WorldWideScience

Sample records for bulk matter evolution

  1. Brane cosmological evolution in a bulk with cosmological constant

    OpenAIRE

    Binetruy, Pierre; Deffayet, Cedric; Ellwanger, Ulrich; Langlois, David

    1999-01-01

    We consider the cosmology of a ``3-brane universe'' in a five dimensional (bulk) space-time with a cosmological constant. We show that Einstein's equations admit a first integral, analogous to the first Friedmann equation, which governs the evolution of the metric in the brane, whatever the time evolution of the metric along the fifth dimension. We thus obtain the cosmological evolution in the brane for any equation of state describing the matter in the brane, without needing the dependence o...

  2. Bulk viscous matter-dominated Universes: asymptotic properties

    International Nuclear Information System (INIS)

    By means of a combined use of the type Ia supernovae and H(z) data tests, together with the study of the asymptotic properties in the equivalent phase space — through the use of the dynamical systems tools — we demonstrate that the bulk viscous matter-dominated scenario is not a good model to explain the accepted cosmological paradigm, at least, under the parametrization of bulk viscosity considered in this paper. The main objection against such scenarios is the absence of conventional radiation and matter-dominated critical points in the phase space of the model. This entails that radiation and matter dominance are not generic solutions of the cosmological equations, so that these stages can be implemented only by means of unique and very specific initial conditions, i. e., of very unstable particular solutions. Such a behavior is in marked contradiction with the accepted cosmological paradigm which requires of an earlier stage dominated by relativistic species, followed by a period of conventional non-relativistic matter domination, during which the cosmic structure we see was formed. Also, we found that the bulk viscosity is positive just until very late times in the cosmic evolution, around z < 1. For earlier epochs it is negative, been in tension with the local second law of thermodynamics

  3. Bulk viscous matter and recent acceleration of the universe

    Energy Technology Data Exchange (ETDEWEB)

    Sasidharan, Athira; Mathew, Titus K. [Cochin University of Science and Technology, Department of Physics, Kochi (India)

    2015-07-15

    We consider a cosmological model dominated by bulk viscous matter with a total bulk viscosity coefficient proportional to the velocity and acceleration of the expansion of the universe in such a way that ζ = ζ{sub 0} + ζ{sub 1}(a)/(a) + ζ{sub 2}(a)/(a). We show that there exist two limiting conditions in the bulk viscous coefficients (ζ{sub 0}, ζ{sub 1}, ζ{sub 2}) which correspond to a universe having a Big Bang at the origin, followed by an early decelerated epoch and then making a smooth transition into an accelerating epoch. We have constrained the model using the type Ia Supernovae data, evaluated the best estimated values of all the bulk viscous parameters and the Hubble parameter corresponding to the two limiting conditions. We found that even though the evolution of the cosmological parameters are in general different for the two limiting cases, they show identical behavior for the best estimated values of the parameters from both limiting conditions. A recent acceleration would occur if ζ{sub 0} + ζ{sub 1} > 1 for the first limiting conditions and if ζ{sub 0} + ζ{sub 1} < 1 for the second limiting conditions. The age of the universe predicted by this model is found to be less than that predicted from the oldest galactic globular clusters. The total bulk viscosity seems to be negative in the past and becomes positive when z ≤ 0.8. So the model violates the local second law of thermodynamics. However, the model satisfies the generalized second law of thermodynamics at the apparent horizon throughout the evolution of the universe. We also made a statefinder analysis of the model and found that it is distinguishably different from the standard ΛCDM model at present, but it shows a de Sitter type behavior in the far future of the evolution. (orig.)

  4. Neutrino emissivity and bulk viscosity of iso-CSL quark matter in neutron stars

    OpenAIRE

    Blaschke, D.; Berdermann, J.

    2007-01-01

    We present results for neutrino emissivities and bulk viscosities of a two-flavor color superconducting quark matter phase with isotropic color-spin-locked (iso-CSL) single-flavor pairing which fulfill the constraints on quark matter derived from cooling and rotational evolution of compact stars. We compare with results for the phenomenologically successful, but yet heuristic 2SC+X phase.

  5. Evolution of bulk damage initiation in DKDP

    Science.gov (United States)

    Carr, Christopher W.; McMillian, T. H.; Staggs, Mike C.; Radousky, Harry B.; Demos, Stavros G.

    2003-05-01

    We investigate the evolution of laser-induced damage initiated in the bulk of DKDP crystals using in-situ microscopy. Experimental results indicate that at peek fluences greater than 10 J/cm2, damage sites are formed with increasing number as a function of the laser fluence. Following plasma formation, cracks are observed which grow in size for tens of seconds after the termination of the laser pulse. Subsequent irradiation leads to modest increase in size only during the initial 2-5 pulses. Experimental results suggest that there is also relaxation of the stresses adjacent to a damage site for several hours after initial damage.

  6. Nuclear Matter Bulk Parameter Scales and Correlations

    International Nuclear Information System (INIS)

    We study the arising of correlations among some isovector bulk parameters in nonrelativistic and relativistic hadronic mean-field models. For the former, we investigate correlations in the nonrelativistic (NR) limit of relativistic point-coupling models. We provide analytical correlations, for the NR limit model, between the symmetry energy and its derivatives, namely, the symmetry energy slope, curvature, skewness and fourth order derivative, discussing the conditions in which they are linear ones. We also show that some correlations presented in the NR limit model are reproduced for relativistic models presenting cubic and quartic self-interactions in its scalar field. As a direct application of such linear correlations, we remark its association with possible crossing points in the density dependence of the linearly correlated bulk parameter. (author)

  7. Jet-induced modifications of the characteristic of the bulk nuclear matter

    Science.gov (United States)

    Marcinkowski, P.; Słodkowski, M.; Kikoła, D.; Sikorski, J.; Porter-Sobieraj, J.; Gawryszewski, P.; Zygmunt, B.

    2016-01-01

    We present our studies on jet induced modifications of the characteristics of bulk nuclear matter. To describe such matter, we use efficient relativistic hydrodynamic simulations in (3+1)-dimension, employing the Graphics Processing Unit (GPU) in the parallel programming framework. We use Cartesian coordinates in the calculations to ensure a high spatial resolution that is constant throughout the evolution of the system. We show our results on how jets modify the hydrodynamics fields and discuss the implications.

  8. Jet-induced modifications of the characteristic of the bulk nuclear matter

    CERN Document Server

    Marcinkowski, P; Kikoła, D; Sikorski, J; Porter-Sobieraj, J; Gawryszewski, P; Zygmunt, B

    2015-01-01

    We present our studies on jet-induced modifications of the characteristic of the bulk nuclear matter. To describe such a matter, we use efficient relativistic hydrodynamic simulations in (3+1) dimensions employing the Graphics Processing Unit (GPU) in the parallel programming framework. We use Cartesian coordinates in the calculations to ensure a high spatial resolution that is constant throughout the evolution of the system. We show our results on how jets modify the hydrodynamics fields and discuss the implications.

  9. Pairing in bulk nuclear matter beyond BCS

    International Nuclear Information System (INIS)

    The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the 3P2−3F2 coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the 3P2−3F2 coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive

  10. Pairing in bulk nuclear matter beyond BCS

    CERN Document Server

    Ding, D; Dickhoff, W H; Dussan, H; Rios, A; Polls, A

    2014-01-01

    The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the ${}^3P_2-{}^3F_2$ coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.

  11. Higher order bulk characteristic parameters of asymmetric nuclear matter

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The bulk parameters characterizing the energy of symmetric nuclear matter and the symmetry energy defined at normal nuclear density ρ0 provide important information on the equation of state (EOS) of isospin asymmetric nuclear matter. While significant progress has been made in determining some lower order bulk characteristic parameters, such as the energy E0(ρ0) and incompress ibility K0 of symmetric nuclear matter as well as the symmetry energy Esym(ρ0) and its slope parameter L, yet the higher order bulk characteristic parameters are still poorly known. Here, we analyze the correlations between the lower and higher order bulk char acteristic parameters within the framework of Skyrme Hartree-Fock energy density functional and then estimate the values of some higher order bulk characteristic parameters. In particular, we obtain J0 = (-355±95) MeV and I0 = (1473±680) MeV for the third order and fourth-order derivative parameters of symmetric nuclear matter at ρ0 and Ksym = (-100 ± 165) MeV, Jsym = (224 ± 385) MeV, Isym = (-1309 ± 2025) MeV for the curvature parameter, third-order and fourth-order derivative parameters of the symmetry energy at ρ0, using the empirical constraints on E0(ρ0), K0, Esym(ρ0), L, and the isoscalar and isovector nucleon effective masses. Furthermore, our results indicate that the three parameters E0(ρ0), K0, and J0 can reasonably characterize the EOS of symmetric nuclear matter up to 2ρ0 while the symmetry energy up to 2ρ0 can be well described by Esym(ρ0), L, and Ksym.

  12. Does Bulk Viscosity Create a Viable Unified Dark Matter Model?

    CERN Document Server

    Li, Baojiu

    2009-01-01

    We investigate in detail the possibility that a single imperfect fluid with bulk viscosity can replace the need for separate dark matter and dark energy in cosmological models. With suitable choices of model parameters, we show that the background cosmology in this model can mimic that of a LCDM Universe to high precision. However, as the cosmic expansion goes through the decelerating-accelerating transition, the density perturbations in this fluid are rapidly damped out. We show that,although this does not significantly affect structure formation in baryonic matter, it makes the gravitational potential decay rapidly at late times, leading to modifications in predictions of cosmological observables such as the CMB power spectrum and weak lensing. This model of unified dark matter is thus difficult to reconcile with astronomical observations. We also clarify the differences with respect to other unified dark matter models where the fluid is barotropic, i.e., p=p(rho), such as the (generalized) Chaplygin gas mo...

  13. The Evolution Model of Intelligent Matter

    Directory of Open Access Journals (Sweden)

    Bazaluk Oleg

    2014-03-01

    Full Text Available The article deals with the evolution model of reasonable matter (noogenesis, discovering the planetary and cosmic scale of the mind development. The author considers a historiography of this problem field, a contribution of scientific community to the development of basic provisions - noogenesis. According to the author, the evolution model of reasonable matter consists of three interdependent and mutually complementary models: 1. Models of continuous and nonlinear complication of structures of reasonable matter (neuro-evolution; 2. Models of continuous and nonlinear complication of types of interacting (or shown functions structures of the system of reasonable matter. 3. Models of continuous and nonlinear complication of the surroundings of reasonable matter (socio-cultural evolution. All these models include the author's understanding and corresponding arguments. In conclusion the author compares models of living and reasonable matter (biological evolution and noogenesis

  14. Crack evolution in bulk metallic glasses

    International Nuclear Information System (INIS)

    In the present study, the mechanisms underlying plastic deformation of a Ni-based bulk metallic glass (BMG) are explored. Based on the microstructural investigations, a model is proposed how fracture emerges in BMGs. After deformation, the glass is macroscopically more fragile indicating a decrease in the viscosity within the shear bands due to shear softening. These fluctuations of viscosity and therefore Poisson ratio between the deformed and undeformed regions appear to be the initiation sites for nanometer-scale cracks, which are aligned parallel to the applied force. Coalescence of voids is believed to form these small cracks, which eventually interconnect along the interface between the sheared and unsheared regions to form a detrimental defect resulting in fracture.

  15. Area evolution, bulk viscosity and entropy principles for dynamical horizons

    CERN Document Server

    Gourgoulhon, E; Gourgoulhon, Eric; Jaramillo, Jose Luis

    2006-01-01

    We derive from Einstein equation an evolution law for the area of a trapping or dynamical horizon. The solutions to this differential equation show a causal behavior. Moreover, in a viscous fluid analogy, the equation can be interpreted as an energy balance law, yielding to a positive bulk viscosity. These two features contrast with the event horizon case, where the non-causal evolution of the area and the negative bulk viscosity require teleological boundary conditions. This reflects the local character of trapping horizons as opposed to event horizons. Interpreting the area as the entropy, we propose to use an area/entropy evolution principle to select a unique dynamical horizon and time slicing in the Cauchy evolution of an initial marginally trapped surface.

  16. Evolution of bulk strain solitons in cylindrical inhomogeneous shells

    Energy Technology Data Exchange (ETDEWEB)

    Shvartz, A., E-mail: andrew.shvartz@mail.ioffe.ru; Samsonov, A.; Dreiden, G.; Semenova, I. [Ioffe Institute, 26 Politekhnicheskaya, St Petersburg 194021 (Russian Federation)

    2015-10-28

    Bulk strain solitary waves in nonlinearly elastic thin-walled cylindrical shells with variable geometrical and physical parameters are studied, and equation for the longitudinal strain component with the variable coefficients is derived. A conservative finite difference scheme is proposed, and the results of numerical simulation of the strain soliton evolution in a shell with the abrupt variations of cross section and physical properties of the material are presented.

  17. Chemical Evolution of Protostellar Matter

    Science.gov (United States)

    Langer, William D.; vanDishoeck, Ewine F.; Bergin, Edwin A.; Blake, Geoffrey A.; Tielens, Alexander G. G. M.; Velusamy, Thangasamy; Whittet, Douglas C. B.

    2000-01-01

    We review the chemical processes that are important in the evolution from a molecular cloud core to a protostellar disk. These cover both gas phase and gas grain interactions. The current observational and theoretical state of this field are discussed.

  18. Galaxy Evolution by the Incompatibility between Dark Matter and Baryonic Matter

    OpenAIRE

    Ding-Yu Chung

    2014-01-01

    The paper derives the galaxy evolution by the non-interacting (incompatibility) between dark matter and baryonic matter in terms of the short-range separation between dark matter and baryonic matter, so dark matter cannot contact baryonic matter. In the conventional CDM (cold dark matter) model, dark matter and baryonic matter are interactive (compatible), so dark matter can contact baryonic matter. However, the conventional CDM model fails to account for the failure to...

  19. Can local bulk effects explain the galactic dark matter?

    Energy Technology Data Exchange (ETDEWEB)

    Heydari-Fard, Malihe; Sepangi, Hamid R, E-mail: m.heydarifard@mail.sbu.ac.ir, E-mail: hr-sepangi@sbu.ac.ir [Department of Physics, Shahid Beheshti University, Evin, Tehran 19839 (Iran, Islamic Republic of)

    2008-08-15

    We obtain the virial theorem within the context of a brane-world model without mirror symmetry or any form of junction condition. Taking a constant curvature bulk (neglecting non-local bulk effects), the local bulk effects generate a geometrical mass, contributing to the gravitational energy which may be used to explain the virial mass discrepancy in clusters of galaxies. We fix the parameters of this model in agreement with observational data.

  20. Can local bulk effects explain the galactic dark matter?

    OpenAIRE

    Heydari-Fard, Malihe; Sepangi, Hamid R.

    2008-01-01

    We obtain the virial theorem within the context of a brane-world model without mirror symmetry or any form of junction condition. Taking a constant curvature bulk (neglecting non-local bulk effects), the local bulk effects generate a geometrical mass, contributing to the gravitational energy which may be used to explain the virial mass discrepancy in clusters of galaxies. We fix the parameter of this model in agreement with observational data.

  1. Baryon number conservation and enforced electric charge neutrality for bulk viscosity in quark matter

    OpenAIRE

    Dong, Hui; Su, Nan; Wang, Qun

    2007-01-01

    General constraints on fluid velocity divergences for particles in quark matter are derived from baryon number conservation and enforced electric charge neutrality. A new oscillation pattern in three-flavor normal quark matter satisfying these conditions is found and its bulk viscosity is calculated. The result may have astrophysical implication for maximum rotation frequencies of compact stars.

  2. Gravity-related spontaneous wave function collapse in bulk matter

    International Nuclear Information System (INIS)

    In the DP-model, gravity-related spontaneous wave function collapses suppress Schrödinger cat states which are conceptually problematic especially for gravity and space-time. We derive the equations of the model for the hydrodynamic-elastic (acoustic) modes in a bulk. Two particular features are discussed: the universal dominance of spontaneous collapses at large wavelengths, and the reduction of spontaneous heating by a slight refinement of the DP-model. (paper)

  3. Galaxy evolution: the effect of dark matter on the chemical evolution of ellipticals and galaxy clusters

    OpenAIRE

    Matteucci, F.; Gibson, B. K.

    1996-01-01

    In this paper we discuss the chemical evolution of elliptical galaxies and its consequences on the evolution of the intracluster medium (ICM). We use chemical evolution models taking into account dark matter halos and compare the results with previous models where dark matter was not considered. In particular, we examine the evolution of the abundances of some relevant heavy elements such as oxygen, magnesium and iron and conclude that models including dark matter halos and an initial mass fu...

  4. Causal Evolutions of Bulk Local Excitations from CFT

    CERN Document Server

    Goto, Kanato; Takayanagi, Tadashi

    2016-01-01

    Bulk localized excited states in an AdS spacetime can be constructed from Ishibashi states with respect to the global conformal symmetry in the dual CFT. We study boundary two point functions of primary operators in the presence of bulk localized excitations in two dimensional CFTs. From two point functions in holographic CFTs, we observe causal propagations of radiations when the mass of dual bulk scalar field is close to the BF bound. This behavior for holographic CFTs is consistent with the locality and causality in classical gravity duals. We also show that this cannot be seen in free fermion CFTs. Moreover, we find that the short distance behavior of two point functions is universal and obeys the relation which generalizes the first law of entanglement entropy.

  5. Bulk viscosity of strange quark matter in density dependent quark mass model

    Indian Academy of Sciences (India)

    J D Anand; N Chandrika Devi; V K Gupta; S Singh

    2000-05-01

    We have studied the bulk viscosity of strange quark matter in the density dependent quark mass model (DDQM) and compared results with calculations done earlier in the MIT bag model where , masses were neglected and first order interactions were taken into account. We find that at low temperatures and high relative perturbations, the bulk viscosity is higher by 2 to 3 orders of magnitude while at low perturbations the enhancement is by 1–2 order of magnitude as compared to earlier results. Also the damping time is 2–3 orders of magnitude lower implying that the star reaches stability much earlier than in MIT bag model calculations.

  6. Quark mass density- and temperature- dependent model for bulk strange quark matter

    OpenAIRE

    al, Yun Zhang et.

    2002-01-01

    It is shown that the quark mass density-dependent model can not be used to explain the process of the quark deconfinement phase transition because the quark confinement is permanent in this model. A quark mass density- and temperature-dependent model in which the quark confinement is impermanent has been suggested. We argue that the vacuum energy density B is a function of temperature. The dynamical and thermodynamical properties of bulk strange quark matter for quark mass density- and temper...

  7. The Search for Fractional Charge Elementary Particles and Very Massive Particles in Bulk Matter

    CERN Document Server

    Perl, Martin Lewis; Kim, P C; Lee, E R; Lee, I T; Loomba, D; Perl, Martin L.; Halyo, Valerie; Kim, Peter C.; Lee, Eric R.; Lee, Irwin T.; Loomba, Dinesh

    2000-01-01

    We describe our ongoing work on, and future plans for, searches in bulk matter for fractional charge elementary particles and very massive elementary particles. Our primary interest is in searching for such particles that may have been produced in the early universe and may be found in the more primeval matter available in the solar system: meteorites, material from the moon's surface, and certain types of ancient terrestrial rocks. In the future we are interested in examining material brought back by sample return probes from asteroids. We will describe our experimental methods that are based on new modifications of the Millikan liquid drop technique and modern technology: micromachining, CCD cameras, and desktop computers. Extensions of our experimental methods and technology allow searches for very massive charged particles in primeval matter; particles with masses greater than 10**13 GeV. In the first such searches carried out on earth there will be uncertainties in the mass search range. Therefore we wil...

  8. Galapagos III World Evolution Summit: why evolution matters

    OpenAIRE

    Paz-y-Miño-C, Guillermo; Espinosa, Avelina

    2013-01-01

    There is no place on Earth like the Galapagos Islands and no better destination to discuss the reality of evolution. Under the theme ‘Why Does Evolution Matter’, the University San Francisco of Quito (USFQ), Ecuador, and its Galapagos Institute for the Arts and Sciences (GAIAS), organized the III World Evolution Summit in San Cristóbal Island. The 200-attendee meeting took place on 1 to 5 June 2013; it included 12 keynote speakers, 20 oral presentations by international scholars, and 31 poste...

  9. Restudy on Time-Evolution of SUSY Dark Matter

    Institute of Scientific and Technical Information of China (English)

    FENG Tai-Fu; LI Xue-Qian; MENG Qing-Wei; REN Zhen-Yu

    2002-01-01

    We restudy the Lee-Weinberg time-evolution equation including the R-parity violation. We carefullyanalyze the intluence of the boundary conditions, equation of state, SUSY parameters, especially the R-parity violation,and other factors on the time-evolution of the SUSY cold dark matter. Our numerical results show that without Rparity violation, only two ranges 20 < mx01 < 30 GeV and 75 < mx01 < 110 GeV can be consistent with data, if30 < mx01 < 75 GeV, there must be at least two kinds of heavy particles contributing to the cold dark matter. However,with the R-parity violation, the heavy neutralino can be dark matter constituent, but it must decay and the R-parityviolation parameter is constrained by the present data.

  10. Correlation between atomic structure evolution and strength in a bulk metallic glass at cryogenic temperature

    OpenAIRE

    Tan, J.; Wang, G.; Z. Y. LIU; Bednarčík, J.; Gao, Yan; Zhai, Q. J.; Mattern, N.; Eckert, J.

    2014-01-01

    A model Zr41.25Ti13.75Ni10Cu12.5Be22.5 (at.%) bulk metallic glass (BMG) is selected to explore the structural evolution on the atomic scale with decreasing temperature down to cryogenic level using high energy X-ray synchrotron radiation. We discover a close correlation between the atomic structure evolution and the strength of the BMG and find out that the activation energy increment of the concordantly atomic shifting at lower temperature is the main factor influencing the strength. Our res...

  11. Universal Optical Response of Si-Si Bonds and its evolution from nanoparticles to bulk crystals

    Energy Technology Data Exchange (ETDEWEB)

    Idrobo Tapia, Juan C [ORNL; Halabica, Andrej [Vanderbilt University; Magruder, Iii, Robert H [ORNL; Haglund, Jr, Richard F [ORNL; Pennycook, Stephen J [ORNL; Pantelides, Sokrates T [ORNL

    2009-01-01

    We use quantum mechanical calculations and classical theories of the optical absorption of free and embedded nanoparticles to demonstrate a universality of the optical response of Si-Si bonds, independent of bonding configurations. We also demonstrate that the classical theory remains valid down to atomic-scale nanoparticles and that the evolution of the optical spectrum of a free nanoparticle would evolve to the bulk spectrum when the particle contains hundreds of thousands of Si atoms.

  12. Nonlinear evolution of dark matter subhalos and applications to warm dark matter

    International Nuclear Information System (INIS)

    We describe the methodology to include nonlinear evolution, including tidal effects, in the computation of subhalo distribution properties in both cold (CDM) and warm (WDM) dark matter universes. Using semi-analytic modeling, we include effects from dynamical friction, tidal stripping, and tidal heating, allowing us to dynamically evolve the subhalo distribution. We calibrate our nonlinear evolution scheme to the CDM subhalo mass function in the Aquarius N-body simulation, producing a subhalo mass function within the range of simulations. We find tidal effects to be the dominant mechanism of nonlinear evolution in the subhalo population. Finally, we compute the subhalo mass function for m χ = 1.5 keV WDM including the effects of nonlinear evolution, and compare radial number densities and mass density profiles of subhalos in CDM and WDM models. We show that all three signatures differ between the two dark matter models, suggesting that probes of substructure may be able to differentiate between them.

  13. Correlation between atomic structure evolution and strength in a bulk metallic glass at cryogenic temperature.

    Science.gov (United States)

    Tan, J; Wang, G; Liu, Z Y; Bednarčík, J; Gao, Y L; Zhai, Q J; Mattern, N; Eckert, J

    2014-01-01

    A model Zr41.25Ti13.75Ni10Cu12.5Be22.5 (at.%) bulk metallic glass (BMG) is selected to explore the structural evolution on the atomic scale with decreasing temperature down to cryogenic level using high energy X-ray synchrotron radiation. We discover a close correlation between the atomic structure evolution and the strength of the BMG and find out that the activation energy increment of the concordantly atomic shifting at lower temperature is the main factor influencing the strength. Our results might provide a fundamental understanding of the atomic-scale structure evolution and may bridge the gap between the atomic-scale physics and the macro-scale fracture strength for BMGs. PMID:24469299

  14. Relationships between soil moisture-holding properties and soil texture, organic matter content, and bulk density

    Science.gov (United States)

    Riley, H. C. F.

    1981-01-01

    Specimens from the surface horizon and the subsoil of 62 soil horizons in Hedmark and Oppland were investigated to study how the mechanical composition of the soil, the organic matter content and the bulk density affect their porosity and air capacity and their total and available water content. Most of the specimens belonged to the loam group, and a smaller number was from sandy and silty types of soil. Equations were established to make it possible to calculate the water retention curves and the amount of available water from the above mentioned parameters. As a rule, errors derived from the equations are no greater than those which are found in similar research in other countries.

  15. Bulk gauge and matter fields in nested warping: II. Symmetry Breaking and phenomenological consequences

    CERN Document Server

    Arun, Mathew Thomas

    2016-01-01

    Generalizing the Randall-Sundrum scenario to higher dimensions with nested warpings has been shown to avoid the constraints besetting the former. In the first paper of this series [JHEP 1509 (2015) 202], the Standard Model gauge and fermion fields were extended into such a six-dimensional bulk and the construction was shown to have several interesting and welcome features. In this paper, we discuss the electroweak symmetry breaking, presenting a novel Higgs localization mechanism that leads to interesting phenomenology in the Higgs sector. Localizing the Higgs modifies the $Z_{\\mu}$ and $W_{\\mu}$ boson wavefunctions, which leads to tree level changes in the oblique parameters. Using these as well as the correction to low-energy four-Fermi operators, we derive the constraints on our model and also discuss the gauge coupling evolution therein. Amusingly, the model can naturally incorporate a Higgs resonance in the 700--800 GeV range.

  16. The evolution of the galaxy content of dark matter haloes

    OpenAIRE

    Contreras, S; Zehavi, I.; Baugh, C. M.; Padilla, N.; Norberg, P.

    2016-01-01

    We use the halo occupation distribution (HOD) framework to characterise the predictions from two independent galaxy formation models for the galactic content of dark matter haloes and its evolution with redshift. Our galaxy samples correspond to a range of fixed number densities defined by stellar mass and span $0 \\le z \\le 3$. We find remarkable similarities between the model predictions. Differences arise at low galaxy number densities which are sensitive to the treatment of heating of the ...

  17. Jet evolution in hot and cold QCD matter

    International Nuclear Information System (INIS)

    In this thesis, we study the evolution of energetic partons in hot and cold QCD matter. In both cases, interactions with the medium lead to energy loss of the parton and its transverse momentum broadens. The propagation of partons in cold nuclear matter can be investigated experimentally in deep-inelastic scattering (DIS) on nuclei. We use the dipole model to calculate transverse momentum broadening in DIS on nuclei and compare to experimental data from HERMES. In hot matter, the evolution of the parton shower is strongly modified. To calculate this modification, we construct an additional scattering term in the QCD evolution equations which accounts for scattering of partons in the quark-gluon plasma. With this scattering term, we compute the modified gluon distribution in the shower at small momentum fractions. Furthermore, we calculate the modified fragmentation function of gluons into pions. The scattering term causes energy loss of the parton shower which leads to a suppression of hadrons with large transverse momentum. In the third part of this thesis, we study double dijet production in hadron collisions. This process contains information about the transverse parton distribution of hadrons. As main result, we find that double dijet production will allow for a study of the transverse growth of hadronic wave functions at the LHC. (orig.)

  18. Jet evolution in hot and cold QCD matter

    Energy Technology Data Exchange (ETDEWEB)

    Domdey, Svend Oliver

    2010-07-23

    In this thesis, we study the evolution of energetic partons in hot and cold QCD matter. In both cases, interactions with the medium lead to energy loss of the parton and its transverse momentum broadens. The propagation of partons in cold nuclear matter can be investigated experimentally in deep-inelastic scattering (DIS) on nuclei. We use the dipole model to calculate transverse momentum broadening in DIS on nuclei and compare to experimental data from HERMES. In hot matter, the evolution of the parton shower is strongly modified. To calculate this modification, we construct an additional scattering term in the QCD evolution equations which accounts for scattering of partons in the quark-gluon plasma. With this scattering term, we compute the modified gluon distribution in the shower at small momentum fractions. Furthermore, we calculate the modified fragmentation function of gluons into pions. The scattering term causes energy loss of the parton shower which leads to a suppression of hadrons with large transverse momentum. In the third part of this thesis, we study double dijet production in hadron collisions. This process contains information about the transverse parton distribution of hadrons. As main result, we find that double dijet production will allow for a study of the transverse growth of hadronic wave functions at the LHC. (orig.)

  19. Flavor evolution of supernova neutrinos in turbulent matter

    International Nuclear Information System (INIS)

    The neutrino signal from the next galactic supernova carries with it an enormous amount of information on the explosion mechanism of a core-collapse supernova, as well as on the stellar progenitor and on the neutrinos themselves. In order to extract this information we need to know how the neutrino flavor evolves over time due to the interplay of neutrino self-interactions and matter effects. Additional turbulence in the supernova matter may impart its own signatures on the neutrino spectrum, and could partly obscure the imprints of collective and matter effects. We investigate the neutrino flavor evolution due to neutrino self-interactions, matter effects due to the shock wave propagation, and turbulence in three progenitors with masses of 8.8 M⊙, 10.8 M⊙ and 18.0 M⊙. In the lightest progenitor we find that the impact of moderate turbulence of the order 10% is limited and occurs only briefly early on. This makes the signatures of collective and matter interactions relatively straightforward to interpret. Similarly, with moderate turbulence the two heavier progenitors exhibit only minor changes in the neutrino spectrum, and collective and matter signatures persists. However, when the turbulence is increased to 30% and 50% the high density matter resonance features in the neutrino spectrum get obscured, while new features arise in the low density resonance channel and in the non-resonant channels. We conclude that with moderate amounts of turbulence spectral features of collective and matter interactions survive in all three progenitors. For the larger amounts of turbulence in the 10.8 M⊙ and 18.0 M⊙ progenitor new features arise, as others disappear

  20. Pedogenesis evolution of mine technosols: focus onto organic matter implication

    Science.gov (United States)

    Grégoire, Pascaud; Marilyne, Soubrand; Laurent, Lemee; Husseini Amelène, El-Mufleh Al; Marion, Rabiet; Emmanuel, Joussein

    2014-05-01

    Keywords: Mine technosols, pedogenesis, organic matter, environmental impact, pyr-GC-MS Technosols include soils subject to strong anthropogenic pressure and particularly to soil influenced by human transformed materials. In this context, abandoned mine sites contain a large amount of transformed waste materials often enriched with metals and/or metalloids. The natural evolution of technosols (pedogenesis) may induces the change in contaminants behaviour in term of stability of bearing phases, modification of pH oxydo-reduction conditions, organic matter turnover, change in permeability, or influence of vegetation cover. The fate of these elements in the soil can induce major environmental problems (contamination of biosphere and water resource). This will contribute to a limited potential use of these soils, which represent yet a large area around the world. The initial contamination of the parental material suggests that the pedological cover would stabilize the soil; however, the chemical reactivity must be taken in consideration particularly with respect to potential metal leachings. In this case, it is quite important to understand the development of soil in this specific context. Consequently, the global aims of this study are to understand the functioning of mine Technosols focusing onto the organic matter implication in their pedogenesis. Indeed, soil organic matter constitutes an heterogeneous fraction of organic compounds that plays an important role in the fate and the transport of metals and metalloids in soils. Three different soil profiles were collected representative to various mining context (contamination, time, climat), respectively to Pb-Ag, Sn and Au exploitations. Several pedological parameters were determined like CEC, pH, %Corg, %Ntot, C/N ratio, grain size distribution and chemical composition. The evolution of the nature of organic matter in Technosol was studied by elemental analyses and thermochemolysis was realized on the total and

  1. 75 FR 60480 - In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire...

    Science.gov (United States)

    2010-09-30

    ..., Inc. of City of Industry, California (collectively, ``Lincoln''). 74 FR 46223 (Sept. 8, 2009). The...''); and Sidergas SpA of Ambrogio (Verona), Italy (``Sidergas''). 74 FR 61706 (Nov. 25, 2009). Respondents... COMMISSION In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding...

  2. Simulated evolution of the dark matter large-scale structure

    CERN Document Server

    Demiański, M; Pilipenko, S; Gottlöber, S

    2011-01-01

    We analyze evolution of the basic properties of simulated large scale structure elements formed by dark matter (DM LSS) and confront it with the observed evolution of the Lyman-$\\alpha$ forest. In three high resolution simulations we selected samples of compact DM clouds of moderate overdensity. Clouds are selected at redshifts $0\\leq z\\leq 3$ with the Minimal Spanning Tree (MST) technique. The main properties of so selected clouds are analyzed in 3D space and with the core sampling approach, what allows us to compare estimates of the DM LSS evolution obtained with two different techniques and to clarify some important aspects of the LSS evolution. In both cases we find that regular redshift variations of the mean characteristics of the DM LSS are accompanied only by small variations of their PDFs, what indicates the self similar character of the DM LSS evolution. The high degree of relaxation of DM particles compressed within the LSS is found along the shortest principal axis of clouds. We see that the inter...

  3. Localization of gravity and bulk matters on a thick anti-de Sitter brane

    International Nuclear Information System (INIS)

    In this paper, we investigate the localization and the mass spectra of gravity and various bulk matter fields on a thick anti-de Sitter (AdS) brane, by presenting the mass-independent potentials of the Kaluza-Klein (KK) modes in the corresponding Schroedinger equations. For gravity, the potential of the KK modes tends to infinity at the boundaries of the extra dimension, which leads to an infinite number of the bound KK modes. Although the gravity zero mode cannot be localized on the AdS brane, the massive modes are trapped on the brane. The scalar perturbations of the thick AdS brane have been analyzed, and the brane is stable under the scalar perturbations. For spin-0 scalar fields and spin-1 vector fields, the potentials of the KK modes also tend to infinity at the boundaries of the extra dimension, and the characteristic of the localization is the same as the case of gravity. For spin-1/2 fermions, by introducing the usual Yukawa coupling ηΨφΨ with the positive coupling constant η, the four-dimensional massless left-chiral fermion and massive Dirac fermions are obtained on the AdS thick brane.

  4. Light-cone Simulations: Evolution of dark matter haloes

    CERN Document Server

    Hein"am"aki, P; Saar, E; Einasto, M; Einasto, J; Virtanen, H; Einasto, Maret; Einasto, Jaan; Virtanen, Heidi

    2005-01-01

    We present a new fast method for simulating pencil-beam type light-cones, using the MLAPM-code (Multi Level Adaptive Particle Mesh) with light-cone additions. We show that by a careful choice of the light-cone orientation, it is possible to avoid extra periodicities in the light-cone. As an example, we apply the method to simulate a 6 Gpc deep light-cone, create the dark matter halo catalogue for the light-cone and study the evolution of haloes from $z=6$ up to the present time. We determine the spatial density of the haloes, their large-scale correlation function, and study the evolution of the mass function. We find a surprisingly simple relation for the dependence of halo maximum mass on redshift, and apply it to derive redshift limits for bright quasars.

  5. The evolution of the galaxy content of dark matter haloes

    CERN Document Server

    Contreras, S; Baugh, C M; Padilla, N; Norberg, P

    2016-01-01

    We use the halo occupation distribution (HOD) framework to characterise the predictions from two independent galaxy formation models for the galactic content of dark matter haloes and its evolution with redshift. Our galaxy samples correspond to a range of fixed number densities defined by stellar mass and span $0 \\le z \\le 3$. We find remarkable similarities between the model predictions. Differences arise at low galaxy number densities which are sensitive to the treatment of heating of the hot halo by active galactic nuclei. The evolution of the form of the HOD can be described in a relatively simple way, and we model each HOD parameter using its value at $z=0$ and an additional evolutionary parameter. In particular, we find that the ratio between the characteristic halo masses for hosting central and satellite galaxies can serve as a sensitive diagnostic for galaxy evolution models. Our results can be used to test and develop empirical studies of galaxy evolution and can facilitate the construction of mock...

  6. Sub-horizon evolution of cold dark matter perturbations through dark matter-dark energy equivalence epoch

    OpenAIRE

    Piattella, O. F.; Martins, D. L. A.; Casarini, L.

    2014-01-01

    We consider a cosmological model of the late universe constituted by standard cold dark matter plus a dark energy component with constant equation of state w and constant effective speed of sound. Neglecting fluctuations in the dark energy component we obtain an equation describing the evolution of sub-horizon cold dark matter perturbations through the epoch of dark matter-dark energy equality. We explore its analytic solutions and calculate an exact w-dependent correction for the dark matter...

  7. Squarks and sleptons between branes and bulk. Gaugino meditation and gravitino dark matter in an SO(10) orbifold GUT

    Energy Technology Data Exchange (ETDEWEB)

    Kersten, J.

    2006-05-15

    We study gaugino-mediated supersymmetry breaking in a six-dimensional SO(10) orbifold GUT model where quarks and leptons are mixtures of brane and bulk fields. The couplings of bulk matter fields to the supersymmetry breaking brane field have to be suppressed in order to avoid large FCNCs. We derive bounds on the soft supersymmetry breaking parameters and calculate the superparticle mass spectrum. If the gravitino is the LSP, the {tau}{sub 1} or the {nu}{sub {tau}}{sub L} turns out to be the NLSP, with characteristic signatures at future colliders and in cosmology. (Orig.)

  8. Squarks and sleptons between branes and bulk. Gaugino meditation and gravitino dark matter in an SO(10) orbifold GUT

    International Nuclear Information System (INIS)

    We study gaugino-mediated supersymmetry breaking in a six-dimensional SO(10) orbifold GUT model where quarks and leptons are mixtures of brane and bulk fields. The couplings of bulk matter fields to the supersymmetry breaking brane field have to be suppressed in order to avoid large FCNCs. We derive bounds on the soft supersymmetry breaking parameters and calculate the superparticle mass spectrum. If the gravitino is the LSP, the τ1 or the ντL turns out to be the NLSP, with characteristic signatures at future colliders and in cosmology. (Orig.)

