WorldWideScience

Sample records for dense medium produced

  1. DENSE MEDIUM CYCLONE OPTIMIZATON

    Energy Technology Data Exchange (ETDEWEB)

    Gerald H. Luttrell; Chris J. Barbee; Peter J. Bethell; Chris J. Wood

    2005-06-30

    Dense medium cyclones (DMCs) are known to be efficient, high-tonnage devices suitable for upgrading particles in the 50 to 0.5 mm size range. This versatile separator, which uses centrifugal forces to enhance the separation of fine particles that cannot be upgraded in static dense medium separators, can be found in most modern coal plants and in a variety of mineral plants treating iron ore, dolomite, diamonds, potash and lead-zinc ores. Due to the high tonnage, a small increase in DMC efficiency can have a large impact on plant profitability. Unfortunately, the knowledge base required to properly design and operate DMCs has been seriously eroded during the past several decades. In an attempt to correct this problem, a set of engineering tools have been developed to allow producers to improve the efficiency of their DMC circuits. These tools include (1) low-cost density tracers that can be used by plant operators to rapidly assess DMC performance, (2) mathematical process models that can be used to predict the influence of changes in operating and design variables on DMC performance, and (3) an expert advisor system that provides plant operators with a user-friendly interface for evaluating, optimizing and trouble-shooting DMC circuits. The field data required to develop these tools was collected by conducting detailed sampling and evaluation programs at several industrial plant sites. These data were used to demonstrate the technical, economic and environmental benefits that can be realized through the application of these engineering tools.

  2. Holographic Renormalization in Dense Medium

    International Nuclear Information System (INIS)

    Park, Chanyong

    2014-01-01

    The holographic renormalization of a charged black brane with or without a dilaton field, whose dual field theory describes a dense medium at finite temperature, is investigated in this paper. In a dense medium, two different thermodynamic descriptions are possible due to an additional conserved charge. These two different thermodynamic ensembles are classified by the asymptotic boundary condition of the bulk gauge field. It is also shown that in the holographic renormalization regularity of all bulk fields can reproduce consistent thermodynamic quantities and that the Bekenstein-Hawking entropy is nothing but the renormalized thermal entropy of the dual field theory. Furthermore, we find that the Reissner-Nordström AdS black brane is dual to a theory with conformal matter as expected, whereas a charged black brane with a nontrivial dilaton profile is mapped to a theory with nonconformal matter although its leading asymptotic geometry still remains as AdS space

  3. Leeuwpan fine coal dense medium plant

    CSIR Research Space (South Africa)

    Lundt, M

    2010-11-01

    Full Text Available Beneficiation 2010, 4–6 May 2010. 671The Journal of The Southern African Institute of Mining and Metallurgy VOLUME 110 NOVEMBER 2010 L Leeuwpan fine coal dense medium plant mixed with magnetite in the launder and enters... with production. Plant equipment operational changes Cyclone spigot changes In an attempt to lower the cut-point density, the spigot on the L 672 NOVEMBER 2010 VOLUME 110 The Journal of The Southern African Institute of Mining and Metallurgy Figure 1...

  4. Charmonium propagation through a dense medium

    Directory of Open Access Journals (Sweden)

    Kopeliovich B.Z.

    2015-01-01

    Full Text Available Attenuation of a colourless c̄c dipole propagating with a large momentum through a hot medium originates from two sources, Debye screening (melting, and inelastic collisions with surrounding scattering centres (absorption. The former never terminates completely production of a bound charmonium in heavy ion collisions, even at very high temperatures. The latter, is controlled my the magnitude of the dipole cross section, related to the transport coefficient, which is the rate of transverse momentum broadening in the medium. A novel procedure of Lorentz boosting of the Schrödinger equation is developed, which allows to calculate the charmonium survival probability employing the path-integral technique, incorporating both melting and absorption. A novel mechanism of charmonium regeneration in a dense medium is proposed.

  5. Coherent neutrino interactions in a dense medium

    International Nuclear Information System (INIS)

    Kiers, K.; Weiss, N.

    1997-01-01

    Motivated by the effect of matter on neutrino oscillations (the MSW effect) we study in more detail the propagation of neutrinos in a dense medium. The dispersion relation for massive neutrinos in a medium is known to have a minimum at nonzero momentum p∼G F ρ/√(2). We study in detail the origin and consequences of this dispersion relation for both Dirac and Majorana neutrinos both in a toy model with only neutral currents and a single neutrino flavor and in a realistic open-quotes standard modelclose quotes with two neutrino flavors. We find that for a range of neutrino momenta near the minimum of the dispersion relation, Dirac neutrinos are trapped by their coherent interactions with the medium. This effect does not lead to the trapping of Majorana neutrinos. copyright 1997 The American Physical Society

  6. Characterisation of Ferrosilicon Dense Medium Separation Material

    International Nuclear Information System (INIS)

    Waanders, F. B.; Mans, A.

    2003-01-01

    Ferrosilicon is used in the dense medium separation of iron ore at Kumba resources, Sishen, South Africa. Due to high cost and losses that occur during use, maximum recovery by means of magnetic separation is aimed for. The purpose of this project was to determine the characteristics of the unused Fe-Si and then to characterise the changes that occur during storage and use thereof. Scanning electron microscopy was used to determine the composition of each sample, whilst Moessbauer spectroscopy yielded a two-sextet spectrum with hyperfine magnetic field strengths of 20 and 31 T, respectively, for the fresh samples. Additional hematite oxide peaks appeared in the Moessbauer spectra after use of the Fe-Si over a length of time, but this did not result in a dramatic degradation of the medium. No definite changes occurred during correct storage methods. It was, however, found that the biggest loss of Fe-Si was due to the abrasion of the particles, which resulted in the formation of an oxihydroxide froth, during the process.

  7. Dense Medium Machine Processing Method for Palm Kernel/ Shell ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Cracked palm kernel is a mixture of kernels, broken shells, dusts and other impurities. In ... machine processing method using dense medium, a separator, a shell collector and a kernel .... efficiency, ease of maintenance and uniformity of.

  8. Dry processing versus dense medium processing for preparing thermal coal

    CSIR Research Space (South Africa)

    De Korte, GJ

    2013-10-01

    Full Text Available of the final product. The separation efficiency of dry processes is, however, not nearly as good as that of dense medium and, as a result, it is difficult to effectively beneficiate coals with a high near-dense content. The product yield obtained from some raw...

  9. Hadrons in hot and dense medium

    International Nuclear Information System (INIS)

    Mallik, S.

    2004-01-01

    We review chiral perturbation theory in some detail and construct interaction terms involving the Goldstone and the different non-Goldstone fields, in presence of external (classical) fields coupled to currents. The ensemble average of the two-point functions of the currents can now be expanded in terms of Feynman diagrams. We evaluate the one-loop diagrams in the neighbourhood of the respective poles to find the effective couplings and masses of the particles in medium. We also describe the virial formula for the self-energy of a particle in medium, giving its pole position. It proves useful if the scattering amplitude of the particle with particles in medium is known experimentally. (author)

  10. Fluidized bed dry dense medium coal beneficiation

    CSIR Research Space (South Africa)

    North, Brian C

    2017-10-01

    Full Text Available medium beneficiation using a fluidized bed was investigated. Bed materials of sand, magnetite and ilmenite were used in a laboratory sized cylindrical fluidized bed. The materials were individually tested, as were mixes of sand and heavy minerals. Coal...

  11. Propagation of monochromatic light in a hot and dense medium

    Energy Technology Data Exchange (ETDEWEB)

    Masood, Samina S. [University of Houston Clear Lake, Department of Physical and Applied Sciences, Houston, TX (United States)

    2017-12-15

    Photons, as quanta of electromagnetic fields, determine the electromagnetic properties of an extremely hot and dense medium. Considering the properties of the photons in the interacting medium of charged particles, we explicitly calculate the electromagnetic properties such as the electric permittivity, magnetic permeability, refractive index and the propagation speed of electromagnetic signals in an extremely hot and dense background. Photons acquire a dynamically generated mass in such a medium. The screening mass of the photon, the Debye shielding length and the plasma frequency are calculated as functions of the statistical parameters of the medium. We study the properties of the propagating particles in astrophysical systems of distinct statistical conditions. The modifications in the properties of the medium lead to the equation of state of the system. We mainly calculate all these parameters for extremely high temperatures of the early universe. (orig.)

  12. Propagation of monochromatic light in a hot and dense medium

    Science.gov (United States)

    Masood, Samina S.

    2017-12-01

    Photons, as quanta of electromagnetic fields, determine the electromagnetic properties of an extremely hot and dense medium. Considering the properties of the photons in the interacting medium of charged particles, we explicitly calculate the electromagnetic properties such as the electric permittivity, magnetic permeability, refractive index and the propagation speed of electromagnetic signals in an extremely hot and dense background. Photons acquire a dynamically generated mass in such a medium. The screening mass of the photon, the Debye shielding length and the plasma frequency are calculated as functions of the statistical parameters of the medium. We study the properties of the propagating particles in astrophysical systems of distinct statistical conditions. The modifications in the properties of the medium lead to the equation of state of the system. We mainly calculate all these parameters for extremely high temperatures of the early universe.

  13. Modelling the Multiphase Flow in Dense Medium Cyclones

    Directory of Open Access Journals (Sweden)

    Kaiwei Chu

    2010-12-01

    Full Text Available Dense medium cyclone (DMC is widely used in mineral industry to separate solids by density. It is simple in design but the flow pattern within it is complex due to the size and density distributions of the feed and process medium solids, and the turbulent vortex formed. Recently, the so-called combined computational fluid dynamics (CFD and discrete element method (DEM (CFD-DEM was extended from two-phase flow to model the flow in DMCs at the University of New South Wales (UNSW. In the CFD-DEM model, the flow of coal particles is modelled by DEM and that of medium flow by CFD, allowing consideration of medium-coal mutual interaction and particle-particle collisions. In the DEM model, Newton's laws of motion are applied to individual particles, and in the CFD model the local-averaged Navier-Stokes equations combined with the volume of fluid (VOF and mixture multiphase flow models are solved. The application to the DMC studies requires intensive computational effort. Therefore, various simplified versions have been proposed, corresponding to the approaches such as Lagrangian particle tracking (LPT method where dilute phase flow is assumed so that the interaction between particles can be ignored, one-way coupling where the effect of particle flow on fluid flow is ignored, and the use of the concept of parcel particles whose properties are empirically determined. In this paper, the previous works on the modelling of DMCs at UNSW are summarized and the features and applicability of the models used are discussed.

  14. Dense medium ore concentrates of Bois-Noirs; Minerais des bois noirs, concentres de milieu dense

    Energy Technology Data Exchange (ETDEWEB)

    Le Bris, J; Leduc, M

    1959-01-20

    The chemical treatment of uranium concentrates of Bois-Noirs ore obtained by heavy medium are discussed. The first part deals with sulfuric acid attack on the concentrate, and the second part with the separation of the solution from residues by filtration. A third part deals with this separation by decantation. The fourth part deals with the carbonation of the pickling solutions obtained. (author) [French] Le present rapport est relatif a l'etude du traitement chimique de concentres uraniferes de minerais des Bois-Noirs obtenus par milieu dense. Une premiere partie est consacree a l'attaque sulfurique des concentres, une deuxieme partie a Ia separation de Ia solution d'attaque des residus par decantation. Une quatrieme partie a la carbonatation des solutions d'attaque obtenues. (auteur)

  15. Dense Medium Plasma Water Purification Reactor (DMP WaPR), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Dense Medium Plasma Water Purification Reactor offers significant improvements over existing water purification technologies used in Advanced Life Support...

  16. Stark broadening in hot, dense laser-produced plasmas

    International Nuclear Information System (INIS)

    Tighe, R.J.; Hooper, C.F. Jr.

    1976-01-01

    Broadened Lyman-α x-ray lines from neon X and argon XVIII radiators, which are immersed in a hot, dense deuterium or deuterium-tritium plasma, are discussed. In particular, these lines are analyzed for several temperature-density cases, characteristic of laser-produced plasmas; special attention paid to the relative importance of ion, electron, and Doppler effects. Static ion microfield distribution functions are tabulated

  17. Fine coal processing with dense-medium cyclones

    CSIR Research Space (South Africa)

    De Korte, GJ

    2012-10-01

    Full Text Available Institute of Mining and Metallurgy. October 1980, pp. 357-361. 24 Horsfall, D.W. 1976. The treatment of fine coal: Upgrading ?0.5 mm coal to obtain a low-ash product. ChemSA, July. 124-129. Kempnich, R.J., van Barneveld, S. and Lusan, A. 1993. Dense... was good and the results were reported by Mengelers and Absil (1976) (see Table 2). The magnetite consumption for the operation at Tertre was approximately 1 kg per feed ton. In 1965, a similar plant was constructed at Winterslag in Belgium. This plant...

  18. High-harmonic generation in a dense medium

    International Nuclear Information System (INIS)

    Strelkov, V.V.; Platonenko, V.T.; Becker, A.

    2005-01-01

    The high-harmonic generation in a plasma or gas under conditions when the single-atom response is affected by neighboring ions or atoms of the medium is studied theoretically. We solve numerically the three-dimensional Schroedinger equation for a single-electron atom in the combined fields of the neighboring particles and the laser, and average the results over different random positions of the particles using the Monte Carlo method. Harmonic spectra are calculated for different medium densities and laser intensities. We observe a change of the harmonic properties due to a random variation of the harmonic phase induced by the field of the medium, when the medium density exceeds a certain transition density. The transition density is found to depend on the harmonic order, but it is almost independent of the fundamental intensity. It also differs for the two (shorter and longer) quantum paths. The latter effect leads for ionic densities in the transition regime to a narrowing of the harmonic lines and a shortening of the attosecond pulses generated using a group of harmonics

  19. Incoherent and coherent backscattering of light by a layer of densely packed random medium

    Energy Technology Data Exchange (ETDEWEB)

    Tishkovets, Victor P. [Institute of Radio Astronomy of NASU, 4 Chervonopraporna Street, Kharkiv 61002 (Ukraine)], E-mail: tishkovets@ira.kharkov.ua

    2007-12-15

    The problem of light scattering by a layer of densely packed discrete random medium is considered. The theory of light scattering by systems of nonspherical particles is applied to derive equations corresponding to incoherent (diffuse) and interference parts of radiation reflected from the medium. A solution of the system of linear equations describing light scattering by a system of particles is represented by iteration. It is shown that the symmetry properties of the T-matrices and of the translation coefficients for the vector Helmholtz harmonics lead to the reciprocity relation for an arbitrary iteration. This relation is applied to consider the backscattering enhancement phenomenon. Equations expressing the incoherent and interference parts of reflected light from statistically homogeneous and isotropic plane-parallel layer of medium are given. In the exact backscattering direction the relation between incoherent and interference parts is identical to that of sparse media.

  20. Diamonds in dense molecular clouds - A challenge to the standard interstellar medium paradigm

    Science.gov (United States)

    Allamandola, L. J.; Sandford, S. A.; Tielens, A. G. G. M.; Herbst, T. M.

    1993-01-01

    Observations of a newly discovered infrared C-H stretching band indicate that interstellar diamond-like material appears to be characteristic of dense clouds. In sharp contrast, the spectral signature of dust in the diffuse interstellar medium is dominated by -CH2- and -CH3 groups. This dichotomy in the aliphatic organic component between the dense and diffuse media challenges standard assumptions about the processes occurring in, and interactions between, these two media. The ubiquity of this interstellar diamond-like material rules out models for meteoritic diamond formation in unusual circumstellar environments and implies that the formation of the diamond-like material is associated with common interstellar processes or stellar types.

  1. Survival of high pT light and heavy flavors in a dense medium

    International Nuclear Information System (INIS)

    Kopeliovich, B. Z.

    2011-01-01

    This talk presents an attempt at a critical overview of the current status of modeling for high-p T processes in nuclei. In particular, it includes discussion of the space-time development of hadronization of highly virtual light and heavy partons, and the related time scales; the role of early production and subsequent attenuation of pre-hadrons in a dense medium. We identify several challenging problems within the current interpretation of high-p T processes and propose solutions for some of them.

  2. Ultra High Intensity laser produced fast electron transport in under-dense and over-dense matter

    International Nuclear Information System (INIS)

    Manclossi, Mauro

    2006-01-01

    This thesis is related to inertial fusion research, and particularly concerns the approach to fast ignition, which is based on the use of ultra-intense laser pulses to ignite the thermonuclear fuel. Until now, the feasibility of this scheme has not been proven and depends on many fundamental aspects of the underlying physics, which are not yet fully understood and which are also very far from controls. The main purpose of this thesis is the experimental study of transport processes in the material over-dense (solid) and under-dense (gas jet) of a beam of fast electrons produced by pulse laser at a intensity of some 10 19 Wcm -2 . (author)

  3. Properties of the Dense Plasma Produced in Plasma Focus

    International Nuclear Information System (INIS)

    Peacock, N.J.; Wilcock, P.D.; Speer, R.J.; Morgan, P.D.

    1969-01-01

    The plasma produced by the focus or quasi-cylindrical magnetic compression which occurs at the open end of a metal-walled, coaxial plasma gun has been studied, using the electrical waveforms and the electromagnetic and reaction particle, emission. The electromagnetic radiation in the XUV region of the spectrum has previously been briefly reported, and the present paper describes further more detailed analyses of the line emission at wavelengths shorter than 10 Å when impurities are added to the gas filling. The emission is characteristic of a plasma with a temperature of a few keV and a density greater than 10 19 cm -3 , while the appearance of optical transitions in highly stripped ions, e. g. A XVIII, gives a measure of the thermalization in the plasma. The stored electrical energy has been doubled and the scaling of the neutron emission with the applied voltage and the initial particle density is presented. The duration of the neutron and X-ray emission is considerably longer than the observed instability growth time in the plasma filament. Calculations of the mode of heating and the confinement of the plasma are compared with experimental observations. (author)

  4. Experimental investigation into the application of a magnetic dense medium cyclone in a production environment / Ilana Katinka Myburgh

    OpenAIRE

    Myburgh, Ilana Katinka

    2001-01-01

    The magnetic dense medium cyclone project was undertaken at Koingnaas Mine on a 250 mm diameter cyclone during 1998 and a 510 mm cyclone during 2000. The aim of the project was to evaluate the performance of a magnetic DM cyclone in a production environment. Previous test work on magnetic DM cyclones were conducted during 1995 and 1996 on small (100 mm) cyclones in a laboratory environment, with medium feed only. Solenoid position, magnetic field strength and medium inlet de...

  5. Propagation of an attosecond pulse in a dense two-level medium

    International Nuclear Information System (INIS)

    Song Xiaohong; Gong Shangqing; Yang Weifeng; Xu Zhizhan

    2004-01-01

    We investigate the propagation of attosecond pulse in a dense two-level medium by using an iterative predictor-corrector finite-difference time-domain method. We find when attosecond pulse is considered, that the standard area theorem will break down even for small area pulses: ideal self-induced transparency cannot occur even for a 2π pulse, while the pulses whose areas are not integer multiples of 2π, such as 1.8π and 2.2π pulses, cannot evolve to 2π pulses as predicted by the standard area theorem. Significantly higher spectra components can occur on all these small area propagating pulses due to strong carrier reshaping. Furthermore, these higher spectral components dependent sensitively on the pulse area: the larger the pulse area is, the more evident are these higher spectral components

  6. A multiple scattering theory for EM wave propagation in a dense random medium

    Science.gov (United States)

    Karam, M. A.; Fung, A. K.; Wong, K. W.

    1985-01-01

    For a dense medium of randomly distributed scatterers an integral formulation for the total coherent field has been developed. This formulation accounts for the multiple scattering of electromagnetic waves including both the twoand three-particle terms. It is shown that under the Markovian assumption the total coherent field and the effective field have the same effective wave number. As an illustration of this theory, the effective wave number and the extinction coefficient are derived in terms of the polarizability tensor and the pair distribution function for randomly distributed small spherical scatterers. It is found that the contribution of the three-particle term increases with the particle size, the volume fraction, the frequency and the permittivity of the particle. This increase is more significant with frequency and particle size than with other parameters.

  7. Retrieval of Dry Snow Parameters from Radiometric Data Using a Dense Medium Model and Genetic Algorithms

    Science.gov (United States)

    Tedesco, Marco; Kim, Edward J.

    2005-01-01

    In this paper, GA-based techniques are used to invert the equations of an electromagnetic model based on Dense Medium Radiative Transfer Theory (DMRT) under the Quasi Crystalline Approximation with Coherent Potential to retrieve snow depth, mean grain size and fractional volume from microwave brightness temperatures. The technique is initially tested on both noisy and not-noisy simulated data. During this phase, different configurations of genetic algorithm parameters are considered to quantify how their change can affect the algorithm performance. A configuration of GA parameters is then selected and the algorithm is applied to experimental data acquired during the NASA Cold Land Process Experiment. Snow parameters retrieved with the GA-DMRT technique are then compared with snow parameters measured on field.

  8. ICE AND DUST IN THE QUIESCENT MEDIUM OF ISOLATED DENSE CORES

    International Nuclear Information System (INIS)

    Boogert, A. C. A.; Huard, T. L.; Knez, C.; Cook, A. M.; Chiar, J. E.; Decin, L.; Blake, G. A.; Tielens, A. G. G. M.; Van Dishoeck, E. F.

    2011-01-01

    The relation between ices in the envelopes and disks surrounding young stellar objects (YSOs) and those in the quiescent interstellar medium (ISM) is investigated. For a sample of 31 stars behind isolated dense cores, ground-based and Spitzer spectra and photometry in the 1-25 μm wavelength range are combined. The baseline for the broad and overlapping ice features is modeled, using calculated spectra of giants, H 2 O ice and silicates. The adopted extinction curve is derived empirically. Its high resolution allows for the separation of continuum and feature extinction. The extinction between 13 and 25 μm is ∼50% relative to that at 2.2 μm. The strengths of the 6.0 and 6.85 μm absorption bands are in line with those of YSOs. Thus, their carriers, which, besides H 2 O and CH 3 OH, may include NH + 4 , HCOOH, H 2 CO, and NH 3 , are readily formed in the dense core phase, before stars form. The 3.53 μm C-H stretching mode of solid CH 3 OH was discovered. The CH 3 OH/H 2 O abundance ratios of 5%-12% are larger than upper limits in the Taurus molecular cloud. The initial ice composition, before star formation occurs, therefore depends on the environment. Signs of thermal and energetic processing that were found toward some YSOs are absent in the ices toward background stars. Finally, the peak optical depth of the 9.7 μm band of silicates relative to the continuum extinction at 2.2 μm is significantly shallower than in the diffuse ISM. This extends the results of Chiar et al. to a larger sample and higher extinctions.

  9. Plastic scintillators in coincidence for the study of multi-particle production of sea level cosmic rays in dense medium

    Science.gov (United States)

    Chuang, L. S.; Chan, K. W.; Wada, M.

    1985-01-01

    Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.

  10. Jet evolution in a dense medium: event-by-event fluctuations and multi-particle correlations

    International Nuclear Information System (INIS)

    Escobedo, Miguel A.; Iancu, Edmond

    2017-01-01

    We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations, the jet evolution is a Markovian stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions describing the gluon distribution in the space of energy [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv: (arXiv:1601.03629), doi: (http://dx.doi.org/10.1007/JHEP05(2016)008), M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv: (arXiv:1609.06104), doi: (http://dx.doi.org/10.1007/JHEP12(2016)104)]. Using these results, we study the event-by-event distribution of the energy lost by the jet at large angles and of the multiplicities of the soft particles which carry this energy. We find that the event-by-event fluctuations are huge: the standard deviation in the energy loss is parametrically as large as its mean value [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv: (arXiv:1601.03629), doi: (http://dx.doi.org/10.1007/JHEP05(2016)008)]. This has important consequences for the phenomenology of di-jet asymmetry in Pb+Pb collisions at the LHC: it implies that the fluctuations in the branching process can contribute to the measured asymmetry on an equal footing with the geometry of the di-jet event (i.e. as the difference between the in-medium path lengths of the two jets). We compute the higher moments of the multiplicity distribution and identify a remarkable regularity known as Koba-Nielsen-Olesen (KNO) scaling [M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv: (arXiv:1609.06104), doi: (http

  11. Jet evolution in a dense medium: event-by-event fluctuations and multi-particle correlations

    Science.gov (United States)

    Escobedo, Miguel A.; Iancu, Edmond

    2017-11-01

    We study the gluon distribution produced via successive medium-induced branchings by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that under suitable approximations, the jet evolution is a Markovian stochastic process, which is exactly solvable. For this process, we construct exact analytic solutions for all the n-point correlation functions describing the gluon distribution in the space of energy [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv:arxiv:arXiv:1601.03629, doi:http://dx.doi.org/10.1007/JHEP05(2016)008, M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv:arxiv:arXiv:1609.06104, doi:http://dx.doi.org/10.1007/JHEP12(2016)104]. Using these results, we study the event-by-event distribution of the energy lost by the jet at large angles and of the multiplicities of the soft particles which carry this energy. We find that the event-by-event fluctuations are huge: the standard deviation in the energy loss is parametrically as large as its mean value [M. A. Escobedo, E. Iancu, Event-by-event fluctuations in the medium-induced jet evolution, JHEP 05 (2016) 008. arXiv:arxiv:arXiv:1601.03629, doi:http://dx.doi.org/10.1007/JHEP05(2016)008]. This has important consequences for the phenomenology of di-jet asymmetry in Pb+Pb collisions at the LHC: it implies that the fluctuations in the branching process can contribute to the measured asymmetry on an equal footing with the geometry of the di-jet event (i.e. as the difference between the in-medium path lengths of the two jets). We compute the higher moments of the multiplicity distribution and identify a remarkable regularity known as Koba-Nielsen-Olesen (KNO) scaling [M. A. Escobedo, E. Iancu, Multi-particle correlations and KNO scaling in the medium-induced jet evolution, JHEP 12 (2016) 104. arXiv:arxiv:arXiv:1609.06104, doi

  12. Heavy Scalar, Vector, and Axial-Vector Mesons in Hot and Dense Nuclear Medium

    Directory of Open Access Journals (Sweden)

    Arvind Kumar

    2014-01-01

    Full Text Available In this work we shall investigate the mass modifications of scalar mesons (D0; B0, vector mesons (D*; B*, and axial-vector mesons (D1; B1 at finite density and temperature of the nuclear medium. The above mesons are modified in the nuclear medium through the modification of quark and gluon condensates. We will find the medium modification of quark and gluon condensates within chiral SU(3 model through the medium modification of scalar-isoscalar fields σ and ζ at finite density and temperature. These medium modified quark and gluon condensates will further be used through QCD sum rules for the evaluation of in-medium properties of the above mentioned scalar, vector, and axial vector mesons. We will also discuss the effects of density and temperature of the nuclear medium on the scattering lengths of the above scalar, vector, and axial-vector mesons. The study of the medium modifications of the above mesons may be helpful for understanding their production rates in heavy-ion collision experiments. The results of present investigations of medium modifications of scalar, vector, and axial-vector mesons at finite density and temperature can be verified in the compressed baryonic matter (CBM experiment of FAIR facility at GSI, Germany.

  13. Dense transient pinches and pulsed power technology: research and applications using medium and small devices

    International Nuclear Information System (INIS)

    Soto, Leopoldo; Pavez, Cristian; Moreno, Jose; Cardenas, Miguel; Zambra, Marcelo; Tarifeno, Ariel; Huerta, Luis; Tenreiro, Claudio; Giordano, Jose Luis; Lagos, Miguel; Escobar, Rodrigo; Ramos, Jorge; Altamirano, Luis; Retamal, Cesar; Silva, Patricio

    2008-01-01

    The Plasma Physics and Plasma Technology Group of the Chilean Nuclear Energy Commission (CCHEN) has, since about ten years ago, used plasma production devices to study dense hot plasmas, particularly Z-pinches and plasma foci (PFs). In the case of Z-pinches, the studies include studies on the dynamics and stability of gas-embedded Z-pinches at currents of thermonuclear interest, and preliminary studies on wire arrays. For PF research, the aim of the work has been to characterize the physics of these plasmas and also to carry out the design and construction of smaller devices-in terms of both input energy and size-capable of providing dense hot plasmas. In addition, taking advantage of the experience in pulsed power technology obtained from experimental researches in dense transient plasmas, an exploratory line of pulsed power applications is being developed. In this paper, a brief review listing the most important results achieved by the Plasma Physics and Plasma Technology Group of the CCHEN is presented, including the scaling studies, PF miniaturization and diagnostics and research on Z-pinches at currents of thermonuclear interest. Then, exploratory applications of pulsed power are presented, including nanoflashes of radiation for radiography and substances detection, high pulsed magnetic fields generation and rock fragmentation.

  14. On the stability of the interface between dense plasma and liquid under electrical pulse discharge in liquid medium

    International Nuclear Information System (INIS)

    Starchyk, P.D.; Porytskyy, P.V.

    2005-01-01

    It is shown that the most important influence on the plasma of electrical pulse discharges in liquid have the processes in a zone of its contact with condensed medium. The investigations of growth of corrugations are conducted which arise on an interface between both the plasma channels of electrical pulse discharges and limiting it liquid. It is shown that the growth of perturbations caused by Rayleigh-Taylor instability are nonlinearly saturated. It is established the interconnection between both the pointed perturbations and the parameters of a dense plasma of discharge channel

  15. Cracks and nanodroplets produced on tungsten surface samples by dense plasma jets

    Science.gov (United States)

    Ticoş, C. M.; Galaţanu, M.; Galaţanu, A.; Luculescu, C.; Scurtu, A.; Udrea, N.; Ticoş, D.; Dumitru, M.

    2018-03-01

    Small samples of 12.5 mm in diameter made from pure tungsten were exposed to a dense plasma jet produced by a coaxial plasma gun operated at 2 kJ. The surface of the samples was analyzed using a scanning electron microscope (SEM) before and after applying consecutive plasma shots. Cracks and craters were produced in the surface due to surface tensions during plasma heating. Nanodroplets and micron size droplets could be observed on the samples surface. An energy-dispersive spectroscopy (EDS) analysis revealed that the composition of these droplets coincided with that of the gun electrode material. Four types of samples were prepared by spark plasma sintering from powders with the average particle size ranging from 70 nanometers up to 80 μm. The plasma power load to the sample surface was estimated to be ≈4.7 MJ m-2 s-1/2 per shot. The electron temperature and density in the plasma jet had peak values 17 eV and 1.6 × 1022 m-3, respectively.

  16. Bending transition in the penetration of a flexible intruder in a two-dimensional dense granular medium.

    Science.gov (United States)

    Algarra, Nicolas; Karagiannopoulos, Panagiotis G; Lazarus, Arnaud; Vandembroucq, Damien; Kolb, Evelyne

    2018-02-01

    We study the quasistatic penetration of a flexible beam into a two-dimensional dense granular medium lying on a horizontal plate. Rather than a buckling-like behavior we observe a transition between a regime of crack-like penetration in which the fiber only shows small fluctuations around a stable straight geometry and a bending regime in which the fiber fully bends and advances through series of loading and unloading steps. We show that the shape reconfiguration of the fiber is controlled by a single nondimensional parameter L/L_{c}, which is the ratio of the length of the flexible beam L to L_{c}, a bending elastogranular length scale that depends on the rigidity of the fiber and on the departure from the jamming packing fraction of the granular medium. We show, moreover, that the dynamics of the bending transition in the course of the penetration experiment is gradual and is accompanied by a symmetry breaking of the granular packing fraction in the vicinity of the fiber. Together with the progressive bending of the fiber, a cavity grows downstream of the fiber and the accumulation of grains upstream of the fiber leads to the development of a jammed cluster of grains. We discuss our experimental results in the framework of a simple model of bending-induced compaction and we show that the rate of the bending transition only depends on the control parameter L/L_{c}.

  17. Bending transition in the penetration of a flexible intruder in a two-dimensional dense granular medium

    Science.gov (United States)

    Algarra, Nicolas; Karagiannopoulos, Panagiotis G.; Lazarus, Arnaud; Vandembroucq, Damien; Kolb, Evelyne

    2018-02-01

    We study the quasistatic penetration of a flexible beam into a two-dimensional dense granular medium lying on a horizontal plate. Rather than a buckling-like behavior we observe a transition between a regime of crack-like penetration in which the fiber only shows small fluctuations around a stable straight geometry and a bending regime in which the fiber fully bends and advances through series of loading and unloading steps. We show that the shape reconfiguration of the fiber is controlled by a single nondimensional parameter L /Lc , which is the ratio of the length of the flexible beam L to Lc, a bending elastogranular length scale that depends on the rigidity of the fiber and on the departure from the jamming packing fraction of the granular medium. We show, moreover, that the dynamics of the bending transition in the course of the penetration experiment is gradual and is accompanied by a symmetry breaking of the granular packing fraction in the vicinity of the fiber. Together with the progressive bending of the fiber, a cavity grows downstream of the fiber and the accumulation of grains upstream of the fiber leads to the development of a jammed cluster of grains. We discuss our experimental results in the framework of a simple model of bending-induced compaction and we show that the rate of the bending transition only depends on the control parameter L /Lc .

  18. The biocompatibility of dense and porous Nickel-Titanium produced by selective laser melting.

    Science.gov (United States)

    Habijan, T; Haberland, C; Meier, H; Frenzel, J; Wittsiepe, J; Wuwer, C; Greulich, C; Schildhauer, T A; Köller, M

    2013-01-01

    Nickel-Titanium shape memory alloys (NiTi-SMA) are of biomedical interest due to their unusual range of pure elastic deformability and their elastic modulus, which is closer to that of bone than any other metallic or ceramic material. Newly developed porous NiTi, produced by Selective Laser Melting (SLM), is currently under investigation as a potential carrier material for human mesenchymal stem cells (hMSC). SLM enables the production of highly complex and tailor-made implants for patients on the basis of CT data. Such implants could be used for the reconstruction of the skull, face, or pelvis. hMSC are a promising cell type for regenerative medicine and tissue engineering due to their ability to support the regeneration of critical size bone defects. Loading porous SLM-NiTi implants with autologous hMSC may enhance bone growth and healing for critical bone defects. The purpose of this study was to assess whether porous SLM-NiTi is a suitable carrier for hMSC. Specimens of varying porosity and surface structure were fabricated via SLM. hMSC were cultured for 8 days on NiTi specimens, and cell viability was analyzed using two-color fluorescence staining. Viable cells were detected on all specimens after 8 days of cell culture. Cell morphology and surface topography were analyzed by scanning electron microscopy (SEM). Cell morphology and surface topology were dependent on the orientation of the specimens during SLM production. The Nickel ion release can be reduced significantly by aligned laser processing conditions. The presented results clearly attest that both dense SLM-NiTi and porous SLM-NiTi are suitable carriers for hMSC. Nevertheless, before carrying out in vivo studies, some work on optimization of the manufacturing process and post-processing is required. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. AN EXPLANATION FOR THE DIFFERENT X-RAY TO OPTICAL COLUMN DENSITIES IN THE ENVIRONMENTS OF GAMMA RAY BURSTS: A PROGENITOR EMBEDDED IN A DENSE MEDIUM

    International Nuclear Information System (INIS)

    Krongold, Yair; Prochaska, J. Xavier

    2013-01-01

    We study the ∼> 10 ratios in the X-ray to optical column densities inferred from afterglow spectra of gamma ray bursts (GRBs) due to gas surrounding their progenitors. We present time-evolving photoionization calculations for these afterglows and explore different conditions of their environment. We find that homogenous models of the environment (constant density) predict X-ray columns similar to those found in the optical spectra, with the bulk of the opacity being produced by neutral material at large distances from the burst. This result is independent of gas density or metallicity. Only models assuming a progenitor immersed in a dense (∼10 2-4 cm –3 ) cloud of gas (with radius ∼10 pc), with a strong, declining gradient of density for the surrounding interstellar medium (ISM) are able to account for the large X-ray to optical column density ratios. However, to avoid an unphysical correlation between the size of this cloud and the size of the ionization front produced by the GRB, the models also require that the circumburst medium is already ionized prior to the burst. The inferred cloud masses are ∼ 6 M ☉ , even if low metallicities in the medium are assumed (Z ∼ 0.1 Z ☉ ). These cloud properties are consistent with those found in giant molecular clouds and our results support a scenario in which the progenitors reside within intense star formation regions of galaxies. Finally, we show that modeling over large samples of GRB afterglows may offer strong constraints on the range of properties in these clouds, and the host galaxy ISM

  20. The biocompatibility of dense and porous Nickel-Titanium produced by selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Habijan, T., E-mail: Tim.Habijan@rub.de [Surgical Research, Department of Surgery, BG Kliniken Bergmannsheil, Ruhr-University Bochum, Buerkle-de-la-Camp-Platz 1, 44789 Bochum (Germany); Haberland, C.; Meier, H. [Institute Product and Service Engineering, Ruhr-University Bochum (Germany); Frenzel, J. [Institute for Materials, Ruhr-University Bochum (Germany); Wittsiepe, J. [Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum (Germany); Wuwer, C.; Greulich, C.; Schildhauer, T.A.; Koeller, M. [Surgical Research, Department of Surgery, BG Kliniken Bergmannsheil, Ruhr-University Bochum, Buerkle-de-la-Camp-Platz 1, 44789 Bochum (Germany)

    2013-01-01

    Nickel-Titanium shape memory alloys (NiTi-SMA) are of biomedical interest due to their unusual range of pure elastic deformability and their elastic modulus, which is closer to that of bone than any other metallic or ceramic material. Newly developed porous NiTi, produced by Selective Laser Melting (SLM), is currently under investigation as a potential carrier material for human mesenchymal stem cells (hMSC). SLM enables the production of highly complex and tailor-made implants for patients on the basis of CT data. Such implants could be used for the reconstruction of the skull, face, or pelvis. hMSC are a promising cell type for regenerative medicine and tissue engineering due to their ability to support the regeneration of critical size bone defects. Loading porous SLM-NiTi implants with autologous hMSC may enhance bone growth and healing for critical bone defects. The purpose of this study was to assess whether porous SLM-NiTi is a suitable carrier for hMSC. Specimens of varying porosity and surface structure were fabricated via SLM. hMSC were cultured for 8 days on NiTi specimens, and cell viability was analyzed using two-color fluorescence staining. Viable cells were detected on all specimens after 8 days of cell culture. Cell morphology and surface topography were analyzed by scanning electron microscopy (SEM). Cell morphology and surface topology were dependent on the orientation of the specimens during SLM production. The Nickel ion release can be reduced significantly by aligned laser processing conditions. The presented results clearly attest that both dense SLM-NiTi and porous SLM-NiTi are suitable carriers for hMSC. Nevertheless, before carrying out in vivo studies, some work on optimization of the manufacturing process and post-processing is required. - Highlights: Black-Right-Pointing-Pointer Specimens, varying in porosity and surface structure were produced via SLM. Black-Right-Pointing-Pointer Biocompatibility of these specimens was analyzed. Black

  1. The biocompatibility of dense and porous Nickel–Titanium produced by selective laser melting

    International Nuclear Information System (INIS)

    Habijan, T.; Haberland, C.; Meier, H.; Frenzel, J.; Wittsiepe, J.; Wuwer, C.; Greulich, C.; Schildhauer, T.A.; Köller, M.

    2013-01-01

    Nickel–Titanium shape memory alloys (NiTi-SMA) are of biomedical interest due to their unusual range of pure elastic deformability and their elastic modulus, which is closer to that of bone than any other metallic or ceramic material. Newly developed porous NiTi, produced by Selective Laser Melting (SLM), is currently under investigation as a potential carrier material for human mesenchymal stem cells (hMSC). SLM enables the production of highly complex and tailor-made implants for patients on the basis of CT data. Such implants could be used for the reconstruction of the skull, face, or pelvis. hMSC are a promising cell type for regenerative medicine and tissue engineering due to their ability to support the regeneration of critical size bone defects. Loading porous SLM-NiTi implants with autologous hMSC may enhance bone growth and healing for critical bone defects. The purpose of this study was to assess whether porous SLM-NiTi is a suitable carrier for hMSC. Specimens of varying porosity and surface structure were fabricated via SLM. hMSC were cultured for 8 days on NiTi specimens, and cell viability was analyzed using two-color fluorescence staining. Viable cells were detected on all specimens after 8 days of cell culture. Cell morphology and surface topography were analyzed by scanning electron microscopy (SEM). Cell morphology and surface topology were dependent on the orientation of the specimens during SLM production. The Nickel ion release can be reduced significantly by aligned laser processing conditions. The presented results clearly attest that both dense SLM-NiTi and porous SLM-NiTi are suitable carriers for hMSC. Nevertheless, before carrying out in vivo studies, some work on optimization of the manufacturing process and post-processing is required. - Highlights: ► Specimens, varying in porosity and surface structure were produced via SLM. ► Biocompatibility of these specimens was analyzed. ► All specimens were completely coated with a layer

  2. Student-Produced Movies as a Medium for Literacy Development

    Science.gov (United States)

    Young, Chase; Rasinski, Timothy V.

    2013-01-01

    In this article the authors integrate literacy with classroom-based technologies to create a student produced movie. The authors explain the steps to classroom movie production that deepens students' comprehension, engages students' in purposeful writing, and utilizes new technologies. (Contains 6 figures.)

  3. Electron transport phenomena and dense plasmas produced by ultra-short pulse laser interaction

    International Nuclear Information System (INIS)

    More, R.M.

    1994-01-01

    Recent experiments with femtosecond lasers provide a test bed for theoretical ideas about electron processes in hot dense plasmas. We briefly review aspects of electron conduction theory likely to prove relevant to femtosecond laser absorption. We show that the Mott-Ioffe-Regel limit implies a maximum inverse bremsstrahlung absorption of about 50% at temperatures near the Fermi temperature. We also propose that sheath inverse bremsstrahlung leads to a minimum absorption of 7-10% at high laser intensity

  4. Development of selective medium for IMP-type carbapenemase-producing Enterobacteriaceae in stool specimens.

    Science.gov (United States)

    Yamamoto, Norihisa; Kawahara, Ryuji; Akeda, Yukihiro; Shanmugakani, Rathina Kumar; Yoshida, Hisao; Hagiya, Hideharu; Hara, Naohiro; Nishi, Isao; Yukawa, Satomi; Asada, Rumiko; Sasaki, Yumi; Maeda, Kazuhiro; Sakamoto, Noriko; Hamada, Shigeyuki; Tomono, Kazunori

    2017-03-24

    Identification of carbapenemase-producing Enterobacteriaceae (CPE) in faecal specimens is challenging. This fact is particularly critical because low-level carbapenem-resistant organisms such as IMP-producing CPE are most prevalent in Japan. We developed a modified selective medium more suitable for IMP-type CPE. Fifteen reference CPE strains producing different types of β-lactamases were used to evaluate the commercially available CHROMagar KPC and chromID CARBA as well as the newly prepared MC-ECC medium (CHROMagar ECC supplemented with meropenem, cloxacillin, and ZnSO 4 ) and M-ECC medium (CHROMagar ECC supplemented with meropenem and ZnSO 4 ). A total of 1035 clinical samples were then examined to detect CPE using chromID CARBA and M-ECC medium. All tested strains producing NDM-, KPC-, and OXA-48-carbapenemases were successfully cultured in the media employed. Although most of the IMP-positive strains did not grow in CHROMagar KPC, chromID CARBA, or MC-ECC, all tested strains grew on M-ECC. When faecal samples were applied to the media, M-ECC medium allowed the best growth of IMP-type CPE with a significantly higher sensitivity (99.3%) than that of chromID CARBA (13.9%). M-ECC medium was determined as the most favourable selective medium for the detection of IMP-type CPE as well as other types of CPE.

  5. Laser-produced dense plasma in extremely high pressure gas and its application to a plasma-bridged gap switch

    International Nuclear Information System (INIS)

    Yamada, J.; Okuda, A.

    1989-01-01

    When an extremely high pressure gas is irradiated by an intense laser light, a dense plasma produced at the focal spot moves towards the focusing lens with a high velocity. Making use of this phenomenon, a new plasma-bridged gap switch is proposed and its switching characteristics is experimentally examined. From the experiments, it is confirmed that the switching time is almost constant with the applied voltage only when the focal spot is just on the positive electrode, indicating that the bridging of gap is caused by the laser light. (author)

  6. Time-resolved Thomson scattering on high-intensity laser-produced hot dense helium plasmas

    International Nuclear Information System (INIS)

    Sperling, P; Liseykina, T; Bauer, D; Redmer, R

    2013-01-01

    The introduction of brilliant free-electron lasers enables new pump–probe experiments to characterize warm and hot dense matter states, i.e. systems at solid-like densities and temperatures of one to several hundred eV. Such extreme conditions are relevant for high-energy density studies such as, e.g., in planetary physics and inertial confinement fusion. We consider here a liquid helium jet pumped with a high-intensity optical short-pulse laser that is subsequently probed with brilliant soft x-ray radiation. The optical short-pulse laser generates a strongly inhomogeneous helium plasma which is characterized with particle-in-cell simulations. We derive the respective Thomson scattering spectrum based on the Born–Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We observe plasmon modes that are generated in the interior of the target and study their temporal evolution. Such pump–probe experiments are promising tools to measure the important plasma parameters density and temperature. The method described here can be applied to various pump–probe scenarios by combining optical lasers, soft x-rays and hard x-ray sources. (paper)

  7. Dense particles and slow sedimenting particles produced by ultraviolet irradiation of poliovirus

    International Nuclear Information System (INIS)

    Wetz, K.; Zeichhardt, H.; Willingmann, P.; Habermehl, K.-O.

    1983-01-01

    Low doses of u.v. radiation rapidly inactivate poliovirus, the virus progressively converting into dense particles (DPs) of buoyant density 1.44 g/ml in CsCl. The DPs are structurally and antigenically related to standard virus (N-antigen), i.e. indistinguishable from virus in their RNA and protein content and in sedimentation properties. Furthermore, there is no difference in reactivity of the structural proteins of virus and DPs with the monofunctional reagent [ 3 H]N-succinimidyl propionate ( 3 H-NSP). However, DPs differ from virus in that their capsids are permeable to several ions, and they can be degraded by RNase and protease. Increasing the radiation dose causes a successive transformation of DPs into 105S slow-sedimenting particles (SSPs), antigenically related to 76S artificial empty capsids (AECs) or H-antigen, but differing physically and structurally. The SSPs have a higher S value than AECs and contain all the capsid proteins, including VP4, and the RNA, both of these macromolecules being absent from AECs. It is concluded, therefore, that transformation from N- to H- antigenicity by u.v. radiation does not require release of RNA and VP4. Conversion of virus particles to SSPs correlates with altered reactivity of VP2 and to a lesser extent VP1 and VP3, with the monofunctional reagent 3 H-NSP. (author)

  8. Dense particles and slow sedimenting particles produced by ultraviolet irradiation of poliovirus

    Energy Technology Data Exchange (ETDEWEB)

    Wetz, K.; Zeichhardt, H.; Willingmann, P.; Habermehl, K.O. (Freie Univ. Berlin (Germany, F.R.))

    1983-06-01

    Low doses of u.v. radiation rapidly inactivate poliovirus, the virus progressively converting into dense particles (DPs) of buoyant density 1.44 g/ml in CsCl. The DPs are structurally and antigenically related to standard virus (N-antigen), i.e. indistinguishable from virus in their RNA and protein content and in sedimentation properties. Furthermore, there is no difference in reactivity of the structural proteins of virus and DPs with the monofunctional reagent (/sup 3/H)N-succinimidyl propionate (/sup 3/H-NSP). However, DPs differ from virus in that their capsids are permeable to several ions, and they can be degraded by RNase and protease. Increasing the radiation dose causes a successive transformation of DPs into 105S slow-sedimenting particles (SSPs), antigenically related to 76S artificial empty capsids (AECs) or H-antigen, but differing physically and structurally. The SSPs have a higher S value than AECs and contain all the capsid proteins, including VP4, and the RNA, both of these macromolecules being absent from AECs. It is concluded, therefore, that transformation from N- to H- antigenicity by u.v. radiation does not require release of RNA and VP4. Conversion of virus particles to SSPs correlates with altered reactivity of VP2 and to a lesser extent VP1 and VP3, with the monofunctional reagent /sup 3/H-NSP.

  9. A scheme to produce a dense positronium plasma for an antihydrogen experiment

    Energy Technology Data Exchange (ETDEWEB)

    Perez, P. [CEA Saclay, DSM/IRFU, 91191 Gif-sur-Yvette Cedex (France)], E-mail: patrice.perez@cea.fr; Liszkay, L.; Rey, J.-M.; Delferrierre, O.; Blideanu, V.; Carty, M.; Curtoni, A.; Ruiz, N.; Sauce, Y. [CEA Saclay, DSM/IRFU, 91191 Gif-sur-Yvette Cedex (France)

    2008-10-31

    A 6 MeV industrial electron linac with 0.2 mA average current will be installed in December 2007 in CEA-Saclay. Equipped with a tungsten target and moderator, it is aimed at producing rates of order 10{sup 8} s{sup -1} slow positrons. This setup is part of a project to demonstrate the feasibility of an experiment to produce the H-bar{sup +} ion for a free fall measurement of H-bar. The energy is below the neutron activation threshold. Its small size and cost could be of interest for a university laboratory or industry, and could be envisaged as a replacement source for the antihydrogen experiments at CERN.

  10. Spectra of neutrons and fusion charged products produced in a dense laser plasma

    International Nuclear Information System (INIS)

    Burtsev, V.A.; Dyatlov, V.D.; Krzhizhanovskij, R.E.; Levkovskij, A.A.

    1977-01-01

    The possibility of laser-produced plasma diagnostics has been investigated by measuring spectra of neutrons and alpha particles produced in the T(d,n) 4 He reaction. Using the Monte Carlo method the spectra have been calculated for nine states of the deuterium-tritium plasma with the temperature of 1;5 and 10 keV and the density of 0.2; 1 and 10 g/cm 3 respectively. The initial radius of the target was assumed to be 0.01 cm at the density of 0.2 g/cm 3 . It is shown that the neutron and alpha spectra can serve as plasma diagnostics parameters in laser fusion

  11. The application of selected radionuclides for monitoring of the D-D reactions produced by dense plasma-focus device.

    Science.gov (United States)

    Jednorog, S; Szydlowski, A; Bienkowska, B; Prokopowicz, R

    The dense plasma focus (DPF) device-DPF-1000U which is operated at the Institute of Plasma Physics and Laser Microfusion is the largest that type plasma experiment in the world. The plasma that is formed in large plasma experiments is characterized by vast numbers of parameters. All of them need to be monitored. A neutron activation method occupies a high position among others plasma diagnostic methods. The above method is off-line, remote, and an integrated one. The plasma which has enough temperature to bring about nuclear fusion reactions is always a strong source of neutrons that leave the reactions area and take along energy and important information on plasma parameters and properties as well. Silver as activated material is used as an effective way of neutrons measurement, especially when they are emitted in the form of short pulses like as it happens from the plasma produced in Dense Plasma-Focus devices. Other elements such as beryllium and yttrium are newly introduced and currently tested at the Institute of Plasma Physics and Laser Microfusion to use them in suitable activation neutron detectors. Some specially designed massive indium samples have been recently adopted for angular neutrons distribution measurements (vertical and horizontal) and have been used in the recent plasma experiment conducted on the DPF-1000U device. This choice was substantiated by relatively long half-lives of the neutron induced isotopes and the threshold character of the 115 In(n,n') 115m In nuclear reaction.

  12. X-ray spectroscopic characterization of laser produced hot dense plasmas

    International Nuclear Information System (INIS)

    Kontogiannopoulos, N.

    2007-12-01

    In this work we performed experiments of emission and absorption spectroscopy of laser produced plasmas, to provide well characterized spectral data which permit to benchmark atomic physics codes. More precisely, we produced xenon and krypton plasmas in NLTE (non local thermodynamic equilibrium) conditions and studied their emission spectra. In a second experiment, we characterized the absorption spectra of zinc sulfide and aluminium plasmas in LTE (local thermodynamic equilibrium) conditions.The first two chapters give an outline of the theory involved in the study of the emission and absorption plasma spectroscopy. Chapter 1 describes the different atomic processes occurring in a plasma. The LTE and the NLTE statistics ruling the equilibrium of the atomic processes are presented. Then, we give a brief description of the different codes of plasma atomic physics used in the analysis of our experimental data, namely HULLAC, SCO and TRANSPEC/AVERROES. In Chapter 2 the macroscopic theory of the radiation transport through a plasma is given. We describe also the self-similar model of Basko and the view factor approach, which permits us to calculate the heating conditions of the absorption foils achieved in the interior of the spherical gold cavity. Chapter 3 gives a description of the instruments used for realizing the two experiments, as well as the technical characteristics of the LULI2000 laser facility used to perform the experiments. Chapter 4 presents the experiment realized to characterize the emission spectra of the xenon and krypton plasmas in NLTE, as well the analysis of the experimental data with TRANSPEC/AVERROES. Finally, the experiment for measuring the absorption spectrum of the ZnS plasma mixture and the analysis of the experimental data with the code SCO are given in Chapter 5

  13. Nonlinear processes in laser-produced dense plasma (observation of the fractional harmonics)

    International Nuclear Information System (INIS)

    Lyu, K.S.

    1988-01-01

    One of the main issues of laser plasma physics interactions is harmonic generation. The harmonic emission spectrum provides clues as to which non-linear processes take place in the plasma. Several effects contribute to a given line as judged from the complexity of the actual spectra. Unfolding of them has not been done satisfactorily yet. Harmonic lines with half integer or integer orders have been observed, but the physics are far from complete. In this dissertation research, we observed the usual second harmonic generation and a set of fractional harmonics which we believe have been observed for the first time in plasma physics. The plasma was produced by a high power laser and we have characterized its properties from the analysis of the radiation spectra, including the harmonic lines, as measured using the methods of transient spectroscopy. We produced the plasma with a Nd:glass laser which had a 65 nsec pulse width (FWHM) with a total energy of up to 6 Joules. The targets were steel alloys, copper, and aluminum. The harmonic generation from the plasma with a planar metal target was not strong. But, it became stronger when we made a dead hole (cavity) at the laser spot on the target surface. The second harmonic line appears first before the time of the peak of laser pulse. The fractional harmonics, which are related to the laser wavelength by rational number other than integers or half integers, appear near or after the time of the laser peak and weaker in UV wavelength range but stronger if some atomic emission line are near by. To understand the plasma evolution better, we developed computer simulation codes. The codes contain all relevant processes necessary to compute the plasma evolution

  14. Synthesis of novel complexing macromolecular surfactants and study of their interactions with cobalt for the development of a decontamination process of textiles in dense CO2 medium

    International Nuclear Information System (INIS)

    Chirat, M.

    2012-01-01

    This study is about textile decontamination in dense CO 2 (liquid CO 2 or supercritical CO 2 ). The study is carried out in the framework of decontamination of textile used in the nuclear industry. The dense CO 2 offers an alternative to aqueous medium used in the current process which generates a huge quantity of contaminated aqueous effluent requiring a post-treatment. Cobalt is the targeted contamination and can be found as ionic species or particles. The cobalt extraction in dense CO 2 is achieved with an additive: a complexing CO 2 -philic/CO 2 -phobic macromolecular surfactant. Several types of additives were synthesized by controlled free radical polymerization: gradient copolymers made with CO 2 -philic groups (silicone-based or fluorinated moieties) and CO 2 -phobic complexing groups (aceto acetoxy, di-ethylphosphonate or phosphonic acid moieties). The copolymer behavior in dense CO 2 was determined by phase diagram measurements (cloud point method) and their self-assembly in dense CO 2 was investigated by small angle neutron scattering. The fluorinated copolymers were found advantageous in terms of solubility. Nevertheless, the silicone-based copolymers showed solubilities which are compatible with the process, therefore they are a good alternative to avoid fluorinated compounds which are unwanted in the conditioning of nuclear wastes. The study of cobalt complexation by the copolymers (UV-vis spectroscopy and inductively coupled plasma-mass spectroscopy) established relations between the type of complexing group and the affinity with the cobalt. The solubility of copolymer-cobalt complexes in dense CO 2 is similar to those of copolymers. Moreover, the self-assembly study of the complex revealed a low aggregation. Finally, the synthesized copolymers were used in particle or ionic decontamination processes. In the case of ionic decontamination process, a rate of 70% of decontamination was reached with the use of gradient copolymer poly(1

  15. Stopping power and energy loss cross section of a point charge penetrating through a dense medium of bound electrons

    International Nuclear Information System (INIS)

    Belkacem, A.; Sigmund, P.; Odense Univ.

