Science.gov

Sample records for high gravity levels

  1. The GRAVITY instrument software/high-level software

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard; Wieprecht, Ekkehard; Ott, Thomas; Kok, Yitping; Yazici, Senol; Anugu, Narsireddy; Dembet, Roderick; Fedou, Pierre; Lacour, Sylvestre; Ott, Jürgen; Paumard, Thibaut; Lapeyrere, Vincent; Kervella, Pierre; Abuter, Roberto; Pozna, Eszter; Eisenhauer, Frank; Blind, Nicolas; Genzel, Reinhard; Gillessen, Stefan; Hans, Oliver; Haug, Marcus; Haussmann, Frank; Kellner, Stefan; Lippa, Magdalena; Pfuhl, Oliver; Sturm, Eckhard; Weber, Johannes; Amorim, Antonio; Brandner, Wolfgang; Rousselet-Perraut, Karine; Perrin, Guy S.; Straubmeier, Christian; Schöller, Markus

    2014-07-01

    GRAVITY is the four-beam, near-infrared, AO-assisted, fringe tracking, astrometric and imaging instrument for the Very Large Telescope Interferometer (VLTI). It is requiring the development of one of the most complex instrument software systems ever built for an ESO instrument. Apart from its many interfaces and interdependencies, one of the most challenging aspects is the overall performance and stability of this complex system. The three infrared detectors and the fast reflective memory network (RMN) recorder contribute a total data rate of up to 20 MiB/s accumulating to a maximum of 250 GiB of data per night. The detectors, the two instrument Local Control Units (LCUs) as well as the five LCUs running applications under TAC (Tools for Advanced Control) architecture, are interconnected with fast Ethernet, RMN fibers and dedicated fiber connections as well as signals for the time synchronization. Here we give a simplified overview of all subsystems of GRAVITY and their interfaces and discuss two examples of high-level applications during observations: the acquisition procedure and the gathering and merging of data to the final FITS file.

  2. Modeling and Scaling of oscillating or pulsating heat transfer devices subjected to earth gravity and to high acceleration levels

    NASA Astrophysics Data System (ADS)

    Delil, A. A. M.

    2001-02-01

    The discussions, presented in this article, suppose that the reader is familiar with the contents of the accompanying article ``Thermal-Gravitational Modeling and Scaling of Two-Phase Heat Transport Systems from Micro-Gravity to Super-Gravity Levels.'' The latter article describes the history of this particular research at NLR, the approach (based on dimension analysis and similarity considerations), the derivation of constitutive equations for (annular) two-phase flow and heat transfer, the identification of thermal-gravitational scaling possibilities, condensation length issues, and the impact of the magnitude of super-gravity and its direction relative to the flow direction. But the discussions are restricted to ``classical'' two-phase loops. The most recent part of the research is discussed in this follow-up article. It concerns the extension of the research to the modelling, scaling and testing of the steady and transient performance of various types of oscillating or pulsating single-phase and two-phase heat transfer devices. This extension was opportune, as it turned out to be essential to properly support the research and development of such oscillating or pulsating heat transfer devices. For these devices several very promising applications have been identified, not only to cool commercial electronics, but also for cooling high-power electronics in spinning satellites and in military combat aircraft. In such applications, the electronics can be exposed to steady and transient accelerations up to levels around 120 m/s2. .

  3. Off-level corrections for gravity meters

    NASA Astrophysics Data System (ADS)

    Niebauer, T. M.; Blitz, Thomas; Constantino, Andy

    2016-04-01

    Gravity meters must be aligned with the local gravity at any location on the surface of the earth in order to measure the full amplitude of the gravity vector. The gravitational force on the sensitive component of the gravity meter decreases by the cosine of the angle between the measurement axis and the local gravity vector. Most gravity meters incorporate two horizontal orthogonal levels to orient the gravity meter for a maximum gravity reading. In order to calculate a gravity correction it is often necessary to estimate the overall angular deviation between the gravity meter and the local gravity vector using two measured horizontal tilt meters. Typically this is done assuming that the two horizontal angles are independent and that the product of the cosines of the horizontal tilts is equivalent to the cosine of the overall deviation. These approximations, however, break down at large angles. This paper derives analytic formulae to transform angles measured by two orthogonal tilt meters into the vertical deviation of the third orthogonal axis. The equations can be used to calibrate the tilt sensors attached to the gravity meter or provide a correction for a gravity meter used in an off-of-level condition.

  4. Monitoring the influence of high-gravity brewing and fermentation temperature on flavour formation by analysis of gene expression levels in brewing yeast.

    PubMed

    Saerens, S M G; Verbelen, P J; Vanbeneden, N; Thevelein, J M; Delvaux, F R

    2008-10-01

    During fermentation, the yeast Saccharomyces cerevisiae produces a broad range of aroma-active substances, which are vital for the complex flavour of beer. In order to obtain insight into the influence of high-gravity brewing and fermentation temperature on flavour formation, we analysed flavour production and the expression level of ten genes (ADH1, BAP2, BAT1, BAT2, ILV5, ATF1, ATF2, IAH1, EHT1 and EEB1) during fermentation of a lager and an ale yeast. Higher initial wort gravity increased acetate ester production, while the influence of higher fermentation temperature on aroma compound production was rather limited. In addition, there is a good correlation between flavour production and the expression level of specific genes involved in the biosynthesis of aroma compounds. We conclude that yeasts with desired amounts of esters and higher alcohols, in accordance with specific consumer preferences, may be identified based on the expression level of flavour biosynthesis genes. Moreover, these results demonstrate that the initial wort density can determine the final concentration of important volatile aroma compounds, thereby allowing beneficial adaptation of the flavour of beer. PMID:18751696

  5. 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.

  6. 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

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

    NASA Technical Reports Server (NTRS)

    Shum, C. K.

    2002-01-01

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

  8. The Gravity Model for High School Students

    ERIC Educational Resources Information Center

    Tribble, Paul; Mitchell, William A.

    1977-01-01

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

  9. 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.

  10. High potassium level

    MedlinePlus

    High potassium level is a problem in which the amount of potassium in the blood is higher than normal. The medical ... There are often no symptoms with a high level of potassium. When symptoms do occur, they may ...

  11. A high frequency resonance gravity gradiometer

    SciTech Connect

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

    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.

  12. 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

  13. 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.

  14. Gravity

    NASA Astrophysics Data System (ADS)

    Poisson, Eric; Will, Clifford M.

    2014-05-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  16. High blood cholesterol levels

    MedlinePlus

    ... gov/ency/article/000403.htm High blood cholesterol levels To use the sharing features on this page, ... called "bad" cholesterol For many people, abnormal cholesterol levels are partly due to an unhealthy lifestyle. This ...

  17. Orthometric corrections from leveling, gravity, density and elevation data: a case study in Taiwan

    NASA Astrophysics Data System (ADS)

    Hwang, C.; Hsiao, Y.-S.

    2003-08-01

    A new orthometric correction (OC) formula is presented and tested with various mean gravity reduction methods using leveling, gravity, elevation, and density data. For mean gravity computations, the Helmert method, a modified Helmert method with variable density and gravity anomaly gradient, and a modified Mader method were used. An improved method of terrain correction computation based on Gaussian quadrature is used in the modified Mader method. These methods produce different results and yield OCs that are greater than 10 cm between adjacent benchmarks (separated by sim2 km) at elevations over 3000 m. Applying OC reduces misclosures at closed leveling circuits and improves the results of leveling network adjustments. Variable density yields variation of OC at millimeter level everywhere, while gravity anomaly gradient introduces variation of OC of greater than 10 cm at higher elevations, suggesting that these quantities must be considered in OC. The modified Mader method is recommended for computing OC.

  18. Hydrological Modeling of Groundwater Disturbance to Gravity Signal for High-accuracy Monitoring of Volcanic Activity

    NASA Astrophysics Data System (ADS)

    Kazama, T.; Okubo, S.

    2007-12-01

    Gravity observation is one of the effective methods to detect magma movements in volcanic eruptions [e.g., Furuya et al., J. Geoph. Res., 2003]. Groundwater-derived disturbances have to be corrected from gravity variations for highly accurate monitoring of volcanic activities. They have been corrected with empirical methods, such as tank models and regression curves [e.g., Imanishi et al., J. Geodyn., 2006]. These methods, however, are not based on hydrological background, and are very likely to eliminate volcanic signals excessively. The correction method of groundwater disturbance has to be developed with hydrological and quantitative approach. We thus estimate the gravity disturbance arising from groundwater as follows. (1) Groundwater distributions are simulated on a hydrological model, utilizing groundwater flow equations. (2) Groundwater-derived gravity value is estimated for each instant of time, by integrating groundwater distributions spatially. (3) The groundwater-derived gravity, as the correction value, is subtracted from observed gravity data. In this study, we simulated groundwater flow and groundwater-derived gravity value on the east part of the Asama volcano, central Japan. A simple hydrological model was supposed, consisting of homogeneous soil, lying on a flat impermeable basement. Hydraulic conductivity, which defines groundwater velocity, was set as 2.0×10-6[m/s], which is consistent with typical volcanic soils. We also observed time variations of watertable height, soil moisture and gravity simultaneously during the summer of 2006 at Asama volcano, and compared the observations with the theoretical values. Both simulated groundwater distributions and gravity changes agree fairly well with observed values. On variations of water level and moisture content, rapid increase at the time of rainfalls and exponential decrease after rainfalls were illustrated. Theoretical gravity changes explained 90% of the observed gravity increase (+20μgals) for

  19. High-resolution gravity field modeling using GRAIL mission data

    NASA Astrophysics Data System (ADS)

    Lemoine, F. G.; Goossens, S. J.; 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.

    2015-12-01

    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: a primary mapping mission from March 1 until May 29, 2012 at an average altitude of 50 km, and an extended mission from August 30 until December 14, 2012, with an average altitude of 23 km before November 18, and 20 and 11 km after. High-resolution gravity field models using both these data sets have been estimated, with the current resolution being degree and order 1080 in spherical harmonics. Here, we focus on aspects of the analysis of the GRAIL data: we investigate eclipse modeling, the influence of empirical accelerations on the results, and we discuss the inversion of large-scale systems. In addition to global models we also estimated local gravity adjustments in areas of particular interest such as Mare Orientale, the south pole area, and the farside. We investigate the use of Ka-band Range Rate (KBRR) data versus numerical derivatives of KBRR data, and show that the latter have the capability to locally improve correlations with topography.

  20. High level nuclear waste

    SciTech Connect

    Crandall, J L

    1980-01-01

    The DOE Division of Waste Products through a lead office at Savannah River is developing a program to immobilize all US high-level nuclear waste for terminal disposal. DOE high-level wastes include those at the Hanford Plant, the Idaho Chemical Processing Plant, and the Savannah River Plant. Commercial high-level wastes, for which DOE is also developing immobilization technology, include those at the Nuclear Fuel Services Plant and any future commercial fuels reprocessing plants. The first immobilization plant is to be the Defense Waste Processing Facility at Savannah River, scheduled for 1983 project submission to Congress and 1989 operation. Waste forms are still being selected for this plant. Borosilicate glass is currently the reference form, but alternate candidates include concretes, calcines, other glasses, ceramics, and matrix forms.

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

    PubMed

    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. PMID:26066251

  2. EGSIEM: Combination of GRACE monthly gravity models on normal equation level

    NASA Astrophysics Data System (ADS)

    Meyer, Ulrich; Jean, Yoomin; Jäggi, Adrian; Mayer-Gürr, Torsten; Neumayer, Hans; Lemoine, Jean-Michel

    2016-04-01

    One of the three geodetic services to be realized in the frame of the EGSIEM project is a scientific combination service. Each associated processing center (AC) will follow a set of common processing standards but will apply its own, independent analysis method. Therefore the quality, robustness and reliability of the combined monthly gravity fields is expected to improve significantly compared to the individual solutions. The Monthly GRACE gravity fields of all ACs are combined on normal equation level. The individual normal equations are weighted depending on pairwise comparisons of the individual gravity field solutions. To derive these weights and for quality control of the individual contributions first a combination of the monthly gravity fields on solution level is performed. The concept of weighting and of the combination on normal equation level is introduced and the formats used for normal equation exchange and gravity field solutions is described. First results of the combination on normal equation level are presented and compared to the corresponding combinations on solution level. EGSIEM has an open data policy and all processing centers of GRACE gravity fields are invited to participate in the combination.

  3. 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

  4. 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

  5. Gravity Waves in Hot Planet Atmospheres with High Speed Flows

    NASA Astrophysics Data System (ADS)

    Cho, J. Y.-K.; Watkins, C. L.

    2013-09-01

    Many global hydrodynamics models have been used to study the large-scale flows of close-in extrasolar planet atmospheres. None of these models, however, resolve gravity waves which can significantly affect the large-scale flow and its associated variability in the atmosphere. Such waves are generated by a variety of mechanisms - including, inter alia, spatially or temporally varying diabatic heating, convective overshoots, hydrodynamic instabilities and adjustment processes. Previously, we have examined mesoscale gravity waves in an inviscid atmosphere with moderately fast background flows [1]. In this work, we study large-scale, as well as mesoscale, waves in atmospheres containing high-speed flows and regions of strong dissipation. The primary focus is on the waves' propagation characteristics and interaction with the mean-flow.

  6. High-Resolution Temperature Mapping of Mesospheric Gravity Waves and Breaking Events

    NASA Astrophysics Data System (ADS)

    Taylor, Michael J.; Pautet, Pierre-Dominique; Zhao, Yucheng; Yuan, Tao; Pendleon, William R.; Fritts, David; Esplin, Roy; McLain, David; Stober, Gunter

    2016-04-01

    This presentation highlights new research capabilities and recent results using a novel infra-red imaging system operating at high-latitudes at the ALOMAR Arctic Observatory, Norway (69°N), and at Amundsen-Scott South Pole Station, Antarctica (90°S). The Advanced Mesospheric Temperature Mapper (AMTM) is a high-performance digital imaging system that measures selected emission lines in the mesospheric OH (3,1) band (at ~1.55 μm) to create high-quality intensity and temperature maps of a broad spectrum of gravity waves at the ~87 km level (with periods ranging from several minutes to many hours). The temperature data are obtained with an unprecedented spatial (~0.5 km) and temporal (typically 30 sec) resolution over a large 120° field of view enabling detailed studies of gravity wave propagation and breaking events in the Mesosphere and Lower Thermosphere (MLT) region, even in the presence of strong aurora and moonlight. New results include high-resolution wintertime studies of continuous (24-hr) gravity wave activity and spectral evolution, and first evidence of gravity wave "self-acceleration" in the MLT region using coordinated lidar and radar measurements. These results are complemented by very high resolution (~4 sec) gravity wave observations using a third AMTM developed for airborne measurements on the National Science Foundation (NSF) Gulfstream V aircraft as part of the DEEPWAVE program. This mission was successfully conducted from New Zealand during the Austral winter, June-July 2014, and obtained spectacular new data on mesospheric mountain waves, including large amplitude breaking events associated with variable orographic forcing over the Southern Alps.

  7. 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.

  8. Grazing Occultation reveals Gravity Wave Breaking in Pluto's High Atmosphere

    NASA Astrophysics Data System (ADS)

    Kern, Susan D.; McCarthy, D. W.; Kulesa, C. A.; Hubbard, W. B.; Person, M. J.; Elliot, J. L.; Gulbis, A. A.

    2007-10-01

    Occultation observations of the star P445.3 (2UCAC 25823784; McDonald & Elliot 2000, AJ 120, 1599) by (134340) Pluto on 2007 March 18.453 UT were simultaneously collected in visible and H-band wavelengths from the 6.5-m MMT (Mt. Hopkins) in Arizona. The event was grazing and slow (6.77 km/s), lasting 4 minutes. These conditions facilitated the detection of large-scale, nearly limb-aligned features in Pluto's atmosphere over a pressure range of 0.1-0.7 μbar (0.01-0.07 Pa; radius range of 1500-1350 km). The data are high signal-to-noise and show these features to be fully resolved and achromatic. The scintillation increases with depth in Pluto's atmosphere and indicates a high-frequency cutoff operating on a broad-band spectrum of gravity waves generated deeper in Pluto's atmosphere. The data are in excellent agreement with atmospheric gravity wave theory (Fritts 1984, RGSP 22, 275). Observations reported here were obtained at the MMT Observatory, a joint facility of The University of Arizona and the Smithsonian Institution. The integration and alignment of both cameras was funded by the Astronomy Camp science education program. We also acknowledge support from NASA's Planetary Astronomy Program via grants NNG04GE48G and NNG04GF25G.

  9. 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).

  10. Bed topography of Jakobshavn Isbræ, Greenland from high-resolution gravity data

    NASA Astrophysics Data System (ADS)

    An, L.; Rignot, E. J.; Morlighem, M.; Paden, J. D.; Holland, D. M.

    2015-12-01

    Jakobshavn Isbræ (JKS) is one of the largest marine terminating outlet glaciers in Greenland, feeding a fjord about 800 m deep in the west coast. JKS sped up more than twofold since 2002 and contributed nearly 1 mm of global sea level rise during the period from 2000 to 2011. Holland et al. (2008) posit that these changes coincided with a change in ocean conditions beneath the former ice tongue, yet little is known about the depth of the glacier at its grounding line and upstream of the grounding line and the sea floor depth of the fjord is not well known either. Here, we present a new approach to infer the glacier bed topography, ice thickness and sea floor bathymetry near the grounding line of JKS using high-resolution airborne gravity data from AirGRAV. AirGRAV data were collected in August 2012 from a helicopter platform. The data combined with radio echo sounding data, discrete point soundings in the fjord and the mass conservation approach on land ice. AirGRAV acquired a 500m spacing grid of free-air gravity data at 50 knots with sub-milligal accuracy, i.e. much higher than NASA Operation IceBridge (OIB)'s 5.2km resolution at 290 knots. We use a 3D inversion of the gravity data combining our observations and a forward modeling of the surrounding gravity field, and constrained at the boundary by radar echo soundings and point bathymetry. We reconstruct seamless bed topography at the grounding line that matches interior data and the sea floor bathymetry. The results reveal the true depth at the elbow of the terminal valley and the bed reversal in the proximity of the current grounding line. The analysis provides guidelines for future gravity survey of narrow fjords in terms of spatial resolution and gravity precision. The results also demonstrate the practicality of using high resolution gravity survey to resolve bed topography near glacier snouts, in places where radar sounding has been significantly challenged in the past. The inversion results are critical

  11. Influence of gravity level and interfacial energies on dispersion-forming tendencies in hypermonotectic Cu-Pb-Al alloys

    NASA Technical Reports Server (NTRS)

    Andrews, J. B.; Curreri, P. A.; Sandlin, A. C.

    1988-01-01

    Results on the nondirectional solidification of several hypermonotectic Cu-Pb-Al alloys were obtained aboard NASA's KC-135 zero-gravity aircraft in order to determine the influence of interfacial energies and gravity levels on dispersion-forming tendencies. The Al content was systematially varied in the alloys. The dispersion-forming ability is correlated with gravity level during solidification, the interfacial energy between the immiscible phases, and the tendency for the minority immiscible phase to wet the walls of the crucible.

  12. Completing Lorentz violating massive gravity at high energies

    SciTech Connect

    Blas, D.; Sibiryakov, S.

    2015-03-15

    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{sub g} and much smaller than that of the massless theory (M{sub P} ≈ 10{sup 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{sub g}{sup −1}. Interestingly, it becomes repulsive at larger distances.

  13. 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.

  14. Thermal-gravitational modeling and scaling of two-phase heat transport systems from micro-gravity to super-gravity levels

    NASA Astrophysics Data System (ADS)

    Delil, A. A. M.

    2001-02-01

    Earlier publications extensively describe NLR research on thermal-gravitational modeling and scaling of two-phase heat transport systems for spacecraft applications. These publications on mechanically and capillary pumped two-phase loops discuss pure geometric scaling, pure fluid to fluid scaling, and combined (hybrid) scaling of a prototype system by a model at the same gravity level, and of a prototype in micro-gravity environment by a scale-model on earth. More recent publications include the scaling aspects of prototype two-phase loops for Moon or Mars applications by scale-models on earth. Recent work, discussed here, concerns extension of thermal-gravitational scaling to super-g acceleration levels. This turned out to be necessary, since a very promising super-g application for (two-phase) heat transport systems will be cooling of high-power electronics in spinning satellites and in military combat aircraft. In such aircraft, the electronics can be exposed during maneuvres to transient accelerations up to 120 m/s2. The discussions focus on ``conventional'' (capillary) pumped two-phase loops. It can be considered as introduction to the accompanying article, which focuses on pulsating and oscillating devices. .

  15. High blood cholesterol levels

    MedlinePlus

    Steps you can take to improve their cholesterol levels, and help prevent heart disease and a heart attack include: Quit smoking. This is the single biggest change you can make to reduce your risk of heart attack and stroke. Eat foods ...

  16. High resolution topography and gravity of 433 Eros

    NASA Astrophysics Data System (ADS)

    Cheng, A.

    2003-04-01

    The Near Earth Asteroid Rendezvous (NEAR) mission determined two independent shape models of asteroid 433 Eros from orbit, using imaging data and using laser altimetry (both shape models were based upon orbit solutions, where the former used a solution from radiometric data, optical navigation, and altimetry, while the latter used only radiometric data and altimetry). The global shape uncertainties are ~20 m, giving a volume determination to within 1%. There are systematic differences between the two shape models: the laser model radius averages 17 m smaller than the imaging model, and the imaging model tends to underestimate the depth of topography. In both models prior work has shown that the interior density of Eros must be close to uniform on km-scales, but there are suggestions of inhomogeneity from center-of-figure offsets and moments of inertia which are not consistent with observed rotation. Simple models show how small changes in mass distribution can reconcile these data, but there is no unique solution. New estimates are obtained for the accuracy of gravity models based upon uniform density distributions within the available shape models. Moreover, the NEAR landing data enable a direct determination of the local gravitational acceleration from laser altimetry as the spacecraft descended below 500 m altitude. Even when close to the surface of the asteroid, the global shape model provides consistent determinations of local gravity and high resolution topography. These considerations give added confidence in the previously reported bulk density (2.67 g/cc), which is significantly less than that of ordinary chondrite meteorites. I will argue that this difference cannot simply be attributed to macroscopic voids or fractures within Eros, but more likely indicates that Eros differs from ordinary chondrites in composition and/or texture.

  17. Regulation by gravity of the transcript levels of MAP65 in azuki bean epicotyls

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    Development of a short and thick body by reorientation of cortical microtubules is required for the resistance of plants to the gravitational force. The 65 kDa microtubule-associated protein (MAP65) has microtubule bundling activity and is involved in the reorientation of cortical microtubules. Here, we investigated the relation between the orientation of cortical microtubules and the transcript levels of VaMAP65-1 under centrifugal hypergravity conditions in azuki bean epicotyls. The percentage of cells with transverse microtubules was decreased, while that with longitudinal microtubules was increased, in proportion to the logarithm of the magnitude of gravity. The orientation of microtubules was restored to the original direction after removal of the hypergravity stimulus. The transcript level of VaMAP65-1 was down-regulated in proportion to the logarithm of the magnitude of gravity (R=-0.99). By removal of hypergravity stimulus, expression of VaMAP65-1 was increased to control levels. Strong correlations were observed between the percentage of cells with longitudinal or transverse microtubules and the transcript levels of VaMAP65-1 (R=-0.93, 0.91). These results suggest that down-regulation of VaMAP65-1 expression is involved in the regulation by gravity of the orientation of cortical microtubules in azuki bean epicotyls. Lanthanum and gadolinium ions, potential blockers of mechanosensitive calcium ion-permeable channels (mechanoreceptors), nullified the down-regulation of expression of VaMAP65-1 gene, suggesting that mechanoreceptors are responsible for regulation by gravity of VaMAP65-1 expression.

  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. Probing Gravity in the High-Redshift Universe with HETDEX

    NASA Astrophysics Data System (ADS)

    Malz, A. I.; Shandera, S.

    2014-01-01

    The addition of dark matter and dark energy to general relativity is degenerate with a modification of the dependence of curvature on the stress-energy tensor in the absence of exotic sources of matter and energy; it is thus valuable to explore the latter as a potential improvement over the former. Though it is inherently difficult to distinguish existing evidence for the general relativity paradigm from that of its more promising alternatives, such theories are associated with different histories for the largely unexplored growth of structure. Zhang, et al. (2007) have enabled discrimination of these possibilities via a new observable parameter EG and have predicted the efficacy of several future astronomical surveys to determine its value. In this work, we examine the ability of the Hobby Eberly Telescope Dark Energy Experiment (HETDEX) to contribute to calculations of this indicator of gravity at the highest redshifts (1.9 < z < 3.5). We show that a prerequisite of such a measurement is a deeper understanding of the nature of Lyman-α emitting galaxies (LAEs). If HETDEX can constrain the statistical properties of the typical LAE velocity dispersion, then it will not be necessary to wait for the (as yet unplanned) next generation of high-resolution spectrographs to obtain a test of general relativity in the high-redshift universe.

  20. Effects of varying gravity levels in parabolic flight on the size-mass illusion.

    PubMed

    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

  1. 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

  2. High-gravity spreading of liquid puddles on wetting flexible substrates

    NASA Astrophysics Data System (ADS)

    Yang, Chen; Burrous, Adam; Xie, Jingjin; Shaikh, Hassan; Elike-Avion, Akofa; Rojas Rodriguez, Luis; Ramachandran, Adithya; Choi, Wonjae; Mazzeo, Aaron D.

    2016-02-01

    This letter describes a mechanical approach of using high gravity to decrease the capillary length and increase the spreading rate of liquid puddles on wetting flexible substrates. By using centrifugation and a flexible substrate floating on a high-density liquid, uniform acceleration enhances the spreading of liquid puddles. Under high gravity of 600 g, the capillary length reduces by a factor of 24.5 to ˜60 μm. The reduction in capillary length results in gravity dominating the spreading of small puddles that would otherwise have slower spreading driven by both surface tension and gravity of 1 g. The resulting measurements suggest that derived expressions in the literature for gravity-driven spreading of puddles under earth's standard gravity extend to predicting the behavior of sufficiently large puddles spreading on flexible substrates exposed to more than 100 g of acceleration. This work explores the spreading of puddles/coatings under high gravity, and the techniques described in this work will allow further interrogation of the transition between surface tension- and gravity-driven spreading.

  3. 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

    2015-07-28

    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

  4. Very extended E8 and A8 at low levels, gravity and supergravity

    NASA Astrophysics Data System (ADS)

    West, Peter

    2003-06-01

    We define a level for a large class of Lorentzian Kac-Moody algebras. Using this we find the representation content of very extended AD-3 and E8 (i.e., E11) at low levels in terms of AD-1 and A10 representations, respectively. The results are consistent with the conjectured very extended A8 and E11 symmetries of gravity and maximal supergravity theories given respectively in preprints hep-th/0104081 and hep-th/0107209. We explain how these results provided further evidence for these conjectures.

  5. The first high-precision gravity survey in the North Pole region

    NASA Astrophysics Data System (ADS)

    Sokolov, A. V.; Krasnov, A. A.; Koneshov, V. N.; Glazko, V. V.

    2016-03-01

    The experience with conducting a marine gravity survey onboard a surface vessel under complicated ice conditions at high latitude is described. In 2014, a high-precision marine gravity survey with two modifications of the Chekan-AM gravimeter was carried out in the North Pole region. The measurements were conducted during two months from aboard the Akademik Fedorov research vessel on a given grid with a total length of 10000 km of the routes. As a result, 70000 gravity points at Arctic latitudes including the region of the geographical North Pole itself are acquired. In this paper, we discuss the methodical aspects of conducting the survey and present the accuracy estimates of the gravity measurements. The comparison of the obtained results with the Earth's gravity models demonstrates the absence of systematic errors and the higher spatial resolution of the measurements with the Chekan-AM gravimeters.

  6. High-level-waste immobilization

    SciTech Connect

    Crandall, J L

    1982-01-01

    Analysis of risks, environmental effects, process feasibility, and costs for disposal of immobilized high-level wastes in geologic repositories indicates that the disposal system safety has a low sensitivity to the choice of the waste disposal form.

  7. Combined Use of Water Level in Boreholes and Continuous Gravity Measurements for Hydrological Numerical Modeling: Example of the Durzon Karstic Basin (Larzac, France)

    NASA Astrophysics Data System (ADS)

    Fores, B.; Champollion, C.; Le Moigne, N.; Chery, J.; Jourde, H.; Erik, D.; Vernant, P.

    2014-12-01

    Karstic hydrosystems are highly nonlinear and heterogeneous but they represent one of the main water resources in the Mediterranean area. Neither local measurements in boreholes nor analysis at the spring can take into account the variability of the water storage. Since 10 years, ground-based gravity measurements (absolute FG5 and relative CG5) allow the monitoring of the water storage in heterogeneous hydrosystems at intermediate scale between boreholes (local scale) and spring (global scale). Since threeyears, a geophysical observatory has been setup in the Mediterranean area (on the Durzon karstic basinin the south of France). Water level in boreholes and rainfall from rain gaugesare classical hydrological observations. They arecompleted by evapotranspiration measurements from a flux tower and continuous gravity measurements from the GWR iGrav#002 superconducting gravimeter. The main objective of thisstudy is to modelthe wholedata sets withexplicit numericalmodels. Hydrus-1D software allows explicit modeling of water storage and 1D-flow in variably saturated media. With a stochastic sampling, we find the underground parameters (porosity, permeability) that reproduce the most the different observations (gravity, water level, evapotranspiration and rainfall). From the results of the modeling, we discuss the size of the area observed by each type of measurements. Furthermore, water storage and transfer variability may be inferred from the synergy of local (boreholes) and more integrative (gravity) measurements. This study shows the potential of gravity measurements at aquifer scale.

  8. High-resolution gravity and seismic-refraction surveys of the Smoke Tree Wash area, Joshua Tree National Park, California

    USGS Publications Warehouse

    Langenheim, Victoria E.; Rymer, Michael J.; Catchings, Rufus D.; Goldman, Mark R.; Watt, Janet T.; Powell, Robert E.; Matti, Jonathan C.

    2016-01-01

    We describe high-resolution gravity and seismic refraction surveys acquired to determine the thickness of valley-fill deposits and to delineate geologic structures that might influence groundwater flow beneath the Smoke Tree Wash area in Joshua Tree National Park. These surveys identified a sedimentary basin that is fault-controlled. A profile across the Smoke Tree Wash fault zone reveals low gravity values and seismic velocities that coincide with a mapped strand of the Smoke Tree Wash fault. Modeling of the gravity data reveals a basin about 2–2.5 km long and 1 km wide that is roughly centered on this mapped strand, and bounded by inferred faults. According to the gravity model the deepest part of the basin is about 270 m, but this area coincides with low velocities that are not characteristic of typical basement complex rocks. Most likely, the density contrast assumed in the inversion is too high or the uncharacteristically low velocities represent highly fractured or weathered basement rocks, or both. A longer seismic profile extending onto basement outcrops would help differentiate which scenario is more accurate. The seismic velocities also determine the depth to water table along the profile to be about 40–60 m, consistent with water levels measured in water wells near the northern end of the profile.

  9. Crustal structure under the central High Atlas Mountains (Morocco) from geological and gravity data

    NASA Astrophysics Data System (ADS)

    Ayarza, P.; Alvarez-Lobato, F.; Teixell, A.; Arboleya, M. L.; Tesón, E.; Julivert, M.; Charroud, M.

    2005-05-01

    Seismic wide angle and receiver function results together with geological data have been used as constraints to build a gravity-based crustal model of the central High Atlas of Morocco. Integration of a newly acquired set of gravity values with public data allowed us to undertake 2-2.5D gravity modelling along two profiles that cross the entire mountain chain. Modelling suggests moderate crustal thickening, and a general state of Airy isostatic undercompensation. Localized thickening appears restricted to the vicinity of a north-dipping crustal-scale thrust fault, that offsets the Moho discontinuity and defines a small crustal root which accounts for the minimum Bouguer gravity anomaly values. Gravity modelling indicates that this root has a northeasterly strike, slightly oblique to the ENE general orientation of the High Atlas belt. A consequence of the obliquity between the High Atlas borders and its internal and deep structure is the lack of correlation between Bouguer gravity anomaly values and topography. Active buckling affecting the crust, a highly elevated asthenosphere, or a combination of both are addressed as side mechanisms that help to maintain the high elevations of the Atlas mountains.

  10. Regional and global gravity models from the analysis of GOCE level-1b data

    NASA Astrophysics Data System (ADS)

    Schall, Judith; Eicker, Annette; Kusche, Jürgen

    2013-04-01

    ESA's GOCE satellite mission delivers accurate data of high resolution and nearly global coverage. The standard approach is to analyse these observations using the globally defined spherical harmonic functions. However, regional (radial) base functions provide the advantage to be more flexible in modelling data of differing density and variability, which clearly is the case for satellite gravity data. Particularly, a regionally adapted regularisation process enables optimal damping of both, regions featuring rough signal and rather smooth areas, at the same time. This is of special interest for GOCE because of its strength in observing the high frequency part of the gravity field. The present paper represents the final results of the project GLOREGOCE which is part of the German funded research programme REAL GOCE. The project mainly aims at providing regionally refined gravity field models by applying the short arc approach on GOCE orbit and (pure) gradiometer data. For easy investigation, regional solutions calculated on small patches all over the globe have been merged and transformed to a spherical harmonic expansion by means of quadrature methods. The power of the regional approach is demonstrated by comparison to spherical harmonic models, which are based on exactly the same processing strategy, standards and data time span. We show, that these global models are comparable in accuracy with respect to the official GOCE models published by ESA. Moreover, we will show that regional models perform even better compared to global models in the higher frequencies: In oceanic areas, the regionally adapted regularisation process leads to a noise reduction of about 10%. A more tailored choice of the regularisation areas tested for the South Sandwich Trench reveals improvements that are nearly twice as large.

  11. High pressure liquid level monitor

    DOEpatents

    Bean, Vern E.; Long, Frederick G.

    1984-01-01

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

  12. 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

  13. Ocean Contribution to Seismic Gravity Changes: the Sea Level Equation for Seismic Perturbations Revisited

    NASA Astrophysics Data System (ADS)

    Broerse, T.; Riva, R.; Vermeersen, B. L. A.

    2014-12-01

    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, such as the Mw ~ 9 2004 Sumatra-Andaman, 2010 Maule (Chile) and 2011 Tohoku-Oki (Japan) events. In Broerse et al. (2011) 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 causes errors up to 57% for modeled 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% due to horizontal ocean floor motion. 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

  14. 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.

  15. High-resolution gravity and geoid models in Tahiti obtained from new airborne and land gravity observations: data fusion by spectral combination

    NASA Astrophysics Data System (ADS)

    Shih, Hsuan-Chang; Hwang, Cheinway; Barriot, Jean-Pierre; Mouyen, Maxime; Corréia, Pascal; Lequeux, Didier; Sichoix, Lydie

    2015-08-01

    For the first time, we carry out an airborne gravity survey and we collect new land gravity data over the islands of Tahiti and Moorea in French Polynesia located in the South Pacific Ocean. The new land gravity data are registered with GPS-derived coordinates, network-adjusted and outlier-edited, resulting in a mean standard error of 17 μGal. A crossover analysis of the airborne gravity data indicates a mean gravity accuracy of 1.7 mGal. New marine gravity around the two islands is derived from Geosat/GM, ERS-1/GM, Jason-1/GM, and Cryosat-2 altimeter data. A new 1-s digital topography model is constructed and is used to compute the topographic gravitational effects. To use EGM08 over Tahiti and Moorea, the optimal degree of spherical harmonic expansion is 1500. The fusion of the gravity datasets is made by the band-limited least-squares collocation, which best integrates datasets of different accuracies and spatial resolutions. The new high-resolution gravity and geoid grids are constructed on a 9-s grid. Assessments of the grids by measurements of ground gravity and geometric geoidal height result in RMS differences of 0.9 mGal and 0.4 cm, respectively. The geoid model allows 1-cm orthometric height determination by GPS and Lidar and yields a consistent height datum for Tahiti and Moorea. The new Bouguer anomalies show gravity highs and lows in the centers and land-sea zones of the two islands, allowing further studies of the density structure and volcanism in the region.

  16. High-Level Radioactive Waste.

    ERIC Educational Resources Information Center

    Hayden, Howard C.

    1995-01-01

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

  17. The CMS high level trigger

    NASA Astrophysics Data System (ADS)

    Gori, Valentina

    2014-05-01

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

  18. The CMS High Level Trigger

    NASA Astrophysics Data System (ADS)

    Trocino, Daniele

    2014-06-01

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

  19. 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

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  1. 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.

  2. 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.

  3. Figuring large optics at the sub-nanometer level: compensation for coating and gravity distortions.

    PubMed

    Gensemer, Stephen; Gross, Mark

    2015-11-30

    Large, precision optics can now be manufactured with surface figures specified at the sub-nanometer level. However, coatings and gravity deform large optics, and there are limits to what can be corrected by clever compensation. Instead, deformations caused by stress from optical mounts and deposited coatings must be incorporated into the optical design. We demonstrate compensation of coating stress on a 370mm substrate to λ/200 by a process of coating and annealing. We also model the same process and identify the leading effects that must be anticipated in fabrication of optics for future gravitational wave detectors and other applications of large, precisely figured optics, and identify the limitations inherent in using coatings to compensate for these deformations. PMID:26698746

  4. 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.