  9. Interplay between bulk medium evolution and (D)GLV energy loss

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Denes; Sun, Deke

    2014-12-15

    We study the consistency between high-p{sub T} nuclear suppression (R{sub AA}) and elliptic flow (v{sub 2}) using Gyulassy–Levai–Vitev (GLV) energy loss or a simpler power-law dE/dL formula, for a variety of bulk evolution models. The results generally confirm our earlier work [1] that found suppressed elliptic flow for transversely expanding media. One exception is the set of hydrodynamic solutions used recently [2] by Betz and Gyulassy, which give significantly higher v{sub 2} but unfortunately assume unrealistic bag-model equation of state. On the other hand, we show that covariant treatment of energy loss introduces an interplay between jet direction and hydrodynamic flow of the medium, which largely counteracts elliptic flow suppression caused by transverse expansion.

  10. Interplay between bulk medium evolution and (D)GLV energy loss

    CERN Document Server

    Molnar, Denes

    2014-01-01

    We study the consistency between high-pT nuclear suppression (R_AA) and elliptic flow (v2) using Gyulassy-Levai-Vitev (GLV) energy loss or a simpler power-law dE/dL formula, for a variety of bulk evolution models. The results generally confirm our earlier work [arXiv:1305.1046] that found suppressed elliptic flow for transversely expanding media. One exception is the set of hydrodynamic solutions used recently [arXiv:1305.6458] by Betz and Gyulassy, which give significantly higher v2 but unfortunately assume unrealistic bag-model equation of state. On the other hand, we show that covariant treatment of energy loss introduces an interplay between jet direction and hydrodynamic flow of the medium, which largely counteracts elliptic flow suppression caused by transverse expansion.

  11. Evolution of soil organic matter composition during long-term bare fallow

    Science.gov (United States)

    Plante, A. F.; Barre, P.; Cecillon, L.

    2012-12-01

    Much of our understanding of soil organic matter (SOM) dynamics stems from results of isotopic (stable and radiocarbon) analyses and decomposition studies. The large majority of decomposition studies involve laboratory incubation experiments, which have several limitations that provide an incomplete picture of SOM dynamics due to their short duration compared to the mean turnover times estimated from isotopic analyses, and due to the constant and optimal conditions typically used. Long-term bare fallow (LTBF) experiments (in which C inputs have been stopped for several decades) provide a unique opportunity to study the evolution of SOM during extended periods of decomposition without fresh organic inputs from growing plants. These experiments are essentially decades-long incubation experiments conducted under field conditions. The objective of the current study was to examine the evolution of SOM composition under LTBF conditions in order to better understand SOM stabilization mechanisms and to better predict the vulnerability of SOM to disturbance and climate change. The evolution of energetic and chemical characteristics of bulk SOM was studied in five LTBF experiments across Europe: Askov (DK), Grignon (FR), Rothamsted (UK), Ultuna (SW) and Versailles (FR), using simultaneous thermal analysis (i.e., thermogravimetry (TG), differential scanning calorimetry (DSC) and evolved CO2 gas analysis (CO2-EGA)) and diffuse reflectance Fourier transformed mid-infrared spectroscopy (DRIFT-MIRS). Our results showed that in spite of the heterogeneity of the soils at the LTBF sites, generalized energetic and chemical pathways exist for SOM decomposition and stabilization. The DRIFT-MIRS indices demonstrated that long-term SOM decomposition is accompanied by a consistent evolution of its bulk chemical composition across most sites. The increased burning temperature and lower energy density of stable SOM suggest that SOM stability may be a function of high activation energy cost

  12. Microstructure, flow behavior, and bulk texture evolution of cold drawn copper–silver composites

    Energy Technology Data Exchange (ETDEWEB)

    Dodla, S., E-mail: srihari.dodla@st.ovgu.de [Institut für Mechanik, Otto-von-Guericke-Universität Magdeburg, D-39106 Magdeburg (Germany); Thiem, P.; Krüger, M. [Institut für Werkstoff- und Fügetechnik, Otto-von-Guericke-Universität Magdeburg, D-39106 Magdeburg (Germany); Dietrich, D. [Institut für Werkstoffwissenschaft und Werkstofftechnik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Bertram, A. [Institut für Mechanik, Otto-von-Guericke-Universität Magdeburg, D-39106 Magdeburg (Germany)

    2015-10-25

    In the last 20 years, several groups used nanostructured composites to produce high strength conductor materials for magnetic applications. The mechanical strength of Cu–Ag composites is strongly influenced by metal forming operations. Within the scope of the paper, the microstructure, the mechanical behavior, and the texture evolution are investigated for two cold drawn Cu-63wt%Ag composite rods. The aim of these investigations is to understand the influence of the microstructure and texture evolution on the mechanical behavior. The investigation is carried out using optical microscopy, scanning electron microscopy (SEM) along with electron backscattered diffraction (EBSD), X-ray diffraction measurements (XRD), and compression testing. The microscopic images show that the drawn samples mainly have a lamellar structure of Cu and Ag phases. However, elliptical shaped regions of primarily solidified copper solid solution are also observed. With increase of plastic deformation, the average lamella thickness of both phases has been decreased. EBSD measurements show that abundant banded regions are observed in the Ag phase while very few banded regions are present in the Cu phase. The bulk XRD measurements reveal that both phases of the drawn samples initially have the same type of texture, and both phases develop the same brass-type [110]〈112〉 texture. The texture intensity increases for both phases as the drawing strain increases. Compression tests are performed at constant strain rate of 10{sup −4} s{sup −1} at room temperature. The stress–strain curves under compression are presented for two different drawn samples. The texture measurements after compression reveal that the texture becomes more pronounced. - Highlights: • Two cold drawn Cu–Ag rods are investigated. • Both phases of the drawn samples initially have the same type of texture. • Several banded regions are observed in the Ag phase. • Texture becomes more pronounced after compression.

  13. Microstructure, flow behavior, and bulk texture evolution of cold drawn copper–silver composites

    International Nuclear Information System (INIS)

    In the last 20 years, several groups used nanostructured composites to produce high strength conductor materials for magnetic applications. The mechanical strength of Cu–Ag composites is strongly influenced by metal forming operations. Within the scope of the paper, the microstructure, the mechanical behavior, and the texture evolution are investigated for two cold drawn Cu-63wt%Ag composite rods. The aim of these investigations is to understand the influence of the microstructure and texture evolution on the mechanical behavior. The investigation is carried out using optical microscopy, scanning electron microscopy (SEM) along with electron backscattered diffraction (EBSD), X-ray diffraction measurements (XRD), and compression testing. The microscopic images show that the drawn samples mainly have a lamellar structure of Cu and Ag phases. However, elliptical shaped regions of primarily solidified copper solid solution are also observed. With increase of plastic deformation, the average lamella thickness of both phases has been decreased. EBSD measurements show that abundant banded regions are observed in the Ag phase while very few banded regions are present in the Cu phase. The bulk XRD measurements reveal that both phases of the drawn samples initially have the same type of texture, and both phases develop the same brass-type [110]〈112〉 texture. The texture intensity increases for both phases as the drawing strain increases. Compression tests are performed at constant strain rate of 10−4 s−1 at room temperature. The stress–strain curves under compression are presented for two different drawn samples. The texture measurements after compression reveal that the texture becomes more pronounced. - Highlights: • Two cold drawn Cu–Ag rods are investigated. • Both phases of the drawn samples initially have the same type of texture. • Several banded regions are observed in the Ag phase. • Texture becomes more pronounced after compression

  14. Bulk Fabrication of WS2 Nanoplates: Investigation on the Morphology Evolution and Electrochemical Performance.

    Science.gov (United States)

    Qian, Jingwen; Peng, Zhijian; Wang, Peilun; Fu, Xiuli

    2016-07-01

    Two-dimensional layered chalcogenide WS2, similar to graphene, is considered to be very interesting for materials scientists. However, to make it a useful material platform, it is necessary to develop sophisticated synthesis methods to control its morphology. In this paper, we present a simple approach to prepare various morphologies of WS2 nanostructures by direct thermal evaporation of WO3 and S powders onto Si substrates sputtered with W film without using any nanostructured W-contained precursors and highly toxic sulfide gases. This method can produce bulk quantities of pure hexagonal, horizontally grown WS2 nanoplates, vertically grown nanoplates, and nanoplate-formed flowers simply by tuning the distance between the substrate and source powders. The synthesis mechanism and morphology evolution model were proposed. Moreover, when employed as a thin-film anode material, the Li-ion battery with as-prepared, vertically grown WS2 nanoplates presented a rechargeable performance between 3 and 0.01 V with a discharge capacity of about 773 mAh/cm(3) after recycling three times, much better than its already-reported counterparts with randomly distributed WS2 nanosheet electrodes, but the battery with horizontally grown WS2 nanoplates could not show any charge-discharge cycling property, which could be attributed to the different structures of WS2 anodes for Li(+) ion intercalation or deintercalation. PMID:27295215

  15. Characteristics and trihalomethane formation reactivity of dissolved organic matter in effluents from membrane bioreactors with and without filamentous bulking.

    Science.gov (United States)

    Xia, Chufan; Ma, Defang; Gao, Baoyu; Hu, Xinxiao; Yue, Qinyan; Meng, Yingjie; Kang, Shuyu; Zhang, Bei; Qi, Yuanfeng

    2016-07-01

    In this study, synthetic wastewater was treated by two identical membrane bioreactors (MBRs): the normal sludge MBR (NS-MBR) and the bulking sludge MBR (BS-MBR). Effects of filamentous bulking on the characteristics and trihalomethane (THM) formation reactivity of MBR effluent dissolved organic matter (EfOM) were investigated. Filamentous sludge bulking had no significant influence on the regulated MBR effluent water quality except NO2-N and NO3-N. NS-MBR effluent had more low molecular weight (LMW) (<5kDa) EfOM (92.43%) than BS-MBR (75.18%). About two-thirds of EfOM from BS-MBR were hydrophilic substances. On the contrary, EfOM from NS-MBR exhibited higher hydrophobicity. The ratio of polysaccharides and proteins in MBR effluents increased after filamentous bulking. There were more protein-like materials, fulvic acid-like and humic acid-like in BS-MBR EfOM. The THM formation reactivity of BS-MBR EfOM was 30.15% of NS-MBR EfOM, whereas BS-MBR EfOM exhibited higher formation reactivity of bromine containing species. PMID:27017128

  16. A simple model linking galaxy and dark matter evolution

    International Nuclear Information System (INIS)

    We construct a simple phenomenological model for the evolving galaxy population by incorporating predefined baryonic prescriptions into a dark matter hierarchical merger tree. The model is based on the simple gas-regulator model introduced by Lilly et al., coupled with the empirical quenching rules of Peng et al. The simplest model already does quite well in reproducing, without re-adjusting the input parameters, many observables, including the main sequence sSFR-mass relation, the faint end slope of the galaxy mass function, and the shape of the star forming and passive mass functions. Similar to observations and/or the recent phenomenological model of Behroozi et al., which was based on epoch-dependent abundance-matching, our model also qualitatively reproduces the evolution of the main sequence sSFR(z) and SFRD(z) star formation rate density relations, the Ms – Mh stellar-to-halo mass relation, and the SFR – Mh relation. Quantitatively the evolution of sSFR(z) and SFRD(z) is not steep enough, the Ms – Mh relation is not quite peaked enough, and, surprisingly, the ratio of quenched to star forming galaxies around M* is not quite high enough. We show that these deficiencies can simultaneously be solved by ad hoc allowing galaxies to re-ingest some of the gas previously expelled in winds, provided that this is done in a mass-dependent and epoch-dependent way. These allow the model galaxies to reduce an inherent tendency to saturate their star formation efficiency, which emphasizes how efficient galaxies around M* are in converting baryons into stars and highlights the fact that quenching occurs at the point when galaxies are rapidly approaching the maximum possible efficiency of converting baryons into stars.

  17. Evolution of the Dark Matter Distribution at the Galactic Center

    OpenAIRE

    Merritt, David

    2003-01-01

    Annihilation radiation from neutralino dark matter at the Galactic center (GC) would be greatly enhanced if the dark matter were strongly clustered around the supermassive black hole (SBH). The existence of a dark-matter "spike" is made plausible by the observed, steeply-rising stellar density near the GC SBH. Here the time-dependent equations describing gravitational interaction of the dark matter particles with the stars are solved. Scattering of dark matter particles by stars would substan...

  18. Microstructure evolution and mechanical properties of Nb-alloyed Cu-based bulk metallic glasses and composites

    International Nuclear Information System (INIS)

    Highlights: • The microstructures of as-cast BMGs undergo a composite-amorphous evolution. • The 15.1% of plasticity and the 2205 MPa of fracture strength are achieved. • The dispersed crystals in glassy matrix enhance the plasticity of BMG. - Abstract: This paper reports the microstructure evolution of Cu50.2 Zr40.8Ti9−xNbx (x = 0.5, 1.0, and 2.0 at.%) bulk metallic glass and bulk metallic glass composites accompanied with the addition of Nb and the corresponding mechanical properties. The X-ray diffraction and characterization of microstructures demonstrate that the microstructures of as-cast alloys undergo a composite-amorphous evolution. DSC analysis indicates that the glass-forming ability of as-cast alloys increases with addition of Nb. The microstructure evolution can be contributed to the combination of the stabilization of Nb on precipitated crystalline phases and cooling time. 1.0 at.% Nb-alloyed sample has the best plasticity (15.1%) and the highest fracture strength (2205 MPa) among three as-cast alloys. This work suggests that the uniformly dispersed tiny crystalline phases in glassy matrix can enhance the plasticity of bulk metallic glasses

  19. Evolution of Characteristic Quantities for Dark Matter Halo Density Profiles

    CERN Document Server

    Romano-Diaz, E; Heller, C; Faltenbacher, A; Jones, D; Shlosman, I; Romano-Diaz, Emilio; Hoffman, Yehuda; Heller, Clayton; Faltenbacher, Andreas; Jones, Daniel; Shlosman, Isaac

    2006-01-01

    We investigate the effect of an assembly history on the evolution of dark matter (DM) halos of 10^{12} Msun/h using Constrained Realizations of random Gaussian fields. Five different realizations of a DM halo with distinct merging histories were constructed and evolved. Our main results are: A halo evolves via a sequence of quiescent phases of a slow mass accretion intermitted by violent episodes of major mergers. In the quiescent phases, the density is well fitted by an NFW profile, the inner scale radius Rs and the mass enclosed within it remain constant, and the virial radius (Rvir) grows linearly with the expansion parameter "a". Within each quiescent phase the concentration parameter ("c") scales as "a", and the mass accretion history (Mvir) is well described by the Tasitsiomi etal. fitting formula. In the violent phases the halos are not in a virial equilibrium and both Rs and Rvir grow discontinuously. The violent episodes drive the halos from one NFW dynamical equilibrium to another. The final structu...

  20. Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

    Science.gov (United States)

    Maeng, Sung Kyu; Sharma, Saroj K.; Abel, Chol D. T.; Magic-Knezev, Aleksandra; Song, Kyung-Guen; Amy, Gary L.

    2012-10-01

    Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM.

  1. Constraining a matter-dominated cosmological model with bulk viscosity proportional to the Hubble parameter

    CERN Document Server

    Avelino, Arturo

    2008-01-01

    We present and constrain a cosmological model where the only component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a bulk viscosity coefficient proportional to the Hubble parameter. The model is constrained using the SNe Ia Gold 2006 sample, the Cosmic Microwave Background (CMB) shift parameter R, the Baryon Acoustic Oscillation (BAO) peak A and the Second Law of Thermodynamics (SLT). It was found that this model is in agreement with the SLT using only the SNe Ia test. However when the model is constrained using the three cosmological tests together (SNe+CMB+BAO) we found: 1.- The model violates the SLT, 2.- It predicts a value of H_0 \\approx 53 km sec^{-1} Mpc^{-1} for the Hubble constant, and 3.- We obtain a bad fit to data with a \\chi^2_{min} \\approx 532. These results indicate that this model is viable just if the bulk viscosity is triggered in recent times.

  2. Sub-horizon evolution of cold dark matter perturbations through dark matter-dark energy equivalence epoch

    International Nuclear Information System (INIS)

    We consider a cosmological model of the late universe constituted by standard cold dark matter plus a dark energy component with constant equation of state w and constant effective speed of sound. By neglecting fluctuations in the dark energy component, we obtain an equation describing the evolution of sub-horizon cold dark matter perturbations through the epoch of dark matter-dark energy equality. We explore its analytic solutions and calculate an exact w-dependent correction for the dark matter growth function, logarithmic growth function and growth index parameter through the epoch considered. We test our analytic approximation with the numerical solution and find that the discrepancy is less than 1% for 0k = during the cosmic evolution up to a = 100

  3. Sub-horizon evolution of cold dark matter perturbations through dark matter-dark energy equivalence epoch

    Energy Technology Data Exchange (ETDEWEB)

    Piattella, O.F.; Martins, D.L.A.; Casarini, L., E-mail: oliver.piattella@pq.cnpq.br, E-mail: denilsonluizm@gmail.com, E-mail: casarini.astro@gmail.com [Department of Physics, Universidade Federal do Espírito Santo, avenida Ferrari 514, 29075-910 Vitória, Espírito Santo (Brazil)

    2014-10-01

    We consider a cosmological model of the late universe constituted by standard cold dark matter plus a dark energy component with constant equation of state w and constant effective speed of sound. By neglecting fluctuations in the dark energy component, we obtain an equation describing the evolution of sub-horizon cold dark matter perturbations through the epoch of dark matter-dark energy equality. We explore its analytic solutions and calculate an exact w-dependent correction for the dark matter growth function, logarithmic growth function and growth index parameter through the epoch considered. We test our analytic approximation with the numerical solution and find that the discrepancy is less than 1% for 0k = during the cosmic evolution up to a = 100.

  4. Internal structural evolution and enhanced tensile plasticity of Ti-based bulk metallic glass and composite via cold rolling

    International Nuclear Information System (INIS)

    Highlights: • Enhancement of tensile plasticity was achieved by cold rolling. • The malleable behavior of cold rolled samples is attributed to the atomic structural evolution and elastic property change. • Shear softened region act as a potential nucleation site of shear bands. - Abstract: The influence of cold rolling on the tensile mechanical properties and deformation behavior of Ti-based bulk metallic glass (BMG: Ti40Zr25Ni8Cu9Be18) and β-Ti dendrite reinforced bulk metallic glass matrix composite (BMGMC: Ti40.2Zr18Ni2.85Cu7.65Be12.3Nb19) has been investigated. The cold-rolled BMG and BMGMC samples with 20% thickness reduction ratio exhibit a pronounced tensile plasticity of 0.8% and 4%, respectively. The malleable behavior of the cold-rolled samples originates from the internal structural evolution and modulation of elastic properties

  5. Occurrence and fate of bulk organic matter and pharmaceutically active compounds in managed aquifer recharge: A review

    KAUST Repository

    Maeng, Sungkyu

    2011-05-01

    Managed aquifer recharge (MAR) is a natural water treatment process that induces surface water to flow in response to a hydraulic gradient through soil/sediment and into a vertical or horizontal well. It is a relatively cost-effective, robust and sustainable technology. Detailed characteristics of bulk organic matter and the occurrence and fate of pharmaceutically active compounds (PhACs) during MAR processes such as bank filtration (BF) and artificial recharge (AR) were reviewed. Understanding the fate of bulk organic matter during BF and AR is an essential step in determining pre- and/or post-treatment requirements. Analysis of organic matter characteristics using a suite of analytical tools suggests that there is a preferential removal of non-humic substances during MAR. Different classes of PhACs were found to behave differently during BF and AR. Antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), beta blockers, and steroid hormones generally exhibited good removal efficiencies, especially for compounds having hydrophobic-neutral characteristics. However, anticonvulsants showed a persistent behavior during soil passage. There were also some redox-dependent PhACs. For example, X-ray contrast agents measured, as adsorbable organic iodine (AOI), and sulfamethoxazole (an antibiotic) degraded more favorably under anoxic conditions compared to oxic conditions. Phenazone-type pharmaceuticals (NSAIDs) exhibited better removal under oxic conditions. The redox transition from oxic to anoxic conditions during soil passage can enhance the removal of PhACs that are sensitive to redox conditions. In general, BF and AR can be included in a multi-barrier treatment system for the removal of PhACs. © 2011.

  6. Constraining a bulk viscous matter-dominated cosmological model using SNe Ia, CMB and LSS

    CERN Document Server

    Avelino, Arturo; Guzmán, F S

    2008-01-01

    We present and constrain a cosmological model which component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a constant bulk viscosity coefficient \\zeta_m. The possible values of \\zeta_m are constrained using the cosmological tests of SNe Ia Gold 2006 sample, the CMB shift parameter R from the three-year WMAP observations, the Baryon Acoustic Oscillation (BAO) peak A from the Sloan Digital Sky Survey (SDSS) and the Second Law of Thermodynamics (SLT). It was found that this model is in agreement with the SLT using only the SNe Ia test. However when the model is submitted to the three cosmological tests together (SNe+CMB+BAO) the results are: 1.- the model violates the SLT, 2.- predicts a value of H_0 \\approx 53 km sec^{-1} Mpc^{-1} for the Hubble constant, and 3.- we obtain a bad fit to data with a \\chi^2_{min} \\approx 400 (\\chi^2_{d.o.f.} \\approx 2.2). These results indicate that this model is ruled out by t...

  7. Time-evolution of dense hadronic matter in high energy heavy ion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Otuka, Naohiko; Ohnishi, Akira [Hokkaido Univ., Sapporo (Japan). Dept. of Physics; Nara, Yasushi; Maruyama, Tomoyuki; Niita, Koji

    1997-05-01

    Time evolution of hadronic resonance matter in ultrarelativistic nucleus-nucleus collisions are studied in the framework of cascade models. We investigate the role of higher baryonic resonances during the time evolution of hot and dense hadronic matter at AGS energies. Although final hadronic spectrum can reproduced well with and without higher baryonic resonances, the inclusion of higher resonances is shown to prevent the temperature from going beyond 200 MeV. (author)

  8. Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

    DEFF Research Database (Denmark)

    Thieme, Lisa; Graeber, Daniel; Kaupenjohann, Martin;

    2016-01-01

    Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at −18 °C and fast......-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed...... spectroscopic properties of DOM....

  9. Effects of effluent organic matter characteristics on the removal of bulk organic matter and selected pharmaceutically active compounds during managed aquifer recharge: Column study

    KAUST Repository

    Maeng, Sungkyu

    2012-10-01

    Soil column experiments were conducted to investigate the effects of effluent organic matter (EfOM) characteristics on the removal of bulk organic matter (OM) and pharmaceutically active compounds (PhACs) during managed aquifer recharge (MAR) treatment processes. The fate of bulk OM and PhACs during an MAR is important to assess post-treatment requirements. Biodegradable OM from EfOM, originating from biological wastewater treatment, was effectively removed during soil passage. Based on a fluorescence excitation-emission matrix (F-EEM) analysis of wastewater effluent-dominated (WWE-dom) surface water (SW), protein-like substances, i.e., biopolymers, were removed more favorably than fluorescent humic-like substances under oxic compared to anoxic conditions. However, there was no preferential removal of biopolymers or humic substances, determined as dissolved organic carbon (DOC) observed via liquid chromatography with online organic carbon detection (LC-OCD) analysis. Most of the selected PhACs exhibited removal efficiencies of greater than 90% in both SW and WWE-dom SW. However, the removal efficiencies of bezafibrate, diclofenac and gemfibrozil were relatively low in WWE-dom SW, which contained more biodegradable OM than did SW (copiotrophic metabolism). Based on this study, low biodegradable fractions such as humic substances in MR may have enhanced the degradation of diclofenac, gemfibrozil and bezafibrate by inducing an oligotrophic microbial community via long term starvation. Both carbamazepine and clofibric acid showed persistent behaviors and were not influenced by EfOM. © 2012 Elsevier B.V.

  10. SU(3) Polyakov linear-sigma model: bulk and shear viscosity of QCD matter in finite magnetic field

    CERN Document Server

    Tawfik, Abdel Nasser; Hussein, T M

    2016-01-01

    Due to off-center relativistic motion of the charged spectators and the local momentum-imbalance of the participants, a short-lived huge magnetic field is likely generated, especially in relativistic heavy-ion collisions. In determining the temperature dependence of bulk and shear viscosities of the QCD matter in vanishing and finite magnetic field, we utilize mean field approximation to the SU($3$) Polyakov linear-sigma model (PLSM). We compare between the results from two different approaches; Green-Kubo correlation and Boltzmann master equation with Chapman-Enskog expansion. We find that both approaches have almost identical results, especially in the hadron phase. In the temperature dependence of bulk and shear viscosities relative to thermal entropy at the critical temperature, there is a rapid decrease in the chiral phase-transition and in the critical temperature with increasing magnetic field. As the magnetic field strength increases, a peak appears at the critical temperature ($T_c$). This can be und...

  11. The basic postulates of the universal evolution model «Evolving matter»

    Directory of Open Access Journals (Sweden)

    Bazaluk Oleg

    2015-02-01

    Full Text Available The author reveals the features of construction of the universal evolution model, which he called «Evolving matter». According to the author, the material world, which is perceived in scales of the Earth and near space, consists of visually and empirically easily detectable states of matter, with different complexity of the internal organisation: inert, living and intelligent matter. The transition from one («parent» state of matter to another («daughter» state is caused by three main factors and two reasons of evolution. The author has carried the following factors of evolution as a complication: a Continuity of self-complication structures, types of interaction and environments of existence of any state of matter, which is supplemented by: – Block of continuous self-complication; – Principle of block of continuous self-complication of dominance; b Nonlinear complication of structure, types of interactions and environments of existence of any state of matter, which is specified by factors: – Hierarchical nonlinear complication; – Orientation of nonlinear hierarchical complication; c Complication isolation. The author carries complications to the evolution reasons: a Active principle, which is inherently the basis for the initial elements of any state of matter, and which forms a self-complication; b Natural selection as the environment influence.

  12. Cosmological Evolution With Interaction Between Dark Energy And Dark Matter

    OpenAIRE

    Bolotin, Yu. L.; Kostenko, A.; Lemets, O. A.; Yerokhin, D. A.

    2013-01-01

    In this review we consider in detail different theoretical topics associated with interaction in the dark sector. We study linear and nonlinear interactions which depend on the dark matter and dark energy densities. We consider a number of different models (including the holographic dark energy and dark energy in a fractal universe) with interacting dark energy (DE) and dark matter (DM), have done a thorough analysis of these models. The main task of this review was not only to give an idea a...

  13. Exact solutions of bulk viscous with string cloud attached to strange quark matter for higher dimensional FRW universe in Lyra geometry

    Science.gov (United States)

    Ćaǧlar, Halife; Aygün, Sezgin

    2016-03-01

    In this study, we have investigated bulk viscous with strange quark matter attached to the string cloud for higher dimensional Friedman-Robertson-Walker (FRW) universe in Lyra geometry. By using varying deceleration parameter and conservation equations we have solved Einstein Field Equations (EFE's) and obtained generalized exact solutions for our model. Also we have found that string is not survived for bulk viscous with strange quark matter attached to the string cloud in framework higher dimensional FRW universe in Lyra geometry. This result agrees with Kiran and Reddy, Krori et al, Sahoo and Mishra and Mohanty et al. in four and five dimensions.

  14. Evolution of specialization and ecological character displacement: metabolic plasticity matters.

    NARCIS (Netherlands)

    C.J.M. Egas

    2005-01-01

    An important question in evolutionary biology, especially with respect to herbivorous arthropods, is the evolution of specialization. In a previous paper, the combined evolutionary dynamics of specialization and ecological character displacement was studied, focusing on the role of herbivore foragin

  15. Evolution and Dynamics of a Matter creation model

    CERN Document Server

    Pan, Supriya; Paliathanasis, Andronikos; Slagter, Reinoud Jan

    2016-01-01

    In the flat Friedmann-Lema\\^{\\i}tre-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the expanding universe, we have considered a general creation rate and analyzed this rate in the framework of dynamical analysis. The dynamical analysis hints the presence of a non-singular universe (without the big bang singularity) with two successive accelerated phases, one at the very early phase of the universe (i.e., inflation), and the other one describes the current accelerating universe, where this early, late accelerated phases are associated with an unstable fixed point (i.e., repeller) and a stable fixed (attractor) points, respectively. We have described this phenomena by analytic solutions of the Hubble function and the scale factor of the FLRW universe. Using Jacobi Last multiplier method, we have found a Lagrangian for this matter creation rate describing this scenar...

  16. The structure and evolution of cold dark matter halos

    CERN Document Server

    Diemand, Jürg

    2009-01-01

    In the standard cosmological model a mysterious cold dark matter (CDM) component dominates the formation of structures. Numerical studies of the formation of CDM halos have produced several robust results that allow unique tests of the hierarchical clustering paradigm. Universal properties of halos, including their mass profiles and substructure properties are roughly consistent with observational data from the scales of dwarf galaxies to galaxy clusters. Resolving the fine grained structure of halos has enabled us to make predictions for ongoing and planned direct and indirect dark matter detection experiments. While simulations of pure CDM halos are now very accurate and in good agreement (recently claimed discrepancies are addressed in detail in this review), we are still unable to make robust, quantitative predictions about galaxy formation and about how the dark matter distribution changes in the process. Whilst discrepancies between observations and simulations have been the subject of much debate in th...

  17. Guided Evolution of Bulk Metallic Glass Nanostructures: A Platform for Designing 3D Electrocatalytic Surfaces.

    Science.gov (United States)

    Doubek, Gustavo; Sekol, Ryan C; Li, Jinyang; Ryu, Won-Hee; Gittleson, Forrest S; Nejati, Siamak; Moy, Eric; Reid, Candy; Carmo, Marcelo; Linardi, Marcelo; Bordeenithikasem, Punnathat; Kinser, Emily; Liu, Yanhui; Tong, Xiao; Osuji, Chinedum O; Schroers, Jan; Mukherjee, Sundeep; Taylor, André D

    2016-03-01

    Electrochemical devices such as fuel cells, electrolyzers, lithium-air batteries, and pseudocapacitors are expected to play a major role in energy conversion/storage in the near future. Here, it is demonstrated how desirable bulk metallic glass compositions can be obtained using a combinatorial approach and it is shown that these alloys can serve as a platform technology for a wide variety of electrochemical applications through several surface modification techniques. PMID:26689722

  18. Internal structural evolution and enhanced tensile plasticity of Ti-based bulk metallic glass and composite via cold rolling

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.M., E-mail: jinman_park@hotmail.com [Global Technology Center, Samsung Electronics Co., Ltd., Suwon, Gyeonggi-do 443-742 (Korea, Republic of); Lim, K.R. [Light Metal Division, Korea Institute of Materials Science, 797 Changwondaero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Park, E.S.; Hong, S.; Park, K.H. [Global Technology Center, Samsung Electronics Co., Ltd., Suwon, Gyeonggi-do 443-742 (Korea, Republic of); Eckert, J. [IFW Dresden, Institute for Complex Materials, P.O. Box 27 01 16, D-01171 Dresden (Germany); TU Dresden, Institute of Materials Science, D-01062 Dresden (Germany); Kim, D.H., E-mail: dohkim@yonsei.ac.kr [Center for Non-crystalline Materials, Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2014-12-05

    Highlights: • Enhancement of tensile plasticity was achieved by cold rolling. • The malleable behavior of cold rolled samples is attributed to the atomic structural evolution and elastic property change. • Shear softened region act as a potential nucleation site of shear bands. - Abstract: The influence of cold rolling on the tensile mechanical properties and deformation behavior of Ti-based bulk metallic glass (BMG: Ti{sub 40}Zr{sub 25}Ni{sub 8}Cu{sub 9}Be{sub 18}) and β-Ti dendrite reinforced bulk metallic glass matrix composite (BMGMC: Ti{sub 40.2}Zr{sub 18}Ni{sub 2.85}Cu{sub 7.65}Be{sub 12.3}Nb{sub 19}) has been investigated. The cold-rolled BMG and BMGMC samples with 20% thickness reduction ratio exhibit a pronounced tensile plasticity of 0.8% and 4%, respectively. The malleable behavior of the cold-rolled samples originates from the internal structural evolution and modulation of elastic properties.

  19. Chemical evolution of circumstellar matter around young stellar objects

    Science.gov (United States)

    van Dishoeck, E. F.; Blake, G. A.

    1995-01-01

    Recent observational studies of the chemical composition of circumstellar matter around both high- and low-mass young stellar objects are reviewed. The molecular abundances are found to be a strong function of evolutionary state, but not of system mass or luminosity. The data are discussed with reference to recent theoretical models.

  20. Evolution and dynamics of a matter creation model

    Science.gov (United States)

    Pan, S.; Haro, J. de; Paliathanasis, A.; Slagter, R. J.

    2016-08-01

    In a flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the expanding universe, we have considered a general creation rate and analysed this rate in the framework of dynamical analysis. The dynamical analysis hints the presence of a non-singular universe (without the big bang singularity) with two successive accelerated phases, one at the very early phase of the universe (i.e. inflation), and the other one describes the current accelerating universe, where this early, late accelerated phases are associated with an unstable fixed point (i.e. repeller) and a stable fixed point (attractor), respectively. We have described this phenomena by analytic solutions of the Hubble function and the scale factor of the FLRW universe. Using Jacobi last multiplier method, we have found a Lagrangian for this matter creation rate describing this scenario of the universe. To match with our early physics results, we introduce an equivalent dynamics driven by a single scalar field, discuss the associated observable parameters and compare them with the latest Planck data sets. Finally, introducing the teleparallel modified gravity, we have established an equivalent gravitational theory in the framework of matter creation.

  1. Evolution and Dynamics of a Matter creation model

    Science.gov (United States)

    Pan, S.; Haro, J. de; Paliathanasis, A.; Slagter, R. J.

    2016-05-01

    In a flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the expanding universe, we have considered a general creation rate and analyzed this rate in the framework of dynamical analysis. The dynamical analysis hints the presence of a non-singular universe (without the big bang singularity) with two successive accelerated phases, one at the very early phase of the universe (i.e. inflation), and the other one describes the current accelerating universe, where this early, late accelerated phases are associated with an unstable fixed point (i.e. repeller) and a stable fixed (attractor) points, respectively. We have described this phenomena by analytic solutions of the Hubble function and the scale factor of the FLRW universe. Using Jacobi Last multiplier method, we have found a Lagrangian for this matter creation rate describing this scenario of the universe. To match with our early physics results, we introduce an equivalent dynamics driven by a single scalar field and discussed the associated observable parameters compared them with the latest PLANCK data sets. Finally, introducing the teleparallel modified gravity, we have established an equivalent gravitational theory in the framework of matter creation.

  2. Cosmological evolution with interaction between dark energy and dark matter

    Science.gov (United States)

    Bolotin, Yuri L.; Kostenko, Alexander; Lemets, Oleg A.; Yerokhin, Danylo A.

    2015-12-01

    In this review we consider in detail different theoretical topics associated with interaction in the dark sector. We study linear and nonlinear interactions which depend on the dark matter and dark energy densities. We consider a number of different models (including the holographic dark energy and dark energy in a fractal universe), with interacting dark energy and dark matter, have done a thorough analysis of these models. The main task of this review was not only to give an idea about the modern set of different models of dark energy, but to show how much can be diverse dynamics of the universe in these models. We find that the dynamics of a universe that contains interaction in the dark sector can differ significantly from the Standard Cosmological Model.

  3. Cosmological Evolution With Interaction Between Dark Energy And Dark Matter

    CERN Document Server

    Bolotin, Yu L; Lemets, O A; Yerokhin, D A

    2013-01-01

    In this review we consider in detail different theoretical topics associated with interaction in the dark sector. We study linear and nonlinear interactions which depend on the dark matter and dark energy densities. We consider a number of different models (including the holographic dark energy and dark energy in a fractal universe) with interacting dark energy (DE) and dark matter (DM), have done a thorough analysis of these models. The main task of this review was not only to give an idea about the modern set of different models of dark energy, but to show how much can be diverse dynamics of the universe in these models. We find that the dynamics of a Universe that contains interaction in the dark sector can differ significantly from the Standard Cosmological Model (SCM).

  4. Evolution of cosmological perturbations in Bose-Einstein condensate dark matter

    OpenAIRE

    Harko, TC

    2011-01-01

    We consider the global cosmological evolution and the evolution of the density contrast in the Bose–Einstein condensate dark matter model, in the framework of a post-Newtonian cosmological approach. In the Bose–Einstein model, dark matter can be described as a non-relativistic, Newtonian gravitational condensate, whose density and pressure are related by a barotropic equation of state. For a condensate with quartic non-linearity, the equation of state is polytropic with index n= 1.The basic e...

  5. Shear and bulk viscosities of quark matter from quark-meson fluctuations in the Nambu-Jona-Lasinio model

    Science.gov (United States)

    Ghosh, Sabyasachi; Peixoto, Thiago C.; Roy, Victor; Serna, Fernando E.; Krein, Gastão

    2016-04-01

    We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses and quark-meson couplings are obtained in the Nambu-Jona-Lasinio model. We found a nontrivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios η /s and ζ /s , where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasiparticle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η /s has a minimum very close to the quantum lower bound, η /s =1 /4 π .

  6. Shear and Bulk Viscosities of Quark Matter from Quark-Meson Fluctuations in the Nambu--Jona-Lasinio model

    CERN Document Server

    Ghosh, Sabyasachi; Roy, Victor; Serna, Fernando E; Krein, Gastão

    2015-01-01

    We have calculated the temperature dependence of shear $\\eta$ and bulk $\\zeta$ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-$\\pi$ and quark-$\\sigma$ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses, and quark-meson couplings are obtained in the Nambu--Jona-Lasinio model. We found a non-trivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios $\\eta/s$ and $\\zeta/s$, where $s$ is the entropy density (also determined in the Nambu--Jona-Lasinio model in the quasi-particle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for $\\eta/s$ has a minimum very close to the conjectured AdS/CFT lower bound, $\\eta/s = 1/4\\pi$.

  7. Can dark matter induce cosmological evolution of the fundamental constants of Nature?

    CERN Document Server

    Stadnik, Y V

    2015-01-01

    Traditional theories, which predict the cosmological evolution of the fundamental constants of Nature, assume that the underlying fields, which give rise to this evolution, are unnaturally light. We demonstrate that massive fields, such as dark matter, also directly produce a cosmological evolution of the fundamental constants. We consider the specific model of a scalar dark matter field $\\phi$, which interacts with Standard Model particles via quadratic couplings in $\\phi$. In this particular model, cosmological evolution of the fundamental constants arises due to changes in $\\left$ in time and space. The most stringent constraints on the physical parameters of the present model come from measurements of the neutron-proton mass difference at the time of the weak interaction freeze-out.