    1989-01-01

    We have derived the dielectric function ε(k,ω) in the Lindhard approximation for a medium consisting of electrons individually bound by harmonic forces. The dielectric function is expressible in terms of a hypergeometric series and approaches well-known results in the limits of negligible binding, large momentum transfer, and long wavelength, respectively. The stopping power of a moving point charge scales very well with the shifted resonance frequency α 0 = (ω O 2 + ω P 2 ) 1/2 (ω O = oscillator frequency; ω P = plasma frequency) that follows from classical dispersion theory. The results differ noticeably from free-electron behavior even at rather high electron density. The discrete excitation levels of an isolated harmonic oscillator are increasingly shifted and broadened with increasing electron density. 15 refs., 2 figs

  16. Synergic and conflicting issues in planning underground use to produce energy in densely populated countries, as Italy

    International Nuclear Information System (INIS)

    Quattrocchi, Fedora; Boschi, Enzo; Spena, Angelo; Buttinelli, Mauro; Cantucci, Barbara; Procesi, Monia

    2013-01-01

    Highlights: ► In densely populated countries, the public need a synergic approach to produce low-carbon energy. ► The paper is mapping coexistent and different underground technologies to produce low-GHG energy. ► The paper calculate Energy Density Potential in Land – EDPL in terms of [GW h/ha/year]. ► Draw-plate technologies platforms (EU-ZEP, etc.) should merge using underground together. ► Synergies among the different uses of deep underground (up to 5000 m) jointing the energy lobbies. -- Abstract: In densely populated countries there is a growing and compelling need to use underground for different and possibly coexisting technologies to produce “low carbon” energy. These technologies include (i) clean coal combustion merged with CO 2 Capture and Storage (CCS); (ii) last-generation nuclear power or, in any case, safe nuclear wastes disposal, both “temporary” and “geological” somewhere in Europe (at least in one site): Nuclear wastes are not necessarily associated to nuclear power plants; (iii) safe natural gas (CH 4 ) reserves to allow consumption also when the foreign pipelines are less available or not available for geopolitical reasons and (iv) “low-space-consuming” renewables in terms of Energy Density Potential in Land (EDPL measured in [GW h/ha/year]) as geothermics. When geothermics is exploited as low enthalpy technology, the heat/cool production could be associated, where possible, to increased measures of “building efficiency”, low seismic risks building reworking and low-enthalpy heat managing. This is undispensable to build up “smart cities”. In any case the underground geological knowledge is prerequisite. All these technologies have been already proposed and defined by the International Energy Agency (IEA) Road Map 2009 as priorities for worldwide security: all need to use underground in a rational and safe manner. The underground is not renewable in most of case histories [10,11]. IEA recently matched and

  17. X-ray spectroscopic characterization of laser produced hot dense plasmas; Caracterisation par spectroscopie X de plasmas chauds et denses crees par lasers de puissance

    Energy Technology Data Exchange (ETDEWEB)

    Kontogiannopoulos, N

    2007-12-15

    In this work we performed experiments of emission and absorption spectroscopy of laser produced plasmas, to provide well characterized spectral data which permit to benchmark atomic physics codes. More precisely, we produced xenon and krypton plasmas in NLTE (non local thermodynamic equilibrium) conditions and studied their emission spectra. In a second experiment, we characterized the absorption spectra of zinc sulfide and aluminium plasmas in LTE (local thermodynamic equilibrium) conditions.The first two chapters give an outline of the theory involved in the study of the emission and absorption plasma spectroscopy. Chapter 1 describes the different atomic processes occurring in a plasma. The LTE and the NLTE statistics ruling the equilibrium of the atomic processes are presented. Then, we give a brief description of the different codes of plasma atomic physics used in the analysis of our experimental data, namely HULLAC, SCO and TRANSPEC/AVERROES. In Chapter 2 the macroscopic theory of the radiation transport through a plasma is given. We describe also the self-similar model of Basko and the view factor approach, which permits us to calculate the heating conditions of the absorption foils achieved in the interior of the spherical gold cavity. Chapter 3 gives a description of the instruments used for realizing the two experiments, as well as the technical characteristics of the LULI2000 laser facility used to perform the experiments. Chapter 4 presents the experiment realized to characterize the emission spectra of the xenon and krypton plasmas in NLTE, as well the analysis of the experimental data with TRANSPEC/AVERROES. Finally, the experiment for measuring the absorption spectrum of the ZnS plasma mixture and the analysis of the experimental data with the code SCO are given in Chapter 5.

  18. Hadrons in dense matter. Proceedings

    International Nuclear Information System (INIS)

    Buballa, M.; Noerenberg, W.; Schaefer, B.J.; Wambach, J.

    2000-03-01

    The following topics were dealt with: Elementary hadronic reactions, Delta dynamics in nuclei, in-medium s-wave ππ-correlations, strangeness in hot and dense matter, medium modifications of vector mesons and dilepton production, medium modifications of charmonium, thermal properties of hot and dense hadronic matter, nuclear matter, spectral functions and QCD sum rules

  19. Lipase-catalyzed acidolysis of canola oil with caprylic acid to produce medium-, long- and medium-chain-type structured lipids

    DEFF Research Database (Denmark)

    Wang, Yingyao; Xia, Luan; Xu, Xuebing

    2012-01-01

    Lipase-catalyzed acidolysis of canola oil with caprylic acid was performed to produce structured lipids (SLs) containing medium-chain fatty acid (M) at position sn-1,3 and long-chain fatty acid (L) at the sn-2 position in a solvent-free system. Six commercial lipases from different sources were...

  20. Development of a Selective Medium for the Fungal Pathogen Fusarium graminearum Using Toxoflavin Produced by the Bacterial Pathogen Burkholderia glumae

    Directory of Open Access Journals (Sweden)

    Boknam Jung

    2013-12-01

    Full Text Available The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting.

  1. Medium- and high-pressure gauges and transducers produced by laser welding technology

    Science.gov (United States)

    Daurelio, Giuseppe; Nenci, Fabio; Cinquepalmi, Massimo; Chita, Giuseppe

    1998-07-01

    Industrial manufacturers produce many types of pressure gauges and transducers according to the applications, for gas or liquid, for high-medium and low pressure ranges. Nowadays the current production technology generally prefers to weld by micro TIG source the metallic corrugated membranes to the gauge or transducer bodies for the products, operating on the low pressure or medium pressure ranges. For the other ones, operating to high pressure range, generally the two components of the transducers are both threaded only and threaded and then circularly welded by micro TIG for the other higher range, till to 1000 bar. In this work the products, operating on the approximately equals 30 divided by 200 bar, are considered. These, when assembled on industrial plants, as an outcome of a non-correct operating sequence, give a 'shifted' electrical signal. This is due to a shift of the 'zero electrical signal' that unbalances the electrical bridge - thin layer sensor - that is the sensitive part of the product. Moreover, for the same problem, often some mechanical settlings of the transducer happen during the first pressure semi-components, with an increasing of the product manufacturing costs. In light of all this, the above referred, in this work the whole transducer has been re-designed according to the specific laser welding technology requirements. On the new product no threaded parts exist but only a circular laser welding with a full penetration depth about 2.5 divided by 3 mm high. Three different alloys have been tested according to the applications and the mechanical properties requested to the transducer. By using a 1.5 KW CO2 laser system many different working parameters have been evaluated for correlating laser parameters to the penetration depths, crown wides, interaction laser-materia times, mechanical and metallurgical properties. Moreover during the laser welding process the measurements of the maximum temperature, reached by the transducer top, has been

  2. The entry of Brazilian fresh fruit small and medium producers into the global market

    Directory of Open Access Journals (Sweden)

    Roberta de Castro Souza

    2010-09-01

    Full Text Available The objective of this paper is to identify some elements which contribute to the entry of small and medium producers into the global market. Specifically, it analyses the case of the greatest Brazilian mango and grape exported region - the Petrolina-Juazeiro (P-J. The conceptual background consists of two approaches. The first conceptual framework is the Global Value Chain (GVC approach which is mainly concerned with the entry of local economies, from developing countries, into the global market. The second approach is the dynamic capability which is mainly concerned with the way the firm could acquire capabilities. The method selected for the empirical part was the multiple-case studies which were made viable by means of semi-structured questionnaires conducted with mango and grape producer agents from P-J Region in Brazil and European buyers. This study indicates that some institutions have been supporting the export activities in terms of irrigation techniques, new techniques of cultivation, financial support and the introduction of some certificates such as EurepGap. Lastly, the mango and grape producers have been undertaking upgrading of product, process and functional.O objetivo deste artigo foi identificar os elementos que contribuem para a entrada de pequenos e médios produtores no mercado global. Especificamente foi analisado o caso da maior região brasileira exportadora de manga e uva in natura, a de Petrolina (PE e Juazeiro (BA. Os aportes teóricos utilizados neste artigo foram: cadeia de valor global e capacitações dinâmicas. O método selecionado para a realização da parte empírica foi o estudo de casos múltiplos. Para a coleta de dados, foram elaborados questionários semi-estruturados e realizadas entrevistas presenciais com produtores de manga e uva, associações de produtores, instituições de apoio localizadas em Petrolina e Juazeiro e compradores europeus de manga e uva. O estudo indicou que algumas institui

  3. Use of medium-range numerical weather prediction model output to produce forecasts of streamflow

    Science.gov (United States)

    Clark, M.P.; Hay, L.E.

    2004-01-01

    This paper examines an archive containing over 40 years of 8-day atmospheric forecasts over the contiguous United States from the NCEP reanalysis project to assess the possibilities for using medium-range numerical weather prediction model output for predictions of streamflow. This analysis shows the biases in the NCEP forecasts to be quite extreme. In many regions, systematic precipitation biases exceed 100% of the mean, with temperature biases exceeding 3??C. In some locations, biases are even higher. The accuracy of NCEP precipitation and 2-m maximum temperature forecasts is computed by interpolating the NCEP model output for each forecast day to the location of each station in the NWS cooperative network and computing the correlation with station observations. Results show that the accuracy of the NCEP forecasts is rather low in many areas of the country. Most apparent is the generally low skill in precipitation forecasts (particularly in July) and low skill in temperature forecasts in the western United States, the eastern seaboard, and the southern tier of states. These results outline a clear need for additional processing of the NCEP Medium-Range Forecast Model (MRF) output before it is used for hydrologic predictions. Techniques of model output statistics (MOS) are used in this paper to downscale the NCEP forecasts to station locations. Forecasted atmospheric variables (e.g., total column precipitable water, 2-m air temperature) are used as predictors in a forward screening multiple linear regression model to improve forecasts of precipitation and temperature for stations in the National Weather Service cooperative network. This procedure effectively removes all systematic biases in the raw NCEP precipitation and temperature forecasts. MOS guidance also results in substantial improvements in the accuracy of maximum and minimum temperature forecasts throughout the country. For precipitation, forecast improvements were less impressive. MOS guidance increases

  4. DEEP HE ii AND C iv SPECTROSCOPY OF A GIANT LYα NEBULA: DENSE COMPACT GAS CLUMPS IN THE CIRCUMGALACTIC MEDIUM OF A z ∼ 2 QUASAR

    Energy Technology Data Exchange (ETDEWEB)

    Battaia, Fabrizio Arrigoni; Hennawi, Joseph F. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Prochaska, J. Xavier; Cantalupo, Sebastiano, E-mail: arrigoni@mpia.de [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2015-08-20

    The recent discovery by Cantalupo et al. of the largest (∼500 kpc) luminous (L ≃ 1.43 × 10{sup 45} erg s{sup −1}) Lyα nebula associated with the quasar UM287 (z = 2.279) poses a great challenge to our current understanding of the astrophysics of the halos hosting massive z ∼ 2 galaxies. Either an enormous reservoir of cool gas is required M ≃ 10{sup 12} M{sub ⊙}, exceeding the expected baryonic mass available, or one must invoke extreme gas clumping factors not present in high-resolution cosmological simulations. However, observations of Lyα emission alone cannot distinguish between these two scenarios. We have obtained the deepest ever spectroscopic integrations in the He ii λ1640 and C iv λ1549 emission lines with the goal of detecting extended line emission, but detect neither line to a 3σ limiting SB ≃ 10{sup −18} erg s{sup −1} cm{sup −2} arcsec{sup −2}. We construct simple models of the expected emission spectrum in the highly probable scenario that the nebula is powered by photoionization from the central hyper-luminous quasar. The non-detection of He ii implies that the nebular emission arises from a mass M{sub c} ≲ 6.4 × 10{sup 10} M{sub ⊙} of cool gas on ∼200 kpc scales, distributed in a population of remarkably dense (n{sub H} ≳ 3 cm{sup −3}) and compact (R ≲ 20 pc) clouds, which would clearly be unresolved by current cosmological simulations. Given the large gas motions suggested by the Lyα line (v ≃ 500 km s{sup −1}), it is unclear how these clouds survive without being disrupted by hydrodynamic instabilities. Our work serves as a benchmark for future deep integrations with current and planned wide-field IFU spectrographs such as MUSE, KCWI, and KMOS. Our observations and models suggest that a ≃10 hr exposure would likely detect ∼10 rest-frame UV/optical emission lines, opening up the possibility of conducting detailed photoionization modeling to infer the physical state of gas in the circumgalactic

  5. DEEP HE ii AND C iv SPECTROSCOPY OF A GIANT LYα NEBULA: DENSE COMPACT GAS CLUMPS IN THE CIRCUMGALACTIC MEDIUM OF A z ∼ 2 QUASAR

    International Nuclear Information System (INIS)

    Battaia, Fabrizio Arrigoni; Hennawi, Joseph F.; Prochaska, J. Xavier; Cantalupo, Sebastiano

    2015-01-01

    The recent discovery by Cantalupo et al. of the largest (∼500 kpc) luminous (L ≃ 1.43 × 10 45 erg s −1 ) Lyα nebula associated with the quasar UM287 (z = 2.279) poses a great challenge to our current understanding of the astrophysics of the halos hosting massive z ∼ 2 galaxies. Either an enormous reservoir of cool gas is required M ≃ 10 12 M ⊙ , exceeding the expected baryonic mass available, or one must invoke extreme gas clumping factors not present in high-resolution cosmological simulations. However, observations of Lyα emission alone cannot distinguish between these two scenarios. We have obtained the deepest ever spectroscopic integrations in the He ii λ1640 and C iv λ1549 emission lines with the goal of detecting extended line emission, but detect neither line to a 3σ limiting SB ≃ 10 −18 erg s −1 cm −2 arcsec −2 . We construct simple models of the expected emission spectrum in the highly probable scenario that the nebula is powered by photoionization from the central hyper-luminous quasar. The non-detection of He ii implies that the nebular emission arises from a mass M c ≲ 6.4 × 10 10 M ⊙ of cool gas on ∼200 kpc scales, distributed in a population of remarkably dense (n H ≳ 3 cm −3 ) and compact (R ≲ 20 pc) clouds, which would clearly be unresolved by current cosmological simulations. Given the large gas motions suggested by the Lyα line (v ≃ 500 km s −1 ), it is unclear how these clouds survive without being disrupted by hydrodynamic instabilities. Our work serves as a benchmark for future deep integrations with current and planned wide-field IFU spectrographs such as MUSE, KCWI, and KMOS. Our observations and models suggest that a ≃10 hr exposure would likely detect ∼10 rest-frame UV/optical emission lines, opening up the possibility of conducting detailed photoionization modeling to infer the physical state of gas in the circumgalactic medium

  6. Method for electrically producing dispersions of a nonconductive fluid in a conductive medium

    Science.gov (United States)

    DePaoli, David W.; Tsouris, Constantinos; Feng, James Q.

    1998-01-01

    A method for use in electrically forming dispersions of a nonconducting fluid in a conductive medium that minimizes power consumption, gas generation, and sparking between the electrode of the nozzle and the conductive medium. The method utilizes a nozzle having a passageway, the wall of which serves as the nozzle electrode, for the transport of the nonconducting fluid into the conductive medium. A second passageway provides for the transport of a flowing low conductivity buffer fluid which results in a region of the low conductivity buffer fluid immediately adjacent the outlet from the first passageway to create the necessary protection from high current drain and sparking. An electrical potential difference applied between the nozzle electrode and an electrode in contact with the conductive medium causes formation of small droplets or bubbles of the nonconducting fluid within the conductive medium. A preferred embodiment has the first and second passageways arranged in a concentric configuration, with the outlet tip of the first passageway withdrawn into the second passageway.

  7. Factors stimulating riboflavin produced by Lactobacillus plantarum CRL 725 grown in a semi-defined medium.

    Science.gov (United States)

    Juarez Del Valle, Marianela; Laiño, Jonathan Emiliano; Savoy de Giori, Graciela; LeBlanc, Jean Guy

    2017-03-01

    Riboflavin (vitamin B 2 ) is one of the B-group water-soluble vitamins and is essential for energy metabolism of the cell. The aim of this study was to determine factors that affect riboflavin production by Lactobacillus (L.) plantarum CRL 725 grown in a semi defined medium and evaluate the expression of its rib genes. The factors found to enhance riboflavin production in this medium were incubation at 30 °C, and the addition of specific medium constituents, such as casamino acids (10 g L -1 ), guanosine (0.04 g L -1 ), and sucrose as carbon source (20 g L -1 ). In these conditions, higher riboflavin concentrations were directly associated with significant increases in the expression of ribA, ribB, and ribC genes. The culture conditions defined in this work and its application to a roseoflavin resistant mutant of L. plantarum allowed for a sixfold increase in riboflavin concentrations in our semi-defined medium which were also significantly higher than those obtained previously using the same strain to ferment soymilk. These conditions should thus be evaluated to increase vitamin production in fermented foods. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Properties of medium-density fiberboard produced in an oil-heated laboratory press

    Science.gov (United States)

    O. Suchsland; G.E. Woodson

    1976-01-01

    Medium-density fiberboards from pressurized double-disk refined fibers have a close correlation between layer density and layer dynamic modulus of elasticity. Density distribution over the thickness was readily controlled by manipulating platen temperature and applied pressure. Thus, overall modulus of elasticity could be adjusted. In contrast to modulus of elasticity...

  9. Theory and experimental show up of axial magnetic fields self-generated in dense laser-produced plasmas

    International Nuclear Information System (INIS)

    El Tamer, M.

    1986-09-01

    The work presented in this thesis concerns the magnetic fields generated in laser produced plasma. A summary of the theoretical and experimental studies concerning the toroidal magnetic fields and realised by different groups of research is presented. Then, we present our original contribution on the generation of axial magnetic fields by the dynamo effect. The experimental work for the detection of magnetic field is based on the Faraday rotation and Zeeman effects. The experimental diagrams are detailed and discussed. The experimental results are presented and compared to the theory. Finaly, we present some consequences of the generation of the axial magnetic fields in laser produced plasma as a discussion of the thermal conductivity [fr

  10. Extracellular Enzymes Produced by the Cultivated Mushroom Lentinus edodes during Degradation of a Lignocellulosic Medium

    Science.gov (United States)

    Leatham, Gary F.

    1985-01-01

    Although the commercially important mushroom Lentinus (= Lentinula) edodes (Berk.) Sing. can be rapidly cultivated on supplemented wood particles, fruiting is not reliable. This study addressed the problem by developing more information about growth and development on a practical oakwood-oatmeal medium. The study determined (i) the components degraded during a 150-day incubation at 22°C, (ii) the apparent vegetative growth pattern, (iii) the likely growth-limiting nutrient, and (iv) assays that can be used to study key extracellular enzymes. All major components of the medium were degraded, lignin selectively so. The vegetative growth rate was most rapid during the initial 90 days, during which weight loss correlated with glucosamine accumulation (assayed after acid hydrolysis). The rate then slowed; in apparent preparation for fruiting, the cultures rapidly accumulated glucosamine (or its oligomer or polymer). Nitrogen was growth limiting. Certain enzyme activities were associated with the pattern of medium degradation, with growth, or with development. They included cellulolytic system enzymes, hemicellulases, the ligninolytic system, (gluco-)amylase, pectinase, acid protease, cell wall lytic enzymes (laminarinase, 1,4-β-d-glucosidase, β-N-acetyl-d-glucosaminidase, α-d-galactosidase, β-d-mannosidase), acid phosphatase, and laccase. Enzyme activities over the 150-day incubation period with and without a fruiting stimulus are reported. These results provide a basis for future investigations into the physiology and biochemistry of growth and fruiting. PMID:16346918

  11. Medium-Throughput Screen of Microbially Produced Serotonin via a G-Protein-Coupled Receptor-Based Sensor.

    Science.gov (United States)

    Ehrenworth, Amy M; Claiborne, Tauris; Peralta-Yahya, Pamela

    2017-10-17

    Chemical biosensors, for which chemical detection triggers a fluorescent signal, have the potential to accelerate the screening of noncolorimetric chemicals produced by microbes, enabling the high-throughput engineering of enzymes and metabolic pathways. Here, we engineer a G-protein-coupled receptor (GPCR)-based sensor to detect serotonin produced by a producer microbe in the producer microbe's supernatant. Detecting a chemical in the producer microbe's supernatant is nontrivial because of the number of other metabolites and proteins present that could interfere with sensor performance. We validate the two-cell screening system for medium-throughput applications, opening the door to the rapid engineering of microbes for the increased production of serotonin. We focus on serotonin detection as serotonin levels limit the microbial production of hydroxystrictosidine, a modified alkaloid that could accelerate the semisynthesis of camptothecin-derived anticancer pharmaceuticals. This work shows the ease of generating GPCR-based chemical sensors and their ability to detect specific chemicals in complex aqueous solutions, such as microbial spent medium. In addition, this work sets the stage for the rapid engineering of serotonin-producing microbes.

  12. Performance summary on a high power dense plasma focus x-ray lithography point source producing 70 nm line features in AlGaAs microcircuits

    International Nuclear Information System (INIS)

    Petr, Rodney; Bykanov, Alexander; Freshman, Jay; Reilly, Dennis; Mangano, Joseph; Roche, Maureen; Dickenson, Jason; Burte, Mitchell; Heaton, John

    2004-01-01

    A high average power dense plasma focus (DPF), x-ray point source has been used to produce ∼70 nm line features in AlGaAs-based monolithic millimeter-wave integrated circuits (MMICs). The DPF source has produced up to 12 J per pulse of x-ray energy into 4π steradians at ∼1 keV effective wavelength in ∼2 Torr neon at pulse repetition rates up to 60 Hz, with an effective x-ray yield efficiency of ∼0.8%. Plasma temperature and electron concentration are estimated from the x-ray spectrum to be ∼170 eV and ∼5·10 19 cm -3 , respectively. The x-ray point source utilizes solid-state pulse power technology to extend the operating lifetime of electrodes and insulators in the DPF discharge. By eliminating current reversals in the DPF head, an anode electrode has demonstrated a lifetime of more than 5 million shots. The x-ray point source has also been operated continuously for 8 h run times at 27 Hz average pulse recurrent frequency. Measurements of shock waves produced by the plasma discharge indicate that overpressure pulses must be attenuated before a collimator can be integrated with the DPF point source

  13. The environmental performance of three alcohol fuel plants producers of small, medium and big scale

    International Nuclear Information System (INIS)

    Borrero, Manuel Antonio Valdes; Pereira, Jose Tomaz Vieira; Miranda, Evaristo Eduardo de

    1999-01-01

    The article discusses the following issues of alcohol fuel plants producers: sizing; performance; natural resources; environmental aspects; and electric power generation. The environmental performance concept is introduced and a performance evaluation methodology are presented and applied. The results are also presented and criticized

  14. Simplified method for preparation of concentrated exoproteins produced by Staphylococcus aureus grown on surface of cellophane bag containing liquid medium.

    Science.gov (United States)

    Ikigai, H; Seki, K; Nishihara, S; Masuda, S

    1988-01-01

    A simplified method for preparation of concentrated exoproteins including protein A and alpha-toxin produced by Staphylococcus aureus was successfully devised. The concentrated proteins were obtained by cultivating S. aureus organisms on the surface of a liquid medium-containing cellophane bag enclosed in a sterilized glass flask. With the same amount of medium, the total amount of proteins obtained by the method presented here was identical with that obtained by conventional liquid culture. The concentration of proteins obtained by the method, however, was high enough to observe their distinct bands stained on polyacrylamide gel electrophoresis. This method was considered quite useful not only for large-scale cultivation for the purification of staphylococcal proteins but also for small-scale study using the proteins. The precise description of the method was presented and its possible usefulness was discussed.

  15. Medium dependence of vector meson properties in heavy ion collisions

    International Nuclear Information System (INIS)

    Faessler, Amand; Fuchs, Christian

    2007-01-01

    Heavy ion collisions produce dense and hot nuclear matter. Dileptons give information about this hot and dense phase. The dileptons are produced by vector mesons. Theoretical calculation of dilepton production in the DLS (Berkeley), the HADES (GSI) experiments and the CERES, HELIOS and NA60 data from CERN give information about possible modifications of the vector meson properties in hot and dense nuclear matter. Here the description in relativistic quantum molecular dynamics of heavy ion collisions and dilepton production are presented and compared with data. (authors) Key words: heavy ion collisions; dense and hot nuclear matter; dileptons; medium dependence

  16. Study of discharges produced by surface waves under medium and high pressure: application to chemical analysis

    International Nuclear Information System (INIS)

    Laye epouse Granier, Agnes

    1986-01-01

    This report deals with the study of microwave discharges produced in argon gas by surface waves in the 20-760 Torr pressure range. Application to chemical analysis by emission optical spectroscopy is also investigated. First of all we study the propagation of a surface wave in a bounded plasma in which the effective collision frequency for momentum transfer ν is higher than the excitation one. The axial electron density profile is determined from two diagnostic techniques, i.e., phase variations of the wave field and Stark broadening of H β line. Then we deduce the discharge characteristics ν, θ (maintaining power of an electron-ion pair) and E eff (effective electric field for discharge sustaining) from the electron density profile. Then an energy balance of the discharge is developed. It explains the change of operating conditions in the 20-50 Torr range. At low pressure the discharge is governed by ambipolar diffusion whereas at high pressure, the electrons are mainly lost by volume recombination of Ar 2 + . Finally, we report on chemical analysis experiment of gases (optimum sensibility in found near 100 Torr) and of metallic solutions sprayed by a graphite oven. Performances of such a design and ICP plasma torches are compared. (author) [fr

  17. Effects of oxidizing medium on the composition, morphology and optical properties of copper oxide nanoparticles produced by pulsed laser ablation

    KAUST Repository

    Gondal, M. A.; Qahtan, Talal F.; Dastageer, Mohamed Abdulkader; Saleh, Tawfik A.; Maganda, Yasin W.; Anjum, Dalaver H.

    2013-01-01

    Pulsed laser ablation in liquid (PLAL) with 532 nm wavelength laser with 5 ns pulse duration is used to produce the nanostructure copper oxide and the effects of oxidizing media (deionized water and hydrogen peroxide) on the composition, morphology and optical properties of the product materials produced by PLAL were studied. XRD and TEM studies indicate that in the absence of hydrogen peroxide, the product material is in two phases (Cu/Cu2O) with the spherical nanoparticle structure, whereas in the presence of hydrogen peroxide in the liquid medium, the product material revealed other two phases (Cu/CuO) with nanorod-like structure. The optical studies revealed a considerable red shift (3.34-2.5 eV) in the band gap energy in the case of hydrogen peroxide in the liquid medium in PLAL synthesis compared to the one in the absence of it. Also the product material in the presence of hydrogen peroxide in the liquid medium showed a reduced photoluminescence intensity indicating the reduced electron-hole recombination rate. The red shift in the band gap energy and the reduced electron-hole recombination rate make the product material an ideal photocatalyst to harvest solar radiation for various applications. The most relevant signals on the FTIR spectrum for the samples are the absorption bands in the region between 450 and 700 cm-1 which are the characteristics bands of copperoxygen bonds. The reported laser ablation approach for the synthesis of Cu2O and CuO nanoparticles has the advantages of being clean method with controlled particle properties. © 2013 Elsevier B.V. All rights reserved.

  18. Effects of oxidizing medium on the composition, morphology and optical properties of copper oxide nanoparticles produced by pulsed laser ablation

    KAUST Repository

    Gondal, M. A.

    2013-12-01

    Pulsed laser ablation in liquid (PLAL) with 532 nm wavelength laser with 5 ns pulse duration is used to produce the nanostructure copper oxide and the effects of oxidizing media (deionized water and hydrogen peroxide) on the composition, morphology and optical properties of the product materials produced by PLAL were studied. XRD and TEM studies indicate that in the absence of hydrogen peroxide, the product material is in two phases (Cu/Cu2O) with the spherical nanoparticle structure, whereas in the presence of hydrogen peroxide in the liquid medium, the product material revealed other two phases (Cu/CuO) with nanorod-like structure. The optical studies revealed a considerable red shift (3.34-2.5 eV) in the band gap energy in the case of hydrogen peroxide in the liquid medium in PLAL synthesis compared to the one in the absence of it. Also the product material in the presence of hydrogen peroxide in the liquid medium showed a reduced photoluminescence intensity indicating the reduced electron-hole recombination rate. The red shift in the band gap energy and the reduced electron-hole recombination rate make the product material an ideal photocatalyst to harvest solar radiation for various applications. The most relevant signals on the FTIR spectrum for the samples are the absorption bands in the region between 450 and 700 cm-1 which are the characteristics bands of copperoxygen bonds. The reported laser ablation approach for the synthesis of Cu2O and CuO nanoparticles has the advantages of being clean method with controlled particle properties. © 2013 Elsevier B.V. All rights reserved.

  19. Influence of galactic arm scale dynamics on the molecular composition of the cold and dense ISM. I. Observed abundance gradients in dense clouds

    Science.gov (United States)

    Ruaud, M.; Wakelam, V.; Gratier, P.; Bonnell, I. A.

    2018-04-01

    Aim. We study the effect of large scale dynamics on the molecular composition of the dense interstellar medium during the transition between diffuse to dense clouds. Methods: We followed the formation of dense clouds (on sub-parsec scales) through the dynamics of the interstellar medium at galactic scales. We used results from smoothed particle hydrodynamics (SPH) simulations from which we extracted physical parameters that are used as inputs for our full gas-grain chemical model. In these simulations, the evolution of the interstellar matter is followed for 50 Myr. The warm low-density interstellar medium gas flows into spiral arms where orbit crowding produces the shock formation of dense clouds, which are held together temporarily by the external pressure. Results: We show that depending on the physical history of each SPH particle, the molecular composition of the modeled dense clouds presents a high dispersion in the computed abundances even if the local physical properties are similar. We find that carbon chains are the most affected species and show that these differences are directly connected to differences in (1) the electronic fraction, (2) the C/O ratio, and (3) the local physical conditions. We argue that differences in the dynamical evolution of the gas that formed dense clouds could account for the molecular diversity observed between and within these clouds. Conclusions: This study shows the importance of past physical conditions in establishing the chemical composition of the dense medium.

  20. Satellite and ground detection of very dense smoke clouds produced on the islands of the Paraná river delta that affected a large region in Central Argentina

    Science.gov (United States)

    Ipiña, A.; Salum, G. M.; Crinó, E.; Piacentini, R. D.

    2012-03-01

    Intense fires were produced on the Paraná river delta islands, Argentina, during most part of 2008, by a combination of an exceptionally dry period and the farmers' use of a fire land-cleaning technique. In April 2008, those fires significantly affected the nearby regions and their inhabitants, from Rosario city to Buenos Aires mega-city. In this work we present satellite as well as ground Aerosol Optical Depth (AOD) at 550 nm data obtained during the propagation of pollution clouds to the central zone of Argentina. The highest value (1.18) was registered at Buenos Aires by atmospheric remote sensing, using the satellite instrument MODIS/Terra on April 18th 2008 at 10:35 local time (= UT - 3 h). On the same day, ground air quality detectors also measured in this city the highest Total Suspended Particle (TSP) value of the month, 2.02 mg/m3. The AOD(550) daily variation at Rosario Astronomical Observatory, which is located near the Paraná riverside, was derived by combining solar ultraviolet erythemal irradiance data (measured with a YES biometre) with model calculations. On April 25th 2008, from 12:00 to 15:30 local time, a rather high and constant AOD(550) value was registered, with a mean value of (0.90 ± 0.21). Cities located on the side of the Rosario-Buenos Aires highway (San Nicolás, Baradero and San Pedro) were also affected, showing a mean AOD(550) between the Rosario and Buenos Aires values. The particulate matter was collected with gridded samplers placed on the Paraná river islands as well as at the Rosario Observatory. They were analysed with a Scanning Electron Microscope (SEM) and mainly showed a biological origin. Even if normally large particles travel small distances from the source, organic aerosol in the range of 40-100 μm and complex asymmetric structures were registered several kilometres away from the aerosol sources on the islands. Another event of intense UV index attenuation (98.6%) occurred on September 18th 2008, due to very dense

  1. Warm-hot gas in X-ray bright galaxy clusters and the H I-deficient circumgalactic medium in dense environments

    Science.gov (United States)

    Burchett, Joseph N.; Tripp, Todd M.; Wang, Q. Daniel; Willmer, Christopher N. A.; Bowen, David V.; Jenkins, Edward B.

    2018-04-01

    We analyse the intracluster medium (ICM) and circumgalactic medium (CGM) in seven X-ray-detected galaxy clusters using spectra of background quasi-stellar objects (QSOs) (HST-COS/STIS), optical spectroscopy of the cluster galaxies (MMT/Hectospec and SDSS), and X-ray imaging/spectroscopy (XMM-Newton and Chandra). First, we report a very low covering fraction of H I absorption in the CGM of these cluster galaxies, f_c = 25^{+25}_{-15} {per cent}, to stringent detection limits (N(H I) detect O VI in any cluster, and we only detect BLA features in the QSO spectrum probing one cluster. We estimate that the total column density of warm-hot gas along this line of sight totals to ˜ 3 per cent of that contained in the hot T > 107 K X-ray emitting phase. Residing at high relative velocities, these features may trace pre-shocked material outside the cluster. Comparing gaseous galaxy haloes from the low-density `field' to galaxy groups and high-density clusters, we find that the CGM is progressively depleted of H I with increasing environmental density, and the CGM is most severely transformed in galaxy clusters. This CGM transformation may play a key role in environmental galaxy quenching.

  2. Esterification for butyl butyrate formation using Candida cylindracea lipase produced from palm oil mill effluent supplemented medium

    Directory of Open Access Journals (Sweden)

    Aliyu Salihu

    2014-12-01

    Full Text Available The ability of Candida cylindracea lipase produced using palm oil mill effluent (POME as a basal medium to catalyze the esterification reaction for butyl butyrate formation was investigated. Butyric acid and n-butanol were used as substrates at different molar ratios. Different conversion yields were observed according to the affinity of the produced lipase toward the substrates. The n-butanol to butyric acid molar ratio of 8 and lipase concentration of 75 U/mg gave the highest butyl butyrate formation of 63.33% based on the statistical optimization using face centered central composite design (FCCCD after 12 h reaction. The esterification potential of the POME based lipase when compared with the commercial lipase from the same strain using the optimum levels was found to show a similar pattern. It can be concluded therefore that the produced lipase possesses appropriate characteristics to be used as a biocatalyst in the esterification reactions for butyl butyrate formation.

  3. Readability of HIV/AIDS educational materials: the role of the medium of communication, target audience, and producer characteristics.

    Science.gov (United States)

    Wells, J A

    1994-12-01

    The reading difficulty of many HIV/AIDS brochures and pamphlets limits their effectiveness. This analysis addresses correlates of readability in 136 HIV/AIDS educational items. Readability is measured using the SMOG Index. The medium of communication is significantly related to readability: comic books and brochures are, on average, more readable than books and pamphlets (10.9 versus 11.9). The target audience also differentiates readability. Materials for HIV antibody test seekers, the general community, and sexually active adults have a more difficult reading grade, averaging 12.1, whereas materials for ethnic minorities average a more readable 9.2. The producer organization's type and location are unrelated to readability, but an AIDS-specific organizational focus correlates with better readability (grade 10.8 vs. 11.8). These findings remain significant in multivariate analysis. The results indicate that brochures and comics are more likely to be comprehended by low-literacy populations, that an understanding of the literacy of target audiences is needed to produce materials with appropriate reading levels, and that policies to influence producer organizations may result in the creation of more readable materials.

  4. Megasphaera hexanoica sp. nov., a medium-chain carboxylic acid-producing bacterium isolated from a cow rumen.

    Science.gov (United States)

    Jeon, Byoung Seung; Kim, Seil; Sang, Byoung-In

    2017-07-01

    Strain MHT, a strictly anaerobic, Gram-stain-negative, non-spore-forming, spherical coccus or coccoid-shaped microorganism, was isolated from a cow rumen during a screen for hexanoic acid-producing bacteria. The microorganism grew at 30-40 °C and pH 5.5-7.5 and exhibited production of various short- and medium-chain carboxylic acids (acetic acid, butyric acid, pentanoic acid, isobutyric acid, isovaleric acid, hexanoic acid, heptanoic acid and octanoic acid), as well as H2 and CO2 as biogas. Phylogenetic analysis based on 16S rRNA gene sequencing demonstrated that MHT represents a member of the genus Megasphaera, with the closest relatives being Megapsphaera indica NMBHI-10T (94.1 % 16S rRNA sequence similarity), Megasphaera elsdenii DSM 20460T (93.8 %) and Megasphaera paucivorans DSM 16981T (93.8 %). The major cellular fatty acids produced by MHT included C12 : 0, C16 : 0, C18 : 1cis 9, and C18 : 0, and the DNA G+C content of the MHT genome is 51.8 mol%. Together, the distinctive phenotypic and phylogenetic characteristics of MHT indicate that this microorganism represents a novel species of the genus Megasphaera, for which the name Megasphaera hexanoica sp. nov. is herein proposed. The type strain of this species is MHT (=KCCM 43214T=JCM 31403T).

  5. Determination of the extent of reduction of dense UO{sub 2} cathodes from direct electrochemical reduction studies in molten chloride medium

    Energy Technology Data Exchange (ETDEWEB)

    Sri Maha Vishnu, D.; Sanil, N. [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Murugesan, N. [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Shakila, L. [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Ramesh, C. [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Mohandas, K.S., E-mail: ksmd@igcar.gov.in [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Nagarajan, K. [Fuel Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2012-08-15

    Electro-reduction of solid UO{sub 2} to U has been studied with molten CaCl{sub 2} or LiCl as the electrolyte medium. Electro-reduction of thick (>3 mm), powder compacted and sintered pellets of UO{sub 2} showed incomplete reduction resulting in a mixture of uranium metal and UO{sub 2}. The extent of reduction of UO{sub 2} to U was determined by employing a novel method called 'metal estimation by hydrogen sensor (MEHS)', in which the hydrogen evolved during the reaction of U metal in the reduced product with con. HBr was measured using an in-house developed polymer electrolyte based amperometric hydrogen sensor. The results of our investigations on incompletely reduced UO{sub 2} pellets in both CaCl{sub 2} and LiCl melts showed that the extent of reduction of different regions of the oxide pellet was different. It varied from 88.3% on the surface of the pellet as against 3.7% towards the centre bulk during electro-reduction in CaCl{sub 2} (at 1173 K). The metallisation was found restricted to the surface of the pellets reduced in LiCl melt (at 923 K). Electro-reduction of small chunks of UO{sub 2} pellet in CaCl{sub 2} melt resulted in products with lower extent of reduction. Based on the measurements, a probable mechanism on the propagation of reduction through the solid UO{sub 2} matrix during the electrochemical reduction process has been proposed.

  6. Unified approach to dense matter

    International Nuclear Information System (INIS)

    Park, Byung-Yoon; Lee, Hee-Jung; Vento, Vicente; Kim, Joon-Il; Min, Dong-Pil; Rho, Mannque

    2005-01-01

    We apply the Skyrme model to dense hadronic matter, which provides a unified approach to high density, valid in the large N c limit. In our picture, dense hadronic matter is described by the classical soliton configuration with minimum energy for the given baryon number density. By incorporating the meson fluctuations on such ground state we obtain an effective Lagrangian for meson dynamics in a dense medium. Our starting point has been the Skyrme model defined in terms of pions, thereafter we have extended and improved the model by incorporating other degrees of freedom such as dilaton, kaons and vector mesons

  7. Stress- and sequence-dependent release into the culture medium of HIV-1 Nef produced in Saccharomyces cerevisiae.

    Science.gov (United States)

    Macreadie, I G; Castelli, L A; Lucantoni, A; Azad, A A

    1995-09-11

    We have produced human immunodeficiency virus type 1 (HIV-1) Nef (a myristylated 206-amino-acid protein) in Saccharomyces cerevisaie and shown that, while Nef is normally found as a predominantly intracellular protein, amounts up to 40 micrograms/ml of Nef are also released into the extracellular medium during stress. By electrophoretic (SDS-PAGE) analysis the extracellular Nef is indistinguishable from intracellular Nef. Conditions of stress that lead to the release of Nef include elevated levels of copper or magnesium ions or growth at elevated temperatures. This release appears to be dependent upon the N-terminal sequences of Nef, including the presence of a myristylation site. Our observations concerning Nef release in yeast suggest new ways in which the behaviour of Nef should be examined in order to gain further insights into the development of AIDS. If the release of Nef is important in the development of AIDS, our work reveals that Nef-associated symptoms may be reduced or delayed by reducing stresses, such as fevers.

  8. Re-energizing energy supply: Electrolytically-produced hydrogen as a flexible energy storage medium and fuel for road transport

    Science.gov (United States)

    Emonts, Bernd; Schiebahn, Sebastian; Görner, Klaus; Lindenberger, Dietmar; Markewitz, Peter; Merten, Frank; Stolten, Detlef

    2017-02-01

    "Energiewende", which roughly translates as the transformation of the German energy sector in accordance with the imperatives of climate change, may soon become a byword for the corresponding processes most other developed countries are at various stages of undergoing. Germany's notable progress in this area offers valuable insights that other states can draw on in implementing their own transitions. The German state of North Rhine-Westphalia (NRW) is making its own contribution to achieving the Energiewende's ambitious objectives: in addition to funding an array of 'clean and green' projects, the Virtual Institute Power to Gas and Heat was established as a consortium of seven scientific and technical organizations whose aim is to inscribe a future, renewable-based German energy system with adequate flexibility. Thus, it is tasked with conceiving of and evaluating suitable energy path options. This paper outlines one of the most promising of these pathways, which is predicated on the use of electrolytically-produced hydrogen as an energy storage medium, as well as the replacement of hydrocarbon-based fuel for most road vehicles. We describe and evaluate this path and place it in a systemic context, outlining a case study from which other countries and federated jurisdictions therein may draw inspiration.

  9. Studying dense plasmas with coherent XUV pulses

    International Nuclear Information System (INIS)

    Stabile, H.

    2006-12-01

    The investigation of dense plasma dynamic requires the development of diagnostics able to ensure the measurement of electronic density with micro-metric space resolution and sub-nanosecond, or even subpicosecond, time resolution (indeed this must be at least comparable with the characteristic tune scale of plasma evolution). In contrast with low-density plasmas, dense plasmas cannot be studied using optical probes in the visible domain, the density range accessible being limited to the critical density (N c equals 1.1*10 21 λ -2 (μm) ∼ 10 21 cm -3 for infrared). In addition, light is reflected even at smaller densities if the medium exhibits sharp density gradients. Hence probing of dense plasmas, for instance those produced by laser irradiation of solids, requires using shorter wavelength radiation. Thanks to their physical properties, high order harmonics generated in rare gases are particularly adapted to the study of dense plasmas. Indeed, they can naturally be synchronized with the generating laser and their pulse duration is very short, which makes it possible to use them in pump-probe experiments. Moreover, they exhibit good spatial and temporal coherencies. Two types of diagnostics were developed during this thesis. The first one was used to study the instantaneous creation of hot-solid-density plasma generated by focusing a femtosecond high-contrast laser on an ultra-thin foil (100 nm) in the 10 18 W/cm 2 intensity regime. The use of high order harmonics, providing a probe beam of sufficiently short wavelengths to penetrate such a medium, enables the study of its dynamics on the 100 fs time scale. The second one uses the harmonics beam as probe beam (λ equals 32 nm) within an interferometric device. This diagnostic was designed to ensure a micro-metric spatial resolution and a temporal resolution in the femtosecond range. The first results in presence of plasma created by irradiation of an aluminum target underline the potentialities of this new

  10. Size properties of colloidal nanoparticles produced by nanosecond pulsed laser ablation and studying the effects of liquid medium and laser fluence

    International Nuclear Information System (INIS)

    Mahdieh, Mohammad Hossein; Fattahi, Behzad

    2015-01-01

    Highlights: • Colloidal aluminum- and titanium-based nanoparticles fabricated by laser ablation. • Various liquid environments and laser fluences were applied as variable parameters. • Physical characteristics of liquid medium influence ablation process and nanoparticle formation. • Size properties of prepared nanoparticles depend on liquid medium and laser fluence. • Ablation of both metals in ethanol results in nanoparticles with smaller size. - Abstract: In this paper, pulsed laser ablation method was used for synthesis of colloidal nanoparticles of aluminum and titanium targets in distilled water, ethanol, and acetone as liquid environments. Ultraviolet–visible (UV–vis) absorption spectrophotometer and scanning electron microscope (SEM) were used for characterization of produced nanoparticles. Using image processing technique and analyzing the SEM images, nanoparticles’ mean size and size distribution were achieved. The results show that liquid medium has strong effect on size properties of produced nanoparticles. From the results, it was found that ablation of both metal targets in ethanol medium leads to formation of smaller size nanoparticles with narrower size distributions. The influence of laser fluence was also investigated. According to the results, higher laser fluence produces larger mean size nanoparticles with broader size distribution

  11. Size properties of colloidal nanoparticles produced by nanosecond pulsed laser ablation and studying the effects of liquid medium and laser fluence

    Energy Technology Data Exchange (ETDEWEB)

    Mahdieh, Mohammad Hossein, E-mail: mahdm@iust.ac.ir; Fattahi, Behzad

    2015-02-28

    Highlights: • Colloidal aluminum- and titanium-based nanoparticles fabricated by laser ablation. • Various liquid environments and laser fluences were applied as variable parameters. • Physical characteristics of liquid medium influence ablation process and nanoparticle formation. • Size properties of prepared nanoparticles depend on liquid medium and laser fluence. • Ablation of both metals in ethanol results in nanoparticles with smaller size. - Abstract: In this paper, pulsed laser ablation method was used for synthesis of colloidal nanoparticles of aluminum and titanium targets in distilled water, ethanol, and acetone as liquid environments. Ultraviolet–visible (UV–vis) absorption spectrophotometer and scanning electron microscope (SEM) were used for characterization of produced nanoparticles. Using image processing technique and analyzing the SEM images, nanoparticles’ mean size and size distribution were achieved. The results show that liquid medium has strong effect on size properties of produced nanoparticles. From the results, it was found that ablation of both metal targets in ethanol medium leads to formation of smaller size nanoparticles with narrower size distributions. The influence of laser fluence was also investigated. According to the results, higher laser fluence produces larger mean size nanoparticles with broader size distribution.

  12. Hyperons in dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Dapo, Haris

    2009-01-28

    The hyperon-nucleon YN low momentum effective interaction (V{sub low} {sub k}) allows for an extensive study of the behavior of hyperons in dense matter, together with an investigation of effects of the presence of hyperons on dense matter. The first step towards this goal is the construction of the matrix elements for the hyperon-nucleon low momentum potential. In order to assess the different properties of hyperons within these potentials we calculate the hyperon single-particle potentials in the Hartree-Fock approximation for all of the interactions. Their dependence on both momentum and density, is studied. The single-particle potentials are then used to determine the chemical potential of hyperons in neutron stars. For nucleonic properties, the nucleon-nucleon V{sub low} {sub k} can be used with the caveat that the calculation of the ground-state energy of symmetric nuclear matter does not correctly reproduce the properties of matter at saturation. With the nucleon-nucleon V{sub low} {sub k} one is unable to reach the densities needed for the calculation of neutron star masses. To circumvent this problem we use two approaches: in the first one, we parametrize the entire nucleonic sector. In the second one, we replace only the three-body force. The former will enable us to study neutron star masses, and the latter for studying the medium's response to the external probe. In this thesis we take the external probe to be the neutrino. By combining this parametrization with the YN V{sub low} {sub k} potential, we calculate the equation of state of equilibrated matter. Performing the calculation in the Hartree-Fock approximation at zero temperature, the concentrations of all particles are calculated. From these we can ascertain at which densities hyperons appear for a wide range of parameters. Finally, we calculate the masses of neutron stars with these concentrations. For the calculation of the medium's response to an external probe, we replace the three

  13. Hyperons in dense matter

    International Nuclear Information System (INIS)

    Dapo, Haris

    2009-01-01

    The hyperon-nucleon YN low momentum effective interaction (V low k ) allows for an extensive study of the behavior of hyperons in dense matter, together with an investigation of effects of the presence of hyperons on dense matter. The first step towards this goal is the construction of the matrix elements for the hyperon-nucleon low momentum potential. In order to assess the different properties of hyperons within these potentials we calculate the hyperon single-particle potentials in the Hartree-Fock approximation for all of the interactions. Their dependence on both momentum and density, is studied. The single-particle potentials are then used to determine the chemical potential of hyperons in neutron stars. For nucleonic properties, the nucleon-nucleon V low k can be used with the caveat that the calculation of the ground-state energy of symmetric nuclear matter does not correctly reproduce the properties of matter at saturation. With the nucleon-nucleon V low k one is unable to reach the densities needed for the calculation of neutron star masses. To circumvent this problem we use two approaches: in the first one, we parametrize the entire nucleonic sector. In the second one, we replace only the three-body force. The former will enable us to study neutron star masses, and the latter for studying the medium's response to the external probe. In this thesis we take the external probe to be the neutrino. By combining this parametrization with the YN V low k potential, we calculate the equation of state of equilibrated matter. Performing the calculation in the Hartree-Fock approximation at zero temperature, the concentrations of all particles are calculated. From these we can ascertain at which densities hyperons appear for a wide range of parameters. Finally, we calculate the masses of neutron stars with these concentrations. For the calculation of the medium's response to an external probe, we replace the three-body force with a density-dependent interaction. This

  14. Oral administration of a medium containing both D-aspartate-producing live bacteria and D-aspartate reduces rectal temperature in chicks.

    Science.gov (United States)

    Do, P H; Tran, P V; Bahry, M A; Yang, H; Han, G; Tsuchiya, A; Asami, Y; Furuse, M; Chowdhury, V S

    2017-10-01

    1. The aim of this study was to investigate the effects on the rectal temperature of young chicks of the oral administration of a medium that contained both live bacteria that produce D-aspartate (D-Asp) and D-Asp. 2. In Experiment 1, chicks were subjected to chronic oral administration of either the medium (containing live bacteria and 2.46 μmol D-Asp) or water from 7 to 14 d of age. Plasma-free amino acids as well as mitochondrial biogenic gene expression in the breast muscle were analysed. In Experiment 2, 7-d-old chicks were subjected to acute oral administration of the above medium or of an equimolar amount of D-Asp to examine their effect on changes in rectal temperature. In Experiment 3, after 1 week of chronic oral administration of the medium, 14-d-old chicks were exposed to either high ambient temperature (HT; 40 ± 1°C, 3 h) or control thermoneutral temperature (CT; 30 ± 1°C, 3 h) to monitor the changes in rectal temperature. 3. Chronic, but not acute, oral administration of the medium significantly reduced rectal temperature in chicks, and a chronic effect also appeared under HT conditions. 4. Chronic oral administration of the medium significantly reduced the mRNA abundance of the avian uncoupling protein (avUCP) in the breast muscle, but led to a significant increase in avian adenine nucleotide translocator (avANT) mRNA in the same muscle. 5. (a) These results indicate that the medium can reduce body temperature through the decline in avUCP mRNA expression in the breast muscle that may be involved in reduced mitochondrial proton leaks and heat production. (b) The increase in avANT further suggests a possible enhancement of adenosine triphosphate (ATP) synthesis.

  15. Options for the ultimate storage of low and medium level radioactive wastes produced at Laguna Verde nuclear power plant

    International Nuclear Information System (INIS)

    Emeterio, Miguel

    1991-01-01

    The devoted time and still to be expend in prepare, execute and teach permanent and safe solutions to the problem of the evaluation of radioactive wastes reflects the political, economic and environmental importance with respect to public health and safety invested in this task, as well as, its technological challenges. In the case of Laguna Verde nuclear power plant, its low and medium level radioactive wastes are stored in the beginning in a temporal store with a capacity of 2000 m 3 sufficient to four years of normal operation; according to what it is necessary to select one of different ways of waste storage. Different technologies has been evaluated and the preliminary conclusion is that for Mexico the more feasible way to store radioactive wastes is in tumulus (Author)

  16. Processes for forming exoergic structures with the use of a plasma and for producing dense refractory bodies of arbitrary shape therefrom

    International Nuclear Information System (INIS)

    Holt, J.B.; Kelly, M.D.

    1990-01-01

    Plasma spraying methods of forming exoergic structures and coatings, as well as exoergic structures produced by such methods, are presented. The methods include the plasma spraying of reactive exoergic materials that are capable of sustaining a combustion synthesis reaction onto a flat substrate or into molds of arbitrary shape and igniting the plasma sprayed materials, either under an inert gas pressure or not, to form refractory materials of varying densities and of varying shapes

  17. Physical Activity Producing Low, but Not Medium or Higher, Vertical Impacts Is Inversely Related to BMI in Older Adults: Findings From a Multicohort Study

    Science.gov (United States)

    Elhakeem, Ahmed; Hannam, Kimberly; Deere, Kevin C; Hartley, April; Clark, Emma M; Moss, Charlotte; Edwards, Mark H; Dennison, Elaine; Gaysin, Tim; Kuh, Diana; Wong, Andrew; Cooper, Cyrus; Cooper, Rachel; Tobias, Jon H

    2018-01-01

    Abstract Background High impact physical activity (PA) is thought to improve skeletal health, but its relation to other health outcomes are unclear. We investigated associations between PA impact magnitude and body mass index (BMI) in older adults. Methods Data were taken from the Cohort for Skeletal Health in Bristol and Avon (COSHIBA), Hertfordshire Cohort Study, and MRC National Survey of Health and Development. Vertical acceleration peaks from 7-day hip-worn accelerometer recordings were used to classify PA as low (0.5 impact. Cohort-specific associations of low, medium, and higher impact PA with BMI were examined using linear regressions and estimates combined using random-effects meta-analysis. Results A total of 1182 participants (mean age = 72.7 years, 68% female) were included. Low, medium, and higher impact PA were inversely related to BMI in initial models. After adjustment for confounders and other impacts, low, but not medium or higher, impacts were inversely related to BMI (−0.31, p impacts). In adjusted analyses of body composition measured by dual-energy X-ray absorptiometry in COSHIBA, low, but not medium or higher, impacts were inversely related to total body fat mass (−0.19, p impact PA was weakly and positively associated with lean mass (0.05, p = .06). Conclusions Greater exposure to PA producing low magnitude vertical impacts was associated with lower BMI and fat mass at older age. Low impact PA may help reduce obesity risk in older adults. PMID:29028919

  18. Some major deviations for biomass determination by indirect method and estimation based on alkali consumption. [Ratio of cell mass produced and alkali consumed; diesel fuel culture medium

    Energy Technology Data Exchange (ETDEWEB)

    Concone, B R.V.; Doin, P A; Pinto, A G

    1978-01-01

    Some factors like the variation of the liquid volume, the variation of cellular nitrogen content and the mass of cells taken with the samples during batch cultivation of microorganisms on diesel oil, were considered for the computation of the ratio between cell mass produced and the mass of alkali consumed to maintain constant the pH of the fermentation medium. The results obtained showed that if such ratios are computed with cell concentration instead of cell mass the deviations can be of the order of 27% caused by the variation of the liquid medium volume. Otherwise, the results showed also that those ratios are variable during batch cultivation on diesel oil probably because of the variations on the nitrogen content of microorganisms. The relative difference between the mass of cells measured and the mass of cells calculated from the alkali consumption curve can be of the order of 63%.

  19. Probiotic effect of Pichia pastoris X-33 produced in parboiled rice effluent and YPD medium on broiler chickens.

    Directory of Open Access Journals (Sweden)

    Diego Gil de Los Santos

    Full Text Available In a previous paper we showed that the yeast Pichia pastoris X-33 grown in parboiled rice effluent supplemented with glycerol byproduct from the biodiesel industry improved the quality of the effluent. In this paper we show the validation of this yeast (PPE as probiotic for broilers. Its effect on feed efficiency and immunomodulation was compared with the same yeast grown in yeast peptone dextrose medium (PPY, with Saccharomyces boulardii (SBY and with the controls fed unsupplemented feed (CON. One-day-old female chicks were vaccinated against infectious bursal disease (IBD and the titers of anti-IBD antibodies were measured by ELISA. PPE group had the highest mean titres on days 14 and 28 (p<0,05, and at 28 days, 64% of the animals showed seroconvertion. The PPE group also showed the best weight gains at 42 days of age, that, on days 7, 14 and 21 were 19%, 15%, and 8.7% higher, respectively, than the control group. The best feed conversion, 8.2% higher than the control group, was obtained by PPY at 42 days. Histopathological studies did not detect any undesirable effects in the supplemented animals. We concluded that Pichia pastoris X-33 when grown in effluents of the rice parboiling industry supplemented with glycerol byproduct from the biodiesel has probiotic properties for poultry.

  20. Pathogenic fungi found in wheat seeds and medium early maturity, produced in three parts of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Anderson Durante Danelli

    2012-03-01

    Full Text Available Seed samples of wheat harvest in 2010 from Santo Augusto, Passo Fundo and Vacaria, RS; were plated on gerbox acrylic sterilized culture medium PSA (potato, sucrose and agar plus antibiotics. Were used 400 seeds of each cultivar total of 45 cultivars. Were distributed equally spaced 25 seeds in each seedling with four replications, totaling 100 seeds per replicate. The seeds were incubated at 25 ± 2°C in an incubator with a photoperiod of 12 hours for 12 days. The experimental design was blocks and the experimental unit consists of four gerbox containing 25 seeds each. Was considered to be infected the seed of conidiophore presence and/or conidia of the fungus. The data were transformed to (x+11/2 and subjected to analysis of variance and means compared by Tukey test at 5% probability. Fungi F. graminearum and Alternaria spp. were detected in high incidence in most lots, performing at respectively 96.0% and 98.0% of samples, thereafter Bipolaris spp. So too, Drechslera siccans was found in 41.5% of samples showing that their incidence is increasing

  1. Bulk properties of the medium produced in relativistic heavy-ion collisions from the beam energy scan program

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, B.; Huang, X.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, W.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, H.; Liu, P.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, L.; Ma, Y. G.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

    2017-10-01

    We present measurements of bulk properties of the matter produced in Au+Au collisions at √{sN N}=7.7 ,11.5 ,19.6 ,27 , and 39 GeV using identified hadrons (π±, K±, p , and p ¯) from the STAR experiment in the Beam Energy Scan (BES) Program at the Relativistic Heavy Ion Collider (RHIC). Midrapidity (|y |<0.1 ) results for multiplicity densities d N /d y , average transverse momenta 〈pT〉 , and particle ratios are presented. The chemical and kinetic freeze-out dynamics at these energies are discussed and presented as a function of collision centrality and energy. These results constitute the systematic measurements of bulk properties of matter formed in heavy-ion collisions over a broad range of energy (or baryon chemical potential) at RHIC.

  2. EBP2R - an innovative enhanced biological nutrient recovery activated sludge system to produce growth medium for green microalgae cultivation.

