Sample records for high gravity levels

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

    E-print Network

    Kim, Jungho

    the bubble was observed to develop in low-g, forming a ``jet'' of heated fluid into the bulk fluid. Ó 2002Highly 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

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

    Microsoft Academic Search

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

    2009-01-01

    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

  3. Groundwater level monitoring using hybrid gravity measurements

    NASA Astrophysics Data System (ADS)

    Nishijima, J.; Fujimitsu, Y.; Oka, D.; Fukuda, Y.; Taniguchi, M.

    2012-12-01

    It is important to monitor the aquifer mass balance between discharge and recharge for the sustainable groundwater usage. The discharge of groundwater causes mass redistributions, which can cause measurable gravity changes. We carried out the repeat hybrid gravity measurements at some fields in order to detect the gravity changes associated with groundwater level changes. We used the instruments for the relative gravity measurement (CG-3M and CG-5 gravimeter: Scintrex Ltd.) and the absolute gravity measurement (A-10 gravimeter: Micro-g LaCoste, Inc.). The A10 absolute gravimeter is a portable absolute gravimeter produced by Micro-g LaCoste Inc. It operates on a 12V DC power supply (i.e. vehicle battery). We can measure the absolute gravity using the vehicle battery at the field. We started repeat gravity measurement at Ito campus, Kyushu university Fukuoka city, Northern part of Kyushu, Japan, where the instrument is usually maintained, since 2008 in order to assess the A10 gravimeter's accuracy and repeatability. We measured 10 sets at each measurement, and 1 set consists of 100 drops. There are 3 groundwater level monitoring wells near the gravity station. It can be seen that there is a good correlation between gravity changes and groundwater level changes. We confirmed that the instrument is maintained good condition in general, although some bad data was included. It seems that the repeatability of A10 gravimeter is better than 10 microgals. The A10 absolute gravimeter (Micro-g LaCoste Inc.) was introduced in order to monitor the gravity changes at base observation points since 2008. We observed seasonal gravity change (Maximum change was 26 micro gal), and we compared with the groundwater level changes. There are good correlation between the gravity changes and the groundwater level changes. We calculated the effect of groundwater level changes using Gwater-1D (Kazama et al., 2010). As a result of the calculation, we can explain the gravity seasonal changes were caused by the groundwater level changes. The gravity changes of the base observation were removed from each observation point. We can see the good correlation between the gravity changes and the groundwater level change in the almost observation point. The effect of the construction of the campus awaits future studies.

  4. High-precision gravity network to monitor temporal variations in gravity across Yucca Mountain, Nevada

    SciTech Connect

    Harris, R.N.; Ponce, D.A.

    1988-12-31

    Repeatable high-precision gravity surveys provide a method of monitoring temporal variations in the gravity field. Fluctuations in the gravity field may indicate water table changes, crustal deformation, or precursors to volcanism and earthquakes. This report describes a high-precision gravity loop which has been established across Yucca Mountain, Nevada in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) program. The purpose of this gravity loop is to monitor temporal variations in gravity across Yucca Mountain in an effort to interpret and predict the stability of the tectonic framework and changes in the subsurface density field. Studies of the tectonic framework which include volcanic hazard seismicity, and faulting studies are in progress. Repeat high-precision gravity surveys are less expensive and can be made more rapidly than a corresponding leveling survey. High-precision gravity surveys are capable of detecting elevation changes of 3 to 5 cm, and thus can be employed as an efficient tool for monitoring vertical crustal movements while supplementing or partially replacing leveling data. The Yucca Mountain gravity network has been tied to absolute gravity measurements established in southern Nevada. These ties provide an absolute datum for comparing repeat occupations of the gravity network, and provide a method of monitoring broad-scale changes in gravity. Absolute gravity measurements were also made at the bottom and top of the Charleston Peak calibration loop in southern Nevada. These absolute gravity measurements provide local control of calibrating gravity meters over the gravity ranges observed at Yucca Mountain. 13 refs., 7 figs., 3 tabs.

  5. High-gravity central stars

    E-print Network

    Thomas Rauch

    2006-07-11

    NLTE spectral analyses of high-gravity central stars by means of state-of-the-art model atmosphere techniques provide information about the precursor AGB stars. The hydrogen-deficient post-AGB stars allow investigations on the intershell matter which is apparently exhibited at the stellar surface. We summarize recent results from imaging, spectroscopy, and spectropolarimetry.

  6. A high gravity chemical vapor deposition apparatus

    Microsoft Academic Search

    Yoshiyuki Abe; Giovanni Maizza; Noboru Sone; Yuji Nagasaka; Tetsuya Suzuki

    1997-01-01

    A high gravity centrifuge facility in which thin films can be produced, especially from gas phase, was developed. The centrifuge facility allows high gravity materials processing up to 100g(g denotes the terrestrial gravity acceleration). With a minor modification, not only thin films from gas phase but also bulk materials could be produced in the facility. For the first demonstrative attempt

  7. Low gravity liquid level sensor rake

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  8. An Improved Platform Levelling System for Airborne Gravity Meters.

    NASA Astrophysics Data System (ADS)

    Brady, N.

    2014-12-01

    Recent advances in sensor technology have enabled Lacoste and Romberg type relative gravity meters to improve in accuracy to the point where other non-sensor related sources of error serve to limit the overall accuracy of the system. One of these sources of error is derived from the inability of the platform, in which the sensor is mounted, to keep the sensor perfectly level during survey flight. Off level errors occur when the aircraft is unable to maintain straight and level flight along a survey line. The levelling platform of a typical Lacoste and Romberg type dynamic gravity meter utilizes a complex feedback loop involving both accelerometers and gyroscopes with an output connected to torque motors mounted to the platform to sense an off level situation and correct for it. The current system is limited by an inability of the platform to distinguish between an acceleration of the platform due to a change in heading, altitude or speed of the aircraft and a true change in the local gravity vertical. Both of these situations cause the platform to tilt in reponse however the aircraft acceleration creates an error in the gravity measurement. These off level errors can be corrected for to a limited degree depending on the algorithm used and the size and duration of the causal acceleration. High precision GPS now provides accurate real time position information which can be used to determine if an accleration is a real level change or due to an anomalous acceleration. The correct implementation of the GPS position can significantly improve the accuracy of the platform levelling including keeping the platform level during course reversals or drape flying during a survey. This can typically improve the quality of the gravity data before any processing corrections. The enhanced platform also reduces the time taken to stabilize the platform at the beginning of a survey line therefore improving the efficiency of the data collection. This paper discusses the method and results of tests of the new GPS aided platform system developed by Dynamic Gravity Systems

  9. The gravity field of the level triaxial ellipsoid

    NASA Astrophysics Data System (ADS)

    Panou, Georgios; Delikaraoglou, Demitris

    2013-04-01

    Geodetic research has traditionally been motivated by the need to approximate closer and closer the physical reality. Several investigations have shown that the earth is approximated better by a triaxial ellipsoid rather than a biaxial one. Furthermore, non-spherical celestial bodies such as planets, physical satellites, asteroids and comets can be modeled by a triaxial ellipsoid. Also, the present day accuracy requirements and the modern computational capabilities push toward the study on the triaxial ellipsoid as a geometrical and a physical model in geodesy and related interdisciplinary sciences. From the viewpoint of its physical characteristics, it is assumed that the triaxial ellipsoid has mass and rotates with constant angular velocity. Also, this ellipsoid is a level (or equipotential) surface of its own gravity field. In this paper, the gravity field of the level triaxial ellipsoid is presented. An ellipsoidal coordinate system and the ellipsoidal harmonics are introduced. The gravitational potential is determined by solving an exterior Dirichlet's boundary-value problem. Hence, the gravity potential is completely and uniquely determined outside the triaxial ellipsoid. From the gravity potential the gravity vector is consequently obtained in the exterior space and on the surface of the level ellipsoid. The gravity field of the level biaxial ellipsoid is included as a degenerate case.

  10. Metabolic heat evolution of Saccharomyces cerevisiae grown under very-high-gravity conditions

    Microsoft Academic Search

    Karnnalin Theerarattananoon; Yen-Han Lin; Ding-Yu Peng

    2008-01-01

    Metabolic heat evolution of Saccharomyces cerevisiae under conditions of various combinations of glucose level (low gravity, 10g glucose\\/l; very-high-gravity, 300g glucose\\/l), temperature, and urea concentration was investigated. The measured overall metabolic heat evolution was 0.416 and 0.476J\\/h, respectively, for 10 and 300g glucose\\/l in the presence of urea. As glucose level was increased from low- to very-high-gravity when urea was

  11. The effect of gravity level on the average primary dendritic spacing of a directionally solidified superalloy

    NASA Technical Reports Server (NTRS)

    Mccay, M. H.; Lee, J. E.; Curreri, P. A.

    1986-01-01

    The effect of alternating low (0.01 g) and high (1.8 g) gravity force on the primary spacings in the dendrite structure in a directionally solidified Ni-based superalloy (PWA 1480, containing 5 pct Co, 10 pct Cr, 4 pct W, 12 pct Ta, 5 pct Al, 1.5 pct Ti, and the balance Ni) was investigated using samples solidified in a directional solidification furnace aboard the NASA KC-135 aircraft that made a series of low-g parabolas. The cross-section slices for each growth rate were polished and etched with Kallings II, and the primary dendritic arm spacings were measured using the method of Jacobi and Schwerdtfeger (1976). The arm spacings were found to fluctuate with gravity force, increasing as the gravity level decreased, and growing finer as gravity increased.

  12. Antarctic marine gravity field from high-density satellite altimetry

    NASA Technical Reports Server (NTRS)

    Sandwell, David T.

    1992-01-01

    High-density (about 2-km profile spacing) Geosat/GM altimetry profiles were obtained for Antarctic waters (6-deg S to 72 deg S) and converted to vertical gravity gradient, using Laplace's equation to directly calculate gravity gradient from vertical deflection grids and Fourier analysis to construct gravity anomalies from two vertical deflection grids. The resultant gravity grids have resolution and accuracy comparable to shipboard gravity profiles. The obtained gravity maps display many interesting and previously uncharted features, such as a propagating rift wake and a large 'leaky transform' along the Pacific-Antarctic Rise.

  13. Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow

    E-print Network

    Witten, Thomas A.

    Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow Michael Baumer University Gravity Wave 2 3 Measurements 3 4 Mechanical Hardware: Problems and Solutions 5 5 Results 7 6 Conclusions investigated a free-surface gravity wave bifurcation in the large-separation regime, that is, where

  14. Global Gravity Fields from Simulated Level1 GRACE Data

    Microsoft Academic Search

    Ulrich Meyer; Björn Frommknecht; Frank Flechtner

    \\u000a The GRACE satellites deliver high quality GPS code and phase, inter-satellite range and range-rate, non-gravitational acceleration,\\u000a and star camera observations that can be used to estimate the static and time variable gravity field of the Earth with unprecedented\\u000a accuracy. Nevertheless, the baseline accuracy that was determined in a pre-launch simulation study could not yet be reached.\\u000a To find out possible

  15. Regional high-resolution spatio-temporal gravity modeling from GRACE data using spherical wavelets

    NASA Astrophysics Data System (ADS)

    Kusche, J.; Schmidt, M.; Han, S.; Sanchez, L.; Shum, C.; Xie, J.

    2005-12-01

    This paper deals with the application of the multi-resolution technique based on spherical wavelet theory to determine regional spatio-temporal gravity models using spaceborne gravimetry data (GRACE, GOCE). The basic idea of the multi-resolution representation is to split an input gravity signal into a number of detail signals. Since each detail signal (levels) is related to a special frequency-band it is in fact computable from different data sets covering specific parts of the frequency spectrum. In our approach we estimate at first the long-wavelength (low-level) part of the gravity field using in situ potential measurements derived from GRACE inter-satellite range-rate and accelerometer measurements using the energy conservation approach. This way we obtain both wavelet based regional and temporal gravity fields with spatial resolution up to ~300 km and varying sampling (each detail signal is computed from a GRACE data frame of different length; between several days for the long wavelengths to a month for the more detailed structures) as well as a mean gravity field model based on more than two years of GRACE data. Solution constraints, when necessary, are implemented in a data-driven optimal procedure. For the static case we compute in addition the high-level detail signals or short-wavelength gravity components, where available, from Faye anomalies derived from terrestrial, airborne and altimetric observations. Since the medium-level detail signals are present in both the satellite and in the surface data they require the use of a combination method. As an example, we apply the developed procedures to determine a regional time-dependent gravity model of the Amazon basin, a mean high-resolution gravity model for Colombia, and other selected regions. It is anticipated that the developed methodologies can be applied to other regions of interest and have the distinct capability of spatial and temporal signal enhancement using the multi-resolution representation of the gravity field model.

  16. High blood cholesterol levels

    MedlinePLUS

    ... 130 mg/dL Almost everyone else may get health benefits from LDL cholesterol that is lower than 160 mg/dL to 190 mg/dL There are several types of drugs to help lower blood cholesterol levels. The drugs work in different ways. Statins are one kind of ...

  17. Effects of gravity level on bubble formation and rise in low-viscosity liquids

    NASA Astrophysics Data System (ADS)

    Suñol, Francesc; González-Cinca, Ricard

    2015-05-01

    We present an experimental analysis of the effects of gravity level on the formation and rise dynamics of bubbles. Experiments were carried out with millimeter-diameter bubbles in the hypergravity environment provided by the large-diameter centrifuge of the European Space Agency. Bubble detachment from a nozzle is determined by buoyancy and surface tension forces regardless of the gravity level. Immediately after detachment, bubble trajectory is deviated by the Coriolis force. Subsequent bubble rise is dominated by inertial forces and follows a zig-zag trajectory with amplitude and frequency dependent on the gravity level. Vorticity production is enhanced as gravity increases, which destabilizes the flow and therefore the bubble path.

  18. Superalloy microstructural variations induced by gravity level during directional solidification

    SciTech Connect

    Johnston, M.H.; Curreri, P.A.; Parr, R.A.; Alter, W.S.

    1985-09-01

    The Ni-base superalloy MAR-M246 (Hf) was directionally solidified during low gravity maneuvers aboard a NASA KC-135 aircraft. Gravity force variations during this process yielded a concomitant variation in microstructure and microsegregation. Secondary dendrite arm spacings are noted to be larger in the low-g portion; this, in turn, decreases the extent of interdendritic segregation. The amount of Hf in both the carbides and interdendritic eutectic increases as the gravity force diminishes. Fewer carbides are present in the low-g regions. 6 references.

  19. The utility of gravity and water-level monitoring at alluvial aquifer wells in southern Arizona

    Microsoft Academic Search

    D. R. Pool

    2008-01-01

    Coincident monitoring of gravity and water levels at 39 wells insouthernArizonaindicatethatwater-levelchangemightnotbe a reliable indicator of aquifer-storage change for alluvial aquifer systems.Onereasonisthatwaterlevelsinwellsthatarescreened acrosssingleormultipleaquifersmightnotrepresentthehydrau- licheadandstoragechangeinalocalunconfinedaquifer.Gravity estimates of aquifer-storage change can be approximated as a one-dimensional feature except near some withdrawal wells and recharge sources. The aquifer storage coefficient is estimated by the linear regression slope of storage change estimated using gravity methods

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

    E-print Network

    Kim, Jungho

    was measured. Steady- state boiling data in low-g and high-g were obtained for various bulk fluid subcoolings subcooling had a negligible impact on boiling performance and a characteristically low heat flux was observedA study of the effects of heater size, subcooling, and gravity level on pool boiling heat transfer

  1. A high frequency resonance gravity gradiometer

    NASA Astrophysics Data System (ADS)

    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

    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.

  2. A high frequency resonance gravity gradiometer

    SciTech Connect

    Bagaev, S. N.; Kvashnin, N. L.; Skvortsov, M. N. [Laser Physics Institute SB RAS, Novosibirsc (Russian Federation); Bezrukov, L. B.; Krysanov, V. A. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Oreshkin, S. I.; Motylev, A. M.; Popov, S. M.; Samoilenko, A. A.; Yudin, I. S. [Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation); Rudenko, V. N. [Institute of Nuclear Physics RAS, Moscow (Russian Federation); Lomonosov MSU, Sternberg Astronomical Institute, Moscow (Russian Federation)

    2014-06-15

    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.

  3. A high frequency resonance gravity gradiometer.

    PubMed

    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

    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

  4. Generation of High-Gravity Field and Application to Materials Science

    NASA Astrophysics Data System (ADS)

    Mashimo, T.

    2008-02-01

    Centrifugation of organic liquids and metals has been widely used in biochemistry field and metallurgy field, respectively. The high-gravity field was recently used for the preprocessing for sintering of composite materials. The sedimentation of atoms was recently realized in alloys and semiconductors under ultra-high gravitational field in 1 million G level. The possibility in use of high gravity has, day by day, increased. In this mini-symposium, the conventional and recent methods for materials processing for functionally graded materials, metastable composite materials, thin film, etc. using high-gravity in gas, liquids, solids and also in vacuum will be treated. In this paper, the history of ultracentrifuges is reviewed, and the applications to materials science is discussed.

  5. New Diamond Deposition Methods and Perspective in High Gravity Process

    NASA Astrophysics Data System (ADS)

    Abe, Yoshiyuki; Shimada, Shouhei; Tappero, Fabrizio; Takagi, Yoshiki; Maizza, Giovanni

    2008-02-01

    The present authors reported appreciable influences of high gravity up to 100 G on diamond film deposited by the DC-plasma CVD in a centrifugal facility. The authors then developed an on-board optical emission spectroscopy (OES) system for the centrifuge to understand the deposition mechanism in high gravity. Several important active species were identified and their gravity dependence was pointed out. In the meanwhile, one of the authors (YT) developed a new diamond deposition method, the so-called spark method, in which diamond could be deposited within 10 seconds by arc-discharge between graphite electrode rods in hydrogen atmosphere. The authors applied the OES system to the spark method apparatus to identify active species in the course of short time arc discharge between graphite electrodes, and to apparatus of the graphite rod heating method, which is method that graphite rod is used as a heater and at the same time a carbon source, of diamond synthesis method with graphite similarly the spark method. The authors are also planning to conduct high gravity experiments of the spark method and the graphite heating method. The latest results obtained from the OES study and the progress in high gravity spark method and graphite heating method will be reported.

  6. Production of 21% (v\\/v) ethanol by fermentation of very high gravity (VHG) wheat mashes

    Microsoft Academic Search

    K. C. Thomas; W. M. Ingledew

    1992-01-01

    Summary Very high gravity wheat mashes containing 300 g or more sugares per liter were prepared by enzymatic hydrolysis of starch and fermented with a commercial preparation of active dry yeast. The active dry yeast used in this study was a blend of several strains ofSaccharomyces cerevisiae. The fermentation was carried out at 20°C at different pitching rates (inoculation levels)

  7. Cognitive high level information fusion

    Microsoft Academic Search

    Leonid I. Perlovsky

    2007-01-01

    Fusion of sensor and communication data currently can only be performed at a late processing stage after sensor and textual information are formulated as logical statements at appropriately high level of abstraction. Contrary to this it seems, the human mind integrates sensor and language signals seamlessly, before signals are understood, at pre-conceptual level. Learning of conceptual contents of the surrounding

  8. Sensitivity enhancement of OD- and OD-CNT-based humidity sensors by high gravity thin film deposition technique

    NASA Astrophysics Data System (ADS)

    Karimov, Kh. S.; Fatima, Noshin; Sulaiman, Khaulah; Mahroof Tahir, M.; Ahmad, Zubair; Mateen, A.

    2015-03-01

    The humidity sensing properties of the thin films of an organic semiconductor material orange dye (OD) and its composite with CNTs deposited at high gravity conditions have been reported. Impedance, phase angle, capacitance and dissipation of the samples were measured at 1 kHz and room temperature conditions. The impedance decreases and capacitance increases with an increase in the humidity level. It was found that the sensitivity of the OD-based thin film samples deposited at high gravity condition is higher than the samples deposited at low gravity condition. The impedances and capacitance sensitivities of the of the samples deposited under high gravity condition are 6.1 times and 1.6 times higher than the films deposited under low gravity condition.

  9. GRAVITY

    NSDL National Science Digital Library

    Ms. Hendricks

    2007-11-06

    3rd Grade Science Standard 4: Students will understand that objects near Earth are pulled toward Earth by gravity Objective 2: Describe the effects of gravity on the motion of an object In this activity we will learn how gravity effects the motion of an object. We will do this by finding out what gravity is and watching experiments on gravity. Finally, we will conduct our own experiment to see first hand how gravity effects everything around us. So, what is gravity? Is it a term that you have heard before? What does it do? Why is it so important? Why do we need to know how it works? If you\\'ve ever wondered what the answers to these questions are, then you\\'re in ...

  10. A Model for High Energy Scattering in Quantum Gravity

    Microsoft Academic Search

    Tom Banks; Willy Fischler

    1999-01-01

    We present a model for high energy two body scattering in a quantum theory of gravity. The model is applicable for center of mass energies higher than the relevant Planck scale. At impact parameters smaller than the Schwarzchild radius appropriate to the center of mass energy and total charge of the initial state, the cross section is dominated by an

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

    NASA Technical Reports Server (NTRS)

    Merte, Herman, Jr.

    1988-01-01

    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.

  12. Transition from an eastern Pacific upper-level mixed Rossby-gravity wave to a western Pacific tropical cyclone

    E-print Network

    Wang, Bin

    Transition from an eastern Pacific upper-level mixed Rossby-gravity wave to a western Pacific- clockwise rotating mixed Rossby-gravity (MRG) wave. The temporal and spatial evolution from an equatorial (2007), Transition from an eastern Pacific upper-level mixed Rossby- gravity wave to a western Pacific

  13. Assessment of the EGM2008 Gravity Field in Algeria Using Gravity and GPS\\/Levelling Data

    Microsoft Academic Search

    S. A. Benahmed Daho

    \\u000a The present work focuses on the evaluation of the EGM2008 geopotential model that was recently released by the NGA (National Geospatial-Intelligence Agency, US)\\/EGM-development team, in Algeria using the free air gravity anomalies supplied by BGI and GETECH, the precise GPS data collected\\u000a from the international TYRGEONET (TYRhenian GEOdynamical NETwork) and ALGEONET (ALGerian GEOdynamical NETwork) projects and\\u000a the last Algerian local

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  15. Highly relativistic spin-gravity coupling for fermions

    E-print Network

    Roman Plyatsko; Mykola Fenyk

    2015-03-29

    Descriptions of highly relativistic fermions in a gravitational field in the classical (nonquantum) and quantum approaches are discussed. The results following from the Mathisson-Papapetrou equations for a fast spinning particle in Schwarzschild's and Kerr's background are considered. Numerical estimates for electron, proton and neutrino in the gravitational field of black holes are presented.The general relativistic Dirac equation is analyzed from the point of view it is using for the adequate description of highly relativistic fermions in a gravitational field, in the linear and nonlinear spin approximation. It is necessary to have some corrected Dirac equation for a highly relativistic fermion with strong spin-gravity coupling.

  16. Investigating High Field Gravity using Astrophysical Techniques

    SciTech Connect

    Bloom, Elliott D.; /SLAC

    2008-02-01

    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.

  17. Regional lunar gravity anomaly recovery with the GRAIL Level-1b data, and pin-point crustal density estimation with the GRAIL Level-2 and LRO topography data

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Heki, K.

    2014-12-01

    We report the lunar gravity anomaly recovery using the GRAIL Level-1b and Level-2 data, downloaded from the PDS Geoscience Node at the Washington University. First, we used the GNV1b (satellite position data) and KBR1b (inter-satellite ranging data) files of the Level-1b data to estimate the surface mass distribution on the Moon following the method of Sugano and Heki (EPS 2004; GRL 2005). We confirmed that we could recover the gravity anomalies similar to the Level-2 data with spatial resolution of ~0.8 degrees using low altitude portions of the data. Next, we downloaded the GRAIL Level-2 data set (spherical harmonics with degree/order complete to 660) together with the topography data by LRO laser altimetry, and tried to estimate the pin-point surface crustal density. First, we selected a certain square as large as ~60 km, and compared the gravity and topography values at grid points within the square. They are roughly proportional, and the slope provides information on the density of the material making the topography. This method, however, causes apparent positive correlation between density and average topographic height of about 0.2 g/cm^3/km. We (wrongly) assume that the mass anomalies lie on the reference surface. Then, the mass above (below) the reference surface is interpreted heavier/lighter than its real density. We performed a-posteriori correction of the altitude-dependent errors in the estimated density. We finally focus on a few positive gravity anomalies on the nearside (such as those close to the Copernicus crater) that are not associated with any topographic high. We will try to constrain the subsurface structure of the dense material responsible for the anomaly using both Level-1b and -2 data.

  18. The influence of gravity level during directional solidification of immiscible alloys

    NASA Technical Reports Server (NTRS)

    Andrews, J. B.; Schmale, A. L.; Sandlin, A. C.

    1992-01-01

    During directional solidification of immiscible (hypermonotectic) alloys it is theoretically possible to establish a stable macroscopically-planar solidification front, and thus avoid sedimentation. Unfortunately, convective instabilities often occur which interfere with the directional solidification process. In this paper, stability conditions are discussed and results presented from directional solidification studies carried out aboard NASA's KC-135 zero-g aircraft. Samples were directionally solidified while the effective gravity level was varied from approximately 0.01 g for 25 s to 1.8 g for 45 s. Dramatic variations in microstructure were observed with gravity level during solidification.

  19. High-resolution simulations of particle-driven gravity currents F. Necker a

    E-print Network

    Meiburg, Eckart H.

    High-resolution simulations of particle-driven gravity currents F. Necker a , C. Haartel a,* , L between 2D and 3D simulations. Ó 2002 Elsevier Science Ltd. All rights reserved. Keywords: Gravity current; Lock-exchange flow; Numerical simulation 1. Introduction Gravity currents, which form when a heavier

  20. Global estimates of gravity wave momentum flux from High Resolution Dynamics Limb Sounder observations

    E-print Network

    Alexander, M. Joan

    Global estimates of gravity wave momentum flux from High Resolution Dynamics Limb Sounder are analyzed to derive global properties of gravity waves. We describe a wavelet analysis technique. The analysis allows a local estimate of the magnitude of gravity wave momentum flux as a function of geographic

  1. Results of co-located gravity and water-level monitoring at alluvial aquifer wells in southern Arizona

    Microsoft Academic Search

    D. R. Pool

    2008-01-01

    Correlation of gravity and water levels at thirty-nine wells in southern Arizona during 1988 to 2002 indicates that water-level change is not always a reliable indicator of aquifer-storage change for alluvial aquifer systems. Gravity change is directly proportional to aquifer storage change where other sources of mass change are minimal. Gravity estimates of aquifer-storage change can be approximated as an

  2. Tests of Quantum Gravity and Large Extra Dimensions Models Using High Energy Gamma Ray Observations

    E-print Network

    F. W. Stecker

    2003-06-09

    Observations of the multi-TeV spectra of the nearby BL Lac objects Mkn 421 and Mkn 501 exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with IR photons having a flux level as determined by various astronomical observations. After correcting for such intergalactic absorption, these spectra can be explained within the framework of synchrotron self-Compton emission models. Stecker & Glashow have shown that the existence of this annihilation via electron-positron pair production puts strong constraints on Lorentz violation. Such constraints have important implications for quantum gravity models and large extra dimension models. We also discuss the implications of observations of high energy gamma-rays from the Crab Nebula on constraining quantum gravity models.

  3. How unimodular gravity theories differ from general relativity at quantum level

    E-print Network

    Bufalo, R; Tureanu, A

    2015-01-01

    We investigate path integral quantization of two versions of unimodular gravity. First a fully diffeomorphism-invariant theory is analyzed, which does not include a unimodular condition on the metric, while still being equivalent to other unimodular gravity theories at classical level. The path integral has the same form as in general relativity (GR), except that the cosmological constant is an unspecified value of a variable, and thus unrelated to any coupling constant. When the state of the universe is a superposition of vacuum states, the path integral is extended to include an integral over the cosmological constant. Second, we analyze the standard unimodular theory of gravity, where the metric determinant is fixed by a constraint. Its path integral differs from the one of GR in two ways: the metric of spacetime satisfies the unimodular condition only in average over space, and both the Hamiltonian constraint and the associated gauge condition have zero average over space. Finally, the canonical relation ...

  4. High energy scattering in QCD and in quantum gravity

    NASA Astrophysics Data System (ADS)

    Lipatov, L. N.

    2014-06-01

    The theory of the high energy scattering in QCD is based on the BFKL equation for the Pomeron wave function and on its generalization for composite multi-gluon states in the crossing channel. At a large number of colors the equations for the gluon composite states have remarkable mathematical properties including their Möbius invariance, holomorphic separability, duality symmetry and integrability. High energy QCD interactions local in the particle rapidities are formulated in the form of the gauge invariant effective action. In the maximally extended N = 4 super-symmetry the Pomeron turns out to be dual to the reggeized graviton in the 10-dimensional anti-de-Sitter space. As a result, the Gribov calculus for the Pomeron interactions should be reformulated here as a generally covariant effective field theory for the reggeized gravitons. We construct the corresponding effective action, which gives a possibility to calculate their trajectory and couplings. The graviton trajectory in the leading order contains an ultraviolet divergency meaning the presence of the double-logarithmic (DL) terms. We sum the DL contributions in all orders of the perturbation theory in the Einstein-Hilbert gravity and in its super-symmetric generalizations. In the N = 8 super gravity the ratio of the scattering amplitude in the DL approximation to the Born expression tends to zero at large energies.

  5. High pressure droplet burning experiments in reduced gravity

    NASA Technical Reports Server (NTRS)

    Chauveau, Christian; Goekalp, Iskender

    1995-01-01

    A parametric investigation of single droplet gasification regimes is helpful in providing the necessary physical ideas for sub-grid models used in spray combustion numerical prediction codes. A research program has been initiated at the LCSR to explore the vaporization regimes of single and interacting hydrocarbon and liquid oxygen droplets under high pressure conditions. This paper summarizes the status of the LCSR program on the high pressure burning of single fuel droplets; recent results obtained under normal and reduced gravity conditions with suspended droplets are presented. In the work described here, parabolic flights of the CNES Caravelle is used to create a reduced gravity environment of the order of 10(exp -2) g(sub O). For all the droplet burning experiments reported here, the suspended droplet initial diameters are scattered around 1.5 mm; and the ambient air temperature is 300 K. The ambient pressure is varied between 0.1 MPa and 12 MPa. Four fuels are investigated: methanol (Pc = 7.9 MPa), n-heptane (Pc = 2.74 MPa), n-hexane (Pc = 3.01 MPa) and n-octane (Pc = 2.48 MPa).

  6. Verifying Low-Level Implementations of High-Level Datatypes

    Microsoft Academic Search

    Christopher L. Conway; Clark Barrett

    2010-01-01

    \\u000a For efficiency and portability, network packet processing code is typically written in low-level languages and makes use of\\u000a bit-level operations to compactly represent data. Although packet data is highly structured, low-level implementation details\\u000a make it difficult to verify that the behavior of the code is consistent with high-level data invariants. We introduce a new\\u000a approach to the verification problem, using

  7. Optimizing High Level Waste Disposal

    SciTech Connect

    Dirk Gombert

    2005-09-01

    If society is ever to reap the potential benefits of nuclear energy, technologists must close the fuel-cycle completely. A closed cycle equates to a continued supply of fuel and safe reactors, but also reliable and comprehensive closure of waste issues. High level waste (HLW) disposal in borosilicate glass (BSG) is based on 1970s era evaluations. This host matrix is very adaptable to sequestering a wide variety of radionuclides found in raffinates from spent fuel reprocessing. However, it is now known that the current system is far from optimal for disposal of the diverse HLW streams, and proven alternatives are available to reduce costs by billions of dollars. The basis for HLW disposal should be reassessed to consider extensive waste form and process technology research and development efforts, which have been conducted by the United States Department of Energy (USDOE), international agencies and the private sector. Matching the waste form to the waste chemistry and using currently available technology could increase the waste content in waste forms to 50% or more and double processing rates. Optimization of the HLW disposal system would accelerate HLW disposition and increase repository capacity. This does not necessarily require developing new waste forms, the emphasis should be on qualifying existing matrices to demonstrate protection equal to or better than the baseline glass performance. Also, this proposed effort does not necessarily require developing new technology concepts. The emphasis is on demonstrating existing technology that is clearly better (reliability, productivity, cost) than current technology, and justifying its use in future facilities or retrofitted facilities. Higher waste processing and disposal efficiency can be realized by performing the engineering analyses and trade-studies necessary to select the most efficient methods for processing the full spectrum of wastes across the nuclear complex. This paper will describe technologies being evaluated at Idaho National Laboratory and the facilities we’ve designed to evaluate options and support optimization.

  8. Completing Lorentz violating massive gravity at high energies

    E-print Network

    Diego Blas; Sergey Sibiryakov

    2015-01-23

    Theories with massive gravitons are interesting for a variety of physical applications, ranging from cosmological phenomena to holographic modeling of condensed matter systems. To date, they have been formulated as effective field theories with a cutoff proportional to a positive power of the graviton mass m_g and much smaller than that of the massless theory (M_P ~ 10^19 GeV in the case of general relativity). In this paper we present an ultraviolet completion for massive gravity valid up to a high energy scale independent of the graviton mass. The construction is based on the existence of a preferred time foliation combined with spontaneous condensation of vector fields. The perturbations of these fields are massive and below their mass the theory reduces to a model of Lorentz violating massive gravity. The latter theory possesses instantaneous modes whose consistent quantization we discuss in detail. We briefly study some modifications to gravitational phenomenology at low-energies. The homogeneous cosmological solutions are the same as in the standard cosmology. The gravitational potential of point sources agrees with the Newtonian one at distances small with respect to m_g^(-1). Interestingly, it becomes repulsive at larger distances.

  9. Completing Lorentz violating massive gravity at high energies

    NASA Astrophysics Data System (ADS)

    Blas, D.; Sibiryakov, S.

    2015-03-01

    Theories with massive gravitons are interesting for a variety of physical applications, ranging from cosmological phenomena to holographic modeling of condensed matter systems. To date, they have been formulated as effective field theories with a cutoff proportional to a positive power of the graviton mass m g and much smaller than that of the massless theory ( M P ? 1019 GeV in the case of general relativity). In this paper, we present an ultraviolet completion for massive gravity valid up to a high energy scale independent of the graviton mass. The construction is based on the existence of a preferred time foliation combined with spontaneous condensation of vector fields. The perturbations of these fields are massive and below their mass, the theory reduces to a model of Lorentz violating massive gravity. The latter theory possesses instantaneous modes whose consistent quantization we discuss in detail. We briefly study some modifications to gravitational phenomenology at low-energies. The homogeneous cosmological solutions are the same as in the standard cosmology. The gravitational potential of point sources agrees with the Newtonian one at distances small with respect to m {/g -1}. Interestingly, it becomes repulsive at larger distances.

  10. HighHigh--LevelSynthesisLevelSynthesis SarajuP.Mohanty

    E-print Network

    Mohanty, Saraju P.

    DataFlowGraph(DFG)/ControlFlow Graphdetails(CFG) 3.TolearnHigh-LevelSynthesis(HLS)withthehelp ofasmallexample 4.TodiscussALGORITHM #12;7 TransitionbetweendomainsTransitionbetweendomains #12;8 WhatisHighWhatisHigh--LevelSynthesis(HLS)??LevelSynthesis(HLS ·Theabilitytosearchthedesignspace ·Documentingthedesignprocess ·AvailabilityofICtechnologytomore people #12;11 HighHigh--LevelSynthesis(HLS)ProcessLevelSynthesis(HLS

  11. Influence of whole-body pitch tilt and kinesthetic cues on the perceived gravity-referenced eye level

    Microsoft Academic Search

    L. Bringoux; K. Tamura; M. Faldon; M. A. Gresty; A. M. Bronstein

    2004-01-01

    We investigated the effects of whole body tilt and lifting the arm against gravity on perceptual estimates of the Gravity-Referenced Eye Level (GREL), which corresponds to the subjective earth-referenced horizon. The results showed that the perceived GREL was influenced by body tilt, that is, lowered with forward tilt and elevated with backward tilt of the body. GREL estimates obtained by

  12. Compiling high level function on low level machines

    Microsoft Academic Search

    1983-01-01

    Low-level computer architectures have been characterised as reduced instruction set computers (RISC machines). Their advocates assume that most programming should be done in a high-level language. This study provides some insights into a variety of compilation techniques for low-level machines gained from the PL.8 compiler. It also suggests some desirable features for low-level machines. In order to focus the discussion,

  13. High-resolution numerical simulations of resuspending gravity currents: Conditions for

    E-print Network

    Meiburg, Eckart H.

    High-resolution numerical simulations of resuspending gravity currents: Conditions for self a computational model for high-resolution simulations of particle-laden gravity currents. The features particles from the bottom surface, resuspended particles entrained over the entire length of the current

  14. Effects of Varying Gravity Levels in Parabolic Flight on the Size-Mass Illusion

    PubMed Central

    Clément, Gilles

    2014-01-01

    When an observer lifts two objects with the same weight but different sizes, the smaller object is consistently reported to feel heavier than the larger object even after repeated trials. Here we explored the effect of reduced and increased gravity on this perceptual size-mass illusion. Experiments were performed on board the CNES Airbus A300 Zero-G during parabolic flights eliciting repeated exposures to short periods of zero g, 0.16 g, 0.38 g, one g, and 1.8 g. Subjects were asked to assess perceived heaviness by actively oscillating objects with various sizes and masses. The results showed that a perceptual size-mass illusion was clearly present at all gravity levels. During the oscillations, the peak arm acceleration varied as a function of the gravity level, irrespective of the mass and size of the objects. In other words we did not observe a sensorimotor size-mass illusion. These findings confirm dissociation between the sensorimotor and perceptual systems for determining object mass. In addition, they suggest that astronauts on the Moon or Mars with the eyes closed will be able to accurately determine the relative difference in mass between objects. PMID:24901519

  15. Pressure drop and void fraction during flow boiling in minichannels at different gravity levels

    NASA Astrophysics Data System (ADS)

    Ajaev, Vladimir; Brutin, David; Tadrist, Lounes

    2012-11-01

    We use mathematical models of two-phase flow to explain recent experimental data on flow boiling in minichannels under the conditions of hypergravity, normal gravity, and microgravity. The experimental data was obtained during parabolic flights and includes simultaneous measurements of void fraction, pressure drop, and heat transfer coefficient. At higher flow rates, void fraction grows linearly along the channel but with different slopes depending on gravity level. Using the models of motion of confined bubbles, we predict the ratio of the slopes of the void fraction profiles which is in excellent agreement with the experimental measurements. At lower flow rates, the void fraction profiles are concave down and eventually flatten away from the channel entrance. This change in the dynamics is explained by a combination of thermal effects in bubble growth, geometric confinement, and bubble coalescense. The relationship between pressure drop measurement results and flow structure is discussed. Finally, experimentally observed heat transfer enhancement under the conditions of microgravity is explained.

  16. Introducing a high gravity field to enhance infiltration of small molecules into polyelectrolyte multilayers.

    PubMed

    Liu, Xiaolin; Zhao, Kun; Jiang, Chao; Wang, Yue; Shao, Lei; Zhang, Yajun; Shi, Feng

    2015-07-01

    Loading functional small molecules into nano-thin films is fundamental to various research fields such as membrane separation, molecular imprinting, interfacial reaction, drug delivery etc. Currently, a general demand for enhancing the loading rate without affecting the film structures exists in most infiltration phenomena. To handle this issue, we have introduced a process intensification method of a high gravity technique, which is a versatile energy form of mechanical field well-established in industry, into the investigations on diffusion/infiltration at the molecular level. By taking a polyelectrolyte multilayer as a model thin film and a photo-reactive molecule, 4,4'-diazostilbene-2,2'-disulfonic acid disodium salt (DAS), as a model small functional molecule, we have demonstrated remarkably accelerated adsorption/infiltration of DAS into a poly(allylamine hydrochloride) (PAH)/poly(acrylic acid) (PAA) multilayer by as high as 20-fold; meanwhile, both the film property of the multilayer and photoresponsive-crosslinking function of DAS were not disturbed. Furthermore, the infiltration of DAS and the surface morphology of the multilayer could be tuned based on their high dependence on the intensity of the high gravity field regarding different rotating speeds. The mechanism of the accelerated adsorption/infiltration under the high gravity field was interpreted by the increased turbulence of the diffusing layer with the thinned laminar boundary layer and the stepwise delivery of the local concentration gradient from the solution to the interior of the multilayer. The introduction of mechanical field provides a simple and versatile strategy to address the paradox of the contradictory loading amount and loading rate, and thus to promote applications of various membrane processes. PMID:26086776

  17. High-Level Data Races

    NASA Technical Reports Server (NTRS)

    Artho, Cyrille; Havelund, Klaus; Biere, Armin; Koga, Dennis (Technical Monitor)

    2003-01-01

    Data races are a common problem in concurrent and multi-threaded programming. They are hard to detect without proper tool support. Despite the successful application of these tools, experience shows that the notion of data race is not powerful enough to capture certain types of inconsistencies occurring in practice. In this paper we investigate data races on a higher abstraction layer. This enables us to detect inconsistent uses of shared variables, even if no classical race condition occurs. For example, a data structure representing a coordinate pair may have to be treated atomically. By lifting the meaning of a data race to a higher level, such problems can now be covered. The paper defines the concepts view and view consistency to give a notation for this novel kind of property. It describes what kinds of errors can be detected with this new definition, and where its limitations are. It also gives a formal guideline for using data structures in a multi-threading environment.