  5. 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

  6. A high-resolution spherical harmonic degree 1500 lunar gravity field from the GRAIL mission

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    The highest resolution lunar gravity field to date has been generated by analyzing Gravity Recovery And Interior Laboratory (GRAIL) data from the Primary and Extended Missions. The Extended Mission Ka-band inter-spacecraft range-rate data have a precision near 0.05 micron/second with spacecraft altitudes as low as a few kilometers above the lunar surface. This new spherical harmonic degree 1500 field involves solving for nearly 2.3 million parameters in a least-square estimation procedure with 5 million observations. This results in an upper triangular 20 TB covariance matrix, computed using the NASA Pleiades Supercomputer. The first figure compares RMS unconstrained gravity field coefficients with uncertainties. The constrained global gravity spectrum (magenta) is determined to about n=900, whereas the Bouguer spectrum is accurate to about n=600. The correlation with gravity derived from constant density topography in the second figure shows that the high-order coefficients (n>700) are improved significantly over the previous degree 1200 field. Moreover, the Ka-band residual RMS is significantly improved for the low-altitude orbit solutions of the last month of the extended mission. The maximum local resolution of this new gravity field corresponds to a surface resolution of 3.6 km.

  7. Gravity modeling reveals that the "Miocene Pyrenean peneplain" developed at high elevation

    NASA Astrophysics Data System (ADS)

    Bosch, Gemma V.; Van Den Driessche, Jean; Robert, Alexandra; Babault, Julien; Le Carlier, Christian

    2016-04-01

    Geodynamics that shaped the present morphology of the western Mediterranean are mostly linked to the African-Eurasia collision and the extension related to the Mediterranean opening. The Pyrenean chain formed by the collision between the Iberian microplate and the Eurasian plate from the Eocene to the late Oligocene. This resulted in lithosphere thickening especially below the Central Pyrenees that becomes thinner eastwards. Whether the later thinning of the lithosphere in the easternmost Pyrenees involves the removal of the lithospheric mantle or not is debated. This issue joins the problematics about the origin of the high-elevation of the "Miocene Pyrenean peneplain" remnants. Indeed the most striking feature of the Pyrenean morphology is the occurrence of high-elevation, low relief erosional surfaces that are interpreted as the remnants of a Miocene single planation surface, dissected and reworked by Quaternary fluvial and glacial erosion. Two end-member interpretations have proposed to explain the high elevation of this original surface. The first considers that the Miocene Pyrenean peneplain develops near sea-level and was later uplifted, the second claims that the planation surface developed at high elevation in response to the inhibition of erosion consecutively to the progressive rise of the base-level of the Pyrenean drainage network. The first interpretation implies the return to normal crustal thickness by erosion and later uplift by removal of the lithospheric mantle. The second interpretation considers that the mean elevation of the original planation surface matches the thickness of the lithosphere below the chain, taking into account some hundred meters of isostatic rebound due to Quaternary erosion. To test these interpretations, we first restore the Miocene original planation surface by mapping and interpolating the high-elevation, low relief surfaces across the Pyrenees. We then performed 1D and 2D gravity models that we compare with recent

  8. Glacier mass balance in high-arctic areas with anomalous gravity

    NASA Astrophysics Data System (ADS)

    Sharov, A.; Rieser, D.; Nikolskiy, D.

    2012-04-01

    All known glaciological models describing the evolution of Arctic land- and sea-ice masses in changing climate treat the Earth's gravity as horizontally constant, but it isn't. In the High Arctic, the strength of the gravitational field varies considerably across even short distances under the influence of a density gradient, and the magnitude of free air gravity anomalies attains 100 mGal and more. On long-term base, instantaneous deviations of gravity can have a noticeable effect on the regime and mass budget of glaciological objects. At best, the gravity-induced component of ice mass variations can be determined on topographically smooth, open and steady surfaces, like those of arctic planes, regular ice caps and landfast sea ice. The present research is devoted to studying gravity-driven impacts on glacier mass balance in the outer periphery of four Eurasian shelf seas with a very cold, dry climate and rather episodic character of winter precipitation. As main study objects we had chosen a dozen Russia's northernmost insular ice caps, tens to hundreds of square kilometres in extent, situated in a close vicinity of strong gravity anomalies and surrounded with extensive fields of fast and/or drift ice for most of the year. The supposition about gravitational forcing on glacioclimatic settings in the study region is based on the results of quantitative comparison and joint interpretation of existing glacier change maps and available data on the Arctic gravity field and solid precipitation. The overall mapping of medium-term (from decadal to half-centennial) changes in glacier volumes and quantification of mass balance characteristics in the study region was performed by comparing reference elevation models of study glaciers derived from Russian topographic maps 1:200,000 (CI = 20 or 40 m) representing the glacier state as in the 1950s-1980s with modern elevation data obtained from satellite radar interferometry and lidar altimetry. Free-air gravity anomalies were

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

    SciTech Connect

    Magueijo, Joao

    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.

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

    NASA Astrophysics Data System (ADS)

    Magueijo, João

    2006-06-01

    In phenomenological quantum gravity theories, Planckian behavior is triggered by the energy of elementary particles approaching the Planck energy, EP, but it is also possible that anomalous behavior strikes systems of particles with total energy near EP. 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 EP 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.

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

    NASA Technical Reports Server (NTRS)

    Wang, Y.; Gupta, A. K.

    2001-01-01

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

  12. High resolution geodetic techniques for monitoring fluid levels over time

    NASA Astrophysics Data System (ADS)

    Hare, Jennifer Thompson

    1998-11-01

    In the first study, a novel surveillance technique is developed in which surface gravity observations are used to monitor the progress of a gas cap waterflood in the 8200 ft (2500 m) deep Prudhoe Bay reservoir, Alaska. This cost-effective method requires that high-precision gravity surveys be repeated every 3 to 5 years. Differences in the gravity field with time reflect changes in the reservoir fluid density distribution. A preliminary field test at Prudhoe Bay indicates survey accuracy of 5 to 10 mu Gal can be achieved for gravity data using a modified Lacoste & Romberg "G" type meter or Scintrex CG-3M combined with Global Positioning System (GPS) positioning. Forward gravity modeling of a suite of reservoir simulations of the proposed waterflood predicts variation in surface measurements of 100 mu Gal after 5 years of injection, and 180 to 250 mu Gal after 15 years. A constrained, least-squares method is used to invert synthetic gravity data for subsurface density distributions. The modeling procedure has been formulated to allow testing of the models for sensitivity to gravity sampling patterns, noise characteristics, and various constraints on model parameters such as density range, total mass, and model moment of inertia. Horizontal feature resolution of the waterflood is about 5000 ft (1520 m) for constrained inverse models from synthetic gravity with 5 mu Gal standard deviation noise. Results of the modeling indicate that inversion of time-lapse gravity data is a viable and promising technique for monitoring reservoir gas cap waterfloods. In the second study, the problem of how to estimate ancient lake levels from the geomorphology of remnant shoreline terraces is investigated. High resolution, GPS controlled, topographic data from around the highstand shoreline of Pleistocene Lake Lahontan in western Nevada provide the means for isolating coherent terrace features which are related to the paleoshoreline level. Determination of an unambiguous point or

  13. Responses of Electromyogram Activity in Adductor Longus Muscle of Rats to the Altered Gravity Levels

    NASA Astrophysics Data System (ADS)

    Ohira, Takashi; Wang, Xiao Dong; Terada, Masahiro; Kawano, Fuminori; Higo, Yoko; Nakai, Naoya; Ochiai, Toshimasa; Gyotoku, Jyunichirou; Nishimoto, Norihiro; Ogura, Akihiko; Ohira, Yoshinobu

    2008-06-01

    Responses of electromyogram (EMG) activities in the rostral and caudal regions of adductor longus (AL) muscle to altered gravity levels during parabolic flight of a jet airplane, as well as hindlimb suspension, were investigated in adult rats. Tonic EMGs in both regions were noted when the rats were exposed to hyper-G, as well as 1-G. The hip joints were adducted and the sedental quadrupedal position was maintained at these G levels. However, the EMG activities in these regions decreased and became phasic, when the hip joints were abducted and extended backward in μ-G environment. Such changes of joint angles caused passive shortening of sarcomeres only in the caudal region of AL. Atrophy and shift toward fast-twitch type were noted in fibers of the caudal region after 16-day unloading. Although fiber transformation was also induced in the rostral region, no atrophy was seen in fast-twitch fibers. The data may suggest that the atrophy and shift of phenotype caused by gravitational unloading in fibers of the caudal region may be related to the decrease in the neural and mechanical activities. Fiber type transformation toward fast-twitch type may be also related to the change of muscle activity from tonic to phasic patterns, which are the typical characteristics of fast-twitch muscle. However, the responses to unloading in fibers of rostral region were not related to the reduction of mechanical load.

  14. Redox potential driven aeration during very-high-gravity ethanol fermentation by using flocculating yeast

    PubMed Central

    Liu, Chen-Guang; Hao, Xue-Mi; Lin, Yen-Han; Bai, Feng-Wu

    2016-01-01

    Ethanol fermentation requires oxygen to maintain high biomass and cell viability, especially under very-high-gravity (VHG) condition. In this work, fermentation redox potential (ORP) was applied to drive the aeration process at low dissolved oxygen (DO) levels, which is infeasible to be regulated by a DO sensor. The performance and characteristics of flocculating yeast grown under 300 and 260 g glucose/L conditions were subjected to various aeration strategies including: no aeration; controlled aeration at −150, −100 and −50 mV levels; and constant aeration at 0.05 and 0.2 vvm. The results showed that anaerobic fermentation produced the least ethanol and had the highest residual glucose after 72 h of fermentation. Controlled aerations, depending on the real-time oxygen demand, led to higher cell viability than the no-aeration counterpart. Constant aeration triggered a quick biomass formation, and fast glucose utilization. However, over aeration at 0.2 vvm caused a reduction of final ethanol concentration. The controlled aeration driven by ORP under VHG conditions resulted in the best fermentation performance. Moreover, the controlled aeration could enhance yeast flocculating activity, promote an increase of flocs size, and accelerate yeast separation near the end of fermentation. PMID:27161047

  15. Redox potential driven aeration during very-high-gravity ethanol fermentation by using flocculating yeast.

    PubMed

    Liu, Chen-Guang; Hao, Xue-Mi; Lin, Yen-Han; Bai, Feng-Wu

    2016-01-01

    Ethanol fermentation requires oxygen to maintain high biomass and cell viability, especially under very-high-gravity (VHG) condition. In this work, fermentation redox potential (ORP) was applied to drive the aeration process at low dissolved oxygen (DO) levels, which is infeasible to be regulated by a DO sensor. The performance and characteristics of flocculating yeast grown under 300 and 260 g glucose/L conditions were subjected to various aeration strategies including: no aeration; controlled aeration at -150, -100 and -50 mV levels; and constant aeration at 0.05 and 0.2 vvm. The results showed that anaerobic fermentation produced the least ethanol and had the highest residual glucose after 72 h of fermentation. Controlled aerations, depending on the real-time oxygen demand, led to higher cell viability than the no-aeration counterpart. Constant aeration triggered a quick biomass formation, and fast glucose utilization. However, over aeration at 0.2 vvm caused a reduction of final ethanol concentration. The controlled aeration driven by ORP under VHG conditions resulted in the best fermentation performance. Moreover, the controlled aeration could enhance yeast flocculating activity, promote an increase of flocs size, and accelerate yeast separation near the end of fermentation. PMID:27161047

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

    PubMed Central

    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

  17. Venus gravity

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

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

  18. Very high gravity (VHG) ethanolic brewing and fermentation: a research update.

    PubMed

    Puligundla, Pradeep; Smogrovicova, Daniela; Obulam, Vijaya Sarathi Reddy; Ko, Sanghoon

    2011-09-01

    There have been numerous developments in ethanol fermentation technology since the beginning of the new millennium as ethanol has become an immediate viable alternative to fast-depleting crude reserves as well as increasing concerns over environmental pollution. Nowadays, although most research efforts are focused on the conversion of cheap cellulosic substrates to ethanol, methods that are cost-competitive with gasoline production are still lacking. At the same time, the ethanol industry has engaged in implementing potential energy-saving, productivity and efficiency-maximizing technologies in existing production methods to become more viable. Very high gravity (VHG) fermentation is an emerging, versatile one among such technologies offering great savings in process water and energy requirements through fermentation of higher concentrations of sugar substrate and, therefore, increased final ethanol concentration in the medium. The technology also allows increased fermentation efficiency, without major alterations to existing facilities, by efficient utilization of fermentor space and elimination of known losses. This comprehensive research update on VHG technology is presented in two main sections, namely VHG brewing, wherein the effects of nutrients supplementation, yeast pitching rate, flavour compound synthesis and foam stability under increased wort gravities are discussed; and VHG bioethanol fermentation studies. In the latter section, aspects related to the role of osmoprotectants and nutrients in yeast stress reduction, substrates utilized/tested so far, including saccharide (glucose, sucrose, molasses, etc.) and starchy materials (wheat, corn, barley, oats, etc.), and mash viscosity issues in VHG bioethanol production are detailed. Thereafter, topics common to both areas such as process optimization studies, mutants and gene level studies, immobilized yeast applications, temperature effect, reserve carbohydrates profile in yeast, and economic aspects are

  19. High-resolution simulations of non-Boussinesq downslope gravity currents in the acceleration phase

    NASA Astrophysics Data System (ADS)

    Dai, Albert; Huang, Yu-lin

    2016-02-01

    Gravity currents generated from an instantaneous buoyancy source of density contrast in the density ratio range of 0.3 ≤ γ ≤ 0.998 propagating downslope in the slope angle range of 0° ≤ θ < 90° have been investigated in the acceleration phase by means of high-resolution two-dimensional simulations of the incompressible variable-density Navier-Stokes equations. For all density contrasts considered in this study, front velocity history shows that, after the heavy fluid is released from rest, the gravity currents go through the acceleration phase, reaching a maximum front velocity Uf,max, followed by the deceleration phase. It is found that Uf,max increases as the density contrast increases and such a relationship is, for the first time, quantitatively described by the improved thermal theory considering the non-Boussinesq effects. Energy budgets show that, as the density contrast increases, the heavy fluid retains more fraction of potential energy loss while the ambient fluid receives less fraction of potential energy loss in the process of energy transfer during the propagation of downslope gravity currents. Previously, it was reported that for the Boussinesq case, the downslope gravity currents have a maximum of Uf,max at θ ≈ 40°. It is found, as is also confirmed by the energy budgets in this study, that the slope angle at which the downslope gravity currents have a maximum of Uf,max may increase beyond 40° as the density contrast increases.

  20. Gravity wave transmission diagram

    NASA Astrophysics Data System (ADS)

    Tomikawa, Yoshihiro

    2016-07-01

    A possibility of gravity wave propagation from a source region to the airglow layer around the mesopause has been discussed based on the gravity wave blocking diagram taking into account the critical level filtering alone. This paper proposes a new gravity wave transmission diagram in which both the critical level filtering and turning level reflection of gravity waves are considered. It shows a significantly different distribution of gravity wave transmissivity from the blocking diagram.

  1. Improvement of the ethanol productivity in a high gravity brewing at pilot plant scale.

    PubMed

    Dragone, Giuliano; Silva, Daniel P; de Almeida e Silva, João Batista; de Almeida Lima, Urgel

    2003-07-01

    A 23 full factorial design was used to study the influence of different experimental variables, namely wort gravity, fermentation temperature and nutrient supplementation, on ethanol productivity from high gravity wort fermentation by Saccharomyces cerevisiae (lager strain), under pilot plant conditions. The highest ethanol productivity (0.69 g l(-1) h(-1)) was obtained at 20 degrees P [degrees P is the weight of extract (sugar) equivalent to the weight of sucrose in a 100 g solution at 20 degrees C], 15 degrees C, with the addition of 0.8% (w/v) yeast extract, 24 mg l(-1) ergosterol and 0.24% (v/v) Tween 80. PMID:12967007

  2. On the recovery of gravity anomalies from high precision altimeter data

    NASA Technical Reports Server (NTRS)

    Lelgemann, D.

    1976-01-01

    A model for the recovery of gravity anomalies from high precision altimeter data is derived which consists of small correction terms to the inverse Stokes' formula. The influence of unknown sea surface topography in the case of meandering currents such as the Gulf Stream is discussed. A formula was derived in order to estimate the accuracy of the gravity anomalies from the known accuracy of the altimeter data. It is shown that for the case of known harmonic coefficients of lower order the range of integration in Stokes inverse formula can be reduced very much.

  3. Evidence of high frequency gravity wave forcing on the meridional residual circulation at the mesopause region

    NASA Astrophysics Data System (ADS)

    Vargas, Fabio; Swenson, Gary; Liu, Alan

    2015-11-01

    Data of high frequency gravity wave propagation direction from globally distributed stations indicate a meridional preference of mesospheric gravity waves to be globally oriented toward the summer pole. This orientation is opposite to the mean residual circulation (from summer to winter pole) at mesospheric altitudes. We discuss here a number of dynamic mechanisms including filtering that may be responsible for the preferential wave orientation, and the effects of the gravity wave forcing imposed on the meridional flow due to dissipative waves. Using nightglow image data recorded in three distinct latitude stations, we have estimated the meridional wave drag (i.e, deceleration) of about - 4.6 ± 0.2 m/s/day during the summer, and 3.8 ± 0.2 m/s/day during the winter, which is significant because the meridional flow has small magnitude. This is a component of dynamic forcing in the mesopause region, not heretofore recognized.

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

    PubMed

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

    2007-02-01

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

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

    PubMed Central

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

    2007-01-01

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

  6. High level white noise generator

    DOEpatents

    Borkowski, Casimer J.; Blalock, Theron V.

    1979-01-01

    A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application.

  7. 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.

  8. Holography as a highly efficient renormalization group flow. I. Rephrasing gravity

    NASA Astrophysics Data System (ADS)

    Behr, Nicolas; Kuperstein, Stanislav; Mukhopadhyay, Ayan

    2016-07-01

    We investigate how the holographic correspondence can be reformulated as a generalization of Wilsonian renormalization group (RG) flow in a strongly interacting large-N quantum field theory. We first define a highly efficient RG flow as one in which the Ward identities related to local conservation of energy, momentum and charges preserve the same form at each scale. To achieve this, it is necessary to redefine the background metric and external sources at each scale as functionals of the effective single-trace operators. These redefinitions also absorb the contributions of the multitrace operators to these effective Ward identities. Thus, the background metric and external sources become effectively dynamical, reproducing the dual classical gravity equations in one higher dimension. Here, we focus on reconstructing the pure gravity sector as a highly efficient RG flow of the energy-momentum tensor operator, leaving the explicit constructive field theory approach for generating such RG flows to the second part of the work. We show that special symmetries of the highly efficient RG flows carry information through which we can decode the gauge fixing of bulk diffeomorphisms in the corresponding gravity equations. We also show that the highly efficient RG flow which reproduces a given classical gravity theory in a given gauge is unique provided the endpoint can be transformed to a nonrelativistic fixed point with a finite number of parameters under a universal rescaling. The results obtained here are used in the second part of this work, where we do an explicit field-theoretic construction of the RG flow and obtain the dual classical gravity theory.

  9. Liquid Droplet Dynamics in Gravity Compensating High Magnetic Field

    NASA Technical Reports Server (NTRS)

    Bojarevics, V.; Easter, S.; Pericleous, K.

    2012-01-01

    Numerical models are used to investigate behavior of liquid droplets suspended in high DC magnetic fields of various configurations providing microgravity-like conditions. Using a DC field it is possible to create conditions with laminar viscosity and heat transfer to measure viscosity, surface tension, electrical and thermal conductivities, and heat capacity of a liquid sample. The oscillations in a high DC magnetic field are quite different for an electrically conducting droplet, like liquid silicon or metal. The droplet behavior in a high magnetic field is the subject of investigation in this paper. At the high values of magnetic field some oscillation modes are damped quickly, while others are modified with a considerable shift of the oscillating droplet frequencies and the damping constants from the non-magnetic case.

  10. 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

  11. High-fidelity gravity modeling applied to spacecraft trajectories and lunar interior analysis

    NASA Astrophysics Data System (ADS)

    Chappaz, Loic P. R.

    As the complexity and boldness of emerging mission proposals increase, and with the rapid evolution of the available computational capabilities, high-accuracy and high-resolution gravity models and the tools to exploit such models are increasingly attractive within the context of spaceflight mechanics, mission design and analysis, and planetary science in general. First, in trajectory design applications, a gravity representation for the bodies of interest is, in general, assumed and exploited to determine the motion of a spacecraft in any given system. The focus is the exploration of trajectories in the vicinity of a system comprised of two small irregular bodies. Within this context, the primary bodies are initially modeled as massive ellipsoids and tools to construct third-body trajectories are developed. However, these dynamical models are idealized representations of the actual dynamical regime and do not account for any perturbing effects. Thus, a robust strategy to maintain a spacecraft near reference third-body trajectories is constructed. Further, it is important to assess the perturbing effect that dominates the dynamics of the spacecraft in such a region as a function of the baseline orbit. Alternatively, the motion of the spacecraft around a given body may be known to extreme precision enabling the derivation of a very high-accuracy gravity field for that body. Such knowledge can subsequently be exploited to gain insight into specific properties of the body. The success of the NASA's GRAIL mission ensures that the highest resolution and most accurate gravity data for the Moon is now available. In the GRAIL investigation, the focus is on the specific task of detecting the presence and extent of subsurface features, such as empty lava tubes beneath the mare surface. In addition to their importance for understanding the emplacement of the mare flood basalts, open lava tubes are of interest as possible habitation sites safe from cosmic radiation and

  12. Development of high accuracy and resolution geoid and gravity maps

    NASA Technical Reports Server (NTRS)

    Gaposchkin, E. M.

    1986-01-01

    Precision satellite to satellite tracking can be used to obtain high precision and resolution maps of the geoid. A method is demonstrated to use data in a limited region to map the geopotential at the satellite altitude. An inverse method is used to downward continue the potential to the Earth surface. The method is designed for both satellites in the same low orbit.

  13. 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.

  14. Towards a high-energy theory for the Higgs phase of gravity

    SciTech Connect

    Graesser, Michael L.; Wise, Mark B.; Low, Ian

    2005-12-01

    Spontaneous Lorentz violation due to a time-dependent expectation value for a massless scalar has been suggested as a method for dynamically generating dark energy. A natural candidate for the scalar is a Goldstone boson arising from the spontaneous breaking of a U(1) symmetry. We investigate the low-energy effective action for such a Goldstone boson in a general class of models involving only scalars, proving that if the scalars have standard kinetic terms then at the classical level the effective action does not have the required features for spontaneous Lorentz violation to occur asymptotically (t{yields}{infinity}) in an expanding Friedman-Robertson-Walker universe. Then we study the large N limit of a renormalizable field theory with a complex scalar coupled to massive fermions. In this model an effective action for the Goldstone boson with the properties required for spontaneous Lorentz violation can be generated. Although the model has shortcomings, we feel it represents progress towards finding a high energy completion for the Higgs phase of gravity.

  15. Global transcription engineering of brewer's yeast enhances the fermentation performance under high-gravity conditions.

    PubMed

    Gao, Cuijuan; Wang, Zhikun; Liang, Quanfeng; Qi, Qingsheng

    2010-08-01

    Global transcription engineering was developed as a tool to reprogram gene transcription for eliciting new phenotypes important for technological applications (Science 2006, 314(5805):1565-1568). A recent report indicated that the beneficial growth advantage of yeast cells expressing the SPT15-300 mutation is the result of enhanced uptake and/or improved utilization of leucine and thus was seen only on defined media with low concentrations of leucine (Appl Environ Microbiol 2009, 75(19):6055-6061). Further investigation towards a leucine-prototrophic strain of industrial lager brewer's yeast indicated that integration one copy of SPT15-300 in SPT15 allele, however, did lead to an increased ethanol tolerance on complex rich medium at high gravity fermentation condition. Under brewing conditions, the SPT15-300 mutant produced 80.78 g/L ethanol from 200 g/L carbohydrates after 384 h, almost twice as much as that of the wild-type strain. The results convinced us that the effect of global regulator modification of yeast is at multi-genes level and is extremely complicated. PMID:20461507

  16. 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.

  17. High Sensitivity Gravity Measurements in the Adverse Environment of Oil Wells

    NASA Astrophysics Data System (ADS)

    Pfutzner, Harold

    2014-03-01

    Bulk density is a primary measurement within oil and gas reservoirs and is the basis of most reserves calculations by oil companies. The measurement is performed with a gamma-ray source and two scintillation gamma-ray detectors from within newly drilled exploration and production wells. This nuclear density measurement, while very precise is also very shallow and is therefore susceptible to errors due to any alteration of the formation and fluids in the vicinity of the borehole caused by the drilling process. Measuring acceleration due to gravity along a well provides a direct measure of bulk density with a very large depth of investigation that makes it practically immune to errors from near-borehole effects. Advances in gravity sensors and associated mechanics and electronics provide an opportunity for routine borehole gravity measurements with comparable density precision to the nuclear density measurement and with sufficient ruggedness to survive the rough handling and high temperatures experienced in oil well logging. We will describe a borehole gravity meter and its use under very realistic conditions in an oil well in Saudi Arabia. The density measurements will be presented. Alberto Marsala (2), Paul Wanjau (1), Olivier Moyal (1), and Justin Mlcak (1); (1) Schlumberger, (2) Saudi Aramco.

  18. Gravity investigations

    SciTech Connect

    Healey, D.L.

    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.

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

    PubMed

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

    2007-09-01

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

  20. 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.

  1. High temperature liquid level sensor

    DOEpatents

    Tokarz, Richard D.

    1983-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Using campaign micro-gravity measurements collected at Kilauea Volcano, Hawai'i (United States), between December 2009 and November 2012, we document significant mass variations at the summit of the volcano. These variations produce a maximum residual gravity change of +370 × 14 μGal near the east margin of Halema'uma'u Crater, within Kilauea's summit caldera, where in March 2008 a new eruptive vent opened. This vent has progressively enlarged through several collapses and now forms a 210x160 m elliptical cavity that is currently occupied by a lava lake whose surface fluctuates between 25 and 200 meters below the vent rim. Five micro-gravity surveys were performed using two Scintrex CG-5 gravimeters. Each survey was completed following a double-looping procedure, and each measurement was corrected for earth-tides, ocean loading, and instrument drift. Gravity changes at each station were then corrected for the free-air effect using vertical displacements calculated from combined ascending and descending InSAR measurements. InSAR data are from both the German Space Agency (DLR) TerraSAR-X satellite and the Italian Space Agency (ASI) Cosmo-SkyMed satellite-constellation. The spatial distribution of the gravity changes suggests that they are predominantly caused by the enlargement of the vent and variations in the height of the summit lava lake. The contribution to the gravity measurements caused by changes in lava level within the conduit feeding the lava lake is therefore estimated using a numerical model that takes into account its geometry, as inferred from visual and remotely sensed (LiDAR) observations, and lava height at the time of each gravity survey, determined from thermal camera data. These results can be used to make inferences on the density of the magma filling the lava lake, which we compare to values obtained using independent data from continuous gravimeters located near the campaign stations. Estimates of the lava level effect on the gravity allow

  3. 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.

  4. 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.

  5. A laboratory model of post-Newtonian gravity with high power lasers and 4th generation light sources

    NASA Astrophysics Data System (ADS)

    Gregori, G.; Levy, M. C.; Wadud, M. A.; Crowley, B. J. B.; Bingham, R.

    2016-04-01

    Using the post-Newtonian formalism of gravity, we attempt to calculate the x-ray Thomson scattering cross section of electrons that are accelerated in the field of a high intensity optical laser. We show that our results are consistent with previous calculations, suggesting that the combination of high power laser and 4th generation light sources may become a powerful platform to test models exploring high order corrections to the Newtonian gravity.

  6. Manifestations of the rotation and gravity of the Earth in high-energy physics experiments

    NASA Astrophysics Data System (ADS)

    Obukhov, Yuri N.; Silenko, Alexander J.; Teryaev, Oleg V.

    2016-08-01

    The inertial (due to rotation) and gravitational fields of the Earth affect the motion of an elementary particle and its spin dynamics. This influence is not negligible and should be taken into account in high-energy physics experiments. Earth's influence is manifest in perturbations in the particle motion, in an additional precession of the spin, and in a change of the constitutive tensor of the Maxwell electrodynamics. Bigger corrections are oscillatory, and their contributions average to zero. Other corrections due to the inhomogeneity of the inertial field are not oscillatory but they are very small and may be important only for the storage ring electric dipole moment experiments. Earth's gravity causes the Newton-like force, the reaction force provided by a focusing system, and additional torques acting on the spin. However, there are no observable indications of the electromagnetic effects due to Earth's gravity.

  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. F. J.; 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. High resolution lunar mascon three dimensional density structure revealed by GRAIL gravity

    NASA Astrophysics Data System (ADS)

    Jianguo, Yan; Yi, Zhang

    2016-07-01

    In the history of the moon exploration, the most amazing achievement is that some mass concentrated areas were found on the near side of the moon1, 2. These mass concentrated areas, which are referred to mascons, are usually covered with a positive gravity anomaly peak, and surrounded by negative gravity anomalies with low geographical elevation1-7. Here we proposed a gravity inverse method including geological constraint to obtain density structure of the lunar mascons. The method was implemented in spherical coordinates and validated with simulation test. Using this method we obtained high resolution density anomaly structure of lunar near side maria mascons basins and far side highland mascons. The high resolution depth information and density anomalies structure of the lunar mascons are presented for the first time. By comparing the near side maria mascons with far side mascons, we found all the mascons have an annulus density structures in their shallow stratums; the mascon depth information also indicates that the mascon depth on lunar far side is much deeper than that on the near side. These results indicate various origination mechanism between nearside and farside mascons.

  9. 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.

  10. High-resolution simulations of downslope gravity currents in the acceleration phase

    NASA Astrophysics Data System (ADS)

    Dai, Albert

    2015-07-01

    Gravity currents generated from an instantaneous buoyancy source propagating down a slope in the range of 0∘ ≤ θ < 90∘ have been investigated in the acceleration phase by means of high-resolution two-dimensional simulations of the incompressible Navier-Stokes equations with the Boussinesq approximation. Front velocity history shows that, after the heavy fluid is released from rest, the flow goes through the acceleration phase, reaching a maximum front velocity Uf,max, and followed by the deceleration phase. The existence of a maximum of Uf,max is found near θ = 40∘, which is supported by the improved theory. It is identified for the first time that the time of acceleration decreases as the slope angle increases, when the slope angle is approximately greater than 10∘, and the time of acceleration increases as the slope angle increases for gravity currents on lower slope angles. A fundamental difference in flow patterns, which helps explain the distinct characteristics of gravity currents on high and low slope angles using scaling arguments, is revealed. Energy budgets further show that, as the slope angle increases, the ambient fluid is more easily engaged in the gravitational convection and the potential energy loss is more efficiently converted into the kinetic energy associated with ambient fluid. The propagation of gravity currents on a slope is found to be qualitatively modified as the depth ratio, i.e., the lock height to channel height ratio, approaches unity. As the depth ratio increases, the conversion of potential energy loss into the kinetic energy associated with heavy fluid is inhibited and the conversion into the kinetic energy associated with ambient fluid is enhanced by the confinement of the top wall.

  11. Synchronous absolute EIT in three thoracic planes at different gravity levels

    NASA Astrophysics Data System (ADS)

    Hahn, G.; Just, A.; Dittmar, J.; Fromm, K. H.; Quintel, M.

    2013-04-01

    The validity of absolute Electrical Impedance Tomography (a-EIT) for assessment of local lung volume has been investigated far less than the well evaluated ventilation monitoring by functional EIT (f-EIT). To achieve progress in a-EIT we investigated 10 healthy volunteers in an upright sitting position by using a-EIT at normal gravity (1 g), weightlessness (0 g) and approx. double gravity (1.8 g) during parabolic flight manoeuvres. Lung resistivity in three thoracic planes was determined by a-EIT using a multiple-plane synchronised Goe-MF II EIT system. Tomograms of resistivity at end-expiration in normal spontaneous breathing were reconstructed by a modified SIRT algorithm. Local lung resistivity was determined separately for both lungs. The respective resistivity values at 1 g and 1.8 g before and after weightlessness show an almost reversible behaviour along the sequence of gravity changes with a tendency to be lower after occurrence of weightlessness. The results reveal not only the expected varying resistivity of lung tissue in cranio-caudal direction but also a clear difference in these cranio-caudal stratifications of local lung volume between the left and right lung. The resolution and stability of absolute EIT seem to be valid and expressive for future investigations of unilateral lung volume under different physiological and pathological conditions.

  12. High fertility level in Tibet.

    PubMed

    Zhang, T

    1997-08-01

    This article presents a profile of fertility patterns in Tibet Autonomous Region for 1989. Data were obtained from the 1982 and 1990 China Censuses and from a 1988 fertility and contraception survey. Findings indicate that the total fertility rate (TFR) was 4.36 children/woman in 1989. TFR in Tibet is higher than in other provinces with a Tibetan population. Tibetan TFR was 4.07 among Tibetan women in Qinghai, 3.30 in Sichuan, 3.0 in Yunnan, and 2.8 in Gansu. TFR was 2.16 in Tibet's towns and 1.82 in Lhasa city, compared to 4.57 in counties. In Tibet, the birth rate rose from 31.05/1000 in 1981, to 31.14 in 1989. Ngari prefecture had an even higher birth rate of 35.67 in 1989. Other Tibetan prefectures had lower birth rates. During 1982-89, the birth rate declined to 26.19 in Lhasa City, to 29.36 in Shannan prefecture, and to 27.09 in Nagqu prefecture. Tibet's TFR fluctuated during 1950-57 between 3.20 and 3.80. It rose after 1958, from 4.0 to over 5.0, and remained high at 4.22 in 1989. TFR increased from older to younger women. The average number of live births also increased from older to younger women. This unusual feature is linked with high infertility and the number of women remaining celibate. Infertility was 17.7% among women aged 60-64 years, 14.8% among women aged 55-59, and 12.2% among women aged 50-54. 45.29% of women had parities of 1-2 children, ranging from 85.21% in the city, 77.92% in towns, and 42.20% in rural areas. The percentage of Tibetan women having 4 or more children was 5.82% in the city, 10.14% in towns, and 42.91% in rural areas. TFR was reversely correlated with educational status. TFR was highest among illiterates and semiliterates (4.59) and lowest for college educated women (1.28). Illiterate and semi-literate women comprised 13% of women with 4 children. PMID:12321529

  13. 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

  14. Investigating asymmetries in mesospheric gravity wave propagation at high-latitudes

    NASA Astrophysics Data System (ADS)

    Taylor, M. J.; Zhao, Y.; Ward, R.; Martin, T.; Pautet, P.; Dyrland, M. E.; Nielsen, K.; Jarvis, M. J.; Moffat-Griffin, T.; Randall, C. E.; Lumpe, J. D.; Bailey, S. M.; Russell, J. M.

    2012-12-01

    A combination of ground based imaging of gravity waves in the mesospheric OH emission (peak altitude ~87 km) and satellite measurements of waves as detected in extensive polar mesospheric clouds, PMC's (mean altitude ~83 km) has been used to investigate summer-winter wave properties in both the Northern and Southern polar regions. Wintertime all-sky image data primarily from two sites (Halley and Rothera) on the Antarctic coast, obtained as part of a collaborative program with British Antarctic Survey, and from the Kjell Henriksen Observatory (KHO) Svalbard in the high Arctic, have been utilized to determine the dominant characteristics of both short and medium scale gravity waves (observed periods up to ~1 hour). These new results, which show distinct asymmetries in their propagation headings, are compared with recent summertime gravity wave measurements using PMC data from the Cloud Imaging and Particle Size (CIPS) experiment on the NASA Aeronomy of Ice in the Mesosphere (AIM) satellite. Our Southern Hemisphere results reveal novel evidence for strong preferences for zonal wave motions particularly for the smaller scale (<100 km horizontal wavelength) suggesting a significant pattern for meridional filtering throughout the Antarctic continent. In contrast, the medium-scale waves exhibited a consistent but quite different motion field. These new results are compared with recent Northern Hemisphere measurements to further investigate polar wave dynamics in the Mesosphere and Lower Thermosphere (MLT) region (~80-100 km).

  15. Updated f(T) gravity constraints from high-redshift cosmography

    NASA Astrophysics Data System (ADS)

    Piedipalumbo, Ester; Moglie, Enrica Della; Cianci, Roberto

    2015-09-01

    In the last dozen years, a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides information about the evolution of the universe from measured distances, only assuming that the geometry can be described by the Friedmann-Lemaitre-Robertson-Walker metric. In this paper, we perform a high-redshift analysis which allows us to put constraints on the cosmographic parameters up to the fifth-order, thus inducing indirect constraints on any gravity theory. Here, we are interested in the so-called teleparallel gravity theory, f(T). Actually, we use the analytical expressions of the present day values of f(T) and its derivatives as functions of the cosmographic parameters to map the cosmography region of confidences into confidence ranges for f(T) and its derivative. Moreover, we show how these can be used to test some teleparallel gravity models without solving the dynamical equations. Our analysis is based on the Union2 Type Ia supernovae (SNIa) data set, a set of 28 measurements of the Hubble parameter, the Hubble diagram constructed from some gamma ray bursts (GRB) luminosity distance indicators and Gaussian priors on the distance from the baryon acoustic oscillations (BAOs) and the Hubble constant h. To perform our statistical analysis and to explore the probability distributions of the cosmographic parameters, we use the Markov chain Monte Carlo (MCMC) method.