    Science.gov (United States)

    Valverde-Pérez, Borja; Ramin, Elham; Smets, Barth F; Plósz, Benedek Gy

    2015-01-01

    Current research considers wastewater as a source of energy, nutrients and water and not just a source of pollution. So far, mainly energy intensive physical and chemical unit processes have been developed to recover some of these resources, and less energy and resource demanding alternatives are needed. Here, we present a modified enhanced biological phosphorus removal and recovery system (referred to as EBP2R) that can produce optimal culture media for downstream micro-algal growth in terms of N and P content. Phosphorus is recovered as a P-stream by diversion of some of the effluent from the upstream anaerobic reactor. By operating the process at comparably low solids retention times (SRT), the nitrogen content of wastewater is retained as free and saline ammonia, the preferred form of nitrogen for most micro-algae. Scenario simulations were carried out to assess the capacity of the EBP2R system to produce nutrient rich organic-carbon depleted algal cultivation media of target composition. Via SRT control, the quality of the constructed cultivation media can be optimized to support a wide range of green micro-algal growth requirements. Up to 75% of the influent phosphorus can be recovered, by diverting 30% of the influent flow as a P-stream at an SRT of 5 days. Through global sensitivity analysis we find that the effluent N-to-P ratio and the P recovered are mainly dependent on the influent quality rather than on biokinetics or stoichiometry. Further research is needed to demonstrate that the system performance predicted through the model-based design can be achieved in reality. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Effect of culture medium on polymer production and temperature on recovery of polymer produced from newly identified Rhyzopus oryzae ST29

    Directory of Open Access Journals (Sweden)

    Tipparat Hongpattarakere

    2008-04-01

    Full Text Available Thermotolerant fungal isolate ST29 was identified by observing on cell morphology and molecular technique based on internal transcribed spacer (ITS gene to be Rhizopus oryzae. Among four culture media tested, the strain exhibited the highest growth in yeast malt extract (YM medium (4.87 g/l, followed by Sabouraud dextrose broth (SDB (4.25 g/l, potato dextrose broth (PDB (4.10 g/l and palm oil mill effluent (POME (3.29 g/l, respectively, after 4 days cultivation at 45oC. However, the strain was found to produce polymer only in POME medium at 45oC, but not in the three synthetic media tested. Effect of temperature on separation of the biopolymer produced by this fungal strain was studied by incubating the culture broth in water bath with temperatures in the range of room temperature to 70oC. The biopolymer was recovered by filtration, centrifugation, and precipitation by adding 4 volumes of 95% ethanol, then freeze-drying. These temperatures therefore had no influence on the biopolymer yields (5.58-5.78 g/l or on biomass yields (2.90-3.29 g/l.

  4. DS Mesons in Asymmetric Hot and Dense Hadronic Matter

    Directory of Open Access Journals (Sweden)

    Divakar Pathak

    2015-01-01

    Full Text Available The in-medium properties of DS mesons are investigated within the framework of an effective hadronic model, which is a generalization of a chiral SU(3 model, to SU(4, in order to study the interactions of the charmed hadrons. In the present work, the DS mesons are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of the DS+ and DS- mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of the DS mesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting between DS+ and DS- mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which are all expected to make a significant difference to observables in heavy ion collision experiments, especially the upcoming Compressed Baryonic Matter (CBM experiment at the future Facility for Antiproton and Ion Research (FAIR, GSI, where matter at high baryonic densities is planned to be produced.

  5. Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China

    Directory of Open Access Journals (Sweden)

    Yan-Yang Lu

    2016-06-01

    Full Text Available An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs and carbonyl compounds (CCs in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, and isovaleraldehyde were relatively abundant in the cabins. Time was found to affect the emissions of the contaminants in the coaches. Except for benzaldehyde, valeraldehyde and benzene, the highest in-vehicle concentrations of VOCs and CCs were observed on the 15th day after coming off the assembly line, and the concentrations exhibited an approximately inverted U-shaped pattern as a function of time. Interestingly, this study also showed that the interior temperature of the coaches significantly affected the VOCs emissions from the interior materials, whereas the levels of CCs were mainly influenced by the relative humidity within the coaches. In China, guidelines and regulations for the in-vehicle air quality assessment of the coaches have not yet been issued. The results of this study provide further understanding of the in-vehicle air quality of air-conditioned coaches and can be used in the development of both specific and general rules regarding medium- and large-size coaches.

  6. Flexible fiber in interaction with a dense granular flow close to the jamming transition

    Directory of Open Access Journals (Sweden)

    Algarra Nicolas

    2017-01-01

    Full Text Available We propose a new fluid/structure interaction in the unusual case of a dense granular medium flowing against an elastic fiber acting as a flexible intruder. We study experimentally the reconfiguration and the forces exerted on the flexible fiber produced by the flow at a constant and low velocity of a two-dimensional disordered packing of grains close but below the jamming transition.

  7. Flexible fiber in interaction with a dense granular flow close to the jamming transition

    Science.gov (United States)

    Algarra, Nicolas; Leang, Marguerite; Lazarus, Arnaud; Vandembroucq, Damien; Kolb, Evelyne

    2017-06-01

    We propose a new fluid/structure interaction in the unusual case of a dense granular medium flowing against an elastic fiber acting as a flexible intruder. We study experimentally the reconfiguration and the forces exerted on the flexible fiber produced by the flow at a constant and low velocity of a two-dimensional disordered packing of grains close but below the jamming transition.

  8. Atoms in dense plasmas

    International Nuclear Information System (INIS)

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs

  9. Atoms in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  10. Quantum dense key distribution

    International Nuclear Information System (INIS)

    Degiovanni, I.P.; Ruo Berchera, I.; Castelletto, S.; Rastello, M.L.; Bovino, F.A.; Colla, A.M.; Castagnoli, G.

    2004-01-01

    This paper proposes a protocol for quantum dense key distribution. This protocol embeds the benefits of a quantum dense coding and a quantum key distribution and is able to generate shared secret keys four times more efficiently than the Bennet-Brassard 1984 protocol. We hereinafter prove the security of this scheme against individual eavesdropping attacks, and we present preliminary experimental results, showing its feasibility

  11. Acid solution is a suitable medium for introducing QX-314 into nociceptors through TRPV1 channels to produce sensory-specific analgesic effects.

    Directory of Open Access Journals (Sweden)

    He Liu

    sciatic nerve selectively blocked the sensory but not the motor functions in naïve and CCI mice. CONCLUSIONS/SIGNIFICANCE: Acid solution is a suitable medium for introducing QX-314 into nociceptors through TRPV1 channels to produce a sensory-specific analgesic effect.

  12. Dense high temperature ceramic oxide superconductors

    Science.gov (United States)

    Landingham, Richard L.

    1993-01-01

    Dense superconducting ceramic oxide articles of manufacture and methods for producing these articles are described. Generally these articles are produced by first processing these superconducting oxides by ceramic processing techniques to optimize materials properties, followed by reestablishing the superconducting state in a desired portion of the ceramic oxide composite.

  13. Modelling dense relational data

    DEFF Research Database (Denmark)

    Herlau, Tue; Mørup, Morten; Schmidt, Mikkel Nørgaard

    2012-01-01

    they are not naturally suited for kernel K-means. We propose a generative Bayesian model for dense matrices which generalize kernel K-means to consider off-diagonal interactions in matrices of interactions, and demonstrate its ability to detect structure on both artificial data and two real data sets....

  14. Is dense codeswitching complex?

    NARCIS (Netherlands)

    Dorleijn, M.

    In this paper the question is raised to what extent dense code switching can be considered complex. Psycholinguistic experiments indicate that code switching involves cognitive costs, both in production and comprehension, a conclusion that could indicate that code switching is indeed complex. In

  15. Simulation of dense colloids

    NARCIS (Netherlands)

    Herrmann, H.J.; Harting, J.D.R.; Hecht, M.; Ben-Naim, E.

    2008-01-01

    We present in this proceeding recent large scale simulations of dense colloids. On one hand we simulate model clay consisting of nanometric aluminum oxide spheres in water using realistic DLVO potentials and a combination of MD and SRD. We find pronounced cluster formation and retrieve the shear

  16. Atoms in dense plasmas

    International Nuclear Information System (INIS)

    More, R.M.

    1987-01-01

    This paper covers some aspects of the theory of atomic processes in dense plasmas. Because the topic is very broad, a few general rules which give useful guidance about the typical behavior of dense plasmas have been selected. These rules are illustrated by semiclassical estimates, scaling laws and appeals to more elaborate calculations. Included in the paper are several previously unpublished results including a new mechanism for electron-ion heat exchange (section II), and an approximate expression for oscillator-strengths of highly charged ions (section V). However the main emphasis is not upon practical formulas but rather on questions of fundamental theory, the structural ingredients which must be used in building a model for plasma events. What are the density effects and how does one represent them? Which are most important? How does one identify an incorrect theory? The general rules help to answer these questions. 106 references, 23 figures, 2 tables

  17. Dense Plasma Focus Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Shengtai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Jungman, Gerard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hayes-Sterbenz, Anna Catherine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    The mechanisms for pinch formation in Dense Plasma Focus (DPF) devices, with the generation of high-energy ions beams and subsequent neutron production over a relatively short distance, are not fully understood. Here we report on high-fidelity 2D and 3D numerical magnetohydrodynamic (MHD) simulations using the LA-COMPASS code to study the pinch formation dynamics and its associated instabilities and neutron production.

  18. Probing dense matter with strange hadrons

    CERN Document Server

    Rafelski, Johann; Rafelski, Johann; Letessier, Jean

    2002-01-01

    Analysis of hadron production experimental data allows to understand the properties of the dense matter fireball produced in relativistic heavy ion collisions. We interpret the analysis results and argue that color deconfined state has been formed at highest CERN-SPS energies and at BNL-RHIC.

  19. Isolation and Characterization of a Catabolite Repression-Insensitive Mutant of a Methanol Yeast, Candida boidinii A5, Producing Alcohol Oxidase in Glucose-Containing Medium

    OpenAIRE

    Sakai, Yasuyoshi; Sawai, Tohru; Tani, Yoshiki

    1987-01-01

    Mutants exhibiting alcohol oxidase (EC 1.1.3.13) activity when grown on glucose in the presence of methanol were found among 2-deoxyglucose-resistant mutants derived from a methanol yeast, Candida boidinii A5. One of these mutants, strain ADU-15, showed the highest alcohol oxidase activity in glucose-containing medium. The growth characteristics and also the induction and degradation of alcohol oxidase were compared with the parent strain and mutant strain ADU-15. In the parent strain, initia...

  20. Dense ceramic articles

    International Nuclear Information System (INIS)

    Cockbain, A.G.

    1976-01-01

    A method is described for the manufacture of articles of substantially pure dense ceramic materials, for use in severe environments. Si N is very suitable for use in such environments, but suffers from the disadvantage that it is not amenable to sintering. Some disadvantages of the methods normally used for making articles of Si N are mentioned. The method described comprises mixing a powder of the substantially pure ceramic material with an additive that promotes densification, and which is capable of nuclear transmutation into a gas when exposed to radiation, and hot pressing the mixture to form a billet. The billet is then irradiated to convert the additive into a gas which is held captive in the billet, and it is then subjected to a hot forging operation, during which the captive gas escapes and an article of substantially pure dense ceramic material is forged. The method is intended primarily for use for Si N, but may be applied to other ceramic materials. The additive may be Li or Be or their compounds, to the extent of at least 5 ppm and not more than 5% by weight. Irradiation is effected by proton or neutron bombardment. (UK)

  1. Using a medium of free amino acids to produce penicillin g acylase in fed-batch cultivations of Bacillus megaterium ATCC 14945

    Directory of Open Access Journals (Sweden)

    R. G. Silva

    2006-03-01

    Full Text Available The production of penicillin G acylase (PGA, an important industrial enzyme from a wild strain of Bacillus megaterium using a pool of free amino acids as substrate was studied in a bench-scale bioreactor. Experiments carried out in shakers showed that the substitution of casein for free amino acids in the presence of cheese whey was the culture medium that provided the highest productivity. Several cultivations were carried out in a bioreactor operated in either batch or fed-batch mode. Batch runs showed that enzyme production is associated with microorganism growth. The following set of amino acids was preferentially consumed: Ala, Arg, Asp, Gly, Lys, Ser, Thr and Trp. On the other hand, the rates of consumption of His, Ile, Leu, Met, Phe, Pro, Tyr and Val were lower.

  2. Geometrical optics of dense aerosols: forming dense plasma slabs.

    Science.gov (United States)

    Hay, Michael J; Valeo, Ernest J; Fisch, Nathaniel J

    2013-11-01

    Assembling a freestanding, sharp-edged slab of homogeneous material that is much denser than gas, but much more rarefied than a solid, is an outstanding technological challenge. The solution may lie in focusing a dense aerosol to assume this geometry. However, whereas the geometrical optics of dilute aerosols is a well-developed field, the dense aerosol limit is mostly unexplored. Yet controlling the geometrical optics of dense aerosols is necessary in preparing such a material slab. Focusing dense aerosols is shown here to be possible, but the finite particle density reduces the effective Stokes number of the flow, a critical result for controlled focusing.

  3. Implantable oxygen microelectrode suitable for medium-term investigations of post-surgical tissue hypoxia and changes in tumor tissue oxygenation produced by radiotherapy

    International Nuclear Information System (INIS)

    Burke, T.R.; Johnson, R.J.; Krishnamsetty, C.B.; Sako, K.; Karakousis, C.; Wojtas, F.

    1980-01-01

    Teflon-covered platinum oxygen probes were used to monitor tissue oxygen levels in post-surgical cancer patients and those treated with radiotherapy. Progressive wound healing was usually accompanied by a decrease in tissue pO2. Radiotherapy produced a slight increase in pO2 while hyperthermia effected a significant increase in the oxygen level during 100% oxygen breathing

  4. Strange mesons in dense nuclear matter

    International Nuclear Information System (INIS)

    Senger, P.

    2000-10-01

    Experimental data on the production of kaons and antikaons in heavy ion collisions at relativistic energies are reviewed with respect to in-medium effects. The K - /K + ratios measured in nucleus-nucleus collisions are 1-2 orders of magnitude larger than in proton-proton collisions. The azimuthal angle distributions of K + mesons indicate a repulsive kaon-nucleon potential. Microscopic transport calculations consistently explain both the yields and the emission patterns of kaons and antikaons when assuming that their properties are modified in dense nuclear matter. The K + production excitation functions measured in light and heavy collision systems provide evidence for a soft nuclear equation-of-state. (orig.)

  5. High performance liquid chromatographic separation of beryllium from some transition metals produced in high energy proton irradiations of medium mass elements: measurement of (p,7Be) cross sections

    International Nuclear Information System (INIS)

    Fassbender, M.; Spellerberg, S.; Qaim, S.M.

    1996-01-01

    A high performance liquid chromatographic (HPLC) method was developed for the separation of 7 Be formed in high energy proton irradiation of medium mass elements like Fe, Cu etc. The bulk of the target material was removed in a preseparation step. Thereafter beryllium was obtained in a high purity within a few minutes elution time using a mixture of 5 mM citric acid and 1.0 mM pyridinedicarboxylic acid as eluent and a SYKAM KO2 analytical cation-exchange column. The effect of Be-carrier on the quality of separation was investigated. The quality of separation deteriorated with the increasing Be-carrier column loading. A certain amount of Be-carrier was, however, necessary in order to quantitate the results. By using low Be-carrier amounts (∝100 μg) and determining the elution yield via a conductometric method, it was possible to obtain quantitative separation results. Besides the analytical column, a semi-preparative column was also used, and the Be separation yield determined gravimetrically. The cross sections for the (p, 7 Be) process on Cu obtained using the two separation columns (analytical and semipreparative) and the two separation yield determination methods agreed within 15%. (orig.)

  6. EBP2R – An innovative enhanced biological nutrient recovery activated sludge system to produce growth medium for green microalgae cultivation

    DEFF Research Database (Denmark)

    Valverde Perez, Borja; Ramin, Elham; Smets, Barth F.

    2015-01-01

    system to produce nutrient rich organic-carbon depleted algal cultivation media of target composition. Via SRT control, the quality of the constructed cultivation media can be optimized to support a wide range of green micro-algal growth requirements. Up to 75% of the influent phosphorus can be recovered...... that the system performance predicted through the model-based design can be achieved in reality....

  7. Charmed hadrons in nuclear medium

    International Nuclear Information System (INIS)

    Tolos, L.; Gamermann, D.; Molina, R.; Nieves, J.; Oset, E.; Garcia-Recio, C.; Ramos, A.

    2010-01-01

    We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner. We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the open-charm meson spectral functions. We discuss the implications of the in-medium properties of open-charm mesons on the D s0 (2317) and the predicted X(3700) scalar resonances. (authors)

  8. Growth of Chlamydomonas reinhardtii in acetate-free medium when co-cultured with alginate-encapsulated, acetate-producing strains of Synechococcus sp. PCC 7002.

    Science.gov (United States)

    Therien, Jesse B; Zadvornyy, Oleg A; Posewitz, Matthew C; Bryant, Donald A; Peters, John W

    2014-01-01

    The model alga Chlamydomonas reinhardtii requires acetate as a co-substrate for optimal production of lipids, and the addition of acetate to culture media has practical and economic implications for algal biofuel production. Here we demonstrate the growth of C. reinhardtii on acetate provided by mutant strains of the cyanobacterium Synechococcus sp. PCC 7002. Optimal growth conditions for co-cultivation of C. reinhardtii with wild-type and mutant strains of Synechococcus sp. 7002 were established. In co-culture, acetate produced by a glycogen synthase knockout mutant of Synechococcus sp. PCC 7002 was able to support the growth of a lipid-accumulating mutant strain of C. reinhardtii defective in starch production. Encapsulation of Synechococcus sp. PCC 7002 using an alginate matrix was successfully employed in co-cultures to limit growth and maintain the stability. The ability of immobilized strains of the cyanobacterium Synechococcus sp. PCC 7002 to produce acetate at a level adequate to support the growth of lipid-accumulating strains of C. reinhartdii offers a potentially practical, photosynthetic alternative to providing exogenous acetate into growth media.

  9. Small and medium sized wine producers dealing with business to business e-commerce: Towards a relational model for enhancing value (co- creation

    Directory of Open Access Journals (Sweden)

    Saba Andrea

    2017-01-01

    Full Text Available The internet has produced a forward-looking shift in the way we communicate, think and run economic activities around the globe. The revolution in Information and Communication Technology (ICT has generated an innovating process in the agri-food sector that is far from being unwind. The wine industry is a case in point. Indeed, the industry has attempted to address the multifaceted challenges posed by electronic commerce since always. Business to business electronic commerce has been slower to develop than its counterpart, i.e. business to consumer E-commerce. However business to business e-commerce is starting to attract an increased interest, by showing a significant business value in terms of potential. Against this background, the slow development of B2B e-commerce has been linked to regulatory and economic reasons. In order to deal with such stumbling blocks, the paper suggests a shift towards an open platform that is aimed at facilitating transactions and interactions among businesses through a continuous problem-solving process in which trust and value is co-created by producers and customers through relational contracting.

  10. [Possibility of the spectral analysis of heterogeneous biological systems. The determination of the mycelium concentration of Actinomyces aureofaciens, a producer of tetracycline, cultured on a medium with corn meal].

    Science.gov (United States)

    Korolev, Iu N; Slugina, M D; Makarevich, V G; Telegin, N L

    1979-03-01

    A possibility of using spectroscopy of attenuated total reflection in the IR region for analysis of the heterogenic system consisting of the microorganisms and plant cells is discussed. The method of spectroscopy is proposed for estimating the mycelium concentration of Act. aureofaciens producing tetracycline in the presence of corn meal in the medium. The experimental data confirming this possibility are presented. The peculiar properties of the spectral analysis under these particular conditions are discussed. It is supposed that the method may be used for analysis of heterogenous systems including other microorganisms.

  11. Mercury's Densely Cratered Surface

    Science.gov (United States)

    1974-01-01

    Mariner 10 took this picture (FDS 27465) of the densely cratered surface of Mercury when the spacecraft was 18,200 kilometers (8085 miles) from the planet on March 29. The dark line across top of picture is a 'dropout' of a few TV lines of data. At lower left, a portion of a 61 kilometer (38 mile) crater shows a flow front extending across the crater floor and filling more than half of the crater. The smaller, fresh crater at center is about 25 kilometers (15 miles) in diameter. Craters as small as one kilometer (about one-half mile) across are visible in the picture.The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.Image Credit: NASA/JPL/Northwestern University

  12. Particle identification system based on dense aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Barnyakov, A.Yu. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Barnyakov, M.Yu. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20, Karl Marx prospect, Novosibirsk, 630092 (Russian Federation); Beloborodov, K.I., E-mail: K.I.Beloborodov@inp.nsk.su [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Bobrovnikov, V.S.; Buzykaev, A.R. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Danilyuk, A.F. [Boreskov Institute of Catalysis, 5, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Golubev, V.B. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Gulevich, V.V. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Kononov, S.A.; Kravchenko, E.A. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); Onuchin, A.P.; Martin, K.A. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20, Karl Marx prospect, Novosibirsk, 630092 (Russian Federation); Serednyakov, S.I. [Budker Institute of Nuclear Physics, 11, akademika Lavrentieva prospect, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090 (Russian Federation); and others

    2013-12-21

    A threshold Cherenkov counter based on dense aerogel with refraction index n=1.13 is described. This counter is used for kaon identification at momenta below 1 GeV/c in the SND detector, which takes data at the VEPP-2000 e{sup +}e{sup −} collider. The results of measurements of the counter efficiency using electrons, muons, pions, and kaons produced in e{sup +}e{sup −} annihilation are presented.

  13. Characterization of purified and Xerogel immobilized Novel Lignin Peroxidase produced from Trametes versicolor IBL-04 using solid state medium of Corncobs

    Directory of Open Access Journals (Sweden)

    Asgher Muhammad

    2012-08-01

    Full Text Available Abstract Background Cost-effective production of industrially important enzymes is a key for their successful exploitation on industrial scale. Keeping in view the extensive industrial applications of lignin peroxidase (LiP, this study was performed to purify and characterize the LiP from an indigenous strain of Trametes versicolor IBL-04. Xerogel matrix enzyme immobilization technique was applied to improve the kinetic and thermo-stability characteristics of LiP to fulfil the requirements of the modern enzyme consumer sector of biotechnology. Results A novel LiP was isolated from an indigenous T. versicolor IBL-04 strain. T. versicolor IBL-04 was cultured in solid state fermentation (SSF medium of corn cobs and maximum LiP activity of 592 ± 6 U/mL was recorded after five days of incubation under optimum culture conditions. The crude LiP was 3.3-fold purified with specific activity of 553 U/mg after passing through the DEAE-cellulose and Sephadex-G-100 chromatography columns. The purified LiP exhibited a relatively low molecular weight (30 kDa homogenous single band on native and SDS-PAGE. The LiP was immobilized by entrapping in xerogel matrix of trimethoxysilane (TMOS and proplytetramethoxysilane (PTMS and maximum immobilization efficiency of 88.6% was achieved. The free and immobilized LiPs were characterized and the results showed that the free and immobilized LiPs had optimum pH 6 and 5 while optimum temperatures were 60°C and 80°C, respectively. Immobilization was found to enhance the activity and thermo-stability potential of LiP significantly and immobilized LiP remained stable over broad pH and temperature range as compare to free enzyme. Kinetic constants Km and Vmax were 70 and 56 μM and 588 and 417 U/mg for the free and immobilized LiPs, respectively. Activity of this novel extra thermo-stable LiP was stimulated to variable extents by Cu2+, Mn2+ and Fe2+ whereas, Cystein, EDTA and Ag+ showed inhibitory effects

  14. Dense sheet Z-pinches

    International Nuclear Information System (INIS)

    Tetsu, Miyamoto

    1999-01-01

    The steady state and quasi-steady processes of infinite- and finite-width sheet z-pinches are studied. The relations corresponding to the Bennett relation and Pease-Braginskii current of cylindrical fiber z-pinches depend on a geometrical factor in the sheet z-pinches. The finite-width sheet z-pinch is approximated by a segment of infinite-width sheet z-pinch, if it is wide enough, and corresponds to a number of (width/thickness) times fiber z-pinch plasmas of the diameter that equals the sheet thickness. If the sheet current equals this number times the fiber current, the plasma created in the sheet z-pinches is as dense as in the fiber z-pinches. The total energy of plasma and magnetic field per unit mass is approximately equal in both pinches. Quasi-static transient processes are different in several aspects from the fiber z-pinch. No radiation collapse occurs in the sheet z-pinch. The stability is improved in the sheet z-pinches. The fusion criterions and the experimental arrangements to produce the sheet z-pinches are also discussed. (author)

  15. PHOTOCHEMICAL HEATING OF DENSE MOLECULAR GAS

    Energy Technology Data Exchange (ETDEWEB)

    Glassgold, A. E. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Najita, J. R. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

    2015-09-10

    Photochemical heating is analyzed with an emphasis on the heating generated by chemical reactions initiated by the products of photodissociation and photoionization. The immediate products are slowed down by collisions with the ambient gas and then heat the gas. In addition to this direct process, heating is also produced by the subsequent chemical reactions initiated by these products. Some of this chemical heating comes from the kinetic energy of the reaction products and the rest from collisional de-excitation of the product atoms and molecules. In considering dense gas dominated by molecular hydrogen, we find that the chemical heating is sometimes as large, if not much larger than, the direct heating. In very dense gas, the total photochemical heating approaches 10 eV per photodissociation (or photoionization), competitive with other ways of heating molecular gas.

  16. Transport properties of dense matter

    International Nuclear Information System (INIS)

    Itoh, Naoki; Mitake, Shinichi; Iyetomi, Hiroshi; Ichimaru, Setsuo

    1983-01-01

    Transport coefficients, electrical and thermal conductivities in particular, are essential physical quantities for the theories of stellar structure. Since the discoveries of pulsars and X-ray stars, an accurate evaluation of the transport coefficients in the dense matter has become indispensable to the quantitative understanding of the observed neutron stars. The authors present improved calculations of the electrical and thermal conductivities of the dense matter in the liquid metal phase, appropriate to white dwarfs and neutron stars. (Auth.)

  17. Evaluation of ilmenite as a possible medium in a dry dense medium fluidized bed

    CSIR Research Space (South Africa)

    Kalenda, TN

    2017-10-01

    Full Text Available Alternative dry coal beneficiation method is in high demand, especially in arid geographical environments. This dry process eliminates the need for water usage and there are suggestions that it has the benefits of high separation precision and quick...

  18. Formation and fragmentation of protostellar dense cores

    International Nuclear Information System (INIS)

    Maury, Anaelle

    2009-01-01

    Stars form in molecular clouds, when they collapse and fragment to produce protostellar dense cores. These dense cores are then likely to contract under their own gravity, and form young protostars, that further evolve while accreting their circumstellar mass, until they reach the main sequence. The main goal of this thesis was to study the formation and fragmentation of protostellar dense cores. To do so, two main studies, described in this manuscript, were carried out. First, we studied the formation of protostellar cores by quantifying the impact of protostellar outflows on clustered star formation. We carried out a study of the protostellar outflows powered by the young stellar objects currently formed in the NGc 2264-C proto-cluster, and we show that protostellar outflows seem to play a crucial role as turbulence progenitors in clustered star forming regions, although they seem unlikely to significantly modify the global infall processes at work on clump scales. Second, we investigated the formation of multiple systems by core fragmentation, by using high - resolution observations that allow to probe the multiplicity of young protostars on small scales. Our results suggest that the multiplicity rate of protostars on small scales increase while they evolve, and thus favor dynamical scenarios for the formation of multiple systems. Moreover, our results favor magnetized scenarios of core collapse to explain the small-scale properties of protostars at the earliest stages. (author) [fr

  19. Neutrino interactions in hot and dense matter

    International Nuclear Information System (INIS)

    Reddy, S.; Prakash, M.; Lattimer, J.M.

    1998-01-01

    We study the charged and neutral current weak interaction rates relevant for the determination of neutrino opacities in dense matter found in supernovae and neutron stars. We establish an efficient formalism for calculating differential cross sections and mean free paths for interacting, asymmetric nuclear matter at arbitrary degeneracy. The formalism is valid for both charged and neutral current reactions. Strong interaction corrections are incorporated through the in-medium single particle energies at the relevant density and temperature. The effects of strong interactions on the weak interaction rates are investigated using both potential and effective field-theoretical models of matter. We investigate the relative importance of charged and neutral currents for different astrophysical situations, and also examine the influence of strangeness-bearing hyperons. Our findings show that the mean free paths are significantly altered by the effects of strong interactions and the multi-component nature of dense matter. The opacities are then discussed in the context of the evolution of the core of a protoneutron star. copyright 1998 The American Physical Society

  20. Seeing the Forest Through the Trees: The Distribution and Properties of Dense Molecular Gas in the Milky Way Galaxy

    Science.gov (United States)

    Ellsworth-Bowers, Timothy P.

    The Milky Way Galaxy serves as a vast laboratory for studying the dynamics and evolution of the dense interstellar medium and the processes of and surrounding massive star formation. From our vantage point within the Galactic plane, however, it has been extremely difficult to construct a coherent picture of Galactic structure; we cannot see the forest for the trees. The principal difficulties in studying the structure of the Galactic disk have been obscuration by the ubiquitous dust and molecular gas and confusion between objects along a line of sight. Recent technological advances have led to large-scale blind surveys of the Galactic plane at (sub-)millimeter wavelengths, where Galactic dust is generally optically thin, and have opened a new avenue for studying the forest. The Bolocam Galactic Plane Survey (BGPS) observed over 190 deg 2 of the Galactic plane in dust continuum emission near lambda = 1.1 mm, producing a catalog of over 8,000 dense molecular cloud structures across a wide swath of the Galactic disk. Deriving the spatial distribution and physical properties of these objects requires knowledge of distance, a component lacking in the data themselves. This thesis presents a generalized Bayesian probabilistic distance estimation method for dense molecular cloud structures, and demonstrates it with the BGPS data set. Distance probability density functions (DPDFs) are computed from kinematic distance likelihoods (which may be double- peaked for objects in the inner Galaxy) and an expandable suite of prior information to produce a comprehensive tally of our knowledge (and ignorance) of the distances to dense molecular cloud structures. As part of the DPDF formalism, this thesis derives several prior DPDFs for resolving the kinematic distance ambiguity in the inner Galaxy. From the collection of posterior DPDFs, a set of objects with well-constrained distance estimates is produced for deriving Galactic structure and the physical properties of dense molecular

  1. Scale-chiral symmetry, ω meson, and dense baryonic matter

    Science.gov (United States)

    Ma, Yong-Liang; Rho, Mannque

    2018-05-01

    It is shown that explicitly broken scale symmetry is essential for dense skyrmion matter in hidden local symmetry theory. Consistency with the vector manifestation fixed point for the hidden local symmetry of the lowest-lying vector mesons and the dilaton limit fixed point for scale symmetry in dense matter is found to require that the anomalous dimension (|γG2| ) of the gluon field strength tensor squared (G2 ) that represents the quantum trace anomaly should be 1.0 ≲|γG2|≲3.5 . The magnitude of |γG2| estimated here will be useful for studying hadron and nuclear physics based on the scale-chiral effective theory. More significantly, that the dilaton limit fixed point can be arrived at with γG2≠0 at some high density signals that scale symmetry can arise in dense medium as an "emergent" symmetry.

  2. Dynamics of dense particle disks

    International Nuclear Information System (INIS)

    Araki, S.; Tremaine, S.; Toronto Univ., Canada)

    1986-01-01

    The present investigation of mechanical equilibrium and collisional transport processes in dense, differentially rotating particle disks is based on the Enskog (1922) theory of dense, hard sphere gases, with the single exception that the spheres are inelastic. The viscous instability suggested as a source of Saturn B ring structure does not arise in the models presented, although the ring may be subject to a phase transition analogous to the liquid-solid transition observed in molecular dynamics simulations of elastic hard spheres. In such a case, the ring would alternately exhibit zero-shear, or solid, and high shear, or liquid, zones. 29 references

  3. Experiments on hot and dense laser-produced plasmas

    International Nuclear Information System (INIS)

    Back, C.A.; Woolsey, N.C.; Asfaw, A.; Glenzer, S.H.; Hammel, B.A.; Keane, C.J.; Lee, R.W.; Liedahl, D.; Moreno, J.C.; Nash, J.K.; Osterheld, A.L.; Calisti, A.; Stamm, R.; Talin, B.; Godbert, L.; Mosse, C.; Ferri, S.; Klein, L.

    1996-01-01

    Plasmas generated by irradiating targets with ∼20 kJ of laser energy are routinely created in inertial confinement fusion research. X-ray spectroscopy provides one of the few methods for diagnosing the electron temperature and electron density. For example, electron densities approaching 10 24 cm -3 have been diagnosed by spectral linewidths. However, the accuracy of the spectroscopic diagnostics depends on the population kinetics, the radiative transfer, and the line shape calculations. Analysis for the complex line transitions has recently been improved and accelerated by the use of a database where detailed calculations can be accessed rapidly and interactively. Examples of data from Xe and Ar doped targets demonstrate the current analytic methods. First we will illustrate complications that arise from the presence of a multitude of underlying spectral lines. Then, we will consider the Ar He-like 1s 2 ( 1 S 0 ) - 1s3p( 1 P 0 ) transition where ion dynamic effects may affect the profile. Here, the plasma conditions are such that the static ion microfield approximation is no longer valid; therefore in addition to the width, the details of the line shape can be used to provide additional information. We will compare the data to simulations and discuss the possible pitfalls involved in demonstrating the effect of ion dynamics on lineshapes

  4. Dense Crowds of Virtual Humans

    NARCIS (Netherlands)

    Stüvel, S.A.

    2016-01-01

    This thesis presents a novel crowd simulation method `Torso Crowds', aimed at the simulation of dense crowds. The method is based on the results of user studies and a motion capture experiment, which are also described in this thesis. Torso Crowds introduces a capsule shape to represent people in

  5. Monitoring of oil palm plantations and growth variations with a dense vegetation model

    DEFF Research Database (Denmark)

    Teng, Khar Chun; Koay, Jun Yi; Tey, Seng Heng

    2014-01-01

    The development of microwave remote sensing models for the monitoring of vegetation has received wide attention in recent years. For vegetation in the tropics, it is necessary to consider a dense medium model for the theoretical modelling of the microwave interaction with the vegetation medium....... In this paper, a multilayer model based on the radiative transfer theory for a dense vegetation medium is developed where the coherence effects and near field interaction effects of closely spaced leaves and branches are considered by incorporating the Dense Medium Phase and Amplitude Correction Theory (DM......-PACT) and Fresnel Phase Corrections. The iterative solutions of the radiative transfer model are computed with input based on ground truth measurements of physical parameters of oil palm plantations in the state of Perak, Malaysia, and compared with the SAR images obtained from RADARSAT2. Preliminary results...

  6. Jets and high pT hadrons in dense matter: recent results from STAR

    International Nuclear Information System (INIS)

    Jacobs, Peter; Klay, Jennifer

    2004-01-01

    We review recent measurements of high transverse momentum (high pT) hadron production in nuclear collisions by the STAR Collaboration at RHIC. The previously observed suppression in central Au+Au collisions has been extended to much higher pT. New measurements from d+Au collisions are presented which help disentangle the mechanisms responsible for the suppression. Inclusive single hadron spectra are enhanced in d+Au relative to p+p, while two-particle azimuthal distributions are observed to be similar in p+p, d+Au and peripheral Au+Au collisions. The large suppression of inclusive hadron production and absence of the away-side jet-like correlations in central Au+Au collisions are shown to be due to interactions of the jets with the very dense medium produced in these collisions

  7. Dense power-law networks and simplicial complexes

    Science.gov (United States)

    Courtney, Owen T.; Bianconi, Ginestra

    2018-05-01

    There is increasing evidence that dense networks occur in on-line social networks, recommendation networks and in the brain. In addition to being dense, these networks are often also scale-free, i.e., their degree distributions follow P (k ) ∝k-γ with γ ∈(1 ,2 ] . Models of growing networks have been successfully employed to produce scale-free networks using preferential attachment, however these models can only produce sparse networks as the numbers of links and nodes being added at each time step is constant. Here we present a modeling framework which produces networks that are both dense and scale-free. The mechanism by which the networks grow in this model is based on the Pitman-Yor process. Variations on the model are able to produce undirected scale-free networks with exponent γ =2 or directed networks with power-law out-degree distribution with tunable exponent γ ∈(1 ,2 ) . We also extend the model to that of directed two-dimensional simplicial complexes. Simplicial complexes are generalization of networks that can encode the many body interactions between the parts of a complex system and as such are becoming increasingly popular to characterize different data sets ranging from social interacting systems to the brain. Our model produces dense directed simplicial complexes with power-law distribution of the generalized out-degrees of the nodes.

  8. Warm Dense Matter: An Overview

    International Nuclear Information System (INIS)

    Kalantar, D H; Lee, R W; Molitoris, J D

    2004-01-01

    This document provides a summary of the ''LLNL Workshop on Extreme States of Materials: Warm Dense Matter to NIF'' which was held on 20, 21, and 22 February 2002 at the Wente Conference Center in Livermore, CA. The warm dense matter regime, the transitional phase space region between cold material and hot plasma, is presently poorly understood. The drive to understand the nature of matter in this regime is sparking scientific activity worldwide. In addition to pure scientific interest, finite temperature dense matter occurs in the regimes of interest to the SSMP (Stockpile Stewardship Materials Program). So that obtaining a better understanding of WDM is important to performing effective experiments at, e.g., NIF, a primary mission of LLNL. At this workshop we examined current experimental and theoretical work performed at, and in conjunction with, LLNL to focus future activities and define our role in this rapidly emerging research area. On the experimental front LLNL plays a leading role in three of the five relevant areas and has the opportunity to become a major player in the other two. Discussion at the workshop indicated that the path forward for the experimental efforts at LLNL were two fold: First, we are doing reasonable baseline work at SPLs, HE, and High Energy Lasers with more effort encouraged. Second, we need to plan effectively for the next evolution in large scale facilities, both laser (NIF) and Light/Beam sources (LCLS/TESLA and GSI) Theoretically, LLNL has major research advantages in areas as diverse as the thermochemical approach to warm dense matter equations of state to first principles molecular dynamics simulations. However, it was clear that there is much work to be done theoretically to understand warm dense matter. Further, there is a need for a close collaboration between the generation of verifiable experimental data that can provide benchmarks of both the experimental techniques and the theoretical capabilities. The conclusion of this

  9. Suprathermal viscosity of dense matter

    International Nuclear Information System (INIS)

    Alford, Mark; Mahmoodifar, Simin; Schwenzer, Kai

    2010-01-01

    Motivated by the existence of unstable modes of compact stars that eventually grow large, we study the bulk viscosity of dense matter, taking into account non-linear effects arising in the large amplitude regime, where the deviation μ Δ of the chemical potentials from chemical equilibrium fulfills μ Δ > or approx. T. We find that this supra-thermal bulk viscosity can provide a potential mechanism for saturating unstable modes in compact stars since the viscosity is strongly enhanced. Our study confirms previous results on strange quark matter and shows that the suprathermal enhancement is even stronger in the case of hadronic matter. We also comment on the competition of different weak channels and the presence of suprathermal effects in various color superconducting phases of dense quark matter.

  10. Dilute and dense axion stars

    Science.gov (United States)

    Visinelli, Luca; Baum, Sebastian; Redondo, Javier; Freese, Katherine; Wilczek, Frank

    2018-02-01

    Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |θ0 | ≡ | θ (r = 0) |, the equilibrium of the system arises from the balance of the kinetic pressure and either self-gravity or axion self-interactions. Starting from a general relativistic framework, we obtain the set of equations describing the configuration of the axion star, which we solve as a function of |θ0 |. For small |θ0 | ≲ 1, we reproduce results previously obtained in the literature, and we provide arguments for the stability of such configurations in terms of first principles. We compare qualitative analytical results with a numerical calculation. For large amplitudes |θ0 | ≳ 1, the axion field probes the full non-harmonic QCD chiral potential and the axion star enters the dense branch. Our numerical solutions show that in this latter regime the axions are relativistic, and that one should not use a single frequency approximation, as previously applied in the literature. We employ a multi-harmonic expansion to solve the relativistic equation for the axion field in the star, and demonstrate that higher modes cannot be neglected in the dense regime. We interpret the solutions in the dense regime as pseudo-breathers, and show that the life-time of such configurations is much smaller than any cosmological time scale.

  11. Dense and accurate whole-chromosome haplotyping of individual genomes

    NARCIS (Netherlands)

    Porubsky, David; Garg, Shilpa; Sanders, Ashley D.; Korbel, Jan O.; Guryev, Victor; Lansdorp, Peter M.; Marschall, Tobias

    2017-01-01

    The diploid nature of the human genome is neglected in many analyses done today, where a genome is perceived as a set of unphased variants with respect to a reference genome. This lack of haplotype-level analyses can be explained by a lack of methods that can produce dense and accurate

  12. Dense Breasts: Answers to Commonly Asked Questions

    Science.gov (United States)

    ... Cancer Prevention Genetics of Breast & Gynecologic Cancers Breast Cancer Screening Research Dense Breasts: Answers to Commonly Asked Questions What are dense breasts? Breasts contain glandular, connective, and fat tissue. Breast density is a term that describes the ...

  13. Dense strongly non-ideal plasma generation by laser isobaric heating

    International Nuclear Information System (INIS)

    Kulik, P.P.; Rozanov, E.K.; Riabii, V.A.; Titov, M.A.

    1975-01-01

    A method of generation of a dense strongly non-ideal plasma by slow isobaric heating of a small target in a high inert gas medium is discussed. The characteristic life-time of dense plasma is 10 -3 sec. Estimations show that such a plasma is homogeneous. Conditions are found for temperature uniformity. The experimental results of the isobaric heating of a thin potassium foil target by a ruby laser beam at 500 atm are described. (Auth.)

  14. Constructing Dense Graphs with Unique Hamiltonian Cycles

    Science.gov (United States)

    Lynch, Mark A. M.

    2012-01-01

    It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

  15. Screening in dense ionic fluids

    International Nuclear Information System (INIS)

    Tosi, M.P.

    1991-01-01

    There has been great progress in recent years in determining and understanding the structure of molten salts. I focus on molten alkali halides and discuss two main points concerning their liquid structure and its relationship with static electrical response in these dense ionic conductors. These are (i) the nature of screening and the related definitions and properties of the screening length and of the dielectric function, and (ii) developments in integral equations techniques for the evaluation of molten salt structure and static screening from given pair potentials. (author). 26 refs, 3 figs, 2 tabs

  16. Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ali, S., E-mail: shahid.ali@ncp.edu.p [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad (Pakistan); IPFN, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ahmed, Z. [COMSATS Institute of Information Technology, Department of Physics, Wah Campus (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ahmad, I. [COMSATS Institute of Information Technology, Department of Physics, Islamabad Campus (Pakistan)

    2009-08-10

    The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

  17. Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

    International Nuclear Information System (INIS)

    Ali, S.; Ahmed, Z.; Mirza, Arshad M.; Ahmad, I.

    2009-01-01

    The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

  18. Neutrino ground state in a dense star

    International Nuclear Information System (INIS)

    Kiers, K.; Tytgat, M.H.

    1998-01-01

    It has recently been argued that long range forces due to the exchange of massless neutrinos give rise to a very large self-energy in a dense, finite-ranged, weakly charged medium. Such an effect, if real, would destabilize a neutron star. To address this issue we have studied the related problem of a massless neutrino field in the presence of an external, static electroweak potential of finite range. To be precise, we have computed to one loop the exact vacuum energy for the case of a spherical square well potential of depth α and radius R. For small wells, the vacuum energy is reliably determined by a perturbative expansion in the external potential. For large wells, however, the perturbative expansion breaks down. A manifestation of this breakdown is that the vacuum carries a non-zero neutrino charge. The energy and neutrino charge of the ground state are, to a good approximation for large wells, those of a neutrino condensate with chemical potential μ=α. Our results demonstrate explicitly that long-range forces due to the exchange of massless neutrinos do not threaten the stability of neutron stars. copyright 1998 The American Physical Society

  19. Wave propagation through a dielectric layer containing densely packed fibers

    International Nuclear Information System (INIS)

    Lee, Siu-Chun

    2011-01-01

    This paper presents the theoretical formulation for the propagation of electromagnetic wave through a dielectric layer containing a random dense distribution of fibers. The diameter of the fibers is comparable to the inter-fiber spacing and wavelength of the incident radiation, but is much smaller than the thickness of the layer. Discontinuity of refractive index across the boundaries of the dielectric layer resulted in multiple internal reflection of both the primary source wave and the scattered waves. As a result the incident waves on the fibers consist of the multiply-reflected primary waves, scattered waves from other fibers, and scattered-reflected waves from the boundaries. The effective propagation constant of the dielectric fiber layer was developed by utilizing the Effective field-Quasicrystalline approximation. The influence of the refractive index of the dielectric medium on the radiative properties of a dense fiber layer was examined by means of numerical analyses.

  20. Deterministic and unambiguous dense coding

    International Nuclear Information System (INIS)

    Wu Shengjun; Cohen, Scott M.; Sun Yuqing; Griffiths, Robert B.

    2006-01-01

    Optimal dense coding using a partially-entangled pure state of Schmidt rank D and a noiseless quantum channel of dimension D is studied both in the deterministic case where at most L d messages can be transmitted with perfect fidelity, and in the unambiguous case where when the protocol succeeds (probability τ x ) Bob knows for sure that Alice sent message x, and when it fails (probability 1-τ x ) he knows it has failed. Alice is allowed any single-shot (one use) encoding procedure, and Bob any single-shot measurement. For D≤D a bound is obtained for L d in terms of the largest Schmidt coefficient of the entangled state, and is compared with published results by Mozes et al. [Phys. Rev. A71, 012311 (2005)]. For D>D it is shown that L d is strictly less than D 2 unless D is an integer multiple of D, in which case uniform (maximal) entanglement is not needed to achieve the optimal protocol. The unambiguous case is studied for D≤D, assuming τ x >0 for a set of DD messages, and a bound is obtained for the average . A bound on the average requires an additional assumption of encoding by isometries (unitaries when D=D) that are orthogonal for different messages. Both bounds are saturated when τ x is a constant independent of x, by a protocol based on one-shot entanglement concentration. For D>D it is shown that (at least) D 2 messages can be sent unambiguously. Whether unitary (isometric) encoding suffices for optimal protocols remains a major unanswered question, both for our work and for previous studies of dense coding using partially-entangled states, including noisy (mixed) states

  1. Jet multiplicity distributions: medium dependence in MLLA

    International Nuclear Information System (INIS)

    Armesto, Nestor; Pajares, Carlos; Quiroga-Arias, Paloma

    2009-01-01

    We study the medium dependence of the multiplicity distributions in the modified leading logarithmic approximation. We focus in the enhancement in the number of branchings as the partons travel trough a dense medium created in a heavy-ion collision. We study the effect of a higher number of splittings in some jet observables by introducing the medium as a constant (f med ) in the splitting functions. Having as our ansatz for the quark and gluon jets mean multiplicities left angle n G right angle =e γy and left angle n Q right angle =r -1 e γy , we study in an analytic approach the dependence with the medium (f med ) of the anomalous dimension (γ), the multiplicity ratio (r), and so the mean multiplicities. We also obtain the higher-order moments of the multiplicity distribution, what allows us to study its dispersion. (orig.)

  2. Breaking Dense Structures: Proving Stability of Densely Structured Hybrid Systems

    Directory of Open Access Journals (Sweden)

    Eike Möhlmann

    2015-06-01

    Full Text Available Abstraction and refinement is widely used in software development. Such techniques are valuable since they allow to handle even more complex systems. One key point is the ability to decompose a large system into subsystems, analyze those subsystems and deduce properties of the larger system. As cyber-physical systems tend to become more and more complex, such techniques become more appealing. In 2009, Oehlerking and Theel presented a (de-composition technique for hybrid systems. This technique is graph-based and constructs a Lyapunov function for hybrid systems having a complex discrete state space. The technique consists of (1 decomposing the underlying graph of the hybrid system into subgraphs, (2 computing multiple local Lyapunov functions for the subgraphs, and finally (3 composing the local Lyapunov functions into a piecewise Lyapunov function. A Lyapunov function can serve multiple purposes, e.g., it certifies stability or termination of a system or allows to construct invariant sets, which in turn may be used to certify safety and security. In this paper, we propose an improvement to the decomposing technique, which relaxes the graph structure before applying the decomposition technique. Our relaxation significantly reduces the connectivity of the graph by exploiting super-dense switching. The relaxation makes the decomposition technique more efficient on one hand and on the other allows to decompose a wider range of graph structures.

  3. Optimal super dense coding over memory channels

    OpenAIRE

    Shadman, Zahra; Kampermann, Hermann; Macchiavello, Chiara; Bruß, Dagmar

    2011-01-01

    We study the super dense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and non-unitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The super dense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where non-unitary encoding leads to an improvement in the super dense coding capacity.

  4. Dense module enumeration in biological networks

    Science.gov (United States)

    Tsuda, Koji; Georgii, Elisabeth

    2009-12-01

    Analysis of large networks is a central topic in various research fields including biology, sociology, and web mining. Detection of dense modules (a.k.a. clusters) is an important step to analyze the networks. Though numerous methods have been proposed to this aim, they often lack mathematical rigorousness. Namely, there is no guarantee that all dense modules are detected. Here, we present a novel reverse-search-based method for enumerating all dense modules. Furthermore, constraints from additional data sources such as gene expression profiles or customer profiles can be integrated, so that we can systematically detect dense modules with interesting profiles. We report successful applications in human protein interaction network analyses.

  5. Dense module enumeration in biological networks

    International Nuclear Information System (INIS)

    Tsuda, Koji; Georgii, Elisabeth

    2009-01-01

    Analysis of large networks is a central topic in various research fields including biology, sociology, and web mining. Detection of dense modules (a.k.a. clusters) is an important step to analyze the networks. Though numerous methods have been proposed to this aim, they often lack mathematical rigorousness. Namely, there is no guarantee that all dense modules are detected. Here, we present a novel reverse-search-based method for enumerating all dense modules. Furthermore, constraints from additional data sources such as gene expression profiles or customer profiles can be integrated, so that we can systematically detect dense modules with interesting profiles. We report successful applications in human protein interaction network analyses.

  6. Locating sources within a dense sensor array using graph clustering

    Science.gov (United States)

    Gerstoft, P.; Riahi, N.

    2017-12-01

    We develop a model-free technique to identify weak sources within dense sensor arrays using graph clustering. No knowledge about the propagation medium is needed except that signal strengths decay to insignificant levels within a scale that is shorter than the aperture. We then reinterpret the spatial coherence matrix of a wave field as a matrix whose support is a connectivity matrix of a graph with sensors as vertices. In a dense network, well-separated sources induce clusters in this graph. The geographic spread of these clusters can serve to localize the sources. The support of the covariance matrix is estimated from limited-time data using a hypothesis test with a robust phase-only coherence test statistic combined with a physical distance criterion. The latter criterion ensures graph sparsity and thus prevents clusters from forming by chance. We verify the approach and quantify its reliability on a simulated dataset. The method is then applied to data from a dense 5200 element geophone array that blanketed of the city of Long Beach (CA). The analysis exposes a helicopter traversing the array and oil production facilities.

  7. STAR FORMATION IN DENSE CLUSTERS

    International Nuclear Information System (INIS)

    Myers, Philip C.

    2011-01-01

    A model of core-clump accretion with equally likely stopping describes star formation in the dense parts of clusters, where models of isolated collapsing cores may not apply. Each core accretes at a constant rate onto its protostar, while the surrounding clump gas accretes as a power of protostar mass. Short accretion flows resemble Shu accretion and make low-mass stars. Long flows resemble reduced Bondi accretion and make massive stars. Accretion stops due to environmental processes of dynamical ejection, gravitational competition, and gas dispersal by stellar feedback, independent of initial core structure. The model matches the field star initial mass function (IMF) from 0.01 to more than 10 solar masses. The core accretion rate and the mean accretion duration set the peak of the IMF, independent of the local Jeans mass. Massive protostars require the longest accretion durations, up to 0.5 Myr. The maximum protostar luminosity in a cluster indicates the mass and age of its oldest protostar. The distribution of protostar luminosities matches those in active star-forming regions if protostars have a constant birthrate but not if their births are coeval. For constant birthrate, the ratio of young stellar objects to protostars indicates the star-forming age of a cluster, typically ∼1 Myr. The protostar accretion luminosity is typically less than its steady spherical value by a factor of ∼2, consistent with models of episodic disk accretion.

  8. Pulsars and cosmic rays in the dense supernova shells

    International Nuclear Information System (INIS)

    Berezinsky, V.S.; Prilutsky, O.F.

    1977-01-01

    Cosmic rays (c.r.) injected by a young pulsar in the dense supernova shell are considered. The maintenance of the Galactic c.r. pool by pulsar production is shown to have a difficulty: adiabatic energy losses of c.r. in the expanding shell demand a high initial c.r. luminosity of pulsar, which results in too high flux of γ-radiation produced through π 0 -decays (in excess over diffuse γ-ray background). (author)

  9. Three-phase flow analysis of dense nonaqueous phase liquid infiltration in horizontally layered porous media

    NARCIS (Netherlands)

    Wipfler, E.L.; Dijke, van M.I.J.; Zee, van der S.E.A.T.M.

    2004-01-01

    We considered dense nonaqueous phase liquid (DNAPL) infiltration into a water-unsaturated porous medium that consists of two horizontal layers, of which the top layer has a lower intrinsic permeability than the bottom layer. DNAPL is the intermediate-wetting fluid with respect to the wetting water

  10. Hugoniot measurements of double-shocked precompressed dense xenon plasmas

    Science.gov (United States)

    Zheng, J.; Chen, Q. F.; Gu, Y. J.; Chen, Z. Y.

    2012-12-01

    The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ˜6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures.

  11. Dense image correspondences for computer vision

    CERN Document Server

    Liu, Ce

    2016-01-01

    This book describes the fundamental building-block of many new computer vision systems: dense and robust correspondence estimation. Dense correspondence estimation techniques are now successfully being used to solve a wide range of computer vision problems, very different from the traditional applications such techniques were originally developed to solve. This book introduces the techniques used for establishing correspondences between challenging image pairs, the novel features used to make these techniques robust, and the many problems dense correspondences are now being used to solve. The book provides information to anyone attempting to utilize dense correspondences in order to solve new or existing computer vision problems. The editors describe how to solve many computer vision problems by using dense correspondence estimation. Finally, it surveys resources, code, and data necessary for expediting the development of effective correspondence-based computer vision systems.   ·         Provides i...

  12. Load Designs For MJ Dense Plasma Foci

    Science.gov (United States)

    Link, A.; Povlius, A.; Anaya, R.; Anderson, M. G.; Angus, J. R.; Cooper, C. M.; Falabella, S.; Goerz, D.; Higginson, D.; Holod, I.; McMahon, M.; Mitrani, J.; Koh, E. S.; Pearson, A.; Podpaly, Y. A.; Prasad, R.; van Lue, D.; Watson, J.; Schmidt, A. E.

    2017-10-01

    Dense plasma focus (DPF) Z-pinches are compact pulse power driven devices with coaxial electrodes. The discharge of DPF consists of three distinct phases: first generation of a plasma sheath, plasma rail gun phase where the sheath is accelerated down the electrodes and finally an implosion phase where the plasma stagnates into a z-pinch geometry. During the z-pinch phase, DPFs can produce MeV ion beams, x-rays and neutrons. Megaampere class DPFs with deuterium fills have demonstrated neutron yields in the 1012 neutrons/shot range with pulse durations of 10-100 ns. Kinetic simulations using the code Chicago are being used to evaluate various load configurations from initial sheath formation to the final z-pinch phase for DPFs with up to 5 MA and 1 MJ coupled to the load. Results will be presented from the preliminary design simulations. LLNL-ABS-734785 This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory (LLNL) under Contract DE-AC52-07NA27344 and with support from the Computing Grand Challenge program at LLNL.

  13. Kinetic Simulations of Dense Plasma Focus Breakdown

    Science.gov (United States)

    Schmidt, A.; Higginson, D. P.; Jiang, S.; Link, A.; Povilus, A.; Sears, J.; Bennett, N.; Rose, D. V.; Welch, D. R.

    2015-11-01

    A dense plasma focus (DPF) device is a type of plasma gun that drives current through a set of coaxial electrodes to assemble gas inside the device and then implode that gas on axis to form a Z-pinch. This implosion drives hydrodynamic and kinetic instabilities that generate strong electric fields, which produces a short intense pulse of x-rays, high-energy (>100 keV) electrons and ions, and (in deuterium gas) neutrons. A strong factor in pinch performance is the initial breakdown and ionization of the gas along the insulator surface separating the two electrodes. The smoothness and isotropy of this ionized sheath are imprinted on the current sheath that travels along the electrodes, thus making it an important portion of the DPF to both understand and optimize. Here we use kinetic simulations in the Particle-in-cell code LSP to model the breakdown. Simulations are initiated with neutral gas and the breakdown modeled self-consistently as driven by a charged capacitor system. We also investigate novel geometries for the insulator and electrodes to attempt to control the electric field profile. The initial ionization fraction of gas is explored computationally to gauge possible advantages of pre-ionization which could be created experimentally via lasers or a glow-discharge. Prepared by LLNL under Contract DE-AC52-07NA27344.

