioactive waste transportation program developed by the US Department of Energy (DOE). To supplement this information, a summary of pertinent federal and state legislation and a glossary of terms are included as appendices, as is a list of publications produced by the Midwestern Office of The Council of State Governments (CSG-MW) as part of the Midwestern High-Level Radioactive Waste Transportation Project.

Sattler, L.R.

1992-10-01

246

Radiative Lifetimes for High Levels of Neutral Fe  

NASA Astrophysics Data System (ADS)

New radiative lifetime measurements for ~ 50 high lying levels of Fe I are reported. Laboratory astrophysics faces a challenge to provide basic spectroscopic data, especially reliable atomic transition probabilities, in the IR region for abundance studies. The availability of HgCdTe (HAWAII) detector arrays has opened IR spectral regions for extensive new spectroscopic studies. The SDSS III APOGEE project in the H-Band is an important example which will penetrate the dust obscuring the Galactic bulge. APOGEE will survey elemental abundances of 100,000 red giant stars in the bulge, bar, disk, and halo of the Milky Way. Many stellar spectra in the H-Band are, as expected, dominated by transitions of Fe I. Most of these IR transitions connect high levels of Fe. Our program has started an effort to meet this challenge with new radiative lifetime measurements on high lying levels of Fe I using time resolved laser induced fluorescence (TRLIF). The TRLIF method is typically accurate to 5% and is efficient. Our goal is to combine these accurate, absolute radiative lifetimes with emission branching fractions [1] to determine log(gf) values of the highest quality for Fe I lines in the UV, visible, and IR. This method was used very successfully by O’Brian et al. [2] on lower levels of Fe I. This method is still the best available for all but very simple spectra for which ab-initio theory is more accurate. Supported by NSF grant AST-0907732. [1] Branching fractions are being measured by M. Ruffoni and J. C. Pickering at Imperial College London. [2] O'Brian, T. R., Wickliffe, M. E., Lawler, J. E., Whaling, W., & Brault, J. W. 1991, J. Opt. Soc. Am. B 8, 1185

Lawler, James E.; Den Hartog, E.; Guzman, A.

2013-01-01

247

Mobility Characterization of Planetary Rover in Reduced Gravity Environment  

NASA Astrophysics Data System (ADS)

This paper describes effects of gravity on mobility performance of wheeled rovers for future lunar/planetary exploration missions. A series of model tests of a wheel-terrain system were performed on an aircraft during variable gravity maneuvers, and it became clear that slip of the wheel becomes high when the gravity is less than 1/2G. In addition to the flight experiments, the same model tests were performed in a laboratory on the ground (1G condition). The experiments were demonstrated with variable wheel loads by using counterweights. As a result of the on-ground experiments, the mobility performance under low wheel load conditions was found to be improved contrary to the flight experiments. In case of the flight experiments, not only the wheel load but also bearing in the terrain changes with respect to the gravity level, while only the wheel load changes in case of the on-ground experiments. Thus, running under a reduced gravity condition becomes difficult because the terrain generates higher rolling resistance by sinkage owing to the lack of bearing of the terrain. That is to say, the mobility performance on lunar/planetary surface is likely to be severer compared to the terrestrial gravity condition.

Kobayashi, Taizo; Ochiai, Hidetoshi; Yamakawa, Junya; Aoki, Shigeru; Matsui, Kai; Miyahara, Akira

2008-01-01

248

TESTING ALTERNATIVE THEORIES OF GRAVITY USING THE SUN  

SciTech Connect

We propose a new approach to test possible corrections to Newtonian gravity using solar physics. The high accuracy of current solar models and new precise observations allow us to constrain corrections to standard gravity at unprecedented levels. Our case study is Eddington-inspired gravity, an attractive modified theory of gravity which results in non-singular cosmology and collapse. The theory is equivalent to standard gravity in vacuum, but it sensibly differs from it within matter. For instance, it affects the evolution and the equilibrium structure of the Sun, giving different core temperature profiles, and deviations in the observed acoustic modes and in solar neutrino fluxes. Comparing the predictions from a modified solar model with observations, we constrain the coupling parameter of the theory, |{kappa}{sub g}| {approx}< 3 Multiplication-Sign 10{sup 5} m{sup 5} s{sup -2} kg{sup -1}. Our results show that the Sun can be used to efficiently constrain alternative theories of gravity.

Casanellas, Jordi; Pani, Paolo; Lopes, Ilidio; Cardoso, Vitor, E-mail: jordicasanellas@ist.utl.pt, E-mail: paolo.pani@ist.utl.pt, E-mail: ilidio.lopes@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt [CENTRA, Departamento de Fisica, Instituto Superior Tecnico, Universidade Tecnica de Lisboa-UTL, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

2012-01-20

249

Space augmentation of military high-level waste disposal  

NASA Technical Reports Server (NTRS)

Space disposal of selected components of military high-level waste (HLW) is considered. This disposal option offers the promise of eliminating the long-lived radionuclides in military HLW from the earth. A space mission which meets the dual requirements of long-term orbital stability and a maximum of one space shuttle launch per week over a period of 20-40 years, is a heliocentric orbit about halfway between the orbits of earth and Venus. Space disposal of high-level radioactive waste is characterized by long-term predictability and short-term uncertainties which must be reduced to acceptably low levels. For example, failure of either the Orbit Transfer Vehicle after leaving low earth orbit, or the storable propellant stage failure at perihelion would leave the nuclear waste package in an unplanned and potentially unstable orbit. Since potential earth reencounter and subsequent burn-up in the earth's atmosphere is unacceptable, a deep space rendezvous, docking, and retrieval capability must be developed.

English, T.; Lees, L.; Divita, E.

1979-01-01

250

High level language-based robotic control system  

NASA Technical Reports Server (NTRS)

This invention is a robot control system based on a high level language implementing a spatial operator algebra. There are two high level languages included within the system. At the highest level, applications programs can be written in a robot-oriented applications language including broad operators such as MOVE and GRASP. The robot-oriented applications language statements are translated into statements in the spatial operator algebra language. Programming can also take place using the spatial operator algebra language. The statements in the spatial operator algebra language from either source are then translated into machine language statements for execution by a digital control computer. The system also includes the capability of executing the control code sequences in a simulation mode before actual execution to assure proper action at execution time. The robot's environment is checked as part of the process and dynamic reconfiguration is also possible. The languages and system allow the programming and control of multiple arms and the use of inward/outward spatial recursions in which every computational step can be related to a transformation from one point in the mechanical robot to another point to name two major advantages.

Rodriguez, Guillermo (inventor); Kruetz, Kenneth K. (inventor); Jain, Abhinandan (inventor)

1994-01-01

251

High level language-based robotic control system  

NASA Technical Reports Server (NTRS)

This invention is a robot control system based on a high level language implementing a spatial operator algebra. There are two high level languages included within the system. At the highest level, applications programs can be written in a robot-oriented applications language including broad operators such as MOVE and GRASP. The robot-oriented applications language statements are translated into statements in the spatial operator algebra language. Programming can also take place using the spatial operator algebra language. The statements in the spatial operator algebra language from either source are then translated into machine language statements for execution by a digital control computer. The system also includes the capability of executing the control code sequences in a simulation mode before actual execution to assure proper action at execution time. The robot's environment is checked as part of the process and dynamic reconfiguration is also possible. The languages and system allow the programming and control of multiple arms and the use of inward/outward spatial recursions in which every computational step can be related to a transformation from one point in the mechanical robot to another point to name two major advantages.

Rodriguez, Guillermo (Inventor); Kreutz, Kenneth K. (Inventor); Jain, Abhinandan (Inventor)

1996-01-01

252

Antarctic outlet glacier mass change resolved at basin scale from satellite gravity gradiometry  

NASA Astrophysics Data System (ADS)

orbit and instrumental measurement of the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) satellite mission offer the highest ever resolution capabilities for mapping Earth's gravity field from space. However, past analysis predicted that GOCE would not detect changes in ice sheet mass. Here we demonstrate that GOCE gravity gradiometry observations can be combined with Gravity Recovery and Climate Experiment (GRACE) gravity data to estimate mass changes in the Amundsen Sea Sector. This refined resolution allows land ice changes within the Pine Island Glacier (PIG), Thwaites Glacier, and Getz Ice Shelf drainage systems to be measured at respectively -67 ± 7, -63 ± 12, and -55 ± 9 Gt/yr over the GOCE observing period of November 2009 to June 2012. This is the most accurate pure satellite gravimetry measurement to date of current mass loss from PIG, known as the "weak underbelly" of West Antarctica because of its retrograde bed slope and high potential for raising future sea level.

Bouman, J.; Fuchs, M.; Ivins, E.; Wal, W.; Schrama, E.; Visser, P.; Horwath, M.

2014-08-01

253

Gravity waves and gravity wave "breaking" as contributors to aviation turbulence  

NASA Astrophysics Data System (ADS)

Turbulence is a well-known hazard to aviation that is responsible for numerous injuries each year, with occasional fatalities, and results in millions of dollars of operational costs to airlines each year. It has been widely accepted that aviation-scale turbulence that occurs in clear air (CAT) at upper levels (upper troposphere and lower stratosphere) has its origins in Kelvin-Helmholtz instabilities induced by enhanced shears and reduced Richardson numbers associated with the jet stream and upper level fronts. However, it is becoming increasingly apparent that gravity waves and gravity wave "breaking" also play a major role in instigating turbulence that affects aviation. Gravity waves and inertia-gravity waves may be produced by a variety of sources, but one major source that impacts aviation seems to be those produced by convection. Several examples of high-resolution numerical simulations that are based on actual encounters with turbulence by commercial aircraft will be presented to demonstrate these situations. Implications for aviation-scale turbulence forecasting will also be discussed.

Sharman, R.; Lane, T. P.; Trier, S. B.; Fovell, R. G.

2012-12-01

254

University-Level Research Projects for High School Students  

NASA Technical Reports Server (NTRS)

The goal of this project was to provide an opportunity for high school students to participate in university-level research projects. In this case, students from Pinkerton Academy (Derry, New Hampshire) were invited to participate in efforts to catalog data from the COMPTEL experiment on NASA's Compton Gamma-Ray Observatory (CGRO). These activities were part of a senior level honors course at Pinkerton. Although the success of this particular program was rather limited, we feel that the general concept is a sound one. In principle, the concept of partnerships between local schools and university researchers is one that could be especially attractive to soft money researchers. Programs can be carefully designed to benefit both the students and the research program.

McConnell, Mark L.

2000-01-01

255

Effects of high vs low-level radiation exposure  

SciTech Connect

In order to appreciate adequately the various possible effects of radiation, particularly from high-level vs low-level radiation exposure (HLRE, vs LLRE), it is necessary to understand the substantial differences between (a) exposure as used in exposure-incidence curves, which are always initially linear and without threshold, and (b) dose as used in dose-response curves, which always have a threshold, above which the function is curvilinear with increasing slope. The differences are discussed first in terms of generally familiar nonradiation situations involving dose vs exposure, and then specifically in terms of exposure to radiation, vs a dose of radiation. Examples are given of relevant biomedical findings illustrating that, while dose can be used with HLRE, it is inappropriate and misleading the LLRE where exposure is the conceptually correct measure of the amount of radiation involved.

Bond, V.P.

1983-01-01

256

CEMENTITIOUS GROUT FOR CLOSING SRS HIGH LEVEL WASTE TANKS - #12315  

SciTech Connect

In 1997, the first two United States Department of Energy (US DOE) high level waste tanks (Tanks 17-F and 20-F: Type IV, single shell tanks) were taken out of service (permanently closed) at the Savannah River Site (SRS). In 2012, the DOE plans to remove from service two additional Savannah River Site (SRS) Type IV high-level waste tanks, Tanks 18-F and 19-F. These tanks were constructed in the late 1950's and received low-heat waste and do not contain cooling coils. Operational closure of Tanks 18-F and 19-F is intended to be consistent with the applicable requirements of the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and will be performed in accordance with South Carolina Department of Health and Environmental Control (SCDHEC). The closure will physically stabilize two 4.92E+04 cubic meter (1.3 E+06 gallon) carbon steel tanks and isolate and stabilize any residual contaminants left in the tanks. The closure will also fill, physically stabilize and isolate ancillary equipment abandoned in the tanks. A Performance Assessment (PA) has been developed to assess the long-term fate and transport of residual contamination in the environment resulting from the operational closure of the F-Area Tank Farm (FTF) waste tanks. Next generation flowable, zero-bleed cementitious grouts were designed, tested, and specified for closing Tanks 18-F and 19-F and for filling the abandoned equipment. Fill requirements were developed for both the tank and equipment grouts. All grout formulations were required to be alkaline with a pH of 12.4 and chemically reduction potential (Eh) of -200 to -400 to stabilize selected potential contaminants of concern. This was achieved by including Portland cement and Grade 100 slag in the mixes, respectively. Ingredients and proportions of cementitious reagents were selected and adjusted, respectively, to support the mass placement strategy developed by closure operations. Subsequent down selection was based on compressive strength and saturated hydraulic conductivity results. Fresh slurry property results were used as the first level of screening. A high range water reducing admixture and a viscosity modifying admixture were used to adjust slurry properties to achieve flowable grouts. Adiabatic calorimeter results were used as the second level screening. The third level of screening was used to design mixes that were consistent with the fill material parameters used in the F-Tank Farm Performance Assessment which was developed to assess the long-term fate and transport of residual contamination in the environment resulting from the operational closures.

Langton, C.; Burns, H.; Stefanko, D.

2012-01-10

257

High level secretion of cellobiohydrolases by Saccharomyces cerevisiae  

PubMed Central

Background The main technological impediment to widespread utilization of lignocellulose for the production of fuels and chemicals is the lack of low-cost technologies to overcome its recalcitrance. Organisms that hydrolyze lignocellulose and produce a valuable product such as ethanol at a high rate and titer could significantly reduce the costs of biomass conversion technologies, and will allow separate conversion steps to be combined in a consolidated bioprocess (CBP). Development of Saccharomyces cerevisiae for CBP requires the high level secretion of cellulases, particularly cellobiohydrolases. Results We expressed various cellobiohydrolases to identify enzymes that were efficiently secreted by S. cerevisiae. For enhanced cellulose hydrolysis, we engineered bimodular derivatives of a well secreted enzyme that naturally lacks the carbohydrate-binding module, and constructed strains expressing combinations of cbh1 and cbh2 genes. Though there was significant variability in the enzyme levels produced, up to approximately 0.3 g/L CBH1 and approximately 1 g/L CBH2 could be produced in high cell density fermentations. Furthermore, we could show activation of the unfolded protein response as a result of cellobiohydrolase production. Finally, we report fermentation of microcrystalline cellulose (Avicel™) to ethanol by CBH-producing S. cerevisiae strains with the addition of beta-glucosidase. Conclusions Gene or protein specific features and compatibility with the host are important for efficient cellobiohydrolase secretion in yeast. The present work demonstrated that production of both CBH1 and CBH2 could be improved to levels where the barrier to CBH sufficiency in the hydrolysis of cellulose was overcome. PMID:21910902

2011-01-01

258

Development of a High Level Waste Tank Inspection System  

SciTech Connect

The Westinghouse Savannah River Technology Center was requested by it`s sister site, West Valley Nuclear Service (WVNS), to develop a remote inspection system to gather wall thickness readings of their High Level Waste Tanks. WVNS management chose to take a proactive approach to gain current information on two tanks t hat had been in service since the early 70`s. The tanks contain high level waste, are buried underground, and have only two access ports to an annular space between the tank and the secondary concrete vault. A specialized remote system was proposed to provide both a visual surveillance and ultrasonic thickness measurements of the tank walls. A magnetic wheeled crawler was the basis for the remote delivery system integrated with an off-the-shelf Ultrasonic Data Acquisition System. A development program was initiated for Savannah River Technology Center (SRTC) to design, fabricate, and test a remote system based on the Crawler. The system was completed and involved three crawlers to perform the needed tasks, an Ultrasonic Crawler, a Camera Crawler, and a Surface Prep Crawler. The crawlers were computer controlled so that their operation could be done remotely and their position on the wall could be tracked. The Ultrasonic Crawler controls were interfaced with ABB Amdata`s I-PC, Ultrasonic Data Acquisition System so that thickness mapping of the wall could be obtained. A second system was requested by Westinghouse Savannah River Company (WSRC), to perform just ultrasonic mapping on their similar Waste Storage Tanks; however, the system needed to be interfaced with the P-scan Ultrasonic Data Acquisition System. Both remote inspection systems were completed 9/94. Qualifications tests were conducted by WVNS prior to implementation on the actual tank and tank development was achieved 10/94. The second inspection system was deployed at WSRC 11/94 with success, and the system is now in continuous service inspecting the remaining high level waste tanks at WSRC.

Appel, D.K.; Loibl, M.W. [Westinghouse Savannah River Company, SC (United States); Meese, D.C. [Westinghouse West Valley Nuclear Services, West Valley, NY (United States)

1995-03-21

259

Color image retrieval: from low-level representation to high-level concept.  

PubMed

This work takes place within the framework of color image retrieval in specialized databases. A CBIR scheme has been proposed allowing to use a description thanks to low-level features in the framework of a high-level concept using a knowledge management. Starting from a representation of the three most frequently used features i.e. color, texture and shape, cooperation techniques are proposed in order to use the expert knowledge in the combination process. Two types of cooperation have been defined; the first is without categorization and the second with categorization. The second approach allows to make a selection of the query category in order to simplify queries in large image databases. Finally, in order to avoid the standard relevance feedback stage, a competition technique has been proposed allowing an unsupervised refinement of the submitted query. The proposed techniques have shown their performances and their robustness and are generalizable to all types of image databases. PMID:17543211

Larabi, M-C; Richard, N; Fernandez-Maloigne, C

2006-01-01

260

High level waste at Hanford: Potential for waste loading maximization  

SciTech Connect

The loading of Hanford nuclear waste in borosilicate glass is limited by phase-related phenomena, such as crystallization or formation of immiscible liquids, and by breakdown of the glass structure because of an excessive concentration of modifiers. The phase-related phenomena cause both processing and product quality problems. The deterioration of product durability determines the ultimate waste loading limit if all processing problems are resolved. Concrete examples and mass-balance based calculations show that a substantial potential exists for increasing waste loading of high-level wastes that contain a large fraction of refractory components.

Hrma, P.R.; Bailey, A.W.

1995-09-01

261

CLASSIFICATION OF THE MGR DEFENSE HIGH LEVEL WASTE DISPOSAL CONTIANER  

SciTech Connect

The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) defense high-level waste disposal container system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333PY ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

J.A. Ziegler

1999-08-31

262

High-level neutron coincidence counter maintenance manual  

SciTech Connect

High-level neutron coincidence counter operational (field) calibration and usage is well known. This manual makes explicit basic (shop) check-out, calibration, and testing of new units and is a guide for repair of failed in-service units. Operational criteria for the major electronic functions are detailed, as are adjustments and calibration procedures, and recurrent mechanical/electromechanical problems are addressed. Some system tests are included for quality assurance. Data on nonstandard large-scale integrated (circuit) components and a schematic set are also included.

Swansen, J.; Collinsworth, P.

1983-05-01

263

Enhanced and Inhibited Gravity Wave Spectra.  

NASA Astrophysics Data System (ADS)

Balloon measurements were used to investigate gravity waves in the upper troposphere and lower stratosphere above the Canadian high Arctic. The amount of gravity wave activity in the stratosphere was found to be related to particular meteorological conditions that influence the generation and propagation of mountain waves. Enhanced wave activity was observed to occur when there was a small change in wind direction in the troposphere and high wind speed at the ground. These conditions correspond to strong wave generation by flow over the ground of upward-propagating waves that do not encounter critical level filtering. Inhibited wave activity was observed when the wind direction changed by more than 180° in the troposphere or when the wind speed was relatively weak at the ground. These conditions correspond to critical level filtering and weak generation of upward-propagating waves. The vertical wavenumber spectrum of perturbation potential energy was enhanced at all resolved scales when the conditions were favorable for upward wave propagation. The average enhanced spectral magnitude increased in proportion to the increase in N2 (buoyancy frequency squared) between the troposphere and stratosphere. When the background atmospheric conditions inhibited upward wave propagation the spectral magnitude did not change between the troposphere and stratosphere, despite a factor of 4 increase in N2. The enhanced spectra are consistent with the current gravity wave paradigm but the inhibited spectra are not so readily explained.

Whiteway, James A.

1999-05-01

264

Superconducting gravity gradiometer for sensitive gravity measurements. I. Theory  

SciTech Connect

Because of the equivalence principle, a global measurement is necessary to distinguish gravity from acceleration of the reference frame. A gravity gradiometer is therefore an essential instrument needed for precision tests of gravity laws and for applications in gravity survey and inertial navigation. Superconductivity and SQUID (superconducting quantum interference device) technology can be used to obtain a gravity gradiometer with very high sensitivity and stability. A superconducting gravity gradiometer has been developed for a null test of the gravitational inverse-square law and space-borne geodesy. Here we present a complete theoretical model of this instrument. Starting from dynamical equations for the device, we derive transfer functions, a common mode rejection characteristic, and an error model of the superconducting instrument. Since a gradiometer must detect a very weak differential gravity signal in the midst of large platform accelerations and other environmental disturbances, the scale factor and common mode rejection stability of the instrument are extremely important in addition to its immunity to temperature and electromagnetic fluctuations. We show how flux quantization, the Meissner effect, and properties of liquid helium can be utilized to meet these challenges.