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

    SciTech Connect

    Ennadifi, Salah Eddine

    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.

  17. High-order discontinuous Galerkin methods for coupled thermoconvective flows under gravity modulation

    NASA Astrophysics Data System (ADS)

    Papanicolaou, N. C.; Aristotelous, A. C.

    2015-10-01

    In this work, we develop a High-Order Symmetric Interior Penalty (SIP) Discontinuous Galerkin (DG) Finite Element Method (FEM) to investigate convective flows in a rectangular cavity subject to both vertical and horizontal temperature gradients. The whole cavity is subject to gravity modulation (g-jitter), simulating a microgravity environment. The sensitivity of the bifurcation problem makes the use of a high-order accurate and efficient technique essential. Our method is validated by solving the plane-parallel flow problem and the results were found to be in good agreement with published results. The numerical method was designed to be easily extendable to even more complex flows.

  18. Gravity Field Recovery from GRACE: Unique Aspects of the High Precision Inter-Satellite Data and Analysis Methods

    NASA Astrophysics Data System (ADS)

    Balmino, G.

    2003-07-01

    The very high accuracy of the Doppler and range measurements between the two low-flying and co-orbiting spacecraft of the GRACE mission, which will be at the μm/sec and ≈10 μm levels respectively, requires that special procedures be applied in the processing of these data. Parts of the existing orbit determination and gravity field parameters retrieval methods and software must be modified in order to fully benefit from the capabilities of this mission. This is being done in the following areas: (i) numerical integration of the equations of motion (summed form, accuracy of the predictor-corrector loop, Encke's formulation): (ii) special inter-satellite dynamical parameterization for very short arcs; (iii) accurate solution of large least-squares problems (normal equations vs. orthogonal decomposition of observation equations); (iv) handling the observation equations with high accuracy. Theoretical concepts and first tests of some of the newly implemented algorithms are presented.

  19. 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.

  20. Geophysical Investigation of Australian-Antarctic Ridge Using High-Resolution Gravity and Bathymetry

    NASA Astrophysics Data System (ADS)

    Kim, S. S.; Lin, J.; Park, S. H.; Choi, H.

    2015-12-01

    Much of the Australian-Antarctic Ridge (AAR) has been remained uncharted until 2011 because of its remoteness and harsh weather conditions. From 2011, the multidisciplinary ridge program initiated by the Korea Polar Research Institute (KOPRI) surveyed the little-explored eastern ends of the AAR to characterize the tectonics, geochemistry, and hydrothermal activity of this intermediate spreading system. In this study, we present a detailed analysis of a 300-km-long supersegment of the AAR to quantify the spatial variations in ridge morphology and axial and off-axis volcanisms as constrained by high-resolution shipboard bathymetry and gravity. The ridge axis morphology alternates between rift valleys and axial highs within relatively short ridge segments. To obtain a geological proxy for regional variations in magma supply, we calculated residual mantle Bouguer gravity anomalies (RMBA), gravity-derived crustal thickness, and residual topography for neighboring seven sub-segments. The results of the analyses revealed that the southern flank of the AAR is associated with shallower seafloor, more negative RMBA, thicker crust, and/or less dense mantle in comparison to the conjugate northern flank. Furthermore, this north-south asymmetry becomes more prominent toward the KR1 supersegment of the AAR. The axial topography of the KR1 supersegment exhibits a sharp transition from axial highs at the western end to rift valleys at the eastern end, with regions of axial highs being associated with more robust magma supply as indicated by more negative RMBA. We also compare and contrast the characteristics of the AAR supersegment with that of other ridges of intermediate spreading rates, including the Juan de Fuca Ridge, Galápagos Spreading Center, and Southeast Indian Ridge west of the Australian-Antarctic Discordance, to investigate the influence of ridge-hotspot interaction on ridge magma supply and tectonics.

  1. 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

  2. CG3TOOL: an interactive computer program to process Scintrex CG-3/3M gravity data for high-resolution applications

    NASA Astrophysics Data System (ADS)

    Gabalda, G.; Bonvalot, S.; Hipkin, R.

    2003-03-01

    A newly developed interactive computer program, CG3TOOL, has been dedicated to the processing of the gravity data acquired by the Scintrex CG-3/3M automated gravity meter. The aim of CG3TOOL is two fold: to allow for an objective evaluation of Scintrex data and to provide a higher resolution in data reductions than those computed in real time by the microprocessor-controlled instrument. The program reads the gravity data acquired in either field or cycle mode (field surveys and continuous recordings, respectively) and then downloaded from the meter to a PC computer. The processing tasks are divided into two successive levels. Level 1 is dedicated to the reduction of the daily data files by applying standard or accurate corrections (earth tide, instrumental drift, atmospheric pressure). The precise corrections are performed up to the microGal (μGal) level, in accordance with the specifications of high-resolution surveys. Level 2 contains a series of processing tools (including network adjustment, anomaly computation, and gravity meter calibration) that will precisely compute and adjust the gravity values with error estimates. The interactive procedures and the program output (plot and text files) have been designed to ease data handling and archiving as well as to provide useful information for future purposes of data interpretation or modeling. CG3TOOL was developed in a standard C language for Unix Sun workstations and uses the standard graphical and mathematical Generic Mapping Tools (GMT) free library, available from the web. The objectives and principles of the computer program are presented below along with corresponding examples of the main processing tasks applied to observed data.

  3. Satellite borne gravity gradiometer study

    NASA Technical Reports Server (NTRS)

    Metzger, E.; Jircitano, A.; Affleck, C.

    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 proven Model VII accelerometers mounted on a slowly rotating fixture. Gravity gradients are being measured to 1.07 EU in a vertical rotation axis orientation. Equally significant are the outstanding operational characteristics such as fast reaction time, low temperature coefficients and high degree of bias stability over long periods of time. The rotating accelerometer gravity gradiometer approach and its present status is discussed and it is the foundation for the orbital gravity gradiometer analyzed. The performance levels achieved in a 1 g environment of the earth and under relatively high seismic disturbances, lend the orbital gravity gradiometer a high confidence level of success.

  4. High-energy scalarons in R2 gravity as a model for Dark Matter in galaxies

    NASA Astrophysics Data System (ADS)

    Corda, C.; Mosquera Cuesta, H. J.; Lorduy Gómez, R.

    2012-01-01

    We show that in the framework of R2 gravity and in the linearized approach it is possible to obtain spherically symmetric stationary states that can be used as a model for galaxies. Such approach could represent a solution to the Dark Matter Problem. In fact, in the model, the Ricci curvature generates a high energy term that can in principle be identified as the dark matter field making up the galaxy. The model can also help to have a better understanding on the theoretical basis of Einstein-Vlasov systems. Specifically, we discuss, in the linearized R2 gravity, the solutions of a Klein-Gordon equation for the spacetime curvature. Such solutions describe high energy scalarons, a field that in the context of galactic dynamics can be interpreted like the no-light-emitting galactic component. That is, these particles can be figured out like wave-packets showing stationary solutions in the Einstein-Vlasov system. In such approximation, the energy of the particles can be thought of as the galactic dark matter component that guarantees the galaxy equilibrium. Thus, because of the high energy of such particles the coupling constant of the R2-term in the gravitational action comes to be very small with respect to the linear term R. In this way, the deviation from standard General Relativity is very weak, and in principle the theory could pass the Solar System tests. As pertinent to the issue under analysis in this paper, we present an analysis on the gravitational lensing phenomena within this framework.Although the main goal of this paper is to give a potential solution to the Dark Matter Problem within galaxies, we add a section where we show that an important property of the Bullet Cluster can in principle be explained in the scenario introduced in this work.To the end, we discuss the generic prospective to give rise to the Dark Matter component of most galaxies within extended gravity.

  5. 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.

  6. Gravity waves and high-altitude CO2 ice cloud formation in the Martian atmosphere

    NASA Astrophysics Data System (ADS)

    Yiǧit, Erdal; Medvedev, Alexander S.; Hartogh, Paul

    2015-06-01

    We present the first general circulation model simulations that quantify and reproduce patches of extremely cold air required for CO2 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 CO2 ice clouds. Our study confirms the key role of GWs in facilitating CO2 cloud formation, discusses their tidal modulation, and predicts clouds at altitudes higher than have been observed to date.

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

    NASA Astrophysics Data System (ADS)

    Fašková, Z.; Macák, M.; Čunderlík, R.; Mikula, K.

    2012-04-01

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

  8. Assessment of Gravity Field and Steady State Ocean Circulation Explorer (GOCE) geoid model using GPS levelling over Sabah and Sarawak

    NASA Astrophysics Data System (ADS)

    Othman, A. H.; Omar, K. M.; Din, A. H. M.; Som, Z. A. M.; Yahaya, N. A. Z.; Pa'suya, M. F.

    2016-06-01

    The GOCE satellite mission has significantly contributed to various applications such as solid earth physics, oceanography and geodesy. Some substantial applications of geodesy are to improve the gravity field knowledge and the precise geoid modelling towards realising global height unification. This paper aims to evaluate GOCE geoid model based on the recent GOCE Global Geopotential Model (GGM), as well as EGM2008, using GPS levelling data over East Malaysia, i.e. Sabah and Sarawak. The satellite GGMs selected in this study are the GOCE GGM models which include GOCE04S, TIM_R5 and SPW_R4, and the EGM2008 model. To assess these models, the geoid heights from these GGMs are compared to the local geometric geoid height. The GGM geoid heights was derived using EGMLAB1 software and the geometric geoid height was computed by available GPS levelling information obtained from the Department Survey and Mapping Malaysia. Generally, the GOCE models performed better than EGM2008 over East Malaysia and the best fit GOCE model for this region is the TIM_R5 model. The TIM_R5 GOCE model demonstrated the lowest R.M.S. of ± 16.5 cm over Sarawak, comparatively. For further improvement, this model should be combined with the local gravity data for optimum geoid modelling over East Malaysia.

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

    PubMed

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

    2004-04-01

    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 arm movements without vision were more biased by whole-body tilt than purely visual estimates. Strikingly, visual GREL estimates became more dependent on whole-body tilt when the indication of level was obtained by arm lifting. These findings indicate that active motor involvement and/or the addition of kinesthetic information increases the body tilt-induced bias when making GREL judgements. The introduction of motor/kinaesthetic cues may induce a switch from a semi-geocentric to a more egocentric frame of reference. This result challenges the assumption that combining non-conflicting multiple sensory inputs and/or using intermodal information provided during action should improve perceptual performance. PMID:14663543

  10. 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

  11. 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.

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

    SciTech Connect

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

    1990-05-03

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

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

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  14. A Robust, Gravity-Insensitive, High-Temperature Condenser for Water Recovery

    NASA Technical Reports Server (NTRS)

    Chen, Weibo; Conboy, Thomas; Ewert, Michael

    2016-01-01

    Regenerative life support systems are vital for NASA's future long-duration human space exploration missions. A Heat Melt Compactor (HMC) system is being developed by NASA to dry and compress trash generated during space missions. The resulting water vapor is recovered and separated from the process gas flow by a gravity-insensitive condenser. Creare is developing a high-temperature condenser for this application. The entire condenser is constructed from metals that have excellent resistance to chemical attack from contaminants and is suitable for high-temperature operation. The metal construction and design configuration also offer greatest flexibility for potential coating and regeneration processes to reduce biofilm growth and thus enhancing the reliability of the condenser. The proposed condenser builds on the gravity-insensitive phase separator technology Creare developed for aircraft and spacecraft applications. This paper will first discuss the design requirements for the condenser in an HMC system that will be demonstrated on the International Space Station (ISS). Then, it will present the overall design of the condenser and the preliminary thermal test results of a subscale condenser. Finally, this paper will discuss the predicted performance of the full-size condenser and the development plan to mature the technology and enhance its long-term reliability for a flight system.

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

    SciTech Connect

    Mohanty, M.K.; Samal, A.R.; Palit, A.

    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.

  16. Physics of Artificial Gravity

    NASA Technical Reports Server (NTRS)

    Bukley, Angie; Paloski, William; Clement, Gilles

    2006-01-01

    This chapter discusses potential technologies for achieving artificial gravity in a space vehicle. We begin with a series of definitions and a general description of the rotational dynamics behind the forces ultimately exerted on the human body during centrifugation, such as gravity level, gravity gradient, and Coriolis force. Human factors considerations and comfort limits associated with a rotating environment are then discussed. Finally, engineering options for designing space vehicles with artificial gravity are presented.

  17. 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.

  18. Application of the spherical harmonic gravity model in high precision inertial navigation systems

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Yang, Gongliu; Li, Xiangyun; Zhou, Xiao

    2016-09-01

    The spherical harmonic gravity model (SHM) may, in general, be considered as a suitable alternative to the normal gravity model (NGM), because it represents the Earth’s gravitational field more accurately. However, the high-resolution SHM has never been used in current inertial navigation systems (INSs) due to its extremely complex expression. In this paper, the feasibility and accuracy of a truncated SHM are discussed for application in a real-time free-INS with a precision demand better than 0.8 nm h‑1. In particular, the time and space complexity are analyzed mathematically to verify the feasibility of the SHM. Also, a test on a typical navigation computer shows a storable range of cut-off degrees. To further evaluate the appropriate degree and accuracy of the truncated SHM, analyses of covariance and truncation error are proposed. Finally, a SHM of degree 12 is demonstrated to be the appropriate model for routine INSs in the precision range of 0.4–0.75 nm h‑1. Flight simulations and road tests show its outstanding performance over the traditional NGM.

  19. 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 μ 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

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

    PubMed

    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 μ 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

  1. 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.

  2. 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…

  3. Parallel Processing at the High School Level.

    ERIC Educational Resources Information Center

    Sheary, Kathryn Anne

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

  4. High-resolution combined global gravity field modelling: Solving large kite systems using distributed computational algorithms

    NASA Astrophysics Data System (ADS)

    Zingerle, Philipp; Fecher, Thomas; Pail, Roland; Gruber, Thomas

    2016-04-01

    One of the major obstacles in modern global gravity field modelling is the seamless combination of lower degree inhomogeneous gravity field observations (e.g. data from satellite missions) with (very) high degree homogeneous information (e.g. gridded and reduced gravity anomalies, beyond d/o 1000). Actual approaches mostly combine such data only on the basis of the coefficients, meaning that previously for both observation classes (resp. models) a spherical harmonic analysis is done independently, solving dense normal equations (NEQ) for the inhomogeneous model and block-diagonal NEQs for the homogeneous. Obviously those methods are unable to identify or eliminate effects as spectral leakage due to band limitations of the models and non-orthogonality of the spherical harmonic base functions. To antagonize such problems a combination of both models on NEQ-basis is desirable. Theoretically this can be achieved using NEQ-stacking. Because of the higher maximum degree of the homogeneous model a reordering of the coefficient is needed which leads inevitably to the destruction of the block diagonal structure of the appropriate NEQ-matrix and therefore also to the destruction of simple sparsity. Hence, a special coefficient ordering is needed to create some new favorable sparsity pattern leading to a later efficient computational solving method. Such pattern can be found in the so called kite-structure (Bosch, 1993), achieving when applying the kite-ordering to the stacked NEQ-matrix. In a first step it is shown what is needed to attain the kite-(NEQ)system, how to solve it efficiently and also how to calculate the appropriate variance information from it. Further, because of the massive computational workload when operating on large kite-systems (theoretically possible up to about max. d/o 100.000), the main emphasis is put on to the presentation of special distributed algorithms which may solve those systems parallel on an indeterminate number of processes and are

  5. 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.

  6. 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.

  7. 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.

    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.

  8. Terrestrial Gravity Fluctuations

    NASA Astrophysics Data System (ADS)

    Harms, Jan

    2015-12-01

    Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10^-23 Hz^-1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. 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

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

    PubMed

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

    2009-09-01

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

  10. 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

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

    PubMed

    Bojados, Mickael; Jamon, Marc

    2014-05-01

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

  12. Very high gravity ethanol and fatty acid production of Zymomonas mobilis without amino acid and vitamin.

    PubMed

    Wang, Haoyong; Cao, Shangzhi; Wang, William Tianshuo; Wang, Kaven Tianyv; Jia, Xianhui

    2016-06-01

    Very high gravity (VHG) fermentation is the mainstream technology in ethanol industry, which requires the strains be resistant to multiple stresses such as high glucose concentration, high ethanol concentration, high temperature and harsh acidic conditions. To our knowledge, it was not reported previously that any ethanol-producing microbe showed a high performance in VHG fermentations without amino acid and vitamin. Here we demonstrate the engineering of a xylose utilizing recombinant Zymomonas mobilis for VHG ethanol fermentations. The recombinant strain can produce ethanol up to 136 g/L without amino acid and vitamin with a theoretical yield of 90 %, which is significantly superior to that produced by all the reported ethanol-producing strains. The intracellular fatty acids of the bacterial were about 16 % of the bacterial dry biomass, with the ratio of ethanol:fatty acids was about 273:1 (g/g). The recombinant strain was achieved by a multivariate-modular strategy tackles with the multiple stresses which are closely linked to the ethanol productivity of Z. mobilis. The over-expression of metB/yfdZ operon enabled the growth of the recombinant Z. mobilis in a chemically defined medium without amino acid and vitamin; and the fatty acids overproduction significantly increased ethanol tolerance and ethanol production. The coupled production of ethanol with fatty acids of the Z. mobilis without amino acid and vitamin under VHG fermentation conditions may permit a significant reduction of the production cost of ethanol and microbial fatty acids. PMID:27033536

  13. Future high sea levels in south Sweden

    SciTech Connect

    Blomgren, S.H.; Hanson, H.

    1997-12-31

    An estimation of future mean high water levels in Oeresund and the southwest Baltic Sea is presented together with a discussion of probable consequences for Falsterbo Peninsula, a trumpet-shaped sandy formation of some 25 km{sup 2} size situated in the very southwest corner of Sweden. A literature review coupled with sea-level measurements and observations made in the area every four hours since October 1945 are given and comprise the base for the present analysis.

  14. 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.

  15. High-level waste processing and disposal

    NASA Astrophysics Data System (ADS)

    Crandall, J. L.; Drause, H.; Sombret, C.; Uematsu, K.

    The national high level waste disposal plans for France, the Federal Republic of Germany, Japan, and the United States are covered. Three conclusions are reached. The first conclusion is that an excellent technology already exists for high level waste disposal. With appropriate packaging, spent fuel seems to be an acceptable waste form. Borosilicate glass reprocessing waste forms are well understood, in production in France, and scheduled for production in the next few years in a number of other countries. For final disposal, a number of candidate geological repository sites have been identified and several demonstration sites opened. The second conclusion is that adequate financing and a legal basis for waste disposal are in place in most countries. Costs of high level waste disposal will probably and about 5 to 10% to the costs of nuclear electric power. Third conclusion is less optimistic.

  16. Comparison of various isostatic marine gravity disturbances

    NASA Astrophysics Data System (ADS)

    Tenzer, Robert; Bagherbandi, Mohammad; Sjöberg, Lars E.

    2015-08-01

    We present and compare four types of the isostatic gravity disturbances compiled at sea level over the world oceans and marginal seas. These isostatic gravity disturbances are computed by applying the Airy-Heiskanen (AH), Pratt-Hayford (PH) and Vening Meinesz-Moritz (VMM) isostatic models. In addition, we compute the complete crust-stripped (CCS) isostatic gravity disturbances which are defined based on a principle of minimizing their spatial correlation with the Moho geometry. We demonstrate that each applied compensation scheme yields a distinctive spatial pattern in the resulting isostatic marine gravity field. The AH isostatic gravity disturbances provide the smoothest gravity field (by means of their standard deviation). The AH and VMM isostatic gravity disturbances have very similar spatial patterns due to the fact that the same isostatic principle is applied in both these definitions expect for assuming a local (in the former) instead of a global (in the latter) compensation mechanism. The PH isostatic gravity disturbances are highly spatially correlated with the ocean-floor relief. The CCS isostatic gravity disturbances reveal a signature of the ocean-floor spreading characterized by an increasing density of the oceanic lithosphere with age.

  17. 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.

  18. 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

  19. 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

  20. Highly compact neutron stars in scalar-tensor theories of gravity: Spontaneous scalarization versus gravitational collapse

    NASA Astrophysics Data System (ADS)

    Mendes, Raissa F. P.; Ortiz, Néstor

    2016-06-01

    Scalar-tensor theories of gravity are extensions of general relativity (GR) including an extra, nonminimally coupled scalar degree of freedom. A wide class of these theories, albeit indistinguishable from GR in the weak field regime, predicts a radically different phenomenology for neutron stars, due to a nonperturbative, strong-field effect referred to as spontaneous scalarization. This effect is known to occur in theories where the effective linear coupling β0 between the scalar and matter fields is sufficiently negative, i.e. β0≲-4.35 , and has been strongly constrained by pulsar timing observations. In the test-field approximation, spontaneous scalarization manifests itself as a tachyonic-like instability. Recently, it was argued that, in theories where β0>0 , a similar instability would be triggered by sufficiently compact neutron stars obeying realistic equations of state. In this work we investigate the end state of this instability for some representative coupling functions with β0>0 . This is done both through an energy balance analysis of the existing equilibrium configurations, and by numerically determining the nonlinear Cauchy development of unstable initial data. We find that, contrary to the β0<0 case, the final state of the instability is highly sensitive to the details of the coupling function, varying from gravitational collapse to spontaneous scalarization. In particular, we show, for the first time, that spontaneous scalarization can happen in theories with β0>0 , which could give rise to novel astrophysical tests of the theory of gravity.

  1. Features of Propagation of the Acoustic-Gravity Waves Generated by High-Power Periodic Radiation

    NASA Astrophysics Data System (ADS)

    Chernogor, L. F.; Frolov, V. L.

    2013-09-01

    We present the results of the bandpass filtering of temporal variations of the Doppler frequency shift of radio signals from a vertical-sounding Doppler radar located near the city of Kharkov when the ionosphere was heated by high-power periodic (with 10 and 15-min periods) radiation from the Sura facility. The filtering was done in the ranges of periods that are close to the acoustic cutoff period and the Brunt—Väisälä period (4-6, 8-12, and 13-17 min). Oscillations with periods of 4-6 min and amplitudes of 50-100 mHz were not recorded in fact. Oscillations with periods of 8-12 and 13-17 min and amplitudes of 60-100 mHz were detected in almost all the sessions. In the former and the latter oscillations, the time of delay with respect to the heater switch-on was close to 100 min and about 40-50 min, respectively. These values correspond to group propagation velocities of about 160 and 320-400 m/s. The Doppler shift oscillations were caused by the acoustic-gravity waves which led to periodic variations in the electron number density with a relative amplitude of about 0.1-1.0%. It was demonstrated that the acoustic-gravity waves were not recorded when the effective power of the Sura facility was equal to 50 MW and they were confidently observed when the effective power was increased up to 130 MW. It is shown that the period of the wave processes was determined by the period of the heating-pause cycles, and the duration of the wave trains did not depend on the duration of the series of heating-pause cycles. The data suggest that the generation mechanism of recorded wave disturbances is different from the mechanism proposed in 1970-1990.

  2. High-frequency gravity waves and homogeneous ice nucleation in tropical tropopause layer cirrus

    NASA Astrophysics Data System (ADS)

    Jensen, Eric J.; Ueyama, Rei; Pfister, Leonhard; Bui, Theopaul V.; Alexander, M. Joan; Podglajen, Aurélien; Hertzog, Albert; Woods, Sarah; Lawson, R. Paul; Kim, Ji-Eun; Schoeberl, Mark R.

    2016-06-01

    The impact of high-frequency gravity waves on homogeneous-freezing ice nucleation in cold cirrus clouds is examined using parcel model simulations driven by superpressure balloon measurements of temperature variability experienced by air parcels in the tropical tropopause region. We find that the primary influence of high-frequency waves is to generate rapid cooling events that drive production of numerous ice crystals. Quenching of ice nucleation events by temperature tendency reversal in the highest-frequency waves does occasionally produce low ice concentrations, but the overall impact of high-frequency waves is to increase the occurrence of high ice concentrations. The simulated ice concentrations are considerably higher than indicated by in situ measurements of cirrus in the tropical tropopause region. One-dimensional simulations suggest that although sedimentation reduces mean ice concentrations, a discrepancy of about a factor of 3 with observed ice concentrations remains. Reconciliation of numerical simulations with the observed ice concentrations will require inclusion of physical processes such as heterogeneous nucleation and entrainment.

  3. High degree gravitational sensitivity from Mars orbiters for the GMM-1 gravity model

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Smith, D. E.; Chan, J. C.; Patel, G. B.; Chinn, D. S.

    1994-01-01

    Orbital sensitivity of the gravity field for high degree terms (greater than 30) is analyzed on satellites employed in a Goddard Mars Model GMM-1, complete in spherical harmonics through degree and order 50. The model is obtained from S-band Doppler data on Mariner 9 (M9), Viking Orbiter 1 (VO1), and Viking Orbiter 2 (VO2) spacecraft, which were tracked by the NASA Deep Space Network on seven different highly eccentric orbits. The main sensitivity of the high degree terms is obtained from the VO1 and VO2 low orbits (300 km periapsis altitude), where significant spectral sensitivity is seen for all degrees out through degree 50. The velocity perturbations show a dominant effect at periapsis and significant effects out beyond the semi-latus rectum covering over 180 degrees of the orbital groundtrack for the low altitude orbits. Because of the wideband of periapsis motion covering nearly 180 degrees in w and +39 degrees in latitude coverage, the VO1 300 km periapsis altitude orbit with inclination of 39 degrees gave the dominant sensitivity in the GMM-1 solution for the high degree terms. Although the VO2 low periapsis orbit has a smaller band of periapsis mapping coverage, it strongly complements the VO1 orbit sensitivity for the GMM-1 solution with Doppler tracking coverage over a different inclination of 80 degrees.

  4. High-altitude gravity waves in the Martian thermosphere observed by MAVEN/NGIMS and modeled by a gravity wave scheme

    NASA Astrophysics Data System (ADS)

    Yiǧit, Erdal; England, Scott L.; Liu, Guiping; Medvedev, Alexander S.; Mahaffy, Paul R.; Kuroda, Takeshi; Jakosky, Bruce M.

    2015-11-01

    First high-altitude observations of gravity wave (GW)-induced CO2 density perturbations in the Martian thermosphere retrieved from NASA's Neutral Gas Ion Mass Spectrometer (NGIMS) instrument on board the Mars Atmosphere Volatile EvolutioN (MAVEN) satellite are presented and interpreted using the extended GW parameterization of Yiğit et al. (2008) and the Mars Climate Database as an input. Observed relative density perturbations between 180 and 220 km of 20-40% demonstrate appreciable local time, latitude, and altitude variations. Modeling for the spatiotemporal conditions of the MAVEN observations suggests that GWs can directly propagate from the lower atmosphere to the thermosphere, produce appreciable dynamical effects, and likely contribute to the observed fluctuations. Modeled effects are somewhat smaller than the observed, but their highly variable nature is in qualitative agreement with observations. Possible reasons for discrepancies between modeling and measurements are discussed.

  5. On the Importance of High Frequency Gravity Waves for Ice Nucleation in the Tropical Tropopause Layer

    NASA Technical Reports Server (NTRS)

    Jensen, Eric J.

    2016-01-01

    Recent investigations of the influence of atmospheric waves on ice nucleation in cirrus have identified a number of key processes and sensitivities: (1) ice concentrations produced by homogeneous freezing are strongly dependent on cooling rates, with gravity waves dominating upper tropospheric cooling rates; (2) rapid cooling driven by high-frequency waves are likely responsible for the rare occurrences of very high ice concentrations in cirrus; (3) sedimentation and entrainment tend to decrease ice concentrations as cirrus age; and (4) in some situations, changes in temperature tendency driven by high-frequency waves can quench ice nucleation events and limit ice concentrations. Here we use parcel-model simulations of ice nucleation driven by long-duration, constant-pressure balloon temperature time series, along with an extensive dataset of cold cirrus microphysical properties from the recent ATTREX high-altitude aircraft campaign, to statistically examine the importance of high-frequency waves as well as the consistency between our theoretical understanding of ice nucleation and observed ice concentrations. The parcel-model simulations indicate common occurrence of peak ice concentrations exceeding several hundred per liter. Sedimentation and entrainment would reduce ice concentrations as clouds age, but 1-D simulations using a wave parameterization (which underestimates rapid cooling events) still produce ice concentrations higher than indicated by observations. We find that quenching of nucleation events by high-frequency waves occurs infrequently and does not prevent occurrences of large ice concentrations in parcel simulations of homogeneous freezing. In fact, the high-frequency variability in the balloon temperature data is entirely responsible for production of these high ice concentrations in the simulations.

  6. High-level radioactive wastes. Supplement 1

    SciTech Connect

    McLaren, L.H.

    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.

  7. PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW)

    SciTech Connect

    CERTA, P.J.

    2006-02-22

    The primary objective of this study is to demonstrate a mission scenario that uses pairwise and incidental blending of high level waste (HLW) to reduce the total mass of HLW glass. Secondary objectives include understanding how recent refinements to the tank waste inventory and solubility assumptions affect the mass of HLW glass and how logistical constraints may affect the efficacy of HLW blending.

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

    SciTech Connect

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

    1987-12-31

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

  9. 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.

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

    NASA Technical Reports Server (NTRS)

    Watkins, M.; Bettadpur, S.

    2000-01-01

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

  11. Chiral gravity, log gravity, and extremal CFT

    SciTech Connect

    Maloney, Alexander; Song Wei; Strominger, Andrew

    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.

  12. The energetics and mechanics of level and gradient skipping: Preliminary results for a potential gait of choice in low gravity environments.

    NASA Astrophysics Data System (ADS)

    Minetti, Alberto E.; Pavei, Gaspare; Biancardi, Carlo M.

    2012-12-01

    Walking and running in low gravity cannot be used at useful speeds, while 'skipping', a gait displayed by kids and spontaneously adopted by astronauts of Apollo missions, proved to have the potential to become the gait of choice in that condition. In this paper the previous biomechanical and metabolic analysis of level skipping is extended to positive and negative gradients, in normal gravity. The results confirm at all gradients the higher (average) ground reaction force during the contact phase, with respect to running at the same speed, which would allow confidently facing the Lunar surface where the dust and regoliths affect, in addition to a lower gravity, the locomotion dynamics. Metabolic data, other gait variables related to the mechanical work done and the locomotor/respiratory coupling have also been investigated.

  13. The CMS High-Level Trigger

    SciTech Connect

    Covarelli, R.

    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.

  14. Plants tolerant of high boron levels.

    PubMed

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

    2007-11-30

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

  15. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    NASA Astrophysics Data System (ADS)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  16. 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.

  17. Experimental study of nucleate boiling heat transfer under low gravity conditions using TLCs for high resolution temperature measurements

    NASA Astrophysics Data System (ADS)

    Wagner, Enno; Sodtke, Christof; Schweizer, Nils; Stephan, Peter

    2006-08-01

    Heat transfer in nucleate boiling is strongly influenced by a very small circular area in the vicinity of the three phase contact line where a thin liquid film approaches the heated wall. This area is characterised by high evaporation rates which trigger a local temperature drop in the wall. The wall temperature drop can be computed using an existing nucleate boiling model. To verify the complex model and the underlying assumptions, an experiment was designed with an artificial nucleation site in a thin electrically heated wall featuring a two-dimensional, high resolution temperature measurement technique using unencapsulated thermochromic liquid crystals and a high speed colour camera. The shape of the bubble is observed simultaneously with a second high speed camera. Experiments were conducted in a low gravity environment of a parabolic flight, causing larger bubble departure diameters than in normal gravity environments. Thus, it was possible to measure the evolution of the predicted temperature drop in a transient boiling process.

  18. High level intelligent control of telerobotics systems

    NASA Technical Reports Server (NTRS)

    Mckee, James

    1988-01-01

    A high level robot command language is proposed for the autonomous mode of an advanced telerobotics system and a predictive display mechanism for the teleoperational model. It is believed that any such system will involve some mixture of these two modes, since, although artificial intelligence can facilitate significant autonomy, a system that can resort to teleoperation will always have the advantage. The high level command language will allow humans to give the robot instructions in a very natural manner. The robot will then analyze these instructions to infer meaning so that is can translate the task into lower level executable primitives. If, however, the robot is unable to perform the task autonomously, it will switch to the teleoperational mode. The time delay between control movement and actual robot movement has always been a problem in teleoperations. The remote operator may not actually see (via a monitor) the results of high actions for several seconds. A computer generated predictive display system is proposed whereby the operator can see a real-time model of the robot's environment and the delayed video picture on the monitor at the same time.

  19. Analysis of the influence of coupled diffusion on transport in protein crystal growth for different gravity levels.

    PubMed

    Castagnolo, D; Vergara, A; Paduano, L; Sartorio, R; Annunziata, O

    2002-10-01

    Diffusion has a central role in protein crystal growth both in microgravity conditions and on ground. Recently several reports have been focused on the importance to use the generalized Fick's equations in n-component systems where crystals grow. In these equations the total flux of each component is produced by the own concentration gradient (main flow) and by the concentration gradient of the other components (cross-flow) present in the system. However in literature the latter effect is often neglected, and the so-called pseudo-binary approximation is used. Lin et al. (1995) proposed a mathematical model to evaluate the concentration profile of the species present around a growing protein crystal. Although the model is reliable, it suffers of the pseudo-binary approximation (neglecting cross term diffusion coefficients and using binary diffusion coefficients), probably because of the lack of multicomponent diffusion data. The present model is based on the experimental set-up proposed by Lin et al. (1995). Nevertheless we have included the coupled diffusion effects, according to the correct description of the matter transport through the generalized Fick's equations. The crystal growth rate is calculated for different gravity levels. The model has been applied to the ternary lysozyme-NaCl-water and quaternary lysozyme-poly(ethylene glycol) (PEG)-NaCl-water systems using recent diffusion data. PMID:12351876

  20. 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.

  1. Performance of the CMS High Level Trigger

    NASA Astrophysics Data System (ADS)

    Perrotta, Andrea

    2015-12-01

    The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved tracking and vertexing algorithms, discussing their impact on the b-tagging performance as well as on the jet and missing energy reconstruction.

  2. 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.

  3. Accelerated carbonation of steelmaking slags in a high-gravity rotating packed bed.

    PubMed

    Chang, E-E; Pan, Shu-Yuan; Chen, Yi-Hung; Tan, Chung-Sung; Chiang, Pen-Chi

    2012-08-15

    Carbon dioxide (CO(2)) sequestration using the accelerated carbonation of basic oxygen furnace (BOF) slag in a high-gravity rotating packed bed (RPB) under various operational conditions was investigated. The effects of reaction time, reaction temperature, rotation speed and slurry flow rate on the CO(2) sequestration process were evaluated. The samples of reacted slurry were analyzed quantitatively using thermogravimetric analysis (TGA) and atomic absorption spectrometry (AAS) and qualitatively using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and transmission electron microscopy (TEM). The sequestration experiments were performed at a liquid-to-solid ratio of 20:1 with a flow rate of 2.5 L min(-1) of a pure CO(2) stream under atmospheric temperature and pressure. The results show that a maximum conversion of BOF slag was 93.5% at a reaction time of 30 min and a rotation speed of 750 rpm at 65°C. The experimental data were utilized to determine the rate-limiting mechanism based on the shrinking core model (SCM), which was validated by the observations of SEM and TEM. Accelerated carbonation in a RPB was confirmed to be a viable method due to its higher mass-transfer rate. PMID:22633879

  4. 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.

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

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd W.

    2012-01-01

    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 approx.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 gamma-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 approx. 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. I will also discuss how the LIV formalism casts doubt on the OPERA superluminal neutrino claim.

  6. Investigating why recycling gravity harvested algae increases harvestability and productivity in high rate algal ponds.

    PubMed

    Park, J B K; Craggs, R J; Shilton, A N

    2013-09-15

    It has previously been shown that recycling gravity harvested algae promotes Pediastrum boryanum dominance and improves harvestability and biomass production in pilot-scale High Rate Algal Ponds (HRAPs) treating domestic wastewater. In order to confirm the reproducibility of these findings and investigate the mechanisms responsible, this study utilized twelve 20 L outdoor HRAP mesocosms operated with and without algal recycling. It then compared the recycling of separated solid and liquid components of the harvested biomass against un-separated biomass. The work confirmed that algal recycling promoted P. boryanum dominance, improved 1 h-settleability by >20% and increased biomass productivity by >25% compared with controls that had no recycling. With regard to the improved harvestability, of particular interest was that recycling the liquid fraction alone caused a similar improvement in settleability as recycling the solid fraction. This may be due to the presence of extracellular polymeric substances in the liquid fraction. While there are many possible mechanisms that could account for the increased productivity with algal recycling, all but two were systematically eliminated: (i) the mean cell residence time was extended thereby increasing the algal concentration and more fully utilizing the incident sunlight and, (ii) the relative proportions of algal growth stages (which have different specific growth rates) was changed, resulting in a net increase in the overall growth rate of the culture. PMID:23866138

  7. Martian atmospheric gravity waves simulated by a high-resolution general circulation model

    NASA Astrophysics Data System (ADS)

    Kuroda, Takeshi; Yiǧit, Erdal; Medvedev, Alexander S.; Hartogh, Paul

    2016-07-01

    Gravity waves (GWs) significantly affect temperature and wind fields in the Martian middle and upper atmosphere. They are also one of the observational targets of the MAVEN mission. We report on the first simulations with a high-resolution general circulation model (GCM) and present a global distributions of small-scale GWs in the Martian atmosphere. The simulated GW-induced temperature variances are in a good agreement with available radio occultation data in the lower atmosphere between 10 and 30 km. For the northern winter solstice, the model reveals a latitudinal asymmetry with stronger wave generation in the winter hemisphere and two distinctive sources of GWs: mountainous regions and the meandering winter polar jet. Orographic GWs are filtered upon propagating upward, and the mesosphere is primarily dominated by harmonics with faster horizontal phase velocities. Wave fluxes are directed mainly against the local wind. GW dissipation in the upper mesosphere generates a body force per unit mass of tens of m s^{-1} per Martian solar day (sol^{-1}), which tends to close the simulated jets. The results represent a realistic surrogate for missing observations, which can be used for constraining GW parameterizations and validating GCMs.