  14. OH megamasers: dense gas & the infrared radiation field

    Science.gov (United States)

    Huang, Yong; Zhang, JiangShui; Liu, Wei; Xu, Jie

    2018-06-01

    To investigate possible factors related to OH megamaser formation (OH MM, L_{H2O}>10L_{⊙}), we compiled a large HCN sample from all well-sampled HCN measurements so far in local galaxies and identified with the OH MM, OH kilomasers (L_{H2O}gas and the dense gas, respectively), we found that OH MM galaxies tend to have stronger HCN emission and no obvious difference on CO luminosity exists between OH MM and non-OH MM. This implies that OH MM formation should be related to the dense molecular gas, instead of the low-density molecular gas. It can be also supported by other facts: (1) OH MMs are confirmed to have higher mean molecular gas density and higher dense gas fraction (L_{HCN}/L_{CO}) than non-OH MMs. (2) After taking the distance effect into account, the apparent maser luminosity is still correlated with the HCN luminosity, while no significant correlation can be found at all between the maser luminosity and the CO luminosity. (3) The OH kMs tend to have lower values than those of OH MMs, including the dense gas luminosity and the dense gas fraction. (4) From analysis of known data of another dense gas tracer HCO^+, similar results can also be obtained. However, from our analysis, the infrared radiation field can not be ruled out for the OH MM trigger, which was proposed by previous works on one small sample (Darling in ApJ 669:L9, 2007). On the contrary, the infrared radiation field should play one more important role. The dense gas (good tracers of the star formation) and its surrounding dust are heated by the ultra-violet (UV) radiation generated by the star formation and the heating of the high-density gas raises the emission of the molecules. The infrared radiation field produced by the re-radiation of the heated dust in turn serves for the pumping of the OH MM.

  15. Inferring segmented dense motion layers using 5D tensor voting.

    Science.gov (United States)

    Min, Changki; Medioni, Gérard

    2008-09-01

    We present a novel local spatiotemporal approach to produce motion segmentation and dense temporal trajectories from an image sequence. A common representation of image sequences is a 3D spatiotemporal volume, (x,y,t), and its corresponding mathematical formalism is the fiber bundle. However, directly enforcing the spatiotemporal smoothness constraint is difficult in the fiber bundle representation. Thus, we convert the representation into a new 5D space (x,y,t,vx,vy) with an additional velocity domain, where each moving object produces a separate 3D smooth layer. The smoothness constraint is now enforced by extracting 3D layers using the tensor voting framework in a single step that solves both correspondence and segmentation simultaneously. Motion segmentation is achieved by identifying those layers, and the dense temporal trajectories are obtained by converting the layers back into the fiber bundle representation. We proceed to address three applications (tracking, mosaic, and 3D reconstruction) that are hard to solve from the video stream directly because of the segmentation and dense matching steps, but become straightforward with our framework. The approach does not make restrictive assumptions about the observed scene or camera motion and is therefore generally applicable. We present results on a number of data sets.

  16. Colour deconfinement in hot and dense matter

    CERN Document Server

    Satz, Helmut

    1996-01-01

    We first introduce the conceptual basis of critical behaviour in strongly interacting matter, with colour deconfinement as QCD analog of the insulator-conductor transition and chiral symmetry restoration as special case of the associated shift in the mass of the constituents. Next we summarize quark-gluon plasma formation in finite temperature lattice QCD. We consider the underlying symmetries and their spontaneous breaking/restoration in the transition, as well as the resulting changes in thermodynamic behaviour. Finally, we turn to the experimental study of strongly interacting matter by high energy nuclear collisions, using charmonium production to probe the confinement status of the produced primordial medium. Recent results from Pb-Pb collisions at CERN may provide first evidence for colour deconfinement.

  17. Composite systems of dilute and dense couplings

    International Nuclear Information System (INIS)

    Raymond, J R; Saad, D

    2008-01-01

    Composite systems, where couplings are of two types, a combination of strong dilute and weak dense couplings of Ising spins, are examined through the replica method. The dilute and dense parts are considered to have independent canonical disordered or uniform bond distributions; mixing the models by variation of a parameter γ alongside inverse temperature β we analyse the respective thermodynamic solutions. We describe the variation in high temperature transitions as mixing occurs; in the vicinity of these transitions we exactly analyse the competing effects of the dense and sparse models. By using the replica symmetric ansatz and population dynamics we described the low temperature behaviour of mixed systems

  18. Effect of the pH of the medium during growth on the enzymic activities of bacteria (Escherichia coli and Micrococcus lysodeikticus) and the biological significance of the changes produced

    Energy Technology Data Exchange (ETDEWEB)

    Gale, E F; Epps, H M.R.

    1942-01-01

    Change in the external pH during growth of E. Coli is followed by an alteration in the enzyme content of the cells. The enzymes can be divided into two groups, those whose formation undergoes a variation so that their activity per cell is constant whatever the medium pH, and those whose formation is greatest when the growth pH approaches their optimum activity pH. In general, a change in the external pH is followed by an alteration in the enzymic constitution of the cells such that an attempt is made to counter the external change and that certain essential activities are maintained at a constant level. 21 references, 15 figures, 3 tables.

  19. Application of laser additive manufacturing to produce dies for aluminium high pressure die casting

    CSIR Research Space (South Africa)

    Pereira, MFVT

    2012-07-01

    Full Text Available through immersion in liquid aluminium. The dipping cycle closely resembles the heating and cooling cycle of a typical aluminium die under casting conditions. The suitability of any LAM technology, that can produce fully dense metallic components... cost vs wrought manufactured 5.2 1,7 2. 2 Average cost Very High Medium High Table 3: Processing and finishing costs of test coupons 3.1 Cyclic Immersion in Molten Aluminium Figure 3 below shows the testing apparatus developed to simulate...

  20. Intense, ultrashort light and dense, hot matter

    Indian Academy of Sciences (India)

    tiphoton and tunneling ionization, the physics of plasma formed in dense matter is .... A typical Gaussian laser pulse of 100 fs dura- .... J range) – and finally it is compressed back to its .... bond-hardening, molecular orientation and reori-.

  1. Finding dense locations in indoor tracking data

    DEFF Research Database (Denmark)

    Ahmed, Tanvir; Pedersen, Torben Bach; Lu, Hua

    2014-01-01

    for semi-constrained indoor movement, and then uses this to map raw tracking records into mapping records representing object entry and exit times in particular locations. Then, an efficient indexing structure, the Dense Location Time Index (DLT-Index) is proposed for indexing the time intervals...... of the mapping table, along with associated construction, query processing, and pruning techniques. The DLT-Index supports very efficient aggregate point queries, interval queries, and dense location queries. A comprehensive experimental study with real data shows that the proposed techniques can efficiently......Finding the dense locations in large indoor spaces is very useful for getting overloaded locations, security, crowd management, indoor navigation, and guidance. Indoor tracking data can be very large and are not readily available for finding dense locations. This paper presents a graph-based model...

  2. Interference Coordination for Dense Wireless Networks

    DEFF Research Database (Denmark)

    Soret, Beatriz; Pedersen, Klaus I.; Jørgensen, Niels T.K.

    2015-01-01

    and dense deployment in Tokyo are compared. Evolution to DenseNets offers new opportunities for further development of downlink interference cooperation techniques. Various mechanisms in LTE and LTE-Advanced are revisited. Some techniques try to anticipate the future in a proactive way, whereas others......The promise of ubiquitous and super-fast connectivity for the upcoming years will be in large part fulfilled by the addition of base stations and spectral aggregation. The resulting very dense networks (DenseNets) will face a number of technical challenges. Among others, the interference emerges...... as an old acquaintance with new significance. As a matter of fact, the interference conditions and the role of aggressor and victim depend to a large extent on the density and the scenario. To illustrate this, downlink interference statistics for different 3GPP simulation scenarios and a more irregular...

  3. Skyrmions, dense matter and nuclear forces

    International Nuclear Information System (INIS)

    Pethick, C.J.

    1984-12-01

    A simple introduction to a number of properties of Skyrme's chiral soliton model of baryons is given. Some implications of the model for dense matter and for nuclear interactions are discussed. (orig.)

  4. Dynamical theory of dense groups of galaxies

    Science.gov (United States)

    Mamon, Gary A.

    1990-01-01

    It is well known that galaxies associate in groups and clusters. Perhaps 40% of all galaxies are found in groups of 4 to 20 galaxies (e.g., Tully 1987). Although most groups appear to be so loose that the galaxy interactions within them ought to be insignificant, the apparently densest groups, known as compact groups appear so dense when seen in projection onto the plane of the sky that their members often overlap. These groups thus appear as dense as the cores of rich clusters. The most popular catalog of compact groups, compiled by Hickson (1982), includes isolation among its selection critera. Therefore, in comparison with the cores of rich clusters, Hickson's compact groups (HCGs) appear to be the densest isolated regions in the Universe (in galaxies per unit volume), and thus provide in principle a clean laboratory for studying the competition of very strong gravitational interactions. The $64,000 question here is then: Are compact groups really bound systems as dense as they appear? If dense groups indeed exist, then one expects that each of the dynamical processes leading to the interaction of their member galaxies should be greatly enhanced. This leads us to the questions: How stable are dense groups? How do they form? And the related question, fascinating to any theorist: What dynamical processes predominate in dense groups of galaxies? If HCGs are not bound dense systems, but instead 1D change alignments (Mamon 1986, 1987; Walke & Mamon 1989) or 3D transient cores (Rose 1979) within larger looser systems of galaxies, then the relevant question is: How frequent are chance configurations within loose groups? Here, the author answers these last four questions after comparing in some detail the methods used and the results obtained in the different studies of dense groups.

  5. Kinetic chemistry of dense interstellar clouds

    International Nuclear Information System (INIS)

    Graedel, T.E.; Langer, W.D.; Frerking, M.A.

    1982-01-01

    A detailed model of the time-dependent chemistry of dense interstellar clouds has been developed to study the dominant chemical processes in carbon and oxygen isotope fractionation, formation of nitrogen-containing molecules, evolution of product molecules as a function of cloud density and temperature, and other topics of interest. The full computation involves 328 individual reactions (expanded to 1067 to study carbon and oxygen isotope chemistry); photodegradation processes are unimportant in these dense clouds and are excluded

  6. Propagation of complex shaped ultrafast pulses in highly optically dense samples

    International Nuclear Information System (INIS)

    Davis, J. C.; Fetterman, M. R.; Warren, W. S.; Goswami, D.

    2008-01-01

    We examine the propagation of shaped (amplitude- and frequency-modulated) ultrafast laser pulses through optically dense rubidium vapor. Pulse reshaping, stimulated emission dynamics, and residual electronic excitation all strongly depend on the laser pulse shape. For example, frequency swept pulses, which produce adiabatic passage in the optically thin limit (independent of the sign of the frequency sweep), behave unexpectedly in optically dense samples. Paraxial Maxwell optical Bloch equations can model our ultrafast pulse propagation results well and provide insight

  7. The environmental performance of three alcohol fuel plants producers of small, medium and big scale; O desempenho eco-ambiental de tres usinas produtoras de alcool combustivel de pequeno, medio e grande porte

    Energy Technology Data Exchange (ETDEWEB)

    Borrero, Manuel Antonio Valdes; Pereira, Jose Tomaz Vieira [Universidade Estadual de Campinas, SP (Brazil); Miranda, Evaristo Eduardo de [Empresa Brasileira de Pesquisa Agropecuaria, Campinas, SP (Brazil). Nucleo de Monitoramento Ambiental e de Recursos Naturais por Satelite

    1999-07-01

    The article discusses the following issues of alcohol fuel plants producers: sizing; performance; natural resources; environmental aspects; and electric power generation. The environmental performance concept is introduced and a performance evaluation methodology are presented and applied. The results are also presented and criticized.

  8. 16. Hot dense plasma atomic processes

    International Nuclear Information System (INIS)

    Werner, Dappen; Totsuji, H.; Nishii, Y.

    2002-01-01

    This document gathers 13 articles whose common feature is to deal with atomic processes in hot plasmas. Density functional molecular dynamics method is applied to the hydrogen plasma in the domain of liquid metallic hydrogen. The effects of the density gradient are taken into account in both the electronic kinetic energy and the exchange energy and it is shown that they almost cancel with each other, extending the applicability of the Thomas-Fermi-Dirac approximation to the cases where the density gradient is not negligible. Another article reports about space and time resolved M-shell X-ray measurements of a laser-produced gas jet xenon plasma. Plasma parameters have been measured by ion acoustic and electron plasma waves Thomson scattering. Photo-ionization becomes a dominant atomic process when the density and the temperature of plasmas are relatively low and when the plasma is submitted to intense external radiation. It is shown that 2 plasmas which have a very different density but have the same ionization parameters, are found in a similar ionization state. Most radiation hydrodynamics codes use radiative opacity data from available libraries of atomic data. Several articles are focused on the determination of one group Rosseland and Planck mean analytical formulas for several single elements used in inertial fusion targets. In another paper the plasma density effect on population densities, effective ionization, recombination rate coefficients and on emission lines from carbon and Al ions in hot dense plasma, is studied. The last article is devoted to a new atomic model in plasmas that considers the occupation probability of the bound state and free state density in the presence of the plasma micro-field. (A.C.)

  9. DENSE MOLECULAR CORES BEING EXTERNALLY HEATED

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gwanjeong; Lee, Chang Won; Kim, Mi-Ryang [Radio Astronomy division, Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon, 34055 (Korea, Republic of); Gopinathan, Maheswar [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263129 (India); Jeong, Woong-Seob, E-mail: archer81@kasi.re.kr [Department of Astronomy and Space Science, University of Science and Technology, 217 Gajungro, Yuseong-gu, Daejeon, 34113 (Korea, Republic of)

    2016-06-20

    We present results of our study of eight dense cores, previously classified as starless, using infrared (3–160 μ m) imaging observations with the AKARI telescope and molecular line (HCN and N{sub 2}H{sup +}) mapping observations with the KVN telescope. Combining our results with the archival IR to millimeter continuum data, we examined the starless nature of these eight cores. Two of the eight cores are found to harbor faint protostars having luminosities of ∼0.3–4.4 L {sub ⊙}. The other six cores are found to remain starless and probably are in a dynamically transitional state. The temperature maps produced using multi-wavelength images show an enhancement of about 3–6 K toward the outer boundary of these cores, suggesting that they are most likely being heated externally by nearby stars and/or interstellar radiation fields. Large virial parameters and an overdominance of red asymmetric line profiles over the cores may indicate that the cores are set into either an expansion or an oscillatory motion, probably due to the external heating. Most of the starless cores show a coreshine effect due to the scattering of light by the micron-sized dust grains. This may imply that the age of the cores is of the order of ∼10{sup 5} years, which is consistent with the timescale required for the cores to evolve into an oscillatory stage due to external perturbation. Our observational results support the idea that the external feedback from nearby stars and/or interstellar radiation fields may play an important role in the dynamical evolution of the cores.

  10. Outline of experimental schemes for measurements of thermophysical and transport properties in warm dense matter at GSI and FAIR

    International Nuclear Information System (INIS)

    Tauschwitz, Anna; Jacoby, Joachim; Maruhn, Joachim; Basko, Mikhail; Efremov, Vladimir; Iosilevskiy, Igor; Neumayer, Paul; Novikov, Vladimir; Tauschwitz, Andreas; Rosmej, Frank

    2010-01-01

    Different experimental schemes for investigation of warm dense matter produced with intense energetic ion beams are presented. The described target configurations allow direct measurements of thermophysical and transport properties of warm dense matter without hydrodynamic recalculations. The presented experiments will be realized at the current GSI synchrotron SIS-18 and the future FAIR facility in the framework of the WDM-collaboration.

  11. An extended GS method for dense linear systems

    Science.gov (United States)

    Niki, Hiroshi; Kohno, Toshiyuki; Abe, Kuniyoshi

    2009-09-01

    Davey and Rosindale [K. Davey, I. Rosindale, An iterative solution scheme for systems of boundary element equations, Internat. J. Numer. Methods Engrg. 37 (1994) 1399-1411] derived the GSOR method, which uses an upper triangular matrix [Omega] in order to solve dense linear systems. By applying functional analysis, the authors presented an expression for the optimum [Omega]. Moreover, Davey and Bounds [K. Davey, S. Bounds, A generalized SOR method for dense linear systems of boundary element equations, SIAM J. Comput. 19 (1998) 953-967] also introduced further interesting results. In this note, we employ a matrix analysis approach to investigate these schemes, and derive theorems that compare these schemes with existing preconditioners for dense linear systems. We show that the convergence rate of the Gauss-Seidel method with preconditioner PG is superior to that of the GSOR method. Moreover, we define some splittings associated with the iterative schemes. Some numerical examples are reported to confirm the theoretical analysis. We show that the EGS method with preconditioner produces an extremely small spectral radius in comparison with the other schemes considered.

  12. Carbon chemistry in dense molecular clouds: Theory and observational constraints

    International Nuclear Information System (INIS)

    Blake, G.A.

    1990-01-01

    For the most part, gas phase models of the chemistry of dense molecular clouds predict the abundances of simple species rather well. However, for larger molecules and even for small systems rich in carbon these models often fail spectacularly. Researchers present a brief review of the basic assumptions and results of large scale modeling of the carbon chemistry in dense molecular clouds. Particular attention is to the influence of the gas phase C/O ratio in molecular clouds, and the likely role grains play in maintaining this ratio as clouds evolve from initially diffuse objects to denser cores with associated stellar and planetary formation. Recent spectral line surveys at centimeter and millimeter wavelengths along with selected observations in the submillimeter have now produced an accurate inventory of the gas phase carbon budget in several different types of molecular clouds, though gaps in our knowledge clearly remain. The constraints these observations place on theoretical models of interstellar chemistry can be used to gain insights into why the models fail, and show also which neglected processes must be included in more complete analyses. Looking toward the future, larger molecules are especially difficult to study both experimentally and theoretically in such dense, cold regions, and some new methods are therefore outlined which may ultimately push the detectability of small carbon chains and rings to much heavier species

  13. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    Energy Technology Data Exchange (ETDEWEB)

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O' Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  14. Thermodynamic instabilities in hot and dense nuclear matter

    Directory of Open Access Journals (Sweden)

    Lavagno A.

    2016-01-01

    Full Text Available We study the presence of thermodynamic instabilities in a hot and dense nuclear medium where a nuclear phase transition can take place. Similarly to the low density nuclear liquid-gas phase transition, we show that such a phase transition is characterized by pure hadronic matter with both mechanical instability (fluctuations on the baryon density that by chemical-diffusive instability (fluctuations on the strangeness concentration. The analysis is performed by requiring the global conservation of baryon number and zero net strangeness in the framework of an effective relativistic mean field theory with the inclusion of the Δ(1232-isobars, hyperons and the lightest pseudoscalar and vector meson degrees of freedom. It turns out that in this situation hadronic phases with different values of strangeness content may coexist, altering significantly meson-antimeson ratios.

  15. Effective Field Theories for Hot and Dense Matter

    Directory of Open Access Journals (Sweden)

    Blaschke D.

    2010-10-01

    Full Text Available The lecture is divided in two parts. The first one deals with an introduction to the physics of hot, dense many-particle systems in quantum field theory [1, 2]. The basics of the path integral approach to the partition function are explained for the example of chiral quark models. The QCD phase diagram is discussed in the meanfield approximation while QCD bound states in the medium are treated in the rainbow-ladder approximation (Gaussian fluctuations. Special emphasis is devoted to the discussion of the Mott effect, i.e. the transition of bound states to unbound, but resonant scattering states in the continnum under the influence of compression and heating of the system. Three examples are given: (1 the QCD model phase diagram with chiral symmetry ¨ restoration and color superconductivity [3], (2 the Schrodinger equation for heavy-quarkonia [4], and (2 Pions [5] as well as Kaons and D-mesons in the finite-temperature Bethe-Salpeter equation [6]. We discuss recent applications of this quantum field theoretical approach to hot and dense quark matter for a description of anomalous J/ψ supression in heavy-ion collisions [7] and for the structure and cooling of compact stars with quark matter interiors [8]. The second part provides a detailed introduction to the Polyakov-loop Nambu–Jona-Lasinio model [9] for thermodynamics and mesonic correlations [10] in the phase diagram of quark matter. Important relationships of low-energy QCD like the Gell-Mann–Oakes–Renner relation are generalized to finite temperatures. The effect of including the coupling to the Polyakov-loop potential on the phase diagram and mesonic correlations is discussed. An outlook is given to effects of nonlocality of the interactions [11] and of mesonic correlations in the medium [12] which go beyond the meanfield description.

  16. Processes in a dense long-pulse electron beam focused on a solid target

    Energy Technology Data Exchange (ETDEWEB)

    Arkhipov, A V; Sominskij, G G [St. Petersburg Technical Univ. (Russian Federation)

    1997-12-31

    The results obtained in beam-target experiments with dense medium-energy electron beam in the regime of long single pulses are presented. The measured power density of the focused beam at the target reached 20 MW/cm{sup 2} in these experiments. The processes caused by dense flows of secondary particles and by a dense target ablation plasma were studied in detail. Substantial target shielding occurs when the energy density at the target exceeds the value of about 1 kJ/cm{sup 2}. The target plasma and the sputtered matter that is responsible for shielding affects also the beam structure, as well as the target etching rates. (J.U.). 3 figs., 5 refs.

  17. Processes in a dense long-pulse electron beam focused on a solid target

    International Nuclear Information System (INIS)

    Arkhipov, A.V.; Sominskij, G.G.

    1996-01-01

    The results obtained in beam-target experiments with dense medium-energy electron beam in the regime of long single pulses are presented. The measured power density of the focused beam at the target reached 20 MW/cm 2 in these experiments. The processes caused by dense flows of secondary particles and by a dense target ablation plasma were studied in detail. Substantial target shielding occurs when the energy density at the target exceeds the value of about 1 kJ/cm 2 . The target plasma and the sputtered matter that is responsible for shielding affects also the beam structure, as well as the target etching rates. (J.U.). 3 figs., 5 refs

  18. Probing hot dense matter with jet energy loss

    International Nuclear Information System (INIS)

    Levai, P.; Barnafoeldi, G.G.; Gyulassy, M.; Vitev, I.; Fai, G.; Zhang, Y.

    2002-01-01

    We study, in a pQCD calculation augmented by nuclear effects, the jet energy loss needed to reproduce the π 0 spectra in Au+Au collisions at large p T , measured by PHENIX at RHIC. The transverse width of the parton momentum distributions (intrinsic k T ) is used phenomenologically to obtain a reliable baseline pp result. Jet quenching is applied to the nuclear spectra (including shadowing and multiscattering) to fit the data. Latest results on fluctuating gluon radiation are considered to measure the opacity of the produced hot dense matter at RHIC energy. (orig.)

  19. Interaction of graphite with a hot, dense deuterium plasma

    International Nuclear Information System (INIS)

    Desko, J.C. Jr.

    1980-01-01

    The erosion of ATJ-S graphite caused by a hot, dense deuterium plasma has been investigated experimentally. The plasma was produced in an electromagnetic shock tube. Plasma characteristics were typically: ion temperature approx. = 800 eV (approx. 1 x 10 7 0 K), number density approx. = 10 16 /cm 3 , and transverse magnetic field approx. = 1 tesla. The energetic ion flux, phi, to the sample surfaces was approx. 10 23 ions/cm 2 -sec for a single pulse duration of approx. 0.1 usec. Sample surfaces were metallographically prepared and examined with a scanning electron microscope before and after exposure

  20. Probing Dense Sprays with Gated, Picosecond, Digital Particle Field Holography

    Directory of Open Access Journals (Sweden)

    James Trolinger

    2011-12-01

    Full Text Available This paper describes work that demonstrated the feasibility of producing a gated digital holography system that is capable of producing high-resolution images of three-dimensional particle and structure details deep within dense particle fields of a spray. We developed a gated picosecond digital holocamera, using optical Kerr cell gating, to demonstrate features of gated digital holography that make it an exceptional candidate for this application. The Kerr cell gate shuttered the camera after the initial burst of ballistic and snake photons had been recorded, suppressing longer path, multiple scattered illumination. By starting with a CW laser without gating and then incorporating a picosecond laser and an optical Kerr gate, we were able to assess the imaging quality of the gated holograms, and determine improvement gained by gating. We produced high quality images of 50–200 μm diameter particles, hairs and USAF resolution charts from digital holograms recorded through turbid media where more than 98% of the light was scattered from the field. The system can gate pulses as short as 3 mm in pathlength (10 ps, enabling image-improving features of the system. The experiments lead us to the conclusion that this method has an excellent capability as a diagnostics tool in dense spray combustion research.

  1. Radiation damage in nonmetallic solids under dense electronic excitation

    International Nuclear Information System (INIS)

    Itoh, Noriaki; Tanimura, Katsumi; Nakai, Yasuo

    1992-01-01

    Basic processes of radiation damage of insulators by dense electronic excitation are reviewed. First it is pointed out that electronic excitation of nonmetallic solids produces the self-trapped excitons and defect-related metastable states having relatively long lifetimes, and that the excitation of these metastable states, produces stable defects. The effects of irradiation with heavy ions, including track registration, are surveyed on the basis of the microscopic studies. It is pointed out also that the excitation of the metastable states plays a role in laser-induced damage at relatively low fluences, while the laser damage has been reported to be governed by heating of free electrons produced by multiphoton excitation. Difference in the contributions of the excitation of metastable defects to laser-induced damage of surfaces, or laser ablation, and laser-induced bulk damage is stressed. (orig.)

  2. INTERACTIONS BETWEEN FORMING STARS AND DENSE GAS IN THE SMALL LOW-MASS CLUSTER CEDERBLAD 110

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, E. F. [Department of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Wong, T. [Department of Astronomy, University of Illinois, Urbana, IL 61801 (United States); Bourke, T. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Thompson, K. L., E-mail: ladd@bucknell.edu [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States)

    2011-12-20

    We present observations of dense gas and outflow activity in the Cederblad 110 region of the Chamaeleon I dark cloud complex. The region contains nine forming low-mass stars in evolutionary stages ranging from Class 0 to Class II/III crowded into a 0.2 pc region with high surface density ({Sigma}{sub YSO} {approx} 150 pc{sup -2}). The analysis of our N{sub 2}H{sup +} (J = 1{yields}0) maps indicates the presence of 13 {+-} 3 solar masses of dense (n {approx} 10{sup 5} cm{sup -3}) gas in this region, much of which is unstable against gravitational collapse. The most unstable material is located near the Class 0 source MMS-1, which is almost certainly actively accreting material from its dense core. Smaller column densities of more stable dense gas are found toward the region's Class I sources, IRS 4, 11, and 6. Little or no dense gas is colocated with the Class II and III sources in the region. The outflow from IRS 4 is interacting with the dense core associated with MMS-1. The molecular component of the outflow, measured in the (J = 1{yields}0) line of {sup 12}CO, appears to be deflected by the densest part of the core, after which it appears to plow through some of the lower column density portions of the core. The working surface between the head of the outflow lobe and the dense core material can be seen in the enhanced velocity dispersion of the dense gas. IRS 2, the Class III source that produces the optical reflection nebula that gives the Cederblad 110 region its name, may also be influencing the dense gas in the region. A dust temperature gradient across the MMS-1 dense core is consistent with warming from IRS 2, and a sharp gradient in dense gas column density may be caused by winds from this source. Taken together, our data indicate that this region has been producing several young stars in the recent past, and that sources which began forming first are interacting with the remaining dense gas in the region, thereby influencing current and future star

  3. Constitutive law of dense granular matter

    International Nuclear Information System (INIS)

    Hatano, Takahiro

    2010-01-01

    The frictional properties of dense granular matter under steady shear flow are investigated using numerical simulation. Shear flow tends to localize near the driving boundary unless the coefficient of restitution is close to zero and the driving velocity is small. The bulk friction coefficient is independent of shear rate in dense and slow flow, whereas it is an increasing function of shear rate in rapid flow. The coefficient of restitution affects the friction coefficient only in such rapid flow. Contrastingly, in dense and slow regime, the friction coefficient is independent of the coefficient of restitution and mainly determined by the elementary friction coefficient and the rotation of grains. It is found that the mismatch between the vorticity of flow and the angular frequency of grains plays a key role to the frictional properties of sheared granular matter.

  4. Multiple and dependent scattering by densely packed discrete spheres: Comparison of radiative transfer and Maxwell theory

    International Nuclear Information System (INIS)

    Ma, L.X.; Tan, J.Y.; Zhao, J.M.; Wang, F.Q.; Wang, C.A.

    2017-01-01

    The radiative transfer equation (RTE) has been widely used to deal with multiple scattering of light by sparsely and randomly distributed discrete particles. However, for densely packed particles, the RTE becomes questionable due to strong dependent scattering effects. This paper examines the accuracy of RTE by comparing with the exact electromagnetic theory. For an imaginary spherical volume filled with randomly distributed, densely packed spheres, the RTE is solved by the Monte Carlo method combined with the Percus–Yevick hard model to consider the dependent scattering effect, while the electromagnetic calculation is based on the multi-sphere superposition T-matrix method. The Mueller matrix elements of the system with different size parameters and volume fractions of spheres are obtained using both methods. The results verify that the RTE fails to deal with the systems with a high-volume fraction due to the dependent scattering effects. Apart from the effects of forward interference scattering and coherent backscattering, the Percus–Yevick hard sphere model shows good accuracy in accounting for the far-field interference effects for medium or smaller size parameters (up to 6.964 in this study). For densely packed discrete spheres with large size parameters (equals 13.928 in this study), the improvement of dependent scattering correction tends to deteriorate. The observations indicate that caution must be taken when using RTE in dealing with the radiative transfer in dense discrete random media even though the dependent scattering correction is applied. - Highlights: • The Muller matrix of randomly distributed, densely packed spheres are investigated. • The effects of multiple scattering and dependent scattering are analyzed. • The accuracy of radiative transfer theory for densely packed spheres is discussed. • Dependent scattering correction takes effect at medium size parameter or smaller. • Performance of dependent scattering correction

  5. Nucleon structure and properties of dense matter

    International Nuclear Information System (INIS)

    Kutschera, M.; Pethick, C.J.; Illinois Univ., Urbana, IL

    1988-01-01

    We consider the properties of dense matter in a framework of the Skyrme soliton model and the chiral bag model. The influence of the nucleon structure on the equation of state of dense matter is emphasized. We find that in both models the energy per unit volume is proportional to n 4/3 , n being the baryon number density. We discuss the properties of neutron stars with a derived equation of state. The role of many-body effects is investigated. The effect of including higher order terms in the chiral lagrangian is examined. The phase transition to quark matter is studied. 29 refs., 6 figs. (author)

  6. Fast Solvers for Dense Linear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kauers, Manuel [Research Institute for Symbolic Computation (RISC), Altenbergerstrasse 69, A4040 Linz (Austria)

    2008-10-15

    It appears that large scale calculations in particle physics often require to solve systems of linear equations with rational number coefficients exactly. If classical Gaussian elimination is applied to a dense system, the time needed to solve such a system grows exponentially in the size of the system. In this tutorial paper, we present a standard technique from computer algebra that avoids this exponential growth: homomorphic images. Using this technique, big dense linear systems can be solved in a much more reasonable time than using Gaussian elimination over the rationals.

  7. Excitation of hydrogen atom by ultrashort laser pulses in optically dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Calisti, A. [Aix Marseille Universite, CNRS, PIIM, Marseille (France); Astapenko, V.A. [Moscow Institute of Physics and Technology, Dolgoprudnyi (Russian Federation); Lisitsa, V.S. [Moscow Institute of Physics and Technology, Dolgoprudnyi (Russian Federation); Russian Research Center ' ' Kurchatov Institute' ' , Moscow (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation)

    2017-10-15

    The features of excitation of a hydrogen atom by ultrashort laser pulses (USP) with a Gaussian envelope in optically dense plasma at a Lyman-beta transition are studied theoretically. The problem is of interest for diagnostics of optically dense media. USP have two doubtless advantages over conventional laser excitation: (a) the USP carrier frequency is shifted to the region of short wavelengths allowing exciting atoms from the ground state and (b) the wide spectrum of USP allows them to penetrate into optically dense media to much longer distances as compared with monochromatic radiation. As actual realistic cases, two examples are considered: hot rarefied plasma (the coronal limit) and dense cold plasma (the Boltzmann equilibrium). Universal expressions for the total probability of excitation of the transition under consideration are obtained in view of absorption of radiation in a medium. As initial data for the spectral form of a line, the results of calculations by methods of molecular dynamics are used. The probability of excitation of an atom is analysed for different values of problem parameters: the pulse duration, the optical thickness of a medium, and the detuning of the pulse carrier frequency from the eigenfrequency of an electron transition. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Probing properties of hot and dense QCD matter with heavy flavor in the PHENIX experiment at RHIC

    Directory of Open Access Journals (Sweden)

    Nouicer Rachid

    2015-01-01

    Full Text Available Hadrons carrying heavy quarks, i.e. charm or bottom, are important probes of the hot and dense medium created in relativistic heavy ion collisions. Heavy quarkantiquark pairs are mainly produced in initial hard scattering processes of partons. While some of the produced pairs form bound quarkonia, the vast majority hadronize into particles carrying open heavy flavor. Heavy quark production has been studied by the PHENIX experiment at RHIC via measurements of single leptons from semi-leptonic decays in both the electron channel at mid-rapidity and in the muon channel at forward rapidity. A large suppression and azimuthal anisotropy of single electrons have been observed in Au + Au collisions at 200 GeV. These results suggest a large energy loss and flow of heavy quarks in the hot, dense matter. The PHENIX experiment has also measured J/ψ production at 200 GeV in p + p, d + Au, Cu + Cu and Au + Au collisions, both at mid- and forward-rapidities, and additionally Cu + Au and U + U at forward-rapidities. In the most energetic collisions, more suppression is observed at forward rapidity than at central rapidity. This can be interpreted either as a sign of quark recombination, or as a hint of additional cold nuclear matter effects. The centrality dependence of nuclear modification factor, RAA(pT, for J/ψ in U + U collisions at √sNN = 193 GeV shows a similar trend to the lighter systems, Au + Au and Cu + Cu, at similar energy 200 GeV.

  9. Cavola experiment site: geophysical investigations and deployment of a dense seismic array on a landslide

    OpenAIRE

    L. Martelli; M. Cercato; P. Augliera; G. Di Giulio; G. Milana; J. Haines; P. Bordoni; F. Cara; undefined Cavola Experiment Team

    2007-01-01

    Geophysical site investigations have been performed in association with deployment of a dense array of 95 3-component seismometers on the Cavola landslide in the Northern Apennines. The aim of the array is to study propagation of seismic waves in the heterogeneous medium through comparison of observation and modelling. The small-aperture array (130 m×56 m) operated continuously for three months in 2004. Cavola landslide consists of a clay body sliding over mudstone-shale b...

  10. Researches concerning the use of mixed Hydrogen in the combustion of dense biomass

    International Nuclear Information System (INIS)

    Negreanu, Gabriel-Paul; Mihaescu, Lucian; Pisa, Ionel; Berbece, Viorel; Lazaroiu, Gheorghe

    2014-01-01

    The paper deals with theoretical basis and experimental tests of mixed hydrogen diffusion in the dense system of biomass. Research regarding hydrogen diffusion in the porous system of biomass is part of wider research focusing on using hydrogen as an active medium for solid biomass combustion. In parallel with hydrogen diffusion in solid biomass, tests regarding biomass combustion previously subjected to a hydrogen flux will be carried out. Keywords: biomass, hydrogen diffusion, combustion, experimental tests

  11. Dense high-temperature plasma transport processes

    International Nuclear Information System (INIS)

    Giniyatova, Sh.G.

    2002-01-01

    In this work the transport processes in dense high-temperature semiclassical plasma are studied on the base of the kinetic equation, where the semiclassical potential was used, in its collision integral. The coefficient of plasma electrical conductivity, viscosity and thermal conductivity were received. There were compared with the other authors' results. The Grad's method was used obtaining of viscosity and thermal coefficients. (author)

  12. The electronic pressure in dense plasmas

    International Nuclear Information System (INIS)

    Pozwolski, A.E.

    1982-01-01

    A thermodynamic calculation of the electronic pressure in a dense plasma is given. Approximations involved by the use of the Debye length are avoided, so the above theory remains valid even if the Debye length is smaller than the interionic distance. (author)

  13. APT: Action localization Proposals from dense Trajectories

    NARCIS (Netherlands)

    van Gemert, J.C.; Jain, M.; Gati, E.; Snoek, C.G.M.; Xie, X.; Jones, M.W.; Tam, G.K.L.

    2015-01-01

    This paper is on action localization in video with the aid of spatio-temporal proposals. To alleviate the computational expensive video segmentation step of existing proposals, we propose bypassing the segmentations completely by generating proposals directly from the dense trajectories used to

  14. Dense Alternating Sign Matrices and Extensions

    Czech Academy of Sciences Publication Activity Database

    Fiedler, Miroslav; Hall, F.J.; Stroev, M.

    2014-01-01

    Roč. 444, 1 March (2014), s. 219-226 ISSN 0024-3795 Institutional support: RVO:67985807 Keywords : alternating sign matrix * dense matrix * totally unimodular matrix * combined matrix * generalized complementary basic matrix Subject RIV: BA - General Mathematics Impact factor: 0.939, year: 2014

  15. Coalescence preference in dense packing of bubbles

    Science.gov (United States)

    Kim, Yeseul; Gim, Bopil; Gim, Bopil; Weon, Byung Mook

    2015-11-01

    Coalescence preference is the tendency that a merged bubble from the contact of two original bubbles (parent) tends to be near to the bigger parent. Here, we show that the coalescence preference can be blocked by densely packing of neighbor bubbles. We use high-speed high-resolution X-ray microscopy to clearly visualize individual coalescence phenomenon which occurs in micro scale seconds and inside dense packing of microbubbles with a local packing fraction of ~40%. Previous theory and experimental evidence predict a power of -5 between the relative coalescence position and the parent size. However, our new observation for coalescence preference in densely packed microbubbles shows a different power of -2. We believe that this result may be important to understand coalescence dynamics in dense packing of soft matter. This work (NRF-2013R1A22A04008115) was supported by Mid-career Researcher Program through NRF grant funded by the MEST and also was supported by Ministry of Science, ICT and Future Planning (2009-0082580) and by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry and Education, Science and Technology (NRF-2012R1A6A3A04039257).

  16. Event-by-event fluctuations in the medium-induced jet evolution

    International Nuclear Information System (INIS)

    Escobedo, Miguel A.; Iancu, Edmond

    2016-01-01

    We develop the event-by-event picture of the gluon distribution produced via medium-induced gluon branching by an energetic jet which propagates through a dense QCD medium. A typical event is characterized by the production of a large number of soft gluons which propagate at large angles with respect to the jet axis and which collectively carry a substantial amount of energy. By explicitly computing 2-gluon correlations, we demonstrate the existence of large event-by-event fluctuations, which reflect the stochastic nature of the branching process. For the two quantities that we have investigated — the energy loss at large angles and the soft gluon multiplicity —, the dispersion is parametrically as large as the respective expectation value. We identify interesting scaling laws, which suggest that the multiplicity distribution should exhibit KNO (Koba-Nielsen-Olesen) scaling. A similar scaling is known to hold for a jet branching in the vacuum, but the medium-induced distribution is found to be considerably broader. We predict that event-by-event measurements of the di-jet asymmetry in Pb+Pb collisions at the LHC should observe large fluctuations in the number of soft hadrons propagating at large angles and also in the total energy carried by these hadrons.

  17. Skin-effect in a dense ionizing plasma

    International Nuclear Information System (INIS)

    Ivanenkov, G.V.; Taranenko, S.B.

    1989-01-01

    Effect of multiple ionization and radiation (bremmstrahlung and photorecombination) on skin effect in a dense plasma is investigated. Limiting cases are considered: 1) fast skin-effect, when plasma movement and any types of losses (radiation, electron thermal conductivity) have no time to manifest themselves during short heating times; 2) deceleration of skinning under effect of radiation achieving equilibrium with Joule heating. Self-simulating solutions of the problem for half-space are investigated. The results are applied to analysing experiments with exploding wires. It is shown that under conditions, typical of heavy-current decelerators tubular structures are produced as a result of heat and current skinning under free dispersion of plasma produced during the explosion. Their dimensions are of the order of dozens of microns, and the temperature exceeds 50 eV. The linear power and complete ''tube'' radiation yield at this stage are able to make a substantial contribution to the energy balance in the group

  18. Jet multiplicity distributions: medium dependence in MLLA

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, Nestor; Pajares, Carlos; Quiroga-Arias, Paloma [Universidade de Santiago de Compostela, Departamento de Fisica de Particulas and IGFAE, Santiago de Compostela (Spain)

    2009-07-15

    We study the medium dependence of the multiplicity distributions in the modified leading logarithmic approximation. We focus in the enhancement in the number of branchings as the partons travel trough a dense medium created in a heavy-ion collision. We study the effect of a higher number of splittings in some jet observables by introducing the medium as a constant (f{sub med}) in the splitting functions. Having as our ansatz for the quark and gluon jets mean multiplicities left angle n{sub G} right angle =e{sup {gamma}}{sup y} and left angle n{sub Q} right angle =r{sup -1}e{sup {gamma}}{sup y}, we study in an analytic approach the dependence with the medium (f{sub med}) of the anomalous dimension ({gamma}), the multiplicity ratio (r), and so the mean multiplicities. We also obtain the higher-order moments of the multiplicity distribution, what allows us to study its dispersion. (orig.)

  19. Human impacts on large benthic foraminifers near a densely populated area of Majuro Atoll, Marshall Islands.

    Science.gov (United States)

    Osawa, Yoko; Fujita, Kazuhiko; Umezawa, Yu; Kayanne, Hajime; Ide, Yoichi; Nagaoka, Tatsutoshi; Miyajima, Toshihiro; Yamano, Hiroya

    2010-08-01

    Human impacts on sand-producing, large benthic foraminifers were investigated on ocean reef flats at the northeast Majuro Atoll, Marshall Islands, along a human population gradient. The densities of dominant foraminifers Calcarina and Amphistegina declined with distance from densely populated islands. Macrophyte composition on ocean reef flats differed between locations near sparsely or densely populated islands. Nutrient concentrations in reef-flat seawater and groundwater were high near or on densely populated islands. delta(15)N values in macroalgal tissues indicated that macroalgae in nearshore lagoons assimilate wastewater-derived nitrogen, whereas those on nearshore ocean reef flats assimilate nitrogen from other sources. These results suggest that increases in the human population result in high nutrient loading in groundwater and possibly into nearshore waters. High nutrient inputs into ambient seawater may have both direct and indirect negative effects on sand-producing foraminifers through habitat changes and/or the collapse of algal symbiosis. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Human impacts on large benthic foraminifers near a densely populated area of Majuro Atoll, Marshall Islands

    International Nuclear Information System (INIS)

    Osawa, Yoko; Fujita, Kazuhiko; Umezawa, Yu; Kayanne, Hajime; Ide, Yoichi; Nagaoka, Tatsutoshi; Miyajima, Toshihiro; Yamano, Hiroya

    2010-01-01

    Human impacts on sand-producing, large benthic foraminifers were investigated on ocean reef flats at the northeast Majuro Atoll, Marshall Islands, along a human population gradient. The densities of dominant foraminifers Calcarina and Amphistegina declined with distance from densely populated islands. Macrophyte composition on ocean reef flats differed between locations near sparsely or densely populated islands. Nutrient concentrations in reef-flat seawater and groundwater were high near or on densely populated islands. δ 15 N values in macroalgal tissues indicated that macroalgae in nearshore lagoons assimilate wastewater-derived nitrogen, whereas those on nearshore ocean reef flats assimilate nitrogen from other sources. These results suggest that increases in the human population result in high nutrient loading in groundwater and possibly into nearshore waters. High nutrient inputs into ambient seawater may have both direct and indirect negative effects on sand-producing foraminifers through habitat changes and/or the collapse of algal symbiosis.

  1. WARM EXTENDED DENSE GAS AT THE HEART OF A COLD COLLAPSING DENSE CORE

    International Nuclear Information System (INIS)

    Shinnaga, Hiroko; Phillips, Thomas G.; Furuya, Ray S.; Kitamura, Yoshimi

    2009-01-01

    In order to investigate when and how the birth of a protostellar core occurs, we made survey observations of four well-studied dense cores in the Taurus molecular cloud using CO transitions in submillimeter bands. We report here the detection of unexpectedly warm (∼30-70 K), extended (radius of ∼2400 AU), dense (a few times 10 5 cm -3 ) gas at the heart of one of the dense cores, L1521F (MC27), within the cold dynamically collapsing components. We argue that the detected warm, extended, dense gas may originate from shock regions caused by collisions between the dynamically collapsing components and outflowing/rotating components within the dense core. We propose a new stage of star formation, 'warm-in-cold core stage (WICCS)', i.e., the cold collapsing envelope encases the warm extended dense gas at the center due to the formation of a protostellar core. WICCS would constitute a missing link in evolution between a cold quiescent starless core and a young protostar in class 0 stage that has a large-scale bipolar outflow.

  2. Physical processes in the interstellar medium

    CERN Document Server

    Spitzer, Lyman

    2008-01-01

    Physical Processes in the Interstellar Medium discusses the nature of interstellar matter, with a strong emphasis on basic physical principles, and summarizes the present state of knowledge about the interstellar medium by providing the latest observational data. Physics and chemistry of the interstellar medium are treated, with frequent references to observational results. The overall equilibrium and dynamical state of the interstellar gas are described, with discussions of explosions produced by star birth and star death and the initial phases of cloud collapse leading to star formation.

  3. Dense Output for Strong Stability Preserving Runge–Kutta Methods

    KAUST Repository

    Ketcheson, David I.

    2016-12-10

    We investigate dense output formulae (also known as continuous extensions) for strong stability preserving (SSP) Runge–Kutta methods. We require that the dense output formula also possess the SSP property, ideally under the same step-size restriction as the method itself. A general recipe for first-order SSP dense output formulae for SSP methods is given, and second-order dense output formulae for several optimal SSP methods are developed. It is shown that SSP dense output formulae of order three and higher do not exist, and that in any method possessing a second-order SSP dense output, the coefficient matrix A has a zero row.

  4. Dense plasma focus - a literature review

    International Nuclear Information System (INIS)

    Tendys, J.

    1976-01-01

    The dense plasma focus (DPF) is a convenient source of short, intense neutron pulses, and dense, high temperature plasma. This review of the literature on the DPF indicates that its operation is still not understood, and attempts to show where the present data is either inadequate or inconsistent. Because the plasma conditions and neutron and x-ray fluxes vary from shot to shot, it is maintained that, to resolve inconsistencies in the present data, spectra need to be measured with energy and time resolution simultaneously, and cannot be built up from a large number of shots. Time resolutions of the order of 1 nsec for pulse lengths of about 100 nsec make these requirements especially difficult. Some theoretical models are presented for the neutron output and its spectrum, but no self-consistent description of the plasma in the focus region is likely for some time. (author)

  5. Highly Dense Isolated Metal Atom Catalytic Sites

    DEFF Research Database (Denmark)

    Chen, Yaxin; Kasama, Takeshi; Huang, Zhiwei

    2015-01-01

    -ray diffraction. A combination of electron microscopy images with X-ray absorption spectra demonstrated that the silver atoms were anchored on five-fold oxygen-terminated cavities on the surface of the support to form highly dense isolated metal active sites, leading to excellent reactivity in catalytic oxidation......Atomically dispersed noble-metal catalysts with highly dense active sites are promising materials with which to maximise metal efficiency and to enhance catalytic performance; however, their fabrication remains challenging because metal atoms are prone to sintering, especially at a high metal...... loading. A dynamic process of formation of isolated metal atom catalytic sites on the surface of the support, which was achieved starting from silver nanoparticles by using a thermal surface-mediated diffusion method, was observed directly by using in situ electron microscopy and in situ synchrotron X...

  6. Anomalous properties of hot dense nonequilibrium plasmas

    International Nuclear Information System (INIS)

    Ferrante, G; Zarcone, M; Uryupin, S A

    2005-01-01

    A concise overview of a number of anomalous properties of hot dense nonequilibrium plasmas is given. The possibility of quasistationary megagauss magnetic field generation due to Weibel instability is discussed for plasmas created in atom tunnel ionization. The collisionless absorption and reflection of a test electromagnetic wave normally impinging on the plasma with two-temperature bi-maxwellian electron velocity distribution function are studied. Due to the wave magnetic field influence on the electron kinetics in the skin layer the wave absorption and reflection significantly depend on the degree of the electron temperature anisotropy. The linearly polarized impinging wave during reflection transforms into an elliptically polarized one. The problem of transmission of an ultrashort laser pulse through a layer of dense plasma, formed as a result of ionization of a thin foil, is considered. It is shown that the strong photoelectron distribution anisotropy yields an anomalous penetration of the wave field through the foil

  7. Deterministic dense coding with partially entangled states

    Science.gov (United States)

    Mozes, Shay; Oppenheim, Jonathan; Reznik, Benni

    2005-01-01

    The utilization of a d -level partially entangled state, shared by two parties wishing to communicate classical information without errors over a noiseless quantum channel, is discussed. We analytically construct deterministic dense coding schemes for certain classes of nonmaximally entangled states, and numerically obtain schemes in the general case. We study the dependency of the maximal alphabet size of such schemes on the partially entangled state shared by the two parties. Surprisingly, for d>2 it is possible to have deterministic dense coding with less than one ebit. In this case the number of alphabet letters that can be communicated by a single particle is between d and 2d . In general, we numerically find that the maximal alphabet size is any integer in the range [d,d2] with the possible exception of d2-1 . We also find that states with less entanglement can have a greater deterministic communication capacity than other more entangled states.

  8. Dense-plasma research using ballistic compressors

    International Nuclear Information System (INIS)

    Hess, H.

    1986-01-01

    An introduction is given to research on dense (or nonideal) plasmas which can be generated to advantage by ballistic compressors. Some properties of ballistic compressors are discussed especially in comparison with shock tubes. A short review is given on the history of these devices for high-pressure plasma generation. The present state of the art is reported including research on the two ZIE (Central Institute for Electron Physics) ballistic compressors. (author)

  9. Collective dynamics in dense fluid mixtures

    International Nuclear Information System (INIS)

    Sinha, S.

    1992-01-01

    This thesis deals with the short wavelength collective dynamics of dense binary fluid mixtures. The analysis shows that at the level of linearized generalized hydrodynamics, the longitudinal modes of the system separates essentially into two parts - one involves the coupling of partial density fluctuations of the two species and the other involves coupling of longitudinal momentum and temperature fluctuations. The authors have shown that the coupling of longitudinal momentum and temperature fluctuations leads to an adequate description of sound propagation in such systems. In particular, they show that structural disorder controls the trapping of sound waves in dense mixtures. The coupling of the partial density fluctuations of the two species leads to a simple description of the partial dynamic structure factors. The results are in agreement with the molecular dynamics simulations of soft sphere mixtures. The partial density fluctuations are the slowest decaying fluctuations on molecular length scales and it turns out that nonlinear coupling of these slow modes leads to important corrections to the long time behavior of the time correlation functions determining the shear viscosity in dense mixtures

  10. Hybrid-Based Dense Stereo Matching

    Science.gov (United States)

    Chuang, T. Y.; Ting, H. W.; Jaw, J. J.

    2016-06-01

    Stereo matching generating accurate and dense disparity maps is an indispensable technique for 3D exploitation of imagery in the fields of Computer vision and Photogrammetry. Although numerous solutions and advances have been proposed in the literature, occlusions, disparity discontinuities, sparse texture, image distortion, and illumination changes still lead to problematic issues and await better treatment. In this paper, a hybrid-based method based on semi-global matching is presented to tackle the challenges on dense stereo matching. To ease the sensitiveness of SGM cost aggregation towards penalty parameters, a formal way to provide proper penalty estimates is proposed. To this end, the study manipulates a shape-adaptive cross-based matching with an edge constraint to generate an initial disparity map for penalty estimation. Image edges, indicating the potential locations of occlusions as well as disparity discontinuities, are approved by the edge drawing algorithm to ensure the local support regions not to cover significant disparity changes. Besides, an additional penalty parameter 𝑃𝑒 is imposed onto the energy function of SGM cost aggregation to specifically handle edge pixels. Furthermore, the final disparities of edge pixels are found by weighting both values derived from the SGM cost aggregation and the U-SURF matching, providing more reliable estimates at disparity discontinuity areas. Evaluations on Middlebury stereo benchmarks demonstrate satisfactory performance and reveal the potency of the hybrid-based dense stereo matching method.

  11. Concept medium programme

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2005-01-01

    The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program......The present essay is an attempt to determine the architectural project of the 21st century in relation to a modern conception of space as the medium of architecture, and of sociality as its program...

  12. Soft X-ray spectroscopy of high-Z ions in a cool dense plasma

    International Nuclear Information System (INIS)

    Presnyakov, L.P.; Shevelko, A.P.; Uskov, D.B.

    1991-01-01

    Spectra of multiply-charged ions with one and two electrons are investigated when a laser-produced plasma interacts with a solid obstacle. The level population densities of the Mg ions, recombining in the region of dense cool plasma near the obstacle, are studied both experimentally and theoretically. Values of the gain coefficient are calculated for the case of carbon ions. (orig.)

  13. Universal medium-range order of amorphous metal oxides.

    Science.gov (United States)

    Nishio, Kengo; Miyazaki, Takehide; Nakamura, Hisao

    2013-10-11

    We propose that the structure of amorphous metal oxides can be regarded as a dual-dense-random-packing structure, which is a superposition of the dense random packing of metal atoms and that of oxygen atoms. Our ab initio molecular dynamics simulations show that the medium-range order of amorphous HfO2, ZrO2, TiO2, In2O3, Ga2O3, Al2O3, and Cu2O is characterized by the pentagonal-bipyramid arrangement of metal atoms and that of oxygen atoms, and prove the validity of our dual-random-sphere-packing model. In other words, we find that the pentagonal medium-range order is universal independent of type of metal oxide.

  14. Equation of state of partially-ionized dense plasmas

    International Nuclear Information System (INIS)

    Rogers, F.J.

    1989-01-01

    This paper describes methods for calculating the equation of state of partially-ionized dense plasmas. The term dense plasma is used rather than strongly coupled plasma, since it is possible that at plasma conditions such that only a few levels can be observed spectroscopically the plasma coupling parameters are not large. Due mainly to their importance in theoretical astrophysics, the properties of partially ionized plasmas have been of interest for a long while. More recently, this interest has intensified due to the development of methods for producing partially ionized plasmas in the laboratory. This has opened up large programs of experimental investigation and of practical application. In this paper we consider detailed statistical mechanical methods that explicitly treat the distribution over ionic species and their energy level structure. These detailed approaches are generally characterized as being in the ''chemical picture'' when a free energy expression is minimized or in the ''physical picture'' when the starting point is the grand canonical ensemble. 52 refs., 2 tabs

  15. Thermophysical properties of multi-shock compressed dense argon.

    Science.gov (United States)

    Chen, Q F; Zheng, J; Gu, Y J; Chen, Y L; Cai, L C; Shen, Z J

    2014-02-21

    In contrast to the single shock compression state that can be obtained directly via experimental measurements, the multi-shock compression states, however, have to be calculated with the aid of theoretical models. In order to determine experimentally the multiple shock states, a diagnostic approach with the Doppler pins system (DPS) and the pyrometer was used to probe multiple shocks in dense argon plasmas. Plasma was generated by a shock reverberation technique. The shock was produced using the flyer plate impact accelerated up to ∼6.1 km/s by a two-stage light gas gun and introduced into the plenum argon gas sample, which was pre-compressed from the environmental pressure to about 20 MPa. The time-resolved optical radiation histories were determined using a multi-wavelength channel optical transience radiance pyrometer. Simultaneously, the particle velocity profiles of the LiF window was measured with multi-DPS. The states of multi-shock compression argon plasma were determined from the measured shock velocities combining the particle velocity profiles. We performed the experiments on dense argon plasmas to determine the principal Hugonoit up to 21 GPa, the re-shock pressure up to 73 GPa, and the maximum measure pressure of the fourth shock up to 158 GPa. The results are used to validate the existing self-consistent variational theory model in the partial ionization region and create new theoretical models.

  16. Dense Output for Strong Stability Preserving Runge–Kutta Methods

    KAUST Repository

    Ketcheson, David I.; Loczi, Lajos; Jangabylova, Aliya; Kusmanov, Adil

    2016-01-01

    We investigate dense output formulae (also known as continuous extensions) for strong stability preserving (SSP) Runge–Kutta methods. We require that the dense output formula also possess the SSP property, ideally under the same step

  17. About chiral models of dense matter and its magnetic properties

    International Nuclear Information System (INIS)

    Kutschera, M.

    1990-12-01

    The chiral models of dense nucleon matter are discussed. The quark matter with broken chiral symmetry is described. The magnetic properties of dense matter are presented and conclusions are given. 37 refs. (A.S.)

  18. Synthesis and characterization of dense membranes of silk fibroin with glycerin

    International Nuclear Information System (INIS)

    Silva, Mariana F.; Moraes, Mariana A. de; Weska, Raquel F.; Nogueira, Grinia M.; Beppu, Marisa M.

    2009-01-01

    The addition of plasticizers seeks improvements in mechanical properties of dense membranes of silk fibroin with possible interactions by hydrogen bonds. The aim of the present study was to produce and characterize dense membranes of silk fibroin containing glycerin in two different concentrations. The characterization of the membranes was performed from scanning electron microscopy (SEM), mechanical traction tests, infrared spectroscopy (FTIR-ATR) and X-ray diffraction (XRD). The results indicated that the addition of glycerin allowed obtaining homogeneous and more crystalline membranes and improved their properties of elongation. (author)

  19. Producing superhydrophobic roof tiles

    International Nuclear Information System (INIS)

    Carrascosa, Luis A M; Facio, Dario S; Mosquera, Maria J

    2016-01-01

    Superhydrophobic materials can find promising applications in the field of building. However, their application has been very limited because the synthesis routes involve tedious processes, preventing large-scale application. A second drawback is related to their short-term life under outdoor conditions. A simple and low-cost synthesis route for producing superhydrophobic surfaces on building materials is developed and their effectiveness and their durability on clay roof tiles are evaluated. Specifically, an organic–inorganic hybrid gel containing silica nanoparticles is produced. The nanoparticles create a densely packed coating on the roof tile surface in which air is trapped. This roughness produces a Cassie–Baxter regime, promoting superhydrophobicity. A surfactant, n-octylamine, was also added to the starting sol to catalyze the sol–gel process and to coarsen the pore structure of the gel network, preventing cracking. The application of ultrasound obviates the need to use volatile organic compounds in the synthesis, thereby making a ‘green’ product. It was also demonstrated that a co-condensation process effective between the organic and inorganic species is crucial to obtain durable and effective coatings. After an aging test, high hydrophobicity was maintained and water absorption was completely prevented for the roof tile samples under study. However, a transition from a Cassie–Baxter to a Wenzel state regime was observed as a consequence of the increase in the distance between the roughness pitches produced by the aging of the coating. (paper)

  20. ON THE FORMATION OF GLYCOLALDEHYDE IN DENSE MOLECULAR CORES

    Energy Technology Data Exchange (ETDEWEB)

    Woods, Paul M.; Kelly, George; Viti, Serena [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Slater, Ben; Brown, Wendy A.; Puletti, Fabrizio; Burke, Daren J.; Raza, Zamaan, E-mail: paul.woods@ucl.ac.uk [Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

    2012-05-01

    Glycolaldehyde is a simple monosaccharide sugar linked to prebiotic chemistry. Recently, it was detected in a molecular core in the star-forming region G31.41+0.31 at a reasonably high abundance. We investigate the formation of glycolaldehyde at 10 K to determine whether it can form efficiently under typical dense core conditions. Using an astrochemical model, we test five different reaction mechanisms that have been proposed in the astrophysical literature, finding that a gas-phase formation route is unlikely. Of the grain-surface formation routes, only two are efficient enough at very low temperatures to produce sufficient glycolaldehyde to match the observational estimates, with the mechanism culminating in CH{sub 3}OH + HCO being favored. However, when we consider the feasibility of these mechanisms from a reaction chemistry perspective, the second grain-surface route looks more promising, H{sub 3}CO + HCO.