Chan, H.A.; Paik, H.J.

1987-06-15

265

Geodesy and gravity experiment in earth orbit using a superconducting gravity gradiometer  

Microsoft Academic Search

A superconducting gravity gradiometer is under development with NASA support for space application. It is planned that a sensitive three-axis gravity gradiometer will be flown in a low-altitude (about 160 km) polar orbit in the 1990's for the purpose of obtaining a high-resolution gravity map of the earth. The large twice-an-orbit term in the harmonic expansion of gravity coming from

H. J. Paik

1985-01-01

266

Multi-Level High School Classes: Astronomy Diagnostic Test Results  

NASA Astrophysics Data System (ADS)

A content survey, the Astronomy Diagnostic Test (ADT) designed for undergraduate non-science astronomy courses, was administered as a post-course survey to five senior high classes in a Maryland high school. In 2001, the five classes chosen included all three levels of physics and an astronomy class. Each class had an even distribution of male and female students, with a total of 115 girls and 104 boys as subjects. Results of the survey include: (1) The Advanced Placement (AP) physics class scored highest and general physics lowest. (2) The AP class, most of whom will major in engineering or computer sciences, had a mean ADT score similar to post-course undergraduate non-science astronomy classes. (3) For all five classes, the girls had lower mean scores than the boys. (4) In two classes the girls' self-reported mean confidence was 40% lower than the boys' confidence; in the other three classes the confidence levels were the same. Additional detailed research was done on the three cosmology and ten physics questions in the ADT; girls outperformed the boys in only two of these thirteen questions.

Hubbard, R.; Hufnagel, B.

2001-12-01

267

Spent Fuel and High-Level Radioactive Waste Transportation Report  

SciTech Connect

This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by SSEB in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste Issues. In addition. this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages will be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

Not Available

1992-03-01

268

High level radioactive waste glass production and product description  

SciTech Connect

This report examines borosilicate glass as a means of immobilizing high-level radioactive wastes. Borosilicate glass will encapsulate most of the defense and some of the commercial HLW in the US. The resulting waste forms must meet the requirements of the WA-SRD and the WAPS, which include a short term PCT durability test. The waste form producer must report the composition(s) of the borosilicate waste glass(es) produced but can choose the composition(s) to meet site-specific requirements. Although the waste form composition is the primary determinant of durability, the redox state of the glass; the existence, content, and composition of crystals; and the presence of glass-in-glass phase separation can affect durability. The waste glass should be formulated to avoid phase separation regions. The ultimate result of this effort will be a waste form which is much more stable and potentially less mobile than the liquid high level radioactive waste is currently.

Sproull, J.F.; Marra, S.L.; Jantzen, C.M.

1993-12-01

269

Long-term high-level waste technology. Composite report  

NASA Astrophysics Data System (ADS)

Research and development studies on the immobilization of high-level wastes from the chemical reprocessing of nuclear reactor fuels are summarized. The reports are grouped under the following tasks: (1) program management and support; (2) waste preparation; (3) waste fixation; and (4) final handling. Some of the highlights are: leaching properties were obtained for titanate and tailored ceramic materials being developed at ICPP to immobilize zirconia calcine; comparative leach tests, hot-cell tests, and process evaluations were conducted of waste form alternatives to borosilicate glass for the immobilization of SRP high-level wastes, experiments were run at ANL to qualify neutron activation analysis and radioactive tracers for measuring leach rates from simulated waste glasses; comparative leach test samples of SYNROC D were prepared, characterized, and tested at LLNL; encapsulation of glass marbles with lead or lead alloys was demonstrated on an engineering scale at PNL; a canister for reference Commercial HLW was designed at PNL; a study of the optimization of salt-crete was completed at SRL; a risk assessment showed that an investment for tornado dampers in the interim storage building of the DWPF is unjustified.

Cornman, W. R.

1981-12-01

270

Spent fuel and high-level radioactive waste transportation report  

SciTech Connect

This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by the Southern States Energy Board (SSEB) in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste issues. In addition, this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages will be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

Not Available

1990-11-01

271

Spent fuel and high-level radioactive waste transportation report  

SciTech Connect

This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by the Southern States Energy Board (SSEB) in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste issues. In addition, this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages sew be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

Not Available

1989-11-01

272

Influence of varying levels of ammonium chloride on urine pH and specific gravity, overall feed conversion, and water consumption in mature wether goats.  

E-print Network

The objective of this study was to evaluate the effect of orally administered ammonium chloride (NH4CL) on pH and specific gravity of urine, overall gain, and water consumption in mature wethers on a grower/finisher ration. Obstructive urolithiasis...

Kennedy, Matthew joseph

2009-05-15

273

Confidence Level and Sensitivity Limits in High Contrast Imaging  

SciTech Connect

In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground and space-based telescopes. Previous theoretical analysis have shown that the time intensity variations of a single speckle follows a modified Rician. It is first demonstrated here that for a circular pupil this temporal intensity distribution also represents the speckle spatial intensity distribution at a fix separation from the point spread function center; this fact is demonstrated using numerical simulations for coronagraphic and non-coronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level. In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding confidence level as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckles noise, a detection threshold up to three times higher is required to obtain a confidence level equivalent to that at 5{sigma} for Gaussian noise. The technique is then tested using TRIDENT CFHT and angular differential imaging NIRI Gemini adaptive optics data. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. A power-law is finally derived to predict the 1-3 x 10{sup -7} confidence level detection threshold when averaging a partially correlated non-Gaussian noise.

Marois, C; LaFreniere, D; Macintosh, B; Doyon, R

2008-06-02

274

Confidence Level and Sensitivity Limits in High Contrast Imaging  

SciTech Connect

In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground and space-based telescopes. Previous theoretical analysis have shown that the time intensity variations of a single speckle follows a modified Rician. It is first demonstrated here that for a circular pupil this temporal intensity distribution also represents the speckle spatial intensity distribution at a fix separation from the point spread function center; this fact is demonstrated using numerical simulations for coronagraphic and non-coronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level. In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding confidence level as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckles noise, a detection threshold up to three times higher is required to obtain a confidence level equivalent to that at 5{sigma} for Gaussian noise. The technique is then tested using TRIDENT CFHT and angular differential imaging NIRI Gemini adaptive optics data. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. A power-law is finally derived to predict the 1-3 x 10{sup -7} confidence level detection threshold when averaging a partially correlated non-Gaussian noise.

Marois, C

2007-11-07

275

Myocytes Oxygenation and High Energy Phosphate Levels during Hypoxia  

PubMed Central

Decrease of ambient oxygen level has been used in myocytes culture experiments in examining the responsiveness to stress secondary to hypoxia. However, none of these studies measure the myocytes oxygenation levels resulting in ambiguity as to whether there is insufficient oxygen delivery. This study examined the hypothesis that at a basal myocardial work state, adequate myocyte oxygenation would be maintained until extremely low arterial pO2 levels were reached. Myocyte pO2 values in normal dogs were calculated from the myocardial deoxymyoglobin (Mb- ?) levels using 1H-spectroscopy (MRS) and were normalized to Mb-? obtained after complete LAD occlusion. During Protocol 1 (n?=?6), Mb-? was measured during sequential reductions of the oxygen fraction of inspired gas (FIO2) from 40, 21, 15, 10, and 5%, while in protocol 2 (n?=?10) Mb-? was measured at FIO2 of 3%. Protocol 3 (n?=?9) evaluated time course of Mb-? during prolonged exposure to FIO2 of 5%. Myocardial blood flow (MBF) was measured with microspheres and high energy phosphate (HEP) levels were determined with 31P-MRS. MVO2 progressively increased in response to the progressive reduction of FIO2 that is accompanied by increased LV pressure, heart rate, and MBF. Mb-? was undetectable during FIO2 values of 21, 15, 10, and 5%. However, FIO2 of 3% or prolonged exposure to FIO2 of 5% caused progressive increases of Mb-? which were associated with decreases of PCr, ATP and the PCr/ATP ratio, as well as increases of inorganic phosphate. The intracellular PO2 values for 20% reductions of PCr and ATP were approximately 7.4 and 1.9 mmHg, respectively. These data demonstrate that in the in vivo system over a wide range of FIO2 and arterial pO2 levels, the myocyte pO2 values remain well above the Km value with respect to cytochrome oxidase, and oxygen availability does not limit mitochondrial oxidative phosphorylation at 5% FIO2. PMID:25268711

Jameel, Mohammad Nurulqadr; Hu, Qingsong; Zhang, Jianyi

2014-01-01

276

Myocytes Oxygenation and High Energy Phosphate Levels during Hypoxia.  

PubMed

Decrease of ambient oxygen level has been used in myocytes culture experiments in examining the responsiveness to stress secondary to hypoxia. However, none of these studies measure the myocytes oxygenation levels resulting in ambiguity as to whether there is insufficient oxygen delivery. This study examined the hypothesis that at a basal myocardial work state, adequate myocyte oxygenation would be maintained until extremely low arterial pO2 levels were reached. Myocyte pO2 values in normal dogs were calculated from the myocardial deoxymyoglobin (Mb- ?) levels using 1H-spectroscopy (MRS) and were normalized to Mb-? obtained after complete LAD occlusion. During Protocol 1 (n?=?6), Mb-? was measured during sequential reductions of the oxygen fraction of inspired gas (FIO2) from 40, 21, 15, 10, and 5%, while in protocol 2 (n?=?10) Mb-? was measured at FIO2 of 3%. Protocol 3 (n?=?9) evaluated time course of Mb-? during prolonged exposure to FIO2 of 5%. Myocardial blood flow (MBF) was measured with microspheres and high energy phosphate (HEP) levels were determined with 31P-MRS. MVO2 progressively increased in response to the progressive reduction of FIO2 that is accompanied by increased LV pressure, heart rate, and MBF. Mb-? was undetectable during FIO2 values of 21, 15, 10, and 5%. However, FIO2 of 3% or prolonged exposure to FIO2 of 5% caused progressive increases of Mb-? which were associated with decreases of PCr, ATP and the PCr/ATP ratio, as well as increases of inorganic phosphate. The intracellular PO2 values for 20% reductions of PCr and ATP were approximately 7.4 and 1.9 mmHg, respectively. These data demonstrate that in the in vivo system over a wide range of FIO2 and arterial pO2 levels, the myocyte pO2 values remain well above the Km value with respect to cytochrome oxidase, and oxygen availability does not limit mitochondrial oxidative phosphorylation at 5% FIO2. PMID:25268711

Jameel, Mohammad Nurulqadr; Hu, Qingsong; Zhang, Jianyi

2014-01-01

277

Department of Energy pretreatment of high-level and low-level wastes  

SciTech Connect

The remediation of the 1 {times} 10{sup 8} gal of highly radioactive waste in the underground storage tanks (USTs) at five US Department of Energy (DOE) sites is one of DOE`s greatest challenges. Therefore, the DOE Office of Environmental Management has created the Tank Focus Area (TFA) to manage an integrated technology development program that results in the safe and efficient remediation of UST waste. The TFA has divided its efforts into five areas, which are safety, characterization, retrieval/closure, pretreatment, and immobilization. All DOE pretreatment activities are integrated by the Pretreatment Technical Integration Manager of the TFA. For FY 1996, the 14 pretreatment tasks are divided into 3 systems: supernate separations, sludge treatment, and solid/liquid separation. The plans and recent results of these TFA tasks, which include two 25,000-gal demonstrations and two former TFA tasks on Cs removal, are presented. The pretreatment goals are to minimize the volume of high-level waste and the radioactivity in low-level waste.

McGinnis, C.P.; Hunt, R.D.

1995-12-31

278

Gravity from spinors  

SciTech Connect

We investigate a possible unified theory of all interactions which is based only on fundamental spinor fields. The vielbein and metric arise as composite objects. The effective quantum gravitational theory can lead to a modification of Einstein's equations due to the lack of local Lorentz symmetry. We explore the generalized gravity with global instead of local Lorentz symmetry in first order of a systematic derivative expansion. At this level diffeomorphisms and global Lorentz symmetry allow for two new invariants in the gravitational effective action. The one which arises in the one loop approximation to spinor gravity is consistent with all present tests of general relativity and cosmology. This shows that local Lorentz symmetry is tested only very partially by present observations. In contrast, the second possible new coupling is severely restricted by present solar system observations.

Wetterich, C. [Institut fuer Theoretische Physik, Philosophenweg 16, 69120 Heidelberg (Germany)

2004-11-15

279

Tides and gravity labs  

NSDL National Science Digital Library

How does gravity cause tides in the oceans? This section, part of an interactive laboratory series for grades 8-12, introduces students to four activities on tides and gravity that cover critical orbital speed between Earth and the moon, gravitational forces between two bodies, tidal effects from the sun and moon, and the change in tidal levels over time. The activities include hands-on animations of concepts whose variables can be manipulated by students. Questions posed to students include answer boxes that are printable upon conclusion of the activities. The final activity involves collecting tidal data over 24-hour and 29-day periods. Student data are stored in printable tables. Views of moon phases for each time period are provided, as is a downloadable worksheet. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2002-01-01

280

Quantum gravity and charge renormalization  

SciTech Connect

We study the question of the gauge dependence of the quantum gravity contribution to the running gauge coupling constant for electromagnetism. The calculations are performed using dimensional regularization in a manifestly gauge-invariant and gauge-condition-independent formulation of the effective action. It is shown that there is no quantum gravity contribution to the running charge, and hence there is no alteration to asymptotic freedom at high energies as predicted by Robinson and Wilczek.

Toms, David J. [School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

2007-08-15

281

A network of superconducting gravimeters detects submicrogal coseismic gravity changes.  

PubMed

With high-resolution continuous gravity recordings from a regional network of superconducting gravimeters, we have detected permanent changes in gravity acceleration associated with a recent large earthquake. Detected changes in gravity acceleration are smaller than 10(-8) meters seconds(-2) (1 micro-Galileo, about 10(-9) times the surface gravity acceleration) and agree with theoretical values calculated from a dislocation model. Superconducting gravimetry can contribute to the studies of secular gravity changes associated with tectonic processes. PMID:15486297

Imanishi, Yuichi; Sato, Tadahiro; Higashi, Toshihiro; Sun, Wenke; Okubo, Shuhei

2004-10-15

282

Abilities of multidimensional gravity  

E-print Network

We show that a number of problems of modern cosmology may be addressed and solved in the framework of multidimensional gravity with high-order curvature invariants, without invoking other fields. As applications of this approach, we mention primordial inflation and particle production after it; description of the modern accelerated stage of the Universe with stable compact extra dimensions; construction of asymmetric thick brane-world models.

K. A. Bronnikov; S. G. Rubin

2007-12-06

283

Modeling and optimization of defense high level waste removal sequencing  

NASA Astrophysics Data System (ADS)

A novel methodology has been developed which makes possible a very fast running computational tool, capable of performing 30 to 50 years of simulation of the entire Savannah River Site (SRS) high level waste complex in less than 2 minutes on a work station. The methodology has been implemented in the Production Planning Model (ProdMod) simulation code which uses Aspen Technology's dynamic simulation software development package SPEEDUP. ProdMod is a pseudo-dynamic simulation code solely based on algebraic equations, using no differential equations. The dynamic nature of the plant process is captured using linear constructs in which the time dependence is implicit. Another innovative approach implemented in ProdMod development is the mapping of event-space on to time-space and vice versa, which accelerates the computation without sacrificing the necessary details in the event-space. ProdMod uses this approach in coupling the time-space continuous simulation with the event-space batch simulation, avoiding the discontinuities inherent in dynamic simulation batch processing. In addition, a general purpose optimization scheme has been devised based on the pseudo-dynamic constructs and the event- and time-space algorithms of ProdMod. The optimization scheme couples a FORTRAN based stand-alone optimization driver with the SPEEDUP based ProdMod simulator to perform dynamic optimization. The scheme is capable of generating single or multiple optimal input conditions for different types of objective functions over single or multiple years of operations depending on the nature of the objective function and operating constraints. The resultant optimal inputs are then interfaced with ProdMod to simulate the dynamic behavior of the waste processing operations. At the conclusion on an optimized advancement step, the simulation parameters are then passed to the optimization driver to generate the next set of optimized parameters. An optimization algorithm using linear programming has been successfully implemented with this general scheme to sequence wastes from different waste tanks for precipitate production and provide optimized sequences to ProdMod for simulating the behavior of the SRS waste complex. Parametric studies using this optimization methodology demonstrate that the devised scheme is appropriate for the real life operations of the SRS waste complex. The computational planning tool based on the coupled simulation and optimization methodology developed in this work is in current use to help planners process the SRS's 34 million gallons of high level radioactive waste efficiently and economically all the way to clean up of all the tanks. This methodology can also be directly applicable to the Hanford Site and aid in the final design and operation of its facilities to process 55 million gallons of high level radioactive waste.

Paul, Pran Krishna

284

Cellular basis of gravity resistance in plants  

NASA Astrophysics Data System (ADS)

Mechanical resistance to the gravitational force is a principal gravity response in plants distinct from gravitropism. In the final step of gravity resistance, plants increase the rigidity of their cell walls via modifications to the cell wall metabolism and apoplastic environment. We studied cellular events that are related to the cell wall changes under hypergravity conditions produced by centrifugation. Hypergravity induced reorientation of cortical microtubules from transverse to longitudinal directions in epidermal cells of stem organs. In Arabidopsis tubulin mutants, the percentage of cells with longitudinal microtubules was high even at 1 g, and it was further increased by hypergravity. Hypocotyls of tubulin mutants also showed either left-handed or right-handed helical growth at 1 g, and the degree of twisting phenotype was intensified under hypergravity conditions. The left-handed helical growth mutants had right-handed microtubule arrays, whereas the right-handed mutant had left-handed arrays. There was a close correlation between the alignment angle of epidermal cell files and the alignment of cortical microtubules. Gadolinium ions suppressed both the twisting phenotype and reorientation of microtubules in tubulin mutants. These results support the hypothesis that cortical microtubules play an es-sential role in maintenance of normal growth phenotype against the gravitational force, and suggest that mechanoreceptors are involved in modifications to morphology and orientation of microtubule arrays by hypergravity. Actin microfilaments, in addition to microtubules, may be involved in gravity resistance. The nucleus of epidermal cells of azuki bean epicotyls, which is present almost in the center of the cell at 1 g, was displaced to the cell bottom by increasing the magnitude of gravity. Cytochalasin D stimulated the sedimentation by hypergravity of the nu-cleus, suggesting that the positioning of the nucleus is regulated by actin microfilaments, which is affected by gravity. We also examined the effects of hypergravity on the osmotic properties of azuki bean epicotyls, and found that epicotyls were capable of maintaining osmoregulation even under hypergravity conditions at least for a short period. The increase in level of total osmotic solutes was suppressed by long-term hypergravity treatment, which was accounted by suppres-sion of translocation of organic solutes such as sugars and amino acids. These various cellular events may contribute to sustaining the cell wall changes or cooperate with the cell wall in gravity resistance. Space experiments on the International Space Station will confirm whether this view is applicable to plant resistance to 1 g gravity, as to the resistance to hypergravity.

Hoson, Takayuki; Matsumoto, Shouhei; Inui, Kenichi; Zhang, Yan; Soga, Kouichi; Wakabayashi, Kazuyuki; Hashimoto, Takashi

285

Some interesting features of new massive gravity  

NASA Astrophysics Data System (ADS)

A sketch of a proof that new massive gravity—the massive 3D gravity model proposed by Bergshoeff, Hohm and Townsend (BHT)—is the only unitary system at the tree level that can be constructed by augmenting 3D general relativity through (curvature)2-terms is presented. Two interesting gravitational properties of the BHT model, namely, time dilation and time delay, which have no counterpart in the usual Einstein 3D gravity, are analyzed as well.

Accioly, Antonio; Helayël-Neto, José; Scatena, Eslley; Morais, Jefferson; Turcati, Rodrigo; Pereira-Dias, Bruno

2011-11-01

286

Observing ocean heat content using satellite gravity and altimetry  

E-print Network

with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat: Physical: Sea level variations; 1223 Geodesy and Gravity: Ocean/Earth/atmosphere interactions (3339); 1227

Jayne, Steven

287

Threshold Gravity Determination and Artificial Gravity Studies Using Magnetic Levitation  

NASA Technical Reports Server (NTRS)

What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required (magnitude and duration)? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for a variable gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

Ramachandran, N.; Leslie, F.

2005-01-01

288

Characterization of composite ceramic high level waste forms.  