  8. Non-conservative evolution in Algols: where is the matter?

    CERN Document Server

    Deschamps, Romain; Jorissen, Alain; Siess, Lionel; Baes, Marteen; Camps, Peter

    2015-01-01

    There is gathering indirect evidence suggesting non-conservative evolutions in Algols. However, the systemic mass-loss rate is poorly constrained by observations and generally set as a free parameter in binary-star evolution simulations. Moreover, systemic mass loss may lead to observational signatures that are still to be found. We investigate the impact of the outflowing gas and the possible presence of dust grains on the spectral energy distribution (SED). We used the 1D plasma code Cloudy and compared the results with the 3D Monte-Carlo radiative transfer code Skirt for dusty simulations. The circumbinary mass-distribution and binary parameters are computed with state-of-the-art binary calculations done with the Binstar evolution code. The outflowing material reduces the continuum flux-level of the stellar SED in the optical and UV. Due to the time-dependence of this effect, it may help to distinguish between different ejection mechanisms. Dust, if present, leads to observable infrared excesses even with ...

  9. Dynamical Evolution of Primordial Dark Matter Haloes through Mergers

    OpenAIRE

    Ogiya, Go; Nagai, Daisuke; Ishiyama, Tomoaki

    2016-01-01

    Primordial dark matter (DM) haloes are the smallest gravitationally bound DM structures from which the first stars, black holes, and galaxies form and grow in the early universe. However, their structures are sensitive to the free streaming scale of DM, which in turn depends on the nature of DM particles. In this work, we test the hypothesis that the slope of the central cusps in primordial DM haloes near the free streaming scale depends on the nature of merging process. By combining and anal...

  10. Investigation of the microcrack evolution in a Ti-based bulk metallic glass matrix composite

    Institute of Scientific and Technical Information of China (English)

    Yongsheng Wang; Zhenxi Guo; Rui Ma; Guojian Hao; Yong Zhang; Junpin Lin; Manling Sui

    2014-01-01

    The initiation and evolution behavior of the shear-bands and microcracks in a Ti-based metallic-glass-matrix composite (MGMC) were investigated by using an in-situ tensile test under transmission electron microscopy (TEM). It was found that the plastic deformation of the Ti-based MGMC related with the generation of the plastic deformation zone in crystalline and shear deformation zone in glass phase near the crack tip. The dendrites can suppress the propagation of the shear band effectively. Before the rapid propagation of cracks, the extending of plastic deformation zone and shear deformation zone ahead of crack tip is the main pattern in the composite.

  11. Dynamical Evolution of Primordial Dark Matter Haloes through Mergers

    CERN Document Server

    Ogiya, Go; Ishiyama, Tomoaki

    2016-01-01

    Primordial dark matter (DM) haloes are the smallest gravitationally bound DM structures from which the first stars, black holes, and galaxies form and grow in the early universe. However, their structures are sensitive to the free streaming scale of DM, which in turn depends on the nature of DM particles. In this work, we test the hypothesis that the slope of the central cusps in primordial DM haloes near the free streaming scale depends on the nature of merging process. By combining and analysing data from a cosmological simulation with the cutoff in the small-scale matter power spectrum as well as a suite of controlled, high-resolution simulations of binary mergers, we find that (1) the primordial DM haloes form preferentially through major mergers in radial orbits and that (2) their central DM density profile is more susceptible to a merging process compared to that of galaxy and cluster-size DM haloes. Our work highlights the importance of dynamical processes on the structure formation during the Dark Age...

  12. Nonlinear Evolution of Cosmological Structures in Warm Dark Matter Models

    CERN Document Server

    Schneider, Aurel; Maccio, Andrea V; Moore, Ben

    2011-01-01

    The dark energy dominated warm dark matter (WDM) model is a promising alternative cosmological scenario. We explore large-scale structure formation in this paradigm. We do this in two different ways: with the halo model approach and with the help of an ensemble of high resolution N-body simulations. Combining these quasi-independent approaches, leads to a physical understanding of the important processes which shape the formation of structures. We take a detailed look at the halo mass function, the concentrations and the linear halo bias of WDM. In all cases we find interesting deviations with respect to CDM. In particular, the concentration-mass relation displays a turnover for group scale dark matter haloes, for the case of WDM particles with masses of the order ~0.25 keV. This may be interpreted as a hint for top-down structure formation on small scales. We implement our results into the halo model and find much better agreement with simulations. On small scales the WDM halo model now performs as well as i...

  13. Dynamical evolution of primordial dark matter haloes through mergers

    Science.gov (United States)

    Ogiya, Go; Nagai, Daisuke; Ishiyama, Tomoaki

    2016-09-01

    Primordial dark matter (DM) haloes are the smallest gravitationally bound DM structures from which the first stars, black holes and galaxies form and grow in the early universe. However, their structures are sensitive to the free streaming scale of DM, which in turn depends on the nature of DM particles. In this work, we test the hypothesis that the slope of the central cusps in primordial DM haloes near the free streaming scale depends on the nature of merging process. By combining and analysing data from a cosmological simulation with the cutoff in the small-scale matter power spectrum as well as a suite of controlled, high-resolution simulations of binary mergers, we find that (1) the primordial DM haloes form preferentially through major mergers in radial orbits; (2) their central DM density profile is more susceptible to a merging process compared to that of galaxy- and cluster-sized DM haloes; (3) consecutive major mergers drive the central density slope to approach the universal form characterized by the Navarro-Frenk-White profile, which is shown to be robust to the impacts of mergers and serves an attractor solution for the density structure of DM haloes. Our work highlights the importance of dynamical processes on the structure formation during the Dark Ages.

  14. Evolution of Hot, Dissipative Quark Matter in Relativistic Nuclear Collisions

    OpenAIRE

    Muronga, Azwinndini; Rischke, Dirk H.(Institute for Theoretical Physics, Goethe University, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main, Germany)

    2004-01-01

    Non-ideal fluid dynamics with cylindrical symmetry in transverse direction and longitudinal scaling flow is employed to simulate the space-time evolution of the quark-gluon plasma produced in heavy-ion collisions at RHIC energies. The dynamical expansion is studied as a function of initial energy density and initial time. A causal theory of dissipative fluid dynamics is used instead of the standard theories which are acausal. We compute the parton momentum spectra and HBT radii from two-parti...

  15. Phase evolution and its effect on magnetic properties of Nd60Al10Fe20Co10 bulk metallic glass

    International Nuclear Information System (INIS)

    The thermal stability of nanocrystalline clusters, the phase evolution, and their effects on magnetic properties were studied for as-cast Nd60Al10Fe20Co10 alloy using differential scanning calorimetry curves, x-ray diffraction patterns, scanning electron microscopy, and high-resolution transition electron microscopy. Thermomagnetic curves and hysteresis loops of the bulk metallic glass were measured during the annealing process. The high thermostability of the hard magnetic properties of the samples observed is attributed to the stability of the nanocrystalline clusters upon annealing, while the slight enhancement in the magnetization is due to the precipitation of some Nd-rich metastable phases. The mechanism of thermostability of the nanocrystalline clusters and the formation of the metastable phases are discussed

  16. Free-volume evolution and its temperature dependence during rolling of Cu60Zr20Ti20 bulk metallic glass

    DEFF Research Database (Denmark)

    Cao, Q.P.; Li, J.F.; Zhou, Y.H.; Horsewell, Andy; Jiang, J.Z.

    2005-01-01

    The free-volume evolution during rolling Cu60Zr20Ti20 bulk metallic glass at room and cryogenic temperatures has been investigated by differential scanning calorimetry. When the specimen is rolled at cryogenic temperature, the free-volume content increases as the rolling proceeds first, and then...... saturates accompanied by the occurrence of phase separation as the thickness reduction exceeds 89%. If the rolling is performed at room temperature, although the free-volume content also rises in the earlier stage, it tends to decrease rather than saturate when the thickness reduction exceeds 87......%, accompanied by partial crystallization. Phase separation does not change the annihilation rate of free volume, while the appearance of crystal/amorphous boundaries can enhance the annihilation....

  17. Atomic-Scale Structural Evolution and Stability of Supercooled Liquid of a Zr-Based Bulk Metallic Glass

    International Nuclear Information System (INIS)

    In this Letter, direct experimental evidence is provided for understanding the thermal stability with respect to crystallization in the Zr41.2Ti13.8Cu12.5Ni10Be22.5 glass-forming liquid. Through high-resolution transmission electron microscopy, the atomic-structure evolution in the glass-forming liquid during the isothermal annealing process is clearly revealed. In contrast with the existing theoretical models, our results reveal that, prior to nanocrystallization, there exists a metastable state prone to forming icosahedralike atomic clusters, which impede the subsequent crystallization and hence stabilize the supercooled liquid. The outcome of the current research underpins the topological origin for the excellent thermal stability displayed by the Zr-based bulk metallic glass.

  18. On the evolution of cured voxel in bulk photopolymerization upon focused Gaussian laser exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bhole, Kiran, E-mail: kirandipali@gmail.com; Gandhi, Prasanna [Suman Mashruwala Advance Microengineering Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra 400076 (India); Kundu, T. [Department of Physics, Indian Institute of Technology Bombay, Mumbai, Maharashtra 400076 (India)

    2014-07-28

    Unconstrained depth photopolymerization is emerging as a promising technique for fabrication of several polymer microstructures such as self propagating waveguides, 3D freeform structures by bulk lithography, and polymer nanoparticles by flash exposure. Experimental observations reveal governing physics beyond Beer Lambert's law and scattering effects. This paper seeks to model unconstrained depth photopolymerization using classical nonlinear Schrödinger equation coupled with transient diffusion phenomenon. The beam propagation part of the proposed model considers scattering effects induced due to spatial variation of the refractive index as a function of the beam intensity. The critical curing energy model is used to further predict profile of polymerized voxel. Profiles of photopolymerized voxel simulated using proposed model are compared with the corresponding experimental results for several cases of exposure dose and duration. The comparison shows close match leading to conclusion that the experimentally observed deviation from Beer Lambert's law is indeed due to combined effect of diffusion of photoinitiator and scattering of light because of change in the refractive index.

  19. On the evolution of cured voxel in bulk photopolymerization upon focused Gaussian laser exposure

    Science.gov (United States)

    Bhole, Kiran; Gandhi, Prasanna; Kundu, T.

    2014-07-01

    Unconstrained depth photopolymerization is emerging as a promising technique for fabrication of several polymer microstructures such as self propagating waveguides, 3D freeform structures by bulk lithography, and polymer nanoparticles by flash exposure. Experimental observations reveal governing physics beyond Beer Lambert's law and scattering effects. This paper seeks to model unconstrained depth photopolymerization using classical nonlinear Schrödinger equation coupled with transient diffusion phenomenon. The beam propagation part of the proposed model considers scattering effects induced due to spatial variation of the refractive index as a function of the beam intensity. The critical curing energy model is used to further predict profile of polymerized voxel. Profiles of photopolymerized voxel simulated using proposed model are compared with the corresponding experimental results for several cases of exposure dose and duration. The comparison shows close match leading to conclusion that the experimentally observed deviation from Beer Lambert's law is indeed due to combined effect of diffusion of photoinitiator and scattering of light because of change in the refractive index.

  20. On the evolution of cured voxel in bulk photopolymerization upon focused Gaussian laser exposure

    International Nuclear Information System (INIS)

    Unconstrained depth photopolymerization is emerging as a promising technique for fabrication of several polymer microstructures such as self propagating waveguides, 3D freeform structures by bulk lithography, and polymer nanoparticles by flash exposure. Experimental observations reveal governing physics beyond Beer Lambert's law and scattering effects. This paper seeks to model unconstrained depth photopolymerization using classical nonlinear Schrödinger equation coupled with transient diffusion phenomenon. The beam propagation part of the proposed model considers scattering effects induced due to spatial variation of the refractive index as a function of the beam intensity. The critical curing energy model is used to further predict profile of polymerized voxel. Profiles of photopolymerized voxel simulated using proposed model are compared with the corresponding experimental results for several cases of exposure dose and duration. The comparison shows close match leading to conclusion that the experimentally observed deviation from Beer Lambert's law is indeed due to combined effect of diffusion of photoinitiator and scattering of light because of change in the refractive index.

  1. Dark Matter Halo Mergers I: Dependence on Environment & Redshift Evolution

    CERN Document Server

    Hester, J A

    2009-01-01

    This paper presents a study of the specific merger rate as a function of group membership, local environment, and redshift in a very large, $500h^{-1} Mpc$, cosmological N-body simulation, the \\textit{Millennium Simulation}. The goal is to provide environmental diagnostics of major merger populations in order to test simulations against observations and provide further constraints on major merger driven galaxy evolution scenarios. A halo sample is defined using the maximum circular velocity, which is both well defined for subhalos and closely correlated with galaxy luminosity. Subhalos, including the precursors of major mergers, are severely tidally stripped. Major mergers between subhalos are therefore extremely rare. Tidal stripping also suppresses dynamical friction, resulting in long major merger time scales when the more massive halo does not host other subhalos. In contrast, when other subhalos are present major merger time scales are several times shorter. This enhancement is likely due to inelastic un...

  2. Evolution of density and velocity profiles of matter in large voids

    CERN Document Server

    Tsizh, Maksym

    2016-01-01

    We analyse the evolution of cosmological perturbations which leads to the formation of large voids in the distribution of galaxies. We assume that perturbations are spherical and all components of the Universe - radiation, matter and dark energy - are continuous media with ideal fluid energy-momentum tensors, which interact only gravitationally. Equations of the evolution of perturbations in the comoving to cosmological background reference frame for every component are obtained from equations of conservation and Einstein's ones and are integrated by modified Euler method. Initial conditions are set at the early stage of evolution in the radiation-dominated epoch, when the scale of perturbation is mush larger than the particle horizon. Results show how the profiles of density and velocity of matter in spherical voids with different overdensity shells are formed.

  3. The joint evolution of baryons and dark matter haloes

    CERN Document Server

    Pedrosa, Susana E; Scannapieco, Cecilia

    2009-01-01

    We have studied the dark matter (DM) distribution in a approx 10^12 h^-1 M_sun mass halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. The presence of baryons produces the concentration of the DM halo with respect to its corresponding dissipationless run, but we found that this response does not only depend on the amount of baryons gathered in the central region but also on the way they have been assembled. DM and baryons affect each other in a complex way so the formation history of a galaxy plays an important role on its final total mass distribution. The Supernova (SN) feedback regulates the star formation and triggers galactic outflows not only in the central galaxy but also in their satellites. Our results suggest that, as the effects of SN feedback get stronger, satellites get less massive and can even be more easily disrupted by dynamical frict...

  4. Next-to-next-to-leading order Skyrme interaction in nuclear matter: Nuclear bulk quantities at second order in perturbation theory

    CERN Document Server

    Moghrabi, Kassem

    2016-01-01

    We present the explicit form of the next-to-next-to-leading order (N$^2$LO) Skyrme interaction in momentum space by including the fourth-order gradient potentials to the standard Skyrme interaction. With the N$^2$LO Skyrme interaction, we evaluate the second-order corrections to the nuclear bulk quantities of nuclear matter: equation of state (EoS) of isospin symmetric and pure neutron matter, density-dependent in-medium effective nucleon mass, isospin-asymmetry energy, pressure and incompressibility. These second-order contributions are ultraviolet (UV) divergent due to the zero range character of the interaction and renormalized using the techniques of dimensional regularization (DR) with the minimal subtraction scheme (MS). We adjust the 18 parameters of the interaction by performing a global fit to the nuclear bulk quantities. Besides the too strong dependence $k_F^{12}$ of several second-order corrections, a very good reproduction of a realistic nuclear matter saturation curve with all the nuclear bulk q...

  5. From the Andes to the Atlantic: the Evolution of Organic Matter in the Amazon River System

    Science.gov (United States)

    Aufdenkampe, A. K.; Mayorga, E.; Hedges, J. I.; McClain, M. E.; Llerena, C. A.; Quay, P. D.; Krusche, A. V.; Richey, J. E.

    2005-05-01

    We compare the compositions of dissolved, fine and coarse particulate organic matter fractions (DOM, FPOM and CPOM respectively) from 31 river sites in Bolivia and Peru with 18 sites along the Amazon mainstem. The diversity of sites - ranging from wet and dry Andean headwater environments, to depositional foreland reaches, to major lowland rivers - allows us to assess the compositional evolution of organic matter along a 5000 km transect draining Peru and a 3000 km transect draining Bolivia. Organic matter size fractions were assessed by concentration, elemental (%OC, %N, C/N), isotopic (13C, 14C, 15N), lignin phenol, hydrolysable amino acid, and mineral surface area analyses. Similar to previous results from the lower Amazon and from Bolivian tributaries, the degree of mineral association was the most important factor in determining the composition of riverine organic matter. However, organic matter within a size class evolves considerably from the Andes to the lowlands. The Bolivian transect showed OM fractions becoming more diagenetically altered downstream, but the Peruvian transect showed a more complicated picture. Together, data suggest that underlying changes to sediment surface area and mineralogy may be the primary control of organic matter composition with fractions, as well as between fractions. These findings highlight the importance of organo-mineral associations and the need to describe mineral phases associated with riverine organic matter.

  6. The Dynamical Response of Dark Matter to Galaxy Evolution Affects Direct-Detection Experiments

    CERN Document Server

    Petersen, Michael S; Weinberg, Martin D

    2016-01-01

    Over a handful of rotation periods, dynamical processes in barred galaxies induce non-axisymmetric structure in dark matter halos. Using n-body simulations of a Milky Way-like barred galaxy, we identify both a trapped dark-matter component, a shadow bar, and a strong response wake in the dark-matter distribution that affects the predicted dark-matter detection rates for current experiments. The presence of a baryonic disk together with well-known dynamical processes (e.g. spiral structure and bar instabilities) increase the dark matter density in the disk plane. We find that the magnitude of the combined stellar and shadow bar evolution, when isolated from the effect of the axisymmetric gravitational potential of the disk, accounts for >30% of this overall increase in disk-plane density. This is significantly larger that of previously claimed deviations from the standard halo model. The dark-matter density and kinematic wakes driven by the Milky Way bar increase the detectability of dark matter overall, espec...

  7. Late Holocene stable carbon and nitrogen isotopic variation of bulk organic matter deposited in Blackwood Sinkhole, Abaco, The Bahamas

    Science.gov (United States)

    Tamalavage, A.; van Hengstum, P. J.; Louchouarn, P.; Fall, P. L.; Donnelly, J. P.

    2015-12-01

    In the modern climate of the Bahamas, a latitudinal precipitation gradient only allows Pine (Pinus caribaea var. bahamensis) dominated forests to exist on the more mesic (humid) northern islands (Abaco, Andros, New Providence, Grand Bahamas). Previous research suggests that the northern Bahamas underwent dramatic environmental changes in the late Holocene (e.g., waves of human arrival, shifts in terrestrial vegetation and animal extinctions). However, disentangling the timing and relative forcing (climatic vs. anthropogenic) of these changes has proven challenging without high-resolution terrestrial climate records. Recently, a late Holocene decadal to multi-decadal laminated sedimentary record was recovered from Blackwood Sinkhole, on Abaco Island. The bottom of the sinkhole is characterized by anoxic, saline groundwater, while the upper, brackish meteoric lens provides a habitat to fish, algae and other organisms. Here, we present δ13Corg and δ15Norg values of bulk organic matter (OM) taken every cm of the 110 cm core to help elucidate changes in the chemical composition of the source of OM reaching the anoxic sediments of the sinkhole. δ13Corg values change at 812 Cal yrs BP (2s: 931-681 Cal yrs BP, 31.7 cm depth) from -30.5 ± 1.6‰ in the lower 80 cm of the core to -27.6 ± 1.2‰ in the upper 30 cm. There is a synchronous change from more enriched δ15N values, 3.7 ± 1.1‰, in the lower portion of the core, to lower δ15N values (1.9 ± .5‰), in the upper portion of the core. A pollen-based reconstruction of terrestrial vegetation from the same core indicates that these isotopic shifts are concomitant with a shift from a dominance of Arecaceae (Palms) and tropical dry hardwoods below 30 cm, to Pinus and Conocarpus predominance above 30 cm. These results indicate that the source of sedimentary OM deposited into the sinkhole changed coherently with regional landscape change. Biomarker analyses will be used to further identify the role of autochthonous

  8. Can Dark Matter Induce Cosmological Evolution of the Fundamental Constants of Nature?

    Science.gov (United States)

    Stadnik, Y V; Flambaum, V V

    2015-11-13

    We demonstrate that massive fields, such as dark matter, can directly produce a cosmological evolution of the fundamental constants of nature. We show that a scalar or pseudoscalar (axionlike) dark matter field ϕ, which forms a coherently oscillating classical field and interacts with standard model particles via quadratic couplings in ϕ, produces "slow" cosmological evolution and oscillating variations of the fundamental constants. We derive limits on the quadratic interactions of ϕ with the photon, electron, and light quarks from measurements of the primordial (4)He abundance produced during big bang nucleosynthesis and recent atomic dysprosium spectroscopy measurements. These limits improve on existing constraints by up to 15 orders of magnitude. We also derive limits on the previously unconstrained linear and quadratic interactions of ϕ with the massive vector bosons from measurements of the primordial (4)He abundance. PMID:26613429

  9. Thermal Evolution of Organic Matter in Source Rocks—Experimental and Scanning Electron Microscopic Studies

    Institute of Scientific and Technical Information of China (English)

    姜开侠; 潘小明

    1991-01-01

    Five major froms(lamellar,banded,crack-like,dissceminated and segregated encrustation(of organic matter distribution in sourc rocks have been revealed under scanning electron microscope by using the heavy metal staining technique.The degree of organic impregnation is related to the amount of liquied hydrocarbons in the rocks,and from this relationship a rough estimation of organic matter can be made on the basis of electron microscopic observations.In conjunction with experimental studies it has been found that the distribution forms of organic matter are a function of its maturity in the process of thermal evolution and accordingly some microscopic criteria can be developed for the assessment of source rocks.

  10. Hydrothermal Habitats: Measurements of Bulk Microbial Elemental Composition, and Models of Hydrothermal Influences on the Evolution of Dwarf Planets

    Science.gov (United States)

    Neveu, Marc Francois Laurent

    Finding habitable worlds is a key driver of solar system exploration. Many solar system missions seek environments providing liquid water, energy, and nutrients, the three ingredients necessary to sustain life. Such environments include hydrothermal systems, spatially-confined systems where hot aqueous fluid circulates through rock by convection. I sought to characterize hydrothermal microbial communities, collected in hot spring sediments and mats at Yellowstone National Park, USA, by measuring their bulk elemental composition. To do so, one must minimize the contribution of non-biological material to the samples analyzed. I demonstrate that this can be achieved using a separation method that takes advantage of the density contrast between cells and sediment and preserves cellular elemental contents. Using this method, I show that in spite of the tremendous physical, chemical, and taxonomic diversity of Yellowstone hot springs, the composition of microorganisms there is surprisingly ordinary. This suggests the existence of a stoichiometric envelope common to all life as we know it. Thus, future planetary investigations could use elemental fingerprints to assess the astrobiological potential of hydrothermal settings beyond Earth. Indeed, hydrothermal activity may be widespread in the solar system. Most solar system worlds larger than 200 km in radius are dwarf planets, likely composed of an icy, cometary mantle surrounding a rocky, chondritic core. I enhance a dwarf planet evolution code, including the effects of core fracturing and hydrothermal circulation, to demonstrate that dwarf planets likely have undergone extensive water-rock interaction. This supports observations of aqueous products on their surfaces. I simulate the alteration of chondritic rock by pure water or cometary fluid to show that aqueous alteration feeds back on geophysical evolution: it modifies the fluid antifreeze content, affecting its persistence over geological timescales; and the

  11. Spectral evolution of bright NS LMXBs with INTEGRAL: an application of the thermal plus bulk Comptonization model

    CERN Document Server

    Mainardi, L I; Farinelli, R; Kuulkers, E; Rodriguez, J; Hannikainen, D; Savolainen, P; Piraino, S; Bazzano, A; Santangelo, A

    2009-01-01

    The aim of this work is to investigate in a physical and quantitative way the spectral evolution of bright Neutron Star Low-Mass X-ray Binaries (NS LMXBs), with special regard to the transient hard X-ray tails. We analyzed INTEGRAL data for five sources (GX 5-1, GX 349+2, GX 13+1, GX 3+1, GX 9+1) and built broad-band X-ray spectra from JEM-X1 and IBIS/ISGRI data. For each source, X-ray spectra from different states were fitted with the recently proposed model compTB. The spectra have been fit with a two-compTB model. In all cases the first compTB describes the dominant part of the spectrum that we interpret as thermal Comptonization of soft seed photons ( 1 keV), likely from the neutron star and the innermost part of the system, the Transition Layer, are Comptonized by matter in a converging flow. The presence and nature of this second compTB component (be it a pure blackbody or Comptonized) are related to the inner local accretion rate which can influence the transient behaviour of the hard tail: high values...

  12. Bulk undercooling

    Science.gov (United States)

    Kattamis, T. Z.

    1984-01-01

    Bulk undercooling methods and procedures will first be reviewed. Measurement of various parameters which are necessary to understand the solidification mechanism during and after recalescence will be discussed. During recalescence of levitated, glass-encased large droplets (5 to 8 mm diam) high speed temperature sensing devices coupled with a rapid response oscilloscope are now being used at MIT to measure local thermal behavior in hypoeutectic and eutectic binary Ni-Sn alloys. Dendrite tip velocities were measured by various investigators using thermal sensors or high speed cinematography. The confirmation of the validity of solidification models of bulk-undercooled melts is made difficult by the fineness of the final microstructure, the ultra-rapid evolution of the solidifying system which makes measurements very awkward, and the continuous modification of the microstructure which formed during recalescence because of precipitation, remelting and rapid coarsening.

  13. Electrocatalysts: Guided Evolution of Bulk Metallic Glass Nanostructures: A Platform for Designing 3D Electrocatalytic Surfaces (Adv. Mater. 10/2016).

    Science.gov (United States)

    Doubek, Gustavo; Sekol, Ryan C; Li, Jinyang; Ryu, Won-Hee; Gittleson, Forrest S; Nejati, Siamak; Moy, Eric; Reid, Candy; Carmo, Marcelo; Linardi, Marcelo; Bordeenithikasem, Punnathat; Kinser, Emily; Liu, Yanhui; Tong, Xiao; Osuji, Chinedum O; Schroers, Jan; Mukherjee, Sundeep; Taylor, André D

    2016-03-01

    On page 1940, A. D. Taylor and co-workers demonstrate nanoporous bicontinuous structures using controlled structural evolution of metallic glass. By using techniques such as dealloying, galvanic replacement, and under-potential deposition, bulk-metallic-glass alloys can be pushed beyond their compositional limitations and tuned for a wide variety of interfacial and electrochemical reactions. Examples are illustrated for hydrogen and methanol oxidation, as well as oxygen reduction reactions. PMID:26947938

  14. Evolutions of matter-wave bright soliton with spatially modulated nonlinearity

    Institute of Scientific and Technical Information of China (English)

    Yongshan Cheng; Fei Liu

    2009-01-01

    The evolution characteristics of a matter-wave bright soliton are investigated by means of the variational approach in the presence of spatially varying nonlinearity.It is found that the atom density envelope of the soliton is changed as a result of the spatial variation of the s-wave scattering length.The stable soliton can exist in appropriate initial conditions.The movement of the soliton depends on the sign and value of the coefficient of spatially modulated nonlinearity.These theoretical predictions are confirmed by the full numerical simulations of the one-dimensional Gross-Pitaevskii equation.

  15. Synthesis of analogues of cometary organic matter: thermochemical evolution and preparation of in-situ observations

    Directory of Open Access Journals (Sweden)

    Fray N.

    2014-02-01

    Full Text Available An organic residue is remaining at 300 K after the VUV photolysis of ices mixture and subsequent heating. This residue is thought to be representative of the organic matter contained in comets. Our experiments show that the thermal evolution is an important process. Indeed, the organic residue remaining at 300 K is not produced completely during the photolysis at low temperature but also during the heating. Furthermore, when heated at temperature higher than 300 K, the residue undergoes chemical evolution which has to be taken into account in astrophysical models. Furthermore, our work allows to propose observational strategy to maximize the chance to detect in-situ some compounds, such as POM and HMT, thanks to COSIMA which is one of the mass spectrometers on board of the Rosetta spacecraft.

  16. Evolution of the Galaxy-Dark Matter Connection and the Assembly of Galaxies in Dark Matter Halos

    Science.gov (United States)

    Yang, Xiaohu; Mo, H. J.; van den Bosch, Frank C.; Zhang, Youcai; Han, Jiaxin

    2012-06-01

    We present a new model to describe the galaxy-dark matter connection across cosmic time, which unlike the popular subhalo abundance-matching technique is self-consistent in that it takes account of the facts that (1) subhalos are accreted at different times and (2) the properties of satellite galaxies may evolve after accretion. Using observations of galaxy stellar mass functions (SMFs) out to z ~ 4, the conditional SMF at z ~ 0.1 obtained from Sloan Digital Sky Survey galaxy group catalogs, and the two-point correlation function (2PCF) of galaxies at z ~ 0.1 as a function of stellar mass, we constrain the relation between galaxies and dark matter halos over the entire cosmic history from z ~ 4 to the present. This relation is then used to predict the median assembly histories of different stellar mass components within dark matter halos (central galaxies, satellite galaxies, and halo stars). We also make predictions for the 2PCFs of high-z galaxies as function of stellar mass. Our main findings are the following: (1) Our model reasonably fits all data within the observational uncertainties, indicating that the ΛCDM concordance cosmology is consistent with a wide variety of data regarding the galaxy population across cosmic time. (2) At low-z, the stellar mass of central galaxies increases with halo mass as M 0.3 and M gsim 4.0 at the massive and low-mass ends, respectively. The ratio M *, c /M reveals a maximum of ~0.03 at a halo mass M ~ 1011.8 h -1 M ⊙, much lower than the universal baryon fraction (~0.17). At higher redshifts the maximum in M *, c /M remains close to ~0.03, but shifts to higher halo mass. (3) The inferred timescale for the disruption of satellite galaxies is about the same as the dynamical friction timescale of their subhalos. (4) The stellar mass assembly history of central galaxies is completely decoupled from the assembly history of its host halo; the ratio M *, c /M initially increases rapidly with time until the halo mass reaches ~1012

  17. Spatiotemporal variations in the abundance and composition of bulk and chromophoric dissolved organic matter in seasonally hypoxia-influenced Green Bay, Lake Michigan, USA.

    Science.gov (United States)

    DeVilbiss, Stephen E; Zhou, Zhengzhen; Klump, J Val; Guo, Laodong

    2016-09-15

    Green Bay, Lake Michigan, USA, is the largest freshwater estuary in the Laurentian Great Lakes and receives disproportional terrestrial inputs as a result of a high watershed to bay surface area ratio. While seasonal hypoxia and the formation of "dead zones" in Green Bay have received increasing attention, there are no systematic studies on the dynamics of dissolved organic matter (DOM) and its linkage to the development of hypoxia. During summer 2014, bulk dissolved organic carbon (DOC) analysis, UV-vis spectroscopy, and fluorescence excitation-emission matrices (EEMs) coupled with PARAFAC analysis were used to quantify the abundance, composition and source of DOM and their spatiotemporal variations in Green Bay, Lake Michigan. Concentrations of DOC ranged from 202 to 571μM-C (average=361±73μM-C) in June and from 279 to 610μM-C (average=349±64μM-C) in August. In both months, absorption coefficient at 254nm (a254) was strongly correlated to bulk DOC and was most abundant in the Fox River, attesting a dominant terrestrial input. Non-chromophoric DOC comprised, on average, ~32% of bulk DOC in June with higher terrestrial DOM and ~47% in August with higher aquagenic DOM, indicating that autochthonous and more degraded DOM is of lower optical activity. PARAFAC modeling on EEM data resulted in four major fluorescent DOM components, including two terrestrial humic-like, one aquagenic humic-like, and one protein-like component. Variations in the abundance of DOM components further supported changes in DOM sources. Mixing behavior of DOM components also indicated that while bulk DOM behaved quasi-conservatively, significant compositional changes occurred during transport from the Fox River to the open bay. PMID:27243792

  18. Collection and characterization of a bulk PM2.5 air particulate matter material for use in reference materials.

    Science.gov (United States)

    Heller-Zeisler, S F; Ondov, J M; Zeisler, R

    1999-01-01

    A contemporary PM2.5 (particulate matter smaller than 2.5 microns aerodynamic diameter) aerosol material from an urban site has been collected for the production of a new standard reference material that will be made available for the development of new PM2.5 air quality standards. Air particulate matter corresponding to the PM2.5 fraction was collected at an established Environmental Protection Agency monitoring site in Baltimore, Maryland. The air-sampling system that has been constructed for this collection separates fine particles with a cyclone separator and deposits them onto an array of Teflon membrane filters. The fine air particulate material is removed by ultrasonication or by mechanical means and collected for further preparation of standards. The composition of the collected PM2.5 aerosol, as well as the composition of the deposited PM2.5 aerosol, are determined by instrumental nuclear activation analysis and other techniques. PMID:10676493

  19. QCD phase transition with a power law chameleon scalar field in the bulk

    OpenAIRE

    Golanbari, T.; Mohammadi, A.; Saaidi, Kh.

    2014-01-01

    In this work, a brane world model with a perfect fluid on brane and a scalar field on bulk has been used to study quark-hadron phase transition. The bulk scalar field has an interaction with brane matter. This interaction comes into non-conservation relation which describe an energy transfer between bulk and brane. Since quark-hadron transition curly depends on the form of evolution equations therefore modification of energy conservation equation and Friedmann equation comes into some interes...

  20. Restudy on Dark Matter Time-Evolution in the Littlest Higgs Model with T-Parity

    Institute of Scientific and Technical Information of China (English)

    QIAO Qing-Peng; TANG Jian; LI Xue-Qian

    2008-01-01

    Following previous study, in the littlest Higgs model (LHM), the heavy photon is supposed to be a possible dark matter candidate and its relic abundance of the heavy photon is estimated in terms of the Boltzman-Lee-Weinberg time-evolution equation. The effect of the T-parity violation is also considered. Our calculations show that when Higgs mass MH taken to be 300 GeV and do not considering T-parity violation, only two narrow ranges 133 < MAn < 135 GeV and 167MAH169 GeV are tolerable with the current astrophysical observation and if 135 < MAH < 167 GeV, there must at least exist another species of heavy particle contributing to the cold dark matter. As long as the T-parity can be violated, the heavy photon can decay into regular standard model particles and would affect the dark matter abundance in the universe, we discuss the constraint on the T-parity violation parameter based on the present data. Direct detection prospects are also discussed in some detail.

  1. Source characterisation of Sedimentary organic matter in mangrove ecosystems of northern Kerala, India: Inferences from bulk characterisation and hydrocarbon biomarkers

    Digital Repository Service at National Institute of Oceanography (India)

    Resmi, P.; Manju, M.N.; Gireeshkumar, T.R.; RatheeshKumar, C.S.; Chandramohanakumar, N.

    Pazhayangadi), CPI < 3 (except Pazhayangadi), TAR values <1 and higher chlorophyll content were observed. From analytical details, there appears to be a change in community structure in these mangrove sediments during pre-monsoon season, i.e., terrestrial... and the distance from theArabian Sea have amajor role in determining sources of organic matter in the mangrove systems of northern Kerala coast. The im- portance of the study lies in the fact that source characterisation using multi-proxy approach from mangrove...

  2. Nuclear and atomic techniques in air pollution studies by transplant lichen exposure, bulk deposition and airborne particulate matter collection after 6 month exposure

    International Nuclear Information System (INIS)

    This work presents the preliminary results obtained in the study 'Air pollution monitoring by sampling airborne particulate matter combined with lichen bioaccumulator exposure', in progress at IDRANAP Center of Excellence EU Project, ICA1-CT-2000-70023, WP2. Transplants of Evernia prunastri and Pseudevernia furfuracea lichen species from the Italian Prealps were exposed for 6 and 12 months at six locations with different degrees and types of industrial activity, as well as on a background site with relatively clean air (Fundata). At each investigated location, bulk deposition was collected for the same periods, while airborne particulate matter was sequentially collected during 2 months, in parallel with those at a reference station (Afumati). Pollution in the investigated areas is mainly due to the following industrial activities: steel manufacturing (Galati); non-ferrous ore processing (Baia Mare); chemicals and non-ferrous industry (Copsa Mica); coal-fired power plant and cement factory (Deva); traffic, coal-fired power plants, inorganic dyes and galvanic treatment factories (Oradea); agriculture, mixed industry and traffic (Afumati). The lichen material was analyzed by INAA, XRFA, and ICP-MS, while the aerosol filters were analyzed by INAA and XRFA. The bulk deposition was analyzed only by INAA. XRFA was carried out at Stuttgart, ICP-MS at Trondheim, while INAA at Bucharest (long lifetime radionuclides) and Delft (short lifetime radionuclides, and, in the case of bulk deposition, short and long lifetime radionuclides). The investigated elements having relevant role in environmental studies were: As, Br, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Ni, Pb, S, Sb, Sc, Se, V, and Zn. Cd, Co, Sb, and Sc could only be determined by INAA and ICP-MS, while Pb and S only by XRFA and ICP-MS. After 6-month exposure, both lichen species showed significant enrichment factors (relative to 'zero level', before exposure) for all the measured elements, except Br, Ca, K, and Mn. Small lichen

  3. [Effects of biochar amendment on cropland soil bulk density, cation exchange capacity, and particulate organic matter content in the North China Plain].