  18. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    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.

  19. High gravity brewing: Nutrient enhanced production of high concentrations of ethanol by brewing yeast

    Microsoft Academic Search

    G. P. Casey; C. A. Magnus; W. M. Ingledew

    1983-01-01

    Summary  Supplementation of high gravity brewing worts with 0.8% yeast extract, 24 ppm ergosterol and 0.24% (v\\/v) Tween 80 can result\\u000a in the production of >14% (v\\/v) alcohol at 14°C within 5 days. Unsupplemented worts require up to 2 weeks to end ferment.\\u000a Overcoming nitrogenous and lipid nutritional deficiencies results in substantial increases in cell mass production, decreased\\u000a fermentation times and

  20. RT-level TPG Exploiting High-Level Synthesis Information

    Microsoft Academic Search

    Silvia Chiusano; Fulvio Corno; Paolo Prinetto

    1999-01-01

    High-level t est pattern g eneration is today a widely investigated research topic. The present paper proposes a fully automated, simulation-based ATPG system, to address test pattern generation for circuits described at the RT-level. The approach is based on a set of suitable testability metrics, and the test pattern generation phase resorts to Genetic Algorithms. Experiments s how the excellent

  1. Overview of high level synthesis tools

    NASA Astrophysics Data System (ADS)

    Georgakakis, Spyridon; Evans, John

    2011-02-01

    High Level Synthesis takes an abstract behavioural or algorithmic description of a digital system and creates a register transfer level structure that realises the described behaviour. Various methodologies have been developed to perform such synthesis tasks. This paper presents the different HLS concepts used in the current leading tools. It makes a comparison between the different approaches and highlights their advantages and limitations. We also present a high level synthesis example.

  2. Results of co-located gravity and water-level monitoring at alluvial aquifer wells in southern Arizona

    NASA Astrophysics Data System (ADS)

    Pool, D. R.

    2008-12-01

    Correlation of gravity and water levels at thirty-nine wells in southern Arizona during 1988 to 2002 indicates that water-level change is not always a reliable indicator of aquifer-storage change for alluvial aquifer systems. Gravity change is directly proportional to aquifer storage change where other sources of mass change are minimal. Gravity estimates of aquifer-storage change can be approximated as an infinite slab except near some withdrawal wells and recharge sources. Linear regression of water-level change against one-dimensional estimates of storage change is an estimate of the aquifer storage coefficient. Non-aquifer gravity signals from temporarily stored water that does not percolate to the aquifer do not normally contribute significant noise to the observation record, but can be greater than four microGal (equivalent to three inches of water) when water is held in the root zone for brief periods following extreme rates of precipitation. The primary reason that gravity and water-level correlation was poor at some wells is that the screening of those wells across the heterogeneous alluvial aquifer did not allow monitoring of hydraulic head in the local water table aquifer. Monitoring of storage change using gravity methods at wells improved understanding of local hydrogeologic conditions. Good correlation of gravity and water levels occurred at wells where the local aquifer is primarily unconfined. Unconfined conditions were indicated at fifteen wells where significant water-level and gravity change were well correlated. Good correlations resulted in extremely large specific yield values, greater than 0.35, at seven wells where significant ephemeral streamflow infiltration likely resulted in unsaturated-zone storage change and delayed deep percolation to the water table. Poor correlation indicates confined, multiple, or perched aquifers. Confined aquifer conditions are likely at three wells where large water-level variations were accompanied by little gravity change. Monitoring of a multiple compressible aquifer system at one well resulted in negative correlation of rising water levels and subsidence-corrected gravity change, which suggests that water-level trends at the well are not a good indicator of overall storage change.

  3. High-Level Languages for Low-Level Protocols

    Microsoft Academic Search

    Iain Oliphant

    2008-01-01

    Abstract Network protocols are often implemented in languages such as C which provide high eciency,but are dicult,to maintain or extend. This project aims to show that by using a high-level language to develop a network protocol an implementa- tion is more readable and modular and therefore is more maintainable and easier to extend. To demonstrate this an implementation of the

  4. High-level language facilities for low-level services

    Microsoft Academic Search

    Christopher W. Fraser; David R. Hanson

    1985-01-01

    EZ is a language-based programming environment that offers the services provided separately by programming languages and operating systems in traditional environments. These services are provided as facilities of a high-level string processing language with a 'persistent' memory in which values exist indefinitely or until changed. In EZ, strings and associative tables provide traditional file and directory services. This paper concentrates

  5. Combined photolysis and catalytic ozonation of dimethyl phthalate in a high-gravity rotating packed bed

    Microsoft Academic Search

    Chia-Chi Chang; Chun-Yu Chiu; Ching-Yuan Chang; Chiung-Fen Chang; Yi-Hung Chen; Dar-Ren Ji; Yue-Hwa Yu; Pen-Chi Chiang

    2009-01-01

    In this study, a high-gravity rotating packed bed (HGRPB) was used as a catalytic ozonation reactor to decompose dimethyl phthalate (DMP), an endocrine disrupting chemical commonly encountered. The HGRPB is an effective gas–liquid mixing equipment which can enhance the ozone mass transfer coefficient. Platinum-containing catalyst (Pt\\/-Al2O3) of Dash 220N and ultra violet (UV) lamp were combined in the high-gravity ozonation

  6. High-Precision Simulation of the Gravity Field of Rapidly-Rotating Barotropes in Hydrostatic Equilibrium

    NASA Astrophysics Data System (ADS)

    Hubbard, W. B.

    2013-12-01

    The so-called theory of figures (TOF) uses potential theory to solve for the structure of highly distorted rotating liquid planets in hydrostatic equilibrium. TOF is noteworthy both for its antiquity (Maclaurin 1742) and its mathematical complexity. Planned high-precision gravity measurements near the surfaces of Jupiter and Saturn (possibly detecting signals ~ microgal) will place unprecedented requirements on TOF, not because one expects hydrostatic equilibrium to that level, but because nonhydrostatic components in the surface gravity, at expected levels ~ 1 milligal, must be referenced to precise hydrostatic-equilibrium models. The Maclaurin spheroid is both a useful test of numerical TOF codes (Hubbard 2012, ApJ Lett 756:L15), and an approach to an efficient TOF code for arbitrary barotropes of variable density (Hubbard 2013, ApJ 768:43). For the latter, one trades off vertical resolution by replacing a continuous barotropic pressure-density relation with a stairstep relation, corresponding to N concentric Maclaurin spheroids (CMS), each of constant density. The benefit of this trade-off is that two-dimensional integrals over the mass distributions at each interface are reduced to one-dimensional integrals, quickly and accurately evaluated by Gaussian quadrature. The shapes of the spheroids comprise N level surfaces within the planet and at its surface, are gravitationally coupled to each other, and are found by self-consistent iteration, relaxing to a final configuration to within the computer's precision limits. The angular and radial variation of external gravity (using the usual geophysical expansion in multipole moments) can be found to the limit of typical floating point precision (~ 1.e-14), much better than the expected noise/signal for either the Juno or Cassini gravity experiments. The stairstep barotrope can be adjusted to fit a prescribed continuous or discontinuous interior barotrope, and can be made to approximate it to any required precision by increasing N. One can insert a higher density of CMSs toward the surface of an interior model in order to more accurately model high-order gravitational moments. The magnitude of high-order moments predicted by TOF declines geometrically with order number, and falls below the magnitude of expected non-hydrostatic terms produced by interior dynamics at ~ order 10 and above. Juno's sensitivity is enough to detect tidal gravity signals from Galilean satellites. The CMS method can be generalized to predict tidal zonal and tesseral terms consistent with an interior model fitted to measured zonal harmonics. For this purpose, two-dimensional Gaussian quadrature is necessary at each CMS interface. However, once the model is relaxed to equilibrium, one need not refit the model to the average zonal harmonics because of the smallness of the tidal terms. I will describe how the CMS method has been validated through comparisons with standard TOF models for which fully or partially analytic solutions exist, as well as through consistency checks. At this stage in software development in preparation for Jupiter orbit, we are focused on increasing the speed of the code in order to more efficiently search the parameter space of acceptable Jupiter interior models, as well as to interface it with advanced hydrogen-helium equations of state.

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

    NASA Astrophysics Data System (ADS)

    Broerse, Taco; Riva, Riccardo; Vermeersen, Bert

    2014-11-01

    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.

  8. Many-Sorted High-Level Nets

    Microsoft Academic Search

    Jonathan Billington

    1989-01-01

    Many-sorted high-level nets (MHLNs) combine abstract data types and Petri nets within the same algebraic framework and include inhibitor arcs and place capacities. Many-sorted signatures are used to define inscriptions. MHLNs are defined at two different levels of abstraction. At an abstract level markings and capacities are defined by terms. This is suitable for specifying classes of systems. At the

  9. MEASUREMENT SYSTEMS FOR HIGH LEVEL DOSIMETRY

    Microsoft Academic Search

    E. J. Hart; H. W. Koch; B. Petree; J. H. Schulman; S. I. Taimuty; H. O. Wyckoff

    1958-01-01

    A variety of dosimetric problems are involved in the investigation and ; practical utilization of gamma-ray and electroc-beam doses of high levels. The ; dose levels considered in this report are 10⁴ to 10⁷ rads. Within ; this range, the response of the dosimetric device should be independent of dose ; rate, independent of the radiation energy, and independent of

  10. 1995 high level synthesis design repository

    Microsoft Academic Search

    Preeti Ranjan Panda; Nikil D. Dutt

    1995-01-01

    Abstract: In this paper we briefly describe a set of designs that earn serve as examples for high level synthesis (HLS) systems. The designs vary in complexity from simple behavioral finite state machines to more complex designs such as microprocessors and floating point units. Most of the designs are described in the VHDL language at the behavioral level. We divide

  11. Fast high-level fault simulator

    Microsoft Academic Search

    S. Deniziak; K. Sapiecha

    2004-01-01

    A new fast fault simulation technique is presented for calculating fault propagation through high level primitives (HLPs). Reduced ordered ternary decision diagrams are used to describe HLPs. The technique is implemented in an HTDD fault simulator. The simulator is evaluated with some ITC99 benchmarks. Besides high efficiency (in comparison with existing fault simulators), it shows flexibility for the adoption of

  12. Centrifugal Sieve for Gravity-Level-Independent Size Segregation of Granular Materials

    NASA Technical Reports Server (NTRS)

    Walton, Otis R.; Dreyer, Christopher; Riedel, Edward

    2013-01-01

    Conventional size segregation or screening in batch mode, using stacked vibrated screens, is often a time-consuming process. Utilization of centrifugal force instead of gravity as the primary body force can significantly shorten the time to segregate feedstock into a set of different-sized fractions. Likewise, under reduced gravity or microgravity, a centrifugal sieve system would function as well as it does terrestrially. When vibratory and mechanical blade sieving screens designed for terrestrial conditions were tested under lunar gravity conditions, they did not function well. The centrifugal sieving design of this technology overcomes the issues that prevented sieves designed for terrestrial conditions from functioning under reduced gravity. These sieves feature a rotating outer (cylindrical or conical) screen wall, rotating fast enough for the centrifugal forces near the wall to hold granular material against the rotating screen. Conventional centrifugal sieves have a stationary screen and rapidly rotating blades that shear the granular solid near the stationary screen, and effect the sieving process assisted by the airflow inside the unit. The centrifugal sieves of this new design may (or may not) have an inner blade or blades, moving relative to the rotating wall screen. Some continuous flow embodiments would have no inner auger or blades, but achieve axial motion through vibration. In all cases, the shearing action is gentler than conventional centrifugal sieves, which have very high velocity differences between the stationary outer screen and the rapidly rotating blades. The new design does not depend on airflow in the sieving unit, so it will function just as well in vacuum as in air. One advantage of the innovation for batch sieving is that a batch-mode centrifugal sieve may accomplish the same sieving operation in much less time than a conventional stacked set of vibrated screens (which utilize gravity as the primary driving force for size separation). In continuous mode, the centrifugal sieves can provide steady streams of fine and coarse material separated from a mixed feedstock flow stream. The centrifugal sieves can be scaled to any desired size and/or mass flow rate. Thus, they could be made in sizes suitable for small robotic exploratory missions, or for semi-permanent processing of regolith for extraction of volatiles of minerals. An advantage of the continuous-mode system is that it can be made with absolutely no gravity flow components for feeding material into, or for extracting the separated size streams from, the centrifugal sieve. Thus, the system is capable of functioning in a true microgravity environment. Another advantage of the continuous-mode system is that some embodiments of the innovation have no internal blades or vanes, and thus, can be designed to handle a very wide range of feedstock sizes, including occasional very large oversized pieces, without jamming or seizing up.

  13. High-Level Application Framework for LCLS

    SciTech Connect

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

    2008-04-22

    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.

  14. High resolution radiosonde observations of turbulence associated with breaking gravity waves

    NASA Astrophysics Data System (ADS)

    Love, P. T.; Geller, M. A.

    2012-12-01

    High vertical resolution radiosonde observations from operational US upper air stations provide new opportunities to study gravity wave breaking processes and their association with clear air turbulence on both individual and climatological bases, through the derivation of turbulence parameters facilitated by 1-second resolution. High resolution sounding data are used to identify gravity waves in the upper troposphere-lower stratosphere. Turbulence parameters are derived from the same soundings by direct measurements of the Thorpe scale from the potential temperature profiles. The association of turbulent layers with gravity wave induced shear instability is assessed in relation to energy budget and theoretical thresholds for turbulence onset. Particular source processes and regions are determined for gravity waves that are observed to induce turbulence by employing reverse ray-tracing techniques.

  15. High Resolution Measurement of Gravity Deflections from the Vertical over Long Baselines

    NASA Astrophysics Data System (ADS)

    Sander, S.; Ferguson, S.; Sander, L.; Elieff, S. H.

    2011-12-01

    Sander Geophysics has operated its AIRGrav system for over ten years and has worked to continually improve the accuracy and resolution of the entire system. New data processing techniques have allowed the extraction of the gravity deflections from the vertical (horizontal components of the airborne gravity data) in addition to the traditionally used scalar gravity measurement, and operations have expanded to acquisition speeds ranging from 15 km/hr to over 1000 km/hr. The gravimeter is based on an assembly of gyroscopes and accelerometers held in a stable spatial orientation, and has horizontal accelerometers of sufficient accuracy that it is possible to estimate the horizontal components of the gravity vector. "Geodetic quality" GPS receivers are used to collect data at a high rate, and these data are post-processed with the recorded gravimeter data to produce estimates of the three gravity vector components. The estimates of the gravity deflections from the vertical are very sensitive to initial settings of sensor parameters, unmodelled gyro and other sensor errors, as well as unpredictable changes in the sensor errors. As a consequence, it is necessary to constrain the long-wavelength errors using some external source of data. All three components of gravity can be measured to sub-mGal resolution, providing the horizontal components can be constrained in a long-wavelength sense. Data recorded during several flights each consisting of a single long line will be presented, showing the estimates of the gravity deflections from the vertical and comparing them with the best available reference data. Figure 1 illustrates the extent of the long lines. The examples will demonstrate that the horizontal gravity components can be measured with high repeatability, and agree with geoid models of the highest order available. Results from airborne and marine surveys acquired at a wide range of speeds will also be presented to illustrate the resolution attained using these varied platforms.

  16. Constraints on Lorentz Invariance Violating Quantum Gravity and Large Extra Dimensions Models using High Energy Gamma Ray Observations

    E-print Network

    F. W. Stecker

    2003-08-21

    Observations of the multi-TeV spectra of the nearby BL objects Mkn 421 and Mkn 501 exhibit the high energy cutoffs predicted to be the result of intergalactic annihilation interactions, primarily with infrared photons having a flux level as determined by various astronomical observations. After correction for this absorption effect, the derived intrinsic spectra of these multi-TeV sources can be explained within the framework of simple synchrotron self-Compton emission models. Stecker and Glashow have shown that the existence of such annihilations via electron-positron pair production interactions up to an energy of 20 TeV puts strong constraints on Lorentz invariance violation. Such constraints have important implications for Lorentz invariance violating (LIV) quantum gravity models as well as LIV models involving large extra dimensions. We also discuss the implications of observations of high energy gamma-rays from the Crab Nebula on constraining quantum gravity models.

  17. A Software Architecture for High Level Applications

    SciTech Connect

    Shen,G.

    2009-05-04

    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.

  18. Importance of terrestrial surface density information and satellite-aided global gravity field models for high precision regional geoid computation

    NASA Astrophysics Data System (ADS)

    Pock, Christian; Mayer-Gürr, Torsten; Rieser, Daniel; Kühtreiber, Norbert

    2015-04-01

    High precision regional geoid determination is a challenging task. Besides the quality of the input data, the quality of the global gravity field data and the density information is essential for a consistent treatment of the gravity field quantities within the remove-compute-restore procedure. In this investigation a surface density model based on geological observations is introduced, replacing the constant standard crustal density. The long-wavelength component of the gravity field is represented by the GOCO05s global gravity field model. The geoid computation is based on a Gauss-Markov model with radial basis function parametrization. The achieved improvements are remarkable and lead to an unprecedented accuracy of the pure gravimetric geoid in Austria. As final outcomes a new geoid solution and a map for the xi and eta components of deflections of the vertical are computed. The achieved results are primarily validated with independent GPS/leveling observations. Secondly validation has been carried out through deflections of the vertical, obtained from precise zenith camera and astronomical measurements. Furthermore, differences between the current official Austrian geoid solution based on data from 2008 and the new estimated geoid are shown. An overview about the achieved improvements and the validation is given in the presentation.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  20. High Degree and Order Gravity Fields of the Moon Derived from GRAIL Data

    NASA Astrophysics Data System (ADS)

    Lemoine, F. G.; Goossens, S. J.; Sabaka, T. J.; Nicholas, J. B.; Mazarico, E.; Loomis, B. D.; Chinn, D. S.; Caprette, D.; McCarthy, J. J.; Neumann, G. A.; Zuber, M. T.; Smith, D. E.

    2012-12-01

    The Gravity Recovery and Interior Laboratory (GRAIL) spacecraft conducted the mapping of the gravity field of the Moon from March 1, 2012 to May 29, 2012. The twin spacecraft acquired highly precise K Band range-rate (KBRR) intersatellite ranging data and Deep Space Network (DSN) data during this prime mission phase from altitudes of 15 to 75 km above the lunar surface over three lunar months. We have processed these data using the NASA GSFC GEODYN orbit determination and geodetic parameter estimation program, and we have determined gravity fields up to degree and order 420 in spherical harmonics. The new gravity solutions show improved correlations with LOLA-derived topography to high degree and order and resolve many lunar features in the geopotential with a resolution of less than 30 km, including for example the central peak of the crater Tycho. We discuss the methodology used for the processing of the GRAIL data, the quality of the orbit determination on the GRAIL satellites and the derivation of the solutions, and their evaluation with independent data, including Lunar Prospector. We show that with these new GRAIL gravity solutions, we can now fit the low altitude, extended mission Lunar Prospector tracking data better than with any previous gravity model that included the LP data.

  1. High Degree and Order Gravity Fields of the Moon Derived from GRAIL Data

    NASA Technical Reports Server (NTRS)

    Lemoine, F. G.; Goossens, S. J.; Sabaka, T. J.; Nicholas, J. B.; Mazarico, E.; Rowlands, D. D.; Loomis, B. D.; Chinn, D. S.; Caprette, D. S.; McCarthy, J. J.; Neumann, G. A.; Zuber, M. T.; Smith, D. E.

    2012-01-01

    The Gravity Recovery and Interior Laboratory (GRAIL) spacecraft conducted the mapping of the gravity field of the Moon from March 1, 2012 to May 29, 2012. The twin spacecraft acquired highly precise K Band range-rate (KBRR) intersatellite ranging data and Deep Space Network (DSN) data during this prime mission phase from altitudes of 15 to 75 km above the lunar surface over three lunar months. We have processed these data using the NASA GSFC GEODYN orbit determination and geodetic parameter estimation program, and we have determined gravity fields up to degree and order 420 in spherical harmonics. The new gravity solutions show improved correlations with LOLA-derived topography to high degree and order and resolve many lunar features in the geopotential with a resolution of less than 30 km, including for example the central peak of the crater Tycho. We discuss the methodology used for the processing of the GRAIL data, the quality of the orbit determination on the GRAIL satellites and the derivation of the solutions, and their evaluation with independent data, including Lunar Prospector. We show that with these new GRAIL gravity solutions, we can now fit the low altitude, extended mission Lunar Prospector tracking data better than with any previous gravity model that included the LP data.

  2. High-degree Gravity Models from GRAIL Primary Mission Data

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

    We have analyzed Ka?band range rate (KBRR) and Deep Space Network (DSN) data from the Gravity Recovery and Interior Laboratory (GRAIL) primary mission (1 March to 29 May 2012) to derive gravity models of the Moon to degree 420, 540, and 660 in spherical harmonics. For these models, GRGM420A, GRGM540A, and GRGM660PRIM, a Kaula constraint was applied only beyond degree 330. Variance?component estimation (VCE) was used to adjust the a priori weights and obtain a calibrated error covariance. The global root?mean?square error in the gravity anomalies computed from the error covariance to 320×320 is 0.77 mGal, compared to 29.0 mGal with the pre?GRAIL model derived with the SELENE mission data, SGM150J, only to 140×140. The global correlations with the Lunar Orbiter Laser Altimeter?derived topography are larger than 0.985 between l = 120 and 330. The free?air gravity anomalies, especially over the lunar farside, display a dramatic increase in detail compared to the pre?GRAIL models (SGM150J and LP150Q) and, through degree 320, are free of the orbit?track?related artifacts present in the earlier models. For GRAIL, we obtain an a posteriori fit to the S?band DSN data of 0.13 mm/s. The a posteriori fits to the KBRR data range from 0.08 to 1.5 micrometers/s for GRGM420A and from 0.03 to 0.06 micrometers/s for GRGM660PRIM. Using the GRAIL data, we obtain solutions for the degree 2 Love numbers, k20=0.024615+/-0.0000914, k21=0.023915+/-0.0000132, and k22=0.024852+/-0.0000167, and a preliminary solution for the k30 Love number of k30=0.00734+/-0.0015, where the Love number error sigmas are those obtained with VCE.

  3. High?degree gravity models from GRAIL primary mission data

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    have analyzed Ka?band range rate (KBRR) and Deep Space Network (DSN) data from the Gravity Recovery and Interior Laboratory (GRAIL) primary mission (1 March to 29 May 2012) to derive gravity models of the Moon to degree 420, 540, and 660 in spherical harmonics. For these models, GRGM420A, GRGM540A, and GRGM660PRIM, a Kaula constraint was applied only beyond degree 330. Variance?component estimation (VCE) was used to adjust the a priori weights and obtain a calibrated error covariance. The global root?mean?square error in the gravity anomalies computed from the error covariance to 320×320 is 0.77 mGal, compared to 29.0 mGal with the pre?GRAIL model derived with the SELENE mission data, SGM150J, only to 140×140. The global correlations with the Lunar Orbiter Laser Altimeter?derived topography are larger than 0.985 between ?=120 and 330. The free?air gravity anomalies, especially over the lunar farside, display a dramatic increase in detail compared to the pre?GRAIL models (SGM150J and LP150Q) and, through degree 320, are free of the orbit?track?related artifacts present in the earlier models. For GRAIL, we obtain an a posteriori fit to the S?band DSN data of 0.13 mm/s. The a posteriori fits to the KBRR data range from 0.08 to 1.5 ?m/s for GRGM420A and from 0.03 to 0.06 ?m/s for GRGM660PRIM. Using the GRAIL data, we obtain solutions for the degree 2 Love numbers, k20=0.024615±0.0000914, k21=0.023915±0.0000132, and k22=0.024852±0.0000167, and a preliminary solution for the k30 Love number of k30=0.00734±0.0015, where the Love number error sigmas are those obtained with VCE.

  4. High-level radioactive wastes. Supplement 1

    SciTech Connect

    McLaren, L.H. (ed.)

    1984-09-01

    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.

  5. High Level Computer Vision Sliding Window Detection

    E-print Network

    Gradients (HOG) Bernt Schiele - schiele@mpi-inf.mpg.de Mario Fritz - mfritz@mpi-inf.mpg.de http://www.d2.mpi-Maxima Suppression Today: - Viola Jones Face Detector - Haar Features - Boosting (cascade) - HOG Pedestrian Detector - HOG descriptor - linear SVM #12;High Level Computer Vision - June 5, 2o13 Overview · Detection task

  6. High Level Synthesis of Synchronous Parallel Controllers

    Microsoft Academic Search

    Krzysztof Biliriski; Erik L. Dagless

    1996-01-01

    In this paper the application of Petri nets to high level synthesis of synchronous parallel controllers is presented. A formal specification of a design is given in a form of an interpreted synchronous Petri net. Behavioral properties of the controller are verified using symbolic traversal of its Petri net model. The net state-space explosion problem is managed using binary decision

  7. High gravity and high cell density mitigate some of the fermentation inhibitory effects of softwood hydrolysates.

    PubMed

    Kapu, Nuwan Sella; Piddocke, Maya; Saddler, Jack John N

    2013-01-01

    After steam pretreatment of lignocellulosic substrates the fermentation of the biomass derived sugars to ethanol is typically problematic because of both the generally low sugar concentrations that can be supplied and the presence of naturally occurring and process derived inhibitors. As the majority of the inhibitory materials are usually associated with the hemicellulose rich, water soluble component, this fraction was supplemented with glucose to simulate high solids, un-detoxified substrate to see if a high gravity/high cell consistency approach might better cope with inhibition. Several yeast strains were assessed, with the Tembec T1, T2 and Lallemand LYCC 6469 strains showing the greatest ethanol productivity and yield. The addition of supplemental glucose enabled the faster and quantitatively higher removal of hydroxymethylfurfural (HMF). High cell density could provide effective fermentation at high sugar concentrations while enhancing inhibitor reduction. A 77% ethanol yield could be achieved using strain LYCC 6469 after 48 h at high cell density. It was apparent that a high cell density approach improved ethanol production by all of the evaluated yeast strains. PMID:23410516

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

    E-print Network

    Thompson, LuAnne

    Equilibrium Tides Along with surface gravity waves, the predictable rise and fall of sea level at the coast are our most familiar periodic motions. These tides do not represent a new class of waves, but rather are the manifestation of strong forcing at precisely repeating periods. Gravitational tide

  9. ALTURAS: A MULTI-PURPOSE RUSSET POTATO CULTIVAR WITH HIGH YIELD AND SPECIFIC GRAVITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alturas, a late- maturing, high-yielding, russet potato cultivar with high tuber specific gravity, was released in 2002 by the USDA-ARS and the Agricultural Experiment Stations of Idaho, Oregon, and Washington. Originally selected for dehydration processing, its cold-sweetening resistance also make...

  10. The CMS High-Level Trigger

    SciTech Connect

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

    2009-12-17

    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.

  11. Measured and predicted effects of gravity level on directional dendritic solidification of NH4Cl-H2O

    NASA Technical Reports Server (NTRS)

    Mccay, T. D.; Mccay, Mary H.

    1993-01-01

    Dendritic growth front rates during vertical directional solidification are predicted for gravity levels of 10 exp 0 g sub e (where e is earth gravity), 10 exp -1 g sub e, 10 exp -2 g sub e, 10 exp -3 g sub e, 10 exp -4 g sub e, and 10 exp -5 g sub e (microgravity) for the physical conditions used for a recent ammonium chloride-water solidification experiment on the International Microgravity Laboratory I (IMLI). The growth front rates at 10 exp 0 g sub e and 10 exp -5 g sub e are validated using ground based laboratory and IMLI experimental data. As the gravity decreases, the growth rates increase until they approach a maximum at approximately 10 exp -4 g sub e. The 10 exp -4 and 10 exp -5 levels are equivalent. Liquid concentration and volume fraction, temperature profiles and fluid flow velocities are also calculated. Kinetic energy calculations for each of the six gravity levels indicate that the threshold for fluid flow to affect the growth front rate is in the range of 10 exp -8 ergs.

  12. Wafer-Level Integration Technique of Surface Mount Devices on a Si-Wafer With Vibration Energy and Gravity Force

    Microsoft Academic Search

    Minoru Sudou; Hidekuni Takao; Kazuaki Sawada; Makoto Ishida

    2007-01-01

    This paper reports about a novel wafer-level integration technique of discrete surface mount devices (SMDs). It enables wafer-level mounting of plural kinds of SMDs on a silicon (Si)-wafer using vibration and gravity force. Deep holes with 400-m depth are formed on the surface of a Si-wafer by deep reactive ion etching process after general integrated circuit process for positioning of

  13. Evaluation of EGM2008 Earth Gravitational Model in Algeria using gravity and GPS/levelling data

    NASA Astrophysics Data System (ADS)

    Benahmed Daho, S. A.

    2009-04-01

    The present work focuses on the evaluation of the EGM2008 geopotential model that was recently released by the NGA (National Geospatial-Intelligence Agency, U.S)/EGM-development team, in Algeria using the free air gravity anomalies supplied by BGI and GETECH, some of the precise GPS data collected from the international TYRGEONET (TYRhenian GEOdynamical NETwork) and ALGEONET (ALGerian GEOdynamical NETwork) projects and the last Algerian local gravimetric geoid model. Additional comparisons of the terrestrial point data with the corresponding values obtained from other geopotential models were made. Five global geopotential models were used in this comparison: the Preliminary Earth Gravitational Model PGM2007A, the combined CHAMP and GRACE model EIGEN-CG01C, the combined GRACE and LAGEOS model EIGEN-GL04C, OSU91A and EGM96. The study shows that all tested models are an improvement over OSU91A geopotential model used in all previous Algerian geoid computations and that new released combined model (EGM2008) is relatively superior to other tested models in the Algerian region. According to our numerical results, the new EGM2008 model fits better the observed values used in this investigation. Its standard deviations fit with GPS/levelling data are 21.4cm and 18.7cm before and after fitting using four-parameters transformation model. We strongly recommend the use of this new model in the remove-restore technique for the computation of the improved geoid for Algeria. In addition to these more general investigations, special GPS campaign has been performed for altimetric auscultation of a storage tank in which we wanted to test the possibilities to replace levelling by GPS measurements. The evaluation revealed promising results but also that much attention has to be paid on the GPS evaluation method. Key words: Geopotential model, TYRGEONET and ALGEONET projects, GPS/levelling data.

  14. High-Level Waste Melter Study Report

    SciTech Connect

    Perez Jr, Joseph M; Bickford, Dennis F; Day, Delbert E; Kim, Dong-Sang; Lambert, Steven L; Marra, Sharon L; Peeler, David K; Strachan, Denis M; Triplett, Mark B; Vienna, John D; Wittman, Richard S

    2001-07-13

    At the Hanford Site in Richland, Washington, the path to site cleanup involves vitrification of the majority of the wastes that currently reside in large underground tanks. A Joule-heated glass melter is the equipment of choice for vitrifying the high-level fraction of these wastes. Even though this technology has general national and international acceptance, opportunities may exist to improve or change the technology to reduce the enormous cost of accomplishing the mission of site cleanup. Consequently, the U.S. Department of Energy requested the staff of the Tanks Focus Area to review immobilization technologies, waste forms, and modifications to requirements for solidification of the high-level waste fraction at Hanford to determine what aspects could affect cost reductions with reasonable long-term risk. The results of this study are summarized in this report.

  15. High-level languages for SCADA

    SciTech Connect

    Shaw, T.

    1986-09-01

    Unlike business systems and even process control systems, SCADA systems incorporate a unique blend of real-time, rapid-time, soon-time, ''background,'' and even off-line processes. Depending on the computing power available, and the architecture chosen, the SCADA system builder may be able to use high-level languages to implement these processes. Advances in computer power and language efficiency have made it possible to minimize the use of assembly codes. A structured, modular, software design enables, the use of a mixture of various high-level languages, each with its own particular strengths. Experience gained over many years on projects executed by Rexnord Automation have ranged from SCADA systems based on the Digital Equipment Corp. PDP-11 computer family with software written in assembly code MACRO and a ''home-brew'' operating system, through SCADA systems based on the DEC VAX computer family with software written in ''C'' and running under the VMS system.

  16. High-Level Waste Melter Review

    SciTech Connect

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

    2002-02-26

    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 for the method of choice for accomplishing this task is to vitrify (glassify) this waste for disposal in a geologic repository. This paper describes the results of the DOE-chartered independent review of alternatives for solidification of Hanford HLW that could achieve major cost reductions with reasonable long-term risks, including recommendations on a path forward for advanced melter and waste form material research and development. The potential for improved cost performance was considered to depend largely on increased waste loading (fewer high-level waste canisters for disposal), higher throughput, or decreased vitrification facility size.

  17. High-level nuclear waste immobilization program

    SciTech Connect

    Gordon, D E

    1980-01-01

    Existing high-level nuclear wastes in the United States are described along with current management techniques and long-term disposal options. All of the disposal options involve some type of immobilization operation to restrict radio-nuclide dispersion; the primary option is disposal of immobilized waste packages in deep (500-1000 meter) geological formations. Several immobilized waste forms currently under development are discussed, and form selection factors and regulatory criteria are identified.

  18. High level synthesis of neural network chips

    Microsoft Academic Search

    Meyer E. Nigri; Philip C. Treleaven

    In this paper we present a Neural Silicon Compiler (NSC) which is dedicated to the generation of Application-Specific Neural Network Chips (ASNNCs) from a high level C-based behavioural language. The integration of this tool into a neural network programming environment permits the translation of a neural application specified in the C-bascd input language into cither binary (for simulation) or silicon

  19. Commissioning of the CMS High Level Trigger

    SciTech Connect

    Agostino, Lorenzo; et al.

    2009-08-01

    The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008.

  20. Dynamic balance in high level athletes.

    PubMed

    Davlin, Christina D

    2004-06-01

    The purpose of this study was to investigate dynamic balance performance in highly skilled athletes. Participating athletes were currently competing at the collegiate Division I, professional, elite, or Olympic levels, or their individual coaches believed the athlete performed comparably to these levels. High level male and female gymnasts (n=57, M age=17.3 yr., SD=4.1), soccer players (n=58, M age= 19.8 yr., SD=1.6), swimmers (n=70, M age= 17.1 yr., SD=2.5), and individuals with no formal competitive sport experience (n=61, M age= 16.8 yr., SD= 2.0) volunteered. Dynamic balance performance was measured on a stabilometer, which requires participants to continuously adjust posture to maintain an unstable platform in the horizontal position for 30 sec. Each participant performed 3 practice trials followed by 7 test trials. Analysis indicated that athletes were superior to nonathletes in balance performance. Gymnasts performed better on the dynamic balance task than all other groups. Soccer players and swimmers performed similarly and were superior to the control subjects. There was no difference between the performance of men and women. Moderate to high negative correlations were found between dynamic balance performance and height and weight. PMID:15291203

  1. Could quantum gravity phenomenology be tested with high intensity lasers?

    SciTech Connect

    Magueijo, Joao [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo N2L 2Y5 (Canada); Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto M5S 3H8 (Canada); Theoretical Physics Group, Imperial College, Prince Consort Road, London SW7 2BZ (United Kingdom)

    2006-06-15

    In phenomenological quantum gravity theories, Planckian behavior is triggered by the energy of elementary particles approaching the Planck energy, E{sub P}, but it is also possible that anomalous behavior strikes systems of particles with total energy near E{sub P}. This is usually perceived to be pathological and has been labeled 'the soccer ball problem'. We point out that there is no obvious contradiction with experiment if coherent collections of particles with bulk energy of order E{sub P} do indeed display Planckian behavior, a possibility that would open a new experimental window. Unfortunately, field theory realizations of 'doubly' (or deformed) special relativity never exhibit a soccer ball problem; we present several formulations where this is undeniably true. Upon closer scrutiny we discover that the only chance for Planckian behavior to be triggered by large coherent energies involves the details of second quantization. We find a formulation where the quanta have their energy-momentum (mass-shell) relations deformed as a function of the bulk energy of the coherent packet to which they belong, rather than the frequency. Given ongoing developments in laser technology, such a possibility would be of great experimental interest.

  2. Liquid level measurement in high level nuclear waste slurries

    SciTech Connect

    Weeks, G.E.; Heckendorn, F.M.; Postles, R.L.

    1990-01-01

    Accurate liquid level measurement has been a difficult problem to solve for the Defense Waste Processing Facility (DWPF). The nuclear waste sludge tends to plug or degrade most commercially available liquid-level measurement sensors. A liquid-level measurement system that meets demanding accuracy requirements for the DWPF has been developed. The system uses a pneumatic 1:1 pressure repeater as a sensor and a computerized error correction system. 2 figs.

  3. Accurate Gravities of F, G, and K stars from High Resolution Spectra Without External Constraints

    E-print Network

    Brewer, John M; Basu, Sarbani; Valenti, Jeff A; Piskunov, Nikolai

    2015-01-01

    We demonstrate a new procedure to derive accurate and precise surface gravities from high resolution spectra without the use of external constraints. Our analysis utilizes Spectroscopy Made Easy (SME) with robust spectral line constraints and uses an iterative process to mitigate degeneracies in the fitting process. We adopt an updated radiative transfer code, a new treatment for neutral perturber broadening, a line list with multiple gravity constraints and separate fitting for global stellar properties and abundance determinations. To investigate the sources of temperature dependent trends in determining log g noted in previous studies, we obtained Keck HIRES spectra of 42 Kepler asteroseismic stars. In comparison to asteroseismically determined log g our spectroscopic analysis has a constant offset of 0.01 dex with a root mean square (RMS) scatter of 0.05 dex. We also analyzed 30 spectra which had published surface gravities determined using the $a/R_*$ technique from planetary transits and found a constan...

  4. Mixing Layer Formation near the Tropopause Due to Gravity Wave Critical Level Interactions in a Cloud-Resolving Model.

    NASA Astrophysics Data System (ADS)

    Moustaoui, Mohamed; Joseph, Binson; Teitelbaum, Hector

    2004-12-01

    A plausible mechanism for the formation of mixing layers in the lower stratosphere above regions of tropical convection is demonstrated numerically using high-resolution, two-dimensional (2D), anelastic, nonlinear, cloud-resolving simulations. One noteworthy point is that the mixing layer simulated in this study is free of anvil clouds and well above the cloud anvil top located in the upper troposphere. Hence, the present mechanism is complementary to the well-known process by which overshooting cloud turrets causes mixing within stratospheric anvil clouds. The paper is organized as a case study verifying the proposed mechanism using atmospheric soundings obtained during the Central Equatorial Pacific Experiment (CEPEX), when several such mixing layers, devoid of anvil clouds, had been observed. The basic dynamical ingredient of the present mechanism is (quasi stationary) gravity wave critical level interactions, occurring in association with a reversal of stratospheric westerlies to easterlies below the tropopause region. The robustness of the results is shown through simulations at different resolutions. The insensitivity of the qualitative results to the details of the subgrid scheme is also evinced through further simulations with and without subgrid mixing terms. From Lagrangian reconstruction of (passive) ozone fields, it is shown that the mixing layer is formed kinematically through advection by the resolved-scale (nonlinear) velocity field.


  5. The effect of enhanced gravity levels on microstructural development in Pb-50 wt pct Sn alloys during controlled directional solidification

    SciTech Connect

    Battaile, C.C. (Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering); Grugel, R.N.; Hmelo, A.B.; Wang, T.G. (Vanderbilt Univ., Nashville, TN (United States). Center for Microgravity Research and Applications)

    1994-04-01

    The Pb-50 wt pct Sn alloys were directionally solidified at 21.1 [mu]m s[sup [minus]1] through a temperature gradient of [approximately]3.5 K mm[sup [minus]1]. With the aid of a centrifuge, the solidifying dendritic interfaces were subjected to constant gravity levels, opposite to the growth direction, up to 15.3 times that of Earth's. Microstructural examination revealed no significant change in the secondary dendrite arm spacing, the interdendritic eutectic spacing, or the primary dendrite trunk diameter as a function of increasing gravity level; the primary dendrite arm spacing, however, decreased significantly. The primary spacing decrease is argued to result from suppressing convection in the bulk liquid or by modification of the rejected solute layer as a result of enhanced buoyancy.

  6. High accuracy electronic material level sensor

    DOEpatents

    McEwan, T.E.

    1997-03-11

    The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: (1) a high accuracy time base that is referenced to a quartz crystal, (2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, (3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or ``ghost`` reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%. 4 figs.

  7. High accuracy electronic material level sensor

    DOEpatents

    McEwan, Thomas E. (Livermore, CA)

    1997-01-01

    The High Accuracy Electronic Material Level Sensor (electronic dipstick) is a sensor based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line or guide wire that is partially immersed in the material being measured; a launcher plate is positioned at the beginning of the guide wire. Reflected pulses are produced at the material interface due to the change in dielectric constant. The time difference of the reflections at the launcher plate and at the material interface are used to determine the material level. Improved performance is obtained by the incorporation of: 1) a high accuracy time base that is referenced to a quartz crystal, 2) an ultrawideband directional sampler to allow operation without an interconnect cable between the electronics module and the guide wire, 3) constant fraction discriminators (CFDs) that allow accurate measurements regardless of material dielectric constants, and reduce or eliminate errors induced by triple-transit or "ghost" reflections on the interconnect cable. These improvements make the dipstick accurate to better than 0.1%.