SciTech Connect

Argonne National Laboratory has developed a composite ceramic waste form for the disposition of high level radioactive waste produced during electrometallurgical conditioning of spent nuclear fuel. The electrorefiner LiCl/KCl eutectic salt, containing fission products and transuranics in the chloride form, is contacted with a zeolite material which removes the fission products from the salt. After salt contact, the zeolite is mixed with a glass binder. The zeolite/glass mixture is then hot isostatic pressed (HIPed) to produce the composite ceramic waste form. The ceramic waste form provides a durable medium that is well suited to incorporate fission products and transuranics in the chloride form. Presented are preliminary results of the process qualification and characterization studies, which include chemical and physical measurements and product durability testing, of the ceramic waste form.

Frank, S. M.; Bateman, K. J.; DiSanto, T.; Johnson, S. G.; Moschetti, T. L.; Noy, M. H.; O'Holleran, T. P.

1997-12-05

289

High-level waste tank farm set point document  

SciTech Connect

Setpoints for nuclear safety-related instrumentation are required for actions determined by the design authorization basis. Minimum requirements need to be established for assuring that setpoints are established and held within specified limits. This document establishes the controlling methodology for changing setpoints of all classifications. The instrumentation under consideration involve the transfer, storage, and volume reduction of radioactive liquid waste in the F- and H-Area High-Level Radioactive Waste Tank Farms. The setpoint document will encompass the PROCESS AREA listed in the Safety Analysis Report (SAR) (DPSTSA-200-10 Sup 18) which includes the diversion box HDB-8 facility. In addition to the PROCESS AREAS listed in the SAR, Building 299-H and the Effluent Transfer Facility (ETF) are also included in the scope.

Anthony, J.A. III

1995-01-15

290

High Level Waste System Impacts from Acid Dissolution of Sludge  

SciTech Connect

This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.

KETUSKY, EDWARD

2006-04-20

291

Socioeconomic studies of high-level nuclear waste disposal.  

PubMed

The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents. PMID:7971963

White, G F; Bronzini, M S; Colglazier, E W; Dohrenwend, B; Erikson, K; Hansen, R; Kneese, A V; Moore, R; Page, E B; Rappaport, R A

1994-11-01

292

Socioeconomic studies of high-level nuclear waste disposal.  

PubMed Central

The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents. PMID:7971963

White, G F; Bronzini, M S; Colglazier, E W; Dohrenwend, B; Erikson, K; Hansen, R; Kneese, A V; Moore, R; Page, E B; Rappaport, R A

1994-01-01

293

Socioeconomic studies of high-level nuclear waste disposal  

SciTech Connect

The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents.

White, G.F. [Univ. of Colorado, Boulder, CO (United States); Bronzini, M.S. [Oak Ridge National Lab., TN (United States); Colglazier, E.W. [National Academy of Sciences, Washington, DC (United States); Dohrenwend, B. [Columbia Univ., New York, NY (United States); Erikson, K. [Yale Univ., New Haven, CT (United States); Hansen, R. [Hansen Research, Winslow, WA (United States); Kneese, A.V. [Resources for the Future, Washington, DC (United States); Moore, R. [Richard Moore, Cheyenne, WY (United States); Page, E.B. [Bechtel, Inc., Washington, DC (United States); Rappaport, R.A. [Univ. of Michigan, Ann Arbor, MI (United States)

1994-11-08

294

A High School Project Seminar on Sea Level Rise  

NASA Astrophysics Data System (ADS)

In Bavaria the curriculum of the upper grade of high school includes a so called project seminar, running over one and a half year. The aims of the seminar are to let the pupils learn to work on a specific topic, to organize themselves in a team, to improve their soft skills and become familiar with the working life. The topic of the project seminar, jointly organized by the Bertold-Brecht-Gymnasium in Munich and the Deutsche Geodätische Forschungsinstitut (DGFI) was on the "Global sea level rise". A team of 13 pupils computed the mean sea level rise by using on the one hand altimetry data of TOPEX, Jason-1 and Jason2 and on the other hand data of globally distributed tide gauges, corrected for vertical crustal movements derived from GPS products. The results of the two independent approaches were compared with each other and discussed considering also statements and discussions found in press, TV, and the web. Finally, a presentation was prepared and presented at school.

Seitz, M.; Bosch, W.

2012-04-01

295

PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION  

SciTech Connect

The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

J.A. Ziegler

2000-11-20

296

High level waste characterization in support of low level waste certification. I. HLW supernate radionuclide characterization  

SciTech Connect

High Level Waste Programs has radioactive waste storage, treatment and processing facilities that are located in the F and H Areas at the Savannah River Site. These facilities include the Effluent Treatment Facility (ETF), F and H Area Tank Farms, Extended Sludge Processing (ESP), and In-Tank Precipitation (ITP). Job wastes are generated from operation, maintenance, and construction activities inside radiological areas. These items may have been contaminated with radioactive supernate, salt, and sludge material. Most of these wastes will be disposed of in the E-area Vaults. Therefore, an isotopic and hazardous characterization must be performed. The characterization of HLW supernate radionuclides is discussed in Chapter I. The characterization for salt and sludge phases, which can also contaminate LLW, will be included in other Chapters.

Jamison, M.E.; d`Entremont, P.D.; Clemmons, J.S.; Bess, C.E.; Brown, D.F.

1994-07-08

297

Pushing the limits of gravity field recovery from high-low satellite-to-satellite tracking - a combination of 10 years of data of the satellite pseudo-constellation CHAMP, GRACE and GOCE.  

NASA Astrophysics Data System (ADS)

For a long time, the primary sources for the observation of time varying gravity from space have been SLR and the GRACE mission where the latter is based on the concept of ultra-precise low-low satellite-to-satellite tracking. Meanwhile, time-variable gravity signals were also successfully derived from the high-low satellite-to-satellite tracking mission CHAMP (Weigelt et al. 2013, JGR:Solid Earth, doi:10.1002/jgrb.50283). This single-satellite solution allows for the derivation of only the strongest annual hydrological signals on the continents, e.g. in the Amazon, and ice-melting in Greenland and is limited to large scales due to its higher noise level. A natural approach to overcome this limitation is to combine the observations of several satellites. Here, we form a pseudo-constellation which - with the exception of the two GRACE satellites - is a loose one and was not designed as such. We present the methodology and the results of combining gravity field estimates based on kinematic orbits from the four satellites of the three missions CHAMP, GRACE and GOCE within the frame of a Kalman filter forming a time series over a span of ten years. The gain compared to the CHAMP-only solution is about half an order of magnitude in terms of degree-RMS, an increased spatial resolution with approximately 750km placing the solutions on the level of the early GRACE solutions and a decreased error level allowing now to clearly identify the hydrology-induced mass changes in Africa, East-Asia and Australia which have been erroneous in the CHAMP-only solution. We demonstrate the quality of the solutions by comparing to (1) K-Band based GRACE solutions, (2) GNSS loading time-series and (3) hydro-meteorological estimation of water storage changes and derive mass estimates for various regions of the world. We also demonstrate that remarkably this combined solution starts to indicate mass change patterns related to glacial isostatic adjustment (GIA).

Weigelt, Matthias; van Dam, Tonie; Baur, Oliver; Steffen, Holger; Tourian, Mohammad J.; Jäggi, Adrian; Prange, Lars; Meyer, Ulrich; Bock, Heike; Mayer-Gürr, Torsten; Zehentner, Norbert; Sneeuw, Nico

2014-05-01

298

Granular Superconductors and Gravity  

NASA Technical Reports Server (NTRS)

As a Bose condensate, superconductors provide novel conditions for revisiting previously proposed couplings between electromagnetism and gravity. Strong variations in Cooper pair density, large conductivity and low magnetic permeability define superconductive and degenerate condensates without the traditional density limits imposed by the Fermi energy (approx. 10(exp -6) g cu cm). Recent experiments have reported anomalous weight loss for a test mass suspended above a rotating Type II, YBCO superconductor, with a relatively high percentage change (0.05-2.1%) independent of the test mass' chemical composition and diamagnetic properties. A variation of 5 parts per 104 was reported above a stationary (non-rotating) superconductor. In experiments using a sensitive gravimeter, bulk YBCO superconductors were stably levitated in a DC magnetic field and exposed without levitation to low-field strength AC magnetic fields. Changes in observed gravity signals were measured to be less than 2 parts in 108 of the normal gravitational acceleration. Given the high sensitivity of the test, future work will examine variants on the basic magnetic behavior of granular superconductors, with particular focus on quantifying their proposed importance to gravity.

Noever, David; Koczor, Ron

1999-01-01

299

A combined global gravity field model based on full normal equations complete to degree/order 720  

NASA Astrophysics Data System (ADS)

Global satellite-only gravity field models are on the one hand known for their excellent quality in the long wavelength part, but on the other hand their spectral resolution is restricted due to Newton's law. Although satellite-only gravity field models which are mainly based on GRACE and GOCE data, such as those of the GOCO-S series, show unprecedented performance in the low to medium wavelengths down to 80-100 km, for many applications also the high-degree spectral information is required to reduce significantly the omission error of satellite-only models, which are in the order of 30 cm in terms of geoid height. Therefore, the satellite information has been complemented by additional terrestrial data sets and altimetry data over the oceans to achieve a high resolution global gravity field solution. This is the challenging task, due to the fact, that terrestrial and altimetric gravity information is not very homogenous, and that there is a total lack of terrestrial gravity field data in some areas. Specific strategies have to be applied to fill these observation gaps. Furthermore, high spectral gravity field determination puts high demands on computer resources, because full normal equations systems become very large, and parallel methods have to be applied. On the way to a first official GOCO-C model, a gravity field model based on full normal equation of all observation groups up to d/o 720 has been retrieved at IAPG. Special emphasis is given to the stochastic modelling of all involved satellite and gravity data types, the related optimum relative weighting in the course of the combination, as well as rigorous error propagation, resulting in a full variance-covariance matrix of the gravity field coefficients. The resulting gravity field model is validated by independent external gravity field information, such as GPS/levelling observations.

Fecher, Thomas; Pail, Roland; Gruber, Thomas

2013-04-01

300

Review of high-level waste form properties. [146 bibliographies  

SciTech Connect

This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several additional waste forms have enough promise to warrant continued research and development to bring their state of development up to that of glass and calcine. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer potential advantages and need further study. Although this report discusses waste form properties, the total waste management system should be considered in the final selection of a waste form option. Canister design, canister materials, overpacks, engineered barriers, and repository characteristics, as well as the waste form, affect the overall performance of a waste management system. These parameters were not considered in this comparison.

Rusin, J.M.

1980-12-01

301

Study of the Earth's short-scale gravity field using the ERTM2160 gravity model  

NASA Astrophysics Data System (ADS)

This paper describes the computation and analysis of the Earth's short-scale gravity field through high-resolution gravity forward modelling using the Shuttle Radar Topography Mission (SRTM) global topography model. We use the established residual terrain modelling technique along with advanced computational resources and massive parallelisation to convert the high-pass filtered SRTM topography - complemented with bathymetric information in coastal zones - to implied short-scale gravity effects. The result is the ERTM2160 model (Earth Residual Terrain Modelled-gravity field with the spatial scales equivalent to spherical-harmonic coefficients up to degree 2160 removed). ERTM2160, used successfully for the construction of the GGMplus gravity maps, approximates the short-scale (i.e., ~10 km down to ~250 m) gravity field in terms of gravity disturbances, quasi/geoid heights and vertical deflections at ~3 billion gridded points within ±60° latitude. ERTM2160 reaches maximum values for the quasi/geoid height of ~30 cm, gravity disturbance in excess of 100 mGal, and vertical deflections of ~30? over the Himalaya mountains. Analysis of the ERTM2160 field as a function of terrain roughness shows in good approximation a linear relationship between terrain roughness and gravity effects, with values of ~1.7 cm (quasi/geoid heights), ~11 mGal (gravity disturbances) and 1.5? (vertical deflections) signal strength per 100 m standard deviation of the terrain. These statistics can be used to assess the magnitude of omitted gravity signals over various types of terrain when using degree-2160 gravity models such as EGM2008. Applications for ERTM2160 are outlined including its use in gravity smoothing procedures, augmentation of EGM2008, fill-in for future ultra-high resolution gravity models in spherical harmonics, or calculation of localised or global power spectra of Earth's short-scale gravity field. ERTM2160 is freely available via http://ddfe.curtin.edu.au/gravitymodels/ERTM2160.

Hirt, Christian; Kuhn, Michael; Claessens, Sten; Pail, Roland; Seitz, Kurt; Gruber, Thomas

2014-12-01

302

Metabolic adaptation to long term changes in gravity environment  

NASA Astrophysics Data System (ADS)

Biochemical analyses of the brain of Cichlid fish larvae, exposed during their very early development for 7 days to an increased acceleration of 3g (hyper-gravity), revealed a decrease in brain nucleoside diphosphate kinase (NDPK) as well as creatine kinase (BB-CK) activity. Using high performance liquid chromatography (HPLC) the concentrations of adenine nucleotides (AMP, ADP, ATP), phosphocreatine (CP), as well as of nicotineamide adenine dinucleotides (NAD, NADP) were analyzed in the brain of hyper-g exposed larvae vs. 1g controls. A slight reduction in the total adenine nucleotides (TAN) as well as the adenylate energy charge (AEC) was found. In parallel a significant increase in the NAD concentration and a corresponding decrease in NADP concentration occurred in larva's hyper-g brains vs. 1g controls. These results give further evidence for an influence of gravity on cellular level and furthermore contribute to a clarification of the cellular signal-response chain for gravity perception.

Slenzka, K.; Appel, R.; Rahmann, H.

303

A high-frequency high-efficiency three-level LCC converter for high-voltage charging applications  

Microsoft Academic Search

For high-voltage charging applications, this paper introduces a variable-frequency zero-voltage-switching three-level LCC resonant converter, which is able to utilize the parasitic components of the high-turns-ratio transformer. By applying the three-level structure in the primary side, low-voltage MOSFETs can be used to minimize the conduction loss. Therefore, the switching frequency can be increased to shrink the size of passive components. In

Yang Qiu; Bing Lu; Bo Yang; Dianbo Fu; Fred C. Lee; F. Canales; R. Gean; W. C. Tipton

2004-01-01

304

Spent nuclear fuel project high-level information management plan  

SciTech Connect

This document presents the results of the Spent Nuclear Fuel Project (SNFP) Information Management Planning Project (IMPP), a short-term project that identified information management (IM) issues and opportunities within the SNFP and outlined a high-level plan to address them. This high-level plan for the SNMFP IM focuses on specific examples from within the SNFP. The plan`s recommendations can be characterized in several ways. Some recommendations address specific challenges that the SNFP faces. Others form the basis for making smooth transitions in several important IM areas. Still others identify areas where further study and planning are indicated. The team`s knowledge of developments in the IM industry and at the Hanford Site were crucial in deciding where to recommend that the SNFP act and where they should wait for Site plans to be made. Because of the fast pace of the SNFP and demands on SNFP staff, input and interaction were primarily between the IMPP team and members of the SNFP Information Management Steering Committee (IMSC). Key input to the IMPP came from a workshop where IMSC members and their delegates developed a set of draft IM principles. These principles, described in Section 2, became the foundation for the recommendations found in the transition plan outlined in Section 5. Availability of SNFP staff was limited, so project documents were used as a basis for much of the work. The team, realizing that the status of the project and the environment are continually changing, tried to keep abreast of major developments since those documents were generated. To the extent possible, the information contained in this document is current as of the end of fiscal year (FY) 1995. Programs and organizations on the Hanford Site as a whole are trying to maximize their return on IM investments. They are coordinating IM activities and trying to leverage existing capabilities. However, the SNFP cannot just rely on Sitewide activities to meet its IM requirements. While the SNFP can use some work done Sitewide and by projects such as the Tank Waste Remediation System (TWRS), they will still need to make some IM investments of their own.

Main, G.C.

1996-09-13

305

A spaceborne gravity gradiometer concept based on cold atom interferometers for measuring Earth's gravity field  

E-print Network

We propose a concept for future space gravity missions using cold atom interferometers for measuring the diagonal elements of the gravity gradient tensor and the spacecraft angular velocity. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behavior and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in the gravity field better than GRACE.

Carraz, Olivier; Massotti, Luca; Haagmans, Roger; Silvestrin, Pierluigi

2014-01-01

306

The DYNAMO Orbiter Project: High Resolution Mapping of Gravity/Magnetic Fields and In Situ Investigation of Mars Atmospheric Escape  

NASA Technical Reports Server (NTRS)

Dynamo is a small Mars orbiter planned to be launched in 2005 or 2007, in the frame of the NASA/CNES Mars exploration program. It is aimed at improving gravity and magnetic field resolution, in order to better understand the magnetic, geologic and thermal history of Mars, and at characterizing current atmospheric escape, which is still poorly constrained. These objectives are achieved by using a low periapsis orbit, similar to the one used by the Mars Global Surveyor spacecraft during its aerobraking phases. The proposed periapsis altitude for Dynamo of 120-130 km, coupled with the global distribution of periapses to be obtained during one Martian year of operation, through about 5000 low passes, will produce a magnetic/gravity field data set with approximately five times the spatial resolution of MGS. Low periapsis provides a unique opportunity to investigate the chemical and dynamical properties of the deep ionosphere, thermosphere, and the interaction between the atmosphere and the solar wind, therefore atmospheric escape, which may have played a crucial role in removing atmosphere, and water, from the planet. There is much room for debate on the importance of current atmosphere escape processes in the evolution of the Martian atmosphere, as early "exotic" processes including hydrodynamic escape and impact erosion are traditionally invoked to explain the apparent sparse inventory of present-day volatiles. Yet, the combination of low surface gravity and the absence of a substantial internally generated magnetic field have undeniable effects on what we observe today. In addition to the current losses in the forms of Jeans and photochemical escape of neutrals, there are solar wind interaction-related erosion mechanisms because the upper atmosphere is directly exposed to the solar wind. The solar wind related loss rates, while now comparable to those of a modest comet, nonetheless occur continuously, with the intriguing possibility of important cumulative and/or enhanced effects over the several billion years of the solar system's life. If the detailed history of the Martian internal field could be traced back, and the current escape processes could be understood well enough to model the expected stronger losses under early Sun conditions, one could go a long way toward constraining this part of the mysterious history of Mars' atmosphere.

Smrekar, S.; Chassefiere, E.; Forget, F.; Reme, H.; Mazelle, C.; Blelly, P. -L.; Acuna, M.; Connerney, J.; Purucker, M.; Lin, R.

2000-01-01

307

No chiral truncation of quantum log gravity?  

E-print Network

At the classical level, chiral gravity may be constructed as a consistent truncation of a larger theory called log gravity by requiring that left-moving charges vanish. In turn, log gravity is the limit of topologically massive gravity (TMG) at a special value of the coupling (the chiral point). We study the situation at the level of linearized quantum fields, focussing on a unitary quantization. While the TMG Hilbert space is continuous at the chiral point, the left-moving Virasoro generators become ill-defined and cannot be used to define a chiral truncation. In a sense, the left-moving asymptotic symmetries are spontaneously broken at the chiral point. In contrast, in a non-unitary quantization of TMG, both the Hilbert space and charges are continuous at the chiral point and define a unitary theory of chiral gravity at the linearized level.

Tomas Andrade; Donald Marolf

2009-09-03

308

Lovelock gravity and Weyl's tube formula  

Microsoft Academic Search

In four space-time dimensions, there are good theoretical reasons for believing that general relativity is the correct geometrical theory of gravity, at least at the classical level. If one admits the possibility of extra space-time dimensions, what would we expect classical gravity to be like? It is often stated that the most natural generalization is Lovelock's theory, which shares many

Steven Willison

2009-01-01

309

Investigation of Gravity Wave Propagation in the Martian Atmosphere.  

NASA Astrophysics Data System (ADS)

Periodic atmospheric variations with the characteristics of gravity waves have been detected in the Martian atmosphere since the early measurements from Viking and Mariner 9. More recent temperature and aerobraking data from Mars Global Surveyor (MGS), and Mars Odyssey (ODY) suggest the presence of lee waves in ice clouds near the Martian surface, and show fluctuations in the thermospheric density with periods and wavelengths typical of gravity waves. Gravity waves are believed to have important effects in the Earth's atmosphere, producing fluctuations in the density, temperature, winds, and airglow intensities in the mesosphere and lower thermosphere, and generating a reversal of the summer to winter temperature gradient, which produces winter warming near the mesopause. If gravity waves are regularly present in the Martian atmosphere, they may also have significant effects on the circulation and energy budget. The effects of sub-grid scale gravity wave processes are generally represented in atmospheric models through a number of parameterization schemes. However, in this work, we determine the propagation of realistic individual gravity waves in the Martian atmosphere, using a linearized one-dimensional full-wave model. Calculations have been performed using atmospheric parameters based on observations of apparent lee waves in high latitude clouds, measured by the MOLA instrument aboard MGS. The results show that some of the generated lee waves are capable of propagating up into the Martian thermosphere. Wave propagation is found to be sensitive to the properties of the background atmosphere, including the wind and temperature structure. Waves which reach the thermosphere produce fluctuations in density with characteristics consistent with those of the density variations detected in ODY aerobraking data. The presence of critical levels and the temperature profile of the Martian atmosphere are found to determine the wavelengths, periods, and direction of propagation of the waves that are able to propagate up to the thermosphere. Gravity waves of modest amplitude are found to deposit momentum and generate significant heating and cooling in the Martian atmosphere.

