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Sample records for processes isentropic

  1. Analysis of isentropic potential vorticities for the relationship between stratospheric polar vortex and the cooling process in China

    NASA Astrophysics Data System (ADS)

    Lu, C.

    2015-12-01

    We analyze the relationships between stratospheric polar vortex anomalies and cooling events in eastern China using isentropic reanalysis data from the European Center for Medium-Range Weather Forecasts. Daily mean data from 2000 to 2011 are used to explore the effective stratospheric signals. First, diagnoses of the 2009/2010 winter show that after the stratospheric sudden warming (SSW) of the Atlantic-East Asian (AEA) pattern, the stratospheric high isentropic potential vorticity(IPV) center derived from the split polar vortex will move to the northeast of the Eurasian continent. The air mass, accompanied by some southward and eastward movements and characterized by high IPV values, will be stretched vertically, leading to apparent reinforcements of the positive vorticity and the development of a cold vortex system in the troposphere. The northerly wind on the western side of the cold vortex can transport cold air southward and downward, resulting in this distinct cooling process in eastern China. Secondly, the Empirical Orthogonal Function analyses of IPV anomalies on the 430 K isentropic surface during 2000-2011 winters indicate that the IPV distribution and time series of the first mode are able to represent the polar vortex variation features, which significantly influence cold-air activity in eastern China, especially in the AEA-type SSW winter. When the time series increases significantly, the polar vortex will be split and the high-IPV center will move to the northeast of the Eurasian continent with downward and southward developments, inducing obvious cooling in eastern China. Moreover, all the four times SSW events of AEA pattern from 2000 to 2011 are reflected in the first time series, and after the strong polar vortex disturbances, cooling processes of different intensities are observed in eastern China. The cooling can sustain at least one week. For this reason the first time series can be used as an available index of polar vortex oscillation and has

  2. Numerical investigations with a hybrid isentropic-sigma model. I - Normal-mode characteristics. II - The inclusion of moist processes

    NASA Technical Reports Server (NTRS)

    Pierce, R. B.; Johnson, Donald R.; Reames, Fred M.; Zapotocny, Tom H.; Wolf, Bart J.

    1991-01-01

    The normal-mode characteristics of baroclinically amplifying disturbances were numerically investigated in a series of adiabatic simulations by a hybrid isentropic-sigma model, demonstrating the effect of coupling an isentropic-coordinate free atmospheric domain with a sigma-coordinate PBL on the normal-mode characteristics. Next, the normal-mode model was modified by including a transport equation for water vapor and adiabatic heating by condensation. Simulations with and without a hydrological component showed that the overall effect of latent heat release is to markedly enhance cyclogenesis and frontogenesis.

  3. Experiments of cylindrical isentropic compression by ultrahigh magnetic field

    NASA Astrophysics Data System (ADS)

    Gu, Zhuowei; Zhou, Zhongyu; Zhang, Chunbo; Tang, Xiaosong; Tong, Yanjin; Zhao, Jianheng; Sun, Chengwei

    2015-09-01

    The high Explosive Magnetic Flux Implosion Compression Generator (EMFICG) is a kind of unique high energy density dynamic technique with characters like ultrahigh pressure and low temperature rising and could be suitable as a tool of cylindrical isentropic compression. The Institute of Fluid Physics, Chinese Academy of Engineering Physics (IFP, CAEP) have developed EMFICG technique and realized cylindrical isentropic compression. In the experiments, a seed magnetic field of 5-6 Tesla were built first and compressed by a stainless steel liner which is driven by high explosive. The inner free surface velocity of sample was measured by PDV. The isentropic compression of a copper sample was verified and the isentropic pressure is over 100 GPa. The cylindrical isentropic compression process has been numerical simulated by 1D MHD code and the simulation results were compared with the experiments. Compared with the transitional X-ray flash radiograph measurement, this method will probably promote the data accuracy.

  4. Isentropic Compression of Argon

    SciTech Connect

    H. Oona; J.C. Solem; L.R. Veeser, C.A. Ekdahl; P.J. Rodriquez; S.M. Younger; W. Lewis; W.D. Turley

    1997-08-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal.

  5. Isentropic Analysis of Convective Motions

    NASA Technical Reports Server (NTRS)

    Pauluis, Olivier M.; Mrowiec, Agnieszka A.

    2013-01-01

    This paper analyzes the convective mass transport by sorting air parcels in terms of their equivalent potential temperature to determine an isentropic streamfunction. By averaging the vertical mass flux at a constant value of the equivalent potential temperature, one can compute an isentropic mass transport that filters out reversible oscillatory motions such as gravity waves. This novel approach emphasizes the fact that the vertical energy and entropy transports by convection are due to the combination of ascending air parcels with high energy and entropy and subsiding air parcels with lower energy and entropy. Such conditional averaging can be extended to other dynamic and thermodynamic variables such as vertical velocity, temperature, or relative humidity to obtain a comprehensive description of convective motions. It is also shown how this approach can be used to determine the mean diabatic tendencies from the three-dimensional dynamic and thermodynamic fields. A two-stream approximation that partitions the isentropic circulation into a mean updraft and a mean downdraft is also introduced. This offers a straightforward way to identify the mean properties of rising and subsiding air parcels. The results from the two-stream approximation are compared with two other definitions of the cloud mass flux. It is argued that the isentropic analysis offers a robust definition of the convective mass transport that is not tainted by the need to arbitrarily distinguish between convection and its environment, and that separates the irreversible convective overturning fromoscillations associated with gravity waves.

  6. Climate Simulations with an Isentropic Finite Volume Dynamical Core

    SciTech Connect

    Chen, Chih-Chieh; Rasch, Philip J.

    2012-04-15

    This paper discusses the impact of changing the vertical coordinate from a hybrid pressure to a hybrid-isentropic coordinate within the finite volume dynamical core of the Community Atmosphere Model (CAM). Results from a 20-year climate simulation using the new model coordinate configuration are compared to control simulations produced by the Eulerian spectral and FV dynamical cores of CAM which both use a pressure-based ({sigma}-p) coordinate. The same physical parameterization package is employed in all three dynamical cores. The isentropic modeling framework significantly alters the simulated climatology and has several desirable features. The revised model produces a better representation of heat transport processes in the atmosphere leading to much improved atmospheric temperatures. We show that the isentropic model is very effective in reducing the long standing cold temperature bias in the upper troposphere and lower stratosphere, a deficiency shared among most climate models. The warmer upper troposphere and stratosphere seen in the isentropic model reduces the global coverage of high clouds which is in better agreement with observations. The isentropic model also shows improvements in the simulated wintertime mean sea-level pressure field in the northern hemisphere.

  7. Isentropic decompression of fluids from crustal and mantle pressures

    NASA Technical Reports Server (NTRS)

    Kieffer, S. W.; Delany, J. M.

    1979-01-01

    Criteria are derived according to which the flow of single-phase magmatic fluids and the rarefaction expansion of low-viscosity liquids and gases may be considered approximately isentropic. Graphs of entropy vs. density with contours of constant pressure and mass fraction are used to examine the possible thermodynamic histories of H2O and CO2 decompressing isentropically from crustal and upper mantle pressures; these graphs offer a simple visual representation of a number of thermodynamic variables involved in isentropic processes. It is shown how the graphs can be used to examine the behavior of volatiles that (1) ascend in volcanic systems originating at different depths within the earth, and (2) decompress from a shock Hugoniot state. Entropy-density graphs are presented separately for H2O and CO2.

  8. Quantifying Isentropic Stratosphere-Troposphere Exchange (STE) of Ozone

    NASA Astrophysics Data System (ADS)

    Yang, H.; Chen, G.; Tang, Q.; Hess, P. G. M.

    2014-12-01

    There is increasing evidence showing that stratosphere-troposphere exchange (STE) of ozone can have a significant impact on the interannual variability and long- term trend of the tropospheric chemistry and radiation budget. Traditional diagnostics of STE ozone flux consider the ozone budget of the lowermost stratosphere by coupling the residual circulation and ozone. However, this method can only provide information of the hemispheric mean ozone flux, and therefore it does not distinguish the exchange of ozone into the tropics from the exchange of ozone into the midlatitudes that may have different tropospheric impacts. This present study extends the traditional approach from the entire lowermost stratosphere to individual isentropic layers in the lower stratosphere, and therefore distinguishes the meridional location of STE. The specified dynamics (SD) version of the Whole Atmosphere Community Climate Model (WACCM) is used for the estimate of isentropic STE flux. The diagnosed meridional structure of ozone flux is generally consistent with studies with other methods (e.g., tracer trajectories or the budget of tropospheric ozone). Different seasonal cycles of ozone STE are found at different isentropic surfaces, emphasizing different tropospheric impacts from ozone STE over different meridional regions. For isentropes between 350K and 380K, net troposphere-to-stratosphere ozone STE flux peaks in summer. For isentropes between 330K and 350K, the net ozone STE flux peaks in summer too, but it is from stratosphere to troposphere. For isentropes between 280K and 330K, larger net stratosphere-to-troposphere ozone STE flux is found in the Northern Hemisphere and peaks in spring, whereas little seasonal variability is detected in the Southern Hemisphere. Furthermore, the diagnostic enables a partition that links the variability in the STE flux to specific dynamic processes. In particular, the air mass STE flux component associated with the isentropic mixing is found

  9. Applications of accurate isentropic exponent determination for fuel gas measurement

    SciTech Connect

    Pack, D.J.; Edwards, T.J.; Fawcett, D.

    1996-07-01

    This paper discusses the determination and application of the isentropic exponent to the various thermodynamic processes found in a high-pressure natural gas transmission system. Increasing demands for more precise measurement of natural gas, coupled with the need for greater efficiency and accountability of transportation and processing operations, had led to the research and development of gas thermodynamic properties including isentropic exponent. The isentropic exponent has many applications, some of which include: the determination of the expansion factor {epsilon}, for calculation of flow using an orifice or venturi-type meter; the volumetric efficiency in a reciprocating compressor; the determination of the compression head for a centrifugal compressor; the engine power required for the given conditions for a gas compressor; the calculation of discharge temperatures for compressors; and the direct measurement of gas density. As can be appreciated, the application of an incorrect value for the isentropic exponent represents an error in the parameter determined. For large volume gas flows, this can translate into a significant cost penalty.

  10. Isentropic Compression Experiments on the Z Accelerator

    NASA Astrophysics Data System (ADS)

    Asay, James

    1999-06-01

    Shock compression techniques are the only viable technique for making accurate EOS measurements in the multi-Mbar pressure regime. These experiments provide specific states of pressure, volume and internal energy on the Hugoniot. In many applications, it is necessary to know the off-Hugoniot isentropic loading response of materials to ultra-high pressures. Techniques for measuring isentropic response are challenging. At low pressures, ramp wave generators are used, while at high megabar pressures, graded density impactors are employed. In these latter experiments is a small amplitude shock results in the compression isentrope centered at some initial state. A new technique that is being developed shows promise for performing isentropic experiments with smooth loading to very high pressure. This approach uses the high current densities produced with fast pulsed power accelerators to create continuous magnetic loading to a few hundred kilobars over time intervals of 100-200 ns. The resulting ramp wave propagates through a planar specimen and are measured using time-resolved VISARS. Application of the differential equations of motion over the risetime of the waves determines pressure-volume states continuously. Experiments on copper and iron, have allowed determination of the isentropic compression curve in copper and the evaluation of the kinetic properties of the alpha-epsilon phase transition in iron. In this presentation, I will review previous studies of isentropic compression, discuss the new technique using Z and the results obtained on iron and copper. A perspective on the opportunities for isentropic compression experiments to multi-Mbar pressures, will be given. * Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL8500.

  11. Isentropic Analysis of a Simulated Hurricane

    NASA Technical Reports Server (NTRS)

    Mrowiec, Agnieszka A.; Pauluis, Olivier; Zhang, Fuqing

    2016-01-01

    Hurricanes, like many other atmospheric flows, are associated with turbulent motions over a wide range of scales. Here the authors adapt a new technique based on the isentropic analysis of convective motions to study the thermodynamic structure of the overturning circulation in hurricane simulations. This approach separates the vertical mass transport in terms of the equivalent potential temperature of air parcels. In doing so, one separates the rising air parcels at high entropy from the subsiding air at low entropy. This technique filters out oscillatory motions associated with gravity waves and separates convective overturning from the secondary circulation. This approach is applied here to study the flow of an idealized hurricane simulation with the Weather Research and Forecasting (WRF) Model. The isentropic circulation for a hurricane exhibits similar characteristics to that of moist convection, with a maximum mass transport near the surface associated with a shallow convection and entrainment. There are also important differences. For instance, ascent in the eyewall can be readily identified in the isentropic analysis as an upward mass flux of air with unusually high equivalent potential temperature. The isentropic circulation is further compared here to the Eulerian secondary circulation of the simulated hurricane to show that the mass transport in the isentropic circulation is much larger than the one in secondary circulation. This difference can be directly attributed to the mass transport by convection in the outer rainband and confirms that, even for a strongly organized flow like a hurricane, most of the atmospheric overturning is tied to the smaller scales.

  12. Isentropic expansion of shock-compressed substances.

    NASA Astrophysics Data System (ADS)

    Zhernokletov, M. V.

    2001-06-01

    The below parts of the paper are devoted to experimental results = obtained by the barrier method when researching metals, explosion = products, and polymers. Metals. The method of isentropic expansion was used to research = trancritical states of copper, lead, bismuth, molybdenum, uranium, = tungsten, nickel, tin, chrome, and zinc. To increase entropy under shock = compression and realize trancritical states during expansion, porous = samples were used. The highest degrees of expansion are reached on = isentropes obtained with use of hemispherical generators of shock waves. = The performed tests showed absence of significant jumps of thermodynamic = function or any hydrodynamic anomalies which could be interpeted as = specific plasma phase transformations. The tests data testify to = continuous change of metals properties at expansion from the condensed = state up to the gas state. Isentropes of explosion products (EP). In tests the shock wave = parameters were determined in inert materials-obstacles directly = contacting HE under research. TNT and two TNT-RDX alloys (50/50 and = 25/75) were used as this HE. The experimental data were compared with = data obtained by calculations using various EOS, including the cubic EOS = (P=3DAρ^3). It is shown that the cubic EOS has significant = disagreement with test in the area below 1 GPa. Polymeric materials. Teflon, polystyrene, plexiglas, phenylone, and = stilbene are studied. Analysis of experimental data testifies that = polystyrene, phenylone, and stilbene undergo a series of = physical-chemical transformations with pressure growth in the front of = shock-waves.

  13. Air motion determination by tracking humidity patterns in isentropic layers

    NASA Technical Reports Server (NTRS)

    Mancuso, R. L.; Hall, D. J.

    1975-01-01

    Determining air motions by tracking humidity patterns in isentropic layers was investigated. Upper-air rawinsonde data from the NSSL network and from the AVE-II pilot experiment were used to simulate temperature and humidity profile data that will eventually be available from geosynchronous satellites. Polynomial surfaces that move with time were fitted to the mixing-ratio values of the different isentropic layers. The velocity components of the polynomial surfaces are part of the coefficients that are determined in order to give an optimum fitting of the data. In the mid-troposphere, the derived humidity motions were in good agreement with the winds measured by rawinsondes so long as there were few or no clouds and the lapse rate was relatively stable. In the lower troposphere, the humidity motions were unreliable primarily because of nonadiabatic processes and unstable lapse rates. In the upper troposphere, the humidity amounts were too low to be measured with sufficient accuracy to give reliable results. However, it appears that humidity motions could be used to provide mid-tropospheric wind data over large regions of the globe.

  14. Quantifying isentropic stratosphere-troposphere exchange of ozone

    NASA Astrophysics Data System (ADS)

    Yang, Huang; Chen, Gang; Tang, Qi; Hess, Peter

    2016-04-01

    There is increased evidence that stratosphere-troposphere exchange (STE) of ozone has a significant impact on tropospheric chemistry and radiation. Traditional diagnostics of STE consider the ozone budget in the lowermost stratosphere (LMS) as a whole. However, this can only render the hemispherically integrated ozone flux and therefore does not distinguish the exchange of ozone into low latitudes from that into high latitudes. The exchange of ozone at different latitudes may have different tropospheric impacts. This present study extends the traditional approach from the entire LMS to individual isentropic layers in the LMS and therefore gives the meridional distribution of STE by the latitudes where each isentropic surface intersects the tropopause. The specified dynamics version of the Whole Atmosphere Community Climate Model is used to estimate the STE ozone flux on each isentropic surface. It is found that net troposphere-to-stratosphere ozone transport occurs in low latitudes along the 350-380 K isentropic surfaces and that net stratosphere-to-troposphere ozone transport takes place in the extratropics along the 280-350 K isentropes. Particularly, the seasonal cycle of extratropical STE ozone flux in the Northern Hemisphere displays a maximum in late spring and early summer, following the seasonal migration of the upper tropospheric jet and associated isentropic mixing. Furthermore, differential diabatic heating and isentropic mixing tend to induce STE ozone fluxes in opposite directions, but the net effect results in a spatiotemporal pattern similar to the STE ozone flux associated with isentropic mixing.

  15. An isentropic compression-heated Ludweig tube transient wind tunnel

    SciTech Connect

    Magari, P.J.; Lagraff, J.E. )

    1991-05-01

    Theoretical development and experimental results show that the Ludweig tube with isentropic heating (LICH) transient wind tunnel described is a viable means of producing flow conditions that are suitable for a variety of experimental investigations. A complete analysis of the wave dynamics of the pump tube compression process is presented. The LICH tube operating conditions are very steady and run times are greater than those of other types of transient facilities such as shock tubes and gas tunnels. This facility is well suited for producing flow conditions that are dynamically similar to those found in a gas turbine, i.e., transonic Mach number, gas-to-wall temperature ratios of about 1.5, and Reynolds numbers greater than 10 to the 6th. 15 refs.

  16. An isentropic compression-heated Ludweig tube transient wind tunnel

    NASA Technical Reports Server (NTRS)

    Magari, Patrick J.; Lagraff, John E.

    1991-01-01

    Theoretical development and experimental results show that the Ludweig tube with isentropic heating (LICH) transient wind tunnel described is a viable means of producing flow conditions that are suitable for a variety of experimental investigations. A complete analysis of the wave dynamics of the pump tube compression process is presented. The LICH tube operating conditions are very steady and run times are greater than those of other types of transient facilities such as shock tubes and gas tunnels. This facility is well suited for producing flow conditions that are dynamically similar to those found in a gas turbine, i.e., transonic Mach number, gas-to-wall temperature ratios of about 1.5, and Reynolds numbers greater than 10 to the 6th.

  17. IWA : an analysis program for isentropic wave measurements.

    SciTech Connect

    Ao, Tommy

    2009-02-01

    IWA (Isentropic Wave Analysis) is a program for analyzing velocity profiles of isentropic compression experiments. IWA applies incremental impedance matching correction to measured velocity profiles to obtain in-situ particle velocity profiles for Lagrangian wave analysis. From the in-situ velocity profiles, material properties such as wave velocities, stress, strain, strain rate, and strength are calculated. The program can be run in any current version of MATLAB (2008a or later) or as a Windows XP executable.

  18. A nonconservative scheme for isentropic gas dynamics

    SciTech Connect

    Chen, Gui-Qiang |; Liu, Jian-Guo

    1994-05-01

    In this paper, we construct a second-order nonconservative for the system of isentropic gas dynamics to capture the physical invariant regions for preventing negative density, to treat the vacuum singularity, and to control the local entropy from dramatically increasing near shock waves. The main difference in the construction of the scheme discussed here is that we use piecewise linear functions to approximate the Riemann invariants w and z instead of the physical variables {rho} and m. Our scheme is a natural extension of the schemes for scalar conservation laws and it can be numerical implemented easily because the system is diagonalized in this coordinate system. Another advantage of using Riemann invariants is that the Hessian matrix of any weak entropy has no singularity in the Riemann invariant plane w-z, whereas the Hessian matrices of the weak entropies have singularity at the vacuum points in the physical plane p-m. We prove that this scheme converges to an entropy solution for the Cauchy problem with L{sup {infinity}} initial data. By convergence here we mean that there is a subsequent convergence to a generalized solution satisfying the entrophy condition. As long as the entropy solution is unique, the whole sequence converges to a physical solution. This shows that this kind of scheme is quite reliable from theoretical view of point. In addition to being interested in the scheme itself, we wish to provide an approach to rigorously analyze nonconservative finite difference schemes.

  19. Measurement and analysis of release isentropes using proton radiography (u)

    SciTech Connect

    Schwartz, Cynthia L; Rigg, Paulo A; Cherne, Frank J; Hixson, Rob S; Greff, Carl W

    2011-01-25

    Off-Hugoniot measurements are needed to further develop predictive models that accurately describe the behavior of metals undergoing phase transitions. Predictive modeling of phase transitions is essential for LANL to meet its programmatic objectives. Understanding the dynamic evolution of density as a function of time during the release process is important to developing high fidelity equation of state models. This is particularly true for metals that have a degree of complexity, such as a solid-solid phase transition. The equations-of-state (EOS) for metals with complexity are more difficult to measure and to model, and states far away from where measurements are easily made can be poorly known. Accurate density measurements can provide us with additional fundamental information that can be used to further constrain the equation of state for a material. Currently release isentrope information is obtained from shock experiments at a sample window interface using optical velocimetry. This data is highly convoluted due to wave interactions between the sample window-interface making it difficult to infer physical processes happening within the material. Proton radiography has the ability to probe the release waves in-situ before these wave interactions can take place. Since multiple radiographs are obtained in each experiment, pRad provides the unique capability of being able to measure both density and wave evolution within the material. The measurement of release wave densities, however, presents new challenges for pRad since the release wave of a shocked transition is not a step function but instead a ramped wave. Previous pRad experiments have generally measured density jumps over step transitions; therefore, new analysis techniques will have to be developed to measure the ramped density change of a release isentrope. Once developed, these new analysis techniques can also be used for experiments that involve ramped compression. This kind of compression is being

  20. Isentropic Cross-Tropopause Ozone Transport in the Northern Hemisphere

    NASA Technical Reports Server (NTRS)

    Jing, P.; Cunnold, D. M.; Wang, H. J.; Yang, E.-S.

    2004-01-01

    This paper investigates isentropic ozone exchange between the extratropical lower stratosphere and the subtropical upper troposphere in the Northern Hemisphere. The quantification method is based on the potential vorticity (PV) mapping of Stratospheric Aerosol and Gas Experiment (SAGE)-II ozone measurements and contour advection calculations using the NASA Goddard Space Center Data Assimilation Office (DAO) analysis for the year 1990. The magnitude of the annual isentropic stratosphere-to-troposphere ozone flux is calculated to be approximately twice the flux that is directed from the troposphere into the stratosphere. The net effect is that approx.46 x 10(exp 9) kg/yr of ozone are transferred quasi horizontally from the extratropical lower stratosphere into the subtropical upper troposphere between the isentropic surfaces of 330 and 370 K. The estimated monthly ozone fluxes show that the isentropic cross-tropopause ozone transport is stronger in summer/fall than in winter/ spring, and this seasonality is more obvious at the upper three levels (i.e., 345, 355, and 365 K) than at 335 K. The distributions of the estimated monthly ozone fluxes indicate that the isentropic stratosphere-to-troposphere ozone exchange is associated with wave breaking and occurs preferentially over the eastern Atlantic Ocean and northwest Africa in winter and over the Atlantic and Pacific Oceans in summer.

  1. Vertical vorticity development owing to down-sliding at slantwise isentropic surface

    NASA Astrophysics Data System (ADS)

    Wu, Guo-Xiong; Liu, Huan-Zhu

    1998-01-01

    Based upon the conservation of Ertel potential vorticity and moist potential vorticity, a 'parcel dynamic' approach is used to investigate the development of vertical vorticity of a parcel which is sliding down a slantwise isentropic surface. An accurate form of the tendency equation of vertical vorticity is deduced to interpret such slantwise vorticity development (SVD). In addition to those dynamic terms in the traditional vertical vorticity equation, the newly developed accurate form includes several thermal terms associated with the changes in stability, vertical wind shear and baroclinity. It is proved that the combinative impacts of these thermal terms on the development of vertical vorticity can be expressed by a succinct theory of SVD. According to this theory, when the horizontal component of potential vorticity and stability possess opposite signs, and the slantwise isentropic surfaces are very steep, the vorticity development of the down-sliding flow at such isentropes can be dramatic. It is also shown that in a convectively unstable and saturated atmosphere, such vorticity development must be accompanied by the development of a low-level jet. Study of a torrential rain process shows that moist potential vorticity analysis is a powerful tool in the study of torrential rain occurrence. Results from the present study are in agreement with the contentions of earlier workers that moist symmetric instability is the cause of some heavy rainbands.

  2. An objective isobaric/isentropic technique for upper air analysis

    NASA Technical Reports Server (NTRS)

    Mancuso, R. L.; Endlich, R. M.; Ehernberger, L. J.

    1981-01-01

    An objective meteorological analysis technique is presented whereby both horizontal and vertical upper air analyses are performed. The process used to interpolate grid-point values from the upper-air station data is the same as for grid points on both an isobaric surface and a vertical cross-sectional plane. The nearby data surrounding each grid point are used in the interpolation by means of an anisotropic weighting scheme, which is described. The interpolation for a grid-point potential temperature is performed isobarically; whereas wind, mixing-ratio, and pressure height values are interpolated from data that lie on the isentropic surface that passes through the grid point. Two versions (A and B) of the technique are evaluated by qualitatively comparing computer analyses with subjective handdrawn analyses. The objective products of version A generally have fair correspondence with the subjective analyses and with the station data, and depicted the structure of the upper fronts, tropopauses, and jet streams fairly well. The version B objective products correspond more closely to the subjective analyses, and show the same strong gradients across the upper front with only minor smoothing.

  3. Isentropic transport and the seasonal cycle amplitude of CO2

    NASA Astrophysics Data System (ADS)

    Barnes, Elizabeth A.; Parazoo, Nicholas; Orbe, Clara; Denning, A. Scott

    2016-07-01

    Carbon-concentration feedbacks and carbon-climate feedbacks constitute one of the largest sources of uncertainty in future climate. Since the beginning of the modern atmospheric CO2 record, seasonal variations in CO2 have been recognized as a signal of the metabolism of land ecosystems, and quantitative attribution of changes in the seasonal cycle amplitude (SCA) of CO2 to ecosystem processes is critical for understanding and projecting carbon-climate feedbacks far into the 21st Century. Here the impact of surface carbon fluxes on the SCA of CO2 throughout the Northern Hemisphere troposphere is investigated, paying particular attention to isentropic transport across latitudes. The analysis includes both a chemical transport model GOES-Chem and an idealized tracer in a gray-radiation aquaplanet. The results of the study can be summarized by two main conclusions: (1) the SCA of CO2 roughly follows surfaces of constant potential temperature, which can explain the observed increase in SCA with latitude along pressure surfaces and (2) increasing seasonal fluxes in lower latitudes have a larger impact on the SCA of CO2 throughout most of the troposphere compared to increasing seasonal fluxes in higher latitudes. These results provide strong evidence that recently observed changes in the SCA of CO2 at high northern latitudes (poleward of 60°N) are likely driven by changes in midlatitude surface fluxes, rather than changes in Arctic fluxes.