  8. Technetium Chemistry in High-Level Waste

    SciTech Connect

    Hess, Nancy J.

    2006-06-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Lyubimova, Tatyana; Zubova, Nadezhda

    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.

  10. Reusable and Extensible High Level Data Distributions

    NASA Technical Reports Server (NTRS)

    Diaconescu, Roxana E.; Chamberlain, Bradford; James, Mark L.; Zima, Hans P.

    2005-01-01

    This paper presents a reusable design of a data distribution framework for data parallel high performance applications. We are implementing the design in the context of the Chapel high productivity programming language. Distributions in Chapel are a means to express locality in systems composed of large numbers of processor and memory components connected by a network. Since distributions have a great effect on,the performance of applications, it is important that the distribution strategy can be chosen by a user. At the same time, high productivity concerns require that the user is shielded from error-prone, tedious details such as communication and synchronization. We propose an approach to distributions that enables the user to refine a language-provided distribution type and adjust it to optimize the performance of the application. Additionally, we conceal from the user low-level communication and synchronization details to increase productivity. To emphasize the generality of our distribution machinery, we present its abstract design in the form of a design pattern, which is independent of a concrete implementation. To illustrate the applicability of our distribution framework design, we outline the implementation of data distributions in terms of the Chapel language.

  11. Gravity Fountains

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2007-01-01

    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.

  12. High-resolution global and local lunar gravity field models using GRAIL mission data

    NASA Astrophysics Data System (ADS)

    Goossens, S. J.; Lemoine, F. G.; Sabaka, T. J.; Nicholas, J. B.; Mazarico, E.; Rowlands, D. D.; Neumann, G. A.; Loomis, B.; Chinn, D. S.; Smith, D. E.; Zuber, M. T.

    2014-12-01

    The Gravity Recovery and Interior Laboratory (GRAIL) spacecraft were designed to map the structure of the Moon through high-precision global gravity mapping. The mission consisted of two spacecraft with Ka-band inter-satellite tracking complemented by tracking from Earth. The mission had two phases: (1) a primary mapping mission from March 1 until May 29, 2012 at an average altitude of 50 km; (2) an extended mission from August 30 until December 14, 2012, with an average altitude of 23 km before November 18, and between 11-20 km through December 14. Both the primary and the extended mission data have been processed into global models of the lunar gravity field at NASA/GSFC using the GEODYN software. Here we present our latest global model, an expansion in spherical harmonics of degree and order 1080. We discuss this new solution in terms of its power spectrum, its free-air and Bouguer anomalies, its associated error spectrum, and its correlations with topography-induced gravity. In addition to global models we also estimated local gravity adjustments in areas of particular interest such as Mare Orientale and the south pole area. We express gravity in terms of anomalies, and estimate them with respect to a global background model. We apply neighbor-smoothing in our estimation procedure. We present a local solution over the south pole area in a resolution of 1/6 by 1/6 of a degree, equivalent to degree and order 1080, and we compare this local solution to our global model.

  13. Microstructural variations induced by gravity level during directional solidification of near-eutectic iron-carbon type alloys

    NASA Astrophysics Data System (ADS)

    Stefanescu, Doru M.; Curreri, Peter A.; Fiske, Michael R.

    1986-07-01

    The effects of gravity on the microstructure of directionally solidified near-eutectic cast irons are studied, using a Bridgman-type automatic directional solidification furnace aboard a NASA KC-135 aircraft which flies parabolic arcs and generates alternating periods of low-g (0.01 to 0.001 g, 30 seconds long) and high-g (1.8 g, 1.5 minutes long). Results show a refinement of the interlamellar spacing of the eutectic during low-g processing of metastable Fe-C eutectic alloys. Low-g processing of stable Fe-C-Si eutectic alloys (lamellar or spheroidal graphite) results in a coarsening of the eutectic grain structure. Secondary dendrite arm spacing of austenite increases in low-g and decreases in high-g. The effectiveness of low-gravity in the removal of buoyancy-driven graphite phase segregation is demonstrated.

  14. Microstructural variations induced by gravity level during directional solidification of near-eutectic iron-carbon type alloys

    NASA Technical Reports Server (NTRS)

    Stefanescu, Doru M.; Fiske, Michael R.; Curreri, Peter A.

    1986-01-01

    The effects of gravity on the microstructure of directionally solidified near-eutectic cast irons are studied, using a Bridgman-type automatic directional solidification furnace aboard a NASA KC-135 aircraft which flies parabolic arcs and generates alternating periods of low-g (0.01 to 0.001 g, 30 seconds long) and high-g (1.8 g, 1.5 minutes long). Results show a refinement of the interlamellar spacing of the eutectic during low-g processing of metastable Fe-C eutectic alloys. Low-g processing of stable Fe-C-Si eutectic alloys (lamellar or spheroidal graphic) results in a coarsening of the eutectic grain structure. Secondary dendrite arm spacing of austenite increases in low-g and decreases in high-g. The effectiveness of low-gravity in the removal of buoyancy-driven graphite phase segregation is demonstrated.

  15. Gravity wave momentum flux variability in the high latitude northern hemisphere winter mesosphere/lower thermosphere

    NASA Astrophysics Data System (ADS)

    De Wit, Rosmarie; Hibbins, Robert; Espy, Patrick

    2013-04-01

    A new SKiYMET meteor radar was installed in Trondheim, Norway (63°N, 10°E) and has been operational since August 2012. The 30 kW transmitter array directs most of the radar power into eight beams at 45° azimuth increments with peak power around 35° off zenith, and a majority of meteor detections at zenith angles between 15° and 50°. High meteor count rates of up to 15000 per day are observed in the mesosphere and lower thermosphere region between 75 and 105 km altitude. The high meteor count rates, combined with the beam geometry, make the system particularly well suited for measuring horizontal winds at very high vertical and temporal resolution. The system is also optimized to derive the vertical flux of horizontal momentum carried by high frequency gravity waves through the mesosphere and lower thermosphere. The radar has been used to study short term variability in the gravity wave momentum flux. Preliminary results on the gravity wave momentum flux variability in the MLT region for the 2012-2013 high latitude northern hemisphere winter season will be presented, together with a description of the system design.

  16. Synoptic-scale variability of arctic gravity wave activity during summer and potential impacts on the high latitude middle atmosphere

    NASA Astrophysics Data System (ADS)

    Gerrard, Andrew John

    Although the role of gravity waves in the global atmospheric circulation is generally understood, discussion of synoptic gravity wave activity, especially pertaining to high latitude summer environments, is lacking in the literature. Tropospherically generated gravity waves greatly contribute to the zonal drag necessary to induce meridional outflow and subsequent upwelling observed in the adiabatically cooled summer mesosphere, ultimately resulting in an environment conducive to mesospheric cloud formation. However, the very gravity wave activity responsible for this induced cooling is also believed to be a major source of variability on mesospheric clouds over shorter time scales, and this topic should be of considerable interest if such clouds are to be used as tracers of the global climate. It is therefore the purpose of this thesis to explore high latitude synoptic gravity wave activity and ultimately seek an understanding of the associated influence on overlaying summer mesospheric clouds. Another goal is to better understand and account for potential variability in high latitude middle and upper atmospheric measurements that can be directly associated with "weather conditions" at lower altitudes. These endeavors are addressed through Rayleigh/aerosol lidar data obtained from the ARCtic LIdar TEchnology (ARCLITE) facility located at Sondrestrom, Greenland (67°N, 310°E), global tropospheric and stratospheric analyses and forecasts, and the Gravity-wave Regional Or Global RAy Tracer (GROGRAT) model. In this study we are able to show that (a) the upper stratospheric gravity wave strength and the brightness of overlaying mesospheric clouds, as measured by representative field proxies, are negatively correlated over time scales of less than a day, (b) such upper stratospheric gravity wave variability is inversely related to mesospheric cloud variability on time scales of ˜1 to 4 hours, (c) gravity wave hindcasts faithfully reproduce experimental lidar observations taken over the month of August 1996, (d) the observed upper stratospheric gravity wave activity is shown to originate from regionalized, non-orographic sources in the troposphere, (e) such gravity wave activity can propagate through the middle atmosphere, potentially impacting overlaying mesospheric clouds, and (f) the forecasting of such upper stratospheric gravity wave activity, and therefore the corresponding mesospheric cloud activity, is feasible. In conclusion, the results herein provide additional evidence of gravity wave influence on mesospheric clouds, a step towards the forecasting of regional gravity wave activity, and ultimately a better understanding of synoptic gravity wave activity at high latitudes.

  17. Bed Topography of Store Glacier and Fjord, Greenland from High-Resolution Gravity Data and Multi-Beam Echo Sounding

    NASA Astrophysics Data System (ADS)

    An, L.; Rignot, E. J.; Muto, A.; Morlighem, M.; Kemp, C.

    2014-12-01

    Store Glacier is a major west Greenland outlet tidewater glacier draining an area of 30,000 square km into Uummannaq Fjord, and flowing at a speed of 4.8 km per year at its terminus. The bed topography of the glacier is poorly known and the fjord bathymetry was partially surveyed for the first time in August 2012. In this study, we present a new approach for the inference of the glacier bed topography, ice thickness and sea floor bathymetry using high-resolution airborne gravity data combined with other data. In August 2012, we acquired a 250 m spacing grid of free-air gravity data at a speed of 50 knots with accuracy at sub-milligal level much higher accuracy than NASA Operation IceBridge (OIB) gravity campaign with approximate 5.2 km resolution at 290 knots flying speed. In August 2012 and 2013, we used multi-beam echo sounding to survey the sea floor bathymetry in front of the glacier, extending to the calving face of the glacier. Inland, we combined radar-derived ice thickness with ice motion vectors to reconstruct the bed topography at a high resolution. Using a 3D inversion of the gravity data, we reconstruct seamless bed topography across the ice front boundary that matches interior data and sea floor bathymetry, and provides information about sediment thickness beneath and in front of the glacier. Comparison of the results with prior maps reveals vast differences. IBCAO3 bathymetry suggests an ice front grounded at sea level while the measured ice front is grounded 550 m below sea level. The seamless topography obtained across the grounding line reveals the presence of a previously unknown sill, which explains why the glacier has been so stable in the last 50 years. The results have important impacts on the interpretation of the glacier stability, and sensitivity to thermal forcing from the ocean and surface melt. This work was conducted at UCI under a contract with the Gordon and Betty More Foundation and with NASA.

  18. Gravity gradiometry on high-T{sub c} superconducting sensors

    SciTech Connect

    Kraus, R.; Cogbill, A.; Stettler, M.

    1996-09-01

    This is the final report of a 1-y LDRD project at LANL. Earth`s gravitational field has minuscule local variations that are difficult to observe with any but the most sensitive instruments. These variations are caused by local variations in the earth`s crust density such as voids or high density material. Such anomalies can be observed directly by mapping the magnitude of the gravitational field (gravimetry) or by measuring the gradient of the gravitational field (gradiometry). It is believed that gradiometry is potentially superior to gravimetry because measurement and interpretation is simpler and less susceptible to masking by other effects, e.g. accelerations. This method introduces no energy or radiation into the region of interest, can be adapted to moving platforms and the capability to take real-time data over large areas is feasible. Scope of this work was to examine feasiiblity and performance of a fieldable gradiometer using high-{Tc} materials.

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  20. A high-resolution spherical harmonic degree 1200 lunar gravity field from the GRAIL mission

    NASA Astrophysics Data System (ADS)

    Park, R. S.; Konopliv, A. S.; Yuan, D. N.; Asmar, S. W.; Watkins, M. M.; Williams, J. G.; Smith, D. E.; Zuber, M. T.

    2014-12-01

    The highest resolution lunar gravity field to date has been generated from processing Gravity Recovery And Interior Laboratory (GRAIL) data from the primary and extended missions. The Ka-band inter-spacecraft range-rate data has a precision near 0.50 micron/second with spacecraft altitudes as close as a few kilometers above the lunar surface. This new spherical harmonic degree 1200 field involves solving for nearly 1.5 million parameters in a least-square estimation procedure and a resulting 8 TB covariance matrix, computed using the NASA Pleiades Supercomputer. The Bouguer spectrum shows that the Bouguer gravity is globally accurate to about n=600. The correlation with topography shows that the high order coefficients (n>900) are improved significantly. Moreover, the Ka-band residual RMS are significantly improved for the orbit solutions for the especially low altitudes of the last month of the extended mission. This new gravity field corresponds to the surface resolution of 5 km.

  1. Atmospheres for hot, high-gravity stars. II - Pure helium models

    NASA Astrophysics Data System (ADS)

    Wesemael, F.

    1981-02-01

    An extensive grid of pure helium stellar model atmosphere calculations for hot, high-gravity stars is presented in order to elucidate the nature and characteristics of the progenitors of the DB white dwarfs. Surface gravities range from log g equals 6.0 (1.0) 9.0, and the effective temperatures from 25,000 K at log g equals 6.0 and 8.0 up to temperatures close to the Eddington limit at each gravity. All models assume (1) hydrostatic equilibrium, (2) steady-state statistical equilibrium, (3) pure helium composition, and (4) plane-parallel geometry. In addition, most are unblanketed and in LTE, and include convective heat transport. It is shown that neutral helium lines are stronger than the unblanketed values by about 15 percent, while the singly-ionized helium lines are found to be strengthened by about 25 percent over a large range of surface gravities and effective temperatures. Multichannel colors and detailed He 1 profiles are tabulated for all LTE unblanketed models.

  2. Decontamination of high-level waste canisters

    SciTech Connect

    Nesbitt, J.F.; Slate, S.C.; Fetrow, L.K.

    1980-12-01

    This report presents evaluations of several methods for the in-process decontamination of metallic canisters containing any one of a number of solidified high-level waste (HLW) forms. The use of steam-water, steam, abrasive blasting, electropolishing, liquid honing, vibratory finishing and soaking have been tested or evaluated as potential techniques to decontaminate the outer surfaces of HLW canisters. Either these techniques have been tested or available literature has been examined to assess their applicability to the decontamination of HLW canisters. Electropolishing has been found to be the most thorough method to remove radionuclides and other foreign material that may be deposited on or in the outer surface of a canister during any of the HLW processes. Steam or steam-water spraying techniques may be adequate for some applications but fail to remove all contaminated forms that could be present in some of the HLW processes. Liquid honing and abrasive blasting remove contamination and foreign material very quickly and effectively from small areas and components although these blasting techniques tend to disperse the material removed from the cleaned surfaces. Vibratory finishing is very capable of removing the bulk of contamination and foreign matter from a variety of materials. However, special vibratory finishing equipment would have to be designed and adapted for a remote process. Soaking techniques take long periods of time and may not remove all of the smearable contamination. If soaking involves pickling baths that use corrosive agents, these agents may cause erosion of grain boundaries that results in rough surfaces.

  3. Improved High-Resolution Lunar Gravity Field Model From SELENE and Historical Tracking Data

    NASA Astrophysics Data System (ADS)

    Goossens, S. J.; Matsumoto, K.; Kikuchi, F.; Liu, Q.; Hanada, H.; Lemoine, F. G.; Rowlands, D. D.; Ishihara, Y.; Noda, H.; Namiki, N.; Iwata, T.; Sasaki, S.

    2011-12-01

    The Kaguya (SELENE) mission (September 2007 - June 2009) consisted of three separate satellites, which were tracked by a variety of terrestrial based tracking systems for the purpose of precision orbit determination and lunar gravity field determination. In addition to standard two-way Doppler and range tracking, Kaguya also carried out 4-way Doppler tracking between the sub-satellite Rstar and the main orbiter while the latter was over the far side of the Moon, and differential VLBI tracking between the two sub-satellites Rstar and Vstar. Kaguya data have been combined with historical tracking data of lunar orbiters (up to Lunar Prospector), and this has resulted in lunar gravity field models expressed in spherical harmonics up to a maximum resolution of degree and order 100. These models mapped the far side gravity field of the Moon for the first time, and helped improve the estimates of the lower degrees. Here, we present an improved, high-resolution lunar gravity field model, expressed in spherical harmonics up to degree and order 150. Our analysis differs in several crucial aspects from our previous models: we have now included the complete Lunar Prospector tracking data set, including data from the extended mission; we also included switching differential VLBI data instead of same-beam data only, which helps to further improve the orbit precision of both sub-satellites; and we extended the arc lengths of both Lunar Prospector (nominal mission only, from 2 days to 4 days, by virtue of having mapped the far side gravity field) and the main satellite of Kaguya (from 12 hours to arc lengths varying between 2 days and 1 week, by virtue of careful modelling of the angular momentum desaturation manoeuvres). The result is a model with smaller formal errors for the lower degrees, and an especially improved orbit prediction performance. Orbit propagation from an initial two-day data arc, at an average altitude of 50 km, results in orbit errors of 110 m after one month, whereas previous lunar gravity models of the same expansion produce orbit errors of 500 m and larger. Improvements are especially seen in the along-track component. With the far side gravity field included, we expect that this model is especially useful for the upcoming GRAIL mission.

  4. Training for High-Level Language Skills

    Microsoft Academic Search

    Cornelius C. Kubler

    1987-01-01

    The majority of attention in foreign language teaching in the United States has in the past been focused on the lower levels of instruction. While many students begin the study of various languages each year, only very few continue to the level where they can truly function. This country's interests demand that we train more students to higher levels of

  5. Evaluation of EGM2008 Earth Gravitational Model in Algeria using gravity and GPS\\/levelling data

    Microsoft Academic Search

    S. A. Benahmed Daho

    2009-01-01

    The present work focuses on the evaluation of the EGM2008 geopotential model that was recently released by the NGA (National Geospatial-Intelligence Agency, U.S)\\/EGM-development team, in Algeria using the free air gravity anomalies supplied by BGI and GETECH, some of the precise GPS data collected from the international TYRGEONET (TYRhenian GEOdynamical NETwork) and ALGEONET (ALGerian GEOdynamical NETwork) projects and the last

  6. A concept for the estimation of high-degree gravity field models in a high performance computing environment

    NASA Astrophysics Data System (ADS)

    Brockmann, Jan Martin; Roese-Koerner, Lutz; Schuh, Wolf-Dieter

    2013-04-01

    The estimation of the global Earth's gravity field parametrized as a finite spherical harmonic series is computationally demanding. The computational effort depends on the one hand on the maximal resolution of the spherical harmonic expansion (i.e. the number of parameters to be estimated) and on the other hand on the number of observations (which might be several millions). All global high-resolution Earth's gravity field models currently available (above degree and order 360) were computed introducing approximations. These approximations significantly reduce the numerical complexity. For example, the prerequisites for the orthogonality of the spherical harmonic base functions, leading to a block diagonal system of normal equations, are often artificially introduced by working with equally distributed data along parallels with constant accuracy. In addition, these methods do not allow for a complex modeling of the observation errors, or the inclusion of redundant observations. The gravity fields are then derived from the block-diagonal normal equations. Within this contribution a concept for the rigorous estimation of high-degree gravity models above degree and order 2000 is presented. Iterative solvers implemented in a high performance computing environment using several thousands compute cores are used to derive the rigorous least-squares solution from millions of observations for more than 4 000 000 unknown parameters. A flexible design was implemented to process an arbitrary number of observation groups. For each of these observation groups a variance component can be estimated to derive a data adaptive weighting factor of each of these observation groups. For this reason a Monte Carlo based variance component estimation is integrated into the iterative solver. The combined solution is derived in a weighted joint estimation from all observation groups which might be preprocessed normal equations (e.g. from the dedicated gravity field missions like CHAMP, GRACE or GOCE) or observations like data sets of point-wise measured terrestrial gravity field information. The concept of the implemented solver is demonstrated. A small scale closed loop simulation serves as proof of concept.

  7. High-resolution airborne gravity imaging over James Ross Island (West Antarctica)

    USGS Publications Warehouse

    Jordan, T.A.; Ferraccioli, F.; Jones, P.C.; Smellie, J.L.; Ghidella, M.; Corr, H.; Zakrajsek, A.F.

    2007-01-01

    James Ross Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological studies because it provides a window on Neogene magmatic processes and paleoenvironments. However, little is known about its internal structure. New airborne gravity data were collected as part of the first high-resolution aerogeophysical survey flown over the island and reveal a prominent negative Bouguer gravity anomaly over Mt Haddington. This is intriguing as basaltic volcanoes are typically associated with positive Bouguer anomalies, linked to underlying mafic intrusions. The negative Bouguer anomaly may be associated with a hitherto unrecognised low-density sub-surface body, such as a breccia-filled caldera, or a partially molten magma chamber.

  8. Einstein Gravity from Conformal Gravity

    E-print Network

    Juan Maldacena

    2011-06-09

    We show that that four dimensional conformal gravity plus a simple Neumann boundary condition can be used to get the semiclassical (or tree level) wavefunction of the universe of four dimensional asymptotically de-Sitter or Euclidean anti-de Sitter spacetimes. This simple Neumann boundary condition selects the Einstein solution out of the more numerous solutions of conformal gravity. It thus removes the ghosts of conformal gravity from this computation. In the case of a five dimensional pure gravity theory with a positive cosmological constant we show that the late time superhorizon tree level probability measure, $|\\Psi [ g ]|^2$, for its four dimensional spatial slices is given by the action of Euclidean four dimensional conformal gravity.

  9. Probing low-scale quantum gravity with high-energy neutrinos

    SciTech Connect

    Ennadifi, Salah Eddine, E-mail: ennadifis@gmail.com [University Mohammed V-Agdal, Laboratory of High Energy Physics, Modeling and Simulation, Faculty of Science (Morocco)

    2013-05-15

    Motivated by the quantum structure of space-time at high scales M{sub QG}, we study the propagation behavior of the high-energy neutrino within the quantum gravity effect. We consider the possible induced dispersive effect and derive the resulting vacuum refraction index {eta}{sub vac}(E{sub {nu}}) Asymptotically-Equal-To 1 + E{sub {nu}}{sup 2}/M{sub QG}{sup 2}. Then, by referring to the SN1987A and basing on the recorded neutrino data we approach the corresponding scale M{sub QG} Asymptotically-Equal-To 10{sup 4} GeV.

  10. Classical and tree-level approaches to gravitational deflection in higher-derivative gravity

    E-print Network

    Accioly, Antonio; Giacchini, Breno; Herdy, Wallace

    2015-01-01

    Among the so-called classical tests of general relativity (GR), light bending has been confirmed with an accuracy that increases as times goes by. Here we study the gravitational deflection of photons within the framework of classical and semiclassical higher-derivative gravity (HDG) -- the only version of GR that is known up to now to be renormalizable along with its matter couplings. Since our computations are restricted to scales much below the Planck cut-off we need not be afraid of the massive spin-2 ghost that haunts HDG. An upper bound on the constant related to the $R^2_{\\mu \

  11. High-level Programming of Low-level Behaviours for Autonomous Robots

    Microsoft Academic Search

    Martin Nils Peter Nilsson

    1994-01-01

    IntroductionProgramming autonomous robots requires a language that is able to express both very high-level algorithms aswell as low-level control. We are developing a concurrent programming framework, which is able to handleboth complex, high-level algorithms and very low-level hardware control in the same language. In order toillustrate these features we shall describe briefly the approach to implementing one high-level algorithm, whichis

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

    PubMed Central

    2011-01-01

    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

  13. Accurate Gravities of F, G, and K stars from High Resolution Spectra Without External Constraints

    NASA Astrophysics Data System (ADS)

    Brewer, John M.; Fischer, Debra A.; Basu, Sarbani; Valenti, Jeff A.; Piskunov, Nikolai

    2015-06-01

    We demonstrate a new procedure to derive accurate and precise surface gravities from high resolution spectra without the use of external constraints. Our analysis utilizes Spectroscopy Made Easy with robust spectral line constraints and uses an iterative process to mitigate degeneracies in the fitting process. We adopt an updated radiative transfer code, a new treatment for neutral perturber broadening, a line list with multiple gravity constraints and separate fitting for global stellar properties and abundance determinations. To investigate the sources of temperature dependent trends in determining log {\\mkern 1mu} g noted in previous studies, we obtained Keck HIRES spectra of 42 Kepler asteroseismic stars. In comparison to asteroseismically determined log {\\mkern 1mu} g our spectroscopic analysis has a constant offset of 0.01 dex with a rms scatter of 0.05 dex. We also analyzed 30 spectra which had published surface gravities determined using the a/{{R}*} technique from planetary transits and found a constant offset of 0.06 dex and rms scatter of 0.07 dex. The two samples covered effective temperatures between 5000 and 6700 K with log {\\mkern 1mu} g between 3.7 and 4.6.

  14. Poster reception - Implementing algorithms on FPGAs using high-level languages and low-level libraries

    Microsoft Academic Search

    Robin J. Bruce; Richard Chamberlain; Malachy Devlin; Stephen Marshall

    2006-01-01

    Until relatively recently, users of FPGA-based computers have needed electronic-design skills to implement high-performance computing (HPC) algorithms. With the advent of high-level languages for FPGAs it is possible for non-experts in FPGA design to implement algorithms by describing them in a high-level syntax. A natural progression from developing high-level languages is to develop low-level libraries that support them.DIME-C is a

  15. Low-level and high-level CSCW support in the Serendipity process modelling environment

    Microsoft Academic Search

    John C. Grundy; John G. Hosking; Warwick B. Mugridget

    1996-01-01

    In order to effectively collaborate using large cooperative work systems, both low-level and high-level CSCW facilities are required. Low-level mechanisms, including collaborative editing, messaging, annotations and communication, are needed. For large-scale cooperation, they should be augmented with higher-level process modelling, work coordination and work context awareness facilities. We describe the integration of both low-level and high-level support for cooperative work

  16. From mid-level to high-level: Semantic inference for multimedia retrieval

    Microsoft Academic Search

    Qianni Zhang; Ebroul Izquierdo

    2010-01-01

    The problem of bridging the semantic gap can be approached by dividing all types of metadata extracted from multimedia content into three levels - low, mid and high - according to their levels of semantic abstraction and try to define the mapping between them. This paper proposes a scheme for extracting high-level semantic information out of mid-level features, which can

  17. Viscosity Measurement of Highly Viscous Liquids Using Drop Coalescence in Low Gravity

    NASA Technical Reports Server (NTRS)

    Antar, Basil N.; Ethridge, Edwin; Maxwell, Daniel

    1999-01-01

    The method of drop coalescence is being investigated for use as a method for determining the viscosity of highly viscous undercooled liquids. Low gravity environment is necessary in this case to minimize the undesirable effects of body forces and liquid motion in levitated drops. Also, the low gravity environment will allow for investigating large liquid volumes which can lead to much higher accuracy for the viscosity calculations than possible under 1 - g conditions. The drop coalescence method is preferred over the drop oscillation technique since the latter method can only be applied for liquids with vanishingly small viscosities. The technique developed relies on both the highly accurate solution of the Navier-Stokes equations as well as on data from experiments conducted in near zero gravity environment. In the analytical aspect of the method two liquid volumes are brought into contact which will coalesce under the action of surface tension alone. The free surface geometry development as well as its velocity during coalescence which are obtained from numerical computations are compared with an analogous experimental model. The viscosity in the numerical computations is then adjusted to bring into agreement of the experimental results with the calculations. The true liquid viscosity is the one which brings the experiment closest to the calculations. Results are presented for method validation experiments performed recently on board the NASA/KC-135 aircraft. The numerical solution for this validation case was produced using the Boundary Element Method. In these tests the viscosity of a highly viscous liquid, in this case glycerine at room temperature, was determined to high degree of accuracy using the liquid coalescence method. These experiments gave very encouraging results which will be discussed together with plans for implementing the method in a shuttle flight experiment.

  18. High-resolution Gravity Field Models of the Moon Using GRAIL mission Data

    NASA Astrophysics Data System (ADS)

    Lemoine, Frank G.; Goossens, Sander; Sabaka, Terrence J.; Nicholas, Joseph B.; Mazarico, Erwan; Rowlands, David D.; Loomis, Bryant D.; Chinn, Douglas S.; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

    2015-04-01

    The Gravity Recovery and Interior Laboratory (GRAIL) mission was designed to map the structure of the lunar interior from crust to core and to advance the understanding of the Moon's thermal evolution by producing a high-quality, high-resolution map of the gravitational field of the Moon. GRAIL consisted of two spacecraft, with Ka-band tracking between the two satellites as the single science instrument, with the addition of Earth-based tracking using the Deep Space Network. The science mission was divided into two phases: a primary mission from March 1, 2012 to May 29, 2012, and an extended mission from August 30, 2012 to December 14, 2012. The altitude varied from 3 km to 94 km above the lunar surface during both mission phases. Both the primary and the extended mission data have been processed into global models of the lunar gravity field at NASA/GSFC using the GEODYN software up to 1080 x 1080 in spherical harmonics. In addition to the high-resolution global models, local models have also been developed. Due to varying spacecraft altitude and ground track spacing, the actual resolution of the global models varies geographically. Information beyond the current resolution is still present in the data, as indicated by relatively higher fits in the last part of the extended mission, where the satellites achieved their lowest altitude above lunar surface. Local models of the lunar gravitational field at high resolution were thus estimated to accommodate this signal. Here, we present the current status of GRAIL gravity modeling at NASA/GSFC, for both global and local models. We discuss the methods we used for the processing of the GRAIL data, and evaluate these solutions with respect to the derived power spectra, Bouguer anomalies, and fits with independent data (such as from the low-altitude phase of the Lunar Prospector mission). We also evaluate the prospects for extending the resolution of our current models

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

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    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.

  20. Classical and tree-level approaches to gravitational deflection in higher-derivative gravity

    NASA Astrophysics Data System (ADS)

    Accioly, Antonio; Helayël-Neto, José; Giacchini, Breno; Herdy, Wallace

    2015-06-01

    Among the so-called classical tests of general relativity (GR), light bending has been confirmed with an accuracy that increases as times goes by. Here we study the gravitational deflection of photons within the framework of classical and semiclassical higher-derivative gravity (HDG)—the only version of GR that is known up to now to be renormalizable along with its matter couplings. Since our computations are restricted to scales much below the Planck cutoff we need not be afraid of the massive spin-2 ghost that haunts HDG. An upper bound on the constant related to the R?? 2 sector of the theory is then found by analyzing—from the classical and semiclassical viewpoints—the deflection angle of a photon passing by the Sun. This upper limit greatly improves that available in the literature.

  1. Adjusting the Ion Permeability of Polyelectrolyte Multilayers through Layer-by-Layer Assembly under a High Gravity Field.

    PubMed

    Jiang, Chao; Luo, Caijun; Liu, Xiaolin; Shao, Lei; Dong, Youqing; Zhang, Yingwei; Shi, Feng

    2015-05-27

    The layer-by-layer (LbL) assembled multilayer has been widely used as good barrier film or capsule due to the advantages of its flexible tailoring of film permeability and compactness. Although many specific systems have been proposed for film design, developing a versatile strategy to control film compactness remains a challenge. We introduced the simple mechanical energy of a high gravity field to the LbL assembly process to tailor the multilayer permeability through adjusting film compactness. By taking poly(diallyldimethylammonium chloride) (PDDA) and poly{1-4[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl sodium salt} (PAzo) as a model system, we investigated the LbL assembly process under a high gravity field. The results showed that the high gravity field introduced effectively accelerated the multilayer deposition process by 20-fold compared with conventional dipping assembly; the adsorption rate was positively dependent on the rotating speed of the high gravity equipment and the concentration of the building block solutions. More interestingly, the film compactness of the PDDA/PAzo multilayer prepared under the high gravity field increased remarkably with the growing rotational speed of the high gravity equipment, as demonstrated through comparisons of surface morphology, cyclic voltammetry curves, and photoisomerization kinetics of PDDA/PAzo multilayers fabricated through the conventional dipping method and through LbL assembly under a high gravity field, respectively. In this way, we have introduced a simple and versatile external form of mechanical energy into the LbL assembling process to improve film compactness, which should be useful for further applications in controlled ion permeability, anticorrosion, and drug loading. PMID:25951984

  2. [Effect of temperature on the no cook, very high gravity ethanol fermentation process].

    PubMed

    Xu, Hongxian; Duan, Gang

    2010-03-01

    The effect of temperature on a very high gravity ethanol fermentation using no cook process was investigated. We found that a gradient temperature control strategy could improve the fermentation efficiency significantly, With the assistance of a new raw starch hydrolyzing enzyme and a gradient temperature control strategy, the ethanol concentration could reach up to 20% (V/V) within 90 h using commercially available dry yeast, when sorghum was used as the raw material and the dry substrate concentration was controlled at 35%. PMID:20518345

  3. Gravity waves and high-altitude CO$_2$ ice cloud formation in the Martian atmosphere

    E-print Network

    Yi?it, Erdal; Hartogh, Paul

    2015-01-01

    We present the first general circulation model simulations that quantify and reproduce patches of extremely cold air required for CO$_2$ condensation and cloud formation in the Martian mesosphere. They are created by subgrid-scale gravity waves (GWs) accounted for in the model with the interactively implemented spectral parameterization. Distributions of GW-induced temperature fluctuations and occurrences of supersaturation conditions are in a good agreement with observations of high-altitude CO$_2$ ice clouds. Our study confirms the key role of GWs in facilitating CO$_2$ cloud formation, discusses their tidal modulation, and predicts clouds at altitudes higher than have been observed to date.

  4. Gravitational waves from the R^-1 high order theory of gravity

    E-print Network

    Christian Corda; Maria Felicia De Laurentis

    2007-11-13

    This paper is a review of a previous research on gravitational waves from the R^-1 high order theory of gravity. It is shown that a massive scalar mode of gravitational waves from the R^-1 theory generates a longitudinal force in addition of the transverse one which is proper of the massless gravitational waves and the response of an arm of an interferometer to this longitudinal effect in the frame of a local observer is computed. Important conseguences from a theoretical point of view could arise from this approach, because it opens to the possibility of using the signals seen from interferometers to understand which is the correct theory of gravitation.

  5. Discovery of high-level tasks in the operating room

    Microsoft Academic Search

    L. Bouarfa; P. P. Jonker; J. Dankelman

    2011-01-01

    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,

  6. High level compilation for fine grained FPGAs

    Microsoft Academic Search

    Maya Gokhale; D. Gomersall

    1997-01-01

    The authors present an integrated tool set to generate highly optimized hardware computation blocks from a C language subset. By starting with a C language description of the algorithm, they address the problem of making FPGA processors accessible to programmers as opposed to hardware designers. Their work is specifically targeted to fine grained FPGAs such as the National Semiconductor CLAyTM

  7. High Level Waste Tank Gamma Profiling paper

    SciTech Connect

    FRANK, MOORE

    2005-01-24

    Cleanup at the Savannah River Site brings with it the need to clean out and close down the radioactive waste tanks constructed in support of the fuel rod dissolution process. An innovative technique for assaying waste tanks has been developed at the Savannah River Site. The technique uses a gamma detector in the annular space between the inner and outer tank walls of double walled tanks. Unique shielding, counting electronics, and deployment techniques were developed. The system provides information to facilitate mapping interstitial liquid levels, sludge layers and other structures in the waste tank located near the tank walls. The techniques used, results, and lessons learned will be discussed.

  8. Gravity investigations

    SciTech Connect

    Healey, D.L. [Geological Survey, Denver, CO (USA)

    1983-12-31

    A large density contrast exists between the Paleozoic rocks (including the rocks of Climax stock) and less dense, Tertiary volcanic rocks and alluvium. This density contrast ranges widely, and herein for interpretive purposes, is assumed to average 0.85 Mg/m{sup 3} (megagrams per cubic meter). The large density contrast makes the gravity method a useful tool with which to study the interface between these rock types. However, little or no density contrast is discernible between the sedimentary Paleozoic rocks that surround the Climax stock and the intrusive rocks of the stock itself. Therefore the gravity method can not be used to define the configuration of the stock. Gravity highs coincide with outcrops of the dense Paleozoic rocks, and gravity lows overlie less-dense Tertiary volcanic rocks and Quaternary alluvium. The positions of three major faults (Boundary, Yucca, and Butte faults) are defined by steep gravity gradients. West of the Climax stock, the Tippinip fault has juxtaposed Paleozoic rocks of similar density, and consequently, has no expression in the gravity data in that area. The gravity station spacing, across Oak Spring Butte, is not sufficient to adequately define any gravity expression of the Tippinip fault. 18 refs., 5 figs.

  9. Testing gravity at the Second post-Newtonian level through gravitational deflection of massive particles

    E-print Network

    A. Bhadra; K. Sarkar; K. K. Nandi

    2006-12-27

    Expression for second post-Newtonian level gravitational deflection angle of massive particles is obtained in a model independent framework. Several of its important implications including the possibility of testing gravitational theories at that level are discussed.

  10. High-resolution Local Gravity Model of the South Pole of the Moon from GRAIL Extended Mission Data

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

    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 1/6deg by 1/6deg (equivalent to that of a degree and order 1080 model in spherical harmonics), covering a cap over the south pole with a radius of 40deg. 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.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  12. A reconfigurable high level FPGA-based coprocessor

    Microsoft Academic Search

    S. Sukhsawas; K. Benkrid; D. Crookes

    2003-01-01

    FPGA technology enjoys both the high performance of a dedicated hardware solution and the flexibility of software that is offered by its inherent reprogrammability feature. Image processing is one application area that can benefit greatly from FPGAs performance and flexibility. This paper presents the design and implementation of a high-level reconfigurable image coprocessor on FPGAs. The image coprocessor high level

  13. Analysis of Cyberbullying Sensitivity Levels of High School Students and Their Perceived Social Support Levels

    ERIC Educational Resources Information Center

    Akturk, Ahmet Oguz

    2015-01-01

    Purpose: The purpose of this paper is to determine the cyberbullying sensitivity levels of high school students and their perceived social supports levels, and analyze the variables that predict cyberbullying sensitivity. In addition, whether cyberbullying sensitivity levels and social support levels differed according to gender was also…

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

    SciTech Connect

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

    2008-02-15

    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.

  15. Bumblebee Pupae Contain High Levels of Aluminium

    PubMed Central

    Exley, Christopher; Rotheray, Ellen; Goulson, David

    2015-01-01

    The causes of declines in bees and other pollinators remains an on-going debate. While recent attention has focussed upon pesticides, other environmental pollutants have largely been ignored. Aluminium is the most significant environmental contaminant of recent times and we speculated that it could be a factor in pollinator decline. Herein we have measured the content of aluminium in bumblebee pupae taken from naturally foraging colonies in the UK. Individual pupae were acid-digested in a microwave oven and their aluminium content determined using transversely heated graphite furnace atomic absorption spectrometry. Pupae were heavily contaminated with aluminium giving values between 13.4 and 193.4 ?g/g dry wt. and a mean (SD) value of 51.0 (33.0) ?g/g dry wt. for the 72 pupae tested. Mean aluminium content was shown to be a significant negative predictor of average pupal weight in colonies. While no other statistically significant relationships were found relating aluminium to bee or colony health, the actual content of aluminium in pupae are extremely high and demonstrate significant exposure to aluminium. Bees rely heavily on cognitive function and aluminium is a known neurotoxin with links, for example, to Alzheimer’s disease in humans. The significant contamination of bumblebee pupae by aluminium raises the intriguing spectre of cognitive dysfunction playing a role in their population decline. PMID:26042788

  16. Bumblebee pupae contain high levels of aluminium.

    PubMed

    Exley, Christopher; Rotheray, Ellen; Goulson, David

    2015-01-01

    The causes of declines in bees and other pollinators remains an on-going debate. While recent attention has focussed upon pesticides, other environmental pollutants have largely been ignored. Aluminium is the most significant environmental contaminant of recent times and we speculated that it could be a factor in pollinator decline. Herein we have measured the content of aluminium in bumblebee pupae taken from naturally foraging colonies in the UK. Individual pupae were acid-digested in a microwave oven and their aluminium content determined using transversely heated graphite furnace atomic absorption spectrometry. Pupae were heavily contaminated with aluminium giving values between 13.4 and 193.4 ?g/g dry wt. and a mean (SD) value of 51.0 (33.0) ?g/g dry wt. for the 72 pupae tested. Mean aluminium content was shown to be a significant negative predictor of average pupal weight in colonies. While no other statistically significant relationships were found relating aluminium to bee or colony health, the actual content of aluminium in pupae are extremely high and demonstrate significant exposure to aluminium. Bees rely heavily on cognitive function and aluminium is a known neurotoxin with links, for example, to Alzheimer's disease in humans. The significant contamination of bumblebee pupae by aluminium raises the intriguing spectre of cognitive dysfunction playing a role in their population decline. PMID:26042788

  17. The use of high-resolution terrain data in gravity field prediction

    NASA Technical Reports Server (NTRS)

    Groten, E.; Becker, M.; Euler, H.-J.; Hausch, W.; Kling, TH.

    1989-01-01

    Different types of gravity prediction methods for local and regional gravity evaluation are developed, tested, and compared. Four different test areas were particularly selected in view of different prediction requirements. Also different parts of the spectrum of the gravity field were considered.

  18. Improvement of the fatigue strength of aluminium alloy welded joints by high hardness and large specific gravity shot peening

    Microsoft Academic Search

    M. Hasegawa; H. Suzuki

    2005-01-01

    The shot peening method, which requires simple equipment and treatment, is extensively employed as a method to improve fatigue strength. However, conventional steel ball shot material has a low specific gravity, so high speed projection is required in order to improve fatigue strength; thus, the accompanying noise and high air flow are problems. Accordingly, in order to improve these aspects,

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

    NASA Technical Reports Server (NTRS)

    Jekeli, Christopher

    1989-01-01

    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.