Parish, H. F.; Schubert, G.; Hickey, M.

2007-12-01

310

High resolution LES study of the nocturnal low level jet  

NASA Astrophysics Data System (ADS)

Katabatic winds are buoyantly driven flows arising along cooled sloping surfaces which play a crucial role in driving the local weather, redistributing scalars such as temperature and moisture in the atmosphere. These winds are established following sunset under strong radiational cooling and rapidly stop after dawn with the formation of the convective boundary layer. They are characterized by a peak in the along slope velocity known as nocturnal low level jet (LLJ) whose effects, on the dynamics of such systems, have been recently investigated but are still not fully understood. The current contribution proposes a Large Eddy Simulation (LES) study at high resolution of idealized katabatic flows along cooled sloping surfaces and aims at gaining a deeper understanding on those that are the dynamics of such thermodynamical systems at the LLJ height. The stably stratified atmosphere is approximated in the Boussinesq sense, rotational effects are not taken into account and the subgrid terms for momentum and buoyancy are independently parametrized adopting Lagrangian scale dependent dynamic models (Bou Zeid et al., 2005). The structure of the mean and turbulent fields obtained from our numerical setup is analysed and results are compared with recent literature and meteorological observations from a narrow alpine valley with steep slopes (Val Ferret, Switzerland). The importance of the subgrid parametrization is tested via run at various resolution.

Giometto, Marco; Calaf, Marc; Oldroyd, Holly; Fang, Jiannong; Parlange, Marc B.

2013-04-01

311

High level glucose increases mutagenesis in human lymphoblastoid cells  

PubMed Central

Epidemiological data have suggested an increased cancer rates in diabetic patients, for which the underlying mechanism is poorly understood. We studied whether high level of glucose (HG) treatment that mimic the hyperglycemic condition in diabetes mellitus is mutagenic. Mutagenesis studies were carried out at both hypoxanthine phosphoribosyltransferase (hprt) and thymidine kinase (tk) loci. Role of p53 in HG-induced mutagenesis was also investigated by using human lymphoblastoid cell lines derived from same donor but differs in p53 statuses; TK6 has wild-type p53, NH32 has null p53, and WTK1 has mutant p53 (ile237). In addition, we studied the influence of antioxidant treatment on HG-induced mutagenesis. Mutation fractions at both loci increased significantly in all three lines at 21 and 28 days after HG treatments. At tk locus, the increase of a class of mutants with normal growth rate is mainly responsible for the overall increased mutant fraction. Compared to TK6 cells, both NH32 and WTK1 cells showed an early onset of mutagenesis. Treatment of cells with antioxidant N-acetyl-L-cysteine partially reduced HG induced mutagenesis. This study is the first to indicate that HG is able to induce gene mutation which may be one of the important mechanisms of diabetes-associated carcinogenesis. PMID:17848982

Zhang, Ying; Zhou, Junqing; Wang, Tieli; Cai, Lu

2007-01-01

312

Quality assurance requirements for high-level waste form production  

SciTech Connect

The US Department of Energy (DOE) Defense Waste Management Plan has the objective of final disposal for high-level waste (HLW) generated from defense programs. The DOE sites that generate HLW are located at the Savannah River Operations Office in Aiken, South Carolina, the Hanford site in Richland, Washington, and the Idaho Operations Office in Idaho Falls, Idaho. The purpose in the development of a quality assurance (QA) specification for organizations involved in HLW production is to establish uniform requirements that ensure that radioactive waste is converted to a waste form and canistered in such a way that it is acceptable in a federal repository licensed by the US Nuclear Regulatory Commission (NRC). A QA specification has been developed that will be applied to those activities important to certification of the product. The basic requirements are defined in national consensus standards and DOE directives. The supplemental requirements identify the QA criteria associated with HLW production where additional guidance is needed to facilitate the DOE repository licensing process.

Chacey, K.A.; DeLannoy, C.R.; Campbell, M.H.

1988-01-01

313

Application of SYNROC to high-level defense wastes  

SciTech Connect

The SYNROC method for immobilization of high-level nuclear reactor wastes is currently being applied to US defense wastes in tank storage at Savannah River, South Carolina. The minerals zirconolite, perovskite, and hollandite are used in SYNROC D formulations to immobilize fission products and actinides that comprise up to 10% of defense waste sludges and coexisting solutions. Additional phases in SYNROC D are nepheline, the host phase for sodium; and spinel, the host for excess aluminum and iron. Up to 70 wt % of calcined sludge can be incorporated with 30 wt % of SYNROC additives to produce a waste form consisting of 10% nepheline, 30% spinel, and approximately 20% each of the radioactive waste-bearing phases. Urea coprecipitation and spray drying/calcining methods have been used in the laboratory to produce homogeneous, reactive ceramic powders. Hot pressing and sintering at temperatures from 1000 to 1100/sup 0/C result in waste form products with greater than 97% of theoretical density. Hot isostatic pressing has recently been implemented as a processing alternative. Characterization of waste-form mineralogy has been done by means of XRD, SEM, and electron microprobe. Leaching of SYNROC D samples is currently being carried out. Assessment of radiation damage effects and physical properties of SYNROC D will commence in FY 81.

Tewhey, J.D.; Hoenig, C.L.; Newkirk, H.W.; Rozsa, R.B.; Coles, D.G.; Ryerson, F.J.

1981-01-01

314

Defense High-Level Waste Leaching Mechanisms Program. Final report  

SciTech Connect

The Defense High-Level Waste Leaching Mechanisms Program brought six major US laboratories together for three years of cooperative research. The participants reached a consensus that solubility of the leached glass species, particularly solubility in the altered surface layer, is the dominant factor controlling the leaching behavior of defense waste glass in a system in which the flow of leachant is constrained, as it will be in a deep geologic repository. Also, once the surface of waste glass is contacted by ground water, the kinetics of establishing solubility control are relatively rapid. The concentrations of leached species reach saturation, or steady-state concentrations, within a few months to a year at 70 to 90/sup 0/C. Thus, reaction kinetics, which were the main subject of earlier leaching mechanisms studies, are now shown to assume much less importance. The dominance of solubility means that the leach rate is, in fact, directly proportional to ground water flow rate. Doubling the flow rate doubles the effective leach rate. This relationship is expected to obtain in most, if not all, repository situations.

Mendel, J.E. (compiler)

1984-08-01

315

Why consider subseabed disposal of high-level nuclear waste  

SciTech Connect

Large areas of the deep seabed warrant assessment as potential disposal sites for high-level radioactive waste because: (1) they are far from seismically and tectonically active lithospheric plate boundaries; (2) they are far from active or young volcanos; (3) they contain thick layers of very uniform fine-grained clays; (4) they are devoid of natural resources likely to be exploited in the forseeable future; (5) the geologic and oceanographic processes governing the deposition of sediments in such areas are well understood, and are remarkably insensitive to past oceanographic and climatic changes; and (6) sedmentary records of tens of millions of years of slow, uninterrupted deposition of fine grained clay support predictions of the future stability of such sites. Data accumulated to date on the permeability, ion-retardation properties, and mechanical strength of pelagic clay sediments indicate that they can act as a primary barrier to the escape of buried nuclides. Work in progress should determine within the current decade whether subseabed disposal is environmentally acceptable and technically feasible, as well as address the legal, political and social issues raised by this new concept.

Heath, G.R.; Hollister, C.D.; Anderson, D.R.; Leinen, M.

1980-01-01

316

THERMAL ANALYSIS OF GEOLOGIC HIGH-LEVEL RADIOACTIVE WASTE PACKAGES  

SciTech Connect

The engineering design of disposal of the high level waste (HLW) packages in a geologic repository requires a thermal analysis to provide the temperature history of the packages. Calculated temperatures are used to demonstrate compliance with criteria for waste acceptance into the geologic disposal gallery system and as input to assess the transient thermal characteristics of the vitrified HLW Package. The objective of the work was to evaluate the thermal performance of the supercontainer containing the vitrified HLW in a non-backfilled and unventilated underground disposal gallery. In order to achieve the objective, transient computational models for a geologic vitrified HLW package were developed by using a computational fluid dynamics method, and calculations for the HLW disposal gallery of the current Belgian geological repository reference design were performed. An initial two-dimensional model was used to conduct some parametric sensitivity studies to better understand the geologic system's thermal response. The effect of heat decay, number of co-disposed supercontainers, domain size, humidity, thermal conductivity and thermal emissivity were studied. Later, a more accurate three-dimensional model was developed by considering the conduction-convection cooling mechanism coupled with radiation, and the effect of the number of supercontainers (3, 4 and 8) was studied in more detail, as well as a bounding case with zero heat flux at both ends. The modeling methodology and results of the sensitivity studies will be presented.

Hensel, S.; Lee, S.

2010-04-20

317

High Level Rule Modeling Language for Airline Crew Pairing  

NASA Astrophysics Data System (ADS)

The crew pairing problem is an airline optimization problem where a set of least costly pairings (consecutive flights to be flown by a single crew) that covers every flight in a given flight network is sought. A pairing is defined by using a very complex set of feasibility rules imposed by international and national regulatory agencies, and also by the airline itself. The cost of a pairing is also defined by using complicated rules. When an optimization engine generates a sequence of flights from a given flight network, it has to check all these feasibility rules to ensure whether the sequence forms a valid pairing. Likewise, the engine needs to calculate the cost of the pairing by using certain rules. However, the rules used for checking the feasibility and calculating the costs are usually not static. Furthermore, the airline companies carry out what-if-type analyses through testing several alternate scenarios in each planning period. Therefore, embedding the implementation of feasibility checking and cost calculation rules into the source code of the optimization engine is not a practical approach. In this work, a high level language called ARUS is introduced for describing the feasibility and cost calculation rules. A compiler for ARUS is also implemented in this work to generate a dynamic link library to be used by crew pairing optimization engines.

Mutlu, Erdal; Birbil, ?. Ilker; Bülbül, Kerem; Yenigün, Hüsnü

2011-09-01

318

The IFR pyroprocessing for high-level waste minimization  

SciTech Connect

The process developed for the recycle of integral fast reactor (IFR) spent fuel utilizes a combination of pyrometallurgical and electrochemical methods and has been termed pyroprocessing. The process has been operated at full scale with simulated spent fuel using nonradioactive fission product elements. A comprehensive demonstration of the pyroprocessing of irradiated IFR fuel will begin later this year. Pyroprocessing involves the anodic dissolution of all the constituent elements of the IFR spent fuel and controlled electrotransport (electrorefining) to separate the actinide elements from the fission products present in the spent fuel. The process be applied to the processing of spent light water reactor (LWR) fuel as well, requiring only the addition of a reduction step to convert the LWR fuel as well, requiring only the addition of a reduction step to convert the LWR oxide fuel to metallic form and a separation step to separate uranium from the transuranic (TRU) elements. The TRU elements are then recovered by electroefining in the same manner as the actinides from the IFR high-level wastes arising from pyroprocessing are virtually free of actinides, and the volume of the wastes is minimized by the intrinsic characteristics of the processing of the processing method.

Laidler, J.J. (Argonne National Lab., IL (United States))

1993-01-01

319

Process Design Concepts for Stabilization of High Level Waste Calcine  

SciTech Connect

The current baseline assumption is that packaging ¡§as is¡¨ and direct disposal of high level waste (HLW) calcine in a Monitored Geologic Repository will be allowed. The fall back position is to develop a stabilized waste form for the HLW calcine, that will meet repository waste acceptance criteria currently in place, in case regulatory initiatives are unsuccessful. A decision between direct disposal or a stabilization alternative is anticipated by June 2006. The purposes of this Engineering Design File (EDF) are to provide a pre-conceptual design on three low temperature processes under development for stabilization of high level waste calcine (i.e., the grout, hydroceramic grout, and iron phosphate ceramic processes) and to support a down selection among the three candidates. The key assumptions for the pre-conceptual design assessment are that a) a waste treatment plant would operate over eight years for 200 days a year, b) a design processing rate of 3.67 m3/day or 4670 kg/day of HLW calcine would be needed, and c) the performance of waste form would remove the HLW calcine from the hazardous waste category, and d) the waste form loadings would range from about 21-25 wt% calcine. The conclusions of this EDF study are that: (a) To date, the grout formulation appears to be the best candidate stabilizer among the three being tested for HLW calcine and appears to be the easiest to mix, pour, and cure. (b) Only minor differences would exist between the process steps of the grout and hydroceramic grout stabilization processes. If temperature control of the mixer at about 80„aC is required, it would add a major level of complexity to the iron phosphate stabilization process. (c) It is too early in the development program to determine which stabilizer will produce the minimum amount of stabilized waste form for the entire HLW inventory, but the volume is assumed to be within the range of 12,250 to 14,470 m3. (d) The stacked vessel height of the hot process vessels in the hydroceramic grout process (i.e., 21 m) appears to be about the same as that estimated by the Direct Cementitious Waste Process in 1998, for which a conceptual design was developed. Some of the conceptual design efforts in the 1998 study may be applicable to the stabilizer processes addressed in this EDF. (e) The gamma radiation fields near the process vessels handling HLW calcine would vary from a range of about 300-350 R/hr at a distance of 2.5 cm from the side of the vessels to a range of about 50-170 R/hr at a distance of 100 cm from the side of the vessels. The calculations were made for combined calcine, which was defined as the total HLW calcine inventory uniformly mixed. (f) The gamma radiation fields near the stabilized waste in canisters would range from about 25-170 R/hr at 2.5 cm from the side of the canister and 5-35 R/hr at 100 cm from the side of the canister, depending on the which bin set was the source of calcine.

T. R. Thomas; A. K. Herbst

2005-06-01

320

Burning experiments and late Paleozoic high O2 levels  

NASA Astrophysics Data System (ADS)

The Paleozoic rise of land plants brought about increased burial of organic matter and a resulting increase in atmospheric oxygen concentrations. Levels as high as 30-35% O2 may have been reached during the Permo-Carboniferous (Berner and Canfield, 1989; Berner, 2001). However, burning experiments based solely on paper (Watson, 1978) have challenged these results, the claim being that if the oxygen made up more than 25% of the atmosphere, the frequency and intensity of forest fires would increase sufficiently to prevent the continued existence of plant life. Thus, since plants have persisted, it is possible that fires served as a negative feedback against excessive oxygen levels. An initial study of Paleozoic wildfire behavior via thermogravimetric analysis (TGA) was conducted under ambient and enriched oxygen conditions to simulate present and ancient atmospheres. The tests focused on natural fuels, specifically tree leaves and wood, tree fern fibers, and sphagnum peat-moss, simulating Permo-Carboniferous upland and swampland ecosystems, respectively. Three conclusions are: (1) enriched oxygen increases the rate of mass loss during burning; (2) fuel chemistry (cellulose vs. lignin) influences burning patterns; and (3) in geometrically heterogeneous fuels, geometry affects burning rate significantly. Both geometrically and chemically, paper resists fire poorly; thus, we found that it loses its mass at lower temperatures than forest materials and is therefore a poor proxy for Paleozoic ecosystems. Further study of Paleozoic wildfire spread behavior is currently being conducted. Fires are lit using pine dowels, which allow for reproducible fuel density. Steady-state, one-dimensional flame-spread is measured with thermocouples anchored two inches above the fuel bed. Both oxygen concentration of the air supply to the fire and moisture content of the fuels are varied, as we suspect that these are two main controls of wildfire spread. Burning fuels of varying moisture contents is central to this study, for fuel moisture is a fire retardant that may offset the fire-enhancing effects of high oxygen conditions. Earliest preliminary results at low moisture show that, as expected, increasing oxygen concentration significantly increases the rate of fuel consumption. This is expressed as both an increase in the speed of the flame spread and the temperature of the flames. It was found that a 35% oxygen (balance nitrogen) gas mixture caused fire to spread at about five times the rate of a fire in ambient air. The fire in the high-oxygen gas mixture was roughly 1.3 times the temperature of the fire in ambient air. The current work is not intended to exactly represent forest ecosystems; rather, it is intended to establish an understanding of flame-spread behavior in natural fuels and future work will include fuels that better represent natural ecosystems such as those used in the TGA experimentation.

Wildman, R.; Essenhigh, R.; Berner, R.; Hickey, L.; Wildman, C.

2003-04-01

321

Millimeter-Wave Measurements of High Level and Low Level Activity Glass Melts  

SciTech Connect

The primary objectives of the current research is to develop on-line sensors for characterizing molten glass in high-level and low-activity waste glass melters using millimeter-wave (MMW) technology and to use this technology to do novel research of melt dynamics. Existing and planned waste glass melters lack sophisticated diagnostics due to the hot, corrosive, and radioactive melter environments. Without process control diagnostics, the Defense Waste Processing Facility (DWPF) and the Waste Treatment Plant (WTP) under construction at Hanford operate by a feed forward process control scheme that relies on predictive models with large uncertainties. This scheme severely limits production throughput and waste loading. Also operations at DWPF have shown susceptibility to anomalies such as pouring, foaming, and combustion gas build up, which can seriously disrupt operations. Future waste chemistries will be even more challenging. The scientific goals of this project are to develop new reliable on-line monitoring capability for important glass process parameters such as temperature profiles, emissivity, density, viscosity, and other characteristics using the unique advantages of millimeter wave electromagnetic radiation that can be eventually implemented in the operating melters. Once successfully developed and implemented, significant cost savings would be realized in melter operations by increasing production through put, reduced storage volumes (through higher waste loading), and reduced risks (prevention or mitigation of anomalies).

Woskov, Paul P.; Sundaram, S.K.; Daniel, William E., Jr.

2006-06-01

322

Engineering ?-amylase levels in wheat grain suggests a highly sophisticated level of carbohydrate regulation during development.  

PubMed

Wheat starch degradation requires the synergistic action of different amylolytic enzymes. Our spatio-temporal study of wheat ?-amylases throughout grain development shows that AMY3 is the most abundant isoform compared with the other known ?-amylases. Endosperm-specific over-expression of AMY3 resulted in an increase of total ?-amylase activity in harvested grains. Unexpectedly, increased activity did not have a significant impact on starch content or composition but led to an increase of soluble carbohydrate (mainly sucrose) in dry grain. In AMY3 overexpression lines (A3OE), germination was slightly delayed and triacylglycerol (TAG) content was increased in the endosperm of mature grain. Despite increased AMY3 transcript and protein content throughout grain development, alterations of ?-amylase activity and starch granule degradation were not detected until grain maturation, suggesting a post-translational inhibition of ?-amylase activity in the endosperm during the starch filling period. These findings show unexpected effects of a high level of ?-amylase on grain development and composition, notably in carbon partitioning and TAG accumulation, and suggest the presence of a hitherto unknown regulatory pathway during grain filling. PMID:25053646

Whan, Alex; Dielen, Anne-Sophie; Mieog, Jos; Bowerman, Andrew F; Robinson, Hannah M; Byrne, Keren; Colgrave, Michelle; Larkin, Philip J; Howitt, Crispin A; Morell, Matthew K; Ral, Jean-Philippe

2014-10-01

323

Neuromuscular onset succession of high level gymnasts during dynamic leg acceleration phases on high bar.  

PubMed

In several athletic disciplines there is evidence that for generating the most effective acceleration of a specific body part the transfer of momentum should run in a "whip-like" consecutive succession of body parts towards the segment which shall be accelerated most effectively (e.g. the arm in throwing disciplines). This study investigated the question how this relates to the succession of neuromuscular activation to induce such "whip like" leg acceleration in sports like gymnastics with changed conditions concerning the body position and momentary rotational axis of movements (e.g. performing giant swings on high bar). The study demonstrates that during different long hang elements, performed by 12 high level gymnasts, the succession of the neuromuscular activation runs primarily from the bar (punctum fixum) towards the legs (punctum mobile). This demonstrates that the frequently used teaching instruction, first to accelerate the legs for a successful realization of such movements, according to a high level kinematic output, is contradictory to the neuromuscular input patterns, being used in high level athletes, realizing these skills with high efficiency. Based on these findings new approaches could be developed for more direct and more adequate teaching methods regarding to an earlier optimization and facilitation of fundamental movement requirements. PMID:23941901

von Laßberg, Christoph; Rapp, Walter; Mohler, Betty; Krug, Jürgen

2013-10-01

324

Ghosts in Massive Gravity  

E-print Network

In the context of Lorentz-invariant massive gravity we show that classical solutions around heavy sources are plagued by ghost instabilities. The ghost shows up in the effective field theory at huge distances from the source, much bigger than the Vainshtein radius. Its presence is independent of the choice of the non-linear terms added to the Fierz-Pauli Lagrangian. At the Vainshtein radius the mass of the ghost is of order of the inverse radius, so that the theory cannot be trusted inside this region, not even at the classical level.