    Science.gov (United States)

    Chen, Hong-Xia; Du, Zhang-Liu; Guo, Wei; Zhang, Qing-Zhong

    2011-11-01

    A 3-year field experiment with randomized block design was conducted to study the effects of biochar amendment on the soil bulk density, cation exchange capacity (CEC), and particulate organic matter C (POM-C) and N (POM-N) contents in a high-yielding cropland in the North China Plain. Four treatments were installed, i.e., chemical NPK (CK), chemical NPK plus 2250 kg x hm(-2) of biochar (C1), chemical NPK plus 4500 kg x hm(-2) of biochar (C2), and 750 kg x hm(-2) of biochar-based slow release fertilizer (CN). Comparing with CK, treatments C1 and C2 significantly decreased the bulk density of 0-7.5 cm soil layer by 4.5% and 6.0%, respectively, and the treatments with biochar amendment increased the CEC in 0-15 cm soil layer, with an increment of 24.5% in treatment C2. Biochar amendment also increased the C (POM-C) and N (POM-N) contents in 0-7.5 cm soil layer, e.g., the POM-C and N contents in treatment C1 and C2 were 250% and 85%, and 260% and 120% higher than those of the CK, respectively. After three years of biochar amendment, the soil had obvious improvement in its physical and chemical properties, and played more active roles in soil carbon sequestration and greenhouse gases emission reduction. PMID:22303671

  4. Mineral matter effects on char structural evolution and oxidation kinetics during coal char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, M.; Yang, N.; Headley, T.; Shaddix, C.; Hardesty, D.

    1997-10-01

    The authors report on recent investigations of the evolution of char structure during carbon burnout and the role of mineral matter in determining this structure. Char samples collected in a carefully controlled laminar, flame-supported entrained flow reactor have been characterized using a number of microscopy tools. Observations of the inorganic structure of chars produced at a variety of combustion conditions are coupled with in-situ optical measurements of the char particle population with an eye towards identifying the mechanism of mineral interaction and its effects on carbon burnout kinetics during pulverized coal char combustion. Preliminary results show a surprising amount of inorganic mineral in solid solution with the carbonaceous matrix. This intimate mixing of organic and inorganic constituents may affect reactivity by both blocking oxygen access to active carbon sites and influencing the microscopic carbon structure that evolves during combustion.

  5. Dark Stars: Dark Matter in the First Stars leads to a New Phase of Stellar Evolution

    CERN Document Server

    Freese, Katherine; Aguirre, Anthony; Bodenheimer, Peter; Gondolo, Paolo; Sellwood, J A; Yoshida, Naoki

    2008-01-01

    The first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide an important heat source for the first stars in the the universe. This talk presents the story of these Dark Stars. We make predictions that the first stars are very massive ($\\sim 800 M_\\odot$), cool (6000 K), bright ($\\sim 10^6 L_\\odot$), long-lived ($\\sim 10^6$ years), and probable precursors to (otherwise unexplained) supermassive black holes. Later, once the initial DM fuel runs out and fusion sets in, DM annihilation can predominate again if the scattering cross section is strong enough, so that a Dark Star is born again.

  6. Mechanical biological treatment of organic fraction of MSW affected dissolved organic matter evolution in simulated landfill.

    Science.gov (United States)

    Salati, Silvia; Scaglia, Barbara; di Gregorio, Alessandra; Carrera, Alberto; Adani, Fabrizio

    2013-08-01

    The aim of this paper was to study the evolution of DOM during 1 year of observation in simulated landfill, of aerobically treated vs. untreated organic fraction of MSW. Results obtained indicated that aerobic treatment of organic fraction of MSW permitted getting good biological stability so that, successive incubation under anaerobic condition in landfill allowed biological process to continue getting a strong reduction of soluble organic matter (DOM) that showed, also, an aromatic character. Incubation of untreated waste gave similar trend, but in this case DOM decreasing was only apparent as inhibition of biological process in landfill did not allow replacing degraded/leached DOM with new material coming from hydrolysis of fresh OM. PMID:23743423

  7. The evolution of future geogenic matter fluxes due Enhanced Weathering: Results from the Antwerp Experiment

    Science.gov (United States)

    Hartmann, Jens; Weiss, Andreas; Struyf, Eric; Schoelynck, Jonas; Meire, Patrick; Amann, Thorben

    2015-04-01

    Understanding the evolution of geogenic matter fluxes in soils due the application of rock products ontop of soils is relevant to evaluate alteration of soil solutions and saturation states of solutes. In the future the practice of applying rock products will continue and areas affected will likely spread (Hartmann et al., 2013). This trend will likely be fuelled by attempts to optimize carbon dioxide removal by increasing biomass production, soil organic carbon stocks, increase crop production or afforestation. All those efforts demand a certain amount of geogenic nutrients, which need to be replaced. To investigate the release patterns and the downward transport of an array of elements, and to study their fate as well as reaction processes, altered through this practice, a mesocosm experiment was established at Antwerp University. Extended results will be presented (c.f., Weiss et al., 2014) focusing on the release and transport of DIC (dissolved inorganic carbon) and Mg (magnesium) in the soil column downwards after the application of 22 kg m-2 olivine powder. Elevated DIC and Mg concentrations are detected in case of olivine is applied to mesocosms with wheat and barley, if compared to the mesocsoms without plants, and without olivine. The change patterns in concentrations and fluxes will be discussed. Hartmann, J., et al. (2013) Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Reviews of Geophysics; 51(2), 113-149. doi: 10.1002/rog.20004 Weiss, A., et al. (2014) The overlooked compartment of the critical-zone-complex, considering the evolution of future geogenic matter fluxes: Agricultural topsoils. Procedia Earth and Planetary Science, 10, 339-342. doi:10.1016/j.proeps.2014.08.032

  8. Biogeochemistry of bulk organic matter and biogenic elements in surface sediments of the Yangtze River Estuary and adjacent sea

    International Nuclear Information System (INIS)

    Highlights: • Biogenic elements cycling in the YRE and adjacent sea surface sediments was discussed. • Factors influencing the biogenic elements distributions were examined. • Potential bioavailability of N and P was determined. • Burial fluxes of TOC, BSi, TN and TP were estimated. • Potential nutrient limitation factors were assessed. - Abstract: This study investigated the distribution and roles of total organic carbon (TOC), biogenic silicon (BSi), various forms of nitrogen (N) and phosphorus (P), and the stable carbon isotope (δ13C) in surface sediments of the Yangtze River Estuary (YRE) and adjacent sea. Terrestrial input accounted for 12–63% of total organic matter in the study area. The distribution of biogenic elements was affected by the Changjiang Diluted Water, the Jiangsu Coastal Current, human activities, marine biological processes, and the sediment grain size. Potentially bioavailable N and P accounted for an average 79.6% of the total N (TN) and 31.8% of the total P (TP), respectively. The burial fluxes for TOC, BSi, TN and TP were 39.74–2194.32, 17.34–517.48, 5.02–188.85 and 3.10–62.72 μmol cm−2 yr−1, respectively. The molar ratios of total N/P (1.2–5.0), Si/P (5.0–14.8) and Fe/P (21–61) indicated that much of the P was sequestered in sediments

  9. Evolution of matter and energy on a cosmic and planetary scale

    CERN Document Server

    Taube, M

    1985-01-01

    My intention in this book is to describe in simple language, using a minimum of mathematics but a maximum of numerical values, the most important developments of science dealing with matter and energy on cosmic and global scales. In the conventional literature all of these findings are distributed among books and journals on physics, astronomy, chemistry, geology, biology, energy, engineering, and the environmental sciences. The main purpose here is to attempt to give a unified description of Nature from the elementary particles to the Universe as a whole. This is used as a basis for analysing the future development of mankind. The future evolution of the Universe, galaxies, stars, and planets gives some hope for the destiny of mankind. The problem of matter and energy flow on the Earth appears soluble even for the distant future. There seems to be no reason why a long period of human development on this planet should not be possible. The book has been prepared based on my lectures at the Warsaw University fr...

  10. The shape of dark matter haloes in the Aquarius simulations: Evolution and memory

    Directory of Open Access Journals (Sweden)

    Sales L.V.

    2012-02-01

    Full Text Available We use the high resolution cosmological N-body simulations from the Aquarius project to investigate in detail the mechanisms that determine the shape of Milky Way-type dark matter haloes. We find that, when measured at the instantaneous virial radius, the shape of individual haloes changes with time, evolving from a typically prolate configuration at early stages to a more triaxial/oblate geometry at the present day. This evolution in halo shape correlates well with the distribution of the infalling material: prolate configurations arise when haloes are fed through narrow filaments, which characterizes the early epochs of halo assembly, whereas triaxial/oblate configurations result as the accretion turns more isotropic at later times. Interestingly, at redshift z = 0, clear imprints of the past history of each halo are recorded in their shapes at different radii, which also exhibit a variation from prolate in the inner regions to triaxial/oblate in the outskirts. Provided that the Aquarius haloes are fair representatives of Milky Way-like 1012M☉ objects, we conclude that the shape of such dark matter haloes is a complex, time-dependent property, with each radial shell retaining memory of the conditions at the time of collapse.

  11. Stellar Structure of Dark Stars: a first phase of Stellar Evolution due to Dark Matter Annihilation

    CERN Document Server

    Freese, Katherine; Spolyar, Douglas; Gondolo, Paolo

    2008-01-01

    Dark Stars are the very first phase of stellar evolution in the history of the universe: the first stars to form (at redshifts $z \\sim 10-50$) are powered by dark matter annihilation instead of fusion (if the dark matter is made of particles which are their own antipartners). We find equilibrium polytropic configurations for these stars; we start from the time DM heating becomes important ($M \\sim 1-10 M_\\odot$) and build up the star via accretion up to 1000$M_\\odot$. The dark stars, with an assumed particle mass of 100 GeV, are found to be very bright with a luminosity of a few $10^6 L_\\odot$, surface temperatures $(4000-10,000)$K, radii $\\sim 10^{14}$cm, and lifetimes of at least $10^6$ years. Dark stars look quite different from standard metal free stars in the absence of DM heating and can be distinguished in future observations, possibly even in JWST or TMT. In addition, dark stars are predicted to have atomic and molecular hydrogen lines.

  12. Laboratory Calibration Studies in Support of ORGANICS on the International Space Station: Evolution of Organic Matter in Space

    Science.gov (United States)

    Ruiterkamp, R.; Ehrenfreund, P.; Halasinski, T.; Salama, F.; Foing, B.; Schmidt, W.

    2002-01-01

    This paper describes the scientific overview and current status of ORGANICS an exposure experiment performed on the International Space Station (ISS) to study the evolution of organic matter in space (PI: P. Ehrenfreund), with supporting laboratory experiments performed at NASA Ames. ORGANICS investigates the chemical evolution of samples submitted to long-duration exposure to space environment in near-Earth orbit. This experiment will provide information on the nature, evolution, and survival of carbon species in the interstellar medium (ISM) and in solar system targets.

  13. Evolution of thermoelectric performance for (Bi,Sb)2Te3 alloys from cutting waste powders to bulks with high figure of merit

    Science.gov (United States)

    Fan, Xi‧an; Cai, Xin zhi; Han, Xue wu; Zhang, Cheng cheng; Rong, Zhen zhou; Yang, Fan; Li, Guang qiang

    2016-01-01

    Bi2Te3 based cutting waste powders from cutting wafers were firstly selected as raw materials to prepare p-type Bi2Te3 based thermoelectric (TE) materials. Through washing, reducing, composition correction, smelting and resistance pressing sintering (RPS) process, p-type (Bi,Sb)2Te3 alloy bulks with different nominal stoichiometries were successfully obtained. The evolution of microstructure and TE performance for (Bi,Sb)2Te3 alloys were investigated in detail. All evidences confirmed that most of contaminants from line cutting process such as cutting fluid and oxides of Bi, Sb or Te could be removed by washing, reducing and smelting process used in this work. The carrier content and corresponding TE properties could be adjusted effectively by appropriate composition correction treatment. At lastly, a bulk with a nominal stoichiometry of Bi0.44Sb1.56Te3 was obtained and its' dimensionless figure of merit (ZT) was about 1.16 at 90 °C. The ZT values of Bi0.36Sb1.64Te3 and Bi0.4Sb1.6Te3 alloy bulks could also reach 0.98 and 1.08, respectively. Different from the conventional recycling technology such as hydrometallurgy extraction methods, the separation and extraction of beneficial elements such as Bi, Sb and Te did not need to be performed and the Bi2Te3 based bulks with high TE properties could be directly obtained from the cutting waste powders. In addition, the recycling technology introduced here was green and more suitable for practical industrial application. It can improve material utilization and lower raw material costs of manufacturers.

  14. Attenuation of bulk organic matter, nutrients (N and P), and pathogen indicators during soil passage: Effect of temperature and redox conditions in simulated soil aquifer treatment (SAT)

    KAUST Repository

    Abel, Chol D T

    2012-07-22

    Soil aquifer treatment (SAT) is a costeffective natural wastewater treatment and reuse technology. It is an environmentally friendly technology that does not require chemical usage and is applicable to both developing and developed countries. However, the presence of organic matter, nutrients, and pathogens poses a major health threat to the population exposed to partially treated wastewater or reclaimed water through SAT. Laboratory-based soil column and batch experiments simulating SAT were conducted to examine the influence of temperature variation and oxidation-reduction (redox) conditions on removal of bulk organic matter, nutrients, and indicator microorganisms using primary effluent. While an average dissolved organic carbon (DOC) removal of 17.7 % was achieved in soil columns at 5 °C, removal at higher temperatures increased by 10 % increments with increase in temperature by 5 °C over the range of 15 to 25 °C. Furthermore, soil column and batch experiments conducted under different redox conditions revealed higher DOC removal in aerobic (oxic) experiments compared to anoxic experiments. Aerobic soil columns exhibited DOC removal 15 % higher than that achieved in the anoxic columns, while aerobic batch showed DOC removal 7.8 % higher than the corresponding anoxic batch experiments. Ammonium-nitrogen removal greater than 99 % was observed at 20 and 25 °C, while 89.7 % was removed at 15 °C, but the removal substantially decreased to 8.8 % at 5 °C. While ammonium-nitrogen was attenuated by 99.9 % in aerobic batch reactors carried out at room temperature, anoxic experiments under similar conditions revealed 12.1 % ammonium-nitrogen reduction, corresponding to increase in nitrate-nitrogen and decrease in sulfate concentration. © Springer Science+Business Media B.V. 2012.

  15. THE EVOLUTION OF ACTIVE GALACTIC NUCLEI IN WARM DARK MATTER COSMOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Menci, N.; Fiore, F.; Lamastra, A. [INAF, Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy)

    2013-04-01

    Recent measurements of the abundance of active galactic nuclei (AGNs) with low luminosities (L{sub 2-10} {<=} 10{sup 44} erg s{sup -1} in the 2-10 keV energy band) at high redshifts (z {>=} 4) provide a serious challenge for cold dark matter (CDM) models based on interaction-driven fueling of AGNs. Using a semi-analytic model of galaxy formation we investigate how such observations fit in a warm dark matter (WDM) scenario of galaxy formation, and compare the results with those obtained in the standard CDM scenario with different efficiencies for the stellar feedback. Taking on our previous exploration of galaxy formation in WDM cosmology, we assume as a reference case a spectrum which is suppressed-compared to the standard CDM case-below a cutoff scale Almost-Equal-To 0.2 Mpc corresponding (for thermal relic WDM particles) to a mass m{sub X} = 0.75 keV. We run our fiducial semi-analytic model with such a WDM spectrum to derive AGN luminosity functions from z Almost-Equal-To 6 to the present over a wide range of luminosities (10{sup 43} {<=} L{sub 2-10}/erg s{sup -1} {<=} 10{sup 46} in the 2-10 keV X-ray band), to compare with recent observations and with the results in the CDM case. When compared with the standard CDM case, the luminosity distributions we obtain assuming a WDM spectrum are characterized by a similar behavior at low redshift, and by a flatter slope at faint magnitudes for z {>=} 3, which provide an excellent fit to present observations. We discuss how such a result compares with CDM models with maximized feedback efficiency, and how future deep AGN surveys will allow for a better discrimination between feedback and cosmological effects on the evolution of AGNs in interaction-driven models for AGN fueling.

  16. Thermal evolution and small scale structure of Sommerfeld enhanced dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aarssen, Laura Gusta van den

    2013-04-15

    Although the existence of Dark Matter (DM) has been confirmed by many independent observations on various scales, its nature still remains a mystery. Leading candidates for the cold, non-baryonic DM are Weakly Interacting Massive Particles (WIMPs), that are well motivated from particle physics and naturally explain the observed relic density by their thermal production mechanism. In this thesis we focus on a particular class of WIMP models in which the Sommerfeld effect has to be taken into account. This is a quantum mechanical phenomenon that can significantly enhance the annihilation cross section in the non-relativistic limit. To describe the non-perturbative effect, we use a non-relativistic effective field theory derived from the full quantum field theory. We include a detailed discussion of the calculation for the righthanded sneutrino, which is the superpartner of the neutrino and a viable DM candidate. The Sommerfeld enhancement can have a profound influence on the thermal evolution of the DM, which can no longer be described by the standard scenario. We introduce a framework to correctly take this effect into account and apply it to a simple leptophilic DM model. A new era of annihilations can decrease the DM density even after usual freeze-out, and in some cases where the Sommerfeld enhancement is especially large, even continue until after matter-radiation equality. The effect on the asymptotic WIMP temperature, which can be directly related to a small scale cutoff in the matter density fluctuations, causes the mass of the smallest gravitationally bound objects to be larger than expected from standard calculations. Furthermore we study the effect of velocity dependent DM self-scattering in relation to the small scale structure formation. Numerical simulations of {Lambda}CDM have shown a remarkable agreement with the large scale structure of the Universe. However, the simulations are in tension with observed abundances, inner densities and velocity

  17. Thermal evolution and small scale structure of Sommerfeld enhanced dark matter

    International Nuclear Information System (INIS)

    Although the existence of Dark Matter (DM) has been confirmed by many independent observations on various scales, its nature still remains a mystery. Leading candidates for the cold, non-baryonic DM are Weakly Interacting Massive Particles (WIMPs), that are well motivated from particle physics and naturally explain the observed relic density by their thermal production mechanism. In this thesis we focus on a particular class of WIMP models in which the Sommerfeld effect has to be taken into account. This is a quantum mechanical phenomenon that can significantly enhance the annihilation cross section in the non-relativistic limit. To describe the non-perturbative effect, we use a non-relativistic effective field theory derived from the full quantum field theory. We include a detailed discussion of the calculation for the righthanded sneutrino, which is the superpartner of the neutrino and a viable DM candidate. The Sommerfeld enhancement can have a profound influence on the thermal evolution of the DM, which can no longer be described by the standard scenario. We introduce a framework to correctly take this effect into account and apply it to a simple leptophilic DM model. A new era of annihilations can decrease the DM density even after usual freeze-out, and in some cases where the Sommerfeld enhancement is especially large, even continue until after matter-radiation equality. The effect on the asymptotic WIMP temperature, which can be directly related to a small scale cutoff in the matter density fluctuations, causes the mass of the smallest gravitationally bound objects to be larger than expected from standard calculations. Furthermore we study the effect of velocity dependent DM self-scattering in relation to the small scale structure formation. Numerical simulations of ΛCDM have shown a remarkable agreement with the large scale structure of the Universe. However, the simulations are in tension with observed abundances, inner densities and velocity profiles of

  18. Effects of organic amendments on natural organic matter in bulk soils from an italian agricultural area as assessed by Fast Field Cycling NMR relaxometry

    Science.gov (United States)

    Scotti, Riccardo; Conte, Pellegrino; Alonzo, Giuseppe; Rao, Maria A.

    2010-05-01

    Losses of soil organic carbon often occur in soil because of intensive agricultural practices. This is due both to removal of organic carbon following harvest production and to insufficient inputs of organic amendments. Natural organic matter (NOM) can be a very appropriate material for enhancing organic carbon content in very stressed agricultural soils. In general, NOM plays an important role in environmental matrices due, for example, to its capacity in retaining water, in interacting with organic and inorganic pollutants, and in enhancing nutrient availability to plants. For this reason, the understanding of the mechanisms with which NOM interacts with other chemicals in the environment is of paramount importance. Structural and conformational NOM characteristics can be analysed by high field (HF) nuclear magnetic resonance (NMR) spectroscopy either in the solid or in the liquid state. In both cases, information on the chemical nature of NOM can be achieved. Moreover, relaxometry studies can be also conducted to provide information on the molecular dynamics of natural organic matter. However, HF-NMR relaxometry limitations are related to the strength of the magnetic fields which limits the range of relaxation rates that can be investigated. In fact, high magnetic fields (e.g. ≥108 Hz) reduce the possibilities to observe molecular dynamics at very low frequencies such as those between 106 and 103 Hz. To this aim, nuclear magnetic resonance relaxometry at low fields and in the fast field cycling (FFC) setup is the most powerful way to retrieve information on the dynamics at low frequencies. Here, FFC-NMR relaxometry studies on soils subjected to different organic amendements are presented. Two farms, in an important agricultural area of Campania Region, Italy, were selected in order to study the effect of different organic amendments on bulk soils. Namely, a compost from municipal solid wastes and wood-wastes (scraps of poplars pruning) were applied in

  19. Fate of bulk organic matter, nitrogen, and pharmaceutically active compounds in batch experiments simulating soil aquifer treatment (SAT) using primary effluent

    KAUST Repository

    Abel, Chol D T

    2013-06-30

    Reduction of bulk organic matter, nitrogen, and pharmaceutically active compounds from primary effluent during managed aquifer recharge was investigated using laboratory-scale batch reactors. Biologically stable batch reactors were spiked with different concentrations of sodium azide to inhibit biological activity and probe the effect of microbial activity on attenuation of various pollutants of concern. The experimental results obtained revealed that removal of dissolved organic carbon correlated with active microbial biomass. Furthermore, addition of 2 mM of sodium azide affected nitrite-oxidizing bacteria leading to accumulation of nitrite-nitrogen in the reactors while an ammonium-nitrogen reduction of 95.5 % was achieved. Removal efficiencies of the hydrophilic neutral compounds phenacetin, paracetamol, and caffeine were independent of the extent of the active microbial biomass and were >90 % in all reactors, whereas removal of pentoxifylline was dependent on the biological stability of the reactor. However, hydrophobic ionic compounds exhibited removal efficiency >80 % in batch reactors with the highest biological activity as evidenced by high concentration of adenosine triphosphate. © 2013 Springer Science+Business Media Dordrecht.

  20. DARK MATTER HALOS AND EVOLUTION OF BARS IN DISK GALAXIES: COLLISIONLESS MODELS REVISITED

    International Nuclear Information System (INIS)

    We construct and evolve three one-parameter families and one two-parameter family of steady-state models of stellar disks embedded in live dark matter (DM) halos in order to study the dynamical and secular phases of bar evolution. These models are tested against those published in the literature in order to extend them and to include the gaseous component in the follow-up paper. Specifically, we are interested in the angular momentum, J, redistribution in the disk-halo system during these two evolutionary phases without distinguishing between the resonant and non-resonant effects. We confirm the previous results and quantify for the first time the dual role that the DM halos play in the bar evolution: more centrally concentrated halos dilute the dynamical processes of the initial bar growth, such as the spontaneous bar instability and the vertical buckling instability, and slow down the J transfer, while facilitating it in the secular phase. The rate of J transfer in the disk and the halo is followed up in order to identify sites and times of peak activity in J emission and absorption. Within the corotation radius, R cr, the disk J remains nearly constant in time, as long as R cr stays within the disk-a sign that the lost angular momentum to the outer disk and the halo is being compensated by an influx of fresh J due to the outward motion of R cr. We demonstrate that this is feasible as long as the bar slowdown dominates the loss of J inside R cr. Next, we find that in some models the bar pattern speed stalls for prolonged time periods, i.e., the bar exhibits a constant rate of tumbling when R cr is located outside the disk. This phenomenon appears concurrent with the near absence of J transfer between the disk and the halo, and is associated with the halo emitting J at the corotation resonance and absorbing it at the inner Lindblad resonance. Furthermore, we confirm that stellar bars generally display the corotation-to-bar size ratios in the range of ∼1-1.4, but

  1. CFHTLenS: Co-evolution of galaxies and their dark matter haloes

    CERN Document Server

    Hudson, Michael J; Coupon, Jean; Hildebrandt, Hendrik; Erben, Thomas; Heymans, Catherine; Hoekstra, Henk; Kitching, Thomas D; Mellier, Yannick; Miller, Lance; Van Waerbeke, Ludovic; Bonnett, Christopher; Fu, Liping; Kuijken, Konrad; Rowe, Barnaby; Schrabback, Tim; Semboloni, Elisabetta; van Uitert, Edo; Velander, Malin

    2013-01-01

    Galaxy-galaxy weak lensing is a direct probe of the mean matter distribution around galaxies. The depth and sky coverage of the CFHT Legacy Survey yield statistically significant galaxy halo mass measurements over a much wider range of stellar masses ($10^{8.75}$ to $10^{11.3} M_{\\odot}$) and redshifts ($0.2 < z < 0.8$) than previous weak lensing studies. The stellar-to-halo mass ratio (SHMR) reaches a maximum of $3.4\\pm0.2$ percent as a function of halo mass at $\\sim 10^{12.25} M_{\\odot}$ (at redshift $z =0.5$). We find, for the first time from weak lensing alone, evidence for significant evolution in the SHMR: the peak ratio falls as a function of cosmic time from $3.8 \\pm 0.3$ percent at $z \\sim 0.7$ to $3.0 \\pm 0.2$ percent at $z \\sim 0.3$, and shifts to lower stellar mass haloes. These evolutionary trends are dominated by red galaxies, and are consistent with a model in which the stellar mass above which star formation is quenched "downsizes" with cosmic time. In contrast, the SHMR of blue, star-fo...

  2. Spin flips - II. Evolution of dark matter halo spin orientation, and its correlation with major mergers

    Science.gov (United States)

    Bett, Philip E.; Frenk, Carlos S.

    2016-09-01

    We expand our previous study on the relationship between changes in the orientation of the angular momentum vector of dark matter haloes (`spin flips') and changes in their mass, to cover the full range of halo masses in a simulation cube of length 100 h-1 Mpc. Since strong disturbances to a halo (such as might be indicated by a large change in the spin direction) are likely also to disturb the galaxy evolving within, spin flips could be a mechanism for galaxy morphological transformation without involving major mergers. We find that 35 per cent of haloes have, at some point in their lifetimes, had a spin flip of at least 45° that does not coincide with a major merger. Over 75 per cent of large spin flips coincide with non-major mergers; only a quarter coincide with major mergers. We find a similar picture for changes to the inner halo spin orientation, although here there is an increased likelihood of a flip occurring. Changes in halo angular momentum orientation, and other such measures of halo perturbation, are therefore very important quantities to consider, in addition to halo mergers, when modelling the formation and evolution of galaxies and confronting such models with observations.

  3. The evolution of X-ray clusters in a cold plus hot dark matter universe

    Science.gov (United States)

    Bryan, Greg L.; Klypin, Anatoly; Loken, Chris; Norman, Michael L.; Burns, Jack O.

    1994-01-01

    We present the first self-consistently computed results on the evolution of X-ray properties of galaxy clusters in a cold + hot dark matter (CHDM) model. We have performed a hydrodynamic plus N-body simulation for the COBE-compatible CHDM model with standard mass components: Omega(sub hot) = 0.3, Omega (sub cold) = 0.6 and Omega(sub baryon) = 0.1 (h = 0.5). In contrast with the CDM model, which fails to reproduce the observed temperature distribution function dN/dT (Bryan et al. 1994b), the CHDM model fits the observational dN/dT quite well. Our results on X-ray luminosity are less firm but even more intriguing. We find that the resulting X-ray luminosity functions at redshifts z = 0.0, 0.2, 0.4, 0.7 are well fit by observations, where they overlap. The fact that both temperatures and luminosities provide a reasonable fit to the available observational data indicates that, unless we are missing some essential physics, there is neither room nor need for a large fraction of gas in rich clusters: 10% (or less) in baryons is sufficient to explain their X-ray properties. We also see a tight correlation between X-ray luminosity and gas temperature.

  4. Semisolid Microstructural Evolution during Partial Remelting of a Bulk Alloy Prepared by Cold Pressing of the Ti-Al-2024Al Powder Mixture

    Directory of Open Access Journals (Sweden)

    Yahong Qin

    2016-03-01

    Full Text Available A new method, powder thixoforming, has been proposed to fabricate an in situ Al3Tip/2024Al composite. During partial remelting, the microstructural evolution of the bulk alloy prepared by cold pressing of the Ti, Al, 2024Al powder mixture was investigated, and the formation mechanism of the Al3Ti particles produced by the reaction between the Ti powder and the Al alloy melt is also discussed in detail. The results indicate that the microstructural evolution of the 2024 alloy matrix can be divided into three stages: a rapid coarsening of the powder grains; a formation of primary α-Al particles surrounded with a continuous liquid film; and a slight coarsening of the primary α-Al particles. Simultaneously, a reaction layer of Al3Ti can be formed on the Ti powder surface when the bulk is heated for 10 min at 640 °C The thickness (X of the reaction layer increases with the time according to the parabolic law of \\(X = -0.43t^{2} + 4.21t + 0.17\\. The stress generated in the reaction layer due to the volume dilatation can be calculated by using the equationσ \\(\\sigma_{Al_{3}Ti} = -\\frac{ E_{Al_{3}Ti} }{6(1-v{Al_{3}Ti}} \\frac{ t^{3}_{Al_{3}Ti} }{t_{Ti}} \\left(\\frac{1}{R} - \\frac{1}{R_{0}} \\right \\. Comparing the obtained data with the results of the drip experiment, the reaction rate for the Ti powder and Al powder mixture is greater than that for the Ti plate and Al alloy mixture, respectively.

  5. Microstructural evolution and homogeneous viscous flow behavior of a Cu–Zr based bulk metallic glass composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.Y., E-mail: zhangxiangyun86@163.com; Yuan, Z.Z.; Li, D.X.

    2014-12-25

    Highlights: • Stress–strain behaviors of the BMGCs are strain rate and temperature dependent. • Micro-crystals are compressed to concave polygon in shape and align in line. • Nano-crystals nuclear and aggregate during high temperature deformation. • Deformation behavior is governed by homogeneous flow of the amorphous matrix. - Abstract: The high temperature compression behavior of Cu{sub 40}Zr{sub 44}Ag{sub 8}Al{sub 8} rods with 6 mm in diameter was investigated and compared with the literature data. Microstructure of the as-cast rods were characterized by X-ray diffraction, scanning electron microscopy and high resolution transmission electron microscope in the composites state with microscale Al{sub 3}Zr particles embedded in the amorphous matrix. Deformation results show that the stress–strain behaviors of the bulk metallic glass composites (BMGCs) are strain rate and temperature dependent. In addition, SEM observations reveal that the initially spherical and randomly distributed microscale particles in the amorphous matrix deform to concave polygon in shape and align perpendicular to the load direction during the compression. Meanwhile nano-crystals precipitate continuously from the matrix and aggregate during deformation. Rheological analysis show that the BMGCs exhibit a transition from Newtonian to non-Newtonian in flow behavior dependent on the stain rate. Particles in the amorphous matrix have reinforcement effect on the BMGCs, but the deformation behavior is still dominated by the homogeneous flow of the amorphous matrix phase.

  6. Coercivity and superparamagnetic evolution of high energy ball milled (HEBM) bulk CoFe2O4 material

    International Nuclear Information System (INIS)

    Ball milling (BM) of bulk CoFe2O4 powder material carried out in order to study its structural stability and attendant property changes with respect to coercivity enhancements and superparamagnetic behaviors, showed that drastic crystallite size reduction occurred within the first 1 h of ball milling. Crystallite size dropped from 74 nm for the as-received material to a value of 11.6 nm for 600 min of ball milling. Combined X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed crystallite size reduction with corresponding increase in interparticle agglomeration/pores with increasing milling time. The maximum coercivity of 0.46 T and the crystallite size of 15.6 nm were recorded with 20 min, while peak residual strain of 0.0066 mm/mm was for 180 min of BM. Material with peak coercivity value did not have peak residual strain, or minimum crystallite size, thereby suggesting that other structural defects contributed to coercivity enhancement. The saturation magnetization (Ms) value decreased continuously with increasing milling time, while remanence magnetization (Mr) and coercivity decreased with increasing BM time, after an initial increase. Moessbauer spectroscopy (MS) measurements confirmed both particle size distribution and decomposition/disordering of the material together with superparamagnetism as BM time increased. The degree of inversion ranged from 41% to 71.7% at different milled states from Moessbauer spectroscopy. The internal magnetic fields of the Fe sites associated with the tetrahedral and octahedral sites were 507.4 kOe and 492 kOe respectively in the unmilled state, while 484 kOe and 468.5 kOe in the 600 min milled state correspondingly.

  7. Nonlinear evolution of dark matter and dark energy in the Chaplygin-gas cosmology

    OpenAIRE

    Bilic, Neven; Lindebaum, Robert J.; Tupper, Gary B.; Viollier, Raoul D.

    2003-01-01

    The hypothesis that dark matter and dark energy are unified through the Chaplygin gas is reexamined. Using generalizations of the spherical model which incorporate effects of the acoustic horizon we show that an initially perturbative Chaplygin gas evolves into a mixed system containing cold dark matter-like gravitational condensate.

  8. Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles

    CERN Document Server

    Dutton, Aaron A

    2014-01-01

    We present the evolution of the structure of relaxed cold dark matter haloes in the cosmology from the Planck satellite. Our simulations cover 5 decades in halo mass, from dwarf galaxies to galaxy clusters. Due to the increased matter density and power spectrum normalization the concentration mass relation in the Planck cosmology has a 20 percent higher normalization at redshift z=0 compared to WMAP cosmology. We confirm that CDM haloes are better described by the Einasto profile; for example, at scales near galaxy half-light radii CDM haloes have significantly steeper density profiles than implied by NFW fits. There is a scatter of 0.2 dex in the Einasto shape parameter at fixed halo mass, adding further to the diversity of CDM halo profiles. The evolution of the concentration mass relation in our simulations is not reproduced by any of the analytic models in the literature. We thus provide a simple fitting formula that accurately describes the evolution between redshifts z=5 to z=0 for both NFW and Einasto ...

  9. Is Dark Matter in Spiral Galaxies Cold Gas? I. Observational Constraints and Dynamical Clues About Galaxy Evolution

    OpenAIRE

    Pfenniger, D.; Combes, F; Martinet, L

    1993-01-01

    Based on dynamical constraints about the Hubble sequence evolution, observational data and a number of "conspiracies", we propose that the dark matter around spiral galaxies is in the form of cold gas, essentially in molecular form and rotationally supported. (full A&A paper (in press) available by anonymous ftp at obssd8.unige.ch in /pub/fractal as postscript file: dm_paper_I.ps (170k), or papers I & II + figures as a compressed tar file dm_papers.Z.tar (2.1 Mb)).

  10. Strengthening Medicare: Will increasing the bulk-billing rate and supply of general practitioners increase access to Medicare-funded general practitioner services and does rurality matter?

    OpenAIRE

    Day, Susan E; Alford, Katrina; Dunt, David; Peacock, Stuart; Gurrin, Lyle; Voaklander, Don

    2005-01-01

    Background Recent increases in the bulk-billing rate have been taken as an indication that the Federal government's Strengthening Medicare initiative, and particularly the bulk-billing incentives, are 'working'. Given the enduring geographic differences in the supply of general practitioners (GPs) it is timely to reconsider the impact that this increase in the provision of 'free care' will have on access to Medicare-funded GP services in rural and urban areas of Australia. Utilisation has bee...

  11. The formation and evolution of young low-mass stars within halos with high concentration of dark matter particles

    CERN Document Server

    Casanellas, Jordi

    2009-01-01

    The formation and evolution of low-mass stars within dense halos of dark matter (DM) leads to evolution scenarios quite different from the classical stellar evolution. As a result of our detailed numerical work, we describe these new scenarios for a range of DM densities on the host halo, a range of scattering cross sections of the DM particles considered, and for stellar masses from 0.7 to 3 M$_{\\odot}$. For the first time, we also computed the evolution of young low-mass stars in their Hayashi track in the pre-main sequence phase and found that, for high DM densities, these stars stop their gravitational collapse before reaching the main sequence, in agreement with similar studies on first stars. Such stars remain indefinitely in an equilibrium state with lower effective temperatures ($|\\Delta T_{eff} |>10^{3} $K for a star of one solar mass), the annihilation of captured DM particles in their core being the only source of energy. In the case of lower DM densities, these proto-stars continue their collapse ...

  12. The shape of dark matter haloes in the Aquarius simulations : Evolution and memory

    NARCIS (Netherlands)

    Vera-Ciro, C. A.; Sales, L. V.; Helmi, A.; Reyle, C; Robin, A; Schultheis, M

    2012-01-01

    We use the high resolution cosmological N-body simulations from the Aquarius project to investigate in detail the mechanisms that determine the shape of Milky Way-type dark matter haloes. We find that, when measured at the instantaneous virial radius, the shape of individual haloes changes with time

  13. Photochemical Alternation of Phragmites australis Plant Litter: New Insight into the Chemical Evolution of Particulate Organic Matter

    Science.gov (United States)

    Carrasquillo, A. J.; Gelfond, C. E.; Kocar, B. D.

    2015-12-01

    The photolysis of natural organic matter (NOM) is a potential pathway for the alteration of material that is not easily biodegraded. Irradiation can alter the physical state of organic matter by facilitating the cycling between the particulate (POM) and dissolved (DOM) pools. However, a detailed understanding of the underlying chemical changes to the material in both phases is lacking. Here, we use a suspension of particles derived from Phragmites australis, a common marsh reed with high lignin content, as our model "recalcitrant" POM substrate. The solution was irradiated for three weeks with regular sampling, and the composition of the POM and the photo-produced DOM were measured separately using a suite of mass spectrometric and spectroscopic techniques. The chemical composition of individual molecules was measured by coupling soft ionization techniques (electrospray (ESI) and matrix assisted laser desorption (MALDI) to high-resolution mass spectrometry. Structural information, including the distribution of the major carbon containing functional groups, was obtained using a combination of FTIR for bulk analyses and scanning transmission x-ray microscopy (STXM) for spatially resolved chemistry. Results are discussed in the context of differences in chemical composition and structure with increased irradiation time for both organic matter pools. We observed a general shift in the mass spectra of POM towards lower molecular weight masses and an increase in the abundance of ions in DOM as a function of irradiation time- hence the larger POM matrix is likely fragmenting into smaller species that are more soluble. Spectroscopic measurements indicate that the abundance of acidic and alcohol functionalities increased with irradiation in both carbon pools. These complementary approaches provide new detailed information about how the chemical composition of recalcitrant NOM evolves as it is exposed to sunlight.