  1. ON THE FORMATION OF GLYCOLALDEHYDE IN DENSE MOLECULAR CORES

    International Nuclear Information System (INIS)

    Woods, Paul M.; Kelly, George; Viti, Serena; Slater, Ben; Brown, Wendy A.; Puletti, Fabrizio; Burke, Daren J.; Raza, Zamaan

    2012-01-01

    Glycolaldehyde is a simple monosaccharide sugar linked to prebiotic chemistry. Recently, it was detected in a molecular core in the star-forming region G31.41+0.31 at a reasonably high abundance. We investigate the formation of glycolaldehyde at 10 K to determine whether it can form efficiently under typical dense core conditions. Using an astrochemical model, we test five different reaction mechanisms that have been proposed in the astrophysical literature, finding that a gas-phase formation route is unlikely. Of the grain-surface formation routes, only two are efficient enough at very low temperatures to produce sufficient glycolaldehyde to match the observational estimates, with the mechanism culminating in CH 3 OH + HCO being favored. However, when we consider the feasibility of these mechanisms from a reaction chemistry perspective, the second grain-surface route looks more promising, H 3 CO + HCO.

  2. The phenomenon of radiative compression in dense magnetized plasmas

    International Nuclear Information System (INIS)

    Choi, Peter

    1998-01-01

    Full text: Localized regions of extremely high energy density have long been observed in dense magnetized plasma, created in different experiments, including vacuum spark, exploding wire, Z-pinch and plasma focus. The physical dimensions of these regions are typically tens to hundreds of microns with a characteristic temperature of few hundred eV upward. A theory of self-compression under enhanced cooling, when the radiation rate exceeds the joule heating rate, was first put forward by Shearer to explain the possible responsible mechanism. More recent work suggests that a radiative collapse formalism could indeed produce eaters of ultra-high density. In the paper the experimental evidences are examined, and the applicability limit of the radiative collapse picture is discussed, when the properties of the driving generator are considered. A new set of relations connecting the driver parameters and the limiting size of the compression is proposed

  3. The Interstellar Medium

    CERN Document Server

    Lequeux, James

    2005-01-01

    Describing interstellar matter in our galaxy in all of its various forms, this book also considers the physical and chemical processes that are occurring within this matter. The first seven chapters present the various components making up the interstellar matter and detail the ways that we are able to study them. The following seven chapters are devoted to the physical, chemical and dynamical processes that control the behaviour of interstellar matter. These include the instabilities and cloud collapse processes that lead to the formation of stars. The last chapter summarizes the transformations that can occur between the different phases of the interstellar medium. Emphasizing methods over results, "The Interstellar Medium" is written for graduate students, for young astronomers, and also for any researchers who have developed an interest in the interstellar medium.

  4. Evolution of dense spatially modulated electron bunches

    Science.gov (United States)

    Balal, N.; Bratman, V. L.; Friedman, A.

    2018-03-01

    An analytical theory describing the dynamics of relativistic moving 1D electron pulses (layers) with the density modulation affected by a space charge has been revised and generalized for its application to the formation of dense picosecond bunches from linear accelerators with laser-driven photo injectors, and its good agreement with General Particle Tracer simulations has been demonstrated. Evolution of quasi-one-dimensional bunches (disks), for which the derived formulas predict longitudinal expansion, is compared with that for thin and long electron cylinders (threads), for which the excitation of non-linear waves with density spikes was found earlier by Musumeci et al. [Phys. Rev. Lett. 106(18), 184801 (2011)] and Musumeci et al. [Phys. Rev. Spec. Top. -Accel. Beams 16(10), 100701 (2013)]. Both types of bunches can be used for efficiency enhancement of THz sources based on the Doppler frequency up-shifted coherent spontaneous radiation of electrons. Despite the strong Coulomb repulsion, the periodicity of a preliminary modulation in dense 1D layers persists during their expansion in the most interesting case of a relatively small change in particle energy. However, the period of modulation increases and its amplitude decreases in time. In the case of a large change in electron energy, the uniformity of periodicity is broken due to different relativistic changes in longitudinal scales along the bunch: the "period" of modulation decreases and its amplitude increases from the rear to the front boundary. Nevertheless, the use of relatively long electron bunches with a proper preliminary spatial modulation of density can provide a significantly higher power and a narrower spectrum of coherent spontaneous radiation of dense bunches than in the case of initially short single bunches with the same charge.

  5. Dense magnetized plasma associated with a fast radio burst.

    Science.gov (United States)

    Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B; Roman, Alexander; Timbie, Peter T; Voytek, Tabitha; Yadav, Jaswant K

    2015-12-24

    Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

  6. Electron conductivity model for dense plasmas

    International Nuclear Information System (INIS)

    Lee, Y.T.; More, R.M.

    1984-01-01

    An electron conductivity model for dense plasmas is described which gives a consistent and complete set of transport coefficients including not only electrical conductivity and thermal conductivity, but also thermoelectric power, and Hall, Nernst, Ettinghausen, and Leduc--Righi coefficients. The model is useful for simulating plasma experiments with strong magnetic fields. The coefficients apply over a wide range of plasma temperature and density and are expressed in a computationally simple form. Different formulas are used for the electron relaxation time in plasma, liquid, and solid phases. Comparisons with recent calculations and available experimental measurement show the model gives results which are sufficiently accurate for many practical applications

  7. Dense hydrogen plasma: Comparison between models

    International Nuclear Information System (INIS)

    Clerouin, J.G.; Bernard, S.

    1997-01-01

    Static and dynamical properties of the dense hydrogen plasma (ρ≥2.6gcm -3 , 0.1< T<5eV) in the strongly coupled regime are compared through different numerical approaches. It is shown that simplified density-functional molecular-dynamics simulations (DFMD), without orbitals, such as Thomas-Fermi Dirac or Thomas-Fermi-Dirac-Weiszaecker simulations give similar results to more sophisticated descriptions such as Car-Parrinello (CP), tight binding, or path-integral Monte Carlo, in a wide range of temperatures. At very low temperature, screening effects predicted by DFMD are still less pronounced than CP simulations. copyright 1997 The American Physical Society

  8. Electrical and thermal conductivities in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faussurier, G., E-mail: gerald.faussurier@cea.fr; Blancard, C.; Combis, P.; Videau, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2014-09-15

    Expressions for the electrical and thermal conductivities in dense plasmas are derived combining the Chester-Thellung-Kubo-Greenwood approach and the Kramers approximation. The infrared divergence is removed assuming a Drude-like behaviour. An analytical expression is obtained for the Lorenz number that interpolates between the cold solid-state and the hot plasma phases. An expression for the electrical resistivity is proposed using the Ziman-Evans formula, from which the thermal conductivity can be deduced using the analytical expression for the Lorenz number. The present method can be used to estimate electrical and thermal conductivities of mixtures. Comparisons with experiment and quantum molecular dynamics simulations are done.

  9. Dense ceramic membranes for methane conversion

    Energy Technology Data Exchange (ETDEWEB)

    Bouwmeester, Henny J.M. [Laboratory for Inorganic Materials Science, Department of Science and Technology and MESA Research Institute, University of Twente, 7500 AE Enschede (Netherlands)

    2003-07-30

    Dense ceramic membranes made from mixed oxygen-ionic and electronic conducting perovskite-related oxides allow separation of oxygen from an air supply at elevated temperatures (>700C). By combining air separation and catalytic partial oxidation of methane to syngas into a ceramic membrane reactor, this technology is expected to significantly reduce the capital costs of conversion of natural gas to liquid added-value products. The present survey is mainly concerned with the material properties that govern the performance of the mixed-conducting membranes in real operating conditions and highlights significant developments in the field.

  10. The Magpie dense z-pinch project

    International Nuclear Information System (INIS)

    Chittenden, J.; Choi, P.; Mitchell, I.; Dangor, A.E.; Haines, M.G.

    1990-01-01

    The authors present a design study on the Mega Ampere Generator for Plasma Implosion Experiments (MAGPIE), a project currently under construction at Imperial College London, to study radiative collapse of a dense Z-pinch plasma created from a 20 um diameter cryogenic hydrogen fiber. The 2 TW generator is composed of four individual 2.4 MV Marx banks of the HERMES III type design with a maximum stored energy of 336 kJ. They drive four 5 ohm Pulse Forming Lines which are combined into a single 1.25 MA in 150 ns to a 150 nH load

  11. Atomic physics in dense plasmas. Recent advances

    International Nuclear Information System (INIS)

    Leboucher-Dalimier, E.; Angelo, P.; Ceccotti, T.; Derfoul, H.; Poquerusse, A.; Sauvan, P.; Oks, E.

    2000-01-01

    This paper presents observations and simulations of novel density-dependent spectroscopic features in hot and dense plasmas. Both time-integrated and time-resolved results using ultra-high resolutions spectrometers are presented; they are justified within the standard spectral line shape theory or the quasi-molecular alternative treatment. A particular attention is paid to the impact of the spatio-temporal evolution of the plasma on the experimental spectra. Satellite-like features and molecular lines in the cases of Flyβ, Heβ are discussed emphasizing their importance for the density diagnostics when ion-ion correlations are significant. (authors)

  12. Structure of a new dense amorphous ice

    International Nuclear Information System (INIS)

    Finney, J.L.; Bowron, D.T.; Soper, A.K.; Loerting, T.; Mayer, E.; Hallbrucker, A.

    2002-01-01

    The detailed structure of a new dense amorphous ice, VHDA, is determined by isotope substitution neutron diffraction. Its structure is characterized by a doubled occupancy of the stabilizing interstitial location that was found in high density amorphous ice, HDA. As would be expected for a thermally activated unlocking of the stabilizing 'interstitial', the transition from VHDA to LDA (low-density amorphous ice) is very sharp. Although its higher density makes VHDA a better candidate than HDA for a physical manifestation of the second putative liquid phase of water, as for the HDA case, the VHDA to LDA transition also appears to be kinetically controlled

  13. Fabrication of dense panels in lithium fluoride

    International Nuclear Information System (INIS)

    Farcy, P.; Roger, J.; Pointud, R.

    1958-04-01

    The authors report a study aimed at the fabrication of large and dense lithium fluoride panels. This sintered lithium fluoride is then supposed to be used for the construction of barriers of protection against a flow of thermal neutrons. They briefly present the raw material which is used under the form of chamotte obtained through a pre-sintering process which is also described. Grain size measurements and sample preparation are indicated. Shaping, drying, and thermal treatment are briefly described, and characteristics of the sintered product are indicated

  14. Quasi-molecular processes in dense plasmas

    International Nuclear Information System (INIS)

    Younger, S.M.

    1991-01-01

    Quasi-molecular phenomena occur in dense plasmas when the interatomic spacing is comparable to the characteristic wavelength of the electrons. If the electronic states are bound, covalent orbitals arise with different excitation energies, radiative rates, and collisional rates than for isolated ions. For continuum electrons, charge localization near transient clusters of nuclei can influence many scattering and transport processes. We identify several novel consequences of quasi-molecular phenomena in plasmas and give a possible explanation of high energy features associated with helium-like emissions lines observed in recent inertial fusion experiments. 7 refs

  15. Graph Quasicontinuous Functions and Densely Continuous Forms

    Directory of Open Access Journals (Sweden)

    Lubica Hola

    2017-07-01

    Full Text Available Let $X, Y$ be topological spaces. A function $f: X \\to Y$ is said to be graph quasicontinuous if there is a quasicontinuous function $g: X \\to Y$ with the graph of $g$ contained in the closure of the graph of $f$. There is a close relation between the notions of graph quasicontinuous functions and minimal usco maps as well as the notions of graph quasicontinuous functions and densely continuous forms. Every function with values in a compact Hausdorff space is graph quasicontinuous; more generally every locally compact function is graph quasicontinuous.

  16. Collaborative Manufacturing for Small-Medium Enterprises

    Science.gov (United States)

    Irianto, D.

    2016-02-01

    Manufacturing systems involve decisions concerning production processes, capacity, planning, and control. In a MTO manufacturing systems, strategic decisions concerning fulfilment of customer requirement, manufacturing cost, and due date of delivery are the most important. In order to accelerate the decision making process, research on decision making structure when receiving order and sequencing activities under limited capacity is required. An effective decision making process is typically required by small-medium components and tools maker as supporting industries to large industries. On one side, metal small-medium enterprises are expected to produce parts, components or tools (i.e. jigs, fixture, mold, and dies) with high precision, low cost, and exact delivery time. On the other side, a metal small- medium enterprise may have weak bargaining position due to aspects such as low production capacity, limited budget for material procurement, and limited high precision machine and equipment. Instead of receiving order exclusively, a small-medium enterprise can collaborate with other small-medium enterprise in order to fulfill requirements high quality, low manufacturing cost, and just in time delivery. Small-medium enterprises can share their best capabilities to form effective supporting industries. Independent body such as community service at university can take a role as a collaboration manager. The Laboratory of Production Systems at Bandung Institute of Technology has implemented shared manufacturing systems for small-medium enterprise collaboration.

  17. Optical recording medium

    International Nuclear Information System (INIS)

    Andriech, A.; Bivol, V.; Tridukh, G.; Tsiuleanu, D.

    2002-01-01

    The invention relates of the micro- and optoelectronics, computer engineering ,in particular, to tjhe optical information media and may be used in hilography. Summary of the invention consists in that the optical image recording medium, containing a dielectric substrates, onto one surface of which there are placed in series a transparent electricity conducting layer, a photo sensitive recording layer of chalcogenic glass and a thin film electrode of aluminium, is provided with an optically transparent protective layer, applied into the thin film electrode. The result of the invention consists in excluding the dependence of chemical processes course into the medium upon environmental conditions

  18. Charmed hadrons in nuclear medium

    NARCIS (Netherlands)

    Tolos, L.; Gamermann, D.; Garcia-Recio, C.; Molina, R.; Nieves, J.; Oset, E.; Ramos, A.

    We study the properties of charmed hadrons in dense matter within a coupled-channel approach which accounts for Pauli blocking effects and meson self-energies in a self-consistent manner We analyze the behaviour in this dense environment of dynamically-generated baryonic resonances as well as the

  19. Towards Dense Nuclear Matter in A Modified Sakai-Sugimoto Model

    Directory of Open Access Journals (Sweden)

    Rho Mannque

    2012-02-01

    Full Text Available As a part of the attempt to address dense baryonic matter, we first review holographic approaches to QCD. The big advantage of the holographic approaches is that they render strongly coupled 4D gauge theories as duals of certain weakly coupled string/supergravity that are well understood. Its relevance to real QCD is one of the central problems in hadron/nuclear physics as well as in the context of applied string theory. None of the models based on these holographic approaches presently available can adequately describe the system we are interested in, namely dense baryonic matter. Nevertheless, some aspects of the holographic approach are found to describe certain processes both in vacuum and in medium. In this talk we only present the structure of a model that appears to be closest to QCD, and has the potential to address the problem.

  20. Predicting diffusivities in dense fluid mixtures

    Directory of Open Access Journals (Sweden)

    C. DARIVA

    1999-09-01

    Full Text Available In this work the Enskog solution of the Boltzmann equation, as corrected by Speedy, together with the Weeks-Chandler-Andersen (WCA perturbation theory of liquids is employed in correlating and predicting self-diffusivities of dense fluids. Afterwards this theory is used to estimate mutual diffusion coefficients of solutes at infinite dilution in sub and supercritical solvents. We have also investigated the behavior of Fick diffusion coefficients in the proximity of a binary vapor-liquid critical point since this subject is of great interest for extraction purposes. The approach presented here, which makes use of a density and temperature dependent hard-sphere diameter, is shown to be excellent for predicting diffusivities in dense pure fluids and fluid mixtures. The calculations involved highly nonideal mixtures as well as systems with high molecular asymmetry. The predicted diffusivities are in good agreement with the experimental data for the pure and binary systems. The methodology proposed here makes only use of pure component information and density of mixtures. The simple algebraic relations are proposed without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent mixtures.

  1. Cold dense baryonic matter and compact stars

    International Nuclear Information System (INIS)

    Hyun Kyu Lee; Sang-Jin Sin; Mannque Rho

    2011-01-01

    Probing dense hadronic matter is thus far an uncharted field of physics. Here we give a brief summary of the highlights of what has been so far accomplished and what will be done in the years ahead by the World Class University III Project at Hanyang University in the endeavor to unravel and elucidate the multi-facet of the cold dense baryonic matter existing in the interior of the densest visible stable object in the universe, i.e. neutron stars, strangeness stars and/or quark stars, from a modest and simplified starting point of an effective field theory modeled on the premise of QCD as well as from a gravity dual approach of hQCD. The core of the matter of our research is the possible origin of the ∼ 99% of the proton mass that is to be accounted for and how the 'vacuum' can be tweaked so that the source of the mass generation can be uncovered by measurements made in terrestrial as well as space laboratories. Some of the issues treated in the program concern what can be done - both theoretically and experimentally - in anticipation of what's to come for basic physics research in Korea. (authors)

  2. Collective dynamics in dense Hg vapour

    International Nuclear Information System (INIS)

    Ishikawa, D; Inui, M; Matsuda, K; Tamura, K; Baron, A Q R; Tsutsui, S; Tanaka, Y; Ishikawa, T

    2004-01-01

    The dynamic structure factor, S(Q,ο), of dense Hg vapour has been measured by high resolution inelastic x-ray scattering for densities of 3.0, 2.1 and 1.0 g cm -3 corresponding to 0.52, 0.36 and 0.17 times the critical density, respectively, and for momentum transfers between 2.0 and 48 nm -1 . Analysis of the longitudinal current-current correlation function in the framework of generalized hydrodynamics reveals that the frequencies of the collective excitations increase faster with Q than estimated from the macroscopic speed of sound. The ratios of the frequencies were found to be 1.27 at 3.0 g cm -3 , 1.12 at 2.1 g cm -3 and 1.10 at 1.0 g cm -3 . The sound velocity obtained from the present experiments is well reproduced by a wavenumber dependent adiabatic sound velocity, which means that the collective modes remain in the spectra of dense Hg vapour. (letter to the editor)

  3. Redesigning Triangular Dense Matrix Computations on GPUs

    KAUST Repository

    Charara, Ali

    2016-08-09

    A new implementation of the triangular matrix-matrix multiplication (TRMM) and the triangular solve (TRSM) kernels are described on GPU hardware accelerators. Although part of the Level 3 BLAS family, these highly computationally intensive kernels fail to achieve the percentage of the theoretical peak performance on GPUs that one would expect when running kernels with similar surface-to-volume ratio on hardware accelerators, i.e., the standard matrix-matrix multiplication (GEMM). The authors propose adopting a recursive formulation, which enriches the TRMM and TRSM inner structures with GEMM calls and, therefore, reduces memory traffic while increasing the level of concurrency. The new implementation enables efficient use of the GPU memory hierarchy and mitigates the latency overhead, to run at the speed of the higher cache levels. Performance comparisons show up to eightfold and twofold speedups for large dense matrix sizes, against the existing state-of-the-art TRMM and TRSM implementations from NVIDIA cuBLAS, respectively, across various GPU generations. Once integrated into high-level Cholesky-based dense linear algebra algorithms, the performance impact on the overall applications demonstrates up to fourfold and twofold speedups, against the equivalent native implementations, linked with cuBLAS TRMM and TRSM kernels, respectively. The new TRMM/TRSM kernel implementations are part of the open-source KBLAS software library (http://ecrc.kaust.edu.sa/Pages/Res-kblas.aspx) and are lined up for integration into the NVIDIA cuBLAS library in the upcoming v8.0 release.

  4. Roentgen contrast medium

    International Nuclear Information System (INIS)

    Tamborski, C.

    1989-01-01

    The patent deals with a roentgen contrast medium containing a perfluorinebrominealkylether of the formula C m F 2m+1 OC n F 2n Br dispersed in water, preferentially in the presence of a non-ionic dispersing agent such as a fluorinated amidoaminoxide. 2 tabs

  5. Radon in geological medium

    Energy Technology Data Exchange (ETDEWEB)

    Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

    1996-12-31

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

  6. Radon in geological medium

    International Nuclear Information System (INIS)

    Hricko, J.

    1995-01-01

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  7. Dense understory dwarf bamboo alters the retention of canopy tree seeds

    Science.gov (United States)

    Qian, Feng; Zhang, Tengda; Guo, Qinxue; Tao, Jianping

    2016-05-01

    Tree seed retention is thought to be an important factor in the process of forest community regeneration. Although dense understory dwarf bamboo has been considered to have serious negative effects on the regeneration of forest community species, little attention has been paid to the relationship between dwarf bamboo and seed retention. In a field experiment we manipulated the density of Fargesia decurvata, a common understory dwarf bamboo, to investigate the retention of seeds from five canopy tree species in an evergreen and deciduous broad-leaved mixed forest in Jinfoshan National Nature Reserve, SW China. We found that the median survival time and retention ratio of seeds increased with the increase in bamboo density. Fauna discriminately altered seed retention in bamboo groves of different densities. Arthropods reduced seed survival the most, and seeds removed decreased with increasing bamboo density. Birds removed or ate more seeds in groves of medium bamboo density and consumed fewer seeds in dense or sparse bamboo habitats. Rodents removed a greater number of large and highly profitable seeds in dense bamboo groves but more small and thin-husked seeds in sparse bamboo groves. Seed characteristics, including seed size, seed mass and seed profitability, were important factors affecting seed retention. The results suggested that dense understory dwarf bamboo not only increased seeds concealment and reduced the probability and speed of seed removal but also influenced the trade-off between predation and risk of animal predatory strategies, thereby impacting the quantity and composition of surviving seeds. Our results also indicated that dense understory dwarf bamboo and various seed characteristics can provide good opportunities for seed storage and seed germination and has a potential positive effect on canopy tree regeneration.

  8. Glaciations and dense interstellar clouds; and reply

    Energy Technology Data Exchange (ETDEWEB)

    McCrea, W H [Sussex Univ., Brighton (UK); Dennison, B; Mansfield, V N

    1976-09-16

    Reference is made to Dennison and Mansfield (Nature 261:32 (1976)) who offered comments on a previous paper by the author (Nature 255:607 (1975)), in which he suggested that a possible cause of an ice age on the Earth was the passage of the solar system through an interstellar matter compression region bordering a spiral arm of the Galaxy. Dennison and Mansfield criticised this suggestion because it led them to expect to find a dense cloud of interstellar matter still very close to the Earth, whereas no such cloud is known. It is stated here that this criticism ignores the structure of the Galaxy, that provided the basis of the suggestion. A reply by Dennison and Mansfield is appended.

  9. Frontiers and challenges in warm dense matter

    CERN Document Server

    Desjarlais, Michael; Redmer, Ronald; Trickey, Samuel

    2014-01-01

    Warm Dense Matter (WDM) occupies a loosely defined region of phase space intermediate between solid, liquid, gas, and plasma, and typically shares characteristics of two or more of these phases. WDM is generally associated with the combination of strongly coupled ions and moderately degenerate electrons, and careful attention to quantum physics and electronic structure is essential. The lack of a small perturbation parameter greatly limits approximate attempts at its accurate description. Since WDM resides at the intersection of solid state and high energy density physics, many high energy density physics (HEDP) experiments pass through this difficult region of phase space. Thus, understanding and modeling WDM is key to the success of experiments on diverse facilities. These include the National Ignition Campaign centered on the National Ignition Facility (NIF), pulsed-power driven experiments on the Z machine, ion-beam-driven WDM experiments on the NDCX-II, and fundamental WDM research at the Linear Coherent...

  10. Intrinsically secure fast reactors with dense cores

    International Nuclear Information System (INIS)

    Slessarev, Igor

    2007-01-01

    Secure safety, resistance to weapons material proliferation and problems of long-lived wastes remain the most important 'painful points' of nuclear power. Many innovative reactor concepts have been developed aimed at a radical enhancement of safety. The promising potential of innovative nuclear reactors allows for shifting accents in current reactor safety 'strategy' to reveal this worth. Such strategy is elaborated focusing on the priority for intrinsically secure safety features as well as on sure protection being provided by the first barrier of defence. Concerning the potential of fast reactors (i.e. sodium cooled, lead-cooled, etc.), there are no doubts that they are able to possess many favourable intrinsically secure safety features and to lay the proper foundation for a new reactor generation. However, some of their neutronic characteristics have to be radically improved. Among intrinsically secure safety properties, the following core parameters are significantly important: reactivity margin values, reactivity feed-back and coolant void effects. Ways of designing intrinsically secure safety features in fast reactors (titled hereafter as Intrinsically Secure Fast Reactors - ISFR) can be found in the frame of current reactor technologies by radical enhancement of core neutron economy and by optimization of core compositions. Simultaneously, respecting resistance to proliferation, by using non-enriched fuel feed as well as a core breeding gain close to zero, are considered as the important features (long-lived waste problems will be considered in a separate paper). This implies using the following reactor design options as well as closed fuel cycles with natural U as the reactor feed: ·Ultra-plate 'dense cores' of the ordinary (monolithic) type with negative total coolant void effects. ·Modular type cores. Multiple dense modules can be embedded in the common reflector for achieving the desired NPP total power. The modules can be used also independently (as

  11. Equation of state of dense baryonic matter

    International Nuclear Information System (INIS)

    Weber, F.; Weigel, M.K.

    1989-01-01

    In a previous investigation we treated nuclear matter as well as neutron matter at zero and finite temperatures in the frame of different relativistic field theoretical models, but with the restriction to nucleons as the only present baryons. This approach is extended by including a larger fraction of baryons and mesons, necessary for a description of baryon matter under extreme conditions. The equation of state (EOS) is calculated in both the Hartree and Hartree-Fock (HF) approximations for dense nuclear as well as neutron matter. Self-interactions of the σ field up to fourth order have been taken into account. For the treatment of many-baryon matter in the HF approach the parameters of the theory had to be readjusted. A phase transition of both many-baryon systems (neutron as well as nuclear matter) in the high-pressure and high-energy-density region has been found. (author)

  12. Nonlinear extraordinary wave in dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Russian University of Peoples’ Friendship (Russian Federation)

    2013-10-15

    Conditions for the propagation of a slow extraordinary wave in dense magnetized plasma are found. A solution to the set of relativistic hydrodynamic equations and Maxwell’s equations under the plasma resonance conditions, when the phase velocity of the nonlinear wave is equal to the speed of light, is obtained. The deviation of the wave frequency from the resonance frequency is accompanied by nonlinear longitudinal-transverse oscillations. It is shown that, in this case, the solution to the set of self-consistent equations obtained by averaging the initial equations over the period of high-frequency oscillations has the form of an envelope soliton. The possibility of excitation of a nonlinear wave in plasma by an external electromagnetic pulse is confirmed by numerical simulations.

  13. Statistical mechanics of dense granular media

    International Nuclear Information System (INIS)

    Coniglio, A; Fierro, A; Nicodemi, M; Ciamarra, M Pica; Tarzia, M

    2005-01-01

    We discuss some recent results on the statistical mechanics approach to dense granular media. In particular, by analytical mean field investigation we derive the phase diagram of monodisperse and bidisperse granular assemblies. We show that 'jamming' corresponds to a phase transition from a 'fluid' to a 'glassy' phase, observed when crystallization is avoided. The nature of such a 'glassy' phase turns out to be the same as found in mean field models for glass formers. This gives quantitative evidence for the idea of a unified description of the 'jamming' transition in granular media and thermal systems, such as glasses. We also discuss mixing/segregation transitions in binary mixtures and their connections to phase separation and 'geometric' effects

  14. A constitutive law for dense granular flows.

    Science.gov (United States)

    Jop, Pierre; Forterre, Yoël; Pouliquen, Olivier

    2006-06-08

    A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.

  15. Dense gas dispersion in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Morten

    1998-09-01

    Dense gas dispersion is characterized by buoyancy induced gravity currents and reduction of the vertical mixing. Liquefied gas releases from industrial accidents are cold because of the heat of evaporation which determines the density for a given concentration and physical properties. The temperature deficit is moderated by the heat flux from the ground, and this convection is an additional source of turbulence which affects the mixing. A simple model as the soil heat flux is used to estimate the ability of the ground to sustain the heat flux during release. The initial enthalpy, release rate, initial entrainment and momentum are discussed for generic source types and the interaction with obstacles is considered. In the MTH project BA experiments source with and without momentum were applied. The continuously released propane gas passed a two-dimensional removable obstacle perpendicular to the wind direction. Ground-level gas concentrations and vertical profiles of concentration, temperature, wind speed and turbulence were measured in front of and behind the obstacle. Ultrasonic anemometers providing fast velocity and concentration signals were mounted at three levels on the masts. The observed turbulence was influenced by the stability and the initial momentum of the jet releases. Additional information were taken from the `Dessert tortoise` ammonia jet releases, from the `Fladis` experiment with transition from dense to passive dispersion, and from the `Thorney Island` continuous releases of isothermal freon mixtures. The heat flux was found to moderate the negative buoyancy in both the propane and ammonia experiments. The heat flux measurements are compared to an estimate by analogy with surface layer theory. (au) 41 tabs., 146 ills., 189 refs.

  16. Concept medium program

    DEFF Research Database (Denmark)

    Bjerrum, Peter

    2003-01-01

    The present essays is an attempt to dertermine the architecural project of the 21st century in realation to a modern conception of space as the medium of architecture, and of society as its program. This attempt adopts the internal point of view of an architect in describing a modern architectural...... project within the framework: concept - program, these notions being concieved as spatial representations primarily and immediately "given" to architecture....

  17. Warm dense mater: another application for pulsed power hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Reinovsky, Robert Emil [Los Alamos National Laboratory

    2009-01-01

    Pulsed Power Hydrodynamics (PPH) is an application of low-impedance pulsed power, and high magnetic field technology to the study of advanced hydrodynamic problems, instabilities, turbulence, and material properties. PPH can potentially be applied to the study of the properties of warm dense matter (WDM) as well. Exploration of the properties of warm dense matter such as equation of state, viscosity, conductivity is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to slightly above solid density) and modest temperatures ({approx}1-10 eV). Conditions characteristic of WDM are difficult to obtain, and even more difficult to diagnose. One approach to producing WDM uses laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers are applying these techniques. Pulsed power hydrodynamic techniques, such as large convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through multiple shock compression and heating of normal density material between a massive, high density, energetic liner and a high density central 'anvil' are possible ways to reach relevant conditions. Another avenue to WDM conditions is through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. In this paper we will examine the challenges to pulsed power technology and to pulsed power systems presented by the opportunity to explore this interesting region of parameter space.

  18. Focus talk on interactions between jets and medium

    International Nuclear Information System (INIS)

    Ruppert, Joerg

    2006-01-01

    The energy and momentum lost by a hard parton propagating through hot and dense matter has to be redistributed during the nuclear medium evolution. Apart from heating the medium, there is the possibility that collective modes are excited leading to the emergence of Mach cones or Cherenkov radiation. Recent two-particle correlation measurements by STAR [F. Wang [STAR Collaboration], J. Phys. G 30, S1299 (2004) [arXiv:nucl-ex/0404010]; C. Gagliardi, these proceedings] and PHENIX [S. S. Adler et al. [PHENIX Collaboration], arXiv:nucl-ex/0507004; N. Ajitanand, these proceedings] at RHIC indicate that such phenomena may play an important role in understanding the jet-medium interactions. Possible collective modes are discussed and it is demonstrated that Mach cones as created by colorless or colored sound are a possible explanation of the hardronic two-particle correlation data

  19. Experimental study of ion stopping power in warm dense matter: charge-state distribution measurements of ions leaving warm dense matter

    International Nuclear Information System (INIS)

    Gauthier, Maxence

    2013-01-01

    The determination if the ion slowing down process (or stopping power) in warm dense matter is essential especially in the frame of inertial confinement fusion. During my thesis, our interest was driven by the modification of the charge state of ion beam emerging from warm dense matter, this quantity playing a major role in ion stopping power calculation. We took advantage of the properties exhibited by ion beams produced by high intensity short pulse lasers to study during two experiments performed at ELFIE and TITAN facilities, the charge state modification of a carbon and helium ion beams emerging from an aluminum foil isochorically heated by an energetic proton beam. In the first two chapters are presented the major challenges regarding the subject from both a theoretical and experimental point of view. Here are exposed the different simulation tools used during the thesis. The third chapter is devoted to the study of the property of laser-produced ion beams in the scope of our experiments aiming at studying the stopping power. We have studied in particular ion beams generated using lower-than-solid density targets during two experiments: helium gas jet and laser-exploded target. In the last chapter are presented the set-ups and results of the two experiments on the charge state of ion beam emerging from warm dense matter. The data we measured in solid-density cold aluminum are successfully compared with the results already obtained in conventional accelerators. (author) [fr

  20. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis

    Science.gov (United States)

    Singh, Lavleen; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0–3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature. PMID:26361799

  1. Are superluminous supernovae and long GRBs the products of dynamical processes in young dense star clusters?

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, E. P. J. [Astronomical Institute Anton Pannekoek, University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Portegies Zwart, S. F. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)

    2013-12-20

    Superluminous supernovae (SLSNe) occur almost exclusively in small galaxies (Small/Large Magellanic Cloud (SMC/LMC)-like or smaller), and the few SLSNe observed in larger star-forming galaxies always occur close to the nuclei of their hosts. Another type of peculiar and highly energetic supernovae are the broad-line Type Ic SNe (SN Ic-BL) that are associated with long-duration gamma-ray bursts (LGRBs). Also these have a strong preference for occurring in small (SMC/LMC-like or smaller) star-forming galaxies, and in these galaxies LGRBs always occur in the brightest spots. Studies of nearby star-forming galaxies that are similar to the hosts of LGRBs show that these brightest spots are giant H II regions produced by massive dense young star clusters with many hundreds of O- and Wolf-Rayet-type stars. Such dense young clusters are also found in abundance within a few hundred parsecs from the nucleus of larger galaxies like our own. We argue that the SLSNe and the SNe Ic-BL/LGRBs are exclusive products of two types of dynamical interactions in dense young star clusters. In our model the high angular momentum of the collapsing stellar cores required for the engines of an SN Ic-BL results from the post-main-sequence mergers of dynamically produced cluster binaries with almost equal-mass components. The merger produces a critically rotating single helium star with sufficient angular momentum to produce an LGRB; the observed 'metal aversion' of LGRBs is a natural consequence of the model. We argue that, on the other hand, SLSNe could be the products of runaway multiple collisions in dense clusters, and we present (and quantize) plausible scenarios of how the different types of SLSNe can be produced.

  2. Radiative-Transfer Modeling of Spectra of Densely Packed Particulate Media

    Science.gov (United States)

    Ito, G.; Mishchenko, M. I.; Glotch, T. D.

    2017-12-01

    Remote sensing measurements over a wide range of wavelengths from both ground- and space-based platforms have provided a wealth of data regarding the surfaces and atmospheres of various solar system bodies. With proper interpretations, important properties, such as composition and particle size, can be inferred. However, proper interpretation of such datasets can often be difficult, especially for densely packed particulate media with particle sizes on the order of wavelength of light being used for remote sensing. Radiative transfer theory has often been applied to the study of densely packed particulate media like planetary regoliths and snow, but with difficulty, and here we continue to investigate radiative transfer modeling of spectra of densely packed media. We use the superposition T-matrix method to compute scattering properties of clusters of particles and capture the near-field effects important for dense packing. Then, the scattering parameters from the T-matrix computations are modified with the static structure factor correction, accounting for the dense packing of the clusters themselves. Using these corrected scattering parameters, reflectance (or emissivity via Kirchhoff's Law) is computed with the method of invariance imbedding solution to the radiative transfer equation. For this work we modeled the emissivity spectrum of the 3.3 µm particle size fraction of enstatite, representing some common mineralogical and particle size components of regoliths, in the mid-infrared wavelengths (5 - 50 µm). The modeled spectrum from the T-matrix method with static structure factor correction using moderate packing densities (filling factors of 0.1 - 0.2) produced better fits to the laboratory measurement of corresponding spectrum than the spectrum modeled by the equivalent method without static structure factor correction. Future work will test the method of the superposition T-matrix and static structure factor correction combination for larger particles

  3. Quantitative contrast-enhanced mammography for contrast medium kinetics studies

    Science.gov (United States)

    Arvanitis, C. D.; Speller, R.

    2009-10-01

    Quantitative contrast-enhanced mammography, based on a dual-energy approach, aims to extract quantitative and temporal information of the tumour enhancement after administration of iodinated vascular contrast media. Simulations using analytical expressions and optimization of critical parameters essential for the development of quantitative contrast-enhanced mammography are presented. The procedure has been experimentally evaluated using a tissue-equivalent phantom and an amorphous silicon active matrix flat panel imager. The x-ray beams were produced by a tungsten target tube and spectrally shaped using readily available materials. Measurement of iodine projected thickness in mg cm-2 has been performed. The effect of beam hardening does not introduce nonlinearities in the measurement of iodine projected thickness for values of thicknesses found in clinical investigations. However, scattered radiation introduces significant deviations from slope equal to unity when compared with the actual iodine projected thickness. Scatter correction before the analysis of the dual-energy images provides accurate iodine projected thickness measurements. At 10% of the exposure used in clinical mammography, signal-to-noise ratios in excess of 5 were achieved for iodine projected thicknesses less than 3 mg cm-2 within a 4 cm thick phantom. For the extraction of temporal information, a limited number of low-dose images were used with the phantom incorporating a flow of iodinated contrast medium. The results suggest that spatial and temporal information of iodinated contrast media can be used to indirectly measure the tumour microvessel density and determine its uptake and washout from breast tumours. The proposed method can significantly improve tumour detection in dense breasts. Its application to perform in situ x-ray biopsy and assessment of the oncolytic effect of anticancer agents is foreseeable.

  4. Breast cancer screening in Korean woman with dense breast tissue

    International Nuclear Information System (INIS)

    Shin, Hee Jung; Ko, Eun Sook; Yi, Ann

    2015-01-01

    Asian women, including Korean, have a relatively higher incidence of dense breast tissue, compared with western women. Dense breast tissue has a lower sensitivity for the detection of breast cancer and a higher relative risk for breast cancer, compared with fatty breast tissue. Thus, there were limitations in the mammographic screening for women with dense breast tissue, and many studies for the supplemental screening methods. This review included appropriate screening methods for Korean women with dense breasts. We also reviewed the application and limitation of supplemental screening methods, including breast ultrasound, digital breast tomosynthesis, and breast magnetic resonance imaging; and furthermore investigated the guidelines, as well as the study results

  5. Breast cancer screening in Korean woman with dense breast tissue

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hee Jung [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Ko, Eun Sook [Dept. of Radiology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Yi, Ann [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-11-15

    Asian women, including Korean, have a relatively higher incidence of dense breast tissue, compared with western women. Dense breast tissue has a lower sensitivity for the detection of breast cancer and a higher relative risk for breast cancer, compared with fatty breast tissue. Thus, there were limitations in the mammographic screening for women with dense breast tissue, and many studies for the supplemental screening methods. This review included appropriate screening methods for Korean women with dense breasts. We also reviewed the application and limitation of supplemental screening methods, including breast ultrasound, digital breast tomosynthesis, and breast magnetic resonance imaging; and furthermore investigated the guidelines, as well as the study results.

  6. A Seemingly Simple Task: Filling a Solenoid Volume in Vacuum with Dense Plasma

    International Nuclear Information System (INIS)

    Anders, Andre; Kauffeldt, Marina; Roy, Prabir; Oks, Efim

    2010-01-01

    Space-charge neutralization of a pulsed, high-current ion beam is required to compress and focus the beam on a target for warm dense matter physics or heavy ion fusion experiments. We described attempts to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary charge-compensating electrons. Among the options are plasma injection from four pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means and by an array of movable Langmuir probes. The plasma is produced at several cathode spots distributed azimuthally on the ring cathode. Beam neutralization and compression are accomplished, though issues of density, uniformity, and pulse-to-pulse reproducibly remain to be solved.

  7. Study of dense-plasma properties using very high-frequency electromagnetic waves (light waves)

    International Nuclear Information System (INIS)

    Gormezano, C.

    1966-06-01

    A study is made of methods based on the use of lasers for measuring the electronic density and temperature of dense plasmas (N e > 10 15 e/cm 3 ): - an interferometric method using a gas laser, based on the. properties of the Perot-Fabry cavities; - a method making use of the 90 deg C scattering produced by the plasma on light emitted by a ruby laser. These methods have been applied to various dense plasmas: - high-frequency plasma torch; - azimuth compression; - plasma bursts produced by focussing a laser beam on a metal target. The measurements have also been carried out using conventional methods of diagnosis. It has thus been possible to measure densities of between 5.10 15 and 10 19 e/cm 3 and temperatures of between 3 and 10 eV. These different-methods are then compared, (author) [fr

  8. Improved models of dense anharmonic lattices

    Energy Technology Data Exchange (ETDEWEB)

    Rosenau, P., E-mail: rosenau@post.tau.ac.il; Zilburg, A.

    2017-01-15

    We present two improved quasi-continuous models of dense, strictly anharmonic chains. The direct expansion which includes the leading effect due to lattice dispersion, results in a Boussinesq-type PDE with a compacton as its basic solitary mode. Without increasing its complexity we improve the model by including additional terms in the expanded interparticle potential with the resulting compacton having a milder singularity at its edges. A particular care is applied to the Hertz potential due to its non-analyticity. Since, however, the PDEs of both the basic and the improved model are ill posed, they are unsuitable for a study of chains dynamics. Using the bond length as a state variable we manipulate its dispersion and derive a well posed fourth order PDE. - Highlights: • An improved PDE model of a Newtonian lattice renders compacton solutions. • Compactons are classical solutions of the improved model and hence amenable to standard analysis. • An alternative well posed model enables to study head on interactions of lattices' solitary waves. • Well posed modeling of Hertz potential.

  9. Neutral helium spectral lines in dense plasmas

    International Nuclear Information System (INIS)

    Omar, Banaz; Wierling, August; Roepke, Gerd; Guenter, Sibylle

    2006-01-01

    Shift and broadening of isolated neutral helium lines 7281 A ring (2 1 P-3 1 S), 7065 A ring (2 3 P-3 3 S), 6678 A ring (2 1 P-3 1 D), 5048 A ring (2 1 P-4 1 S), 4922 A ring (2 1 P-4 1 D), and 4713 A ring (2 3 P-4 3 S) in a dense plasma are investigated. Based on a quantum statistical theory, the electronic contributions to the shift and width are considered, using the method of thermodynamic Green functions. Dynamic screening of the electron-atom interaction is included. Compared to the width, the electronic shift is more affected by dynamical screening. This effect increases at high density. A cut-off procedure for strong collisions is used. The contribution of the ions is taken into account in a quasi-static approximation, with both the quadratic Stark effect and the quadrupole interaction included. The results for shift and width agree well with the available experimental and theoretical data

  10. Deterministic dense coding and entanglement entropy

    International Nuclear Information System (INIS)

    Bourdon, P. S.; Gerjuoy, E.; McDonald, J. P.; Williams, H. T.

    2008-01-01

    We present an analytical study of the standard two-party deterministic dense-coding protocol, under which communication of perfectly distinguishable messages takes place via a qudit from a pair of nonmaximally entangled qudits in a pure state |ψ>. Our results include the following: (i) We prove that it is possible for a state |ψ> with lower entanglement entropy to support the sending of a greater number of perfectly distinguishable messages than one with higher entanglement entropy, confirming a result suggested via numerical analysis in Mozes et al. [Phys. Rev. A 71, 012311 (2005)]. (ii) By explicit construction of families of local unitary operators, we verify, for dimensions d=3 and d=4, a conjecture of Mozes et al. about the minimum entanglement entropy that supports the sending of d+j messages, 2≤j≤d-1; moreover, we show that the j=2 and j=d-1 cases of the conjecture are valid in all dimensions. (iii) Given that |ψ> allows the sending of K messages and has √(λ 0 ) as its largest Schmidt coefficient, we show that the inequality λ 0 ≤d/K, established by Wu et al. [Phys. Rev. A 73, 042311 (2006)], must actually take the form λ 0 < d/K if K=d+1, while our constructions of local unitaries show that equality can be realized if K=d+2 or K=2d-1

  11. Thermochemistry of dense hydrous magnesium silicates

    Science.gov (United States)

    Bose, Kunal; Burnley, Pamela; Navrotsky, Alexandra

    1994-01-01

    Recent experimental investigations under mantle conditions have identified a suite of dense hydrous magnesium silicate (DHMS) phases that could be conduits to transport water to at least the 660 km discontinuity via mature, relatively cold, subducting slabs. Water released from successive dehydration of these phases during subduction could be responsible for deep focus earthquakes, mantle metasomatism and a host of other physico-chemical processes central to our understanding of the earth's deep interior. In order to construct a thermodynamic data base that can delineate and predict the stability ranges for DHMS phases, reliable thermochemical and thermophysical data are required. One of the major obstacles in calorimetric studies of phases synthesized under high pressure conditions has been limitation due to the small (less than 5 mg) sample mass. Our refinement of calorimeter techniques now allow precise determination of enthalpies of solution of less than 5 mg samples of hydrous magnesium silicates. For example, high temperature solution calorimetry of natural talc (Mg(0.99) Fe(0.01)Si4O10(OH)2), periclase (MgO) and quartz (SiO2) yield enthalpies of drop solution at 1044 K to be 592.2 (2.2), 52.01 (0.12) and 45.76 (0.4) kJ/mol respectively. The corresponding enthalpy of formation from oxides at 298 K for talc is minus 5908.2 kJ/mol agreeing within 0.1 percent to literature values.

  12. Borehole stability in densely welded tuffs

    International Nuclear Information System (INIS)

    Fuenkajorn, K.; Daemen, J.J.K.

    1992-07-01

    The stability of boreholes, or more generally of underground openings (i.e. including shafts, ramps, drifts, tunnels, etc.) at locations where seals or plugs are to be placed is an important consideration in seal design for a repository (Juhlin and Sandstedt, 1989). Borehole instability or borehole breakouts induced by stress redistribution could negate the effectiveness of seals or plugs. Breakout fractures along the wall of repository excavations or exploratory holes could provide a preferential flowpath for groundwater or gaseous radionuclides to bypass the plugs. After plug installation, swelling pressures exerted by a plug could induce radial cracks or could open or widen preexisting cracks in the rock at the bottom of the breakouts where the tangential compressive stresses have been released by the breakout process. The purpose of the work reported here is to determine experimentally the stability of a circular hole in a welded tuff sample subjected to various external boundary loads. Triaxial and biaxial borehole stability tests have been performed on densely welded Apache Leap tuff samples and Topopah Spring tuff samples. The nominal diameter of the test hole is 13.3 or 14.4 mm for triaxial testing, and 25.4 mm for biaxial testing. The borehole axis is parallel to one of the principal stress axes. The boreholes are drilled through the samples prior to applying external boundary loads. The boundary loads are progressively increased until breakouts occur or until the maximum load capacity of the loading system has been reached. 74 refs

  13. Packing frustration in dense confined fluids.

    Science.gov (United States)

    Nygård, Kim; Sarman, Sten; Kjellander, Roland

    2014-09-07

    Packing frustration for confined fluids, i.e., the incompatibility between the preferred packing of the fluid particles and the packing constraints imposed by the confining surfaces, is studied for a dense hard-sphere fluid confined between planar hard surfaces at short separations. The detailed mechanism for the frustration is investigated via an analysis of the anisotropic pair distributions of the confined fluid, as obtained from integral equation theory for inhomogeneous fluids at pair correlation level within the anisotropic Percus-Yevick approximation. By examining the mean forces that arise from interparticle collisions around the periphery of each particle in the slit, we calculate the principal components of the mean force for the density profile--each component being the sum of collisional forces on a particle's hemisphere facing either surface. The variations of these components with the slit width give rise to rather intricate changes in the layer structure between the surfaces, but, as shown in this paper, the basis of these variations can be easily understood qualitatively and often also semi-quantitatively. It is found that the ordering of the fluid is in essence governed locally by the packing constraints at each single solid-fluid interface. A simple superposition of forces due to the presence of each surface gives surprisingly good estimates of the density profiles, but there remain nontrivial confinement effects that cannot be explained by superposition, most notably the magnitude of the excess adsorption of particles in the slit relative to bulk.

  14. Deuterium fractionation in dense interstellar clouds

    International Nuclear Information System (INIS)

    Millar, T.J.; Bennett, A.; Herbst, E.

    1989-01-01

    The time-dependent gas-phase chemistry of deuterium fractionation in dense interstellar clouds ranging in temperature between 10 and 70 K was investigated using a pseudo-time-dependent model similar to that of Brown and Rice (1986). The present approach, however, considers much more complex species, uses more deuterium fractionation reactions, and includes the use of new branching ratios for dissociative recombinations reactions. Results indicate that, in cold clouds, the major and most global source of deuterium fractionation is H2D(+) and ions derived from it, such as DCO(+) and H2DO(+). In warmer clouds, reactions of CH2D(+), C2HD(+), and associated species lead to significant fractionation even at 70 K, which is the assumed Orion temperature. The deuterium abundance ratios calculated at 10 K are consistent with those observed in TMC-1 for most species. However, a comparison between theory and observatiom for Orion, indicates that, for species in the ambient molecular cloud, the early-time results obtained with the old dissociative recombination branching ratios are superior if a temperature of 70 K is utilized. 60 refs

  15. Deuterium fractionation in dense interstellar clouds

    Science.gov (United States)

    Millar, T. J.; Bennett, A.; Herbst, Eric

    1989-05-01

    The time-dependent gas-phase chemistry of deuterium fractionation in dense interstellar clouds ranging in temperature between 10 and 70 K was investigated using a pseudo-time-dependent model similar to that of Brown and Rice (1986). The present approach, however, considers much more complex species, uses more deuterium fractionation reactions, and includes the use of new branching ratios for dissociative recombinations reactions. Results indicate that, in cold clouds, the major and most global source of deuterium fractionation is H2D(+) and ions derived from it, such as DCO(+) and H2DO(+). In warmer clouds, reactions of CH2D(+), C2HD(+), and associated species lead to significant fractionation even at 70 K, which is the assumed Orion temperature. The deuterium abundance ratios calculated at 10 K are consistent with those observed in TMC-1 for most species. However, a comparison between theory and observatiom for Orion, indicates that, for species in the ambient molecular cloud, the early-time results obtained with the old dissociative recombination branching ratios are superior if a temperature of 70 K is utilized.

  16. Matching Cost Filtering for Dense Stereo Correspondence

    Directory of Open Access Journals (Sweden)

    Yimin Lin

    2013-01-01

    Full Text Available Dense stereo correspondence enabling reconstruction of depth information in a scene is of great importance in the field of computer vision. Recently, some local solutions based on matching cost filtering with an edge-preserving filter have been proved to be capable of achieving more accuracy than global approaches. Unfortunately, the computational complexity of these algorithms is quadratically related to the window size used to aggregate the matching costs. The recent trend has been to pursue higher accuracy with greater efficiency in execution. Therefore, this paper proposes a new cost-aggregation module to compute the matching responses for all the image pixels at a set of sampling points generated by a hierarchical clustering algorithm. The complexity of this implementation is linear both in the number of image pixels and the number of clusters. Experimental results demonstrate that the proposed algorithm outperforms state-of-the-art local methods in terms of both accuracy and speed. Moreover, performance tests indicate that parameters such as the height of the hierarchical binary tree and the spatial and range standard deviations have a significant influence on time consumption and the accuracy of disparity maps.

  17. Generation of dense, pulsed beams of refractory metal atoms using two-stage laser ablation

    International Nuclear Information System (INIS)

    Kadar-Kallen, M.A.; Bonin, K.D.

    1994-01-01

    We report a technique for generating a dense, pulsed beam of refractory metal atoms using two-stage laser ablation. An atomic beam of uranium was produced with a peak, ground-state number density of 1x10 12 cm -3 at a distance of z=27 cm from the source. This density can be scaled as 1/z 3 to estimate the density at other distances which are also far from the source

  18. X-ray Spectroscopy of Hot Dense Plasmas: Experimental Limits, Line Shifts and Field Effects

    International Nuclear Information System (INIS)

    Renner, Oldrich; Sauvan, Patrick; Dalimier, Elisabeth; Riconda, Caterina; Rosmej, Frank B.; Weber, Stefan; Nicolai, Philippe; Peyrusse, Olivier; Uschmann, Ingo; Hoefer, Sebastian; Kaempfer, Tino; Loetzsch, Robert; Zastrau, Ulf; Foerster, Eckhart; Oks, Eugene

    2008-01-01

    High-resolution x-ray spectroscopy is capable of providing complex information on environmental conditions in hot dense plasmas. Benefiting from application of modern spectroscopic methods, we report experiments aiming at identification of different phenomena occurring in laser-produced plasma. Fine features observed in broadened profiles of the emitted x-ray lines and their satellites are interpreted using theoretical models predicting spectra modification under diverse experimental situations.

  19. Improving near-real time deforestation monitoring in tropical dry forests by combining dense Sentinel-1 time series with Landsat and ALOS-2 PALSAR-2

    NARCIS (Netherlands)

    Reiche, Johannes; Hamunyela, Eliakim; Verbesselt, Jan; Hoekman, Dirk; Herold, Martin

    2018-01-01

    Combining observations from multiple optical and synthetic aperture radar (SAR) satellites can provide temporally dense and regular information at medium resolution scale, independently of weather, season, and location. This has the potential to improve near real-time deforestation monitoring in dry

  20. Heterogeneously Catalysed Chemical Reactions in Carbon Dioxide Medium

    DEFF Research Database (Denmark)

    Musko, Nikolai E.

    In this PhD-study the different areas of chemical engineering, heterogeneous catalysis, supercritical fluids, and phase equilibrium thermodynamics have been brought together for selected reactions. To exploit the beneficial properties of supercritical fluids in heterogeneous catalysis, experimental...... studies of catalytic chemical reactions in dense and supercritical carbon dioxide have been complemented by the theoretical calculations of phase equilibria using advanced thermodynamic models. In the recent years, the use of compressed carbon dioxide as innovative, non-toxic and non-flammable, cheap......, and widely available reaction medium for many practical and industrial applications has drastically increased. Particularly attractive are heterogeneously catalysed chemical reactions. The beneficial use of CO2 is attributed to its unique properties at dense and supercritical states (at temperatures...

  1. Development of a new medium containing date syrup for production ...

    African Journals Online (AJOL)

    USER

    2010-08-16

    Aug 16, 2010 ... A confirmatory experiment of the optimal medium composition ... product of date industry; it is rich in carbohydrates (75% w/w) and small ... producers at cheap prices. ... date syrup using a combination of statistical strategies.

  2. Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics

    Science.gov (United States)

    Hansen, S. B.; Harding, E. C.; Knapp, P. F.; Gomez, M. R.; Nagayama, T.; Bailey, J. E.

    2018-05-01

    The burning core of an inertial confinement fusion (ICF) plasma produces bright x-rays at stagnation that can directly diagnose core conditions essential for comparison to simulations and understanding fusion yields. These x-rays also backlight the surrounding shell of warm, dense matter, whose properties are critical to understanding the efficacy of the inertial confinement and global morphology. We show that the absorption and fluorescence spectra of mid-Z impurities or dopants in the warm dense shell can reveal the optical depth, temperature, and density of the shell and help constrain models of warm, dense matter. This is illustrated by the example of a high-resolution spectrum collected from an ICF plasma with a beryllium shell containing native iron impurities. Analysis of the iron K-edge provides model-independent diagnostics of the shell density (2.3 × 1024 e/cm3) and temperature (10 eV), while a 12-eV red shift in Kβ and 5-eV blue shift in the K-edge discriminate among models of warm dense matter: Both shifts are well described by a self-consistent field model based on density functional theory but are not fully consistent with isolated-atom models using ad-hoc density effects.

  3. Optimizing Grain Boundary Complexions to Produce Dense Pressure-Less Sintered Boron Carbide (B4C)

    Science.gov (United States)

    2008-11-14

    discontinuous distribution of the yttria. At this stage it is difficult to determine if the discontinuity is genuine or results from dewetting upon cooling...sample. However, the tendency of the film to form beads indicates a dewetting behavior. The weak interface between the yttria and the boron carbide...conform to the dewetting behavior. There is a possibility of a complexion transition as the sample is cooled down in the furnace. At high temperature the

  4. Mining connected global and local dense subgraphs for bigdata

    Science.gov (United States)

    Wu, Bo; Shen, Haiying

    2016-01-01

    The problem of discovering connected dense subgraphs of natural graphs is important in data analysis. Discovering dense subgraphs that do not contain denser subgraphs or are not contained in denser subgraphs (called significant dense subgraphs) is also critical for wide-ranging applications. In spite of many works on discovering dense subgraphs, there are no algorithms that can guarantee the connectivity of the returned subgraphs or discover significant dense subgraphs. Hence, in this paper, we define two subgraph discovery problems to discover connected and significant dense subgraphs, propose polynomial-time algorithms and theoretically prove their validity. We also propose an algorithm to further improve the time and space efficiency of our basic algorithm for discovering significant dense subgraphs in big data by taking advantage of the unique features of large natural graphs. In the experiments, we use massive natural graphs to evaluate our algorithms in comparison with previous algorithms. The experimental results show the effectiveness of our algorithms for the two problems and their efficiency. This work is also the first that reveals the physical significance of significant dense subgraphs in natural graphs from different domains.