Paolo Creminelli; Alberto Nicolis; Michele Papucci; Enrico Trincherini

2005-05-16

325

Removal of cesium from a high-level calcined waste by high temperature volatilization  

SciTech Connect

Pyrochemical methods are being evaluated for the separation of actinides and fission products from inert material in high-level waste calcine. Separation processes have the potential of reducing waste disposal costs by reducing the volume of high-level waste requiring final disposal in a repository. Tests were conducted to evaluate high temperature volatilization for removing {sup 137}Cs from four types of calcines. The results for pilot plant calcines indicate greater than 99% cesium removal for alumina and fluorinel/sodium calcines heated at 1000{degree}C and 99% removal for zirconia calcine heated at 1100{degree}C. Tests with actual calcine generated at the New Waste Calcining Facility (NWCF) from a blend of aluminium, sodium and zirconium/fluorinel wastes resulted in 96% cesium removal at 1000{degree}C and greater than 99% removal at 1170{degree}C.

Del Debbio, J.A.

1994-11-01

326

Processing of Bulk YBa2Cu3O(7-x) High Temperature Superconductor Materials for Gravity Modification Experiments and Performance Under AC Levitation  

NASA Technical Reports Server (NTRS)

We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of bulk-processed high temperature superconductor disks. Others have indicated that large annular disks (on the order of 25cm diameter) and AC levitation fields play an essential role in their observed experiments. We report experiments in processing such large bulk superconductors. Successful results depend on material mechanical characteristics, and pressure and heat treat protocols. Annular disks having rough dimensions of 30cm O.D., 7cm I.D. and 1 cm thickness have been routinely fabricated and tested under AC levitation fields ranging from 45 to 300OHz. Implications for space transportation initiatives and power storage flywheel technology will be discussed.

Koczor, Ronald; Noever, David; Hiser, Robert

1999-01-01

327

JET MIXING ANALYSIS FOR SRS HIGH-LEVEL WASTE RECOVERY  

SciTech Connect

The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank to ensure uniformity of the discharge stream. Mixing is accomplished with one to four slurry pumps located within the tank liquid. The slurry pump may be fixed in position or they may rotate depending on the specific mixing requirements. The high-level waste in Tank 48 contains insoluble solids in the form of potassium tetraphenyl borate compounds (KTPB), monosodium titanate (MST), and sludge. Tank 48 is equipped with 4 slurry pumps, which are intended to suspend the insoluble solids prior to transfer of the waste to the Fluidized Bed Steam Reformer (FBSR) process. The FBSR process is being designed for a normal feed of 3.05 wt% insoluble solids. A chemical characterization study has shown the insoluble solids concentration is approximately 3.05 wt% when well-mixed. The project is requesting a Computational Fluid Dynamics (CFD) mixing study from SRNL to determine the solids behavior with 2, 3, and 4 slurry pumps in operation and an estimate of the insoluble solids concentration at the suction of the transfer pump to the FBSR process. The impact of cooling coils is not considered in the current work. The work consists of two principal objectives by taking a CFD approach: (1) To estimate insoluble solids concentration transferred from Tank 48 to the Waste Feed Tank in the FBSR process and (2) To assess the impact of different combinations of four slurry pumps on insoluble solids suspension and mixing in Tank 48. For this work, several different combinations of a maximum of four pumps are considered to determine the resulting flow patterns and local flow velocities which are thought to be associated with sludge particle mixing. Two different elevations of pump nozzles are used for an assessment of the flow patterns on the tank mixing. Pump design and operating parameters used for the analysis are summarized in Table 1. The baseline pump orientations are chosen by the previous work [Lee et. al, 2008] and the initial engineering judgement for the conservative flow estimate since the modeling results for the other pump orientations are compared with the baseline results. As shown in Table 1, the present study assumes that each slurry pump has 900 gpm flowrate for the tank mixing analysis, although the Standard Operating Procedure for Tank 48 currently limits the actual pump speed and flowrate to a value less than 900 gpm for a 29 inch liquid level. Table 2 shows material properties and weight distributions for the solids to be modeled for the mixing analysis in Tank 48.

Lee, S.

2011-07-05

328

PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION  

SciTech Connect

In accordance with the Nuclear Waste Policy Amendments Act of 1987, Yucca Mountain was designated as the site to be investigated as a potential repository for the disposal of high-level radioactive waste. The Yucca Mountain site is an undeveloped area located on the southwestern edge of the Nevada Test Site (NTS), about 100 miles northwest of Las Vegas. The site currently lacks rail service or an existing right-of-way. If the Yucca Mountain site is found suitable for the repository, rail service is desirable to the Office of Civilian Waste Management (OCRWM) Program because of the potential of rail transportation to reduce costs and to reduce the number of shipments relative to highway transportation. A Preliminary Rail Access Study evaluated 13 potential rail spur options. Alternative routes within the major options were also developed. Each of these options was then evaluated for potential land use conflicts and access to regional rail carriers. Three potential routes having few land use conflicts and having access to regional carriers were recommended for further investigation. Figure 1-1 shows these three routes. The Jean route is estimated to be about 120 miles long, the Carlin route to be about 365 miles long, and Caliente route to be about 365 miles long. The remaining ten routes continue to be monitored and should any of the present conflicts change, a re-evaluation of that route will be made. Complete details of the evaluation of the 13 routes can be found in the previous study. The DOE has not identified any preferred route and recognizes that the transportation issues need a full and open treatment under the National Environmental Policy Act. The issue of transportation will be included in public hearings to support development of the Environmental Impact Statement (EIS) proceedings for either the Monitored Retrievable Storage Facility or the Yucca Mountain Project or both.

D.C. Richardson

2003-03-19

329

High-level waste issues and resolutions document  

SciTech Connect

The High-Level Waste (HLW) Issues and Resolutions Document recognizes US Department of Energy (DOE) complex-wide HLW issues and offers potential corrective actions for resolving these issues. Westinghouse Management and Operations (M&O) Contractors are effectively managing HLW for the Department of Energy at four sites: Idaho National Engineering Laboratory (INEL), Savannah River Site (SRS), West Valley Demonstration Project (WVDP), and Hanford Reservation. Each site is at varying stages of processing HLW into a more manageable form. This HLW Issues and Resolutions Document identifies five primary issues that must be resolved in order to reach the long-term objective of HLW repository disposal. As the current M&O contractor at DOE`s most difficult waste problem sites, Westinghouse recognizes that they have the responsibility to help solve some of the complexes` HLW problems in a cost effective manner by encouraging the M&Os to work together by sharing expertise, eliminating duplicate efforts, and sharing best practices. Pending an action plan, Westinghouse M&Os will take the initiative on those corrective actions identified as the responsibility of an M&O. This document captures issues important to the management of HLW. The proposed resolutions contained within this document set the framework for the M&Os and DOE work cooperatively to develop an action plan to solve some of the major complex-wide problems. Dialogue will continue between the M&Os, DOE, and other regulatory agencies to work jointly toward the goal of storing, treating, and immobilizing HLW for disposal in an environmentally sound, safe, and cost effective manner.

Not Available

1994-05-01

330

Level 1 Tornado PRA for the High Flux Beam Reactor  

SciTech Connect

This report describes a risk analysis primarily directed at providing an estimate for the frequency of tornado induced damage to the core of the High Flux Beam Reactor (HFBR), and thus it constitutes a Level 1 Probabilistic Risk Assessment (PRA) covering tornado induced accident sequences. The basic methodology of the risk analysis was to develop a ``tornado specific`` plant logic model that integrates the internal random hardware failures with failures caused externally by the tornado strike and includes operator errors worsened by the tornado modified environment. The tornado hazard frequency, as well as earlier prepared structural and equipment fragility data, were used as input data to the model. To keep modeling/calculational complexity as simple as reasonable a ``bounding`` type, slightly conservative, approach was applied. By a thorough screening process a single dominant initiating event was selected as a representative initiator, defined as: ``Tornado Induced Loss of Offsite Power.`` The frequency of this initiator was determined to be 6.37E-5/year. The safety response of the HFBR facility resulted in a total Conditional Core Damage Probability of .621. Thus, the point estimate of the HFBR`s Tornado Induced Core Damage Frequency (CDF) was found to be: (CDF){sub Tornado} = 3.96E-5/year. This value represents only 7.8% of the internal CDF and thus is considered to be a small contribution to the overall facility risk expressed in terms of total Core Damage Frequency. In addition to providing the estimate of (CDF){sub Tornado}, the report documents, the relative importance of various tornado induced system, component, and operator failures that contribute most to (CDF){sub Tornado}.

Bozoki, G.E.; Conrad, C.S.

1994-05-01

331

High Level Multimodal Fusion and Semantics Thanassis Perperis  

E-print Network

of pornography. Keywords: Harmful Content Detection, Semantic Video Analysis, Knowledge Engineering, Ontologies and pornography detection by means of a unified approach exporting various levels of semantic abstractions

Kouroupetroglou, Georgios

332

Non-Newtonian gravity or gravity anomalies?  

NASA Technical Reports Server (NTRS)

Geophysical measurements of G differ from laboratory values, indicating that gravity may be non-Newtonian. A spherical harmonic formulation is presented for the variation of (Newtonian) gravity inside the Earth. Using the GEM-10B Earth Gravitational Field Model, it is shown that long-wavelength gravity anomalies, if not corrected, may masquerade as non-Newtonian gravity by providing significant influences on experimental observation of delta g/delta r and G. An apparent contradiction in other studies is also resolved: i.e., local densities appear in equations when average densities of layers seem to be called for.

Rubincam, David P.; Chao, B. Fong; Schatten, Kenneth H.; Sager, William W.

1988-01-01

333

Performance and limits of current satellite-only and combined gravity field models (Invited)  

NASA Astrophysics Data System (ADS)

During the last decade, the successful operation of the dedicated satellite missions GOCE and GRACE have revolutionized our picture of the Earth's gravity field, because they delivered a static global gravity field map with high and homogeneous accuracy for spatial lengthscales down to 80-100 km. The current satellite-only models of the fourth generation including GOCE data have reached accuracies of about 3 cm in geoid height and less than 1 mGal in gravity anomalies at degree/order 200 (100 km spatial half-wavelength). Due to the attenuation of the gravity field with orbit altitude, gravity field models derived only from satellite data will never be able to achieve very high spatial resolutions of only a few kilometres. However, precise knowledge of the Earth's gravity field structure with very high resolution is essential not only for a range of geoscience disciplines, such as solid Earth geophysics for lithospheric modelling and geological interpretation, exploration geophysics, and several climate research applications such as ocean circulation or sea level change research, but also for geodesy (e.g., surveying, inertial navigation) and civil engineering (e.g., construction, modelling of water flow for hydro-engineering). For this reason, satellite-only models are complemented by combined gravity field models, which contain very high-resolution or even point-wise gravity field information obtained by terrestrial gravity measurements over continents, and satellite altimetry over the oceans. To further increase the spatial resolution beyond 10-20 km, measured terrestrial and satellite data can also be augmented by high-resolution gravity field signals synthesized from topographic models, although the latter is not useful anymore for geophysical interpretation. In this contribution we explore the performance and the limits of the most recent satellite-only and combined Earth's gravity field models. On the basis of selected case studies from different geoscientific disciplines, we investigate commission and omission errors and thus the contribution and impact of satellite gravity data on gravity field applications. In solid Earth geophysics, based on a case study in the active continental margin of the Andes region it will be demonstrated that the new information derived from satellite gravity data makes a significant impact on the modelling of lithospheric structures, especially in those regions where the terrestrial data basis is poor or unreliable. We will also explore the impact of globally homogeneous satellite gravity information on the estimation of the geodetic mean dynamic topography (MDT), with special emphasis on a correct stochastic modelling and the estimation of its errors. A comparison with drifter data shall demonstrate the increasing performance of global gravity field data, but also their limits concerning very high-frequency structures. Finally, we will also investigate the impact of satellite gravity data on the global unification of height systems, i.e. the estimation of height offsets among different countries of the world. Especially here, the limits of satellite-only models and the enrichment with terrestrial gravity to reduce the omission error and thus to improve the height offset estimates will be addressed.

Pail, R.

2013-12-01

334

High level waste interim storge architecture selection - decision report  

SciTech Connect

The U.S. Department of Energy (DOE) has embarked upon a course to acquire Hanford Site tank waste treatment and immobilization services using privatized facilities (RL 1996a). This plan contains a two-phased approach. Phase I is a proof-of-principle/connnercial demonstration- scale effort and Phase II is a fiill-scale production effort. In accordance with the planned approach, interim storage and disposal of various products from privatized facilities are to be DOE fumished. The high-level waste (BLW) interim storage options, or alternative architectures, were identified and evaluated to provide the framework from which to select the most viable method of Phase I BLW interim storage (Calmus 1996). This evaluation, hereafter referred to as the Alternative Architecture Evaluation, was performed to established performance and risk criteria (technical merit, cost, schedule, etc.). Based on evaluation results, preliminary architectures and path forward reconunendations were provided for consideration in the architecture decision- maldng process. The decision-making process used for selection of a Phase I solidified BLW interim storage architecture was conducted in accordance with an approved Decision Plan (see the attachment). This decision process was based on TSEP-07,Decision Management Procedure (WHC 1995). The established decision process entailed a Decision Board, consisting of Westinghouse Hanford Company (VY`HC) management staff, and included appointment of a VTHC Decision Maker. The Alternative Architecture Evaluation results and preliminary recommendations were presented to the Decision Board members for their consideration in the decision-making process. The Alternative Architecture Evaluation was prepared and issued before issuance of @C-IP- 123 1, Alternatives Generation and Analysis Procedure (WI-IC 1996a), but was deemed by the Board to fully meet the intent of WHC-IP-1231. The Decision Board members concurred with the bulk of the Alternative Architecture Evaluation results and recommendations. However, the Board required changes to some criteria definitions and weightings in establishing its own recommendation basis. This report documents information presented to the Decision Board, and the Decision Board`s recommendations and basis for these recommendations. The Board`s recommendations were fully adopted by the WHC Decision Maker, R. J. Murkowski, Manager, TWRS Storage and Disposal. The Decision Board`s recommendation is as follows. The Phase I BLW Interim storage concept architecture will use Vaults 2 and 3 of the Hanford Site Spent Nuclear Fuel Canister Storage Building, being located in the Hanford Site 200 East Area, and include features to faciliate addition of one or more vaults at a later date.

Calmus, R.B.

1996-09-27

335

Confidence Level and Sensitivity Limits in High-Contrast Imaging  

NASA Astrophysics Data System (ADS)

In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground- and space-based telescopes. Previous theoretical analyses have shown that the time intensity variations of a single speckle follow a modified Rician. It is first demonstrated here that for a circular pupil, this temporal intensity distribution also represents the speckle spatial intensity distribution at a fixed separation from the point-spread function center; this fact is demonstrated using numerical simulations for coronagraphic and noncoronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level (CL). In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding CL as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckle noise, a detection threshold up to 3 times higher is required to obtain a CL equivalent to that at 5 ? for Gaussian noise. The technique is then tested on data acquired by simultaneous spectral differential imaging with TRIDENT and by angular differential imaging with NIRI. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. Finally, a power law is derived to predict the 1-3×10-7 CL detection threshold when averaging a partially correlated non-Gaussian noise. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Also based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

Marois, Christian; Lafrenière, David; Macintosh, Bruce; Doyon, René

2008-01-01

336

[Kinetic theory and boundary conditions for flows of highly inelastic spheres: Applications to gravity driven granular flows down bumpy inclines  

SciTech Connect

We studied the effects of isotropic boundary vibrations on unconfined granular materials that are compressed by gravity and dilated by the agitation of horizontal, vibrating boundaries. Because the vibrations are isotropic, the assemblies experience no mean motion. Consequently, the resulting boundary value problem is simpler than the boundary value problem that results when the vibrating surface is inclined. However, in both cases, we confront difficulties associated the occurrence of a free surface, and must implement recently derived boundary conditions for vibrating boundaries. We calculate the steady state solid fraction and granular temperature profiles throughout assemblies of identical, smooth, inelastic spheres that are unconfined from above and thermalized from below by bumpy, horizontal surfaces that randomly vibrate about zero mean velocity. The analysis is based upon a kinetic constitutive theory and conditions that account for the effects of boundary vibrations on the momentum and energy transferred to the spheres. In presenting the results, we pay special attention to the thermalized states of fixed masses subjected to varying boundary vibrations and varying masses subjected to fixed vibrations. In the first study, we find that as the vibration of the boundary intensifies, the assemblies of fixed mass become deeper, more dilute, and more thermalized. In the second, we find that as the assemblies become more massive, fixed boundary vibrations effectively thermalize decreasing fractions of the total mass.

Richman, M.W.

1992-01-01

337

Time-dependent gravity in Southern California, May 1974 to April 1979  

NASA Technical Reports Server (NTRS)

The Southern California gravity survey, begun in May 1974 to obtain high spatial and temporal density gravity measurements to be coordinated with long-baseline three dimensional geodetic measurements of the Astronomical Radio Interferometric Earth Surveying project, is presented. Gravity data was obtained from 28 stations located in and near the seismically active San Gabriel section of the Southern California Transverse Ranges and adjoining San Andreas Fault at intervals of one to two months using gravity meters relative to a base station standard meter. A single-reading standard deviation of 11 microGal is obtained which leads to a relative deviation of 16 microGal between stations, with data averaging reducing the standard error to 2 to 3 microGal. The largest gravity variations observed are found to correlate with nearby well water variations and smoothed rainfall levels, indicating the importance of ground water variations to gravity measurements. The largest earthquake to occur during the survey, which extended to April, 1979, is found to be accompanied in the station closest to the earthquake by the largest measured gravity changes that cannot be related to factors other than tectonic distortion.

Whitcomb, J. H.; Franzen, W. O.; Given, J. W.; Pechmann, J. C.; Ruff, L. J.

1980-01-01

338

46 CFR 182.530 - Bilge high level alarms.  

Code of Federal Regulations, 2013 CFR

...constructed of wood must, in addition to paragraph (a), provide bilge level alarms in all watertight compartments except small buoyancy chambers. (c) A visual indicator must be provided at the operating station to indicate when any automatic bilge pump...

2013-10-01

339

Low Copper and High Manganese Levels in Prion Protein Plaques  

PubMed Central

Accumulation of aggregates rich in an abnormally folded form of the prion protein characterize the neurodegeneration caused by transmissible spongiform encephalopathies (TSEs). The molecular triggers of plaque formation and neurodegeneration remain unknown, but analyses of TSE-infected brain homogenates and preparations enriched for abnormal prion protein suggest that reduced levels of copper and increased levels of manganese are associated with disease. The objectives of this study were to: (1) assess copper and manganese levels in healthy and TSE-infected Syrian hamster brain homogenates; (2) determine if the distribution of these metals can be mapped in TSE-infected brain tissue using X-ray photoelectron emission microscopy (X-PEEM) with synchrotron radiation; and (3) use X-PEEM to assess the relative amounts of copper and manganese in prion plaques in situ. In agreement with studies of other TSEs and species, we found reduced brain levels of copper and increased levels of manganese associated with disease in our hamster model. We also found that the in situ levels of these metals in brainstem were sufficient to image by X-PEEM. Using immunolabeled prion plaques in directly adjacent tissue sections to identify regions to image by X-PEEM, we found a statistically significant relationship of copper-manganese dysregulation in prion plaques: copper was depleted whereas manganese was enriched. These data provide evidence for prion plaques altering local transition metal distribution in the TSE-infected central nervous system. PMID:23435237

Johnson, Christopher J.; Gilbert, P.U.P.A.; Abrecht, Mike; Baldwin, Katherine L.; Russell, Robin E.; Pedersen, Joel A.; Aiken, Judd M.; McKenzie, Debbie

2013-01-01

340

NEAR Views the Asteroid Eros (Gravity Slope)  

NSDL National Science Digital Library

Views of the asteroid Eros generated by data from the laser rangefinder. This false color image shows the gravity slope at various regions on the object. The gravity slope is the angle between the local gravitation field (computed assuming a constant density for the asteroid) and the normal to the surface. Blue is low slope, red is high slope.