  14. Dark matter perturbations and viscosity: a causal approach

    OpenAIRE

    Acquaviva, Giovanni; John, Anslyn; Pénin, Aurélie

    2016-01-01

    The inclusion of dissipative effects in cosmic fluids modifies their clustering properties and could have observable effects on the formation of large scale structures. We analyse the evolution of density perturbations of cold dark matter endowed with causal bulk viscosity. The perturbative analysis is carried out in the Newtonian approximation and the bulk viscosity is described by the causal Israel-Stewart (IS) theory. In contrast to the non-causal Eckart theory, we obtain a third order evo...

  15. The Effect of Dark Matter on the First Stars: A New Phase of Stellar Evolution

    OpenAIRE

    Freese, Katherine; Gondolo, Paolo; Spolyar, Douglas

    2007-01-01

    Dark matter (DM) in protostellar halos can dramatically alter the current theoretical framework for the formation of the first stars. Heat from supersymmetric DM annihilation can overwhelm any cooling mechanism, consequently impeding the star formation process and possibly leading to a new stellar phase. The first stars to form in the universe may be ``dark stars''; i.e., giant (larger than 1 AU) hydrogen-helium stars powered by DM annihilation instead of nuclear fusion. Possibilities for det...

  16. Simulation of organic matter and pollutant evolution during composting : the COP-compost model

    OpenAIRE

    Lashermes, Gwenaëlle; Zhang, Yuan; Houot, Sabine; Barriuso Benito, Enrique; Steyer, Jean-Philippe; Patureau, Dominique

    2013-01-01

    Organic pollutants (OPs) are potentially present in composts and the assessment of their content and bioaccessibility in these composts is of paramount importance. In this work, we proposed a model to simulate the behavior of OPs and the dynamic of organic C during composting. This model, named COP-Compost, includes two modules. An existing organic C module is based on the biochemical composition of the initial waste mixture and simulates the organic matter transformation during composting. A...

  17. Preservation and Evolution of Organic Matter During Experimental Fossilisation of the Hyperthermophilic Archaea Methanocaldococcus jannaschii

    OpenAIRE

    Orange, François; Disnar, Jean-Robert; Gautret, Pascale; Westall, Francès; Bienvenu, Nadège; Lottier, Nathalie; Prieur, Daniel

    2012-01-01

    Identification of the earliest traces of life is made difficult by the scarcity of the preserved microbial remains and by the alteration and potential contamination of the organic matter (OM) content of rocks. These factors can confuse interpretations of the biogenicity and syngenicity of fossilised structures and organic molecules found in ancient rocks. In order to improve our knowledge of the fossilisation processes and their effects at the molecular level, we made a preliminary study of t...

  18. The role of dark matter in the dynamical evolution of galaxy clusters in the framework of the N-body problem

    Science.gov (United States)

    Tutukov, A. V.; Dremov, V. V.; Dremova, G. N.

    2009-10-01

    Numerical N-body studies of the dynamical evolution of a cluster of 1000 galaxies were carried out in order to investigate the role of dark matter in the formation of cD galaxies. Two models explicitly describing the darkmatter as a full-fledged component of the cluster having its own physical characteristics are constructed. These treat the dark matter as a continuous underlying substrate and as “grainy” matter. The ratio of the masses of the dark and luminous matter of the cluster is varied in the range 3-100. The observed logarithmic spectrum dN ˜ dM / M is used as an initial mass spectrum for the galaxies. A comparative numerical analysis of the evolution of the mass spectrum, the dynamics of mergers of the cluster galaxies, and the evolution of the growth of the central, supermassive cD galaxy suggests that dynamical friction associated with dark matter accelerates the formation of the cD galaxy via the absorption of galaxies colliding with it. Taking into account a dark-matter “substrate” removes the formation of multiple mass-accumulation centers, and makes it easier to form a cD galaxy that accumulates 1-2% of the cluster mass within the Hubble time scale (3-8 billion years), consistent with observations.

  19. Regular Bulk Solutions in Brane-worlds with Inhomogeneous Dust and Generalized Dark Radiation

    CERN Document Server

    Herrera-Aguilar, A; da Rocha, Roldao

    2015-01-01

    From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the brane-world and inhomogeneous dark radiation in the bulk as well are considered -- as exact dynamical collapse solutions. Based on the analysis on the inhomogeneous static exterior of a collapsing sphere of homogeneous dark radiation on the brane, the associated black string warped horizon is studied, as well as the 5D bulk metric near the brane. Moreover, the black string and the bulk are shown to be more regular upon time evolution, for suitable values for the dark radiation parameter in the model, by analyzing the physical soft singularities.

  20. Regular Bulk Solutions in Brane-Worlds with Inhomogeneous Dust and Generalized Dark Radiation

    Directory of Open Access Journals (Sweden)

    A. Herrera-Aguilar

    2015-01-01

    Full Text Available From the dynamics of a brane-world with matter fields present in the bulk, the bulk metric and the black string solution near the brane are generalized, when both the dynamics of inhomogeneous dust/generalized dark radiation on the brane-world and inhomogeneous dark radiation in the bulk as well are considered as exact dynamical collapse solutions. Based on the analysis on the inhomogeneous static exterior of a collapsing sphere of homogeneous dark radiation on the brane, the associated black string warped horizon is studied, as well as the 5D bulk metric near the brane. Moreover, the black string and the bulk are shown to be more regular upon time evolution, for suitable values for the dark radiation parameter in the model, by analyzing the soft physical singularities.

  1. Phenomenological Consequences of Enhanced Bulk Viscosity Near the QCD Critical Point

    CERN Document Server

    Monnai, Akihiko; Yin, Yi

    2016-01-01

    In the proximity of the QCD critical point the bulk viscosity of quark-gluon matter is expected to be proportional to nearly the third power of the critical correlation length, and become significantly enhanced. This work is the first attempt to study the phenomenological consequences of enhanced bulk viscosity near the QCD critical point. For this purpose, we implement the expected critical behavior of the bulk viscosity within a non-boost-invariant, longitudinally expanding $1+1$ dimensional causal relativistic hydrodynamical evolution at non-zero baryon density. We demonstrate that the critically-enhanced bulk viscosity induces a substantial non-equilibrium pressure, effectively softening the equation of state, and leads to sizable effects in the flow velocity and single particle distributions at the freeze-out. The observable effects that may arise due to the enhanced bulk viscosity in the vicinity of the QCD critical point can be used as complimentary information to facilitate searches for the QCD critic...

  2. The significance of biogeochemical cycles of macro- and microelements in connection with man-made evolution of the living matter

    International Nuclear Information System (INIS)

    Biogeochemistry as an integrated science studying the elemental composition of the living matter and its role in migration, transformation, accumulation of chemical elements and their compounds in the biosphere, has again become the leading scientific branch highlighting the man-made evolution of the planet and the pathways of interaction between the man and environment. Nowadays the central problem of biogeochemistry as science about the biosphere is that of pollution of the different taxons of the biosphere. In the most case man-made factors effect on the different organisms and the flow of chemical elements changing their local, regional and global biogeochemical cycles. The concept of balance of O2, CO2 and H2O as general condition of the sustained development of the biosphere is considered. The questions of biological rhythms, appearance of microelementhoses and modern systemic biogeochemical methodology of assessment of taxons of the biosphere are considered too

  3. Why evolution has to matter to cognitive psychology and to philosophy of mind

    OpenAIRE

    Proust, Joëlle

    2007-01-01

    Growing suspicions were raised however that an exclusively language-oriented view of the mind, focussing on the characterization of anhistorical, static mental states through their propositional contents, was hardly compatible with what is currently known of brain architecture and did not fare well when confronted with results from many behavioral studies of mental functions. My aim in what follows is to show that these forms of dissatisfaction stem from the fact that brain evolution and deve...

  4. Trace the evolution of organic matter in interplanetary objects using residue analogues

    Science.gov (United States)

    Danger, G.; Fresneau, A.; Abou Mrad, N.; de Marcellus, P.; Orthous-Daunay, F. R.; Modica, P.; Vuitton, V.; Duvernay, F.; Flandinet, L.; Le Sergeant d'Hendecourt, L.; Thissen, R.; Chiavassa, T.

    2015-10-01

    This contribution focuses on one aspect of our work, which is related to the analysis of refractory residues formed from the UV irradiation and the subsequent warming-up to room temperature of astrophysical ice analogs, the RAHIIA project. The understanding of the chemical composition of these refractory residues, commonly called "yellow stuff", as well as the possible pathways to their formation in astrophysical environments, is an important step to establish what kind of organic matter could be available within interplanetary objects such as comets or asteroids, part of which end up as preserved meteorites on telluric planets.

  5. Origin and Evolution of Prebiotic Organic Matter as Inferred from the Tagish Lake Meteorite

    Science.gov (United States)

    Herd, Christopher D.; Blinova, Alexandra; Simkus, Danielle N.; Huang, Yongsong; Tarozo, Rafael; Alexander, Conel M.; Gyngard, Frank; Nittler, Larry R.; Cody, George D.; Fogel, Marilyn L.; Kebukawa, Yoko; Kilcoyne, A. L.; Hilts, Robert W.; Slater, Greg F.; Glavin, Daniel P.; Dworkin, Jason P.; Callahan, Michael P.; Elsila, Jamie E.; De Gregorio, Bradley T.; Stroud, Rhonda M.

    2011-01-01

    The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites' asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration and at least some molecules of pre-biotic importance formed during the alteration.

  6. Origin and Evolution of Prebiotic Organic Matter As Inferred from the Tagish Lake Meteorite

    Science.gov (United States)

    Herd, Christopher D. K.; Blinova, Alexandra; Simkus, Danielle N.; Huang, Yongsong; Tarozo, Rafael; Alexander, Conel M. O.'D.; Gyngard, Frank; Nittler, Larry R.; Cody, George D.; Fogel, Marilyn L.; Kebukawa, Yoko; Kilcoyne, A. L. David; Hilts, Robert W.; Slater, Greg F.; Glavin, Daniel P.; Dworkin, Jason P.; Callahan, Michael P.; Elsila, Jamie E.; De Gregorio, Bradley T.; Stroud, Rhonda M.

    2011-06-01

    The complex suite of organic materials in carbonaceous chondrite meteorites probably originally formed in the interstellar medium and/or the solar protoplanetary disk, but was subsequently modified in the meteorites’ asteroidal parent bodies. The mechanisms of formation and modification are still very poorly understood. We carried out a systematic study of variations in the mineralogy, petrology, and soluble and insoluble organic matter in distinct fragments of the Tagish Lake meteorite. The variations correlate with indicators of parent body aqueous alteration. At least some molecules of prebiotic importance formed during the alteration.

  7. The Co-Evolution of Total Density Profiles and Central Dark Matter Fractions in Simulated Early-Type Galaxies

    CERN Document Server

    Remus, Rhea-Silvia; Naab, Thorsten; Burkert, Andreas; Hirschmann, Michaela; Hoffmann, Tadziu L; Johansson, Peter H

    2016-01-01

    We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profiles, gamma_tot, and the dark matter fractions within the half-mass radius, f_DM, in early-type galaxies. The relation can be described as gamma_tot = A f_DM + B and holds for all systems at all redshifts. We test different feedback models and find that the general trend is independent of the assumed feedback processes and is set by the decreasing importance of dissipative processes towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower dark matter fractions and steeper total density slopes at high redshifts and at lower masses for a given redshift. The values for A and B change distinctively with the assumed feedback model, and thus this relation can be used as a test for feedback models. A similar correlation exists between gamma_tot and the stellar mass surface density Sigma_*. The model with weak stel...

  8. Influence of chemical and structural evolution of dissolved organic matter on electron transfer capacity during composting

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiao-Song [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Innovation base of Ground Water and Environmental System Engineering, Chinese Research Academy of Environmental Science, Beijing 100012 (China); Xi, Bei-Dou, E-mail: hexs82@126.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Innovation base of Ground Water and Environmental System Engineering, Chinese Research Academy of Environmental Science, Beijing 100012 (China); Cui, Dong-Yu [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Innovation base of Ground Water and Environmental System Engineering, Chinese Research Academy of Environmental Science, Beijing 100012 (China); Liu, Yong [Guangdong Key Laboratory of Agro-Environmental Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Tan, Wen-Bin; Pan, Hong-Wei; Li, Dan [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Innovation base of Ground Water and Environmental System Engineering, Chinese Research Academy of Environmental Science, Beijing 100012 (China)

    2014-03-01

    Highlights: • Electron transfer capability (ETC) of compost-derived DOM was investigated. • Composting treatment increased the ETC of DOM from municipal solid wastes. • The ETC increase related to humic matter, and molecule weight, and N and S content. - Abstract: Dissolved organic matter (DOM) can mediate electron transfer and change chemical speciation of heavy metals. In this study, the electron transfer capability (ETC) of compost-derived DOM was investigated through electrochemical approaches, and the factors influencing the ETC were studied using spectral and elemental analysis. The results showed that the electron accepting capacity (EAC) and electron donating capacity (EDC) of compost-derived DOM were 3.29–40.14 μmol{sub e−} (g C){sup −1} and 57.1– 346.07 μmol{sub e−} (g C){sup −1}, respectively. Composting treatment increased the fulvic- and humic-like substance content, oxygenated aliphatic carbon content, lignin-derived aromatic carbon content, molecule weight, and N and S content of DOM, but decreased the aliphatic carbon content and the C and H content. This conversion increased the EDC and EAC of the DOM during composting.

  9. Influence of chemical and structural evolution of dissolved organic matter on electron transfer capacity during composting

    International Nuclear Information System (INIS)

    Highlights: • Electron transfer capability (ETC) of compost-derived DOM was investigated. • Composting treatment increased the ETC of DOM from municipal solid wastes. • The ETC increase related to humic matter, and molecule weight, and N and S content. - Abstract: Dissolved organic matter (DOM) can mediate electron transfer and change chemical speciation of heavy metals. In this study, the electron transfer capability (ETC) of compost-derived DOM was investigated through electrochemical approaches, and the factors influencing the ETC were studied using spectral and elemental analysis. The results showed that the electron accepting capacity (EAC) and electron donating capacity (EDC) of compost-derived DOM were 3.29–40.14 μmole− (g C)−1 and 57.1– 346.07 μmole− (g C)−1, respectively. Composting treatment increased the fulvic- and humic-like substance content, oxygenated aliphatic carbon content, lignin-derived aromatic carbon content, molecule weight, and N and S content of DOM, but decreased the aliphatic carbon content and the C and H content. This conversion increased the EDC and EAC of the DOM during composting

  10. Poster 37. Evolution of the organic matter in water treatment plants of Spanish PWRs

    International Nuclear Information System (INIS)

    Taking into account the influence that the organic compounds from the makeup water plant have in the secondary system chemistry, a study has been performed on the evolution of the following two families: short chain halogenated hydrocarbons and humic substances. The halogenated substances are decomposed at high temperatures producing inorganic halides. The humic substances constitute the major part of the TOC in the natural waters. Due to chemical characteristics, their behaviour in water treatment plants has not been studied in depth. This work aims to find out the capability that the usual water purification procedures have for the elimination of these substances. (author)

  11. DARK MATTER HALOS AND EVOLUTION OF BARS IN DISK GALAXIES: VARYING GAS FRACTION AND GAS SPATIAL RESOLUTION

    International Nuclear Information System (INIS)

    We conduct numerical experiments by evolving gaseous/stellar disks embedded in live dark matter halos aiming at quantifying the effect of gas spatial resolution and gas content on the bar evolution. Three model sequences have been constructed using different resolutions, and the gas fraction has been varied along each sequence within the range of fg = 0%-50%, but keeping the disk and halo properties unchanged. We find that the spatial resolution becomes important with an increase in the gas content. For the higher resolution model sequences, we observe a bimodal behavior in the bar evolution with respect to the gas fraction, especially during the secular phase of this evolution. The switch from the gas-poor to gas-rich behavior is abrupt and depends on the resolution used, being reasonably confined to fg ∼ 5%-12%. The diverging evolution has been observed in nearly all basic parameters characterizing bars, such as the bar strength, central mass concentration, bar vertical buckling amplitude, bar size, etc. We find that the presence of the gas component severely limits the bar growth and affects its pattern speed evolution. Gas-poor models display rapidly decelerating bars, while gas-rich models exhibit bars with constant or even slowly accelerating tumbling. We also find that the gas-rich models have bar corotation (CR) radii within the disk at all times, in contrast with gas-poor and purely stellar disks. In addition, the CR-to-bar size ratio is less than 2 for gas-rich models. Next, we have confirmed that the disk angular momentum within the CR remains unchanged in the gas-poor models, as long as the CR stays within the disk, but experiences a sharp drop before leveling off in the gas-rich models. Finally, we discuss a number of observed correlations between various parameters of simulated bars, such as between the bar sizes and the gas fractions, between the bar strength and the buckling amplitude, and between the bar strength and its size, etc.

  12. The Evolution of Matter in the Embedded Stages of Low-Mass Protostars

    Science.gov (United States)

    Jorgensen, Jes; Lommen, D.; Bourke, T. L.; van Dishoeck, E. F.; Wilner, D.; PROSAC Team

    2008-03-01

    One of the most important questions about low-mass star formation is how circumstellar disks form and evolve through the embedded protostellar stages. We present the results of high angular resolution (1-2"; 200-400 AU) observations from a large program, PROSAC, studying embedded low-mass protostars (Class 0 and I objects) with the Submillimeter Array. In total 17 sources have been observed in a variety of lines of common molecular species together with continuum at (sub)millimeter wavelengths. The continuum observations reveal the presence of compact emission on the smallest scales in all sources which can best be attributed to thermal emission from dust in the circumstellar disks. The inferred masses of the central disks are comparable for both Class 0 and I objects suggesting that disks are formed and rapidly grow in size early in the evolution of the protostars. Line observations of the more evolved Class I systems reveal rotational signatures which in turn constrain the central stellar masses. Together with single-dish continuum data, these observations for the first time allow us to trace evolution of the mass of the stars, disks and envelopes through these pivotal stages.

  13. Physical and chemical evolution of reduced organic matter in the ISM

    Science.gov (United States)

    Jenniskens, Peter; Blake, David F.

    1995-01-01

    Icy mantles on interstellar grains have been a topic of study in airborne astronomy. Recent laboratory analog studies of the yield of organic residue from UV photolyzed ices have shown that this mechanism can be the most significant source of complex reduced organic matter in the interstellar medium. However, the total yield is a function of the occurrence of heating events that evaporate the ice, i.e. T is greater than 130 K, and the mechanism for such events is debated. Recently, we proposed that the recombination of radicals in the ice does not need high temperature excursions and, instead, occurs during a structural transformation of water ice at temperatures in the range 38 - 68 K.

  14. Detecting dark matter using centrifuging techniques

    OpenAIRE

    Mitra, S.; Foot, R.

    2003-01-01

    A new and inexpensive technique for detecting self interacting dark matter in the form of small grains in bulk matter is proposed. Depending on the interactions with ordinary matter, dark matter grains in bulk matter may be isolated by using a centrifuge and using ordinary matter as a filter. The case of mirror matter interacting with ordinary matter via photon-mirror photon kinetic mixing provides a concrete example of this type of dark matter candidate.

  15. The formation and evolution of dark matter halos early in cosmic history

    Science.gov (United States)

    Ernest, Alllan David; Collins, Matthew P.

    2015-08-01

    Observational evidence points to the formation of super-massive black holes, heavy elements and halo structure much earlier in cosmic history than expected [1], and this is challenging for Lambda Cold Dark Matter (LCDM) theory. However, if photon scattering cross sections were less than expected it becomes possible for halos to form at earlier times and relax the tensions that exist with LCDM theory. This may indeed be the case: it has recently been shown [2,3] that photon-particle scattering cross sections vary significantly with the eigenspectral distribution of the scattering particle in deep gravity wells, an effect that depends on the degree of localization of the particle wavefunction and the proximity of the halo to thermal equilibrium. Cross sections tend to be lower the larger and deeper the gravitational well. This purely quantum effect means that accepted cross sections, as measured on Earth and used to determine the rate and timing of halo formation, may not be applicable to deep gravity wells, not only at the present epoch but throughout cosmic history.By combining reduced photon scattering cross sections with Carr’s primordial black hole mass spectrum formulation[4] calculated at the last phase transition (t = 1 s), it is possible to provide a scenario of halo formation that enables galaxies and halos to form much earlier in cosmic history, yet maintain consistency with cosmic microwave background observations and primordial nucleosynthesis. In addition this scenario provides a unified model relating globular clusters, dwarf spheroidal galaxies and bulges, enables an understanding of the black hole-bulge/black hole-dark halo relations, and enables prediction of dark to visible matter, based on the physical parameters of a halo. This scenario will be presented and discussed.[1] Xue-Bing Wu et al, 2015, Nature, 518,512-515 doi: 10.1038/nature14241[2] Ernest A. D., 2009, J. Phys. A: Math. Theor. 42 115207, 115208[3] Ernest A. D, 2012, in Advances in

  16. The formation and evolution of bars in low surface brightness galaxies with cold dark matter halos

    CERN Document Server

    Mayer, L; Mayer, Lucio; Wadsley, James

    2003-01-01

    We perform several high resolution N-Body/SPH simulations of low surface brightness galaxies (LSBs) embedded in cold dark matter halos to study how likely is bar formation in such systems. The behavior of various collisionless galaxy models is studied both in isolation and in the presence of a large perturbing satellite. We also consider models with a dominant gaseous component in the disk. We find that in general bar formation requires disk masses at least a factor of 2 higher than those inferred for LSBs under the assumption of a normal stellar mass-to-light ratio. Low surface density stellar disks contributing less than 10% of the total virial mass are stable within NFW halos spanning a range of concentrations. However, a purely gaseous disk can form a bar even for quite low masses and for realistic temperatures provided that cooling is very efficient (we adopt an isothermal equation of state) and that the halo has a very low concentration, c < 5. The bars that form in these LSB models are shorter than ...

  17. Preservation and evolution of organic matter during experimental fossilisation of the hyperthermophilic archaea Methanocaldococcus jannaschii.

    Science.gov (United States)

    Orange, François; Disnar, Jean-Robert; Gautret, Pascale; Westall, Frances; Bienvenu, Nadège; Lottier, Nathalie; Prieur, Daniel

    2012-12-01

    Identification of the earliest traces of life is made difficult by the scarcity of the preserved microbial remains and by the alteration and potential contamination of the organic matter (OM) content of rocks. These factors can confuse interpretations of the biogenicity and syngenicity of fossilised structures and organic molecules found in ancient rocks. In order to improve our knowledge of the fossilisation processes and their effects at the molecular level, we made a preliminary study of the fate of OM during experimental fossilisation. Changes in the composition and quantity of amino acids, monosaccharides and fatty acids were followed with HPLC, GC and GC-MS analyses during 1 year of silicification of the hyperthermophilic Archaea Methanocaldococcus jannaschii. Although the cells themselves did not fossilise and the accompanying extracellular polymeric substances (EPS) did, our analyses showed that the OM initially present in both cells and EPS was uniformly preserved in the precipitated silica, with amino acids and fatty acids being the best preserved compounds. This study thus completes previous data obtained by electron microscopy investigations of simulated microbial fossilisation and can help better identification and interpretation of microbial biosignatures in both ancient rocks and in recent hydrothermal formations and sediments. PMID:23254852

  18. INTERACTION OF LASER RADIATION WITH MATTER: Influence of Ca and Pb impurities on the bulk optical strength of ultrapure NaCl and KCl crystals

    Science.gov (United States)

    Vinogradov, An V.; Voszka, R.; Kovalev, Valerii I.; Faĭzullov, F. S.; Janszky, J.

    1987-06-01

    A significant increase (by a factor of about 3) of the bulk damage threshold in the case of interaction of CO2 laser radiation pulses with ultrapure NaCl and KCl crystals grown in a reactive atmosphere was observed on introduction of divalent metal ions Ca and Pb in concentrations of 10-5-10-6 mol/mol. Impurities were introduced in concentrations of 10-8-10-3 and 2×10-7-10-4 mol/mol into the melts of KCl and NaCl, respectively. The concentration of other impurities (including OH) did not exceed ~10-6 mol/mol. A physical model was developed to account for the observed dependence on the basis of an analogy between a system of colloidal particles and F centers in a crystal and a liquid-vapor system.

  19. Bulk dynamics for interfacial growth models

    OpenAIRE

    López, Cristóbal; Santos, Fernando; Garrido, P. L.

    2000-01-01

    We study the influence of the bulk dynamics of a growing cluster of particles on the properties of its interface. First, we define a general bulk growth model by means of a continuum Master equation for the evolution of the bulk density field. This general model just considers an arbitrary addition of particles (though it can be easily generalized to consider subtraction) with no other physical restriction. The corresponding Langevin equation for this bulk density field is derived where the i...

  20. Evolution of dissolved organic matter under lake ice in Lake Hoare, Antarctica

    Science.gov (United States)

    Ebert, J.; Castendyk, D.; McKnight, D. M.

    2013-12-01

    DOM is present in all aquatic ecosystems on Earth and plays an important role in the global carbon cycle. DOM is comprised of a complex, heterogeneous mixture of organic compounds derived from both microbial and terrestrial sources and is analyzed using fluorescence spectroscopy. Lake Hoare, located in the McMurdo Dry Valleys, Antarctica is a perennially ice covered lake that occupies a 4-km-long, closed-basin fed by a diurnal meltwater stream called Andersen Creek, runoff from the Canada Glacier, and overflow from an adjacent pond. Previous studies in Antarctica suggest that DOM evolves under lake ice as a function of solar radiation and biological processes. This study explores the evolution of DOM in Andersen Creek and Lake Hoare water measured over a 4-hour time period in mid-summer 2013 in response to changes in stream discharge, solar radiation, water temperature, and biological activity. Water samples were collected from 15 ice boreholes and 5 ice-free stream locations between 19:30 and 18:30 hours on 17 December, and again between 23:30 hours and 00:30 hours. Four boreholes in the perennial lake ice were sampled at two depths: (1) immediately below lake ice and (2) one meter below lake ice. All samples were analyzed using a Horiba-Jorbin Yvon Fluoromax 4 fluorometer and were blank, Raman, and inner-filter corrected. Indices were calculated from the resulting excitation emission matrices (EEMs). Samples were then analyzed using a biogeochemically diverse model, which gives information regarding the properties of DOM. Preliminary fluorescence index (FI) values show spatial and temporal variability, with higher FI values shown in stream samples than in lake samples. This could indicate higher microbial activity in stream water than below perennial lake ice. For shore ice boreholes near the stream inlet, the humification index (HIX) decreased with time suggesting that incoming stream water is less humified than lake water. In-lake processes are more likely to

  1. Stable isotopes of bulk organic matter to trace carbon and nitrogen dynamics in an estuarine ecosystem in Babitonga Bay (Santa Catarina, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Grace Virginia, E-mail: vgbarros@gmail.com [Dipartimento di Scienze Ambientali, Universita Ca' Foscari, Dorsoduro 2137, 30123 Venezia (Italy); University of UNIVILLE, Joinville, Santa Catarina (Brazil); Martinelli, Luiz Antonio [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba, SP (Brazil); Oliveira Novais, Therezinha M. [University of UNIVILLE, Joinville, Santa Catarina (Brazil); Ometto, Jean Pierre H.B. [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba, SP (Brazil); Zuppi, Gian Maria [Dipartimento di Scienze Ambientali, Universita Ca' Foscari, Dorsoduro 2137, 30123 Venezia (Italy)

    2010-04-15

    The biogeochemical processes affecting the transport and cycling of terrestrial organic carbon in coastal and transition areas are still not fully understood. One means of distinguishing between the sources of organic materials contributing to particulate organic matter (POM) in Babitonga Bay waters and sediments is by the direct measurement of {delta}{sup 13}C of dissolved inorganic carbon (DIC) and {delta}{sup 13}C and {delta}{sup 15}N in the organic constituents. An isotopic survey was taken from samples collected in the Bay in late spring of 2004. The results indicate that the {delta}{sup 13}C and {delta}{sup 15}N compositions of OM varied from - 21.7 per mille to - 26.2 per mille and from + 9.2 per mille to - 0.1 per mille , respectively. {delta}{sup 13}C from DIC ranges from + 0.04 per mille to - 12.7 per mille . The difference in the isotope compositions enables the determination of three distinct end-members: terrestrial, marine and urban. Moreover, the evaluation of source contribution to the particulate organic matter (POM) in the Bay, enables assessment of the anthropogenic impact. Comparing the depleted values of {delta}{sup 13}C{sub DIC} and {delta}{sup 13}C{sub POC} it is possible to further understand the carbon dynamic within Babitonga Bay.

  2. Why evolution matters for species conservation: perspectives from three case studies of plant metapopulations.

    Science.gov (United States)

    Olivieri, Isabelle; Tonnabel, Jeanne; Ronce, Ophélie; Mignot, Agnès

    2016-01-01

    We advocate the advantage of an evolutionary approach to conservation biology that considers evolutionary history at various levels of biological organization. We review work on three separate plant taxa, spanning from one to multiple decades, illustrating extremes in metapopulation functioning. We show how the rare endemics Centaurea corymbosa (Clape Massif, France) and Brassica insularis in Corsica (France) may be caught in an evolutionary trap: disruption of metapopulation functioning due to lack of colonization of new sites may have counterselected traits such as dispersal ability or self-compatibility, making these species particularly vulnerable to any disturbance. The third case study concerns the evolution of life history strategies in the highly diverse genus Leucadendron of the South African fynbos. There, fire disturbance and the recolonization phase after fires are so integral to the functioning of populations that recruitment of new individuals is conditioned by fire. We show how past adaptation to different fire regimes and climatic constraints make species with different life history syndromes more or less vulnerable to global changes. These different case studies suggest that management strategies should promote evolutionary potential and evolutionary processes to better protect extant biodiversity and biodiversification. PMID:27087848

  3. Dark matter, dark energy and the time evolution of masses in the Universe

    CERN Document Server

    Sola, Joan

    2014-01-01

    The traditional "explanation" for the observed acceleration of the universe is the existence of a positive cosmological constant. However, this can hardly be a truly convincing explanation, as an expanding universe is not expected to have a static vacuum energy density. So, it must be an approximation. This reminds us of the so-called fundamental "constants" of nature. Recent and past measurements of the fine structure constant and of the proton-electron mass ratio suggest that basic quantities of the standard model, such as the QCD scale parameter $\\LQCD$, might not be conserved in the course of the cosmological evolution. The masses of the nucleons and of the atomic nuclei would be time-evolving. This can be consistent with General Relativity provided the vacuum energy itself is a dynamical quantity. Another framework realizing this possibility is QHD (Quantum Haplodynamics), a fundamental theory of bound states. If one assumes that its running couplings unify at the Planck scale and that such scale changes...

  4. The size evolution of galaxy discs formed within Lambda Cold Dark Matter haloes

    CERN Document Server

    Firmani, C

    2009-01-01

    By means of galaxy evolutionary models, we explore the direct consequences of the LCDM cosmogony on the size evolution of galactic discs, avoiding intentionally the introduction of intermediate (uncertain) astrophysical processes. Based on the shape of the rotation curves and guided by a simplicity criterion, we adopt an average galaxy mass baryon fraction of 0.03. In order to study general behaviors, only models with the average initial conditions are analyzed. The stellar and B-band effective radii, R* and RB, of individual galaxies grow significantly with time (inside-out disc formation) with laws that are weakly dependent on mass, M*,or luminosity, LB. However, the change of R* with z at fixed M* is slow; for z0.75. We find also that at z=0, R* ~ M*^0.38 and RB ~ LB^0.40, remaining the slopes of these relations almost the same up to z ~ 3. Our predictions are in reasonable agreement with observational inferences on the typical radius change with z of late-type galaxies more luminous (massive) than high va...

  5. A little bit of sex matters for genome evolution in asexual plants

    Directory of Open Access Journals (Sweden)

    Diego eHojsgaard

    2015-02-01

    Full Text Available Genome evolution in asexual organisms is theoretically expected to be shaped by various factors:first, hybrid origin and polyploidy confer a genomic constitution of highly heterozygous genotypes with multiple copies of genes;second, asexuality confers a lack of recombination and variation in populations, which reduces the efficiency of selection against deleterious mutations;hence, the accumulation of mutations and a gradual increase in mutational load (Muller’s ratchetwould lead to rapid extinction of asexual lineages;third, allelic sequence divergence is expected to result in rapid divergence of lineages (Meselson effect.Recent transcriptome studies on the asexual polyploid complex Ranunculus auricomus using single-nucleotide polymorphisms confirmed neutral allelic sequence divergence within a short time frame, but rejected a hypothesis of a genome-wide accumulation of mutations in asexuals compared to sexuals, except for a few genes related to reproductive development.We discuss a general model that the observed incidence of facultative sexuality in plants may unmask deleterious mutations with partial dominance and expose them efficiently to purging selection.A little bit of sex may help to avoid genomic decay and extinction.

  6. [Effect of the subsurface constructed wetland evolution into free surface flow constructed wetland on the removal of organic matter, nitrogen, and phosphor in wastewater].

    Science.gov (United States)

    Wei, Ze-Jun; Xie, Jian-Ping; Huang, Yu-Ming

    2012-11-01

    Many previous studies demonstrated that the performance of the subsurface constructed wetlands (SSCW) for wastewater treatment was superior to that of the free flow surface constructed wetlands (FFSCW). However, our results indicated that the performance of FFSCW derived from the evolution of SSCW due to clogging for COD, TOC, total nitrogen (TN), and total phosphor (TP) removal was higher than those of SSCW with the same substrate and plant. The laboratory culture experiments were adopted to evaluate the effect of the constructed wetland evolution on the organic matter mineralization, nitrification/denitrification as well as removal of nitrogen and phosphor. It was shown that, after evolution of SSCW into FFSCW, the mineralization rate for organic matter (as TOC) was 1.82 mg x h(-1), and it was 1.49 mg x h(-1) for SSCW. The removal efficiency for NO3(-) was 96.8%, and it was 58.1% for SSCW. The abiotic denitrification removal efficiency was 40%, and it was 28.2% for SSCW. In addition, the maximum equilibrium adsorption capacity of the substrate after evolution for phosphor (as P) was 160 mg x kg(-1), and it was 140 mg x kg(-1) for SSCW substrate. The organic coverage of the substrate was found to be beneficial to phosphor removal. The nitrification ability decreased after evolution. These results suggest the important effect of constructed wetland evolution on its performance. PMID:23323410

  7. Organic-matter production and preservation and evolution of anoxia in the Holocene Black Sea

    Science.gov (United States)

    Arthur, M.A.; Dean, W.E.

    1998-01-01

    Dating of sediments collected in gravity cores during Leg 1 of the 1988 R/V Knorr expedition to the Black Sea suggests that the onset of water-column anoxia at ???7.5 ka was virtually synchronous across the basin over a depth range of ???200 - 2250 m. A finely laminated, organic carbon (OC) rich sapropel (unit II) was produced as a result of this anoxia. The trigger for increased OC production and development of anoxia was the spillover of saline waters through the Bosporus that probably began at ???9.0 ka and peaked between ???7.0 and 5.5 ka. This spillover enhanced vertical mixing and nutrient cycling and caused a short-term (2-3 kyr) burst in surface-water productivity during the early part of unit II deposition. Continued incursion of saline waters enhanced vertical stability and inhibited mixing of nutrients into surface waters, thus limiting primary production and decreasing the OC flux to sediments beginning ???5.5 ka. Concentration, accumulation rate, and degree of preservation of organic matter all decreased in the upper part of unit II as a result of decreasing productivity, but anoxia persisted throughout most of the water column. The end of unit II sapropel deposition was synchronous across the Black Sea as the result of the first blooms of the coccolith Emiliania huxleyi, which presumably marked an increase in surface-water salinity above 11 and the beginning of unit I deposition. The high coccolith-carbonate fluxes that occurred during deposition of unit I diluted the OC concentration in the sediments, but OC accumulation rates are about the same as those in upper part of unit II.

  8. QCD phase transition with a power law chameleon scalar field in the bulk

    CERN Document Server

    Golanbari, T; Saaidi, Kh

    2014-01-01

    In this work, a brane world model with a perfect fluid on brane and a scalar field on bulk has been used to study quark-hadron phase transition. The bulk scalar field has an interaction with brane matter. This interaction comes into non-conservation relation which describe an energy transfer between bulk and brane. Since quark-hadron transition curly depends on the form of evolution equations therefore modification of energy conservation equation and Friedmann equation comes into some interesting results about the time of transition. The evolution of physical quantities relevant to quantitative of early times namely energy density $\\rho$ temperature $T$ and scale factor $a$ have been considered utilizing two formalisms as crossover formalism and first order phase transition formalism. The results show that the quark-hadron phase transition in occurred about nanosecond after big bang and the general behavior temperature is similar in both of two formalism.

  9. QCD phase transition with a power law chameleon scalar field in the bulk

    Science.gov (United States)

    Golanbari, Tayeb; Mohammadi, Abolhassan; Saaidi, Khaled

    2014-03-01

    In this paper, a braneworld model with a perfect fluid on brane and a scalar field on bulk has been used to study quark-hadron phase transition. The bulk scalar field has an interaction with brane matter. This interaction comes into nonconservation relation which describes an energy transfer between bulk and brane. Since quark-hadron transition truly depends on the form of evolution equations, modification of energy conservation equation and Friedmann equation gives rise to some interesting results about the time of transition. The evolution of physical quantities relevant to the quantitative of early times namely energy density ρ, temperature T and scale factor a have been considered utilizing two formalism, crossover formalism and first-order phase transition formalism. The results show that the quark-hadron phase transition occurred about a nanosecond after big bang and the general behavior temperature is similar in both of two formalism.

  10. The link between the assembly of the inner dark matter halo and the angular momentum evolution of galaxies in the EAGLE simulation

    Science.gov (United States)

    Zavala, Jesús; Frenk, Carlos S.; Bower, Richard; Schaye, Joop; Theuns, Tom; Crain, Robert A.; Trayford, James W.; Schaller, Matthieu; Furlong, Michelle

    2016-08-01

    We explore the co-evolution of the specific angular momentum of dark matter haloes and the cold baryons that comprise the galaxies within. We study over 2000 galaxies within the reference cosmological hydrodynamical simulation of the `Evolution and Assembly of GaLaxies and their Environments' (EAGLE) project. We employ a methodology within which the evolutionary history of a system is specified by the time-evolving properties of the Lagrangian particles that define it at z = 0. We find a strong correlation between the evolution of the specific angular momentum of today's stars (cold gas) and that of the inner (whole) dark matter halo they are associated with. This link is particularly strong for the stars formed before the epoch of maximum expansion and subsequent collapse of the central dark matter halo (turnaround). Spheroids are assembled primarily from stars formed prior to turnaround, and suffer a net loss of angular momentum associated with the strong merging activity during the assembly of the inner dark matter halo. Stellar discs retain their specific angular momentum since they are comprised of stars formed mainly after turnaround, from gas that mostly preserves the high specific angular momentum it acquired by tidal torques during the linear growth of the halo. Since the specific angular momentum loss of the stars is tied to the galaxy's morphology today, it may be possible to use our results to predict, statistically, the maximum loss of specific angular momentum of the inner part of a halo given the morphology of the galaxy it hosts.