  4. Isentropic compression of hydrogen: Probing conditions deep in planetary interiors

    NASA Astrophysics Data System (ADS)

    Becker, Andreas; Nettelmann, Nadine; Holst, Bastian; Redmer, Ronald

    2013-07-01

    We perform ab initio calculations for the equation of state of dense liquid hydrogen and deuterium using quantum molecular dynamics simulations based on finite-temperature density functional theory. This extensive data set allows us to determine specific density-temperature-pressure tracks such as the cold curve, precompressed and principal Hugoniot curves, and isentropes which are essential for the analysis and interpretation of high-pressure experiments. In this study we focus on conditions probed by recent quasi-isentropic shock compression experiments that have reached a so-far unprecedented 108-fold compression of gaseous deuterium. As these states of matter are relevant for the deep interior of Jupiter-like exoplanets we simultaneously give predictions for their isentropes.

  5. Inverse Analysis of Isentropic Compression Experiments, V0.1

    Energy Science and Technology Software Center (ESTSC)

    2005-04-01

    The purpose of the program INVICE is to extract information about the mechanical compression isentrope of a material by analysis of experimental velocity profile data. The software is used to analyze raw data from high-pressure isentropic compression experiments performed at various drive facilities (primarily the Z Machine at Sandia National Laboratories) as part of DOE’s Stockpile Stewardship Program or other programs studying condensed matter at high pressures. The program uses a two-step Lax-Wendroff finitedifferencing schememore » to integrate the one-dimensional (planar) equations of motion backward in the Lagrangian spatial coordinate, and a downhill simplex method with optional simulated annealing to perform minimization for extracting an isentrope.« less

  6. Isentropic "Shock Waves" in Numerical Simulations of Astrophysical Problems

    NASA Astrophysics Data System (ADS)

    Bisnovatyi-Kogan, G. S.; Moiseenko, S. G.

    2016-03-01

    Strong discontinuities in solutions of the gas dynamic equations under isentropic conditions, i.e., with continuity of entropy at the discontinuity, are examined. Solutions for a standard shock wave with continuity of energy at the discontinuity are compared with those for an isentropic "shock wave." It is shown that numerical simulation of astrophysical problems in which high-amplitude shock waves are encountered (supernova explosions, modelling of jets) with conservation of entropy, rather than of energy, leads to large errors in the shock calculations. The isentropic equations of gas dynamics can be used only when there are no strong discontinuities in the solution or when the intensity of the shocks is not high and they do not significantly affect the flow.

  7. Isentropic Compression of Iron with the Z Accelerator

    SciTech Connect

    Asay, J.R.; Bernard, M.A.; Hall, C.A.; Hayes, D.B.; Holland, K.G.; McDaniel, D.H.; Rosenthal, S.E.; Spielman, R.B.; Stygar, W.A.

    1999-06-10

    Development of isentropic loading techniques is a long standing goal of the shock physics community. The authors have used the Sandia Z Accelerator to produce smoothly increasing pressure loading on planar iron specimens over time durations of 100 ns and for pressures to 300 Mbar. Free surface velocity measurements on the rear surface of the continuously loaded specimens were made on specimens 0.5-mm and 0.8-mm thick and clearly show the effects of wave evolution into the well known two-wave structure resulting from the {alpha}-{var_epsilon} phase transition beginning at 125 kbar. The resulting wave profiles are analyzed with a rate-dependent, phase transition model to extract information on phase transformation kinetics for isentropic compression of iron. Comparison of the experiments and calculations demonstrate the value of isentropic loading for studying phase transition kinetics.

  8. How to Plan and Analyze an Isentropic Compression Experiment (ICE)

    SciTech Connect

    Hare, D E

    2004-08-06

    This report is a how-to manual for planning and analyzing an Isentropic Compression Experiment (ICE). Here the specific task is to find the unreacted Hugoniot of high explosive (HE) using Sandia National Laboratories Z-machine facility. However, many of the principles are broadly applicable to general ICE problems.

  9. Isentropic compression experiments on the Sandia Z accelerator

    SciTech Connect

    HALL,CLINT A.

    2000-02-21

    A long-standing goal of the equation of state (EOS) community has been the development of a loading capability for direct measurement of material properties along an isentrope. Previous efforts on smooth bore launchers have been somewhat successful, but quite difficult to accurately reproduce, had pressure limitations, or tended to be a series of small shocks as opposed to a smoothly increasing pressure load. A technique has recently been developed on the Sandia National Laboratories Z accelerator which makes use of the high current densities and magnetic fields available to produce nearly isentropic compression of samples that are approximately 1 mm in thickness over approximately 120 ns. Velocity interferometry is used to measure the rear surface motion of these samples. The resulting time resolved velocity profiles from multiple sample thicknesses provide information about mechanical response under isentropic loading conditions and phase transition kinetics. Feasibility experiments have been performed to pressures of approximately 130 kbar in copper and 300 kbar in iron with effects of the {alpha}-{var_epsilon} phase change kinetics in iron clearly observed. Work is in progress to achieve 1--2% accuracy in P-v space along an isentrope, provide uniaxial strain, and to eliminate magnetic field and current diffusion within the sample of interest.

  10. Seasonal Ozone Variations in the Isentropic Layer between 330 and 380 K as Observed by SAGE 2: Implications of Extratropical Cross-Tropopause Transport

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Cunnold, Derek M.; Zawodny, Joseph M.; Pierce, R. Bradley; Olson, Jennifer R.; Kent, Geoffrey S.; Skeens, Kristi, M.

    1998-01-01

    To provide observational evidence on the extratropical cross-tropopause transport between the stratosphere and the troposphere via quasi-isentropic processes in the middleworld (the part of the atmosphere in which the isentropic surfaces intersect the tropopause), this report presents an analysis of the seasonal variations of the ozone latitudinal distribution in the isentropic layer between 330 K and 380 K based on the measurements from the Stratospheric Aerosol and Gas Experiment (SAGE) II. The results from SAGE II data analysis are consistent with (1) the buildup of ozone-rich air in the extratropical middleworld through the large-scale descending mass circulation during winter, (2) the spread of ozone-rich air in the isentropic layer from midlatitudes to subtropics via quasi-isentropic transport during spring, (3) significant photochemical ozone removal and the absence of an ozone-rich supply of air to the layer during summer, and (4) air mass exchange between the subtropics and the extratropics during the summer monsoon period. Thus the SAGE II observed ozone seasonal variations in the middleworld are consistent with the existing model calculated annual cycle of the diabatic circulation as well as the conceptual role of the eddy quasi-adiabatic transport in the stratosphere-troposphere exchange reported in the literature.

  11. The South Asian Monsoon Circulation in Moist Isentropic coordinates

    NASA Astrophysics Data System (ADS)

    Thazhe Purayil, Sabin; Pauluis, Olivier

    2016-04-01

    The atmospheric circulation and thermodynamic structure during the South Asian Summer Monsoon season is analyzed in isentropic coordinates through the mass transport represented in terms of the potential temperature and equivalent potential temperature. This approach, originally developed to analyze the global meridional circulation, makes it possible to identify the thermodynamic properties of the inflow and outflow of different air mass. To understand the thermodynamic properties of air mass in south Asian monsoon region, we have used three diagnostics; a) the joint distribution of the mass transport as a function of dry and moist entropy, b) the vertical mass flux over the monsoon domain and c) the mass transport and isentropic thickness for different moist ventilation range of tropical atmosphere. The thermodynamic properties of the various air masses, such as the inflow of warm moist air in the boundary layer, upper tropospheric outflow, and midlatitude dry air intrusion are being systematically identified. The isentropic distribution of the vertical mass flux transport in terms of equivalent potential temperature is used to explain the characteristics of ascending and descending air parcels over the Indian subcontinent. Diagnosis based on the isentropic thickness reveals that the regional monsoon circulation and associated precipitation features can be systematically explained by this method. This technique is used to study the evolution of the monsoon flow in the seasonal scale. We used the data from AMIP-type simulations carried out with prescribed Sea Surface Temperature and sea ice for a 25 year period (1981-2005) from the GFDL High-resolution atmospheric model (HiRAM) with an average grid spacing of ~25km over the globe.

  12. An isentropic compression heated Ludwieg tube transient wind tunnel

    NASA Technical Reports Server (NTRS)

    Magari, Patrick J.; Lagraff, John E.

    1988-01-01

    Syracuse University's Ludwieg tube with isentropic compression facility is a transient wind tunnel employing a piston drive that incorporates insentropic compression heating of the test gas located ahead of a piston. The facility is well-suited for experimental investigations concerning supersonic and subsonic vehicles over a wide range of pressures, Reynolds numbers, and temperatures; all three parameters can be almost independently controlled. Work at the facility currently includes wake-induced stagnation point heat transfer and supersonic boundary layer transition.

  13. Isentropic Compression of Multicomponent Mixtures of Fuels and Inert Gases

    NASA Technical Reports Server (NTRS)

    Barragan, Michelle; Julien, Howard L.; Woods, Stephen S.; Wilson, D. Bruce; Saulsberry, Regor L.

    2000-01-01

    In selected aerospace applications of the fuels hydrazine and monomethythydrazine, there occur conditions which can result in the isentropic compression of a multicomponent mixture of fuel and inert gas. One such example is when a driver gas such as helium comes out of solution and mixes with the fuel vapor, which is being compressed. A second example is when product gas from an energetic device mixes with the fuel vapor which is being compressed. Thermodynamic analysis has shown that under isentropic compression, the fuels hydrazine and monomethylhydrazine must be treated as real fluids using appropriate equations of state. The appropriate equations of state are the Peng-Robinson equation of state for hydrazine and the Redlich-Kwong-Soave equation of state for monomethylhydrazine. The addition of an inert gas of variable quantity and input temperature and pressure to the fuel compounds the problem for safety design or analysis. This work provides the appropriate thermodynamic analysis of isentropic compression of the two examples cited. In addition to an entropy balance describing the change of state, an enthalpy balance is required. The presence of multicomponents in the system requires that appropriate mixing rules are identified and applied to the analysis. This analysis is not currently available.

  14. Dynamic response of single crystalline copper subjected to quasi-isentropic laser and gas-gun driven loading

    NASA Astrophysics Data System (ADS)

    Meyers, M.; Jarmakani, H.; McNaney, J. M.; Schneider, M.; Nguyen, J. H.; Kad, B.

    2006-08-01

    Single crystalline copper was subjected to quasi-isentropic compression via gas-gun and laser loading at pressures between 18 GPa and 59 GPa. The deformation substructure was analyzed via transmission electron microscopy (TEM). Twins and laths were evident at the highest pressures, and stacking faults and dislocation cells in the intermediate and lowest pressures, respectively. The Preston-Tonks-Wallace (PTW) constitutive description was used to model the slip-twinning process in both cases.

  15. Dynamic response of single crystalline copper subjected to quasi-isentropic laser and gas-gun driven loading

    SciTech Connect

    Meyers, M; Jarmakani, H; McNaney, J; Schneider, M; Nguyen, J; Kad, B

    2006-05-22

    Single crystalline copper was subjected to quasi-isentropic compression via gas-gun and laser loading at pressures between 18 GPa and 59 GPa. The deformation substructure was analyzed via transmission electron microscopy (TEM). Twins and laths were evident at the highest pressures, and stacking faults and dislocation cells in the intermediate and lowest pressures, respectively. The Preston-Tonks-Wallace (PTW) constitutive description was used to model the slip-twinning process in both cases.

  16. Verification of conventional equations of state for tantalum under quasi-isentropic compression

    SciTech Connect

    Binqiang, Luo; Guiji, Wang; Jianjun, Mo; Hongpin, Zhang; Fuli, Tan; Jianheng, Zhao; Cangli, Liu; Chengwei, Sun

    2014-11-21

    Shock Hugoniot data have been widely used to calibrate analytic equations of state (EOSs) of condensed matter at high pressures. However, the suitability of particular analytic EOSs under off-Hugoniot states has not been sufficiently verified using experimental data. We have conducted quasi-isentropic compression experiments (ICEs) of tantalum using the compact pulsed power generator CQ-4, and explored the relation of longitudinal stress versus volume of tantalum under quasi-isentropic compression using backward integration and characteristic inverse methods. By subtracting the deviatoric stress and additional pressure caused by irreversible plastic dissipation, the isentropic pressure can be extracted from the longitudinal stress. Several theoretical isentropes are deduced from analytic EOSs and compared with ICE results to validate the suitability of these analytic EOSs in isentropic compression states. The comparisons show that the Gruneisen EOS with Gruneisen Gamma proportional to volume is accurate, regardless whether the Hugoniot or isentrope is used as the reference line. The Vinet EOS yields better accuracy in isentropic compression states. Theoretical isentropes derived from Tillotson, PUFF, and Birch-Murnaghan EOSs well agree with the experimental isentrope in the range of 0–100 GPa, but deviate gradually with pressure increasing further.

  17. Modeling non-equilibrium phase transitions in isentropically compressed Bi

    SciTech Connect

    Kane, J; Smith, R

    2005-09-19

    We report here on modeling of non-equilibrium phase transitions in Bi samples isentropically compressed to 120 GPa by a ramped drive, which is produced using the Janus laser. In the experiments, the Bi samples are attached to windows of LiF or sapphire, and the velocity history of the sample-window interface is recorded with line VISAR. The 1D response of the targets is modeled using a multiphase Bi EOS, the Andrews-Hayes method for non-equilibrium transitions, and a Boettger-Wallace kinetics model. The pressure drive is deduced by back integration of VISAR data from shots performed with Al samples.

  18. Isentropic compressive wave generator and method of making same

    DOEpatents

    Barker, L.M.

    An isentropic compressive wave generator and method of making same are disclosed. The wave generator comprises a disk or flat pillow member having component materials of different shock impedances formed in a configuration resulting in a smooth shock impedance gradient over the thickness thereof for interpositioning between an impactor member and a target specimen for producing a shock wave of a smooth predictable rise time. The method of making the pillow member comprises the reduction of the component materials to a powder form and forming the pillow member by sedimentation and compressive techniques.

  19. Design of a miniature explosive isentropic compression experiment

    SciTech Connect

    Tasker, Douglas G

    2010-01-01

    The purpose of this design study is to adapt the High Explosive Pulsed Power Isentropic Compression Experiment (HEPP-ICE) to milligram quantities of materials at stresses of {approx}100 GPa. For this miniature application we assume that a parallel plate stripline of {approx}2.5 mm width is needed to compress the samples. In any parallel plate load, the rising currents flow preferentially along the outside edges of the load where the specific impedance is a minimum [1]. Therefore, the peak current must be between 1 and 2 MA to reach a stress of 100 GPa in the center of a 2.5 mm wide parallel plate load; these are small relative to typical HEPP-ICE currents. We show that a capacitor bank alone exceeds the requirements of this miniature ICE experiment and a flux compression generator (FCG) is not necessary. The proposed circuit will comprise one half of the 2.4-MJ bank, i.e., the 6-mF, 20-kV, 1.2 MJ capacitor bank used in the original HEPP-ICE circuit. Explosive opening and closing switches will still be required because the rise time of the capacitor circuit would be of the order of 30 {micro}s without them. For isentropic loading in these small samples, stress rise times of {approx}200 ns are required.

  20. Simultaneous determination of Hugoniot and Isentrope in gas gun experiments

    SciTech Connect

    Thoe, R S

    2007-02-22

    We have been exploring the use of the ''reverse ballistics'' method to obtain Hugoniot and off Hugoniot Equation Of State. This method uses the unknown sample as the flyer and collides it into a window whose EOS is well known. A VISAR determines the particle velocity which when combined with the windows EOS gives a direct determination of the pressure. Since the pressure and particle velocity are continuous across the interface the shock speed in the flyer can be determined: Us = P/(rhoUp). Subtracting the time of arrival of the shock at the back of the flyer from the times of arrival of the rarefaction wave allows the determination of the release isentrope centered at the measured Hugoniot point and extending down to the release pressure as determined by the impedance of the sabot. Besides obtaining both Hugoniot and isentrope data on a single shot, this method has an advantage in that all the timing information is accomplished within the interferometer, i.e. no dependence of cable delays etc.

  1. A study of binder materials subjected to isentropic compression loading.

    SciTech Connect

    Hall, Clint Allen; Orler, E. Bruce; Sheffield, Steve A; Gustavsen, Rick L.; Sutherland, Gerrit; Baer, Melvin R.; Hooks, D.E.

    2005-07-01

    Binders such as Estane, Teflon, Kel F and HTPB are typically used in heterogeneous explosives to bond polycrystalline constituents together as an energetic composite. Combined theoretical and experimental studies are underway to unravel the mechanical response of these materials when subjected to isentropic compression loading. Key to this effort is the determination of appropriate constitutive and EOS property data at extremely high stress-strain states as required for detailed mesoscale modeling. The Sandia Z accelerator and associated diagnostics provides new insights into mechanical response of these nonreactive constituents via isentropic ramp-wave compression loading. Several thicknesses of samples, varied from 0.3 to 1.2 mm, were subjected to a ramp load of {approx}42 Kbar over 500 ns duration using the Sandia Z-machine. Profiles of transmitted ramp waves were measured at window interfaces using conventional VISAR. Shock physics analysis is then used to determine the nonlinear material response of the binder materials. In this presentation we discuss experimental and modeling details of the ramp wave loading ICE experiments designed specifically for binder materials.

  2. Z-Pinch Driven Isentropic Compression for Inertial Fusion

    SciTech Connect

    Asay, J.R.; Hall, C.A.; Holland, K.G.; Slutz, S.A.; Spielman, R.B.; Stygar, W.A.

    1999-02-01

    The achievement of high gain with inertial fusion requires the compression of hydrogen isotopes to high density and temperatures. High densities can be achieved most efficiently by isentropic compression. This requires relatively slow pressure pulses on the order of 10-20 nanoseconds; however, the pressure profile must have the appropriate time. We present 1-D numerical simulations that indicate such a pressure profile can be generated by using pulsed power driven z pinches. Although high compression is calculated, the initial temperature is too low for ignition. Ignition could be achieved by heating a small portion of this compressed fuel with a short (-10 ps) high power laser pulse as previously described. Our 1-D calculations indicate that the existing Z-accelerator could provide the driving current (-20 MA) necessary to compress fuel to roughly 1500 times solid density. At this density the required laser energy is approximately 10 kJ. Multidimensional effects such as the Rayleigh-Taylor were not addressed in this brief numerical study. These effects will undoubtedly lower fuel compression for a given chive current. Therefore it is necessary to perform z-pinch driven compression experiments. Finally, we present preliminary experimental data from the Z-accelerator indicating that current can be efficiently delivered to appropriately small loads (- 5 mm radius) and that VISAR can be used measure high pressure during isentropic compression.

  3. Examination of Isentropic Circulation Response to A Doubling of Carbon Dioxide Using Statistical Transformed Eulerian Mean

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Pauluis, O. M.

    2012-12-01

    Responses of the isentropic circulation to a doubling of carbon dioxide (CO2) are examined in an atmospheric general circulation model on both dry and moist isentropes using the method of statistical transformed Eulerian mean (STEM). The STEM formulation allows an estimation of the atmospheric circulation on moist isentropes and separates the isentropic circulation into the Eulerian-mean and the eddy components. It also allows a decomposition of the global warming response into the changes in commonly used zonal and monthly mean climate variables such as the mean meridional velocity, isentropic surfaces, meridional eddy flux, and eddy variance. It is found that, as a consequence of CO2 doubling, the dry isentropic circulation weakens across all latitudes in both hemispheres. The weaker circulation within the tropical Hadley Cell is mainly a result of the reduction in mean meridional circulation while the reduction in eddy sensible heat flux largely contributes to the slow down of the circulation in the midlatitudes. The total heat transport analyzed on dry isentropes, however, increases in the tropics because of the increase in dry effective stratification whereas it decreases in the extratropics following the reduction in poleward eddy sensible heat transport. Furthermore, distinct features are found on moist isentropes. The tropical circulation also weakens on moist isentropes but not much change is found in total heat transport. The extratropical circulation shifts poleward on moist isentropes with an intensification (weakening) of the circulation on the poleward (equatorward) flank, which is primarily due to the change in eddy latent heat transport and mean moist isentropic surface. The total heat transport in the midlatitudes also shows a poleward shift but is of smaller magnitude. The difference between the dry and moist isentropic circulation reveals the role of moisture associated with the eddies, which strongly intensifies in the midlatitudes and dominates

  4. Isentropic compression studies using the NHMFL single turn

    SciTech Connect

    Tasker, Douglas G; Mielke, Charles; Rodriguez, George; Rickel, Dwight

    2010-10-19

    Magnetic isentropic compression experiments (ICE) provide the most accurate shock free compression data for materials at megabar stresses. Recent ICE experiments performed on the Sandia Z-machine (Asay, 1999) and at the Los Alamos High Explosive Pulsed Power facility (Tasker, 2006) are providing our nation with data on material properties in extreme dynamic high stress environments. The LANL National High Magnetic Field Laboratory (NHMFL) can offer a less complex ICE experiment at high stresses (up to {approx}1Mbar) with a high sample throughput and relatively low cost. This is not to say that the NHMFL technique will replace the other methods but rather complement them. For example, NHMFL-ICE is ideal for the development of advanced diagnostics, e.g., to detect phase changes. We will discuss the physics of the NHMFL-ICE experiments and present data from the first proof-of-principle experiments that were performed in September 2010.

  5. Metal liner-driven quasi-isentropic compression of deuterium

    SciTech Connect

    Weinwurm, Marcus; Bland, Simon N.; Chittenden, Jeremy P.

    2013-09-15

    Properties of degenerate hydrogen and deuterium (D) at pressures of the order of terapascals are of key interest to Planetary Science and Inertial Confinement Fusion. In order to recreate these conditions in the laboratory, we present a scheme, where a metal liner drives a cylindrically convergent quasi-isentropic compression in a D fill. We first determined an external pressure history for driving a self-similar implosion of a D shell from a fictitious flow simulation [D. S. Clark and M. Tabak, Nucl. Fusion 47, 1147 (2007)]. Then, it is shown that this D implosion can be recreated inside a beryllium liner by shaping the current pulse. For a peak current of 10.8 MA cold and nearly isochoric D is assembled at around 12 500 kg/m{sup 3}. Finally, our two-dimensional Gorgon simulations show the robustness of the implosion method to the magneto-Rayleigh-Taylor instability when using a sufficiently thick liner.

  6. Analysis of non-isentropic compressible Euler equations with relaxation

    NASA Astrophysics Data System (ADS)

    Li, Tong; Zhao, Kun

    2015-12-01

    This paper is contributed to the study of the one-dimensional non-isentropic compressible Euler equations with relaxation. It is shown that classical solutions do not exist globally-in-time under general conditions on initial data. Indeed, finite-time blowup occurs in a quantity related to the first moment. On the other hand, when the initial datum is sufficiently close to a constant equilibrium state, it is shown that the equations possess a unique global-in-time classical solution, and the solution converges to the equilibrium state in the long-time run. When the domain is finite, the convergence rate is shown to be exponential, due to boundary effects.

  7. Metal liner-driven quasi-isentropic compression of deuterium

    NASA Astrophysics Data System (ADS)

    Weinwurm, Marcus; Bland, Simon N.; Chittenden, Jeremy P.

    2013-09-01

    Properties of degenerate hydrogen and deuterium (D) at pressures of the order of terapascals are of key interest to Planetary Science and Inertial Confinement Fusion. In order to recreate these conditions in the laboratory, we present a scheme, where a metal liner drives a cylindrically convergent quasi-isentropic compression in a D fill. We first determined an external pressure history for driving a self-similar implosion of a D shell from a fictitious flow simulation [D. S. Clark and M. Tabak, Nucl. Fusion 47, 1147 (2007)]. Then, it is shown that this D implosion can be recreated inside a beryllium liner by shaping the current pulse. For a peak current of 10.8 MA cold and nearly isochoric D is assembled at around 12 500 kg/m3. Finally, our two-dimensional Gorgon simulations show the robustness of the implosion method to the magneto-Rayleigh-Taylor instability when using a sufficiently thick liner.

  8. Power calculations for isentropic compressions of cryogenic nitrogen

    NASA Technical Reports Server (NTRS)

    Adock, J. B.; Ogburn, M. E.

    1976-01-01

    A theoretical analysis has been made of the power required for isentropic compressions of cryogenic nitrogen in order to determine the extent that the drive power for cryogenic tunnels might be affected by real gas effects. The analysis covers temperatures from 80 to 310K, pressures from 1.0 to 8.8 atm and fan pressure ratios from 1.025 to 1.200. The power required to compress cryogenic nitrogen was found to be lower than that required for an ideal diatomic gas by as much as 9.5 percent. Simple corrections to the ideal gas values were found to give accurate estimates of the real gas power values.

  9. Power calculations for isentropic compressions of cryogenic nitrogen

    NASA Technical Reports Server (NTRS)

    Adcock, J. B.; Ogburn, M. E.

    1977-01-01

    A theoretical analysis was made of the power required for isentropic compressions of cryogenic nitrogen in order to determine the extent to which the drive power for cryogenic tunnels might be affected by real-gas effects. The analysis covers temperatures from 80 to 310 K, pressures from 1.0 to 8.8 atm, and fan pressure ratios from 1.025 to 1.200. The power required to compress cryogenic nitrogen was found to be as much as 9.5 percent lower than that required to compress an ideal diatomic gas. Simple corrections to the ideal-gas values were found to give accurate estimates of the real-gas power values.

  10. Magnetically-Driven Isentropic Compression Status and Future Advances

    NASA Astrophysics Data System (ADS)

    Deeney, Christopher

    2005-07-01

    Since the development of magnetically driven isentropic compression experiments (ICE) on the Z accelerator by Asay et al, this technique has continued to grow in maturity. At lower pressures, isentropic compression has been employed to identify and then study phase transitions and their kinetics. In addition, experiments have used the same techniques to study re-solidification, the response of explosives, and the crush up of porous materials. Most of these experiments rely on the ability of ICE to generate very smooth ramps that can be applied to multiple samples for relative experiments. For equation of state studies, the intrinsic accuracy and peak pressures continue to demand improvement in understanding, analysis techniques and diagnostics. We have spent significant effort in these areas over the last few years because we believe that we must demonstrate a well characterized and understood method to obtain accurate EOS data with well-behaved materials to give confidence in future comparisons between ICE data and calculations of material properties. In our presentation, we will discuss the status of Z experiments, our recent data at multi-megabar pressures with aluminum and other materials, and the status of our analysis abilities. We will also discuss the need for future improvements in diagnostics plus the anticipated capabilities of the ZR facility and the small pulser. This work was supported by the United States Department of Energy's National Nuclear Security Administration under contract No. DE-AC04-94AL85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company..

  11. Isentropic Compression in a Strip Line, Numerical Simulations and Comparison with GEPI Shot 268

    SciTech Connect

    Lefrancois, A.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Isentropic compressions in a strip line geometry are performed on the GEPI facility at Centre d'etudes de Gramat in order to study isentrope, associated Hugoniot and phase changes. 3D GEPI configuration has been calculated here to test the new beta version of the electromagnetism package coupled with the dynamics in LS-DYNA{reg_sign} and compared with the GEPI experiment number 268.

  12. Isentropic Compression for TATB Based HE Samples, Numerical Simulations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A; Vandersall, K; L'Eplattenier, P; Burger, M

    2006-02-06

    Isentropic compression experiments and numerical simulations on TATB based HE were performed respectively at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope and associated Hugoniot of this HE [1]. 3D configurations have been calculated here to test the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shot 1967.