Shirah, Greg; Bridgman, Tom; Newcombe, Marte; Smith, David; Zuber, Maria

2001-01-29

341

Improved Airborne Gravity Results Using New Relative Gravity Sensor Technology  

NASA Astrophysics Data System (ADS)

Airborne gravity data has contributed greatly to our knowledge of subsurface geophysics particularly in rugged and otherwise inaccessible areas such as Antarctica. Reliable high quality GPS data has renewed interest in improving the accuracy of airborne gravity systems and recent improvements in the electronic control of the sensor have increased the accuracy and ability of the classic Lacoste and Romberg zero length spring gravity meters to operate in turbulent air conditions. Lacoste and Romberg type gravity meters provide increased sensitivity over other relative gravity meters by utilizing a mass attached to a horizontal beam which is balanced by a ';zero length spring'. This type of dynamic gravity sensor is capable of measuring gravity changes on the order of 0.05 milliGals in laboratory conditions but more commonly 0.7 to 1 milliGal in survey use. The sensor may have errors induced by the electronics used to read the beam position as well as noise induced by unwanted accelerations, commonly turbulence, which moves the beam away from its ideal balance position otherwise known as the reading line. The sensor relies on a measuring screw controlled by a computer which attempts to bring the beam back to the reading line position. The beam is also heavily damped so that it does not react to most unwanted high frequency accelerations. However this heavily damped system is slow to react, particularly in turns where there are very high Eotvos effects. New sensor technology utilizes magnetic damping of the beam coupled with an active feedback system which acts to effectively keep the beam locked at the reading line position. The feedback system operates over the entire range of the system so there is now no requirement for a measuring screw. The feedback system operates at very high speed so that even large turbulent events have minimal impact on data quality and very little, if any, survey line data is lost because of large beam displacement errors. Airborne testing along with results from ground based van testing and laboratory results have shown that the new sensor provides more consistent gravity data, as measured by repeated line surveys, as well as preserving the inherent sensitivity of the Lacoste and Romberg zero length spring design. The sensor also provides reliability during survey operation as there is no mechanical counter screw. Results will be presented which show the advantages of the new sensor system over the current technology in both data quality and survey productivity. Applications include high resolution geoid mapping, crustal structure investigations and resource mapping of minerals, oil and gas.

Brady, N.

2013-12-01

342

Granular convection and the Brazil nut effect in reduced gravity.  

PubMed

We present laboratory experiments of a vertically vibrated granular medium consisting of 1-mm-diameter glass beads with embedded 8-mm-diameter intruder glass beads. The experiments were performed in the laboratory as well as in a parabolic flight under reduced-gravity conditions (on Martian and Lunar gravity levels). We measured the mean rise velocity of the large glass beads and present its dependence on the fill height of the sample containers, the excitation acceleration, and the ambient gravity level. We find that the rise velocity scales in the same manner for all three gravity regimes and roughly linearly with gravity. PMID:23679551

Güttler, Carsten; von Borstel, Ingo; Schräpler, Rainer; Blum, Jürgen

2013-04-01

343

Synthesis of regional crust and upper-mantle structure from seismic and gravity data  

NASA Technical Reports Server (NTRS)

Available seismic and ground based gravity data are combined to infer the three dimensional crust and upper mantle structure in selected regions. This synthesis and interpretation proceeds from large-scale average models suitable for early comparison with high-altitude satellite potential field data to more detailed delineation of structural boundaries and other variations that may be significant in natural resource assessment. Seismic and ground based gravity data are the primary focal point, but other relevant information (e.g. magnetic field, heat flow, Landsat imagery, geodetic leveling, and natural resources maps) is used to constrain the structure inferred and to assist in defining structural domains and boundaries. The seismic data consists of regional refraction lines, limited reflection coverage, surface wave dispersion, teleseismic P and S wave delay times, anelastic absorption, and regional seismicity patterns. The gravity data base consists of available point gravity determinations for the areas considered.

Alexander, S. S.; Lavin, P. M.

1979-01-01

344

Functional assessment of high level ice-dancing.  

PubMed

In these studies the anthropometric characteristics and some functional characteristics of ice-dancers are analysed. It has been shown that the maximum oxygen uptake is similar to that of classical ballet dancers. Tests effected on the ice revealed a high production of lactate, the involvement of the anaerobic metabolism, and high heart rates. It is concluded that the high production of lactate during the free dance on ice is due to the isometric muscular contraction, necessary to maintain certain positions. PMID:2593659

Roi, G S; Mevio, M; Occhi, G; Gemma, S; Facchini, R

1989-06-01

345

Transient increase in the levels of gamma-tubulin complex in reorientation of cortical microtubules by gravity in azuki bean epicotyls  

NASA Astrophysics Data System (ADS)

Azuki bean (Vigna angularis Ohwi et Ohashi) seedlings were exposed to centrifugal hypergravity, and the changes in the orientation of cortical microtubules and the expression of genes cording ?-tubulin complex (VaTUBG and VaSpc98p) were examined. By 300 g treatment, the percentage of cells with transverse microtubules was decreased, while that with longitudinal microtubules was increased in epicotyls. Hypergravity increased the expression of VaTUBG and VaSpc98p transiently. Also, the expression of both genes was increased transiently by removal of hypergravity stimulus. Lanthanum and gadolinium ions, potential blockers of mechanosensitive calcium ion-permeable channels (mechanoreceptors), nullified reorientation of microtubules as well as up-regulation of expression of VaTUBG and VaSpc98p by hypergravity. These results suggest that mechanoreceptors on the plasma membrane may perceive the gravity signal, which leads to reorientation of cortical microtubules by transiently stimulating the formation of ?-tubulin complex.

Soga, Kouichi; Kotake, Toshihisa; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

346

Quantum Physics Einstein's Gravity  

E-print Network

Quantum Physics confronts Einstein's Gravity Matt Visser Physics Department Washington University Saint Louis USA Science Saturdays 13 October 2001 #12; Quantum Physics confronts Einstein's Gravity Abstract: The search for an overall master theory that is compatible both with quantum physics

Visser, Matt

347

Structure and State of Stress of the Chilean Subduction Zone from Terrestrial and Satellite-Derived Gravity and Gravity Gradient Data  

NASA Astrophysics Data System (ADS)

It is well known that the quality of gravity modelling of the Earth's lithosphere is heavily dependent on the limited number of available terrestrial gravity data. More recently, however, interest has grown within the geoscientific community to utilise the homogeneously measured satellite gravity and gravity gradient data for lithospheric scale modelling. Here, we present an interdisciplinary approach to determine the state of stress and rate of deformation in the Central Andean subduction system. We employed gravity data from terrestrial, satellite-based and combined sources using multiple methods to constrain stress, strain and gravitational potential energy (GPE). Well-constrained 3D density models, which were partly optimised using the combined regional gravity model IMOSAGA01C (Hosse et al. in Surv Geophys, 2014, this issue), were used as bases for the computation of stress anomalies on the top of the subducting oceanic Nazca plate and GPE relative to the base of the lithosphere. The geometries and physical parameters of the 3D density models were used for the computation of stresses and uplift rates in the dynamic modelling. The stress distributions, as derived from the static and dynamic modelling, reveal distinct positive anomalies of up to 80 MPa along the coastal Jurassic batholith belt. The anomalies correlate well with major seismicity in the shallow parts of the subduction system. Moreover, the pattern of stress distributions in the Andean convergent zone varies both along the north-south and west-east directions, suggesting that the continental fore-arc is highly segmented. Estimates of GPE show that the high Central Andes might be in a state of horizontal deviatoric tension. Models of gravity gradients from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite mission were used to compute Bouguer-like gradient anomalies at 8 km above sea level. The analysis suggests that data from GOCE add significant value to the interpretation of lithospheric structures, given that the appropriate topographic correction is applied.

Gutknecht, B. D.; Götze, H.-J.; Jahr, T.; Jentzsch, G.; Mahatsente, R.; Zeumann, St.

2014-11-01

348

Structure and State of Stress of the Chilean Subduction Zone from Terrestrial and Satellite-Derived Gravity and Gravity Gradient Data  

NASA Astrophysics Data System (ADS)

It is well known that the quality of gravity modelling of the Earth's lithosphere is heavily dependent on the limited number of available terrestrial gravity data. More recently, however, interest has grown within the geoscientific community to utilise the homogeneously measured satellite gravity and gravity gradient data for lithospheric scale modelling. Here, we present an interdisciplinary approach to determine the state of stress and rate of deformation in the Central Andean subduction system. We employed gravity data from terrestrial, satellite-based and combined sources using multiple methods to constrain stress, strain and gravitational potential energy (GPE). Well-constrained 3D density models, which were partly optimised using the combined regional gravity model IMOSAGA01C (Hosse et al. in Surv Geophys, 2014, this issue), were used as bases for the computation of stress anomalies on the top of the subducting oceanic Nazca plate and GPE relative to the base of the lithosphere. The geometries and physical parameters of the 3D density models were used for the computation of stresses and uplift rates in the dynamic modelling. The stress distributions, as derived from the static and dynamic modelling, reveal distinct positive anomalies of up to 80 MPa along the coastal Jurassic batholith belt. The anomalies correlate well with major seismicity in the shallow parts of the subduction system. Moreover, the pattern of stress distributions in the Andean convergent zone varies both along the north-south and west-east directions, suggesting that the continental fore-arc is highly segmented. Estimates of GPE show that the high Central Andes might be in a state of horizontal deviatoric tension. Models of gravity gradients from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite mission were used to compute Bouguer-like gradient anomalies at 8 km above sea level. The analysis suggests that data from GOCE add significant value to the interpretation of lithospheric structures, given that the appropriate topographic correction is applied.

Gutknecht, B. D.; Götze, H.-J.; Jahr, T.; Jentzsch, G.; Mahatsente, R.; Zeumann, St.

2014-07-01

349

Low gravity solidification structures in the tin-15 wt pct lead and tin-3 wt pct bismuth alloys  

NASA Technical Reports Server (NTRS)

The tin-15 wt pct lead and tin-3 wt pct bismuth alloys have been solidified in the low-gravity environment provided by the Space Processing Applications Rocket (SPAR), on the KC-135 airplane, and at high 'g' levels in a centrifuge furnace. In each case the resultant cast structure was significantly different from that obtained in ground based experiments. Earlier low-gravity studies with the metal-model system NH4Cl-H2O presaged these results. This paper presents and discusses the influence of changes in the gravity force on the grain structure of these materials.

Johnston, M. H.; Parr, R. A.

1982-01-01

350

Superconductors as very high-speed system-level interconnects  

Microsoft Academic Search

The anticipated propagation characteristics at 77 K of superconducting transmission lines using the new high critical temperature superconductor Ba-Y-Cu-O are calculated and compared with propagation characteristics at 77 K and 300 K of normal aluminum interconnects. The major advantages of superconducting interconnections are: 1) packing density can be increased without incurring the penalties of high loss associated with very dense

O. K. Kwon; B. W. Langley; R. F. W. Pease; M. R. Beasley

1987-01-01

351

Eating Disorder Prevention: An Experimental Comparison of High Level Dissonance, Low Level Dissonance, and No-Treatment Control  

Microsoft Academic Search

The purpose of this experiment was to provide an empirical comparison of two dissonance-based eating disorder prevention paradigms and a no-treatment control condition. Asymptomatic and symptomatic participants (N = 155) were randomly assigned to one of three experimental conditions: high level dissonance, low level dissonance, or no-treatment control. Group × symptomatic status interactions, main effects, and pairwise comparisons were examined

Melinda Green; Norman Scott; Irina Diyankova; Courtney Gasser

2005-01-01

352

Supplementation Levels of Concentrate Containing High Levels of Cassava Chip on Rumen Ecology and Microbial Protein Synthesis in Cattle  

Microsoft Academic Search

The object of this study was to determine the influence of supplementation of level concentrate containing high levels of cassava chip on rumen ecology, microbial protein synthesis in cattle. Four, rumen fistulated cattle with initial body weight of 400 ± 10kg were randomly assigned according to a 4 x 4 Latin square design. The dietary treatments were concentrate cassava chip

2006-01-01

353

Artifacts in regional gravity representations with spherical radial basis functions  

NASA Astrophysics Data System (ADS)

With the increasing number of high-resolution gravity observations, which became available in the recent years, global Earth gravity models can be regionally refined. While global gravity models are usually represented in spherical harmonic basis functions with global support, a very promising option to model the regional refinements is the use of spherical radial basis functions with quasi-compact support. These functions are not necessarily orthogonal on a sphere, and usually, more functions are used in regional modelling than minimally needed from a global point of view. This makes the modelling more difficult. Furthermore, no techniques or choices of radial basis functions and other parameters in the regional modelling approach are established so far, as it is the case for global gravity modelling in spherical harmonics. In this article, a closed-loop simulation is used to investigate the mathematical modelling accuracy of different radial basis functions, which are compared to each other. Furthermore, artificial effects, which occur in the modelling results with very low levels of noise on the observations, are investigated. The whole study is performed on synthetic observations of a residual gravitational potential signal for the Himalaya area with different levels of noise. Spherical radial basis functions are a compromise between spatial and frequency localization, which are mutually exclusive. We show that spatial localization properties are even more important than frequency localization in the regional case, even though a band-limited signal is modeled.

Bentel, K.; Schmidt, M.; Rolstad Denby, C.

2013-09-01

354

Radiating Instabilities of Internal Inertio-gravity Waves  

NASA Astrophysics Data System (ADS)

The vertical radiation of local convective and shear instabilities of internal inertio- gravity waves is examined within linear stability theory. A steady, plane-parallel Boussinesq flow with vertical profiles of horizontal velocity and static stability re- sembling an internal inertio-gravity wave packet without mean vertical shear is used as dynamical framework. The influence of primary-wave frequency and amplitude as well as orientation and horizontal wavenumber of the instability on vertical radi- ation is discussed. Considerable radiation occurs at small to intermediate instability wavenumbers for basic state gravity waves with high to intermediate frequencies and moderately convectively supercritical amplitudes. Radiation is then strongest when the horizontal wavevector of the instability is aligned parallel to the horizontal wavevector of the basic state gravity wave. These radiating modes are essentially formed by shear instability. Modes of convective instability, that occur at large instability wavenum- bers or strongly convectively supercritical amplitudes, as well as modes at convec- tively subcritical amplitudes are nonradiating, trapped in the region of instability. The radiation of an instability is found to be related to the existence of critical levels, a radiating mode being characterized by the absence of critical levels outside the region of instability of the primary wave.

Kwasniok, F.; Schmitz, G.

355

The GRAVITY metrology system: modeling a metrology in optical fibers  

E-print Network

GRAVITY is the second generation VLT Interferometer (VLTI) instrument for high-precision narrow-angle astrometry and phase-referenced interferometric imaging. The laser metrology system of GRAVITY is at the heart of its astrometric mode, which must measure the distance of 2 stars with a precision of 10 micro-arcseconds. This means the metrology has to measure the optical path difference between the two beam combiners of GRAVITY to a level of 5 nm. The metrology design presents some non-common paths that have consequently to be stable at a level of 1 nm. Otherwise they would impact the performance of GRAVITY. The various tests we made in the past on the prototype give us hints on the components responsible for this error, and on their respective contribution to the total error. It is however difficult to assess their exact origin from only OPD measurements, and therefore, to propose a solution to this problem. In this paper, we present the results of a semi-empirical modeling of the fibered metrology system, r...

Blind, N; Eisenhauer, F; Weber, J; Gillessen, S; Lippa, M; Burtscher, L; Hans, O; Haug, M; Haussmann, F; Huber, S; Janssen, A; Kellner, S; Kok, Y; Ott, T; Pfuhl, O; Sturm, E; Wieprecht, E; Amorim, A; Brandner, W; Perrin, G; Perraut, K; Straubmeier, C

2014-01-01

356

Radon action level for high-rise buildings  

Microsoft Academic Search

Radon and its progeny are the major contributors to the natural radiation dose received by human beings. Many countries and radiological authorities have recommended radon action levels to limit the indoor radon concentrations, and, hence, the annual doses to the general public. Since the sources of indoor radon and the methods for reducing its concentration are different for different types

J. K. C. Leung; M. Y. W. Tso; C. W. Ho

1999-01-01

357

High reliability second level interconnects using polymer core BGAs  

Microsoft Academic Search

The growing need for shorter interconnects for better electrical performance has shifted package designs more and more towards ball grid arrays (PGAs). This has brought into focus the requirement for a reliable second level interconnect. Due to the thermal mismatch between the package material (e.g. ceramic) and the PWB board the solder interconnects are prone to failure during temperature excursions.

S. Movva; G. Aguirre

2004-01-01

358

UNCORRECTEDPROOF High levels of genetic structuring as a result  

E-print Network

levels of deforestation have led to the fragmentation of many natural popu- lations of plant and animal extinctions, are only now starting to become apparent. Whilst not as obviously apparent, the genetic effects the population less able to adapt to changes in its environment, increasing the risk of extinction (Keller

Provan, Jim

359

Assessment of Career Skills at the High School Level.  

ERIC Educational Resources Information Center

Administered an instrument containing self-evaluation and development, career-awareness, career decision-making, employment-seeking, and work-effectiveness items to 939 grade 12 students. The results indicated that females obtained significantly higher mean scores than males; Advanced Level students obtained significantly higher mean scores than…

Khan, Sar B.; Alvi, Sabir A.

1984-01-01

360

Airborne Gravity Gradiometry Resolves a Full Range of Gravity Frequencies  

Microsoft Academic Search

Airborne Full Tensor Gradiometry (Air\\\\-FTGR) was flown at high altitude coincident with Airborne Gravity (AG) flown in 2003 in West Arnhem Land, Australia. A preliminary analysis of two data sets indicates that the Air\\\\-FTGR system has the capability of resolving intermediate to long wavelengths features that may be associated with relatively deeper geological structures. A comparison of frequency filtered slices

J. Mataragio; J. Brewster; J. Mims

2007-01-01

361

78 FR 14840 - U.S.-EU High Level Regulatory Cooperation Forum-Stakeholder Session  

Federal Register 2010, 2011, 2012, 2013

...OFFICE OF MANAGEMENT AND BUDGET U.S.-EU High Level Regulatory Cooperation...AGENCY: Office of Management and Budget. ACTION...and the Office of Management and Budget (OMB...U.S.-EU High Level Regulatory...

2013-03-07

362

Model studies of time-dependent ducting for high-frequency gravity waves and associated airglow responses in the upper atmosphere  

Microsoft Academic Search

This doctoral dissertation has mainly concentrated on modeling studies of shorter period acoustic-gravity waves propagating in the upper atmosphere. Several cases have been investigated in the literature, which are focusing on the propagation characteristics of highfrequency gravity wave packets. The dissertation consists of five main divisions of which each has its own significance to be addressed, and these five chapters

Yonghui Yu

2007-01-01

363

Gravity, light and plant form  

NASA Technical Reports Server (NTRS)

Plants have evolved highly sensitive and selective mechanisms that detect and respond to various aspects of their environment. As a plant develops, it integrates the environmental information perceived by all of its sensory systems and adapts its growth to the prevailing environmental conditions. Light is of critical importance because plants depend on it for energy and, thus, survival. The quantity, quality and direction of light are perceived by several different photosensory systems that together regulate nearly all stages of plant development, presumably in order to maintain photosynthetic efficiency. Gravity provides an almost constant stimulus that is the source of critical spatial information about its surroundings and provides important cues for orientating plant growth. Gravity plays a particularly important role during the early stages of seedling growth by stimulating a negative gravitropic response in the primary shoot that orientates it towards the source of light, and a positive gravitropic response in the primary root that causes it to grow down into the soil, providing support and nutrient acquisition. Gravity also influences plant form during later stages of development through its effect on lateral organs and supporting structures. Thus, the final form of a plant depends on the cumulative effects of light, gravity and other environmental sensory inputs on endogenous developmental programs. This article is focused on developmental interactions modulated by light and gravity.

Hangarter, R. P.

1997-01-01

364

Dual-level parallelism for high-order CFD methods  

E-print Network

high-order methods and implemented in the spectral/hp element framework to take advantage ..... in a shared table, which can be referenced based on thread IDs. .... Periodic conditions are imposed in the homogeneous direction. The initial

2004-01-02

365

Wafer level reliability for high-performance VLSI design  

NASA Technical Reports Server (NTRS)

As very large scale integration architecture requires higher package density, reliability of these devices has approached a critical level. Previous processing techniques allowed a large window for varying reliability. However, as scaling and higher current densities push reliability to its limit, tighter control and instant feedback becomes critical. Several test structures developed to monitor reliability at the wafer level are described. For example, a test structure was developed to monitor metal integrity in seconds as opposed to weeks or months for conventional testing. Another structure monitors mobile ion contamination at critical steps in the process. Thus the reliability jeopardy can be assessed during fabrication preventing defective devices from ever being placed in the field. Most importantly, the reliability can be assessed on each wafer as opposed to an occasional sample.

Root, Bryan J.; Seefeldt, James D.