  5. Dense chlorinated solvents and other DNAPLs in groundwater

    DEFF Research Database (Denmark)

    Broholm, K.

    1996-01-01

    Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996......Anmeldelse af Pankow,J.F. & Cherry,J.A.: Dense chlorinated solvents and other DNAPLs in groundwater. Waterloo Press, Portland, Oregon, USA, 1996...

  6. Interparticle interaction and transport processes in dense semiclassical plasmas

    International Nuclear Information System (INIS)

    Baimbetov, F.B.; Giniyatova, Sh.G.

    2005-01-01

    On the basis of the density response formalism an expression for the pseudopotential of dense semiclassical plasma, which takes account of quantum-mechanical effects, local field corrections, and electronic screening effects is obtained. The static structure factors taking into account both local fields and quantum-mechanical effects are calculated. An electrical conductivity, thermal conductivity, and viscosity of dense semiclassical plasma are studied

  7. Medium effects in strange quark matter and strange stars

    International Nuclear Information System (INIS)

    Schertler, K.; Greiner, C.; Thoma, M.H.

    1997-01-01

    We investigate the properties of strange quark matter at zero temperature including medium effects. The quarks are considered as quasiparticles which acquire an effective mass generated by the interaction with the other quarks of the dense system. The effective quark masses are derived from the zero momentum limit of the dispersion relations following from an effective quark propagator obtained from resumming one-loop self-energy diagrams in the hard dense loop approximation. This leads to a thermodynamic self-consistent description of strange quark matter as an ideal Fermi gas of quasiparticles. Within this approach we find that medium effects reduce the overall binding energy with respect to 56 Fe of strange quark matter. For typical values of the strong coupling constant (α s >or∼1) strange quark matter is not absolutely stable. The application to pure strange quark matter stars shows that medium effects have, nevertheless, no impact on the mass-radius relation of the stars. However, a phase transition to hadronic matter at the surface of the stars becomes more likely. (orig.)

  8. Absorption of X-rays in the interstellar medium

    International Nuclear Information System (INIS)

    Ride, S.K.; Stanford Univ., Calif.; Walker, A.B.C. Jr.; Stanford Univ., Calif.

    1977-01-01

    In order to interpret soft X-ray spectra of cosmic X-ray sources, it is necessary to know the photoabsorption cross-section of the intervening interstellar material. Current models suggest that the interstellar medium contains two phases which make a substantial contribution to the X-ray opacity: cool, relatively dense clouds that exist in pressure equilibrium with hot, tenuous intercloud regions. We have computed the soft X-ray photoabsorption cross-section (per hydrogen atom) of each of these two phases. The calculation are based on a model of the interstellar medium which includes chemical evolution of the galaxy, the formation of molecules and grains, and the ionization structure of each of each phase. These cross-sections of clouds and of intercloud regions can be combined to yield the total soft X-ray photoabsorption cross-section of the interstellar medium. By choosing the appropriate linear combination of cloud and intercloud cross-sections, we can tailor the total cross-section to a particular line-of-sight. This approach, coupled with our interstellar model, enables us to better describe a wide range of interstellar features such as H II regions, dense (molecular) clouds, or the ionized clouds which may surround binary X-ray sources. (orig.) [de

  9. Computation as Medium

    DEFF Research Database (Denmark)

    Jochum, Elizabeth Ann; Putnam, Lance

    2017-01-01

    Artists increasingly utilize computational tools to generate art works. Computational approaches to art making open up new ways of thinking about agency in interactive art because they invite participation and allow for unpredictable outcomes. Computational art is closely linked...... to the participatory turn in visual art, wherein spectators physically participate in visual art works. Unlike purely physical methods of interaction, computer assisted interactivity affords artists and spectators more nuanced control of artistic outcomes. Interactive art brings together human bodies, computer code......, and nonliving objects to create emergent art works. Computation is more than just a tool for artists, it is a medium for investigating new aesthetic possibilities for choreography and composition. We illustrate this potential through two artistic projects: an improvisational dance performance between a human...

  10. Spiegel. Medium. Kunst

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    of this kind as the marks of a meta-complex of method out of which new models of the image continually arise. The waxing intangibility of proliferating images be they of the mind, in dreams, through gestures, and the equally rampant growth of microstructuring in allocations of knowledge lay a challenge before...... to research. As a void in the apprehension of the world, the mirror obtained a scholarly perspective and the more so in areas beyond its own qualities as a medium, i.e. in images and metaphor, the paradigms of all research looking to image and text. This investigation sets out to comprehend paradoxes......, and space (albeit no expanse) is there to consider the methodological pros and cons of such a selective approach. Even in this synopsis, it has to be and can be stated that what makes for the affinities between psychological, literary and image-research approaches in research on the mirror is the shared...

  11. The diffuse interstellar medium

    Science.gov (United States)

    Cox, Donald P.

    1990-01-01

    The last 20 years of the efforts to understand the diffuse ISM are reviewed, with recent changes of fundamental aspects being highlighted. Attention is given to the interstellar pressure and its components, the weight of the ISM, the midplane pressure contributions, and pressure contributions at 1 kpc. What velocity dispersions, cosmic ray pressure, and magnetic field pressure that can be expected for a gas in a high magnetic field environment is addressed. The intercloud medium is described, with reference to the work of Cox and Slavin (1989). Various caveats are discussed and a number of areas for future investigation are identified. Steps that could be taken toward a successful phase segregation model are discussed.

  12. Fabrication of dense panels in lithium fluoride; Fabrication de panneaux denses en fluorure de lithium

    Energy Technology Data Exchange (ETDEWEB)

    Farcy, P.; Roger, J.; Pointud, R.

    1958-04-15

    The authors report a study aimed at the fabrication of large and dense lithium fluoride panels. This sintered lithium fluoride is then supposed to be used for the construction of barriers of protection against a flow of thermal neutrons. They briefly present the raw material which is used under the form of chamotte obtained through a pre-sintering process which is also described. Grain size measurements and sample preparation are indicated. Shaping, drying, and thermal treatment are briefly described, and characteristics of the sintered product are indicated.

  13. Dense Fe cluster-assembled films by energetic cluster deposition

    International Nuclear Information System (INIS)

    Peng, D.L.; Yamada, H.; Hihara, T.; Uchida, T.; Sumiyama, K.

    2004-01-01

    High-density Fe cluster-assembled films were produced at room temperature by an energetic cluster deposition. Though cluster-assemblies are usually sooty and porous, the present Fe cluster-assembled films are lustrous and dense, revealing a soft magnetic behavior. Size-monodispersed Fe clusters with the mean cluster size d=9 nm were synthesized using a plasma-gas-condensation technique. Ionized clusters are accelerated electrically and deposited onto the substrate together with neutral clusters from the same cluster source. Packing fraction and saturation magnetic flux density increase rapidly and magnetic coercivity decreases remarkably with increasing acceleration voltage. The Fe cluster-assembled film obtained at the acceleration voltage of -20 kV has a packing fraction of 0.86±0.03, saturation magnetic flux density of 1.78±0.05 Wb/m 2 , and coercivity value smaller than 80 A/m. The resistivity at room temperature is ten times larger than that of bulk Fe metal

  14. Study of microwave emission from a dense plasma focus

    International Nuclear Information System (INIS)

    Gerdin, G.; Venneri, F.; Tanisi, M.

    1985-01-01

    Microwave emission was detected in a 12.5 kJ dense plasma focus, using microwave horns and detectors placed in various locations outside the device. The results show that the parallel plates connecting the focus to its capacitor banks act as antennas and transmission lines, rather than wave guides. Subsequent measurements were performed with a microwave detector (R-band) attached to the focus anode, directly looking into the coaxial gun region, allowing to restrict the microwave emitting region to the muzzle end of the focus. The microwave frequency spectrum, determined with a time of flight detection system, strongly suggests the lower hybrid instability as the driving mechanism of the emissions. Comparing the time sequence of the emissions with those of other observable phenomena in the focus, a model was developed, to explain the possible relationship between the generation of microwave radiation and turbulence induced resistivity in the focus pinch. According to the model, microwaves and enhanced resistivity are caused by current driven instabilities occurring in the current sheath produced at the outer boundary of the pinch during the initial compression phase. Comparisons of the model predictions with observed experimental results are presented, including time resolved measurements of the pinch resistivity

  15. FttC-Based Fronthaul for 5G Dense/Ultra-Dense Access Network: Performance and Costs in Realistic Scenarios

    Directory of Open Access Journals (Sweden)

    Franco Mazzenga

    2017-10-01

    Full Text Available One distinctive feature of the next 5G systems is the presence of a dense/ultra-dense wireless access network with a large number of access points (or nodes at short distances from each other. Dense/ultra-dense access networks allow for providing very high transmission capacity to terminals. However, the deployment of dense/ultra-dense networks is slowed down by the cost of the fiber-based infrastructure required to connect radio nodes to the central processing units and then to the core network. In this paper, we investigate the possibility for existing FttC access networks to provide fronthaul capabilities for dense/ultra-dense 5G wireless networks. The analysis is realistic in that it is carried out considering an actual access network scenario, i.e., the Italian FttC deployment. It is assumed that access nodes are connected to the Cabinets and to the corresponding distributors by a number of copper pairs. Different types of cities grouped in terms of population have been considered. Results focus on fronthaul transport capacity provided by the FttC network and have been expressed in terms of the available fronthaul bit rate per node and of the achievable coverage.

  16. Producing cement

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E G

    1923-09-12

    A process and apparatus are described for producing Portland cement in which pulverized shale is successively heated in a series of inclined rotary retorts having internal stirrers and oil gas outlets, which are connected to condensers. The partially treated shale is removed from the lowermost retort by a conveyor, then fed separately or conjointly into pipes and thence into a number of vertically disposed retorts. Each of these retorts may be fitted interiorly with vertical arranged conveyors which elevate the shale and discharge it over a lip, from whence it falls to the bottom of the retorts. The lower end of each casing is furnished with an adjustable discharge door through which the spent shale is fed to a hopper, thence into separate trucks. The oil gases generated in the retorts are exhausted through pipes to condensers. The spent shale is conveyed to a bin and mixed while hot with ground limestone. The admixed materials are then ground and fed to a rotary kiln which is fired by the incondensible gases derived from the oil gases obtained in the previous retorting of the shale. The calcined materials are then delivered from the rotary kiln to rotary coolers. The waste gases from the kiln are utilized for heating the retorts in which the ground shale is heated for the purpose of extracting therefrom the contained hydrocarbon oils and gases.

  17. Rates of Thermonuclear Reactions in Dense Plasmas

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bornatici, M.

    2000-01-01

    The problem of plasma screening of thermonuclear reactions has attracted considerable scientific interest ever since Salpeter's seminal paper, but it is still faced with controversial statements and without any definite conclusion. It is of relevant importance to thermonuclear reactions in dense astrophysical plasmas, for which charge screening can substantially affect the reaction rates. Whereas Salpeter and a number of subsequent investigations have dealt with static screening, Carraro, Schafer, and Koonin have drawn attention to the fact that plasma screening of thermonuclear reactions is an essentially dynamic effect. In addressing the issue of collective plasma effects on the thermonuclear reaction rates, the first critical overview of most of the work carried out so far is presented and the validity of the test particle approach is assessed. In contrast to previous investigations, we base our description on the kinetic equation for nonequilibrium plasmas, which accounts for the effects on the rates of thermonuclear reactions of both plasma fluctuations and screening and allows one to analyze explicitly the effects of the fluctuations on the reaction rates. Such a kinetic formulation is more general than both Salpeter's approach and the recently developed statistical approaches and makes it possible to obtain a more comprehensive understanding of the problem. A noticeable result of the fluctuation approach is that the static screening, which affects both the interaction and the self-energy of the reacting nuclei, does not affect the reaction rates, in contrast with the results obtained so far. Instead, a reduction of the thermonuclear reaction rates is obtained as a result of the effect of plasma fluctuations related to the free self-energy of the reacting nuclei. A simple physical explanation of the slowing down of the reaction rates is given, and the relation to the dynamically screened test particle approach is discussed. Corrections to the reaction rates

  18. Neutrino reactions in hot and dense matter

    International Nuclear Information System (INIS)

    Lohs, Andreas

    2015-01-01

    In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

  19. Neutrino reactions in hot and dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Lohs, Andreas

    2015-04-13

    In this thesis, neutrino reactions in hot and dense matter are studied. In particular, this work is concerned with neutrino-matter interactions that are relevant for neutrino transport in core-collapse supernovae (CCSNe). The majority of the energy from a CCSN is released in the form of neutrinos. Accurate understanding and computation of these interactions is most relevant to achieve sufficiently reliable predictions for the evolution of CCSNe and other related question such as the production of heavy elements or neutrino oscillations. For this purpose this work follows the combined approach of searching for new important neutrino reactions and improving the computation of those reactions that are already implemented. First we estimate the relevance of charged-current weak interactions that include muon-neutrinos or muons, as well as the role of neutron decay for neutrino transport in CCSNe. All of these reactions were previously neglected in CCSN-simulations. We derive and compute the matrix element and subsequent semi-analytic expressions for transport properties like the inverse mean free path of the new reactions. It is found that these reactions are important for muon neutrinos and low energy electron antineutrinos at very high densities in the protoneutron star surface. Consequently their implementation might lead to several changes in the prediction of CCSNe signatures such as the nucleosynthesis yields. Second we improve the precision in the computation of well known neutrino-nucleon reactions like neutrino absorption on neutrons. We derive semi-analytic expressions for transport properties that use less restrictive approximations while keeping the computational demand constant. Therefore we consider the full relativistic kinematics of all participating particles i.e. allowing for relativistic nucleons and finite lepton masses. Also the weak magnetism terms of the matrix elements are explicitly included to all orders. From our results we suggest that the

  20. Dense-gas dispersion advection-diffusion model

    International Nuclear Information System (INIS)

    Ermak, D.L.

    1992-07-01

    A dense-gas version of the ADPIC particle-in-cell, advection- diffusion model was developed to simulate the atmospheric dispersion of denser-than-air releases. In developing the model, it was assumed that the dense-gas effects could be described in terms of the vertically-averaged thermodynamic properties and the local height of the cloud. The dense-gas effects were treated as a perturbation to the ambient thermodynamic properties (density and temperature), ground level heat flux, turbulence level (diffusivity), and windfield (gravity flow) within the local region of the dense-gas cloud. These perturbations were calculated from conservation of energy and conservation of momentum principles along with the ideal gas law equation of state for a mixture of gases. ADPIC, which is generally run in conjunction with a mass-conserving wind flow model to provide the advection field, contains all the dense-gas modifications within it. This feature provides the versatility of coupling the new dense-gas ADPIC with alternative wind flow models. The new dense-gas ADPIC has been used to simulate the atmospheric dispersion of ground-level, colder-than-ambient, denser-than-air releases and has compared favorably with the results of field-scale experiments

  1. Finding Hierarchical and Overlapping Dense Subgraphs using Nucleus Decompositions

    Energy Technology Data Exchange (ETDEWEB)

    Seshadhri, Comandur [The Ohio State Univ., Columbus, OH (United States); Pinar, Ali [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sariyuce, Ahmet Erdem [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Catalyurek, Umit [The Ohio State Univ., Columbus, OH (United States)

    2014-11-01

    Finding dense substructures in a graph is a fundamental graph mining operation, with applications in bioinformatics, social networks, and visualization to name a few. Yet most standard formulations of this problem (like clique, quasiclique, k-densest subgraph) are NP-hard. Furthermore, the goal is rarely to nd the \\true optimum", but to identify many (if not all) dense substructures, understand their distribution in the graph, and ideally determine a hierarchical structure among them. Current dense subgraph nding algorithms usually optimize some objective, and only nd a few such subgraphs without providing any hierarchy. It is also not clear how to account for overlaps in dense substructures. We de ne the nucleus decomposition of a graph, which represents the graph as a forest of nuclei. Each nucleus is a subgraph where smaller cliques are present in many larger cliques. The forest of nuclei is a hierarchy by containment, where the edge density increases as we proceed towards leaf nuclei. Sibling nuclei can have limited intersections, which allows for discovery of overlapping dense subgraphs. With the right parameters, the nuclear decomposition generalizes the classic notions of k-cores and k-trusses. We give provable e cient algorithms for nuclear decompositions, and empirically evaluate their behavior in a variety of real graphs. The tree of nuclei consistently gives a global, hierarchical snapshot of dense substructures, and outputs dense subgraphs of higher quality than other state-of-theart solutions. Our algorithm can process graphs with tens of millions of edges in less than an hour.

  2. Cell type-specific sorting of neuropeptides : a mechanism to modulate peptide composition of large dense core vesicles

    NARCIS (Netherlands)

    Klumperman, J.; Spijker, S.; Minnen, J. van; Sharp-Baker, H.; Smit, A.B.; Geraerts, W.P.M.

    1996-01-01

    The CNS of Lymnaea stagnalis contains two populations of egg-laying hormone (ELH)-producing neurons that differ in size and topology. In type I neurons, all peptides located C-terminally from the cleavage site Arg-Ser-Arg-Arg180-183 are sorted into secretory large dense-core vesicles (LDCV), whereas

  3. The Rosseland Mean Opacity in Dense Plasmas

    Science.gov (United States)

    van Horn, H. M.

    1992-05-01

    In post-main-sequence phases of stellar evolution, densities in the interiors of stars become large enough so that hbar omega_p /kT>1, where omega_p is the electron plasma frequency. The plasma is thus a strongly dispersive medium at frequencies near the peak of the Planck function, and only photons with frequencies omega >omega_p can propagate in the plasma. These effects must be taken into account in computing radiative transfer in stellar interiors. Here I first identify several late evolutionary stages in which these effects may be significant. Then I use the formalism Harris 1965 has developed to treat radiative transfer in a dispersive medium in order to derive the resulting modification of the Rosseland mean opacity kappa_R . The resulting expression is the same as that presented (without a full derivation) by Aharony & Opher 1979, who interpreted the frequency-dependent absorption coefficient kappa_ ω as that in vacuo. However, the absorption coefficient in a plasma scales from that in vacuum according to the relation kappa_ ω=n_ω(-1) kappa_ ω((vac)) (Bekefi 1966, p. 52), where n_ω equiv (kc/omega ) = [1-(omega_p (2/) omega (2)right ](1/2)) is the index of refraction of the plasma. With this correction, we find the Rosseland mean opacity to be given by the expression {1\\over \\kappa_R}={{\\int_{\\omega_p}^{\\infty} {n_{\\omega}^3 \\over \\kappa_{\\omega}^{(vac)}}{partial B_{\\omega} \\over partial T} \\bigg|_{\\omega} d\\omega} \\over{\\int_0^{\\infty}{partial B_{\\omega} \\over partial T} \\bigg|_{\\omega} d\\omega}}. This research has been supported in part by NASA grant NAGW-2444 and in part by NSF grant AST 91-15132. \\centerline{References} Aharony, U., and Opher, R. 1979, A&A, 79, 27. Bekefi, G. 1966, Radiation Processes in Plasmas, (John Wiley & Sons, Inc.: New York). Harris, E. G. 1965, Phys. Rev., 138, B479.

  4. Dense interstellar cloud chemistry: Basic issues and possible dynamical solution

    International Nuclear Information System (INIS)

    Prasad, S.S.; Heere, K.R.; Tarafdar, S.P.

    1989-01-01

    Standing at crossroad of enthusiasm and frustration, dense intertellar cloud chemistry has a squarely posed fundamental problem: Why do the grains appear to play at best a minor role in the chemistry? Grain surface chemistry creates considerable difficulties when the authors treat dense clouds as static objects and ignore the implications of the processes by which the clouds became dense in the first place. A new generation of models which treat chemical and dynamical evolutions concurrently are therefore presented as possible solution to the current frustrations. The proposed modeling philosophy and agenda could make the next decade quite exciting for interstellar chemistry

  5. Dense time discretization technique for verification of real time systems

    International Nuclear Information System (INIS)

    Makackas, Dalius; Miseviciene, Regina

    2016-01-01

    Verifying the real-time system there are two different models to control the time: discrete and dense time based models. This paper argues a novel verification technique, which calculates discrete time intervals from dense time in order to create all the system states that can be reached from the initial system state. The technique is designed for real-time systems specified by a piece-linear aggregate approach. Key words: real-time system, dense time, verification, model checking, piece-linear aggregate

  6. Photons in dense nuclear matter: Random-phase approximation

    Science.gov (United States)

    Stetina, Stephan; Rrapaj, Ermal; Reddy, Sanjay

    2018-04-01

    We present a comprehensive and pedagogic discussion of the properties of photons in cold and dense nuclear matter based on the resummed one-loop photon self-energy. Correlations among electrons, muons, protons, and neutrons in β equilibrium that arise as a result of electromagnetic and strong interactions are consistently taken into account within the random phase approximation. Screening effects, damping, and collective excitations are systematically studied in a fully relativistic setup. Our study is relevant to the linear response theory of dense nuclear matter, calculations of transport properties of cold dense matter, and investigations of the production and propagation of hypothetical vector bosons such as the dark photons.

  7. Uniform, dense arrays of vertically aligned, large-diameter single-walled carbon nanotubes.

    Science.gov (United States)

    Han, Zhao Jun; Ostrikov, Kostya

    2012-04-04

    Precisely controlled reactive chemical vapor synthesis of highly uniform, dense arrays of vertically aligned single-walled carbon nanotubes (SWCNTs) using tailored trilayered Fe/Al(2)O(3)/SiO(2) catalyst is demonstrated. More than 90% population of thick nanotubes (>3 nm in diameter) can be produced by tailoring the thickness and microstructure of the secondary catalyst supporting SiO(2) layer, which is commonly overlooked. The proposed model based on the atomic force microanalysis suggests that this tailoring leads to uniform and dense arrays of relatively large Fe catalyst nanoparticles on which the thick SWCNTs nucleate, while small nanotubes and amorphous carbon are effectively etched away. Our results resolve a persistent issue of selective (while avoiding multiwalled nanotubes and other carbon nanostructures) synthesis of thick vertically aligned SWCNTs whose easily switchable thickness-dependent electronic properties enable advanced applications in nanoelectronic, energy, drug delivery, and membrane technologies.

  8. GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

    Science.gov (United States)

    Lécz, Zs.; Konoplev, I. V.; Seryi, A.; Andreev, A.

    2016-10-01

    This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration.

  9. Stochastic motion of a particle in a model fluctuating medium

    International Nuclear Information System (INIS)

    Moreau, M.; Gaveau, B.; Perera, A.; Frankowicz, M.

    1993-01-01

    We present several models of time fluctuating media with finite memory, consisting in one and two-dimensional lattices, the Modes of which fluctuate between two internal states according to a Poisson process. A particle moves on the lattice, the diffusion by the Modes depending on their internal state. Such models can be used for the microscopic theory of reaction constants in a dense phase, or for the study of diffusion or reactivity in a complex medium. In a number of cases, the transmission probability of the medium is computed exactly; it is shown that stochastic resonances can occur, an optimal transmission being obtained for a convenient choice of parameters. In more general situations, approximate solutions are given in the case of short and moderate memory of the obstacles. The diffusion in an infinite two-dimensional lattice is studied, and the memory is shown to affect the distribution of the particles rather than the diffusion law. (author). 25 refs, 5 figs

  10. Toward Measuring Galactic Dense Molecular Gas Properties and 3D Distribution with Hi-GAL

    Science.gov (United States)

    Zetterlund, Erika; Glenn, Jason; Maloney, Phil

    2016-01-01

    The Herschel Space Observatory's submillimeter dust continuum survey Hi-GAL provides a powerful new dataset for characterizing the structure of the dense interstellar medium of the Milky Way. Hi-GAL observed a 2° wide strip covering the entire 360° of the Galactic plane in broad bands centered at 70, 160, 250, 350, and 500 μm, with angular resolution ranging from 10 to 40 arcseconds. We are adapting a molecular cloud clump-finding algorithm and a distance probability density function distance-determination method developed for the Bolocam Galactic Plane Survey (BGPS) to the Hi-GAL data. Using these methods we expect to generate a database of 105 cloud clumps, derive distance information for roughly half the clumps, and derive precise distances for approximately 20% of them. With five-color photometry and distances, we will measure the cloud clump properties, such as luminosities, physical sizes, and masses, and construct a three-dimensional map of the Milky Way's dense molecular gas distribution.The cloud clump properties and the dense gas distribution will provide critical ground truths for comparison to theoretical models of molecular cloud structure formation and galaxy evolution models that seek to emulate spiral galaxies. For example, such models cannot resolve star formation and use prescriptive recipes, such as converting a fixed fraction of interstellar gas to stars at a specified interstellar medium density threshold. The models should be compared to observed dense molecular gas properties and galactic distributions.As a pilot survey to refine the clump-finding and distance measurement algorithms developed for BGPS, we have identified molecular cloud clumps in six 2° × 2° patches of the Galactic plane, including one in the inner Galaxy along the line of sight through the Molecular Ring and the termination of the Galactic bar and one toward the outer Galaxy. Distances have been derived for the inner Galaxy clumps and compared to Bolocam Galactic Plane

  11. A pulsed power hydrodynamics approach to exploring properties of warm dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Reinovsky, Robert Emil [Los Alamos National Laboratory

    2008-01-01

    Pulsed Power Hydrodynamics, as an application of low-impedance, pulsed power, and high magnetic field technology developed over the last decade to study advanced hydrodynamic problems, instabilities, turbulence, and material properties, can potentially be applied to the study of the behavior and properties of warm dense matter (WDM) as well. Exploration of the properties, such as equation of state and conductivity, of warm dense matter is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to a few times solid density) and modest temperatures ({approx}1-10 eV). Warm dense matter conditions can be achieved by laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers is applying these techniques using petawatt scale laser systems, but the microscopic size scale of the WDM produced in this way limits access to some physics phenomena. Pulsed power hydrodynamics techniques, either through high convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques both offer the prospect for producing warm dense matter in macroscopic quantities. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. Similarly, liner compression of normal density material, perhaps using multiple reflected shocks can provide access to the challenging region above normal density -- again with the requirement of very large amounts of driving energy. In this paper we will provide an introduction to techniques that might be applied to explore this

  12. Dreams of a New Medium

    Directory of Open Access Journals (Sweden)

    Aden Evens

    2009-01-01

    Full Text Available Problematic at best, the desire for a transparent interface nevertheless drives much of digital culture and technology. But not the Web; or at least, not Web 1.0. Thoroughly commercialized, comfortably parsed into genres, serving billions of pages of predigested content to passive consumers, the World Wide Web as developed in the '90s unabashedly embraces its role as medium. While so many digital technologies work to hide their mediacy--drawing in the user with a total simulated sensorium, dematerializing the resistances of size and weight, untangling the knots of cables tying user to machine and machine to cubicle, minimizing the interface--Web 1.0 proudly clings to the browser as a glaring reminder of its medial character. While Web 2.0 has not forsaken the browser altogether, it nevertheless seems to offer a different sort of mediation. Arising alongside the atomization of browser functions, the ubiquitization of connectivity, and the coincidence of producer and user, Web 2.0 retains the form of a medium while reaching for the experiential logic of immediacy. This is not the immediacy of the transparent interface; rather, Web 2.0 effects an immediate relationship between the individual and culture. The interface does not disappear, but its mediacy is subsumed under the general form of cultural participation. Focusing on the "version upgrade" from Web 1.0 to 2.0, this essay will explore the implications for mediacy of this transition, noting that the fantasy of immediacy which drives Web 2.0 is layered and complex. The typical account of immediacy proposes to eliminate the interface and so construct a virtual reality (VR. But Web 2.0 mostly sidesteps the virtual, propelled instead by a fantasy of intuition in which the Web already knows what you want because it is you. Crucially, fantasies about the digital are effective: the computer's futurity inhabits our world, finding its expression in politics, advertising, budgeting, strategic planning

  13. Fabrication, Properties and Applications of Dense Hydroxyapatite: A Review

    Directory of Open Access Journals (Sweden)

    Mythili Prakasam

    2015-12-01

    Full Text Available In the last five decades, there have been vast advances in the field of biomaterials, including ceramics, glasses, glass-ceramics and metal alloys. Dense and porous ceramics have been widely used for various biomedical applications. Current applications of bioceramics include bone grafts, spinal fusion, bone repairs, bone fillers, maxillofacial reconstruction, etc. Amongst the various calcium phosphate compositions, hydroxyapatite, which has a composition similar to human bone, has attracted wide interest. Much emphasis is given to tissue engineering, both in porous and dense ceramic forms. The current review focusses on the various applications of dense hydroxyapatite and other dense biomaterials on the aspects of transparency and the mechanical and electrical behavior. Prospective future applications, established along the aforesaid applications of hydroxyapatite, appear to be promising regarding bone bonding, advanced medical treatment methods, improvement of the mechanical strength of artificial bone grafts and better in vitro/in vivo methodologies to afford more particular outcomes.

  14. Densely crosslinked polycarbosiloxanes .2. Thermal and mechanical properties

    NARCIS (Netherlands)

    Flipsen, T.A C; Derks, R.; van der Vegt, H.A.; Stenekes, R.; Pennings, A.J; Hadziioannou, G

    1997-01-01

    The thermal and mechanical properties of two densely crosslinked polycarbosiloxane systems were investigated in relation to the molecular structure. The networks were prepared from functional branched prepolymers and crosslinked via a hydrosilylation curing reaction. The prepolymers having only

  15. Automated Motion Estimation for 2D Cine DENSE MRI

    Science.gov (United States)

    Gilliam, Andrew D.; Epstein, Frederick H.

    2013-01-01

    Cine displacement encoding with stimulated echoes (DENSE) is a magnetic resonance (MR) method that directly encodes tissue displacement into MR phase images. This technique has successfully interrogated many forms of tissue motion, but is most commonly used to evaluate cardiac mechanics. Currently, motion analysis from cine DENSE images requires manually delineated anatomical structures. An automated analysis would improve measurement throughput, simplify data interpretation, and potentially access important physiological information during the MR exam. In this article, we present the first fully automated solution for the estimation of tissue motion and strain from 2D cine DENSE data. Results using both simulated and human cardiac cine DENSE data indicate good agreement between the automated algorithm and the standard semi-manual analysis method. PMID:22575669

  16. Finding dense locations in symbolic indoor tracking data

    DEFF Research Database (Denmark)

    Ahmed, Tanvir; Pedersen, Torben Bach; Lu, Hua

    2017-01-01

    presents two graph-based models for constrained and semi-constrained indoor movement, respectively, and then uses the models to map raw tracking records into mapping records that represent object entry and exit times in particular locations. Subsequently, an efficient indexing structure called Hierarchical...... Dense Location Time Index (HDLT-Index) is proposed for indexing the time intervals of the mapping table, along with index construction, query processing, and pruning techniques. The HDLT-Index supports very efficient aggregate point, interval, and duration queries as well as dense location queries......Finding the dense locations in large indoor spaces is very useful for many applications such as overloaded area detection, security control, crowd management, indoor navigation, and so on. Indoor tracking data can be enormous and are not immediately ready for finding dense locations. This paper...

  17. Physics of dense matter, neutron stars, and supernova

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1989-02-01

    Nuclear and astrophysical evidence on the equation of state of dense matter is examined. The role of hyperonization of matter in the development of proto-neutron stars is briefly discussed. 7 refs., 4 figs

  18. Fabrication, Properties and Applications of Dense Hydroxyapatite: A Review

    Science.gov (United States)

    Prakasam, Mythili; Locs, Janis; Salma-Ancane, Kristine; Loca, Dagnija; Largeteau, Alain; Berzina-Cimdina, Liga

    2015-01-01

    In the last five decades, there have been vast advances in the field of biomaterials, including ceramics, glasses, glass-ceramics and metal alloys. Dense and porous ceramics have been widely used for various biomedical applications. Current applications of bioceramics include bone grafts, spinal fusion, bone repairs, bone fillers, maxillofacial reconstruction, etc. Amongst the various calcium phosphate compositions, hydroxyapatite, which has a composition similar to human bone, has attracted wide interest. Much emphasis is given to tissue engineering, both in porous and dense ceramic forms. The current review focusses on the various applications of dense hydroxyapatite and other dense biomaterials on the aspects of transparency and the mechanical and electrical behavior. Prospective future applications, established along the aforesaid applications of hydroxyapatite, appear to be promising regarding bone bonding, advanced medical treatment methods, improvement of the mechanical strength of artificial bone grafts and better in vitro/in vivo methodologies to afford more particular outcomes. PMID:26703750

  19. Reply to 'Comment on 'Quantum dense key distribution''

    International Nuclear Information System (INIS)

    Degiovanni, I.P.; Berchera, I. Ruo; Castelletto, S.; Rastello, M.L.; Bovino, F.A.; Colla, A.M.; Castagnoli, G.

    2005-01-01

    In this Reply we propose a modified security proof of the quantum dense key distribution protocol, detecting also the eavesdropping attack proposed by Wojcik in his Comment [Wojcik, Phys. Rev. A 71, 016301 (2005)

  20. Dilemmas of Warfare in Densely Populated Civilian Areas

    OpenAIRE

    Moshe Tamir

    2012-01-01

    This essay attempts to present operational perspectives on conducting warfare in densely populated areas. It also distinguishes between three types of combat within this general category, with the goal of shedding light on this complex type of warfare.

  1. Strangeness in hot and dense nuclear matter

    International Nuclear Information System (INIS)

    Nappi, E.

    2009-01-01

    Ultra-relativistic heavy-ion collisions are believed to provide the extreme conditions of energy densities able to lead to a transition to a short-lived state, called Quark-Gluon Plasma (QGP), where the quarks are no longer bound inside hadrons. The studies performed so far, formerly at SPS (CERN) and later at RHIC (BNL) allowed to achieve a multitude of crucial results consistent with the hypothesis that a new phase of the QCD matter has been indeed created. However, the emerging picture is that of the formation of a strongly interacting medium with negligibly small viscosity, a perfect liquid, rather than the ideal perturbative QCD parton-gas predicted by most theorists. The head-on collision between lead nuclei at the unprecedented energies of the forthcoming Large Hadron Collider (LHC) at CERN, due to start in 2008, will allow to measure the properties of compressed and excited nuclear matter at even higher initial densities and temperatures, far above the predicted QCD phase transition point. The longer duration of the quark-gluon plasma phase and the much more abundant production of hard probes, which depend much less on details of the later hadronic phase, will likely provide a consistent and uncontroversial experimental evidence of the QGP formation. Among the signals what witness the charge in the nature of the state of nuclear matter, the chemical equilibrium value of the strangeness plays a key role since it is directly sensitive to the matter properties and provides information on the link between the partonic and the hadronic phases. The aim of this course is to overview the underlying goals, the current status and the prospect of the physics of the nucleus-nucleus collisions at ultrarelativistic energies. Among the experimental methods adopted to investigate the challenging signatures of the QGP formation, emphasis on those related to the strangeness flavour will be given.

  2. Relating quantum discord with the quantum dense coding capacity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Qiu, Liang, E-mail: lqiu@cumt.edu.cn; Li, Song; Zhang, Chi [China University of Mining and Technology, School of Sciences (China); Ye, Bin [China University of Mining and Technology, School of Information and Electrical Engineering (China)

    2015-01-15

    We establish the relations between quantum discord and the quantum dense coding capacity in (n + 1)-particle quantum states. A necessary condition for the vanishing discord monogamy score is given. We also find that the loss of quantum dense coding capacity due to decoherence is bounded below by the sum of quantum discord. When these results are restricted to three-particle quantum states, some complementarity relations are obtained.

  3. Rheology of dense suspensions of non colloidal particles

    OpenAIRE

    Guazzelli , Elisabeth

    2017-01-01

    International audience; Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liq...

  4. Rheology of dense suspensions of non colloidal particles

    OpenAIRE

    Guazzelli Élisabeth

    2017-01-01

    Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical co...

  5. Neutrinos and Nucleosynthesis in Hot and Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, George [Univ. of California, San Diego, CA (United States)

    2016-01-14

    The Topical Collaboration for Neutrinos and Nucleosynthesis in Hot and Dense matter brought together researchers from a variety of nuclear science specialties and a number of institutions to address nuclear physics and neutrino physics problems associated with dense matter and the origin of the elements. See attached final technical reports for (1) the UCSD award and (2) a copy of the report for the whole TC

  6. Relating quantum discord with the quantum dense coding capacity

    International Nuclear Information System (INIS)

    Wang, Xin; Qiu, Liang; Li, Song; Zhang, Chi; Ye, Bin

    2015-01-01

    We establish the relations between quantum discord and the quantum dense coding capacity in (n + 1)-particle quantum states. A necessary condition for the vanishing discord monogamy score is given. We also find that the loss of quantum dense coding capacity due to decoherence is bounded below by the sum of quantum discord. When these results are restricted to three-particle quantum states, some complementarity relations are obtained

  7. Interaction of Interstellar Shocks with Dense Obstacles: Formation of ``Bullets''

    Science.gov (United States)

    Gvaramadze, V. V.

    The so-called cumulative effect take place in converging conical shock waves arising behind dense obstacles overtaken by incident interstellar shock. A significant part of energy of converging flow of matter swept-up by a radiative conical shock can be transferred to a dense jet-like ejection (``bullet'') directed along the cone axis. Possible applications of this effect for star-forming regions (e.g., OMC-1) and supernova remnants (e.g., Vela SNR) are discussed.

  8. Mesons in the nuclear Medium

    CERN Document Server

    Kotulla, M

    2006-01-01

    We discuss recent experimental results on the modification of hadron properties in a nuclear medium. Particular emphasis is placed on an $\\omega$ production experiment performed by the CBELSA/TAPS collaboration at the ELSA accelerator. The data shows a smaller $\\omega$ meson mass together with a significant increase of its width in the nuclear medium.

  9. MAPPING ALPINE VEGETATION LOCATION PROPERTIES BY DENSE MATCHING

    Directory of Open Access Journals (Sweden)

    R. Niederheiser

    2016-06-01

    Full Text Available Highly accurate 3D micro topographic mapping in mountain research demands for light equipment and low cost solutions. Recent developments in structure from motion and dense matching techniques provide promising tools for such applications. In the following, the feasibility of terrestrial photogrammetry for mapping topographic location properties of sparsely vegetated areas in selected European mountain regions is investigated. Changes in species composition at alpine vegetation locations are indicators of climate change consequences, such as the pronounced rise of average temperatures in mountains compared to the global average. Better understanding of climate change effects on plants demand for investigations on a micro-topographic scale. We use professional and consumer grade digital single-lens reflex cameras mapping 288 plots each 3 x 3 m on 18 summits in the Alps and Mediterranean Mountains within the GLORIA (GLobal Observation Research Initiative in Alpine environments network. Image matching tests result in accuracies that are in the order of millimetres in the XY-plane and below 0.5 mm in Z-direction at the second image pyramid level. Reconstructing vegetation proves to be a challenge due to its fine and small structured architecture and its permanent movement by wind during image acquisition, which is omnipresent on mountain summits. The produced 3D point clouds are gridded to 6 mm resolution from which topographic parameters such as slope, aspect and roughness are derived. At a later project stage these parameters will be statistically linked to botanical reference data in order to conclude on relations between specific location properties and species compositions.

  10. Theory of the shock process in dense fluids

    International Nuclear Information System (INIS)

    Wallace, D.C.

    1991-01-01

    A shock is assumed to be a steady plane wave, and irreversible thermodynamics is assumed valid. The fluid is characterized by heat conduction and by viscous or viscoelastic response, according to the strain rate. It is shown that setting the viscosity zero produces a solution which constitutes a lower bound through the shock process for the shear stress, and upper bounds for the temperature, entropy, pressure, and heat current. It is shown that there exists an upper bound to the dynamic stresses which can be achieved during shock compression, that this bound corresponds to a purely elastic response of the fluid, and that solution for the shock process along this bound constitutes lower bounds for the temperature and entropy. It is shown that a continuous steady shock is possible only if the heat current is positive and the temperature is an increasing function of compression almost everywhere. In his theory of shocks in gases, Rayleigh showed that there is a maximum shock strength for which a continuous steady solution can exist with heat conduction but without viscosity. Two more limits are shown to exist for dense fluids, based on the fluid response in the leading edge of the shock: for shocks at the overdriven threshold and above, no solution is possible without heat transport; for shocks near the viscous fluid limit and above, viscous fluid theory is not valid, and the fluid response in the leading edge of the shock is approximately that of a nonplastic solid. The viscous fluid limit is estimated to be 13 kbar for water and 690 kbar for mercury

  11. Modeling of dilute and dense dispersed fluid-particle flow

    Energy Technology Data Exchange (ETDEWEB)

    Laux, Harald

    1998-08-01

    A general two-fluid model is derived and applied in CFD computations to various test cases of important industrial multiphase flows. It is general in the sense of its applicability to dilute and dense dispersed fluid-particle flows. The model is limited to isothermal flow without mass transfer and only one particle phase is described. The instantaneous fluid phase equations, including the phase interaction terms, are derived from a volume averaging technique, and the instantaneous particle phase equations are derived from the kinetic theory of granular material. Whereas the averaging procedure, the treatment of the interaction terms, and the kinetic theory approach have been reported in literature prior to this work the combination of the approaches is new. The resulting equations are derived without ambiguity in the interpretation of the particle phase pressure (equation-of-state of particle phase). The basic modeling for the particle phase is improved in two steps. Because in the basic modeling only stresses due to kinetic and collisional interactions are included, a simple model for an effective viscosity is developed in order to allow also frictional stresses within the particle phase. Moreover, turbulent stresses and turbulent dispersion of particles play often an important role for the transport processes. Therefore in a second step, a two-equation turbulence model for both fluid and particle phase turbulence is derived by applying the phasic average to the instantaneous equations. The resulting k-{epsilon}-k{sup d}-{epsilon}{sup d} model is new. Mathematical closure is attempted such that the resulting set of equations is valid for both dilute arid dense flows. During the development of the closure relations a clear distinction is made between granular or ''viscous'' microscale fluctuations and turbulent macro scale fluctuations (true particle turbulence) within the particle phase. The set of governing equations is discretized by using a

  12. Modeling of dilute and dense dispersed fluid-particle flow

    Energy Technology Data Exchange (ETDEWEB)

    Laux, Harald

    1998-08-01

    A general two-fluid model is derived and applied in CFD computations to various test cases of important industrial multiphase flows. It is general in the sense of its applicability to dilute and dense dispersed fluid-particle flows. The model is limited to isothermal flow without mass transfer and only one particle phase is described. The instantaneous fluid phase equations, including the phase interaction terms, are derived from a volume averaging technique, and the instantaneous particle phase equations are derived from the kinetic theory of granular material. Whereas the averaging procedure, the treatment of the interaction terms, and the kinetic theory approach have been reported in literature prior to this work the combination of the approaches is new. The resulting equations are derived without ambiguity in the interpretation of the particle phase pressure (equation-of-state of particle phase). The basic modeling for the particle phase is improved in two steps. Because in the basic modeling only stresses due to kinetic and collisional interactions are included, a simple model for an effective viscosity is developed in order to allow also frictional stresses within the particle phase. Moreover, turbulent stresses and turbulent dispersion of particles play often an important role for the transport processes. Therefore in a second step, a two-equation turbulence model for both fluid and particle phase turbulence is derived by applying the phasic average to the instantaneous equations. The resulting k-{epsilon}-k{sup d}-{epsilon}{sup d} model is new. Mathematical closure is attempted such that the resulting set of equations is valid for both dilute arid dense flows. During the development of the closure relations a clear distinction is made between granular or ''viscous'' microscale fluctuations and turbulent macro scale fluctuations (true particle turbulence) within the particle phase. The set of governing equations is discretized by using a finite volume method

  13. Romanian complex data center for dense seismic network

    Directory of Open Access Journals (Sweden)

    Constantin Ionescu

    2011-04-01

    ="Light List" /> Medium Shading 1" /> Medium Shading 2" /> Medium List 1" /> Medium List 2" /> Medium Grid 1" /> Medium Grid 2" /> Medium Grid 3" /> Medium Shading 1 Accent 1" /> Medium Shading 2 Accent 1" />

  14. AN AERIAL-IMAGE DENSE MATCHING APPROACH BASED ON OPTICAL FLOW FIELD

    Directory of Open Access Journals (Sweden)

    W. Yuan

    2016-06-01

    Full Text Available Dense matching plays an important role in many fields, such as DEM (digital evaluation model producing, robot navigation and 3D environment reconstruction. Traditional approaches may meet the demand of accuracy. But the calculation time and out puts density is hardly be accepted. Focus on the matching efficiency and complex terrain surface matching feasibility an aerial image dense matching method based on optical flow field is proposed in this paper. First, some high accurate and uniformed control points are extracted by using the feature based matching method. Then the optical flow is calculated by using these control points, so as to determine the similar region between two images. Second, the optical flow field is interpolated by using the multi-level B-spline interpolation in the similar region and accomplished the pixel by pixel coarse matching. Final, the results related to the coarse matching refinement based on the combined constraint, which recognizes the same points between images. The experimental results have shown that our method can achieve per-pixel dense matching points, the matching accuracy achieves sub-pixel level, and fully meet the three-dimensional reconstruction and automatic generation of DSM-intensive matching’s requirements. The comparison experiments demonstrated that our approach’s matching efficiency is higher than semi-global matching (SGM and Patch-based multi-view stereo matching (PMVS which verifies the feasibility and effectiveness of the algorithm.

  15. Soft X-ray spectrometer design for warm dense plasma measurements on DARHT Axis-I

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, Nicholas Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, John Oliver [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Coleman, Joshua Eugene [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-07-11

    A preliminary design study is being performed on a soft X-ray spectrometer to measure K-shell spectra emitted by a warm dense plasma generated on Axis-I of the Dual-Axis Radiographic Hydrodynamic Testing (DARHT) facility at Los Alamos National Laboratory. The 100-ns-long intense, relativistic electron pulse with a beam current of 1.7 kA and energy of 19.8 MeV deposits energy into a thin metal foil heating it to a warm dense plasma. The collisional ionization of the target by the electron beam produces an anisotropic angular distribution of K-shell radiation and a continuum of both scattered electrons and Bremsstrahlung up to the beam energy of 19.8 MeV. The principal goal of this project is to characterize these angular distributions to determine the optimal location to deploy the soft X-ray spectrometer. In addition, a proof-of-principle design will be presented. The ultimate goal of the spectrometer is to obtain measurements of the plasma temperature and density to benchmark equation-of-state models of the warm dense matter regime.

  16. Dense Plasma Focus-Based Nanofabrication of III-V Semiconductors: Unique Features and Recent Advances.

    Science.gov (United States)

    Mangla, Onkar; Roy, Savita; Ostrikov, Kostya Ken

    2015-12-29

    The hot and dense plasma formed in modified dense plasma focus (DPF) device has been used worldwide for the nanofabrication of several materials. In this paper, we summarize the fabrication of III-V semiconductor nanostructures using the high fluence material ions produced by hot, dense and extremely non-equilibrium plasma generated in a modified DPF device. In addition, we present the recent results on the fabrication of porous nano-gallium arsenide (GaAs). The details of morphological, structural and optical properties of the fabricated nano-GaAs are provided. The effect of rapid thermal annealing on the above properties of porous nano-GaAs is studied. The study reveals that it is possible to tailor the size of pores with annealing temperature. The optical properties of these porous nano-GaAs also confirm the possibility to tailor the pore sizes upon annealing. Possible applications of the fabricated and subsequently annealed porous nano-GaAs in transmission-type photo-cathodes and visible optoelectronic devices are discussed. These results suggest that the modified DPF is an effective tool for nanofabrication of continuous and porous III-V semiconductor nanomaterials. Further opportunities for using the modified DPF device for the fabrication of novel nanostructures are discussed as well.

  17. Circumstellar Interaction in Supernovae in Dense Environments—An Observational Perspective

    Science.gov (United States)

    Chandra, Poonam

    2018-02-01

    In a supernova explosion, the ejecta interacting with the surrounding circumstellar medium (CSM) give rise to variety of radiation. Since CSM is created from the mass loss from the progenitor, it carries footprints of the late time evolution of the star. This is one of the unique ways to get a handle on the nature of the progenitor system. Here, I will focus mainly on the supernovae (SNe) exploding in dense environments, a.k.a. Type IIn SNe. Radio and X-ray emission from this class of SNe have revealed important modifications in their radiation properties, due to the presence of high density CSM. Forward shock dominance in the X-ray emission, internal free-free absorption of the radio emission, episodic or non-steady mass loss rate, and asymmetry in the explosion seem to be common properties of this class of SNe.

  18. Frequency-dependent absorbance of broadband terahertz wave in dense plasma sheet

    Science.gov (United States)

    Peng, Yan; Qi, Binbin; Jiang, Xiankai; Zhu, Zhi; Zhao, Hongwei; Zhu, Yiming

    2018-05-01

    Due to the ability of accurate fingerprinting and low-ionization for different substances, terahertz (THz) technology has a lot of crucial applications in material analysis, information transfer, and safety inspection, etc. However, the spectral characteristic of atmospheric gas and ionized gas has not been widely investigated, which is important for the remote sensing application. Here, in this paper, we investigate the absorbance of broadband terahertz wave in dense plasma sheet generated by femtosecond laser pulses. It was found that as the terahertz wave transmits through the plasma sheet formed, respectively, in carbon dioxide, oxygen, argon and nitrogen, spectrum presents completely different and frequency-dependent absorbance. The reasons for these absorption peaks are related to the molecular polarity, electric charge, intermolecular and intramolecular interactions, and collisional absorption of gas molecules. These results have significant implications for the remote sensing of gas medium.

  19. Pions in the nuclear medium

    International Nuclear Information System (INIS)

    Chanfray, G.

    1996-07-01

    We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then address the question of p-wave pion-nucleus interaction and collective pionic modes in nuclei and draw the consequences for in medium ππ correlations especially in the scalar-isoscalar channel. We finally discuss the modification of the rho meson mass spectrum at finite density and/or temperature in connection with relativistic heavy ion collisions

  20. Penetration of Cosmic Rays into Dense Molecular Clouds: Role of Diffuse Envelopes

    Science.gov (United States)

    Ivlev, A. V.; Dogiel, V. A.; Chernyshov, D. O.; Caselli, P.; Ko, C.-M.; Cheng, K. S.

    2018-03-01

    A flux of cosmic rays (CRs) propagating through a diffuse ionized gas can excite MHD waves, thus generating magnetic disturbances. We propose a generic model of CR penetration into molecular clouds through their diffuse envelopes, and identify the leading physical processes controlling their transport on the way from a highly ionized interstellar medium to the dense interior of the cloud. The model allows us to describe a transition between a free streaming of CRs and their diffusive propagation, determined by the scattering on the self-generated disturbances. A self-consistent set of equations, governing the diffusive transport regime in an envelope and the MHD turbulence generated by the modulated CR flux, is characterized by two dimensionless numbers. We demonstrate a remarkable mutual complementarity of different mechanisms leading to the onset of the diffusive regime, which results in a universal energy spectrum of the modulated CRs. In conclusion, we briefly discuss implications of our results for several fundamental astrophysical problems, such as the spatial distribution of CRs in the Galaxy as well as the ionization, heating, and chemistry in dense molecular clouds. This paper is dedicated to the memory of Prof. Vadim Tsytovich.

  1. Geometrical optimization of the dense plasma focus

    International Nuclear Information System (INIS)

    Lee, S.; Chen, Y.H.

    1982-01-01

    A 12 kJ DPF device with a periodic time of 12μsec, UMDPF1 has been optimized geometrically to produce a higher neutron yield of 1.5x10 9 at 10 torr filling pressure than from the same device before optimization. With the same optimization procedure a faster DPF device with a periodic time of 3.7μsec, UMDPF2, of the same energy has also been optimized to give a peak neutron yield of 6.3x10 9 at 16 torr filling pressure. Experimental evidence shows that over and above the increase in neutron production due to an increase in current according to the Isup(3.3) scaling law, a faster current rise time may have an additional effect of enhancement in neutron production. The outcome of this project is that a new high pressure regime of 16 torr with an enhanced neutron yield of 6.3x10 9 and improved yield reproducibility for an input energy of 12 kJ has thus been established. There is every reason to believe that this optimization procedure can be extended to other DPF devices. (author)

  2. Strange particles from dense hadronic matter

    International Nuclear Information System (INIS)

    Rafelski, J.; Letessier, J.; Tounsi, A.

    1996-01-01

    After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as functions of heavy ion energy. Our presentation is comprehensive and self contained: we introduce the procedures used in data interpretation in considerable detail, discuss the particular importance of selected experimental results, and show how they impact the theoretical developments. (author)

  3. DENSE CORES IN THE PIPE NEBULA: AN IMPROVED CORE MASS FUNCTION

    International Nuclear Information System (INIS)

    Rathborne, J. M.; Lada, C. J.; Muench, A. A.; Alves, J. F.; Kainulainen, J.; Lombardi, M.

    2009-01-01

    In this paper, we derive an improved core mass function (CMF) for the Pipe Nebula from a detailed comparison between measurements of visual extinction and molecular-line emission. We have compiled a refined sample of 201 dense cores toward the Pipe Nebula using a two-dimensional threshold identification algorithm informed by recent simulations of dense core populations. Measurements of radial velocities using complimentary C 18 O (1-0) observations enable us to cull out from this sample those 43 extinction peaks that are either not associated with dense gas or are not physically associated with the Pipe Nebula. Moreover, we use the derived C 18 O central velocities to differentiate between single cores with internal structure and blends of two or more physically distinct cores, superposed along the same line of sight. We then are able to produce a more robust dense core sample for future follow-up studies and a more reliable CMF than was possible previously. We confirm earlier indications that the CMF for the Pipe Nebula departs from a single power-law-like form with a break or knee at M ∼ 2.7 ± 1.3 M sun . Moreover, we also confirm that the CMF exhibits a similar shape to the stellar initial mass function (IMF), but is scaled to higher masses by a factor of ∼4.5. We interpret this difference in scaling to be a measure of the star formation efficiency (22% ± 8%). This supports earlier suggestions that the stellar IMF may originate more or less directly from the CMF.

  4. Effects of the bottom boundary condition in numerical investigations of dense water cascading on a slope

    Science.gov (United States)

    Berntsen, Jarle; Alendal, Guttorm; Avlesen, Helge; Thiem, Øyvind

    2018-05-01

    The flow of dense water along continental slopes is considered. There is a large literature on the topic based on observations and laboratory experiments. In addition, there are many analytical and numerical studies of dense water flows. In particular, there is a sequence of numerical investigations using the dynamics of overflow mixing and entrainment (DOME) setup. In these papers, the sensitivity of the solutions to numerical parameters such as grid size and numerical viscosity coefficients and to the choices of methods and models is investigated. In earlier DOME studies, three different bottom boundary conditions and a range of vertical grid sizes are applied. In other parts of the literature on numerical studies of oceanic gravity currents, there are statements that appear to contradict choices made on bottom boundary conditions in some of the DOME papers. In the present study, we therefore address the effects of the bottom boundary condition and vertical resolution in numerical investigations of dense water cascading on a slope. The main finding of the present paper is that it is feasible to capture the bottom Ekman layer dynamics adequately and cost efficiently by using a terrain-following model system using a quadratic drag law with a drag coefficient computed to give near-bottom velocity profiles in agreement with the logarithmic law of the wall. Many studies of dense water flows are performed with a quadratic bottom drag law and a constant drag coefficient. It is shown that when using this bottom boundary condition, Ekman drainage will not be adequately represented. In other studies of gravity flow, a no-slip bottom boundary condition is applied. With no-slip and a very fine resolution near the seabed, the solutions are essentially equal to the solutions obtained with a quadratic drag law and a drag coefficient computed to produce velocity profiles matching the logarithmic law of the wall. However, with coarser resolution near the seabed, there may be a

  5. Effects of strong and electromagnetic correlations on neutrino interactions in dense matter

    International Nuclear Information System (INIS)

    Reddy, S.; Prakash, M.; Lattimer, J.M.; Reddy, S.; Pons, J.A.

    1999-01-01

    An extensive study of the effects of correlations on both charged and neutral current weak interaction rates in dense matter is performed. Both strong and electromagnetic correlations are considered. The propagation of particle-hole interactions in the medium plays an important role in determining the neutrino mean free paths. The effects due to Pauli blocking and density, spin, and isospin correlations in the medium significantly reduce the neutrino cross sections. As a result of the lack of experimental information at high density, these correlations are necessarily model dependent. For example, spin correlations in nonrelativistic models are found to lead to larger suppressions of neutrino cross sections compared to those of relativistic models. This is due to the tendency of the nonrelativistic models to develop spin instabilities. Notwithstanding the above caveats, and the differences between nonrelativistic and relativistic approaches such as the spin- and isospin-dependent interactions and the nucleon effective masses, suppressions of order 2 - 3, relative to the case in which correlations are ignored, are obtained. Neutrino interactions in dense matter are especially important for supernova and early neutron star evolution calculations. The effects of correlations for protoneutron star evolution are calculated. Large effects on the internal thermodynamic properties of protoneutron stars, such as the temperature, are found. These translate into significant early enhancements in the emitted neutrino energies and fluxes, especially after a few seconds. At late times, beyond about 10 s, the emitted neutrino fluxes decrease more rapidly compared to simulations without the effects of correlations, due to the more rapid onset of neutrino transparency in the protoneutron star. copyright 1999 The American Physical Society

  6. Experimental Studies of the Transport Parameters of Warm Dense Matter

    Energy Technology Data Exchange (ETDEWEB)

    Chouffani, Khalid [Idaho State Univ., Pocatello, ID (United States)

    2014-12-01

    There is a need to establish fundamental properties of matter and energy under extreme physical conditions. Although high energy density physics (HEDP) research spans a wide range of plasma conditions, there is one unifying regime that is of particular importance and complexity: that of warm dense matter, the transitional state between solid state condensed matter and energetic plasmas. Most laboratory experimental conditions, including inertial confinement implosion, fall into this regime. Because all aspects of laboratory-created high-energy-density plasmas transition through the warm dense matter regime, understanding the fundamental properties to determine how matter and energy interact in this regime is an important aspect of major research efforts in HEDP. Improved understanding of warm dense matter would have significant and wide-ranging impact on HEDP science, from helping to explain wire initiation studies on the Sandia Z machine to increasing the predictive power of inertial confinement fusion modeling. The central goal or objective of our proposed research is to experimentally determine the electrical resistivity, temperature, density, and average ionization state of a variety of materials in the warm dense matter regime, without the use of theoretical calculations. Since the lack of an accurate energy of state (EOS) model is primarily due to the lack of experimental data, we propose an experimental study of the transport coefficients of warm dense matter.