  11. Records of bulk organic matter and plant pigments in sediment of the "red-tide zone" adjacent to the Changjiang River estuary

    Science.gov (United States)

    Kang, Zhenjun; Yu, Rencheng; Kong, Fanzhou; Wang, Yunfeng; Gao, Yan; Chen, Jianhua; Guo, Wei; Zhou, Mingjiang

    2016-09-01

    Cultural eutrophication caused by nutrient over-enrichment in coastal waters will lead to a cascading set of ecosystem changes and deleterious ecological consequences, such as harmful algal blooms (HABs) and hypoxia. During the past two decades since the late 1990s, recurrent large-scale HABs (red tides) and an extensive hypoxic zone have been reported in the coastal waters adjacent to the Changjiang River estuary. To retrieve the history of eutrophication and its associated ecosystem changes, a sediment core was collected from the "red-tide zone" adjacent to the Changjiang River estuary. The core was dated using the 210Pb radioisotope and examined for multiple proxies, including organic carbon (OC), total nitrogen (TN), stable isotopes of C and N, and plant pigments. An apparent up-core increase of OC content was observed after the 1970s, accompanied by a rapid increase of TN. The concurrent enrichment of δ13C and increase of the C/N ratio suggested the accumulation of organic matter derived from marine primary production during this stage. The accumulation of OC after the 1970s well reflected the significant increase of primary production in the red-tide zone and probably the intensification of hypoxia as well. Plant pigments, including chlorophyll a, β-carotene, and diatoxanthin, showed similar patterns of variation to OC throughout the core, which further confirmed the important contribution of microalgae, particularly diatoms, to the deposited organic matter. Based on the variant profiles of the pigments representative of different microalgal groups, the potential changes of the phytoplankton community since the 1970s were discussed.

  12. Records of bulk organic matter and plant pigments in sediment of the "red-tide zone" adjacent to the Changjiang River estuary

    Science.gov (United States)

    Kang, Zhenjun; Yu, Rencheng; Kong, Fanzhou; Wang, Yunfeng; Gao, Yan; Chen, Jianhua; Guo, Wei; Zhou, Mingjiang

    2016-01-01

    Cultural eutrophication caused by nutrient over-enrichment in coastal waters will lead to a cascading set of ecosystem changes and deleterious ecological consequences, such as harmful algal blooms (HABs) and hypoxia. During the past two decades since the late 1990s, recurrent large-scale HABs (red tides) and an extensive hypoxic zone have been reported in the coastal waters adjacent to the Changjiang River estuary. To retrieve the history of eutrophication and its associated ecosystem changes, a sediment core was collected from the "red-tide zone" adjacent to the Changjiang River estuary. The core was dated using the 210Pb radioisotope and examined for multiple proxies, including organic carbon (OC), total nitrogen (TN), stable isotopes of C and N, and plant pigments. An apparent up-core increase of OC content was observed after the 1970s, accompanied by a rapid increase of TN. The concurrent enrichment of δ13C and increase of the C/N ratio suggested the accumulation of organic matter derived from marine primary production during this stage. The accumulation of OC after the 1970s well reflected the significant increase of primary production in the red-tide zone and probably the intensification of hypoxia as well. Plant pigments, including chlorophyll a, β-carotene, and diatoxanthin, showed similar patterns of variation to OC throughout the core, which further confirmed the important contribution of microalgae, particularly diatoms, to the deposited organic matter. Based on the variant profiles of the pigments representative of different microalgal groups, the potential changes of the phytoplankton community since the 1970s were discussed.

  13. Role of biodegradation in the removal of pharmaceutically active compounds with different bulk organic matter characteristics through managed aquifer recharge: Batch and column studies

    KAUST Repository

    Maeng, Sungkyu

    2011-10-01

    Natural water treatment systems such as bank filtration have been recognized as providing effective barriers in the multi-barrier approach for attenuation of organic micropollutants for safe drinking water supply. In this study, the role of biodegradation in the removal of selected pharmaceutically active compounds (PhACs) during soil passage was investigated. Batch studies were conducted to investigate the removal of 13 selected PhACs from different water sources with respect to different sources of biodegradable organic matter. Neutral PhACs (phenacetine, paracetamol, and caffeine) and acidic PhACs (ibuprofen, fenoprofen, bezafibrate, and naproxen) were removed with efficiencies greater than 88% from different organic matter water matrices during batch studies (hydraulic retention time (HRT): 60 days). Column experiments were then performed to differentiate between biodegradation and sorption with regard to the removal of selected PhACs. In column studies, removal efficiencies of acidic PhACs (e.g., analgesics) decreased under conditions of limited biodegradable carbon. The removal efficiencies of acidic PhACs were found to be less than 21% under abiotic conditions. These observations were attributed to sorption under abiotic conditions established by a biocide (20 mM sodium azide), which suppresses microbial activity/biodegradation. However, under biotic conditions, the removal efficiencies of these acidic PhACs were found to be greater than 59%. This is mainly attributed to biodegradation. Moreover, the average removal efficiencies of hydrophilic (polar) neutral PhACs (paracetamol, pentoxifylline, and caffeine) with low octanol/water partition coefficients (log K ow less than 1) were low (11%) under abiotic conditions. However, under biotic conditions, removal efficiencies of the neutral PhACs were greater than 98%. In contrast, carbamazepine persisted and was not easily removed under either biotic or abiotic conditions. This study indicates that biodegradation

  14. Effects of Biomass Type and Combustion Conditions on the Bulk and Molecular Properties of Biochar-Derived Dissolved Organic Matter as Determined by Ultrahigh Resolution Mass Spectrometry

    Science.gov (United States)

    Cooper, W. T.; D'Andrili, J.; Ostrowicki, K.; Zimmerman, A. R.

    2008-12-01

    Biochar, the residual products of biomass combustion excluding vapor phase condensates, can be a major component of soil organic matter in regions prone to fires or where slash and burn or slash and char agriculture is practiced. Dissolution or leaching of biochar may be the primary mechanism for biochar turnover in soils as it is thought to be extremely refractory in solid form. Although researchers have made significant progress recently in understanding biochar's physical and chemical properties, we know of no comprehensive study of the relationship between these properties and the solubility or chemistry of dissolved organic matter (DOM) derived from biochar (or black carbon). Thus, we have thus begun a series of studies of the relationship between the chemical and morphological properties of biochars made from a variety of biomass types (woods and grasses) produced under a range of controlled conditions (temperature and atmosphere) and the quantity, quality and lability of leacheate derived from those biochars. After a series of time-course leaching experiments (3, 10 and 20 day), leacheate was quantified by total organic carbon analysis and incubated both abiotically and with microbe inoculates. The pre- and post- incubation leachates were then analyzed with the 9.4 T instrument at the National High Magnetic Field Laboratory in Tallahassee, FL, the same instrument that has been used in most of the pioneering mass spectrometry analyses of natural DOM. Traditional electrospray ionization (ESI) and the relatively new atmospheric pressure photoionization techniques were both employed to convert dissolved DOM molecules into gas-phase ions which were then identified by ultrahigh resolution FT-ICR MS. The unique chemical formulas of the 2,000 - 4,000 individual compounds identified were then characterized by van Krevelen analysis (elemental O/C vs H/C ratios), Kendrick mass defects, and double bond equivalencies. In this presentation we will use these molecular

  15. Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

    Science.gov (United States)

    Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

    2011-01-01

    The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected. PMID:21330721

  16. The impact of agriculture terraces on soil organic matter, aggregate stability, water repellency and bulk density. A study in abandoned and active farms in the Sierra de Enguera, Eastern Spain.

    Science.gov (United States)

    Cerdà, Artemi; Burguet, Maria; Keesstra, Saskia; Prosdocimi, Massimo; Di Prima, Simone; Brevik, Erik; Novara, Agata; Jordan, Antonio; Tarolli, Paolo

    2016-04-01

    Soil erosion, land degradation, lack of organic matter, erodible soils, rock outcrops… are a consequence of the human abuse and misuse of the soil resources. And this is a worldwide environmental issue (Novara et al., 2011; Vanlauwe et al., 2015; Musinguzi et al., 2015; Pereira et al., 2015; Mwagno et al., 2016). Agriculture terraces are a strategy to reduce the soil erosion, improve the soil fertility and allow the ploughing (Cerdà et al., 2010; Li et al., 2014). Although this idea is well accepted there are few scientific evidences that demonstrate that soils in the terraced areas are more stable, fertile and sustainable that the soil in non terraced areas. In fact, the ploughing in comparison to the abandoned or not ploughed land results in the soil degradation (Lieskovský and Kenderessy, 2014; Gao et al., 2015; Parras-Alcántara et al., 2014). This is mainly due to the lack of vegetation that increase the surface runoff (Cerdà et al., 1998; Keesstra et al., 2007). And why is necessary to develop also in terraced landscapes soil erosion control strategies (Mekonnen et al., 2015a; Mekonnen et al., 2015b; Prosdocimi et al., 2016). Our objective was to assess the soil organic matter content (Walkley and Black, 1934), the soil bulk density (ring method), the aggregate stabilility (drop impact) and the water repellency (Water Drop Penetration Time test) in four study sites in the Sierra de Enguera. Two sites were terraced: one abandoned 40 years before the measurements and the other still active with olive crops. And two control sites non-terraced. We used the paired plot strategy to compare the impact of terracing and abandonment. At each site we collected randomly 50 soil samples at 0-2 cm, 4-6 and 8-10 cm depth. At each sampling point 100 WDPT measurements where carried out, and one sample for the bulk density, and one for the organic matter, and one for the soil aggregate stability were collected. The soil surface samples shown the largest differences. The

  17. The link between the assembly of the inner dark matter halo and the angular momentum evolution of galaxies in the EAGLE simulation

    CERN Document Server

    Zavala, Jesus; Bower, Richard; Schaye, Joop; Theuns, Tom; Crain, Robert A; Trayford, James W; Schaller, Matthieu; Furlong, Michelle

    2015-01-01

    We explore the co-evolution of the specific angular momentum of dark matter haloes and the cold baryons that comprise the galaxies within. We study over two thousand central galaxies within the reference cosmological hydrodynamical simulation of the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) project. We employ a methodology within which the evolutionary history of a system is specified by the time-evolving properties of the Lagrangian particles that define it at z=0. We find a strong correlation between the evolution of the specific angular momentum of today's stars (cold gas) and that of the inner (whole) dark matter halo they are associated with. This link is particularly strong for the stars formed before the epoch of maximum expansion and subsequent collapse of the central dark matter halo (turnaround). Spheroids are typically assembled primarily from stars formed prior to turnaround, and are therefore destined to suffer a net loss of angular momentum associated with the strong me...

  18. The impact of agriculture terraces on soil organic matter, aggregate stability, water repellency and bulk density. A study in abandoned and active farms in the Sierra de Enguera, Eastern Spain.

    Science.gov (United States)

    Cerdà, Artemi; Burguet, Maria; Keesstra, Saskia; Prosdocimi, Massimo; Di Prima, Simone; Brevik, Erik; Novara, Agata; Jordan, Antonio; Tarolli, Paolo

    2016-04-01

    Soil erosion, land degradation, lack of organic matter, erodible soils, rock outcrops… are a consequence of the human abuse and misuse of the soil resources. And this is a worldwide environmental issue (Novara et al., 2011; Vanlauwe et al., 2015; Musinguzi et al., 2015; Pereira et al., 2015; Mwagno et al., 2016). Agriculture terraces are a strategy to reduce the soil erosion, improve the soil fertility and allow the ploughing (Cerdà et al., 2010; Li et al., 2014). Although this idea is well accepted there are few scientific evidences that demonstrate that soils in the terraced areas are more stable, fertile and sustainable that the soil in non terraced areas. In fact, the ploughing in comparison to the abandoned or not ploughed land results in the soil degradation (Lieskovský and Kenderessy, 2014; Gao et al., 2015; Parras-Alcántara et al., 2014). This is mainly due to the lack of vegetation that increase the surface runoff (Cerdà et al., 1998; Keesstra et al., 2007). And why is necessary to develop also in terraced landscapes soil erosion control strategies (Mekonnen et al., 2015a; Mekonnen et al., 2015b; Prosdocimi et al., 2016). Our objective was to assess the soil organic matter content (Walkley and Black, 1934), the soil bulk density (ring method), the aggregate stabilility (drop impact) and the water repellency (Water Drop Penetration Time test) in four study sites in the Sierra de Enguera. Two sites were terraced: one abandoned 40 years before the measurements and the other still active with olive crops. And two control sites non-terraced. We used the paired plot strategy to compare the impact of terracing and abandonment. At each site we collected randomly 50 soil samples at 0-2 cm, 4-6 and 8-10 cm depth. At each sampling point 100 WDPT measurements where carried out, and one sample for the bulk density, and one for the organic matter, and one for the soil aggregate stability were collected. The soil surface samples shown the largest differences. The

  19. Mind, Matter, and Evolution

    DEFF Research Database (Denmark)

    Sørensen, Bent; Thellefsen, Torkild; Brier, Søren

    2012-01-01

    In the program article “The Architectures of Theories” (1893), C. S. Peirce presented his trichotomies within psychology, biology, physics and philosophy, and in terms of these trichotomies, it could easily be predicted, according to Peirce, what kind of metaphysics it would be appropriate to con...

  20. Microstructure evolution in Nd:YAG laser-welded (Zr53Cu30Ni9Al8)Si0.5 bulk metallic glass alloy

    International Nuclear Information System (INIS)

    To generate a rapid welding thermal cycle for a (Zr53Cu30Ni9Al8)Si0.5 bulk metallic glass (BMG) weld, the Nd:YAG pulse laser welding process with pre-selected welding variables is used in this study. The microstructure development and crystallization behavior in the weld fusion zone (WFZ) and the heat-affected zone (HAZ) are investigated by scanning electron microscopy (SEM), micro-area X-ray diffractometry (XRD) and transmission electron microscopy (TEM). From the results, it is observed that the HAZ is liable to crystallize, although no crystallization occurs within the WFZ. The spherical type crystalline phases (with a particle size of 20-200 nm) observed in the HAZ, which are rich in Zr, Cu and Ni, result in a change of chemical composition in this region. Furthermore, if the particle size in the crystallized area is greater than 50 nm, cracks may form.

  1. Geological evolution of the marine selenium cycle: Insights from the bulk shale δ82/76Se record and isotope mass balance modeling

    Science.gov (United States)

    Mitchell, Kristen; Mansoor, Sannan Z.; Mason, Paul R. D.; Johnson, Thomas M.; Van Cappellen, Philippe

    2016-05-01

    Bulk δ82/76Se values of representative marine shales from the Paleoarchean to the present day vary between approximately -3 and + 3 ‰ with only local deviations beyond this range. This muted Se isotope variability in the shale record contrasts with the relatively large fractionations associated with abiotic and microbial Se oxyanion reduction seen in experimental studies. Long-term temporal trends in the bulk shale data do not directly correlate with changes in redox conditions of the global ocean, although a minor but significant shift towards more negative formation-averaged δ82/76Se values appears to track oxygenation of the deep ocean at the end of the Proterozoic. We hypothesize that extensive δ82/76Se variability in the shale data was suppressed due to the early emergence of biological assimilatory uptake and the resulting persistence of low seawater Se concentrations, coupled with small authigenic Se outputs throughout most of geological time. In the modern ocean, Se is an essential micronutrient with a relatively short residence time of about 11,500 yrs. The marine Se cycle is dominated by assimilation into biomass and subsequent recycling in the water column and surface sediments, i.e. processes that result in only minimal isotopic fractionation. We suggest that similar processes dominated back through the geological record to Archean times. Our model shows that paleoceanographic information could in principle be extracted from proxy data on the Se isotopic composition of seawater, once isotopic differences can be readily discerned between individual sedimentary Se pools.

  2. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  3. Bulk solitary waves in elastic solids

    Science.gov (United States)

    Samsonov, A. M.; Dreiden, G. V.; Semenova, I. V.; Shvartz, A. G.

    2015-10-01

    A short and object oriented conspectus of bulk solitary wave theory, numerical simulations and real experiments in condensed matter is given. Upon a brief description of the soliton history and development we focus on bulk solitary waves of strain, also known as waves of density and, sometimes, as elastic and/or acoustic solitons. We consider the problem of nonlinear bulk wave generation and detection in basic structural elements, rods, plates and shells, that are exhaustively studied and widely used in physics and engineering. However, it is mostly valid for linear elasticity, whereas dynamic nonlinear theory of these elements is still far from being completed. In order to show how the nonlinear waves can be used in various applications, we studied the solitary elastic wave propagation along lengthy wave guides, and remarkably small attenuation of elastic solitons was proven in physical experiments. Both theory and generation for strain soliton in a shell, however, remained unsolved problems until recently, and we consider in more details the nonlinear bulk wave propagation in a shell. We studied an axially symmetric deformation of an infinite nonlinearly elastic cylindrical shell without torsion. The problem for bulk longitudinal waves is shown to be reducible to the one equation, if a relation between transversal displacement and the longitudinal strain is found. It is found that both the 1+1D and even the 1+2D problems for long travelling waves in nonlinear solids can be reduced to the Weierstrass equation for elliptic functions, which provide the solitary wave solutions as appropriate limits. We show that the accuracy in the boundary conditions on free lateral surfaces is of crucial importance for solution, derive the only equation for longitudinal nonlinear strain wave and show, that the equation has, amongst others, a bidirectional solitary wave solution, which lead us to successful physical experiments. We observed first the compression solitary wave in the

  4. Utility of δ13C and C/N values of bulk sedimentary organic matter in the reconstruction of former sea levels and paleoenvironment, Luquillo Critical Zone, Puerto Rico

    Science.gov (United States)

    Khan, N. S.; Vane, C.; Horton, B. P.; Scatena, F. N.

    2012-12-01

    vegetation occupies the same niche as mangroves in the low-latitudes. Our preliminary analysis suggests that together δ13C and C/N serve as a suitable sea-level indicator in the tropics because they hold a relationship to tidal elevation that is identifiable in the sedimentary record. This work provides alternative means for filling gaps in data associated with other proxies, as well as provides the first quantitative reconstruction of Holocene relative sea-level change using δ13C and C/N of bulk sedimentary organic matter.

  5. Total Suspended Matter (TSM) and Maximum Signal Depth (Z90_max) for Monitoring the Evolution of Sediment Resuspension Process in Shallow Coastal Environments

    Science.gov (United States)

    Filipponi, Federico; Zucca, Francesco; Taramelli, Andrea; Valentini, Emiliana

    2015-12-01

    Monitoring sediment fluxes patterns in coastal area, like dispersion, sedimentation and resuspension processes, is a relevant topic for scientists, decision makers and natural resources management. Time series analysis of Earth Observation (EO) data may contribute to the understanding and the monitoring of processes in sedimentary depositional marine environment, especially for shallow coastal areas. This research study show the ability of optical medium resolution imagery to interpret the evolution of sediment resuspension from seafloor in coastal areas during intense wind forcings. Intense bora wind events in northern Adriatic Sea basin during winter season provoke considerable wave-generated resuspension of sediments, which cause variation in water column turbidity. Total Suspended Matter (TSM) product has been selected as proxy for qualitative and quantitative analysis of resuspended sediments. In addition, maximum signal depth (Z90_max), has been used to evaluate the evolution of sediment concentration in the water column.

  6. Spherically symmetric hydrodynamic model calculations on the evolution of interstellar matter and on stellar evolution in the cove of spiral-galaxies

    International Nuclear Information System (INIS)

    A numerical model is presented for a galactic core with radial symmetry, describing the mechanism of repeated bursts of stellar evolution. Repeated burst occur under the condition that energy is transfered by stellar winds and supernovae explosions from the massive stars, formed in the bursts at high gas pressures, to the interstellar medium. Thus the gas component of the model core expands until massive stars are no longer available. The following contraction of the gas distribution, caused by energy dissipation, results in a new burst, thus starting a new evolutional cycle. In the numerical model a large part of massive stars results in a high production rate for turbulent kinetic energy, so that a repeated excitation of bursts becomes possible. (orig./WB)

  7. Orbital magnetization in insulators: Bulk versus surface

    Science.gov (United States)

    Bianco, Raffaello; Resta, Raffaele

    2016-05-01

    The orbital magnetic moment of a finite piece of matter is expressed in terms of the one-body density matrix as a simple trace. We address a macroscopic system, insulating in the bulk, and we show that its orbital moment is the sum of a bulk term and a surface term, both extensive. The latter only occurs when the transverse conductivity is nonzero and it is due to conducting surface states. Simulations on a model Hamiltonian validate our theory.

  8. Evolution of Pretreatment Methods for Nanofiltration Membrane Used for Dissolved Organic Matter Removal in Raw Water Supply

    Directory of Open Access Journals (Sweden)

    Sirikul Siriraksophon

    2016-07-01

    Full Text Available Coagulation and microfiltration using polyaluminium chloride (PACl were investigated as a pretreatment process by nanofiltration to reduce dissolved organic matter in both raw water and treated water at water treatment plants. The dissolved organic matter in the raw water supply may be a precursor of carcinogens produced during the disinfection process. Raw water from pumping stations and treated water from Hat Yai Provincial Waterworks Authority, Songkhla Province, Thailand were used as samples for this study. Fractionation of raw water samples by DAX-8 and XAD-4 resin revealed that they contained hydrophilic, transphilic and hydrophobic groups with hydrophilic the major organic component. PACl coagulation resulted in a higher dissolved organic matter removal than microfiltration techniques. A hybrid coagulation-nanofiltration process was studied. This effectively reduced dissolved organic matter as dissolved organic carbon and UV-254 by 86% and 94% respectively. The hybrid coagulation-nanofiltration process reduced dissolved organic carbons of the hydrophobic group more effectively than the hydrophilic group. Chloroform and bromodichloroform were the two major species of the trihalomethane group produced when raw water reacted with chlorine. The hybrid coagulation-nanofiltration process reduced the trihalomethane formation potential (THMFP in raw water samples by up to 90%

  9. Faecal bulking efficacy of Australasian breakfast cereals.

    Science.gov (United States)

    Monro, John A

    2002-01-01

    Faecal bulk may play an important role in preventing a range of disorders of the large bowel, but as yet there is little information available on the relative faecal bulking capacities of various foods. Breakfast cereals are often promoted as a good source of potential bulk for 'inner health' because they provide dietary fibre, but their relative abilities to provide faecal bulk per se have not been described. The faecal bulking efficacy of 28 representative Australasian breakfast cereals was therefore measured. A rat model developed for the purpose, and shown to give similar responses as humans to cereal fibres, was used to measure faecal bulking efficacy as increases in fully hydrated faecal weight/100 g diet, based on precise measurements of food intake, faecal dry matter output and faecal water-holding capacity (g water held without stress/g faecal dry matter). Compared to a baseline diet containing 50% sucrose, increments in hydrated faecal weight due to 50% breakfast cereal ranged from slightly negative (Cornflakes, -2 g/100 g diet) to about 80 g/100 g diet (San Bran). Most breakfast cereals increased hydrated faecal weight by between 10 and 20 g/100 g diet from a baseline of 21 +/- 1.5 g/100 g diet, but four products containing high levels of wheat bran had an exceptionally large impact on hydrated faecal weight (increment > 20 g/100 g diet), and the changes resulted more from relative changes in dry matter output than in faecal water retention/gram. However, as faecal water retention was about 2.5 g water/g faecal dry matter on average, increases in dry matter represented large increases in faecal water load. Faecal bulking indices (FBI) for most of the breakfast cereals were less than 20 (wheat bran = 100). The content of wheat bran equivalents for faecal bulk (WBE(fb)) in the breakfast cereals was calculated from FBI. Most breakfast cereals contributed, per serve, less than 10% of a theoretical daily reference value for faecal bulk (DRV(fb) = 63 WBE

  10. Chaotic motion and the evolution of morphological components in a time-dependent model of a barred galaxy within a dark matter halo

    CERN Document Server

    Machado, Rubens E G

    2016-01-01

    Studies of dynamical stability (chaotic versus regular motion) in galactic dynamics often rely on static analytical models of the total gravitational potential. Potentials based upon self-consistent N-body simulations offer more realistic models, fully incorporating the time-dependent nature of the systems. Here we aim at analysing the fractions of chaotic motion within different morphological components of the galaxy. We wish to investigate how the presence of chaotic orbits evolves with time, and how their spatial distribution is associated with morphological features of the galaxy. We employ a time-dependent analytical potential model that was derived from an N-body simulation of a strongly barred galaxy. With this analytical potential we may follow the dynamical evolution of ensembles of orbits. Using the Generalized Alignment Index (GALI) chaos detection method, we study the fraction of chaotic orbits, sampling the dynamics of both the stellar disc and of the dark matter halo. Within the stellar disc, th...

  11. Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?

    CERN Document Server

    Eistrup, Christian; van Dishoeck, Ewine F

    2016-01-01

    [Abridged] Chemical evolution in the protoplanetary disk midplane can modify the composition of ices and gases. We have investigated if and how chemical evolution affects the abundances and distributions of key volatile species in the midplane of a protoplanetary disk in the 0.2-30 AU range. A full chemical network including gas-phase, gas-grain interactions and grain-surface chemistry is used to evolve chemistry in time, for 1 Myr. Great diversity is observed in the relative abundance ratios of the main considered species: H2O, CO, CO2, CH4, O2, NH3 and N2. The choice of ionisation level, the choice of initial abundances, as well as the extent of chemical reaction types included are all factors that affect the chemical evolution. The only exception is the inheritance scenario with a low ionisation level, which results in negligible changes compared with the initial abundances, regardless of whether grain-surface chemistry is included. The chemical processing changes the C/O ratios for gas and ice significant...

  12. Dark Matter

    OpenAIRE

    Zacek, Viktor

    2007-01-01

    The nature of the main constituents of the mass of the universe is one of the outstanding riddles of cosmology and astro-particle physics. Current models explaining the evolution of the universe, and measurements of the various components of its mass, all have in common that an appreciable contribution to that mass is non-luminous and non-baryonic, and that a large fraction of this so-called dark matter must be in the form of non-relativistic massive particles (Cold Dark Matter: CDM). In the ...

  13. Time Evolution of Electric Fields in CDMS Detectors

    CERN Document Server

    Leman, S W; Brink, P L; Cabrera, B; Chagani, H; Cherry, M; Cushman, P; Silva, E Do Couto E; Doughty, T; Figueroa-Feliciano, E; Mandic, V; McCarthy, K A; Mirabolfathi, N; Pyle, M; Reisetter, A; Resch, R; Sadoulet, B; Serfass, B; Sundqvist, K M; Tomada, A; Young, B A; Zhang, J

    2011-01-01

    The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3" diameter x 1" thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors, the later providing a $\\sim$1 V cm$^{-1}$ electric field in the detector bulk. Cumulative radiation exposure which creates $\\sim 200\\times 10^6$ electron-hole pairs is sufficient to produce a comparable reverse field in the detector thereby degrading the ionization channel performance. To study this, the existing CDMS detector Monte Carlo has been modified to allow for an event by event evolution of the bulk electric field, in three spatial dimensions. Our most resent results and interpretation are discussed.

  14. Spin flips I: Evolution of the angular momentum orientation of Milky Way-mass dark matter haloes

    CERN Document Server

    Bett, Philip E

    2011-01-01

    During the growth of a cold dark matter halo, the direction of its spin can undergo rapid changes. These could disrupt or even destroy a stellar disc forming in the halo. We investigate the frequency of significant changes in the orientation of the angular momentum vector of dark matter haloes ("spin flips"), and their degree of correlation with mergers. We focus on haloes of mass similar to that of the Milky Way (MW) halo at redshift z=0 (log M/(Msol/h) = 12.0 to 12.5) and consider flips in the spin of the whole halo or just its inner parts. We find that a greater fraction of major mergers are associated with large spin flips than minor mergers. However, since major mergers are rare, the vast majority (93%) of large whole-halo spin flips (angle change >= 45 degrees) coincide with small mass changes, not major mergers. The spin vector of the inner halo experiences much more frequent flips than the halo as a whole. Over their entire lifetime (i.e. after the halo acquires half of its final mass), over 10% of ha...

  15. Evolution of organic matter fractions after application of co-compost of sewage sludge with pruning waste to four Mediterranean agricultural soils. A soil microcosm experiment.

    Science.gov (United States)

    Pérez-Lomas, A L; Delgado, G; Párraga, J; Delgado, R; Almendros, G; Aranda, V

    2010-10-01

    The effect of co-compost application from sewage sludge and pruning waste, on quality and quantity of soil organic carbon (SOC) in four Mediterranean agricultural soils (South Spain), was studied in soil microcosm conditions. Control soil samples (no co-compost addition) and soils treated with co-composts to a rate equivalent of 140 Mg ha(-1) were incubated for 90 days at two temperatures: 5 and 35 degrees C. The significances of incubation temperature and the addition of co-compost, on the evolution of the different fractions of SOC, were studied using a 2(3) factorial design. The co-compost amendment increased the amounts of humic fractions: humic acids (HA) (1.9 times), fulvic acids (FA) (3.3 times), humin (1.5 times), as well as the free organic matter (1.4 times) and free lipids (21.8 times). Incubation of the soils enhanced its biological activity mainly in the amended soils and at 35 degrees C, leading to progressive SOC mineralization and humification, concomitant to the preferential accumulation of HA. The incubation results show large differences depending on temperature and soil types. This fact allows us to select suitable organic amendment for the soil when a rapid increase in nutrients through mineralization is preferred, or in cases intending the stabilization and preservation of the SOC through a process of humification. In soils with HA of more than 5 E(4)/E(6) ratio, the incubation temperature increased rates of mineralization and humification, whereas lower temperatures limited the extent of both processes. In these soils the addition of co-compost in spring or summer is the most recommendable. In soils with HA of lower E(4)/E(6) ratio (<5), the higher temperature favoured mineralization but not humification, whereas the low temperature maintained the SOC levels and even increased the HA/FA ratio. In these soils the moment of addition of organic amendment should be decided depending on the effect intended. On the other hand, the lower the SOC

  16. Evolution and Statistics of Non-Sphericity of Dark Matter Halos from Cosmological N-Body Simulation

    CERN Document Server

    Suto, Daichi; Nishimichi, Takahiro; Sasaki, Shin; Suto, Yasushi

    2016-01-01

    We revisit the non-sphericity of cluster-mass scale halos from cosmological N-body simulation on the basis of triaxial modelling. In order to understand the difference between the simulation results and the conventional ellipsoidal collapse model (EC), we first consider the evolution of individual simulated halos. The major difference between EC and the simulation becomes appreciable after the turn-around epoch. Moreover, it is sensitive to the individual evolution history of each halo. Despite such strong dependence on individual halos, the resulting nonsphericity of halos exhibits weak but robust mass dependence in a statistical fashion; massive halos are more spherical up to the turn-around, but gradually become less spherical by z = 0. This is clearly inconsistent with the EC prediction; massive halos are usually more spherical. In addition, at z=0, inner regions of the halos are less spherical than outer regions, i.e., the density distribution inside the halos is highly inhomogeneous and therefore not se...

  17. Dark Matter

    CERN Document Server

    Zacek, Viktor

    2007-01-01

    The nature of the main constituents of the mass of the universe is one of the outstanding riddles of cosmology and astro-particle physics. Current models explaining the evolution of the universe, and measurements of the various components of its mass, all have in common that an appreciable contribution to that mass is non-luminous and non-baryonic, and that a large fraction of this so-called dark matter must be in the form of non-relativistic massive particles (Cold Dark Matter: CDM). In the spirit of the Lake Louise Winter Institute Lectures we take a look at the latest astronomical discoveries and report on the status of direct and indirect Dark Matter searches.

  18. Dissolved organic matter dynamic and resident microbiota evolution in soil amended with fresh and composted olive mill wastes

    Science.gov (United States)

    Gigliotti, Giovanni; Massaccesi, Luisa; Federici, Ermanno; Fidati, Laura; Nasini, Luigi; Proietti, Primo

    2013-04-01

    The disposal of olive mill wastes represents a problem of environmental relevance particularly in the Mediterranean countries where olive oil is mostly produced. Among the several valorisation and recycling methods proposed, interesting for its operational simplicity and convenience is land spreading, either directly or after composting. However, the agriculture use of the water-saturated husk produced by the new two-phase oil extraction systems may be hampered by its consistency and its high content of phenolic compounds, which may finally lead to phytotoxicity. Humid husk may indeed modify the dynamic of soil organic matter (SOM) and the structure and function of microbial communities. On the other hand, organic amendments are known to positively affect SOM fractions, particularly by increasing the concentration and quality of dissolved organic matter (DOM), which may eventually lead to an increase in microbial activity. The aim of this work was to investigate, during a 90-day field trial, the modifications in soil DOM composition and the effects on the soil microbiota induced by a humid husk, obtained from a new generation two-phase oil extraction plant, spread in an olive orchard either as a fresh amendment or after a composting process. With respect to the control, the soil amended with either fresh or composted husk showed an increase in water extractable organic carbon (WEOC). Interestingly, while during the first 30 days the soil amended with the composted husk showed a WEOC content higher than the one amended with the fresh husk, after that time only in the latter the WEOC remained significantly higher than in the control. The total content of phenolic compounds showed a similar trend, with the only difference that their concentration in the soil amended with both treatments remained higher than the control for the entire trial. Similarly, both treatments induced an increase in soil reducing sugars, with an higher effect observed in the soil amended with

  19. Chemical evolution and life

    OpenAIRE

    Malaterre Christophe

    2015-01-01

    In research on the origins of life, the concept of “chemical evolution” aims at explaining the transition from non-living matter to living matter. There is however strong disagreement when it comes to defining this concept more precisely, and in particular with reference to a chemical form of Darwinian evolution: for some, chemical evolution is nothing but Darwinian evolution applied to chemical systems before life appeared; yet, for others, it is the type of evolution that happened before na...

  20. Macroscopic and direct light propulsion of bulk graphene material

    CERN Document Server

    Zhang, Tengfei; Wu, Yingpeng; Xiao, Peishuang; Yi, Ningbo; Lu, Yanhong; Ma, Yanfeng; Huang, Yi; Zhao, Kai; Yan, Xiao-Qing; Liu, Zhi-Bo; Tian, Jian-Guo; Chen, Yongsheng

    2015-01-01

    It has been a great challenge to achieve the direct light manipulation of matter on a bulk scale. In this work, the direct light propulsion of matter was observed on a macroscopic scale for the first time using a bulk graphene based material. The unique structure and properties of graphene and the morphology of the bulk graphene material make it capable of not only absorbing light at various wavelengths but also emitting energetic electrons efficiently enough to drive the bulk material following Newtonian mechanics. Thus, the unique photonic and electronic properties of individual graphene sheets are manifested in the response of the bulk state. These results offer an exciting opportunity to bring about bulk scale light manipulation with the potential to realize long-sought proposals in areas such as the solar sail and space transportation driven directly by sunlight.

  1. Gravitational potential wells and the cosmic bulk flow

    CERN Document Server

    Kumar, Abhinav; Feldman, Hume A; Watkins, Richard

    2015-01-01

    The bulk flow is a volume average of the peculiar velocities and a useful probe of the mass distribution on large scales. The gravitational instability model views the bulk flow as a potential flow that obeys a Maxwellian Distribution. We use two N-body simulations, the LasDamas Carmen and the Horizon Run, to calculate the bulk flows of various sized volumes in the simulation boxes. Once we have the bulk flow velocities as a function of scale, we investigate the mass and gravitational potential distribution around the volume. We found that matter densities can be asymmetrical and difficult to detect in real surveys, however, the gravitational potential and its gradient may provide better tools to investigate the underlying matter distribution. This study shows that bulk flows are indeed potential flows and thus provides information on the flow sources. We also show that bulk flow magnitudes follow a Maxwellian distribution on scales $>10\\ h^{-1}$Mpc.

  2. Gravitational potential wells and the cosmic bulk flow

    Science.gov (United States)

    Wang, Yuyu; Kumar, Abhinav; Feldman, Hume; Watkins, Richard

    2016-03-01

    The bulk flow is a volume average of the peculiar velocities and a useful probe of the mass distribution on large scales. The gravitational instability model views the bulk flow as a potential flow that obeys a Maxwellian Distribution. We use two N-body simulations, the LasDamas Carmen and the Horizon Run, to calculate the bulk flows of various sized volumes in the simulation boxes. Once we have the bulk flow velocities as a function of scale, we investigate the mass and gravitational potential distribution around the volume. We found that matter densities can be asymmetrical and difficult to detect in real surveys, however, the gravitational potential and its gradient may provide better tools to investigate the underlying matter distribution. This study shows that bulk flows are indeed potential flows and thus provides information on the flow sources. We also show that bulk flow magnitudes follow a Maxwellian distribution on scales > 10h-1 Mpc.

  3. Dark matter perturbations and viscosity: a causal approach

    CERN Document Server

    Acquaviva, Giovanni; Pénin, Aurélie

    2016-01-01

    The inclusion of dissipative effects in cosmic fluids modifies their clustering properties and could have observable effects on the formation of large scale structures. We analyse the evolution of density perturbations of cold dark matter endowed with causal bulk viscosity. The perturbative analysis is carried out in the Newtonian approximation and the bulk viscosity is described by the causal Israel-Stewart (IS) theory. In contrast to the non-causal Eckart theory, we obtain a third order evolution equation for the density contrast that depends on three free parameters. For certain parameter values, the density contrast and growth factor in IS mimic their behaviour in $\\Lambda$CDM when $z \\geq 1$. Interestingly, and contrary to intuition, certain sets of parameters lead to an increase of the clustering.