  8. Pt-catalyzed ozonation of aqueous phenol solution using high-gravity rotating packed bed.

    PubMed

    Chang, Chia-Chi; Chiu, Chun-Yu; Chang, Ching-Yuan; Chang, Chiung-Fen; Chen, Yi-Hung; Ji, Dar-Ren; Tseng, Jyi-Yeong; Yu, Yue-Hwa

    2009-09-15

    In this study, a high-gravity rotating packed bed (HGRPB or HG) was used as a catalytic ozonation (Cat-OZ) reactor to decompose phenol. The operation of HGRPB system was carried out in a semi-batch apparatus which combines two major parts, namely the rotating packed bed (RPB) and photo-reactor (PR). The high rotating speed of RPB can give a high volumetric gas-liquid mass transfer coefficient with one or two orders of magnitude higher than those in the conventional packed beds. The platinum-containing catalyst (Dash 220N, Pt/gamma-Al(2)O(3)) and activated alumina (gamma-Al(2)O(3)) were packed in the RPB respectively to adsorb molecular ozone and the target pollutant of phenol on the surface to catalyze the oxidation of phenol. An ultra violet (UV) lamp (applicable wavelength lambda=200-280 nm) was installed in the PR to enhance the self-decomposition of molecular ozone in water to form high reactive radical species. Different combinations of advanced oxidation processes (AOPs) with the HGRPB for the degradation of phenol were tested. These included high-gravity OZ (HG-OZ), HG catalytic OZ (HG-Cat-OZ), HG photolysis OZ (HG-UV-OZ) and HG-Cat-OZ with UV (HG-Cat-UV-OZ). The decomposition efficiency of total organic compound (eta(TOC)) of HG-UV-OZ with power of UV (P(UV)) of 16W is 54% at applied dosage of ozone per volume sample m(A,in)=1200 mg L(-1) (reaction time t=20 min), while that of HG-OZ without the UV irradiation is 24%. After 80 min oxidation (m(A,in)=4800 mg L(-1)), the eta(TOC) of HG-UV-OZ is as high as 94% compared to 82% of HG-OZ process. The values of eta(TOC) for HG-Cat-OZ process with m(S)=42 g are 56% and 87% at m(A,in)=1200 and 4800 mg L(-1), respectively. By increasing the catalyst mass to 77 g, the eta(TOC) for the HG-Cat-OZ process reaches 71% and 90% at m(A,in)=1200 and 4800 mg L(-1), respectively. The introduction of Pt/gamma-Al(2)O(3) as well as UV irradiation in the HG-OZ process can enhance the eta(TOC) of phenol significantly, while gamma

  9. GRAIL gravity field determination using the Celestial Mechanics Approach

    NASA Astrophysics Data System (ADS)

    Arnold, Daniel; Bertone, Stefano; Jäggi, Adrian; Beutler, Gerhard; Mervart, Leos

    2015-11-01

    The NASA mission GRAIL (Gravity Recovery and Interior Laboratory) inherited its concept from the GRACE (Gravity Recovery and Climate Experiment) mission to determine the gravity field of the Moon. We present lunar gravity fields based on the data of GRAIL's primary mission phase. Gravity field recovery is realized in the framework of the Celestial Mechanics Approach, using a development version of the Bernese GNSS Software along with Ka-band range-rate data series as observations and the GNI1B positions provided by NASA JPL as pseudo-observations. By comparing our results with the official level-2 GRAIL gravity field models we show that the lunar gravity field can be recovered with a high quality by adapting the Celestial Mechanics Approach, even when using pre-GRAIL gravity field models as a priori fields and when replacing sophisticated models of non-gravitational accelerations by appropriately spaced pseudo-stochastic pulses (i.e., instantaneous velocity changes). We present and evaluate two lunar gravity field solutions up to degree and order 200 - AIUB-GRL200A and AIUB-GRL200B. While the first solution uses no gravity field information beyond degree 200, the second is obtained by using the official GRAIL field GRGM900C up to degree and order 660 as a priori information. This reduces the omission errors and demonstrates the potential quality of our solution if we resolved the gravity field to higher degree.

  10. 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

  11. EAP high-level product architecture

    NASA Astrophysics Data System (ADS)

    Gudlaugsson, T. V.; Mortensen, N. H.; Sarban, R.

    2013-04-01

    EAP technology has the potential to be used in a wide range of applications. This poses the challenge to the EAP component manufacturers to develop components for a wide variety of products. Danfoss Polypower A/S is developing an EAP technology platform, which can form the basis for a variety of EAP technology products while keeping complexity under control. High level product architecture has been developed for the mechanical part of EAP transducers, as the foundation for platform development. A generic description of an EAP transducer forms the core of the high level product architecture. This description breaks down the EAP transducer into organs that perform the functions that may be present in an EAP transducer. A physical instance of an EAP transducer contains a combination of the organs needed to fulfill the task of actuator, sensor, and generation. Alternative principles for each organ allow the function of the EAP transducers to be changed, by basing the EAP transducers on a different combination of organ alternatives. A model providing an overview of the high level product architecture has been developed to support daily development and cooperation across development teams. The platform approach has resulted in the first version of an EAP technology platform, on which multiple EAP products can be based. The contents of the platform have been the result of multi-disciplinary development work at Danfoss PolyPower, as well as collaboration with potential customers and research institutions. Initial results from applying the platform on demonstrator design for potential applications are promising. The scope of the article does not include technical details.

  12. The high-level trigger of ALICE

    NASA Astrophysics Data System (ADS)

    Tilsner, H.; Alt, T.; Aurbakken, K.; Grastveit, G.; Helstrup, H.; Lindenstruth, V.; Loizides, C.; Nystrand, J.; Roehrich, D.; Skaali, B.; Steinbeck, T.; Ullaland, K.; Vestbo, A.; Vik, T.

    One of the main tracking detectors of the forthcoming ALICE Experiment at the LHC is a cylindrical Time Projection Chamber (TPC) with an expected data volume of about 75 MByte per event. This data volume, in combination with the presumed maximum bandwidth of 1.2 GByte/s to the mass storage system, would limit the maximum event rate to 20 Hz. In order to achieve higher event rates, online data processing has to be applied. This implies either the detection and read-out of only those events which contain interesting physical signatures or an efficient compression of the data by modeling techniques. In order to cope with the anticipated data rate, massive parallel computing power is required. It will be provided in form of a clustered farm of SMP-nodes, based on off-the-shelf PCs, which are connected with a high bandwidth low overhead network. This High-Level Trigger (HLT) will be able to process a data rate of 25 GByte/s online. The front-end electronics of the individual sub-detectors is connected to the HLT via an optical link and a custom PCI card which is mounted in the clustered PCs. The PCI card is equipped with an FPGA necessary for the implementation of the PCI-bus protocol. Therefore, this FPGA can also be used to assist the host processor with first-level processing. The first-level processing done on the FPGA includes conventional cluster-finding for low multiplicity events and local track finding based on the Hough Transformation of the raw data for high multiplicity events. PACS: 07.05.-t Computers in experimental physics - 07.05.Hd Data acquisition: hardware and software - 29.85.+c Computer data analysis

  13. Regulation of high density lipoprotein levels

    SciTech Connect

    Krauss, R.M.

    1982-03-01

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

  14. The effects of high level infrasound

    SciTech Connect

    Johnson, D.L.

    1980-02-01

    This paper will attempt to survey the current knowledge on the effects of relative high levels of infrasound on humans. While this conference is concerned mainly about hearing, some discussion of other physiological effects is appropriate. Such discussion also serves to highlight a basic question, 'Is hearing the main concern of infrasound and low frequency exposure, or is there a more sensitive mechanism'. It would be comforting to know that the focal point of this conference is indeed the most important concern. Therefore, besides hearing loss and auditory threshold of infrasonic and low frequency exposure, four other effects will be provided. These are performance, respiration, annoyance, and vibration.

  15. High-level waste qualification: Managing uncertainty

    SciTech Connect

    Pulsipher, B.A.

    1993-09-01

    A vitrification facility is being developed by the U.S. Department of Energy (DOE) at the West Valley Demonstration Plant (WVDP) near Buffalo, New York, where approximately 300 canisters of high-level nuclear waste glass will be produced. To assure that the produced waste form is acceptable, uncertainty must be managed. Statistical issues arise due to sampling, waste variations, processing uncertainties, and analytical variations. This paper presents elements of a strategy to characterize and manage the uncertainties associated with demonstrating that an acceptable waste form product is achieved. Specific examples are provided within the context of statistical work performed by Pacific Northwest Laboratory (PNL).

  16. Service Oriented Architecture for High Level Applications

    SciTech Connect

    Chu, Chungming; Chevtsov, Sergei; Wu, Juhao; Shen, Guobao; /Brookhaven

    2012-06-28

    Standalone high level applications often suffer from poor performance and reliability due to lengthy initialization, heavy computation and rapid graphical update. Service-oriented architecture (SOA) is trying to separate the initialization and computation from applications and to distribute such work to various service providers. Heavy computation such as beam tracking will be done periodically on a dedicated server and data will be available to client applications at all time. Industrial standard service architecture can help to improve the performance, reliability and maintainability of the service. Robustness will also be improved by reducing the complexity of individual client applications.

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

    SciTech Connect

    Kifune, T.

    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 γ-rays supplies trustworthy observation data and we are now seeing the true image of the universe through high-energy γ-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 γ-ray detection is not free from the effect of quantum gravity when γ-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 γ-ray observations, as well as on the radiation and propagation mechanism of γ-rays under the influence of the LIV effect.

  18. The High Level Data Reduction Library

    NASA Astrophysics Data System (ADS)

    Ballester, P.; Gabasch, A.; Jung, Y.; Modigliani, A.; Taylor, J.; Coccato, L.; Freudling, W.; Neeser, M.; Marchetti, E.

    2015-09-01

    The European Southern Observatory (ESO) provides pipelines to reduce data for most of the instruments at its Very Large telescope (VLT). These pipelines are written as part of the development of VLT instruments, and are used both in the ESO's operational environment and by science users who receive VLT data. All the pipelines are highly specific geared toward instruments. However, experience showed that the independently developed pipelines include significant overlap, duplication and slight variations of similar algorithms. In order to reduce the cost of development, verification and maintenance of ESO pipelines, and at the same time improve the scientific quality of pipelines data products, ESO decided to develop a limited set of versatile high-level scientific functions that are to be used in all future pipelines. The routines are provided by the High-level Data Reduction Library (HDRL). To reach this goal, we first compare several candidate algorithms and verify them during a prototype phase using data sets from several instruments. Once the best algorithm and error model have been chosen, we start a design and implementation phase. The coding of HDRL is done in plain C and using the Common Pipeline Library (CPL) functionality. HDRL adopts consistent function naming conventions and a well defined API to minimise future maintenance costs, implements error propagation, uses pixel quality information, employs OpenMP to take advantage of multi-core processors, and is verified with extensive unit and regression tests. This poster describes the status of the project and the lesson learned during the development of reusable code implementing algorithms of high scientific quality.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  20. CMS High Level Trigger Timing Measurements

    NASA Astrophysics Data System (ADS)

    Richardson, Clint

    2015-12-01

    The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  2. High accuracy electronic material level sensor

    DOEpatents

    McEwan, Thomas E.

    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%.

  3. 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.

  4. 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.

  5. 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.

  6. Sensorimotor aspects of high-speed artificial gravity: III. Sensorimotor adaptation

    NASA Technical Reports Server (NTRS)

    DiZio, Paul; Lackner, James R.; Young, L. R. (Principal Investigator)

    2002-01-01

    As a countermeasure to the debilitating physiological effects of weightlessness, astronauts could live continuously in an artificial gravity environment created by slow rotation of an entire spacecraft or be exposed to brief daily "doses" in a short radius centrifuge housed within a non-rotating spacecraft. A potential drawback to both approaches is that head movements made during rotation may be disorienting and nauseogenic. These side effects are more severe at higher rotation rates, especially upon first exposure. Head movements during rotation generate aberrant vestibular stimulation and Coriolis force perturbations of the head-neck motor system. This article reviews our progress toward distinguishing vestibular and motor factors in side effects of rotation, and presents new data concerning the rates of rotation up to which adaptation is possible. We have studied subjects pointing to targets during constant velocity rotation, because these movements generate Coriolis motor perturbations of the arm but do not involve unusual vestibular stimulation. Initially, reaching paths and endpoints are deviated in the direction of the transient lateral Coriolis forces generated. With practice, subjects soon move in straighter paths and land on target once more. If sight of the arm is permitted, adaptation is more rapid than in darkness. Initial arm movement trajectory and endpoint deviations are proportional to Coriolis force magnitude over a range of rotation speeds from 5 to 20 rpm, and there is rapid, complete motor adaptation at all speeds. These new results indicate that motor adaptation to high rotation rates is possible. Coriolis force perturbations of head movements also occur in a rotating environment but adaptation gradually develops over the course of many head movements.

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

    SciTech Connect

    Taylor, R.W.; Fromm, A.J. ); Okita, P. )

    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.

  8. 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.

  9. Visual high-level regions respond to high-level stimulus content in the absence of low-level confounds.

    PubMed

    Schindler, Andreas; Bartels, Andreas

    2016-05-15

    High-level regions of the ventral stream exhibit strong category selectivity to stimuli such as faces, houses, or objects. However, recent studies suggest that at least part of this selectivity stems from low-level differences inherent to images of the different categories. For example, visual outdoor and indoor scenes as well as houses differ in spatial frequency, rectilinearity and obliqueness when compared to face or object images. Correspondingly, scene responsive para-hippocampal place area (PPA) showed strong preference to low-level properties of visual scenes also in the absence of high-level scene content. This raises the question whether all high-level responses in PPA, the fusiform face area (FFA), or the object-responsive lateral occipital compex (LOC) may actually be explained by systematic differences in low-level features. In the present study we contrasted two classes of simple stimuli consisting of ten rectangles each. While both were matched in visual low-level features only one class of rectangle arrangements gave rise to a percept compatible with a high-level 3D layout such as a scene or an object. We found that areas PPA, transverse occipital sulcus (TOS, also referred to as occipital place area, OPA), as well as FFA and LOC showed robust responses to the visual scene class compared to the low-level matched control. Our results suggest that visual category responsive regions are not purely driven by low-level visual features but also by the high-level perceptual stimulus interpretation. PMID:26975552

  10. Beam size measurement at high radiation levels

    SciTech Connect

    Decker, F.J.

    1991-05-01

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

  11. 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.

  12. Will the level of seismic noise at Livingston Observatory interfere with the detection of gravity waves from binary inspirals?

    NASA Astrophysics Data System (ADS)

    Rizzi, Anthony

    2002-11-01

    A major impediment to gravity wave detection in interferometer detectors such as Laser Interferometer Gravitational Wave Observatory (LIGO) is nongravitational wave-induced motion of the test masses. All types of noise sources including environmental sources contribute to this problem. Seismic motion is a significant source of such motion. I introduce a method to quantify the contribution of a given noise source to motion that is most deleterious to gravity wave detection, e.g., motion that mimics gravity wave signatures. I define such a benchmark in two senses: A relative benchmark that quantifies the degree of intrinsic interference with the gravity wave detection and an absolute benchmark which incorporates scaling factors appropriate to a given experiment. To give statistical meaning to the method and to illustrate it, I benchmark Gaussian noise and seismic colored Gaussian noise; both benchmark at 0 false events/day, which, applying a simple statistical model, implies <1 event for even year-long data runs. Finally, the relative benchmark for seismic noise at the Livingston observatory is (for the band from approx100-400 Hz), using two 24 h data sets, 40-290 false events/day. Given the LIGO I noise curves, it is shown that the seismic noise should not interfere with the detection of binary inspiral generated gravity waves using optimal filtering. Its absolute benchmark is 0 false events/day, which, applying as above a simple statistical model, implies <1 event/year. In rough terms, if only Livingston seismic noise and gravity waves were impinging on the detector, one would expect to see neutron star binary inspiral's that occur anywhere in the universe.

  13. Gravity science investigation of Ceres from Dawn

    NASA Astrophysics Data System (ADS)

    Park, Ryan; Konopliv, Alexander; Bills, Bruce; Castillo-Rogez, Julie; Asmar, Sami; Rambaux, Nicolas; Raymond, Carol; Russell, Christopher; Zuber, Maria; Ermakov, Anton; King, Scott; Rayman, Marc

    2016-04-01

    The Dawn gravity science investigation utilizes the DSN radiometric tracking of the spacecraft and on-board framing camera images to determine the global shape and gravity field of Ceres. The gravity science data collected during Approach, Survey, and High-Altitude Mapping Orbit phases were processed. Currently, the latest gravity field called CERES08A is available, which is globally accurate to degree and order 5. Combining the gravity and shape data gives the bulk density of 2162.5±8 kg/m3. The low Bouguer gravity at high topography area, or vice versa, indicates that the surface of Ceres is likely compensated and that its interior presents a low-viscosity layer at depth. The degree 2 gravity harmonics show that the rotation of Ceres is very nearly about a principal axis. This consistent with hydrostatic equilibrium at 1% level, and infers a mean moment of inertia of Ceres is 0.36, implying some degree of central condensation. Based on a simple two-layer model of Ceres and assuming carbonaceous chondrites and hydrostatic equilibrium, the core size is expected to be ~280 km with corresponding average thickness of the outer shell of ~190 km.

  14. High-level connectionist models. Semiannual report

    SciTech Connect

    Pollack, J.B.

    1989-08-01

    The major achievement of this semiannum was the significant revision and extension of the Recursive Auto-Associative Memory (RAAM) work for publication in the journal Artificial Intelligence. Included as an appendix to this report, the article includes several new elements: (1) Background - The work was more clearly set into the area of recursive distributed representations, machine learning, and the adequacy of the connectionist approach for high-level cognitive modeling; (2) New Experiment - RAAM was applied to finding compact representations for sequences of letters; (3) Analysis - The developed representations were analyzed as features which range from categorical to distinctive. Categorical features distinguish between conceptual categories while distinctive features vary within categories and discriminate or label the members. The representations were also analyzed geometrically; and (4) Applications - Feasibility studies were performed and described on inference by association, and on using RAAM-generated patterns along with cascaded networks for natural language parsing. Both of these remain long-term goals of the project.

  15. Umbra's High Level Architecture (HLA) Interface

    SciTech Connect

    GOTTLIEB, ERIC JOSEPH; MCDONALD, MICHAEL J.; OPPEL III, FRED J.

    2002-04-01

    This report describes Umbra's High Level Architecture HLA library. This library serves as an interface to the Defense Simulation and Modeling Office's (DMSO) Run Time Infrastructure Next Generation Version 1.3 (RTI NG1.3) software library and enables Umbra-based models to be federated into HLA environments. The Umbra library was built to enable the modeling of robots for military and security system concept evaluation. A first application provides component technologies that ideally fit the US Army JPSD's Joint Virtual Battlespace (JVB) simulation framework for Objective Force concept analysis. In addition to describing the Umbra HLA library, the report describes general issues of integrating Umbra with RTI code and outlines ways of building models to support particular HLA simulation frameworks like the JVB.

  16. Airway injury during high-level exercise.

    PubMed

    Kippelen, Pascale; Anderson, Sandra D

    2012-05-01

    Airway epithelial cells act as a physical barrier against environmental toxins and injury, and modulate inflammation and the immune response. As such, maintenance of their integrity is critical. Evidence is accumulating to suggest that exercise can cause injury to the airway epithelium. This seems the case particularly for competitive athletes performing high-level exercise, or when exercise takes place in extreme environmental conditions such as in cold dry air or in polluted air. Dehydration of the small airways and increased forces exerted on to the airway surface during severe hyperpnoea are thought to be key factors in determining the occurrence of injury of the airway epithelium. The injury-repair process of the airway epithelium may contribute to the development of the bronchial hyper-responsiveness that is documented in many elite athletes. PMID:22247295

  17. 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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  19. Effects of gravity level during directional solidification on the microstructure of hypermonotectic Al-In-Sn alloys

    SciTech Connect

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

    1986-11-01

    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.

  20. Dynamics of three-level Λ-type atom interacting with one mode cavity field with both classical gravity and quantum radiation: Lie algebra approach

    NASA Astrophysics Data System (ADS)

    Abd El-Wahab, N. H.; Abdel Rady, A. S.; Osman, Abdel-Nasser A.; Salah, Ahmed

    2015-10-01

    In this paper, a model is introduced to investigate the interaction between a three-level atom and one-mode of the radiation field. The atomic motion and the classical homogenous gravitational field are taken into consideration. For this purpose, we first introduce a set of new atomic operators obeying an su(3) algebraic structure to derive an effective Hamiltonian for the system under consideration. By solving the Schrödinger equation in the interaction picture, the exact solution is given when the atom and the field are initially prepared in excited state and coherent state, respectively. The influences of the gravity parameter on the collapses-revivals phenomena, the atomic momentum diffusion, the Mandel Q-parameter, the normal squeezing phenomena and the coherent properties for the considered system are examined. It is found that the gravity parameter has important effects on the properties of these phenomena.

  1. 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

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

    SciTech Connect

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

    1990-06-01

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

  3. 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 ... that occur when a pebble is thrown into a still pond, such "gravity waves" sometimes appear when the relatively stable and stratified air ...

  4. HIGH LEVEL RF FOR THE SNS RING.

    SciTech Connect

    ZALTSMAN,A.; BLASKIEWICZ,M.; BRENNAN,J.; BRODOWSKI,J.; METH,M.; SPITZ,R.; SEVERINO,F.

    2002-06-03

    A high level RF system (HLRF) consisting of power amplifiers (PA's) and ferrite loaded cavities is being designed and built by Brookhaven National Laboratory (BNL) for the Spallation Neutron Source (SNS) project. It is a fixed frequency, two harmonic system whose main function is to maintain a gap for the kicker rise time. Three cavities running at the fundamental harmonic (h=l) will provide 40 kV and one cavity at the second harmonic (h=2) will provide 20 kV. Each cavity has two gaps with a design voltage of 10 kV per gap and will be driven by a power amplifier (PA) directly adjacent to it. The PA uses a 600kW tetrode to provide the necessary drive current. The anode of the tetrode is magnetically coupled to the downstream cell of the cavity. Drive to the PA will be provided by a wide band, solid state amplifier located remotely. A dynamic tuning scheme will be implemented to help compensate for the effect of beam loading.

  5. 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.

  6. On the facet-skeletal transition of snow crystals - Experiments in high and low gravity

    NASA Technical Reports Server (NTRS)

    Alena, T.; Hallett, J.; Saunders, C. P. R.

    1990-01-01

    A laboratory investigation of the influence of air velocity on the growth of columnar ice crystals from the vapor over the range -3 to -5 C shows that the linear growth velocity increases and that columns transform to sheath crystals or needles as air velocity increases from a few cm/s to 40 cm/s. Comparison with a similar transition of plates to dendrites shows that, macroscopically, in both cases the facets sprout rounded tips at a critical velocity which is lower for higher ambient supersaturation. Studies in low gravity show that chamber scale convection under normal gravity may have significant influence on growth even in the absence of an imposed air velocity. Falling snow crystals become more skeletal in shape as they grow and fall with increasing velocity. This development depends critically on temperature (+ or - 0.5 C) and demonstrates that the snow crystal shape is even more dependent on environmental growth conditions that previously thought.

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

    NASA Technical Reports Server (NTRS)

    Bristow, W. A.; Greenwald, R. A.

    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 the radar returns, using HF ray tracing through a model ionosphere perturbed by a model gravity wave. The simulation determined the return power in the ground-scattered portion of the signal as a function of range, and this was compared to HF radar data from the Goose Bay HF radar at a time when evidence of gravity waves was present in the data. By varying the amplitude of the electron density perturbation in the model it was possible to estimate the perturbation of the actual wave. It was found that the perturbations that are observed by the Goose Bay HF radar are of the order of 20% to 35%. It was also found that the number of observable power enhancements, and the relative amplitudes of these enhancements, depended on the vertical thickness of the gravity wave's source region. From the simulations and observations it was estimated that the source region for the case presented here was approximately 20 km thick. In addition, the energy in the wave packet was calculated and compared to an estimate of the available energy in the source region. It was found that the wave energy was about 0.2% of the estimated available source region energy.

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

    SciTech Connect

    Bristow, W.A.; Greenwald, R.A.

    1995-03-01

    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 the radar returns, using HF ray tracing through a model ionosphere perturbed by a model gravity wave. The simulation determined the return power in the ground-scattered portion of the signal as a function of range, and this was compared to HF radar data from the Goose Bay HF radar at a time when evidence of gravity waves was present in the data. By varying the amplitude of the electron density perturbation in the model it was possible to estimate the perturbation of the actual wave. It was found that the perturbations that are observed by the Goose Bay HF radar are of the order of 20% to 35%. It was also found that the number of observable power enhancements, and the relative amplitudes of these enhancements, depended on the vertical thickness of the gravity wave`s source region. From the simulations and observations it was estimated that the source region for the case presented here was approximately 20 km thick. In addition, the energy in the wave packet was calculated and compared to an estimate of the available energy in the source region. It was found that the wave energy was about 0.2% of the estimated available source region energy. 20 refs., 12 figs.

  9. Comparison of publically available Moho depth and crustal thickness grids with newly derived grids by 3D gravity inversion for the High Arctic region.

    NASA Astrophysics Data System (ADS)

    Lebedeva-Ivanova, Nina; Gaina, Carmen; Minakov, Alexander; Kashubin, Sergey

    2016-04-01

    We derived Moho depth and crustal thickness for the High Arctic region by 3D forward and inverse gravity modelling method in the spectral domain (Minakov et al. 2012) using lithosphere thermal gravity anomaly correction (Alvey et al., 2008); a vertical density variation for the sedimentary layer and lateral crustal variation density. Recently updated grids of bathymetry (Jakobsson et al., 2012), gravity anomaly (Gaina et al, 2011) and dynamic topography (Spasojevic & Gurnis, 2012) were used as input data for the algorithm. TeMAr sedimentary thickness grid (Petrov et al., 2013) was modified according to the most recently published seismic data, and was re-gridded and utilized as input data. Other input parameters for the algorithm were calibrated using seismic crustal scale profiles. The results are numerically compared with publically available grids of the Moho depth and crustal thickness for the High Arctic region (CRUST 1 and GEMMA global grids; the deep Arctic Ocean grids by Glebovsky et al., 2013) and seismic crustal scale profiles. The global grids provide coarser resolution of 0.5-1.0 geographic degrees and not focused on the High Arctic region. Our grids better capture all main features of the region and show smaller error in relation to the seismic crustal profiles compare to CRUST 1 and GEMMA grids. Results of 3D gravity modelling by Glebovsky et al. (2013) with separated geostructures approach show also good fit with seismic profiles; however these grids cover the deep part of the Arctic Ocean only. Alvey A, Gaina C, Kusznir NJ, Torsvik TH (2008). Integrated crustal thickness mapping and plate recon-structions for the high Arctic. Earth Planet Sci Lett 274:310-321. Gaina C, Werner SC, Saltus R, Maus S (2011). Circum-Arctic mapping project: new magnetic and gravity anomaly maps of the Arctic. Geol Soc Lond Mem 35, 39-48. Glebovsky V.Yu., Astafurova E.G., Chernykh A.A., Korneva M.A., Kaminsky V.D., Poselov V.A. (2013). Thickness of the Earth's crust in the

  10. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

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

    NASA Astrophysics Data System (ADS)

    Santos, O.

    2002-01-01

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

  12. 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

  13. 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.

  14. DEFENSE HIGH LEVEL WASTE GLASS DEGRADATION

    SciTech Connect

    W. Ebert

    2001-09-20

    The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to

  15. Fermilab tevatron high level RF accelerating systems

    SciTech Connect

    Kerns, Q.; Kerns, C.; Miller, H.; Reid, J.; Tawzer, S.; Webber, R.; Wildman, D.

    1985-10-01

    Eight tuned rf cavities have been installed and operated in the F0 straight section of the Tevatron. Their mechanical placement along the beam line enables them to be operated for colliding beams as two independent groups of four cavities, group 1-4 accelerating antiprotons and group 5-8 accelerating protons. The only difference is that the spacing between cavities 4 and 5 was increased to stay clear of the F0 colliding point. The cavities can easily be rephased by switching cables in a low-level distribution system (fan-out) so that the full accelerating capability of all eight cavities can be used during fixed target operations. Likewise, the cables from capacitive probes on each cavity gap can be switched to proper lengths and summed in a fan-back system to give an rf signal representing the amplitude and phase as ''seen by the beam,'' separately for protons and antiprotons. Such signals have been used to phase lock the Tevatron to the Main Ring for synchronous transfer. A cavity consists of two quarter-wave resonators placed back to back with a coaxial drift tube separating the two accelerating gaps by ..pi.. radians. The cavities are very similar to the prototype which has been previously described/sup 3/ and is operating as Station 8 in the Tevatron. Only additional water cooling around the high current region of the drift tube supports and a double loop used to monitor the unbalance current through the Hipernom mode damping resistor have been added. Each cavity has a Q of about7100, a shunt impedance of 1.2 M..cap omega.., and is capable of running cw with a peak accelerating voltage of 360

  16. The effects of winds and atmospheric structure on long-range gravity wave propagation at high latitudes

    NASA Astrophysics Data System (ADS)

    Heale, C. J.; Snively, J. B.; Hickey, M. P.

    2013-12-01

    Recent studies of waves over Halley, Antarctica by Nielsen et al. [JASTP, 71,8 2009; JGR, 117, D5, 2012] suggest that gravity waves at high latitude sites are less likely to exhibit narrow ducting in the mesosphere and lower thermosphere (MLT) region than at mid-to-low latitude sites, and thus may be less likely to travel large horizontal distances. These studies estimate that 82% of the wave events are freely propagating (not ducted), when compared to ~25% in some mid/low-latitude studies [Isler et al., JGR, 102, D22, 1997]. This is due to relatively weak meridional winds at high latitudes, which are typically not strong enough to provide a Doppler ducted environment. However, thermal reflection of gravity waves may still occur in the lower thermosphere, which may lead to deep non-ideal thermal ducting between the thermosphere and ground, providing another mechanism for long range propagation that would not necessarily be identifiable in measurements at OH airglow heights. In general, the horizontal propagation of gravity waves is highly dependent on the wave parameters and background atmosphere/wind structure. This complex interaction will determine dissipation processes, propagation trajectories, packet spatial extents and spectral evolutions, among other things. We use a 2D, nonlinear, compressible model [e.g., Snively et al., JGR, 113, A06303, 2008] to study specific cases of long-range propagation of atmospheric gravity waves in high-latitude atmospheric conditions, and a 1D steady-state compressible full-wave model [e.g., Hickey et al., JGR, 102, A6 1997] to study effects of varying atmospheric parameters. We investigate possible conditions which are (or are not) conducive to sustained propagation via reflections, and how these conditions may vary in space or time. Background temperature and wind structure are specified to represent profiles over Halley, Antarctica, in order to compare with observations at the same location and to assess the effects of

  17. 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.

  18. High-Gravity Carbonation Process for Enhancing CO2 Fixation and Utilization Exemplified by the Steelmaking Industry.

    PubMed

    Pan, Shu-Yuan; Chen, Yi-Hung; Chen, Chun-Da; Shen, Ai-Lin; Lin, Michael; Chiang, Pen-Chi

    2015-10-20

    The high-gravity carbonation process for CO2 mineralization and product utilization as a green cement was evaluated using field operation data from the steelmaking industry. The effect of key operating factors, including rotation speed, liquid-to-solid ratio, gas flow rate, and slurry flow rate, on CO2 removal efficiency was studied. The results indicated that a maximal CO2 removal of 97.3% was achieved using basic oxygen furnace slag at a gas-to-slurry ratio of 40, with a capture capacity of 165 kg of CO2 per day. In addition, the product with different carbonation conversions (i.e., 0%, 17%, and 48%) was used as supplementary cementitious materials in blended cement at various substitution ratios (i.e., 0%, 10%, and 20%). The performance of the blended cement mortar, including physicochemical properties, morphology, mineralogy, compressive strength, and autoclave soundness, was evaluated. The results indicated that the mortar with a high carbonation conversion of slag exhibited a higher mechanical strength in the early stage than pure portland cement mortar, suggesting its suitability for use as a high early strength cement. It also possessed superior soundness compared to the mortar using fresh slag. Furthermore, the optimal operating conditions of the high-gravity carbonation were determined by response surface models for maximizing CO2 removal efficiency and minimizing energy consumption. PMID:26397167

  19. Proof of concept and performance optimization of high gravity batch-type centrifugal dryer for dewatering fine coal

    SciTech Connect

    Smith, L.B.; Durney, T.

    1991-01-01

    The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer's systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)

  20. Electrochemical energy storage by polyaniline nanofibers: high gravity assisted oxidative polymerization vs. rapid mixing chemical oxidative polymerization.

    PubMed

    Zhao, Yibo; Wei, Huige; Arowo, Moses; Yan, Xingru; Wu, Wei; Chen, Jianfeng; Wang, Yiran; Guo, Zhanhu

    2015-01-14

    Polyaniline (PANI) nanofibers prepared by high gravity chemical oxidative polymerization in a rotating packed bed (RPB) have demonstrated a much higher specific capacitance of 667.6 F g(-1) than 375.9 F g(-1) of the nanofibers produced by a stirred tank reactor (STR) at a gravimetric current of 10 A g(-1). Meanwhile, the cycling stability of the electrode is 62.2 and 65.9% for the nanofibers from RPB and STR after 500 cycles, respectively. PMID:25431883

  1. Network congestion analysis of gravity generated models

    NASA Astrophysics Data System (ADS)

    Maniadakis, Dimitris; Varoutas, Dimitris

    2014-07-01

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

  2. High bicarbonate levels in narcoleptic children.

    PubMed

    Franco, Patricia; Junqua, Aurelie; Guignard-Perret, Anne; Raoux, Aude; Perier, Magali; Raverot, Veronique; Claustrat, Bruno; Gustin, Marie-Paule; Inocente, Clara Odilia; Lin, Jian-Sheng

    2016-04-01

    The objective of this study was to evaluate the levels of plasma bicarbonate levels in narcoleptic children. Clinical, electrophysiological data and bicarbonate levels were evaluated retrospectively in children seen in our paediatric national reference centre for hypersomnia. The cohort included 23 control subjects (11.5 ± 4 years, 43% boys) and 51 patients presenting de-novo narcolepsy (N) (12.7 ± 3.7 years, 47% boys). In narcoleptic children, cataplexy was present in 78% and DQB1*0602 was positive in 96%. The control children were less obese (2 versus 47%, P = 0.001). Compared with control subjects, narcoleptic children had higher bicarbonate levels (P = 0.02) as well as higher PCO2 (P < 0.01) and lower venous pH gas (P < 0.01). Bicarbonate levels higher than 27 mmol L(-1) were found in 41.2% of the narcoleptic children and 4.2% of the controls (P = 0.001). Bicarbonate levels were correlated with the Adapted Epworth Sleepiness Scale (P = 0.01). Narcoleptic patients without obesity often had bicarbonate levels higher than 27 mmol L (-1) (55 versus 25%, P = 0.025). No differences were found between children with and without cataplexy. In conclusion, narcoleptic patients had higher bicarbonate plasma levels compared to control children. This result could be a marker of hypoventilation in this pathology, provoking an increase in PCO2 and therefore a respiratory acidosis, compensated by an increase in plasma bicarbonates. This simple screening tool could be useful for prioritizing children for sleep laboratory evaluation in practice. PMID:26574184

  3. 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.

  4. High-Accuracy Measurements of the Centre of Gravity of Avalanches in Proportional Chambers

    DOE R&D Accomplishments Database

    Charpak, G.; Jeavons, A.; Sauli, F.; Stubbs, R.

    1973-09-24

    In a multiwire proportional chamber the avalanches occur close to the anode wires. The motion of the positive ions in the large electric fields at the vicinity of the wires induces fast-rising positive pulses on the surrounding electrodes. Different methods have been developed in order to determine the position of the centre of the avalanches. In the method we describe, the centre of gravity of the pulse distribution is measured directly. It seems to lead to an accuracy which is limited only by the stability of the spatial distribution of the avalanches generated by the process being measured.

  5. National Geodetic Survey Gravity Network

    NASA Astrophysics Data System (ADS)

    Moose, R. E.