  7. Dense xenon nanoplasmas in intense laser fields

    International Nuclear Information System (INIS)

    Hilse, P.; Moll, M.; Schlanges, M.; Bornath, Th.

    2010-01-01

    Complete text of publication follows. One reason for the on-going interest in laser-cluster interactions is the efficient absorption of the radiation energy of near-infrared femtosecond laser pulses by clusters. Consequently, in laser-cluster experiments the emission of highly charged ions, very energetic electrons, higher harmonics, fast fragments as well at strong x-rays in the multi-keV range is observed. The cluster response is highly nonlinear. Different theoretical models and simulations indicate that resonant collective absorption plays a central role. The rapid expansion of irradiated clusters is essential as, at a certain time, the cluster reaches the density fulfilling the resonance condition. This can occur during a single pulse. A better control can be achieved by dual-pulse laser excitation with varying time delay between two pulses. A further optimization is possible by pulse shaping which is a modern tool in laser experiments. With pulse shaping, the dynamics of the system determined by heating, ionization and expansion can be specifically affected. For an understanding of the underlying physical processes in the dynamics of laser-cluster interaction, a theoretical description is presented using a genetic algorithm and basing on the relatively simple nanoplasma model. Recently, experiments as well as calculations were performed for silver clusters. Highly charged silver ions could be produced very efficiently with a pulse structure consisting of a smaller pre-pulse followed by a larger main pulse. The focus of the present contribution is on xenon clusters and their different behavior compared to metallic clusters as silver. Acknowledgements. This work was supported by the Deutsche Forschungsgemeinschaft via SFB 652.

  8. Medium energy hadron scattering from nuclei

    International Nuclear Information System (INIS)

    Ginocchio, J.N.; Wenes, G.

    1986-01-01

    The Glauber approximation for medium energy scattering of hadronic projectiles from nuclei is combined with the interacting boson model of nuclei to produce a transition matrix for elastic and inelastic scattering in algebraic form which includes coupling to all the intermediate states. We present closed form analytic expresions for the transition matrix elements for the three dynamical symmetries of the interacting boson model; that is for, a spherical quadrupole vibrator, a γ unstable rotor, and both prolate and oblate axially symmetric rotors. We give examples of application of this formalism to proton scattering from 154 Sm and 154 Gd. 27 refs., 5 figs., 1 tab

  9. Accelerated Recombination in Cold Dense Plasmas with Metastable Ions due to Resonant Deexcitation

    International Nuclear Information System (INIS)

    Ralchenko, Yu.V.; Maron, M.

    2001-01-01

    In a recombining plasma the metastable states are known to accumulate population thereby slowing down the recombination process. We show that a proper account of the doubly-excited autoionizing states, populated through collisional 3-body recombination of metastable ions, results in a significant acceleration of recombination. 3-body recombination followed by collisional (de)excitations and autoionization effectively produces deexcitation via the following chain of elementary events: A fully time-dependent collisional-radiative (CR) modeling for stripped ions of carbon recombining in a cold dense plasma demonstrates an order of magnitude faster recombination of He-like ions. The CR model used in calculations is discussed in details

  10. Water and vapor permeability at different temperatures of poly (3-Hydroxybutyrate dense membranes

    Directory of Open Access Journals (Sweden)

    Luiz H. Poley

    2005-03-01

    Full Text Available Polyhydroxyalkanoates (PHAs are polymers produced from renewable resources with biodegradability and biocompatibility, being therefore attractive for medical and pharmaceutical purposes. Poly (3-hydroxybutyrate (PHB is the most important polymer of this family by considering the biotechnology process of its synthesis. In the present study, dense films of PHB were prepared by casting from chloroform solutions (1% m/m. Permeability studies with water, methanol, ethanol and n-propanol were performed using the gravimetric method at different temperatures (from 50 ºC to 65 ºC. Results provide new data on permeability coefficients of PHB membranes.

  11. Characteristics of light reflected from a dense ionization wave with a tunable velocity

    OpenAIRE

    Zhidkov, A.; Esirkepov, T.; Fujii, T.; Nemoto, K.; Koga, J.; Bulanov, S. V.

    2009-01-01

    An optically-dense ionization wave (IW) produced by two femtosecond laser pulses focused cylindrically and crossing each other is shown to be an efficient coherent x-ray converter. The resulting velocity of a quasi-plane IW in the vicinity of pulse intersection increases with the angle between the pulses from the group velocity of ionizing pulses to infinity allowing an easy tuning the wavelength of x-rays. The x-ray spectra of a converted, lower frequency coherent light change from the monoc...

  12. Characteristics of light reflected from a dense ionization wave with a tunable velocity.

    Science.gov (United States)

    Zhidkov, A; Esirkepov, T; Fujii, T; Nemoto, K; Koga, J; Bulanov, S V

    2009-11-20

    An optically dense ionization wave (IW) produced by two femtosecond (approximately 10/30 fs) laser pulses focused cylindrically and crossing each other may become an efficient coherent x-ray converter in accordance with the Semenova-Lampe theory. The resulting velocity of a quasiplane IW in the vicinity of pulse intersection changes with the angle between the pulses from the group velocity of ionizing pulses to infinity allowing a tuning of the wavelength of x rays and their bunching. The x-ray spectra after scattering of a lower frequency and long coherent light pulse change from the monochromatic to high order harmoniclike with the duration of the ionizing pulses.

  13. Pharmaceutical production of nano particles using supercritical or dense gas technology

    International Nuclear Information System (INIS)

    Regtop, H.

    2002-01-01

    Full text: The primary aim of our proposed research is to develop pharmaceutical formulations with enhanced pharmacokinetics and increased bioavailability. The particular drug delivery systems of interest are, oral, aerosols, injectable and topical with well-recognised and distinct problems of bioavailability. More than 40% of all drugs in the USP or BP are insoluble or have some problem with solubility. It is estimated in 2000, the total combined sales of drugs that are insoluble or poorly soluble was US$37 billion. Precise and predictable drug delivery is made more possible by producing uniform micron size particles or powders, which can improve the efficiency and effectiveness of therapeutical formulations. Hence the purpose of micronisation is to increase bioavailability and also to allow other modes of administration, eg insulin is a protein, which is an injectable for the treatment of diabetes, but recently particles of 1-4 microns of insulin are in phase 3 clinical trials to deliver the drug to diabetics as an inhalant. In addition aerosolised drugs such as mucolytics, antibiotics, antiinflammatory drugs and hormones have recently been trailed. Finely powdered pharmaceuticals are however difficult to process by current techniques. In spray drying the operating temperatures are often too high for heat sensitive drugs. Thermal degradation of compounds can also be experienced in milling due to high rates of shear and requires high energy inputs and do not produce particles within a narrow range distribution. A relatively new technique which has been used and developed by Eiffel Technologies to produce uniform micron and sub micron size particles is a dense gas process in which the gas is used as an antisolvent to precipitate compounds from solution. Pharmaceutical processing with dense gas is relatively new and is an efficient process for producing high purity micronised particles with defined morphological structures and with a narrow size distribution rate

  14. Development of Carrot Medium Suitable for Conidia Production of Venturia nashicola

    Directory of Open Access Journals (Sweden)

    Eu Ddeum Choi

    2017-02-01

    Full Text Available The causal fungus of pear scab, Venturia nashicola, grows slowly and rarely produces conidia on artificial media in the laboratory, but it produced conidia on the Cheongah medium containing Cheongah powder. V. nashicola grew too slow to produce conidia until 15 days after cultivation but produced conidia with 4 × 10⁴ conidia/plate 30 days after cultivation on the Cheongah medium containing 1% Cheongah powder. V. nashicola showed a peak production of conidia with 4.5 × 10⁵ conidia/plate 60 days after cultivation on the carrot medium containing 2% carrot powder, one of the constituents of Cheongah powder. The carrot medium is considered to be the best medium to obtain conidia of V. nashicola in the laboratory until now. This is the first report on the development of a suitable medium for conidia production of V. nashicola, as far as we know.

  15. Medium modifications of vector mesons

    International Nuclear Information System (INIS)

    Pant, L.M.

    2004-01-01

    The omega photoproduction in nuclear medium with the ELSA facility at Bonn and the present status of the HADES collaboration to investigate the in-medium hadron properties in proton, heavy ions and hadron induced reactions at GSI, Darmstadt are presented. Efforts are under way to utilise the electron beam at Indore for experimental hadron physics in order to step into the intermediate energy nuclear physics regime. The skeletal outline of the high energy electron beam now available at CAT, Indore is discussed

  16. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  17. Wet skins tanning with chromium in dense CO{sub 2} under pressure; Tannage au chrome de peaux humides en CO{sub 2} dense sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Saldinari, L. [Tanneries Roux SA, 26 - Romans Sur Isere (France)]|[Tanneries du Puy (France)]|[Tanneries d' Annonay, 07 (France); Dutel, Ch. [Societe ATC (France); Perre, Ch. [CEA Centre de Pierrelatte (DCC/DTE/SLC), 26 (France)

    2000-07-01

    An ancestral gesture steadily improved through the centuries, the transformation of skins into leather includes several stages of which the principal one is tanning. Today, 90 % of the world's leather products are tanned with chromium. However, this stage is an environmental liability, and reducing the volume and chromium content of the waste has become a major issue. A first study on skin degreasing by dense CO{sub 2} helped sharply reduce the volume of the fatty effluents. To replace water by dense CO{sub 2} as the tanning medium was the logical next step. The present study was carried out in cooperation with three tanneries in the Rhone-Alpes-Auvergne area of France and a manufacturer of tanning materials. The difficulty of the study was the chemically opposed character of the two media involved. CO{sub 2} is a non-polar and lipophilic solvent while inorganic chromium is insoluble. The water present in the treated skin is a polar and ionic reaction medium and one of the reagents in tanning chemistry. The mixture of these two partially miscible compounds gives a pH 3 by carbonic acid formation. Tanning is based on the reactivity of collagen, the main component of the skin, with hydroxylated complexes of chromium. Collagen is a protein containing some chemical functions, amines (R-NH{sub 2}) and carboxylic (R-COOH) for example. These functions impart an amphoteric character to the compound. The WERNER theory of complex salts explains the formation of hydroxylated complexes of chromium and their fixing on the carboxylic functions of collagen by oxolation. pH is the key parameter in tanning. The success of the process demands chromium impregnation without fixing it at a pH lower than 5, and then to fix it by increasing the pH. This opened two alternatives for transferring chromium in the skin: solubilize chromium in CO{sub 2} via soluble organometallic complexes; or put the chromium salt into suspension without solubilizing it. The best results were obtained

  18. Warm dense matter and Thomson scattering at FLASH

    International Nuclear Information System (INIS)

    Faeustlin, Roland Rainer

    2010-05-01

    X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)

  19. Probing warm dense lithium by inelastic X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Saiz, E; Riley, D [School of Mathematics and Physics, Queen' s University of Belfast, Belfast (United Kingdom); Gregori, G [Clarendon Laboratory, University of Oxford, Parks Road, Oxford (United Kingdom); Gregori, G; Clarke, R J; Neely, D; Notley, M M; Spindloe, C [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX (United Kingdom); Gericke, D O; Vorberger, J; Wunsch, K [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry (United Kingdom); Barbrel, B; Koenig, M [Laboratoire pour l' Utilisation des Laser Intenses, Ecole Polytechnique - Universite Paris-6, 91 - Palaiseau (France); Freeman, R R; Weber, R L; Van Woerkom, L [Department of Physics, The Ohio State University, Columbus, Ohio (United States); Glenzer, S H; Landen, O L; Neumayer, P; Price, D [Lawrence Livermore National Laboratory, Livermore, California (United States); Khattak, F Y [Department of Physics, Kohat University of Science and Technology, Kohat-26000, NWFP (Pakistan); Pelka, A; Roth, M; Schollmeier, M [Institut fur Kernphysik, Technische Universitat Darmstadt (Germany)

    2008-10-15

    One of the grand challenges of contemporary physics is understanding strongly interacting quantum systems comprising such diverse examples as ultracold atoms in traps, electrons in high-temperature superconductors and nuclear matter. Warm dense matter, defined by temperatures of a few electron volts and densities comparable with solids, is a complex state of such interacting matter. Moreover, the study of warm dense matter states has practical applications for controlled thermonuclear fusion, where it is encountered during the implosion phase, and it also represents laboratory analogues of astrophysical environments found in the core of planets and the crusts of old stars. Here we demonstrate how warm dense matter states can be diagnosed and structural properties can be obtained by inelastic X-ray scattering measurements on a compressed lithium sample. Combining experiments and ab initio simulations enables us to determine its microscopic state and to evaluate more approximate theoretical models for the ionic structure. (authors)

  20. Warm dense matter and Thomson scattering at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Faeustlin, Roland Rainer

    2010-05-15

    X-ray free electron lasers are powerful tools to investigate moderately to strongly correlated solid density low temperature plasmas, named warm dense matter. These plasmas are of most interest for astrophysics and laser plasma interaction, particularly inertial confinement fusion. This work utilizes the ultrashort soft x-ray pulse duration and high brilliance of the free electron laser in Hamburg, FLASH, to generate warm dense matter and to study its ultrafast processes. The techniques applied are absorption measurement, emission spectroscopy and Thomson scattering. Radiative hydrodynamics and Thomson scattering simulations are used to investigate the impact of temperature and density gradients in the sample and to fit the experimental data. The measurements result in a comprehensive picture of soft x-ray matter interaction related to warm dense matter and yield insight into ultrafast equilibration and relaxation mechanisms, in particular impact ionization and radiative recombination. (orig.)

  1. Arbitrary electron acoustic waves in degenerate dense plasmas

    Science.gov (United States)

    Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.

    2017-05-01

    A theoretical investigation is carried out of the nonlinear dynamics of electron-acoustic waves in a collisionless and unmagnetized plasma whose constituents are non-degenerate cold electrons, ultra-relativistic degenerate electrons, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense plasma. It is shown that only negative large amplitude EA solitary waves can exist in such a plasma system. The present analysis may be important to understand the collective interactions in degenerate dense plasmas, occurring in dense astrophysical environments as well as in laser-solid density plasma interaction experiments.

  2. Eculizumab for dense deposit disease and C3 glomerulonephritis.

    Science.gov (United States)

    Bomback, Andrew S; Smith, Richard J; Barile, Gaetano R; Zhang, Yuzhou; Heher, Eliot C; Herlitz, Leal; Stokes, M Barry; Markowitz, Glen S; D'Agati, Vivette D; Canetta, Pietro A; Radhakrishnan, Jai; Appel, Gerald B

    2012-05-01

    The principle defect in dense deposit disease and C3 glomerulonephritis is hyperactivity of the alternative complement pathway. Eculizumab, a monoclonal antibody that binds to C5 to prevent formation of the membrane attack complex, may prove beneficial. In this open-label, proof of concept efficacy and safety study, six subjects with dense deposit disease or C3 glomerulonephritis were treated with eculizumab every other week for 1 year. All had proteinuria >1 g/d and/or AKI at enrollment. Subjects underwent biopsy before enrollment and repeat biopsy at the 1-year mark. The subjects included three patients with dense deposit disease (including one patient with recurrent dense deposit disease in allograft) and three patients with C3 glomerulonephritis (including two patients with recurrent C3 glomerulonephritis in allograft). Genetic and complement function testing revealed a mutation in CFH and MCP in one subject each, C3 nephritic factor in three subjects, and elevated levels of serum membrane attack complex in three subjects. After 12 months, two subjects showed significantly reduced serum creatinine, one subject achieved marked reduction in proteinuria, and one subject had stable laboratory parameters but histopathologic improvements. Elevated serum membrane attack complex levels normalized on therapy and paralleled improvements in creatinine and proteinuria. Clinical and histopathologic data suggest a response to eculizumab in some but not all subjects with dense deposit disease and C3 glomerulonephritis. Elevation of serum membrane attack complex before treatment may predict response. Additional research is needed to define the subgroup of dense deposit disease/C3 glomerulonephritis patients in whom eculizumab therapy can be considered.

  3. Pion condensation in cold dense matter and neutron stars

    International Nuclear Information System (INIS)

    Haensel, P.; Proszynski, M.

    1982-01-01

    We study possible influence, on the neutron star structure, of a pion condensation occurring in cold dense matter. Several equations of state with pion-condensed phase are considered. The models of neutron stars are calculated and confronted with existing observational data on pulsars. Such a confrontation appears to rule out the models of dense matter with an abnormal self-bound state, and therefore it seems to exclude the possibility of the existence of abnormal superheavy neutron nuclei and abnormal neutron stars with a liquid pion-condensed surface

  4. Matching of dense plasma focus devices with fission reactors

    International Nuclear Information System (INIS)

    Harms, A.A.; Heindler, M.

    1978-01-01

    The potential role of dense plasma focus devices as compact neutron sources for fissile fuel breeding in conjunction with existing fission reactors is considered. It is found that advanced plasma focus devices can be used effectively in conjunction with neutronically efficient fission reactors to constitute ''self-sufficient'' breeders. Correlations among the various parameters such as the power output and conversion ratio of the fission reactor with the neutron yield and capacitor bank energy of the dense plasma focus device are presented and discussed

  5. Kinetic theory of the interdiffusion coefficient in dense plasmas

    International Nuclear Information System (INIS)

    Boercker, D.B.

    1986-08-01

    Naive applications of Spitzer's theory to very dense plasmas can lead to negative diffusion coefficients. The interdiffusion coefficients in Binary Ionic Mixtures (two species of point ions in a uniform neutralizing background) have been calculated recently using molecular dynamics techniques. These calculations can provide useful benchmarks for theoretical evaluations of the diffusion coefficient in dense plasma mixtures. This paper gives a brief description of a kinetic theoretic approximation to the diffusion coefficient which generalizes Spitzer to high density and is in excellent agreement with the computer simulations. 15 refs., 1 fig., 2 tabs

  6. Metric Accuracy Evaluation of Dense Matching Algorithms in Archeological Applications

    Directory of Open Access Journals (Sweden)

    C. Re

    2011-12-01

    Full Text Available In the cultural heritage field the recording and documentation of small and medium size objects with very detailed Digital Surface Models (DSM is readily possible by through the use of high resolution and high precision triangulation laser scanners. 3D surface recording of archaeological objects can be easily achieved in museums; however, this type of record can be quite expensive. In many cases photogrammetry can provide a viable alternative for the generation of DSMs. The photogrammetric procedure has some benefits with respect to laser survey. The research described in this paper sets out to verify the reconstruction accuracy of DSMs of some archaeological artifacts obtained by photogrammetric survey. The experimentation has been carried out on some objects preserved in the Petrie Museum of Egyptian Archaeology at University College London (UCL. DSMs produced by two photogrammetric software packages are compared with the digital 3D model obtained by a state of the art triangulation color laser scanner. Intercomparison between the generated DSM has allowed an evaluation of metric accuracy of the photogrammetric approach applied to archaeological documentation and of precision performances of the two software packages.

  7. Optical bistability induced by quantum coherence in a negative index atomic medium

    International Nuclear Information System (INIS)

    Zhang Hong-Jun; Sun Hui; Li Jin-Ping; Yin Bao-Yin; Guo Hong-Ju

    2013-01-01

    Bistability behaviors in an optical ring cavity filled with a dense V-type four-level atomic medium are theoretically investigated. It is found that the optical bistability can appear in the negative refraction frequency band, while both the bistability and multi-stability can occur in the positive refraction frequency bands. Therefore, optical bistability can be realized from conventional material to negative index material due to quantum coherence in our scheme. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  8. The small GTPase Cdc42 modulates the number of exocytosis-competent dense-core vesicles in PC12 cells

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Mai [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Kitaguchi, Tetsuya [Cell Signaling Group, Waseda Bioscience Research Institute in Singapore (WABOIS), Waseda University, 11 Biopolis Way, 05-01/02 Helios, Singapore 138667 (Singapore); Numano, Rika [The Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tennpaku-cho, Toyohashi, Aichi 441-8580 (Japan); Ikematsu, Kazuya [Forensic Pathology and Science, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8523 (Japan); Kakeyama, Masaki [Laboratory of Environmental Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033 (Japan); Murata, Masayuki; Sato, Ken [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan); Tsuboi, Takashi, E-mail: takatsuboi@bio.c.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902 (Japan)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer Regulation of exocytosis by Rho GTPase Cdc42. Black-Right-Pointing-Pointer Cdc42 increases the number of fusion events from newly recruited vesicles. Black-Right-Pointing-Pointer Cdc42 increases the number of exocytosis-competent dense-core vesicles. -- Abstract: Although the small GTPase Rho family Cdc42 has been shown to facilitate exocytosis through increasing the amount of hormones released, the precise mechanisms regulating the quantity of hormones released on exocytosis are not well understood. Here we show by live cell imaging analysis under TIRF microscope and immunocytochemical analysis under confocal microscope that Cdc42 modulated the number of fusion events and the number of dense-core vesicles produced in the cells. Overexpression of a wild-type or constitutively-active form of Cdc42 strongly facilitated high-KCl-induced exocytosis from the newly recruited plasma membrane vesicles in PC12 cells. By contrast, a dominant-negative form of Cdc42 inhibited exocytosis from both the newly recruited and previously docked plasma membrane vesicles. The number of intracellular dense-core vesicles was increased by the overexpression of both a wild-type and constitutively-active form of Cdc42. Consistently, activation of Cdc42 by overexpression of Tuba, a Golgi-associated guanine nucleotide exchange factor for Cdc42 increased the number of intracellular dense-core vesicles, whereas inhibition of Cdc42 by overexpression of the Cdc42/Rac interactive binding domain of neuronal Wiskott-Aldrich syndrome protein decreased the number of them. These findings suggest that Cdc42 facilitates exocytosis by modulating both the number of exocytosis-competent dense-core vesicles and the production of dense-core vesicles in PC12 cells.

  9. The small GTPase Cdc42 modulates the number of exocytosis-competent dense-core vesicles in PC12 cells

    International Nuclear Information System (INIS)

    Sato, Mai; Kitaguchi, Tetsuya; Numano, Rika; Ikematsu, Kazuya; Kakeyama, Masaki; Murata, Masayuki; Sato, Ken; Tsuboi, Takashi

    2012-01-01

    Highlights: ► Regulation of exocytosis by Rho GTPase Cdc42. ► Cdc42 increases the number of fusion events from newly recruited vesicles. ► Cdc42 increases the number of exocytosis-competent dense-core vesicles. -- Abstract: Although the small GTPase Rho family Cdc42 has been shown to facilitate exocytosis through increasing the amount of hormones released, the precise mechanisms regulating the quantity of hormones released on exocytosis are not well understood. Here we show by live cell imaging analysis under TIRF microscope and immunocytochemical analysis under confocal microscope that Cdc42 modulated the number of fusion events and the number of dense-core vesicles produced in the cells. Overexpression of a wild-type or constitutively-active form of Cdc42 strongly facilitated high-KCl-induced exocytosis from the newly recruited plasma membrane vesicles in PC12 cells. By contrast, a dominant-negative form of Cdc42 inhibited exocytosis from both the newly recruited and previously docked plasma membrane vesicles. The number of intracellular dense-core vesicles was increased by the overexpression of both a wild-type and constitutively-active form of Cdc42. Consistently, activation of Cdc42 by overexpression of Tuba, a Golgi-associated guanine nucleotide exchange factor for Cdc42 increased the number of intracellular dense-core vesicles, whereas inhibition of Cdc42 by overexpression of the Cdc42/Rac interactive binding domain of neuronal Wiskott–Aldrich syndrome protein decreased the number of them. These findings suggest that Cdc42 facilitates exocytosis by modulating both the number of exocytosis-competent dense-core vesicles and the production of dense-core vesicles in PC12 cells.

  10. Onset of color decoherence for soft gluon radiation in a medium

    Science.gov (United States)

    Mehtar-Tani, Y.; Salgado, C. A.; Tywoniuk, K.

    2011-12-01

    We report on recent studies of the phenomenon of color decoherence in jets in QCD media. The effect is most clearly observed in the radiation pattern of a quark-antiquark antenna, created in the same quantum state, traversing a dense color deconfined plasma. Multiple scattering with the medium color charges gradually destroys the coherence of the antenna. In the limit of opaque media, this ultimately leads to independent radiation off the antenna constituents. Accordingly, radiation off the total charge vanishes implying a memory loss effect induced by the medium.

  11. Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

    Science.gov (United States)

    Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

    2014-05-01

    Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. CRUNCH, Dispersion Model for Continuous Dense Vapour Release in Atmosphere

    International Nuclear Information System (INIS)

    Jagger, S.F.

    1987-01-01

    1 - Description of program or function: The situation modelled is as follows. A dense gas emerges from a source such that it can be considered to emerge through a rectangular area, placed in the vertical plane and perpendicular to the plume direction, which assumes that of the ambient wind. The gas flux at the source, and in every plane perpendicular to the plume direction, is constant in time and a stationary flow field has been attained. For this to apply, the characteristic time of release must be much larger than that for dispersal of the contaminant. The plume can be thought to consist of a number of rectangular elements or 'puffs' emerging from the source at regular time intervals. The model follows the development of these puffs at a series of downwind points. These puffs are immediately assumed to advect with the ambient wind at their half-height. The plume also slumps due to the action of gravity and is allowed to entrain air through its sides and top surface. Spreading of a fluid element is caused by pressure differences across this element and since the pressure gradient in the wind direction is small, the resulting pressure differences and slumping velocities are small also, thus permitting this convenient approximation. Initially, as the plume slumps, its vertical dimension decreases and with it the slumping velocity and advection velocity. Thus the plume advection velocity varies as a function of downwind distance. With the present steady state modelling, and to satisfy continuity constraints, there must be consequent adjustment of plume height. Calculation of this parameter from the volume flux ensures this occurs. As the cloud height begins to grow, the advection velocity increases and the plume height decreases accordingly. With advection downwind, the cloud gains buoyancy by entraining air and, if the cloud is cold, by absorbing heat from the ground. Eventually the plume begins to disperse as would a passive pollutant, through the action of

  13. Working group report on hadrons in the nuclear medium

    Energy Technology Data Exchange (ETDEWEB)

    Ent, R. [CEBAF, Newport News, VA (United States); Milner, R.G. [Masachusetts Inst. of Technology, Cambridge, MA (United States)

    1994-04-01

    This working group focussed on the subject of hadrons in the nuclear medium. It encompassed both the understanding of the nucleus itself in terms of its binding and its structure, and the use of the nucleus as a medium to probe QCD and the structure of hadrons. Both aspects were addressed during the workshop, though the emphasis tended towards the latter. Almost inescapably this working group had some overlap with the other working groups, as the nucleus can also be used as a medium to probe the production and structure of vector mesons. Also, inclusive and semi-inclusive processes can be used as a probe of nuclear effects, for instance in the case of deep-inelastic scattering for x > 1. In this summary report the authors will try to restrict themselves to only those issues where the nuclear medium is important. To increase their understanding of the nucleus in terms of its binding and structure, they would like to know the effect of a dense nuclear medium on a nucleon, to know the non-nucleonic degrees of freedom needed to describe a nuclear system, and to understand the implications of the fact that a bound nucleon is necessarily off its mass-shell. The results of many lepton scattering experiments during the last two decades have raised these questions, but at this moment there are no definitive answers. The hope is that the well-known electron probe, with sufficient energy to probe the short-range properties of nuclei, can provide insight. Especially, the authors would like a conclusive answer to the question if, and to what extent, quark degrees of freedom are necessary to describe a nuclear system.

  14. Working group report on hadrons in the nuclear medium

    International Nuclear Information System (INIS)

    Ent, R.; Milner, R.G.

    1994-01-01

    This working group focussed on the subject of hadrons in the nuclear medium. It encompassed both the understanding of the nucleus itself in terms of its binding and its structure, and the use of the nucleus as a medium to probe QCD and the structure of hadrons. Both aspects were addressed during the workshop, though the emphasis tended towards the latter. Almost inescapably this working group had some overlap with the other working groups, as the nucleus can also be used as a medium to probe the production and structure of vector mesons. Also, inclusive and semi-inclusive processes can be used as a probe of nuclear effects, for instance in the case of deep-inelastic scattering for x > 1. In this summary report the authors will try to restrict themselves to only those issues where the nuclear medium is important. To increase their understanding of the nucleus in terms of its binding and structure, they would like to know the effect of a dense nuclear medium on a nucleon, to know the non-nucleonic degrees of freedom needed to describe a nuclear system, and to understand the implications of the fact that a bound nucleon is necessarily off its mass-shell. The results of many lepton scattering experiments during the last two decades have raised these questions, but at this moment there are no definitive answers. The hope is that the well-known electron probe, with sufficient energy to probe the short-range properties of nuclei, can provide insight. Especially, the authors would like a conclusive answer to the question if, and to what extent, quark degrees of freedom are necessary to describe a nuclear system

  15. Sector boundary distortion in the interplanetary medium

    International Nuclear Information System (INIS)

    Suess, S.T.; Feynman, J.

    1977-01-01

    We address the theoretical problem of the effect of a solar wind meridional velocity gradient on the orientation, or tipping, of a line embedded within the interplanetary plasma. We find that rotations of from 30degree to 75degree, between 1.5 solar radii and I AU, are produced when observed values for the solar wind velocity and its meridional gradient are used. This is not a small effect, nor is it difficult to calculate: it is a natural consequence of any meridional velocity gradient in the interplanetary medium. In relating this result to observed sector boundaries we note that the latitude dependence of the width of interplanetary magnetic sectors (dominant polarity or Rosenberg-Coleman effect) implies that sector boundaries at I AU are generally inclined at an angle of from 10degree to 20degree to the solar equatorial plane. Conversely, studies of photospheric magnetic fields have led to the conclusion that sector boundaries near the sun are, on the average, at large angles (approx.90degree) to the solar equatorial plane. If the dominant polarity effect were to be produced by rotation in the interplanetary medium, the sign of the solar wind meridional velocity gradient must not change at the equator, but the gradient does have to change sign for +/- boundary crossings in comparison to -/+ boundary crossings

  16. Laser-assisted electron scattering in strong-field ionization of dense water vapor by ultrashort laser pulses

    International Nuclear Information System (INIS)

    Wilke, M; Al-Obaidi, R; Moguilevski, A; Kothe, A; Engel, N; Metje, J; Kiyan, I Yu; Aziz, E F

    2014-01-01

    We report on strong-field ionization of dense water gas in a short infrared laser pulse. By employing a unique combination of photoelectron spectroscopy with a liquid micro-jet technique, we observe how the character of electron emission at high kinetic energies changes with the increase of the medium density. This change is associated with the process of laser-assisted electron scattering (LAES) on neighboring particles, which becomes a dominant mechanism of hot electron emission at higher medium densities. The manifestation of this mechanism is found to require densities that are orders of magnitude lower than those considered for heating the laser-generated plasmas via the LAES process. The experimental results are supported by simulations of the LAES yield with the use of the Kroll–Watson theory. (paper)

  17. Anomalous optical and electronic properties of dense sodium

    International Nuclear Information System (INIS)

    Li Dafang; Liu Hanyu; Wang Baotian; Shi Hongliang; Zhu Shaoping; Yan Jun; Zhang Ping

    2010-01-01

    Based on the density functional theory, we systematically study the optical and electronic properties of the insulating dense sodium phase (Na-hp4) reported recently (Ma et al., 2009). The structure is found optically anisotropic. Through Bader analysis, we conclude that ionicity exists in the structure and becomes stronger with increasing pressure.

  18. Green-function description of dense polymeric systems

    NARCIS (Netherlands)

    Schoot, van der P.P.A.M.

    2000-01-01

    A self-consistent Green-function description of concentrated polymer solutions and dense polymeric melts is presented. The method, which applies to both uniform and nonuniform systems, is used in this work to calculate the static structure factor of a homogeneous fluid of Gaussian model chains.

  19. Planar simplification and texturing of dense point cloud maps

    NARCIS (Netherlands)

    Ma, L.; Whelan, T.; Bondarau, Y.; With, de P.H.N.; McDonald, J.

    2013-01-01

    Dense RGB-D based SLAM techniques and highfidelity LIDAR scanners are examples from an abundant set of systems capable of providing multi-million point datasets. These large datasets quickly become difficult to process and work with due to the sheer volume of data, which typically contains

  20. Incremental and batch planar simplification of dense point cloud maps

    NARCIS (Netherlands)

    Whelan, T.; Ma, L.; Bondarev, E.; With, de P.H.N.; McDonald, J.

    2015-01-01

    Dense RGB-D SLAM techniques and high-fidelity LIDAR scanners are examples from an abundant set of systems capable of providing multi-million point datasets. These datasets quickly become difficult to process due to the sheer volume of data, typically containing significant redundant information,

  1. Influence of Food Packaging on Children's Energy-dense Snack ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Childhood obesity is a major global public health concern. Rates of obese and overweight children have increased in low- and middle-income countries such as Guatemala. This research will study the influence of food packaging on Guatemalan preschool and school-aged children's energy-dense snack (EDS) food ...

  2. Plasma focus - dense Z pinch and their applications

    International Nuclear Information System (INIS)

    Ishii, Shozo

    1986-02-01

    ''Workshop on the possibility of Z-pinch as a intense pulse light source'' in 1983 and ''Research meeting on plasma focus and Z-pinch'' in 1984 were held at Institute of Plasma Physics, Nagoya University under a collaborating research program. Research activities reported at the meetings on plasma focus, dense Z-pinch, and related phenomena are summerized. (author)

  3. Mechanics of dense suspensions in turbulent channel flows

    NARCIS (Netherlands)

    Picano, F.; Costa, P.; Breugem, W.P.; Brandt, L.

    2015-01-01

    Dense suspensions are usually investigated in the laminar limit where inertial effects are insignificant. When the flow rate is high enough, i.e. at high Reynolds number, the flow may become turbulent and the interaction between solid and liquid phases modifies the turbulence we know in single-phase

  4. Estimation of Dense Image Flow Fields in Fluids

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Conradsen, Knut; Ersbøll, Bjarne Kjær

    or an estimate there-of is known. Estimated flow fields in weather satellite imagery might also be used on an operational basis as inputs to short-term weather prediction. In this article we describe a method for the estimation of dense flow fields. Local measurements of motion are obtained by analysis...

  5. A comparative study of fast dense stereo vision algorithms

    NARCIS (Netherlands)

    Sunyoto, H.; Mark, W. van der; Gavrila, D.M.

    2004-01-01

    With recent hardware advances, real-time dense stereo vision becomes increasingly feasible for general-purpose processors. This has important benefits for the intelligent vehicles domain, alleviating object segmentation problems when sensing complex, cluttered traffic scenes. In this paper, we

  6. Sparse symmetric preconditioners for dense linear systems in electromagnetism

    NARCIS (Netherlands)

    Carpentieri, Bruno; Duff, Iain S.; Giraud, Luc; Monga Made, M. Magolu

    2004-01-01

    We consider symmetric preconditioning strategies for the iterative solution of dense complex symmetric non-Hermitian systems arising in computational electromagnetics. In particular, we report on the numerical behaviour of the classical incomplete Cholesky factorization as well as some of its recent

  7. Energy eigenvalues of helium-like atoms in dense plasmas

    International Nuclear Information System (INIS)

    Hashino, Tasuke; Nakazaki, Shinobu; Kato, Takako; Kashiwabara, Hiromichi.

    1987-04-01

    Calculations based on a variational method with wave functions including the correlation of electrons are carried out to obtain energy eigenvalues of Schroedinger's equation for helium-like atoms embedded in dense plasmas, taking the Debye-Hueckel approximation. Energy eigenvalues for the 1 1 S, 2 1 S, and 2 3 S states are obtained as a function of Debye screening length. (author)

  8. Formation of fibrous materials from dense caseinate dispersions

    NARCIS (Netherlands)

    Manski, J.M.; Goot, van der A.J.; Boom, R.M.

    2007-01-01

    Application of shear and cross-linking enzyme transglutaminase (Tgase) induced fibrous hierarchical structures in dense (30% w/w) calcium caseinate (Ca-caseinate) dispersions. Using Tgase was essential for the anisotropic structure formation. The fibrous materials showed anisotropy on both micro-

  9. Common intersection points in dense fluids via equations of state

    International Nuclear Information System (INIS)

    Parsafar, G. A.; Noorian, R.

    2001-01-01

    Some new of state which are derived for dense fluids in recent years, namely the linear isotherm regularity, the dense system equation of state, Ihm-Song-Mason equation of state, and a newly derived semi-empirical equation of state have used to investigate the common intersection point of isobaric expansivity (α p ) in dense fluids. We have shown that the accuracy of these equations of state in predicting such a common intersection point is reduced from the new semi-imperial equation of state, dense system equation of state, linear isotherm regularity, to Ihm-Song-Mason equation of state. respectively. Form physical point of view, the van der Waals equation of state is used to investigate such an intersection point. It is shown that the van der Waals repulsion forces and temperature dependency of the effective molecular diameter are important for existence of this common point. Finally, we have shown that the common intersection points of the isotherms of thermal pressure coefficient, the isotherms of heat capacity at constant volume, and the iso chores of internal pressure for a fluid are related to each other. Also, the common intersection points of the reduced bulk modulus and 1/(Tα p ) for isotherms of a fluid both appear at the same density

  10. Estimation of Dense Image Flow Fields in Fluids

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Conradsen, Knut; Ersbøll, Bjarne Kjær

    1998-01-01

    or an estimate there-of is known. Estimated flow fields in weather satellite imagery might also be used on an operational basis as inputs to short-term weather prediction. In this article we describe a method for the estimation of dense flow fields. Local measurements of motion are obtained by analysis...

  11. Gas-particle interactions in dense gas-fluidised beds

    NARCIS (Netherlands)

    Li, J.; Kuipers, J.A.M.

    2003-01-01

    The occurrence of heterogeneous flow structures in gas-particle flows seriously affects gas¿solid contacting and transport processes in dense gas-fluidized beds. A computational study, using a discrete particle method based on Molecular Dynamics techniques, has been carried out to explore the

  12. Multi-scaling of the dense plasma focus

    Science.gov (United States)

    Saw, S. H.; Lee, S.

    2015-03-01

    The dense plasma focus is a copious source of multi-radiations with many potential new applications of special interest such as in advanced SXR lithography, materials synthesizing and testing, medical isotopes and imaging. This paper reviews the series of numerical experiments conducted using the Lee model code to obtain the scaling laws of the multi-radiations.

  13. Interaction of ultrarelativistic electron and proton bunches with dense plasmas

    CERN Document Server

    Rukhadze, A A

    2012-01-01

    Here we discuss the possibility of employment of ultrarelativistic electron and proton bunches for generation of high plasma wakefields in dense plasmas due to the Cherenkov resonance plasma-bunch interaction. We estimate the maximum amplitude of such a wake and minimum system length at which the maximum amplitude can be generated at the given bunch parameters.

  14. Dense Descriptors for Optical Flow Estimation: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Ahmadreza Baghaie

    2017-02-01

    Full Text Available Estimating the displacements of intensity patterns between sequential frames is a very well-studied problem, which is usually referred to as optical flow estimation. The first assumption among many of the methods in the field is the brightness constancy during movements of pixels between frames. This assumption is proven to be not true in general, and therefore, the use of photometric invariant constraints has been studied in the past. One other solution can be sought by use of structural descriptors rather than pixels for estimating the optical flow. Unlike sparse feature detection/description techniques and since the problem of optical flow estimation tries to find a dense flow field, a dense structural representation of individual pixels and their neighbors is computed and then used for matching and optical flow estimation. Here, a comparative study is carried out by extending the framework of SIFT-flow to include more dense descriptors, and comprehensive comparisons are given. Overall, the work can be considered as a baseline for stimulating more interest in the use of dense descriptors for optical flow estimation.

  15. Active and Nonlinear Microrheology of Dense Colloidal Suspensions

    OpenAIRE

    Harrer, Christian Josef

    2013-01-01

    In this work, we have investigated active and nonlinear microrheology of dense colloidal suspensions, i.e., the forced motion of a singled-out tracer particle by an external force, both in the framework of MCT and via event-driven Brownian Dynamics simulations.

  16. Ranks of dense alternating sign matrices and their sign patterns

    Czech Academy of Sciences Publication Activity Database

    Fiedler, Miroslav; Gao, W.; Hall, F.J.; Jing, G.; Li, Z.; Stroev, M.

    2015-01-01

    Roč. 471, April (2015), s. 109-121 ISSN 0024-3795 R&D Projects: GA ČR(CZ) GA14-07880S Institutional support: RVO:67985840 Keywords : alternating sign matrix * dense matrix * sign pattern matrix Subject RIV: BA - General Mathematics Impact factor: 0.965, year: 2015 http://www.sciencedirect.com/science/article/pii/S0024379515000257

  17. Light localization in cold and dense atomic ensemble

    International Nuclear Information System (INIS)

    Sokolov, Igor

    2017-01-01

    We report on results of theoretical analysis of possibilities of light strong (Anderson) localization in a cold atomic ensemble. We predict appearance of localization in dense atomic systems in strong magnetic field. We prove that in absence of the field the light localization is impossible. (paper)

  18. Energy Flow in Dense Off-Equilibrium Plasma

    Science.gov (United States)

    2016-07-15

    brings the electron density and light emission into LTE at the measured spectral temperature while leaving the ions cold. Because of their large mass... measurements of ionization potential lowering and collision times indense plasmas, allowing us to distinguish between competing dense-plasma models...Hydrodynamic analysis of shockwaves generated by sparks yielded similar measurements ina different, more accessible system. Ultra-fast observations

  19. Deterministic dense coding and faithful teleportation with multipartite graph states

    International Nuclear Information System (INIS)

    Huang, C.-Y.; Yu, I-C.; Lin, F.-L.; Hsu, L.-Y.

    2009-01-01

    We propose schemes to perform the deterministic dense coding and faithful teleportation with multipartite graph states. We also find the sufficient and necessary condition of a viable graph state for the proposed schemes. That is, for the associated graph, the reduced adjacency matrix of the Tanner-type subgraph between senders and receivers should be invertible.

  20. Dense sampled transmission matrix for high resolution angular spectrum imaging through turbid media via compressed sensing (Conference Presentation)

    Science.gov (United States)

    Jang, Hwanchol; Yoon, Changhyeong; Choi, Wonshik; Eom, Tae Joong; Lee, Heung-No

    2016-03-01

    We provide an approach to improve the quality of image reconstruction in wide-field imaging through turbid media (WITM). In WITM, a calibration stage which measures the transmission matrix (TM), the set of responses of turbid medium to a set of plane waves with different incident angles, is preceded to the image recovery. Then, the TM is used for estimation of object image in image recovery stage. In this work, we aim to estimate highly resolved angular spectrum and use it for high quality image reconstruction. To this end, we propose to perform a dense sampling for TM measurement in calibration stage with finer incident angle spacing. In conventional approaches, incident angle spacing is made to be large enough so that the columns in TM are out of memory effect of turbid media. Otherwise, the columns in TM are correlated and the inversion becomes difficult. We employ compressed sensing (CS) for a successful high resolution angular spectrum recovery with dense sampled TM. CS is a relatively new information acquisition and reconstruction framework and has shown to provide superb performance in ill-conditioned inverse problems. We observe that the image quality metrics such as contrast-to-noise ratio and mean squared error are improved and the perceptual image quality is improved with reduced speckle noise in the reconstructed image. This results shows that the WITM performance can be improved only by executing dense sampling in the calibration stage and with an efficient signal reconstruction framework without elaborating the overall optical imaging systems.

  1. The structure of protostellar dense cores: a millimeter continuum study

    International Nuclear Information System (INIS)

    Motte, Frederique

    1998-01-01

    A comprehensive theoretical scenario explains low-mass star formation and describes the gravitational collapse of an isolated 'ideal' dense core. The major aim of this thesis is to check the standard model predictions on the structure of protostellar dense cores (or envelopes). The earliest stages of star formation remain poorly known because the protostars are still deeply embedded in massive, opaque circumstellar cocoons. On the one hand, sensitive bolometer arrays very recently allow us to measure the millimeter continuum emission arising from dense cores. Such observations are a powerful tool to constrain the density structure of proto-stellar dense cores (on large length scale). In particular, we studied the structure of isolated proto-stellar envelopes in Taurus and protostars in the ρ Ophiuchi cluster. In order to accurately derive their envelope density power law, we simulated the observation of several envelope models. Then we show that most of the Taurus protostars present a density structure consistent with the standard model predictions. In contrast, dense cores in ρ Ophiuchi main cloud are highly fragmented and protostellar envelope have finite size. Moreover fragmentation appears to be essential in determining the final stellar mass of ρ Oph forming stars. In clusters, fragmentation may thus be at the origin of the stellar initial mass function (IMF). On the other hand, our interferometric millimeter continuum observations are tracing (with higher angular resolution) the inner part of protostellar envelopes. Our study show that disks during protostellar stages are not yet massive and thus do not perturb the analysis of envelope density structure. (author) [fr

  2. Properties of the nuclear medium

    International Nuclear Information System (INIS)

    Baldo, M; Burgio, G F

    2012-01-01

    We review our knowledge on the properties of the nuclear medium that have been studied, over many years, on the basis of many-body theory, laboratory experiments and astrophysical observations. Throughout the presentation particular emphasis is placed on the possible relationship and links between the nuclear medium and the structure of nuclei, including the limitations of such an approach. First we consider the realm of phenomenological laboratory data and astrophysical observations and the hints they can give on the characteristics that the nuclear medium should possess. The analysis is based on phenomenological models, that however have a strong basis on physical intuition and an impressive success. More microscopic models are also considered, and it is shown that they are able to give invaluable information on the nuclear medium, in particular on its equation of state. The interplay between laboratory experiments and astrophysical observations is particularly stressed, and it is shown how their complementarity enormously enriches our insights into the structure of the nuclear medium. We then introduce the nucleon–nucleon interaction and the microscopic many-body theory of nuclear matter, with a critical discussion about the different approaches and their results. The Landau–Fermi liquid theory is introduced and briefly discussed, and it is shown how fruitful it can be in discussing the macroscopic and low-energy properties of the nuclear medium. As an illustrative example, we discuss neutron matter at very low density, and it is shown how it can be treated within the many-body theory. The general bulk properties of the nuclear medium are reviewed to indicate at which stage of our knowledge we stand, taking into account the most recent developments both in theory and experiments. A section is dedicated to the pairing problem. The connection with nuclear structure is then discussed, on the basis of the energy density functional method. The possibility of

  3. Prospect of stem cell conditioned medium in regenerative medicine.

    Science.gov (United States)

    Pawitan, Jeanne Adiwinata

    2014-01-01

    Stem cell-derived conditioned medium has a promising prospect to be produced as pharmaceuticals for regenerative medicine. To investigate various methods to obtain stem cell-derived conditioned medium (CM) to get an insight into their prospect of application in various diseases. Systematic review using keywords "stem cell" and "conditioned medium" or "secretome" and "therapy." Data concerning treated conditions/diseases, type of cell that was cultured, medium and supplements to culture the cells, culture condition, CM processing, growth factors and other secretions that were analyzed, method of application, and outcome were noted, grouped, tabulated, and analyzed. Most of CM using studies showed good results. However, the various CM, even when they were derived from the same kind of cells, were produced by different condition, that is, from different passage, culture medium, and culture condition. The growth factor yields of the various types of cells were available in some studies, and the cell number that was needed to produce CM for one application could be computed. Various stem cell-derived conditioned media were tested on various diseases and mostly showed good results. However, standardized methods of production and validations of their use need to be conducted.

  4. DEVELOPMENT OF ANALYTICAL MODELS FOR THE ANALYSIS OF FOUNDATIONS OF BUILDINGS AND STRUCTURES IN THE DENSE URBAN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Koreneva Elena Borisovna

    2012-10-01

    Full Text Available The author proposes analytical methods of analysis of foundation slabs in the dense environment of present-day cities and towns. The two analytical models, including the model of semi-infinite and finite beams are considered. The influence produced by adjacent tunnels, deep excavations and foundation pits is examined. Bedding properties are described through the employment of the Winkler model. Account of additional deflections and angles of deflections must be taken in the above-mentioned cases.

  5. Multiple solutions to dense systems in radar scattering using a preconditioned block GMRES solver

    Energy Technology Data Exchange (ETDEWEB)

    Boyse, W.E. [Advanced Software Resources, Inc., Santa Clara, CA (United States)

    1996-12-31

    Multiple right-hand sides occur in radar scattering calculations in the computation of the simulated radar return from a body at a large number of angles. Each desired angle requires a right-hand side vector to be computed and the solution generated. These right-hand sides are naturally smooth functions of the angle parameters and this property is utilized in a novel way to compute solutions an order of magnitude faster than LINPACK The modeling technique addressed is the Method of Moments (MOM), i.e. a boundary element method for time harmonic Maxwell`s equations. Discretization by this method produces general complex dense systems of rank 100`s to 100,000`s. The usual way to produce the required multiple solutions is via LU factorization and solution routines such as found in LINPACK. Our method uses the block GMRES iterative method to directly iterate a subset of the desired solutions to convergence.

  6. 1 Medium Regiment, (SAHA), SAA

    African Journals Online (AJOL)

    Scientia Militaria: South African Journal of Military Studies. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 16, No 4 (1986) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. 1 Medium Regiment, (S.A.H.A.), ...

  7. Hadron photoproduction at medium energy

    International Nuclear Information System (INIS)

    Dainton, J.B.

    1985-04-01

    Results from measurements of multibody photoproduction at medium incident photon energy (2.8 to 4.8 GeV) are presented and discussed. Particular emphasis is placed on topics which are not well understood and which therefore motivate experiments with the upgraded electron accelerator and storage ring ELSA at the University of Bonn, FR Germany. (author)

  8. Animal Locomotion in Different Mediums

    Indian Academy of Sciences (India)

    Wetlands are repositories of unique biodiversity. Wetlandorganisms are well adapted to their habitat, lying at theinterface of aquatic and terrestrial environments. In order tounderstand their adaptations in a better way, it is essential tograsp the basic properties of the medium in which variousorganisms live. This is attempted ...

  9. Medium optimization for protopectinase production by batch culture ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-11

    Nov 11, 2011 ... Optimization of medium compositions for protopectinase production by ... food industry, pharmacy and cosmetic manufacture due to ... energy intensive and industrial wastes (Iglesias and ... group of enzymes, which produce the enzymatic ... development time and overall costs (Pan et al., 2008; Ren.

  10. Astrophysical Nuclear Reaction Rates in the Dense Metallic Environments

    Science.gov (United States)

    Kilic, Ali Ihsan

    2017-09-01

    Nuclear reaction rates can be enhanced by many orders of magnitude in dense and relatively cold astrophysical plasmas such as in white dwarfs, brown dwarfs, and giant planets. Similar conditions are also present in supernova explosions where the ignition conditions are vital for cosmological models. White dwarfs are compact objects that have both extremely high interior densities and very strong local magnetic fields. For the first time, a new formula has been developed to explain cross section and reaction rate quantities for light elements that includes not only the nuclear component but also the material dependence, magnetic field, and crystal structure dependency in dense metallic environments. I will present the impact of the developed formula on the cross section and reaction rates for light elements. This could have possible technological applications in energy production using nuclear fusion reactions.

  11. Dynamic conductivity and partial ionization in dense fluid hydrogen

    Science.gov (United States)

    Zaghoo, Mohamed

    2018-04-01

    A theoretical description for optical conduction experiments in dense fluid hydrogen is presented. Different quantum statistical approaches are used to describe the mechanism of electronic transport in hydrogen's high-temperature dense phase. We show that at the onset of the metallic transition, optical conduction could be described by a strong rise in atomic polarizability, due to increased ionization, whereas in the highly degenerate limit, the Ziman weak scattering model better accounts for the observed saturation of reflectance. The inclusion of effects of partial ionization in the highly degenerate region provides great agreement with experimental results. Hydrogen's fluid metallic state is revealed to be a partially ionized free-electron plasma. Our results provide some of the first theoretical transport models that are experimentally benchmarked, as well as an important guide for future studies.

  12. Projective block Lanczos algorithm for dense, Hermitian eigensystems

    International Nuclear Information System (INIS)

    Webster, F.; Lo, G.C.

    1996-01-01

    Projection operators are used to effect open-quotes deflation by restrictionclose quotes and it is argued that this is an optimal Lanczos algorithm for memory minimization. Algorithmic optimization is constrained to dense, Hermitian eigensystems where a significant number of the extreme eigenvectors must be obtained reliably and completely. The defining constraints are operator algebra without a matrix representation and semi-orthogonalization without storage of Krylov vectors. other semi-orthogonalization strategies for Lanczos algorithms and conjugate gradient techniques are evaluated within these constraints. Large scale, sparse, complex numerical experiments are performed on clusters of magnetic dipoles, a quantum many-body system that is not block-diagonalizable. Plane-wave, density functional theory of beryllium clusters provides examples of dense complex eigensystems. Use of preconditioners and spectral transformations is evaluated in a preprocessor prior to a high accuracy self-consistent field calculation. 25 refs., 3 figs., 5 tabs

  13. Observations of non-linear plasmon damping in dense plasmas

    Science.gov (United States)

    Witte, B. B. L.; Sperling, P.; French, M.; Recoules, V.; Glenzer, S. H.; Redmer, R.

    2018-05-01

    We present simulations using finite-temperature density-functional-theory molecular-dynamics to calculate dynamic dielectric properties in warm dense aluminum. The comparison between exchange-correlation functionals in the Perdew, Burke, Ernzerhof approximation, Strongly Constrained and Appropriately Normed Semilocal Density Functional, and Heyd, Scuseria, Ernzerhof (HSE) approximation indicates evident differences in the electron transition energies, dc conductivity, and Lorenz number. The HSE calculations show excellent agreement with x-ray scattering data [Witte et al., Phys. Rev. Lett. 118, 225001 (2017)] as well as dc conductivity and absorption measurements. These findings demonstrate non-Drude behavior of the dynamic conductivity above the Cooper minimum that needs to be taken into account to determine optical properties in the warm dense matter regime.

  14. Pulsar-irradiated stars in dense globular clusters

    Science.gov (United States)

    Tavani, Marco

    1992-01-01

    We discuss the properties of stars irradiated by millisecond pulsars in 'hard' binaries of dense globular clusters. Irradiation by a relativistic pulsar wind as in the case of the eclipsing millisecond pulsar PSR 1957+20 alter both the magnitude and color of the companion star. Some of the blue stragglers (BSs) recently discovered in dense globular clusters can be irradiated stars in binaries containing powerful millisecond pulsars. The discovery of pulsar-driven orbital modulations of BS brightness and color with periods of a few hours together with evidence for radio and/or gamma-ray emission from BS binaries would valuably contribute to the understanding of the evolution of collapsed stars in globular clusters. Pulsar-driven optical modulation of cluster stars might be the only observable effect of a new class of binary pulsars, i.e., hidden millisecond pulsars enshrouded in the evaporated material lifted off from the irradiated companion star.

  15. Temperature Measurements of Dense Plasmas by Detailed Balance

    International Nuclear Information System (INIS)

    Holl, A; Redmer, R; Ropke, G; Reinholz, H; Thiele, R; Fortmann, C; Forster, E; Cao, L; Tschentscher, T; Toleikis, S; Glenzer, S H

    2006-01-01

    Plasmas at high electron densities of n e = 10 20 - 10 26 cm -3 and moderate temperatures T e = 1 - 20 eV are important for laboratory astrophysics, high energy density science and inertial confinement fusion. These plasmas are usually referred to as Warm Dense Matter (WDM) and are characterized by a coupling parameter of Λ ∼> 1 where correlations become important. The characterization of such plasmas is still a challenging task due to the lack of direct measurement techniques for temperatures and densities. They propose to measure the Thomson scattering spectrum of vacuum-UV radiation off density fluctuations in the plasma. Collective Thomson scattering provides accurate data for the electron temperature applying first principles. Further, this method takes advantage of the spectral asymmetry resulting from detailed balance and is independent of collisional effects in these dense systems

  16. Isolation and morphological characterization of antibiotic producing ...

    African Journals Online (AJOL)

    Purpose: To isolate and characterize antibiotic producing actinomycetes from soil samples in Belgaum, Karnataka, India. Methods: Crowded plate technique was used for the isolation of actinomycetes in media such as soybean – casein digest medium and actinomycetes isolation agar. The morphological and cultural ...

  17. The EOS and neutrino interactions in dense matter

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, M; Reddy, S [Dept. of Physics and Astronomy, SUNY at Stony Brook, Stony Brook, NY (United States)

    1998-06-01

    The deleptonization and cooling times of a newly born neutron star depend on the equation of state (EOS) and neutrino opacities in dense matter. Through model calculations we show that effects of Pauli blocking and many-body correlations due to strong interactions reduce both the neutral and charged current neutrino cross sections by large factors compared to the case in which these effects are ignored. (orig.)

  18. Efficient and Invariant Convolutional Neural Networks for Dense Prediction

    OpenAIRE

    Gao, Hongyang; Ji, Shuiwang

    2017-01-01

    Convolutional neural networks have shown great success on feature extraction from raw input data such as images. Although convolutional neural networks are invariant to translations on the inputs, they are not invariant to other transformations, including rotation and flip. Recent attempts have been made to incorporate more invariance in image recognition applications, but they are not applicable to dense prediction tasks, such as image segmentation. In this paper, we propose a set of methods...