  13. Non-local thermodynamic equilibrium effects on isentropic coefficient in argon and helium thermal plasmas

    SciTech Connect

    Sharma, Rohit; Singh, Kuldip

    2014-03-15

    In the present work, two cases of thermal plasma have been considered; the ground state plasma in which all the atoms and ions are assumed to be in the ground state and the excited state plasma in which atoms and ions are distributed over various possible excited states. The variation of Zγ, frozen isentropic coefficient and the isentropic coefficient with degree of ionization and non-equilibrium parameter θ(= T{sub e}/T{sub h}) has been investigated for the ground and excited state helium and argon plasmas at pressures 1 atm, 10 atm, and 100 atm in the temperature range from 6000 K to 60 000 K. For a given value of non-equilibrium parameter, the relationship of Zγ with degree of ionization does not show any dependence on electronically excited states in helium plasma whereas in case of argon plasma this dependence is not appreciable till degree of ionization approaches 2. The minima of frozen isentropic coefficient shifts toward lower temperature with increase of non-equilibrium parameter for both the helium and argon plasmas. The lowering of non-equilibrium parameter decreases the frozen isentropic coefficient more emphatically in helium plasma at high pressures in comparison to argon plasma. The increase of pressure slightly reduces the ionization range over which isentropic coefficient almost remains constant and it does not affect appreciably the dependence of isentropic coefficient on non-equilibrium parameter.

  14. Separation of acoustic waves in isentropic flow perturbations

    SciTech Connect

    Henke, Christian

    2015-04-15

    The present contribution investigates the mechanisms of sound generation and propagation in the case of highly-unsteady flows. Based on the linearisation of the isentropic Navier–Stokes equation around a new pathline-averaged base flow, it is demonstrated for the first time that flow perturbations of a non-uniform flow can be split into acoustic and vorticity modes, with the acoustic modes being independent of the vorticity modes. Therefore, we can propose this acoustic perturbation as a general definition of sound. As a consequence of the splitting result, we conclude that the present acoustic perturbation is propagated by the convective wave equation and fulfils Lighthill’s acoustic analogy. Moreover, we can define the deviations of the Navier–Stokes equation from the convective wave equation as “true” sound sources. In contrast to other authors, no assumptions on a slowly varying or irrotational flow are necessary. Using a symmetry argument for the conservation laws, an energy conservation result and a generalisation of the sound intensity are provided. - Highlights: • First splitting of non-uniform flows in acoustic and non-acoustic components. • These result leads to a generalisation of sound which is compatible with Lighthill’s acoustic analogy. • A closed equation for the generation and propagation of sound is given.

  15. Influence of the vector interaction and an external magnetic field on the isentropes near the chiral critical end point

    NASA Astrophysics Data System (ADS)

    Costa, Pedro

    2016-06-01

    The location of the critical end point (CEP) and the isentropic trajectories in the QCD phase diagram are investigated. We use the (2 +1 ) Nambu-Jona-Lasinio model with the Polyakov loop coupling for different scenarios, namely by imposing zero strange quark density, which is the case in the ultrarelativistic heavy ion collisions, and β equilibrium. The influence of strong magnetic fields and of the vector interaction on the isentropic trajectories around the CEP is discussed. It is shown that the vector interaction and the magnetic field, having opposite effects on the first-order transition, affect the isentropic trajectories differently: as the vector interaction increases, the first-order transition becomes weaker and the isentropes become smoother; when a strong magnetic field is considered, the first-order transition is strengthened and the isentropes are pushed to higher temperatures. No focusing of isentropes in region towards the CEP is seen.

  16. Mesoscale Modeling of LX-17 Under Isentropic Compression

    SciTech Connect

    Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S; Baer, M R

    2010-03-06

    Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the lower density TATB adiabatic EOS data demonstrated the least agreement with VISAR velocity data.

  17. Adaptation of existing facilities to isentropic compression experiments

    SciTech Connect

    Tasker, Douglas G; Mielke, Charles H; Rodriguez, George; Rickel, Dwight G

    2011-01-07

    We demonstrate that the established pulsed power infrastructure at the National High Magnetic Field Laboratory - Pulsed Field Facility (NHMFL-PFF) at the Los Alamos National Laboratory can be adapted to obtain high quality isentropic compression experiment (ICE) data on materials in extreme conditions of dynamic high pressure. Experiments utilized a single-turn magnet pulsed power system at the NHMFL-PFF that was originally designed to measure actinide samples in extremes of high magnetic field (to 300 Tesla). A simple modification to the single-turn magnet has converted it to a fast turnaround dynamic high pressure measurement system. This paper details the work done including important background details that indicate that much more can be accomplished with optimization of the load characteristics in terms of ultimate peak pressures. To match the rise time of the NHMFL capacitor bank ({approx}2 {mu}s versus {approx}0.5 {mu}s for the Sandia Z-machine) the sample dimensions can be relatively large, i.e., up to 5 mm thickness. The maximum stresses are {approx}50GPa (0.5 Mbar) at the maximum bank voltage (60 kV) and higher pressures may be possible if the sample is tamped. For the design and predictions of performance of the NHMFL-ICE experiment it is important to have good predictive models. A SPICE code simulation was chosen to model all aspects of the experiment, electrical and physical. To this end, accurate dynamic load models were developed to simulate the compression and expansion of the dynamic load at high pressures using shock physics principles. A series experiments have been performed which demonstrated the feasibility of the NHMFL-ICE technique. The results will be shown and discussed. The NHMFL-ICE technique is an excellent method for measuring equations of state (EOS) at megabar pressures. Because a complete EOS can be obtained in one experiment from zero to the peak pressure, and because many shots can be fired in one day, the technique promises to

  18. Optimal decay rate of the non-isentropic compressible Navier-Stokes-Poisson system in R

    NASA Astrophysics Data System (ADS)

    Zhang, Guojing; Li, Hai-Liang; Zhu, Changjiang

    In this paper, the compressible non-isentropic Navier-Stokes-Poisson (NSP) system is considered in R and the influences of internal electric field on the qualitative behaviors of solutions are analyzed. We observe that the electric field leads to the rotating phenomena in charge transport and reduces the speed of fluid motion, but it does not influence the transport of charge density and the heat diffusion. Indeed, we show that both density and temperature of the NSP system converge to their equilibrium state at the same rate (1 as the non-isentropic compressible Navier-Stokes system, but the momentum decays at the rate (1, which is slower than the rate (1 for the pure compressible Navier-Stokes system. These convergence rates are also shown to be optimal for the non-isentropic compressible NSP system.

  19. Shock waves and drag in the numerical calculation of isentropic transonic flow

    NASA Technical Reports Server (NTRS)

    Steger, J. L.; Baldwin, B. S.

    1972-01-01

    Properties of the shock relations for steady, irrotational, transonic flow are discussed and compared for the full and approximate governing potential in common use. Results from numerical experiments are presented to show that the use of proper finite difference schemes provide realistic solutions and do not introduce spurious shock waves. Analysis also shows that realistic drags can be computed from shock waves that occur in isentropic flow. In analogy to the Oswatitsch drag equation, which relates the drag to entropy production in shock waves, a formula is derived for isentropic flow that relates drag to the momentum gain through an isentropic shock. A more accurate formula for drag, based on entropy production, is also derived, and examples of wave drag evaluation based on these formulas are given and comparisons are made with experimental results.

  20. User manual for INVICE 0.1-beta : a computer code for inverse analysis of isentropic compression experiments.

    SciTech Connect

    Davis, Jean-Paul

    2005-03-01

    INVICE (INVerse analysis of Isentropic Compression Experiments) is a FORTRAN computer code that implements the inverse finite-difference method to analyze velocity data from isentropic compression experiments. This report gives a brief description of the methods used and the options available in the first beta version of the code, as well as instructions for using the code.

  1. DYNAMIC RESPONSE OF SINGLE CRYSTALLINE COPPER SUBJECTED TO QUASI-ISENTROPIC, GAS-GUN DRIVEN LOADING

    SciTech Connect

    Jarmakani, H; Mc Naney, J M; Schneider, M S; Cao, B Y; Orlikowski, D; Nguyen, J H; Kad, B; Meyers, M A

    2005-11-02

    A transmission electron microscopy study of quasi-isentropic gas-gun loading (peak pressures between 18 GPa and 52 GPa) of [001] monocrystalline copper was carried out. The defect substructures at these different pressures were analyzed. Current experimental evidence suggests a deformation substructure that transitions from slip to twinning, where twinning occurs at the higher pressures ({approx}52 GPa), and heavily dislocated laths and dislocation cells take place at the intermediate and lower pressures. Evidence of stacking faults at the intermediate pressures was also found. Dislocation cell sizes decreased with increasing pressure and increased with distance away from the surface of impact. The results from the quasi-isentropic experiments are compared with that of flyer-plate and laser shock experiments carried out by Cao et al. [1] and Schneider et al. [2], respectively. The Preston-Tonks-Wallace and Zerilli-Armstrong constitutive descriptions are used to model both isentropic and shock compression experiments and predict the pressure at which the slip-twinning transition occurs in both cases. Both models predict a higher transition for isentropic then for shock experiments, and indeed, that twinning should not take place in the ICE experiments at the pressures investigated.

  2. Variational particle scheme for the porous medium equation and for the system of isentropic Euler equations

    SciTech Connect

    Westdickenberg, Michael; Wilkening, Jon

    2008-12-10

    We introduce variational particle schemes for the porous medium equation and the system of isentropic Euler equations in one space dimension. The methods are motivated by the interpretation of each of these partial differential equations as a 'steepest descent' on a suitable abstract manifold. We show that our methods capture very well the nonlinear features of the flows.

  3. Optimization of current waveform tailoring for magnetically driven isentropic compression experiments.

    PubMed

    Waisman, E M; Reisman, D B; Stoltzfus, B S; Stygar, W A; Cuneo, M E; Haill, T A; Davis, J-P; Brown, J L; Seagle, C T; Spielman, R B

    2016-06-01

    The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest. PMID:27370469

  4. Optimization of current waveform tailoring for magnetically driven isentropic compression experiments

    NASA Astrophysics Data System (ADS)

    Waisman, E. M.; Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Cuneo, M. E.; Haill, T. A.; Davis, J.-P.; Brown, J. L.; Seagle, C. T.; Spielman, R. B.

    2016-06-01

    The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called "bricks," that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.-Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel "current-adder" architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L2 norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

  5. Development and initial test of the University of Wisconsin global isentropic-sigma model

    NASA Technical Reports Server (NTRS)

    Zapotocny, Tom H.; Johnson, Donald R.; Reames, Fred M.

    1994-01-01

    The description of a global version of the University of Wisconsin (UW) hybrid isentropic-sigma (theta-sigma) model and the results from an initial numerical weather prediction experiment are presented in this paper. The main objectives of this initial test are to (1) discuss theta-sigma model development and computer requirements, (2) demonstrate the ability of the UW theta-sigma model for global numerical weather prediction using realistic orography and parameterized physical processes, and (3) compare the transport of an inert trace constituent against a nominally 'identical' sigma coordinate model. Initial and verifying data for the 5-day simulations presented in this work were supplied by the Goddard Earth Observing System (GEOS-1) data assimilation system. The time period studied is 1-6 February 1985. This validation experiment demonstrates that the global UW theta-sigma model produces a realistic 5-day simulation of the mass and momentum distributions when compared to both the identical sigma model and GEOS-1 verification. Root-mean-square errors demonstrate that the theta-sigma model is slightly more accurate than the nominally identical sigma model with respect to standard synoptic variables. Of particular importance, the UW theta-sigma model displays a distinct advantage over the conventional sigma model with respect to the prognostic simulation of inert trace constituent transport in amplifying baroclinic waves of the extratropics. This is especially true in the upper troposphere and stratosphere where the spatial integrity and conservation of an inert trace constituent is severely compromised in the sigma model compared to the theta-sigma model.

  6. Isentropic Compression up to 200 KBars for LX 04, Numerical Simulations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A.; Hare, D.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Isentropic compression experiments and numerical simulations on LX-04 (HMX / Viton 85/15) were performed respectively at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope and associated Hugoniot of this HE. 2D and 3D configurations have been calculated here to test the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shot 1067 on LX 04. The electromagnetism module is being developed in the general-purpose explicit and implicit finite element program LS-DYNA{reg_sign} in order to perform coupled mechanical/thermal/electromagnetism simulations. The Maxwell equations are solved using a Finite Element Method (FEM) for the solid conductors coupled with a Boundary Element Method (BEM) for the surrounding air (or vacuum). More details can be read in the references.

  7. Isentropic Compression with a Rectangular Configuration for Tungstene and Tantalum, Computations and Comparison with Experiments

    SciTech Connect

    Lefrancois, A.; Reisman, D. B.; Bastea, M.; L'Eplattenier, P.; Burger, M.

    2006-02-13

    Isentropic compression experiments and numerical simulations on metals are performed at Z accelerator facility from Sandia National Laboratory and at Lawrence Livermore National Laboratory in order to study the isentrope, associated Hugoniot and phase changes of these metals. 3D configurations have been calculated here to benchmark the new beta version of the electromagnetism package coupled with the dynamics in Ls-Dyna and compared with the ICE Z shots 1511 and 1555. The electromagnetism module is being developed in the general-purpose explicit and implicit finite element program LS-DYNA{reg_sign} in order to perform coupled mechanical/thermal/electromagnetism simulations. The Maxwell equations are solved using a Finite Element Method (FEM) for the solid conductors coupled with a Boundary Element Method (BEM) for the surrounding air (or vacuum). More details can be read in the references.

  8. Isentropic Compression Loading of HMX and the Pressure-induced Phase Transition at 27 GPa

    SciTech Connect

    Hare, D E; Reisman, D B; Dick, J J; Forbes, J W

    2004-02-25

    The 27 GPa pressure-induced epsilon-phi phase transition in HMX is explored using the Isentropic Compression Experiment (ICE) technique at the Sandia National Laboratories Z-machine facility. Our data indicate that this phase transition is sluggish and if it does occur to any extent under the time scales (200-500 ns) and strain rates (5 x 10{sup 5}) typical of ICE loading conditions, the amount of conversion is small.

  9. Electronic excitation and isentropic coefficients of high temperature planetary atmosphere plasmas

    SciTech Connect

    Colonna, Gianpiero; Capitelli, Mario

    2012-07-15

    In this paper, we have discussed the effects of electronically excited states of atomic species in affecting the isentropic coefficients of plasmas, focusing on mixtures representing the atmospheres of Jupiter, Mars, and Earth. General behaviors have been rationalized on the basis of simplified approaches. The contribution of the electronically excited states has been evidenced by comparing results obtained considering only the ground state and those obtained using either Fermi or Griem cutoff criteria.

  10. On rotating star solutions to the non-isentropic Euler-Poisson equations

    NASA Astrophysics Data System (ADS)

    Wu, Yilun

    2015-12-01

    This paper investigates rotating star solutions to the Euler-Poisson equations with a non-isentropic equation of state. As a first step, the equation for gas density with a prescribed entropy and angular velocity distribution is studied. The resulting elliptic equation is solved either by the method of sub and supersolutions or by a variational method, depending on the value of the adiabatic index. The reverse problem of determining angular velocity from gas density is also considered.

  11. Large time behavior of the isentropic compressible Navier-Stokes-Maxwell system

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Li, Fucai; Zhang, Zhipeng

    2016-08-01

    In this paper, we study the large time behavior of the isentropic compressible Navier-Stokes-Maxwell system introduced by Jiang and Li (Nonlinearity 25(6):1735-1752, 2012) in the whole space {{{R}}^3} when the initial data are a small perturbation of some given constant state. We obtain the desired result through taking the refined analysis on the time decay property and Green's function of the linearized system. Moreover, we also obtain the optimal time rate of the solution.

  12. Riemann problem with delta initial data for the isentropic relativistic Chaplygin Euler equations

    NASA Astrophysics Data System (ADS)

    Shao, Zhiqiang

    2016-06-01

    In this paper, we study the Riemann problem with the initial data containing the Dirac delta function for the isentropic relativistic Chaplygin Euler equations. Under suitably generalized Rankine-Hugoniot relation and entropy condition, we constructively obtain the global existence of generalized solutions including delta shock waves that explicitly exhibit four kinds of different structures. Moreover, it can be found that the solutions constructed here are stable for the perturbation of the initial data.

  13. Design and Fabrication of RF/CRF Aerogel Flier-Plates with Graded Density For Laser-Driven Quasi-Isentropic Compression Experiments

    NASA Astrophysics Data System (ADS)

    Shen, Yang; Zhou, Bin; Du, Ai; Huang, Xiuguang; Halperin, William

    2014-03-01

    Resorcinol Formaldehyde (RF)/Carbonized Resorcinol Formaldehyde (CRF) aerogel flier-plates with graded density were designed and fabricated via simple and effective approaches, for increasing the peak pressure and shaping the compression profile in Laser-driven quasi-isentropic compression (ICE) experiments. Sol-gel technique and flexible micro-mould were involved in launching density gradients into aerogel. Resorcinol (R)-formaldehyde (F)-water system catalyzed by sodium carbonate (C) was employed to provide organic RF aerogel, various of sol with different recipes were cast into the mould layer by layer; A carbon dioxide (CO2) supercritical fluid drying (SCFD) process and a four-step pyrolysis process were applied to convert RF hydrogel into RF aerogel, RF aerogel into CRF aerogel, respectively. After a four-step pyrolysis process, RF aerogel was converted to CRF aerogel. The strategies were demonstrated to be simple and effective in launching density gradients into RF/CRF aerogel flyer-plates. It was found in the Laser-Driven Quasi-Isentropic compression experiments of Al that the rise time of the ramp compression wave was about 50% longer for the graded density RF aerogel case.

  14. Influence of isentropic transport on seasonal ozone variations in the lower stratosphere and subtropical upper troposphere

    NASA Technical Reports Server (NTRS)

    Jing, P.; Cunnold, D. M.; Yang, E.-S.; Wang, H.-J.

    2005-01-01

    The isentropic cross-tropopause ozone transport has been estimated in both hemispheres in 1999 based on the potential vorticity mapping of Stratospheric Aerosol and Gas Experiment 11 ozone measurements and contour advection calculations using the NASA Goddard Space Flight Center Global and Modeling Assimilation Office analysis. The estimated net isentropic stratosphere-to-troposphere ozone flux is approx.118 +/- 61 x 10(exp9)kg/yr globally within the layer between 330 and 370 K in 1999; 60% of it is found in the Northern Hemisphere, and 40% is found in the Southern Hemisphere. The monthly average ozone fluxes are strongest in summer and weakest in winter in both hemispheres. The seasonal variations of ozone in the lower stratosphere (LS) and upper troposphere (UT) have been analyzed using ozonesonde observations from ozonesonde stations in the extratropics and subtropics, respectively. It is shown that observed ozone levels increase in the UT over subtropical ozonesonde stations and decrease in the LS over extratropical stations in late spring/early summer and that the ozone increases in the summertime subtropical UT are unlikely to be explained by photochemical ozone production and diabatic transport alone. We conclude that isentropic transport is a significant contributor to ozone levels in the subtropical upper troposphere, especially in summer.

  15. Observations and Modeling of Composition of Upper Troposphere/Lower Stratosphere (UTILS): Isentropic Mixing Events and Morphology of HNO3 as Observed by HIRDLS and Comparison with Results from Global Modeling Initiative

    NASA Technical Reports Server (NTRS)

    Rodriquez, J. M.; Douglass, A.R.; Yoshida, Y.; Strahan, S.; Duncan, B.; Olsen, M.; Gille, J.; Yudin, V.; Nardi, B.

    2008-01-01

    isentropic exchange of air masses between the tropical upper troposphere and mid-latitude lowermost stratosphere (the so-called "middle world") is an important pathway for stratospheric-tropospheric exchange. A seasonal, global view of this process has been difficult to obtain, in part due to the lack of the vertical resolution in satellite observations needed to capture the laminar character of these events. Ozone observations at a resolution of about 1 km from the High Resolution Dynamic Limb Sounder (HIRDLS) on NASA's Aura satellite show instances of these intrusions. Such intrusions should also be observable in HN03 observations; however, the abundances of nitric acid could be additionally controlled by chemical processes or incorporation and removal into ice clouds. We present a systematic examination of the HIRDLS data on O3 and HNO3 to determine the seasonal and spatial characteristics of the distribution of isentropic intrusions. At the same time, we compare the observed distributions with those calculated by the Global Modeling Initiative combined tropospheric-stratospheric model, which has a vertical resolution of about I km. This Chemical Transport Model (CTM) is driven by meteorological fields obtained from the GEOS-4 system of NASA/Goddard Global Modeling and Assimilation Office (GMAO), for the Aura time period, at a vertical resolution of about 1 km. Such comparison brings out the successes and limitations of the model in representing isentropic stratospheric-tropospheric exchange, and the different processes controlling HNO3 in the UTAS.

  16. Isentropic Compression Experiments Performed By LLNL On Energetic Material Samples Using The Z Accelerator

    SciTech Connect

    Vandersall, K S; Reisman, D B; Forbes, J W; Hare, D E; Garcia, F; Uphaus, T M; Elsholz, A J; Tarver, C M; Eggert, J H

    2007-10-25

    Several experiments have been conducted by LLNL researchers using isentropic compression experiments (ICE) on energetic materials as samples from Fiscal Year 2001 (FY01) to Fiscal Year 2005 (FY05). Over this span of time, advancements of the experimental techniques and modeling of the results have evolved to produce improved results. This report documents the experiments that have been performed, provides details of the results generated, and modeling and analysis advances to fully understand the results. Publications on the topics by the various principal investigators (PI's) are detailed in the Appendices for quick reference for the work as it progressed.

  17. Isentropic compression of fused quartz and liquid hydrogen to several Mbar

    NASA Technical Reports Server (NTRS)

    Hawke, R. S.; Duerre, D. E.; Huebel, J. G.; Keeler, R. N.; Klapper, H.

    1972-01-01

    Models of the major planets are in part based on the equations of state of very compressible materials such as hydrogen and helium. A technique of isentropically compressing soft material to several Mbar and some preliminary results on fused quartz (silicon dioxide) and liquid hydrogen is described. Quartz was found to be an electrical non-conductor up to 5 Mbar and has a volume of about 0.15 cubic centimeters per gram at that pressure. Liquid hydrogen was found to have a volume of about 1 cm3/g at a pressure of about 2 Mbar. It was not determined if it was transformed into a metal.

  18. Isentropic Compression Driven by High-Explosive Application to TI-6AL-4V

    NASA Astrophysics Data System (ADS)

    Voltz, C.; Sollier, A.; Maillet, J.-B.; Bouyer, V.

    2009-12-01

    We report on an isentropic compression experiment of Ti-6Al-4V alloy based on the use of the release of detonation products from a high-explosive to generate a ramp wave compression in a multisteps target. VISAR and DLI measurements of the rear free surface velocities of the different steps allow computing the sound velocity of the material during its compression, which is characteristic of the EOS of the material. The experimental device is described and the sound velocity measurements are analyzed. We obtain Ti-6Al-4V strength along the compression up to 15 GPa. The results are compared with two dimensional elastic-plastic simulations.

  19. Isentropic expansion of copper plasma in Mbar pressure range at “Luch” laser facility

    SciTech Connect

    Bel'kov, S. A.; Derkach, V. N.; Garanin, S. G.; Mitrofanov, E. I.; Voronich, I. N.; Fortov, V. E.; Levashov, P. R.; Minakov, D. V.

    2014-01-21

    We present experimental results on thermodynamic properties of dense copper plasma in Mbar pressure range. The laser facility “Luch” with laser intensity 10{sup 14} W/cm{sup 2} is used to compress copper up to ∼8 Mbar by a strong shock wave; subsequent expansion of copper plasma into Al, Ti, Sn allows us to obtain release isentropes of copper by the impedance–matching method. A theoretical analysis and quantum simulations show that in our experiments strongly coupled quantum plasma is generated.

  20. Isentropic compressive wave generator impact pillow and method of making same

    DOEpatents

    Barker, Lynn M.

    1985-01-01

    An isentropic compressive wave generator and method of making same. The w generator comprises a disk or flat "pillow" member having component materials of different shock impedances formed in a configuration resulting in a smooth shock impedance gradient over the thickness thereof for interpositioning between an impactor member and a target specimen for producing a shock wave of a smooth predictable rise time. The method of making the pillow member comprises the reduction of the component materials to a powder form and forming the pillow member by sedimentation and compressive techniques.

  1. On the reachable cycles via the unified perspective of cryocoolers. Part B: Cryocoolers with isentropic expanders

    SciTech Connect

    Maytal, Ben-Zion; Pfotenhauer, John M.

    2014-01-29

    Solvay, Stirling and Gifford-McMahon types of cryocoolers employ an isentropic expander which is their elementary mechanism for temperature reduction (following the unified model of cryocoolers as described in a previous paper, Part A). Solvay and Stirling cryocoolers are driven by a larger temperature reduction than that of the Gifford-McMahon cycle, for a similar compression ratio. These cryocoolers are compared from the view of the unified model, in terms of the lowest attainable temperature, compression ratio, the size of the interchanger and the applied heat load.

  2. DYNAMIC RESPONSE OF COPPER SUBJECTED TO QUASI-ISENTROPIC, GAS-GUN DRIVEN LOADING

    SciTech Connect

    Jarmakani, H; McNaney, J M; Schneider, M S; Orlikowski, D; Nguyen, J H; Kad, B; Meyers, M A

    2005-09-29

    A transmission electron microscopy study of quasi-isentropic high-pressure loading (peak pressures between 18 GPa and 52 GPa) of polycrystalline and monocrystalline copper was carried out. Deformation mechanisms and defect substructures at different pressures were analyzed. Current evidence suggests a deformation substructure consisting of twinning at the higher pressures and heavily dislocated laths and dislocation cells at the intermediate and lower pressures, respectively. Evidence of stacking faults at the intermediate pressures was also found. Dislocation cell sizes decreased with increasing pressure and increased with distance away from the surface of impact.

  3. Computer Programs for Calculating the Isentropic Flow Properties for Mixtures of R-134a and Air

    NASA Technical Reports Server (NTRS)

    Kvaternik, Raymond G.

    2000-01-01

    Three computer programs for calculating the isentropic flow properties of R-134a/air mixtures which were developed in support of the heavy gas conversion of the Langley Transonic Dynamics Tunnel (TDT) from dichlorodifluoromethane (R-12) to 1,1,1,2 tetrafluoroethane (R-134a) are described. The first program calculates the Mach number and the corresponding flow properties when the total temperature, total pressure, static pressure, and mole fraction of R-134a in the mixture are given. The second program calculates tables of isentropic flow properties for a specified set of free-stream Mach numbers given the total pressure, total temperature, and mole fraction of R-134a. Real-gas effects are accounted for in these programs by treating the gases comprising the mixture as both thermally and calorically imperfect. The third program is a specialized version of the first program in which the gases are thermally perfect. It was written to provide a simpler computational alternative to the first program in those cases where real-gas effects are not important. The theory and computational procedures underlying the programs are summarized, the equations used to compute the flow quantities of interest are given, and sample calculated results that encompass the operating conditions of the TDT are shown.

  4. Line-imaging ORVIS measurements of interferometric windows under quasi-isentropic compression

    NASA Astrophysics Data System (ADS)

    Ao, Tommy; Hickman, Randy J.; Payne, Sheri L.; Trott, Wayne M.