  20. Acceleration levels on board the Space Station and a tethered elevator for micro and variable-gravity applications

    NASA Technical Reports Server (NTRS)

    Lorenzini, E. C.; Cosmo, M.; Vetrella, S.; Moccia, A.

    1988-01-01

    This paper investigates the dynamics and acceleration levels of a new tethered system for micro and variable-gravity applications. The system consists of two platforms tethered on opposite sides to the Space Station. A fourth platform, the elevator, is placed in between the Space Station and the upper platform. Variable-g levels on board the elevator are obtained by moving this facility along the upper tether, while micro-g experiments are carried out on board the Space Station. By controlling the length of the lower tether the position of the system CM can be maintained on board the Space Station despite variations of the station's distribution of mass. The paper illustrates the mathematical model, the environmental perturbations and the control techniques which have been adopted for the simulation and control of the system dynamics. Two sets of results from two different simulation runs are shown. The first set shows the system dynamics and the acceleration spectra on board the Space Station and the elevator during station-keeping. The second set of results demonstrates the capability of the elevator to attain a preselected g-level.

  1. Extended Gravity Theories and the Einstein-Hilbert Action

    E-print Network

    David Wands

    1993-07-23

    I discuss the relation between arbitrarily high-order theories of gravity and scalar-tensor gravity at the level of the field equations and the action. I show that $(2n+4)$-order gravity is dynamically equivalent to Brans-Dicke gravity with an interaction potential for the Brans-Dicke field and $n$ further scalar fields. This scalar-tensor action is then conformally equivalent to the Einstein-Hilbert action with $n+1$ scalar fields. This clarifies the nature and extent of the conformal equivalence between extended gravity theories and general relativity with many scalar fields.

  2. Sound Transformations Based on the SMS High Level Attributes

    Microsoft Academic Search

    Xavier Serra; Jordi Bonada

    1998-01-01

    The basic Spectral Modeling Synthesis (SMS) technique models sounds as the sum of sinusoids plus a residual. Though this analysis\\/synthesis system has proved to be successful in transforming sounds, more powerful and intuitive musical transformations can be achieved by moving into the SMS high-level attribute plane. In this paper we describe how to extract high level sound attributes from the

  3. Simplifying optimistic distributed simulations in the High Level Architecture

    Microsoft Academic Search

    Fernando Vardanega; Carlos Maziero

    The recent studies in the distributed simulation area are focused in the High Level Architecture, defined by the DoD\\/USA, which proposes a standard environment to de- velop and run distributed simulations. The HLA compo- nents are designed to ensure a high level of interoperabil- ity among simulations and, also, to allow maximum com- ponent reusability. This paper proposes a new

  4. Neural Network Based Macromodels for High Level Power Estimation

    Microsoft Academic Search

    Kuntal Roy

    2007-01-01

    In this article, a neural network based macromodeling technique is proposed for high level power estimation of logic circuits. With the advent of high-density microelectronic devices, power dissipation of VLSI circuits has become a critical concern. Consequently power estimation accuracy at higher levels is an important issue to avoid costly redesign steps. Artificial Neural Network (ANN) with its capability to

  5. MEMORY AWARE HIGH-LEVEL SYNTHESIS FOR EMBEDDED SYSTEMS

    E-print Network

    Paris-Sud XI, Université de

    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

  6. Compositional System-Level Design Exploration with Planning of High-Level Synthesis

    E-print Network

    Carloni, Luca

    by synthesis tools, among which high-level synthesis (HLS), e.g. from SystemC to RTL, has evolved SoC. Contributions. We propose a HLS-driven design method- ology for compositional system of synthesizable components which are both designed in high-level languages and characterized through HLS

  7. Bridging the Gap between High-Level Reasoning and Low-Level Control

    E-print Network

    Erdem, Esra

    show the applicability of this framework on two LEGO MINDSTORMS NXT robots, in an action domain] describes a system, LEGOLOG1 , that controls a LEGO MINDSTORMS RIS robot us- ing the high-level control Python LEGO MINDSTORMS BLUETOOTH Fig. 1. The overall system architecture high-level control for a Khepera

  8. Predictors of Placement in Lower Level versus Higher Level High School Mathematics

    ERIC Educational Resources Information Center

    Archbald, Doug; Farley-Ripple, Elizabeth N.

    2012-01-01

    Educators and researchers have long been interested in determinants of access to honors level and college prep courses in high school. Factors influencing access to upper level mathematics courses are particularly important because of the hierarchical and sequential nature of this subject and because students who finish high school with only lower…

  9. High-level algorithm and architecture transformations for DSP synthesis

    Microsoft Academic Search

    Keshab K. Parhi

    1995-01-01

    This survey paper reviews numerous high-level transformation techniques which can be applied at the algorithm or the architecture\\u000a level to improve the performance of digital signal and image processing architectures and circuits implemented using VLSI\\u000a technology. Successful design of VLSI signal and image processors requires careful selection of algorithms, architectures,\\u000a implementation styles, and synthesis techniques. High-level transformations can play an

  10. High-level Verification of Handwritten Numeral Strings

    Microsoft Academic Search

    L. S. OLIVEIRA; F. B ORTOLOZZI; C. Y. S UEN

    In this paper we discuss the use of high-level verification on handwritten numeral strings. First of all, we introduce the concept of levels of verification and present the baseline system used to carry out the experiments. Two different strategies were developed: absolute and one-to-one verifiers. A thorough error analysis is also presented in order to identify under which conditions high-level

  11. Region-based high-level semantics extraction with CEDD

    Microsoft Academic Search

    Yuzhu Zhou; Le Li; Tong Zhao; Honggang Zhang

    2010-01-01

    Given an image, our proposed model can extract its dominant high-level semantics information through low-level feature extraction and image classification. It contains 3 main parts: image segmentation, feature extraction and classification. To our knowledge, this is the first model that applies Color and Edge Directivity Descriptor (CEDD), a multiple feature extraction algorithm, into the high-level semantics extraction field. Further, we

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

    PubMed Central

    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

    2014-01-01

    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. Key Points We present a high-resolution gravity model of the south pole of the Moon Improved correlations with topography to higher degrees than global models Improved fits to the data and reduced striping that is present in global models PMID:26074637

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

    PubMed Central

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

    2014-01-01

    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

  14. Magic for the masses: safer high-level low-level programming through customizable static analyses

    Microsoft Academic Search

    Ralf Mitschke; Andreas Sewe; Mira Mezini

    2011-01-01

    Writing high-performance virtual machines in a high-level language requires an escape-hatch, such that unavoidable low-level tasks can be performed efficiently. To this end, the org.vmmagic framework used by Jikes RVM and other VMs makes it possible to extend the Java language with the needed low-level facilities. For these facilities and the constraints they impose, though, tool support is almost nonexistent,

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

    SciTech Connect

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

    1994-12-31

    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.

  16. High Energy Astrophysics Tests of Lorentz Invariance and Quantum Gravity Models

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd W.

    2011-01-01

    High-energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10-35 m. I will discuss here the possible signatures of Lorentz invariance violation (LIV) from observations of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and gamma-ray bursts. Other sensitive tests are provided by observations ofthe spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) to the amount of LIV at a proton Lorentz factor of -2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space based detection techniques to improve searches for LIV in the future.

  17. Optical Mass Gauging System for Measuring Liquid Levels in a Reduced Gravity Environment

    NASA Technical Reports Server (NTRS)

    Sullenberger, Ryan M.; Munoz, Wesley M.; Lyon, Matt P.; Vogel, Kenny; Yalin, Azer P.; Korman, Valentin; Polzin, Kurt A.

    2010-01-01

    A compact and rugged fiber-coupled liquid volume sensor designed for flight on a sounding rocket platform is presented. The sensor consists of a Mach-Zehnder interferometer capable of measuring the amount of liquid contained in a tank under any gravitational conditions, including a microgravity environment, by detecting small changes in the index of refraction of the gas contained within a sensing region. By monitoring changes in the interference fringe pattern as the system undergoes a small compression provided by a piston, the ullage volume of a tank can be directly measured allowing for a determination of the liquid volume. To demonstrate the technique, data are acquired using two tanks containing different volumes of liquid, which are representative of the levels of liquid in a tank at different time periods during a mission. The two tanks are independently exposed to the measurement apparatus, allowing for a determination of the liquid level in each. In a controlled, laboratory test of the unit, the system demonstrated a capability of measuring a liquid level in an individual tank of 10.53 mL with a 2% error. The overall random uncertainty for the flight system is higher than that one test, at +/- 1.5 mL.

  18. Stable superconducting magnet. [high current levels below critical temperature

    NASA Technical Reports Server (NTRS)

    Boom, R. W. (inventor)

    1967-01-01

    Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training.

  19. Gravity, Time, and Lagrangians

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2010-01-01

    Feynman mentioned to us that he understood a topic in physics if he could explain it to a college freshman, a high school student, or a dinner guest. Here we will discuss two topics that took us a while to get to that level. One is the relationship between gravity and time. The other is the minus sign that appears in the Lagrangian. (Why would one…

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

    USGS Publications Warehouse

    McGuire, V.L.

    2011-01-01

    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).

  1. Brane-World Gravity

    NASA Astrophysics Data System (ADS)

    Maartens, Roy; Koyama, Kazuya

    2010-09-01

    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.

  2. The shallow structure of Klauea caldera from high-resolution Bouguer gravity and total magnetic anomaly mapping

    E-print Network

    Williams-Jones, Glyn

    The shallow structure of Klauea caldera from high-resolution Bouguer gravity and total magnetic the summit caldera of Klauea Volcano, Hawai'i. Two significant and distinctive magnetic anomalies were identified within the caldera. One is interpreted to be associated with a long-lived prehistoric eruptive

  3. National high-level waste systems analysis report

    SciTech Connect

    Kristofferson, K.; Oholleran, T.P.; Powell, R.H.

    1995-09-01

    This report documents the assessment of budgetary impacts, constraints, and repository availability on the storage and treatment of high-level waste and on both existing and pending negotiated milestones. The impacts of the availabilities of various treatment systems on schedule and throughput at four Department of Energy sites are compared to repository readiness in order to determine the prudent application of resources. The information modeled for each of these sites is integrated with a single national model. The report suggests a high-level-waste model that offers a national perspective on all high-level waste treatment and storage systems managed by the Department of Energy.

  4. Reference commercial high-level waste glass and canister definition.

    SciTech Connect

    Slate, S.C.; Ross, W.A.; Partain, W.L.

    1981-09-01

    This report presents technical data and performance characteristics of a high-level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository. The borosilicate glass contained in the stainless steel canister represents the probable type of high-level waste product that will be produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high-level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented.

  5. Aeromagnetic study of the midcontinent gravity high of central United States

    USGS Publications Warehouse

    King, Elizabeth R.; Zietz, Isidore

    1971-01-01

    A composite map of detailed aeromagnetic surveys over the midcontinent gravity high provides coverage of the 600-mi-long buried belt of mafic rocks of the Keweenawan Series from their outcrop localities in Minnesota and Wisconsin through Iowa and Nebraska. A map of the subsurface extent of the mafic rocks, based on the intricate magnetic patterns, shows that the rocks form a long, semicontinuous block, averaging 40 mi wide and consisting mainly of a sequence of layered flows. This sequence is probably fault-bounded and has been tilted up along the margins, where the linearity of the anomalies indicates steeper dips. The associated clastic rocks, indicated by a smoother magnetic pattern, occur in basins along both sides of the mafic belt and in grabens and a series of axial basins on the upper surface of the block. The well-defined outliers of flows marginal to the main block and the truncation of some of the outermost flow units along a diagonal boundary striking at an angle to them suggest that the present boundaries of the block are postdepositional structural features. The basins and the edges of the block appear to have controlled later, largely vertical movement in the overlying Paleozoic and younger sedimentary cover. Calculated models based on coincident magnetic and detailed gravity profiles along typical cross sections of the midcontinent gravity high show that the block of mafic rocks is steep-sided and as much as several miles thick. The free-air gravity anomaly, which consists of a large positive maximum flanked by minima, averages very close to zero, indicating that this major crustal feature is regionally compensated, although locally each of its components shows a large departure from equilibrium. Remanent magnetization is a primary factor in the interpretation of the magnetic data. Magnetic property studies of Keweenawan mafic rocks in the Lake Superior region show that remanent magnetization may be five times the magnetization induced by the present Earth's field and differs from it radically in direction. This magnetization was acquired before the flows were tilted into their present positions. A computed magnetic profile shows that a trough of flows with such a magnetization and inward-dipping limbs can account for the observed persistent lows along the western edge of the block, the relatively low magnetic values along the axis of the block, and the large positive anomaly along the eastern side of the block. Flows as much as 1 mi thick near the base of the sequence have a remanent magnetization with a nearly opposite polarity. This reverse polarity has been measured on both sides of Lake Superior and is probably also present farther south, particularly in Iowa where the outer units of the block in an area north of Des Moines give rise to a prominent magnetic low. The axis of this long belt of Keweenawan mafic rocks cuts discordantly through the prevailing east-west-trending fabric of the older Precambrian terrane from southern Kansas to Lake Superior. This belt has several major left-lateral offsets, one of which produces a complete hiatus in the vicinity of the 40th parallel where an east-west transcontinental rift or fracture zone has been proposed. The axial basins of clastic rocks are outlined by linear magnetic anomalies and show a concordant relation to the structure of the mafic flows. These basins are oriented at an angle to the main axis, suggesting that the entire feature originated as a major rift composed of a series of short, linear, en echelon segments with offsets similar to the transform faults characterizing the present mid-ocean rift system. This midcontinent rift may well have been part of a Keweenawan global rift system with initial offsets consisting of transform faults along pre-existing fractures, but apparently it never fully developed laterally into an ocean basin, and the upwelling mafic material was localized along a relatively narrow belt.

  6. Aeromagrnetic study of the midcontinent gravity high of central United States

    USGS Publications Warehouse

    King, Elizabeth R.; Zietz, Isidore

    1971-01-01

    A composite map of detailed aeromagnetic surveys over the midcontinent gravity high provides coverage of the 600-mi-long buried belt of mafic rocks of the Keweenawan Series from their outcrop localities in Minnesota and Wisconsin through Iowa and Nebraska. A map of the subsurface extent of the mafic rocks, based on the intricate magnetic patterns, shows that the rocks form a long, semicontinuous block, averaging 40 mi wide and consisting mainly of a sequence of layered flows. This sequence is probably fault-bounded and has been tilted up along the margins, where the linearity of the anomalies indicates steeper dips. The associated clastic rocks, indicated by a smoother magnetic pattern, occur in basins along both sides of the mafic belt and in grabens and a series of axial basins on the upper surface of the block. The well-defined outliers of flows marginal to the main block and the truncation of some of the outermost flow units along a diagonal boundary striking at an angle to them suggest that the present boundaries of the block are postdepositional structural features. The basins and the edges of the block appear to have controlled later, largely vertical movement in the overlying Paleozoic and younger sedimentary cover. Calculated models based on coincident magnetic and detailed gravity profiles along typical cross sections of the midcontinent gravity high show that the block of mafic rocks is steep-sided and as much as several miles thick. The free-air gravity anomaly, which consists of a large positive maximum flanked by minima, averages very close to zero, indicating that this major crustal feature is regionally compensated, although locally each of its components shows a large departure from equilibrium. Remanent magnetization is a primary factor in the interpretation of the magnetic data. Magnetic property studies of Keweenawan mafic rocks in the Lake Superior region show that remanent magnetization may be five times the magnetization induced by the present Earth's field and differs from it radically in direction. This magnetization was acquired before the flows were tilted into their present positions. A computed magnetic profile shows that a trough of flows with such a magnetization and inward-dipping limbs can account for the observed persistent lows along the western edge of the block, the relatively low magnetic values along the axis of the block, and the large positive anomaly along the eastern side of the block. Flows as much as 1 mi thick near the base of the sequence have a remanent magnetization with a nearly opposite polarity. This reverse polarity has been measured on both sides of Lake Superior and is probably also present farther south, particularly in Iowa where the outer units of the block in an area north of Des Moines give rise to a prominent magnetic low. The axis of this long belt of Keweenawan mafic rocks cuts discordantly through the prevailing east-west-trending fabric of the older Precambrian terrane from southern Kansas to Lake Superior. This belt has several major left-lateral offsets, one of which produces a complete hiatus in the vicinity of the 40th parallel where an east-west transcontinental rift or fracture zone has been proposed. The axial basins of clastic rocks are outlined by linear magnetic anomalies and show a concordant relation to the structure of the mafic flows. These basins are oriented at an angle to the main axis, suggesting that the entire feature originated as a major rift composed of a series of short, linear, en echelon segments with offsets similar to the transform faults characterizing the present mid-ocean rift system. This midcontinent rift may well have been part of a Keweenawan global rift system with initial offsets consisting of transform faults along pre-existing fractures, but apparently it never fully developed laterally into an ocean basin, and the upwelling mafic material was localized along a relatively narrow belt.

  7. Evaluation of theories of complex movement planning in different levels of gravity.

    PubMed

    Tagliabue, M; Pedrocchi, A; Baroni, G; Pedotti, A; Ferrigno, G

    2005-01-01

    Due to high redundancy of degrees of freedom in the human body, we can perform any movement, from the simplest to the most complex, in many different ways. Several studies are still trying to identify the motor strategies that master this redundancy and generate the movements whose characteristics are highly stereotyped. The aim of this work is to build a simulator that is able to evaluate different motor planning hypotheses. The most interesting applications of this tool occur in studies of the motor strategy in microgravity conditions. The comparison between simulated movements and kinematics data recorded both on Earth, and during a 5-month mission on board the Mir station shows that for a complex whole-body movement (such as trunk bending) a single planning criterion cannot explain all movement aspects. However, the simulator allows an understanding of the motor planning adaptation of astronauts. In space, the lack of equilibrium constraint (which on Earth brings about the center of mass control) leads to a new motor strategy that minimizes dynamic interactions with the floor. PMID:15835041

  8. The ATLAS high level trigger region of interest builder.;

    SciTech Connect

    Blair, R.; Dawson, J.; Drake, G.; Haberichter, W.; Schlereth, J.; Zhang, J.; Ermoline, Y.; Pope, B.; Aboline, M.; High Energy Physics; Michigan State Univ.

    2008-04-01

    This article describes the design, testing and production of the ATLAS Region of Interest Builder (RoIB). This device acts as an interface between the Level 1 trigger and the high level trigger (HLT) farm for the ATLAS LHC detector. It distributes all of the Level 1 data for a subset of events to a small number of (16 or less) individual commodity processors. These processors in turn provide this information to the HLT. This allows the HLT to use the Level 1 information to narrow data requests to areas of the detector where Level 1 has identified interesting objects.

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

    NASA Technical Reports Server (NTRS)

    Fukumori, Ichiro

    1995-01-01

    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.

  10. Transportation system modeling using the High Level Architecture 

    E-print Network

    Melouk, Sharif

    2004-09-30

    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 ...

  11. Vitrification of sulphate bearing high level wastes in borosilicate matrix

    Microsoft Academic Search

    P. B Jahagirdar; P. K Wattal

    1998-01-01

    The paper deals with the development and characterization of vitreous matrices for the containment of sulphate bearing high level wastes. Studies were conducted in the sodium borosilicate system with the introduction of CaO, BaO, MgO, etc., and also in the lead borosilicate system. The results reveal that the lead borosilicate system is compatible with sulphate bearing high level wastes. Detailed

  12. Synthesising Generative Probabilistic Models for High-Level Activity Recognition

    Microsoft Academic Search

    Christoph Burghardt; Maik Wurdel; Sebastian Bader; Gernot Ruscher; Thomas Kirste

    \\u000a High-level (hierarchical) behaviour with long-term correlations is difficult to describe with first-order Markovian models\\u000a like Hidden Markov models. We therefore discuss different approaches to synthesise generative probabilistic models for activity\\u000a recognition based on different symbolic high-level description. Those descriptions of complex activities are compiled into\\u000a robust generative models. The underlying assumptions for our work are (i) we need probabilistic models

  13. High-Level Waste System Process Interface Description

    SciTech Connect

    d'Entremont, P.D.

    1999-01-14

    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.

  14. Measures of effectiveness for high-level fusion

    Microsoft Academic Search

    Erik Blasch; Pierre Valin; Eloi Bosse

    2010-01-01

    Current advances in technology, sensor collection, data storage, and data distribution have afforded more complex, distributed, and operational information fusion systems (IFSs). IFSs notionally consist of low-level (data collection, registration, and association in time and space) and high-level fusion (user coordination, situational awareness, and mission control). Low-level IFSs typically rely on standard metrics for evaluation such as timeliness, accuracy, and

  15. Discovery of high-level tasks in the operating room.

    PubMed

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

    2011-06-01

    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

  16. High CO2 levels in the Proterozoic atmosphere estimated from

    E-print Network

    Kaufman, Alan Jay

    .............................................................. High CO2 levels in the Proterozoic fractionation in these large, morphologically complex micro- fossils suggest elevated levels of carbon dioxide at nanometre resolution using a field-emission scanning electron microscope (FE-SEM). A handful of 1­4-mm

  17. Field Trips as Cognitive Motivators for High Level Science Learning

    ERIC Educational Resources Information Center

    Hurley, Marlene M.

    2006-01-01

    Using a composite example of field trips from several years of traveling to Yellowstone with high school biology students, the author illustrates how to raise the cognitive level of science instruction and student learning through science field trips. The author examines what teachers can do to raise the level of both teaching and learning in all…

  18. HIGH LEVEL OF CENTRALIZATION AND LOCAL DEBT IN SLOVENIA

    Microsoft Academic Search

    Maja Klun

    As a new member of the European Union, Slovenia made several legislation changes during the accession process and as a small country could benef it a great deal from the large EU single market. Despite so many changes almost none were at the local level. Local government in Slovenia has to deal with a high level of centralization of public

  19. High Epitope Expression Levels Increase Competition between T Cells

    E-print Network

    Bonhoeffer, Sebastian

    High Epitope Expression Levels Increase Competition between T Cells Almut Scherer, Marcel Salathe epitope ligand. We have developed an individual- based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell

  20. Some experiences with experimental high level fusion systems

    Microsoft Academic Search

    J. Biermann

    2007-01-01

    A very short overview is given on experience gained in the area of high level information fusion (JDL level 2 and 3) since 1988. The main characteristics of the referenced projects and experimental systems for the support of intelligence officers in land battle missions will be outlined. The different approaches to analyse and model military intelligence processing and the development

  1. THE ENHANCEMENT OF LOW-LEVEL CLASSIFICATIONS IN SEQUENTIAL SYNTACTIC HIGH-LEVEL CLASSIFIERS

    Microsoft Academic Search

    Deborah E. Goshorn

    This paper surveys a new research field of object behavior classification using sequential syntactic pattern recognition, which recognizes high-level object behaviors while in paral- lel recovering from low-level object recognition classification errors. A new approach of syntactical object behavior clas- sification with a robust implementation is introduced. It is an innovative approach that requires no training, only a pri- ori

  2. A framework for translating a high level security policy into low level security mechanisms

    Microsoft Academic Search

    Ahmad A. Hassan; W. M. Bahgat

    2009-01-01

    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

  3. High Level High Performance Computing for Multitask Learning of Time-varying Models

    E-print Network

    High Level High Performance Computing for Multitask Learning of Time-varying Models Marco-scale problems and is amenable to parallelization. We then compare high level high performance implementation strategies that rely on JIT decorators. The approach enables, in particular, to offload computations to a GPU

  4. The American High School Graduation Rate: Trends and Levels

    Microsoft Academic Search

    James J. Heckman; Paul A. LaFontaine

    2008-01-01

    This paper uses multiple data sources and a unified methodology to estimate the trends and levels of the U.S. high school graduation rate. Correcting for important biases that plague previous calculations, we establish that (a) the true high school graduation rate is substantially lower than the official rate issued by the National Center for Educational Statistics; (b) it has been

  5. The American High School Graduation Rate: Trends and Levels

    Microsoft Academic Search

    James J. Heckman; Paul A. LaFontaine

    2007-01-01

    This paper uses multiple data sources and a unified methodology to estimate the trends and levels of the U.S. high school graduation rate. Correcting for important biases that plague previous calculations, we establish that (a) the true high school graduation rate is substantially lower than the official rate issued by the National Center for Educational Statistics; (b) it has been

  6. High-Performance Implementation of the Level-3 KAZUSHIGE GOTO

    E-print Network

    Batory, Don

    . 2. HIGH-PERFORMANCE IMPLEMENTATION OF MATRIX-MATRIX MULTIPLI- CATION To understand how to convert for transforming high-performance implementations on cache-based architectures of matrix-matrix multiplication into implementations of other commonly used matrix-matrix computations (the level-3 BLAS) is presented. Exceptional

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

    E-print Network

    Cabeche, Dion Tunick

    2011-01-01

    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 ...

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

    E-print Network

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

    2010-01-01

    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...

  9. Terrestrial Gravity Fluctuations

    E-print Network

    Harms, Jan

    2015-01-01

    The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.

  10. Terrestrial Gravity Fluctuations

    E-print Network

    Jan Harms

    2015-07-21

    The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.

  11. A High-Level Single-Sideband Transmitter

    Microsoft Academic Search

    1948-01-01

    Double-sideband suppressed-carrier signals can be generated with relatively high efficiency at high power levels in grid-modulated balanced modulators so biased that very little plate current flows in the absence of audio input. When tubes having a constant-current characteristic are used, and the necessary quadrature phase shift between pairs of audio- and radio-frequency excitation voltages exists, two high-power balanced modulators of

  12. Preparation and characterization of zinc sulfide nanoparticles under high-gravity environment

    SciTech Connect

    Chen Jianfeng; Li Yaling; Wang Yuhong; Yun, Jimmy; Cao Dapeng

    2004-02-02

    Nanosized ZnS particles were prepared under high-gravity environment generated by the rotating packed bed reactor (RPBR) using zinc nitrate solution and hydrogen sulfide gas as raw materials. The effects of experimental conditions such as reactant concentration, reaction temperature, rotating speed of the RPBR and aging time, on the preparation of nanosized ZnS particles were investigated. A set of suitable operating parameters (the aging time of 48 h, concentration of zinc nitrate of 0.1 mol/l, reaction temperature of 45 deg. C and rotating speed of the RPBR of 1500-1800 rotation/min) for the preparation of nanosized ZnS were recommended. Under these optimum conditions, well-dispersed ZnS nanoparticles was obtained. The crystal structure, optical properties, size and morphology of the product were also characterized by XRD, UV-Vis spectrophotometer, and TEM, respectively. Results indicate that the prepared ZnS has a good absorption for light in the wavelength range of 200-330 nm. XRD analysis also shows the prepared ZnS is in a sphalerite crystal phase. The process has great potential of commercialization.

  13. High Energy Astrophysics Tests of Lorentz Invariance and Quantum Gravity Models

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    2011-01-01

    High energy astrophysics observations provide the best possibilities to detect a very small violation of Lorentz invariance such as may be related to the structure of space-time near the Planck scale of approximately 10(exp -35)m. I will discuss the possible signatures of Lorentz invariance violation (LIV) that can be manifested by observing of the spectra, polarization, and timing of gamma-rays from active galactic nuclei and y-ray bursts. Other sensitive tests are provided by observations of the spectra of ultrahigh energy cosmic rays and neutrinos. Using the latest data from the Pierre Auger Observatory one can already derive an upper limit of 4.5 x 10(exp -23) on the fraction of LIV at a Lorentz factor of approximately 2 x 10(exp 11). This result has fundamental implications for quantum gravity models. I will also discuss the possibilities of using more sensitive space-based detection techniques to improve searches for LIV in the future.

  14. Kinematic and highly reduced-dynamic LEO orbit determination for gravity field estimation

    Microsoft Academic Search

    A. Jäggi; G. Beutler; H. Bock; U. Hugentobler

    Kinematic positions of low Earth orbiting satellites equipped with spaceborne GPS receivers are widely used as input for subsequent\\u000a gravity field estimation procedures. Positions relying on reduced-dynamic orbit determination, however, are often considered\\u000a as inappropriate for this task, because they depend to some extent on the gravity field model underlying the orbit estimation.\\u000a We review the principles of reduced-dynamic orbit

  15. 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

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

    2008-01-01

    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.

  16. Mercury levels in high-end consumers of fish.

    PubMed Central

    Hightower, Jane M; Moore, Dan

    2003-01-01

    Consumption of food containing mercury has been identified as a health risk. The U.S. Environmental Protection Agency (U.S. EPA) and the National Academy of Sciences recommend keeping the whole blood mercury level < 5.0 microg/L or the hair level < 1.0 microg/g. This corresponds to a reference dose (RfD) of 0.1 microg/kg body weight per day. All patients in a 1-year period (n = 720) who came for an office visit in a private internal medicine practice in San Francisco, California, were evaluated for mercury excess using the current RfD. One hundred twenty-three patients were tested (93 females, 30 males). Of these, data were statistically analyzed for 89 subjects. Mercury levels ranged from 2.0 to 89.5 microg/L for the 89 subjects. The mean for 66 women was 15 microg/L [standard deviation (SD) = 15], and for 23 men was 13 microg/L (SD = 5); 89% had levels exceeding the RfD. Subjects consumed 30 different forms or types of fish. Swordfish had the highest correlation with mercury level. Sixty-seven patients with serial blood levels over time after stopping fish showed a decline in mercury levels; reduction was significant (p < 0.0001). A substantial fraction of patients had diets high in fish consumption; of these, a high proportion had blood mercury levels exceeding the maximum level recommended by the U.S. EPA and National Academy of Sciences. The mean level for women in this survey was 10 times that of mercury levels found in a recent population survey by the U.S. Centers for Disease Control and Prevention. Some children were > 40 times the national mean. PMID:12676623

  17. High-level aminoglycoside resistant enterococci isolated from swine.

    PubMed Central

    Jackson, C. R.; Fedorka-Cray, P. J.; Barrett, J. B.; Ladely, S. R.

    2005-01-01

    Approximately 42% (187/444) of swine enterococci collected between the years 1999 and 2000 exhibited high-level resistance to gentamicin (MIC > or =500 microg/ml), kanamycin (MIC > or =500 microg/ml), or streptomycin (MIC > or =1000 microg/ml). Eight aminoglycoside resistance genes were detected using PCR, most frequently ant(6)-Ia and aac(6')-Ii from Enterococcus faecium. Twenty-four per cent (45/187) of total high-level aminoglycoside-resistant isolates and 26% (4/15) of isolates resistant to high levels of all three antimicrobials were negative for all genes tested. These data suggest that enterococci isolated from swine contain diverse and possibly unidentified aminoglycoside resistance genes. PMID:15816164

  18. Low-power high-level synthesis for FPGA architectures

    Microsoft Academic Search

    Deming Chen; Jason Cong; Yiping Fan

    2003-01-01

    This paper addresses two aspects of low-power design for FPGA circuits. First, we present an RT-level power estimator for FPGAs with consideration of wire length. The power estimator closely reflects both dynamic and static power contributed by various FPGA components in 0.1um technology. The power estimation error is 16.2% on average. Second, we present a low power high level synthesis

  19. EPLX: A High Level Language for Electronic Switching Systems

    Microsoft Academic Search

    Stephen G. Chappell; N. Guttman; W. H. Jessop; Terry L. Shockey

    1978-01-01

    EPLX is the first high-level language used withi.n the Bell System in writing Electronic Switching System (ESS) programs. An extension o f a predecessor low-level language, it features structured control flow statements and data typing faci.lities. This paper stresses features of EPLX that allowed it to be incorporated into existing ESS software development, tools and methods and into the software

  20. High-Level Verification of Handwritten Numeral Strings

    Microsoft Academic Search

    Luiz E. Soares De Oliveira; Robert Sabourin; Flávio Bortolozzi; Ching Y. Suen

    2001-01-01

    In this paper we discuss the use of high-level verification on handwritten numeral strings. First of all, we introduce the concept of levels of verification and present t he baseline system used to carry out the experiments. Two different strategies were developed: absolute and one-to-one verifiers. A thorough error analysis is also presented in order to identify under which conditions

  1. Detection method and observed data of high-energy gamma rays under the influence of quantum gravity

    SciTech Connect

    Kifune, T. [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan)

    2014-05-20

    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 10{sup 13} ? 10{sup 17} 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.

  2. The effects of gravity level during directional solidification on the microstructure of hypermonotectic Al-In-Sn alloys

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Kaukler, W. F.

    1986-01-01

    Five hypermonotectic Al-In-Sn compositions were directionally solidified in a Bridgman-type furnace at normal gravity and during aircraft low-gravity maneuvers. The tendency of the Al-30In alloy to form an indium-rich band at the start of unidirectional growth (SUG) made it difficult to study the integration of L sub 2 into the solidification interface. Hypermonotectic compositions closer to monotectic slightly hypermonotectic caused only a partial band on L sub 2 to form at SUG and allowed the study of such variables as gravity, composition, and monotectic dome height on integration of excess L sub 2 into the solid plus L sub 2 interface. It was found that formation of aligned composite structures for the Al-In-Sn system is not only a function of G and R but also of the degree to which the composition varies from monotectic. Most of the aligned fibrous structures formed from hypermonotectic Al-In-Sn had spacings that were of the order of irregular fibrous structures reported for on monotectic Al-In-Sn. The spacings for the large fibers and aligned globules found for ground and low-gravity processed Al-In-18-Sn-22, respectively, were significantly larger than the others measured and were of the order expected for cell spacings under the growth conditions utilized. It was found that the integration into the solidification front of excess L sub 2 in low gravity was a function of the Sn composition of the alloy.

  3. Teaching Parallel Programming Using Both High-Level and Low-Level Languages

    Microsoft Academic Search

    Yi Pan

    2002-01-01

    We discuss the use of both high-level and low-level languages in the teaching of senior undergraduate and junior graduate classes in parallel and distributed computing.We briefly introduce several language standards and discuss why we have chosen to use OpenMP and MPI in our parallel computing class.Major features of OpenMP are briefly intro- duced and advantages of using OpenMP over message

  4. High Level Waste (HLW) Feed Process Control Strategy

    SciTech Connect

    STAEHR, T.W.

    2000-06-14

    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.

  5. Low voltage to high voltage level shifter and related methods

    NASA Technical Reports Server (NTRS)

    Mentze, Erik J. (Inventor); Hess, Herbert L. (Inventor); Buck, Kevin M. (Inventor); Cox, David F. (Inventor)

    2006-01-01

    A shifter circuit comprises a high and low voltage buffer stages and an output buffer stage. The high voltage buffer stage comprises multiple transistors arranged in a transistor stack having a plurality of intermediate nodes connecting individual transistors along the stack. The transistor stack is connected between a voltage level being shifted to and an input voltage. An inverter of this stage comprises multiple inputs and an output. Inverter inputs are connected to a respective intermediate node of the transistor stack. The low voltage buffer stage has an input connected to the input voltage and an output, and is operably connected to the high voltage buffer stage. The low voltage buffer stage is connected between a voltage level being shifted away from and a lower voltage. The output buffer stage is driven by the outputs of the high voltage buffer stage inverter and the low voltage buffer stage.

  6. Deep ocean inertia-gravity waves simulated in a high-resolution global coupled atmosphere-ocean GCM

    Microsoft Academic Search

    Nobumasa Komori; Wataru Ohfuchi; Bunmei Taguchi; Hideharu Sasaki; Patrice Klein

    2008-01-01

    In order to investigate the deep ocean inertia-gravity waves, a high-resolution global coupled atmosphere-ocean simulation is carried out with a coupling interval of 20 minutes. Large (~10-3 m s-1) root-mean-square variability of vertical velocity is found in middepths (2000-4000 m), which is not reported in previous studies using realistic ocean simulations. Horizontal distribution of the large variability roughly corresponds to

  7. Deep ocean inertia-gravity waves simulated in a high-resolution global coupled atmosphere–ocean GCM

    Microsoft Academic Search

    Nobumasa Komori; Wataru Ohfuchi; Bunmei Taguchi; Hideharu Sasaki; Patrice Klein

    2008-01-01

    In order to investigate the deep ocean inertia-gravity waves, a high-resolution global coupled atmosphere–ocean simulation is carried out with a coupling interval of 20 minutes. Large (?10?3 m s?1) root-mean-square variability of vertical velocity is found in middepths (2000–4000 m), which is not reported in previous studies using realistic ocean simulations. Horizontal distribution of the large variability roughly corresponds to

  8. Injuries in high-level heptathlon and decathlon

    Microsoft Academic Search

    P Edouard; J-B Morin; J Pruvost; A Kerspern

    2011-01-01

    BackgroundDecathlon and heptathlon are track and field disciplines during which participants run, jump, and throw. The training and the competitions are highly demanding from both the physical and psychological standpoints because of the frequency and intensity of the events that could lead to important risk of injury.ObjectiveTo prospectively determine the frequency, location and types of injuries suffered by the high-level

  9. High levels of fluctuating asymmetry in isolated stickleback populations

    PubMed Central

    2012-01-01

    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

  10. THE XAL INFRASTRUCTURE FOR HIGH LEVEL CONTROL ROOM APPLICATIONS

    SciTech Connect

    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

    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.

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

    PubMed

    Furuya, K

    1992-01-01

    "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

  12. Structuring Peer Interaction To Promote High-Level Cognitive Processing.

    ERIC Educational Resources Information Center

    King, Alison

    2002-01-01

    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…

  13. PLUTONIUM\\/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    Microsoft Academic Search

    D. C. Richardson

    2003-01-01

    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

  14. Automated Dynamic Symbology for Visualization of High Level Fusion

    Microsoft Academic Search

    Youngseok Kim; Thenkurussi Kesavadas

    Symbols play an important role in identifying informative objects and are widely used in geo-spatial decision support systems and applications. In high level fusion applications, however, simply placing symbols often lead to information overload problem; symbols quickly grow fast in many applications, such as the post disaster monitoring system we are interested in. This leads to cluttered and overlapped icons.

  15. High Performance User Level Sockets over Gigabit Ethernet Pavan Balaji*

    E-print Network

    Balaji, Pavan

    and that obtained by the end users. One such physical network which is of particular interest is Gigabit Ethernet [7High Performance User Level Sockets over Gigabit Ethernet Pavan Balaji* Piyush Shivam* Pete of our knowledge, this is the first such design and implementation for Gigabit Ethernet. Keywords

  16. Putting high-level Petri nets to work in industry

    E-print Network

    van der Aalst, Wil

    systems of the 90's. Therefore, we propose a Petri net model ex- tended with `colour', `time is a Petri net extended with `colour', `time' and `hierarchy'. We start with an in- formal introductionPutting high-level Petri nets to work in industry W.M.P. van der Aalst Department of Mathematics

  17. Efficient Scheduling of Conditional Behaviors for High-Level Synthesis

    E-print Network

    Paris-Sud XI, Université de

    and time-to-market constraints get tighter there is strong motivation for high-level synthesis (HLS). HLS of a mixed nature. In the past efficient tools for the former type have been developed but so far HLS the development of the CODESIS HLS tool for further experimentation. Categories and Subject Descriptors: J.6

  18. High-level similarity of dentitions in carnivorans and rodents

    E-print Network

    Evans, Alistair

    of tooth crowns directly reflects the foods they consume. Moreover, the absolute values of dental. These results suggest that scale-independent forces have determined the high- level dental shape in lineages the teeth that allow more food to be divided in each occlusal stroke. If we view teeth as `tools

  19. Rice lines with high leaf mineral nutrient levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphorus (P) and Potassium (K), and sometimes other mineral nutrients are often applied as fertilizer, in addition to Nitrogen, to help achieve high yields in Texas rice production. For some mineral nutrients, total levels in soil would be sufficient to support the desired rice crop growth, but th...