  4. Dark matter perturbations and viscosity: A causal approach

    Science.gov (United States)

    Acquaviva, Giovanni; John, Anslyn; Pénin, Aurélie

    2016-08-01

    The inclusion of dissipative effects in cosmic fluids modifies their clustering properties and could have observable effects on the formation of large-scale structures. We analyze the evolution of density perturbations of cold dark matter endowed with causal bulk viscosity. The perturbative analysis is carried out in the Newtonian approximation and the bulk viscosity is described by the causal Israel-Stewart (IS) theory. In contrast to the noncausal Eckart theory, we obtain a third-order evolution equation for the density contrast that depends on three free parameters. For certain parameter values, the density contrast and growth factor in IS mimic their behavior in Λ CDM when z ≥1 . Interestingly, and contrary to intuition, certain sets of parameters lead to an increase of the clustering.

  5. T-Duality Simplifies Bulk-Boundary Correspondence

    Science.gov (United States)

    Mathai, Varghese; Thiang, Guo Chuan

    2016-07-01

    Recently, we introduced T-duality in the study of topological insulators. In this paper, we study the bulk-boundary correspondence for three phenomena in condensed matter physics, namely, the quantum Hall effect, the Chern insulator, and time reversal invariant topological insulators. In all of these cases, we show that T-duality trivializes the bulk-boundary correspondence.

  6. Does size matter? An assessment of quota market evolution and performance in the Great Barrier Reef fin-fish fishery

    Directory of Open Access Journals (Sweden)

    James Innes

    2014-09-01

    Full Text Available In fisheries managed using individual transferable quotas (ITQs it is generally assumed that quota markets are well-functioning, allowing quota to flow on either a temporary or permanent basis to those able to make best use of it. However, despite an increasing number of fisheries being managed under ITQs, empirical assessments of the quota markets that have actually evolved in these fisheries remain scarce. The Queensland Coral Reef Fin-Fish Fishery (CRFFF on the Great Barrier Reef has been managed under a system of ITQs since 2004. Data on individual quota holdings and trades for the period 2004-2012 were used to assess the CRFFF quota market and its evolution through time. Network analysis was applied to assess market structure and the nature of lease-trading relationships. An assessment of market participants’ abilities to balance their quota accounts, i.e., gap analysis, provided insights into market functionality and how this may have changed in the period observed. Trends in ownership and trade were determined, and market participants were identified as belonging to one out of a set of seven generalized types. The emergence of groups such as investors and lease-dependent fishers is clear. In 2011-2012, 41% of coral trout quota was owned by participants that did not fish it, and 64% of total coral trout landings were made by fishers that owned only 10% of the quota. Quota brokers emerged whose influence on the market varied with the bioeconomic conditions of the fishery. Throughout the study period some quota was found to remain inactive, implying potential market inefficiencies. Contribution to this inactivity appeared asymmetrical, with most residing in the hands of smaller quota holders. The importance of transaction costs in the operation of the quota market and the inequalities that may result are discussed in light of these findings.

  7. Thermal relics in cosmology with bulk viscosity

    International Nuclear Information System (INIS)

    In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, which cannot be explained by conventional cosmology and particle physics. (orig.)

  8. Thermal relics in cosmology with bulk viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, A. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Lambiase, G. [Universita di Salerno, Dipartimento di Fisica E.R. Caianiello, Fisciano (Italy); INFN, Gruppo Collegato di Salerno, Fisciano (Italy)

    2015-03-01

    In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, which cannot be explained by conventional cosmology and particle physics. (orig.)

  9. Color Superconducting Quark Matter in Neutron Stars

    OpenAIRE

    Heiselberg, H.

    1999-01-01

    Color superconductivity in quark matter is studied for electrically charge neutral neutron star matter in $\\beta$-equilibrium. Both bulk quark matter and mixed phases of quark and nuclear matter are treated. The electron chemical potential and strange quark mass affect the various quark chemical potentials and therefore also the color superconductivity due to dicolor pairing or color-flavor locking.

  10. Anisotropic cosmological models with bulk viscosity and particle creation in Saez–Ballester theory of gravitation

    Indian Academy of Sciences (India)

    Chandel S; Ram Shri

    2016-03-01

    The paper deals with the study of particle creation and bulk viscosity in the evolution of spatially homogeneous and anisotropic Bianchi type-V cosmological models in the framework of Saez–Ballester theory of gravitation. Particle creation and bulk viscosity are considered as separate irreversible processes. The energy–momentum tensor is modified to accommodate the viscous pressure and creation pressure which is associated with the creation of matter out of gravitational field. A special law of variation of Hubble parameter is applied to obtain exact solutions of field equations in two types of cosmologies, one with power-law expansion and the other with exponential expansion. Cosmological model with power-law expansion has a Big-Bang singularity at time $t = 0$, whereas the model with exponential expansion has no finite singularity. We study bulk viscosity and particle creation in each model in four different cases. The bulk viscosity coefficient is obtained for full causal, Eckart’s and truncated theories. All physical parameters are calculated and thoroughly discussed in both models.

  11. Static and dynamic magnetic properties of CoPt{sub 3}. Nanoparticles in comparison with bulk matter; Statische und dynamische magnetische Eigenschaften von CoPt{sub 3}. Nanopartikel im Vergleich zum Volumenmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, C.

    2006-09-22

    In this work the structural and magnetic characteristics of CoPt{sub 3}-particles are examined. In particular the determination of the g-factor is of interest as well as the damping behavior of the magnetization vector under influence of a microwave radiation. Moreover the magnetic anisotropy energy density of individual particles is covered by the presented thesis. The particles exist in the chemically disordered phase. They are monocrystalline and monodisperse with a mean diameter of d=4.04 nm and a width of the size distribution of {sigma}=0.15, as determined by transmission electron microscopy. Moreover the particles are embedded into a polymer with high dilution (0.08 vol%). To compare the results for the particles CoPt{sub 3} films and bulk-material are prepared and examined with the same procedure. X-ray diffraction (XRD) shows that all three sample systems are an alloy and do not appear as cobalt clusters embedded in platinum. The lattice constant of the particles is increased by 0.5% in comparison to the bulk material (a{sub NP}=0.388{+-}0.003 nm). The evaluation of the peak widths of the XRD experiments exhibit a crystalline size of 95.5{+-}6.5 nm of the films and 48.5{+-}6.5 nm of the bulk material. The evaluation of the relative intensities of (111)- and (200)-peaks points the fact that both the film and the particles preferentially grow in the (111)-direction. The films are polycrystalline in the film-plane. From magnetic resonance measurements the g-factor and the damping constant {alpha} is extracted. The measurement shows that both the g-factor (about 2%) and the damping-constant {alpha} (about 125%) is increased in comparison to the film, and/or bulk material. For the films M{sub eff} is determined from angle-dependent resonance-field measurements. From the temperature dependence of the resonance field the magnetic anisotropy is determined. Because of the fact that the measurements could be done only to a minimum of 50 K the value of the anisotropy

  12. Dark matter mini-halo around the compact objects: the formation, evolution and possible contribution to the cosmic ray electrons/positrons

    International Nuclear Information System (INIS)

    Dark matter particles may be captured by a star and then thermalized in the star's core. At the end of its life a massive star collapses suddenly and a compact object is formed. The dark matter particles redistribute accordingly. In the inelastic dark matter model, an extended dense dark matter mini-halo surrounding the neutron star may be formed. Such mini-halos may be common in the Galaxy. The electron/positron flux resulting in the annihilation of dark matter particles, however, is unable to give rise to observable signal unless a nascent mini-halo is within a distance ∼ a few 0.1 pc from the Earth

  13. The influence of preexisting structure and halokinesis on organic matter preservation and thrust system evolution in the Ionian Basin, Northwest Greece

    Energy Technology Data Exchange (ETDEWEB)

    Karakitsios, V. [Univ. of Athens (Greece)

    1995-07-01

    The opening of the Ionian basin and its internal differentiation is attested to by lateral facies and thickness variations of the formations deposited during the Pliensbachian and Tithonian (synrift formations). The beginning of the synrift sequence is represented by the Siniais Limestones (Pliensbachian) and their lateral equivalent, the Louros Limestones. The geometric characteristics of the extensional basin depend on both extension related to the latest opening of the Tethys ocean and halokinesis of the Ionian zone evaporitic substratum. The accumulation of organic matter in the {open_quotes}Lower and Upper Posidonia beds{close_quotes} of the Ionian zone during the Toarcian and Tithonian is directly related to the geometry of the synrift period of the Ionian basin. Restricted subbasins were formed where the geometry of the basin favored stagnation and consequently the locally euxinic conditions of bottom waters. Anoxic conditions persisted locally to the postrift period in areas where the {open_quotes}Upper Siliceous Zone{close_quotes} (Albian-Cenomanian) of the Vigla Limestones is well developed; these areas probably represent subbasins that were preserved by the continuation of halokinetic movements during the postrift period. During the early Miocene Alpine orogeny, collision-related compressive stresses on the margin induced the reactivation of preexisting fractures, which were responsible for the inversion tectonics that affected the Mesozoic basin. The geometric characteristics of the inverted basin were dependent on lithology (evaporates), geometry of the extensional structures, and direction of the compressional phase. The geological evolution in the Ionian basin is an example of inversion tectonics of a basin with an evaporitic substratum. The opening of the Ionian basin and the inversion tectonics influence both the source rocks and the probable hydrocarbon traps of the Ionian zone.

  14. The Nature and Origin of Aromatic Organic Matter in the Tagish Lake Meteorite

    Science.gov (United States)

    Clemett, S. J.; Keller, L. P.; Nakamura, K.; McKay, D. S.

    2004-01-01

    The Tagish Lake meteorite is an unusual carbonaceous chondrite that does not fit well within existing chondrite taxonomy. Bulk analyses suggest approx. 5 wt.% C of which approx. 1 wt.% is in the form of organic matter and the remainder is present as inorganic carbonate. The exact nature and form of this organic component is, as is the case with the other ordinary and carbonaceous chondrites, still poorly understood. Yet its significance has far reaching implications, from contributing to the abiotic evolution of the early Earth and Mars, to providing geothermal constraints in the evolution of the Solar nebula.

  15. Lectures on dark matter

    International Nuclear Information System (INIS)

    These lectures concentrate on evolution and generation of dark matter perturbations. The purpose of the lectures is to present, in a systematic way, a comprehensive review of the cosmological parameters that can lead to observable effects in the dark matter clustering properties. We begin by reviewing the relativistic linear perturbation theory formalism. We discuss the gauge issue and derive Einstein's and continuity equations for several popular gauge choices. We continue by developing fluid equations for cold dark matter and baryons and Boltzmann equations for photons, massive and massless neutrinos. We then discuss the generation of initial perturbations by the process of inflation and the parameters of that process that can be extracted from the observations. Finally we discuss evolution of perturbations in various regimes and the imprint of the evolution on the dark matter power spectrum both in the linear and in the nonlinear regime. (author)

  16. Renormalization group approach to causal bulk viscous cosmological models

    Energy Technology Data Exchange (ETDEWEB)

    Belinchon, J A [Grupo Inter-Universitario de Analisis Dimensional, Dept. Fisica ETS Arquitectura UPM, Av. Juan de Herrera 4, Madrid (Spain); Harko, T [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (China); Mak, M K [Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)

    2002-06-07

    The renormalization group method is applied to the study of homogeneous and flat Friedmann-Robertson-Walker type universes, filled with a causal bulk viscous cosmological fluid. The starting point of the study is the consideration of the scaling properties of the gravitational field equations, the causal evolution equation of the bulk viscous pressure and the equations of state. The requirement of scale invariance imposes strong constraints on the temporal evolution of the bulk viscosity coefficient, temperature and relaxation time, thus leading to the possibility of obtaining the bulk viscosity coefficient-energy density dependence. For a cosmological model with bulk viscosity coefficient proportional to the Hubble parameter, we perform the analysis of the renormalization group flow around the scale-invariant fixed point, thereby obtaining the long-time behaviour of the scale factor.

  17. Renormalization group approach to causal bulk viscous cosmological models

    International Nuclear Information System (INIS)

    The renormalization group method is applied to the study of homogeneous and flat Friedmann-Robertson-Walker type universes, filled with a causal bulk viscous cosmological fluid. The starting point of the study is the consideration of the scaling properties of the gravitational field equations, the causal evolution equation of the bulk viscous pressure and the equations of state. The requirement of scale invariance imposes strong constraints on the temporal evolution of the bulk viscosity coefficient, temperature and relaxation time, thus leading to the possibility of obtaining the bulk viscosity coefficient-energy density dependence. For a cosmological model with bulk viscosity coefficient proportional to the Hubble parameter, we perform the analysis of the renormalization group flow around the scale-invariant fixed point, thereby obtaining the long-time behaviour of the scale factor

  18. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  19. Ferromagnetic bulk glassy alloys

    International Nuclear Information System (INIS)

    This paper deals with the review on the formation, thermal stability and magnetic properties of the Fe-based bulk glassy alloys in as-cast bulk and melt-spun ribbon forms. A large supercooled liquid region over 50 K before crystallization was obtained in Fe-(Al, Ga)-(P, C, B, Si), Fe-(Cr, Mo, Nb)-(Al, Ga)-(P, C, B) and (Fe, Co, Ni)-Zr-M-B (M=Ti, Hf, V, Nb, Ta, Cr, Mo and W) systems and bulk glassy alloys were produced in a thickness range below 2 mm for the Fe-(Al, Ga)-(P, C, B, Si) system and 6 mm for the Fe-Co-(Zr, Nb, Ta)-(Mo, W)-B system by copper-mold casting. The ring-shaped glassy Fe-(Al, Ga)-(P, C, B, Si) alloys exhibit much better soft magnetic properties as compared with the ring-shaped alloy made from the melt-spun ribbon because of the formation of the unique domain structure. The good combination of high glass-forming ability and good soft magnetic properties indicates the possibility of future development as a new bulk glassy magnetic material

  20. Heat transport in bulk/nanoporous/bulk silicon devices

    Energy Technology Data Exchange (ETDEWEB)

    Criado-Sancho, M. [Departamento de Ciencias y Técnicas Físicoquimicas, Facultad de Ciencias, UNED, Senda del Rey 9, 20040 Madrid (Spain); Jou, D., E-mail: David.Jou@uab.cat [Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain); Institut d' Estudis Catalans, Carme 47, 08001 Barcelona, Catalonia (Spain)

    2013-02-04

    We study heat transport in bulk/nanoporous/bulk silicon devices; we show that, despite bulk/nanoporous devices may act as thermal rectifiers, the non-linear aspects of their joint thermal conductance are not strong enough to lead to a negative differential thermal resistance, necessary to allow bulk/nanoporous/bulk Si devices to act as thermal transistors. Furthermore, we explicitly study the effective thermal conductivity of the mentioned devices for several temperatures, geometries, porosities, and pore size.

  1. Interacting Dark Matter disguised as Warm Dark Matter

    OpenAIRE

    Boehm, Celine; Riazuelo, Alain; Hansen, Steen H.; Schaeffer, Richard

    2001-01-01

    We explore some of the consequences of Dark Matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when Dark Matter and photons are coupled, Dark Matter perturbations can experience a new damping regime in addition to the usual collisional Silk da...

  2. Bulk materials handling review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-02-15

    The paper provides details of some of the most important coal handling projects and technologies worldwide. It describes development by Aubema Crushing Technology GmbH, Bedeschi, Cimbria Moduflex, DBT, Dynamic Air Conveying Systems, E & F Services, InBulk Technologies, Nord-Sen Metal Industries Ltd., Pebco Inc, Primasonics International Ltd., R.J.S. Silo Clean (International) Ltd., Takraf GmbH, and The ACT Group. 17 photos.

  3. Cosmological Evolution of Brane World Moduli

    CERN Document Server

    Brax, P; Davis, A C; Rhodes, C S; Brax, Ph.

    2003-01-01

    We study cosmological consequences of non-constant brane world moduli in five dimensional brane world models with bulk scalars and two boundary branes. We focus on the case where the brane tension is an exponential function of the bulk scalar field, $U_b \\propto \\exp{(\\alpha \\phi)}$. In the limit $\\alpha \\to 0$, the model reduces to the two-brane model of Randall-Sundrum, whereas larger values of $\\alpha$ allow for a less warped bulk geometry. Using the moduli space approximation we derive the four-dimensional low-energy effective action from a supergravity-inspired five-dimensional theory. For arbitrary values of $\\alpha$, the resulting theory has the form of a bi-scalar-tensor theory. We show that, in order to be consistent with local gravitational observations, $\\alpha$ has to be small (less than $10^{-2}$) and the separation of the branes must be large. We study the cosmological evolution of the interbrane distance and the bulk scalar field for different matter contents on each branes. Our findings indica...

  4. Extension of Radiative Viscosity to Superfluid Matter

    Institute of Scientific and Technical Information of China (English)

    PI Chun-Mei; YANG Shu-Hua; ZHENG Xiao-Ping

    2011-01-01

    The radiative viscosity of superfluid npe matter is studied and it is found that to the lowest order of δμ/T,the ratio of radiative viscosity to bulk viscosity is the same as that of its normal matter.As one of the most important transport coefficients,the bulk viscosities of simple npe matter,of hyperon matter and even of quark matter,both in normal and superfluid states,have been extensively studied,[1-18] for more detail see Ref.[19].%The radiative viscosity of superfluid npe matter is studied and it is found that to the lowest order of δμ/T, the ratio of radiative viscosity to bulk viscosity is the same as that of its normal matter.

  5. Bulk Viscosity and Particle Creation in the Inflationary Cosmology

    OpenAIRE

    Eshaghi, Mehdi; Riazi, Nematollah; Kiasatpour, Ahmad

    2015-01-01

    We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and unstable, we try to solve the bulk viscosity equation of the cosmic fluid with particle creation through the full causal theory. By adopting an appropriate function for particle creation rate of "Creation of Cold Dark Matter" model, we obtain analytical solutions...

  6. Cosmological perturbations in mimetic matter model

    CERN Document Server

    Matsumoto, Jiro; Sushkov, Sergey V

    2015-01-01

    We investigate the cosmological evolution of mimetic matter model with arbitrary scalar potential. The cosmological reconstruction is explicitly done for different choices of potential. The cases that mimetic matter model shows the evolution as Cold Dark Matter(CDM), wCDM model, dark matter and dark energy with dynamical $Om(z)$ or phantom dark energy with phantom-non-phantom crossing are presented in detail. The cosmological perturbations for such evolution are studied in mimetic matter model. For instance, the evolution behavior of the matter density contrast which is different from usual one, i.e. $\\ddot \\delta + 2 H \\dot \\delta - \\kappa ^2 \\rho \\delta /2 = 0$ is investigated. The possibility of peculiar evolution of $\\delta$ in the model under consideration is shown. Special attention is paid to the behavior of matter density contrast near to future singularity where decay of perturbations may occur much earlier the singularity.

  7. Exotic States of Nuclear Matter

    Science.gov (United States)

    Lombardo, Umberto; Baldo, Marcello; Burgio, Fiorella; Schulze, Hans-Josef

    2008-02-01

    ência et al. Quartetting in nuclear matter and [symbol] particle condensation in nuclear systems / G. Röpke & P. Schuck et al. -- pt. C. Neutron star structure and dynamics. Shear viscosity of neutron matter from realistic nuclear interactions / O. Benhar & M. Valli. Protoneutron star dynamo: theory and observations / A. Bonanno & V. Urpin. Magnetic field dissipation in neutron stars: from magnetars to isolated neutron stars / J. A. Pons. Gravitational radiation and equations of state in super-dense cores of core-collapse supernovae / K. Kotake. Joule heating in the cooling of magnetized neutron stars / D. N. Aguilera, J. A. Pons & J. A. Miralles. Exotic fermi surface of dense neutron matter / M. V. Zverev, V. A. Khodel & J. W. Clark. Coupling of nuclear and electron modes in relativistic stellar matter / A. M. S. Santos et al. Neutron stars in the relativistic Hartree-Fock theory and hadron-quark phase transition / B. Y. Sun ... [et al.] -- pt. D. Prospects of present and future observations. Measurements of neutron star masses / D. G. Yakovlev. Dense nuclear matter: constraints from neutron stars / J. M. Lattimer. Neutron star versus heavy-ion data: is the nuclear equation of state hard or soft? / J. Schaffner-Bielich ... [et al.]. Surface emission from x-ray dim isolated neutron stars / R. Turolla. High energy neutrino astronomy / E. Migneco. What gravitational waves say about the inner structure of neutron stars / V. Ferrari. Reconciling 2 M[symbol] pulsars and SN1987A: two branches of neutron stars / P. Haensel, M. Bejger & J. L. Zdunik. EOS of dense matter and fast rotation of neutron stars / J. L. Zdunik ... [et al.] -- pt. E. Quark and strange matter in neutron stars. Bulk viscosity of color-superconducting quark matter / M. Alford. Chiral symmetry restoration and quark deconfinement at large densities and temperature / A. Drago, L. Bonanno & A. Lavagno. Color superconducting quark matter in compact stars / D. B. Blaschke, T. Klähn & F. Sandin. Thermal

  8. Characterization and evolution of dissolved organic matter in acidic forest soil and its impact on the mobility of major and trace elements (case of the Strengbach watershed)

    Science.gov (United States)

    Gangloff, Sophie; Stille, Peter; Pierret, Marie-Claire; Weber, Tiphaine; Chabaux, François

    2014-04-01

    Dissolved Organic Carbon (DOC) plays an important role in the behavior of major and trace elements in the soil and influences their transfer from soil to soil solution. The first objective of this study is to characterize different organic functional groups for the Water Extractable Organic Carbon (WEOC) fractions of a forest soil as well as their evolution with depth. The second objective is to clarify the influence of these organic functional groups on the migration of the trace elements in WEOC fractions compared to those in the soil solution obtained by lysimeter plates. All experiments have been performed on an acidic forest soil profile (five depths in the first meter) of the experimental spruce parcel in the Stengbach catchment. The Infra-red spectra of the freeze-dried WEOC fractions show a modification of the molecular structure with depth, i.e. a decrease of the polar compounds such as polysaccharides and an increase of the less polar hydro-carbon functional groups with a maximum value of the aromaticity at 30 cm depth. A Hierarchical Ascending Classification (HAC) of the evolution of Water Extractable Chemical Elements (WECE) with the evolution of the organic functional groups in the organic matter (OM) enriched soil compartments permits recognition of relationships between trace element behavior and the organic functional group variations. More specifically, Pb is preferentially bound to the carboxylic acid function of DOC mainly present in the upper soil compartment and rare earth elements (REE) show similar behavior to Fe, V and Cr with a good affinity to carboxy-phenolic and phenolic groups of DOC. The experimental results show that heavy REE compared to light REE are preferentially bound to the aromatic functional group. This different behavior fractionates the REE pattern of soil solutions at 30 cm depth due to the here observed aromaticity enrichment of DOC. These different affinities for the organic functional groups of the DOC explain some

  9. Bulk viscous cosmology with causal transport theory

    International Nuclear Information System (INIS)

    We consider cosmological scenarios originating from a single imperfect fluid with bulk viscosity and apply Eckart's and both the full and the truncated Müller-Israel-Stewart's theories as descriptions of the non-equilibrium processes. Our principal objective is to investigate if the dynamical properties of Dark Matter and Dark Energy can be described by a single viscous fluid and how such description changes when a causal theory (Müller-Israel-Stewart's, both in its full and truncated forms) is taken into account instead of Eckart's non-causal one. To this purpose, we find numerical solutions for the gravitational potential and compare its behaviour with the corresponding ΛCDM case. Eckart's and the full causal theory seem to be disfavoured, whereas the truncated theory leads to results similar to those of the ΛCDM model for a bulk viscous speed in the interval 10−11 || cb2 ∼−8

  10. Brane plus Bulk Supersymmetry in Ten Dimensions

    CERN Document Server

    Bergshoeff, E A; Ortín, Tomas; Roest, D; Van Proeyen, A

    2001-01-01

    We discuss a generalized form of IIA/IIB supergravity depending on all R-R potentials C^(p) (p=0,1,...,9) as the effective field theory of Type IIA/IIB superstring theory. For the IIA case we explicitly break this R-R democracy to either p=5 which allows us to write a new bulk action that can be coupled to N=1 supersymmetric brane actions. The case of 8-branes is studied in detail using the new bulk & brane action. The supersymmetric negative tension branes without matter excitations can be viewed as orientifolds in the effective action. These D8-branes and O8-planes are fundamental in Type I' string theory. A BPS 8-brane solution is given which satisfies the jump conditions on the wall. As an application of our results we derive a quantization of the mass parameter and the cosmological constant in string units.

  11. Bulk viscous cosmology in early Universe

    Indian Academy of Sciences (India)

    C P Singh

    2008-07-01

    The effect of bulk viscosity on the early evolution of Universe for a spatially homogeneous and isotropic Robertson-Walker model is considered. Einstein's field equations are solved by using `gamma-law' equation of state = ( - 1)ρ, where the adiabatic parameter gamma () depends on the scale factor of the model. The `gamma' function is defined in such a way that it describes a unified solution of early evolution of the Universe for inflationary and radiation-dominated phases. The fluid has only bulk viscous term and the coefficient of bulk viscosity is taken to be proportional to some power function of the energy density. The complete general solutions have been given through three cases. For flat space, power-law as well as exponential solutions are found. The problem of how the introduction of viscosity affects the appearance of singularity, is briefly discussed in particular solutions. The deceleration parameter has a freedom to vary with the scale factor of the model, which describes the accelerating expansion of the Universe.

  12. Matter and cosmology

    International Nuclear Information System (INIS)

    The author summarizes some of the many questions and answers which have been raised over the years regarding the nature of matter, the origin of its forms and the associated concept of cosmology including the formation of the universe, our place in it and its course of evolution. An examination of the development of the classical concept of matter and its subsequent transformations within the space-time fields of relativity and quantum theory is also presented

  13. Wormholes in Bulk Viscous Cosmology

    OpenAIRE

    Jamil, Mubasher

    2008-01-01

    We investigate the effects of the accretion of phantom energy with non-zero bulk viscosity onto a Morris-Thorne wormhole. We have found that if the bulk viscosity is large then the mass of wormhole increases rapidly as compared to small or zero bulk viscosity.

  14. The extension of radiative viscosity to superfluid matter

    OpenAIRE

    Pi, Chun-Mei; Yang, Shu-Hua; Zheng, Xiao-Ping

    2010-01-01

    The radiative viscosity of superfluid $npe$ matter is studied, and it is found that to the lowest order of $\\delta \\mu/T$ the ratio of radiative viscosity to bulk viscosity is the same as that of the normal matter.

  15. Dark Matter

    OpenAIRE

    Einasto, Jaan

    2013-01-01

    I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Dark matter is the dominant matter component in the Universe, thus properties of dark matter particles determine the structure of the cosmic...

  16. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  17. Explosive bulk charge

    Science.gov (United States)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  18. Bulk muscles, loose cables.

    Science.gov (United States)

    Liyanage, Chamari R D G; Kodali, Venkata

    2014-01-01

    The accessibility and usage of body building supplements is on the rise with stronger internet marketing strategies by the industry. The dangers posed by the ingredients in them are underestimated. A healthy young man came to the emergency room with palpitations and feeling unwell. Initial history and clinical examination were non-contributory to find the cause. ECG showed atrial fibrillation. A detailed history for any over the counter or herbal medicine use confirmed that he was taking supplements to bulk muscle. One of the components in these supplements is yohimbine; the onset of symptoms coincided with the ingestion of this product and the patient is symptom free after stopping it. This report highlights the dangers to the public of consuming over the counter products with unknown ingredients and the consequential detrimental impact on health. PMID:25326558

  19. Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation

    Energy Technology Data Exchange (ETDEWEB)

    Piattella, O.F.; Rodrigues, D.C.; Fabris, J.C. [Departamento de Física, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Pacheco, J.A. de Freitas, E-mail: oliver.piattella@pq.cnpq.br, E-mail: davi.rodrigues@ufes.br, E-mail: fabris@pq.cnpq.br, E-mail: pacheco@oca.eu [Université de Nice-Sophia Antipolis, Observatoire de la Côte d' Azur, Laboratoire Lagrange, Nice Cedex 4 (France)

    2013-11-01

    We discuss solutions of Vlasov-Einstein equation for collisionless dark matter particles in the context of a flat Friedmann universe. We show that, after decoupling from the primordial plasma, the dark matter phase-space density indicator Q = ρ/(σ{sub 1D}{sup 2}){sup 3/2} remains constant during the expansion of the universe, prior to structure formation. This well known result is valid for non-relativistic particles and is not ''observer dependent'' as in solutions derived from the Vlasov-Poisson system. In the linear regime, the inclusion of velocity dispersion effects permits to define a physical Jeans length for collisionless matter as function of the primordial phase-space density indicator: λ{sub J} = (5π/G){sup 1/2}Q{sup −1/3}ρ{sub dm}{sup −1/6}. The comoving Jeans wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the comoving wavenumber due to free-streaming, contributing to the cut-off of the density fluctuation power spectrum at the lowest scales. We discuss the physical differences between these two scales. For dark matter particles of mass equal to 200 GeV, the derived Jeans mass is 4.3 × 10{sup −6}M{sub ⊙}.

  20. Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation

    International Nuclear Information System (INIS)

    We discuss solutions of Vlasov-Einstein equation for collisionless dark matter particles in the context of a flat Friedmann universe. We show that, after decoupling from the primordial plasma, the dark matter phase-space density indicator Q = ρ/(σ1D2)3/2 remains constant during the expansion of the universe, prior to structure formation. This well known result is valid for non-relativistic particles and is not ''observer dependent'' as in solutions derived from the Vlasov-Poisson system. In the linear regime, the inclusion of velocity dispersion effects permits to define a physical Jeans length for collisionless matter as function of the primordial phase-space density indicator: λJ = (5π/G)1/2Q−1/3ρdm−1/6. The comoving Jeans wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the comoving wavenumber due to free-streaming, contributing to the cut-off of the density fluctuation power spectrum at the lowest scales. We discuss the physical differences between these two scales. For dark matter particles of mass equal to 200 GeV, the derived Jeans mass is 4.3 × 10−6M⊙

  1. Does Evolution matter?: a case study in Brazil of the effects of an evolutionary-thinking academic atmosphere in postgraduate students' belief in God/religious belief

    OpenAIRE

    Ivan A. Dias; Rodrigo H. Willemart; Marques, Antonio C.

    2012-01-01

    Although the theory of evolution is more than 150 years old, a substantial proportion of the world population does not mention it when explaining the origin of human beings. The usual alternative conception is offered by creationism, one of the main obstacles to full acceptance of evolution in many countries. National polls have demonstrated that schooling and religiosity are negatively correlated, with scientists being one of the least religious professionals. Herein we analyzed both (1) the...

  2. YBCO bulk superconductors doped with gadolinium and samarium

    Czech Academy of Sciences Publication Activity Database

    Volochová, D.; Piovarči, S.; Radušovská, M.; Antal, V.; Kováč, J.; Jurek, Karel; Jirsa, Miloš; Diko, P.

    2013-01-01

    Roč. 494, NOV (2013), s. 36-40. ISSN 0921-4534 Institutional support: RVO:68378271 Keywords : YBCO bulk superconductors * critical temperature * critical current density * peak effect Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.110, year: 2013

  3. Matter may matter

    CERN Document Server

    Haghani, Zahra; Sepangi, Hamid Reza; Shahidi, Shahab

    2014-01-01

    We propose a gravitational theory in which the effective Lagrangian of the gravitational field is given by an arbitrary function of the Ricci scalar, the trace of the matter energy-momentum tensor, and the contraction of the Ricci tensor with the matter energy-momentum tensor. The matter energy-momentum tensor is generally not conserved, thus leading to the appearance of an extra-force, acting on massive particles in a gravitational field. The stability conditions of the theory with respect to local perturbations are also obtained. The cosmological implications of the theory are investigated, representing an exponential solution. Hence a Ricci tensor - energy-momentum tensor coupling may explain the recent acceleration of the Universe, without resorting to the mysterious dark energy.

  4. Bulk Higgs and the 750 GeV diphoton signal

    CERN Document Server

    Frank, Mariana; Toharia, Manuel

    2016-01-01

    We consider scenarios of warped extra-dimensions with all matter fields in the bulk and in which both the hierarchy and the flavor puzzles of the Standard Model are addressed. The simplest extra dimensional extension of the Standard Model Higgs sector, i.e a 5D bulk Higgs doublet, can be a natural and simple explanation to the 750 GeV excess of diphotons hinted at the LHC, with the resonance responsible for the signal being the lightest CP odd excitation coming from the Higgs sector. No new matter content is invoked, the only new ingredient being the presence of (positive) brane localized kinetic terms associated to the 5D bulk Higgs, which allow to reduce the mass of the lightest CP odd Higgs excitation to 750 GeV. Production and decay of this resonance can naturally fit the observed signal when the mass scale of the rest of extradimensional resonances is of order 1 TeV.

  5. Evolution of the phase-space density and the Jeans scale for dark matter derived from the Vlasov-Einstein equation

    CERN Document Server

    Piattella, Oliver F; Fabris, Júlio C; Pacheco, José A de Freitas

    2013-01-01

    Solutions of Vlasov-Einstein equation for collisionless particles (representing dark matter) are discussed in the context of a flat Friedmann universe. It is shown that, after decoupling from the primordial plasma, the dark matter phase-space density indicator Q remains constant during the expansion of the universe, prior to structure formation. This well known result is valid for non-relativistic particles and is not "observer dependent" as in solutions derived from the Vlasov-Poisson system. In the linear regime, the inclusion of velocity dispersion effects permits to define the physical Jeans length for collisionless matter as a function of the primordial phase-space density indicator Q, i.e., lambda_J = (5pi/G)^(1/2) Q^(-1/3) rho^(-1/6). The comoving Jeans wavenumber at matter-radiation equality is smaller by a factor of 2-3 than the comoving wavenumber due to free streaming, contributing to the cut-off of the density fluctuation power spectrum at the lowest scales. The physical differences between these ...

  6. Inflation from bulk viscosity

    CERN Document Server

    Bamba, Kazuharu

    2015-01-01

    We explore the perfect fluid description of the inflationary universe. In particular, we investigate a fluid model with the bulk-viscosity term. We find that the three observables of inflationary cosmology: the spectral index of the curvature perturbations, the tensor-to-scalar ratio of the density perturbations, and the running of the spectral index, can be consistent with the recent Planck results. We also reconstruct the explicit equation of state (EoS) of the viscous fluid from the spectral index of the curvature perturbations compatible with the Planck analysis. In the reconstructed models of the viscous fluid, the tensor-to-scalar ratio of the density perturbations can satisfy the constraints obtained from the Planck satellite. The running of the spectral index can explain the Planck data. In addition, it is demonstrated that in the reconstructed models of the viscous fluid, the graceful exit from inflation can be realized. Furthermore, we show that the singular inflation can occur in the viscous fluid ...

  7. DEMONSTRATION BULK VITRIFICATION SYSTEM (DBVS) EXTERNAL REVIEW

    International Nuclear Information System (INIS)

    The Hanford mission to retrieve and immobilize 53 million gallons of radioactive waste from 177 underground storage tanks will be accomplished using a combination of processing by the waste treatment plant currently under construction, and a supplemental treatment that would process low-activity waste. Under consideration for this treatment is bulk vitrification, a versatile joule-heated melter technology which could be deployed in the tank farms. The Department proposes to demonstrate this technology under a Research, Development and Demonstration (RD and D) permit issued by the Washington State Department of Ecology using both non-radioactive simulant and blends of actual tank waste. From the demonstration program, data would be obtained on cost and technical performance to enable a decision on the potential use of bulk vitrification as the supplemental treatment technology for Hanford. An independent review by sixteen subject matter experts was conducted to assure that the technical basis of the demonstration facility design would be adequate to meet the objectives of the Demonstration Bulk Vitrification System (DBVS) program. This review explored all aspects of the program, including flowsheet chemistry, project risk, vitrification, equipment design and nuclear safety, and was carried out at a time when issues can be identified and corrected. This paper describes the mission need, review approach, technical recommendations and follow-on activities for the DBVS program

  8. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and...... three low-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low...

  9. Quark matter droplets in neutron stars

    Science.gov (United States)

    Heiselberg, H.; Pethick, C. J.; Staubo, E. F.

    1993-01-01

    We show that, for physically reasonable bulk and surface properties, the lowest energy state of dense matter consists of quark matter coexisting with nuclear matter in the presence of an essentially uniform background of electrons. We estimate the size and nature of spatial structure in this phase, and show that at the lowest densities the quark matter forms droplets embedded in nuclear matter, whereas at higher densities it can exhibit a variety of different topologies. A finite fraction of the interior of neutron stars could consist of matter in this new phase, which would provide new mechanisms for glitches and cooling.

  10. Interacting dark matter disguised as warm dark matter

    International Nuclear Information System (INIS)

    We explore some of the consequences of dark-matter-photon interactions on structure formation, focusing on the evolution of cosmological perturbations and performing both an analytical and a numerical study. We compute the cosmic microwave background anisotropies and matter power spectrum in this class of models. We find, as the main result, that when dark matter and photons are coupled, dark matter perturbations can experience a new damping regime in addition to the usual collisional Silk damping effect. Such dark matter particles (having quite large photon interactions) behave like cold dark matter or warm dark matter as far as the cosmic microwave background anisotropies or matter power spectrum are concerned, respectively. These dark-matter-photon interactions leave specific imprints at sufficiently small scales on both of these two spectra, which may allow us to put new constraints on the acceptable photon-dark-matter interactions. Under the conservative assumption that the abundance of 1012M· galaxies is correctly given by the cold dark matter, and without any knowledge of the abundance of smaller objects, we obtain the limit on the ratio of the dark-matter-photon cross section to the dark matter mass σγ-DM/mDM -6σTh/(100 GeV)≅6x10-33 cm2 GeV-1

  11. Synchrotron Infrared Microspectroscopy Detecting the Evolution of Huntingtons Disease Neuropathology and Suggesting Unique Correlates of Dysfunction in White versus Gray Brain Matter

    Energy Technology Data Exchange (ETDEWEB)

    Bonda M.; Miller L.; Perrin V.; Vileno B.; Runne H.; Kretlow A.; Forro L.; Luthi-Carter R. and Jeney S.