1987-01-01

366

Corrosion issues in high-level nuclear waste containers  

NASA Astrophysics Data System (ADS)

In this dissertation different aspects of corrosion and electrochemistry of copper, candidate canister material in Scandinavian high-level nuclear waste disposal program, including the thermodynamics and kinetics of the reactions that are predicted to occur in the practical system have been studied. A comprehensive thermodynamic study of copper in contact with granitic groundwater of the type and composition that is expected in the Forsmark repository in Sweden has been performed. Our primary objective was to ascertain whether copper would exist in the thermodynamically immune state in the repository, in which case corrosion could not occur and the issue of corrosion in the assessment of the storage technology would be moot. In spite of the fact that metallic copper has been found to exist for geological times in granitic geological formations, copper is well-known to be activated from the immune state to corrode by specific species that may exist in the environment. The principal activator of copper is known to be sulfur in its various forms, including sulfide (H2S, HS-, S2-), polysulfide (H2Sx, HSx -, Sx 2-), poly sulfur thiosulfate ( SxO3 2-), and polythionates (SxO6 2-). A comprehensive study of this aspect of copper chemistry has never been reported, and yet an understanding of this issue is vital for assessing whether copper is a suitable material for fabricating canisters for the disposal of HLNW. Our study identifies and explores those species that activate copper; these species include sulfur-containing entities as well as other, non-sulfur species that may be present in the repository. The effects of temperature, solution pH, and hydrogen pressure on the kinetics of the hydrogen electrode reaction (HER) on copper in borate buffer solution have been studied by means of steady-state polarization measurements, including electrochemical impedance spectroscopy (EIS). In order to obtain electrokinetic parameters, such as the exchange current density and the cathodic Tafel slope, two stages of optimization have been performed. From the optimization process, the activation energy (Eac) of the HER on copper was obtained as ?32 kJ mol-1. Moreover, the mechanism of the hydrogen evolution reaction (HER) on copper in mildly alkaline media has been studied by means of EIS over the frequency range of 0.01 Hz ? f ? 5 kHz. The impedance spectra were modeled using a mechanism based upon the Volmer-Heyrovsky-Tafel steps for hydrogen evolution and by considering the reactions involved in hydrogen atom and hydroxyl group adsorption on the copper surface. A single set of kinetic parameters, including the rate constants and transfer coefficient, have been derived for each pH by optimization of the mechanistic model on the experimental impedance (EIS) data. It is postulated that the HER proceeds through the Volmer-Heyrovsky-Tafel mechanism with the Volmer reaction being the rate-determining step. The kinetics of growth of the passive sulfide film on copper in deaerated aqueous sodium chloride solution as a function of applied potential, sulfide species concentrations and temperature were explored by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The electronic and compositional properties of the passive layer were investigated with Mott-Schottky analysis and X-ray photoelectron spectroscopy (XPS). It is found that metal vacancies are predominant defects in the barrier layer which is in agreement with the p-type character of the film observed experimentally. A point defect model (PDM) for formation and dissolution of the passive sulfide film on copper is proposed. Finally, the behavior of the system interpreted in terms of reaction mechanisms and kinetic parameters extracted from the experimental impedance data by mathematical optimization using a genetic algorithm approach. The diffusion coefficient of cation vacancies is obtained directly from optimization of the proposed model onto the EIS experimental data and was found to be essentially independent from the applied potential within th

Asl, Samin Sharifi

367

HighLevel Perception, Representation, and Analogy: A Critique of Artificial Intelligence Methodology  

E-print Network

High­Level Perception, Representation, and Analogy: A Critique of Artificial Intelligence of Experimental and Theoretical Artificial Intelligence. #12; High­Level Perception, Representation, and Analogy: A Critique of Artificial Intelligence Methodology Abstract High­level perception---the process of making

Indiana University

368

A Network of Superconducting Gravimeters Detects Submicrogal Coseismic Gravity Changes  

Microsoft Academic Search

With high-resolution continuous gravity recordings from a regional network of superconducting gravimeters, we have detected permanent changes in gravity acceleration associated with a recent large earthquake. Detected changes in gravity acceleration are smaller than 10-8 meters seconds-2 (1 micro-Galileo, about 10-9 times the surface gravity acceleration) and agree with theoretical values calculated from a dislocation model. Superconducting gravimetry can contribute

Yuichi Imanishi; Tadahiro Sato; Toshihiro Higashi; Wenke Sun; Shuhei Okubo

2004-01-01

369

Absolute-gravity stations in Western Dronning Maud Land, Antarctica  

NASA Astrophysics Data System (ADS)

Absolute-gravity stations are an important part of the geodetic infrastructure of the Antarctic. They provide accurate starting values for gravity surveys performed e.g. for the determination of the geoid, for geological studies and for geophysical investigations. The time variation in gravity determined from repeated absolute-gravity measurements provides insights into the Glacial Isostatic Adjustment (GIA) and into solid Earth deformation due to variation in contemporary ice load. Given sufficient joint coverage with International Terrestrial Reference Frame (ITRF) sites, gravity rates in high latitudes could in principle provide an independent check of the geocentricity of the z-dot (velocities in the direction of the rotation axis of the Earth) of the ITRF. We review the absolute gravity stations in Western and Central Dronning Maud Land. The oldest station is at the Finnish base Aboa, with 5 measurements by the Finnish Geodetic Institute (FGI) starting with the FINNARP 1993 expedition. Measurements at Maitri (India) and Novolazarevskaya (Russia) were first performed in 2004 by the National Geophysical Research Institute (NGRI) of India, and by the FGI, respectively. In the season 2010/11 a new station was constructed at Troll (Norway). In the season 2011/12 the aforementioned four sites were occupied by the FG5-221 absolute gravimeter of the FGI. At Sanae IV (South Africa) there are previous occupations by the FG5-221, in 2003/4 and 2005/6. All these bases have continuous GNSS stations. Numerous supporting measurements have been made at the sites: microgravity networks, levelling and GNSS ties to excentres etc., for controlling the stability of the stations. At some sites, nearby glacier elevations were surveyed to monitor the attraction of the variable close-field snow and ice masses. We give a description of the sites and the measurements performed at them. The work has benefited from the co-operation in the COST Action ES0701 "Improved Constraints on Models of GIA".

Mäkinen, Jaakko; Rasindra, Ravik; Chand, Uttam; Tiwari, Virendra; Lukin, Valery; Anisimov, Michail; Melvaer, Yngve; Melland, Gudmund; Koivula, Hannu; Näränen, Jyri; Poutanen, Markku

2013-04-01

370

Bit-Level Allocation for Low Power in Behavioural High-Level Synthesis  

Microsoft Academic Search

\\u000a An allocation algorithm at the bit-level specially suited for data dominated applications is presented. In addition to classical\\u000a low power methods, it implements novel design strategies to reduce power consumption. These new features consist of the successive\\u000a transformation of specification operations until a circuit implementation with minimum power consumption in functional and\\u000a storage units is obtained. Thus, some of the

María C. Molina; Rafael Ruiz-sautua; José M. Mendías; Román Hermida

2003-01-01

371

A High School Level Course On Robot Design And Construction  

NASA Astrophysics Data System (ADS)

The Robotics Design and Construction Class at Sehome High School was developed to offer gifted and/or highly motivated students an in-depth introduction to a modern engineering topic. The course includes instruction in basic electronics, digital and radio electronics, construction skills, robotics literacy, construction of the HERO 1 Heathkit Robot, computer/ robot programming, and voice synthesis. A key element which leads to the success of the course is the involvement of various community assets including manpower and financial assistance. The instructors included a physics/electronics teacher, a computer science teacher, two retired engineers, and an electronics technician.

Sadler, Paul M.; Crandall, Jack L.

1984-02-01

372

Computational modeling of high-level cognition and brain function.  

PubMed

This article describes a computational modeling architecture, 4CAPS, which is consistent with key properties of cortical function and makes good contact with functional neuroimaging results. Like earlier cognitive models such as SOAR, ACT-R, 3CAPS, and EPIC, the proposed cognitive model is implemented in a computer simulation that predicts observable variables such as human response times and error patterns. In addition, the proposed 4CAPS model accounts for the functional decomposition of the cognitive system and predicts fMRI activation levels and their localization within specific cortical regions, by incorporating key properties of cortical function into the design of the modeling system. PMID:10524604

Just, M A; Carpenter, P A; Varma, S

1999-01-01

373

High-temperature heat capacity and density of simulated high-level waste glass  

NASA Astrophysics Data System (ADS)

The heat capacities of two simulated high-level waste borosilicate glasses and glass melts have been determined from differential scanning calorimetry and drop-calorimetry measurements between 345 K and 1673 K. The densities of the glass melts have been measured by double-bob Archimedean method between 1273 K and 1573 K. The volume expansivity between glass transition temperature and 1573 K has been determined by combining the measured densities and density of supercooled melts below 1273 K reported previously. Both of the heat capacity and the volume expansivity of the simulated high-level waste glass melts are characterized by a large increase at the glass transition temperature and the rapid decrease with increasing temperature. The configurational contributions to the heat capacity and the volume expansivity at the glass transition temperature are 35% and 88%, respectively. The significant change of the heat capacity is probably attributed to temperature dependence of chemical mixing of boron, aluminum and silicon in the tetrahedral sites, while the change of the volume expansivity is caused by temperature-induced coordination change of boron.

Sugawara, Toru; Katsuki, Junki; Shiono, Takashi; Yoshida, Satoshi; Matsuoka, Jun; Minami, Kazuhiro; Ochi, Eiji

2014-11-01

374

Trends in high sea levels of German North Sea gauges compared to regional mean sea level changes  

NASA Astrophysics Data System (ADS)

The impacts of rising mean sea levels will be felt most acutely during periods of extreme high sea levels which are caused by the combination of mean sea level, tides and storm surges. In this paper, we examine sea level records from six tide gauges along the German North Sea coastline to determine if changes in high sea levels observed throughout the 20th century and early 21st century were primarily driven by increases in mean sea level (i.e. like what has been observed by other authors in most parts of the world) or whether other factors, such as changes in ocean tides or storm surges also contributed significantly to observed changes in high water in this region. Time-series of annual 80th, 85th, 90th, 95th, 99th, and 99.9th percentiles are derived from the sea level records and trends are assessed using linear regression for the entire time periods for which datasets are available at each site and for the common period from 1953 to 2008. The percentile time-series are subsequently reduced relative to mean sea level and a second set of trends are estimated. At all sites and percentile levels, significant positive trends are evident for the observed sea level data. Once the percentile time-series are reduced relative to mean sea level the remaining trends are still significant at the 1?-confidence level, with the exception of the 99.9th percentiles since the standard errors are large. Using a non-linear trend analysis, on the long Cuxhaven record, we find that prior to the mid-1950s and from about 1990 onwards, changes in high sea levels were not different from mean sea level changes. However, from the mid-1950s to 1990 changes were significantly different from those observed in mean sea level. Possible reasons for this appear to be due to changes in the amplitudes of several main tidal constituents, which are apparent since the mid-1950s and decadal variability in the storm activity (with strong westerly winds in the North Atlantic region from 1960 to the 1990s).

Mudersbach, Christoph; Wahl, Thomas; Haigh, Ivan D.; Jensen, Jürgen

2013-08-01

375

Work Exploration At The Junior-High Level  

ERIC Educational Resources Information Center

The New Horizons Project provides 300 Des Moines inter-city junior high school students, who possess skills but are not making satisfactory academic progress, with work-study, extra guidance, and individual attention in an effort to increase their chance of vocational, social, civic and academic success. (Author/JG)

Devin, Paul

1969-01-01

376

ZERO-VALENT IRON FOR HIGH-LEVEL ARSENITE REMOVAL  

EPA Science Inventory

This study conducted by flow through column systems was aimed at investigating the feasibility of using zero-valent iron for arsenic remediation in groundwater. A high concentration arsenic solution (50 mg l-1) was prepared by using sodium arsenite (arsenic (III)) to simulate gr...

377

Low-power ring counter drives high-level loads  

NASA Technical Reports Server (NTRS)

Ring counter dissipates very low power in standby conditions, yet drives high-current loads on a low duty-factor basis. Complementary transistors are used so that in one selected stage both transistors are conducting while the transistors of the other stage are cut off.

1966-01-01

378

Vitrification of High-Level Alumina Nuclear Waste.  

National Technical Information Service (NTIS)

Borosilicate and borophosphate glass compositions have been developed to vitrify simulated high-alumina calcined nuclear defense waste. The effects of the alkali (Li sub 2 O,Na sub 2 O) to borate ratio and the Li sub 2 O to Na sub 2 O ratio on the glass m...

J. R. Brotzman

1980-01-01

379

Project Water Science. General Science High School Level.  

ERIC Educational Resources Information Center

This teacher's guide presents 12 hands-on laboratory activities for high school science classes that cover the environmental issue of water resources in California. The activities are separated into three sections. Five activities in the section on water quality address the topics of groundwater, water hardness, bottled water, water purity, and…

Water Education Foundation, Sacramento, CA.

380

CREATIVE THINKING IN CHILDREN AT THE JUNIOR HIGH SCHOOL LEVELS.  

ERIC Educational Resources Information Center

THIS PROJECT INVESTIGATED THE FACTORS OF "DIVERGENT PRODUCTIVE THINKING" WHICH CONTRIBUTE MOST TO CREATIVE BEHAVIOR. TWO JUNIOR HIGH SCHOOLS WERE INVOLVED. ONE WAS RELATIVELY LARGE, IN A MODERATE-INCOME AREA. THE OTHER WAS SMALLER, AND WAS SITUATED IN A PROFESSIONAL COMMUNITY. IN THE SMALLER SCHOOL SOME 220 STUDENTS WERE TESTED IN TWO 3-HOUR…

GUILFORD, J.P.; AND OTHERS

381

How much gravity is needed to establish the perceptual upright?  

PubMed

Might the gravity levels found on other planets and on the moon be sufficient to provide an adequate perception of upright for astronauts? Can the amount of gravity required be predicted from the physiological threshold for linear acceleration? The perception of upright is determined not only by gravity but also visual information when available and assumptions about the orientation of the body. Here, we used a human centrifuge to simulate gravity levels from zero to earth gravity along the long-axis of the body and measured observers' perception of upright using the Oriented Character Recognition Test (OCHART) with and without visual cues arranged to indicate a direction of gravity that differed from the body's long axis. This procedure allowed us to assess the relative contribution of the added gravity in determining the perceptual upright. Control experiments off the centrifuge allowed us to measure the relative contributions of normal gravity, vision, and body orientation for each participant. We found that the influence of 1 g in determining the perceptual upright did not depend on whether the acceleration was created by lying on the centrifuge or by normal gravity. The 50% threshold for centrifuge-simulated gravity's ability to influence the perceptual upright was at around 0.15 g, close to the level of moon gravity but much higher than the threshold for detecting linear acceleration along the long axis of the body. This observation may partially explain the instability of moonwalkers but is good news for future missions to Mars. PMID:25184481

Harris, Laurence R; Herpers, Rainer; Hofhammer, Thomas; Jenkin, Michael

2014-01-01

382

Effects of high doping levels on silicon solar cell performance  

NASA Technical Reports Server (NTRS)

Open-circuit voltages measured in silicon solar cells made from 0.01 ohm-cm material are 150 mV lower than voltages calculated from simple diffusion theory and cannot be explained by poor diffusion lengths or surface leakage currents. An analytical study was made to determine whether high doping effects, which increase the intrinsic carrier concentration, could account for the low observed voltages and to determine the limits on voltage and efficiency imposed by high doping effects. The results indicate that the observed variation of voltage with base resistivity is predicted by these effects. A maximum efficiency of 19% (AMO) and a voltage of 0.7 volts were calculated for 0.1 ohm-cm cells assuming an optimum diffused layer impurity profile.

Godlewski, M. P.; Brandhorst, H. W., Jr.; Baraona, C. R.

1975-01-01

383

High levels of melatonin generated during the brewing process.  

PubMed

Beer is a beverage consumed worldwide. It is produced from cereals (barley or wheat) and contains a wide array of bioactive phytochemicals and nutraceutical compounds. Specifically, high melatonin concentrations have been found in beer. Beers with high alcohol content are those that present the greatest concentrations of melatonin and vice versa. In this study, gel filtration chromatography and ELISA were combined for melatonin determination. We brewed beer to determine, for the first time, the beer production steps in which melatonin appears. We conclude that the barley, which is malted and ground in the early process, and the yeast, during the second fermentation, are the largest contributors to the enrichment of the beer with melatonin. PMID:23607887

Garcia-Moreno, H; Calvo, J R; Maldonado, M D

2013-08-01

384

Sampling and analyses of SRP high-level waste sludges  

Microsoft Academic Search

Twelve 3-liter samples of high-heat waste sludges were collected from four Savannah River Plant waste tanks with a hydraulically operated sample collector of unique design. Ten of these samples were processed in Savannah River Laboratory shielded cell facilities, yielding 5.3 kg of washed, dried sludge products for waste solidification studies. After initial drying, each batch was washed by settling and

J. A. Stone; J. A. Kelley; T. S. McMillan

1976-01-01

385

High levels of ochratoxin A in licorice and derived products  

Microsoft Academic Search

The ochratoxin A (OTA) content of 30 samples of licorice root and derived products (licorice-confectionery, licorice block, and licorice extract) was analyzed by a standard HPLC-fluorescence technique and confirmed by methyl-ester formation. All analyzed samples of licorice and derived products were found to contain ochratoxin A, and some of them showed extremely high concentrations up to 252.8 ng\\/g of OTA. Highest

A. Ariño; M. Herrera; G. Estopañan; T. Juan

2007-01-01

386

Reflection and Conversion of Magneto-Gravity Waves in the Solar Chromosphere: Windows to the Upper Atmosphere  

E-print Network

The detection of upward propagating internal gravity waves in the Sun's chromosphere has recently been reported by Straus et al., who postulated that these may efficiently couple to Alfven waves in magnetic regions. This may be important in transporting energy to higher levels. Here we explore the propagation, reflection and mode conversion of linear gravity waves in a VAL C atmosphere, and find that even weak magnetic fields usually reflect gravity waves back downward as slow magnetoacoustic waves well before they reach the Alfven/acoustic equipartition height at which mode conversion might occur. However, for certain highly inclined magnetic field orientations in which the gravity waves manage to penetrate near or through the equipartition level, there can be substantial conversion to either or both upgoing Alfven and acoustic waves. Wave energy fluxes comparable to the chromospheric radiative losses are expected.

Newington, Marie

2009-01-01

387

Project MAGNET High-level Vector Survey Data Reduction  

NASA Technical Reports Server (NTRS)

Since 1951, the U.S. Navy, under its Project MAGNET program, has been continuously collecting vector aeromagnetic survey data to support the U.S. Defense Mapping Agency's world magnetic and charting program. During this forty-year period, a variety of survey platforms and instrumentation configurations have been used. The current Project MAGNET survey platform is a Navy Orion RP-3D aircraft which has been specially modified and specially equipped with a redundant suite of navigational positioning, attitude, and magnetic sensors. A review of the survey data collection procedures and calibration and editing techniques applied to the data generated by this suite of instrumentation will be presented. Among the topics covered will be the determination of its parameters from the low-level calibration maneuvers flown over geomagnetic observatories.

Coleman, Rachel J.

1992-01-01

388

Project MAGNET high-level vector survey data reduction  

NASA Astrophysics Data System (ADS)

Since 1951, the U.S. Navy, under its Project MAGNET program, has been continuously collecting vector aeromagnetic survey data to support the U.S. Defense Mapping Agency's world magnetic and charting program. During this forty-year period, a variety of survey platforms and instrumentation configurations have been used. The current Project MAGNET survey platform is a Navy Orion RP-3D aircraft which has been specially modified and specially equipped with a redundant suite of navigational positioning, attitude, and magnetic sensors. A review of the survey data collection procedures and calibration and editing techniques applied to the data generated by this suite of instrumentation will be presented. Among the topics covered will be the determination of its parameters from the low-level calibration maneuvers flown over geomagnetic observatories.

Coleman, Rachel J.

1992-06-01

389

High-speed driving of a two-level system  

NASA Astrophysics Data System (ADS)

A simple result is found for the optimal protocol of drivings for a general two-level Hamiltonian, which transports a given initial state to a given final state in minimal time, under additional conditions on the drivings. If one of the three possible drivings is unconstrained in strength the problem is analytically completely solvable. A surprise arises for a class of states when one driving is bounded by a constant c and the other drivings are constant. Then, for large c, the optimal driving is of type bang-off-bang and for increasing c one recovers the unconstrained result. However, for smaller c the optimal driving can suddenly switch to bang-bang type. It is also shown that for general states one may have a multistep protocol. The present paper explicitly proves and considerably extends the author's results contained in Phys. Rev. Lett. 111, 260501 (2013), 10.1103/PhysRevLett.111.260501.

Hegerfeldt, Gerhard C.

2014-09-01

390

Repeated Assessment by High-Throughput Assay Demonstrates that Sperm DNA Methylation Levels Are Highly Reproducible  

PubMed Central

Objective To assess reliability of high-throughput assay of sperm DNA methylation. Design Observational study comparing DNA methylation of sperm isolated from three divided and twelve longitudinally collected semen samples. Setting Academic Medical Center Patients One man undergoing screening semen analysis during evaluation of the infertile couple and two healthy fertile male volunteers. Interventions Spermatozoa were separated from seminal plasma and somatic cells using gradient separation. DNA was extracted from spermatozoa, and DNA methylation was assessed at 1,505 DNA-sequence specific sites. Main Outcome Measures Repeatability of sperm DNA methylation measures, estimated by correlation coefficients. Results DNA methylation levels were highly correlated within matched sets of divided samples (all r?0.97) and longitudinal samples (average r=0.97). Conclusions The described methodology reliably assesses methylation of sperm DNA at large numbers of sites. Methylation profiles were consistent over time. High-throughput assessment of sperm DNA methylation is a promising tool for studying the role of epigenetic state in male fertility. PMID:22035967

Cortessis, Victoria K.; Siegmund, Kimberly; Houshdaran, Sahar; Laird, Peter W.; Sokol, Rebecca Z.