    1986-12-01

    In 1966, the U.S. National Gravity Base Network was established through the cooperative efforts of several government agencies and academic institutions involved in nationwide gravity observations. The network was reobserved between 1975 and 1979 by the National Geodetic Survey (NGS) using field procedures designed to give high-quality gravity differences. The report discusses the adjustment and the areas where apparent gravity change was observed. NGS plans to densify and maintain this network and to improve the accuracy of the station values by additional high-quality relative ties and by making observations with a new, absolute gravity meter in each of the states.

  6. 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

  7. Statistics of high-level scene context

    PubMed Central

    Greene, Michelle R.

    2013-01-01

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

  8. High School Accounting at Two Instructional Levels.

    ERIC Educational Resources Information Center

    Helme, Rebecca E.

    1980-01-01

    Offering two levels of accounting results in a broader base of student enrollment. Reiterating theory, giving practical examples, and stressing "why" as well as "how" enable the instructor to foster the environment the students need. The teacher must also instill self-confidence in the students. (JOW)

  9. Period analysis at high noise level

    NASA Astrophysics Data System (ADS)

    Kovacs, G.

    1980-05-01

    Analytical expressions are derived for the variances of three types of periodograms due to normal-distributed noise present in the data: the conventional Fourier spectrum, the method of Warner and Robinson (1972), and Jurkevich's method (1971). The equivalence of the Jurkevich method and that of Warner and Robinson is proved. The optimum phase cell number of the Warner-Robinson method is given; this number depends on the data length, signal form, and noise level. Results are illustrated by the analysis of two typical forms of light curves: an eclipsing type light curve and an RRa curve.

  10. High-energy scatterings in infinite-derivative field theory and ghost-free gravity

    NASA Astrophysics Data System (ADS)

    Talaganis, Spyridon; Mazumdar, Anupam

    2016-07-01

    In this paper, we will consider scattering diagrams in the context of infinite-derivative theories. First, we examine a finite-order, higher-derivative scalar field theory and find that we cannot eliminate the growth of scattering diagrams for large external momenta. Then, we employ an infinite-derivative scalar toy model and obtain that the external momentum dependence of scattering diagrams is convergent as the external momenta become very large. In order to eliminate the external momentum growth, one has to dress the bare vertices of the scattering diagrams by considering renormalised propagator and vertex loop corrections to the bare vertices. Finally, we investigate scattering diagrams in the context of a scalar toy model which is inspired by a ghost-free and singularity-free infinite-derivative theory of gravity, where we conclude that infinite derivatives can eliminate the external momentum growth of scattering diagrams and make the scattering diagrams convergent in the ultraviolet.

  11. Searching for quantum gravity with high-energy atmospheric neutrinos and AMANDA-II

    NASA Astrophysics Data System (ADS)

    Kelley, John Lawrence

    2008-06-01

    The AMANDA-II detector, operating since 2000 in the deep ice at the geographic South Pole, has accumulated a large sample of atmospheric muon neutrinos in the 100 GeV to 10 TeV energy range. The zenith angle and energy distribution of these events can be used to search for various phenomenological signatures of quantum gravity in the neutrino sector, such as violation of Lorentz invariance (VLI) or quantum decoherence (QD). Analyzing a set of 5511 candidate neutrino events collected during 1387 days of livetime from 2000 to 2006, we find no evidence for such effects and set upper limits on VLI and QD parameters using a maximum likelihood method. Given the absence of new flavor-changing physics, we use the same methodology to determine the conventional atmospheric muon neutrino flux above 100 GeV.

  12. High Power Amplifier Harmonic Output Level Measurement

    NASA Technical Reports Server (NTRS)

    Perez, R. M.; Hoppe, D. J.; Khan, A. R.

    1995-01-01

    A method is presented for the measurement of the harmonic output power of high power klystron amplifiers, involving coherent hemispherical radiation pattern measurements of the radiated klystron output. Results are discussed for the operation in saturated and unsaturated conditions, and with a waveguide harmonic filter included.

  13. How High Glucose Levels Affect Tendon Homeostasis.

    PubMed

    Snedeker, Jess G

    2016-01-01

    Among the many factors playing a role in tendon disease, unregulated biochemical reactions between glucose and the collagen extracellular matrix are coming increasingly into focus. We have shown that formation of advanced glycation end-products that cross-link the collagen extracellular matrix can drastically affect cellular level mechanical properties of the matrix, and in turn affect cell-level biomechanical stimuli during physiological loading of the tissue. We suggest that these may adversely affect tendon cell response to matrix damage, as well as the quality of the consequent repair. If such mechanical feedback loops are altered, the ability of tendon cells to maintain tissue in a functional, healthy state may be compromised. Although key foundational elements of biochemical, biomechanical, and biological understanding are now in place, the full extent of how these aspects interact, including the precise mechanisms by which advanced glycation end-products pathologically disrupt connective tissue homeostasis and damage repair, are only beginning to be adequately appreciated. PMID:27535261

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

    PubMed Central

    2012-01-01

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

  15. 46 CFR 182.530 - Bilge high level alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Bilge high level alarms. 182.530 Section 182.530... TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a... operating station to indicate a high water level in each of the following normally unmanned spaces: (1)...

  16. 46 CFR 182.530 - Bilge high level alarms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Bilge high level alarms. 182.530 Section 182.530... TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a... operating station to indicate a high water level in each of the following normally unmanned spaces: (1)...

  17. 46 CFR 119.530 - Bilge high level alarms.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the...

  18. 46 CFR 119.530 - Bilge high level alarms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the...

  19. 46 CFR 182.530 - Bilge high level alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Bilge high level alarms. 182.530 Section 182.530... TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a... operating station to indicate a high water level in each of the following normally unmanned spaces: (1)...

  20. 46 CFR 182.530 - Bilge high level alarms.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Bilge high level alarms. 182.530 Section 182.530... TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a... operating station to indicate a high water level in each of the following normally unmanned spaces: (1)...

  1. 46 CFR 119.530 - Bilge high level alarms.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the...

  2. 46 CFR 119.530 - Bilge high level alarms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the...

  3. 46 CFR 119.530 - Bilge high level alarms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Bilge high level alarms. 119.530 Section 119.530... Bilge and Ballast Systems § 119.530 Bilge high level alarms. (a) Each vessel must be provided with a visual and audible alarm at the operating station to indicate a high water level in each of the...

  4. New Antarctic gravity anomaly grid for enhanced geodetic and geophysical studies in Antarctica

    NASA Astrophysics Data System (ADS)

    Scheinert, M.; Ferraccioli, F.; Schwabe, J.; Bell, R.; Studinger, M.; Damaske, D.; Jokat, W.; Aleshkova, N.; Jordan, T.; Leitchenkov, G.; Blankenship, D. D.; Damiani, T. M.; Young, D.; Cochran, J. R.; Richter, T. D.

    2016-01-01

    Gravity surveying is challenging in Antarctica because of its hostile environment and inaccessibility. Nevertheless, many ground-based, airborne, and shipborne gravity campaigns have been completed by the geophysical and geodetic communities since the 1980s. We present the first modern Antarctic-wide gravity data compilation derived from 13 million data points covering an area of 10 million km2, which corresponds to 73% coverage of the continent. The remove-compute-restore technique was applied for gridding, which facilitated leveling of the different gravity data sets with respect to an Earth gravity model derived from satellite data alone. The resulting free-air and Bouguer gravity anomaly grids of 10 km resolution are publicly available. These grids will enable new high-resolution combined Earth gravity models to be derived and represent a major step forward toward solving the geodetic polar data gap problem. They provide a new tool to investigate continental-scale lithospheric structure and geological evolution of Antarctica.

  5. Time-variable gravity signal in Greenland revealed by high-low satellite-to-satellite tracking

    NASA Astrophysics Data System (ADS)

    Weigelt, M.; Dam, T.; Jäggi, A.; Prange, L.; Tourian, M. J.; Keller, W.; Sneeuw, N.

    2013-07-01

    In the event of a termination of the Gravity Recovery and Climate Experiment (GRACE) mission before the launch of GRACE Follow-On (due for launch in 2017), high-low satellite-to-satellite tracking (hl-SST) will be the only dedicated observing system with global coverage available to measure the time-variable gravity field (TVG) on a monthly or even shorter time scale. Until recently, hl-SST TVG observations were of poor quality and hardly improved the performance of Satellite Laser Ranging observations. To date, they have been of only very limited usefulness to geophysical or environmental investigations. In this paper, we apply a thorough reprocessing strategy and a dedicated Kalman filter to Challenging Minisatellite Payload (CHAMP) data to demonstrate that it is possible to derive the very long-wavelength TVG features down to spatial scales of approximately 2000 km at the annual frequency and for multi-year trends. The results are validated against GRACE data and surface height changes from long-term GPS ground stations in Greenland. We find that the quality of the CHAMP solutions is sufficient to derive long-term trends and annual amplitudes of mass change over Greenland. We conclude that hl-SST is a viable source of information for TVG and can serve to some extent to bridge a possible gap between the end-of-life of GRACE and the availability of GRACE Follow-On.

  6. 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.

  7. Fermilab Tevatron high level rf accelerating systems

    SciTech Connect

    Kerns, Q.; Kerns, C.; Miller, H.; Tawser, S.; Reid, J.; Webber, R.; Wildman, D.

    1985-06-01

    Eight tuned rf cavities have been installed and operated in the F0 straight section of the Tevatron. Their mechanical placement along the beam line enables them to be operated for colliding beams as two independent groups of four cavities, group 1-4 accelerating antiprotons and group 5-8 accelerating protons. The only difference is that the spacing between cavities 4 and 5 was increased to stay clear of the F0 colliding point. The cavities can easily be rephased by switching cables in a low-level distribution system (fan-out) so that the full accelerating capability of all eight cavities can be used during fixed target operations. Likewise, the cables from capacitive probes on each cavity gap can be switched to proper lengths and summed in a fan-back system to give an rf signal representing the amplitude and phase as ''seen by the beam,'' separately for protons and antiprotons. Such signals have been used to phase lock the Tevatron to the Main Ring for synchronous transfer.

  8. High resolution evidence for the Garrett-Munk spectrum of stratospheric gravity waves

    NASA Technical Reports Server (NTRS)

    Dewan, E. M.; Grossbard, N.; Quesada, A. F.; Good, R. E.

    1984-01-01

    Vertical profiles of scalar horizontal winds have been measured at high resolution (10 m) in the 13 to 37 km region of the stratosphere. This resolution (at that range of altitude) represents the state-of-the-art, and is unique. The technique used smoke trails laid by rockets in the stratosphere, and were taken by AFGL at Wallops Island, VA, White Sands Missile Range, NM, and Ft. Churchill, Canada, in the 1977-78 time period. Two or three cameras were used to give the time-lapse photographs. The goal was to ascertain whether or not the internal waves of the stratosphere behave consistently with the Garrett-Munk model which was originally created for oceanic internal waves. Five profiles of horizontal wind are presented. It is concluded: (1) stratospheric internal waves obey the Garrett-Munk model for vertical wave numbers; (2) there is not statistically significant evidence for a break in the curve at high wave numbers when due allowance is made for aliasing effects; and (3) the power density level of the spectra are almost equal on a log-log scale in spite of the difference in time, season, and geographical location.

  9. 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 μg/g dry wt. and a mean (SD) value of 51.0 (33.0) μg/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

  10. Quantum massive conformal gravity

    NASA Astrophysics Data System (ADS)

    Faria, F. F.

    2016-04-01

    We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard first order canonical quantization method. It is shown that quantum massive conformal gravity is renormalizable but has ghost states. A possible decoupling of these ghost states at high energies is discussed.

  11. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from...

  12. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from...

  13. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true High-level radioactive waste. 227.30 Section 227.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from...

  14. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from...

  15. A global view of gravity waves in the Martian atmosphere inferred from a high-resolution general circulation model

    NASA Astrophysics Data System (ADS)

    Kuroda, Takeshi; Medvedev, Alexander S.; Yiǧit, Erdal; Hartogh, Paul

    2015-11-01

    Global characteristics of the small-scale gravity wave (GW) field in the Martian atmosphere obtained from a high-resolution general circulation model (GCM) are presented for the first time. The simulated GW-induced temperature variances are in a good agreement with available radio occultation data in the lower atmosphere between 10 and 30 km. The model reveals a latitudinal asymmetry with stronger wave generation in the winter hemisphere and two distinctive sources of GWs: mountainous regions and the meandering winter polar jet. Orographic GWs are filtered, while propagating upward, and the mesosphere is primarily dominated by harmonics with faster horizontal phase velocities. Wave fluxes are directed mainly against the local wind. GW dissipation in the upper mesosphere generates body forces of tens of m s-1 per Martian solar day (sol-1), which tend to close the simulated jets. The results represent a realistic surrogate for missing observations, which can be used for constraining GW parameterizations and validating GCM simulations.

  16. Removal of phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field

    NASA Astrophysics Data System (ADS)

    Gao, Jin-tao; Guo, Lei; Zhong, Yi-wei; Ren, Hong-ru; Guo, Zhan-cheng

    2016-07-01

    A new approach of removing the phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super- gravity field was investigated. The iron-slag separation by super-gravity resulted in phosphorus being effectively removed from the iron-rich phase and concentrated as a phosphorus-rich phase at a temperature below the melting point of iron. The samples obtained by super-gravity exhibited obvious layered structures. All the iron grains concentrated at the bottom of the sample along the super-gravity direction, whereas the molten slag concentrated in the upper part of the sample along the opposite direction. Meanwhile, fine apatite crystals collided and grew into larger crystals and concentrated at the slag-iron interface. Consequently, in the case of centrifugation with a gravity coefficient of G = 900, the mass fractions of the slag phase and iron-rich phase were similar to their respective theoretical values. The mass fraction of MFe in the iron-rich phase was as high as 97.77wt% and that of P was decreased to 0.092wt%.

  17. Cascading gravity is ghost free

    SciTech Connect

    Rham, Claudia de; Khoury, Justin; Tolley, Andrew J.

    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.

  18. Gravity Currents

    NASA Astrophysics Data System (ADS)

    Simpson, John E.

    1997-03-01

    This book comprehensively describes all aspects of gravity flow, a physical process in the environment that is covered by many disciplines including meteorology, oceanography, the earth sciences and industrial processes. The first edition was very well received, and the author has brought the new edition completely up to date, with much new material. Simpson describes gravity currents with a variety of laboratory experiments, many from his own work. Gravity Currents is a valuable supplementary textbook for undergraduates and a reference work for research workers. The general reader will also find much of interest, since the author clearly describes the physics of flows involved without advanced mathematics, and with numerous photographs and illustrations.

  19. Gravity Currents

    NASA Astrophysics Data System (ADS)

    Simpson, John E.

    1999-11-01

    This book comprehensively describes all aspects of gravity flow, a physical process in the environment that is covered by many disciplines including meteorology, oceanography, the earth sciences and industrial processes. The first edition was very well received, and the author has brought the new edition completely up to date, with much new material. Simpson describes gravity currents with a variety of laboratory experiments, many from his own work. Gravity Currents is a valuable supplementary textbook for undergraduates and a reference work for research workers. The general reader will also find much of interest, since the author clearly describes the physics of flows involved without advanced mathematics, and with numerous photographs and illustrations.

  20. 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).

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  2. 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.

  3. 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.

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

    NASA Astrophysics Data System (ADS)

    Aktinol, Eduardo

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

  5. 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…

  6. 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.

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

    PubMed

    Nishiyama, T; Morinaga, S; Nagayama, K

    2009-03-01

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

  8. Gravity brake

    DOEpatents

    Lujan, Richard E.

    2001-01-01

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

  9. The 3-D motion of the centre of gravity of the human body during level walking. II. Lower limb amputees.

    PubMed

    Tesio, L; Lanzi, D; Detrembleur, C

    1998-03-01

    OBJECTIVE: To analyse the motion of the centre of gravity (CG) of the body during gait in unilateral lower limb amputees with good kinematic patterns. DESIGN: Three transtibial (below-knee, BK) and four transfemoral (above-knee, AK) amputees were required to perform successive walks over a 2.4 m long force plate, at freely chosen cadence and speed. BACKGROUND: In previous studies it has been shown that in unilateral lower limb amputee gait, the motion of the CG can be more asymmetric than might be suspected from kinematic analysis. METHODS: The mechanical energy changes of the CG due to its motion in the vertical, forward and lateral direction were measured. Gait speed ranged 0.75-1.32 m s(-1) in the different subjects. This allowed calculation of (a) the positive work done by muscles to maintain the motion of the CG with respect to the ground ('external' work, W(ext)) and (b) the amount of the pendulum-like, energy-saving transfer between gravitational potential energy and kinetic energy of the CG during each step (percent recovery, R). Step length and vertical displacement of the CG were also measured. RESULTS: The recorded variables were kept within the normal limits, calculated in a previous work, when an average was made of the steps performed on the prosthetic (P) and on the normal (N) limb. Asymmetries were found, however, between the P and the N step. In BK amputees, the P step R was 5% greater and W(ext) was 21% lower than in the N step; in AK amputees, in the P step R was 54% greater and W(ext) was 66% lower than in the N step. Asymmetries were also found in the relative magnitude of the external work provided by each lower limb during the single stance as compared with the double stance: a marked deficit of work occurred at the P to N transition. PMID:11415775

  10. 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.

  11. Gravity, magnetic, and high-precision relocated seismicity profiles suggest a connection between the Hayward and Calaveras Faults, northern California

    NASA Astrophysics Data System (ADS)

    Ponce, D. A.; Simpson, R. W.; Graymer, R. W.; Jachens, R. C.

    2004-07-01

    Gravity, magnetic, and seismicity data profiled across the Hayward Fault Zone were generated as part of ongoing studies to help determine the geologic and tectonic setting of the San Francisco Bay region. These data, combined with previous geophysical studies that indicate that the Hayward Fault Zone dips 75°NE near San Leandro and follows a preexisting structure, reveal a possible direct connection between the seismogenic portion of the Hayward and Calaveras Faults at depth. Although the relocated seismicity data are regional in nature, they suggest that the dip of the Hayward Fault Zone may vary from near vertical in the northwestern part of the fault to about 75°NE at San Leandro in the central part of the fault to about 50°NE in the southeastern part of the fault. Gravity and magnetic data, profiled across the Hayward Fault Zone, were processed using standard geophysical techniques. Cross sections of high-precision relocated hypocenters were constructed along each profile from the northwestern to the southeastern end of the Hayward Fault Zone. Profiles and cross sections are referenced to Pinole Point, where the Hayward Fault enters San Pablo Bay, and are spaced 2.5 km apart. Topographic profiles shown on the seismicity cross sections were generated using U.S. Geological Survey (USGS) 7.5-min, 30-m digital elevation models. Relocation of seismicity data was accomplished using a regional double-difference method. The double-difference method incorporates ordinary travel time measurements and cross correlation of P and S wave differential travel time measurements. Relative locations between earthquakes have hypocentral errors of about 100 m horizontally and 250 m vertically. Absolute location uncertainties were not determined but are probably dramatically improved compared to the USGS's Northern California Seismic Network catalog data.

  12. 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, J.-L.; Khatunstsev, I. V.; Hauchecorne, A.; Markiewicz, W.; Marcq, E.; Lebonnois, S.; Patsaeva, M. V.; Turin, A. V.

    2015-10-01

    Based on the analysis of UV images (at 365 nm) of Venus cloud top collected with VMC camera on board Venus Express[4,5], it is found that the zonal wind speed south of the equator (from 5°S to 15°s) shows a conspicuous variation with geographic longitude of Venus, correlated with underlying relief of Aphrodite Terra. 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. The cloud albedo map at 365 nm varies also in longitude and latitude, perhaps the result of increased vertical mixing associated to wave breaking, and decreased abundance of the UV absorber which makes the contrast in images.

  13. 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.

  14. Observed correlation of Venus topography with the zonal wind and albedo at cloud top level: the role of stationary gravity waves.

    NASA Astrophysics Data System (ADS)

    Bertaux, Jean-Loup; Khatunstsev, Igor; Hauchecorne, Alain; Markiewicz, Wojtek; Emmanuel, Marcq; Sébastien, Lebonnois; Marina, Patsaeva; Alex, Turin; Anna, Fedorova

    2016-04-01

    Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67±2 km) collected with VMC (Venus Monitoring Camera) on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°s) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. 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. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth by Lindzen [1981], but is not reproduced in a current GCM of Venus atmosphere. Consistent with present findings, the two VEGA mission balloons experienced a small, but significant, difference of westward velocity, at their 53 km floating altitude. The albedo at 365 nm varies also with longitude and latitude in a pattern strikingly similar in the low latitude regions to a recent map of cloud top H2O [Fedorova et al., 2015], in which a lower UV albedo is correlated with increased H2O. We argue that H2O enhancement is the sign of upwelling, suggesting that the UV absorber is also brought to cloud top by upwelling.

  15. 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).

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

    NASA Astrophysics Data System (ADS)

    Hassan, Ahmed A.; Bahgat, Waleed M.

    2010-01-01

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

  17. Born-Infeld-Horava gravity

    SciTech Connect

    Guellue, Ibrahim; Sisman, Tahsin Cagri; Tekin, Bayram

    2010-05-15

    We define various Born-Infeld gravity theories in 3+1 dimensions which reduce to Horava's model at the quadratic level in small curvature expansion. In their exact forms, our actions provide z{yields}{infinity} extensions of Horava's gravity, but when small curvature expansion is used, they reproduce finite z models, including some half-integer ones.

  18. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1990-01-01

    The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.

  19. Gravity Field Recovery with Simulated GOCE Observations

    NASA Astrophysics Data System (ADS)

    Marty, J.; Bruinsma, S.; Balmino, G.; Abrikosov, O.; Foerste, C.; Rothacher, M.

    2005-12-01

    Numerical simulations of the gravity field parameter recovery using the direct method, with satellite positions as pseudo observations instead of simulated GPS Satellite-to-Satellite (SST) tracking data, and with gravity gradients (SGG data), were done and are ongoing in the framework of the European GOCE Gravity Consortium test and validation plan for GOCE mission data processing. This work shows the latest results from the CNES and GFZ software packages, GINS and EPOS, respectively. After the iterative least-squares orbit adjustment procedure has converged to the highest attainable precision level, the gravity field normal equations are computed in a subsequent step. These SST normal equations, representing the long wavelength gravity field signal, are then reduced for arc-dependent parameters (i.e. state vector at epoch, empirical parameters) and cumulated over the entire observation period. Secondly, the gravity gradient measurements (SGG) are processed, taking into account the coloured noise in these data, and yield (high resolution) normal equations. They are combined with the SST normal equations and the gravity field and gradiometer common mode calibration parameters are simultaneously estimated. The coloured noise in the SGG data is based on the latest and realistic gradiometer specifications. The precision in the measurement bandwidth is approximately 3-5 milliEotvos, but rapidly decreasing for lower frequencies. Due to this behaviour, the observation equations have to be filtered in order to obtain the most accurate recovery. The filter algorithm, design and results are presented to considerable detail since this particular step is the key element that will enable the achievement of the GOCE mission objectives from the ground segment point of view.

  20. Partial gravity - Human impacts on facility design

    NASA Technical Reports Server (NTRS)

    Capps, Stephen; Moore, Nathan

    1990-01-01

    Partial gravity affects the body differently than earth gravity and microgravity environments. The main difference from earth gravity is human locomotion; while the main dfference from microgravity is the specific updown orientation and reach envelopes which increase volume requirements. Much data are available on earth gravity and microgravity design; however, very little information is available on human reactions to reduced gravity levels in IVA situations (without pressure suits). Therefore, if humans commit to permanent lunar habitation, much research should be conducted in the area of partial gravity effects on habitat design.

  1. Low-level awareness accompanies "unconscious" high-level processing during continuous flash suppression.

    PubMed

    Gelbard-Sagiv, Hagar; Faivre, Nathan; Mudrik, Liad; Koch, Christof

    2016-01-01

    The scope and limits of unconscious processing are a matter of ongoing debate. Lately, continuous flash suppression (CFS), a technique for suppressing visual stimuli, has been widely used to demonstrate surprisingly high-level processing of invisible stimuli. Yet, recent studies showed that CFS might actually allow low-level features of the stimulus to escape suppression and be consciously perceived. The influence of such low-level awareness on high-level processing might easily go unnoticed, as studies usually only probe the visibility of the feature of interest, and not that of lower-level features. For instance, face identity is held to be processed unconsciously since subjects who fail to judge the identity of suppressed faces still show identity priming effects. Here we challenge these results, showing that such high-level priming effects are indeed induced by faces whose identity is invisible, but critically, only when a lower-level feature, such as color or location, is visible. No evidence for identity processing was found when subjects had no conscious access to any feature of the suppressed face. These results suggest that high-level processing of an image might be enabled by-or co-occur with-conscious access to some of its low-level features, even when these features are not relevant to the processed dimension. Accordingly, they call for further investigation of lower-level awareness during CFS, and reevaluation of other unconscious high-level processing findings. PMID:26756173

  2. Process for solidifying high-level nuclear waste

    DOEpatents

    Ross, Wayne A.

    1978-01-01

    The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products.

  3. 46 CFR 153.409 - High level alarms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false High level alarms. 153.409 Section 153.409 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Gauging Systems § 153.409 High level alarms. When Table...

  4. Physical Activity Levels in Portuguese High School Physical Education

    ERIC Educational Resources Information Center

    Marmeleira, Jose Francisco Filipe; Aldeias, Nuno Micael Carrasqueira; da Graca, Pedro Miguel dos Santos Medeira

    2012-01-01

    The main aim of this study was to evaluate the physical activity (PA) levels of high school Portuguese students during physical education (PE) and investigate the association of PA levels with students' goal orientation and intrinsic motivation. Forty-six students from three high schools participated. Heart rate telemetry and pedometry were used…

  5. 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…

  6. Deciphering Jupiter's atmospheric dynamics using the upcoming Juno gravity measurements

    NASA Astrophysics Data System (ADS)

    Kaspi, Yohai; Galanti, Eli

    2016-07-01

    This summer, the Juno spacecraft will arrive at Jupiter in course for close flybys of the planet, obtaining a high precision gravity spectrum of Jupiter. This data can be used to estimate the depth of Jupiter's observed cloud-level wind, and decipher the possible internal flows, that might be decoupled from the surface wind. In this talk, we discuss the Juno gravity experiment, and the possible outcomes with regard to the flows on Jupiter. We show several ways in which the gravity spectrum might be used to study the large scale flows: 1. measurements of the high order even harmonics which beyond J10 are dominated by the dynamics; 2. measurements of odd gravity harmonics which have no contribution from a static planet, and therefore are a pure signature of dynamics; 3. upper limits on the depth of the surface flow can be obtained by comparing low order even harmonics from dynamical models to the difference between the measured low order even harmonics and the largest possible values of a static planet; 4. direct latitudinally varying measurements of the gravity field exerted on the spacecraft. We will discuss how these methods may be applied given the expected sensitivities of the Juno gravity experiment. In addition, we present an inverse adjoint model, which allows given the gravity data, to infer the flows that produce it. This will allow, hopefully, to make significant progress in one of the longest-standing question in planetary atmospheric dynamics regarding the nature of the flows on the giant planets.

  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. Evaluating Material Flammability in Microgravity and Martian Gravity Compared to the NASA Standard Normal Gravity Test

    NASA Technical Reports Server (NTRS)

    Oslon, Sandra. L.; Ferkul, Paul

    2012-01-01

    Drop tower tests are conducted at Martian gravity to determine the flammability of three materials compared to previous tests in other normal gravity and reduced gravity environments. The comparison is made with consideration of a modified NASA standard test protocol. Material flammability limits in the different gravity and flow environments are tabulated to determine the factor of safety associated with normal gravity flammability screening. Previous testing at microgravity and Lunar gravity indicated that some materials burned to lower oxygen concentrations in low gravity than in normal gravity, although the low g extinction limit criteria are not the same as 1g due to time constraints in drop testing. Similarly, the data presented in this paper for Martian gravity suggest that there is a gravity level below Earth s at which materials burn more readily than on Earth. If proven for more materials, this may indicate the need to include a factor of safety on 1g flammability limits.

  9. Soldering Tested in Reduced Gravity

    NASA Technical Reports Server (NTRS)

    Struk, Peter M.; Pettegrew, Richard D.; Watson, J. Kevin; Down, Robert S.; Haylett, Daniel R.

    2005-01-01

    Whether used occasionally for contingency repair or routinely in nominal repair operations, soldering will become increasingly important to the success of future long-duration human space missions. As a result, it will be critical to have a thorough understanding of the service characteristics of solder joints produced in reduced-gravity environments. The National Center for Space Exploration Research (via the Research for Design program), the NASA Glenn Research Center, and the NASA Johnson Space Center are conducting an experimental program to explore the influence of reduced gravity environments on the soldering process. Solder joint characteristics that are being considered include solder fillet geometry, porosity, and microstructural features. Both through-hole (see the drawing and image on the preceding figure) and surface-mounted devices are being investigated. This effort (the low-gravity portion being conducted on NASA s KC-135 research aircraft) uses the soldering hardware currently available on the International Space Station. The experiment involves manual soldering by a contingent of test operators, including both highly skilled technicians and less skilled individuals to provide a skill mix that might be encountered in space mission crews. The experiment uses both flux-cored solder and solid-core solder with an externally applied flux. Other experimental parameters include the type of flux, gravitational level (nominally zero,

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  11. 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.

  12. Plasma hormone levels in human subject during stress loads in microgravity and at readaptation to Earth's gravity.

    PubMed

    Macho, L; Koska, J; Ksinantova, L; Vigas, M; Noskov, V B; Grigoriev, A I; Kvetnansky, R

    2001-07-01

    In great part of the investigations of endocrine system functions in astronauts during space flights the plasma levels of hormones and metabolites were determined only in resting conditions, usually from one blood sample collection. Such levels reflected the psychical and physical state and new hormonal homeostasis of organism at the time of blood collection, however, the functional capacity of neuroendocrine system to respond to various stress stimuli during space flight remained unknown. The aim of present investigations was to study dynamic changes of hormone levels during the stress and metabolic loads (insulin induced hypoglycemia, physical exercise and oral glucose tolerance test) at the exposure of human subject to microgravity on the space station MIR. The responses of sympatico-adrenomedullary system to these stress and workloads were presented by Kvetnansky et al. PMID:12650202

  13. [Biology of size and gravity].

    PubMed

    Yamashita, Masamichi; Baba, Shoji A

    2004-03-01

    Gravity is a force that acts on mass. Biological effects of gravity and their magnitude depend on scale of mass and difference in density. One significant contribution of space biology is confirmation of direct action of gravity even at the cellular level. Since cell is the elementary unit of life, existence of primary effects of gravity on cells leads to establish the firm basis of gravitational biology. However, gravity is not limited to produce its biological effects on molecules and their reaction networks that compose living cells. Biological system has hierarchical structure with layers of organism, group, and ecological system, which emerge from the system one layer down. Influence of gravity is higher at larger mass. In addition to this, actions of gravity in each layer are caused by process and mechanism that is subjected and different in each layer of the hierarchy. Because of this feature, summing up gravitational action on cells does not explain gravity for biological system at upper layers. Gravity at ecological system or organismal level can not reduced to cellular mechanism. Size of cells and organisms is one of fundamental characters of them and a determinant in their design of form and function. Size closely relates to other physical quantities, such as mass, volume, and surface area. Gravity produces weight of mass. Organisms are required to equip components to support weight and to resist against force that arise at movement of body or a part of it. Volume and surface area associate with mass and heat transport process at body. Gravity dominates those processes by inducing natural convection around organisms. This review covers various elements and process, with which gravity make influence on living systems, chosen on the basis of biology of size. Cells and biochemical networks are under the control of organism to integrate a consolidated form. How cells adjust metabolic rate to meet to the size of the composed organism, whether is gravity

  14. 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

  15. Application of high-pass filtering techniques on gravity and magnetic data of the eastern Qattara Depression area, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Zahra, Hesham Shaker; Oweis, Hesham T.

    2016-06-01

    In this work, a reconnaissance study is presented to delineate the subsurface tectonics and lithological inferences of the eastern area of Qattara Depression using the Bouguer gravity and aeromagnetic data. To achieve this goal, several transformation techniques and filtering processes are accomplished on these maps. At first, the total intensity aeromagnetic map is processed through the application of reduction to the magnetic north pole technique. The fast Fourier transform is carried out on the gravity and RTP magnetic data for establishing and defining the residual (shallow) sources. The frequency high-pass filtering is used to enhance the anomaly wavelengths associated with the shallow sources. The used processing techniques are the polynomial surface fitting enhancement, Laplacian, Strike Filtering, Enhancement Utilization, Suppression Utilization, Butterworth Filtering Utilization, Butterworth high-pass filter, Euler's deconvolution and forward modeling. The equivalent depths of the isolated short wavelength anomalies are 0.759 and 0.340 km below the flight surface, and the depths of the intermediate wavelength anomalies are 1.28 and 2.00 km for the gravity and magnetic data, respectively. Finally, the quantitative interpretations of the Bouguer gravity and RTP magnetic maps of the study area, reflect the occurrence of the various types of structures and their components. The main tectonic deformations of the study area have NNW-SSE, NNE-SSW, NE-SW, NW-SE and E-W trends.

  16. Crustal architecture of the Faroe-Shetland Margin: insights from a newly merged high resolution gravity and magnetic dataset

    NASA Astrophysics Data System (ADS)

    Rippington, Stephen; Mazur, Stan; Anderson, Chris

    2014-05-01

    The Faroe-Shetland region is geologically complex; it has undergone several phases of extension and rifting since the middle Palaeozoic (Ritchie et al., 2011; Coward et al., 2003), culminating in the Eocene with continental breakup between Northwest Europe and Greenland (Gernigon et al., 2012). Final breakup may have been facilitated by the presence of the Iceland Plume and was accompanied by the emplacement of voluminous basaltic rocks, attributed to the North Atlantic Igneous Province (White and McKenzie, 1989). It is difficult to image beneath the thick Paleogene basalts in the region using conventional seismic methods, because the high impedance contrast between the sediments and shallow basalts causes strong reflections. These mask deeper and weaker reflections and cause prominent inter-bed multiples (White et al., 1999). Consequently, determining the location and shape of basins and basement highs, and elucidating the timing and manner of their formation, remains a major cause of uncertainty in the appraisal of the hydrocarbon potential of the region. Gravity and magnetic data record variations in the density and susceptibility of the entire crust. Consequently, the thick basalt piles that are shallow in the section do not hinder the ability to detect deeper features. Instead, the principal challenge is distinguishing superposed bodies, with different densities and susceptibilities, from the combined gravity and magnetic anomalies. In this study, seismic data and horizons from the shallow section are used in combination with gravity and magnetic data to produce map view interpretations, and 2D and 3D models of the crust in the Faroe-Shetland region. These models help distinguish important variations in timing of rifting in different basins, and reveal the crustal architecture of the Faroe-Shetland Basin from the seabed to the Moho. We present a new structural and kinematic interpretation of the geology of the region, and propose an asymmetric simple shear

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  18. 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.

  19. Influence of Venus topography on the zonal wind and UV albedo at cloud top level: The role of stationary gravity waves

    NASA Astrophysics Data System (ADS)

    Bertaux, Jean-Loup; Khatuntsev, I. V.; Hauchecorne, A.; Markiewicz, W. J.; Marcq, E.; Lebonnois, S.; Patsaeva, M.; Turin, A.; Fedorova, A.

    2016-06-01

    Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67 ± 2 km) collected with Venus Monitoring Camera on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°S) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underlying relief of Aphrodite Terra. We interpret this pattern as the result of stationary gravity waves produced at ground level by the uplift of air when the horizontal wind encounters a mountain slope. These waves can propagate up to the cloud top level, break there, and transfer their momentum to the zonal flow. Such upward propagation of gravity waves and influence on the wind speed vertical profile was shown to play an important role in the middle atmosphere of the Earth by Lindzen (1981) but is not reproduced in the current GCM of Venus atmosphere from LMD. (Laboratoire de Météorologie Dynamique) In the equatorial regions, the UV albedo at 365 nm varies also with longitude. We argue that this variation may be simply explained by the divergence of the horizontal wind field. In the longitude region (from 60° to -10°) where the horizontal wind speed is increasing in magnitude (stretch), it triggers air upwelling which brings the UV absorber at cloud top level and decreases the albedo and vice versa when the wind is decreasing in magnitude (compression). This picture is fully consistent with the classical view of Venus meridional circulation, with upwelling at equator revealed by horizontal air motions away from equator: the longitude effect is only an additional but important modulation of this effect. This interpretation is comforted by a recent map of cloud top H2O, showing that near the equator the lower UV albedo longitude region is correlated with increased H2O. We argue that H2O enhancement is the sign of upwelling, suggesting that the UV absorber is also brought to cloud top by upwelling.

  20. 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…

  1. Gravity and Biology

    NASA Technical Reports Server (NTRS)

    Morey-Holton, Emily R.

    1996-01-01

    Gravity has been the most constant environmental factor throughout the evolution of biological species on Earth. Organisms are rarely exposed to other gravity levels, either increased or decreased, for prolonged periods. Thus, evolution in a constant 1G field has historically prevented us from appreciating the potential biological consequences of a multi-G universe. To answer the question 'Can terrestrial life be sustained and thrive beyond our planet?' we need to understand the importance of gravity on living systems, and we need to develop a multi-G, rather than a 1G, mentality. The science of gravitational biology took a giant step with the advent of the space program, which provided the first opportunity to examine living organisms in gravity environments lower than could be sustained on Earth. Previously, virtually nothing was known about the effects of extremely low gravity on living organisms, and most of the initial expectations were proven wrong. All species that have flown in space survive in microgravity, although no higher organism has ever completed a life cycle in space. It has been found, however, that many systems change, transiently or permanently, as a result of prolonged exposure to microgravity.