    2009-06-01

    A line-imaging optically recording velocity interferometer system (ORVIS) has been implemented on the Veloce pulsed power generator to enable measurement of spatially resolved velocity histories of materials under dynamic compression. Interferometric windows are regularly used to maintain the high-pressure state of shock and ramp (quasi-isentropic) loaded materials. Although imaging through a shock or rapid ramp (<= 10 ns) loaded transparent window material has been reasonably successful, for slower ramp loading (˜ 440 ns) experiments, the elastic-plastic yielding of the window has an adverse effect on return light to the line-imaging ORVIS. The results of quasi-isentropic loading experiments with various interferometric windows such as LiF, NaCl, SiO2, PMMA, and sapphire are presented. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  5. Systematic approach to using isentropic stress reverberation techniques in approximating equation of state.

    PubMed

    Plume, Gifford; Rousseau, Carl-Ernst

    2015-03-01

    Isentropic stress reverberations are used to obtain multiple Hugoniot states from a single plate impact experiment using a layered plate geometry, where a low impedance inner layer is embedded within a high impedance bulk structure. The mathematical framework used in this technique uses the classical Rankine-Hugoniot equations in the method of impedance matching, where the bulk material is required to have a known Hugoniot. Factors including the wave velocities in the materials, input pulse duration, inner layer thickness, and diameter of the test samples affect the number of states that can be generated from a single experiment. Experiments using 6061 aluminum and polycarbonate, respectively, as the bulk material and inner layer, accurately generated six Hugoniot states for the polycarbonate. Experiments using A572 grade 50 structural steel as the bulk material accurately generated ten Hugoniot states for the polycarbonate. For each experiment, the method can be used to generate a Hugoniot equation defining the material response of the inner layer within the domain encompassed by the specific test. The method is also confined to the low to moderate stress regions, within which Hugoniot and isentropic representations of the material are almost identical. PMID:25832246

  6. Systematic approach to using isentropic stress reverberation techniques in approximating equation of state

    NASA Astrophysics Data System (ADS)

    Plume, Gifford; Rousseau, Carl-Ernst

    2015-03-01

    Isentropic stress reverberations are used to obtain multiple Hugoniot states from a single plate impact experiment using a layered plate geometry, where a low impedance inner layer is embedded within a high impedance bulk structure. The mathematical framework used in this technique uses the classical Rankine-Hugoniot equations in the method of impedance matching, where the bulk material is required to have a known Hugoniot. Factors including the wave velocities in the materials, input pulse duration, inner layer thickness, and diameter of the test samples affect the number of states that can be generated from a single experiment. Experiments using 6061 aluminum and polycarbonate, respectively, as the bulk material and inner layer, accurately generated six Hugoniot states for the polycarbonate. Experiments using A572 grade 50 structural steel as the bulk material accurately generated ten Hugoniot states for the polycarbonate. For each experiment, the method can be used to generate a Hugoniot equation defining the material response of the inner layer within the domain encompassed by the specific test. The method is also confined to the low to moderate stress regions, within which Hugoniot and isentropic representations of the material are almost identical.

  7. Tables of isentropic expansions of parahydrogen and related transport properties for total temperatures from 25 K to 300 K and for total pressures from 1 ATM to 10 ATM

    NASA Technical Reports Server (NTRS)

    Haut, R. C.; Adcock, J. B.

    1976-01-01

    The isentropic expansions of parahydrogen at various total pressures and total temperatures were numerically determined by iterating Mach number and by using a modified interval halving method. The calculated isentropic values and related properties are presented in tabulated form.

  8. Layering Principles from One Approach to Isentropic Analysis and Modeling of the Atmosphere

    NASA Astrophysics Data System (ADS)

    Fulker, D. W.

    2015-12-01

    Meteorologists often treat potential temperature (theta)—the temperature a parcel would have if moved adiabatically to the surface—as a vertical coordinate. The resulting layers (isentropes) are lagrangian-like. Bosart, in a 2002 tribute to Reed, writes "PV as a tracer [along isentropes] enabled Reed, Danielson … to adopt a Lagrangian perspective in studies of cyclogenesis and upper-level frontogenesis." Bosart also mentions Shapiro's work on clear-air turbulence and Bleck's modeling: "Bleck ... simulated cyclogenesis using a simple model [on] surfaces of constant potential temperature." From the author's work helping Bleck and Shapiro with isentropic analysis and modeling, the following principles are offered as potentially useful in defining reusable, consistent data layers across space and time in multiple domains. Monotonicity— Layers reflect transformed coordinates, mappable to/from elevation, hence strictly monotonic across the geographic domain. I.e., layers cannot intersect. Bleck devised an invertible algorithm mapping pressure along soundings to a coordinate resembling potential temperature (departing only to maintain monotonicity). A collection of these (at one observing time) is a sampled representation of the transform between (lat, lon, elev) and (lat, lon, theta). Suggested principle: Data layers possess, for a geographic sample set, invertible algorithms to map between elevation and a monotonic transform coordinate. Intralayer Interpolation — The transformed coordinate may need evaluation at points not in the sample set. The Bleck/Shapiro work showed how easily monotonicity is violated when gridding sample data. This problem was solved via another transform: interpolation on the log of layer differences (i.e., thickness). Suggested principle: Data layers possess a monotonicity-preserving algorithm to interpolate coordinate values to geographic points not in the sample set.Representation— The Bleck/Shapiro work entailed no data sharing

  9. High-Pressure Quasi-Isentropic Loading and Unloading of Interferometer Windows on the Veloce Pulsed Power Generator

    NASA Astrophysics Data System (ADS)

    Ao, Tommy; Asay, James; Knudson, Marcus; Davis, Jean-Paul

    2007-06-01

    The Isentropic Compression Experiment technique has proven to be a valuable complement to the well-established method of shock compression of condensed matter. However, whereas the high-pressure compression response of window materials has been studied extensively under shock loading, similar knowledge of these materials under ICE loading is limited. We present recent experimental results on the isentropic compression of the high-pressure windows sapphire and LiF. It has previously been observed that c-cut sapphire yields under shock loading at the HEL of ˜15-18GPa, and subsequently loses transparency at higher stresses. However, it will be shown that under isentropic ramp wave loading sapphire appears to remain elastic and transparent at stresses well above 20GPa [D.B. Hayes et al, JAP 94, 2331 (2003)]. LiF is another frequently used window material in isentropic loading and unloading experiments, yet the unloading response of LiF is usually neglected. Research is in progress to measure strength properties of LiF for ramp loading and unloading. It will be shown how the strength of LiF may influence wave profile analysis and thus inferred material strength. Sandia is a multiprogram laboratory operated by Sandia Corp., a Lockheed Martin Company, for the US DOE's NNSA under Contract No.DE-AC04-94AL85000.

  10. Analytic Determination of Product Isentrope for an Ammonium Nitrate-Aluminum Explosive

    NASA Astrophysics Data System (ADS)

    Anderson, Eric; Short, Mark; Jackson, Scott

    2015-06-01

    Ammonium nitrate mixed with aluminum powder forms a non-ideal explosive often referred to as Ammonal. Non-ideal detonation can result in significant energy release behind the detonation sonic surface that does not contribute to the detonation velocity, but may affect the expansion energy of the product gases. In this work, we use scaled cylinder expansion tests to characterize both the diameter effect and product energy variation with scale for Ammonal. The results of two scaled cylinder tests with 50.8-mm and 72.6-mm inner diameters are compared to prior data at other scales. We find that cylinder wall velocity increases with increasing charge diameter and also with increasing charge length. We also use the analytic method of Jackson to compute the isentropes of the partially-reacted product states in all tests to demonstrate the charge-size dependence of Ammonal and quantify the potential energy of the product state for each condition.

  11. Isentropic mixing in the Arctic stratosphere during the 1992-1993 and 1993-1994 winters

    NASA Technical Reports Server (NTRS)

    Dahlberg, Steven P.; Bowman, Kenneth P.

    1995-01-01

    Dynamic isolation of the winter Arctic circumpolar vortex during 1992-1993 and 1993-1994 (the second and third northern hemisphere winters of the UARS mission) is studied using quasi-horizontal isentropic trajectories. Ejection of vortex air and entrainment of mid-latitude air into the vortex are quantified and compared with climatological values obtained from the analysis of 16 Arctic winters. A number of unusual features of both winters are discussed. The most notable features are the anomalous isolation experienced by the vortex during December 1992 and the unusual degree of isolation and persistence of the vortex during February and March of both years. the 1992-1993 winter season is the most consistently isolated vortex on record. Only during January 1993, when entrainment is large, is this pattern of extreme isolation broken.

  12. Metal liner-driven cylindrically convergent isentropic compression of cryogenic deuterium

    NASA Astrophysics Data System (ADS)

    Weinwurm, Marcus; Bland, Simon N.; Chittenden, Jeremy P.

    2014-05-01

    In order to take advantage of geometrical convergence, we investigated a method, where a beryllium liner drives a cylindrical shockless compression in a cryogenic deuterium fill. The metal liner acts as a current carrier as well as a pressure boundary to the fill. The required driving pressure was obtained through a fictitious flow (FF) simulation [D S Clark and M Tabak 2007 Nucl. Fusion 47 1147]. A current model that can recreate the FF compression inside the liner by shaping the current pulse, is then introduced. This method also allows efficient compression of hydrogen at low entropy, enabling the recreation of conditions present in the interior of gas giants and potentially the observation of a transition into a metallic state. Our two-dimensional simulations show that thick liners remain robust to magneto-Rayleigh-Taylor instability growth, suggesting that cylindrical isentropic ramp compression is a promising scheme for extending deuterium's experimentally measured equation of state.

  13. The Cauchy problem for the pressureless Euler/isentropic Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Choi, Young-Pil; Kwon, Bongsuk

    2016-07-01

    We present a new hydrodynamic model consisting of the pressureless Euler equations and the isentropic compressible Navier-Stokes equations where the coupling of two systems is through the drag force. This coupled system can be derived, in the hydrodynamic limit, from the particle-fluid equations that are frequently used to study the medical sprays, aerosols and sedimentation problems. For the proposed system, we first construct the local-in-time classical solutions in an appropriate L2 Sobolev space. We also establish the a priori large-time behavior estimate by constructing a Lyapunov functional measuring the fluctuation of momentum and mass from the averaged quantities, and using this together with the bootstrapping argument, we obtain the global classical solution. The large-time behavior estimate asserts that the velocity functions of the pressureless Euler and the compressible Navier-Stokes equations are aligned exponentially fast as time tends to infinity.

  14. Bulk Properties of Isentropic Mixing into the Tropics in the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Minschwaner, K.; Dessler, A. E.; Elkins, J. W.; Volk, C. M.; Fahey, D. W.; Loewenstein, M.; Podolske, J. R.; Chan, K. R.; Roche, A. E.

    1996-01-01

    Timescales for mixing of midlatitude air into the tropical lower stratosphere are deduced from observations of long-lived tracers N2O and CCl3F. Bulk mixing between tropical and midlatitude regions is assumed to be isentropic and relatively slow compared with local mixing within each region. The mean value of the mixing timescale ranges from 12 to 18 months near 20 km. There is a tendency for shorter mixing times at higher and lower altitudes, although vertical profiles of mixing cannot be definitively established by the data. A more robust quantity is given by the fraction of midlatitude air entrained into the tropical upwelling region. Implied mixing fractions exceed 50% above 22 km.

  15. Existence of Global Solutions for Unsteady Isentropic Gas Flow in a Laval Nozzle

    NASA Astrophysics Data System (ADS)

    Tsuge, Naoki

    2012-07-01

    In this paper, we study the motion of isentropic gas in the Laval nozzle. The Laval nozzle is the most important type of nozzle utilized in some turbines. In particular, we consider unsteady flows, including transonic gas flows, and prove the existence of global solutions for the Cauchy problem. In spite of its importance, this problem has received little attention until now. The most difficult point is to obtain bounded estimates for approximate solutions. To overcome this, we introduce a modified Godunov scheme. The corresponding approximate solutions consist of piecewise steady-state solutions of an auxiliary equation and yield a sharper bounded estimate. As a result, we find an invariant region for our solutions. Finally, in order to prove their convergence, we use the compensated compactness framework.

  16. High strain rates effects in quasi-isentropic compression of solids

    SciTech Connect

    Ravelo, Ramon; Holian, Brad L; Germann, Timothy C

    2009-01-01

    We have performed large-scale molecular-dynamics (MD) simulations of shock loading and quasi-isentropic compression in defective copper crystals, modeling the interatomic interactions with an embedded-atom method potential. For samples with a relatively low density of pre-existing defects, the strain rate dependence of the flow stress follows a power law in the 10{sup 9}-10{sup 12} s{sup -1} regime with an exponent of 0.40. For initially damaged, isotropic crystals the flow stress exhibits a narrow linear region in strain rate, which then bends over at high strain rates in a manner reminiscent of shear thinning in fluids. The MD results can be described by a modification of Eyring's theory of Couette shear flow in fluids.

  17. Prediction of flow rates through an orifice at pressures corresponding to the transition between molecular and isentropic flow

    SciTech Connect

    DeMuth, S.F.; Watson, J.S.

    1985-01-01

    A model of compressible flow through an orifice, in the region of transition from free molecular to isentropic expansion flow, has been developed and tested for accuracy. The transitional or slip regime is defined as the conditions where molecular interactions are too many for free molecular flow modeling, yet not great enough for isentropic expansion flow modeling. Due to a lack of literature establishing a well-accepted model for predicting transitional flow, it was felt such work would be beneficial. The model is nonlinear and cannot be satisfactorily linearized for a linear regression analysis. Consequently, a computer routine was developed which minimized the sum of the squares of the residual flow for the nonlinear model. The results indicate an average accuracy within 15% of the measured flow throughout the range of test conditions. Furthermore, the results of the regression analysis indicate that the transitional regime lies between Knudsen numbers of approximately 2 and 45. 4 refs., 3 figs., 1 tab.

  18. CHARICE 1.0 : an IDL application for characteristics-based inverse analysis of isentropic compression experiments.

    SciTech Connect

    Davis, Jean-Paul

    2007-09-01

    CHARICE is a multi-platform computer application that analyzes velocity waveform data from ramp-wave experiments to determine a material's quasi-isentropic loading response in stress and density using an iterative characteristics-based approach. The application was built using ITT Visual Information Solutions Interactive Data Language (IDL{reg_sign}), and features graphical interfaces for all user interaction. This report describes the calculation method and available analysis options, and gives instructions for using the application.

  19. A Survey of the Isentropic Euler Vortex Problem Using High-Order Methods

    NASA Technical Reports Server (NTRS)

    Spiegel, Seth C.; Huynh, H. T.; DeBonis, James R.

    2015-01-01

    The flux reconstruction (FR) method offers a simple, efficient, and easy to implement method, and it has been shown to equate to a differential approach to discontinuous Galerkin (DG) methods. The FR method is also accurate to an arbitrary order and the isentropic Euler vortex problem is used here to empirically verify this claim. This problem is widely used in computational fluid dynamics (CFD) to verify the accuracy of a given numerical method due to its simplicity and known exact solution at any given time. While verifying our FR solver, multiple obstacles emerged that prevented us from achieving the expected order of accuracy over short and long amounts of simulation time. It was found that these complications stemmed from a few overlooked details in the original problem definition combined with the FR and DG methods achieving high-accuracy with minimal dissipation. This paper is intended to consolidate the many versions of the vortex problem found in literature and to highlight some of the consequences if these overlooked details remain neglected.

  20. Coupled ocean-atmosphere modeling on horizontally icosahedral and vertically hybrid-isentropic/isopycnic grids.

    NASA Astrophysics Data System (ADS)

    Bleck, Rainer; Sun, Shan; Li, Haiqin; Benjamin, Stan

    2016-04-01

    Current efforts to close the gap between weather prediction and climate models have led to the construction of a coupled ocean-atmosphere system consisting of two high-resolution component models, operating on matching icosahedral grids and utilizing adaptive, near-isentropic/isopycnic vertical coordinates. The two components models, FIM and HYCOM (the latter converted to an icosahedral mesh for this purpose), have been tested extensively in twice-daily global medium-range weather prediction (http://fim.noaa.gov) and in real-time ocean data assimilation (http://hycom.org), respectively. The use of matching horizontal grids, currently at resolutions of 15km, 30km and 60km, avoids coastline ambiguities and interpolation errors at the air-sea interface. The intended purpose of the coupled model being subseasonal-to-seasonal prediction, our focus is on mid-term precipitation biases and the statistical steadiness of the atmospheric circulation (blocking frequency, Rossby wave breaking, meridional heat transport, etc.), as well as on possible causes of ocean model drift. An attempt is made to isolate the weather model's role in modifying water mass properties and ocean circulations (including meridional overturning) by comparing coupled model results to ocean-only experiments forced by observed atmospheric boundary conditions. A multi-decadal run at 60km resolution is used to illustrate ENSO variability in the coupled system.

  1. Computing Isentropic Flow Properties of Air/R-134a Mixtures

    NASA Technical Reports Server (NTRS)

    Kvaternik, Ray

    2006-01-01

    MACHRK is a computer program that calculates isentropic flow properties of mixtures of air and refrigerant R-134a (tetrafluoroethane), which are used in transonic aerodynamic testing in a wind tunnel at Langley Research Center. Given the total temperature, total pressure, static pressure, and mole fraction of R-134a in a mixture, MACHRK calculates the Mach number and the following associated flow properties: dynamic pressure, velocity, density, static temperature, speed of sound, viscosity, ratio of specific heats, Reynolds number, and Prandtl number. Real-gas effects are taken into account by treating the gases comprising the mixture as both thermally and calorically imperfect. The Redlich-Kwong equation of state for mixtures and the constant-pressure ideal heat-capacity equation for the mixture are used in combination with the departure- function approach of thermodynamics to obtain the equations for computing the flow properties. In addition to the aforementioned calculations for air/R-134a mixtures, a research version of MACHRK can perform the corresponding calculations for mixtures of air and R-12 (dichlorodifluoromethane) and for air/SF6 mixtures. [R-12 was replaced by R-134a because of environmental concerns. SF6 has been considered for use in increasing the Reynolds-number range.

  2. Effects of various assumptions on the calculated liquid fraction in isentropic saturated equilibrium expansions

    NASA Technical Reports Server (NTRS)

    Bursik, J. W.; Hall, R. M.

    1980-01-01

    The saturated equilibrium expansion approximation for two phase flow often involves ideal-gas and latent-heat assumptions to simplify the solution procedure. This approach is well documented by Wegener and Mack and works best at low pressures where deviations from ideal-gas behavior are small. A thermodynamic expression for liquid mass fraction that is decoupled from the equations of fluid mechanics is used to compare the effects of the various assumptions on nitrogen-gas saturated equilibrium expansion flow starting at 8.81 atm, 2.99 atm, and 0.45 atm, which are conditions representative of transonic cryogenic wind tunnels. For the highest pressure case, the entire set of ideal-gas and latent-heat assumptions are shown to be in error by 62 percent for the values of heat capacity and latent heat. An approximation of the exact, real-gas expression is also developed using a constant, two phase isentropic expansion coefficient which results in an error of only 2 percent for the high pressure case.

  3. Analysis of Isentropic Transport in the Lower Tropical Stratosphere from Laminae Observed in Shadoz Ozone Profiles

    NASA Astrophysics Data System (ADS)

    Portafaix, T.; Bencherif, H.; Godin-Beekmann, S.; Begue, N.; Culot, A.

    2014-12-01

    The subtropical dynamical barrier located in the lower stratosphere on the edge of the Tropical Stratospheric Reservoir (TSR), controls and limits exchanges between tropical and extratropical lower stratosphere. The geographical position of stations located near from the edge of the Tropical Stratospheric Reservoir is interesting since they are regularly interested by air-mass filaments originated from TSR or mid-latitudes. During such filamentary events, profiles of chemical species are modified according to the origin and the height of the air mass. These perturbations called "laminae" are generally associated to quasi-horizontal transport events. Many SHADOZ (Southern Hemisphere ADditional OZonesondes) stations from all around the southern tropics were selected in order to study the variability of laminae. Profiles from ozonesondes were analyzed to detect laminae using a statistical standard deviation method from the climatology. Time series of laminae were investigated by a multilinear regression model in order to estimate the influence of several proxy on laminae variability from 1998 to 2013. Different forcings such as QBO, ENSO or IOD were applied. The first objective is to better quantify isentropic transport as function of the station location and the influence of the QBO on the laminae occurrences. Finally, cases studies were conducted from high-resolution advection model MIMOSA. These allow us to identify the air mass origin and to highlight privileged roads where meridional transport occurs between tropics and midlatitudes.

  4. Mechanical response of metals under dynamic loading off the principal Hugoniot and isentrope

    NASA Astrophysics Data System (ADS)

    Seagle, Christopher

    2015-06-01

    Controlled dynamic loading of materials on phase-space paths off the principal Hugoniot and isentrope provide a stringent test of equation of state models in regions not typically experimentally constrained. Maturation of hardware design and pulse-shaping capabilities for shock-ramp experiments at Sandia's Z Machine have been exploited to test the mechanical response of a wide range of metals on ramp compression initiated from a well-defined Hugoniot state. A range of 1-8 km/s impact velocities are possible before initiating a ramp wave in a test sample. Capabilities and challenges of this type of experiment will be presented along with recent data on platinum, tin, cerium, and tantalum. Results of these experiments will be discussed in relation to existing equation of state data and models, and the future outlook for experimental constraints on material response on controlled off-principal loading paths. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Disposition of transuranic residues from plutonium isentropic compression experiment (Pu-ICE) constucted at Z machine

    SciTech Connect

    Goyal, Kapil K; French, David M; Humphrey, Betty J; Gluth, Jeffry

    2010-01-01

    In 1992, the U.S. Congress passed legislation to discontinue above- and below-ground testing of nuclear weapons. Because of this, the U.S. Department of Energy (DOE) must rely on laboratory experiments and computer-based calculations to verify the reliability of the nuclear stockpile. The Sandia National Laboratories/New Mexico (SNL/NM) Z machine was developed to support the science-based approach for mimicking nuclear explosions and stockpile stewardship. Plutonium (Pu) isotopes with greater than ninety-eight percent enrichment were used in the experiments. In May 2006, SNL/NM received authority that the Z Machine Isentropic Compression Experiments could commence. Los Alamos National Laboratory (LANL) provided the plutonium targets and loaded the target assemblies provided by SNL/NM. Three experiments were conducted from May through July 2006. The residues from each experiment, which weighed up to 913 pounds, were metallic and were packaged into a 55-gallon drum each. SNL/NM conducts the experiments and provides temporary storage for the drums until shipment to LANL for final waste certification for disposal at the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. This paper presents a comprehensive approach for documenting generator knowledge for characterization of waste in cooperation with scientists at the two laboratories and addresses a variety of essential topics.

  6. Cosmography of KNdS black holes and isentropic phase transitions

    NASA Astrophysics Data System (ADS)

    McInerney, James; Satishchandran, Gautam; Traschen, Jennie

    2016-05-01

    We present a new analysis of Kerr-Newman-deSitter black holes in terms of thermodynamic quantities that are defined in the observable portion of the Universe; between the black hole and cosmological horizons. In particular, we replace the mass m with a new ‘area product’ parameter X. The physical region of parameter space is found analytically and thermodynamic quantities are given by simple algebraic functions of these parameters. We find that different geometrical properties of the black holes are usefully distinguished by the sum of the black hole and cosmological entropies. The physical parameter space breaks into a region in which the total entropy, together with Λ, a and q uniquely specifies the black hole, and a region in which there is a two-fold degeneracy. In this latter region, there are isentropic pairs of black holes, having the same Λ, a, and q, but different X. The thermodynamic volumes and masses differ in such that there are high and low density branches. The partner spacetimes are related by a simple inversion of X, which has a fixed point at the state of maximal total entropy. We compute the compressibility at fixed total entropy and find that it diverges at the maximal entropy point. Hence a picture emerges of high and low density phases merging at this critical point.

  7. Isentropic scaling analysis of ozone in the upper troposphere and lower stratosphere

    NASA Astrophysics Data System (ADS)

    Cho, John Y. N.; Thouret, ValéRie; Newell, Reginald E.; Marenco, Alain

    2001-05-01

    We examine ozone concentrations recorded by 7630 commercial flights from August 1994 to December 1997 for spatial scaling properties. The large amount of data allows an approximately isentropic analysis of ozone variability in the upper troposphere and lower stratosphere. Since ozone is a good passive tracer at cruise altitudes, the results provide a strong diagnostic for scalar advection theories and models. Calculations of structure functions and increment probability distribution functions show that ozone variability scales anomalously from ˜2 to ˜2000 km, although not continuously in this interval. We find no evidence for the simple scaling predicted for smooth advection/diffusion, even at the large scales. At mesoscales the upper tropospheric ozone field is rougher and more intermittent than in the lower stratosphere. Within the troposphere the equatorial ozone field is rougher than at higher latitudes, and the intermittency decreases with increasing latitude. In the stratosphere the intermittency and roughness are greater at high latitudes and over land than at midlatitudes and over the ocean.

  8. Equation of state and isentropic release of aluminum foam and polyvinylidene fluoride systems

    NASA Astrophysics Data System (ADS)

    Borg, John P.; Maines, Warren R.; Chhabildas, Lalit C.

    2014-06-01

    There is considerable interest in developing a better understanding of the dynamic behavior of multicomponent heterogeneous systems. This study investigates and compares the dynamic response of 21% dense aluminum foam, filled with polyvinylidene fluoride (PVDF or Kynar). Experiments were conduced in a 60 mm bore gun in a one-dimensional reverse plate impact configuration at velocities ranging from 350 m/s to 2200 m/s. The particle velocity of the backside of a thin anvil, also referred to as a witness plate, was monitored with a velocity interferometer. The resulting shock Hugoniot and isentropic release states are inferred from the particle velocity records using an impedance matching technique. The experiments indicate that the heterogeneous system achieves a wide distribution of states even though it was loaded in a one-dimensional plane-strain configuration. The system maintains its strength up to shock levels near 5 GPa, above which the PVDF appears to melt upon release. Simulations were conducted using an Eulerian hydrocode where the foam filled structures are computationally resolved, i.e., mesoscale simulations. The mesoscale simulations were used to resolve not only the average response but also characterize a wide range of stress and temperature distributions during both loading and release. These simulations are in good agreement with the available experimental data and give insight into the dynamic response not accessible via experimental measurements.

  9. Yield Response of Tantalum for Quasi-Isentropic Loading and Unloading

    NASA Astrophysics Data System (ADS)

    Asay, James R.; Ao, Tommy; Vogler, Tracy J.; Gray, George T., III

    2009-06-01

    Magnetic loading was used to study initial yield strength of pure annealed and cold-worked polycrystalline and single crystal Ta samples for ramp loading at strain rates of ˜10^6/s and the flow strength after peak compression to ˜17 GPa at about 5x10^4/s. For sample thicknesses of 0.5--6 mm, it was found that for annealed pure polycrystalline Ta, the quasi-isentrope elastic limit (IEL) was essentially constant at ˜3.2 GPa with propagation distance. There was no apparent effect of sample purity on precursor amplitude to within experimental uncertainty, although cold-working resulted in loss of the elastic peak and a reduced IEL of ˜1.7 GPa. The flow strength at peak loading stress was estimated from the quasi-elastic unloading and found to increase with peak stress. These results will be discussed in terms of constitutive models for Ta. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  10. Sound Speed of Liquid Iron Along the Outer Core Isentrope: New Pre-heated Ramp Compression Experiments

    NASA Astrophysics Data System (ADS)

    Asimow, P. D.; Nguyen, J.; Akin, M. C.; Fatýanov, O. V.