  20. Session-Level Load Balancing for High-Dimensional Systems

    E-print Network

    Bhulai, Sandjai

    1 Session-Level Load Balancing for High-Dimensional Systems Dennis Roubos and Sandjai Bhulai Abstract--Load balancing is critical for the performance of big server clusters. Although many load balancers are available for improving performance in parallel applications, the load- balancing problem

  1. Reliability-Centric High-Level Synthesis , N. Mansouri

    E-print Network

    Paris-Sud XI, Université de

    1 Reliability-Centric High-Level Synthesis S. Tosun , N. Mansouri , E. Arvas , M. Kandemir-down. As a result, it is becoming necessary to treat reliability as a first-class citizen in system design. In particular, reliability decisions taken early in system design can have significant benefits in terms

  2. Overview of high-level waste management accomplishments

    Microsoft Academic Search

    H. Lawroski; J. R. Berreth; W. A. Freeby

    1980-01-01

    Storage of power reactor spent fuel is discussed in relation to the lack of reprocessing operations particularly in the U.S. By considering the above solidification and storage scenario, there is more than reasonable assurance that acceptable, stable, low heat generation rate, solidified waste can be produced and safely disposed. By maintaining the liquid and solidified high level waste in secure,

  3. Extending Java for High-Level Web Service Construction

    Microsoft Academic Search

    Aske Simon Christensen; Anders Mller; Michael I. Schwartzbach

    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

  4. Extending Java for high-level Web service construction

    Microsoft Academic Search

    Aske Simon Christensen; Anders Møller; Michael I. Schwartzbach

    2003-01-01

    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

  5. The High Level Software Programs : TUNE and ID-COMP

    Microsoft Academic Search

    Lidia Tosi

    In order to aid the commissioning of the ELETTRA Storage Ring, several high level software programs have been developed. In this paper, a description of the programs TUNB and ID-COMP are given. The fist is a program which allows the user both to set desired tune values to the machine and to perform resonance scans througout the tune diagram. ID-

  6. An Alternate Paradigm for High-Level Application Development

    Microsoft Academic Search

    D. Douglas

    1997-01-01

    We discuss an alternative to traditional paradigms under which high-level accelerator applications are developed. In this revised view, emphasis is placed on use of pre-existing tools, speed of development, accessibility to the user, and ease of modification, rather than traditional fiduciary parameters such as generality, robustness, security, and completeness. Applications developed under this paradigm can be easily generated, readily modified,

  7. Analysis of high-level features for vocal emotion recognition

    Microsoft Academic Search

    Hicham Atassi; Anna Esposito; Zdenek Smekal

    2011-01-01

    The paper deals with the vocal emotion recognition which is a very important task for several applications in the field of human-machine interaction. There is a plenty of algorithms proposed up to date for this purpose that exploit different types of features and classifiers. Our previous work showed that high-level features perform very well in terms of emotion classification from

  8. Using High-Level Visual Information for Color Constancy

    Microsoft Academic Search

    Joost Van De Weijer; Cordelia Schmid; Jakob J. Verbeek

    2007-01-01

    We propose to use high-level visual information to im- prove illuminant estimation. Several illuminant estimation approaches are applied to compute a set of possible illu- minants. For each of them an illuminant color corrected image is evaluated on the likelihood of its semantic content: is the grass green, the road grey, and the sky blue, in cor- respondence with our

  9. High-level speaker verification with support vector machines

    Microsoft Academic Search

    W. M. Campbell; J. R. Campbell; D. A. Reynolds; D. A. Jones; T. R. Leek

    2004-01-01

    Recently, high-level features such as word idiolect, pronunciation, phone usage, prosody, etc., have been successfully used in speaker verification. The benefit of these features was demonstrated in the NIST extended data task for speaker verification; with enough conversational data, a recognition system can become \\

  10. Effect of high levels of film compression on surfactant transport

    Microsoft Academic Search

    J. Morris; E. P. Ingenito; L. Mark; R. D. Kamm; M. Johnson

    1999-01-01

    A previously developed adsorption-limited model [Otis, 1994; Ingenito, 1999] that describes the transport of lung surfactant to and from an air-liquid interface has been extended to allow for diffusion in the bulk phase. We used this model to compare to experimental data from Schurch [1989]. We find that high levels of film compression lead transiently to large changes in adsorption

  11. SES-Based Ontological Process for High Level Information Fusion

    E-print Network

    1 SES-Based Ontological Process for High Level Information Fusion Hojun Lee Arizona Center. The System Entity Structure (SES) is an ontology framework that can facilitate information exchange and represent knowledge in a network-centric environment. We explore an idea of adopting the SES ontology

  12. A Preview of High School Level Economic Software.

    ERIC Educational Resources Information Center

    Kincade, Jeannine H.

    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…

  13. High Level RTOS Scheduler Modeling for a Fast Design Validation

    Microsoft Academic Search

    Fabiano Hessel; César A. M. Marcon; Tatiana Gadelha Serra Dos Santos

    2007-01-01

    The use of higher level specification models will open new sceneries for optimization and architecture exploration like CPU\\/RTOS tradeoffs. Scheduling decision for realtime embedded applications has a great impact on system performance and, therefore, it is an important issue in RTOS design. Moreover, it is highly desirable to have the system designer able to evaluate and select the right scheduling

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

    ERIC Educational Resources Information Center

    Alexander, Glen; And Others

    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…

  15. Natural disaster risks Many Bolivians face high levels

    E-print Network

    Richner, Heinz

    Natural disaster risks Many Bolivians face high levels of risk from natural disasters like floods, natural disasters endan- ger crops and livestock, and there- with food security. In cities, rapid awareness and spur improved risk management from the bottom up. Project leaders took advantage of Bolivia

  16. THE DEPARTMENT OF DEFENSE HIGH LEVEL ARCHITECTURE Judith S. Dahmann

    E-print Network

    THE DEPARTMENT OF DEFENSE HIGH LEVEL ARCHITECTURE Judith S. Dahmann Defense Modeling and Simulation of a common technical architecture for use across all classes of simulations in the US Department of Defense) for distributed simulations are described. 1. INTRODUCTION The Defense Modeling and Simulation Office (DMSO

  17. High level cognitive information processing in neural networks

    NASA Technical Reports Server (NTRS)

    Barnden, John A.; Fields, Christopher A.

    1992-01-01

    Two related research efforts were addressed: (1) high-level connectionist cognitive modeling; and (2) local neural circuit modeling. The goals of the first effort were to develop connectionist models of high-level cognitive processes such as problem solving or natural language understanding, and to understand the computational requirements of such models. The goals of the second effort were to develop biologically-realistic model of local neural circuits, and to understand the computational behavior of such models. In keeping with the nature of NASA's Innovative Research Program, all the work conducted under the grant was highly innovative. For instance, the following ideas, all summarized, are contributions to the study of connectionist/neural networks: (1) the temporal-winner-take-all, relative-position encoding, and pattern-similarity association techniques; (2) the importation of logical combinators into connection; (3) the use of analogy-based reasoning as a bridge across the gap between the traditional symbolic paradigm and the connectionist paradigm; and (4) the application of connectionism to the domain of belief representation/reasoning. The work on local neural circuit modeling also departs significantly from the work of related researchers. In particular, its concentration on low-level neural phenomena that could support high-level cognitive processing is unusual within the area of biological local circuit modeling, and also serves to expand the horizons of the artificial neural net field.

  18. High-Level Synthesis of Digital Microfluidic Biochips

    E-print Network

    Chakrabarty, Krishnendu

    16 High-Level Synthesis of Digital Microfluidic Biochips FEI SU Intel Corporation and KRISHNENDU CHAKRABARTY Duke University Microfluidic biochips offer a promising platform for massively parallel DNA-generation system-on-chip (SOC) designs that are expected to include microfluidic components. We propose a system

  19. Interpreting a Dynamic and Uncertain World: High-Level Vision

    Microsoft Academic Search

    Richard J. Howarth

    1995-01-01

    When interpreting a dynamic and uncertain world it is important to have a high-level vision component that can guide the reasoning of the whole vision system. This guidance is provided by an attentional mechanism that exploits knowledge of the specific problem being solved. Here we survey work relevant to the development of such an attentional mechanism, using surveillance as an

  20. Climate Fluctuations and Record-High Levels of Lake Michigan.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A., Jr.

    1987-11-01

    Lake Michigan reached record-high levels during 1985 and 1986 just 10 years after attaining its previous record highs of this century. The climate of the basin has become cloudier and cooler over the past 40 years, loading to decreased evaporation and transpiration, but the principal factor for the increased water in the basin is extremely heavy precipitation in the most recent 15 years. Precipitation in this 15-year period averaged 107 percent above the 90-year average, and since 1970 only two years have been dry and 10 have been classified as wet, or much above normal. No other prior period has experienced comparably wet conditions since quality basin-wide records began in 1895. The current record-high levels on Lake Michigan and all other Great Lakes are producing a mixture of impacts including advantages to shipping and hydropower generation and disadvantages to shorelines. Most of the impacts on Lake Michigan have been disastrous with beaches destroyed, shorelines eroded, mid near-shore structures badly damaged. Illinois, with its high-valued 101-km shoreline, is involved in a myriad of vary costly adjustments being performed by individuals, lakeside communities, and state agencies. The federal government is reacting and attempting solutions, such as altered flows between the lakes and increased diversions. However, outlooks call for sustained high levels for at least the next six years and with no major means to sizably reduce levels in sight, damages and costly adjustments will continue into the foreseeable future. The situation illustrates how our complex society has become vulnerable to climate fluctuations. In such a regional case where any extreme has advantages and disadvantages to different economic interests, isolated solutions to ameliorate losses are difficult to achieve and often ineffectual, with resolution most likely needed at the regional policy level.

  1. Time-dependent convective flows with high viscosity contrasts under micro gravity conditions.

    NASA Astrophysics Data System (ADS)

    Zaussinger, Florian; Egbers, Christoph; Krebs, Andreas; Schwarzbach, Felix; Kunze, Christian

    2015-04-01

    Thermal driven convection in spherical geometry is of main interest in geo- and astrophysical research. To capture certain aspects of temperature dependent viscosity we investigate the micro-gravity experiment GeoFlow-IIb, located on the ISS. This unique experimental setup consists of a bottom heated and top cooled spherical gap, filled with the silicon oil 1-Nonanol. However, rotation and varying temperature gradients can be applied, to spread the experimental parameter space. The main focus of the current mission is the investigation of time dependent convective flow structures. Since the ISS requirements makes it impossible to use tracer particles, the flow structures are captured by interferometry, whose outcome is analysed by an ground based adapted image processing technique. To guarantee valid results the experimental time of each parameter is in the order of the thermal time scale, which is about 40 min. We are presenting latest results of plume-like and sheet-like time-dependent convective patterns in the spherical shell, their evolution and temporal behaviour under high viscosity contrasts. Due to an unexpected nonlinear coupling between the temperature dependent viscosity of the working fluid and the applied dielectrophoretic force field, we are able to maintain a viscosity contrast of 50 and more. This gives the chance to compare cautiously our experimental results with theoretical assumptions of the mantle convection theory. Besides, numerical simulations in the same parameter regime are performed, which give the opportunity to deduce the internal structure of the experimental flow flied. The main focus of the presented results are the long time temporal evolution of convective plumes in the spherical gap, image capturing- and processing techniques and the deduction of the internal flow field based on planar interferometry pictures.

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

    SciTech Connect

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

    1992-01-01

    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.

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

    PubMed Central

    2013-01-01

    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

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

    NASA Astrophysics Data System (ADS)

    Saito, Keiki; Ishibashi, Akihiro

    2013-01-01

    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 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 that this is in general not the case in the cosmological context. We address this problem in a simple class of f(R) gravity theories on the assumptions that (i) the background, or coarse-grained metric averaged over several wavelengths, has Friedmann-Lemaître-Robertson-Walker (FLRW) symmetry, and that (ii) when our f(R) theory reduces to Einstein gravity, the field equations of Einstein gravity should be reproduced. We show by explicit computation that the effective gravitational stress-energy tensor for a cosmological model in our f(R) theories, as well as that obtained in the corresponding scalar-tensor theory, takes a similar form to that in general relativity and is in fact traceless, hence acting again like a radiation fluid. If assumption (ii) above is dropped, then an undetermined integration constant appears and the resultant effective stress-energy tensor acquires a term that is in proportion to the background metric, hence being, in principle, able to describe a cosmological constant. Whether this effective cosmological constant term is positive and whether it has the right magnitude as dark energy depends upon the value of the integration constant.

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

    PubMed

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

    2012-08-31

    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

  6. Overview of high-level waste management accomplishments

    SciTech Connect

    Lawroski, H; Berreth, J R; Freeby, W A

    1980-01-01

    Storage of power reactor spent fuel is necessary at present because of the lack of reprocessing operations particularly in the U.S. By considering the above solidification and storage scenario, there is more than reasonable assurance that acceptable, stable, low heat generation rate, solidified waste can be produced, and safely disposed. The public perception of no waste disposal solutions is being exploited by detractors of nuclear power application. The inability to even point to one overall system demonstration lends credibility to the negative assertions. By delaying the gathering of on-line information to qualify repository sites, and to implement a demonstration, the actions of the nuclear power detractors are self serving in that they can continue to point out there is no demonstration of satisfactory high-level waste disposal. By maintaining the liquid and solidified high-level waste in secure above ground storage until acceptable decay heat generation rates are achieved, by producing a compatible, high integrity, solid waste form, by providing a second or even third barrier as a compound container and by inserting the enclosed waste form in a qualified repository with spacing to assure moderately low temperature disposal conditions, there appears to be no technical reason for not progressing further with the disposal of high-level wastes and needed implementation of the complete nuclear power fuel cycle.

  7. Chiral Gravity, Log Gravity and Extremal CFT

    E-print Network

    Alexander Maloney; Wei Song; Andrew Strominger

    2009-03-26

    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.

  8. Chiral gravity, log gravity, and extremal CFT

    SciTech Connect

    Maloney, Alexander [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Song Wei [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States); Strominger, Andrew [Center for the Fundamental Laws of Nature Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2010-03-15

    We show that the linearization of all exact solutions of classical chiral gravity around the AdS{sub 3} vacuum have positive energy. Nonchiral 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 conformal field theories (CFT). Moreover we show that log gravity contains chiral gravity within it as a decoupled charge superselection sector. We formally 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.

  9. F2-region atmospheric gravity waves due to high-power HF heating and subauroral polarization streams

    NASA Astrophysics Data System (ADS)

    Mishin, E.; Sutton, E.; Milikh, G.; Galkin, I.; Roth, C.; Förster, M.

    2012-06-01

    We report the first evidence of atmospheric gravity waves (AGWs) generated in the F2 region by high-power HF heating and subauroral polarization streams. Data come from the CHAMP and GRACE spacecraft overflying the High-frequency Active Auroral Research Program (HAARP) heating facility. These observations facilitate a new method of studying the ionosphere-thermosphere coupling in a controlled fashion by using various HF-heating regimes. They also reveal the subauroral F2 region to be a significant source of substorm AGWs, in addition to the well-known auroral E region.

  10. (abstract) Venus Gravity Field

    NASA Technical Reports Server (NTRS)

    Konopliv, A. S.; Sjogren, W. L.

    1995-01-01

    A global gravity field model of Venus to degree and order 75 (5772 spherical harmonic coefficients) has been estimated from Doppler radio tracking of the orbiting spacecraft Pioneer Venus Orbiter (1979-1992) and Magellan (1990-1994). After the successful aerobraking of Magellan, a near circular polar orbit was attained and relatively uniform gravity field resolution (approximately 200 km) was obtained with formal uncertainties of a few milligals. Detailed gravity for several highland features are displayed as gravity contours overlaying colored topography. The positive correlation of typography with gravity is very high being unlike that of the Earth, Moon, and Mars. The amplitudes are Earth-like, but have significantly different gravity-topography ratios for different features. Global gravity, geoid, and isostatic anomaly maps as well as the admittance function are displayed.

  11. FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

    SciTech Connect

    Williams, M

    2008-05-09

    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.

  12. Ionization chamber for measurements of high-level tritium gas

    SciTech Connect

    Carstens, D.H.W.; David, W.R.

    1980-01-01

    The construction and calibration of a simple ionization-chamber apparatus for measurement of high level tritium gas is described. The apparatus uses an easily constructed but rugged chamber containing the unknown gas and an inexpensive digital multimeter for measuring the ion current. The equipment after calibration is suitable for measuring 0.01 to 100% tritium gas in hydrogen-helium mixes with an accuracy of a few percent. At both the high and low limits of measurements deviations from the predicted theoretical current are observed. These are briefly discussed.

  13. Estimating gravity wave parameters from oblique high-frequency backscatter: Modeling and analysis

    Microsoft Academic Search

    W. A. Bristow; R. A. Greenwald

    1995-01-01

    A new technique for estimating electron density perturbation amplitudes of traveling ionospheric disturbances (TIDs), using HF radar data, is presented. TIDs are observed in HF radar data as enhancements of the ground-scattered power which propagate through the radar's field of view. These TIDs are the ionospheric manifestation of atmospheric acoustic-gravity waves. TID electron density perturbation amplitudes were estimated by simulating

  14. Review of High Level Waste Tanks Ultrasonic Inspection Data

    SciTech Connect

    Wiersma, B

    2006-03-09

    A review of the data collected during ultrasonic inspection of the Type I high level waste tanks has been completed. The data was analyzed for relevance to the possibility of vapor space corrosion and liquid/air interface corrosion. The review of the Type I tank UT inspection data has confirmed that the vapor space general corrosion is not an unusually aggressive phenomena and correlates well with predicted corrosion rates for steel exposed to bulk solution. The corrosion rates are seen to decrease with time as expected. The review of the temperature data did not reveal any obvious correlations between high temperatures and the occurrences of leaks. The complex nature of temperature-humidity interaction, particularly with respect to vapor corrosion requires further understanding to infer any correlation. The review of the waste level data also did not reveal any obvious correlations.

  15. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    SciTech Connect

    Fox, K.

    2010-09-07

    High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

  16. High-level waste management technology program plan

    SciTech Connect

    Harmon, H.D.

    1995-01-01

    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.

  17. 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

    Bexfield, C.E.; McBride, J.H.; Pugin, Andre 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

    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.

  18. Developing a High-Level Fault Simulation Standard

    Microsoft Academic Search

    Stanislaw Deniziak; Krzysztof Sapiecha

    2001-01-01

    Recent developments in deep-submicron technology challenge current integrated circuit testing methods. The increasing complexity of designed systems makes test development more time-consuming. Moreover, nanometer technology introduces new defects or higher data rate errors. To reduce manufacturing costs and time to market, we must develop efficient fault detection and location methods. Using high-level fault simulation stimulates the development of new, fast

  19. Mixing Processes in High-Level Waste Tanks - Final Report

    SciTech Connect

    Peterson, P.F.

    1999-05-24

    The mixing processes in large, complex enclosures using one-dimensional differential equations, with transport in free and wall jets is modeled using standard integral techniques. With this goal in mind, we have constructed a simple, computationally efficient numerical tool, the Berkeley Mechanistic Mixing Model, which can be used to predict the transient evolution of fuel and oxygen concentrations in DOE high-level waste tanks following loss of ventilation, and validate the model against a series of experiments.

  20. Integrating Planning into Reactive High-Level Robot Programs

    Microsoft Academic Search

    Yves Lespérance; Ng Ho-kong

    2000-01-01

    . IndiGolog is a high-level programming language forrobots and intelligent agents that supports on-line planning and planexecution in dynamic and incompletely known environments. Programsmay perform sensing actions that acquire information at runtimeand react to exogenous actions. In this paper, we show howIndiGolog can be used to write robot control programs that combineplanning, sensing,and reactivity. Moreover,we present enhancementsto IndiGolog in three

  1. Deep borehole disposal of high-level radioactive waste

    Microsoft Academic Search

    Joshua S. Stein; Geoffrey A. Freeze; Patrick Vane Brady; Peter N. Swift; Robert Paul Rechard; Bill Walter Arnold; Joseph F. Kanney; Stephen J. Bauer

    2009-01-01

    Preliminary evaluation of deep borehole disposal of high-level radioactive waste and spent nuclear fuel indicates the potential for excellent long-term safety performance at costs competitive with mined repositories. Significant fluid flow through basement rock is prevented, in part, by low permeabilities, poorly connected transport pathways, and overburden self-sealing. Deep fluids also resist vertical movement because they are density stratified. Thermal

  2. The American High School Graduation Rate: Trends and Levels

    Microsoft Academic Search

    James J. Heckman; Paul A. LaFontaine

    2010-01-01

    This paper applies a unified methodology to multiple data sets to estimate both the levels and trends in U.S. high school graduation rates. We establish that (a) the true rate is substantially lower than widely used measures, (b) it peaked in the early 1970s, © majority-minority differentials are substantial and have not converged for 35 years, (d) lower post-1970 rates

  3. High-level synthesis using computation-unit integrated memories

    Microsoft Academic Search

    Chao Huang; Srivaths Ravi; Anand Raghunathan; Niraj K. Jha

    2004-01-01

    High-level synthesis (HLS) of memory-intensive applications has fea- tured several innovations in terms of enhancements made to the basic memory organi- zation and data layout. However, increasing performance and energy demands faced by application-specific integrated circuits (ASICs) are forcing designers to alter the fundamental architectural template of the HLS output, namely, a controller-datapath associated with a memory subsystem (monolithic, banked,

  4. Automatic rule generation for high-level vision

    NASA Technical Reports Server (NTRS)

    Rhee, Frank Chung-Hoon; Krishnapuram, Raghu

    1992-01-01

    Many high-level vision systems use rule-based approaches to solving problems such as autonomous navigation and image understanding. The rules are usually elaborated by experts. However, this procedure may be rather tedious. In this paper, we propose a method to generate such rules automatically from training data. The proposed method is also capable of filtering out irrelevant features and criteria from the rules.

  5. Compiling High-Level Languages for Vector Architectures

    Microsoft Academic Search

    Christopher D. Rickett; Sung-eun Choi; Bradford L. Chamberlain

    2004-01-01

    \\u000a In this paper, we investigate the issues of compiling high-level languages for vector architectures. Vector architectures\\u000a have regained popularity in recent years, from simple desktop computers with small vector units motivated by multimedia applications\\u000a to large-scale vector multiprocessing machines motivated by ever-growing computational demands. We show that generating code\\u000a for various types of vector architectures can be done using several

  6. [Corrosion testing of high level radioactive waste. Final report

    SciTech Connect

    NONE

    1996-06-01

    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.

  7. Layout-driven high level synthesis for FPGA based architectures

    Microsoft Academic Search

    Min Xu; Fadi J. Kurdahi

    1998-01-01

    In this paper, we address the problem of layout-driven scheduling-binding as these steps have a direct relevance on the final performance of the design. The importance of effective and efficient accounting of layout effects is well-established in High-Level Synthesis (HLS),since it allows more efficient exploration of the design space and the generation of solutions with predictable metrics. This feature is

  8. High-level modelling and analysis of tcas

    Microsoft Academic Search

    C. Livadas; J. Lygeros; N. Lynch

    2000-01-01

    Abstract In this paper, we demonstrate a high-level approach to modeling,and analyzing complex,safety-critical systems through a case study in the area of air traffic management. In particular, we focus our attention on the Traffic Alert and Collision Avoidance System (TCAS) [11, 12]; an on-board conflict detection and resolution system which alerts pilots to the presence of nearby aircraft that pose

  9. High-Level Modeling and Analysis of TCAS

    Microsoft Academic Search

    Carolos Livadas; John Lygeros; Nancy A. Lynch

    1999-01-01

    In this paper, we demonstrate a high-level approach to modeling and analyzing complex safety-critical systems through a case study in the area of air traffic management. In particular, we focus our attention on the Traffic Alert and Collision Avoidance System (TCAS) (11, 12); an on-board conflict detection and resolution system which alerts pilots to the presence of nearby aircraft that

  10. Security Mechanisms in High-Level Network Protocols

    Microsoft Academic Search

    Victor L. Voydock; Stephen T. Kent

    1983-01-01

    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

  11. Case for retrievable high-level nuclear waste disposal

    USGS Publications Warehouse

    Roseboom, Eugene H., Jr.

    1994-01-01

    Plans for the nation's first high-level nuclear waste repository have called for permanently closing and sealing the repository soon after it is filled. However, the hydrologic environment of the proposed site at Yucca Mountain, Nevada, should allow the repository to be kept open and the waste retrievable indefinitely. This would allow direct monitoring of the repository and maintain the options for future generations to improve upon the disposal methods or use the uranium in the spent fuel as an energy resource.

  12. CQSIM High-Level Design Document Ren Dongxu CQSIM -Report

    E-print Network

    Lan, Zhiling

    of job and node structure into the same format. In this version, SWF job trace and be read and formatted the simulator runs well. #12;CQSIM High-Level Design Document Ren Dongxu 4 / 6 5. RESULT SDSC-BLUE-2000-4.1-cln.swf Dongxu 5 / 6 Wait time ANL-Intrepid-2009-1.swf Algorithm: FCFS / WFP Backfill: EASY Avg. Utilization

  13. A high-level compilation toolchain for heterogeneous systems

    Microsoft Academic Search

    W. Luk; J. G. F. Coutinho; T. Todman; Y. M. Lam; W. Osborne; K. W. Susanto; Q. Liu; W. S. Wong

    2009-01-01

    This paper describes Harmonic, a toolchain that targets multiprocessor heterogeneous systems comprising different types of processing elements such as general-purposed processors (GPPs), digital signal processors (DSP), and field-programmable gate arrays (FPGAs) from a high-level C program. The main goal of Harmonic is to improve an application by partitioning and optimising each part of the program, and selecting the most appropriate

  14. High Level Information Fusion (HLIF) with nested fusion loops

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Fischer, Amber

    2013-05-01

    Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusion—perhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

  15. High levels of IL-7 cause dysregulation of thymocyte development.

    PubMed

    El-Kassar, Nahed; Flomerfelt, Francis A; Choudhury, Baishakhi; Hugar, Lee A; Chua, Kevin S; Kapoor, Veena; Lucas, Philip J; Gress, Ronald E

    2012-10-01

    IL-7 signaling is required for thymocyte development and its loss has a severe deleterious effect on thymus function. Thymocyte-stromal cell interactions and other mechanisms tightly regulate IL-7 expression. We show that disruption of that regulation by over-expression of IL-7 inhibits T-cell development and promotes extensive B-cell lymphopoiesis in the thymus. Our data reveal that high levels of IL-7 negate Notch-1 function in thymocytes found in IL-7 transgenic mice and in co-culture with OP9-DL1 cells. While high levels of IL-7R are present on thymocytes, increased suppressor of cytokine signaling-1 expression blunts IL-7 downstream signaling, resulting in hypo-phosphorylation of proteins in the PI3K-Akt pathway. Consequently, GSK3? remains active and inhibits Notch-1 signaling as observed by decreased Hes-1 and Deltex expression in thymic progenitors. This is the first demonstration that high levels of IL-7 antagonize Notch-1 signaling and suggest that IL-7 may affect T- versus B-lineage choice in the thymus. PMID:22899673

  16. High levels of IL-7 cause dysregulation of thymocyte development

    PubMed Central

    El-Kassar, Nahed; Flomerfelt, Francis A.

    2012-01-01

    IL-7 signaling is required for thymocyte development and its loss has a severe deleterious effect on thymus function. Thymocyte–stromal cell interactions and other mechanisms tightly regulate IL-7 expression. We show that disruption of that regulation by over-expression of IL-7 inhibits T-cell development and promotes extensive B-cell lymphopoiesis in the thymus. Our data reveal that high levels of IL-7 negate Notch-1 function in thymocytes found in IL-7 transgenic mice and in co-culture with OP9-DL1 cells. While high levels of IL-7R are present on thymocytes, increased suppressor of cytokine signaling-1 expression blunts IL-7 downstream signaling, resulting in hypo-phosphorylation of proteins in the PI3K-Akt pathway. Consequently, GSK3? remains active and inhibits Notch-1 signaling as observed by decreased Hes-1 and Deltex expression in thymic progenitors. This is the first demonstration that high levels of IL-7 antagonize Notch-1 signaling and suggest that IL-7 may affect T- versus B-lineage choice in the thymus. PMID:22899673

  17. Gravity wave breaking in easterly flow over Greenland and associated low level barrier and reverse tip-jets

    Microsoft Academic Search

    Haraldur Ólafsson; Hálfdán Ágústsson

    2009-01-01

    A first evidence of severe turbulence in the lower stratosphere during easterly tropospheric flow over Greenland is presented.\\u000a A numerical simulation shows the turbulence to be associated with gravity wave breaking and that simulating with a horizontal\\u000a resolution of 3 km gives substantially greater and more realistic turbulence than at a 9 km horizontal resolution. It is concluded\\u000a that real-time simulations at

  18. Numerical solution of the altimetry-gravimetry BVP for high-resolution modelling of the altimetry-derived gravity data

    NASA Astrophysics Data System (ADS)

    ?underlík, Róbert; Macák, Marek; Minarechová, Zuzana; Mikula, Karol

    2015-04-01

    We present a numerical solution of the altimetry-gravimetry boundary-value problem using the finite volume method, which discretizes the 3D computational domain between an ellipsoidal approximation of the Earth's surface and an upper boundary given at the mean altitude of the GOCE orbits. A parallel implementation of the finite volume numerical scheme and large-scale parallel computations on clusters with distributed memory allow high-resolution modelling of the altimetry-derived gravity disturbances over oceans. Here the Dirichlet boundary conditions in form of the disturbing potential are prescribed. They are obtained by nonlinear diffusion filtering of the geopotential generated on the mean sea surface from the GRACE/GOCE-based satellite-only geopotential model. On the upper boundary, the Dirichlet boundary conditions generated from the same model are prescribed as well. Numerical experiments present the detailed gravity disturbances derived over oceans from the DTU13 mean sea surface model and the GO_CONS_GCF_2_DIR_R5 geopotential model. Their comparison with the DTU13_GRAV altimetry-derived gravity data indicates an importance of a-priori information about the mean dynamic topography for achieved accuracy, especially in zones of main ocean geosprophic surface currents.

  19. A Process Modeling Language Consisting of High Level UML-based Diagrams and Low Level Process Language

    Microsoft Academic Search

    Shih-chien Chou

    2002-01-01

    This article presents a process modeling language consisting of high level UML-based diagrams and a low level process language. The high level diagrams facilitate process program development, while the low level process language models processes as process programs. Between them is a mapping to further facilitate program development.

  20. Exceptionally high levels of multiple mating in an army ant

    NASA Astrophysics Data System (ADS)

    Denny, A. Jay; Franks, Nigel R.; Powell, Scott; Edwards, Keith J.

    Most species of social insects have singly mated queens, although there are notable exceptions. Competing hypotheses have been proposed to explain the evolution of high levels of multiple mating, but this issue is far from resolved. Here we use microsatellites to investigate mating frequency in the army ant Eciton burchellii and show that queens mate with an exceptionally large number of males, eclipsing all but one other social insect species for which data are available. In addition we present evidence that suggests that mating is serial, continuing throughout the lifetime of the queen. This is the first demonstration of serial mating among social hymenoptera. We propose that high paternity within colonies is most likely to have evolved to increase genetic diversity and to counter high pathogen and parasite loads.

  1. High-level power analysis and optimization techniques

    NASA Astrophysics Data System (ADS)

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching activity and power consumption. Unlike previous techniques, the presented techniques consider the effects of glitching activity at control and data path signals, and are well-suited to control flow intensive as well as data flow intensive designs. RTL circuit transformations are presented that reduce the generation and propagation of glitches through the circuit. Power management techniques identify sub-circuits that are idle in each clock cycle, and re-design the circuit in order to minimize activity in idle sub-circuits. This thesis presents a low-overhead power management technique based on controller re-specification, where power management in the data path is achieved by re-designing the logic that generates the control signals to the data path such that the activity in various data path components, including internal signals of multiplexer trees and inputs to functional units and comparators, is reduced. Addressing power consumption at the higher (behavior and architecture) levels results in significantly increased power savings, and can lead to fewer and faster design iterations. (Abstract shortened by UMI.)

  2. SMALL SATELLITE WITH WIRELESS POWER TRANSMISSION AS POSSIBLE WAY TO GET SUPER LOW MICRO GRAVITY CONDITIONS

    Microsoft Academic Search

    Rostislav K. Tchuyan; Andrey B. Grechnev; Leonid A. Kvasnikov; Andrey P. Smakhtin; Victor S. Zemskov; Valery P. Shalimov; Vladimir L. Savvin; Georgy F. Resh

    The organization of space manufacturing the high quality materials, such as super homogeneous crystals, clear medicine etc., is the most important problem of the XXI century. This is the well-known idea to use micro gravity conditions aboard spacecraft for above-mentioned production. By modern performances the growth of high quality semiconductor crystals needs super low level of the gravity accelerations about

  3. Ultrasonic level sensors for liquids under high pressure

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.; Mazel, D. S.; Hodges, D. Y.

    1986-01-01

    An ultrasonic level sensor of novel design continuously measures the level of a liquid subjected to a high pressure (up to about 40 MPa), as is sometimes required for the effective transfer of the liquid. The sensor operates as a composite resonator fabricated from a standard high-pressure plug. A flat-bottom hole is machined into the plug along its center line. An ultrasonic transducer is bonded rigidly to the interior surface of the bottom wall, while the exterior surface is in contact with the liquid. Although the bottom wall is designed to satisfy the pressure code, it is still sufficiently thin to permit ready excitation of the axisymmetric plate modes of vibration. The liquid level is measured by a conventional pulse-echo technique. A prototype sensor was tested successfully in a 2300-l water vessel at pressures up to about 37 MPa. A spectral analysis of the transmitted pulse reveals that the flexural, extensional, thickness-shear, and radial plate modes are excited into vibration, but none of these appears to be significantly affected by the pressurization of the liquid.

  4. Measurement of bone conduction levels for high frequencies.

    PubMed

    Lenhardt, Martin L; Richards, Douglas G; Madsen, Alan G; Goldstein, Barbara A; Shulman, Abraham; Guinta, Robert

    2002-01-01

    For assessment of safety, it is necessary to measure the maximum possible force exerted by a bone conduction device coupled to the human head. Calibration of bone conduction hearing aids and vibrators in the audiometric range is based on measurement of acceleration and force using an artificial mastoid. Extending the measurement to the high audio range was accomplished using a live head. To assess safety of the UltraQuiet tinnitus treatment system, as an example, acceleration was measured from 5 to 20 kHz on a live human head as compared with calibrated levels at 6 kHz on an artificial mastoid and the live head. Using head acceleration and anchoring it to established calibration levels is a means of establishing clinical safety. Stimulation in the high audio frequencies at low levels was found to be safe. In contrast, stimulation with ultrasound requires more energy (approximately 75-90 dB re 6 kHz), which may increase the risk of damage to the car. PMID:14763229

  5. Permitting plan for the high-level waste interim storage

    SciTech Connect

    Deffenbaugh, M.L.

    1997-04-23

    This document addresses the environmental permitting requirements for the transportation and interim storage of solidified high-level waste (HLW) produced during Phase 1 of the Hanford Site privatization effort. Solidified HLW consists of canisters containing vitrified HLW (glass) and containers that hold cesium separated during low-level waste pretreatment. The glass canisters and cesium containers will be transported to the Canister Storage Building (CSB) in a U.S. Department of Energy (DOE)-provided transportation cask via diesel-powered tractor trailer. Tri-Party Agreement (TPA) Milestone M-90 establishes a new major milestone, and associated interim milestones and target dates, governing acquisition and/or modification of facilities necessary for: (1) interim storage of Tank Waste Remediation Systems (TWRS) immobilized HLW (IHLW) and other canistered high-level waste forms; and (2) interim storage and disposal of TWRS immobilized low-activity tank waste (ILAW). An environmental requirements checklist and narrative was developed to identify the permitting path forward for the HLW interim storage (HLWIS) project (See Appendix B). This permitting plan will follow the permitting logic developed in that checklist.

  6. Characterization of Transducers and Resonators under High Drive Levels

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Bao, X.; Sigel, D. A.; Gradziel, M. J.; Askins, S. A.; Dolgin, B. P.; Bar-Cohen, Y.

    2001-01-01

    In many applications, piezoelectric transducers are driven at AC voltage levels well beyond the level for which the material was nominally characterized. In this paper we describe an experimental setup that allows for the determination of the main transducer or resonator properties under large AC drive. A sinusoidal voltage from a waveform generator is amplified and applied across the transducer/resonator in series with a known high power resistor. The amplitude of applied voltage and the amplitude and the relative phase of the current through the resistor are monitored on a digital scope. The frequency of the applied signal is swept through resonance and the voltage/current signals are recorded. After corrections for the series resistance and parasitic elements the technique allows for the determination of the complex impedance spectra of the sample as a function of frequency. In addition, access to the current signal allows for the direct investigation of non-linear effects through the application of Fourier transform techniques on the current signal. Our results indicate that care is required when interpreting impedance data at high drive level due to the frequency dependence of the dissipated power. Although the transducer/resonator at a single frequency and after many cycles may reach thermal equilibrium, the spectra as a whole cannot be considered an isothermal measurement due to the temperature change with frequency. Methods to correct for this effect will be discussed. Results determined from resonators of both soft and hard PZT and a ultrasonic horn transducer are presented.

  7. Space augmentation of military high-level waste disposal

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  8. High level language-based robotic control system

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Frolov, Vladimir; Chernogor, Leonid; Rozumenko, Victor

    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

  10. Estimating a High-Resolution Lunar Gravity Field and Time-Varying Core Signature

    NASA Astrophysics Data System (ADS)

    Park, R. S.; Asmar, S. W.; Fahnestock, G. G.; Konopliv, A. S.; Kruizinga, G. L.; Lu, W.; Watkins, M.; Williams, J. G.; Yuan, D.

    2011-12-01

    An overall Gravity Recovery And Interior Laboratory (GRAIL) mission capability is presented based on a sensitivity analysis considering detailed spacecraft dynamics and kinematics models with realistic measurement uncertainties. Also shown is the effect of various perturbing forces, measurement models, and data arc lengths on overall estimation performance. The largest source of un-modeled error comes from the spacecraft thermal re-radiation force, and in order to characterize its error contribution, an a priori error constraint model is derived based on orbit geometry and expected force magnitude. The result shows that estimating a lunar gravity field is robust against both dynamics and kinematics errors and a nominal field of degree 300 or better can be determined according to the Kaula rule. The core signature, however, is more sensitive to modeling errors and satisfying the science requirement depends on how accurately the spacecraft dynamics can be modeled.

  11. Engineering Escherichia coli for high-level production of propionate.

    PubMed

    Akawi, Lamees; Srirangan, Kajan; Liu, Xuejia; Moo-Young, Murray; Perry Chou, C

    2015-07-01

    Mounting environmental concerns associated with the use of petroleum-based chemical manufacturing practices has generated significant interest in the development of biological alternatives for the production of propionate. However, biological platforms for propionate production have been limited to strict anaerobes, such as Propionibacteria and select Clostridia. In this work, we demonstrated high-level heterologous production of propionate under microaerobic conditions in engineered Escherichia coli. Activation of the native Sleeping beauty mutase (Sbm) operon not only transformed E. coli to be propionogenic (i.e., propionate-producing) but also introduced an intracellular "flux competition" between the traditional C2-fermentative pathway and the novel C3-fermentative pathway. Dissimilation of the major carbon source of glycerol was identified to critically affect such "flux competition" and, therefore, propionate synthesis. As a result, the propionogenic E. coli was further engineered by inactivation or overexpression of various genes involved in the glycerol dissimilation pathways and their individual genetic effects on propionate production were investigated. Generally, knocking out genes involved in glycerol dissimilation (except glpA) can minimize levels of solventogenesis and shift more dissimilated carbon flux toward the C3-fermentative pathway. For optimal propionate production with high C3:C2-fermentative product ratios, glycerol dissimilation should be channeled through the respiratory pathway and, upon suppressed solventogenesis with minimal production of highly reduced alcohols, the alternative NADH-consuming route associated with propionate synthesis can be critical for more flexible redox balancing. With the implementation of various biochemical and genetic strategies, high propionate titers of more than 11 g/L with high yields up to 0.4 g-propionate/g-glycerol (accounting for ~50 % of dissimilated glycerol) were achieved, demonstrating the potential for industrial application. To our knowledge, this represents the most effective engineered microbial system for propionate production with titers and yields comparable to those achieved by anaerobic batch cultivation of various native propionate-producing strains of Propionibacteria. PMID:25948049

  12. Estimating gravity wave parameters from oblique high-frequency backscatter: Modeling and analysis

    Microsoft Academic Search

    W. A. Bristow; R. A. Greenwald

    1995-01-01

    A new technique for estimating electron density perturbation amplitudes of traveling ionospheric disturbances (TIDs), using HF radar data, is presented. TIDs are observed in HF radar data as enhancements of the ground-scattered power which propagate through the radar`s field of view. These TIDs are the ionospheric manifestation of atmospheric acoustic-gravity waves. TID electron density perturbation amplitudes were estimated by simulating

  13. Symmetries In Evolving Space-time and Their Connection To High-frequency Gravity Wave Production

    E-print Network

    A. W. Beckwith

    2008-04-01

    We present how a worm hole bridge from a prior to the present universe allows us to use symmetry arguments which allow us to generate relic gravity waves, and also non massless gravitons. The relic gravitons are produced due to thermal / vacuum energy transferral from a prior universe using a pseudo time dependent version of the Wheeler De Witt equation as presented by Crowell (2005)

  14. Salivary Fluoride Levels after Use of High-Fluoride Dentifrice

    PubMed Central

    Vale, Glauber Campos; Cruz, Priscila Figueiredo; Bohn, Ana Clarissa Cavalcante Elvas; de Moura, Marcoeli Silva

    2015-01-01

    The aim of the study was to evaluate salivary fluoride (F) availability after toothbrushing with a high-F dentifrice. Twelve adult volunteers took part in this crossover and blind study. F concentration in saliva was determined after brushing with a high-F dentifrice (5000?µg?F/g) or with a conventional F concentration dentifrice (1100?µg?F/g) followed by a 15?mL distilled water rinse. Samples of nonstimulated saliva were collected on the following times: before (baseline), and immediately after spit (time = 0) and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45, 60, 90, and 120?min. F analysis was performed with a fluoride-sensitive electrode and the area under curve of F salivary concentration × time (µg?F/mL × min?1) was calculated. At baseline, no significant difference was found among dentifrices (P > 0.05). After brushing, both dentifrices caused an elevated fluoride level in saliva; however salivary F concentration was significantly higher at all times, when high-F dentifrice was used (P < 0.01). Even after 120?min, salivary F concentration was still higher than the baseline values for both dentifrices (P < 0.001). High-F dentifrice enhanced the bioavailability of salivary F, being an option for caries management in patients with high caries risk. PMID:25821849

  15. Alternate methods for high level pyrotechnic shock simulation

    NASA Astrophysics Data System (ADS)

    Gray, Phillip J., Sr.