  2. 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.

  3. 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

  4. Exploring Gravity Wave Predictability and Dynamics in Deepwave

    NASA Astrophysics Data System (ADS)

    Doyle, J. D.; Fritts, D. C.; Smith, R. B.; Eckermann, S. D.; Taylor, M. J.; Dörnbrack, A.; Uddstrom, M.; Reynolds, C. A.; Reinecke, A.; Jiang, Q.

    2014-12-01

    The DEEP propagating gravity WAVE program (DEEPWAVE) is a comprehensive, airborne and ground-based measurement and modeling program centered on New Zealand and focused on providing a new understanding of gravity wave dynamics and impacts from the troposphere through the mesosphere and lower thermosphere (MLT). This program employed the NSF/NCAR GV (NGV) research aircraft from a base in New Zealand in a 6-week field measurement campaign in June-July 2014. During the field phase, the NGV was equipped with new lidar and airglow instruments, as well as dropwindsondes and a full suite of flight level instruments including the microwave temperature profiler (MTP), providing temperatures and vertical winds spanning altitudes from immediately above the NGV flight altitude (~13 km) to ~100 km. The region near New Zealand was chosen since all the relevant GW sources (e.g., mountains, cyclones, jet streams) occur strongly here, and upper-level winds in austral winter permit gravity waves to propagate to very high altitudes. The COAMPS adjoint modeling system provided forecast sensitivity in real time during the six-week DEEPWAVE field phase. Five missions were conducted using the NGV to observe regions of high forecast sensitivity, as diagnosed using the COAMPS adjoint model. In this presentation, we provide a summary of the sensitivity characteristics and explore the implications for predictability of low-level winds crucial for gravity wave launching, as well as predictability of gravity wave characteristics in the stratosphere. In general, the sensitive regions were characterized by localized strong dynamics, often involving intense baroclinic systems with deep convection. The results of the adjoint modeling system suggest that gravity wave launching and the characteristics of the gravity waves can be linked to these sensitive regions near frontal zones within baroclinic systems. The predictability links between the tropospheric fronts, cyclones, jet regions, and gravity

  5. Tongji-GRACE01: A GRACE-only static gravity field model recovered from GRACE Level-1B data using modified short arc approach

    NASA Astrophysics Data System (ADS)

    Chen, Qiujie; Shen, Yunzhong; Zhang, Xingfu; Chen, Wu; Hsu, Houze

    2015-09-01

    The modified short arc approach, where the position vector in force model are regarded as pseudo observation, is implemented in the SAtellite Gravimetry Analysis Software (SAGAS) developed by Tongji university. Based on the SAGAS platform, a static gravity field model (namely Tongji-GRACE01) complete to degree and order 160 is computed from 49 months of real GRACE Level-1B data spanning the period 2003-2007 (including the observations of K-band range-rate, reduced dynamic orbits, non-conservative accelerations and altitudes). The Tongji-GRACE01 model is compared with the recent GRACE-only models (such as GGM05S, AIUB-GRACE03S, ITG-GRACE03, ITG-GRACE2010S, and ITSG-GRACE2014S) and validated with GPS-leveling data sets in different countries. The results show that the Tongji-GRACE01 model has a considered quality as GGM05S, AIUB-GRACE03S and ITG-GRACE03. The Tongji-GRACE01 model is available at the International Centre for Global Earth Models (ICGEM) web page (http://icgem.gfz-potsdam.de/ICGEM/).

  6. On the impact of airborne gravity data to fused gravity field models

    NASA Astrophysics Data System (ADS)

    Bolkas, Dimitrios; Fotopoulos, Georgia; Braun, Alexander

    2016-03-01

    In gravity field modeling, fused models that utilize satellite, airborne and terrestrial gravity observations are often employed to deal with erroneous terrestrially derived gravity datasets. These terrestrial datasets may suffer from long-wavelength systematic errors and inhomogeneous data coverage, which are not prevalent in airborne and satellite datasets. Airborne gravity acquisition plays an essential role in gravity field modeling, providing valuable information of the Earth's gravity field at medium and short wavelengths. Thus, assessing the impact of airborne gravity data to fused gravity field models is important for identifying problematic regions. Six study regions that represent different gravity field variability and terrestrial data point-density characteristics are investigated to quantify the impact of airborne gravity data to fused gravity field models. The numerical assessments of these representative regions resulted in predictions of airborne gravity impact for individual states and provinces in the USA and Canada, respectively. Prediction results indicate that, depending on the terrestrial data point-density and gravity field variability, the expected impact of airborne gravity can reach up to 3mGal (in terms of standard deviation) in Canada and Alaska (over areas of 1° × 1°). However, in the mainland US region, small changes are expected (0.2-0.4 mGal over areas of 1° × 1°) due to the availability of high spatial resolution terrestrial data. These results can serve as a guideline for setting airborne gravity data acquisition priorities and for improving future planning of airborne gravity surveys.

  7. On the impact of airborne gravity data to fused gravity field models

    NASA Astrophysics Data System (ADS)

    Bolkas, Dimitrios; Fotopoulos, Georgia; Braun, Alexander

    2016-06-01

    In gravity field modeling, fused models that utilize satellite, airborne and terrestrial gravity observations are often employed to deal with erroneous terrestrially derived gravity datasets. These terrestrial datasets may suffer from long-wavelength systematic errors and inhomogeneous data coverage, which are not prevalent in airborne and satellite datasets. Airborne gravity acquisition plays an essential role in gravity field modeling, providing valuable information of the Earth's gravity field at medium and short wavelengths. Thus, assessing the impact of airborne gravity data to fused gravity field models is important for identifying problematic regions. Six study regions that represent different gravity field variability and terrestrial data point-density characteristics are investigated to quantify the impact of airborne gravity data to fused gravity field models. The numerical assessments of these representative regions resulted in predictions of airborne gravity impact for individual states and provinces in the USA and Canada, respectively. Prediction results indicate that, depending on the terrestrial data point-density and gravity field variability, the expected impact of airborne gravity can reach up to 3mGal (in terms of standard deviation) in Canada and Alaska (over areas of 1° × 1°). However, in the mainland US region, small changes are expected (0.2-0.4 mGal over areas of 1° × 1°) due to the availability of high spatial resolution terrestrial data. These results can serve as a guideline for setting airborne gravity data acquisition priorities and for improving future planning of airborne gravity surveys.

  8. Gravity settling

    DOEpatents

    Davis, Hyman R.; Long, R. H.; Simone, A. A.

    1979-01-01

    Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

  9. Simulating Gravity

    ERIC Educational Resources Information Center

    Pipinos, Savas

    2010-01-01

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

  10. MJO-related intraseasonal variation of gravity waves in the Southern Hemisphere tropical stratosphere revealed by high-resolution AIRS observations

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Chikara; Sato, Kaoru; Alexander, M. Joan; Hoffmann, Lars

    2016-07-01

    The intraseasonal variability of gravity waves (GWs) in the austral summer middle stratosphere was examined using dedicated high-resolution temperature retrieval from the Atmospheric Infrared Sounder data. Composite maps were made of stratospheric GW temperature variances, large-scale zonal winds around the tropopause, and precipitation based on the real-time multivariate Madden-Julian Oscillation (MJO) index. Regional distributions of these quantities are synchronized with the MJO: The GW variances are larger for stronger precipitation and for more strongly westward wind around the tropopause at a given precipitation. These results suggest that the GWs observed by Atmospheric Infrared Sounder (AIRS) in the stratosphere originate from convection. Moreover, it is shown that the zonal wind around the tropopause likely controls the GW propagation into the stratosphere by a critical level filtering mechanism and/or the GW generation by an obstacle source effect. This means that the MJO can modulate the middle atmospheric circulation by regulating the GWs in two ways, namely, generation and propagation.

  11. Neptunium estimation in dissolver and high-level-waste solutions

    SciTech Connect

    Pathak, P.N.; Prabhu, D.R.; Kanekar, A.S.; Manchanda, V.K.

    2008-07-01

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

  12. HIGH-LEVEL OZONE DISINFECTION OF MUNICIPAL WASTEWATER EFFLUENTS

    EPA Science Inventory

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

  13. Predicting gravity and sediment thickness in Afghanistan

    NASA Astrophysics Data System (ADS)

    Jung, W.; Brozena, J.; Peters, M.

    2013-02-01

    The US Naval Research Laboratory conducted comprehensive high-altitude (7 km above mean sea level) aero-geophysical surveys over Afghanistan in 2006 (Rampant Lion I). The surveys were done in collaboration with the US Geological Survey and upon the request of Islamic Republic of Afghanistan Ministry of Mines. In this study, we show that a best fitting admittance between topography and airborne gravity in western Afghanistan can be used to predict airborne gravity for the no-data area of eastern Afghanistan where the mountains are too high to conduct airborne surveys, due to the threat of ground fire. The differences between the airborne and the predicted gravity along a tie-track through the no-data area were found to be within ±12 mGal range with rms difference 7.3 mGal, while those between the predicted gravity from a simple Airy model (with compensation depth of 32 km and crustal density of 2.67 g cm-3) and the airborne gravity were within ±22 mGal range with rms difference 10.3 mGal. A combined airborne free-air anomaly has been constructed by merging the predicted gravity with the airborne data. We also demonstrate that sediment thickness can be estimated for basin areas where surface topography and airborne free-air anomaly profiles do not show a correlation presumably because of thick sediments. In order to estimate sediment thickness, we first determine a simple linear relationship from a scatter plot of the airborne gravity points and the interpolated Shuttle Radar Topography Mission (SRTM) topography along the Rampant Lion I tracks, and computed corresponding quasi-topography tracks by multiplying the linear relationship with the airborne free-air anomalies. We then take the differences between the SRTM and quasi-topography as a first-order estimate of sediment thickness. A global gravity model (GOCO02S), upward continued to the same altitude (7 km above mean sea level) as the data collection, was compared with the low-pass filtered (with cutoff

  14. 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.

  15. Effect of tapioca starch and amyloglucosidase concentration on very high gravity simultaneous saccharification and fermentation (VHG-SSF) of bioethanol

    NASA Astrophysics Data System (ADS)

    Sugih, A. K.; Santoso, I. V.; Kristijarti, A. P.

    2015-12-01

    Tapioca starch is isolated from the root of cassava plant (Manihot esculenta). It is produced in a large quantity in Indonesia and other south east Asian countries. Tapioca starch has been commonly used as a feedstock for food as well as non-food industries. Due to its high carbohydrate content, tapioca starch has the potentiality to be used as a raw material for bioethanol production. In this research, a novel approach (Very High Gravity Simultaneous Sacharification and Fermentation/ VHG-SSF) to synthesise highly concentrated ethanol from tapioca starch was investigated. Tapioca starch suspension was first gelatinised for two hours at 90°C and hydrolised at the same temperature for another two hours using commercial α- amylase (Liquozyme Supra, 0.16%-v/ w starch). The pretreated suspension was sterilised and mixed with nitrogenous supplement. In order to start the fermentation, Saccharomyces cereviseae NRRL Y-132 inoculum (10%-v/v; 107 cells/ ml) and commercial amyloglucosidase (Dextrozyme GA, 35-105 AGU/ g starch) were added to the mixture. The initial total carbohydrate, yeast extract, and peptone concentrations of the fermentation broths were 30-40 %-w/v, 1%-w/v, and 2%-w/v, respectively. VHG-SSF was allowed to proceed for 6 days at 30°C with rotary shaker speed of 100 rpm. The concentration of glucose and ethanol during fermentation was monitored using HPLC. The experimental result shows that tapioca starch has been successfully converted to ethanol with a final concentration of 10.12-16.14 %-w/v, which is corresponding to yield of 34.68-56.83 %-w ethanol/ w-converted sugar. The result suggests that VHG-SSF is a prospective method to synthesise bioethanol from tapioca starch.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2003-01-01

    The following paper 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.

  18. 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

  19. 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…

  20. Decision Document for Heat Removal from High Level Waste Tanks

    SciTech Connect

    WILLIS, W.L.

    2000-07-31

    This document establishes the combination of design and operational configurations that will be used to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. The chosen method--to use the primary and annulus ventilation systems to remove heat from the high-level waste tanks--is documented herein.

  1. 46 CFR 182.530 - Bilge high level alarms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Bilge high level alarms. 182.530 Section 182.530 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) MACHINERY INSTALLATION Bilge and Ballast Systems § 182.530 Bilge high level alarms. (a) On a vessel of at least 7.9 meters (26 feet) in...

  2. 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.

  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. Effect of high fluoride and high fat on serum lipid levels and oxidative stress in rabbits.

    PubMed

    Sun, Liyan; Gao, Yanhui; Zhang, Wei; Liu, Hui; Sun, Dianjun

    2014-11-01

    The purpose of this study was to explore the effects of high fluoride and high fat on triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total antioxidant capacity (T-AOC), lipid peroxide (LPO) and malondialdehyde (MDA) in rabbits. A factorial experimental design was used, with two factors (fluoride and fat) and three levels. Seventy-two male rabbits were randomly assigned into nine groups according to initial weight and serum lipid levels. The rabbits were fed with basic feed, moderate fat feed or high fat feed and drank tap water, fluoridated water at levels of 50 and 100mgfluorion/L freely. Biological materials were collected after 5 months, and serum lipid, T-AOC, LPO, and MDA levels were then measured. Using these data, the separate and interactive effects of high fluoride and high fat were analyzed. High fluoride and high fat both increased serum levels of TC, HDL-C and LDL-C significantly (P<0.05), and there was also a synergistic effect between high fluoride and high fat (P<0.05). High fluoride and high fat had different effects on TG levels: high fat significantly increased TG levels (P<0.01) whereas high fluoride had nothing to do with TG levels (P>0.05). High fat significantly elevated LPO and MDA levels and lowered T-AOC levels in serum (P<0.05). Similarly, high fluoride significantly increased LPO and MDA levels in serum (P<0.05). However, there was no interactive effect between high fat and high fluoride on these indexes. In summary, high fluoride and high fat increased serum TC and LDL-C levels individually and synergistically, and this would cause and aggravate hypercholesterolemia in rabbits. At the same time, high fluoride and high fat both made the accumulation of product of oxidative stress in experimental animals. PMID:25461561

  5. Three-dimensional inversion of regional P and S arrival times in the East Aleutians and sources of subduction zone gravity highs

    NASA Astrophysics Data System (ADS)

    Abers, Geoffrey A.

    1994-03-01

    Free-air gravity highs over forearcs represent a large fraction of the power in the Earth's anomalous field, yet their origin remains uncertain. Seismic velocities, as indicators of density, are estimated here as a means to compare the relative importance of upper plate sources for the gravity high with sources in the downgoing plate. P and S arrival times for local earthquakes, recorded by a seismic network in the eastern Aleutians, are inverted for three-dimensional velocity structure between the volcanic arc and the downgoing plate. A three-dimensional ray tracing scheme is used to invert the 7974 P and 6764 S arrivals for seismic velocities and hypocenters of 635 events. One-dimensional inversions show that station P residuals are systematically 0.25-0.5 s positive at stations 0-30 km north of the Aleutian volcanic arc, indicating slow material, while residuals at stations 10-30 km south of the arc are 0.1-0.25 s negative. Both features are explained in three-dimensional inversions by velocity variations at depths less than 25-35 km. Tests using a one-dimensional or a two-dimensional slab starting model show that below 100 km depth, velocities are poorly determined and trade off almost completely with hypocenters for earthquakes at these depths. The locations of forearc velocity highs, in the crust of the upper plate, correspond to the location of the gravity high between the trench and volcanic arc. Free-air anomalies, calculated from the three-dimensional velocity inversion result, match observed gravity for a linear density-velocity relationship between 0.1 and 0.3 (Mg m-3)/(km s-1), when a 50-km-thick slab is included with a density of 0.055±0.005 Mg m-3. Values outside these ranges do not match the observed gravity. The slab alone contributes one third to one half of the total 75-150 mGal amplitude of the gravity high but predicts a high that is much broader than is observed. The inclusion of upper-plate velocity anomalies predicts the correct width of

  6. Venus Gravity Handbook

    NASA Technical Reports Server (NTRS)

    Konopliv, Alexander S.; Sjogren, William L.

    1996-01-01

    This report documents the Venus gravity methods and results to date (model MGNP90LSAAP). It is called a handbook in that it contains many useful plots (such as geometry and orbit behavior) that are useful in evaluating the tracking data. We discuss the models that are used in processing the Doppler data and the estimation method for determining the gravity field. With Pioneer Venus Orbiter and Magellan tracking data, the Venus gravity field was determined complete to degree and order 90 with the use of the JPL Cray T3D Supercomputer. The gravity field shows unprecedented high correlation with topography and resolution of features to the 2OOkm resolution. In the procedure for solving the gravity field, other information is gained as well, and, for example, we discuss results for the Venus ephemeris, Love number, pole orientation of Venus, and atmospheric densities. Of significance is the Love number solution which indicates a liquid core for Venus. The ephemeris of Venus is determined to an accuracy of 0.02 mm/s (tens of meters in position), and the rotation period to 243.0194 +/- 0.0002 days.

  7. A Direct Comparison of Two High Precision Relative Gravity Meters at Optimal Performance

    NASA Astrophysics Data System (ADS)

    van Westrum, D.

    2015-12-01

    NGS has maintained and operated GWR Superconducting Gravimeter #024 since 1995. It has been widely considered one of the most quiet instruments from that era. It was recently upgraded with state of the art electronics and its operating parameters reoptimzied. A Micro-g LaCoste gPhoneX, installed on a high precision tilt table, was collocated with the SG at the Table Mountain Geophysical Observatory near Boulder, CO and the two instruments operated side by side for approximately two months. Results in both the frequency domain and selected time series from large seismic signals (e.g. earthquakes) will be presented, allowing for a direct comparison between the instruments in identical, ideal conditions.

  8. The effect of high altitude on nasal nitric oxide levels.

    PubMed

    Altundag, Aytug; Salihoglu, Murat; Cayonu, Melih; Cingi, Cemal; Tekeli, Hakan; Hummel, Thomas

    2014-09-01

    The aim of the present study was to investigate whether nasal nitric oxide (nNO) levels change in relation to high altitude in a natural setting where the weather conditions were favorable. The present study included 41 healthy volunteers without a history of acute rhinosinusitis within 3 weeks and nasal polyposis. The study group consisted of 31 males (76 %) and 10 females (24 %) and the mean age of the study population was 38 ± 10 years. The volunteers encamped for 2 days in a mountain village at an altitude of 1,500 m above sea level (masl) and proceeded to highlands at an altitude of 2,200 masl throughout the day. The measurements of nNO were done randomly, either first at the mountain village or at sea level. Each participant had nNO values both at sea level and at high altitude at the end of the study. The nNO values of sea level and high altitude were compared to investigate the effect of high altitude on nNO levels. The mean of average nNO measurements at the high altitude was 74.2 ± 41 parts-per-billion (ppb) and the mean of the measurements at sea level was 93.4 ± 45 ppb. The change in nNO depending on the altitude level was statistically significant (p < 0.001). The current investigation showed that nNO levels were decreased at high altitude even if the weather conditions were favorable, such as temperature, humidity, and wind. PMID:24972544

  9. First test of high frequency Gravity Waves from inflation using Advanced LIGO

    SciTech Connect

    Lopez, Alejandro; Freese, Katherine E-mail: ktfreese@umich.edu

    2015-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  11. Sensorimotor aspects of high-speed artificial gravity: II. The effect of head position on illusory self motion

    NASA Technical Reports Server (NTRS)

    Mast, F. W.; Newby, N. J.; Young, L. R.

    2002-01-01

    The effects of cross-coupled stimuli on the semicircular canals are shown to be influenced by the position of the subject's head with respect to gravity and the axis of rotation, but not by the subject's head position relative to the trunk. Seventeen healthy subjects made head yaw movements out of the horizontal plane while lying on a horizontal platform (MIT short radius centrifuge) rotating at 23 rpm about an earth-vertical axis. The subjects reported the magnitude and duration of the illusory pitch or roll sensations elicited by the cross-coupled rotational stimuli acting on the semicircular canals. The results suggest an influence of head position relative to gravity. The magnitude estimation is higher and the sensation decays more slowly when the head's final position is toward nose-up (gravity in the subject's head x-z-plane) compared to when the head is turned toward the side (gravity in the subject's head y-z-plane). The results are discussed with respect to artificial gravity in space and the possible role of pre-adaptation to cross-coupled angular accelerations on earth.

  12. Identification of candidate genes for yeast engineering to improve bioethanol production in very high gravity and lignocellulosic biomass industrial fermentations

    PubMed Central

    2011-01-01

    Background The optimization of industrial bioethanol production will depend on the rational design and manipulation of industrial strains to improve their robustness against the many stress factors affecting their performance during very high gravity (VHG) or lignocellulosic fermentations. In this study, a set of Saccharomyces cerevisiae genes found, through genome-wide screenings, to confer resistance to the simultaneous presence of different relevant stresses were identified as required for maximal fermentation performance under industrial conditions. Results Chemogenomics data were used to identify eight genes whose expression confers simultaneous resistance to high concentrations of glucose, acetic acid and ethanol, chemical stresses relevant for VHG fermentations; and eleven genes conferring simultaneous resistance to stresses relevant during lignocellulosic fermentations. These eleven genes were identified based on two different sets: one with five genes granting simultaneous resistance to ethanol, acetic acid and furfural, and the other with six genes providing simultaneous resistance to ethanol, acetic acid and vanillin. The expression of Bud31 and Hpr1 was found to lead to the increase of both ethanol yield and fermentation rate, while Pho85, Vrp1 and Ygl024w expression is required for maximal ethanol production in VHG fermentations. Five genes, Erg2, Prs3, Rav1, Rpb4 and Vma8, were found to contribute to the maintenance of cell viability in wheat straw hydrolysate and/or the maximal fermentation rate of this substrate. Conclusions The identified genes stand as preferential targets for genetic engineering manipulation in order to generate more robust industrial strains, able to cope with the most significant fermentation stresses and, thus, to increase ethanol production rate and final ethanol titers. PMID:22152034

  13. 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 [(ΔTeff)rms ˜ 219 K, (Δlog g)rms ˜ 0.37 dex, and (Δ[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.

  14. Lunar gravity - A harmonic analysis

    NASA Technical Reports Server (NTRS)

    Ferrari, A. J.

    1977-01-01

    A sixteenth-degree and sixteenth-order spherical harmonic lunar gravity field has been derived from the long-term Keplerian variations in the orbits of the Apollo subsatellites and Lunar Orbiter 5. This model resolves the major mascon gravity anomalies of the lunar near side and is in very good agreement with line-of-sight acceleration results. The far-side map shows the major ringed basins to be strong localized negative anomalies located in broad regions of positive gravity which correspond closely to the highlands. The rms pressure levels calculated from equivalent-surface height variations show that the moon and earth support nearly equal pressures, whereas Mars is appreciably stronger. The moon appears to support larger loads than earth owing to its weaker central gravity field and perhaps a colder upper lithosphere. Significant differences between the low-degree gravity and topography spectra indicate that the longer-wavelength topographic features are isostatically compensated.

  15. Does high serum uric acid level cause aspirin resistance?

    PubMed

    Yildiz, Bekir S; Ozkan, Emel; Esin, Fatma; Alihanoglu, Yusuf I; Ozkan, Hayrettin; Bilgin, Murat; Kilic, Ismail D; Ergin, Ahmet; Kaftan, Havane A; Evrengul, Harun

    2016-06-01

    In patients with coronary artery disease (CAD), though aspirin inhibits platelet activation and reduces atherothrombotic complications, it does not always sufficiently inhibit platelet function, thereby causing a clinical situation known as aspirin resistance. As hyperuricemia activates platelet turnover, aspirin resistance may be specifically induced by increased serum uric acid (SUA) levels. In this study, we thus investigated the association between SUA level and aspirin resistance in patients with CAD. We analyzed 245 consecutive patients with stable angina pectoris (SAP) who in coronary angiography showed more than 50% occlusion in a major coronary artery. According to aspirin resistance, two groups were formed: the aspirin resistance group (Group 1) and the aspirin-sensitive group (Group 2). Compared with those of Group 2, patients with aspirin resistance exhibited significantly higher white blood cell counts, neutrophil counts, neutrophil-to-lymphocyte ratios, SUA levels, high-sensitivity C-reactive protein levels, and fasting blood glucose levels. After multivariate analysis, a high level of SUA emerged as an independent predictor of aspirin resistance. The receiver-operating characteristic analysis provided a cutoff value of 6.45 mg/dl for SUA to predict aspirin resistance with 79% sensitivity and 65% specificity. Hyperuricemia may cause aspirin resistance in patients with CAD and high SUA levels may indicate aspirin-resistant patients. Such levels should thus recommend avoiding heart attack and stroke by adjusting aspirin dosage. PMID:26656902

  16. An overview of very high level software design methods

    NASA Technical Reports Server (NTRS)

    Asdjodi, Maryam; Hooper, James W.

    1988-01-01

    Very High Level design methods emphasize automatic transfer of requirements to formal design specifications, and/or may concentrate on automatic transformation of formal design specifications that include some semantic information of the system into machine executable form. Very high level design methods range from general domain independent methods to approaches implementable for specific applications or domains. Applying AI techniques, abstract programming methods, domain heuristics, software engineering tools, library-based programming and other methods different approaches for higher level software design are being developed. Though one finds that a given approach does not always fall exactly in any specific class, this paper provides a classification for very high level design methods including examples for each class. These methods are analyzed and compared based on their basic approaches, strengths and feasibility for future expansion toward automatic development of software systems.

  17. Effects of modified gravity in galactic clustering

    NASA Astrophysics Data System (ADS)

    Verma, Murli; Krishna Yadav, Bal

    2016-07-01

    We discuss the distinct effects of the modified gravity, especially f(R) gravity in structure formation. The small redshift as well as high redshift epochs are studied with a potential set of diagnostics distinguishing between the standard general relativistic and the modified gravity. These diagnostics are further put to test against the observations obtained in clustering surveys.

  18. Student Achievement Levels Raised at Chandler High School.

    ERIC Educational Resources Information Center

    Profiles, Programs & Products, 1983

    1983-01-01

    Chandler (Arizona) High School has reported a dramatic increase in student achievement levels since implementing a number of management, curriculum, and discipline policy changes. Among the program changes that contributed to these gains are: (1) creation of a positive school environment, with high expectations for teachers, emphasis on high…

  19. A Testing Instrument for High School Arabic, Level III.

    ERIC Educational Resources Information Center

    Wolowelsky, Joel B.

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

  20. Combustion Synthesis of TiB2-TiC/42CrMo4 Composites with Gradient Joint Prepared in Different High-Gravity Fields

    NASA Astrophysics Data System (ADS)

    Huang, Xuegang; Huang, Jie; Zhao, Zhongmin; Yin, Chun; Zhang, Long; Wu, Junyan

    2015-12-01

    The novel TiB2-TiC/42CrMo4-laminated composite materials were successfully fabricated by combustion synthesis in different high-gravity fields. This ceramic/metal composite material possesses continuously graded composition, and multilevel gradient microstructure, which is composed of TiB2-TiC ceramic substrate, ceramic-based intermediate layer, metal-based intermediate layer, and 42CrMo4 substrate. The ceramic-based intermediate layer is the main gradient transition region in the joint which shows that the TiB2 and TiC grains decrease gradually in size and volume fraction from the ceramic substrate to metal substrate. The experiment reveals that the increased high-gravity field not only leads to the higher combustion temperature and the remarkable thermal explosion mode, but also attributes to the enhanced interdiffusion and convection between the molten steel surface and liquid TiB2-based ceramic. So, the reliable fusion bonding of TiB2-TiC/42CrMo4 composite materials is achieved. Moreover, the phase separation and forced filling effect of high-gravity field is the key to improve the densification and bond performance of the joint. The ceramic/metal joint in the continuous gradient composition and microstructure represents not only the transitional change of Vickers hardness, but also the high shear bond strength of 420 ± 25 MPa.

  1. Solidifying Cast Iron in Low Gravity

    NASA Technical Reports Server (NTRS)

    Hendrix, J. C.; Curreri, P. A.; Stefanescu, D. M.

    1986-01-01

    Report describes study of solidification of cast iron in low and normal gravity. Because flotation, sedimentation, and convection suppressed, alloys that solidify at nearly zero gravity have unusual and potentially useful characteristics. Study conducted in airplane that repeatedly flew along parabolic trajectories. Appears iron/carbon alloys made at low gravity have greater carbon content (as high as 5 to 10 percent) than those made of Earth gravity because carbon particles do not float to top of melt.

  2. Imaging and Analysis of Void-defects in Solder Joints Formed in Reduced Gravity using High-Resolution Computed Tomography

    NASA Technical Reports Server (NTRS)

    Easton, John W.; Struk, Peter M.; Rotella, Anthony

    2008-01-01

    As a part of efforts to develop an electronics repair capability for long duration space missions, techniques and materials for soldering components on a circuit board in reduced gravity must be developed. This paper presents results from testing solder joint formation in low gravity on a NASA Reduced Gravity Research Aircraft. The results presented include joints formed using eutectic tin-lead solder and one of the following fluxes: (1) a no-clean flux core, (2) a rosin flux core, and (3) a solid solder wire with external liquid no-clean flux. The solder joints are analyzed with a computed tomography (CT) technique which imaged the interior of the entire solder joint. This replaced an earlier technique that required the solder joint to be destructively ground down revealing a single plane which was subsequently analyzed. The CT analysis technique is described and results presented with implications for future testing as well as implications for the overall electronics repair effort discussed.

  3. Gravity Modeling for Variable Fidelity Environments

    NASA Technical Reports Server (NTRS)

    Madden, Michael M.

    2006-01-01

    Aerospace simulations can model worlds, such as the Earth, with differing levels of fidelity. The simulation may represent the world as a plane, a sphere, an ellipsoid, or a high-order closed surface. The world may or may not rotate. The user may select lower fidelity models based on computational limits, a need for simplified analysis, or comparison to other data. However, the user will also wish to retain a close semblance of behavior to the real world. The effects of gravity on objects are an important component of modeling real-world behavior. Engineers generally equate the term gravity with the observed free-fall acceleration. However, free-fall acceleration is not equal to all observers. To observers on the sur-face of a rotating world, free-fall acceleration is the sum of gravitational attraction and the centrifugal acceleration due to the world's rotation. On the other hand, free-fall acceleration equals gravitational attraction to an observer in inertial space. Surface-observed simulations (e.g. aircraft), which use non-rotating world models, may choose to model observed free fall acceleration as the gravity term; such a model actually combines gravitational at-traction with centrifugal acceleration due to the Earth s rotation. However, this modeling choice invites confusion as one evolves the simulation to higher fidelity world models or adds inertial observers. Care must be taken to model gravity in concert with the world model to avoid denigrating the fidelity of modeling observed free fall. The paper will go into greater depth on gravity modeling and the physical disparities and synergies that arise when coupling specific gravity models with world models.

  4. Time variable Earth's gravity field from SLR satellites

    NASA Astrophysics Data System (ADS)

    Sośnica, Krzysztof; Jäggi, Adrian; Meyer, Ulrich; Thaller, Daniela; Beutler, Gerhard; Arnold, Daniel; Dach, Rolf

    2015-10-01

    The time variable Earth's gravity field contains information about the mass transport within the system Earth, i.e., the relationship between mass variations in the atmosphere, oceans, land hydrology, and ice sheets. For many years, satellite laser ranging (SLR) observations to geodetic satellites have provided valuable information of the low-degree coefficients of the Earth's gravity field. Today, the Gravity Recovery and Climate Experiment (GRACE) mission is the major source of information for the time variable field of a high spatial resolution. We recover the low-degree coefficients of the time variable Earth's gravity field using SLR observations up to nine geodetic satellites: LAGEOS-1, LAGEOS-2, Starlette, Stella, AJISAI, LARES, Larets, BLITS, and Beacon-C. We estimate monthly gravity field coefficients up to degree and order 10/10 for the time span 2003-2013 and we compare the results with the GRACE-derived gravity field coefficients. We show that not only degree-2 gravity field coefficients can be well determined from SLR, but also other coefficients up to degree 10 using the combination of short 1-day arcs for low orbiting satellites and 10-day arcs for LAGEOS-1/2. In this way, LAGEOS-1/2 allow recovering zonal terms, which are associated with long-term satellite orbit perturbations, whereas the tesseral and sectorial terms benefit most from low orbiting satellites, whose orbit modeling deficiencies are minimized due to short 1-day arcs. The amplitudes of the annual signal in the low-degree gravity field coefficients derived from SLR agree with GRACE K-band results at a level of 77 %. This implies that SLR has a great potential to fill the gap between the current GRACE and the future GRACE Follow-On mission for recovering of the seasonal variations and secular trends of the longest wavelengths in gravity field, which are associated with the large-scale mass transport in the system Earth.

  5. Determination of the nuclear level density at high excitation energy

    SciTech Connect

    Chbihi, A.; Sobotka, L.G.; Nicolis, N.G.; Sarantites, D.G.; Stracener, D.W.; Majka, Z. ); Hensley, D.C.; Beene, J.R.; Halbert, M.L. )

    1991-02-01

    Evaporation simulations are presented to illustrate the problems associated with the determination of the nuclear level density constant at high excitation energy from evaporation spectra. The methods of using either the total (whole chain) spectra or the difference (from two different initial excitation energies) spectra are discussed. Data from the study of the reaction 701 MeV {sup 28}Si+{sup 100}Mo are presented and both methods are used to extract the level density constant. We find that in order to reproduce the slopes of the light particle spectra the level density constant must have a value near 1/10{ital A}-- 1 / 11 {ital A} for excited nuclei with statistical temperatures in the range of 3.5 to 5.5 MeV. This presumes that the only parameter adjustment required to treat the decay of highly exited nuclei is the level density constant. If this is so, the shapes of the evaporation spectra imply a reduction in the level density constant from the value required to explain the decay of less highly excited nuclei, a conclusion reached by others. However, the reduced level density constant leads to an overproduction of deuterons and tritons. This suggests that a more complicated set of parameter adjustments may be required to treat the decay of highly excited nuclei.

  6. Selection of artificial gravity by animals during suborbital rocket flights

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  7. Expanding Gravity

    NASA Astrophysics Data System (ADS)

    Aisenberg, Sol

    2005-04-01

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

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

    NASA Technical Reports Server (NTRS)

    Balakotaiah, V.

    1996-01-01

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

  9. Is nonrelativistic gravity possible?

    SciTech Connect

    Kocharyan, A. A.

    2009-07-15

    We study nonrelativistic gravity using the Hamiltonian formalism. For the dynamics of general relativity (relativistic gravity) the formalism is well known and called the Arnowitt-Deser-Misner (ADM) formalism. We show that if the lapse function is constrained correctly, then nonrelativistic gravity is described by a consistent Hamiltonian system. Surprisingly, nonrelativistic gravity can have solutions identical to relativistic gravity ones. In particular, (anti-)de Sitter black holes of Einstein gravity and IR limit of Horava gravity are locally identical.

  10. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, M.; Masson, F.; Hwang, C.; Cheng, C.; Le Moigne, N.; Lee, C.; Kao, R.; Hsieh, N.

    2009-12-01

    AGTO is a scientific project between Taiwanese and French institutes which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao island, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. At the end of 2009, the relative gravity network will be densified again in its eastern part, i.e. in the Longitudinal Valley and the Central Range. A fourth set of absolute gravity measurements will also be performed at the same period. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 μGal. Only the site located in Tainan University has higher standard deviation, due to the city noise. The stronger change in gravity reaches -7 μGal a -1 west of the Longitudinal Valley and might be explained by tectonic movement along a fault. A large decrease of -5 μGal a-1 is also measured in Tainan city and could be correlated with uplift of this region, also denoted by InSAR, leveling and GPS. Changes occurring in the Central Range are more difficult to interpret due to the small

  11. An Investigation of Source and Receiver Apprehension at the Junior High, Senior High and College Levels.

    ERIC Educational Resources Information Center

    McDowell, Earl E.; McDowell, Carlene E.

    1978-01-01

    The Personal Report of Communication Apprehension and the Receiver Apprehension Test are used to determine the relationship between speech and listening apprehension at each educational level (junior high, senior high, and college); differences among educational levels and between sexes; and the interaction effect of educational level and sex. (JF)

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  13. Oxidative Stress Levels in Aqueous Humor from High Myopic Patients

    PubMed Central

    Kim, Eun Bi; Kim, Ha Kyoung; Hyon, Joon Young; Wee, Won Ryang

    2016-01-01

    Purpose To compare oxidative stress status in the aqueous humor of highly myopic eyes and control eyes. Methods Aqueous humor samples were collected from 15 highly myopic eyes (high myopia group) and 23 cataractous eyes (control group) during cataract surgery. Central corneal thickness, corneal endothelial cell density, hexagonality of corneal endothelial cells, and cell area of corneal endothelial cells were measured using specular microscopy. Axial length was measured using ultrasound biometry. 8-Hydroxydeoxyguanosine (8-OHdG) and malondialdehyde levels were measured using enzyme-linked immunosorbent assay. Results 8-OHdG level was lower in the aqueous humor of myopic patients than in that of control group (p = 0.014) and was positively correlated with central corneal thickness and negatively correlated with axial length (r = 0.511, p = 0.02; r = -0.382, p < 0.001). There was no correlation between 8-OHdG level and corneal endothelial cell density, hexagonality, or cell area. Malondialdehyde level did not show any correlation with any parameters evaluated. Conclusions 8-OHdG might be a sensitive biomarker for evaluating oxidative stress status in the eye. Oxidative stress level was lower in the aqueous humor of highly myopic eyes compared to that in control eyes, which indicates lower metabolic activity in these eyes. PMID:27247516

  14. 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.