    2015-12-01

    Detailed elasticity data on liquid Fe and candidate molten core alloys should offer new constraints on the under-constrained problem of Earth's core composition. Density, sound speed, and the gradient in sound speed with pressure are each potentially distinct experimental constraints and are each well-known for Earth. The gradient in sound speed, though, has not been used because sound speed depends on both T and P, such that data must be collected or reconstructed along the correct, nearly adiabatic, thermal profile. Reconstruction requires the Grüneisen γ, which is composition-dependent, and data over a large P-T space to allow extrapolation. Both static and dynamic compression methods could be used, but the conditions (140 - 330 GPa and 4000 - 6000 K) are very challenging for static methods and standard shock compression only samples the outer core P-T profile at a single P. Instead we are applying quasi-isentropic dynamic ramp compression, using pre-heating of the target and impedance of the leading edge of a graded-density impactor (GDI) to select a probable outer core isentrope. The target material is melted and raised to a point on the outer core isentrope by the initial shock, then quasi-isentropically ramped to a maximum P by increasing shock impedance of trailing GDI layers. Particle velocity is monitored by photonic doppler velocimetry (PDV) at two step thicknesses at the interface of Fe or Fe-alloy target and MgO windows. The difference in arrival time of each particle velocity at the two steps directly gives the Lagrangian sound speed vs. particle velocity, which is integrated to obtain Pand density. At the writing of this abstract, we have completed one shot of this type. We successfully heated a two-step Fe target in a Mo capsule with MgO windows to 1350 °C, maintaining sufficient alignment and reflectivity to collect PDV signal returns. We characterized the velocity correction factor for PDV observation through MgO windows, and have confirmed

  11. Disposition of transuranic residues from plutonium isentropic compression experiment (Pu-ice) conducted at Z machine

    SciTech Connect

    Goyal, Kapil K; French, David M; Humphrey, Betty J; Gluth, Jeffry

    2010-01-01

    In 1992, the U.S. Congress passed legislation to discontinue above- and below-ground testing of nuclear weapons. Because of this, the U.S. Department of Energy (DOE) must rely on laboratory experiments and computer-based calculations to verify the reliability of the nation's nuclear stockpile. The Sandia National Laboratories/New Mexico (SNL/NM) Z machine was developed by the DOE to support its science-based approach to stockpile stewardship. SNL/NM researchers also use the Z machine to test radiation effects on various materials in experiments designed to mimic nuclear explosions. Numerous components, parts, and materials have been tested. These experiments use a variety of radionuclides; however, plutonium (Pu) isotopes with greater than ninety-eight percent enrichment are the primary radionuclides used in the experiments designed for stockpile stewardship. In May 2006, SNL/NM received authority that the Z Machine Isentropic Compression Experiments could commence. Los Alamos National Laboratory (LANL) provided the plutonium targets and loaded the target assemblies, which were fabricated by SNL/NM. LANL shipped the loaded assemblies to SNL/NM for Z machine experiments. Three experiments were conducted from May through July 2006. The residues from each experiment, which weighed up to 913 pounds, were metallic and packaged into a respective 55-gallon drum each. Based on a memorandum of understanding between the two laboratories, LANL provides the plutonium samples and the respective radio-isotopic information. SNL/NM conducts the experiments and provides temporary storage for the drums until shipment to LANL for final waste certification for disposal at the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. This paper presents a comprehensive approach for documenting generator knowledge for characterization of waste in cooperation with scientists at the two laboratories and addresses a variety of topics such as material control and accountability

  12. Isentropic mass exchange between the Tropics and extratropics in the stratosphere

    NASA Technical Reports Server (NTRS)

    Chen, Ping; Holton, James R.; O'Neill, Alan; Swinbank, Richard

    1994-01-01

    The isentropic mass exchange between the Tropics and extratropics in the stratosphere is investigated with a semi-Lagrangian transport model for the periods from 1 June to 31 October 1992 and from 1 December 1992 to 30 April 1993 using winds from the U.K. Meteorological Office data assimilation system. Calculations with an idealized, initially zonally symmetric tracer show that in the middle and upper stratosphere the bulk of tropical air is transported into the midlatitudes of the winter hemisphere although there exist quasi-permeable barriers in the subtropics. The transport takes place in the form of planetary-scale 'tongues' of material that are drawn poleward in association with the episodic amplification of planetary-scale waves in high latitudes of the winter hemisphere. Once air of tropical origin is transported to the midlatitudes it is irreversibly mixed with the midlatitude air in the 'surf zone.' Air of tropical origin can, however, hardly penetrate into the interior of the winter polar vortex until the breakdown of the vortex. Transport of tropical air into the midlatitudes of the summer hemisphere is strongly inhibited. In the lower stratosphere, tropical air is transported into the northern and southern midlatitudes. During the period from 1 June to 31 October 1992, the amount of tropical air transported into the Northern Hemisphere is, however, much smaller than that transported into the Southern Hemisphere, and there exist strong gradients in the tracer field in the equatorial region, indicating that there is a quasi-permeable barrier to cross-equator mass exchange. During the period from 1 December 1992 to 30 April 1993, on the other hand, roughly the same amounts of tropical air are transported into the Southern Hemisphere, and there exist strong gradients in the tracer field in the equatorial region, indicating that there is a quasi-permeable barrier to cross-equator mass exchange. During the period from 1 December 1992 to 30 April 1993, on the

  13. The compact capacitor bank CQ-1.5 employed in magnetically driven isentropic compression and high velocity flyer plate experiments

    NASA Astrophysics Data System (ADS)

    Wang, Guiji; Sun, Chengwei; Tan, Fuli; Zhao, Jianheng; Zhang, Ning; Liu, Cangli; Mo, Jianjun; Wang, Ganghua; Wang, Xiaosong

    2008-05-01

    Based on the low inductance capacitor, the parallel-plate transmission line, and the explosive network closing switch, a compact pulsed power generator CQ-1.5 has been developed at the Institute of Fluid Physics and is capable to deliver a current of peak of 1.5MA within rise time of 500-570ns into a 2-3nH inductive load. The work is motivated to do isentropic compression experiments (ICEs) on metals up to 30-50GPa and to launch flyer plates at velocities over 8km/s. The experiments were conducted with the diagnostics of both Doppler pin system and velocity interferometer system for any reflectors, and the measured free surface velocity histories of ICE samples were treated with a backward integration code. The results show that the isentropes of Cu and Al samples under 35GPa are close to their Hugoniots within a deviation of 3%. The LY12 aluminum flyer plates were accelerated to a velocity over 8.96km/s.

  14. Principal Quasi-Isentropes of Several Materials to Multi-Megabar Pressure from Analysis of Magnetically Driven Ramp Compression Data

    NASA Astrophysics Data System (ADS)

    Davis, Jean-Paul; Martin, Matthew; Knudson, Marcus

    2011-06-01

    Quasi-isentropic ramp-wave experiments promise accurate equation-of-state (EOS) data in the solid phase at relatively low temperatures and multimegabar pressures. In this range of pressure, isothermal diamond-anvil techniques have limited pressure accuracy due to reliance on theoretical EOS of calibration standards, thus accurate quasi-isentropic compression data would help immensely in constraining EOS models. Multi-megabar ramp compression experiments using the Z Machine at Sandia as a magnetic drive with stripline targets have been performed on tantalum, copper, gold, beryllium, molybdenum, and aluminum metals as well as lithium fluoride crystal. Much of the data from these experiments are analyzed using a single-sample inverse Lagrangian approach. This technique, and the quantification of its uncertainties, will be described in detail. Results will be presented for selected materials, with comparisons to independently developed EOS. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  15. Modeling and Analysis of Global and Regional Climate Change in Relation to Atmospheric Hydrologic Processes

    NASA Technical Reports Server (NTRS)

    Johnson, Donald R.

    1998-01-01

    The goal of this research is the continued development and application of global isentropic modeling and analysis capabilities to describe hydrologic processes and energy exchange in the climate system, and discern regional climate change. This work involves a combination of modeling and analysis efforts involving 4DDA datasets and simulations from the University of Wisconsin (UW) hybrid isentropic-sigma (theta-sigma) coordinate model and the GEOS GCM.

  16. Thermodynamics of hydrogen and helium plasmas in megabar and multi-megabar pressure range under strong shock and isentropic compression

    NASA Astrophysics Data System (ADS)

    Gryaznov, V. K.; Iosilevskiy, I. L.; Fortov, V. E.

    2016-01-01

    An approach based on the chemical picture of plasma is proposed for the description of thermodynamics and the equation of the state of warm dense matter. Corresponding to this approach, the effects of Coulomb interaction, the short range repulsion of atoms and molecules, free electron degeneracy, and radiation pressure contributions are taken into account. A family of models based upon this approach is presented and discussed. The possibilities of these models for the description of strongly coupled plasma of hydrogen isotopes and noble gases under megabar and terapascal pressures under shock and isentropic compression are demonstrated. The asymptotic properties of the models at high temperatures are demonstrated, showing their application to the very accurate description of solar plasma.

  17. Thermodynamic properties of gaseous fluorocarbons and isentropic equilibrium expansions of two binary mixtures of fluorocarbons and argon

    NASA Technical Reports Server (NTRS)

    Talcott, N. A., Jr.

    1977-01-01

    Equations and computer code are given for the thermodynamic properties of gaseous fluorocarbons in chemical equilibrium. In addition, isentropic equilibrium expansions of two binary mixtures of fluorocarbons and argon are included. The computer code calculates the equilibrium thermodynamic properties and, in some cases, the transport properties for the following fluorocarbons: CCl2F, CCl2F2, CBrF3, CF4, CHCl2F, CHF3, CCL2F-CCl2F, CCLF2-CClF2, CF3-CF3, and C4F8. Equilibrium thermodynamic properties are tabulated for six of the fluorocarbons(CCl3F, CCL2F2, CBrF3, CF4, CF3-CF3, and C4F8) and pressure-enthalpy diagrams are presented for CBrF3.

  18. Influence of Sub-grid-Scale Isentropic Transports on McRAS Evaluations using ARM-CART SCM Datasets

    NASA Technical Reports Server (NTRS)

    Sud, Y. C.; Walker, G. K.; Tao, W. K.

    2004-01-01

    In GCM-physics evaluations with the currently available ARM-CART SCM datasets, McRAS produced very similar character of near surface errors of simulated temperature and humidity containing typically warm and moist biases near the surface and cold and dry biases aloft. We argued it must have a common cause presumably rooted in the model physics. Lack of vertical adjustment of horizontal transport was thought to be a plausible source. Clearly, debarring such a freedom would force the incoming air to diffuse into the grid-cell which would naturally bias the surface air to become warm and moist while the upper air becomes cold and dry, a characteristic feature of McRAS biases. Since, the errors were significantly larger in the two winter cases that contain potentially more intense episodes of cold and warm advective transports, it further reaffirmed our argument and provided additional motivation to introduce the corrections. When the horizontal advective transports were suitably modified to allow rising and/or sinking following isentropic pathways of subgrid scale motions, the outcome was to cool and dry (or warm and moisten) the lower (or upper) levels. Ever, crude approximations invoking such a correction reduced the temperature and humidity biases considerably. The tests were performed on all the available ARM-CART SCM cases with consistent outcome. With the isentropic corrections implemented through two different numerical approximations, virtually similar benefits were derived further confirming the robustness of our inferences. These results suggest the need for insentropic advective transport adjustment in a GCM due to subgrid scale motions.

  19. Generation of isentropic compression by use of multi-layer composite flyer and its influence on system thermodynamics: A simulation study

    NASA Astrophysics Data System (ADS)

    Ray, Aditi

    2014-05-01

    Recently the possibility of achieving quasi-isentropic compression using functionally graded materials, in both gas gun and explosive driven systems was explored by hydro-dynamic simulations. In the current paper, we show that multi-layered composite flyer with progressively increasing shock impedances, referred to as graded density impactor (GDI), has the potential to enable increased flexibility in suitably tailoring the applied-pressure profiles, further relaxing constraints on the thermodynamic path of compressed material. Present simulation study pertaining to constant velocity impact of GDI reveals that linear ramp pulses of different pressure rise times, with comparable peak values can be realized only by changing the layer thicknesses of a particular GDI. We report generation of three different slope ramp pulses by five layer GDI made of PMMA, Al, Ti, Cu and Ta with different set of thicknesses obtained by genetic algorithm based optimization technique. Generation of long duration (μs) isentropic pressures using discrete GDI is a significant step, since it is devoid of fabrication difficulties of ultra-thin lamellae of FGM. Signatures of isentropic compression of a thin Cu target under different slope ramp loadings are identified from basic thermodynamic aspects in terms of temperature rise and entropy production. It is shown that that extent of entropy increase is closely related to the slope of ramping pulse. Further, a physical model has been constructed to determine approximate time profile of pressure pulse generated by equal layer-width GDI.

  20. Isentropic analysis of the Indian Summer Monsoon circulation and its implications for the active and break periods

    NASA Astrophysics Data System (ADS)

    Pauluis, O. M.; Sandeep, S.; Ravindran, A. M.

    2014-12-01

    The atmospheric flow during the Indian Summer Monsoon here is analyzed in isentropic coordinates in two different ways. First, the lateral mass transport fo air is separated in terms of both the potential temperature and equivalent potential temperature. This approach, originally developed to analyze the global meridional circulation, makes it possible to identify the thermodynamic properties of the inflow and outflow. It is shown here how the properties of various air masses, such as the inflow of warm moist air in the boundary layer, upper tropospheric outflow, and midlatitudes dry air intrusion, can be systematically identified. Second, we analyze the vertical overturning in terms of terms of the equivalent potential temperature of the ascending and subsiding air parcels over the indian subcontinent, which allows us to further infer the thermodynamic transformation occurring during the monsoon. This technique is first used to look at the evolution of the flow through the seasonal cycle. We then further analyze the circulation patterns associated with monsoon breaks and active periods. In doing so, we identify midtropospheric in usions of dry air from the midlatitudes as a key precursor of monsoon breaks. The meteorological conditions associated for such intrusion to reach the subcontinent are then discussed.

  1. A comparison of regional isentropic-sigma and sigma model simulations of the January 1979 Chicago blizzard

    NASA Technical Reports Server (NTRS)

    Zapotocny, Tom H.; Johnson, Donald R.; Reames, Fred M.

    1993-01-01

    In an initial effort in regional numerical weather prediction, results from the University of Wisconsin isentropic-sigma (UW theta-sigma) hybrid model and an 'identical' sigma model are compared. The two main objectives are to demonstrate the capability of the UW theta-sigma model for regional numerical weather prediction and to identify advantages of the hybrid model in simulating atmospheric water vapor transport and precipitation relative to the sigma model. The 72-h simulations produced by the two models extend over a region covering the western Pacific Ocean, North America, and the western Atlantic Ocean. The simulations begin at 0000 UTC 13 January 1979, a period during which an intense Chicago blizzard develops over the central United States. This period also includes the rapid development of a cyclone in the western Pacific Ocean. Results using the Global Weather Experiment (GWE) ECMWF level IIIB data as initial and verification data indicate that both models produce reasonable and similar 72-h simulations, with the UW theta-sigma model mass and momentum distributions being slightly more accurate than the sigma model. Of particular importance for the Chicago blizzard is that the UW theta-sigma model more accurately simulates water vapor transport northward from the Gulf of Mexico and westward from the Atlantic Ocean. As a result, the hybrid model more accurately simulates observed precipitation, especially over the northeastern U.S. and southeastern Canada.

  2. Chemical discontinuity at the extratropical tropopause and isentropic stratosphere-troposphere exchange pathways diagnosed using Aura MLS data

    NASA Astrophysics Data System (ADS)

    Jin, J. J.; Livesey, N. J.; Manney, G. L.; Jiang, J. H.; Schwartz, M. J.; Daffer, W. H.

    2013-05-01

    The chemical discontinuity at the extratropical tropopause (ExTP) and stratosphere-troposphere exchange (STE) pathways are investigated using the long-lived chemical species carbon monoxide (CO) and ozone (O3) measured by the Aura Microwave Limb Sounder (MLS). A relative coordinate, tropopause latitude (TpLat), is developed based on potential vorticity (PV) from the Goddard Earth Observing System version 5 (GEOS-5) data assimilation system. TpLat is defined as the shortest geographic distance along an isentropic surface from the extratropical tropopause (ExTP) to an observation location. Our results show that this coordinate highlights the sharp chemical discontinuities at the ExTP more clearly than the widely-used equivalent latitude coordinate. Geographical distributions of STE pathways and barriers are investigated based on meridional gradients in O3 abundances in the new TpLat coordinate in conjunction with analysis of Rossby wave breaking between 330 K and 360 K. In northern hemispheric (NH) winter (Dec-Jan-Feb), NH STE pathways are seen mainly above the northeast Pacific. In NH summer (Jun-Jul-Aug), the NH pathway covers all longitudes at 330 K. However, it is mainly located above Asia at 340 K and above the Atlantic and the North Pacific at 350 K and 360 K. In the southern hemisphere (SH), there is a weaker STE region above the Eastern Indian Ocean and the southwestern Pacific, at and above 350 K in SH winter, and a stronger STE region over the Southeastern Pacific at these levels during SH summer. In addition, this study shows NH PV gradients are slightly stronger near the ExTP in summer than in winter even though the subtropical jet is weaker and Rossby wave breaking is stronger in summer than in winter.

  3. Technical Review Report for the Application for Contents Amendment for Shipping Isentropic Compression Experiment (ICE) Apparatus in 9977 Packaging

    SciTech Connect

    West, M

    2009-04-16

    This report documents the review of Application for Contents Amendment for Shipping Isentropic Compression Experiment (ICE) Apparatus in 9977 Packaging, prepared by Savannah River Packaging Technology (SRPT) of Savannah River National Laboratory (SRNL) of Savannah River Nuclear Solutions, LLC, -- the Submittal -- at the request of the Department of Energy's (DOE) National Nuclear Security Agency's (NNSA) Albuquerque Facility Operations Division, for the shipment of the ICE apparatus from Los Alamos National Laboratory (LANL), to Sandia National Laboratory (SNL). The ICE apparatus consists of a stainless steel assembly containing about 8 grams of {sup 239}Pu or its dose equivalent as noted in Table 1, Comparison of 9977 Content C.1 and the ICE Radioactive Contents, of the Submittal. The ICE target is mounted on the transport container assembly base. A Viton{sup R} O-ring seals the transport container base to the transport container body. Another Viton{sup R} O-ring seals the transport container handle to the transport container body. The ICE apparatus weighs less than 30 pounds and has less than 0.6 watts decay heat rate. For the Model 9977 Package, the maximum payload weight is 100 pounds and the maximum decay heat rate is 19 watts. Thus, the maximum payload weight and the maximum decay heat rate for the Model 9977 Package easily bound those for the ICE apparatus. This Addendum supplements the Safety Analysis Report for Packaging (SARP), Revision 2, for the Model 9977 Package and Addendum 1, Revision 2, to Revision 2 of the Model 9977 Package SARP. The ICE apparatus is considered as part of Content Envelope C.6, Samples and Sources, under the submittal for the Model 9978 Package SARP currently under review. The Staff at Lawrence Livermore National Laboratory (LLNL) recommends that the Submittal be approved by the DOE-Headquarters Certifying Official (EM-60), and incorporated into a subsequent revision to the current Certificate of Compliance (CoC), to the Model

  4. THERMAL ESCAPE IN THE HYDRODYNAMIC REGIME: RECONSIDERATION OF PARKER's ISENTROPIC THEORY BASED ON RESULTS OF KINETIC SIMULATIONS

    SciTech Connect

    Volkov, Alexey N.; Johnson, Robert E.

    2013-03-10

    The one-dimensional steady-state problem of thermal escape from a single-component atmosphere of mon- and diatomic gases is studied in the hydrodynamic (blow-off) regime using the direct simulation Monte Carlo method for an evaporative-type condition at the lower boundary. The simulations are performed for various depths into an atmosphere, indicated by a Knudsen number, Kn{sub 0}, equal to the ratio of the mean free path of molecules to the radial position of the source surface, ranging from 10 to 10{sup -5}, and for the range of the source Jeans parameter, {lambda}{sub 0}, equal to the ratio of gravitational and thermal energies, specific to blow-off. The results of kinetic simulations are compared with the isentropic model (IM) and the Navier-Stokes model. It is shown that the IM can be simplified if formulated in terms of the local Mach number and Jeans parameter. The simulations predict that at Kn{sub 0} < {approx} 10{sup -3} the flow includes a near-surface non-equilibrium Knudsen layer, a zone where the flow can be well approximated by the IM, and a rarefied far field. The corresponding IM solutions, however, only approach Parker's critical solution as {lambda}{sub 0} approaches the upper limit for blow-off. The IM alone is not capable for predicting the flow and requires boundary conditions at the top of the Knudsen layer. For small Kn{sub 0}, the scaled escape rate and energy loss rate are found to be independent of {lambda}{sub 0}. The simulation results can be scaled to any single-component atmosphere exhibiting blow-off if the external heating above the lower boundary is negligible, in particular, to sublimation-driven atmospheres of Kuiper belt objects.

  5. Quasi-isentropic Compression of Iron and Magnesium Oxide to 3 Mbar at the Omega Laser Facility

    NASA Astrophysics Data System (ADS)

    Wang, J.; Smith, R. F.; Coppari, F.; Eggert, J. H.; Boehly, T.; Collins, G.; Duffy, T. S.

    2011-12-01

    Developing a high-pressure, modest temperature ramp compression drive permits exploration of new regions of thermodynamic space, inaccessible through traditional methods of shock or static compression, and of particular relevance to material conditions found in planetary interiors both within and outside our solar system. Ramp compression is a developing technique that allows materials to be compressed along a quasi-isentropic path and provides the ability to study materials in the solid state to higher pressures than can be achieved with diamond anvil cell or shock wave methods. Iron and magnesium oxide are geologically important materials each representative of one of the two major interior regions (core and mantle) of terrestrial planets. An experimental platform for ramp loading of iron (Fe) and magnesium oxide (MgO), has been established and tested in experiments at the Omega Laser Facility, University of Rochester. Omega is a 60-beam ultraviolet (352 nm) neodymium glass laser which is capable of delivery kilojoules of energy in ~10 ns pulses onto targets of a few mm in dimension. In the current experiments, we used a composite ramped laser pulse involving typically 15 beams with total energy of 2.6-3.3 kJ. The laser beams were used to launch spatially planar ramp compression waves into Fe and MgO targets. Each target had four steps that were approximately 5-7 μm thick. Detection of the ramp wave arrival and its velocity at the free surface of each step was made using a VISAR velocity interferometer. Through the use of Lagrangian analysis on the measured wave profiles, stress-density states in iron and magnesium oxide have been determined to pressures of 291 GPa and 260 GPa respectively. For Fe, the α-ɛ transition of iron is overdriven by an initial shock pulse of ~90.1 GPa followed by ramp compression to the peak pressure. The results will be compared with shock compression and diamond anvil cell data for both materials.

  6. Constructing Synoptic Maps of Stratospheric Column Ozone from HALOE, SAGE and Balloonsonde Data Using Potential Vorticity Isentropic Coordinate Transformations

    NASA Technical Reports Server (NTRS)

    Hollandsworth, Stacey M.; Schoeberl, Mark R.; Morris, Gary A.; Long, Craig; Zhou, Shuntai; Miller, Alvin J.

    1999-01-01

    In this study we utilize potential vorticity - isentropic (PVI) coordinate transformations as a means of combining ozone data from different sources to construct daily, synthetic three-dimensional ozone fields. This methodology has been used successfully to reconstruct ozone maps in particular regions from aircraft data over the period of the aircraft campaign. We expand this method to create high-resolution daily global maps of profile ozone data, particularly in the lower stratosphere, where high-resolution ozone data are sparse. Ozone climatologies in PVI-space are constructed from satellite-based SAGE II and UARS/HALOE data, both of which-use solar occultation techniques to make high vertical resolution ozone profile measurements, but with low spatial resolution. A climatology from ground-based balloonsonde data is also created. The climatologies are used to establish the relationship between ozone and dynamical variability, which is defined by the potential vorticity (in the form of equivalent latitude) and potential temperature fields. Once a PVI climatology has been created from data taken by one or more instruments, high-resolution daily profile ozone field estimates are constructed based solely on the PVI fields, which are available on a daily basis from NCEP analysis. These profile ozone maps could be used for a variety of applications, including use in conjunction with total ozone maps to create a daily tropospheric ozone product, as input to forecast models, or as a tool for validating independent ozone measurements when correlative data are not available. This technique is limited to regions where the ozone is a long-term tracer and the flow is adiabatic. We evaluate the internal consistency of the technique by transforming the ozone back to physical space and comparing to the original profiles. Biases in the long-term average of the differences are used to identify regions where the technique is consistently introducing errors. Initial results show

  7. Isentropic compression of argon

    SciTech Connect

    Veeser, L.R.; Ekdahl, C.A.; Oona, H.

    1997-06-01

    The compression was done in an MC-1 flux compression (explosive) generator, in order to study the transition from an insulator to a conductor. Since conductivity signals were observed in all the experiments (except when the probe is removed), both the Teflon and the argon are becoming conductive. The conductivity could not be determined (Teflon insulation properties unknown), but it could be bounded as being {sigma}=1/{rho}{le}8({Omega}cm){sub -1}, because when the Teflon breaks down, the dielectric constant is reduced. The Teflon insulator problem remains, and other ways to better insulate the probe or to measure the conductivity without a probe is being sought.

  8. Thermodynamic properties of a nonideal helium plasma at quasi-isentropic compression by a factor of 575 at a pressure of 3000 GPa

    NASA Astrophysics Data System (ADS)

    Mochalov, M. A.; Il'kaev, R. I.; Fortov, V. E.; Mikhailov, A. L.; Arinin, V. A.; Blikov, A. O.; Komrakov, V. A.; Ryzhkov, A. V.; Ogorodnikov, V. A.; Yukhimchuk, A. A.

    2015-04-01

    The quasi-isentropic compressibility of a nonideal helium plasma has been measured in a two-cascade spherical chamber with separated cavities with the use of an explosive charge with the mass of ≈55 kg. The experiment has been performed on an X-ray diffraction complex consisting of three betatrons and a multichannel optoelectronic system for recording X-ray images. The density of the compressed helium plasma measured at the initial pressures of the gas in the outer and inner cavities P 1 = 36.4 MPa and P 2 = 5.1 MPa, respectively, is ρ = 4.6 g/cm3, which corresponds to the degree of compression σ = 575 at pressure P≈3000 GPa under the condition of strong nonideality (γ ˜ 7) and noticeable degeneracy of electrons ( nλ3 ˜ 5). The pressure of compressed helium has been determined from the results of the gas-dynamics calculation.