2011-01-01

391

Extended Gravity  

E-print Network

We shall show equivalence between Palatini-$f(\\calR)$ theories and Brans-Dicke (BD) theories at the level of action principles in generic dimension with generic matter coupling. We do that by introducing the Helmholtz Lagrangian associated to Palatini-$f(\\calR)$ theory and then performing frame transformations in order to recover Einstein frame and Brans-Dicke frame. This clarifies the relation among different formulations and the transformations among different frames. Additionally, it defines a formulation {\\it a l\\'a Palatini} for the Brans-Dicke theory which is dynamically equivalent to metric BD (unlike the standard Palatini-formulation of metric BD theory which are {\\it not} dynamically equivalent). In conclusion we discuss interpretation of extended theories of gravitation and perspectives.

L. Fatibene; S. Garruto

2014-03-27

392

Extended Gravity  

E-print Network

We shall show equivalence between Palatini-$f(\\calR)$ theories and Brans-Dicke (BD) theories at the level of action principles in generic dimension with generic matter coupling. We do that by introducing the Helmholtz Lagrangian associated to Palatini-$f(\\calR)$ theory and then performing frame transformations in order to recover Einstein frame and Brans-Dicke frame. This clarifies the relation among different formulations and the transformations among different frames. Additionally, it defines a formulation {\\it a l\\'a Palatini} for the Brans-Dicke theory which is dynamically equivalent to metric BD (unlike the standard Palatini-formulation of metric BD theory which are {\\it not} dynamically equivalent). In conclusion we discuss interpretation of extended theories of gravitation and perspectives.

Fatibene, L

2014-01-01

393

Noninvasive respiratory management of high level spinal cord injury  

PubMed Central

This article describes noninvasive acute and long-term management of the respiratory muscle paralysis of high spinal cord injury (SCI). This includes full-setting, continuous ventilatory support by noninvasive intermittent positive pressure ventilation (NIV) to support inspiratory muscles and mechanically assisted coughing (MAC) to support inspiratory and expiratory muscles. The NIV and MAC can also be used to extubate or decannulate ‘unweanable’ patients with SCI, to prevent intercurrent respiratory tract infections from developing into pneumonia and acute respiratory failure (ARF), and to eliminate tracheostomy and resort to costly electrophrenic/diaphragm pacing (EPP/DP) for most ventilator users, while permitting glossopharyngeal breathing (GPB) for security in the event of ventilator failure. PMID:22525322

Bach, John R.

2012-01-01

394

High Levels of Carbon Dioxide Threaten Oyster Survival  

NSDL National Science Digital Library

It has been widely reported that the build up of carbon dioxide (CO2) in the air, which is caused by human behavior, will likely lead to climate change and have major implications for life on earth. But less focus has been given to global warmingÃÂs evil twin, ocean acidification, which occurs when CO2 lowers the pH of water bodies, thus making them more acidic. This lesser known phenomenon may have catastrophic effects on all sea life. Inna Sokolova, associate professor of biology at the University of North Carolina at Charlotte, studies the affect of high carbon dioxide on oyster survival, growth and shell hardness. The results of her research suggest that creatures once thought to be fairly adaptable to changes in the environment, may be in serious trouble.

APS Communications Office (American Physiological Society Communications Office)

2010-08-04

395

High level triggers for explosive mafic volcanism: Albano Maar, Italy  

NASA Astrophysics Data System (ADS)

Colli Albani is a quiescent caldera complex located within the Roman Magmatic Province (RMP), Italy. The recent Via dei Laghi phreatomagmatic eruptions led to the formation of nested maars. Albano Maar is the largest and has erupted seven times between ca 69-33 ka. The highly explosive nature of the Albano Maar eruptions is at odds with the predominant relatively mafic (SiO2 = 48-52 wt.%) foiditic (K2O = 9 wt.%) composition of the magma. The deposits have been previously interpreted as phreatomagmatic, however they contain large amounts (up to 30%vol) of deep seated xenoliths, skarns and all pre-volcanic subsurface units. All of the xenoliths have been excavated from depths of up to 6 km, rather than being limited to the depth at which magma and water interaction is likely to have occurred, suggesting an alternative trigger for eruption. High precision geochemical glass and mineral data of fresh juvenile (magmatic) clasts from the small volume explosive deposits indicate that the magmas have evolved along one of two evolutionary paths towards foidite or phonolite. The foiditic melts record ca. 50% mixing between the most primitive magma and Ca-rich melt, late stage prior to eruption. A major result of our study is finding that the generation of Ca-rich melts via assimilation of limestone, may provide storage for significant amounts of CO2 that can be released during a mixing event with silicate magma. Differences in melt evolution are inferred as having been controlled by variations in storage conditions: residence time and magma volume.

Cross, J. K.; Tomlinson, E. L.; Giordano, G.; Smith, V. C.; De Benedetti, A. A.; Roberge, J.; Manning, C. J.; Wulf, S.; Menzies, M. A.

2014-03-01

396

Lunar Scout Two spacecraft gravity experiment  

NASA Technical Reports Server (NTRS)

Measurement of the gravity field of the Moon has a high science priority because of its implications for the internal structure and thermal history of the Moon, and it has a high priority for future exploration activities because of the influence of lunar gravity on spacecraft navigation and orbit maintenance. The current state of knowledge in the lunar gravity field (and the uncertainty in the knowledge) is based primarily on data accumulated from the Lunar Orbiter and Apollo programs. Data are sparse and emphasize the equatorial band (+/- 30 deg) on the near side of the Moon. There are no tracking data on the far side and only the Lunar Orbiter 5 provides a small amount of high inclination data. A host of gravity models developed from different combinations of tracking data have large discrepancies in their predictions of spacecraft motion and orbit lifetimes. There are also large disagreements in the Mercator projections of the gravity acceleration from each model, especially on the far side, where the contours tend to have no obvious relationship with the local topography. The science and engineering requirements for global gravity field mapping will be satisfied with continuous radio metric tracking of Lunar Scout 1 in a low polar orbit using the Deep Space Network and Lunar Scout 2 in a high elliptical orbit. The gravity field of the Moon will be mapped during the Scout Program using a two spacecraft concept. In the two spacecraft concept, one spacecraft is placed in a high altitude eccentric orbit while the second spacecraft is in a low altitude polar orbit. The gravity experiment requires a radio frequency that will permit two-way Doppler tracking between the spacecraft and the Deep Space Network (DSN). Both spacecraft carry NASA standard transponder systems for data transmission to Earth as well as for tracking and orbit determination. Data sufficient to produce a gravity field map could be acquired within one month with this system.

Cheng, Andrew F.

1993-01-01

397

Hyperhomocysteinemia, Insulin Resistance and High HS- CRP Levels in Prehypertension  

PubMed Central

Background: Pre-hypertension refers to blood pressure in the range of 120 to 139 mm of Hg / 80 to 89 mm of Hg and its prevalence is increasing in India. Previous studies have documented the increase in homocysteine, C-reactive protein and insulin resistance and their role in the development of hypertension. In recent years much attention has been focused on subjects with prehypertension, as the risk for development of cardiovascular disease is higher in these subjects compared to those with normal blood pressure. Objectives: To evaluate the serum homocysteine, hs-CRP level and insulin resistance in subjects with prehypertension. Materials and Methods: Sixty prehypertensives and 32 normotensives were recruited according to Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of blood pressure (JNC 7) guidelines. Serum homocysteine, vitamin B12, folate, insulin, hs-CRP and lipid profile were analysed. Independent t-test was carried out to compare two groups and pearson correlation analyses were carried out between various parameters with systolic blood pressure (SBP) and diastolic blood pressure (DBP). Results: Cardiovascular risk factors like serum homocysteine, insulin resistance and inflammatory marker hs-CRP were significantly increased in prehypertensives. Total cholesterol, TG, LDL-C and VLDL-C were significantly increased when compared to normotensives. Serum homocysteine correlated positively and vitamin B12 and folate negatively with Systolic Blood Pressure. Conclusion: The present study concludes that the established cardiovascular risk factors, homocysteine, insulin resistance, and hs-CRP which have roles in the etiopathogenesis of hypertension, were elevated in subjects with prehypertension. Thus, early detection and life style modification may reduce the risk or delay the onset of hypertension and other cardiovascular complications. PMID:25302190

Talikoti, Prashanth; Hamide, Abdoul

2014-01-01

398

Herpes-like viruses associated with high mortality levels in larvae and spat of Pacific oysters,  

E-print Network

Herpes-like viruses associated with high mortality levels in larvae and spat of Pacific oysters-like virus associated with high mortality levels among hatchery-reared lar- vae of the Pacific oyster, C on the Pacific oyster larvae reared in several French hatcheries. Significant mortality levels were observed

Paris-Sud XI, Université de

399

Using symbolic computer algebra for subexpression factorization and subexpression decomposition in high level synthesis  

Microsoft Academic Search

In high level synthesis, signals can usually be regarded as symbols. With modern symbolic computer algebra, behavioral-level circuit descriptions consisting of symbols can be transformed into more efficient codes for hardware implementation. In this paper, two high level transformation techniques, subexpression factorization and subexpression decomposition, which are based on modern symbolic computer algebra, are proposed to optimize both area and

Xianwu Xing; Ching-chuen Jong

2005-01-01

400

PLUTONIUM SOLUBILITY IN HIGH-LEVEL WASTE ALKALI BOROSILICATE GLASS  

SciTech Connect

The solubility of plutonium in a Sludge Batch 6 (SB6) reference glass and the effect of incorporation of Pu in the glass on specific glass properties were evaluated. A Pu loading of 1 wt % in glass was studied. Prior to actual plutonium glass testing, surrogate testing (using Hf as a surrogate for Pu) was conducted to evaluate the homogeneity of significant quantities of Hf (Pu) in the glass, determine the most appropriate methods to evaluate homogeneity for Pu glass testing, and to evaluate the impact of Hf loading in the glass on select glass properties. Surrogate testing was conducted using Hf to represent between 0 and 1 wt % Pu in glass on an equivalent molar basis. A Pu loading of 1 wt % in glass translated to {approx}18 kg Pu per Defense Waste Processing Facility (DWPF) canister, or about 10X the current allowed limit per the Waste Acceptance Product Specifications (2500 g/m{sup 3} of glass or about 1700 g/canister) and about 30X the current allowable concentration based on the fissile material concentration limit referenced in the Yucca Mountain Project License Application (897 g/m{sup 3}3 of glass or about 600 g Pu/canister). Based on historical process throughput data, this level was considered to represent a reasonable upper bound for Pu loading based on the ability to provide Pu containing feed to the DWPF. The task elements included evaluating the distribution of Pu in the glass (e.g. homogeneity), evaluating crystallization within the glass, evaluating select glass properties (with surrogates), and evaluating durability using the Product Consistency Test -- Method A (PCT-A). The behavior of Pu in the melter was evaluated using paper studies and corresponding analyses of DWPF melter pour samples.The results of the testing indicated that at 1 wt % Pu in the glass, the Pu was homogeneously distributed and did not result in any formation of plutonium-containing crystalline phases as long as the glass was prepared under 'well-mixed' conditions. The incorporation of 1 wt % Pu in the glass did not adversely impact glass viscosity (as assessed using Hf surrogate) or glass durability. Finally, evaluation of DWPF glass pour samples that had Pu concentrations below the 897 g/m{sup 3} limit showed that Pu concentrations in the glass pour stream were close to targeted compositions in the melter feed indicating that Pu neither volatilized from the melt nor stratified in the melter when processed in the DWPF melter.

Marra, J.; Crawford, C.; Fox, K.; Bibler, N.

2011-01-04

401

Effects of altered gravity on the cell cycle, actin cytoskeleton and proteome in Physarum polycephalum  

NASA Astrophysics Data System (ADS)

Some researchers suggest that the changes of cell cycle under the effect of microgravity may be associated with many serious adverse physiological changes. In the search for underlying mechanisms and possible new countermeasures, we used the slime mold Physarum polycephalum in which all the nuclei traverse the cell cycle in natural synchrony to study the effects of altered gravity on the cell cycle, actin cytoskeleton and proteome. In parallel, the cell cycle was analyzed in Physarum incubated (1) in altered gravity for 20 h, (2) in altered gravity for 40 h, (3) in altered gravity for 80 h, and (4) in ground controls. The cell cycle, the actin cytoskeleton, and proteome in the altered gravity and ground controls were examined. The results indicated that the duration of the G2 phase was lengthened 20 min in high aspect ratio vessel (HARV) for 20 h, and prolonged 2 h in altered gravity either for 40 h or for 80 h, whereas the duration of other phases in the cell cycle was unchanged with respect to the control. The microfilaments in G2 phase had a reduced number of fibers and a unique abnormal morphology in altered gravity for 40 h, whereas the microfilaments in other phases of cell cycle were unchanged when compared to controls. Employing classical two-dimensional electrophoresis (2-DE), we examined the effect of the altered gravity on P. polycephalum proteins. The increase in the duration of G2 phase in altered gravity for 40 h was accompanied by changes in the 2-DE protein profiles, over controls. Out of a total of 200 protein spots investigated in G2 phase, which were reproducible in repeated experiments, 72 protein spots were visually identified as specially expressed, and 11 proteins were up-regulated by 2-fold and 28 proteins were down-regulated by 2-fold over controls. Out of a total of three low-expressed proteins in G2 phase in altered gravity for 40 h, two proteins were unknown proteins, and one protein was spherulin 3b by MALDI-TOF mass spectrometry (MS). Our results suggest that a low level of spherulin 3b in G2 phase, which may lead to a reduction of Poly(b-L-malate) (PMLA), may contribute to the lengthened duration of G2 phase in altered gravity for 40 h. Present results indicate that altered gravity results in the prolongation of G2 phase with significantly altered actin cytoskeleton and proteome in P. polycephalum.

He, Jie; Zhang, Xiaoxian; Gao, Yong; Li, Shuijie; Sun, Yeqing

402

Assessment of autonomic function in high level athletes by pupillometry.  

PubMed

Spectral analysis of heart rate variability has become a noninvasive standard method for assessment of autonomic nervous system activity in athletes. The effect of exercise training on autonomic regulation of pupillary light reflex is not known. The purpose of this study was to evaluate pupil autonomic function in athletes. We studied 46 highly trained athletes practicing gymnastics, swimming, long-distance running, soccer, and 51 healthy control subjects, using a portable infrared pupillometry. Five left pupil light response curves were recorded for each subject; the 485 pupillogram records were processed by a computer system. The following pupillometric parameters calculated were significantly higher (P<0.05) in runners than in controls: reflex amplitude (2.1 mm; 95% CI, 1.9-2.3 vs. 1.8 mm; 95% CI, 1.7-1.9), mean percent reflex amplitude of initial diameter (34%; 95% CI, 32-37 vs. 30%, 95% CI, 28-31) and mean time at which pupil redilated 75% of reflex amplitude (2.15 s; 95% CI, 1.99-2.31 vs. 1.86 s; 95% CI, 1.78-1.93). Sex, age, height, weight, body mass index and years of sports practice had no significant influence in the evaluated parameters. The results were consistent with an increased parasympathetic activity and a reduced sympathetic activity of pupillary light reflex in endurance-trained runners, supporting the hypothesis of a generalized "dysautonomy" associated with this type of training. PMID:12559205

Filipe, João A Capão; Falcão-Reis, F; Castro-Correia, J; Barros, Henrique

2003-02-28

403

Exposure to high levels of glucose increases the expression levels of genes involved in cholesterol biosynthesis in rat islets  

PubMed Central

Cells continually adjust their gene expression profiles in order to adapt to the availability of nutrients. Glucose is a major regulator of pxancreatic ?-cell function and cell growth. However, the mechanism of ?-cell adaptation to high levels of glucose remains uncertain. To identify the specific targets responsible for adaptation to high levels of glucose, the differentially expressed genes from primary rat islets treated with 3.3 and 16.7 mmol/l glucose for 24 h were detected by DNA microarray. The results revealed that the expression levels of genes that encode enzymes required for de novo cholesterol biosynthesis [3-hydroxy-3-methylglutaryl-CoA synthase 1 (Hmgcs1), 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), mevalonate (diphospho) decarboxylase (Mvd), isopentenyl-diphosphate ?-isomerase 1 (Idi1), squalene epoxidase (Sqle) and 7-dehydrocholesterol reductase (Dhcr7)] were significantly increased in islets treated with high levels of glucose compared with those in the islets treated with lower glucose levels. Quantitative polymerase chain reaction further confirmed that glucose stimulated the expression levels of these genes in a dose- and time-dependent manner. A similar result was obtained in islets isolated from rats subjected to 12, 24, 48 and 72 h of continuous glucose infusion. It has previously been recognized that cholesterol homeostasis is important for ?-cell function. The present study provides, to the best of our knowledge, the first evidence for the involvement of the de novo cholesterol biosynthesis pathway in the adaptation of rat islets to high levels of glucose in vitro and in vivo. PMID:25120636

SUN, YIXUAN; ZHANG, YUQING; LI, NA; ZHANG, HUA; ZHOU, LIBIN; SHAO, LI

2014-01-01

404

Measuring the vertical gradient of gravity  

NSDL National Science Digital Library

The free-air effect tells us that as elevation above sea level increases, gravitational acceleration g decreases at the rate of about 0.3086 mgal/meter. This effect is routinely corrected for when making gravity surveys. We will use the LaCoste & Romberg gravimeter to measure the free-air effect in a tall building on campus, and compare with the theoretical value. keywords: gravity; vertical gradient; gravimeter

Sternberg, Rob

405

Auto-tuning on the macro scale : high level algorithmic auto-tuning for scientific applications  

E-print Network

In this thesis, we describe a new classification of auto-tuning methodologies spanning from low-level optimizations to high-level algorithmic tuning. This classification spectrum of auto-tuning methods encompasses the space ...

Chan, Cy P

2012-01-01

406

APPLICATION OF A THIN FILM EVAPORATOR SYSTEM FOR MANAGEMENT OF LIQUID HIGH-LEVEL WASTES AT HANFORD  

SciTech Connect

A modular, transportable evaporator system, using thin film evaporative technology, is planned for deployment at the Hanford radioactive waste storage tank complex. This technology, herein referred to as a wiped film evaporator (WFE), will be located at grade level above an underground storage tank to receive pumped liquids, concentrate the liquid stream from 1.1 specific gravity to approximately 1.4 and then return the concentrated solution back into the tank. Water is removed by evaporation at an internal heated drum surface exposed to high vacuum. The condensed water stream will be shipped to the site effluent treatment facility for final disposal. This operation provides significant risk mitigation to failure of the aging 242-A Evaporator facility; the only operating evaporative system at Hanford maximizing waste storage. This technology is being implemented through a development and deployment project by the tank farm operating contractor, Washington River Protection Solutions (WRPS), for the Office of River Protection/Department of Energy (ORP/DOE), through Columbia Energy & Environmental Services, Inc. (Columbia Energy). The project will finalize technology maturity and install a system at one of the double-shell tank farms. This paper discusses results of pre-project pilot-scale testing by Columbia Energy and ongoing technology maturation development scope through fiscal year 2012, including planned additional pilot-scale and full-scale simulant testing and operation with actual radioactive tank waste.

TEDESCHI AR; WILSON RA

2010-01-14

407

Long-term Global Morphology of Gravity Wave Activity Using UARS Data  

NASA Technical Reports Server (NTRS)

An extensive body of research this quarter is documented. Further methodical analysis of temperature residuals in Cryogenic Limb Array Etalon Spectrometer (CLAES) Version 8 level 3AT data show signatures during December 1992 at middle and high northern latitudes that, when compared to Naval Research Laboratory/Mountain Wave Forecast Model (NRL)/(MWFM) mountain wave hindcasts, reveal evidence of long mountain waves in these data over Eurasia, Greenland, Scandinavia and North America. The explicit detection of gravity waves in limb-scanned Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures is modeled at length, to derive visibility functions. These insights are used to convert CRISTA gravity wave temperature residuals into data that more closely resemble gravity wave fluctuations detected in data from other satellite instruments, such as Microwave Limb Sounder (MLS), Limb Infrared Monitor of the Stratosphere (LIMS) and Global Positioning System/Meteorology (GPS)/(MET). Finally, newly issued mesospheric temperatures from inversion of CRISTA 15gin emissions are analyzed using a new method that uses separate Kalman fits to the ascending and descending node data. This allows us to study global gravity wave amplitudes at two local times, 12 hours apart. In the equatorial mesosphere, where a large diurnal tidal temperature signal exists, we see modulations of gravity wave activity that are consistent with gravity wave-tidal interactions produced by tidal temperature variability.

Eckermann, Stephen D.; Jackman, C. (Technical Monitor)

2000-01-01

408