  15. Photovoltaic (PV) Impact Assessment for Very High Penetration Levels

    SciTech Connect

    Cheng, Danling; Mather, Barry A.; Seguin, Richard; Hambrick, Joshua; Broadwater, Robert P.

    2016-01-01

    This paper describes a granular approach for investigating the impacts of very high photovoltaic (PV) generation penetration. Studies on two real-world distribution feeders connected to PV plants are presented. The studies include both steady-state and time-series power flow analyses, which include the effects of solar variability. The goal of the study is to predict the effects of increasing levels of PV generation as it reaches very high penetration levels. The loss and return of generation with and without regulation is simulated to capture short-term problems such as voltage fluctuations. Impact results from the analyses are described along with potential mitigations.

  16. Disposal of high-level nuclear waste in space

    NASA Astrophysics Data System (ADS)

    Coopersmith, Jonathan

    1992-08-01

    A solution of launching high-level nuclear waste into space is suggested. Disposal in space includes solidifying the wastes, embedding them in an explosion-proof vehicle, and launching it into earth orbit, and then into a solar orbit. The benefits of such a system include not only the safe disposal of high-level waste but also the establishment of an infrastructure for large-scale space exploration and development. Particular attention is given to the wide range of technical choices along with the societal, economic, and political factors needed for success.

  17. Sterilization, high-level disinfection, and environmental cleaning.

    PubMed

    Rutala, William A; Weber, David J

    2011-03-01

    Failure to perform proper disinfection and sterilization of medical devices may lead to introduction of pathogens, resulting in infection. New techniques have been developed for achieving high-level disinfection and adequate environmental cleanliness. This article examines new technologies for sterilization and high-level disinfection of critical and semicritical items, respectively, and because semicritical items carry the greatest risk of infection, the authors discuss reprocessing semicritical items such as endoscopes and automated endoscope reprocessors, endocavitary probes, prostate biopsy probes, tonometers, laryngoscopes, and infrared coagulation devices. In addition, current issues and practices associated with environmental cleaning are reviewed. PMID:21315994

  18. High level radioactive waste management facility design criteria

    SciTech Connect

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

    1993-10-01

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

  19. The Use of ARTEMIS with High-Level Applications

    SciTech Connect

    B. A. Bowling; H. Shoaee; S. Witherspoon

    1995-10-01

    ARTEMIS is an online accelerator modeling server developed at CEBAF. One of the design goals of ARTEMIS was to provide an integrated modeling environment for high- level accelerator diagnostic and control applications such as automated beam steering, Linac Energy management (LEM) and the fast feedback system. This report illustrates the use of ARTEMIS in these applications as well as the application interface using the EPICS cdev device support API. Concentration is placed on the design and implementation aspects of high- level applications which utilize the ARTEMIS server for information on beam dynamics. Performance benchmarks for various model operations provided by ARTEMIS are also discussed.

  20. Final report on cermet high-level waste forms

    SciTech Connect

    Kobisk, E.H.; Quinby, T.C.; Aaron, W.S.

    1981-08-01

    Cermets are being developed as an alternate method for the fixation of defense and commercial high level radioactive waste in a terminal disposal form. Following initial feasibility assessments of this waste form, consisting of ceramic particles dispersed in an iron-nickel base alloy, significantly improved processing methods were developed. The characterization of cermets has continued through property determinations on samples prepared by various methods from a variety of simulated and actual high-level wastes. This report describes the status of development of the cermet waste form as it has evolved since 1977. 6 tables, 18 figures.

  1. Airborne Gravity Gradiometry Resolves a Full Range of Gravity Frequencies

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

    Airborne Full Tensor Gradiometry (Air\\-FTGR) was flown at high altitude coincident with Airborne Gravity (AG) flown in 2003 in West Arnhem Land, Australia. A preliminary analysis of two data sets indicates that the Air\\-FTGR system has the capability of resolving intermediate to long wavelengths features that may be associated with relatively deeper geological structures. A comparison of frequency filtered slices and power spectral density (PSD) for both data sets using the short (> 5 km), intermediate (10 km) and long (20 km) wavelengths reveals that high altitude Air\\-FTGR data show greater response in high frequency anomalies than a conventional Airborne Gravity and matches well with the AG even at the longest wavelengths anomalies. The effect of line spacing and target resolution was examined between the two data sets. Reprocessed gradient and AG data at 2, 4 and 6 km line spacing suggest that Air\\-FTGR could be effectively flown at a comparatively wider line spacing to resolve similar targets the AG would resolve with tighter line spacing. Introduction Airborne Full Tensor Gradiometry (Air\\-FTGR) data have been available to the mining industry since 2002 and their use for geologic applications is well established. However, Air\\-FTGR data has been mostly considered and used in mapping and delineation of near surface geological targets. This is due to the fact that gravity gradiometer measurements are well suited to capture the high frequency signal associated with near\\-surface targets ( Li, 2001). This is possible because the gradiometer signal strength falls off with the cube of the distance to the target. Nonetheless, in recent years there has been an increasing demand from the mining, oil, and gas industry in utilizing Full Tensor Gravity Gradiometer as a mapping tool for both regional and prospect level surveys. Air\\-FTGR as a Regional Mapping Tool Several, relatively low altitude surveys have been successfully flown in Brazil, Canada and Australia

  2. 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.

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

    NASA Astrophysics Data System (ADS)

    Yu, Yonghui

    This doctoral dissertation has mainly concentrated on modeling studies of shorter period acoustic-gravity waves propagating in the upper atmosphere. Several cases have been investigated in the literature, which are focusing on the propagation characteristics of highfrequency gravity wave packets. The dissertation consists of five main divisions of which each has its own significance to be addressed, and these five chapters are also bridged in order with each other to present a theme about gravity wave ducting dynamics, energetics, and airglows. The first chapter is served as an introduction of the general topic about atmospheric acoustic-gravity waves. Some of the historical backgrounds are provided as an interesting refreshment and also as a motivation reasoning this scientific research for decades. A new 2-D, time-dependent, and nonlinear model is introduced in the second chapter (the AGE-TIP model, acronymically named atmospheric gravity waves for the Earth plus tides and planetary waves). The model is developed during this entire doctoral study and has carried out almost all research results in this dissertation. The third chapter is a model application for shorter period gravity waves ducted in a thermally stratified atmosphere. In spite of mean winds the thermal ducting occurs because ducted waves are fairly common occurrences in airglow observations. One-dimensional Fourier analysis is applied to identify the ducted wave modes that reside within multiple thermal ducts. Besides, the vertical energy flux and the wave kinetic energy density are derived as wave diagnostic variables to better understand the time-resolved vertical transport of wave energy in the presence of multiple thermal ductings. The fourth chapter is also a model application for shorter period gravity waves, but it instead addresses the propagation of high-frequency gravity waves in the presence of mean background wind shears. The wind structure acts as a significant directional filter to the

  4. Eustatic control of gravity tectonics: Concept, mechanism and limits

    SciTech Connect

    Raillard, S.; Allix, P.; Guerin, G.; Lecanu, H. )

    1996-01-01

    Gravity tectonics over a ductile decollement characterizes deformation of the Albian to Recent section in the West African margin, from Gabon to Angola. Largely studied during the past 20 years as a prolific petroleum play, it is now well known that three mains factors will control gravity driven deformation: the ductile layer, the slope as a response to the crustal activity and the overlying sedimentary loading. For the West African passive margin, the slope effect at the first glance can be considered as constant and gravity driven deformation as a result of salt layer distribution (in time and space) and sedimentary loading. If previous papers have already shown that the type and distribution of the deposits control the development of the classical structural domains : updip extensional to downdip contractional, this study will focused on the factor which control the sedimentary loading. Based on several natural examples combining seismic stratigraphy, sequential stratigraphy and structural studies and also analogical modelling, it is demonstrated that: (1) as sediment distribution and then sedimentary loading is controlled by relative sea level changes, thus sea level changes can be directly related to gravity driven deformation : large sea level fall will provide an important increase of clastics supply which will enhanced gravity gliding. On the contrary, relative sea level high will stop the deformation because of the decreasing amount of detritics and their homogeneous distribution. (2) the salt downdip withdrawal during extension will enhance the eustatic effect. (3) episodic crustal activity, materialized by westward tilting of the margin will interfere on this mechanism.

  5. Eustatic control of gravity tectonics: Concept, mechanism and limits

    SciTech Connect

    Raillard, S.; Allix, P.; Guerin, G.; Lecanu, H.

    1996-12-31

    Gravity tectonics over a ductile decollement characterizes deformation of the Albian to Recent section in the West African margin, from Gabon to Angola. Largely studied during the past 20 years as a prolific petroleum play, it is now well known that three mains factors will control gravity driven deformation: the ductile layer, the slope as a response to the crustal activity and the overlying sedimentary loading. For the West African passive margin, the slope effect at the first glance can be considered as constant and gravity driven deformation as a result of salt layer distribution (in time and space) and sedimentary loading. If previous papers have already shown that the type and distribution of the deposits control the development of the classical structural domains : updip extensional to downdip contractional, this study will focused on the factor which control the sedimentary loading. Based on several natural examples combining seismic stratigraphy, sequential stratigraphy and structural studies and also analogical modelling, it is demonstrated that: (1) as sediment distribution and then sedimentary loading is controlled by relative sea level changes, thus sea level changes can be directly related to gravity driven deformation : large sea level fall will provide an important increase of clastics supply which will enhanced gravity gliding. On the contrary, relative sea level high will stop the deformation because of the decreasing amount of detritics and their homogeneous distribution. (2) the salt downdip withdrawal during extension will enhance the eustatic effect. (3) episodic crustal activity, materialized by westward tilting of the margin will interfere on this mechanism.

  6. Joint Tomographic Imaging of 3-­-D Density Structure Using Cosmic Ray Muons and High-­-Precision Gravity Data

    NASA Astrophysics Data System (ADS)

    Rowe, C. A.; Guardincerri, E.; Roy, M.; Dichter, M.

    2015-12-01

    As part of the CO2 reservoir muon imaging project headed by the Pacific Northwest National Laboraory (PNNL) under the U.S. Department of Energy Subsurface Technology and Engineering Research, Development, and Demonstration (SubTER) iniative, Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) plan to leverage the recently decommissioned and easily accessible Tunnel Vault on LANL property to test the complementary modeling strengths of muon radiography and high-precision gravity surveys. This tunnel extends roughly 300 feet into the hillside, with a maximum depth below the surface of approximately 300 feet. We will deploy LANL's Mini Muon Tracker (MMT), a detector consisting of 576 drift tubes arranged in alternating parallel planes of orthogonally oriented tubes. This detector is capable of precise determination of trajectories for incoming muons with angular resolution of a few milliradians. We will deploy the MMT at several locations within the tunnel, to obtain numerous crossing muon trajectories and permit a 3D tomographic image of the overburden to be built. In the same project, UNM will use a Scintrex digital gravimeter to collect high-precision gravity data from a dense grid on the hill slope above the tunnel as well as within the tunnel itself. This will provide both direct and differential gravity readings for density modeling of the overburden. By leveraging detailed geologic knowledge of the canyon and the lithology overlying the tunnel, as well as the structural elements, elevations and blueprints of the tunnel itself, we will evaluate the muon and gravity data both independently and in a simultaneous, joint inversion to build a combined 3D density model of the overburden.

  7. Modeling future high-resolution dynamic sea level change

    NASA Astrophysics Data System (ADS)

    Brunnabend, Sandra-Esther; Dijkstra, Henk A.; Kliphuis, Michael A.; van Werkhoven, Ben; Bal, Henri E.; van Meersbergen, Maarten; Seinstra, Frank; Maassen, Jason

    2015-04-01

    Different studies have shown that resolving ocean eddies and representing boundary currents are of major importance when simulating changes in dynamic sea level on regional scale. Therefore, we use the strongly eddying global model version of the Parallel Ocean Program to simulate high-resolution future (up to the year 2100) sea surface height variations (SSH) under the SRES-A1B atmospheric forcing scenario. Results show dynamic sea level changes in the Southern Ocean that are caused by the southward shift in the westerly winds. The warming ocean (global mean sea surface temperature rises by about 2°C over the period 2000-2100) leads to a strong reduction of the Atlantic Meridional Overturning Circulation (AMOC). The magnitude of this reduction is affected by a feedback involving the heat transport to the sub-polar gyre region and evaporation over the North Atlantic region. The ocean circulation changes cause regional deviations from global mean sea level change in the North Atlantic. At coastal regions of eastern North America, dynamic sea level change leads to a positive deviation from global mean sea level change in the order of several decimeters. In the sub-polar gyre region a negative deviation from global mean sea level occurs. In the western North Atlantic, not only mean regional sea level is changed but also its variability, caused by shifted eddy pathways. This leads to a change in the frequency distribution of SSH anomalies, which has important consequences for regional sea level extremes.

  8. The gravity field of Jupiter

    NASA Technical Reports Server (NTRS)

    Anderson, J. D.

    1976-01-01

    Preliminary analysis of two-way Doppler data from Pioneers 10 and 11 has provided the first detailed model of the Jovian gravity field. A review of the determination of the zonal harmonic coefficients through the sixth degree is presented, and the results are used to derive a number of geodetic parameters in the atmospheric region of the planet. On a level surface at a pressure of one bar, the net acceleration due to gravity is found to vary from a maximum of 2707 cm/sec squared at the poles to a minimum of 2322 cm/sec squared at the equator. The large dynamical flattening at the one-bar level produces a significant deviation of the local vertical from the Jovicentric radius vector. The angular difference is as much as 3.83 degrees of arc in the high temperature zones of the planet. These considerations are important for the accurate modeling of the atmosphere of Jupiter and for the interpretation of occultation data.

  9. The tracking of high level waste shipments-TRANSCOM system

    SciTech Connect

    Johnson, P.E.; Joy, D.S.; Pope, R.B.

    1995-12-31

    The TRANSCOM (transportation tracking and communication) system is the U.S. Department of Energy`s (DOE`s) real-time system for tracking shipments of spent fuel, high-level wastes, and other high-visibility shipments of radioactive material. The TRANSCOM system has been operational since 1988. The system was used during FY1993 to track almost 100 shipments within the US.DOE complex, and it is accessed weekly by 10 to 20 users.

  10. Satellites to Delta n = 1 transitions between high-lying levels of multiply ionized atoms

    NASA Astrophysics Data System (ADS)

    Koenig, R.; Kolk, K.-H.; Koshelev, K. N.; Kunze, H.-J.

    1989-04-01

    In a theta pinch discharge satellites to Delta n = 1 transitions between high-lying levels are observed for the ions Si IX, Si X, and Si XI, but not for Si XII. They are identified as Delta n = 1 transitions between the corresponding levels of doubly excited systems. At high densities, the series of Rydberg levels above their respective thermal limit are collisionally coupled to their ionization limit. The intensity ratio of a transition to that of its satellite thus offers the unique possibility of measuring the ratio of the population density in the ground energy level of the next ionization stage to that in the lowest excited levels of this ion.

  11. The ATLAS Data Acquisition and High Level Trigger system

    NASA Astrophysics Data System (ADS)

    The ATLAS TDAQ Collaboration

    2016-06-01

    This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.

  12. Student Achievement Levels Climb at Ribault Senior High School.

    ERIC Educational Resources Information Center

    Profiles, Programs & Products, 1983

    1983-01-01

    Ribault (Florida) Senior High School has reported a dramatic increase in student achievement levels since implementing a comprehensive college preparation curriculum. Among the program changes that contributed to those gains are: (1) the establishment and consistent enforcement of a strong discipline program, including rules for student conduct, a…

  13. A comparison of high-level waste form characteristics

    SciTech Connect

    Salmon, R.; Notz, K.J.

    1991-01-01

    There are currently about 1055 million curies of high-level waste with a thermal output of about 2950 kilowatts (KW) at four sites in the United States: West Valley Demonstration Project (WVDP), Savannah River Site (SRS), Hanford Site (HANF), and Idaho National Engineering Laboratory (INEL). These quantities are expected to increase to about 1200 million curies and 3570 kw by the end of year 2020. Under the Nuclear Waste Policy Act, this high-level waste must ultimately be disposed of in a geologic repository. Accordingly, canisters of high-level waste immobilized in borosilicate glass or glass-ceramic mixtures are to be produced at the four sites and stored there until a repository becomes available. Data on the estimated production schedules and on the physical, chemical, and radiological characteristics of the canisters of immobilized high-level waste have been collected in OCRWM's Waste Characteristics Data Base, including recent updates an revisions. Comparisons of some of these data for the four sites are presented in this report. 14 refs., 3 tabs.

  14. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Definitions § 227.30...

  15. 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…

  16. 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.

  17. MIXING PROCESSES IN HIGH-LEVEL WASTE TANKS

    EPA Science Inventory

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

  18. THE XAL INFRASTRUCTURE FOR HIGH LEVEL CONTROL ROOM APPLICATIONS

    SciTech Connect

    Shishlo, Andrei P; Allen, Christopher K; Chu, Paul; Galambos, John D; Pelaia II, Tom

    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.

  19. High-Level waste process and product data annotated bibliography

    SciTech Connect

    Stegen, G.E.

    1996-02-13

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

  20. 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...

  1. Typewriter Modifications for Persons Who Are High-Level Quadriplegics.

    ERIC Educational Resources Information Center

    O'Reagan, James R.; And Others

    Standard, common electric typewriters are not completely suited to the needs of a high-level quadriplegic typing with a mouthstick. Experiences show that for complete control of a typewriter a mouthstick user needs the combined features of one-button correction, electric forward and reverse indexing, and easy character viewing. To modify a…

  2. 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…

  3. The Politics of High-Level Manpower Supply in Tanzania

    ERIC Educational Resources Information Center

    Brooke-Smith, Robin

    1978-01-01

    In its policies related to high-level manpower, the Tanzanian Government attaches great importance to the university, viewing it as a key institution in its policies for national development. Describes the difficulties the administration of President Nyerere has had in using the university as a political tool and analyzes various instances of…

  4. Directional solidification of Cu- Pb and Bi- Ga monotectic alloys under normal gravity and during parabolic flight

    NASA Astrophysics Data System (ADS)

    Dhindaw, B. K.; Stefanescu, D. M.; Singh, A. K.; Curreri, P. A.

    1988-11-01

    Cu-Pb and Bi-Ga monotectic alloys of nominal hypermonotectic compositions were directionally solidified under various furnace translation rates, temperature gradients, and gravity levels. Gravity was varied by solidifying the alloys under ground conditions and in the furnace aboard NASA KC-135 aircraft, flying on parabolic trajectories. High translation rates, high gradients, high gravity levels, and higher density and lower thermal conductivity of the L2 phase favored the formation of fiber composite structure, while the opposite conditions resulted in structures consisting of L2 droplets in α matrix. A modified particle engulfment theory as originally enunciated by Ulhmann et al. is proposed to explain these observations.

  5. Directional solidification of Cu-Pb and Bi-Ga monotectic alloys under normal gravity and during parabolic flight

    NASA Technical Reports Server (NTRS)

    Dhindaw, B. K.; Stefanescu, D. M.; Singh, A. K.; Curreri, P. A.

    1988-01-01

    Cu-Pb and Bi-Ga monotectic alloys of nominal hypermonotectic compositions were directionally solidified under various furnace translation rates, temperature gradients, and gravity levels. Gravity was varied by solidifying the alloys under ground conditions and in the furnace aboard NASA KC-135 aircraft, flying on parabolic trajectories. High translation rates, high gradients, high gravity levels, and higher density and lower thermal conductivity of the L2 phase favored the formation of fiber composite structure, while the opposite conditions resulted in structures consisting of L2 droplets in alpha matrix. A modified particle engulfment theory as originally enunciated by Ulhmann et al. (1964) is proposed to explain these observations.

  6. Effective Communication: High-Level Management Receptive to Low-Level Management Ideas.

    ERIC Educational Resources Information Center

    Chressanthis, June D.; Janousek, Kelly

    Based on the premise that senior staff or high-level managers have the knowledge and experience required to make daily decisions and also have a degree of power and respect, this document proposes that these managers are in a position to be effective leaders who can and should foster an atmosphere of receptiveness for innovation and positive…

  7. Cosmological tests of gravity

    SciTech Connect

    Jain, Bhuvnesh; Khoury, Justin

    2010-07-15

    Modifications of general relativity provide an alternative explanation to dark energy for the observed acceleration of the universe. We review recent developments in modified gravity theories, focusing on higher-dimensional approaches and chameleon/f(R) theories. We classify these models in terms of the screening mechanisms that enable such theories to approach general relativity on small scales (and thus satisfy solar system constraints). We describe general features of the modified Friedman equation in such theories. The second half of this review describes experimental tests of gravity in light of the new theoretical approaches. We summarize the high precision tests of gravity on laboratory and solar system scales. We describe in some detail tests on astrophysical scales ranging from {approx} kpc (galaxy scales) to {approx} Gpc (large-scale structure). These tests rely on the growth and inter-relationship of perturbations in the metric potentials, density and velocity fields which can be measured using gravitational lensing, galaxy cluster abundances, galaxy clustering and the integrated Sachs-Wolfe effect. A robust way to interpret observations is by constraining effective parameters, such as the ratio of the two metric potentials. Currently tests of gravity on astrophysical scales are in the early stages - we summarize these tests and discuss the interesting prospects for new tests in the coming decade.

  8. Detection of High-Potential Oil and Gas Fields Using Normalized Full Gradient of Gravity Anomalies: A Case Study in the Tabas Basin, Eastern Iran

    NASA Astrophysics Data System (ADS)

    Aghajani, Hamid; Moradzadeh, Ali; Zeng, Hualin

    2011-10-01

    The normalized full gradient (NFG) represents the full gradient of the gravity anomaly at a point divided by the average of the full gradient at the same point. The NFG minimum between two maxima in an NFG section or a closed minimum surrounded by closed maxima on an NFG map may indicate density-deficient anomalies closely related to possible oil-gas reservoirs. On a cross-section, closed minima can be used to estimate the depth to centers of possible hydrocarbon reservoirs. The NFG map can also be used to locate oil-gas exploratory wells for estimation of the depth of possible reservoirs. The objective of this paper is to use two and three-dimensional (2D and 3D) NFG on gravity data of the Tabas basin in Yazd province, eastern Iran. A hypothetical model is first considered to explore the NFG characteristics and their relationship with the geometry of the model. The physical properties of the model are then studied to simplify the interpretation of real data. Finally 2D and 3D NFG models are developed for real gravity data to predict the location of any possible high potential oil-gas reservoirs. The results obtained indicate two zones in the northern and central parts of the Tabas basin suitable for hydrocarbon prospecting. However, the favorable zone located in the middle of the basin in which anticline E is detected at a depth of 5-7 km is more important for the purpose of hydrocarbon exploration.

  9. High-Precise Gravity Observations at Archaeological Sites: How We Can Improve the Interpretation Effectiveness and Reliability?

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev

    2015-04-01

    Microgravity investigations are comparatively rarely used for searching of hidden ancient targets (e.g., Eppelbaum, 2013). It is caused mainly by small geometric size of the desired archaeological objects and various types of noise complicating the observed useful signal. At the same time, development of modern generation of field gravimetric equipment allows to register microGal (10-8 m/s2) anomalies that offer a new challenge in this direction. Correspondingly, an accuracy of gravity variometers (gradientometers) is also sharply increased. How we can improve the interpretation effectiveness and reliability? Undoubtedly, it must be a multi-stage process. I believe that we must begin since nonconventional methodologies for reducing topographic effect and terrain correction computation. Topographic effect reducing The possibilities of reducing topographic effects by grouping the points of additional gravimetric observations around the central point located on the survey network were demonstrated in (Khesin et al., 1996). A group of 4 to 8 additional points is located above and below along the relief approximately symmetrically and equidistant from the central point. The topographic effect is reduced to the obtained difference between the gravity field in the center of the group and its mean value for the whole group. Application of this methodology in the gold-pyrite deposit Gyzyl-Bulakh (Lesser Caucasus, western Azerbaijan) indicated its effectiveness. Computation of terrain correction Some geophysicists compare the new ideas in the field of terrain correction (TC) in gravimetry with the 'perpetuum mobile' invention. However, when we speak about very detailed gravity observations, the problem of most optimal computation of surrounding relief influence is of a great importance. Let us will consider two approaches applied earlier in ore geophysics. First approach A first method was applied in the Gyzyl-Bulakh gold-pyrite deposit situated in the Mekhmana ore region of

  10. Third-order development of shape, gravity, and moment of inertia for highly flattened celestial bodies. Application to Ceres

    NASA Astrophysics Data System (ADS)

    Rambaux, N.; Chambat, F.; Castillo-Rogez, J. C.

    2015-12-01

    Context. We investigate the hydrostatic shape and gravitational potential coefficients of self-gravitating and rotating bodies large enough to have undergone internal differentiation and chemical stratification. Quantifying these properties under the assumption of hydrostatic equilibrium forms the basis for interpreting shape and gravity data in terms of interior structure and infer deviations from hydrostaticity that can bring information on the thermal and chemical history of the objects. Aims: The main purpose is to show the importance of developing the reference hydrostatic shape for relatively fast rotating bodies up to third order to reach an accuracy of a few tens of meters. This paper especially focuses on Ceres, for which high-resolution shape data are being obtained by the Dawn spacecraft, with a projected accuracy better than 200 m/pixel. Methods: To improve the accuracy on the determination of geodetic parameters, we numerically integrated Clairaut's equations of rotational equilibrium expanded up to third order in a small parameter m, the geodetic parameter. Results: Previous studies of Ceres have been based on shape models developed to first order. However, we show that the first-order theory underestimates (a-c) (where a and c are the equatorial and polar radii) by 1.8 km, which leads to underestimating the extent of mass concentration and is insufficient to interpret the upcoming observations by Dawn space mission. Instead, by using the third-order theory, we obtain an accuracy of 25 meters that is better than the accuracy expected from Dawn. Then, we derive the following geodetical quantities: flattening and other shape parameters, gravitational potential coefficients, and moments of inertia, by using the Ceres models constrained by observations obtained with the Hubble Space Telescope and ground-based adaptive optics telescopes. The difference in equatorial and polar radii for a large parametric space of interior models is investigated, and the

  11. TESTING ALTERNATIVE THEORIES OF GRAVITY USING THE SUN

    SciTech Connect

    Casanellas, Jordi; Pani, Paolo; Lopes, Ilidio; Cardoso, Vitor E-mail: paolo.pani@ist.utl.pt E-mail: vitor.cardoso@ist.utl.pt

    2012-01-20

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

  12. High levels of plasma protein C in nephrotic syndrome.

    PubMed

    Pabinger-Fasching, I; Lechner, K; Niessner, H; Schmidt, P; Balzar, E; Mannhalter, C

    1985-02-18

    In patients with severe nephrotic syndrome determinations of plasma protein C: Ag levels (8 patients: 5 adults, 3 children) and protein C activity (3 out of 8 patients) revealed significantly elevated plasma protein C concentrations. Furthermore we observed a significant inverse correlation of protein C: Ag to AT III: Ag levels. No protein C: Ag could be detected in the urine of two patients studied. We conclude from our data, that changes of plasma protein C do not contribute to the high thrombotic tendency in nephrotic syndrome. PMID:3838827

  13. Superconducting gravity gradiometer for sensitive gravity measurements. I. Theory

    SciTech Connect

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

    1987-06-15

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

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

    SciTech Connect

    Richman, M.W.

    1992-01-01

    In this quarter, we extended our study of the effects of isotropic boundary vibrations to steady, gravity driven, inclined granular flows. These flows are more complex than those considered last quarter because of the presence of slip and mean velocity gradients at the boundary. Consequently, it was first necessary to modify the boundary conditions derived by Richman (1992) to account for corrections to the flow particle velocity distribution function from velocity gradients. In what follows we only summarize the results obtained.

  15. 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.

  16. High levels of molecular chlorine in the Arctic atmosphere

    NASA Astrophysics Data System (ADS)

    Liao, Jin; Huey, L. Gregory; Liu, Zhen; Tanner, David J.; Cantrell, Chris A.; Orlando, John J.; Flocke, Frank M.; Shepson, Paul B.; Weinheimer, Andrew J.; Hall, Samuel R.; Ullmann, Kirk; Beine, Harry J.; Wang, Yuhang; Ingall, Ellery D.; Stephens, Chelsea R.; Hornbrook, Rebecca S.; Apel, Eric C.; Riemer, Daniel; Fried, Alan; Mauldin, Roy L.; Smith, James N.; Staebler, Ralf M.; Neuman, J. Andrew; Nowak, John B.

    2014-02-01

    Chlorine radicals can function as a strong atmospheric oxidant, particularly in polar regions, where levels of hydroxyl radicals are low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone, and the oxidation of mercury to more toxic forms. Here we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We report high levels of molecular chlorine, of up to 400 pptv. Concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimate that the chlorine radicals produced from the photolysis of molecular chlorine oxidized more methane than hydroxyl radicals, on average, and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyses mercury oxidation and the breakdown of tropospheric ozone. We therefore suggest that molecular chlorine exerts a significant effect on the atmospheric chemistry of the Arctic.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  18. Validation of GOCE gravity gradient grids for geophysical applications

    NASA Astrophysics Data System (ADS)

    Fecher, Thomas; Pail, Roland; Rexer, Moritz

    2015-04-01

    In addition to global gravity models parameterized in spherical harmonic coefficients, gravity functionals such as gravity gradients, as they have been measured by the GOCE satellite, are an important data product for many user groups. Exemplarily, in geophysical modelling, the directional information contained in the gravity gradients can further constrain the inversion problem. Global and regional gravity gradient grids have been computed in the frame of the ESA STSE GOCE+ project GeoExplore in a local north-oriented frame in two altitudes of 225 km and 255 km, basically as a combination of GOCE and GRACE information in a regional combination approach. In parallel, in the frame of the project GOCE High-level Processing Facility (HPF) global grids based purely on GOCE information have been produced by applying the space-wise approach. Following a recommendation of the ESA GOCE User Workshop (Paris, November 2014), these grids have to be validated externally before they can be reliably used for geophysical applications. In this paper, these grid products are validated against external gravity information, by applying global gravity field models and terrestrial data bases in well-surveyed areas. By comparing the gravity gradient grid products against reference values computed from the global satellite-only model GOCO05S (both the official as well as an unregularized version of it), it shall be evaluated if systematic effects show up, which might be related to the specific features of the combination strategy. The differences shall be analysed applying statistical test methods, and the error estimates associated with the grid products shall be evaluated. In parallel, it shall be investigated whether the gravity gradient grid product indeed contains more (high-frequency) signals than global models. This shall further be elaborated on by a validation against a combined gravity field model, which also includes terrestrial gravity and satellite altimetry data, as well as

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  20. GRAVITY detector systems

    NASA Astrophysics Data System (ADS)

    Mehrgan, Leander H.; Finger, Gert; Accardo, Matteo; Lizon, Jean-Louis; Stegmeier, Joerg; Eisenhauer, Frank

    2014-07-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed to enhance the near-infrared astrometric and spectro-imaging capabilities of VLTI. It will combine the AO corrected beams of the four VLT telescopes. The GRAVITY instrument uses a total of five eAPD detectors, four of which are for wavefront sensing and one for the Fringe tracker. In addition two Hawaii2RG are used, one for the acquisition camera and one for the spectrometer. A compact bath cryostat is used for each WFS unit, one for each of the VLT Unit Telescopes. Both Hawaii2RG detectors have a cutoff wavelength of 2.5 microns. A new and unique element of GRAVITY is the use of infrared wavefront sensors. For this reason SELEX-Galileo has developed a new high speed avalanche photo diode detector for ESO. The SAPHIRA detector, which stands for Selex Avalanche Photodiodes for Highspeed Infra Red Applications, has been already evaluated by ESO. At a frame rate of 1 KHz, a read noise of less than one electron can be demonstrated. A more detailed presentation about the performance of the SPAHIRA detector will be given at this conference 1. Each SAPHIRA detector is installed in an LN2 bath cryostat. The detector stage, filter wheel and optics are mounted on the cold plate of the LN2 vessel and enclosed by a radiation shield. All seven detector systems are controlled and read out by the standard ESO NGC controller. The NGC is a controller platform which can be adapted and customized for all infrared and optical detectors. This paper will discuss specific controller modifications implemented to meet the special requirements of the GRAVITY detector systems and give an overview of the GRAVITY detector systems and their performance.

  1. Measuring the effects of high CO₂ levels in Caenorhabditis elegans.

    PubMed

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

    2014-08-01

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

  2. A high resolution water level forecast for the German Bight

    NASA Astrophysics Data System (ADS)

    Niehüser, Sebastian; Dangendorf, Sönke; Arns, Arne; Jensen, Jürgen

    2016-04-01

    Many coastal regions worldwide are potentially endangered by storm surges which can cause disastrous damages and loss of life. Due to climate change induced sea level rise, an accumulation of such events is expected by the end of the 21th century. Therefore, advanced storm surge warnings are needed to be prepared when another storm surge hits the coast. In the shallow southeastern North Sea these storm surge warnings are nowadays routinely provided for selected tide gauge locations along a coastline through state-of-the-art forecast systems, which are based on a coupled system of empirical tidal predictions and numerical storm surge forecasts. Along the German North Sea coastline, the Federal Maritime and Hydrographic Agency in cooperation with the German Weather Service is responsible for the storm surge warnings. They provide accurate, high frequency and real-time water level forecasts for up to six days ahead at selected tide gauge sites via internet, telephone and broadcast. Since water levels along the German North Sea coastline are dominated by shallow water effects and a very complex bathymetric structure of the seabed, the pointwise forecast is not necessarily transferable to un-gauged areas between the tide gauges. Here we aim to close this existing gap and develop water level forecasts with a high spatial (continuously with a resolution of at least 1 kilometer) as well as a high temporal (at least 15-minute values) resolution along the entire German North Sea coastline. We introduce a new methodology for water level forecasts which combines empirical or statistical and numerical models. While the tidal forecast is performed by non-parametric interpolation techniques between un-gauged and gauged sites, storm surges are estimated on the basis of statistical/empirical storm surge formulas taken from a numerical model hindcast. The procedure will be implemented in the operational mode forced with numerical weather forecasts.

  3. 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.

  4. Management of data quality of high level waste characterization

    SciTech Connect

    Winters, W.I., Westinghouse Hanford

    1996-06-12

    Over the past 10 years, the Hanford Site has been transitioning from nuclear materials production to Site cleanup operations. High-level waste characterization at the Hanford Site provides data to support present waste processing operations, tank safety programs, and future waste disposal programs. Quality elements in the high-level waste characterization program will be presented by following a sample through the data quality objective, sampling, laboratory analysis and data review process. Transition from production to cleanup has resulted in changes in quality systems and program; the changes, as well as other issues in these quality programs, will be described. Laboratory assessment through quality control and performance evaluation programs will be described, and data assessments in the laboratory and final reporting in the tank characterization reports will be discussed.

  5. Evaluation and selection of candidate high-level waste forms

    SciTech Connect

    Bernadzikowski, T. A.; Allender, J. S.; Butler, J. L.; Gordon, D. E.; Gould, Jr., T. H.; Stone, J. A.

    1982-03-01

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

  6. Multipurpose optimization models for high level waste vitrification

    SciTech Connect

    Hoza, M.

    1994-08-01

    Optimal Waste Loading (OWL) models have been developed as multipurpose tools for high-level waste studies for the Tank Waste Remediation Program at Hanford. Using nonlinear programming techniques, these models maximize the waste loading of the vitrified waste and optimize the glass formers composition such that the glass produced has the appropriate properties within the melter, and the resultant vitrified waste form meets the requirements for disposal. The OWL model can be used for a single waste stream or for blended streams. The models can determine optimal continuous blends or optimal discrete blends of a number of different wastes. The OWL models have been used to identify the most restrictive constraints, to evaluate prospective waste pretreatment methods, to formulate and evaluate blending strategies, and to determine the impacts of variability in the wastes. The OWL models will be used to aid in the design of frits and the maximize the waste in the glass for High-Level Waste (HLW) vitrification.

  7. Radioactive high level waste insight modelling for geological disposal facilities

    NASA Astrophysics Data System (ADS)

    Carter, Alexander; Kelly, Martin; Bailey, Lucy

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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    SciTech Connect

    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.

  17. Phase-field modelling of β(Ti) solidification in Ti-45at.%Al: columnar dendrite growth at various gravity levels

    NASA Astrophysics Data System (ADS)

    Viardin, A.; Berger, R.; Sturz, L.; Apel, M.; Hecht, U.

    2016-03-01

    The effect of solutal convection on the solidification of γ titanium aluminides, specifically on β(Ti) dendrite growth, is not well known. With the aim of supporting directional solidification experiments under hyper-gravity using a large diameter centrifuge, 2D-phase field simulations of β(Ti) dendrite growth have been performed for the binary alloy Ti-45at.%Al and various gravity scenarios. Both, the direction and magnitude of the gravity vector were varied systematically in order to reveal the subtle interplay between the convective flow pattern and mushy zone characteristics. In this presentation, gravity effects are discussed for early dendrite growth. For selected cases the evolution on longer timescales is also analyse of and oscillatory modes leading to dynamically stable steady state growth are outlined. In a dedicated simulation series forced flow is superimposed, as to mimic thermally driven fluid flow expected to establish on the macroscopic scale (sample size) in the centrifugal experiments. Above a certain threshold this flow turns dominant and precludes solutally driven convective effects.