  9. Fabrication of graded density impactor via underwater shock wave and quasi-isentropic compression testing at two-stage gas gun facility

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Li, Xiaojie; Hokamoto, Kazuyuki

    2014-12-01

    We show direct evidence that underwater shock wave enables us to bond multithin plates with flat, parallel, and high-strength interfaces, which are key requirements for functionally graded material (also called graded density impactor). This phenomenon is ascribed to the super short duration of the high-speed underwater shock wave, reducing the surface tension, diffusion, evaporation, deposition, and viscous flow of matter. Thin magnesium, aluminum, titanium, copper, and molybdenum foils were welded together and designed with the increase in density. Experimental evidence and numerical simulation show that well bonding between the multilayer structures. Microstructure examinations reveal that the dominant interfacial form shifts from waviness to linearity. Graded density impactor with multilayer structure is proved that can produce quasi-isentropic compression in two-stage gas gun experiment with a designed pressure loading profile, which suggests a feasible method to simulate the conditions we want to study that were previously inaccessible in a precisely controlled laboratory environment.

  10. Modeling and Analysis of Global and Regional Climate Change in Relation to Atmospheric Hydrologic Processes

    NASA Technical Reports Server (NTRS)

    Johnson, Donald R.

    2001-01-01

    This research was directed to the development and application of global isentropic modeling and analysis capabilities to describe hydrologic processes and energy exchange in the climate system, and discern regional climate change. An additional objective was to investigate the accuracy and theoretical limits of global climate predictability which are imposed by the inherent limitations of simulating trace constituent transport and the hydrologic processes of condensation, precipitation and cloud life cycles.

  11. Existence of global weak solutions to compressible isentropic finitely extensible nonlinear bead-spring chain models for dilute polymers: The two-dimensional case

    NASA Astrophysics Data System (ADS)

    Barrett, John W.; Süli, Endre

    2016-07-01

    We prove the existence of global-in-time weak solutions to a general class of models that arise from the kinetic theory of dilute solutions of nonhomogeneous polymeric liquids, where the polymer molecules are idealized as bead-spring chains with finitely extensible nonlinear elastic (FENE) type spring potentials. The class of models under consideration involves the unsteady, compressible, isentropic, isothermal Navier-Stokes system in a bounded domain Ω in Rd, d = 2, for the density ρ, the velocity u ˜ and the pressure p of the fluid, with an equation of state of the form p (ρ) =cpργ, where cp is a positive constant and γ > 1. The right-hand side of the Navier-Stokes momentum equation includes an elastic extra-stress tensor, which is the classical Kramers expression. The elastic extra-stress tensor stems from the random movement of the polymer chains and is defined through the associated probability density function that satisfies a Fokker-Planck-type parabolic equation, a crucial feature of which is the presence of a centre-of-mass diffusion term. This extends the result in our paper J.W. Barrett and E. Süli (2016) [9], which established the existence of global-in-time weak solutions to the system for d ∈ { 2 , 3 } and γ >3/2, but the elastic extra-stress tensor required there the addition of a quadratic interaction term to the classical Kramers expression to complete the compactness argument on which the proof was based. We show here that in the case of d = 2 and γ > 1 the existence of global-in-time weak solutions can be proved in the absence of the quadratic interaction term. Our results require no structural assumptions on the drag term in the Fokker-Planck equation; in particular, the drag term need not be corotational. With a nonnegative initial density ρ0 ∈L∞ (Ω) for the continuity equation; a square-integrable initial velocity datum u˜0 for the Navier-Stokes momentum equation; and a nonnegative initial probability density function ψ0

  12. Clear air turbulence as a response to meso- and synoptic-scale dynamic processes

    NASA Technical Reports Server (NTRS)

    Keller, John L.

    1990-01-01

    The paper presents both the Roach equation for the rate of energy dissipation due to clear air turbulence and Richardson number tendencies in isentropic coordinates and examines the implications of these formulations to determine whether there is a dynamic interdependence between Ri and the nonturbulent deformation processes. The equation representing the ln(Ri) tendency is applied diagnostically to grids from an isentropic analysis of archived soundings. The evolution of the Richardson number fields over 12-hour time periods is examined using a mechanistic model. It is suggested that the application of the Roach equation for the turbulent dissipation rate should have a more restricted use. Analyses of the meso-alpha scale Richardson number and of the Richardson number tendency fields reveal a phase relationship consistent with the theoretical predictions.

  13. Process

    SciTech Connect

    Geenen, P.V.; Bennis, J.

    1989-04-04

    A process is described for minimizing the cracking tendency and uncontrolled dimensional change, and improving the strength of a rammed plastic refractory reactor liner comprising phosphate-bonded silicon carbide or phosphate-bonded alumina. It consists of heating the reactor liner placed or mounted in a reactor, prior to its first use, from ambient temperature up to a temperature of from about 490/sup 0/C to about 510/sup 0/C, the heating being carried out by heating the liner at a rate to produce a temperature increase of the liner not greater than about 6/sup 0/C per hour.

  14. Transfer Partial Molar Isentropic Compressibilities of ( l-Alanine/ l-Glutamine/Glycylglycine) from Water to 0.512 {mol} \\cdot {kg}^{-1} Aqueous {KNO}3/0.512 {mol} \\cdot {kg}^{-1} Aqueous {K}2{SO}4 Solutions Between 298.15 K and 323.15 K

    NASA Astrophysics Data System (ADS)

    Riyazuddeen; Gazal, Umaima

    2013-03-01

    Speeds of sound of ( l-alanine/ l-glutamine/glycylglycine + 0.512 {mol}\\cdot {kg}^{-1} aqueous {KNO}3/0.512 {mol}\\cdot {kg}^{-1} aqueous {K}2{SO}4) systems have been measured for several molal concentrations of amino acid/peptide at different temperatures: T = (298.15 to 323.15) K. Using the speed-of-sound and density data, the parameters, partial molar isentropic compressibilities φ _{kappa }0 and transfer partial molar isentropic compressibilities Δ _{tr} φ _{kappa }0, have been computed. The trends of variation of φ _{kappa }0 and Δ _{tr} φ _{kappa }0 with changes in molal concentration of the solute and temperature have been discussed in terms of zwitterion-ion, zwitterion-water dipole, ion-water dipole, and ion-ion interactions operative in the systems.

  15. Isentropic advection and convective lifting of water vapor in the UT - LS as observed over Brazil (22° S) in February 2004 by in situ high-resolution measurements of H2O, CH4, O3 and temperature

    NASA Astrophysics Data System (ADS)

    Durry, G.; Huret, N.; Hauchecorne, A.; Marecal, V.; Pommereau, J.-P.; Jones, R. L.; Held, G.; Larsen, N.; Renard, J.-B.

    2006-12-01

    The micro-SDLA balloonborne diode laser spectrometer was flown twice from Bauru (22° S, Brazil) in February 2004 during HIBISCUS to yield in situ H2O measurements in the Upper Troposphere (UT) and Lower Stratosphere (LS) and in particular in the Tropical Tropopause Layer (TTL). The overall TTL was found warmer (with a subsaturated cold point near -79°C) and the LS moister compared to former measurements obtained in tropical oceanic conditions. The use of specific balloons with a slow descent, combined with the high-resolution of the laser sensor, allowed us to observe in situ in the UT, the TTL and the LS several thin layers correlated on H2O, CH4, O3, temperature and PV. A component of these layers is associated with the isentropic transport into the UT- LS of extratropical stratospheric air masses. Moreover, the examination of temperature and tracer (CH4, O3) profiles gives insights on the potential contribution of convective transport of H2O in the TTL.

  16. Diabatic processes and the evolution of two contrasting extratropical cyclones

    NASA Astrophysics Data System (ADS)

    Martinez-Alvarado, Oscar; Gray, Suzanne; Methven, John

    2016-04-01

    Two contrasting extratropical cyclones were observed over the United Kingdom during the summer 2012 field campaign of the DIAMET (DIAbatic influences on Mesoscale structures in ExtraTropical storms) project. The first cyclone, observed in July, was a shallow system typical of summer over west Europe while the second cyclone, observed in August, was a much deeper system which developed a potential vorticity (PV) tower. The evolution of these two cyclones was analysed and compared in terms of diabatic effects with respect to two aspects. The first aspect is the amount and distribution of heat produced during the development of each cyclone, measured by the cross-isentropic motion around the cyclone centre. The second aspect is the modification to the circulation around the cyclones' centres, measured by area-averaged isentropic vorticity. The contributions from individual diabatic processes, such as convection, cloud microphysics and radiation, to these two aspects is also considered. The cyclones were analysed via hindcast simulations with a research version of the Met Office Unified Model, enhanced with on-line tracers of diabatic changes of potential temperature and PV. A new methodology for the interpretation of these tracers was also implemented and used. The hindcast simulations were compared with the available dropsonde observations from the field campaign as well as operational analyses and radar rainfall rates. It is shown that, while boundary layer and turbulent mixing processes and cloud microphysics processes contributed to the development of both cyclones, the main differences between the cyclones in terms of diabatic effects could be attributed to differences in convective activity. It is also shown that the contribution from all these diabatic processes to changes in the circulation was modulated by the characteristics of advection around each cyclone in a highly nonlinear fashion. This research establishes a new framework for a systematic comparison

  17. Impact and Collisional Processes in the Solar System

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.

    1985-01-01

    The mechanical and thermodynamic aspects of shock impact cratering and accretionary processes on solid planets and satellites are being investigated experimentally. The recently proposed model of Melosh, describing the physics controlling the size and velocity of only lightly shocked spalled ejecta surrounding the crushed rock region of an impact crater, was studied at the Ames gun facility. Spall velocity measurements using lead and aluminum bullets were conducted. In addition, shock temperatures of silicates and volatile bearing minerals were measured using radiative techniques. Finally impact devolatilization of minerals and accretion of planetary atmospheres were examined. Measurements of the release isentropes of CaCO3 were carried out. The effect on the water budgets of planets of reactions which occur when metallic iron (which would be present in chondritic material) is introduced into a simple accretion model is under investigation.

  18. Impact and collisional processes in the solar system

    NASA Technical Reports Server (NTRS)

    Ahrens, T. J.

    1985-01-01

    The mechanical and thermodynamic aspects of shock impact cratering and accretionary processes on solid planets and satellites are being investigated experimentally. The recently proposed model of Melosh, describing the physics controlling the size and velocity of only lightly shocked spalled ejecta surrounding the crushed rock region of an impact crater, was studied at the Ames gun facility. Spall velocity measurements using lead and aluminum bullets were conducted. In addition, shock temperatures of silicates and volatile-bearing minerals were measured using radiative techniques. Finally impact devolatilization of minerals and accretion of planetary atmospheres were examined. Measurements of the release isentropes of CaCO3 were carried out. The effect on the water budgets of planets of reactions which occur when metallic iron (which would be present in chondritic material) is introduced into a simple accretion model is under investigation.

  19. Coupling Processes Between Atmospheric Chemistry and Climate

    NASA Technical Reports Server (NTRS)

    Ko, M. K. W.; Weisenstein, Debra; Shia, Run-Li; Sze, N. D.

    1997-01-01

    This is the first semi-annual report for NAS5-97039 summarizing work performed for January 1997 through June 1997. Work in this project is related to NAS1-20666, also funded by NASA ACMAP. The work funded in this project also benefits from work at AER associated with the AER three-dimensional isentropic transport model funded by NASA AEAP and the AER two-dimensional climate-chemistry model (co-funded by Department of Energy). The overall objective of this project is to improve the understanding of coupling processes between atmospheric chemistry and climate. Model predictions of the future distributions of trace gases in the atmosphere constitute an important component of the input necessary for quantitative assessments of global change. We will concentrate on the changes in ozone and stratospheric sulfate aerosol, with emphasis on how ozone in the lower stratosphere would respond to natural or anthropogenic changes. The key modeling tools for this work are the AER two-dimensional chemistry-transport model, the AER two-dimensional stratospheric sulfate model, and the AER three-wave interactive model with full chemistry.

  20. The mesoscale forcing of a midlatitude upper-tropospheric jet streak by a simulated convective system. 1: Mass circulation and ageostrophic processes

    NASA Technical Reports Server (NTRS)

    Wolf, Bart J.; Johnson, D. R.

    1995-01-01

    The mutual forcing of a midlatitude upper-tropospheric jet streak by organized mesoscale adiabatic and diabatic processes within a simulated convective system (SCS) is investigated. Using isentropic diagnostics, results from a three-dimensional numerical simulation of an SCS are examined to study the isallobaric flow field, modes of dominant ageostrophic motion, and stability changes in relation to the mutual interdependence of adiabatic processes and latent heat release. Isentropic analysis affords an explicit isolation of a component of isallobaric flow associated with diabatic processes within the SCS. Prior to convective development within the simulations, atmospheric destabilization occurs through adiabatic ageostrophic mass adjustment and low-level convergence in association with the preexisting synoptic-scale upper-tropospheric jet streak. The SCS develops in a baroclinic zone and quickly initiates a vigorous mass circulation. By the mature stage, a pronounced vertical couplet of low-level convergence and upper-level mass divergence is established, linked by intense midtropospoheric diabatic heating. Significant divergence persists aloft for several hours subsequent to SCS decay. The dominant role of ageostrophic motion within which the low-level mass convergence develops is the adiabatic isallobaric component, while the mass divergence aloft develops principally through the diabatic isallobaric component. Both compnents are intrinsically linked to the convectively forced vertical mass transport. The inertial diabatic ageostrophic component is largest near the level of maximum heating and is responsible for the development of inertial instability to the north of SCS, resulting in this quadrant being preferred for outflow. The inertial advective component, the dominant term that produces the new downstream wind maximum, rapidly develops north of the SCS and through mutual adjustment creates the baroclinic support for the new jet streak.

  1. Performance Predictions of Supersonic Intakes with Isentropic-Compression Forebody

    NASA Astrophysics Data System (ADS)

    Nakashima, K.; Saito, Tsutomu

    Intake is an important component of next generation air-breathing engines such as Ram/Scram jet engines, as well as conventional jet-propulsion systems. The supersonic intake decelerates compresses the air inflow by shocks or compression waves to appropriate flow conditions for a specific engine system. The performance of supersonic intakes is evaluated mainly by the mass flow rate and the total pressure recovery rate.

  2. Non-isentropic unsteady transonic small disturbance theory

    NASA Technical Reports Server (NTRS)

    Fuglsang, D. F.; Williams, M. H.

    1985-01-01

    Modifications to transonic small disturbance theory (TSD) which more accurately model the Euler equations and seem to remove the problem of nonunique potential flow solutions are presented. The modifications are implemented in the two-dimensional computer code XTRAN2L, and steady and unsteady flow calculations made for the NACA 0012, NLR 7301, and NACA 64A010A airfoils. Comparisons are made with unmodified and modified TSD, Euler, and full potential theories and with experimental data. The modified theory requires only minor coding changes in existing algorithms for calculating small disturbance flows, and results in relatively small increases in computational cost.

  3. CFD Results for an Axisymmetric Isentropic Relaxed Compression Inlet

    NASA Technical Reports Server (NTRS)

    Hirt, Stefanie M.; Tacina, Kathleen M.; Conners, Timothy R.; Merret, Jason M.; Howe, Donald C.

    2008-01-01

    The OVERFLOW code was used to calculate the flow field for a family of five relaxed compression inlets, which were part of a screening study to determine a configuration most suited to the application of microscale flow control technology as a replacement for bleed. Comparisons are made to experimental data collected for each of the inlets in the 1- by 1-Foot Supersonic Wind Tunnel at the NASA Glenn Research Center (GRC) to help determine the suitability of computational fluid dynamics (CFD) as a tool for future studies of these inlets with flow control devices. Effects on the wind tunnel results of the struts present in a high subsonic flow region accounted for most of the inconsistency between the results. Based on the level of agreement in the present study, it is expected that CFD can be used as a tool to aid in the design of a study of this class of inlets with flow control.

  4. Hydrocarbon Processing`s gas processes `96

    SciTech Connect

    1996-04-01

    This review summarizes 71 processes, describing the process, its application, products, operating conditions, economics, installations, and licensor. Processes include desulfurization, CO{sub 2} removal, sulfur recovery, NGL recovery, deoxygenation, hydrogen production and separation, cryogenic separation of hydrocarbon fractions, dehydration, liquefaction of natural gas, LPG recovery, denitrogenation, and synthesis gas production. While most processes apply to natural gas, some are also useful for refinery gas, synthesis gas, coal mine gas, and tail gas from other processes.

  5. The interaction of radiative and dynamical processes during a simulated sudden stratospheric warming

    NASA Technical Reports Server (NTRS)

    Pierce, R. B.; Blackshear, W. T.; Fairlie, T. D.; Grose, W. L.; Turner, R. E.

    1993-01-01

    An analysis of a spontaneous sudden stratospheric warming that occurred during a 2-year integration of the Langley Research Center (LaRC) Atmospheric Simulation Model is presented. The simulated warming resembles observed 'wave 1' warmings in the Northern Hemisphere stratosphere and provides an opportunity to investigate the radiative and dynamical processes occurring during the warming event. Isentropic analysis of potential vorticity sources and sinks indicates that dynamically induced departures from radiative equilibrium play an important role in the warming event. Enhanced radiative cooling associated with a series of upper stratospheric warm pools leads to radiative dampening within the polar vortex. Within the 'surf zone' large-scale radiative cooling leads to diabatic advection of high potential vorticity air from aloft. Lagrangian area diagnostics of the simulated warming agree well with Limb Infrared Monitor of the Stratosphere (LIMS) analyses. Dynamical mixing is shown to account for the majority of the decrease in the size of the polar vortex during the simulated warming. An investigation of the nonlinear deformation of material lines that are initially coincident with diagnosed potential vorticity isopleths is conducted to clarify the relationship between the Lagrangian area diagnostics and potential vorticity advection during wave breaking events.

  6. Ozone seasonality above the tropical tropopause: reconciling the Eulerian and Lagrangian perspectives of transport processes

    NASA Astrophysics Data System (ADS)

    Abalos, M.; Ploeger, F.; Konopka, P.; Randel, W. J.; Serrano, E.

    2013-11-01

    We aim to reconcile the recently published, apparently contrasting results regarding the relative importance of tropical upwelling versus horizontal transport for the seasonality of ozone above the tropical tropopause. Different analysis methods in the literature (Lagrangian versus Eulerian, and isentropic versus pressure vertical coordinates) yield different perspectives of ozone transport, and the results must be carefully compared in equivalent terms to avoid misinterpretation. By examining the Lagrangian calculations in the Eulerian formulation, we show here that the results are in fact consistent with each other and with a common understanding of the ozone transport processes near and above the tropical tropopause. We further emphasize that the complementary approaches are suited for answering two different scientific questions: (1) what drives the observed seasonal cycle in ozone at a particular level above the tropical tropopause? and (2) how important is horizontal transport from mid-latitudes for ozone concentrations in the tropical lower stratosphere? Regarding the first question, the analysis of the transformed Eulerian mean (TEM) ozone budget shows that the annual cycle in tropical upwelling is the main forcing of the ozone seasonality at altitudes with large vertical gradients in the tropical lower stratosphere. To answer the second question a Lagrangian framework must be used, and the results show that a large fraction (~50%) of the ozone molecules ascending through the tropical lower stratosphere is of extra-tropical origin and has been in-mixed from mid-latitudes.

  7. Ozone seasonality above the tropical tropopause: reconciling the Eulerian and Lagrangian perspectives of transport processes

    NASA Astrophysics Data System (ADS)

    Abalos, M.; Ploeger, F.; Konopka, P.; Randel, W. J.; Serrano, E.

    2013-07-01

    We aim to reconcile the recently published, apparently contrasting results regarding the relative importance of tropical upwelling versus horizontal transport for the seasonality of ozone above the tropical tropopause. Different analysis methods in the literature (Lagrangian versus Eulerian, and isentropic versus pressure vertical coordinates) yield different perspectives of ozone transport, and the results must be carefully compared in equivalent terms to avoid misinterpretation. By examining the Lagrangian calculations in the Eulerian formulation, we show here that the results are in fact consistent with each other and with a common understanding of the ozone transport processes near and above the tropical tropopause. We further emphasize that the complementary approaches are suited for answering two different scientific questions: (1) what drives the observed seasonal cycle in ozone at a particular level above the tropical tropopause? and (2) how important is horizontal transport from mid-latitudes for ozone concentrations in the tropical lower stratosphere? Regarding the first question, the analysis of the Transformed Eulerian Mean (TEM) ozone budget shows that the annual cycle in tropical upwelling is the main forcing of the ozone seasonality at altitudes with large vertical gradients in the tropical lower stratosphere. To answer the second question a Lagrangian framework must be used, and the results show that a large fraction (∼50%) of the ozone molecules ascending through the tropical lower stratosphere is of extra-tropical origin and has been in-mixed from mid-latitudes.

  8. Meat Processing.

    ERIC Educational Resources Information Center

    Legacy, Jim; And Others

    This publication provides an introduction to meat processing for adult students in vocational and technical education programs. Organized in four chapters, the booklet provides a brief overview of the meat processing industry and the techniques of meat processing and butchering. The first chapter introduces the meat processing industry and…

  9. Hydrocarbon Processing`s petrochemical processes `97

    SciTech Connect

    1997-03-01

    The paper compiles information on numerous petrochemical processes, describing the application, the process, yields, economics, commercial plants, references, and licensor. Petrochemicals which are synthesized include: alkylbenzene, methylamines, ammonia, benzene, bisphenol-A, BTX aromatics, butadiene, butanediol, butyraldehyde, caprolactam, cumene, dimethyl terephthalate, ethanolamines, ethylbenzene, ethylene, ethylene glycols, ethylene oxide, formaldehyde, maleic anhydride, methanol, olefins, paraxylene, phenol, phthalic anhydride, polycaproamide, polyethylene, polyethylene terephthalate, polypropylene, PVC, styrene, terephthalic acid, urea, vinyl chloride, and xylene isomers.

  10. Use of GTE, Mozaic, Sonex, and UARS-MLS Data in Understanding Tropospheric Processes Critical to Model Development

    NASA Technical Reports Server (NTRS)

    Newell, Reginald E. (Principal Investigator)

    2003-01-01

    During the first year we focused on the analysis of data collected on over 7600 commercial aircraft flights (the MOZAIC program). The aim was to further our understanding of the fundamental dynamical processes that drive mesoscale phenomena in the upper troposphere and lower stratosphere, and their effects on the advection of passive scalars. Through these studies we made the following findings. 2001]: We derived the Kolmogorov equation for the third-order velocity structure function on an f-plane. We showed how the sign of the function yields the direction of the energy cascade. The remarkable linearity of the measured off diagonal third-order structure function was studied. We suggested that the Coriolis term, which appears explicitly in this equation, may be crucial in understanding the observed kinetic energy spectra at scales larger than 100 km, instead of the nonlinear advection term as previously assumed. Also, we showed that decreases with latitude for mid- to high-latitudes, and tabulated the values. Ozone concentration structure functions were calculated by restricting the data points to approximately isentropic pairings. In this way we were able to make comparisons with scalar advection theories. We found that, at even the largest scales, there was no evidence for the simple scaling predicted for smooth advection/diffusion.

  11. Meteorological Processes Affecting the Transport of Emissions from the Navajo Generating Station to Grand Canyon National Park.

    NASA Astrophysics Data System (ADS)

    Lindsey, Charles G.; Chen, Jun; Dye, Timothy S.; Willard Richards, L.; Blumenthal, Donald L.

    1999-08-01

    During the 1990 Navajo Generating Station (NGS) Winter Visibility Study, a network of surface and upper-air meteorological measurement systems was operated in and around Grand Canyon National Park to investigate atmospheric processes in complex terrain that affected the transport of emissions from the nearby NGS. This network included 15 surface monitoring stations, eight balloon sounding stations (equipped with a mix of rawinsonde, tethersonde, and Airsonde sounding systems), three Doppler radar wind profilers, and four Doppler sodars. Measurements were made from 10 January through 31 March 1990. Data from this network were used to prepare objectively analyzed wind fields, trajectories, and streak lines to represent transport of emissions from the NGS, and to prepare isentropic analyses of the data. The results of these meteorological analyses were merged in the form of a computer animation that depicted the streak line analyses along with measurements of perfluorocarbon tracer, SO2, and sulfate aerosol concentrations, as well as visibility measurements collected by an extensive surface monitoring network. These analyses revealed that synoptic-scale circulations associated with the passage of low pressure systems followed by the formation of high pressure ridges accompanied the majority of cases when NGS emittants appeared to be transported to the Grand Canyon. The authors' results also revealed terrain influences on transport within the topography of the study area, especially mesoscale flows inside the Lake Powell basin and along the plain above the Marble Canyon.

  12. Shuttle Processing

    NASA Technical Reports Server (NTRS)

    Guodace, Kimberly A.

    2010-01-01

    This slide presentation details shuttle processing flow which starts with wheel stop and ends with launching. The flow is from landing the orbiter is rolled into the Orbiter Processing Facility (OPF), where processing is performed, it is then rolled over to the Vehicle Assembly Building (VAB) where it is mated with the propellant tanks, and payloads are installed. A different flow is detailed if the weather at Kennedy Space Center requires a landing at Dryden.

  13. Peat Processing

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Humics, Inc. already had patented their process for separating wet peat into components and processing it when they consulted NERAC regarding possible applications. The NERAC search revealed numerous uses for humic acid extracted from peat. The product improves seed germination, stimulates root development, and improves crop yields. There are also potential applications in sewage disposal and horticultural peat, etc.

  14. Anaerobic Process.

    PubMed

    Li, Wei-Zun; Qian, Yang; Chang, Chein-Chi; Ju, Meiting

    2015-10-01

    A review of the literature published in 2014 on the focus of Anaerobic Process. It is divided into the following sections. •Pretreatment •Organic waste •multiple-stage co-digestion •Process Methodology and Technology. PMID:26420080

  15. Process automation

    SciTech Connect

    Moser, D.R.

    1986-01-01

    Process automation technology has been pursued in the chemical processing industries and to a very limited extent in nuclear fuel reprocessing. Its effective use has been restricted in the past by the lack of diverse and reliable process instrumentation and the unavailability of sophisticated software designed for process control. The Integrated Equipment Test (IET) facility was developed by the Consolidated Fuel Reprocessing Program (CFRP) in part to demonstrate new concepts for control of advanced nuclear fuel reprocessing plants. A demonstration of fuel reprocessing equipment automation using advanced instrumentation and a modern, microprocessor-based control system is nearing completion in the facility. This facility provides for the synergistic testing of all chemical process features of a prototypical fuel reprocessing plant that can be attained with unirradiated uranium-bearing feed materials. The unique equipment and mission of the IET facility make it an ideal test bed for automation studies. This effort will provide for the demonstration of the plant automation concept and for the development of techniques for similar applications in a full-scale plant. A set of preliminary recommendations for implementing process automation has been compiled. Some of these concepts are not generally recognized or accepted. The automation work now under way in the IET facility should be useful to others in helping avoid costly mistakes because of the underutilization or misapplication of process automation. 6 figs.

  16. Recovery process

    SciTech Connect

    Apffel, F.

    1989-06-13

    This patent describes a process for manufacturing char and hydrocarbons from discarded used tires. The process consists of: introducing the substantially whole tires into a reactor; pyrolyzing the substantially whole tires in a reaction chamber continuously at a temperature and pressure and for a reaction time sufficient to cause the tires to dissociate into a vapor and a solid phase; the pyrolyzing step including directly heating the tires with a radiant heat source at temperatures of 1000{sup 0} to 3000{sup 0}F; producing char from the solid phase; and processing the vapor phase to produce hydrocarbons.