    Two effective methods to recreate a realistic pyrotechnic shock are presented. The first method employs a resonant beam and is used for SRS levels of 12,000 G or more. The test unit is at one end of the beam and a hammer strikes the opposite end causing a shock to be transmitted to the other end of the fixture. The second method is based on a standard shaker system with a resonant beam to amplify the input signal. The engineer defines the duration of the shock signal induced to the vibration amplifier using the GenRad 2514 controller. The shock signal is then input via the shaker to the resonant beam, which amplifies the signal to produce the desired response at the end of the fixture. The shock response spectrum stays within a +/-6 dB tolerance with levels as high as 3000 G peak. These methods are repeatable, reliable, cost-effective, and consistent with a real pyroevent.

  16. Effects of high vs low-level radiation exposure

    SciTech Connect

    Bond, V.P.

    1983-01-01

    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.

  17. Point stability at shallow depths: experience from tilt measurements in the Lower Rhine Embayment, Germany, and implications for high-resolution GPS and gravity recordings

    NASA Astrophysics Data System (ADS)

    Kümpel, H.-J.; Lehmann, K.; Fabian, M.; Mentes, Gy.

    2001-09-01

    From 1996 to 1999, we have studied ground tilts at depths of between 2m and 5m at three sites in the Lower Rhine Embayment (LRE), western Germany. The LRE is a tectonically active extensional sedimentary basin roughly 50km×100km. The purpose of the tilt measurements was (a) to provide insight into the magnitude, nature and variability of background tilts and (b) to assess possible limitations of high-resolution GPS campaigns and microgravity surveys due to natural ground deformation. The tilt readings, sensed by biaxial borehole tiltmeters of baselength 0.85m, cover a frequency range from 10-8Hz to 10-2Hz (periods from minutes to years). Assuming that the tilt signals represent ground displacements on a scale typically not larger than several times the tiltmeters' baselength, and that tilt signals at shallow depth could in a simple geometric way be related to changes in surface elevation and gravity, we try to estimate the magnitude level of point movements and corresponding Bouguer gravity effects that is generally not surpassed. The largest tilt signals observed were some +/-50µradyr-1. If they were observable over a ground section of extension, e.g. 10m, the converted rates may correspond to about +/-0.5mm per 10myr-1 in vertical ground displacement, and +/-0.1µgalyr-1 in Bouguer gravity effect, respectively. Large signals are mostly related to seasonal effects, probably linked to thermomechanical strain. Other causes of ground deformation identified include seepage effects after rainfalls (order of +/-10µrad) and diurnal strains due to thermal heating and/or fluctuations in the water consumption of nearby trees (order of +/-1µrad). Episodic step-like tilt anomalies with amplitudes up to 22µrad at one of the observation sites might reflect creep events associated to a nearby active fault. Except for short-term ground deformation caused by the passage of seismic waves from distant earthquakes, amplitudes of non-identified tilt signals in the studied frequency range seem not to exceed +/-2µrad. As the larger tilt signals are close to the precision achieved with modern GPS systems and superconducting gravimeters when converted into height and gravity changes, further enhancement in resolution of these techniques may require simultaneous recording of local ground deformation at the observation sites.

  18. Increased hepcidin levels in high-altitude pulmonary edema.

    PubMed

    Altamura, Sandro; Bärtsch, Peter; Dehnert, Christoph; Maggiorini, Marco; Weiss, Günter; Theurl, Igor; Muckenthaler, Martina U; Mairbäurl, Heimo

    2015-02-01

    Low iron availability enhances hypoxic pulmonary vasoconstriction (HPV). Considering that reduced serum iron is caused by increased erythropoiesis, insufficient reabsorption, or elevated hepcidin levels, one might speculate that exaggerated HPV in high-altitude pulmonary edema (HAPE) is related to low serum iron. To test this notion we measured serum iron and hepcidin in blood samples obtained in previously published studies at low altitude and during 2 days at 4,559 m (HA1, HA2) from controls, individuals with HAPE, and HAPE-susceptible individuals where prophylactic dexamethasone and tadalafil prevented HAPE. As reported, at 4,559 m pulmonary arterial pressure was increased in healthy volunteers but reached higher levels in HAPE. Serum iron levels were reduced in all groups at HA2. Hepcidin levels were reduced in all groups at HA1 and HA2 except in HAPE, where hepcidin was decreased at HA1 but unexpectedly high at HA2. Elevated hepcidin in HAPE correlated with increased IL-6 at HA2, suggesting that an inflammatory response related to HAPE contributes to increased hepcidin. Likewise, platelet-derived growth factor, a regulator of hepcidin, was increased at HA1 and HA2 in controls but not in HAPE, suggesting that hypoxia-controlled factors that regulate serum iron are inappropriately expressed in HAPE. In summary, we found that HAPE is associated with inappropriate expression of hepcidin without inducing expected changes in serum iron within 2 days at HA, likely due to too short time. Although hepcidin expression is uncoupled from serum iron availability and hypoxia in individuals developing HAPE, our findings indicate that serum iron is not related with exaggerated HPV. PMID:25525212

  19. Mars: Crustal Structure Inferred from Bouguer Gravity Anomalies

    Microsoft Academic Search

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

    1973-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

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

    SciTech Connect

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

    2012-01-10

    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.

  2. Corrosion and failure processes in high-level waste tanks

    SciTech Connect

    Mahidhara, R.K.; Elleman, T.S.; Murty, K.L. [North Carolina State Univ., Raleigh, NC (United States)

    1992-11-01

    A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.

  3. High-level neutron coincidence counter maintenance manual

    SciTech Connect

    Swansen, J.; Collinsworth, P.

    1983-05-01

    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.

  4. THE AMERICAN HIGH SCHOOL GRADUATION RATE: TRENDS AND LEVELS*

    PubMed Central

    Heckman, James J.; LaFontaine, Paul A.

    2009-01-01

    This paper applies a unified methodology to multiple data sets to estimate both the levels and trends in U.S. high school graduation rates. We establish that (a) the true rate is substantially lower than widely used measures; (b) it peaked in the early 1970s; (c) majority/minority differentials are substantial and have not converged for 35 years; (d) lower post-1970 rates are not solely due to increasing immigrant and minority populations; (e) our findings explain part of the slowdown in college attendance and rising college wage premiums; and (f) widening graduation differentials by gender help explain increasing male-female college attendance gaps. PMID:20625528

  5. Survey of the characteristics of very high level languages

    SciTech Connect

    Loffman, R.S.

    1986-01-01

    Although there is no consensus on the characteristics of very high level languages (VHLLs), ample evidence exists that users of such languages have several expectations. As a result of an extensive survey of the literature and communications with researchers, it was concluded that six characteristics of VHLLs are desired. These are that the language (1) be nonprocedural, (2) allow implicit referencing, (3) provide a good interface between user and computer, (4) allow for verification, (5) be extensible, and (6) provide the means for better data representation. It was also concluded that no existing language has all six characteristics.

  6. A Collaborative Model of Low-Level and High-Level Descriptors for Semantics-Based Music Information Retrieval

    Microsoft Academic Search

    Jun Wang; Haojiang Deng; Qin Yan; Jinlin Wang

    2008-01-01

    Although technologies of both low-level and high-level descriptors for music information retrieval (MIR) are advancing, there are some essential deficiencies while utilizing them separately. In this paper we propose a model where the low-level and high-level descriptors collaborate to support semantics-based MIR. The ontology of ldquomusic scenerdquo domain is constructed as a demonstration, and a set of domain related low-level

  7. HIGH LEVELS OF URANIUM IN GROUNDWATER OF ULAANBAATAR, MONGOLIA

    PubMed Central

    Nriagu, Jerome; Nam, Dong-Ha; Ayanwola, Titilayo A.; Dinh, Hau; Erdenechimeg, Erdenebayar; Ochir, Chimedsuren; Bolormaa, Tsend-Ayush

    2011-01-01

    Water samples collected from 129 wells in seven of the nine sub-divisions of Ulaanbaatar were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) using Clean Lab methods. The levels of many trace elements were found to be very low with the average concentrations (ranges in brackets) being 0.9 (<0.1-7.9) ?g/L for As; 7.7 (0.12-177) ?g/L for Mn; 0.2 (<0.05-1.9) ?g/L for Co; 16 (<0.1-686) ?g/L for Zn; 0.7 (<0.1-1.8) ?g/L for Se; <0.1 (<0.02-0.69) ?g/L for Cd; and 1.3 (<0.02-32) ?g/L for Pb. The levels of uranium were surprisingly elevated (mean, 4.6 ?g/L; range <0.01-57 ?g/L, with the values for many samples exceeding the World Health Organization's guideline of 15 ?g/L for uranium in drinking water. Local rocks and soils appear to be the natural source of the uranium. The levels of uranium in Ulaanbaatar's groundwater are in the range that has been associated with nephrotoxicity, high blood pressure, bone dysfunction and likely reproductive impairment in human populations. We consider the risk associated with drinking the groundwater with elevated levels of uranium in Ulaanbaatar to be a matter for some public health concern and conclude that the paucity of data on chronic effects of low level exposure is a risk factor for continuing the injury to many people in this city. PMID:22142646

  8. Selection from Industrial Lager Yeast Strains of Variants with Improved Fermentation Performance in Very-High-Gravity Worts?

    PubMed Central

    Huuskonen, Anne; Markkula, Tuomas; Vidgren, Virve; Lima, Luis; Mulder, Linda; Geurts, Wim; Walsh, Michael; Londesborough, John

    2010-01-01

    There are economic and other advantages if the fermentable sugar concentration in industrial brewery fermentations can be increased from that of currently used high-gravity (ca. 14 to 17°P [degrees Plato]) worts into the very-high-gravity (VHG; 18 to 25°P) range. Many industrial strains of brewer's yeast perform poorly in VHG worts, exhibiting decreased growth, slow and incomplete fermentations, and low viability of the yeast cropped for recycling into subsequent fermentations. A new and efficient method for selecting variant cells with improved performance in VHG worts is described. In this new method, mutagenized industrial yeast was put through a VHG wort fermentation and then incubated anaerobically in the resulting beer while maintaining the ?-glucoside concentration at about 10 to 20 g·liter?1 by slowly feeding the yeast maltose or maltotriose until most of the cells had died. When survival rates fell to 1 to 10 cells per 106 original cells, a high proportion (up to 30%) of survivors fermented VHG worts 10 to 30% faster and more completely (residual sugars lower by 2 to 8 g·liter?1) than the parent strains, but the sedimentation behavior and profiles of yeast-derived flavor compounds of the survivors were similar to those of the parent strains. PMID:20081007

  9. Remote ignitability analysis of high-level radioactive waste

    SciTech Connect

    Lundholm, C.W.; Morgan, J.M.; Shurtliff, R.M.; Trejo, L.E.

    1992-09-01

    The Idaho Chemical Processing Plant (ICPP), was used to reprocess nuclear fuel from government owned reactors to recover the unused uranium-235. These processes generated highly radioactive liquid wastes which are stored in large underground tanks prior to being calcined into a granular solid. The Resource Conservation and Recovery Act (RCRA) and state/federal clean air statutes require waste characterization of these high level radioactive wastes for regulatory permitting and waste treatment purposes. The determination of the characteristic of ignitability is part of the required analyses prior to calcination and waste treatment. To perform this analysis in a radiologically safe manner, a remoted instrument was needed. The remote ignitability Method and Instrument will meet the 60 deg. C. requirement as prescribed for the ignitability in method 1020 of SW-846. The method for remote use will be equivalent to method 1020 of SW-846.

  10. Separation processes for high-level radioactive waste treatment

    SciTech Connect

    Sutherland, D.G.

    1992-11-01

    During World War II, production of nuclear materials in the United States for national defense, high-level waste (HLW) was generated as a byproduct. Since that time, further quantities of HLW radionuclides have been generated by continued nuclear materials production, research, and the commercial nuclear power program. In this paper HLW is defined as the highly radioactive material resulting from the processing of spent nuclear fuel. The HLW is the liquid waste generated during the recovery of uranium and plutonium in a fuel processing plant that generally contains more than 99% of the nonvolatile fission products produced during reactor operation. Since this paper deals with waste separation processes, spent reactor fuel elements that have not been dissolved and further processed are excluded.

  11. High-level waste melter alternatives assessment report

    SciTech Connect

    Calmus, R.B.

    1995-02-01

    This document describes the Tank Waste Remediation System (TWRS) High-Level Waste (HLW) Program`s (hereafter referred to as HLW Program) Melter Candidate Assessment Activity performed in fiscal year (FY) 1994. The mission of the TWRS Program is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and encapsulated strontium and cesium isotopic sources) in an environmentally sound, safe, and cost-effective manner. The goal of the HLW Program is to immobilize the HLW fraction of pretreated tank waste into a vitrified product suitable for interim onsite storage and eventual offsite disposal at a geologic repository. Preparation of the encapsulated strontium and cesium isotopic sources for final disposal is also included in the HLW Program. As a result of trade studies performed in 1992 and 1993, processes planned for pretreatment of tank wastes were modified substantially because of increasing estimates of the quantity of high-level and transuranic tank waste remaining after pretreatment. This resulted in substantial increases in needed vitrification plant capacity compared to the capacity of original Hanford Waste Vitrification Plant (HWVP). The required capacity has not been finalized, but is expected to be four to eight times that of the HWVP design. The increased capacity requirements for the HLW vitrification plant`s melter prompted the assessment of candidate high-capacity HLW melter technologies to determine the most viable candidates and the required development and testing (D and T) focus required to select the Hanford Site HLW vitrification plant melter system. An assessment process was developed in early 1994. This document describes the assessment team, roles of team members, the phased assessment process and results, resulting recommendations, and the implementation strategy.

  12. LIQUIDUS TEMPERATURE AND PRIMARY CRYSTALLIZATION PHASES IN HIGH-ZIRCONIA HIGH-LEVEL WASTE BOROSILICATE GLASSES

    EPA Science Inventory

    Liquidus temperature (TL) studies of high-Zr high-level waste (HLW) borosilicate glasses have identified three primary phases: baddelyite (ZrO2), zircon (ZrSiO4), and alkali-zirconium silicates, such as parakeldyshite (Na2ZrSi2O7). Using published TL data for HLW glasses with the...

  13. A High-Level Approach to Synthesis of High-Performance Codes for Quantum Chemistry

    E-print Network

    Ramanujam, J. "Ram"

    A High-Level Approach to Synthesis of High-Performance Codes for Quantum Chemistry Gerald for a class of computations encountered in quantum chemistry and physics. These computations are expressible contractions. Currently, manual development of accurate quantum chemistry models in this domain is very tedious

  14. How to achieve high-level expression of microbial enzymes

    PubMed Central

    Liu, Long; Yang, Haiquan; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Du, Guocheng; Chen, Jian

    2013-01-01

    Microbial enzymes have been used in a large number of fields, such as chemical, agricultural and biopharmaceutical industries. The enzyme production rate and yield are the main factors to consider when choosing the appropriate expression system for the production of recombinant proteins. Recombinant enzymes have been expressed in bacteria (e.g., Escherichia coli, Bacillus and lactic acid bacteria), filamentous fungi (e.g., Aspergillus) and yeasts (e.g., Pichia pastoris). The favorable and very advantageous characteristics of these species have resulted in an increasing number of biotechnological applications. Bacterial hosts (e.g., E. coli) can be used to quickly and easily overexpress recombinant enzymes; however, bacterial systems cannot express very large proteins and proteins that require post-translational modifications. The main bacterial expression hosts, with the exception of lactic acid bacteria and filamentous fungi, can produce several toxins which are not compatible with the expression of recombinant enzymes in food and drugs. However, due to the multiplicity of the physiological impacts arising from high-level expression of genes encoding the enzymes and expression hosts, the goal of overproduction can hardly be achieved, and therefore, the yield of recombinant enzymes is limited. In this review, the recent strategies used for the high-level expression of microbial enzymes in the hosts mentioned above are summarized and the prospects are also discussed. We hope this review will contribute to the development of the enzyme-related research field. PMID:23686280

  15. Spent fuel and high-level radioactive waste transportation report

    SciTech Connect

    Not Available

    1990-11-01

    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.

  16. Spent Fuel and High-Level Radioactive Waste Transportation Report

    SciTech Connect

    Not Available

    1992-03-01

    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.

  17. ATW system impact on high-level waste

    SciTech Connect

    Arthur, E.D.

    1992-12-01

    This report discusses the Accelerator Transmutation of Waste (ATW) concept which aims at destruction of key long-lived radionuclides in high-level nuclear waste (HLW), both fission products and actinides. This focus makes it different from most other transmutation concepts which concentrate primarily on actinide burning. The ATW system uses an accelerator-driven, sub-critical assembly to create an intense thermal neutron environment for radionuclide transmutation. This feature allows rapid transmutation under low-inventory system conditions, which in turn, has a direct impact on the size of chemical separations and materials handling components of the system. Inventories in ATW are factors of eight to thirty times smaller than reactor systems of equivalent thermal power. Chemical separations systems are relatively small in scale and can be optimized to achieve high decontamination factors and minimized waste streams. The low-inventory feature also directly impacts material amounts remaining in the system at its end of life. In addition to its low-inventory operation, the accelerator-driven neutron source features of ATW are key to providing a sufficient level of neutrons to allow transmutation of long-lived fission products.

  18. ATW system impact on high-level waste

    SciTech Connect

    Arthur, E.D.

    1992-01-01

    This report discusses the Accelerator Transmutation of Waste (ATW) concept which aims at destruction of key long-lived radionuclides in high-level nuclear waste (HLW), both fission products and actinides. This focus makes it different from most other transmutation concepts which concentrate primarily on actinide burning. The ATW system uses an accelerator-driven, sub-critical assembly to create an intense thermal neutron environment for radionuclide transmutation. This feature allows rapid transmutation under low-inventory system conditions, which in turn, has a direct impact on the size of chemical separations and materials handling components of the system. Inventories in ATW are factors of eight to thirty times smaller than reactor systems of equivalent thermal power. Chemical separations systems are relatively small in scale and can be optimized to achieve high decontamination factors and minimized waste streams. The low-inventory feature also directly impacts material amounts remaining in the system at its end of life. In addition to its low-inventory operation, the accelerator-driven neutron source features of ATW are key to providing a sufficient level of neutrons to allow transmutation of long-lived fission products.

  19. VITRIFICATION OF HIGH LEVEL WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Fox, K.; Peeler, D.

    2009-06-17

    The objective of this study was to experimentally measure the properties and performance of a series of glasses with compositions that could represent high level waste Sludge Batch 5 (SB5) as vitrified at the Savannah River Site Defense Waste Processing Facility. These data were used to guide frit optimization efforts as the SB5 composition was finalized. Glass compositions for this study were developed by combining a series of SB5 composition projections with a group of candidate frits. The study glasses were fabricated using depleted uranium and their chemical compositions, crystalline contents and chemical durabilities were characterized. Trevorite was the only crystalline phase that was identified in a few of the study glasses after slow cooling, and is not of concern as spinels have been shown to have little impact on the durability of high level waste glasses. Chemical durability was quantified using the Product Consistency Test (PCT). All of the glasses had very acceptable durability performance. The results of this study indicate that a frit composition can be identified that will provide a processable and durable glass when combined with SB5.

  20. High level radioactive waste glass production and product description

    SciTech Connect

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

    1993-12-01

    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.

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

    SciTech Connect

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

    1995-12-31

    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.

  2. A high-level approach to synthesis of high-performance codes for quantum chemistry

    Microsoft Academic Search

    Gerald Baumgartner; David E. Bernholdt; Daniel Cociorva; Robert J. Harrison; So Hirata; Chi-Chung Lam; Marcel Nooijen; Russell M. Pitzer; J. Ramanujam; P. Sadayappan

    2002-01-01

    This paper discusses an approach to the synthesis of high-performance parallel programs for a class of computations encountered in quantum chemistry and physics. These computations are expressible as a set of tensor contractions and arise in electronic structure modeling. An overview is provided of the synthesis system, that transforms a high-level specification of the computation into high-performance parallel code, tailored

  3. Sunflower mutant containing high levels of palmitic acid in high oleic background

    Microsoft Academic Search

    José M. Fernández-Martínez; Manuel Mancha; Jorge Osorio; Rafael Garcés

    1997-01-01

    A new sunflower mutant, CAS-12, was obtained, which has both high palmitic (?30%) and high oleic acid contents, and also a\\u000a substantial amount of palmitoleic acid (?7%). The mutant was selected after X-ray irradiation of dry seeds of the inbred line\\u000a BSD-2-423, which had normal palmitic (?3%) and high oleic (?88%) acid levels. The increase of palmitic and palmitoleic acids

  4. Confidence Level and Sensitivity Limits in High Contrast Imaging

    SciTech Connect

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

    2008-06-02

    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.

  5. Confidence Level and Sensitivity Limits in High Contrast Imaging

    SciTech Connect

    Marois, C

    2007-11-07

    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.

  6. High Resolution Magnetic and Gravity Surveys to Constrain Maar Geometry and Eruption Mechanisms, Rattlesnake Crater, Arizona

    NASA Astrophysics Data System (ADS)

    Marshall, A. M.; Kruse, S. E.; Connor, C.; Connor, L.; Abdollahzadeh, M.; Harburger, A.; Richardson, J. A.; Courtland, L. M.; Farrell, A. K.; Kiflu, H. G.; Malservisi, R.; McNiff, C. M.; Njoroge, M.; Nushart, N.; Rookey, K.

    2013-12-01

    Located 25 kilometers east of Flagstaff, Arizona, Rattlesnake Crater is an oblong phreatomagmatic feature in the San Francisco Volcanic Field. The shallow crater is approximately 1.4 kilometers at its widest point, and surrounded by an uneven tuff ring which is overlapped by a scoria cone volcano on the southeastern side. Improved understanding of its formation and evolution requires geophysical study because there are very few outcrops, and no digging is permitted on site. Geologic features related to the crater are further obscured by deposits from the overlapping scoria cone, as well as tephra from eruptions at nearby Sunset Crater. We present the results of a detailed magnetic and gravity survey in and around Rattlesnake Crater. A substantial NW-SE trending elongate magnetic anomaly (1400 nT) and a smaller similarly trending anomaly are observed inside the crater, as well as a longer wavelength positive gravitational anomaly (+1.0-1.5 mGal) across the crater. The magnetic survey was completed on foot with a 50 meter line spacing inside the crater, and 100 meter line spacing across a portion of the surrounding area outside the crater. The gravity survey was done on two intersecting survey lines - one running west to east, and another roughly north to south, with recordings every 100 meters extending at least 1000 meters outside the crater in all four directions. 2D models of the magnetic and gravity data are presented illustrating the possible geometry of the diatreme, and the approximate size and shape of the major intrusive features. Eruption estimates based on the models are calculated, and the models are favorably compared to the size and depth estimates given in a recent publication (Valentine 2012) that used xenolith content to estimate the size and depth of the diatreme.

  7. Analysis of Metagenomic Data Containing High Biodiversity Levels

    PubMed Central

    Valverde, José R.; Mellado, Rafael P.

    2013-01-01

    In this paper we have addressed the problem of analysing Next Generation Sequencing samples with an expected large biodiversity content. We analysed several well-known 16S rRNA datasets from experimental samples, including both large and short sequences, in numbers of tens of thousands, in addition to carefully crafted synthetic datasets containing more than 7000 OTUs. From this data analysis several patterns were identified and used to develop new guidelines for experimentation in conditions of high biodiversity. We analysed the suitability of different clustering packages for these type of situations, the problem of even sampling, the relative effectiveness of Chao1 and ACE estimators as well as their effect on sampling size for a variety of population distributions. As regards practical analysis procedures, we advocated an approach that retains as much high-quality experimental data as possible. By carefully applying selection rules combining the taxonomic assignment with clustering strategies, we derived a set of recommendations for ultra-sequencing data analysis at high biodiversity levels. PMID:23505458

  8. Airborne gravity is here

    Microsoft Academic Search

    Sigmund Hammer

    1982-01-01

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey,

  9. Kelvin and Rossby gravity wave packets in the lower stratosphere of some high-top CMIP5 models

    NASA Astrophysics Data System (ADS)

    Lott, Francois; Denvil, Sébastien; Butchard, Neal; Cagnazzo, Chiara; Giorgetta, Marco; Hardiman, Steven; Manzini, Elisa; Krismer, Thomas; Duvel, Jean-Philippe; Maury, Pauline; Scinocca, John

    2015-04-01

    We analyse the stratospheric Kelvin and Rossby-gravity wave packets with periods of a few days in nine high-top (i.e. with stratosphere) models of the fifth Coupled Model Intercomparison Project (CMIP5). These models simulate realistic aspects of these waves, and represent them better than the tropospheric convectively coupled waves analyzed in previous studies. There is nevertheless a large spread among the models, and those with a Quasi-biennial Oscillation (QBO) produce larger amplitude waves than the models without a QBO. For the Rossby-gravity waves this is explained by the fact that models without a QBO never have positive zonal mean zonal winds in the lower stratosphe re, a situation that is favorable to the propagation of Rossby-gravity waves. For the Kelvin waves, larger amplitudes in the presence of a QBO is counter intuitive because Kelvin waves are expected to have larger amplitude when the zonal mean zonal wind is negative, and this is always satisfied in models without a QBO. We attribute the larger amplitude to the fact that models tuned to have a QBO require finer vertical resolution in the stratosphere. We also find that models with large precipitation variability tend to produce larger amplitude waves. However, the effect is not as pronounced as was found in previous studies. In fact, even models with weak precipitation variability still have quite realistic stratospheric waves, indicating either that (i) other sources can be significant or that (ii) the dynamical filtering mitigates the differences in the sources between models.

  10. Bridging low-level features and high-level semantics via fMRI brain imaging for video classification

    Microsoft Academic Search

    Xintao Hu; Fan Deng; Kaiming Li; Tuo Zhang; Hanbo Chen; Xi Jiang; Jinglei Lv; Dajiang Zhu; Carlos Faraco; Degang Zhang; Arsham Mesbah; Junwei Han; Xiansheng Hua; Li Xie; Stephen Miller; Lei Guo; Tianming Liu

    2010-01-01

    The multimedia content analysis community has made significant effort to bridge the gap between low-level features and high-level semantics perceived by human cognitive systems such as real-world objects and concepts. In the two fields of multimedia analysis and brain imaging, both topics of low-level features and high level semantics are extensively studied. For instance, in the multimedia analysis field, many

  11. High-Level Language Production in Parkinson's Disease: A Review

    PubMed Central

    Altmann, Lori J. P.; Troche, Michelle S.

    2011-01-01

    This paper discusses impairments of high-level, complex language production in Parkinson's disease (PD), defined as sentence and discourse production, and situates these impairments within the framework of current psycholinguistic theories of language production. The paper comprises three major sections, an overview of the effects of PD on the brain and cognition, a review of the literature on language production in PD, and a discussion of the stages of the language production process that are impaired in PD. Overall, the literature converges on a few common characteristics of language production in PD: reduced information content, impaired grammaticality, disrupted fluency, and reduced syntactic complexity. Many studies also document the strong impact of differences in cognitive ability on language production. Based on the data, PD affects all stages of language production including conceptualization and functional and positional processing. Furthermore, impairments at all stages appear to be exacerbated by impairments in cognitive abilities. PMID:21860777

  12. High-level waste tank farm set point document

    SciTech Connect

    Anthony, J.A. III

    1995-01-15

    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.

  13. High Level Waste System Impacts from Acid Dissolution of Sludge

    SciTech Connect

    KETUSKY, EDWARD

    2006-04-20

    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.

  14. A High-Level Language for Rule-Based Modelling

    PubMed Central

    Pedersen, Michael; Phillips, Andrew; Plotkin, Gordon D.

    2015-01-01

    Rule-based languages such as Kappa excel in their support for handling the combinatorial complexities prevalent in many biological systems, including signalling pathways. But Kappa provides little structure for organising rules, and large models can therefore be hard to read and maintain. This paper introduces a high-level, modular extension of Kappa called LBS-?. We demonstrate the constructs of the language through examples and three case studies: a chemotaxis switch ring, a MAPK cascade, and an insulin signalling pathway. We then provide a formal definition of LBS-? through an abstract syntax and a translation to plain Kappa. The translation is implemented in a compiler tool which is available as a web application. We finally demonstrate how to increase the expressivity of LBS-? through embedded scripts in a general-purpose programming language, a technique which we view as generally applicable to other domain specific languages. PMID:26043208

  15. Using the CMS High Level Trigger as a Cloud Resource

    NASA Astrophysics Data System (ADS)

    Colling, David; Huffman, Adam; McCrae, Alison; Lahiff, Andrew; Grandi, Claudio; Cinquilli, Mattia; Gowdy, Stephen; Coarasa, Jose Antonio; Tiradani, Anthony; Ozga, Wojciech; Chaze, Olivier; Sgaravatto, Massimo; Bauer, Daniela

    2014-06-01

    The CMS High Level Trigger is a compute farm of more than 10,000 cores. During data taking this resource is heavily used and is an integral part of the experiment's triggering system. However, outside of data taking periods this resource is largely unused. We describe why CMS wants to use the HLT as a cloud resource (outside of data taking periods) and how this has been achieved. In doing this we have turned a single-use cluster into an agile resource for CMS production computing. While we are able to use the HLT as a production cloud resource, there is still considerable further work that CMS needs to carry out before this resource can be used with the desired agility. This report, therefore, represents a snapshot of this activity at the time of CHEP 2013.

  16. High level radioactive waste vitrification process equipment component testing

    SciTech Connect

    Siemens, D.H.; Heath, W.O.; Larson, D.E.; Craig, S.N.; Berger, D.N.; Goles, R.W.

    1985-04-01

    Remote operability and maintainability of vitrification equipment were assessed under shielded-cell conditions. The equipment tested will be applied to immobilize high-level and transuranic liquid waste slurries that resulted from plutonium production for defense weapons. Equipment tested included: a turntable for handling waste canisters under the melter; a removable discharge cone in the melter overflow section; a thermocouple jumper that extends into a shielded cell; remote instrument and electrical connectors; remote, mechanical, and heat transfer aspects of the melter glass overflow section; a reamer to clean out plugged nozzles in the melter top; a closed circuit camera to view the melter interior; and a device to retrieve samples of the glass product. A test was also conducted to evaluate liquid metals for use in a liquid metal sealing system.

  17. Socioeconomic studies of high-level nuclear waste disposal.

    PubMed Central

    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

    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

  18. Risk assessment for subseabed disposal of high level radioactive waste

    SciTech Connect

    Klett, R.D.

    1987-01-01

    Feasibility studies for subseabed high-level waste (HLW) disposal required development of new evaluation standards, performance assessment procedures, and models. The steps for the Subseabed Disposal Project (SDP) risk assessment are interactive as the design develops and the models and data base become more complete. The reference system (including transportation, emplacement, the operating repository, and possible abnormal events) is defined. Since no official radiological protection criteria exist for subseabed HLW disposal, evaluation standards are defined. Analytic and compartmental models are developed for sensitivity and repetitive risk analyses. These fast and convenient computer models are verified with numeric programs. Analysis begins with parametric studies to define the senitivity of each input parameter. This is followed by an attenuation factor analysis to define the effectiveness of each component, and the robustness and limitations of the system. Peak individual, time integrated world population, and biota doses are computed using reference parameters.

  19. Sandia National Laboratories' new high level acoustic test facility

    SciTech Connect

    Rogers, J. D.; Hendrick, D. M.

    1989-01-01

    A high intensity acoustic test facility has been designed and is under construction at Sandia National Laboratories in Albuquerque, NM. The chamber is designed to provide an acoustic environment of 154dB (re 20 {mu}Pa) overall sound pressure level over the bandwidth of 50 Hz to 10,000 Hz. The chamber has a volume of 16,000 cubic feet with interior dimensions of 21.6 ft {times} 24.6 ft {times} 30 ft. The construction of the chamber should be complete by the summer of 1990. This paper discusses the design goals and constraints of the facility. The construction characteristics are discussed in detail, as are the acoustic performance design characteristics. The authors hope that this work will help others in designing acoustic chambers. 12 refs., 6 figs.

  20. A high-level language for rule-based modelling.

    PubMed

    Pedersen, Michael; Phillips, Andrew; Plotkin, Gordon D

    2015-01-01

    Rule-based languages such as Kappa excel in their support for handling the combinatorial complexities prevalent in many biological systems, including signalling pathways. But Kappa provides little structure for organising rules, and large models can therefore be hard to read and maintain. This paper introduces a high-level, modular extension of Kappa called LBS-?. We demonstrate the constructs of the language through examples and three case studies: a chemotaxis switch ring, a MAPK cascade, and an insulin signalling pathway. We then provide a formal definition of LBS-? through an abstract syntax and a translation to plain Kappa. The translation is implemented in a compiler tool which is available as a web application. We finally demonstrate how to increase the expressivity of LBS-? through embedded scripts in a general-purpose programming language, a technique which we view as generally applicable to other domain specific languages. PMID:26043208

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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.

  2. THE HIGH-ENERGY IMPULSIVE GROUND-LEVEL ENHANCEMENT

    SciTech Connect

    McCracken, K. G. [Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742 (United States); Moraal, H. [Centre for Space Research, School for Physical and Chemical Sciences, North-West University, Potchefstroom 2520 (South Africa); Shea, M. A. [CSPAR, University of Alabama at Huntsville, Huntsville, AL 35899 (United States)

    2012-12-20

    We have studied short-lived (21 minute average duration), highly anisotropic pulses of cosmic rays that constitute the first phase of 10 large ground-level enhancements (GLEs), and which extend to rigidities in the range 5-20 GV. We provide a set of constraints that must be met by any putative acceleration mechanism for this type of solar-energetic-particle (SEP) event. The pulses usually have very short rise-times (three to five minutes) at all rigidities, and exhibit the remarkable feature that the intensity drops precipitously by 50% to 70% from the maximum within another three to five minutes. Both the rising and falling phases exhibit velocity dispersion, which indicates that there are particles with rigidities in the range 1 < P (GV) < 3 in the beam, and the evidence is that there is little scattering en route from the Sun. We name these events the high-energy impulsive ground-level enhancement (HEI GLE). We argue that the time-dependence observed at Earth at {approx}5 GV is a close approximation to that of the SEP pulse injected into the open heliospheric magnetic field in the vicinity of the Sun. We conclude that the temporal characteristics of the HEI GLE impose nine constraints on any putative acceleration process. Two of the HEI GLEs are preceded by short-lived, fast-rising neutron and >90 MeV gamma-ray bursts, indicating that freshly accelerated SEPs had impinged on higher-density matter in the chromosphere prior to the departure of the SEP pulse for Earth. This study was based on an updated archive of the 71 GLEs in the historic record, which is now available for public use.

  3. High {sup 222}Rn levels, enhanced plateout, increased diffusion coefficient

    SciTech Connect

    Leonard, B.E.

    1994-12-31

    In a previous study of plateout and resuspension effects for {sup 222}Rn progeny, an unexpected suppression of the airborne {sup 218}Po and {sup 214}Po levels, which is total unrelated and not predicted by theory or other works, was observed when high {sup 222}Rn concentrations were utilized in a 0.283-m{sup 3} test chamber. Two separate time-dependent methods were used and are reported here to measure this airborne progeny suppression effect to attempt to possibly determine the magnitude and cause of the effect and possible consequences on prior and current ongoing radon research by others. The earlier buildup method was used to observe the buildup phase of {sup 222} Rn and its daughters from a constant emanation source, a constant air change rate (ACH), and initially zero concentrations Rn and progeny. The data were compared with theory using Leonard`s solutions to the Bateman equations to determine the magnitude of the suppression. The second method, referred to as the {open_quotes}down{close_quotes} method, was to measure the decrease in {sup 222}Rn and progeny concentrations from an initially injected high {sup 222}Rn activity concentration in the test chamber, the decrease resulting from a constant ACH of {approximately}0.1 h{sup -1} imposed by the gradual removal of air from the chamber at a constant rate of {approximately}0.5 l/min. No {sup 222}Rn emanation source was present during the second method after the initial injection so that the level of the {sup 222}Rn underwent a monotonic decrease in concentration.

  4. Adaptation, high-level vision, and the phenomenology of perception

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.

    2002-06-01

    To what extent do we have shared or unique visual experiences? This paper examines how the answer to this question is constrained by known processes of visual adaptation. Adaptation constantly recalibrates visual sensitivity so that our vision is matched to the stimuli that we are currently exposed to. These processes normalize perception not only to low-level features in the image, but to high-level, biologically relevant properties of the visual world. They can therefore strongly impact many natural perceptual judgments. To the extent that observers are exposed to and thus adapted by a different environment, their vision will be normalized in different ways and their subjective visual experience will differ. These differences are illustrated by considering how adaptation can influence human face perception. To the extent that observers are exposed and adapted to common properties in the environment, their vision will be adjusted toward common states, and in this respect they will have a common visual experience. This is illustrated by reviewing the effects of adaptation on the perception of image blur. In either case, it is the similarities or differences in the stimuli - and not the intrinsic similarities or differences in the observers - which determine the relative states of adaptation. Thus at least some aspects of our private internal experience are controlled by external factors that are accessible to objective measurement.

  5. A High School Project Seminar on Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Seitz, M.; Bosch, W.

    2012-04-01

    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.

  6. Earth Gravity Field from Space - from Sensors to Earth Sciences

    NASA Astrophysics Data System (ADS)

    Beutler, G.; Drinkwater, M. R.; Rummel, R.; von Steiger, R.

    2003-10-01

    The ESA explorer core mission GOCE, to be launched in 2006, will enhance our knowledge of the global static gravity field and of the geoid by orders of magnitude. The U.S. satellite gravity mission GRACE (2002-2006) is currently measuring, in addition, the temporal variations of the gravity field. With these new data a whole range of fascinating new possibilities will be opened for solid Earth physics, oceanography, geodesy and sea-level research. The new generation of gravity missions employs sensor concepts for gravity field measurement, orbit and attitude control and orbit determination that show interesting similarities with space experiments planned in the field of fundamental physics. This volume is the result of a workshop that brought together some 50 acknowledged experts in their field to discuss (1) strategies for ultra precision orbit determination and gravity field modelling with the data of the upcoming gravity field missions, (2) the use of accurate and high resolution gravity models in Earth sciences whereby, in particular, synergy is expected between the various science fields in their use of this type of new information, and (3) gravity field requirements and possible sensor and mission concepts for the time after GRACE and GOCE. Link: http://www.wkap.nl/prod/b/1-4020-1408-2

  7. Introduction Basics of gravity theory

    E-print Network

    Visser, Matt

    Introduction Basics of gravity theory Actions and Field Equations Phenomenology Discussion;Introduction Basics of gravity theory Actions and Field Equations Phenomenology Discussion and Conclusions Is there a way out? A high-energy theory of gravity? Fact GR is a classical theory what happens in the Plank

  8. Sea level rise Contribution from High Mountain Asia by 20150

    NASA Astrophysics Data System (ADS)

    Zhao, Liyun; Moore, John; Ding, Ran

    2015-04-01

    We estimate individual area and volume change by 2050 of all 83,460 glaciers of high mountain Asia (HMA), with a total area of 118,263 km2, delineated in the Randolph Glacier Inventory version 4.0 which separates glacier complexes in its previous version into individual glaciers. We used the 25 km resolution regional climate model RegCM 3.0 temperature and precipitation change projections forced by the IPCC A1B scenario. Glacier simulations were based on a novel surface mass balance-altitude parameterization fitted to observational data, and various volume-area scaling approaches using Shuttle Radar Topography Mission surface topography of each individual glacier. We generate mass balance-altitude relations for all the glaciers by region using nearest available glacier measurements. Two method are used to model the Equilibrium line altitude (ELA) variation. One is to use ELA sensitivities to temperature and precipitation change vary by region based on the relative importance of sublimation and melting processes. The other is solved ELA implicitly for every year using the temperature at ELA and Degree Day model. We project total glacier area loss in high mountain Asia in 2050 to be 22% of their extent in 2000, and they will contribute 5-8 mm to global sea level rise.

  9. Control of high level radioactive waste-glass melters

    SciTech Connect

    Bickford, D.F.; Choi, A.S.

    1991-01-01

    Slurry Fed Melters (SFM) are being developed in the United States, Europe and Japan for the conversion of high-level radioactive waste to borosilicate glass for permanent disposal. The high transition metal, noble metal, nitrate, organic, and sulfate contents of these wastes lead to unique melter redox control requirements. Pilot waste-glass melter operations have indicated the possibility of nickel sulfide or noble-metal fission-product accumulation on melter floors, which can lead to distortion of electric heating patterns, and decrease melter life. Sulfide formation is prevented by control of the redox chemistry of the melter feed. The redox state of waste-glass melters is determined by balance between the reducing potential of organic compounds in the feed, and the oxidizing potential of gases above the melt, and nitrates and polyvalent elements in the waste. Semiquantitative models predicting limitations of organic content have been developed based on crucible testing. Computerized thermodynamic computations are being developed to predict the sequence and products of redox reactions and is assessing process variations. Continuous melter test results have been compared to improved computer staged-thermodynamic-models of redox behavior. Feed chemistry control to prevent sulfide and moderate noble metal accumulations are discussed. 17 refs., 3 figs.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

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

    SciTech Connect

    Rusin, J.M.

    1980-12-01

    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.