  18. Executive functions in kindergarteners with high levels of disruptive behaviours.

    PubMed

    Monette, Sébastien; Bigras, Marc; Guay, Marie-Claude

    2015-11-01

    Executive function (EF) deficits have yet to be demonstrated convincingly in children with disruptive behaviour disorders (DBD), as only a few studies have reported these. The presence of EF weaknesses in children with DBD has often been contested on account of the high comorbidity between DBD and attention-deficit/hyperactivity disorder (ADHD) and of methodological shortcomings regarding EF measures. Against this background, the link between EF and disruptive behaviours in kindergarteners was investigated using a carefully selected battery of EF measures. Three groups of kindergarteners were compared: (1) a group combining high levels of disruptive behaviours and ADHD symptoms (COMB); (2) a group presenting high levels of disruptive/aggressive behaviours and low levels of ADHD symptoms (AGG); and (3) a normative group (NOR). Children in the COMB and AGG groups presented weaker inhibition capacities compared with normative peers. Also, only the COMB group showed weaker working memory capacities compared with the NOR group. Results support the idea that preschool children with DBD have weaker inhibition capacities and that this weakness could be common to both ADHD and DBD. PMID:26198079

  19. Handbook of high-level radioactive waste transportation

    SciTech Connect

    Sattler, L.R.

    1992-10-01

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

  20. Materials Science of High-Level Nuclear Waste Immobilization

    SciTech Connect

    Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

    2009-01-09

    With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams.

  1. Combined absolute and relative gravity measurement for microgravity monitoring in Aso volcanic field

    NASA Astrophysics Data System (ADS)

    Sofyan, Yayan; Nishijima, Jun; Yoshikawa, Shin; Fujimitsu, Yasuhiro; Kagiyama, Tsuneomi; Fukuda, Yoichi

    2014-05-01

    Absolute measurement with a portable A10-017 absolute gravimeter at some benchmarks in the Aso volcanic field are valuable for reducing uncertainties of regional gravity variations and will be useful for delineating the long term trends of gravity changes. A10 absolute gravimeter is a new generation of portable absolute instrument and has accuracy 10 microGal. To further the development of a high precision gravity data, we also conducted measurement using two relative gravimeter (Scintrex CG-5 [549] and LaCoste type G-1016) to be combined with an A10 absolute gravimeter. The using absolute gravimeter along with relative gravimeter can reduce drift correction factor and improve the result of gravity change data in microgravity monitoring. Microgravity monitoring is a valued tool for mapping the redistribution of subsurface mass and for assessing changes in the fluid as a dynamic process in volcanic field. Gravity changes enable the characterization of subsurface processes: i.e., the mass of the intrusion or hydrothermal flow. A key assumption behind gravity monitoring is that changes in earth's gravity reflect mass-transport processes at depth [1]. The absolute gravity network was installed at seven benchmarks using on May 2010, which re-occupied in October 2010, and June 2011. The relative gravity measurements were performed at 28 benchmarks in one month before the eruption on May 2011 and then followed by series of gravity monitoring after the eruption in every three to five months. Gravity measurements covered the area more than 60 km2 in the west side of Aso caldera. Some gravity benchmarks were measured using both absolute and relative gravimeter and is used as the reference benchmarks. In longer time period, the combined gravity method will improve the result of gravity change data for monitoring in the Aso volcanic field. As a result, the gravity changes detected the hydrothermal flow in the subsurface which has a correlation to water level fluctuation in the

  2. High Levels of Molecular Chlorine found in the Arctic Atmosphere

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Liu, Z.; Tanner, D.; Cantrell, C. A.; Orlando, J. J.; Flocke, F. M.; Shepson, P. B.; Weinheimer, A. J.; Hall, S. R.; Beine, H.; Wang, Y.; Ingall, E. D.; Thompson, C. R.; Hornbrook, R. S.; Apel, E. C.; Fried, A.; Mauldin, L.; Smith, J. N.; Staebler, R. M.; Neuman, J. A.; Nowak, J. B.

    2014-12-01

    Chlorine radicals are a strong atmospheric oxidant, particularly in polar regions where levels of hydroxyl radicals can be quite low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone and the oxidation of mercury to more toxic forms. Here, we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We detected high levels of molecular chlorine of up to 400 pptv. Concentrations peaked in the early morning and late afternoon and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimated that the chlorine radicals produced from the photolysis of molecular chlorine on average oxidized more methane than hydroxyl radicals and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyzed mercury oxidation and the breakdown of tropospheric ozone. Therefore, we propose that molecular chlorine exerts a significant effect on the atmospheric chemistry in the Arctic. While the formation mechanisms of molecular chlorine are not yet understood, the main potential sources of chlorine include snowpack, sea salt, and sea ice. There is recent evidence of molecular halogen (Br2 and Cl2) formation in the Arctic snowpack. The coverage and composition of the snow may control halogen chemistry in the Arctic. Changes of sea ice and snow cover in the changing climate may affect air-snow-ice interaction and have a significant impact on the levels of radicals, ozone, mercury and methane in the Arctic troposphere.

  3. Driving of the SAO by gravity waves as observed from satellite

    NASA Astrophysics Data System (ADS)

    Ern, M.; Preusse, P.; Riese, M.

    2015-04-01

    It is known that atmospheric dynamics in the tropical stratosphere have an influence on higher altitudes and latitudes as well as on surface weather and climate. In the tropics, the dynamics are governed by an interplay of the quasi-biennial oscillation (QBO) and semiannual oscillation (SAO) of the zonal wind. The QBO is dominant in the lower and middle stratosphere, and the SAO in the upper stratosphere/lower mesosphere. For both QBO and SAO the driving by atmospheric waves plays an important role. In particular, the role of gravity waves is still not well understood. In our study we use observations of the High Resolution Dynamics Limb Sounder (HIRDLS) satellite instrument to derive gravity wave momentum fluxes and gravity wave drag in order to investigate the interaction of gravity waves with the SAO. These observations are compared with the ERA-Interim reanalysis. Usually, QBO westward winds are much stronger than QBO eastward winds. Therefore, mainly gravity waves with westward-directed phase speeds are filtered out through critical-level filtering already below the stratopause region. Accordingly, HIRDLS observations show that gravity waves contribute to the SAO momentum budget mainly during eastward wind shear, and not much during westward wind shear. These findings confirm theoretical expectations and are qualitatively in good agreement with ERA-Interim and other modeling studies. In ERA-Interim most of the westward SAO driving is due to planetary waves, likely of extratropical origin. Still, we find in both observations and ERA-Interim that sometimes westward-propagating gravity waves may contribute to the westward driving of the SAO. Four characteristic cases of atmospheric background conditions are identified. The forcings of the SAO in these cases are discussed in detail, supported by gravity wave spectra observed by HIRDLS. In particular, we find that the gravity wave forcing of the SAO cannot be explained by critical-level filtering alone; gravity

  4. Quantum gravity and charge renormalization

    SciTech Connect

    Toms, David J.

    2007-08-15

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

  5. Radiative Lifetimes for High Levels of Neutral Fe

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  6. Feasibility of disposal of high-level radioactive wastes into the seabed: Engineering

    SciTech Connect

    Hickerson, J.; Freeman, T.J.; Boisson, J.Y.; Gera, F.; Murray, N.; Nakamura, H.; Nieuwenhuis, J.D.; Schaller, K.H.

    1988-04-01

    This report summarizes the work of the Engineering Studies Task Group (ESTG) of the Seabed Working Group during its study of emplacement systems for the subseabed disposal of high level radioactive waste. ESTG has performed design studies of emplacement systems, costed them, and estimated operational reliabilities. Mathematical models for important physical and engineering processes were developed and a large number of laboratory tests, sea trials, and in situ experiments for the purpose of understanding the emplacement environment and developing the specialized equipment necessary for emplacement were performed. Attention was focused on two systems. The first would emplace a 450-m column of waste packages in predrilled holes 750 m deep. The second would use free falling gravity penetrators launched from a disposal ship to embed waste packages about 50 m below the seafloor in an array that separated each by an average of 180 m from its neighbors. Studies of each system covered all aspects, from the configuration and functions of the port facilities through transport to the ocean site, emplacement operations, and post emplacement behavior of the waste packages. Cost and reliability studies were similarly broad. ESTG concludes that viable disposal systems for subseabed emplacement of waste are feasible. If appropriate sites can be found, it appears that straightforward methods are available for producing satisfactory waste packages that can survive a 500-yr emplacement period. 172 refs., 40 figs., 19 tabs.

  7. Bubble Detachment in Variable Gravity Under the Influence of Electric Fields

    NASA Technical Reports Server (NTRS)

    Herman, Cila; Chang, Shinan; Iacona, Estelle

    2002-01-01

    The objective of the research is to investigate the behavior of individual air bubbles injected through an orifice into an electrically insulating liquid under the influence of a static electric field. Situations were considered with both uniform and nonuniform electric fields. Bubble formation and detachment were visualized in terrestrial gravity as well as for several levels of reduced gravity (lunar, martian and microgravity) using a high-speed video camera. Bubble volume, dimensions and contact angles at detachment were measured. In addition to the experimental studies, a simple model, predicting bubble characteristics at detachment in an initially uniform electric field was developed. The model, based on thermodynamic considerations, accounts for the level of gravity as well as the magnitude of the uniform electric field. The results of the study indicate that the level of gravity and the electric field magnitude significantly affect bubble behavior as well as shape, volume and dimensions.

  8. Bubble Formation and Detachment in Reduced Gravity Under the Influence of Electric Fields

    NASA Technical Reports Server (NTRS)

    Herman, Cila; Iacona, Estelle; Chang, Shinan

    2002-01-01

    The objective of the study is to investigate the behavior of individual air bubbles injected through an orifice into an electrically insulating liquid under the influence of a static electric field. Both uniform and nonuniform electric field configurations were considered. Bubble formation and detachment were recorded and visualized in reduced gravity (corresponding to gravity levels on Mars, on the Moon as well as microgravity) using a high-speed video camera. Bubble volume, dimensions and contact angle at detachment were measured. In addition to the experimental studies, a simple model, predicting bubble characteristics at detachment was developed. The model, based on thermodynamic considerations, accounts for the level of gravity as well as the magnitude of the uniform electric field. Measured data and model predictions show good agreement and indicate that the level of gravity and the electric field magnitude significantly affect bubble shape, volume and dimensions.

  9. 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.

  10. ALICE: Project Overview and High Level Science Products

    NASA Astrophysics Data System (ADS)

    Soummer, Remi; Choquet, Elodie; Pueyo, Laurent; Brendan Hagan, J.; Gofas-Salas, Elena; Rajan, Abhijith; Perrin, Marshall D.; Chen, Christine; Debes, John H.; Golimowski, David A.; Hines, Dean C.; Schneider, Glenn; N'Diaye, Mamadou; Mawet, Dimitri; Marois, Christian; Barman, Travis

    2015-01-01

    We report on the status of the ALICE project (Archival Legacy Investigation of Circumstellar Environments), which consists in a consistent reanalysis of the entire HST-NICMOS coronagraphic archive. Over the last two years, we have developed a sophisticated pipeline able to handle the data of the 400 stars of the archive. This pipeline builds on the Karhunen-Loeve Image Projection (KLIP) algorithm, and was completed in the fall of 2014. We discuss the first processing and analysis results of the overall reduction campaign. As we will deliver high-level science products to the STScI MAST archive, we are defining a new standard format for high-contrast science products, which will be compatible with every new high-contrast imaging instrument (GPI, SPHERE, P1640, CHARIS, etc.) and used by the JWST coronagraphs. We present here the specifications of this standard.

  11. Proof of concept and performance optimization of high gravity batch-type centrifugal dryer for dewatering fine coal. Final report, September 20, 1989--September 21, 1991

    SciTech Connect

    Smith, L.B.; Durney, T.

    1991-12-31

    The primary objective of the project was to assemble, analyze and make use of those data that could help to clearly identify, optimize and confirm the technical and economic advantages that the new high gravity centrifugal dryer technology can provide to the coal industry and to end users. Other objectives were: to confirm the feasibility of the dryer for drying coals from a number of different seams; to use the data base for optimizing the dryer`s systems, and: to produce projected technical and economic comparisons with thermal dryers as applied to an existing coal processing plant flow sheet. (JL)

  12. The 3-D motion of the centre of gravity of the human body during level walking. I. Normal subjects at low and intermediate walking speeds.

    PubMed

    Tesio, L; Lanzi, D; Detrembleur, C

    1998-03-01

    OBJECTIVE: To measure the mechanical energy changes of the centre of gravity (CG) of the body in the forward, lateral and vertical direction during normal level walking at intermediate and low speeds. DESIGN: Eight healthy adults performed successive walks at speeds ranging from 0.25 to 1.75 m s(-1) over a dedicated force platform system. BACKGROUND: In previous studies, it was shown that the motion of the CG during gait can be altered more than the motion of individual segments. However, more detailed normative data are needed for clinical analysis. METHODS: The positive work done during the step to accelerate the body CG in the forward direction, W(f), to lift it, W(v), to accelerate it in the lateral direction, W(I), and the actual work done by the muscles to maintain its motion with respect to the ground ('external' work), W(ext), were measured. This allowed the calculation of the pendulum-like transfer between gravitational potential energy and kinetic energy of the CG, (percentage recovery, R). At the optimal speed of about 1.3 m s(-1), this transfer allows saving of as much as 65% of the muscular work which would have been otherwise needed to keep the body in motion with respect to the ground. The distance covered by the CG at each step either forward (step length, S(I)), or vertically (vertical displacement, S(v)) was also recorded. RESULTS: W(I) was, as a median, only 1.6-5.9% of W(ext). This ratio was higher, the lower the speed. At each step, W(ext) is needed to sustain two distinct increments of the total mechanical energy of the CG, E(tot). The increment a takes place during the double stance phase; the increment b takes place during the single stance phase. Both of these increments increased with speed. Over the speed range analyzed, the power spent to to sustain the a increment was 2.8-3.9 times higher than the power spent to sustain the b increment. PMID:11415774

  13. 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

  14. Threshold Gravity Determination and Artificial Gravity Studies Using Magnetic Levitation

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.; Leslie, F.

    2005-01-01

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

  15. 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.

  16. 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.

  17. 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.

  18. Ultrasonic level sensors for liquids under high pressure

    NASA Astrophysics Data System (ADS)

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

    1986-09-01

    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.

  19. High level language-based robotic control system

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  20. 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.

  1. 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.

  2. Laser welding in a reduced gravity environment

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Kaukler, William F.

    1992-01-01

    Preliminary results on the effects of reduced gravity on laser welding of stainless steel and other materials are reported. Laser welding experiments using a low power (10-18 watts) Nd-YAG laser have been performed on the NASA KC-135, which flies parabolic maneuvers to simulate reduced gravity conditions. Experiments on 0.005-0.010 inch thick stainless steel samples displayed a pronounced change in weld bead width, depth of penetration and surface ripple with changes in gravity level.

  3. Thermosyphon Flooding in Reduced Gravity Environments

    NASA Technical Reports Server (NTRS)

    Gibson, Marc Andrew

    2013-01-01

    An innovative experiment to study the thermosyphon flooding limits was designed and flown on aparabolic flight campaign to achieve the Reduced Gravity Environments (RGE) needed to obtainempirical data for analysis. Current correlation models of Faghri and Tien and Chung do not agreewith the data. A new model is presented that predicts the flooding limits for thermosyphons inearths gravity and lunar gravity with a 95 confidence level of +- 5W.

  4. Elevated glucose levels in early puerperium, and association with high cortisol levels during parturition.

    PubMed

    Risberg, Anitha; Sjöquist, Mats; Wedenberg, Kaj; Larsson, Anders

    2016-07-01

    Background Gestational diabetes is one of the commonest metabolic problems associated with pregnancy and an accurate diagnosis is critical for the care. Research has shown that pregnant women have high levels of cortisol during the last stage of parturition. As cortisol is a diabetogenic hormone causing increased glucose levels, we wanted to study the association between cortisol and glucose levels during parturition. Materials and methods Glucose and cortisol were analyzed during parturition in 50 females divided according to slow (n = 11) and normal labors (n = 39). Blood samples were analyzed three times during the parturition and four times in the first day after delivery. Glucose levels were also measured once in each trimester. Results In the normal group, the glucose concentration increased from 6.2 (IQR 5.6-8.0) mmol/L in the latency phase to 11.6 (10.0-13.3) mmol/L at aftercare (p < 0.05). After parturition the glucose concentrations decreased gradually. There were significant Spearman rank correlations between glucose and cortisol values. Conclusions The changes associated with birth cause significant elevations of cortisol and glucose around parturition. PMID:26985979

  5. 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.

  6. University-Level Research Projects for High School Students

    NASA Technical Reports Server (NTRS)

    McConnell, Mark L.

    2000-01-01

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

  7. 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.

  8. 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

  9. Positive signs in massive gravity

    NASA Astrophysics Data System (ADS)

    Cheung, Clifford; Remmen, Grant N.

    2016-04-01

    We derive new constraints on massive gravity from unitarity and analyticity of scattering amplitudes. Our results apply to a general effective theory defined by Einstein gravity plus the leading soft diffeomorphism-breaking corrections. We calculate scattering amplitudes for all combinations of tensor, vector, and scalar polarizations. The high-energy behavior of these amplitudes prescribes a specific choice of couplings that ameliorates the ultraviolet cutoff, in agreement with existing literature. We then derive consistency conditions from analytic dispersion relations, which dictate positivity of certain combinations of parameters appearing in the forward scattering amplitudes. These constraints exclude all but a small island in the parameter space of ghost-free massive gravity. While the theory of the "Galileon" scalar mode alone is known to be inconsistent with positivity constraints, this is remedied in the full massive gravity theory.

  10. Granular Superconductors and Gravity

    NASA Technical Reports Server (NTRS)

    Noever, David; Koczor, Ron

    1999-01-01

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

  11. Approaches to Quantum Gravity

    NASA Astrophysics Data System (ADS)

    Oriti, Daniele

    2009-03-01

    Preface; Part I. Fundamental Ideas and General Formalisms: 1. Unfinished revolution C. Rovelli; 2. The fundamental nature of space and time G. 't Hooft; 3. Does locality fail at intermediate length scales R. Sorkin; 4. Prolegomena to any future quantum gravity J. Stachel; 5. Spacetime symmetries in histories canonical gravity N. Savvidou; 6. Categorical geometry and the mathematical foundations of quantum gravity L. Crane; 7. Emergent relativity O. Dreyer; 8. Asymptotic safety R. Percacci; 9. New directions in background independent quantum gravity F. Markopoulou; Questions and answers; Part II: 10. Gauge/gravity duality G. Horowitz and J. Polchinski; 11. String theory, holography and quantum gravity T. Banks; 12. String field theory W. Taylor; Questions and answers; Part III: 13. Loop Quantum Gravity T. Thiemann; 14. Covariant loop quantum gravity? E. LIvine; 15. The spin foam representation of loop quantum gravity A. Perez; 16. 3-dimensional spin foam quantum gravity L. Freidel; 17. The group field theory approach to quantum gravity D. Oriti; Questions and answers; Part IV. Discrete Quantum Gravity: 18. Quantum gravity: the art of building spacetime J. Ambjørn, J. Jurkiewicz and R. Loll; 19. Quantum Regge calculations R. Williams; 20. Consistent discretizations as a road to quantum gravity R. Gambini and J. Pullin; 21. The causal set approach to quantum gravity J. Henson; Questions and answers; Part V. Effective Models and Quantum Gravity Phenomenology: 22. Quantum gravity phenomenology G. Amelino-Camelia; 23. Quantum gravity and precision tests C. Burgess; 24. Algebraic approach to quantum gravity II: non-commutative spacetime F. Girelli; 25. Doubly special relativity J. Kowalski-Glikman; 26. From quantum reference frames to deformed special relativity F. Girelli; 27. Lorentz invariance violation and its role in quantum gravity phenomenology J. Collins, A. Perez and D. Sudarsky; 28. Generic predictions of quantum theories of gravity L. Smolin; Questions and

  12. 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

  13. Development of a High Level Waste Tank Inspection System

    SciTech Connect

    Appel, D.K.; Loibl, M.W.; Meese, D.C.

    1995-03-21

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

  14. Defense High Level Waste Disposal Container System Description Document

    SciTech Connect

    N. E. Pettit

    2001-07-13

    The Defense High Level Waste Disposal Container System supports the confinement and isolation of waste within the Engineered Barrier System of the Monitored Geologic Repository (MGR). Disposal containers are loaded and sealed in the surface waste handling facilities, transferred to the underground through the accesses using a rail mounted transporter, and emplaced in emplacement drifts. The defense high level waste (HLW) disposal container provides long-term confinement of the commercial HLW and defense HLW (including immobilized plutonium waste forms [IPWF]) placed within disposable canisters, and withstands the loading, transfer, emplacement, and retrieval loads and environments. US Department of Energy (DOE)-owned spent nuclear fuel (SNF) in disposable canisters may also be placed in a defense HLW disposal container along with commercial HLW waste forms, which is known as co-disposal. The Defense High Level Waste Disposal Container System provides containment of waste for a designated period of time, and limits radionuclide release. The disposal container/waste package maintains the waste in a designated configuration, withstands maximum handling and rockfall loads, limits the individual canister temperatures after emplacement, resists corrosion in the expected handling and repository environments, and provides containment of waste in the event of an accident. Defense HLW disposal containers for HLW disposal will hold up to five HLW canisters. Defense HLW disposal containers for co-disposal will hold up to five HLW canisters arranged in a ring and one DOE SNF canister inserted in the center and/or one or more DOE SNF canisters displacing a HLW canister in the ring. Defense HLW disposal containers also will hold two Multi-Canister Overpacks (MCOs) and two HLW canisters in one disposal container. The disposal container will include outer and inner cylinders, outer and inner cylinder lids, and may include a canister guide. An exterior label will provide a means by

  15. Stagnation Region Heat Transfer Augmentation at Very High Turbulence Levels

    SciTech Connect

    Ames, Forrest; Kingery, Joseph E.

    2015-06-17

    A database for stagnation region heat transfer has been extended to include heat transfer measurements acquired downstream from a new high intensity turbulence generator. This work was motivated by gas turbine industry heat transfer designers who deal with heat transfer environments with increasing Reynolds numbers and very high turbulence levels. The new mock aero-combustor turbulence generator produces turbulence levels which average 17.4%, which is 37% higher than the older turbulence generator. The increased level of turbulence is caused by the reduced contraction ratio from the liner to the exit. Heat transfer measurements were acquired on two large cylindrical leading edge test surfaces having a four to one range in leading edge diameter (40.64 cm and 10.16 cm). Gandvarapu and Ames [1] previously acquired heat transfer measurements for six turbulence conditions including three grid conditions, two lower turbulence aero-combustor conditions, and a low turbulence condition. The data are documented and tabulated for an eight to one range in Reynolds numbers for each test surface with Reynolds numbers ranging from 62,500 to 500,000 for the large leading edge and 15,625 to 125,000 for the smaller leading edge. The data show augmentation levels of up to 136% in the stagnation region for the large leading edge. This heat transfer rate is an increase over the previous aero-combustor turbulence generator which had augmentation levels up to 110%. Note, the rate of increase in heat transfer augmentation decreases for the large cylindrical leading edge inferring only a limited level of turbulence intensification in the stagnation region. The smaller cylindrical leading edge shows more consistency with earlier stagnation region heat transfer results correlated on the TRL (Turbulence, Reynolds number, Length scale) parameter. The downstream regions of both test surfaces continue to accelerate the flow but at a much lower rate than the leading edge. Bypass transition occurs

  16. 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) μg/L for As; 7.7 (0.12-177) μg/L for Mn; 0.2 (<0.05-1.9) μg/L for Co; 16 (<0.1-686) μg/L for Zn; 0.7 (<0.1-1.8) μg/L for Se; <0.1 (<0.02-0.69) μg/L for Cd; and 1.3 (<0.02-32) μg/L for Pb. The levels of uranium were surprisingly elevated (mean, 4.6 μg/L; range <0.01-57 μg/L, with the values for many samples exceeding the World Health Organization's guideline of 15 μg/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

  17. Modern Alchemy: Solidifying high-level nuclear waste

    SciTech Connect

    Newton, C.C.

    1997-07-01

    The U.S. Department of Energy is putting a modern version of alchemy to work to produce an answer to a decades-old problem. It is taking place at the Savannah River Site (SRS) in Aiken, South Carolina and at the West Valley Demonstration Project (WVDP) near Buffalo, New York. At both locations, contractor Westinghouse Electric Corporation is applying technology that is turning liquid high-level radioactive waste (HLW) into a stabilized, durable glass for safer and easier management. The process is called vitrification. SRS and WVDP are now operating the nation`s first full-scale HLW vitrification plants.

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

    SciTech Connect

    Mahidhara, R.K.; Elleman, T.S.; Murty, K.L.

    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.

  19. CLASSIFICATION OF THE MGR DEFENSE HIGH LEVEL WASTE DISPOSAL CONTIANER

    SciTech Connect

    J.A. Ziegler

    1999-08-31

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

  20. 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

  1. Solidification of Savannah River Plant high-level waste

    SciTech Connect

    Maher, R; Shafranek, L F; Stevens, III, W R

    1983-01-01

    The Department of Energy, in accord with recommendations from the Du Pont Company, has started construction of a Defense Waste Processing Facility (DWPF) at the Savannah River Plant. The facility should be completed by the end of 1988, and full-scale operation should begin in 1990. This facility will immobilize in borosilicate glass the large quantity of high-level radioactive waste now stored at the plant plus the waste to be generated from continued chemical reprocessing operations. The existing wastes at the Savannah River Plant will be completely converted by about 2010. 21 figures.

  2. 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.

  3. Market Designs for High Levels of Variable Generation: Preprint

    SciTech Connect

    Milligan, M.; Holttinen, H.; Kiviluoma, J.; Orths, A.; Lynch, M.; Soder, L.

    2014-10-01

    Variable renewable generation is increasing in penetration in modern power systems, leading to higher variability in the supply and price of electricity as well as lower average spot prices. This raises new challenges, particularly in ensuring sufficient capacity and flexibility from conventional technologies. Because the fixed costs and lifetimes of electricity generation investments are significant, designing markets and regulations that ensure the efficient integration of renewable generation is a significant challenge. This papers reviews the state of play of market designs for high levels of variable generation in the United States and Europe and considers new developments in both regions.

  4. Linearization of the Fermilab recycler high level RF

    SciTech Connect

    Joseph E Dey; Tom Kubicki; John Reid

    2003-05-28

    In studying the Recycler high level RF, it was found that at 89 kHz, the lowest frequency required by the system, some nonlinearities in magnitude and phase were discovered. The visible evidence of this was that beam injected in a barrier bucket had a definite slope at the top. Using a network analyzer, the S-parameter S{sub 21} was realized for the overall system and from mathematical modeling a second order numerator and denominator transfer function was found. The inverse of this transfer function gives their linearization transfer function. The linearization transfer function was realized in hardware by summing a high pass, band pass and low pass filter together. The resulting magnitude and phase plots, along with actual beam response will be shown.

  5. Unscreening Modified Gravity in the Matter Power Spectrum.

    PubMed

    Lombriser, Lucas; Simpson, Fergus; Mead, Alexander

    2015-06-26

    Viable modifications of gravity that may produce cosmic acceleration need to be screened in high-density regions such as the Solar System, where general relativity is well tested. Screening mechanisms also prevent strong anomalies in the large-scale structure and limit the constraints that can be inferred on these gravity models from cosmology. We find that by suppressing the contribution of the screened high-density regions in the matter power spectrum, allowing a greater contribution of unscreened low densities, modified gravity models can be more readily discriminated from the concordance cosmology. Moreover, by variation of density thresholds, degeneracies with other effects may be dealt with more adequately. Specializing to chameleon gravity as a worked example for screening in modified gravity, employing N-body simulations of f(R) models and the halo model of chameleon theories, we demonstrate the effectiveness of this method. We find that a percent-level measurement of the clipped power at k<0.3h/Mpc can yield constraints on chameleon models that are more stringent than what is inferred from Solar System tests or distance indicators in unscreened dwarf galaxies. Finally, we verify that our method is also applicable to the Vainshtein mechanism. PMID:26197114

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  7. Gravity Waves

    NASA Technical Reports Server (NTRS)

    Vanzandt, T. E.

    1985-01-01

    Atmospheric parameters fluctuate on all scales. In the mesoscale these fluctuations are occasionally sinusoidal so that they can be interpreted as gravity waves. Usually, however, the fluctuations are noise like, so that their cause is not immediately evident. Results of mesoscale observations in the 20 to 120 m altitude range that are suitable for incorporation into a model atmosphere are very limited. In the stratosphere and lower mesosphere observations are sparse and very little data has been summarized into appropriate form. There is much more data in the upper mesosphere and lower thermosphere, but again very little of it has been summarized. The available mesoscale spectra of horizontal wind u versus vertical wave number m in the 20 to 120 km altitude range are shown together with a spectrum from the lower atmosphere for comparison. Further information about these spectra is given. In spite of the large range of altitudes and latitudes, the spectra from the lower atmosphere (NASA, 1971 and DEWAN, 1984) are remarkably similar in both shape and amplitude. The mean slopes of -2.38 for the NASA spectrum and -2.7 for the Dewan spectra are supported by the mean slope of -2.75 found by ROSENBERG et al. (1974). The mesospheric spectrum is too short to establish a shape. Its amplitude is about an order of magnitude larger than the NASA spectrum in the same wave number range. The NASA and Dewan spectra suggest that the mesoscale spectra in the lower atmosphere are insensitive to meteorological conditions.

  8. Wind resource quality affected by high levels of renewables

    DOE PAGESBeta

    Diakov, Victor

    2015-06-17

    For solar photovoltaic (PV) and wind resources, the capacity factor is an important parameter describing the quality of the resource. As the share of variable renewable resources (such as PV and wind) on the electric system is increasing, so does curtailment (and the fraction of time when it cannot be avoided). At high levels of renewable generation, curtailments effectively change the practical measure of resource quality from capacity factor to the incremental capacity factor. The latter accounts only for generation during hours of no curtailment and is directly connected with the marginal capital cost of renewable generators for a givenmore » level of renewable generation during the year. The Western U.S. wind generation is analyzed hourly for a system with 75% of annual generation from wind, and it is found that the value for the system of resources with equal capacity factors can vary by a factor of 2, which highlights the importance of using the incremental capacity factor instead. Finally, the effect is expected to be more pronounced in smaller geographic areas (or when transmission limitations imposed) and less pronounced at lower levels of renewable energy in the system with less curtailment.« less

  9. Wind resource quality affected by high levels of renewables

    SciTech Connect

    Diakov, Victor

    2015-06-17

    For solar photovoltaic (PV) and wind resources, the capacity factor is an important parameter describing the quality of the resource. As the share of variable renewable resources (such as PV and wind) on the electric system is increasing, so does curtailment (and the fraction of time when it cannot be avoided). At high levels of renewable generation, curtailments effectively change the practical measure of resource quality from capacity factor to the incremental capacity factor. The latter accounts only for generation during hours of no curtailment and is directly connected with the marginal capital cost of renewable generators for a given level of renewable generation during the year. The Western U.S. wind generation is analyzed hourly for a system with 75% of annual generation from wind, and it is found that the value for the system of resources with equal capacity factors can vary by a factor of 2, which highlights the importance of using the incremental capacity factor instead. Finally, the effect is expected to be more pronounced in smaller geographic areas (or when transmission limitations imposed) and less pronounced at lower levels of renewable energy in the system with less curtailment.

  10. Attenuation of high-level impulses by earmuffs.

    PubMed

    Zera, Jan; Mlynski, Rafal

    2007-10-01

    Attenuation of high-level acoustic impulses (noise reduction) by various types of earmuffs was measured using a laboratory source of type A impulses and an artificial test fixture compatible with the ISO 4869-3 standard. The measurements were made for impulses of peak sound-pressure levels (SPLs) from 150 to 170 dB. The rise time and A duration of the impulses depended on their SPL and were within a range of 12-400 mus (rise time) and 0.4-1.1 ms (A duration). The results showed that earmuff peak level attenuation increases by about 10 dB when the impulse's rise time and the A duration are reduced. The results also demonstrated that the signals under the earmuff cup have a longer rise and A duration than the original impulses recorded outside the earmuff. Results of the measurements were used to check the validity of various hearing damage risk criteria that specify the maximum permissible exposure to impulse noise. The present data lead to the conclusion that procedures in which hearing damage risk is assessed only from signal attenuation, without taking into consideration changes in the signal waveform under the earmuff, tend to underestimate the risk of hearing damage. PMID:17902846

  11. The CMS High Level Trigger System: Experience and Future Development

    NASA Astrophysics Data System (ADS)

    Bauer, G.; Behrens, U.; Bowen, M.; Branson, J.; Bukowiec, S.; Cittolin, S.; Coarasa, J. A.; Deldicque, C.; Dobson, M.; Dupont, A.; Erhan, S.; Flossdorf, A.; Gigi, D.; Glege, F.; Gomez-Reino, R.; Hartl, C.; Hegeman, J.; Holzner, A.; Hwong, Y. L.; Masetti, L.; Meijers, F.; Meschi, E.; Mommsen, R. K.; O'Dell, V.; Orsini, L.; Paus, C.; Petrucci, A.; Pieri, M.; Polese, G.; Racz, A.; Raginel, O.; Sakulin, H.; Sani, M.; Schwick, C.; Shpakov, D.; Simon, S.; Spataru, A. C.; Sumorok, K.

    2012-12-01

    The CMS experiment at the LHC features a two-level trigger system. Events accepted by the first level trigger, at a maximum rate of 100 kHz, are read out by the Data Acquisition system (DAQ), and subsequently assembled in memory in a farm of computers running a software high-level trigger (HLT), which selects interesting events for offline storage and analysis at a rate of order few hundred Hz. The HLT algorithms consist of sequences of offline-style reconstruction and filtering modules, executed on a farm of 0(10000) CPU cores built from commodity hardware. Experience from the operation of the HLT system in the collider run 2010/2011 is reported. The current architecture of the CMS HLT, its integration with the CMS reconstruction framework and the CMS DAQ, are discussed in the light of future development. The possible short- and medium-term evolution of the HLT software infrastructure to support extensions of the HLT computing power, and to address remaining performance and maintenance issues, are discussed.

  12. Historical high-resolution dynamic sea level variations

    NASA Astrophysics Data System (ADS)

    Brunnabend, Sandra-Esther; Dijkstra, Henk A.; Kliphuis, Michael; van Werkhoven, Ben; Bal, Henri E.; Maassen, Jason; van Meersbergen, Maarten; Seinstra, Frank

    2014-05-01

    To investigate future changes in the dynamics of the ocean and therefore in dynamic sea level, ocean models need to be able to adequately represent oceanic dynamical processes. Therefore, resolving ocean eddies and representing boundary currents is of major importance. In this study, we investigate historical variations in dynamical sea surface height using the strongly eddying global version of the Parallel Ocean Program (POP). First, differences in high and low-resolution ocean model results (0.1 vs. 1.0 degree) were analyzed using a climatological atmospheric forcing dataset. Second, we forced the high-resolution model by atmospheric conditions over the period from 1950 to 2000 that are derived from a simulation using the ECHAM5-OM1 model (within the ESSENCE project, see www.knmi.nl/~sterl/Essence/). In general, the large-scale ocean fields of the POP model simulation agree well with those of the low-resolution ocean model (MPI-OM) results. Variations occur due to the different models used and, especially, due to the capability of the high-resolution POP model to resolve eddies. A comparison of high-resolution ocean model results with in-situ measurements, such as dynamic topography provided by altimetry, and salinity and temperature provided by the WOA2013, also show good agreement.

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

    SciTech Connect

    Not Available

    1989-11-01

    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 sew be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  14. 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.

  15. 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.

  16. Unexpectedly high mercury level in pelleted commercial fish feed

    SciTech Connect

    Choi, M.H.; Cech, J.J. Jr.

    1998-10-01

    An unexpectedly high mercury (Hg) level was found in a pelleted commercial fish feed used to feed fish in laboratory and fish farm settings. Mean total Hg (T-Hg) concentration in the commercial fish pellets was 66 ppb. Mean total selenium (T-Se) concentration in the pellets was 1,120 ppb (ranging from 790 to 1,360 ppb). Total Hg and Se in the whole blood of Sacramento blackfish and in the fish feed were determined by inductively coupled plasma-mass spectrometry (ICP-MS). During a 10-week sampling period T-Hg in blood fluctuated between 35 and 56 ppb. A highly significant, positive correlation was found between T-Hg in the fish blood and in the fish feed through the sampling period. On the other hand, no correlation was found between T-Se in the fish feed and T-Hg or T-Se blood level. Researchers working with fish in Hg studies need to know that fish pellets may contain Hg and to consider the influence of these pellets in their results.

  17. 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

  18. 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.

  19. 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.

  20. Multi-Level High School Classes: Astronomy Diagnostic Test Results

    NASA Astrophysics Data System (ADS)

    Hubbard, R.; Hufnagel, B.

    2001-12-01

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