  19. Nucleation of strange matter in dense stellar cores

    International Nuclear Information System (INIS)

    Horvath, J.E.; Benvenuto, O.G.; Vucetich, H.

    1992-01-01

    We investigate the nucleation of strange quark matter inside hot, dense nuclear matter. Applying Zel'dovich's kinetic theory of nucleation we find a lower limit of the temperature T for strange-matter bubbles to appear, which happens to be satisfied inside the Kelvin-Helmholtz cooling era of a compact star life but not much after it. Our bounds thus suggest that a prompt conversion could be achieved, giving support to earlier expectations for nonstandard type-II supernova scenarios

  20. New look at radiative association in dense interstellar clouds

    International Nuclear Information System (INIS)

    Herbst, E.

    1980-01-01

    A corrected statistical theory of radiative association reactions is presented and discussed. Calculations are undertaken to determine the rate coefficients of a variety of radiative association reactions of possible importance in dense interstellar clouds. Our results confirm the suggestion of Smith and Adams that certain radiative association reactions occur quite rapidly at low temperature and are probably important in the synthesis of complex interstellar molecules

  1. Proton Radiography for the Diagnostics of a Dense Plasma

    Science.gov (United States)

    Barminova, H. Y.

    2017-12-01

    The possibility of using high-energy proton radiography for dense plasma diagnostics is discussed. The designed telescopic ion optical system for a proton radiography installation with a 1 GeV beam is presented. The schematic diagram of the proton microscope is given. It is shown that the estimate of spatial resolution for the installation obtained with consideration of chromatic aberrations of magnetic quadrupole lenses is limited from below.

  2. Studies of RF Breakdown of Metals in Dense Gases

    CERN Document Server

    Hanlet, Pierrick M; Ankenbrandt, Charles; Johnson, Rolland P; Kaplan, Daniel; Kuchnir, Moyses; Moretti, Alfred; Paul, Kevin; Popovic, Milorad; Yarba, Victor; Yonehara, Katsuya

    2005-01-01

    A study of RF breakdown of metals in gases has begun as part of a program to develop RF cavities filled with dense hydrogen gas to be used for muon ionization cooling. A pressurized 800 MHz test cell has been used at Fermilab to compare the conditioning and breakdown behavior of copper, molybdenum, chromium, and beryllium electrodes as functions of hydrogen and helium gas density. These results are compared to the predicted or known RF breakdown behavior of these metals in vacuum.

  3. Vortex structures in dense electron-positron-ion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Q [Theoretical Plasma Physics Division, PINSTECH, P O Nilore, Islamabad (Pakistan)], E-mail: qamar_haque@hotmail.com

    2009-11-15

    A linear dispersion relation for electrostatic quantum drift and acoustic waves has been found for dense electron-positron-ion magnetoplasmas. Both the fermion and thermal temperature effects have been considered for electrons and positrons. In the nonlinear regime, a stationary solution in the form of dipolar vortices has been obtained. For illustration, the results were applied to the astrophysical plasma of the atmosphere of neutron stars/pulsars.

  4. Non-dense domain operator matrices and Cauchy problems

    International Nuclear Information System (INIS)

    Lalaoui Rhali, S.

    2002-12-01

    In this work, we study Cauchy problems with non-dense domain operator matrices. By assuming that the entries of an unbounded operator matrix are Hille-Yosida operators, we give a necessary and sufficient condition ensuring that the part of this operator matrix generates a semigroup in the closure of its domain. This allows us to prove the well-posedness of the corresponding Cauchy problem. Our results are applied to delay and neutral differential equations. (author)

  5. Memory-efficient analysis of dense functional connectomes

    Directory of Open Access Journals (Sweden)

    Kristian Loewe

    2016-11-01

    Full Text Available The functioning of the human brain relies on the interplay and integration of numerous individual units within a complex network. To identify network configurations characteristic of specific cognitive tasks or mental illnesses, functional connectomes can be constructed based on the assessment of synchronous fMRI activity at separate brain sites, and then analyzed using graph-theoretical concepts. In most previous studies, relatively coarse parcellations of the brain were used to define regions as graphical nodes. Such parcellated connectomes are highly dependent on parcellation quality because regional and functional boundaries need to be relatively consistent for the results to be interpretable. In contrast, dense connectomes are not subject to this limitation, since the parcellation inherent to the data is used to define graphical nodes, also allowing for a more detailed spatial mapping of connectivity patterns. However, dense connectomes are associated with considerable computational demands in terms of both time and memory requirements. The memory required to explicitly store dense connectomes in main memory can render their analysis infeasible, especially when considering high-resolution data or analyses across multiple subjects or conditions. Here, we present an object-based matrix representation that achieves a very low memory footprint by computing matrix elements on demand instead of explicitly storing them. In doing so, memory required for a dense connectome is reduced to the amount needed to store the underlying time series data. Based on theoretical considerations and benchmarks, different matrix object implementations and additional programs (based on available Matlab functions and Matlab-based third-party software are compared with regard to their computational efficiency in terms of memory requirements and computation time. The matrix implementation based on on-demand computations has very low memory requirements thus enabling

  6. Memory-Efficient Analysis of Dense Functional Connectomes.

    Science.gov (United States)

    Loewe, Kristian; Donohue, Sarah E; Schoenfeld, Mircea A; Kruse, Rudolf; Borgelt, Christian

    2016-01-01

    The functioning of the human brain relies on the interplay and integration of numerous individual units within a complex network. To identify network configurations characteristic of specific cognitive tasks or mental illnesses, functional connectomes can be constructed based on the assessment of synchronous fMRI activity at separate brain sites, and then analyzed using graph-theoretical concepts. In most previous studies, relatively coarse parcellations of the brain were used to define regions as graphical nodes. Such parcellated connectomes are highly dependent on parcellation quality because regional and functional boundaries need to be relatively consistent for the results to be interpretable. In contrast, dense connectomes are not subject to this limitation, since the parcellation inherent to the data is used to define graphical nodes, also allowing for a more detailed spatial mapping of connectivity patterns. However, dense connectomes are associated with considerable computational demands in terms of both time and memory requirements. The memory required to explicitly store dense connectomes in main memory can render their analysis infeasible, especially when considering high-resolution data or analyses across multiple subjects or conditions. Here, we present an object-based matrix representation that achieves a very low memory footprint by computing matrix elements on demand instead of explicitly storing them. In doing so, memory required for a dense connectome is reduced to the amount needed to store the underlying time series data. Based on theoretical considerations and benchmarks, different matrix object implementations and additional programs (based on available Matlab functions and Matlab-based third-party software) are compared with regard to their computational efficiency. The matrix implementation based on on-demand computations has very low memory requirements, thus enabling analyses that would be otherwise infeasible to conduct due to

  7. Single-shot optical conductivity measurement of dense aluminum plasmas

    International Nuclear Information System (INIS)

    Churina, I. V.; Cho, B.-I.; Bernstein, A.; Stoker, D. S.; Dalton, A.; Symes, D. R.; Ditmire, T.

    2009-01-01

    The optical conductivity of a dense femtosecond laser-heated aluminum plasma heated to 0.1-1.5 eV was measured using frequency-domain interferometry with chirped pulses, permitting simultaneous observation of optical probe reflectivity and probe pulse phase shift. Coupled with published models of bound-electron contributions to the conductivity, these two independent experimental data yielded a direct measurement of both real and imaginary components of the plasma conductivity.

  8. Interaction between laser-produced plasma and guiding magnetic field

    International Nuclear Information System (INIS)

    Hasegawa, Jun; Takahashi, Kazumasa; Ikeda, Shunsuke; Nakajima, Mitsuo; Horioka, Kazuhiko

    2013-01-01

    Transportation properties of laser-produced plasma through a guiding magnetic field were examined. A drifting dense plasma produced by a KrF laser was injected into an axisymmetric magnetic field induced by permanent ring magnets. The plasma ion flux in the guiding magnetic field was measured by a Faraday cup at various distances from the laser target. Numerical analyses based on a collective focusing model were performed to simulate plasma particle trajectories and then compared with the experimental results. (author)

  9. Magnetic fields and dense chromospheres in dMe stars

    International Nuclear Information System (INIS)

    Mullan, D.J.

    1975-01-01

    We examine in a semi-quantitative fashion the hypothesis that dense chromospheres of dMe stars are heated by dissipation of hydromagnetic waves. We propose that dMe stars are a set of magnetic stars on the lower main sequence, with strong fields presumably generated by dynamo action in deep convective envelopes. We discuss how the combination of magnetic fields and dense chromospheres in dMe stars provides a consistent interpretation of the following features: 1) The dMe stars which are most likely to be flares stars are those with hydrogen lines in emission. However, it is proposed that in certain conditions, Balmer lines may appear in absorption, and we suggest that 'negative flares' can be explained at least in part by the occurrence of strong absorption in Hα. 2) The propagation of flare-initiated coronal waves can trigger sympathetic stellar flares. 3) Apart from flare activity, emission line strengths in dMe stars must exhibit time variations due to the emergence of new magnetic flux ropes through the stellar surface. 4) The combination of strong magnetic fields with dense chromospheres makes the Faraday rotation measure large enough to have potentially a detectable effect on polarized visible light. 5) It is suggested that grain formation occurs in starspots on dMe stars. (orig./WL) [de

  10. Rheology of dense suspensions of non colloidal particles

    Science.gov (United States)

    Guazzelli, Élisabeth

    2017-06-01

    Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers) or non-Newtonian fluids that we will also address.

  11. Rheology of dense suspensions of non colloidal particles

    Directory of Open Access Journals (Sweden)

    Guazzelli Élisabeth

    2017-01-01

    Full Text Available Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing and in natural phenomena (e.g. flows of slurries, debris, and lava. Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers or non-Newtonian fluids that we will also address.

  12. On parametrised cold dense matter equation of state inference

    Science.gov (United States)

    Riley, Thomas E.; Raaijmakers, Geert; Watts, Anna L.

    2018-04-01

    Constraining the equation of state of cold dense matter in compact stars is a major science goal for observing programmes being conducted using X-ray, radio, and gravitational wave telescopes. We discuss Bayesian hierarchical inference of parametrised dense matter equations of state. In particular we generalise and examine two inference paradigms from the literature: (i) direct posterior equation of state parameter estimation, conditioned on observations of a set of rotating compact stars; and (ii) indirect parameter estimation, via transformation of an intermediary joint posterior distribution of exterior spacetime parameters (such as gravitational masses and coordinate equatorial radii). We conclude that the former paradigm is not only tractable for large-scale analyses, but is principled and flexible from a Bayesian perspective whilst the latter paradigm is not. The thematic problem of Bayesian prior definition emerges as the crux of the difference between these paradigms. The second paradigm should in general only be considered as an ill-defined approach to the problem of utilising archival posterior constraints on exterior spacetime parameters; we advocate for an alternative approach whereby such information is repurposed as an approximative likelihood function. We also discuss why conditioning on a piecewise-polytropic equation of state model - currently standard in the field of dense matter study - can easily violate conditions required for transformation of a probability density distribution between spaces of exterior (spacetime) and interior (source matter) parameters.

  13. Rheological Behavior of Dense Assemblies of Granular Materials

    International Nuclear Information System (INIS)

    Sundaresan, Sankaran; Tardos, Gabriel I.; Subramaniam, Shankar

    2011-01-01

    Assemblies of granular materials behave differently when they are owing rapidly, from when they are slowly deforming. The behavior of rapidly owing granular materials, where the particle-particle interactions occur largely through binary collisions, is commonly related to the properties of the constituent particles through the kinetic theory of granular materials. The same cannot be said for slowly moving or static assemblies of granular materials, where enduring contacts between particles are prevalent. For instance, a continuum description of the yield characteristics of dense assemblies of particles in the quasistatic ow regime cannot be written explicitly on the basis of particle properties, even for cohesionless particles. Continuum models for this regime have been proposed and applied, but these models typically assume that the assembly is at incipient yield and they are expressed in terms of the yield function, which we do not yet know how to express in terms of particle-level properties. The description of the continuum rheology in the intermediate regime is even less understood. Yet, many practically important flows in nature and in a wide range of technological applications occur in the dense flow regime and at the transition between dilute and dense regimes; the lack of validated continuum rheological models for particle assemblies in these regimes limits predictive modeling of such flows. This research project is aimed at developing such rheological models.

  14. Isotopologues of dense gas tracers in NGC 1068

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junzhi; Qiu, Jianjie [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, 200030, Shanghai (China); Zhang, Zhi-Yu [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Shi, Yong [School of Astronomy and Space Science, Nanjing University, Nanjing, 210093 (China); Zhang, Jiangshui [Center For Astrophysics, GuangZhou University, 510006, GuangZhou (China); Fang, Min, E-mail: jzwang@shao.ac.cn [ESO, Karl Schwarzschild Strasse 2, D-85748 Garching bei Munich (Germany)

    2014-11-20

    We present observations of isotopic lines of dense gas tracers toward the nuclear region of nearby Seyfert 2 galaxy NGC 1068 with the IRAM 30 m telescope and the Atacama Pathfinder Experiment (APEX) 12 m telescope. We detected four isotopic lines (H{sup 13}CN 1-0, H{sup 13}CO{sup +} 1-0, HN{sup 13}C 1-0, and HC{sup 18}O{sup +} 1-0) at the 3 mm band with the IRAM 30 m telescope and obtained upper limits of other lines. We calculated optical depths of dense gas tracers with the detected isotopic lines of HCN 1-0, HCO{sup +} 1-0, and HNC 1-0. We find that the {sup 14}N/{sup 15}N abundance ratio is greater than 420 if we adopt the upper limit of HC{sup 15}N(1-0) emission. Combining this with fluxes of 1-0 lines from IRAM 30 m observations and the upper limit of 3-2 lines from APEX 12 m observations, we also estimated the excitation condition of molecular gas in the nuclear region of NGC 1068, which is less dense than that in the extreme starburst regions of galaxies.

  15. Wet skins tanning with chromium in dense CO2 under pressure

    International Nuclear Information System (INIS)

    Saldinari, L.; Dutel, Ch.; Perre, Ch.

    2000-01-01

    An ancestral gesture steadily improved through the centuries, the transformation of skins into leather includes several stages of which the principal one is tanning. Today, 90 % of the world's leather products are tanned with chromium. However, this stage is an environmental liability, and reducing the volume and chromium content of the waste has become a major issue. A first study on skin degreasing by dense CO 2 helped sharply reduce the volume of the fatty effluents. To replace water by dense CO 2 as the tanning medium was the logical next step. The present study was carried out in cooperation with three tanneries in the Rhone-Alpes-Auvergne area of France and a manufacturer of tanning materials. The difficulty of the study was the chemically opposed character of the two media involved. CO 2 is a non-polar and lipophilic solvent while inorganic chromium is insoluble. The water present in the treated skin is a polar and ionic reaction medium and one of the reagents in tanning chemistry. The mixture of these two partially miscible compounds gives a pH 3 by carbonic acid formation. Tanning is based on the reactivity of collagen, the main component of the skin, with hydroxylated complexes of chromium. Collagen is a protein containing some chemical functions, amines (R-NH 2 ) and carboxylic (R-COOH) for example. These functions impart an amphoteric character to the compound. The WERNER theory of complex salts explains the formation of hydroxylated complexes of chromium and their fixing on the carboxylic functions of collagen by oxolation. pH is the key parameter in tanning. The success of the process demands chromium impregnation without fixing it at a pH lower than 5, and then to fix it by increasing the pH. This opened two alternatives for transferring chromium in the skin: solubilize chromium in CO 2 via soluble organometallic complexes; or put the chromium salt into suspension without solubilizing it. The best results were obtained with the second option, which

  16. Medium modifications with recoil polarization

    Energy Technology Data Exchange (ETDEWEB)

    Brand, J.F.J. van den [Nationaal Instituut voor Kernfysica en Hoge Energiefysica, Amsterdam (Netherlands); Ent, R. [CEBAF, Newport News, VA (United States)

    1994-04-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He({rvec e},e{prime},{rvec p}){sup 3}H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium.

  17. Medium modifications with recoil polarization

    International Nuclear Information System (INIS)

    Brand, J.F.J. van den; Ent, R.

    1994-01-01

    The authors show that the virtual Compton scattering process allows for a precise study of the off-shell electron-nucleon vertex. In a separable model, they show the sensitivity to new unconstrained structure functions of the nucleon, beyond the usual Dirac and Pauli form factors. In addition, they show the sensitivity to bound nucleon form factors using the reaction 4He(rvec e,e',rvec p) 3 H. A nucleon embedded in a nucleus represents a complex system. Firstly, the bound nucleon is necessarily off-shell and in principle a complete understanding of the dynamical structure of the nucleon is required in order to calculate its off-shell electromagnetic interaction. Secondly, one faces the possibility of genuine medium effects, such as for example quark-exchange contributions. Furthermore, the electromagnetic coupling to the bound nucleon is dependent on the nuclear dynamics through the self-energy of the nucleon in the nuclear medium

  18. Mn nanoparticles produced by inert gas condensation

    International Nuclear Information System (INIS)

    Ward, M B; Brydson, R; Cochrane, R F

    2006-01-01

    The results from experiments using the inert gas condensation method to produce nanoparticles of manganese are presented. Structural and compositional data have been collected through electron diffraction, EDX (energy dispersive X-ray) and EELS (electron energy loss spectroscopy). Both Mn 3 O 4 and pure Mn particles have been produced. Moisture in untreated helium gas causes the particles to oxidize, whereas running the helium through a liquid nitrogen trap removes the moisture and produces β-Mn particles in a metastable state. The particle sizes and the size distribution have been determined. Particle sizes range from 2nm to above 100 nm, however the majority of particles lie in the range below 20 nm with a modal particle size of 6 nm. As well as the modal particle size of 6 nm, there is another peak in the frequency curve at 16 nm that represents another group particles that lie in the range 12 to 20 nm. The smaller particles are single crystals, but the larger particles appear to have a dense region around their edge with a less dense centre. Determination of their exact nature is ongoing

  19. [Antimicrobial Activity of Substances Produced by Trichoderma citrinoviride Strain VKPM F-1228: Optimization of Cultivation and Assessment of Spectrum of Individual Peptaibols].

    Science.gov (United States)

    Sadykova, V S; Kurakov, A V; Korshun, V A; Rogozhin, E A; Gromovykh, T I; Kuvarina, A E; Baranova, A A

    2015-01-01

    The Trichoderma citrinoviride VKPM F-1228 strain produces a complex of peptide-based antibiotics with antibacterial and antimycotic action. Synthesis of peptaibols is closely related to the conidiogenesis in the culture. The optimal procedure of the strain cultivation for production of peptaibols is stationary growing for 14 days at a temperature of 28 degrees C and pH 7.5 followed by formation of a dense mycelium film on the modified Saburo medium containing 30 gr/l of glucose and 12.5 gr/l of peptone. Eight individual peptaibols were extracted. The spectrum of their activity was estimated with the use of opportunistic bacteria and micromycetes as well as pathogenic clinical aspergilli. Compounds 9, 13, 14, 15 and 16 were shown active against opportunistic fungi and bacteria including methicillin resistant S. aureus, whereas compounds 9, 13 and 14 in addition showed antimycotic activity against clinical aspergilli.

  20. Medium Duty Electric Vehicle Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, Robin J. D. [Smith Electric Vehicles Corporation, Kansas City, MO (United States)

    2015-05-31

    The Smith Electric Vehicle Demonstration Project (SDP) was integral to the Smith business plan to establish a manufacturing base in the United States (US) and produce a portfolio of All Electric Vehicles (AEV’s) for the medium duty commercial truck market. Smith focused on the commercial depot based logistics market, as it represented the market that was most ready for the early adoption of AEV technology. The SDP enabled Smith to accelerate its introduction of vehicles and increase the size of its US supply chain to support early market adoption of AEV’s that were cost competitive, fully met the needs of a diverse set of end users and were compliant with Federal safety and emissions requirements. The SDP accelerated the development and production of various electric drive vehicle systems to substantially reduce petroleum consumption, reduce vehicular emissions of greenhouse gases (GHG), and increase US jobs.

  1. Cosmic rays and the interstellar medium

    International Nuclear Information System (INIS)

    Wolfendale, A.W.

    1986-01-01

    It is inevitable that there is a close connection between cosmic rays and the ISM insofar as the propagation of cosmic rays is conditioned by the magnetic field in the ISM and the cosmic rays interact with the gas (and photon fluxes) in this medium. This paper deals with both topics. Propagation effects manifest themselves as an anisotropy in arrival directions and a review is given of anisotropy measurements and their interpretation. The status of studies of cosmic ray interactions is examined whit particular reference to the information about the ISM itself which comes from observations of the flux of secondary γ-rays produced by cosmic ray interactions with gas, the situation regarding molecular as in the Inner Galaxy being of particular concern

  2. Light Vector Mesons in the Nuclear Medium

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen

    2008-07-01

    The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff

  3. Medium Theory and Social Systems

    DEFF Research Database (Denmark)

    Tække, Jesper

      the  possibility  for  observation both of a social micro and a social macro level from a medium perspective. In the next  section  the paper  frames  the macro  level by  a  tentative  synthesis of  the medium  theory  and  the  sociological systems theory briefly describing a socio......-evolutionary process where new media alter  the societal capacity to handle complexity  in  time and space.  In  this section it becomes probable  that  by  means  of  different  media,  social  systems  give  different  possibilities  for  actual  social  performance.  In a way,  social  systems  themselves can be......  seen as medium  for  formation. Finally  the  paper  takes  the micro  level  perspective  by  applying  the  theory  to  newsgroups,  interpreting  them as self-organizing interactive systems giving a differentiated and diversified scope for social  inclusion.  ...

  4. Lattice Boltzmann Simulation of Permeability and Tortuosity for Flow through Dense Porous Media

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2014-01-01

    Full Text Available Discrete element method (DEM is used to produce dense and fixed porous media with rigid mono spheres. Lattice Boltzmann method (LBM is adopted to simulate the fluid flow in interval of dense spheres. To simulating the same physical problem, the permeability is obtained with different lattice number. We verify that the permeability is irrelevant to the body force and the media length along flow direction. The relationships between permeability, tortuosity and porosity, and sphere radius are researched, and the results are compared with those reported by other authors. The obtained results indicate that LBM is suited to fluid flow simulation of porous media due to its inherent theoretical advantages. The radius of sphere should have ten lattices at least and the media length along flow direction should be more than twenty radii. The force has no effect on the coefficient of permeability with the limitation of slow fluid flow. For mono spheres porous media sample, the relationship of permeability and porosity agrees well with the K-C equation, and the tortuosity decreases linearly with increasing porosity.

  5. Fluorescence and absorption spectroscopy for warm dense matter studies and ICF plasma diagnostics

    Science.gov (United States)

    Hansen, Stephanie

    2017-10-01

    The burning core of an inertial confinement fusion (ICF) plasma at stagnation is surrounded by a shell of warm, dense matter whose properties are difficult both to model (due to a complex interplay of thermal, degeneracy, and strong coupling effects) and to diagnose (due to low emissivity and high opacity). We demonstrate a promising technique to study the warm dense shells of ICF plasmas based on the fluorescence emission of dopants or impurities in the shell material. This emission, which is driven by x-rays produced in the hot core, exhibits signature changes in response to compression and heating. High-resolution measurements of absorption and fluorescence features can refine our understanding of the electronic structure of material under high compression, improve our models of density-driven phenomena such as ionization potential depression and plasma polarization shifts, and help diagnose shell density, temperature, mass distribution, and residual motion in ICF plasmas at stagnation. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This work was supported by the U.S. Department of Energy, Office of Science Early Career Research Program, Office of Fusion Energy Sciences under FWP-14-017426.

  6. The importance of modeling nonhydrostatic processes for dense water reproduction in the Southern Adriatic Sea

    Science.gov (United States)

    Bellafiore, Debora; McKiver, William J.; Ferrarin, Christian; Umgiesser, Georg

    2018-05-01

    Dense water (DW) formation commonly occurs in the shallow Northern Adriatic Sea during winter outbreaks, when there is a combination of the cooling of surface waters by the winds and high salinity as a result of reduced river inputs. These DWs subsequently propagate southwards over a period of weeks/months, eventually arriving in the Southern Adriatic Sea. The investigation is based on a new nonhydrostatic (NH) formulation of the 3D finite element model SHYFEM that is validated for a number of theoretical test cases. Subsequently this model is used to simulate, through high-resolution numerical simulations, an extreme DW event that occurred in the Adriatic Sea in 2012. We perform both hydrostatic (HY) and NH simulations in order to explicitly see the impact of NH processes on the DW dynamics. The modeled results are compared to observations collected in the field campaign of March-April 2012 in the Southern Adriatic Sea. The NH run correctly reproduces the across isobath bottom-trapped gravity current characterizing the canyon DW pathways. It also more accurately captures the frequency and intensity of dense water cascading pulsing events, as the inclusion of NH processes produces stronger currents with different DW mixing characteristics. Finally, the NH run simulates internal gravity waves (IGW), generated during the cascading at the edge of the canyon, which propagate downslope. This IGW activity is not captured in the HY case.

  7. Medium energy ion scattering (MEIS)

    International Nuclear Information System (INIS)

    Dittmann, K.; Markwitz, A.

    2009-01-01

    This report gives an overview about the technique and experimental study of medium energy ion scattering (MEIS) as a quantitative technique to determine and analyse the composition and geometrical structure of crystalline surfaces and near surface-layers by measuring the energy and yield of the backscattered ions. The use of a lower energy range of 50 to 500 keV accelerated ions impinging onto the target surface and the application of a high-resolution electrostatic energy analyser (ESA) makes medium energy ion scattering spectroscopy into a high depth resolution and surface-sensitive version of RBS with less resulting damage effects. This report details the first steps of research in that field of measurement technology using medium energetic backscattered ions detected by means of a semiconductor radiation detector instead of an ESA. The study of medium energy ion scattering (MEIS) has been performed using the 40 keV industrial ion implanter established at GNS Sciences remodelled with supplementary high voltage insulation for the ion source in order to apply voltages up to 45 kV, extra apertures installed in the beamline and sample chamber in order to set the beam diameter accurately, and a semiconductor radiation detector. For measurement purposes a beam of positive charged helium ions accelerated to an energy of about 80 keV has been used impinging onto target surfaces of lead implanted into silicon (PbSi), scandium implanted into aluminium (ScAl), aluminium foil (Al) and glassy carbon (C). First results show that it is possible to use the upgraded industrial implanter for medium energy ion scattering. The beam of 4 He 2+ with an energy up to 88 keV has been focussed to 1 mm in diameter. The 5 nA ion beam hit the samples under 2 x 10 -8 mbar. The results using the surface barrier detector show scattering events from the samples. Cooling of the detector to liquid nitrogen temperatures reduced the electronic noise in the backscattering spectrum close to zero. A

  8. Prediction of a Densely Loaded Particle-Laden Jet using a Euler-Lagrange Dense Spray Model

    Science.gov (United States)

    Pakseresht, Pedram; Apte, Sourabh V.

    2017-11-01

    Modeling of a dense spray regime using an Euler-Lagrange discrete-element approach is challenging because of local high volume loading. A subgrid cluster of droplets can lead to locally high void fractions for the disperse phase. Under these conditions, spatio-temporal changes in the carrier phase volume fractions, which are commonly neglected in spray simulations in an Euler-Lagrange two-way coupling model, could become important. Accounting for the carrier phase volume fraction variations, leads to zero-Mach number, variable density governing equations. Using pressure-based solvers, this gives rise to a source term in the pressure Poisson equation and a non-divergence free velocity field. To test the validity and predictive capability of such an approach, a round jet laden with solid particles is investigated using Direct Numerical Simulation and compared with available experimental data for different loadings. Various volume fractions spanning from dilute to dense regimes are investigated with and without taking into account the volume displacement effects. The predictions of the two approaches are compared and analyzed to investigate the effectiveness of the dense spray model. Financial support was provided by National Aeronautics and Space Administration (NASA).

  9. Elaboration and evaluation of a new screening medium for detection and presumptive identification of extended-spectrum beta-lactamase-producing organisms (ESBL Elaboração e avaliação de um novo meio de triagem para a detecção e identificação presuntiva de enterobactérias produtoras de beta-lactamase de espectro estendido (ESBL

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Pessôa de Menezes e Silva

    2000-10-01

    Full Text Available The new ß-lactamases have arisen largely as a consequence of heavy use of new expanded spectrum ß-lactam antibiotics. Health professionals need to be aware of the resistance problems caused by the new enzymes, and know the correct procedures to detect, prevent and control such problems. In this study, a new screening medium called Ceftazidime-Inositol-Vancomycin-Amphotericin B Agar (CIVA was elaborated and the microbiological performance was evaluated for the detection and presumptive identification of ESBL-producing members of Enterobacteriaceae. It was performed in 126 stool samples from hospitalized patients at Santa Monica Hospital (Vila Velha, ES, Brazil, who had been heavily exposed to broad-spectrum antibiotic combinations. The bacteria were detected by the medium based on their colony colours (due to inositol fermentation. Additional tests were required for correct identification of these strains. No false positive rates were detected.As novas beta-lactamases têm aparecido, na maioria das vezes, como consequência do amplo uso de antibióticos beta-lactâmicos de largo espectro. Os profissionais de saúde precisam estar atentos acerca do problema da resistência bacteriana causado por estas novas enzimas e conhecer os corretos procedimentos para detectar, prevenir e controlar tais situações. Neste estudo, um novo meio de triagem foi desenvolvido no setor de Microbiologia do Marcos Daniel Laboratório - Vitória, ES (denominado CIVA - Ceftazidima-Inositol-Vancomicina-Anfotericina B e a sua performance microbiológica foi avaliada quanto à detecção e identificação presuntiva de enterobactérias produtoras de ESBL. Foram realizadas 126 culturas de amostras fecais de pacientes hospitalizados no Hospital Santa Monica (Vila Velha, ES, Brasil, previamente expostos a combinações de antibióticos de largo espectro. As bactérias foram detectadas pelo meio baseado nas cores das colônias desenvolvidas (devido à fermentação do

  10. Study of dense-plasma properties using very high-frequency electromagnetic waves (light waves); Etude des proprietes des plasmas denses au moyen d'ondes electromagnetiques de tres haute frequence (ondes lumineuses)

    Energy Technology Data Exchange (ETDEWEB)

    Gormezano, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    A study is made of methods based on the use of lasers for measuring the electronic density and temperature of dense plasmas (N{sub e} > 10{sup 15}e/cm{sup 3}): - an interferometric method using a gas laser, based on the. properties of the Perot-Fabry cavities; - a method making use of the 90 deg C scattering produced by the plasma on light emitted by a ruby laser. These methods have been applied to various dense plasmas: - high-frequency plasma torch; - azimuth compression; - plasma bursts produced by focussing a laser beam on a metal target. The measurements have also been carried out using conventional methods of diagnosis. It has thus been possible to measure densities of between 5.10{sup 15} and 10{sup 19} e/cm{sup 3} and temperatures of between 3 and 10 eV. These different-methods are then compared, (author) [French] On etudie la mesure de la densite et de la temperature electronique des plasmas denses (N{sub e} > 10{sup 15} e/cm{sup 3}) a I'aide de methodes utilisant des lasers: - une methode interferometrique utilisant un laser a gaz, basee sur les proprietes des cavites Perot Fabry; -- une methode utilisant la diffusion a 900 deg C par le plasma de la lumiere issue d'un laser a rubis. Ces methodes ont ete appliquees sur differents plasmas denses: - Torche a plasma haute-frequence; - Compression azimutale; - Bouffees de plasma produites par la focalisation d'un faisceau laser sur une cible metallique. Les mesures ont ete egalement faites a I'aide de diagnostics classiques. On a pu ainsi mesurer des densites comprises entre 5.10{sup 15} et 10{sup 19} e/cm{sup 3} et des temperatures comprises entre 3 et 10 eV. On compare ensuite ces differentes methodes. (auteur)

  11. Study of dense-plasma properties using very high-frequency electromagnetic waves (light waves); Etude des proprietes des plasmas denses au moyen d'ondes electromagnetiques de tres haute frequence (ondes lumineuses)

    Energy Technology Data Exchange (ETDEWEB)

    Gormezano, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    A study is made of methods based on the use of lasers for measuring the electronic density and temperature of dense plasmas (N{sub e} > 10{sup 15}e/cm{sup 3}): - an interferometric method using a gas laser, based on the. properties of the Perot-Fabry cavities; - a method making use of the 90 deg C scattering produced by the plasma on light emitted by a ruby laser. These methods have been applied to various dense plasmas: - high-frequency plasma torch; - azimuth compression; - plasma bursts produced by focussing a laser beam on a metal target. The measurements have also been carried out using conventional methods of diagnosis. It has thus been possible to measure densities of between 5.10{sup 15} and 10{sup 19} e/cm{sup 3} and temperatures of between 3 and 10 eV. These different-methods are then compared, (author) [French] On etudie la mesure de la densite et de la temperature electronique des plasmas denses (N{sub e} > 10{sup 15} e/cm{sup 3}) a I'aide de methodes utilisant des lasers: - une methode interferometrique utilisant un laser a gaz, basee sur les proprietes des cavites Perot Fabry; -- une methode utilisant la diffusion a 900 deg C par le plasma de la lumiere issue d'un laser a rubis. Ces methodes ont ete appliquees sur differents plasmas denses: - Torche a plasma haute-frequence; - Compression azimutale; - Bouffees de plasma produites par la focalisation d'un faisceau laser sur une cible metallique. Les mesures ont ete egalement faites a I'aide de diagnostics classiques. On a pu ainsi mesurer des densites comprises entre 5.10{sup 15} et 10{sup 19} e/cm{sup 3} et des temperatures comprises entre 3 et 10 eV. On compare ensuite ces differentes methodes. (auteur)

  12. Screening of yeasts capable of producing cellulase-free xylanase

    African Journals Online (AJOL)

    Professor

    2015-06-10

    Jun 10, 2015 ... of their ability to degrade xylan, which was found in the medium by using agar degradation halos, the ... These enzymes are produced by molds, bacteria, yeasts ... collected, stored in sterile plastic bags and transported under.

  13. Cashew apple juice as microbial cultivation medium for non-immunogenic hyaluronic acid production

    OpenAIRE

    Oliveira, Adriano H.; Ogrodowski, Cristiane C.; de Macedo, André C.; Santana, Maria Helena A.; Gonçalves, Luciana R.B.

    2014-01-01

    In this work, natural cashew apple juice was used as cultivation medium as an alternative to substitute brain heart infusion medium. The effect of aeration and juice supplementation with yeast extract on the production of hyaluronic acid in batch fermentation was also investigated. Similar levels of cell mass were obtained in inoculum using cashew apple juice supplemented with yeast extract or the conventional brain heart infusion medium. Fermentation in Erlenmeyer flasks produced low biomass...

  14. Parton fragmentation in the vacuum and in the medium

    CERN Document Server

    Albino, S.; Arleo, F.; Besson, Dave Z.; Brooks, William K.; Buschbeck, B.; Cacciari, M.; Christova, E.; Corcella, G.; D'Enterria, David G.; Dolejsi, Jiri; Domdey, S.; Estienne, M.; Hamacher, Klaus; Heinz, M.; Hicks, K.; Kettler, D.; Kumano, S.; Moch, S.O.; Muccifora, V.; Pacetti, S.; Perez-Ramos, R.; Pirner, H.J.; Pronko, Alexandre Pavlovich; Radici, M.; Rak, J.; Roland, C.; Rudolph, Gerald; Rurikova, Z.; Salgado, C.A.; Sapeta, S.; Saxon, David H.; Seidl, Ralf-Christian; Seuster, R.; Stratmann, M.; Tannenbaum, Michael J.; Tasevsky, M.; Trainor, T.; Traynor, D.; Werlen, M.; Zhou, C.

    2008-01-01

    We present the mini-proceedings of the workshop on ``Parton fragmentation in the vacuum and in the medium'' held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) in February 2008. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of quark and gluon fragmentation into hadrons at different accelerator facilities (LEP, B-factories, JLab, HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) light-quark and gluon fragmentation in the vacuum including theoretical (global fits analyses and MLLA) and experimental (data from e+e-, p-p, e-p collisions) aspects, (ii) strange and heavy-quark fragmentation, (iii) parton fragmentation in cold QCD matter (nuclear DIS), and (iv) medium-modified fragmentation in hot and dense QCD matter (high-energy nucleus-nucleus collisions). These mini-proceedings consist of an introduction and short summ...

  15. 1991 US-Japan workshop on Nuclear Fusion in Dense Plasmas

    International Nuclear Information System (INIS)

    Ichimaru, S.; Tajima, T.

    1991-10-01

    The scientific areas covered at the Workshop may be classified into the following subfields: (1) basic theory of dense plasma physics and its interface with atomic physics and nuclear physics; (2) physics of dense z-pinches, ICF plasmas etc; (3) stellar interior plasmas; (4) cold fusion; and (5) other dense plasmas

  16. Accretion from an inhomogeneous medium

    International Nuclear Information System (INIS)

    Livio, M.; Soker, N.; Koo, M. de; Savonije, G.J.

    1986-01-01

    The problem of accretion by a compact object from an inhomogeneous medium is studied in the general γnot=1 case. The mass accretion rate is found to decrease with increasing γ. The rate of accretion of angular momentum is found to be significantly lower than the rate at which angular momentum is deposited into the Bondi-Hoyle, symmetrical, accretion cylinder. The consequences of the results are studied for the cases of neutron stars accreting from the winds of early-type companions and white dwarfs and main-sequence stars accreting from winds of cool giants. (author)

  17. A Heterogeneous Medium Analytical Benchmark

    International Nuclear Information System (INIS)

    Ganapol, B.D.

    1999-01-01

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results

  18. Development of brachytherapy medium doserate

    International Nuclear Information System (INIS)

    Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

    2010-01-01

    Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

  19. Two-dimensional particle-in-cell simulation of the expansion of a plasma into a rarefied medium

    International Nuclear Information System (INIS)

    Sarri, G; Quinn, K; Kourakis, I; Borghesi, M; Murphy, G C; Drury, L O C; Dieckmann, M E; Ynnerman, A; Bret, A

    2011-01-01

    The expansion of a dense plasma through a more rarefied ionized medium has been studied by means of two-dimensional particle-in-cell simulations. The initial conditions involve a density jump by a factor of 100, located in the middle of an otherwise equally dense electron-proton plasma with uniform proton and electron temperatures of 10 eV and 1 keV, respectively. Simulations show the creation of a purely electrostatic collisionless shock together with an ion-acoustic soliton tied to its downstream region. The shock front is seen to evolve in filamentary structures consistently with the onset of the ion-ion instability. Meanwhile, an un-magnetized drift instability is triggered in the core part of the dense plasma. Such results explain recent experimental laser-plasma experiments, carried out in similar conditions, and are of intrinsic relevance to non-relativistic shock scenarios in the solar and astrophysical systems.

  20. Two-dimensional particle-in-cell simulation of the expansion of a plasma into a rarefied medium

    Energy Technology Data Exchange (ETDEWEB)

    Sarri, G; Quinn, K; Kourakis, I; Borghesi, M [Centre for Plasma Physics, The Queens University of Belfast, Belfast BT7 1NN (United Kingdom); Murphy, G C; Drury, L O C [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland); Dieckmann, M E; Ynnerman, A [Department of Science and Technology (ITN), Linkoeping University, 60174 Norrkoping (Sweden); Bret, A, E-mail: gsarri01@qub.ac.uk [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2011-07-15

    The expansion of a dense plasma through a more rarefied ionized medium has been studied by means of two-dimensional particle-in-cell simulations. The initial conditions involve a density jump by a factor of 100, located in the middle of an otherwise equally dense electron-proton plasma with uniform proton and electron temperatures of 10 eV and 1 keV, respectively. Simulations show the creation of a purely electrostatic collisionless shock together with an ion-acoustic soliton tied to its downstream region. The shock front is seen to evolve in filamentary structures consistently with the onset of the ion-ion instability. Meanwhile, an un-magnetized drift instability is triggered in the core part of the dense plasma. Such results explain recent experimental laser-plasma experiments, carried out in similar conditions, and are of intrinsic relevance to non-relativistic shock scenarios in the solar and astrophysical systems.

  1. Polarimetry on dense samples of spin-polarized {sup 3}He by magnetostatic detection

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, E.; Ebert, M.; Heil, W.; Surkau, R. [Mainz Univ. (Germany). Inst. fuer Physik

    1997-12-21

    A very sensitive low-field fluxgate magnetometer is used to detect the static magnetic field produced by dense samples of spin-polarized {sup 3}He gas contained in spherical glass cells at pressures around several bars. The {sup 3}He nuclear polarization can be extracted with high precision {Delta}P/P<1% by utilizing magnetostatic detection in combination with adiabatic fast-passage spin reversal. The polarization losses can be kept well below 0.1% thus making this type of polarimetry almost non-destructive. More simply even, P can be measured with reduced accuracy by the change of field when the cell is removed from the fluxgate. In this case the accuracy is limited to about 10% due to the uncertainties about the susceptibilities of the cell walls. (orig.). 29 refs.

  2. Polarimetry on dense samples of spin-polarized 3He by magnetostatic detection

    International Nuclear Information System (INIS)

    Wilms, E.; Ebert, M.; Heil, W.; Surkau, R.

    1997-01-01

    A very sensitive low-field fluxgate magnetometer is used to detect the static magnetic field produced by dense samples of spin-polarized 3 He gas contained in spherical glass cells at pressures around several bars. The 3 He nuclear polarization can be extracted with high precision ΔP/P<1% by utilizing magnetostatic detection in combination with adiabatic fast-passage spin reversal. The polarization losses can be kept well below 0.1% thus making this type of polarimetry almost non-destructive. More simply even, P can be measured with reduced accuracy by the change of field when the cell is removed from the fluxgate. In this case the accuracy is limited to about 10% due to the uncertainties about the susceptibilities of the cell walls. (orig.)

  3. Munc13 controls the location and efficiency of dense-core vesicle release in neurons.

    Science.gov (United States)

    van de Bospoort, Rhea; Farina, Margherita; Schmitz, Sabine K; de Jong, Arthur; de Wit, Heidi; Verhage, Matthijs; Toonen, Ruud F

    2012-12-10

    Neuronal dense-core vesicles (DCVs) contain diverse cargo crucial for brain development and function, but the mechanisms that control their release are largely unknown. We quantified activity-dependent DCV release in hippocampal neurons at single vesicle resolution. DCVs fused preferentially at synaptic terminals. DCVs also fused at extrasynaptic sites but only after prolonged stimulation. In munc13-1/2-null mutant neurons, synaptic DCV release was reduced but not abolished, and synaptic preference was lost. The remaining fusion required prolonged stimulation, similar to extrasynaptic fusion in wild-type neurons. Conversely, Munc13-1 overexpression (M13OE) promoted extrasynaptic DCV release, also without prolonged stimulation. Thus, Munc13-1/2 facilitate DCV fusion but, unlike for synaptic vesicles, are not essential for DCV release, and M13OE is sufficient to produce efficient DCV release extrasynaptically.

  4. Collisional particle-in-cell modeling for energy transport accompanied by atomic processes in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, R.; Beg, F. N. [Center for Energy Research, University of California, San Diego, California 92093 (United States); Leblanc, P.; Sentoku, Y. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Wei, M. S. [General Atomics, San Diego, California 92121 (United States)

    2013-07-15

    Fully relativistic collisional Particle-in-Cell (PIC) code, PICLS, has been developed to study extreme energy density conditions produced in intense laser-solid interaction. Recent extensions to PICLS, such as the implementation of dynamic ionization, binary collisions in a partially ionized plasma, and radiative losses, enhance the efficacy of simulating intense laser plasma interaction and subsequent energy transport in resistive media. Different ionization models are introduced and benchmarked against each other to check the suitability of the model. The atomic physics models are critical to determine the energy deposition and transport in dense plasmas, especially when they consist of high Z (atomic number) materials. Finally we demonstrate the electron transport simulations to show the importance of target material on fast electron dynamics.

  5. Fine focusing of intense heavy ions for the production of hot dense matter

    International Nuclear Information System (INIS)

    Heimrich, B.

    1989-02-01

    In order to perform the first experimental studies on the interaction of intense ion beams with matter an electrostatic quadrupole doublet was developed which focuses the space-charge carrying ion beam of the RFQ accelerator at the GSI Darmstadt on an area of 1 mm 2 . By an especially manufactured target holder this intense ion beam was stopped in tungsten targets and the first plasma induced by heavy ions was produced. Electrons and ions which are emitted from the plasmas have been spectroscoped by an especially for this fabricated spectrometer in their energy and time distribution in the eV region by which first comparisons between theory and praxis on the heating of dense matter by intense ion beams could be made. (orig./HSI) [de

  6. Dense granular Flows: a conceptual design of high-power neutron source

    Directory of Open Access Journals (Sweden)

    Yang Lei

    2017-01-01

    Full Text Available A high-power neutron source system is very useful for multifunctional applications, such as material facilities for advanced nuclear power, space radiation studies, radiography and tomography. Here the idea of inclined dense granular flow is utilized and developed in a new conceptual design of a compact high-power target to produce a high-energy and high-flux neutron irradiation (the flux is up to 1015 n/cm2/s or even 1016. Comparing to the traditional solid and liquid heavy metal targets, this design has advantages in material choice, fluid stability, heat removal, etc. In this paper the natures of the granular flows in an inclined chute are investigated and preliminary experimental and numerical results are reported. Then the feasibility of this design is discussed.

  7. Effect of electron degeneracy on fast-particles energy deposition in dense plasma systems

    International Nuclear Information System (INIS)

    Johzaki, T.; Nakao, Y.; Nakashima, H.; Kudo, K.

    1997-01-01

    The effects of electron degeneracy on fast-particles energy deposition in dense plasmas are investigated by making transport calculations for the fast particles. It is found that the degeneracy substantially affects the profiles of energy deposition of 3.52-MeV α-particles. On the other hand, the effect on the energy deposition of 14.1-MeV neutrons is negligibly small because the recoil ions, which transfer the neutron energy to the plasma constituents, are produced in a whole plasma volume due to the long mean-free-path of neutrons. The coupled transport-hydrodynamic calculations show that these effects of degeneracy are negligible in the ignition and burn characteristics of central ignition D-T targets. (author)

  8. Study of a dense metal membrane reactor for hydrogen separation from hydroiodic acid decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Tosti, Silvano; Borelli, Rodolfo; Borgognoni, Fabio [ENEA, Dipartimento FPN, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy); Favuzza, Paolo; Tarquini, Pietro [ENEA, Dipartimento TER, C.R. ENEA Casaccia, Via Anguillarese 301, Roma (Italy); Rizzello, Claudio [Tesi Sas, Via Bolzano 28, Roma (Italy)

    2008-10-15

    A membrane reactor has been studied for separating the hydrogen produced by the dissociation of hydroiodic acid in the thermochemical-sulfur iodine process. A dense metal membrane tube of wall thickness 0.250 mm has been considered in this analysis for hosting a fixed-bed catalyst: the selective separation of hydrogen from an azeotropic H{sub 2}O-HI mixture has been studied in the temperature range of 700-800 K. The materials being considered for the construction of the membrane tube are niobium and tantalum; as a matter of fact, the most commonly used Pd-Ag membranes cannot withstand the corrosive environment generated by the hydroiodic acid. The Damkohler-Peclet analysis has been used for designing the membrane reactor, while a finite element method has simulated its behaviour: the effect of the temperature and pressure on the HI conversion and hydrogen yield has been evaluated. (author)

  9. Conventional and dense gas techniques for the production of liposomes: a review.

    Science.gov (United States)

    Meure, Louise A; Foster, Neil R; Dehghani, Fariba

    2008-01-01

    The aim of this review paper is to compare the potential of various techniques developed for production of homogenous, stable liposomes. Traditional techniques, such as Bangham, detergent depletion, ether/ethanol injection, reverse-phase evaporation and emulsion methods, were compared with the recent advanced techniques developed for liposome formation. The major hurdles for scaling up the traditional methods are the consumption of large quantities of volatile organic solvent, the stability and homogeneity of the liposomal product, as well as the lengthy multiple steps involved. The new methods have been designed to alleviate the current issues for liposome formulation. Dense gas liposome techniques are still in their infancy, however they have remarkable advantages in reducing the use of organic solvents, providing fast, single-stage production and producing stable, uniform liposomes. Techniques such as the membrane contactor and heating methods are also promising as they eliminate the use of organic solvent, however high temperature is still required for processing.

  10. Bayesian quantification of thermodynamic uncertainties in dense gas flows

    International Nuclear Information System (INIS)

    Merle, X.; Cinnella, P.

    2015-01-01

    A Bayesian inference methodology is developed for calibrating complex equations of state used in numerical fluid flow solvers. Precisely, the input parameters of three equations of state commonly used for modeling the thermodynamic behavior of the so-called dense gas flows, – i.e. flows of gases characterized by high molecular weights and complex molecules, working in thermodynamic conditions close to the liquid–vapor saturation curve – are calibrated by means of Bayesian inference from reference aerodynamic data for a dense gas flow over a wing section. Flow thermodynamic conditions are such that the gas thermodynamic behavior strongly deviates from that of a perfect gas. In the aim of assessing the proposed methodology, synthetic calibration data – specifically, wall pressure data – are generated by running the numerical solver with a more complex and accurate thermodynamic model. The statistical model used to build the likelihood function includes a model-form inadequacy term, accounting for the gap between the model output associated to the best-fit parameters and the true phenomenon. Results show that, for all of the relatively simple models under investigation, calibrations lead to informative posterior probability density distributions of the input parameters and improve the predictive distribution significantly. Nevertheless, calibrated parameters strongly differ from their expected physical values. The relationship between this behavior and model-form inadequacy is discussed. - Highlights: • Development of a Bayesian inference procedure for calibrating dense-gas flow solvers. • Complex thermodynamic models calibrated by using aerodynamic data for the flow. • Preliminary Sobol analysis used to reduce parameter space. • Piecewise polynomial surrogate model constructed to reduce computational cost. • Calibration results show the crucial role played by model-form inadequacies

  11. Monocular oral reading after treatment of dense congenital unilateral cataract

    Science.gov (United States)

    Birch, Eileen E.; Cheng, Christina; Christina, V; Stager, David R.

    2010-01-01

    Background Good long-term visual acuity outcomes for children with dense congenital unilateral cataracts have been reported following early surgery and good compliance with postoperative amblyopia therapy. However, treated eyes rarely achieve normal visual acuity and there has been no formal evaluation of the utility of the treated eye for reading. Methods Eighteen children previously treated for dense congenital unilateral cataract were tested monocularly with the Gray Oral Reading Test, 4th edition (GORT-4) at 7 to 13 years of age using two passages for each eye, one at grade level and one at +1 above grade level. In addition, right eyes of 55 normal children age 7 to 13 served as a control group. The GORT-4 assesses reading rate, accuracy, fluency, and comprehension. Results Visual acuity of treated eyes ranged from 0.1 to 2.0 logMAR and of fellow eyes from −0.1 to 0.2 logMAR. Treated eyes scored significantly lower than fellow and normal control eyes on all scales at grade level and at +1 above grade level. Monocular reading rate, accuracy, fluency, and comprehension were correlated with visual acuity of treated eyes (rs = −0.575 to −0.875, p < 0.005). Treated eyes with 0.1-0.3 logMAR visual acuity did not differ from fellow or normal control eyes in rate, accuracy, fluency, or comprehension when reading at grade level or at +1 above grade level. Fellow eyes did not differ from normal controls on any reading scale. Conclusions Excellent visual acuity outcomes following treatment of dense congenital unilateral cataracts are associated with normal reading ability of the treated eye in school-age children. PMID:20603057

  12. Parallel Access of Out-Of-Core Dense Extendible Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Otoo, Ekow J; Rotem, Doron

    2007-07-26

    Datasets used in scientific and engineering applications are often modeled as dense multi-dimensional arrays. For very large datasets, the corresponding array models are typically stored out-of-core as array files. The array elements are mapped onto linear consecutive locations that correspond to the linear ordering of the multi-dimensional indices. Two conventional mappings used are the row-major order and the column-major order of multi-dimensional arrays. Such conventional mappings of dense array files highly limit the performance of applications and the extendibility of the dataset. Firstly, an array file that is organized in say row-major order causes applications that subsequently access the data in column-major order, to have abysmal performance. Secondly, any subsequent expansion of the array file is limited to only one dimension. Expansions of such out-of-core conventional arrays along arbitrary dimensions, require storage reorganization that can be very expensive. Wepresent a solution for storing out-of-core dense extendible arrays that resolve the two limitations. The method uses a mapping function F*(), together with information maintained in axial vectors, to compute the linear address of an extendible array element when passed its k-dimensional index. We also give the inverse function, F-1*() for deriving the k-dimensional index when given the linear address. We show how the mapping function, in combination with MPI-IO and a parallel file system, allows for the growth of the extendible array without reorganization and no significant performance degradation of applications accessing elements in any desired order. We give methods for reading and writing sub-arrays into and out of parallel applications that run on a cluster of workstations. The axial-vectors are replicated and maintained in each node that accesses sub-array elements.

  13. Laterally cyclic loading of monopile in dense sand

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Hededal, Ole; Svensson, M.

    2011-01-01

    In order to investigate the response from laterally cyclic loading of monopiles a large centrifuge tests series is ongoing at the Technical University of Denmark (DTU). This paper will present some of the tests carried out with a focus on the influence of accumulation of rotation when changing...... the loading conditions. In these tests the load conditions are controlled by two load characteristics, one controlling the level of the cyclic loading and one controlling the characteristic of the cyclic loading. The centrifuge tests were performed in dense dry sand on a pile with prototype dimensions...

  14. Repetitively pulsed capacitor bank for the dense-plasma focus

    International Nuclear Information System (INIS)

    Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

    1975-12-01

    This report describes a 1 pulse per second capacitor bank designed to energize a dense-plasma focus (DPF). The DPF is a neutron source capable (with moderate scaling) of delivering a minimum of 10 15 neutrons per pulse or neutron flux of 2 x 10 13 N/cm 2 .s. The average power consumption, which has become a major issue due to the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. This small source size high flux neutron source could be extemely useful to qualify fission reactor material irradiation results for fusion reactor design

  15. Chemical potential calculations in dense liquids using metadynamics

    Science.gov (United States)

    Perego, C.; Giberti, F.; Parrinello, M.

    2016-10-01

    The calculation of chemical potential has traditionally been a challenge in atomistic simulations. One of the most used approaches is Widom's insertion method in which the chemical potential is calculated by periodically attempting to insert an extra particle in the system. In dense systems this method fails since the insertion probability is very low. In this paper we show that in a homogeneous fluid the insertion probability can be increased using metadynamics. We test our method on a supercooled high density binary Lennard-Jones fluid. We find that we can obtain efficiently converged results even when Widom's method fails.

  16. Coherent scattering of neutrinos by 'nuclear pasta' in dense matter

    International Nuclear Information System (INIS)

    Sonoda, Hidetaka

    2007-01-01

    We examine coherent scattering cross section of neutrino and nucleon systems via weak-neutral current at subnuclear densities, which will be important in supernova cores. Below melting density and temparature of nuclei, nuclear shape becomes rodlike and slablike; this is called nuclear 'pasta'. Transition of structure will greatly influence coherent effects which can not easily be predicted. We calculate static structure factor of nuclear matter using data of several nuclear models, and discuss the effects of existence of nuclear pasta on neutrino opacity in hot dense matter

  17. Performance analysis of simultaneous dense coding protocol under decoherence

    Science.gov (United States)

    Huang, Zhiming; Zhang, Cai; Situ, Haozhen

    2017-09-01

    The simultaneous dense coding (SDC) protocol is useful in designing quantum protocols. We analyze the performance of the SDC protocol under the influence of noisy quantum channels. Six kinds of paradigmatic Markovian noise along with one kind of non-Markovian noise are considered. The joint success probability of both receivers and the success probabilities of one receiver are calculated for three different locking operators. Some interesting properties have been found, such as invariance and symmetry. Among the three locking operators we consider, the SWAP gate is most resistant to noise and results in the same success probabilities for both receivers.

  18. On the spatial distributions of dense cores in Orion B

    Science.gov (United States)

    Parker, Richard J.

    2018-05-01

    We quantify the spatial distributions of dense cores in three spatially distinct areas of the Orion B star-forming region. For L1622, NGC 2068/NGC 2071, and NGC 2023/NGC 2024, we measure the amount of spatial substructure using the Q-parameter and find all three regions to be spatially substructured (Q Orion B, the mass segregation cannot be dynamical. Our results are also inconsistent with simulations in which the most massive stars form via competitive accretion, and instead hint that magnetic fields may be important in influencing the primordial spatial distributions of gas and stars in star-forming regions.

  19. Spherically symmetric relativistic model for spiral galaxies and dense stars

    International Nuclear Information System (INIS)

    Hojman, R.; Rodrigues, L.M.C.; Sasse, F.D.

    1990-01-01

    The behaviour of the pressure and the density as well as the gravitational field of a dense star are studied in some detail. For such a purpose and to take into account relativistic effects, we find a family of exact solutions of the Tolman-Oppenheimer-Volkov equation, which contains as a particular case solutions corresponding to a γ-law equation of state. The mentioned family can also be used to model the (luminous or dark) matter content of spiral galaxies, as it fits the observed data for their orbital velocities profiles. (author)

  20. Ultrasound propagation in dense aerogels filled with liquid 4He

    International Nuclear Information System (INIS)

    Matsumoto, K; Ohmori, K; Abe, S; Kanamori, K; Nakanishi, K

    2012-01-01

    Longitudinal ultrasound propagation was studied in dense aerogels filled with liquid 4 He. Sound velocity and attenuation were measured at the frequency of 6 MHz in both normal and superfluid phases. Pressure dependence of velocity and attenuation were also studied. Studied aerogels had porosities about 85%. They had two different types of structure, tangled strand structure and aggregated particles structure. The pore size distributions were narrow. Reduction of superfluid transition temperature mainly depended on not porosity but mean pore size. The structure of gel played an important role in sound velocity and attenuation.