  13. Cementitious Grout for Closing SRS High Level Waste Tanks - 12315

    SciTech Connect

    Langton, C.A.; Stefanko, D.B.; Burns, H.H. [Savannah River National Laboratory (United States); Waymer, J.; Mhyre, W.B. [URS Quality and Testing (United States); Herbert, J.E.; Jolly, J.C. Jr. [Savannah River Remediation, LLC, Savannah River Site, Aiken, SC 29808 (United States)

    2012-07-01

    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. Ancillary equipment abandoned in the tanks will also be filled to the extent practical. 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 to be chemically reducing with a reduction potential (Eh) of -200 to -400. Grouts with this chemistry stabilize 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 to support the mass placement strategy developed by Savannah River Remediation (SRR) 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. The cement and slag contents of a mix selected for filling Tanks 18-F and 19-F should be limited to no more than 125 and 210 lbs/cyd, respectively, to limit the heat generated as the result of hydration reaction during curing and thereby enable mass pour placement. Trial mixes with water to total cementitious materials ratios of 0.550 to 0.580 and 125 lbs/cyd of cement and 210 lbs/cyd of slag met the strength and permeability requirements. Mix LP no.8-16 was selected for closing SRS Tanks 18-F and 19-F because it meets or exceeds the design requirements with the least amount of Portland cement and blast furnace slag. This grout is expected to flow at least 45 feet. A single point of discharge should be sufficient for unrestricted flow conditions. However, additional entry points should be identified as back-up in case restrictions in the tank impede flow. The LP no.8 series of trial mixes had surprisingly high design compressive strengths (2000 to 4000/5000 psi) which were achieved at extended curing times (28 to 90 days, respectively) given the small amount of Portland cement in the mixes (100 to 185 lbs/cyd). The grouts were flowable structural fills containing 3/8 inch gravel and concrete sand aggregate. These grouts did not segregate and require no compaction. They have low permeabilities (? 10{sup -9} cm/s) and are consequen

  14. Pool boiling heat transfer on small heaters: effect of gravity and subcooling

    E-print Network

    Kim, Jungho

    Abstract Measurements of space and time resolved subcooled pool boiling of FC-72 in low, earth, and high to increase in size with bulk fluid temperature. Boiling curves at various subcoolings and gravity levelsPool boiling heat transfer on small heaters: effect of gravity and subcooling Jungho Kim a,*, John

  15. High-level disinfection of gastrointestinal endoscope reprocessing.

    PubMed

    Chiu, King-Wah; Lu, Lung-Sheng; Chiou, Shue-Shian

    2015-02-20

    High level disinfection (HLD) of the gastrointestinal (GI) endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition, GI endoscopy is a semicritical medical device. Hence, such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and post-procedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself. PMID:25699232

  16. Using continuous GPS and absolute gravity to separate vertical land movements and changes in sea-level at tide-gauges in the UK.

    PubMed

    Teferle, F N; Bingley, R M; Williams, S D P; Baker, T F; Dodson, A H

    2006-04-15

    Researchers investigating climate change have used historical tide-gauge measurements from all over the world to investigate the changes in sea-level that have occurred over the last century or so. However, such estimates are a combination of any true sea-level variations and any vertical movements of the land at the specific tide-gauge. For a tide- gauge record to be used to determine the climate related component of changes in sea-level, it is therefore necessary to correct for the vertical land movement component of the observed change in sea-level.In 1990, the Institute of Engineering Surveying and Space Geodesy and Proudman Oceanographic Laboratory started developing techniques based on the Global Positioning System (GPS) for measuring vertical land movements (VLM) at tide-gauges in the UK. This paper provides brief details of these early developments and shows how they led to the establishment of continuous GPS (CGPS) stations at a number of tide-gauges. The paper then goes on to discuss the use of absolute gravity (AG), as an independent technique for measuring VLM at tide-gauges. The most recent results, from CGPS time-series dating back to 1997 and AG time-series dating back to 1995/1996, are then used to demonstrate the complementarity of these two techniques and their potential for providing site-specific estimates of VLM at tide-gauges in the UK. PMID:16537148

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

    PubMed

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

    2013-10-01

    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

  18. Oasis: A high-level/high-performance open source Navier-Stokes solver

    NASA Astrophysics Data System (ADS)

    Mortensen, Mikael; Valen-Sendstad, Kristian

    2015-03-01

    Oasis is a high-level/high-performance finite element Navier-Stokes solver written from scratch in Python using building blocks from the FEniCS project (fenicsproject.org). The solver is unstructured and targets large-scale applications in complex geometries on massively parallel clusters. Oasis utilizes MPI and interfaces, through FEniCS, to the linear algebra backend PETSc. Oasis advocates a high-level, programmable user interface through the creation of highly flexible Python modules for new problems. Through the high-level Python interface the user is placed in complete control of every aspect of the solver. A version of the solver, that is using piecewise linear elements for both velocity and pressure, is shown to reproduce very well the classical, spectral, turbulent channel simulations of Moser et al. (1999). The computational speed is strongly dominated by the iterative solvers provided by the linear algebra backend, which is arguably the best performance any similar implicit solver using PETSc may hope for. Higher order accuracy is also demonstrated and new solvers may be easily added within the same framework.

  19. THERMAL ANALYSIS OF GEOLOGIC HIGH-LEVEL RADIOACTIVE WASTE PACKAGES

    SciTech Connect

    Hensel, S.; Lee, S.

    2010-04-20

    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.

  20. High-level simulation of JWST event-driven operations

    NASA Astrophysics Data System (ADS)

    Henry, R.; Kinzel, W.

    2012-09-01

    The James Webb Space Telescope (JWST) has an event-driven architecture: an onboard Observation Plan Executive (OPE) executes an Observation Plan (OP) consisting of a sequence of observing units (visits). During normal operations, ground action to update the OP is only expected to be necessary about once a week. This architecture is designed to tolerate uncertainty in visit duration, and occasional visit failures due to inability to acquire guide stars, without creating gaps in the observing timeline. The operations concept is complicated by the need for occasional scheduling of timecritical science and engineering visits that cannot tolerate much slippage without inducing gaps, and also by onboard momentum management. A prototype Python tool called the JWST Observation Plan Execution Simulator (JOPES) has recently been developed to simulate OP execution at a high level and analyze the response of the Observatory and OPE to both nominal and contingency scenarios. Incorporating both deterministic and stochastic behavior, JOPES has potential to be a powerful tool for several purposes: requirements analysis, system verification, systems engineering studies, and test data generation. It has already been successfully applied to a study of overhead estimation bias: whether to use conservative or average-case estimates for timing components that are inherently uncertain, such as those involving guide-star acquisition. JOPES is being enhanced to support interfaces to the operational Proposal Planning Subsystem (PPS) now being developed, with the objective of "closing the loop" between testing and simulation by feeding simulated event logs back into the PPS.

  1. Defense High-Level Waste Leaching Mechanisms Program. Final report

    SciTech Connect

    Mendel, J.E. (compiler)

    1984-08-01

    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.

  2. Application of SYNROC to high-level defense wastes

    SciTech Connect

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

    1981-01-01

    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.

  3. Magma and fluid migration at Yellowstone Caldera in the last three decades inferred from InSAR, leveling, and gravity measurements

    NASA Astrophysics Data System (ADS)

    Tizzani, P.; Battaglia, M.; Castaldo, R.; Pepe, A.; Zeni, G.; Lanari, R.

    2015-04-01

    We studied the Yellowstone caldera geological unrest between 1977 and 2010 by investigating temporal changes in differential Interferometric Synthetic Aperture Radar (InSAR), precise spirit leveling and gravity measurements. The analysis of the 1992-2010 displacement time series, retrieved by applying the SBAS InSAR technique, allowed the identification of three areas of deformation: (i) the Mallard Lake (ML) and Sour Creek (SC) resurgent domes, (ii) a region close to the Northern Caldera Rim (NCR), and (iii) the eastern Snake River Plain (SRP). While the eastern SRP shows a signal related to tectonic deformation, the other two regions are influenced by the caldera unrest. We removed the tectonic signal from the InSAR displacements, and we modeled the InSAR, leveling, and gravity measurements to retrieve the best fitting source parameters. Our findings confirmed the existence of different distinct sources, beneath the brittle-ductile transition zone, which have been intermittently active during the last three decades. Moreover, we interpreted our results in the light of existing seismic tomography studies. Concerning the SC dome, we highlighted the role of hydrothermal fluids as the driving force behind the 1977-1983 uplift; since 1983-1993 the deformation source transformed into a deeper one with a higher magmatic component. Furthermore, our results support the magmatic nature of the deformation source beneath ML dome for the overall investigated period. Finally, the uplift at NCR is interpreted as magma accumulation, while its subsidence could either be the result of fluids migration outside the caldera or the gravitational adjustment of the source from a spherical to a sill-like geometry.

  4. Process Design Concepts for Stabilization of High Level Waste Calcine

    SciTech Connect

    T. R. Thomas; A. K. Herbst

    2005-06-01

    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.

  5. 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)

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

    2009-12-01

    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.

  6. AIRS high-resolution stratospheric temperature retrievals evaluated with operational Level-2 data and ERA-Interim

    NASA Astrophysics Data System (ADS)

    Meyer, Catrin I.; Hoffmann, Lars

    2015-04-01

    The Atmospheric InfraRed Sounder (AIRS) aboard NASA's Aqua satellite provides stratospheric temperature observations for a variety of scientific tasks. However, the horizontal resolution of the operational temperature retrievals is generally not sufficient for studies of gravity waves. The retrieval discussed here provides stratospheric temperature profiles for each individual AIRS footprint and therefore has nine times better horizontal sampling than the operational data. The retrieval configuration is optimized so that the results provide a trade-off between spatial resolution and retrieval noise which is considered optimal for gravity wave analysis. Here the quality of the high-resolution data is assessed by comparing a nine-year record (2003 - 2011) of stratospheric temperatures with results from the AIRS operational Level-2 data and the ERA-Interim meteorological reanalysis. Due to the large amount of data we performed a statistical comparison of the high-resolution retrieval and reference data sets based on zonal averages and time-series. The temperature data sets are split into day and night, because the AIRS high-resolution retrieval uses different configurations for day- and night-time conditions to cope with non-LTE effects. The temperature data are averaged on a latitudinal grid with a resolution of one degree. The zonal averages are calculated on a daily basis and show significant day-to-day variability. To further summarize the data we calculated monthly averages from the daily averaged data and also computed zonal means. Additionally, the standard deviation of the three data sets was computed. The comparisons show that the high-resolution temperature data are in good agreement with the reference data sets. The bias in the zonal averages is mostly within ± 2 K and reaches a maximum of 7 K to ERA-Interim and 4 K to the AIRS operational data at the stratopause, which is related to the different resolutions of the data sets. Variability is nearly the same in all three data sets, having maximum standard deviations around the polar vortex in the mid and upper stratosphere. The evaluation presented here indicates that the high-resolution temperature retrievals are well-suited for scientific studies and that they will become a valuable asset for further studies of stratospheric gravity waves. Reference: Meyer, C. I. and L. Hoffmann, Validation of AIRS high-resolution stratospheric temperature retrievals, Proc. SPIE 9242, Remote Sensing of Clouds and the Atmosphere XIX; and Optics in Atmospheric Propagation and Adaptive Systems XVII, 92420L (17 October 2014); doi: 10.1117/12.2066967

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

    PubMed

    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

    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

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

    PubMed Central

    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

    2014-01-01

    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

  9. Burning experiments and late Paleozoic high O2 levels

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    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.

  10. Electricity from Gravity

    NASA Astrophysics Data System (ADS)

    Masters, Roy

    2007-03-01

    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.

  11. Gravity Waves

    Atmospheric Science Data Center

    2013-04-19

    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 ...

  12. Monthly gravity field models derived from GRACE Level 1B data using a modified short-arc approach

    NASA Astrophysics Data System (ADS)

    Chen, Qiujie; Shen, Yunzhong; Zhang, Xingfu; Hsu, Houze; Chen, Wu; Ju, Xiaolei; Lou, Lizhi

    2015-03-01

    In this study, a new time series of Gravity Recovery and Climate Experiment (GRACE) monthly solutions, complete to degree and order 60 spanning from January 2003 to August 2011, has been derived based on a modified short-arc approach. Our models entitled Tongji-GRACE01 are available on the website of International Centre for Global Earth Models http://icgem.gfz-potsdam.de/ICGEM/. The traditional short-arc approach, with no more than 1 h arcs, requires the gradient corrections of satellite orbits in order to reduce the impact of orbit errors on the final solution. Here the modified short-arc approach has been proposed, which has three major differences compared to the traditional one: (1) All the corrections of orbits and range rate measurements are solved together with the geopotential coefficients and the accelerometer biases using a weighted least squares adjustment; (2) the boundary position parameters are not required; and (3) the arc length can be extended to 2 h. The comparisons of geoid degree powers and the mass change signals in the Amazon basin, the Antarctic, and Antarctic Peninsula demonstrate that our model is comparable with the other existing models, i.e., the Centre for Space Research RL05, Jet Propulsion Laboratory RL05, and GeoForschungsZentrum RL05a models. The correlation coefficients of the mass change time series between our model and the other models are better than 0.9 in the Antarctic and Antarctic Peninsula. The mass change rates in the Antarctic and Antarctic Peninsula derived from our model are -92.7 ± 38.0 Gt/yr and -23.9 ± 12.4 Gt/yr, respectively, which are very close to those from other three models and with similar spatial patterns of signals.

  13. Generating Whole-System VMs from high-level models using PyPy

    E-print Network

    Paris-Sud XI, Université de

    implemented in low-level languages and using a low-level style for performance reasons. This trend results models of whole-system VMs in a high-level language, which exclude all low-level implementation details Words: pypy, python, rpython, whole system virtual machine, translation toolchain, high-level language

  14. Large-scale gravity wave characteristics simulated with a high-resolution global thermosphere-ionosphere model

    Microsoft Academic Search

    L. C. Gardner; R. W. Schunk

    2011-01-01

    Waves in the atmosphere, ionosphere, magnetosphere, and oceans are important mechanisms for dissipating and distributing energy throughout the Earth-atmosphere system. Internal waves are extremely important in the atmosphere, and past global studies have looked at the impacts of gravity waves on the thermosphere using gravity wave parameterizations. Here, in contrast, a medium-scale gravity wave is studied in a global thermosphere-ionosphere

  15. The direction of gravity

    NASA Astrophysics Data System (ADS)

    Linder, E. V.

    2014-03-01

    Gravity directs the paths of light rays and the growth of structure. Moreover, gravity on cosmological scales does not simply point down: It accelerates the universal expansion by pulling outward, either due to a highly negative pressure dark energy or an extension of general relativity. We have examined methods to test the properties of gravity through cosmological measurements. We have then considered specific possibilities for a sound gravitational theory based on the Galilean shift symmetry. The evolution of the laws of gravity from the early universe to the present acceleration to the future fate - the paths of gravity - carries rich information on this fundamental force of physics, and on the mystery of dark energy.

  16. Qualification of Innovative High Level Waste Pipeline Unplugging Technologies

    SciTech Connect

    McDaniel, D.; Gokaltun, S.; Varona, J.; Awwad, A.; Roelant, D.; Srivastava, R. [Applied Research Center, Florida International University, Miami, FL (United States)

    2008-07-01

    In the past, some of the pipelines have plugged during high level waste (HLW) transfers resulting in schedule delays and increased costs. Furthermore, pipeline plugging has been cited by the 'best and brightest' technical review as one of the major issues that can result in unplanned outages at the Waste Treatment Plant causing inconsistent operation. As the DOE moves toward a more active high level waste retrieval, the site engineers will be faced with increasing cross-site pipeline waste slurry transfers that will result in increased probability of a pipeline getting plugged. Hence, availability of a pipeline unplugging tool/technology is crucial to ensure smooth operation of the waste transfers and in ensuring tank farm cleanup milestones are met. FIU had earlier tested and evaluated various unplugging technologies through an industry call. Based on mockup testing, two technologies were identified that could withstand the rigors of operation in a radioactive environment and with the ability to handle sharp 90 elbows. We present results of the second phase of detailed testing and evaluation of pipeline unplugging technologies and the objective is to qualify these pipeline unplugging technologies for subsequent deployment at a DOE facility. The current phase of testing and qualification comprises of a heavily instrumented 3-inch diameter (full-scale) pipeline facilitating extensive data acquisition for design optimization and performance evaluation, as it applies to three types of plugs atypical of the DOE HLW waste. Furthermore, the data from testing at three different lengths of pipe in conjunction with the physics of the process will assist in modeling the unplugging phenomenon that will then be used to scale-up process parameters and system variables for longer and site typical pipe lengths, which can extend as much as up to 19,000 ft. Detailed information resulting from the testing will provide the DOE end-user with sufficient data and understanding of the technology, and its limitations to aid in the benefit-cost analysis for management decision whether to deploy the technology or to abandon the pipeline as has been done in the past. In conclusion: The ultimate objective of this study is to qualify NuVision's unplugging technology for use at Hanford. Experimental testing has been conducted using three pipeline lengths and three types of blockages. Erosion rates have been obtained and pressure data is being analyzed. An amplification of the inlet pressure has been observed along the pipeline and is the key to determining up to what pipe lengths the technology can be used without surpassing the site pressure limit. In addition, we will attempt to establish what the expected unplugging rates will be at the longer pipe lengths for each of the three blockages tested. Detailed information resulting from the testing will provide the DOE end-user with sufficient data and understanding of the technology, and its limitations so that management decisions can be made whether the technology has a reasonable chance to successfully unplug a pipeline, such as a cross site transfer line or process transfer pipeline at the Waste Treatment Plant. (authors)

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

    Microsoft Academic Search

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

    2000-01-01

    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

  18. HIGH LEVEL WASTE SLUDGE BATCH 4 VARIABILITY STUDY

    SciTech Connect

    Fox, K; Tommy Edwards, T; David Peeler, D; David Best, D; Irene Reamer, I; Phyllis Workman, P

    2006-10-02

    The Defense Waste Processing Facility (DWPF) is preparing for vitrification of High Level Waste (HLW) Sludge Batch 4 (SB4) in early FY2007. To support this process, the Savannah River National Laboratory (SRNL) has provided a recommendation to utilize Frit 503 for vitrifying this sludge batch, based on the composition projection provided by the Liquid Waste Organization on June 22, 2006. Frit 418 was also recommended for possible use during the transition from SB3 to SB4. A critical step in the SB4 qualification process is to demonstrate the applicability of the durability models, which are used as part of the DWPF's process control strategy, to the glass system of interest via a variability study. A variability study is an experimentally-driven assessment of the predictability and acceptability of the quality of the vitrified waste product that is anticipated from the processing of a sludge batch. At the DWPF, the durability of the vitrified waste product is not directly measured. Instead, the durability is predicted using a set of models that relate the Product Consistency Test (PCT) response of a glass to the chemical composition of that glass. In addition, a glass sample is taken during the processing of that sludge batch, the sample is transmitted to SRNL, and the durability is measured to confirm acceptance. The objective of a variability study is to demonstrate that these models are applicable to the glass composition region anticipated during the processing of the sludge batch - in this case the Frit 503 - SB4 compositional region. The success of this demonstration allows the DWPF to confidently rely on the predictions of the durability/composition models as they are used in the control of the DWPF process.

  19. Level 1 Tornado PRA for the High Flux Beam Reactor

    SciTech Connect

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

    1994-05-01

    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}.

  20. Gravity in Gauge Mediation

    E-print Network

    Zygmunt Lalak; Stefan Pokorski; Krzysztof Turzynski

    2008-08-18

    We investigate O'Raifeartaigh-type models for F-term supersymmetry breaking in gauge mediation scenarios in the presence of gravity. It is pointed out that the vacuum structure of those models is such that in metastable vacua gravity mediation contribution to scalar masses is always suppressed to the level below 1 percent, almost sufficient for avoiding FCNC problem. Close to that limit, gravitino mass can be in the range 10-100 GeV, opening several interesting possibilities for gauge mediation models, including Giudice-Masiero mechanism for mu and Bmu generation. Gravity sector can include stabilized moduli.

  1. Propagation of small-scale gravity waves through large-scale internal wave fields: Eikonal effects at low-frequency approximation critical levels

    NASA Astrophysics Data System (ADS)

    Walterscheid, R. L.

    2000-07-01

    The propagation of small-scale internal gravity wave packets through a background of large-scale internal gravity waves is investigated using Eikonal theory. When background variations are sufficiently slow, it is possible to ignore both the time dependency and the vertical velocity of the background while retaining the Doppler effects of the horizontal winds. This approximation, here referred to as the low-frequency approximation (LFA), is used as a reference approximation to elucidate the peculiar aspects of wave propagation through time-dependent wave backgrounds. The greatest difference between stationary and time-dependent wave background occurs near levels where the frequency measured in the Earth-fixed frame is canceled by the Doppler term due to the horizontal background wind (LFA critical level). In stationary flow, propagation is blocked, and wave amplitude can become very large. The focus of this paper is non-LFA effects near LFA critical levels (LFA/CLs). Major findings are as follows: the LFA overpredicts variations in the intrinsic frequency in a time-dependent background wave field because the variation of observed frequency is exactly out of phase with the variation of the Doppler term. Non-LFA effects at an LFA/CL are strong because as a packet approaches an LFA/CL, its intrinsic frequency decreases, its ascent slows, and its wavenumber vector rotates toward the vertical and increases in magnitude; thus the packet increasingly senses both the time dependency and the vertical component of the background wind. The maximum cancelation between wave frequency and the Doppler term (i.e., minimum intrinsic frequency) will usually occur above LFA/CL. The minimum intrinsic frequency is significantly nonzero and is not a strong function of vertical wavelength. The background vertical velocity allows freer propagation through intrinsic frequency minima. Counterintuitively, the time variation of wave action near such levels appears less pronounced for the slower waves (the ones that should feel Doppler effects most strongly). Eikonal simulations suggest that intrinsic frequency minima associated with LFA/CL and strong Doppler effects are favored locations for wave breakdown, but wave breakdown in a time-dependent background depends on the initial wave-packet amplitude; thus Doppler effects and time dependency should both play a role in shaping the vertical wavenumber spectrum [Hines, 1991a, b; Broutman et al., 1997]. This work supports findings of Eckermann [1997] that the effects of time dependency can drastically reduce the response of a wave packet to a wave background comprising downward propagating waveforms (upward energy transfer).

  2. Efficient Implementation of High-Level Languages on User-Level Communication Architectures

    Microsoft Academic Search

    Wilson C. Hsieh; Kirk L. Johnson; M. Frans Kaashoek; Deborah A. Wallach; William E. Weihl

    User-level communication architectures — parallel archit ectures that give user code direct but protected access to the network — provide communication performance t hat is an order of magnitude higher than previous-generation message-passing architectures. Unf ortunately, in order to take advantage of this level of performance, programmers must concern themselves with low-level issues that are often hardware- dependent (e.g., what

  3. FPGA Analysis Tool: High-Level Flows for Low-Level Design Analysis in Reconfigurable Computing

    Microsoft Academic Search

    Krzysztof Kepa; Fearghal Morgan; Krzysztof Kosciuszkiewicz; Lars Braun; Michael Hübner; Jürgen Becker

    2009-01-01

    The growth of the reconfigurable systems community exposes diverse requirements with regard to functionality of Electronic\\u000a Design Automation (EDA) tools. Those targeting reconfigurable design analysis and manipulation require low-level design tools\\u000a for bitstream debugging and IP core design assurance. While tools for low-level analy sis of design netlists do exist there\\u000a is a need for a low-level, open-source, extended tool

  4. Efficient Implementation of High-Level Languages on User-Level Communication Architectures

    Microsoft Academic Search

    W. C. Hsieh; K. L. Johnson; M. F. Kaashoek; D. A. Wallach; W. E. Weihl

    1994-01-01

    Abstract User-level communication,architectures — parallel architectures that give user code direct but protected access to the network — provide communication,performance,that is an order of magnitude,higher than previous-generation message-passing architectures. Unfortunately, in order to take advantage of this level of performance, programmers must concern themselves with low-level issues that are often hardwaredependent (e.g., what primitives to use for large and small

  5. High-Performance Parallel Computations Using Python as High-Level Language

    Microsoft Academic Search

    Stefano Masini; Paolo Bientinesi

    \\u000a High-performance and parallel computations have always represented a challenge in terms of code optimization and memory usage,\\u000a and have typically been tackled with languages that allow a low-level management of resources, like Fortran, C and C++. Nowadays,\\u000a most of the implementation effort goes into constructing the bookkeeping logic that binds together functionalities taken from\\u000a standard libraries. Because of the increasing

  6. A High-Level Implementation of a High Performance Pipeline FFT on Virtex-E FPGAs

    Microsoft Academic Search

    S. Sukhsawas; Khaled Benkrid

    2004-01-01

    This paper presents a high-level implementation of pipeline FFT. The design has been coded in Handel-C language and targeted Xilinx Virtex-E FPGA series. It is fully implemented and tested on real hardware using Celoxica RC1000-PP prototyping board. The implementation results show that our implementation outperforms other implementation of FFT on the same series of FPGA. An implementation of 1024-point FFT

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

    NASA Astrophysics Data System (ADS)

    Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

    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.

  8. Characterization of transducers and resonators under high drive levels

    Microsoft Academic Search

    S. Sherrit; X. Bao; D. A. Sigel; M. J. Gradziel; S. A. Askins; B. P. Dolgin; Y. Bar-Cohen

    2001-01-01

    In many applications, piezoelectric transducers are driven at AC voltage levels well beyond the level for which the material was nominally characterized. In this paper we describe an experimental setup that allows for the determination of the main transducer or resonator properties under large AC drive. A sinusoidal voltage from a waveform generator is amplified and applied across the transducer\\/resonator

  9. Liouville gravity from Einstein gravity

    E-print Network

    D. Grumiller; R. Jackiw

    2007-12-28

    We show that Liouville gravity arises as the limit of pure Einstein gravity in 2+epsilon dimensions as epsilon goes to zero, provided Newton's constant scales with epsilon. Our procedure - spherical reduction, dualization, limit, dualizing back - passes several consistency tests: geometric properties, interactions with matter and the Bekenstein-Hawking entropy are as expected from Einstein gravity.

  10. Physical Activity Levels of Greek High School Students

    Microsoft Academic Search

    Christina Bertaki; Maria Michalopoulou; Christina Argyropoulou; Chrysoula Bitzidou

    The aim of the present study was to assess physical activity for high school students in Greece and de- termine gender and high school grade effects on total score of physical activity as well as physical activity of high intensity, of moderate intensity and related to walking. The participants were 517 high school students aged 15-18 (M= 16.74 + 0.8

  11. Gravity model studies of Newberry Volcano, Oregon

    SciTech Connect

    Gettings, M.E.; Griscom, A.

    1988-09-10

    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.

  12. GOCE gravity field models following the time-wise approach

    NASA Astrophysics Data System (ADS)

    Brockmann, Jan Martin; Höck, Eduard; Loth, Ina; Mayer-Gürr, Torsten; Pail, Roland; Schuh, Wolf-Dieter; Zehentner, Norbert

    2015-04-01

    Since the launch of the European Space Agency's (ESA) Gravity field and Ocean Circulation Explorer (GOCE) satellite in 2009 and its end in 2013, a sequence of official GOCE gravity field models was released. One of the series of models follows the so called time-wise approach (EGM_TIM). They are purely based on GOCE observations such that they are independent of any other gravity field information available and describe the Earth's gravity field as seen by GOCE. Recently, the fifth release, EGM_TIM_RL05, was computed and made available to users. The models of the time-wise series were computed within the ESA funded High-level Processing Facility (HPF) and are part of the official ESA GOCE products. Calibrated gravity gradients in the gradiometer reference frame and the satellites position as derived by GPS measurements entered the solutions as observations. Together with the spherical harmonic coefficients, a realistic the full covariance matrix is provided reflecting the model quality. This contribution summarizes the gravity field models derived with the time-wise approach. The method is summarized and the progress along the five releases is highlighted. Special focus is put on the final release 5, the gravity field model which includes all data collected during the entire GOCE mission. This model, parametrized as 78,957 spherical harmonic coefficients (spatial resolution of 71 km), was determined from 4*109,799,264 gravity gradient measurements and 108,754,709 three dimensional positions within a joint least squares adjustment procedure. As this gravity field models only depend on GOCE observations, the gain of GOCE compared to other missions and other gravity field products can be clearly demonstrated. With release 5 of the time-wise model, a pure GOCE based model with a mean global accuracy of 2.4 cm at a spatial resolution of 100 km for the geoid is available (0.7 mGal for gravity anomalies).

  13. High Technology Internship at the Secondary Level. Final Report.

    ERIC Educational Resources Information Center

    Noll, Clifford J.

    A program was conducted during the Spring semester, 1985, in the San Antonio area to place high school juniors and seniors from three high schools in the Edgewood Independent School District in three-month interships in high-technology industries. Students traveled to their training locations on school-provided transportation on Mondays through…

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

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

  15. Development of high-waste loaded high-level nuclear waste glasses for high-temperature melter

    SciTech Connect

    Kim, D.S.; Hrma, P.R.; Lamar, D.A.; Elliott, M.L.

    1994-04-01

    This paper describes the approach taken in formulating glasses that can be processed at 1150 to 1500{degrees}C by applying glass property/composition models developed at Pacific Northwest Laboratory. Compositions and melting temperatures for glasses with high waste loading that are acceptable and able to be processed were determined for two different Hanford waste types. The glasses meet high-level waste glass acceptability criteria and are suitable for processing in a continuous Joule-heated melter.

  16. Development of high-waste loaded high-level nuclear waste glasses for high-temperature melter

    SciTech Connect

    Kim, D.S.; Hrma, P.; Lamar, D.A.; Elliott, M.L. [Pacific Northwest Lab., Richland, WA (United States)

    1994-12-31

    This paper describes the approach taken in formulating glasses that can be processed at 1150 to 1500{degrees}C by applying glass property/composition models developed at Pacific Northwest Laboratory. Compositions and melting temperatures for glasses with high waste loading that are acceptable and able to be processed were determined for two different Hanford waste types. The glasses meet high-level waste glass acceptability criteria and are suitable for processing in a continuous Joule-heated melter.

  17. Basement Aquifers : How Useful Are Gravity Data ?

    NASA Astrophysics Data System (ADS)

    Genthon, P.; Mouhouyouddine, A. H.; Hinderer, J.; Hector, B.; Yameogo, S.

    2014-12-01

    Gravity data with a few microgal precision were proved to be able to constrain the specific yield of various kinds of aquifer in West Africa from annual fluctuations of both the gravimetric and piezometric signals (Pfeffer et al., Geophys. J. Int., 2011; Hector et al., Geophys. J. Int., 2013). However some recent papers reported a disappointing potential of gravity measurements during a pumping experiment in a sandy aquifer (Blainey et al., WRR, 2007; Herckenrath et al., WRR, 2012) and their poor ability in constraining the transmissity and specific yield of the aquifer, which are the parameters to which pumping tests give access. Fresh basement rocks present generally a null porosity and the structure of basement aquifers is given by the weathering profile. In tropical climate, this profile consists of a few tens meter thick saprolite layer, with noticeable porosity but low permeability overlying the weathering front. This weathering front includes in many instances a fractured medium and presents a high permeability with variable porosity. It is hardly sampled in coring experiments. We present some numerical simulation results on the ability of gravity to constrain the transmissivity of this medium. Due to poroelasticity of clay minerals in the saprolite, soil subsidence is expected to occur during pumping with a significant gravity effect. Gravity measurements have therefore to be completed with leveling data at a millimetric precision. We present first the results of numerical modeling of the gravity and subsidence for a theoretical horizontally stratified basement aquifer, and show that gravity and leveling are able to provide independently the poroelasticity coefficient and a single transmissivity coefficient for the bottom of the aquifer, if the properties of the upper saprolites are known. We will discuss then the general case, where the aquifer presents a vertical fracture where the weathering profile thickens.

  18. Tank Waste Remediation System High-Level Waste Melter Vitrification System Development and Testing Strategy

    SciTech Connect

    Calmus, R.B.

    1995-02-16

    This document provides the general strategy for developing and testing the performance of candidate high-level waste melter systems and establishing the basis for selecting the preferred melter system for the high-level waste vitrification plant.

  19. 75 FR 61228 - Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ...NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts Pursuant...high-level radioactive waste. The Board will consider technical lessons that can be gained from those experiences that may be...

  20. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...Submissions for Liquid Chemical Sterilants/High Level Disinfectants, and user information and training. [65 FR 36325, June 8,...

  1. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...Submissions for Liquid Chemical Sterilants/High Level Disinfectants, and user information and training. [65 FR 36325, June 8,...

  2. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...Submissions for Liquid Chemical Sterilants/High Level Disinfectants, and user information and training. [65 FR 36325, June 8,...

  3. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...Submissions for Liquid Chemical Sterilants/High Level Disinfectants, and user information and training. [65 FR 36325, June 8,...

  4. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Identification. A liquid chemical sterilant/high level disinfectant is a germicide that is...Submissions for Liquid Chemical Sterilants/High Level Disinfectants, and user information and training. [65 FR 36325, June 8,...

  5. High-level language translation in SYMBOL 2R

    Microsoft Academic Search

    J. W. Anderberg; C. L. Smith

    1973-01-01

    The SYMBOL 2R Computing System represents an attempt to bridge the gap between machine languages and higher level programming languages. This gap has always limited the users' ability to communicate with the machine, thus creating a communication problem. Early attempts at solving this communication problem consisted of developing a series of user-oriented programming languages, i.e., assembler languages and higher level

  6. Dual gravity and E11

    E-print Network

    Peter West

    2014-11-04

    We consider the equation of motion in the gravity sector that arises from the non-linear realisation of the semi-direct product of E11 and its first fundamental representation, denoted by l1, in four dimensions. This equation is first order in derivatives and at low levels relates the usual field of gravity to a dual gravity field. When the generalised space-time is restricted to be the usual four dimensional space-time we show that this equation does correctly describe Einstein's theory at the linearised level. We also comment on previous discussions of dual gravity.

  7. Low Copper and High Manganese Levels in Prion Protein Plaques

    PubMed Central

    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

    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

  8. Low copper and high manganese levels in prion protein plaques

    USGS Publications Warehouse

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

    2013-01-01

    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.

  9. System-Level Memory Optimization for High-Level Synthesis of Component-Based SoCs

    E-print Network

    Carloni, Luca

    of abstraction higher than RTL [4], the use of high-level synthesis (HLS) tools [11, 14, 20], and the reuse of SystemC processes, and syn- thesized with HLS tools [17, 19]. From a single high-level specification, HLS accelerator while the architect of another SoC may choose a slower but smaller one. State-of-the-art HLS tools

  10. Mapping Low-Level Features to High-Level Semantic Concepts in Region-Based Image Retrieval

    Microsoft Academic Search

    Wei Jiang; Kap Luk Chan; Mingjing Li; Hongjiang Zhang

    2005-01-01

    In this a novel supervised learning method is proposed to map low-level visual features to high-level semantic conceptsfor region-based image retrieval. The contributions of this paper lie in threefolds. (I) For each semantic concept, a set of low-level tokens are extracted f m m the segmented regions of training images. Those to- kens capture the representative information for describing the

  11. ULS: A Dual-Vth/High-Nano-CMOS Universal Level Shifter for System-Level Power Management

    E-print Network

    Mohanty, Saraju P.

    for efficient realization of ULS. A prototype ULS is presented for 32nm nano-CMOS technology nodeULS: A Dual-Vth/High- Nano-CMOS Universal Level Shifter for System-Level Power Management Saraju P Nano-Electro-Mechanical-System (DDNEMS), Secure Digital Camera (SDC), and Net- Centric Multimedia

  12. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  13. Secondary arm coarsening and microsegregation in superalloy PWA-1480 single crystals: Effect of low gravity

    NASA Technical Reports Server (NTRS)

    Vijayakumar, M.; Tewari, S. N.; Lee, J. E.; Curreri, P. A.

    1990-01-01

    Single crystal specimens of nickel base superalloy PWA-1480 were directionally solidified on ground and during low gravity (20 sec) and high gravity (90 sec) parabolic maneuver of KC-135 aircraft. Thermal profiles were measured during solidification by two in-situ thermocouples positioned along the sample length. The samples were quenched during either high or low gravity cycles so as to freeze the structures of the mushy zone developing under different gravity levels. Microsegregation was measured by examining the solutal profiles on several transverse cross-sections across primary dendrites along their length in the quenched mushy zone. Effect of gravity level on secondary arm coarsening kinetics and microsegregation have been investigated. The results indicate that there is no appreciable difference in the microsegregation and coarsening kinetics behavior in the specimens grown under high or low gravity. This suggests that short duration changes in gravity/levels (0.02 to 1.7 g) do not influence convection in the interdendritic region. Examination of the role of natural convection, in the melt near the primary dendrite tips, on secondary arm spacings requires low gravity periods longer than presently available on KC-135. Secondary arm coarsening kinetics show a reasonable fit with the predictions from a simple analytical model proposed by Kirkwood for a binary alloy.

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

    E-print Network

    Indiana University

    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

  15. 40 CFR 1065.725 - High-level ethanol-gasoline blends.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false High-level ethanol-gasoline blends. 1065.725 Section...Standards § 1065.725 High-level ethanol-gasoline blends. For testing vehicles capable of operating on a high-level ethanol-gasoline blend, create a test...

  16. Development of Crystal-Tolerant High-Level Waste Glasses

    SciTech Connect

    Matyas, Josef; Vienna, John D.; Schaible, Micah J.; Rodriguez, Carmen P.; Crum, Jarrod V.; Arrigoni, Alyssa L.; Tate, Rachel M.

    2010-12-17

    Twenty five glasses were formulated. They were batched from HLW AZ-101 simulant or raw chemicals and melted and tested with a series of tests to elucidate the effect of spinel-forming components (Ni, Fe, Cr, Mn, and Zn), Al, and noble metals (Rh2O3 and RuO2) on the accumulation rate of spinel crystals in the glass discharge riser of the high-level waste (HLW) melter. In addition, the processing properties of glasses, such as the viscosity and TL, were measured as a function of temperature and composition. Furthermore, the settling of spinel crystals in transparent low-viscosity fluids was studied at room temperature to access the shape factor and hindered settling coefficient of spinel crystals in the Stokes equation. The experimental results suggest that Ni is the most troublesome component of all the studied spinel-forming components producing settling layers of up to 10.5 mm in just 20 days in Ni-rich glasses if noble metals or a higher concentration of Fe was not introduced in the glass. The layer of this thickness can potentially plug the bottom of the riser, preventing glass from being discharged from the melter. The noble metals, Fe, and Al were the components that significantly slowed down or stopped the accumulation of spinel at the bottom. Particles of Rh2O3 and RuO2, hematite and nepheline, acted as nucleation sites significantly increasing the number of crystals and therefore decreasing the average crystal size. The settling rate of ?10-?m crystal size around the settling velocity of crystals was too low to produce thick layers. The experimental data for the thickness of settled layers in the glasses prepared from AZ-101 simulant were used to build a linear empirical model that can predict crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass. The developed model predicts the thicknesses of accumulated layers quite well, R2 = 0.985, and can be become an efficient tool for the formulation of the crystal-tolerant HLW glasses for higher waste loading. A physical modeling effort revealed that the Stokes and Richardson-Zaki equations can be used to adequately predict the accumulation rate of spinel crystals of different sizes and concentrations in the glass discharge riser of HLW melters. The determined shape factor for the glass beads was only 0.73% lower than the theoretical shape factor for a perfect sphere. The shape factor for the spinel crystals matched the theoretically predicted value to within 10% and was smaller than that of the beads, given the larger drag force caused by the larger surface area-to-volume ratio of the octahedral crystals. In the hindered settling experiments, both the glass bead and spinel suspensions were found to follow the predictions of the Richardson-Zaki equation with the exponent n = 3.6 and 2.9 for glass beads and spinel crystals, respectively.

  17. Scaleable Board-Level High Performance Optical Polymer Waveguide Technologies

    Microsoft Academic Search

    Fuhan Liu; Fengtao Wang; Jianjun Yu; D. Guidotti; A. Adibi; Gee-Kung Chang; R. Tummala; M. Moynihan; B. Sicard

    2006-01-01

    We present key technologies developed at Georgia Tech PRC for manufacture able and scaleable high performance waveguides on packages or on printed circuit boards (PCBs). The rough and irregular topographic surface is the first challenge when waveguides are implanted onto a high-density interconnects (HDI) board. Optical buffer layer technology is developed to modify the rough and irregular topography of PCB

  18. High level of activation Coupled product is very stable, especially

    E-print Network

    Lebendiker, Mario

    between matrix and activated group is especially suitable for immobilising small proteins and peptides protein and peptide ligands. The advantages of high stability and a spacer arm combined with the high flow for pharmaceutical companies producing therapeutic products, especially those working with synthetic peptides

  19. EFFECT OF FEED INTAKE LEVEL AND INFLUENCE OF BREED AND SEX ON THE RELATIONSHIPS BETWEEN THE PHYSICAL COMPOSITION OF THE BOVINE CARCASS AND SPECIFIC GRAVITY 1

    Microsoft Academic Search

    A. Fortin; J. T. Reid; A. M. Maiga; D. W. Sim; G. H. Wellington

    Summary Relationships between the physical composi- tion of the carcass and specific gravity were established for two breeds of cattle fed ad libitum or 65 to 70% ad libitum. Holstein and Angus bulls, steers and heifers were slaughtered at body weights ranging from 120.7 to 706.7 kilograms. Specific gravity and physical compo- sition of the right side of the carcass

  20. Geographic distribution of zonal wind and UV albedo at cloud top level from VMC camera on Venus Express: Influence of Venus topography through stationary gravity waves vertical propagation.