  17. MULTIPHOTON PROCESSES

    SciTech Connect

    2002-07-05

    The Gordon Research Conference (GRC) on MULTIPHOTON PROCESSES was held at Tilton School, Tilton, NH. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  18. Grants Process

    Cancer.gov

    The NCI Grants Process provides an overview of the end-to-end lifecycle of grant funding. Learn about the types of funding available and the basics for application, review, award, and on-going administration within the NCI.

  19. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  20. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:27620084

  1. Disinfection Processes.

    PubMed

    Munakata, Naoko; Kuo, Jeff

    2016-10-01

    A review of the literature published in 2015 on topics relating to disinfection processes is presented. This review is divided into the following sections: disinfection methods, disinfection byproducts, and microbiology and microbial communities. PMID:27620087

  2. COLLAGEN PROCESSING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collagen dispersions, produced from fibrils recovered from milled bovine collagen, have shown promise in environmental remediation in applications as settling aids, filtration aids, fractionation media, oil drop stabilizers, and water purification aids. Macroporous structures, processed by controll...

  3. Word Processing.

    ERIC Educational Resources Information Center

    McWilliams, Peter

    1982-01-01

    Describes the kinds of computer equipment needed for a personal word processing system. The characteristics and capabilities of specific devices, including keyboards, printers, and disk drives, are discussed. (JL)

  4. Processive catalysis.

    PubMed

    van Dongen, Stijn F M; Elemans, Johannes A A W; Rowan, Alan E; Nolte, Roeland J M

    2014-10-20

    Nature's enzymes are an ongoing source of inspiration for scientists. The complex processes behind their selectivity and efficiency is slowly being unraveled, and these findings have spawned many biomimetic catalysts. However, nearly all focus on the conversion of small molecular substrates. Nature itself is replete with inventive catalytic systems which modify, replicate, or decompose entire polymers, often in a processive fashion. Such processivity can, for example, enhance the rate of catalysis by clamping to the polymer substrate, which imparts a large effective molarity. Reviewed herein are the various strategies for processivity in nature's arsenal and their properties. An overview of what has been achieved by chemists aiming to mimic one of nature's greatest tricks is also included. PMID:25244684

  5. Power processing

    NASA Technical Reports Server (NTRS)

    Schwarz, F. C.

    1971-01-01

    Processing of electric power has been presented as a discipline that draws on almost every field of electrical engineering, including system and control theory, communications theory, electronic network design, and power component technology. The cost of power processing equipment, which often equals that of expensive, sophisticated, and unconventional sources of electrical energy, such as solar batteries, is a significant consideration in the choice of electric power systems.

  6. Anodizing Process

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This anodizing process traces its origin to the 1960's when Reynolds Metals Company, under contract with Goddard Space Flight Center, developed a multipurpose anodizing electrolyte (MAE) process to produce a hard protective finish for spacecraft aluminum. MAE produces a high-density, abrasion-resistant film prior to the coloring step, in which the pores of the film are impregnated with a metallic form of salt. Tru-Color product applications include building fronts, railing, curtain walls, doors and windows.

  7. Process Analyzer

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The ChemScan UV-6100 is a spectrometry system originally developed by Biotronics Technologies, Inc. under a Small Business Innovation Research (SBIR) contract. It is marketed to the water and wastewater treatment industries, replacing "grab sampling" with on-line data collection. It analyzes the light absorbance characteristics of a water sample, simultaneously detects hundreds of individual wavelengths absorbed by chemical substances in a process solution, and quantifies the information. Spectral data is then processed by ChemScan analyzer and compared with calibration files in the system's memory in order to calculate concentrations of chemical substances that cause UV light absorbance in specific patterns. Monitored substances can be analyzed for quality and quantity. Applications include detection of a variety of substances, and the information provided enables an operator to control a process more efficiently.

  8. FLUORINATION PROCESS

    DOEpatents

    McMillan, T.S.

    1957-10-29

    A process for the fluorination of uranium metal is described. It is known that uranium will react with liquid chlorine trifluoride but the reaction proceeds at a slow rate. However, a mixture of a halogen trifluoride together with hydrogen fluoride reacts with uranium at a significantly faster rate than does a halogen trifluoride alone. Bromine trifluoride is suitable for use in the process, but chlorine trifluoride is preferred. Particularly suitable is a mixture of ClF/sub 3/ and HF having a mole ratio (moles

  9. Recovery process

    SciTech Connect

    Apffel, F.

    1987-03-03

    A process is described for manufacturing carbon black and hydrocarbons from discarded tires, comprising: introducing the tires into a reactor; pyrolyzing the tires in a pyrolysis reaction vessel substantially in the absence of artificially introduced oil heating media at a temperature and pressure and for a reaction time sufficient to cause the tires to dissociate into a vapor phase and a solid phase; the pyrolyzing step including directly, internally heating the tires in the reaction vessel using microwave energy; producing carbon black from the solid phase; and processing the vapor phase to produce hyrocarbons.

  10. Semiconductor processing

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The primary thrust of the semiconductor processing is outlined. The purpose is to (1) advance the theoretical basis for bulk growth of elemental and compound semiconductors in single crystal form, and (2) to develop a new experimental approaches by which semiconductor matrices with significantly improved crystalline and chemical perfection can be obtained. The most advanced approaches to silicon crystal growth is studied. The projected research expansion, directed toward the capability of growth of 4 inch diameter silicon crystals was implemented. Both intra and interdepartmental programs are established in the areas of process metallurgy, heat transfer, mass transfer, and systems control. Solutal convection in melt growth systems is also studied.

  11. Gasification process

    SciTech Connect

    Woldy, P.N.; Kaufman, H.C.; Dach, M.M.; Beall, J.F.

    1981-02-03

    This version of Texaco's gasification process for high-ash-content solids is not extended to include the production of superheated steam, as described in US Patent 4,247,302. The hot, raw gas stream passes through fewer coolers, producing a high-pressure steam instead of a superheated steam.

  12. Coating Process

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A black chrome coating, originally developed for spacecraft solar cells, led to the development of an efficient flat plate solar collector. The coating, called Chromonyx, helps the collector absorb more heat. Olympic Solar Corporation was formed to electroplate the collector. The coating technique allows 95% of the sun's energy to be utilized. The process is widely used.

  13. SEPARATION PROCESS

    DOEpatents

    Stoughton, R.W.

    1961-10-24

    A process for separating tetravalent plutonium from aqueous solutions and from niobium and zirconium by precipitation on lanthanum oxalate is described. The oxalate ions of the precipitate may be decomposed by heating in the presence of an oxidizing agent, forming a plutonium compound readily soluble in acid. (AEC)

  14. Information Processing.

    ERIC Educational Resources Information Center

    Jennings, Carol Ann; McDonald, Sandy

    This publication contains instructional materials for teacher and student use for a course in information processing. The materials are written in terms of student performance using measurable objectives. The course includes 10 units. Each instructional unit contains some or all of the basic components of a unit of instruction: performance…

  15. Radiative processes

    NASA Technical Reports Server (NTRS)

    Frederick, J. E.; Leovy, C.; Anderson, D. E., Jr.; Anderson, G. P.; Dickinson, R. E.; Drayson, S. R.; Fels, S.; Hall, L. A.; Kiehl, J.; Mentall, J. E.

    1985-01-01

    Solar radiation and the processes that control its deposition in the Earth atmosphere are considered. The published data obtained since 1978 define a reference solar spectral irradiance for use in atmospheric chemical and dynamical studies, while long term satellite measurements are now providing information on variations in the output of the Sun over a range of time scales. As concerns absorption of solar radiation in the atmosphere, new cross section data for molecular oxygen and ozone are now available. Line-by-line calculations used to predict infrared flux divergences, both as regards assumptions made in radiative transfer calculations and in the spectroscopic parameters used as inputs are examined. Also examined are the influence of radiative processes on planetary scale wave activity, photochemical acceleration of radiative damping, and the breakdown of local thermodynamic equilibrium at mesospheric altitudes.

  16. Restoration Process

    NASA Technical Reports Server (NTRS)

    1979-01-01

    In the accompanying photos, a laboratory technician is restoring the once-obliterated serial number of a revolver. The four-photo sequence shows the gradual progression from total invisibility to clear readability. The technician is using a new process developed in an applications engineering project conducted by NASA's Lewis Research Center in conjunction with Chicago State University. Serial numbers and other markings are frequently eliminated from metal objects to prevent tracing ownership of guns, motor vehicles, bicycles, cameras, appliances and jewelry. To restore obliterated numbers, crime laboratory investigators most often employ a chemical etching technique. It is effective, but it may cause metal corrosion and it requires extensive preparatory grinding and polishing. The NASA-Chicago State process is advantageous because it can be applied without variation to any kind of metal, it needs no preparatory work and number recovery can be accomplished without corrosive chemicals; the liquid used is water.

  17. Process Monitor

    Energy Science and Technology Software Center (ESTSC)

    2003-12-01

    This library is used to get process information (eg memory and timing). By setting an environment variable, the runtime system loads libprocmon.so while loading your executable. This library causes the SIGPROF signal to be triggered at time intervals. The procmon signal handler calls various system routines (eg clock_gettime, malinfo, getrusage, and ioctl {accessing the /proc filesystem}) to gather information about the process. The information is then printed to a file which can be viewed graphicallymore » via procmon_plot.pl. This information is obtained via a sampling approach. As with any sampling approach, the information it gathers will not be completely accurate. For example, if you are looking at memory high-water mark the memory allocation and freeing could have occurred between samples and thus would not be "seen" by this program. See "Usage" below for environment variables that affect this monitor (eg time between sampling).« less

  18. Fermentation process

    SciTech Connect

    Lutzen, N.W.

    1982-02-23

    Fermentation process consists essentially of fermenting a 10-45% w/w aqueous slurry of granular starch for the production of ethanol with an ethanol-producing microorganism in the presence of alpha-amylase and glucoamylase, the conduct of said fermentation being characterized by low levels of dextrin and fermentable sugars in solution in the fermentation broth throughout the fermentation, and thereafter recovering enzymes from the fermentation broth for use anew in fermentation of granular starch.

  19. Hydropyrolysis process

    DOEpatents

    Ullman, Alan Z.; Silverman, Jacob; Friedman, Joseph

    1986-01-01

    An improved process for producing a methane-enriched gas wherein a hydrogen-deficient carbonaceous material is treated with a hydrogen-containing pyrolysis gas at an elevated temperature and pressure to produce a product gas mixture including methane, carbon monoxide and hydrogen. The improvement comprises passing the product gas mixture sequentially through a water-gas shift reaction zone and a gas separation zone to provide separate gas streams of methane and of a recycle gas comprising hydrogen, carbon monoxide and methane for recycle to the process. A controlled amount of steam also is provided which when combined with the recycle gas provides a pyrolysis gas for treatment of additional hydrogen-deficient carbonaceous material. The amount of steam used and the conditions within the water-gas shift reaction zone and gas separation zone are controlled to obtain a steady-state composition of pyrolysis gas which will comprise hydrogen as the principal constituent and a minor amount of carbon monoxide, steam and methane so that no external source of hydrogen is needed to supply the hydrogen requirements of the process. In accordance with a particularly preferred embodiment, conditions are controlled such that there also is produced a significant quantity of benzene as a valuable coproduct.

  20. Ceramic Processing

    SciTech Connect

    EWSUK,KEVIN G.

    1999-11-24

    Ceramics represent a unique class of materials that are distinguished from common metals and plastics by their: (1) high hardness, stiffness, and good wear properties (i.e., abrasion resistance); (2) ability to withstand high temperatures (i.e., refractoriness); (3) chemical durability; and (4) electrical properties that allow them to be electrical insulators, semiconductors, or ionic conductors. Ceramics can be broken down into two general categories, traditional and advanced ceramics. Traditional ceramics include common household products such as clay pots, tiles, pipe, and bricks, porcelain china, sinks, and electrical insulators, and thermally insulating refractory bricks for ovens and fireplaces. Advanced ceramics, also referred to as ''high-tech'' ceramics, include products such as spark plug bodies, piston rings, catalyst supports, and water pump seals for automobiles, thermally insulating tiles for the space shuttle, sodium vapor lamp tubes in streetlights, and the capacitors, resistors, transducers, and varistors in the solid-state electronics we use daily. The major differences between traditional and advanced ceramics are in the processing tolerances and cost. Traditional ceramics are manufactured with inexpensive raw materials, are relatively tolerant of minor process deviations, and are relatively inexpensive. Advanced ceramics are typically made with more refined raw materials and processing to optimize a given property or combination of properties (e.g., mechanical, electrical, dielectric, optical, thermal, physical, and/or magnetic) for a given application. Advanced ceramics generally have improved performance and reliability over traditional ceramics, but are typically more expensive. Additionally, advanced ceramics are typically more sensitive to the chemical and physical defects present in the starting raw materials, or those that are introduced during manufacturing.

  1. Processing system

    NASA Technical Reports Server (NTRS)

    Hilland, J. E.

    1983-01-01

    To implement the analysis techniques and to provide end-to-end processing, a system was designed with the following capabilities: receive and catalog data from many sources; organize the data on mass storage for rapid access; edit for reasonableness; create new data sets by sorting on parameter, averaging and merging; provide statistical analysis and display tools; and distribute data on demand. Consideration was given to developing a flexible system that could meet immediate workshop needs and respond to future requirements. System architecture and data set details implemented are discussed.

  2. Image Processing

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A new spinoff product was derived from Geospectra Corporation's expertise in processing LANDSAT data in a software package. Called ATOM (for Automatic Topographic Mapping), it's capable of digitally extracting elevation information from stereo photos taken by spaceborne cameras. ATOM offers a new dimension of realism in applications involving terrain simulations, producing extremely precise maps of an area's elevations at a lower cost than traditional methods. ATOM has a number of applications involving defense training simulations and offers utility in architecture, urban planning, forestry, petroleum and mineral exploration.

  3. Lithospheric processes

    SciTech Connect

    Baldridge, W.S.; Wohletz, K.; Fehler, M.C.

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The main objective was to improve understanding of the origin and evolution of the Earth`s lithosphere by studying selected processes, such as deformation and magmatic intrusion during crustal extension, formation and extraction of mantle melts, fluid transport of heat and mass, and surface processes that respond to deep-seated events. Additional objectives were to promote and develop innovative techniques and to support relevant educational endeavors. Seismic studies suggest that underplating of crust by mantle melts is an important crustal-growth mechanism, that low-angle faults can be seismogenic, and that shear deformation creates mantle anisotropy near plate boundaries. Results of geochemical work determined that magmas from oceanic intraplate islands are derived from a uniform depth in the upper mantle, whereas melts erupted at mid-ocean ridges are mixed from a range of depths. The authors have determined the extent and style of fluid infiltration and trace-element distribution in natural magmatic systems, and, finally, investigated {sup 21}Ne as a tool for dating of surficial materials.

  4. Process Analyzer

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Under a NASA Small Business Innovation Research (SBIR) contract, Axiomatics Corporation developed a shunting Dielectric Sensor to determine the nutrient level and analyze plant nutrient solutions in the CELSS, NASA's space life support program. (CELSS is an experimental facility investigating closed-cycle plant growth and food processing for long duration manned missions.) The DiComp system incorporates a shunt electrode and is especially sensitive to changes in dielectric property changes in materials at measurements much lower than conventional sensors. The analyzer has exceptional capabilities for predicting composition of liquid streams or reactions. It measures concentrations and solids content up to 100 percent in applications like agricultural products, petrochemicals, food and beverages. The sensor is easily installed; maintenance is low, and it can be calibrated on line. The software automates data collection and analysis.

  5. Oligomerization process

    DOEpatents

    Smith, Jr., Lawrence A.; hearn, Dennis; Jones, Jr., Edward M.

    1991-01-01

    A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300.degree. F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  6. Etherification process

    DOEpatents

    Smith, Jr., Lawrence A.; Hearn, Dennis; Jones, Jr., Edward M.

    1990-01-01

    A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  7. WELDING PROCESS

    DOEpatents

    Zambrow, J.; Hausner, H.

    1957-09-24

    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  8. Etherification process

    DOEpatents

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1990-08-21

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figs.

  9. Oligomerization process

    DOEpatents

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1991-03-26

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figures.

  10. Image Processing

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Electronic Imagery, Inc.'s ImageScale Plus software, developed through a Small Business Innovation Research (SBIR) contract with Kennedy Space Flight Center for use on space shuttle Orbiter in 1991, enables astronauts to conduct image processing, prepare electronic still camera images in orbit, display them and downlink images to ground based scientists for evaluation. Electronic Imagery, Inc.'s ImageCount, a spin-off product of ImageScale Plus, is used to count trees in Florida orange groves. Other applications include x-ray and MRI imagery, textile designs and special effects for movies. As of 1/28/98, company could not be located, therefore contact/product information is no longer valid.

  11. Crystallization process

    DOEpatents

    Adler, Robert J.; Brown, William R.; Auyang, Lun; Liu, Yin-Chang; Cook, W. Jeffrey

    1986-01-01

    An improved crystallization process is disclosed for separating a crystallizable material and an excluded material which is at least partially excluded from the solid phase of the crystallizable material obtained upon freezing a liquid phase of the materials. The solid phase is more dense than the liquid phase, and it is separated therefrom by relative movement with the formation of a packed bed of solid phase. The packed bed is continuously formed adjacent its lower end and passed from the liquid phase into a countercurrent flow of backwash liquid. The packed bed extends through the level of the backwash liquid to provide a drained bed of solid phase adjacent its upper end which is melted by a condensing vapor.

  12. Lithospheric processes

    SciTech Connect

    Baldridge, W.

    2000-12-01

    The authors used geophysical, geochemical, and numerical modeling to study selected problems related to Earth's lithosphere. We interpreted seismic waves to better characterize the thickness and properties of the crust and lithosphere. In the southwestern US and Tien Shari, crust of high elevation is dynamically supported above buoyant mantle. In California, mineral fabric in the mantle correlate with regional strain history. Although plumes of buoyant mantle may explain surface deformation and magmatism, our geochemical work does not support this mechanism for Iberia. Generation and ascent of magmas remains puzzling. Our work in Hawaii constrains the residence of magma beneath Hualalai to be a few hundred to about 1000 years. In the crust, heat drives fluid and mass transport. Numerical modeling yielded robust and accurate predictions of these processes. This work is important fundamental science, and applies to mitigation of volcanic and earthquake hazards, Test Ban Treaties, nuclear waste storage, environmental remediation, and hydrothermal energy.

  13. Large-scale Stratospheric Transport Processes

    NASA Technical Reports Server (NTRS)

    Plumb, R. Alan

    2003-01-01

    The PI has undertaken a theoretical analysis of the existence and nature of compact tracer-tracer relationships of the kind observed in the stratosphere, augmented with three-dimensional model simulations of stratospheric tracers (the latter being an extension of modeling work the group did during the SOLVE experiment). This work achieves a rigorous theoretical basis for the existence and shape of these relationships, as well as a quantitative theory of their width and evolution, in terms of the joint tracer-tracer PDF distribution. A paper on this work is almost complete and will soon be submitted to Rev. Geophys. We have analyzed lower stratospheric water in simulations with an isentropic-coordinate version of the MATCH transport model which we recently helped to develop. The three-dimensional structure of lower stratospheric water, in particular, attracted our attention: dry air is, below about 400K potential temperature, localized in the regions of the west Pacific and equatorial South America. We have been analyzing air trajectories to determine how air passes through the tropopause cold trap. This work is now being completed, and a paper will be submitted to Geophys. Res. Lett. before the end of summer. We are continuing to perform experiments with the 'MATCH' CTM, in both sigma- and entropy-coordinate forms. We earlier found (in collaboration with Dr Natalie Mahowald, and as part of an NSF-funded project) that switching to isentropic coordinates made a substantial improvement to the simulation of the age of stratospheric air. We are now running experiments with near-tropopause sources in both versions of the model, to see if and to what extent the simulation of stratosphere-troposphere transport is dependent on the model coordinate. Personnel Research is supervised by the PI, Prof. Alan Plumb. Mr William Heres conducts the tracer modeling work and performs other modeling tasks. Two graduate students, Ms Irene Lee and Mr Michael Ring, have been participating

  14. Data Processing

    NASA Astrophysics Data System (ADS)

    Grangeat, P.

    A new area of biology has been opened up by nanoscale exploration of the living world. This has been made possible by technological progress, which has provided the tools needed to make devices that can measure things on such length and time scales. In a sense, this is a new window upon the living world, so rich and so diverse. Many of the investigative methods described in this book seek to obtain complementary physical, chemical, and biological data to understand the way it works and the way it is organised. At these length and time scales, only dedicated instrumentation could apprehend the relevant phenomena. There is no way for our senses to observe these things directly. One important field of application is molecular medicine, which aims to explain the mechanisms of life and disease by the presence and quantification of specific molecular entities. This involves combining information about genes, proteins, cells, and organs. This in turn requires the association of instruments for molecular diagnosis, either in vitro, e.g., the microarray or the lab-on-a-chip, or in vivo, e.g., probes for molecular biopsy, and tools for molecular imaging, used to localise molecular information in living organisms in a non-invasive way. These considerations concern both preclinical research for drug design and human medical applications. With the development of DNA and RNA chips [1], genomics has revolutionised investigative methods for cells and cell processes [2,3]. By sequencing the human genome, new ways have been found for understanding the fundamental mechanisms of life [4]. A revolution is currently under way with the analysis of the proteome [5-8], i.e., the complete set of proteins that can be found in some given biological medium, such as the blood plasma. The goal is to characterise certain diseases by recognisable signatures in the proteomic profile, as determined from a blood sample or a biopsy, for example [9-13]. What is at stake is the early detection of

  15. Information Processing - Administrative Data Processing

    NASA Astrophysics Data System (ADS)

    Bubenko, Janis

    A three semester, 60-credit course package in the topic of Administrative Data Processing (ADP), offered in 1966 at Stockholm University (SU) and the Royal Institute of Technology (KTH) is described. The package had an information systems engineering orientation. The first semester focused on datalogical topics, while the second semester focused on the infological topics. The third semester aimed to deepen the students’ knowledge in different parts of ADP and at writing a bachelor thesis. The concluding section of this paper discusses various aspects of the department’s first course effort. The course package led to a concretisation of our discipline and gave our discipline an identity. Our education seemed modern, “just in time”, and well adapted to practical needs. The course package formed the first concrete activity of a group of young teachers and researchers. In a forty-year perspective, these people have further developed the department and the topic to an internationally well-reputed body of knowledge and research. The department has produced more than thirty professors and more than one hundred doctoral degrees.

  16. Hydrothermal Processes

    NASA Astrophysics Data System (ADS)

    German, C. R.; von Damm, K. L.

    2003-12-01

    What is Hydrothermal Circulation?Hydrothermal circulation occurs when seawater percolates downward through fractured ocean crust along the volcanic mid-ocean ridge (MOR) system. The seawater is first heated and then undergoes chemical modification through reaction with the host rock as it continues downward, reaching maximum temperatures that can exceed 400 °C. At these temperatures the fluids become extremely buoyant and rise rapidly back to the seafloor where they are expelled into the overlying water column. Seafloor hydrothermal circulation plays a significant role in the cycling of energy and mass between the solid earth and the oceans; the first identification of submarine hydrothermal venting and their accompanying chemosynthetically based communities in the late 1970s remains one of the most exciting discoveries in modern science. The existence of some form of hydrothermal circulation had been predicted almost as soon as the significance of ridges themselves was first recognized, with the emergence of plate tectonic theory. Magma wells up from the Earth's interior along "spreading centers" or "MORs" to produce fresh ocean crust at a rate of ˜20 km3 yr-1, forming new seafloor at a rate of ˜3.3 km2 yr-1 (Parsons, 1981; White et al., 1992). The young oceanic lithosphere formed in this way cools as it moves away from the ridge crest. Although much of this cooling occurs by upward conduction of heat through the lithosphere, early heat-flow studies quickly established that a significant proportion of the total heat flux must also occur via some additional convective process (Figure 1), i.e., through circulation of cold seawater within the upper ocean crust (Anderson and Silbeck, 1981). (2K)Figure 1. Oceanic heat flow versus age of ocean crust. Data from the Pacific, Atlantic, and Indian oceans, averaged over 2 Ma intervals (circles) depart from the theoretical cooling curve (solid line) indicating convective cooling of young ocean crust by circulating seawater

  17. Design of Axisymmetric Exhaust Nozzles by Method of Characteristics Incorporating a Variable Isentropic Exponent

    NASA Technical Reports Server (NTRS)

    Guentert, Eleanor Costilow; Neumann, Harvey E.

    1959-01-01

    Limitations on fully developed laminar flows due to compressibility and property variations are examined. The cases, for liquids and for gases, wherein such motions are "exact" are determined and solutions are given. For more general conditions, not permitting an exact fully developed flow, limitations are set. Two cases arise depending on the size of the temperature variation across the channel. Both the forced and free flow are solved for the case of large temperature variation. Finally, there are described briefly some circumstances under which streamwise variations of velocity occur. The case where the velocity varies inversely with the square root of the distance is solved.

  18. High pressure, quasi-isentropic compression experiments on the Omega laser

    SciTech Connect

    Lorenz, K; Edwards, M; Jankowski, A; Pollaine, S; Smith, R; Remington, B

    2006-05-26

    The high energy density of pulsed lasers can be used to generate shockless loading in solids to high pressures and compressions but low temperatures. We have used the Omega laser to extend the capabilities of this technique to multi-Mbar pressures and compressions approaching a factor of 2 in aluminum foils. The energy from a 3.7 ns laser pulse is used to drive a strong shock through a 200 {micro}m polystyrene disc. The disc material unloads from a high-pressure state and expands across a 300 {micro}m vacuum gap where it stagnates against the sample to produce a smooth, monotonically increasing load with rise times from a few to {approx} 20 ns. Ramped compression reasing waves having peak pressures of 14-200 GPa (0.14-2.0 Mbar) and peak compressions {rho}/{rho}{sub 0} of 1.1-2.0 were generated in the aluminum samples using laser pulse energies of 400 J to 2 kJ. Wave profiles from a series of successively thicker targets loaded to 120 GPa show the evolution of the high-pressure compression wave within the sample. The initial loading in the sample is shockless, and develops into a shock at a depth of 20-25 {micro}m. We compare these wave profiles with hydrodynamic simulations from which we extract material temperatures and plastic strain rates behind the compression wave. Limitations and future prospects for this new shockless loading technique are discussed.

  19. Assessing mesoscale material response under shock & isentropic compression via high-resolution line-imaging VISAR.

    SciTech Connect

    Hall, Clint Allen; Furnish, Michael David; Podsednik, Jason W.; Reinhart, William Dodd; Trott, Wayne Merle; Mason, Joshua

    2003-10-01

    Of special promise for providing dynamic mesoscale response data is the line-imaging VISAR, an instrument for providing spatially resolved velocity histories in dynamic experiments. We have prepared two line-imaging VISAR systems capable of spatial resolution in the 10-20 micron range, at the Z and STAR facilities. We have applied this instrument to selected experiments on a compressed gas gun, chosen to provide initial data for several problems of interest, including: (1) pore-collapse in copper (two variations: 70 micron diameter hole in single-crystal copper) and (2) response of a welded joint in dissimilar materials (Ta, Nb) to ramp loading relative to that of a compression joint. The instrument is capable of resolving details such as the volume and collapse history of a collapsing isolated pore.

  20. Unsteady specific work and isentropic efficiency of a radial turbine driven by pulsed detonations

    NASA Astrophysics Data System (ADS)

    Rouser, Kurt P.

    There has been longstanding government and industry interest in pressure-gain combustion for use in Brayton cycle based engines. Theoretically, pressure-gain combustion allows heat addition with reduced entropy loss. The pulsed detonation combustor (PDC) is a device that can provide such pressure-gain combustion and possibly replace typical steady deflagration combustors. The PDC is inherently unsteady, however, and comparisons with conventional steady deflagration combustors must be based upon time-integrated performance variables. In this study, the radial turbine of a Garrett automotive turbocharger was coupled directly to and driven, full admission, by a PDC in experiments fueled by hydrogen or ethylene. Data included pulsed cycle time histories of turbine inlet and exit temperature, pressure, velocity, mass flow, and enthalpy. The unsteady inlet flowfield showed momentary reverse flow, and thus unsteady accumulation and expulsion of mass and enthalpy within the device. The coupled turbine-driven compressor provided a time-resolved measure of turbine power. Peak power increased with PDC fill fraction, and duty cycle increased with PDC frequency. Cycle-averaged unsteady specific work increased with fill fraction and frequency. An unsteady turbine efficiency formulation is proposed, including heat transfer effects, enthalpy flux-weighted total pressure ratio, and ensemble averaging over multiple cycles. Turbine efficiency increased with frequency but was lower than the manufacturer reported conventional steady turbine efficiency.

  1. A small helium liquifier which provides continuous cooling based on cycled isentropic expansion

    NASA Technical Reports Server (NTRS)

    Winter, C.; Gygax, S.; Myrtle, K.; Barton, R.

    1985-01-01

    This simple cryocooler provides a small reservoir of liquid helium at a stable temperature of 4.2K. It uses a novel adaptation of the Simon expansion cryocooler to provide continuous cooling. Operation is in a four stage cycle: (1) A closed vessel of helium under high pressure is cooled to 12K using a conventional Gifford-McMahon closed-cycle cryocooler. (2) The pressure is released adiabatically providing cooling to 4.2K. (3) Liquid helium is collected in a second, well insulated, vessel. (4) The first vessel is repressurized. The cycle time is 15-30 minutes. In this manner, a pool of liquid helium is continuously maintained in the second vessel, with a temperature stability of 0.03 degrees. The continuous cooling power available is 3mW. This design provides simplicity and reliability through the absence of any orifices or moving parts at cryogenic temperatures except for the conventional Gifford-McMahon cryocooler.

  2. Large-scale isentropic mixing properties of the Antarctic polar vortex from analyzed winds

    NASA Technical Reports Server (NTRS)

    Bowman, Kenneth P.

    1993-01-01

    Winds derived from analyzed geopotential height fields are used to study quasi-horizontal mixing by the large-scale flow in the lower stratosphere during austral spring. This is the period when the Antarctic ozone hole appears and disappears. Trajectories are computed for large ensembles of particles initially inside and outside the main polar vortex. Mixing and transport are diagnosed through estimates of finite time Lyapunov exponents and Lagrangian dispersion statistics of the tracer trajectories. At 450 K and above prior to the vortex breakdown: Lyapunov exponents are a factor of 2 smaller inside the vortex than outside; diffusion coefficients are an order of magnitude smaller inside than outside the vortex; and the trajectories reveal little exchange of air across the vortex boundary. At lower levels (425 and 400 K) mixing is greater, and there is substantial exchange of air across the vortex boundary. In some years there are large wave events that expel small amounts of vortex air into the mid-latitudes. At the end of the spring season during the vortex breakdown there is rapid mixing of air across the vortex boundary, which is evident in the mixing diagnostics and the tracer trajectories.

  3. The isentropic light piston annular cascade facil ity at RAE Pyestock

    NASA Astrophysics Data System (ADS)

    Brooks, A. J.; Colbourne, D. E.; Wedlake, E. T.; Jones, T. V.; Oldfield, M. L. G.; Schultz, D. L.; Loftus, P. J.

    1985-09-01

    An accurate assessment of heat transfer rates to turbine vanes and blades is an important aspect of efficient cooling system design and component life prediction in gas turbines. Techniques have been developed at Oxford University which permit such measurements to be obtained in test rigs which provide short duration steady flow through a turbine cascade. The temperature ratio between the gas stream and the turbine correctly models that found in an engine environment. Reynolds number and Mach numaber can be varied over a wide range to match engine conditions. The design, construction and operation of a new facility at Royal Aircraft Establishment (RAE) Pyestock, incorporating these techniques, is described. Heat transfer and aerodynamic measurements have been made on airfoil surfaces and endwalls of a fully annular cascade of nozzle guide vanes. These results are discussed and compared with those obtained from the same profile in 2-D cascade tests, and with computed 3-D flow predictions.

  4. Studies of laser-driven isentropic compression of iron in the context of geophysics

    NASA Astrophysics Data System (ADS)

    Mazevet, S.; Huser, G.; Occelli, F.; Festa, F.; Brambrink, E.; Amadou, N.; Vinci, T.; Diziere, A.; Benuzzi-Mounaix, A.; Koenig, M.; Guyot, F.; Morard, G.; Myanishi, K.; Kodama, R.; Ozaki, N.; de Resseguier, Th.

    2010-11-01

    The study of iron using dynamic compression paths yielding parameters different from that achieved on the principal Hugoniot might allow to access parameters relevant for the understanding of the solid-liquid phase transition in the Earth core (330 GPa, 5000 K). Beside the geophysical interest, dynamic compression allows to study the dynamics of the alpha-epsilon phase transition, as compression characteristic times are comparable with reaction kinetics. We have performed laser-driven ramp compression experiments on iron samples using the LULI laser facility. Different pressure ramp shapes and target samples will be presented. These results are also important to design future experiments using very large-scale facilities, which would allow to explore pressure-temperature conditions relevant to terrestrial-type exoplanets, which were recently discovered.

  5. Condensed argon isentropic compression with ultrahigh magnetic field pressure: Experimental design. Post-shot report

    SciTech Connect

    Bykov, A.I.; Boriskov, G.V.; Dolotenko, M.I.

    1996-12-31

    This report continues the series of work devoted to experimental study of a high-dense condensed argon state. Remember that according to work of Kwon et. al., hexagonal close-packed structure is profitable in terms of energy rather than face-centered argon structure (stable with zero pressure). What is most interesting and intriguing here is the issue of possible argon metallization, when it is compressed up to the densities more than 9.17 g/cm{sup 3}. In the experiment of 1995 (the arrangement and data are described in a cited reference) the authors recorded appearance of conductivity in argon, which is non-conductive in the initial state, when it is compressed more than a factor of four. The peak value of argon specific conductivity recorded in this experiment did not exceed 10 (Ohm x cm){sup {minus}1}. This value of conductivity is characteristic of semiconductors, but not metals, which have 10{sup 4} (Ohm x cm){sup {minus}1}. At this stage of the work the main attention is paid to recording of argon conductive state and studying the possibilities of multiframed radiography of the sample in the compressed state.

  6. Electrotechnologies to process foods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electrical energy is being used to process foods. In conventional food processing plants, electricity drives mechanical devices and controls the degree of process. In recent years, several processing technologies are being developed to process foods directly with electricity. Electrotechnologies use...

  7. Hydrocarbon Processing`s process design and optimization `96

    SciTech Connect

    1996-06-01

    This paper compiles information on hydrocarbon processes, describing the application, objective, economics, commercial installations, and licensor. Processes include: alkylation, ammonia, catalytic reformer, crude fractionator, crude unit, vacuum unit, dehydration, delayed coker, distillation, ethylene furnace, FCCU, polymerization, gas sweetening, hydrocracking, hydrogen, hydrotreating (naphtha, distillate, and resid desulfurization), natural gas processing, olefins, polyethylene terephthalate, refinery, styrene, sulfur recovery, and VCM furnace.

  8. Extensible packet processing architecture

    DOEpatents

    Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

    2013-08-20

    A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

  9. Processing Process: The Event of Making Art

    ERIC Educational Resources Information Center

    Richardson, Jack; Walker, Sydney

    2011-01-01

    The article takes up the notion of process and artmaking as an event to be understood neither as a singular moment of forces (e.g., artist, artwork, viewer, and/or site) coming together, nor as the "end" of a productive process that is then superseded by another event. Rather, the authors suggest that the artmaking process can be understood as an…

  10. Coal liquefaction process with enhanced process solvent

    DOEpatents

    Givens, Edwin N.; Kang, Dohee

    1984-01-01

    In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

  11. A Distributed Processing Approach to Word Processing/Data Processing.

    ERIC Educational Resources Information Center

    Adams, Robert D.; Magnuson, Jerry R.

    1980-01-01

    A word processing system developed at the University of Kansas is described. A cost-benefit analysis of the system v standard typewriter, mag-card, and other advanced word processing systems is developed. Intangible benefits such as worker satisfaction and reduced training and editing needs are discussed, and possible uses outlined. (MSE)

  12. Blood Donation Process

    MedlinePlus

    ... Blood Donation Information > Blood Donation Process Blood Donation Process Page Content Donating blood is a safe, simple, ... this test, as well as during the donation process, is sterile, used only once and then disposed. ...

  13. Drug Development Process

    MedlinePlus

    ... Approvals The Drug Development Process The Drug Development Process Share Tweet Linkedin Pin it More sharing options ... public. More Information More in The Drug Development Process Step 1: Discovery and Development Step 2: Preclinical ...

  14. Blood Donation Process

    MedlinePlus

    ... Home > Donating Blood > Donation Process Printable Version Donation Process View Video Getting Ready for Your Donation The ... worry about. Make a Donation Appointment The Donation Process Step by Step Donating blood is a simple ...

  15. Special parallel processing workshop

    SciTech Connect

    1994-12-01

    This report contains viewgraphs from the Special Parallel Processing Workshop. These viewgraphs deal with topics such as parallel processing performance, message passing, queue structure, and other basic concept detailing with parallel processing.

  16. Desalination processes and performance

    SciTech Connect

    Summers, L. J.

    1995-06-01

    Different desalination processes are evaluated for feed, capacity, performance, energy requirements, and cost. These include distillation, reverse osmosis, or electrodialysis. Detailed information is given on distillation processes and membrane processes.

  17. Solvent refining process

    SciTech Connect

    Mead, T.C.; Sequeira, A.J.; Smith, B.F.

    1981-10-13

    An improved process is described for solvent refining lubricating oil base stocks from petroleum fractions containing both aromatic and nonaromatic constituents. The process utilizes n-methyl-2-pyrrolidone as a selective solvent for aromatic hydrocarbons wherein the refined oil fraction and the extract fraction are freed of final traces of solvent by stripping with gaseous ammonia. The process has several advantages over conventional processes including a savings in energy required for the solvent refining process, and reduced corrosion of the process equipment.

  18. Conscious processing and the process goal paradox.

    PubMed

    Mullen, Richard; Hardy, Lew

    2010-06-01

    The three experiments reported here examined the process goal paradox, which has emerged from the literature on goal setting and conscious processing. We predicted that skilled but anxious performers who adopted a global movement focus using holistic process goals would outperform those who used part-oriented process goals. In line with the conscious processing hypothesis, we also predicted that performers using part process goals would experience performance impairment in test compared with baseline conditions. In all three experiments, participants performed motor tasks in baseline and test conditions. Cognitive state anxiety increased in all of the test conditions. The results confirmed our first prediction; however, we failed to find unequivocal evidence to support our second prediction. The consistent pattern of the results lends support to the suggestion that, for skilled athletes who perform under competitive pressure, using a holistic process goal that focuses attention on global aspects of a motor skill is a more effective attentional focus strategy than using a part process goal. PMID:20587818

  19. Idaho Chemical Processing Plant Process Efficiency improvements

    SciTech Connect

    Griebenow, B.

    1996-03-01

    In response to decreasing funding levels available to support activities at the Idaho Chemical Processing Plant (ICPP) and a desire to be cost competitive, the Department of Energy Idaho Operations Office (DOE-ID) and Lockheed Idaho Technologies Company have increased their emphasis on cost-saving measures. The ICPP Effectiveness Improvement Initiative involves many activities to improve cost effectiveness and competitiveness. This report documents the methodology and results of one of those cost cutting measures, the Process Efficiency Improvement Activity. The Process Efficiency Improvement Activity performed a systematic review of major work processes at the ICPP to increase productivity and to identify nonvalue-added requirements. A two-phase approach was selected for the activity to allow for near-term implementation of relatively easy process modifications in the first phase while obtaining long-term continuous improvement in the second phase and beyond. Phase I of the initiative included a concentrated review of processes that had a high potential for cost savings with the intent of realizing savings in Fiscal Year 1996 (FY-96.) Phase II consists of implementing long-term strategies too complex for Phase I implementation and evaluation of processes not targeted for Phase I review. The Phase II effort is targeted for realizing cost savings in FY-97 and beyond.

  20. Making process improvement 'stick'.

    PubMed

    Studer, Quint

    2014-06-01

    To sustain gains from a process improvement initiative, healthcare organizations should: Explain to staff why a process improvement initiative is needed. Encourage leaders within the organization to champion the process improvement, and tie their evaluations to its outcomes. Ensure that both leaders and employees have the skills to help sustain the sought-after process improvements. PMID:24968631

  1. Hyperspectral processing in graphical processing units

    NASA Astrophysics Data System (ADS)

    Winter, Michael E.; Winter, Edwin M.

    2011-06-01

    With the advent of the commercial 3D video card in the mid 1990s, we have seen an order of magnitude performance increase with each generation of new video cards. While these cards were designed primarily for visualization and video games, it became apparent after a short while that they could be used for scientific purposes. These Graphical Processing Units (GPUs) are rapidly being incorporated into data processing tasks usually reserved for general purpose computers. It has been found that many image processing problems scale well to modern GPU systems. We have implemented four popular hyperspectral processing algorithms (N-FINDR, linear unmixing, Principal Components, and the RX anomaly detection algorithm). These algorithms show an across the board speedup of at least a factor of 10, with some special cases showing extreme speedups of a hundred times or more.

  2. Image processing applied to laser cladding process

    SciTech Connect

    Meriaudeau, F.; Truchetet, F.

    1996-12-31

    The laser cladding process, which consists of adding a melt powder to a substrate in order to improve or change the behavior of the material against corrosion, fatigue and so on, involves a lot of parameters. In order to perform good tracks some parameters need to be controlled during the process. The authors present here a low cost performance system using two CCD matrix cameras. One camera provides surface temperature measurements while the other gives information relative to the powder distribution or geometric characteristics of the tracks. The surface temperature (thanks to Beer Lambert`s law) enables one to detect variations in the mass feed rate. Using such a system the authors are able to detect fluctuation of 2 to 3g/min in the mass flow rate. The other camera gives them information related to the powder distribution, a simple algorithm applied to the data acquired from the CCD matrix camera allows them to see very weak fluctuations within both gaz flux (carriage or protection gaz). During the process, this camera is also used to perform geometric measurements. The height and the width of the track are obtained in real time and enable the operator to find information related to the process parameters such as the speed processing, the mass flow rate. The authors display the result provided by their system in order to enhance the efficiency of the laser cladding process. The conclusion is dedicated to a summary of the presented works and the expectations for the future.

  3. Thermochemical water decomposition processes

    NASA Technical Reports Server (NTRS)

    Chao, R. E.

    1974-01-01

    Thermochemical processes which lead to the production of hydrogen and oxygen from water without the consumption of any other material have a number of advantages when compared to other processes such as water electrolysis. It is possible to operate a sequence of chemical steps with net work requirements equal to zero at temperatures well below the temperature required for water dissociation in a single step. Various types of procedures are discussed, giving attention to halide processes, reverse Deacon processes, iron oxide and carbon oxide processes, and metal and alkali metal processes. Economical questions are also considered.

  4. Unconventional olefin processes

    SciTech Connect

    Hu, Y.C.

    1982-11-01

    Ethylene and coproducts are produced from steam cracking of hydrocarbons such as ethane, propane, butane, naphtha and gas oil in tubular reactor coils installed in externally fired heaters. Due to increasing costs of raw materials and uncertainty of supply, there were flurries of research and development for alternative feedstocks and processes. Alternative processes include crude or residual oil cracking processes, ethanol dehydration processes and syngas based processes. In this series of articles the state-of-the-art for these processes is reviewed and they are assessed for their potential for commercialization.

  5. Digital image processing.

    PubMed

    Seeram, Euclid

    2004-01-01

    Digital image processing is now commonplace in radiology, nuclear medicine and sonography. This article outlines underlying principles and concepts of digital image processing. After completing this article, readers should be able to: List the limitations of film-based imaging. Identify major components of a digital imaging system. Describe the history and application areas of digital image processing. Discuss image representation and the fundamentals of digital image processing. Outline digital image processing techniques and processing operations used in selected imaging modalities. Explain the basic concepts and visualization tools used in 3-D and virtual reality imaging. Recognize medical imaging informatics as a new area of specialization for radiologic technologists. PMID:15352557

  6. Acoustic signal processing toolbox for array processing

    NASA Astrophysics Data System (ADS)

    Pham, Tien; Whipps, Gene T.

    2003-08-01

    The US Army Research Laboratory (ARL) has developed an acoustic signal processing toolbox (ASPT) for acoustic sensor array processing. The intent of this document is to describe the toolbox and its uses. The ASPT is a GUI-based software that is developed and runs under MATLAB. The current version, ASPT 3.0, requires MATLAB 6.0 and above. ASPT contains a variety of narrowband (NB) and incoherent and coherent wideband (WB) direction-of-arrival (DOA) estimation and beamforming algorithms that have been researched and developed at ARL. Currently, ASPT contains 16 DOA and beamforming algorithms. It contains several different NB and WB versions of the MVDR, MUSIC and ESPRIT algorithms. In addition, there are a variety of pre-processing, simulation and analysis tools available in the toolbox. The user can perform simulation or real data analysis for all algorithms with user-defined signal model parameters and array geometries.

  7. Nonlinear Markov processes

    NASA Astrophysics Data System (ADS)

    Frank, T. D.

    2008-06-01

    Some elementary properties and examples of Markov processes are reviewed. It is shown that the definition of the Markov property naturally leads to a classification of Markov processes into linear and nonlinear ones.

  8. GREENSCOPE: Sustainable Process Modeling

    EPA Science Inventory

    EPA researchers are responding to environmental problems by incorporating sustainability into process design and evaluation. EPA researchers are also developing a tool that allows users to assess modifications to existing and new chemical processes to determine whether changes in...

  9. Infrared processing of foods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infrared (IR) processing of foods has been gaining popularity over conventional processing in several unit operations, including drying, peeling, baking, roasting, blanching, pasteurization, sterilization, disinfection, disinfestation, cooking, and popping . It has shown advantages over conventional...

  10. The requirements discovery process

    SciTech Connect

    Bahill, A.T.; Dean, F.F.

    1997-02-01

    Cost and schedule overruns are often caused by poor requirements that are produced by people who do not understand the requirement process. This paper provides a high-level overview of the requirements discovery process.

  11. Gas-separation process

    DOEpatents

    Toy, Lora G.; Pinnau, Ingo; Baker, Richard W.

    1994-01-01

    A process for separating condensable organic components from gas streams. The process makes use of a membrane made from a polymer material that is glassy and that has an unusually high free volume within the polymer material.

  12. Materials processing in space

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The feasibility and possible advantages of processing materials in a nongravitational field are considered. Areas of investigation include biomedical applications, the processing of inorganic materials, and flight programs and funding.

  13. Natural Language Processing.

    ERIC Educational Resources Information Center

    Chowdhury, Gobinda G.

    2003-01-01

    Discusses issues related to natural language processing, including theoretical developments; natural language understanding; tools and techniques; natural language text processing systems; abstracting; information extraction; information retrieval; interfaces; software; Internet, Web, and digital library applications; machine translation for…

  14. News: Process intensification

    EPA Science Inventory

    Conservation of materials and energy is a major objective to the philosophy of sustainability. Where production processes can be intensified to assist these objectives, significant advances have been developed to assist conservation as well as cost. Process intensification (PI) h...

  15. Process evaluation distributed system

    NASA Technical Reports Server (NTRS)

    Moffatt, Christopher L. (Inventor)

    2006-01-01

    The distributed system includes a database server, an administration module, a process evaluation module, and a data display module. The administration module is in communication with the database server for providing observation criteria information to the database server. The process evaluation module is in communication with the database server for obtaining the observation criteria information from the database server and collecting process data based on the observation criteria information. The process evaluation module utilizes a personal digital assistant (PDA). A data display module in communication with the database server, including a website for viewing collected process data in a desired metrics form, the data display module also for providing desired editing and modification of the collected process data. The connectivity established by the database server to the administration module, the process evaluation module, and the data display module, minimizes the requirement for manual input of the collected process data.

  16. INNOVATIVE THERMAL TREATMENT PROCESSES

    EPA Science Inventory

    The paper contains discussions of several innovative thermal processes for treating or destroying hazardous wastes. Processes discussed can be included in the categories wet oxidation, molten glass, fluidized bed incineration, pyrolysis, molten salt, electric reactors, and plasma...

  17. WASTE ACTIVATED SLUDGE PROCESSING

    EPA Science Inventory

    A study was made at pilot scale of a variety of processes for dewatering and stabilization of waste activated sludge from a pure oxygen activated sludge system. Processes evaluated included gravity thickening, dissolved air flotation thickening, basket centrifugation, scroll cent...

  18. Laser Processing Architecture for Improved Material Processing

    NASA Astrophysics Data System (ADS)

    Livingston, Frank E.; Helvajian, Henry

    This chapter presents a novel architecture and software-hardware design system for materials processing techniques that are widely applicable to laser direct-write patterning tools. This new laser material processing approach has been crafted by association with the genome and genotype concepts, where predetermined and prescribed laser pulse scripts are synchronously linked with the tool path geometry, and each concatenated pulse sequence is intended to induce a specific material transformation event and thereby express a particular material attribute. While the experimental approach depends on the delivery of discrete amplitude modulated laser pulses to each focused volume element with high fidelity, the architecture is highly versatile and capable of more advanced functionality. The capabilities of this novel architecture fall short of the coherent spatial control techniques that are now emerging, but can be readily applied to fundamental investigations of complex laser-material interaction phenomena, and easily integrated into commercial and industrial laser material processing applications. Section 9.1 provides a brief overview of laser-based machining and materials processing, with particular emphasis on the advantages of controlling energy deposition in light-matter interactions to subtly affect a material's thermodynamic properties. This section also includes a brief discussion of conventional approaches to photon modulation and process control. Section 9.2 comprehensively describes the development and capabilities of our novel laser genotype pulse modulation technique that facilitates the controlled and precise delivery of photons to a host material during direct-write patterning. This section also reviews the experimental design setup and synchronized photon control scheme, along with performance tests and diagnostic results. Section 9.3 discusses selected applications of the new laser genotype processing technique, including optical property variations

  19. Fuel gas conditioning process

    DOEpatents

    Lokhandwala, Kaaeid A.

    2000-01-01

    A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

  20. The plasma hearth process: Process residuals characterization

    SciTech Connect

    Leatherman, G.L.; Geimer, R.; Batdorf, J.; Hassel, G.; Wolfe, P.; Carney, K.P.

    1994-12-31

    The Plasma Hearth Process (PHP) is a high-temperature waste treatment process being developed by Science Applications International Corporation (SAIC) for the Department of Energy (DOE) that destroys hazardous organics while stabilizing radionuclides and hazardous metals in a vitreous slag waste form. The PHP has potential application for the treatment of a wide range of mixed waste types in both the low-level and transuranic (TRU) mixed waste categories. DOE, through the Office of Technology Development`s Mixed Waste Integrated Program (MWIP) is conducting a three phase development project to ready the PHP for implementation in the DOE complex.

  1. Polar processing project

    NASA Astrophysics Data System (ADS)

    Tom, C. N.; Davies, W. J.; Goycochea, J. F.

    1993-09-01

    The purpose of this project was to explore the use of polar processing techniques in SIGINT-related signal processing applications. An investigation of ways to apply the CORDIC arithmetic algorithm to signal processing problems, and an application of the TMC2330 Coordinate Transformer chip in a coprocessor or accelerator board for a Sun workstation are covered.

  2. The Constitutional Amendment Process

    ERIC Educational Resources Information Center

    Chism, Kahlil

    2005-01-01

    This article discusses the constitutional amendment process. Although the process is not described in great detail, Article V of the United States Constitution allows for and provides instruction on amending the Constitution. While the amendment process currently consists of six steps, the Constitution is nevertheless quite difficult to change.…

  3. Change Processes in Organization.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on change processes in organizations. "Mid-stream Corrections: Decisions Leaders Make during Organizational Change Processes" (David W. Frantz) analyzes three organizational leaders to determine whether and how they take corrective actions or adapt their decision-making processes when…

  4. How yogurt is processed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This month’s Processing column on the theme of “How Is It Processed?” focuses on yogurt. Yogurt is known for its health-promoting properties. This column will provide a brief overview of the history of yogurt and the current market. It will also unveil both traditional and modern yogurt processing t...

  5. Image-Processing Educator

    NASA Technical Reports Server (NTRS)

    Gunther, F. J.

    1986-01-01

    Apple Image-Processing Educator (AIPE) explores ability of microcomputers to provide personalized computer-assisted instruction (CAI) in digital image processing of remotely sensed images. AIPE is "proof-of-concept" system, not polished production system. User-friendly prompts provide access to explanations of common features of digital image processing and of sample programs that implement these features.

  6. The Natural Learning Process

    ERIC Educational Resources Information Center

    Criss, Ellen

    2008-01-01

    Teacher-educator and researcher Daniel L. Kohut suggests in "Musical Performance: Learning Theory and Pedagogy" that there are many problems that result from the way music teachers often teach. Most teachers focus on the process, not the goal. The Natural Learning Process that Kohut advocates is the same process that young children use when they…

  7. Current Duplicating Processes

    ERIC Educational Resources Information Center

    Groneman, Nancy

    1978-01-01

    While business instructors are still teaching spirit and stencil duplicating processes, most businesses now use copiers or offset printing processes. The article discusses offset and copier skills needed by office workers, pointing out that the processes being taught should be compatible with those used in business. (MF)

  8. Process Analytical Chemistry.

    ERIC Educational Resources Information Center

    Callis, James B.; And Others

    1987-01-01

    Discusses process analytical chemistry as a discipline designed to supply quantitative and qualitative information about a chemical process. Encourages academic institutions to examine this field for employment opportunities for students. Describes the five areas of process analytical chemistry, including off-line, at-line, on-line, in-line, and…

  9. How tofu is processed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This month’s Processing column will continue the theme of “How Is It Processed?” The column will focus on tofu, which is sometimes called “the cheese of Asia.” It is a nutritious, protein-rich bean curd made by coagulating soy milk. There are many different types of tofu, and they are processed in a...

  10. Semisolid Metal Processing Consortium

    SciTech Connect

    Apelian,Diran

    2002-01-10

    Mathematical modeling and simulations of semisolid filling processes remains a critical issue in understanding and optimizing the process. Semisolid slurries are non-Newtonian materials that exhibit complex rheological behavior. There the way these slurries flow in cavities is very different from the way liquid in classical casting fills cavities. Actually filling in semisolid processing is often counter intuitive