    NASA Astrophysics Data System (ADS)

    Bertaux, Jean-Loup; Khatunstsev, Igor; Hauchecorne, Alain; Markiewicz, Wojciech; Marcq, Emmanuel; Lebonnois, Sébastien; Patsaeva, Marina; Turin, Alexander

    2015-04-01

    UV images (at 365 nm) of Venus cloud top collected with VMC camera on board Venus Express allowed to derive a large number of wind measurements at altitude 67±2 km from tracking of cloud features in the period 2006-2012. Both manual (45,600) and digital (391,600) individual wind measurements over 127 orbits were analyzed showing various patterns with latitude and local time. A new longitude-latitude geographic map of the zonal wind shows a conspicuous region of strongly decreased zonal wind, a remarkable feature that was unknown up to now. While the average zonal wind near equator (from 5°S to 15°s) is -100.9 m/s in the longitude range 200-330°, it reaches -83.4 m/s in the range 60-100°, a difference of 17.5 m/s. When compared to the altimetry map of Venus, it is found that the zonal wind pattern is well correlated with the underlying relief in the region of Aphrodite Terra, with a downstream shift of about 30° (˜3,200 km). We interpret this pattern as the result of stationary gravity waves produced at ground level by the up lift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to cloud top level, break there and transfer their momentum to the zonal flow. A similar phenomenon is known to operate on Earth with an influence on mesospheric winds. The LMD-GCM for Venus was run with or without topography, with and without a parameterization of gravity waves and does not display such an observed change of velocity near equator. The cloud albedo map at 365 nm varies also in longitude and latitude. We speculate that it might be the result of increased vertical mixing associated to wave breaking, and decreased abundance of the UV absorber which makes the contrast in images. The impact of these new findings on current super rotation theories remains to be assessed. This work was triggered by the presence of a conspicuous peak at 117 days in a time series of wind measurements. This is the length of the solar day as seen at the ground of Venus. Since VMC measurements are done preferably in a local time window centred on the sub-solar point, any parameter having a geographic longitude dependence will show a peak at 117 days.

  1. Professional Staffing Levels and Fourth-Grade Student Research in Rural Schools with High-Poverty Levels

    ERIC Educational Resources Information Center

    Krueger, Karla Steege; Donham, Jean

    2013-01-01

    Rural schools in high-poverty areas are often understaffed. This descriptive phenomenological study examined fourth-grade state research projects in high-poverty rural Iowa schools to reveal the influence of school librarians' staffing levels on student learning of research skills. To determine evidence of students' critical literacy, ethical use…

  2. High Performance User Level Sockets over Gigabit Ethernet

    Microsoft Academic Search

    Pavan Balaji; Piyush Shivam; Pete Wyckoff; Dhabaleswar K. Panda

    2002-01-01

    While a number of User-Level Protocols have been devel- oped to reduce the gap between the performance capabil- ities of the physical network and the performance actually available, applications that have already been developed on kernel based protocols such as TCP have largely been ignored. There is a need to make these existing TCP ap- plications take advantage of the

  3. New Generation Nuclear Plant -- High Level Functions and Requirements

    SciTech Connect

    J. M. Ryskamp; E. J. Gorski; E. A. Harvego; S. T. Khericha; G. A. Beitel

    2003-09-01

    This functions and requirements (F&R) document was prepared for the Next Generation Nuclear Plant (NGNP) Project. The highest-level functions and requirements for the NGNP preconceptual design are identified in this document, which establishes performance definitions for what the NGNP will achieve. NGNP designs will be developed based on these requirements by commercial vendor(s).

  4. Environmental Concerns High nutrient, bacterial and salinity levels--along

    E-print Network

    -oxygen levels--in some Texas watersheds have raised concerns among residents and state officials about public health, water quality, water-use limitations, aquatic habitat and reduced or lost recreational opportunities. Potential sources of this pollution include natural sources, feral hogs, wastewater

  5. Generation of Efficient High-Level Hardware Code from Dataflow Programs

    E-print Network

    Paris-Sud XI, Université de

    to abstract usual low-level technicalities associated with hardware description languages. The usual low-level generated by the HLS tools is usually target-dependant and at a low level of abstraction (i.e. gate-levelGeneration of Efficient High-Level Hardware Code from Dataflow Programs Nicolas Siret and Matthieu

  6. No chiral truncation of quantum log gravity?

    Microsoft Academic Search

    Tomás Andrade; Donald Marolf

    2010-01-01

    At the classical level, chiral gravity may be constructed as a consistent truncation of a larger theory called log gravity\\u000a by requiring that left-moving charges vanish. In turn, log gravity is the limit of topologically massive gravity (TMG) at\\u000a a special value of the coupling (the chiral point). We study the situation at the level of linearized quantum fields, focussing

  7. Acceleration of Gravity 2

    NSDL National Science Digital Library

    Michael Horton

    2009-05-30

    This lab is between a Level 2 and Level 3 inquiry activity in that it should be assigned after students understand acceleration but before they learn about the acceleration gravity. Because there are many sources of error when using a pendulum, students c

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

    PubMed

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

    2014-06-25

    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

  9. Cascading gravity is ghost free

    SciTech Connect

    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

    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.

  10. From Low-Level to High-Level: Comparative Study of Music Similarity Measures

    Microsoft Academic Search

    Dmitry Bogdanov; Joan Serrà; Nicolas Wack; Perfecto Herrera

    2009-01-01

    Studying the ways to recommend music to a user is a central task within the music information research commu- nity. From a content-based point of view, this task can be regarded as obtaining a suitable distance measurement be- tween songs defined on a certain feature space. We pro- pose two such distance measures. First, a low-level mea- sure based on

  11. A high-level requirements engineering methodology for electronic system-level design

    Microsoft Academic Search

    N. Gorse; P. Bélanger; Alexandre Chureau; El Mostapha Aboulhamid; Yvon Savaria

    2007-01-01

    Current electronic systems’ complexity severely limits their validation. Even if development frameworks keep improving and are heavily supported by the industry, methods for hardware\\/software electronic systems co-design are reaching a major crisis. Although the community is heading towards higher abstraction levels, requirements remain out of the validation scope. We therefore present a requirements engineering methodology that intersects formal, linguistic, and

  12. Liquidus Temperature and Primary Crystallization Phases in High-Zirconia High-Level Waste Borosilicate Glasses

    SciTech Connect

    Plaisted, Trevor J.; Hrma, Pavel R.; Vienna, John D.; Jiricka, Antonin

    1999-12-09

    Liquidus temperature (TL) studies of high-Zr high-level waste (HLW) borosilicate glasses have identified three primary phases: baddelyite (ZrO2), zircon (ZrSiO4), and alkali-zirconium silicates, such as parakeldyshite (Na2ZrSi2O7). Using published TL data for HLW glasses with these primary phases, we have computed partial specific TLs for major glass components. On the Na2O-SiO2-ZrO2 submixture, we have determined approximate positions of the boundaries between the baddelyite, zircon, and parakeldyshite primary phase fields. The maximum that can dissolve at 1150?C in a borosilicate HLW glass subjected to common processability and acceptability constraints appears to be 16.5 mass% ZrO2.

  13. Wafer level reliability for high-performance VLSI design

    NASA Technical Reports Server (NTRS)

    Root, Bryan J.; Seefeldt, James D.

    1987-01-01

    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.

  14. Exploiting Aura OMI Level 2 Data with High Resolution Visualization

    NASA Astrophysics Data System (ADS)

    Wei, J. C.; Yang, W.; Johnson, J. E.; Zhao, P.; Gerasimov, I. V.; Pham, L.; Vicente, G. A.; Shen, S.

    2014-12-01

    Satellite data products are important for a wide variety of applications that can bring far-reaching benefits to the science community and the broader society. These benefits can best be achieved if the satellite data are well utilized and interpreted, such as model inputs from satellite, or extreme event (such as volcano eruption, dust storm, …etc) interpretation from satellite. Unfortunately, this is not always the case, despite the abundance and relative maturity of numerous satellite data products provided by NASA and other organizations. One way to help users better understand the satellite data is to provide data along with 'Images', including accurate pixel-level (Level 2) information, pixel coverage area delineation, and science team recommended quality screening for individual geophysical parameters. Goddard Earth Sciences Data and Information Services Center (GES DISC) always strives to best support (i.e., Software-as-a-service, SaaS) the user-community for NASA Earth Science Data. In this case, we will present a new visualization tool that helps users exploiting Aura Ozone Monitoring Instrument (OMI) Level 2 data. This new visualization service utilizes Open Geospatial Consortium (OGC) standard-compliant Web Mapping Service (WMS) and Web Coverage Service (WCS) calls in the backend infrastructure. The functionality of the service allows users to select data sources (e.g., multiple parameters under the same measurement, like NO2 and SO2 from OMI Level 2 or same parameter with different methods of aggregation, like NO2 in OMNO2G and OMNO2D products), defining area-of-interest and temporal extents, zooming, panning, overlaying, sliding, and data subsetting and reformatting. The interface will also be able to connect to other OGC WMS and WCS servers, which will greatly enhance its expandability to integrate additional outside data/map sources (such as Global Imagery Browse Services (GIBS)).

  15. Review of high level fault modeling approaches for mixed-signal systems

    Microsoft Academic Search

    Likun Xia; Bell Ian; Wilkinson Antony

    2010-01-01

    In the modern analogue design, Transistor Level Fault Simulation (TLFS) plays the important part since every fault in the\\u000a whole circuit has to be simulated at that level. Unfortunately, it is a very CPU intensive task even though it maintains the\\u000a high accuracy. Therefore, High Level Fault Modeling (HLFM) and High Level Fault Simulation (HLFS) are required in order to

  16. High Level antitative Hardware Prediction Modeling using Statistical methods

    E-print Network

    Kuzmanov, Georgi

    , artificial neural networks, (logistic) regression, and data transformations. ese models take a high of slices, the number of flip- flops, and the number of wires. It utilizes automatic model selection of 14% for the number of multipliers in case of Xilinx and an error of only 18% for the number of wires

  17. High Levels of Natural Radiation: Radiation Doses and Health Effects

    Microsoft Academic Search

    1998-01-01

    Limits on exposure to artificial radiation have been pushed down over the past few decades, while at the same time we have become more aware of the potential for high doses from natural sources. If these two trends were graphed at the same scale they would have crossed years ago, leaving us now with significant numbers of people receiving natural

  18. Industrial Laboratory Techniques on the High School Level

    ERIC Educational Resources Information Center

    Harmon, Richard L.

    1972-01-01

    In order to make chemistry teaching interesting and relevant, a special course was planned with an intent to teach industrial laboratory techniques to juniors and seniors in high school. The program was taught through laboratory experiments and utilized individualized instruction. List of topics covered in course are included. (PS)

  19. Sellafield; From high level notoriety to intermediate acceptance

    SciTech Connect

    Preece, J.A. [British Nuclear Fuels plc, Risley, Warrington, Cheshire, WA3 6AS (United Kingdom)

    1990-10-01

    This paper discusses a highly publicized accident at Sellafield, involving radioactive pollution, after which a period of continuous adverse media coverage eroded public confidence in the plant and its operators. The author presents alternative recovery strategies attempted before identification of an open information, open door policy as the optimal route to a restored reputation. The success of the new policies is described.

  20. Remote ignitability analysis of high-level radioactive waste

    Microsoft Academic Search

    C. W. Lundholm; J. M. Morgan; R. M. Shurtliff; L. E. Trejo

    1992-01-01

    The Idaho Chemical Processing Plant (ICPP), was used to reprocess nuclear fuel from government owned reactors to recover the unused uranium-235. These processes generated highly radioactive liquid wastes which are stored in large underground tanks prior to being calcined into a granular solid. The Resource Conservation and Recovery Act (RCRA) and state\\/federal clean air statutes require waste characterization of these

  1. Project Water Science. General Science High School Level.

    ERIC Educational Resources Information Center

    Water Education Foundation, Sacramento, CA.

    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…

  2. Risk Factors and Levels of Risk for High School Dropouts

    ERIC Educational Resources Information Center

    Suh, Suhyun; Suh, Jingyo

    2007-01-01

    The study in this article identifies three major risk categories of high school dropouts and evaluates the impact of possible prevention strategies. As students accumulate these risks, they became more likely to drop out and prevention programs become less effective. Additionally, it was found that factors influencing the decision to drop out vary…

  3. [Effects of dilution rates on the oscillatory behaviors of a very high gravity continuous ethanol fermentation system].

    PubMed

    Luo, Xin-Peng; Chen, Li-Jie; Wang, Fang; Bai, Feng-Wu

    2005-07-01

    Continuous ethanol fermentation using very high gravity medium containing 280 g/L glucose, 5 g/L yeast extract and 3 g/L peptone was run at the dilute rates of 0.006 h(-1), 0.012 h(-1), 0.017 h(-1), 0.024 h(-1) and 0.032 h(-1) (based on the total working volume) in a combined bioreactor system composed of a stirred tank and three-stage tubular bioreactors in series. Oscillations marked by big fluctuations of residual glucose, ethanol and biomass were observed at the dilution rate of 0.012 h(-1). The Hopf Bifurcation theory was used to analyze and predict the occurring of these oscillations and the dilution rates that incited oscillations. Theoretical analysis revealed that oscillations can occur at designated specific growth rates and was validated by experimental results. The benefits of oscillations for the fermentation system were also discussed by comparing the fermentation results with those without oscillations. PMID:16176100

  4. Lunar gravity gradiometry and requirement analysis

    NASA Astrophysics Data System (ADS)

    Cai, Lin; Zhou, Zebing; Gao, Fang; Luo, Jun

    2013-08-01

    The current lunar gravity field models are mostly concluded from lunar exploration programs either by observations of satellite orbit perturbations or by intersatellite ranging and ranging rate measurements between two low-orbiting spacecrafts. Especially, the measurements from the Gravity Recovery and Interior Laboratory (GRAIL) have been used to produce the Moon’s gravity field models with spatial resolutions up to spherical harmonic degree 420 and 660 for the primary mission and extended mission, respectively. This paper presents a method using satellite gravity gradiometry, which not only can determine a moon’s gravity field model with a higher resolution, but also can obtain the medium and short wavelength components information with a higher accuracy. This advantage is still obvious in comparison with the results from GRAIL’s extended mission even though the maximum degree of the model derived from the mission is close to that achieved by the satellite gradiometry discussed in this study. Based on the simulations and analysis, a mission with the hypothesis of an orbit height of about 20 km, a mission duration of about 14 days, and a gradiometer accuracy level of about 30 mE/?{Hz} is proposed, and it permits determination of a lunar gravity field model with a high accuracy of 14 mGal and a geoid with an accuracy of 20.5 cm, both at a spatial resolution of 7 km, corresponding to spherical harmonic degree and order 789. The effects of gravity gradient measurement errors, orbit height, tracking accuracy, mission duration and sampling rate are analytically investigated by the direct relationship between the satellite gravimetry measurements and coefficients of the Moon’s gravitational potential, which is verified by the least-squares method.

  5. A high-quality global gravity field model from CHAMP GPS tracking data and accelerometry (EIGEN1S)

    Microsoft Academic Search

    Christoph Reigber; Georges Balmino; Peter Schwintzer; Richard Biancale; Albert Bode; Jean-Michel Lemoine; Rolf König; Sylvain Loyer; Hans Neumayer; Jean-Charles Marty; Franz Barthelmes; Felix Perosanz; Shen Yuan Zhu

    2002-01-01

    Using three months of GPS satellite-to-satellite tracking and accelerometer data of the CHAMP satellite mission, a new long-wavelength global gravity field model, called EIGEN-1S, has been prepared in a joint German-French effort. The solution is derived solely from analysis of satellite orbit perturbations, i.e. independent of oceanic and continental surface gravity data. EIGEN-1S results in a geoid with an approximation

  6. High Level Architecture (HLA) federation with Umbra and OPNET federates.

    SciTech Connect

    Oppel, Fred John III; Hart, Brian; Van Leeuwen, Brian P.

    2004-03-01

    Network-centric systems that depend on mobile wireless ad hoc networks for their information exchange require detailed analysis to support their development. In many cases, this critical analysis is best provided with high-fidelity system simulations that include the effects of network architectures and protocols. In this research, we developed a high-fidelity system simulation capability using an HLA federation. The HLA federation, consisting of the Umbra system simulator and OPNET Modeler network simulator, provides a means for the system simulator to both affect, and be affected by, events in the network simulator. Advances are also made in increasing the fidelity of the wireless communication channel and reducing simulation run-time with a dead reckoning capability. A simulation experiment is included to demonstrate the developed modeling and simulation capability.

  7. High level multiplex genotyping by MALDI-TOF mass spectrometry

    Microsoft Academic Search

    Laura Hall; Igor Smirnov; Larry Haff; Philip Ross

    1998-01-01

    A primer extension assay is used to perform highly multiplexed genotyping of single nucleotide polymorphisms (SNPs) present in genomic DNA amplified by a multiplex PCR. The assay uses matrix-assisted laser desorption ionization time-of-flight mass spectrometry to accurately measure the masses of short oligonucleotide primers extended by a single dideoxynucleotide. The multiplexed genotyping assays rely on the natural molecular weight differences

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

    Microsoft Academic Search

    TEDESCHI AR; WILSON RA

    2010-01-01

    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

  9. Quench cooling under reduced gravity

    NASA Astrophysics Data System (ADS)

    Chatain, D.; Mariette, C.; Nikolayev, V. S.; Beysens, D.

    2013-07-01

    We report quench cooling experiments performed with liquid O2 under different levels of gravity, simulated with magnetic gravity compensation. A copper disk is quenched from 300 to 90 K. It is found that the cooling time in microgravity is very long in comparison with any other gravity level. This phenomenon is explained by the insulating effect of the gas surrounding the disk. A weak gas pressurization (which results in subcooling of the liquid with respect to the saturation temperature) is shown to drastically improve the heat exchange, thus reducing the cooling time (about 20 times). The effect of subcooling on the heat transfer is analyzed at different gravity levels. It is shown that this type of experiment cannot be used for the analysis of the critical heat flux of the boiling crisis. The film boiling heat transfer and the minimum heat flux of boiling are analyzed as functions of gravity and subcooling.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  11. A Method to Abstract RTL IP Blocks into C++ Code and Enable High-Level Synthesis

    E-print Network

    Carloni, Luca

    (system-level design) [5], the use of high-level synthesis (HLS) is gaining consensus [11]: indeed, there are now sev- eral commercial HLS tools which are capable to take a single Permission to make digital (VHDL, Verilog) clk Logic Synthesis (LS) C++/SystemC IP High-level Synthesis (HLS) HLS design space HLS

  12. Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

    Microsoft Academic Search

    Talima Pearson; Philip Giffard; Stephen Beckstrom-Sternberg; Raymond Auerbach; Heidie Hornstra; Apichai Tuanyok; Erin P Price; Mindy B Glass; Benjamin Leadem; James S Beckstrom-Sternberg; Gerard J Allan; Jeffrey T Foster; David M Wagner; Richard T Okinaka; Siew Hoon Sim; Ofori Pearson; Zaining Wu; Jean Chang; Rajinder Kaul; Alex R Hoffmaster; Thomas S Brettin; Richard A Robison; Mark Mayo; Jay E Gee; Patrick Tan; Bart J Currie; Paul Keim

    2009-01-01

    BACKGROUND: Phylogeographic reconstruction of some bacterial populations is hindered by low diversity coupled with high levels of lateral gene transfer. A comparison of recombination levels and diversity at seven housekeeping genes for eleven bacterial species, most of which are commonly cited as having high levels of lateral gene transfer shows that the relative contributions of homologous recombination versus mutation for

  13. Familial Clustering of High Factor VIII Levels in Patients With Venous Thromboembolism

    Microsoft Academic Search

    C. M. Schambeck; K. Hinney; I. Haubitz; B. Mansouri Taleghani; D. Wahler; F. Keller

    High levels of factor VIII (FVIII) but not von Willebrand factor (vWF) are known to increase the risk for venous thromboembolism. Whether high FVIII levels originate from hereditary defects or from acquired conditions remains unanswered. The objective of our study was to investigate whether there is evidence for familial clustering of elevated FVIII levels in families in which $1 member

  14. High-Level Semantic Based Image Characterization Using Artificial Neural Networks

    Microsoft Academic Search

    Eduardo Ferreira Ribeiro; C. A. Z. Barcelos; M. A. Batista

    2007-01-01

    Low-level attributes such as color, shape and texture generally fail in describing the high-level semantic concepts. This work presents, through the formation of a high- level characteristics vector, the representation of the subjective knowledge used by humans for the verification of which aspects are most important for image characterization. Such vector will be formed by using the Artificial Intelligence techniques,

  15. High Level Computer Vision Part-Based Models for Object Class Recognition

    E-print Network

    High Level Computer Vision Part-Based Models for Object Class Recognition Part 3 Bernt Schiele Level Computer Vision - July o3, 2o13 · Bag of Words Models (BoW) object model = histogram of local: flexible spatial relationships 2 #12;High Level Computer Vision - July o3, 2o13 Part-Based Models

  16. High-Level Computer Vision -Final Project 1 Start date: 24.06

    E-print Network

    High-Level Computer Vision - Final Project 1 Logistics · Start date: 24.06 · Proposal: 3 slides member #12;High-Level Computer Vision - Final Project 2 Project goal · Choose an existing computer vision-Level Computer Vision - Final Project Proposal Slides Structure · Slide 1 ­ Task and motivation Task statement

  17. Quantum gravity.

    NASA Astrophysics Data System (ADS)

    Ma?lanka, K.

    A model of reality based on quantum fields, but with a classical treatment of gravity, is inconsistent. Finding a solution has proved extremely difficult, possibly due to the beauty and conceptual simplicity of general relativity. There is a variety of approaches to a consistent theory of quntum gravity. At present, it seems that superstring theory is the most promising candidate.

  18. High-order nonlinear Schrödinger equation for the envelope of slowly modulated gravity waves on the surface of finite-depth fluid and its quasi-soliton solutions

    E-print Network

    I. S. Gandzha; Yu. V. Sedletsky; D. S. Dutykh

    2015-01-23

    We consider the high-order nonlinear Schr\\"odinger equation derived earlier by Sedletsky [Ukr. J. Phys. 48(1), 82 (2003)] for the first-harmonic envelope of slowly modulated gravity waves on the surface of finite-depth irrotational, inviscid, and incompressible fluid with flat bottom. This equation takes into account the third-order dispersion and cubic nonlinear dispersive terms. We rewrite this equation in dimensionless form featuring only one dimensionless parameter $kh$, where $k$ is the carrier wavenumber and $h$ is the undisturbed fluid depth. We show that one-soliton solutions of the classical nonlinear Schr\\"{o}dinger equation are transformed into quasi-soliton solutions with slowly varying amplitude when the high-order terms are taken into consideration. These quasi-soliton solutions represent the secondary modulations of gravity waves.

  19. Satellite borne gravity gradiometer study

    Microsoft Academic Search

    E. Metzger; A. Jircitano; C. Affleck

    1976-01-01

    Gravity gradiometry is recognized to be a very difficult instrumentation problem because extremely small differential acceleration levels have to be measured, 0.1 EU corresponds to an acceleration of 10 to the minus 11th power g at two points 1 meter apart. A feasibility model of a gravity gradiometer is being developed for airborne applications using four modified versions of the

  20. High dispersion spectroscopy of solar-type superflare stars. I. Temperature, surface gravity, metallicity, and vsin i

    NASA Astrophysics Data System (ADS)

    Notsu, Yuta; Honda, Satoshi; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Nogami, Daisaku; Shibata, Kazunari

    2015-06-01

    We conducted high-dispersion spectroscopic observations of 50 superflare stars with Subaru High Dispersion Spectrograph (HDS), and measured the stellar parameters of them. These 50 targets were selected from the solar-type (G-type main sequence) superflare stars that we had discovered from the Kepler photometric data. As a result of these spectroscopic observations, we found that more than half (34) of our 50 targets have no evidence of binary systems. We then estimated the effective temperature (Teff), surface gravity (log g), metallicity ([Fe/H]), and projected rotational velocity (vsin i) of these 34 superflare stars on the basis of our spectroscopic data. The accuracy of our estimations is higher than that of the Kepler Input Catalog (KIC) values, and the differences between our values and KIC values [(?Teff)rms ˜ 219 K, (?log g)rms ˜ 0.37 dex, and (?[Fe/H])rms ˜ 0.46 dex] are comparable to the large uncertainties and systematic differences of KIC values reported by the previous researchers. We confirmed that the estimated Teff and log g values of the 34 superflare stars are roughly in the range of solar-type stars. In particular, these parameters and the brightness variation period (P0) of nine of the stars are in the range of "Sun-like" stars (5600 ? Teff ? 6000 K, log g ? 4.0, and P0 > 10 d). Five of the 34 target stars are fast rotators (vsin i ? 10 km s-1), while 22 stars have relatively low vsin i values (vsin i < 5 km s-1). These results suggest that stars that have spectroscopic properties similar to the Sun can have superflares, and this supports the hypothesis that the Sun might cause a superflare.

  1. Atom interferometric gravity sensor system

    Microsoft Academic Search

    Dave Brown; Lorraine Mauser; Brenton Young; Mark Kasevich; Hugh F. Rice; Vincent Benischek

    2012-01-01

    Real-time gravity measurements provide an accurate, high-resolution snapshot of the local gravity signature. Information developed from the gravity signature can be a significant contributor to battle space situational awareness, providing enhanced knowledge of the local operating environment and of the location of each operational participant in that environment. The Strategic Systems Programs (SSP) Navigation Branch (SP24) and Lockheed Martin, Maritime

  2. Copper uptake by Eichhornia crassipes exposed at high level concentrations.

    PubMed

    Melignani, Eliana; de Cabo, Laura Isabel; Faggi, Ana María

    2015-06-01

    The objective of this study was to assess the growth of water hyacinth (Eichhornia crassipes) and its ability to accumulate Cu from polluted water with high Cu concentrations and a mixture of other contaminants under short-term exposure, in order to use this species for the remediation of highly contaminated sites. Two hydroponic experiments were performed under greenhouse conditions for 7 days. One of them consisted of growing water hyacinth in Hoagland solution supplemented with 15 or 25 mg Cu/L and a control. The other one contained water hyacinth growing in polluted river water supplemented with 15 mg Cu/L and a control. Cu was accumulated principally in roots. The maximum Cu concentration was 23,387.2 mg/kg dw in the treatment of 25 mg Cu/L in Hoagland solution. Cu translocation from roots to leaves was low. The mixture of 15 mg Cu/L with polluted water did not appear to have toxic effects on the water hyacinth. This plant showed a remarkable uptake capacity under elevated Cu concentrations in a mixture of pollutants similar to pure industrial effluents in a short time of exposure. This result has not been reported before, to our knowledge. This species is suitable for phytoremediation of waters subject to discharge of mixed industrial effluents containing elevated Cu concentrations (?15 mg Cu/L), as well as nutrient-rich domestic wastewaters. PMID:25529492

  3. Effect of water immersion on cardiopulmonary physiology at high gravity (+Gz)

    NASA Technical Reports Server (NTRS)

    Arieli, R.; Boutellier, U.; Farhi, L. E.

    1986-01-01

    The cardiopulmonary responses of eight male subject between 21-31 years exposed to 1, 2, and 3 Gz during immersion at 35 + or - 0.5 C to heart level and during control dry rides are studied. Ventilation, O2 consumption, the end-tidal pressure of CO2, heart frequency, cardiac output, functional residual capacity, and the arterial pressure of CO2 were measured. It is observed that as Gz increases ventilation, heart frequency, and O2 consumption increase, and the end-tidal and arterial pressures of CO2 decrease during dry rides, but are not altered during immersion. It is detected that the functional residual capacity is lower during immersion and decreases in both the dry and immersed state as Gz increases, and cardiac output decreases as Gz increases in dry rides. It is noted that changes produced by acceleration in a Gz direction are due to the effect on the systemic circulation rather than to the effect on the lungs.

  4. Wide-angle, three-component seismic reflection profiling of the crust along the East Coast Gravity High, southern Appalachians, using quarry blasts

    Microsoft Academic Search

    Robert B. Hawman

    1996-01-01

    Inversion of refraction\\/wide-angle reflection travel times for two-dimensional velocity structure along the axis of the East Coast Gravity High in the Carolina Terrane of Georgia indicates much higher crustal P wave velocities than previously modeled. Thirty-nine timed quarry blasts recorded with a 20-element array of three-component recorders at 330-m spacings provide reversed and overlapping coverage along the profile which crosses

  5. Morphology of gravity-wave energy as observed from 4 years (1998-2001) of high vertical resolution U.S. radiosonde data

    Microsoft Academic Search

    Ling Wang; Marvin A. Geller

    2003-01-01

    Gravity-wave energy densities have been derived from 4 years (1998-2001) of U.S. high vertical resolution (~30 m) radiosonde wind and temperature data. This data set includes more than 90 stations that extend from 14°S to 71°N and 135°E to 55°W and cover such varied terrain as tropical islands, midcontinent plains, and mountainous regions, and they extend to the Arctic. This

  6. Time dependent corrections to absolute gravity determinations in the establishment of modern gravity control

    NASA Astrophysics Data System (ADS)

    Dykowski, Przemyslaw; Krynski, Jan

    2015-04-01

    The establishment of modern gravity control with the use of exclusively absolute method of gravity determination has significant advantages as compared to the one established mostly with relative gravity measurements (e.g. accuracy, time efficiency). The newly modernized gravity control in Poland consists of 28 fundamental stations (laboratory) and 168 base stations (PBOG14 - located in the field). Gravity at the fundamental stations was surveyed with the FG5-230 gravimeter of the Warsaw University of Technology, and at the base stations - with the A10-020 gravimeter of the Institute of Geodesy and Cartography, Warsaw. This work concerns absolute gravity determinations at the base stations. Although free of common relative measurement errors (e.g. instrumental drift) and effects of network adjustment, absolute gravity determinations for the establishment of gravity control require advanced corrections due to time dependent factors, i.e. tidal and ocean loading corrections, atmospheric corrections and hydrological corrections that were not taken into account when establishing the previous gravity control in Poland. Currently available services and software allow to determine high accuracy and high temporal resolution corrections for atmospheric (based on digital weather models, e.g. ECMWF) and hydrological (based on hydrological models, e.g. GLDAS/Noah) gravitational and loading effects. These corrections are mostly used for processing observations with Superconducting Gravimeters in the Global Geodynamics Project. For the area of Poland the atmospheric correction based on weather models can differ from standard atmospheric correction by even ±2 µGal. The hydrological model shows the annual variability of ±8 µGal. In addition the standard tidal correction may differ from the one obtained from the local tidal model (based on tidal observations). Such difference at Borowa Gora Observatory reaches the level of ±1.5 µGal. Overall the sum of atmospheric and hydrological effects and tidal model uncertainty easily exceeds the Total Uncertainty of the A10-020 gravimeter which makes these effects vital for current and future absolute gravity determinations for the needs of the gravity control. This work presents the variability of the atmospheric, hydrological and tidal corrections based on selected models for the area of Poland, especially for the time period of the survey of base stations of the gravity control in Poland in 2012 and 2013. The discrepancies between simplified corrections and the advanced ones are presented showing the importance of the use of advanced corrections. Additionally a time series of 5 years of absolute gravity determinations with the A10-020 gravimeter on laboratory and field stations at Borowa Gora Observatory test network has been analyzed to access the observed variation of gravity with the use of advanced correction models. Also gravity measured in two epochs on a few PBOG14 stations were used to examine the determined gravity difference. The analysis of the A10-020 data includes metrological calibrations as well as traceability to the ICAG and ECAG campaigns.

  7. GEMM--Based Level 3 BLAS: High-Performance Model Implementations and Performance Evaluation Benchmark

    Microsoft Academic Search

    Bo Kagstrom; Charles Van Loan; Per Ling

    1997-01-01

    The level 3 Basic Linear Algebra Subprograms (BLAS) are designed to performvarious matrix multiply and triangular system solving computations. The developmentof optimal level 3 BLAS code is costly and time consuming, because itrequires assembly level programming\\/thinking. However, it is possible to developa portable and high-performance level 3 BLAS library mainly relying on a highlyoptimized GEMM, the routine for the general

  8. HYPERFINE STRUCTURE CONSTANTS OF ENERGETICALLY HIGH-LYING LEVELS OF ODD PARITY OF ATOMIC VANADIUM

    SciTech Connect

    Güzelçimen, F.; Yap?c?, B.; Demir, G.; Er, A.; Öztürk, I. K.; Ba?ar, Gö. [Faculty of Science, Physics Department, Istanbul University, Tr-34134 Vezneciler, Istanbul (Turkey); Kröger, S. [Hochschule für Technik und Wirtschaft Berlin, Wilhelminenhofstrasse 75A, D-12459 Berlin (Germany); Tamanis, M.; Ferber, R.; Docenko, D. [Laser Centre and Institute of Astronomy, The University of Latvia, Rainis Boulevard 19, LV-1586 Riga (Latvia); Ba?ar, Gü., E-mail: gbasar@istanbul.edu.tr, E-mail: sophie.kroeger@htw-berlin.de [Faculty of Science and Letters, Physics Engineering Department, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey)

    2014-09-01

    High-resolution Fourier transform spectra of a vanadium-argon plasma have been recorded in the wavelength range of 365-670 nm (15,000-27,400 cm{sup –1}). Optical bandpass filters were used in the experimental setup to enhance the sensitivity of the Fourier transform spectrometer. In total, 138 atomic vanadium spectral lines showing resolved or partially resolved hyperfine structure have been analyzed to determine the magnetic dipole hyperfine structure constants A of the involved energy levels. One of the investigated lines has not been previously classified. As a result, the magnetic dipole hyperfine structure constants A for 90 energy levels are presented: 35 of them belong to the configuration 3d {sup 3}4s4p and 55 to the configuration 3d {sup 4}4p. Of these 90 constants, 67 have been determined for the first time, with 23 corresponding to the configuration 3d {sup 3}4s4p and 44 to 3d {sup 4}4p.

  9. MELT RATE ENHANCEMENT FOR HIGH ALUMINUM HLW (HIGH LEVEL WASTE) GLASS FORMULATION FINAL REPORT 08R1360-1

    Microsoft Academic Search

    KRUGER AA; MATLACK KS; KOT W; PEGG IL; JOSEPH I; BARDAKCI T; GAN H; GONG W; CHAUDHURI M

    2010-01-01

    This report describes the development and testing of new glass formulations for high aluminum waste streams that achieve high waste loadings while maintaining high processing rates. The testing was based on the compositions of Hanford High Level Waste (HLW) with limiting concentrations of aluminum specified by the Office of River Protection (ORP). The testing identified glass formulations that optimize waste

  10. Gravity, Magnetism, and "Down": Non-Physics College Students' Conceptions of Gravity

    ERIC Educational Resources Information Center

    Asghar, Anila; Libarkin, Julie C.

    2010-01-01

    This study investigates how students enrolled in entry-level geology, most of whom would graduate from college without university-level physics courses, thought about and applied the concept of gravity while solving problems concerning gravity. The repercussions of students' gravity concepts are then considered in the context of non-physics…

  11. Defense waste processing facility: the vitrification of high-level nuclear waste

    Microsoft Academic Search

    Brumley

    1986-01-01

    The Defense Waste Processing Facility (DWPF) will be the United States' first production scale facility and the worlds' largest plant for the vitrification of high-level nuclear waste. The EDWPF, which is under construction at the Department of Energy's Savannah River Plant (SRP) will immobilize the highly radioactive fraction f over 33 million gallons of high-level nuclear waste. The facility is

  12. An FPGA Software Defined Radio Platform with a High-Level Synthesis Design Flow

    E-print Network

    Paris-Sud XI, Université de

    An FPGA Software Defined Radio Platform with a High-Level Synthesis Design Flow Vaibhav Bhatnagar a highly versatile software radio platform along with laid-back designing tools. To this aim, an FPGA systems. Index Terms-- Flexible Software Defined Radio, High-Level Synthesis, FPGA platform. I

  13. GRAIL Gravity Field Determination Using the Celestial Mechanics Approach

    NASA Astrophysics Data System (ADS)

    Arnold, Daniel; Jäggi, Adrian; Bertone, Stefano; Beutler, Gerhard; Meyer, Ulrich; Mervart, Leos; Bock, Heike

    2014-05-01

    To determine the gravity field of the Moon, the NASA mission GRAIL (Gravity Recovery and Interior Laboratory) inherits its concept from the GRACE (Gravity Recovery and Climate Experiment) mission. The use of inter-satellite Ka-band range-rate (KBRR) observations enables data acquisition even when the spacecraft are not tracked from the Earth. The data allows for a highly accurate estimation of the lunar gravity field on both sides of the Moon, which is crucial to improve the understanding of its internal structure and thermal evolution. In this presentation we discuss GRAIL-based lunar gravity fields generated with the Celestial Mechanics Approach. KBRR observations and position data (GNI1B products) are used to solve for the lunar gravity field parameters in a generalized orbit determination problem. Apart from normalized spherical harmonic coefficients up to degrees n ? 200, also arc- and satellite-specific parameters, like initial state vectors and pseudo-stochastic pulses, are set up as common parameters for all measurement types. The latter shall compensate for imperfect models of non-gravitational accelerations, e.g., caused by solar radiation pressure. In addition, especially for the data of the primary mission phase, it is essential to estimate time bias parameters for the KBRR observations. We compare our results from the nominal and from the extended mission phase with the official Level 2 gravity field models first released in October 2013. Our results demonstrate that the lunar gravity field can be recovered with a high quality by adapting the Celestial Mechanics Approach, even when using pre-GRAIL or pre-SELENE gravity field models as a priori fields and when replacing sophisticated models of non-gravitational accelerations by appropriately spaced and constrained pseudo-stochastic pulses.

  14. High Levels of Carbon Dioxide Threaten Oyster Survival

    NSDL National Science Digital Library

    APS Communications Office (American Physiological Society Communications Office)

    2010-08-04

    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 warmingÂ?s 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.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  16. The production of matter from curvature in a particular linearized high order theory of gravity and the longitudinal response function of interferometers

    E-print Network

    Christian Corda

    2007-03-26

    The strict analogy between scalar-tensor theories of gravity and high order gravity is well known in literature. In this paper it is shown that, from a particular high order gravity theory known in literature, it is possible to produce, in the linearized approch, particles which can be seen like massive scalar modes of gravitational waves and the response of interferometers to this type of particles is analyzed. The presence of the mass generates a longitudinal force in addition of the transverse one which is proper of the massless gravitational waves and the response of an arm of an interferometer to this longitudinal effect in the frame of a local observer is computed. This longitudinal response function is directly connected with the function of the Ricci scalar in the particular action of this high order theory. Important conseguences from a theoretical point of view could arise from this approach, because it opens to the possibility of using the signals seen from interferometers to understand which is the correct theory of gravitation.

  17. Creatine accumulation and exchange by HEK293 cells stably expressing high levels of a creatine transporter.

    PubMed

    Dodd, J R; Zheng, T; Christie, D L

    1999-10-18

    We have generated a stable HEK293 cell line expressing high levels of a creatine transporter (CREAT). This cell line (HEK293-CREAT) was used to study the properties of CREAT in terms of the accumulation and release of creatine. HEK293-CREAT cells accumulated high steady state levels of creatine under saturating creatine levels (approx. 25-fold higher intracellular creatine levels than seen in control cells). The accumulation of high levels of creatine affected [3H]creatine uptake by decreasing the Vmax for transport. High intracellular creatine levels were maintained in the absence of extracellular creatine. External creatine stimulated the release of stored creatine by an exchange mechanism dependent on extracellular Na+. These studies have shown that cellular creatine levels can be affected by the amount of creatine transporter in the membrane and exchange through the creatine transporter. These findings highlight the importance of the creatine transporter in the maintenance of intracellular creatine levels. PMID:10572933

  18. PRS: A High Level Supervision and Control Language for Autonomous Mobile Robots \\Lambda

    E-print Network

    Alami, Rachid

    ­time demands of its environ­ ment; and (6) Its meta­level (or reflective) reasoning capabilities. C­PRS 1 has and tools, are used in these architecture and are linked to PRS. For example, a high level planner can

  19. Low-level interfaces for high-level parallel I/O

    NASA Technical Reports Server (NTRS)

    Nieuwejaar, Nils; Kotz, David

    1995-01-01

    As the I/O needs of parallel scientific applications increase, file systems for multiprocessors are being designed to provide applications with parallel access to multiple disks. Many parallel file systems present applications with a conventional Unix-like interface that allows the application to access multiple disks transparently. By tracing all the activity of a parallel file system in a production, scientific computing environment, we show that many applications exhibit highly regular, but nonconsecutive I/O access patterns. Since the conventional interface does not provide an efficient method of describing these patterns, we present three extensions to the interface that support strided, nested-strided, and nested-batched I/O requests. We show how these extensions can be used to express common access patterns.

  20. SPARK: a high-level synthesis framework for applying parallelizing compiler transformations

    Microsoft Academic Search

    Sumit Gupta; Nikil Dutt; Rajesh Gupta; Alex Nicolau

    2003-01-01

    This paper presents a modular and extensible high-level synthesis research system, called SPARK, that takes a behavioral description in ANSI-C as input and produces synthesizable register-transfer level VHDL. SPARK uses parallelizing compiler technology, developed previously, to enhance instruction-level parallelism and re-instruments it for high-level synthesis by incorporating ideas of mutual exclusivity of operations, resource sharing and hardware cost models. In