    2011-09-02

    Huntington's disease (HD), caused by a mutation of the corresponding gene encoding the protein huntingtin (htt), is characterized by progressive deterioration of cognitive and motor functions, paralleled by extensive loss of striatal neurons. At the cellular level, pathogenesis involves an early and prolonged period of neuronal dysfunction followed by neuronal death. Understanding the molecular events driving these deleterious processes is critical to the successful development of therapies to slow down or halt the progression of the disease. Here, we examined biochemical processes in a HD ex vivo rat model, as well as in a HD model for cultured neurons using synchrotron-assisted Fourier transform infrared microspectroscopy (S-FTIRM). The model, based on lentiviral-mediated delivery of a fragment of the HD gene, expresses a mutant htt fragment in one brain hemisphere and a wild-type htt fragment in the control hemisphere. S-FTIRM allowed for high spatial resolution and distinction between spectral features occurring in gray and white matter. We measured a higher content of {beta}-sheet protein in the striatal gray matter exposed to mutant htt as early as 4 weeks following the initiation of mutant htt exposure. In contrast, white matter tracts did not exhibit any changes in protein structure but surprisingly showed reduced content of unsaturated lipids and a significant increase in spectral features associated with phosphorylation. The former is reminiscent of changes consistent with a myelination deficiency, while the latter is characteristic of early pro-apoptotic events. These findings point to the utility of the label-free FTIRM method to follow mutant htt's {beta}-sheet-rich transformation in striatal neurons ex vivo, provide further evidence for mutant htt amyloidogenesis in vivo, and demonstrate novel chemical features indicative of white matter changes in HD. Parallel studies in cultured neurons expressing the same htt fragments showed similar

  12. Bulk Comptonization by turbulence in accretion discs

    Science.gov (United States)

    Kaufman, J.; Blaes, O. M.

    2016-06-01

    Radiation pressure dominated accretion discs around compact objects may have turbulent velocities that greatly exceed the electron thermal velocities within the disc. Bulk Comptonization by the turbulence may therefore dominate over thermal Comptonization in determining the emergent spectrum. Bulk Comptonization by divergenceless turbulence is due to radiation viscous dissipation only. It can be treated as thermal Comptonization by solving the Kompaneets equation with an equivalent `wave' temperature, which is a weighted sum over the power present at each scale in the turbulent cascade. Bulk Comptonization by turbulence with non-zero divergence is due to both pressure work and radiation viscous dissipation. Pressure work has negligible effect on photon spectra in the limit of optically thin turbulence, and in this limit radiation viscous dissipation alone can be treated as thermal Comptonization with a temperature equivalent to the full turbulent power. In the limit of extremely optically thick turbulence, radiation viscous dissipation is suppressed, and the evolution of local photon spectra can be understood in terms of compression and expansion of the strongly coupled photon and gas fluids. We discuss the consequences of these effects for self-consistently resolving and interpreting turbulent Comptonization in spectral calculations in radiation magnetohydrodynamic simulations of high luminosity accretion flows.

  13. Electron Scattering From Atoms, Molecules, Nuclei, and Bulk Matter

    CERN Document Server

    Whelan, Colm T

    2005-01-01

    Topics that are covered include electron scattering in the scanning TEM; basic theory of inelastic electron imaging; study of confined atoms by electron excitation; helium bubbles created in extreme pressure with application to nuclear safety; lithium ion implantation; electron and positron scattering from clusters; electron scattering from physi- and chemi-absorbed molecules on surfaces; coincidence studies; electron scattering from biological molecules; electron spectroscopy as a tool for environmental science; electron scattering in the presence of intense fields; electron scattering from astrophysical molecules; electon interatctions an detection of x-ray radiation.

  14. The many faces of strange matter: compact stars, cosmic rays, and dark matter

    CERN Document Server

    Xu, Renxin

    2015-01-01

    The state of cold bulk matter at around nuclear density depends on the fundamental strong interaction between quarks at low-energy scale, so-called non-perturbative quantum chromo-dynamics. Such kind of matter is conjectured to be condensed matter of 3-flavour (u, d and s) quark clusters in this note, being manifested in the form of compact stars, cosmic rays, and even dark matter.

  15. Dark matter

    OpenAIRE

    Einasto, J.

    2011-01-01

    I give a review of the development of the concept of dark matter. The dark matter story passed through several stages from a minor observational puzzle to a major challenge for theory of elementary particles. Modern data suggest that dark matter is the dominant matter component in the Universe, and that it consists of some unknown non-baryonic particles. Properties of dark matter particles determine the structure of the cosmic web.

  16. Dark Matter

    OpenAIRE

    Bahcall, Neta

    1996-01-01

    Observations in the optical, in X-rays, and gravitational lensing of galaxies, clusters of galaxies, and large-scale structure are beginning to provide clues to the dark matter problem. I review the impact of these observations on some of the main questions relating to dark matter: How much dark matter is there? Where is it located? What is the nature of the dark matter? and what is the amount of baryonic dark matter.

  17. Evolution: from cosmogenesis to biogenesis

    International Nuclear Information System (INIS)

    The volume contains the material of an interdisciplinary evolution symposium. The purpose was to shed some light on possible connections between steps of evolution of matter on different levels of organisation. The topics involved are as follow: cosmogenesis; galactic and stellar evolution; formation and evolution of the solar system; global atmospheric and tectonic changes of Earth; viral evolution; phylogeny and evolution of terrestrial life; evolution of neural system; hominization. The material also includes some discussions of the underlying phenomena and laws of nature. (author)

  18. Kinetic multi-layer model of aerosol surface and bulk chemistry (KM-SUB: the influence of interfacial transport and bulk diffusion on the oxidation of oleic acid by ozone

    Directory of Open Access Journals (Sweden)

    M. Shiraiwa

    2010-04-01

    Full Text Available We present a novel kinetic multi-layer model that explicitly resolves mass transport and chemical reaction at the surface and in the bulk of aerosol particles (KM-SUB. The model is based on the PRA framework of gas-particle interactions (Pöschl-Rudich-Ammann, 2007, and it includes reversible adsorption, surface reactions and surface-bulk exchange as well as bulk diffusion and reaction. Unlike earlier models, KM-SUB does not require simplifying assumptions about steady-state conditions and radial mixing. The temporal evolution and concentration profiles of volatile and non-volatile species at the gas-particle interface and in the particle bulk can be modeled along with surface concentrations and gas uptake coefficients.

    In this study we explore and exemplify the effects of bulk diffusion on the rate of reactive gas uptake for a simple reference system, the ozonolysis of oleic acid particles, in comparison to experimental data and earlier model studies. We demonstrate how KM-SUB can be used to interpret and analyze experimental data from laboratory studies, and how the results can be extrapolated to atmospheric conditions. In particular, we show how interfacial and bulk transport, i.e., surface accommodation, bulk accommodation and bulk diffusion, influence the kinetics of the chemical reaction. Sensitivity studies suggest that in fine air particulate matter oleic acid and compounds with similar reactivity against ozone (carbon-carbon double bonds can reach chemical lifetimes of many hours only if they are embedded in a (semi-solid matrix with very low diffusion coefficients (≤10−10 cm2 s−1. Depending on the complexity of the investigated system, unlimited numbers of volatile and non-volatile species and chemical reactions can be flexibly added and treated with KM-SUB. We propose and intend to pursue the application of KM-SUB as a basis for the development of a detailed master mechanism of aerosol

  19. Kinetic multi-layer model of aerosol surface and bulk chemistry (KM-SUB: the influence of interfacial transport and bulk diffusion on the oxidation of oleic acid by ozone

    Directory of Open Access Journals (Sweden)

    M. Shiraiwa

    2010-01-01

    Full Text Available We present a novel kinetic multi-layer model that explicitly resolves mass transport and chemical reaction at the surface and in the bulk of aerosol particles (KM-SUB. The model is based on the PRA framework of gas-particle interactions (Pöschl et al., 2007, and it includes reversible adsorption, surface reactions and surface-bulk exchange as well as bulk diffusion and reaction. Unlike earlier models, KM-SUB does not require simplifying assumptions about steady-state conditions and radial mixing. The temporal evolution and concentration profiles of volatile and non-volatile species at the gas-particle interface and in the particle bulk can be modeled along with surface concentrations and gas uptake coefficients.

    In this study we explore and exemplify the effects of bulk diffusion on the rate of reactive gas uptake for a simple reference system, the ozonolysis of oleic acid particles, in comparison to experimental data and earlier model studies. We demonstrate how KM-SUB can be used to interpret and analyze experimental data from laboratory studies, and how the results can be extrapolated to atmospheric conditions. In particular, we show how interfacial transport and bulk transport, i.e., surface accommodation, bulk accommodation and bulk diffusion, influence the kinetics of the chemical reaction. Sensitivity studies suggest that in fine air particulate matter oleic acid and compounds with similar reactivity against ozone (C=C double bonds can reach chemical lifetimes of multiple hours only if they are embedded in a (semi-solid matrix with very low diffusion coefficients (≤10−10 cm2 s−1.

    Depending on the complexity of the investigated system, unlimited numbers of volatile and non-volatile species and chemical reactions can be flexibly added and treated with KM-SUB. We propose and intend to pursue the application of KM-SUB as a basis for the development of a detailed master mechanism of

  20. Food matters - tracing the imprints of the Neolithic transition in the human genome through the study of NAT2 polymorphisms evolution

    Czech Academy of Sciences Publication Activity Database

    Podgorná, Eliška; Černý, Viktor; Poloni, E. S.

    Pilsen: University of West Bohemia, 2013 - (Turek, J.) ISBN 978-80-261-0255-7. [Annual Meeting of the European Association of Archaeologists /19./. 04.09.2013-08.09.2013, Plzeň] R&D Projects: GA ČR GA13-37998S Institutional support: RVO:67985912 Keywords : human evolution * cultural selection * Africa * Sahel * pastoralism * sedentarism * NAT2 * polymorphism * drug metabolism Subject RIV: AC - Archeology, Anthropology, Ethnology

  1. Evolution of Interacting Viscous Dark Energy Model in Einstein Cosmology

    Institute of Scientific and Technical Information of China (English)

    CHEN Ju-Hua; ZHOU Sheng; WANG Yong-Jiu

    2011-01-01

    We investigate the evolution of the viscous dark energy (DE) interacting with the dark matter (DM) in the Einstein cosmology model. By using the linearizing theory of the dynamical system, we find that, in our model,there exists a stable late time scaling solution which corresponds to the accelerating universe. We also find the unstable solution under some appropriate parameters. In order to alleviate the coincidence problem, some authors considered the effect of quantum correction due to the conform anomaly and the interacting dark energy with the dark matter. However, if we take into account the bulk viscosity of the cosmic fluid, the coincidence problem will be softened just like the interacting dark energy cosmology model. That is to say, both the non-perfect fluid model and the interacting the dark energy cosmic model can alleviate or soften the singularity of the universe.%@@ We investigate the evolution of the viscous dark energy (DE) interacting with the dark matter (DM) in the Einstein cosmology model.By using the linearizing theory of the dynamical system, we find that, in our model, there exists a stable late time scaling solution which corresponds to the accelerating universe.We also find the unstable solution under some appropriate parameters.In order to alleviate the coincidence problem, some authors considered the effect of quantum correction due to the conform anomaly and the interacting dark energy with the dark matter.However, if we take into account the bulk viscosity of the cosmic fluid, the coincidence problem will be softened just like the interacting dark energy cosmology model.That is to say, both the non-perfect fluid model and the interacting the dark energy cosmic model can alleviate or soften the singularity of the universe.

  2. Computer simulation of dust grain evolution

    Science.gov (United States)

    Liffman, K.

    1989-01-01

    The latest results are reported from a Monte Carlo code that is being developed at NASA Ames. The goal of this program, is to derive from the observed and presumed properties of the interstellar medium (ISM) the following information: (1) the size spectrum of interstellar dust; (2) the chemical structure of interstellar dust; (3) interstellar abundances; and (4) the lifetime of a dust grain in the ISM. Presently this study is restricted to refractory interstellar material, i.e., the formation and destruction of ices are not included in the program. The program is embedded in an analytic solution for the bulk chemical evolution of a two-phase interstellar medium in which stars are born in molecular clouds, but new nucleosynthesis products and stellar return are entered into a complementary intercloud medium. The well-mixed matter of each interstellar phase is repeatedly cycled stochastically through the complementary phase and back. Refractory dust is created by thermal condensation as stellar matter flows away from sites of nucleosynthesis such as novae and supernovae and/or from the matter returned from evolved intermediate stars. The history of each particle is traced by standard Monte Carlo techniques as it is sputtered and fragmented by supernova shock waves in the intercloud medium. It also accretes an amorphous mantle of gaseous refractory atoms when its local medium joins with the molecular cloud medium. Finally it encounters the possibility of astration (destruction by star formation) within the molecular clouds.

  3. Computer simulation of dust grain evolution

    International Nuclear Information System (INIS)

    The latest results are reported from a Monte Carlo code that is being developed at NASA Ames. The goal of this program, is to derive from the observed and presumed properties of the interstellar medium (ISM) the following information: (1) the size spectrum of interstellar dust; (2) the chemical structure of interstellar dust; (3) interstellar abundances; and (4) the lifetime of a dust grain in the ISM. Presently this study is restricted to refractory interstellar material, i.e., the formation and destruction of ices are not included in the program. The program is embedded in an analytic solution for the bulk chemical evolution of a two-phase interstellar medium in which stars are born in molecular clouds, but new nucleosynthesis products and stellar return are entered into a complementary intercloud medium. The well-mixed matter of each interstellar phase is repeatedly cycled stochastically through the complementary phase and back. Refractory dust is created by thermal condensation as stellar matter flows away from sites of nucleosynthesis such as novae and supernovae and/or from the matter returned from evolved intermediate stars. The history of each particle is traced by standard Monte Carlo techniques as it is sputtered and fragmented by supernova shock waves in the intercloud medium. It also accretes an amorphous mantle of gaseous refractory atoms when its local medium joins with the molecular cloud medium. Finally it encounters the possibility of astration (destruction by star formation) within the molecular clouds

  4. SEM and FIB-SEM investigations on potential gas shales in the Dniepr-Donets Basin (Ukraine): pore space evolution in organic matter during thermal maturation

    Science.gov (United States)

    Misch, D.; Mendez-Martin, F.; Hawranek, G.; Onuk, P.; Gross, D.; Sachsenhofer, R. F.

    2016-02-01

    Porosity and permeability are essential parameters for reservoir rocks. Techniques developed for conventional reservoir rocks characterized by large pores, cannot be applied to study gas shales. Therefore, high resolution techniques are increasingly used to determine reservoir quality of shale gas plays. Within the frame of the recent study, Upper Visean black shales (“Rudov Beds”) from the Dniepr-Donets-Basin (DDB, Ukraine) were characterized by X-ray diffraction, conventional SEM imaging and FIB/BIB-SEM. According to SEM and FIB/BIB-SEM data, nanopores are not abundant in primary macerals (e.g., vitrinite) even in overmature rocks, whereas they develop within secondary organic matter (bitumen) formed mainly at gas window maturity. Frequently occurring sub-micrometre porosity, probably related to gas generation from bituminous organic matter, was detected within mudstones at a vitrinite reflectance > 2.0 % Rr. However, such pores have also been detected occasionally in solid bitumen at oil window maturity (0.9 % Rr). Authigenic nanoscale clay minerals and calcite occur within pyrobitumen at gas window maturity. Furthermore, Rudov Beds can be subdivided into mineralogical facies zones by SEM imaging and X-ray diffraction. A basin-centred, brittle siliceous facies is most likely caused by increased contribution from deeper water radiolaria and is separated from a marginal clayey and carbonate-rich facies.

  5. Zinc uptake by brain cells: `surface' versus `bulk'

    Science.gov (United States)

    DeStasio, Gelsomina; Pochon, S.; Lorusso, G. F.; Tonner, B. P.; Mercanti, Delio; Ciotti, M. Teresa; Oddo, Nino; Galli, Paolo; Perfetti, P.; Margaritondo, G.

    1996-08-01

    The uptake of zinc by cerebellar rat cultures upon exposure to 0022-3727/29/8/023/img12 solutions was comparatively investigated using two well known condensed matter physics techniques: synchrotron photoelectron spectromicroscopy and inductively coupled plasma atomic emission spectroscopy. The objective was to apply a strategy - well known in surface physics - to distinguish between `surface' and `bulk' phenomena. The results clearly demonstrate that exposure significantly enhances the bulk (cell cytoplasm) Zn concentration with respect to the physiological level, whereas the effect on the surface (cell membrane) is negligible.

  6. Mining the bulk positron lifetime

    Energy Technology Data Exchange (ETDEWEB)

    Aourag, H.; Guittom, A. [Centre de Recherche Nucleaire d' Alger (CRNA), Alger Gare - Algiers (Algeria)

    2009-02-15

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Mining the bulk positron lifetime

    International Nuclear Information System (INIS)

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Advances in bulk port development

    Energy Technology Data Exchange (ETDEWEB)

    Soros, P. (Soros Associates Consulting Engineers, New York, NY (USA))

    1991-03-01

    The article features several recently developed bulk ports which illustrate aspects of new technology or concepts in maritime transport. Low handling capacity bulk terminals at Ponta da Madeira, Brazil and Kooragang Island, Australia and the low-cost bulk port at Port of Corpus Christi, Texas are described. Operations at the ports of Pecket and Tocopilla in Chile, which had special technical problems, are mentioned. Coal terminals at Port Kembla, Australia and St. Johns River in Florid Jacksonville, Florida are featured as examples of terminals which had to be designed to meet high environmental standards. 13 refs., 2 figs., 14 photos.

  9. Bulk Nuclear Properties from Reactions

    OpenAIRE

    Danielewicz, P.

    2002-01-01

    Extraction of bulk nuclear properties by comparing reaction observables to results from semiclassical transport-model simulations is discussed. Specific properties include the nuclear viscosity, incompressibility and constraints on the nuclear pressure at supranormal densities.

  10. Bulk charges in eleven dimensions

    CERN Document Server

    Hawking, Stephen William

    1998-01-01

    Eleven dimensional supergravity has electric type currents arising from the Chern-Simon and anomaly terms in the action. However the bulk charge integrates to zero for asymptotically flat solutions with topological trivial spatial sections. We show that by relaxing the boundary conditions to generalisations of the ALE and ALF boundary conditions in four dimensions one can obtain static solutions with a bulk charge preserving between 1/16 and 1/4 of the supersymmetries. One can introduce membranes with the same sign of charge into these backgrounds. This raises the possibility that these generalized membranes might decay quantum mechanically to leave just a bulk distribution of charge. Alternatively and more probably, a bulk distribution of charge can decay into a collection of singlely charged membranes. Dimensional reductions of these solutions lead to novel representations of extreme black holes in four dimensions with up to four charges. We discuss how the eleven-dimensional Kaluza-Klein monopole wrapped a...

  11. Evolution of organic matter in a eutrophic lake: transition from biological material to kerogen and implications for origin of lacustrine type 1 oils

    Energy Technology Data Exchange (ETDEWEB)

    Hollander, D.J.; Vandenbroucke, M.; Behar, F.H.; McKenzie, J.A.

    1989-03-01

    A detailed study of the optically determined amorphous organic matter (type 1) in the water column and the sediments from eutrophic Lake Greifen provide a model for determining the pathway by which lacustrine algae are incorporated into sediments and later transformed into type 1 kerogens. Mass balancing of organic fractions (fulvic acids, humic acids, and stable residues (proto-kerogen)) in combination with infrared spectroscopy and gas chromatographic studies of these fractions suggest that two processes in the formation of kerogens are proceeding simultaneously: (1) selective decomposition of the structurally and functionally unique fulvic acids and (2) polycondensation/polymerization of structurally and functionally related fractions in the lacustrine algae leading to the formation of complex humic acids and finally to the stable residue phase.

  12. Observational implications of a strong phase transition in the dense matter equation of state for the rotational evolution of neutron stars

    CERN Document Server

    Bejger, M; Haensel, P; Zdunik, J L; Fortin, M

    2016-01-01

    We explore the implications of a strong first-order phase transition region in the dense matter equation of state in the interiors of rotating neutron stars, and the resulting creation of two disjoint families of neutron-stars' configurations (the so-called high-mass twins). Rotating, axisymmetric and stationary stellar configurations are obtained numerically in the framework of general relativity, and their global parameters and stability are studied. The equation of state-induced instability divides stable neutron star configurations into two disjoint families: neutron stars (second family) and hybrid stars (third family), with an overlapping region in mass, the high-mass twin star region. These two regions are divided by an instability strip. Its existence has interesting astrophysical consequences for rotating neutron stars. We note that it provides a "natural" explanation for the rotational frequency cutoff in the observed distribution of neutron stars spins, and for the apparent lack of back-bending in ...

  13. Memory Matters

    Science.gov (United States)

    ... Got Homework? Here's Help White House Lunch Recipes Memory Matters KidsHealth > For Kids > Memory Matters Print A ... of your complex and multitalented brain. What Is Memory? When an event happens, when you learn something, ...

  14. Invisible Matter

    OpenAIRE

    Dolgov, A. D.

    1995-01-01

    These lectures have been given to particle physicists, mostly experimentalists and very briefly and at a pedestrian level review the problems of dark matter. The content of the lectures is the following: 1. Introduction. 2. Cosmological background. 3. Luminous matter. 4. Primordial nucleosynthesis and the total amount of baryons. 5. Gravitating invisible matter. 6. Baryonic crisis. 7. Inflationary omega. 8. Intermediate summary. 9. Possible forms of dark matter. 10. Structure formation: basic...

  15. Ideal bulk pressure of active Brownian particles

    Science.gov (United States)

    Speck, Thomas; Jack, Robert L.

    2016-06-01

    The extent to which active matter might be described by effective equilibrium concepts like temperature and pressure is currently being discussed intensely. Here, we study the simplest model, an ideal gas of noninteracting active Brownian particles. While the mechanical pressure exerted onto confining walls has been linked to correlations between particles' positions and their orientations, we show that these correlations are entirely controlled by boundary effects. We also consider a definition of local pressure, which describes interparticle forces in terms of momentum exchange between different regions of the system. We present three pieces of analytical evidence which indicate that such a local pressure exists, and we show that its bulk value differs from the mechanical pressure exerted on the walls of the system. We attribute this difference to the fact that the local pressure in the bulk does not depend on boundary effects, contrary to the mechanical pressure. We carefully examine these boundary effects using a channel geometry, and we show a virial formula for the pressure correctly predicts the mechanical pressure even in finite channels. However, this result no longer holds in more complex geometries, as exemplified for a channel that includes circular obstacles.

  16. Does Evolution matter?: a case study in Brazil of the effects of an evolutionary-thinking academic atmosphere in postgraduate students' belief in God/religious belief

    Directory of Open Access Journals (Sweden)

    Ivan A. Dias

    2012-06-01

    Full Text Available Although the theory of evolution is more than 150 years old, a substantial proportion of the world population does not mention it when explaining the origin of human beings. The usual alternative conception is offered by creationism, one of the main obstacles to full acceptance of evolution in many countries. National polls have demonstrated that schooling and religiosity are negatively correlated, with scientists being one of the least religious professionals. Herein we analyzed both (1 the profile of 1st semester undergraduate students and (2, thesis and dissertations, concerning religious and evolutionary thoughts from Biology and Veterinary Schools at the largest university of South America. We have shown that students of Biology are biased towards evolution before they enter university and also that the presence of an evolutionary-thinking academic atmosphere influences the deism/religiosity beliefs of postgraduate students.Embora a teoria da evolução tenha mais de 150 anos, uma proporção substancial da população mundial não se refere a ela para explicar a origem dos seres humanos. A alternativa conceitual usual é oferecida pelo criacionismo, um dos principais obstáculos à aceitação plena da Evolução em muitos países. Pesquisas nacionais demonstraram que nível de instrução e religiosidade estão correlacionados negativamente, com os cientistas como sendo um dos profissionais menos religiosos. Aqui analisamos tanto (1 o perfil dos calouros do 1º semestre de 2011 como (2 as teses e as dissertações, com relação à expressão de concepções religiosas e evolutivas, das faculdades de Biologia e Veterinária da maior universidade da América do Sul. Demonstramos que os estudantes de Biologia tendem ao evolucionismo antes mesmo de entrar na universidade e que a presença de uma atmosfera acadêmica evolucionista influencia a expressão de deísmo/religiosidade entre os estudantes de pós-graduação.

  17. Cold Dark Matter from Dark Energy

    OpenAIRE

    Davidson, Aharon; Karasik, David; Lederer, Yoav

    2001-01-01

    Dark energy/matter unification is first demonstrated within the framework of a simplified model. Geodetic evolution of a cosmological constant dominated bubble Universe, free of genuine matter, is translated into a specific FRW cosmology whose effectively induced dark component highly resembles the cold dark matter ansatz. The realistic extension constitutes a dark soliton which bridges past (radiation and/or matter dominated) and future (cosmological constant dominated) Einstein regimes; its...

  18. Design of an Extreme Ultraviolet Spectrometer Suite for Isochoric-Heated Warm-Dense-Matter Studies

    Science.gov (United States)

    Ivancic, S.; Stillman, C. R.; Nilson, P. M.; Froula, D. H.

    2015-11-01

    An ultrafast streaked extreme ultraviolet (XUV) spectrometer (5 to 35 nm) is in development for the measurement of warm dense matter (WDM). In contrast to other forms of pyrometry where the temperature is inferred from bulk x-ray emission, XUV emission is restricted to the sample surface, allowing for the measurement of temperature at the material-vacuum interface. The measurement of the surface temperature is of particular importance in constraining models for the release of WDM. The divergence of surface and bulk temperature measurements may indicate gradients in temperature in the target. Coupling the XUV spectrometer to an ultrafast streak camera allows for the observation of picosecond time-scale evolution of the surface layer temperature. Two high-throughput XUV spectrometers are being designed to measure the time-resolved and absolute XUV emission. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  19. Ghost Dark Matter

    CERN Document Server

    Furukawa, Tomonori; Ichiki, Kiyotomo; Sugiyama, Naoshi; Mukohyama, Shinji

    2010-01-01

    We revisit ghost dark matter, the possibility that ghost condensation may serve as an alternative to dark matter. In particular, we investigate the Friedmann-Robertson-Walker (FRW) background evolution and the large-scale structure (LSS) in the $\\Lambda$GDM universe, i.e. a late-time universe dominated by a cosmological constant and ghost dark matter. The FRW background of the $\\Lambda$GDM universe is indistinguishable from that of the standard $\\Lambda$CDM universe if $M\\gtrsim 1 {\\rm eV}$, where $M$ is the scale of spontaneous Lorentz breaking. From the LSS we find a stronger bound: $M\\gtrsim 10 {\\rm eV}$. For smaller $M$, ghost dark matter would have non-negligible sound speed after the matter-radiation equality, and thus the matter power spectrum would significantly differ from observation. These bounds are compatible with the phenomenological upper bound $M\\lesssim 100 {\\rm GeV}$ known in the literature.

  20. Tilting the Primordial Power Spectrum with Bulk Viscosity

    OpenAIRE

    Lidsey, James E.

    1993-01-01

    Within the context of the cold dark matter model, current observations suggest that inflationary models which generate a tilted primordial power spectrum with negligible gravitational waves provide the most promising mechanism for explaining large scale clustering. The general form of the inflationary potential which produces such a spectrum is a hyperbolic function and is interpreted physically as a bulk viscous stress contribution to the energy-momentum of a perfect baryotropic fluid. This ...

  1. Theoretical expectations for bulk flows in large-scale surveys

    Science.gov (United States)

    Feldman, Hume A.; Watkins, Richard

    1994-01-01

    We calculate the theoretical expectation for the bulk motion of a large-scale survey of the type recently carried out by Lauer and Postman. Included are the effects of survey geometry, errors in the distance measurements, clustering properties of the sample, and different assumed power spectra. We considered the power spectrum calculated from the Infrared Astronomy Satellite (IRAS)-QDOT survey, as well as spectra from hot + cold and standard cold dark matter models. We find that measurement uncertainty, sparse sampling, and clustering can lead to a much larger expectation for the bulk motion of a cluster sample than for the volume as a whole. However, our results suggest that the expected bulk motion is still inconsistent with that reported by Lauer and Postman at the 95%-97% confidence level.

  2. Bulk and shear viscosities of hot and dense hadron gas

    CERN Document Server

    Kadam, Guru Prakash

    2014-01-01

    We estimate bulk and shear viscosity at finite temperature and baryon densities of hadronic matter within hadron resonance gas model. For bulk viscosity we use low energy theorems of QCD for the energy momentum tensor correlators. For shear viscosity coefficient, we estimate the same using molecular kinetic theory to relate the shear viscosity coefficient to average momentum of the hadrons in the hot and dense hadron gas. The bulk viscosity to entropy ratio increases with chemical potential and is related to the reduction of velocity of sound at nonzero chemical potential. The shear viscosity to entropy ratio on the other hand, shows a nontrivial behavior with the ratio decreasing with chemical potential for small temperatures but increasing with chemical potential at high temperatures and is related to decrease of entropy density with chemical potential at high temperature due to finite volume of the hadrons.

  3. Bulk Viscosity and Particle Creation in the Inflationary Cosmology

    CERN Document Server

    Eshaghi, Mehdi; Kiasatpour, Ahmad

    2015-01-01

    We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and unstable, we try to solve the bulk viscosity equation of the cosmic fluid with particle creation through the full causal theory. By adopting an appropriate function for particle creation rate of "Creation of Cold Dark Matter" model, we obtain analytical solutions which do not suffer from the initial singularity and are in agreement with equivalent solutions of Lambda-CDM model. We constrain the free parameter of particle creation in our model based on recent Planck data. It is also found that the inflationary solution is driven by bulk viscosity with or without particle creation.

  4. The Evolution of Dwarf Galaxy Satellites with Different Dark Matter Density Profiles in the ErisMod Simulations. I. The Early Infalls

    Science.gov (United States)

    Tomozeiu, Mihai; Mayer, Lucio; Quinn, Thomas

    2016-02-01

    We present the first simulations of tidal stirring of dwarf galaxies in the Local Group carried out in a fully cosmological context. We use the ErisDARK cosmological simulation of a Milky Way (MW)-sized galaxy to identify some of the most massive subhalos (Mvir > 108 M⊙) that fall into the main host before z = 2. Subhalos are replaced before infall with extremely high-resolution models of dwarf galaxies comprising a faint stellar disk embedded in a dark matter halo. The set of models contains cuspy halos as well as halos with “cored” profiles (with the cusp coefficient γ = 0.6) consistent with recent results of hydrodynamical simulations of dwarf galaxy formation. The simulations are then run to z = 0 with as many as 54 million particles and resolutions as small as ∼4 pc using the new parallel N-body code ChaNGa. The stellar components of all satellites are significantly affected by tidal stirring, losing stellar mass, and undergoing a morphological transformation toward a pressure supported spheroidal system. However, while some remnants with cuspy halos maintain significant rotational flattening and disk-like features, all the shallow halo models achieve vrot/σ⋆ < 0.5 and round shapes typical of dSph satellites of the MW and M31. Mass loss is also enhanced in the latter, and remnants can reach luminosities and velocity dispersions as low as those of ultra-faint dwarfs.

  5. The Evolution of Dwarf Galaxy Satellites with Different Dark Matter Density Profiles in the ErisMod Simulations. I. The Early Infalls

    Science.gov (United States)

    Tomozeiu, Mihai; Mayer, Lucio; Quinn, Thomas

    2016-02-01

    We present the first simulations of tidal stirring of dwarf galaxies in the Local Group carried out in a fully cosmological context. We use the ErisDARK cosmological simulation of a Milky Way (MW)-sized galaxy to identify some of the most massive subhalos (Mvir > 108 M⊙) that fall into the main host before z = 2. Subhalos are replaced before infall with extremely high-resolution models of dwarf galaxies comprising a faint stellar disk embedded in a dark matter halo. The set of models contains cuspy halos as well as halos with “cored” profiles (with the cusp coefficient γ = 0.6) consistent with recent results of hydrodynamical simulations of dwarf galaxy formation. The simulations are then run to z = 0 with as many as 54 million particles and resolutions as small as ∼4 pc using the new parallel N-body code ChaNGa. The stellar components of all satellites are significantly affected by tidal stirring, losing stellar mass, and undergoing a morphological transformation toward a pressure supported spheroidal system. However, while some remnants with cuspy halos maintain significant rotational flattening and disk-like features, all the shallow halo models achieve vrot/σ⋆ round shapes typical of dSph satellites of the MW and M31. Mass loss is also enhanced in the latter, and remnants can reach luminosities and velocity dispersions as low as those of ultra-faint dwarfs.

  6. The evolution of dwarf galaxy satellites with different dark matter density profiles in the ErisMod simulations. I. The early infalls

    CERN Document Server

    Tomozeiu, Mihai; Quinn, Thomas

    2015-01-01

    We present the first simulations of tidal stirring of dwarf galaxies in the Local Group carried out in a cosmological context. We use the ErisDARK simulation of a MW-sized galaxy to identify some of the most massive subhalos ($M_{vir} > 10^8 M_{\\odot}$) that fall into the main host before $z=2$. Subhalos are replaced before infall with high-resolution models of dwarf galaxies comprising a faint stellar disk embedded in a dark matter halo. The set of models contains cuspy halos as well as halos with "cored" profiles (with asymptotic inner slope $\\gamma = 0.6$). The simulations are then run to $z=0$ with as many as 54 million particles and resolution as small as $\\sim 4$ pc using the N-Body code ChaNGa. The stellar components of all satellites are significantly affected by tidal stirring, losing stellar mass and undergoing a morphological transformation towards a pressure supported spheroidal system. However, while some remnants with cuspy halos maintain significant rotational flattening and disk-like features,...

  7. Chemical evolution and life

    Directory of Open Access Journals (Sweden)

    Malaterre Christophe

    2015-01-01

    Full Text Available In research on the origins of life, the concept of “chemical evolution” aims at explaining the transition from non-living matter to living matter. There is however strong disagreement when it comes to defining this concept more precisely, and in particular with reference to a chemical form of Darwinian evolution: for some, chemical evolution is nothing but Darwinian evolution applied to chemical systems before life appeared; yet, for others, it is the type of evolution that happened before natural selection took place, the latter being the birthmark of living systems. In this contribution, I review the arguments defended by each side and show how both views presuppose a dichotomous definition of “life”.

  8. Evolution of massive stars

    International Nuclear Information System (INIS)

    The evolution of stars with masses larger than 15 sun masses is reviewed. These stars have large convective cores and lose a substantial fraction of their matter by stellar wind. The treatment of convection and the parameterisation of the stellar wind mass loss are analysed within the context of existing disagreements between theory and observation. The evolution of massive close binaries and the origin of Wolf-Rayet Stars and X-ray binaries is also sketched. (author)

  9. The Evolution of beliefs and opinions on matters related to marriage and sexual behaviour among French-speaking Catholic Quebecers and English-speaking Protestant Ontarians

    Directory of Open Access Journals (Sweden)

    Miller, Caia

    2006-01-01

    Full Text Available EnglishThe authors argue that the important changes in behaviour related to family andsexual life that were seen in Quebec during the second half of the 20th centuryare a consequence of a major transformation of the foundation of the normativesystem shared by the members of Quebec's main socio-religious group, French speakingCatholics. Using data from Gallup polls, the authors compare theevolution of the opinions of French-speaking Quebec Catholics and English speakingOntario Protestants on matters related to sexual and family behaviourfrom the 1950s to the beginning of the 2000s. The general result is that theevolution of the differences between the two groups is compatible with thehypothesis.FrenchLes auteurs proposent d’expliquer les importants changements qui se sontproduits, dans le Québec de la deuxième moitié du 20e siècle, dans lescomportements liés à la famille et à la vie sexuelle par la transformation dusystème normatif des membres de son principal groupe socio-religieux, lesfrancophones catholiques. À partir des données de sondages Gallup, ilscomparent l'évolution des opinions des francophones catholiques du Québec etdes anglophones protestants de l’Ontario sur des questions liées à la famille etau comportement sexuel et de famille des années 1950 à 2000. L’évolution desdifférences entre les deux groupes est compatible avec l’hypothèse.

  10. Looking for a bulk point

    CERN Document Server

    Maldacena, Juan; Zhiboedov, Alexander

    2015-01-01

    We consider Lorentzian correlators of local operators. In perturbation theory, singularities occur when we can draw a position-space Landau diagram with null lines. In theories with gravity duals, we can also draw Landau diagrams in the bulk. We argue that certain singularities can arise only from bulk diagrams, not from boundary diagrams. As has been previously observed, these singularities are a clear diagnostic of bulk locality. We analyze some properties of these perturbative singularities and discuss their relation to the OPE and the dimensions of double-trace operators. In the exact nonperturbative theory, we expect no singularity at these locations. We prove this statement in 1+1 dimensions by CFT methods.

  11. Gamma probe dry bulk densities

    International Nuclear Information System (INIS)

    The gamma density probe is a useful instrument for measuring water content in small volumes of soil. Essentially, the gamma probe measures the density of the soil and water between a source and a detector. To transpose the gamma densities into water content, the dry bulk density of the soil is needed. A nondestructive method for estimating dry bulk densities for use with the gamma probe is proposed. The procedure is based on the assumption that water content values in a field dry condition were more stable than the dry bulk density values and could be transferred from one point to another. The procedure was successfully used on three areas in Reynolds Creek Experimental Watershed in southwest Idaho. (U.S.)

  12. Microstructure evolution during pressureless sintering of bulk oxide ceramics

    Directory of Open Access Journals (Sweden)

    Karel Maca

    2009-06-01

    Full Text Available The author’s experience concerning the infl uence of the choice of different pressureless heating schedules on the fi nal microstructure of oxide ceramic materials is summarized in the paper. Alumina, ceria, strontium titanate, as well as tetragonal (3 mol% Y2O3 and cubic (8 mol% Y2O3 zirconia were cold isostatically pressed or injection moulded and pressureless sintered with different heating schedules – namely with Constant-Rate of Heating with different dwell temperatures (CRH, with Rate-Controlled Sintering (RCS and with Two-Step Sintering (TSS. It was examined whether some of these three sintering schedules, with the same fi nal density achieved, can lead to a decrease of the grain size of sintered ceramics. The results showed that only TSS (and only for selected materials brought significant decrease of the grain size.

  13. Bulk Viscosity of Interacting Hadrons

    OpenAIRE

    Wiranata, A.; M. Prakash

    2009-01-01

    We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature ari...

  14. Bulk Viscosity of Interacting Hadrons

    CERN Document Server

    Wiranata, A

    2009-01-01

    We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.

  15. The Galaxy Dark Matter Connection

    OpenAIRE

    Bosch, Frank C. van den; Yang, Xiaohu; Mo, H. J.

    2004-01-01

    What galaxy lives in what halo? The answer to this simple question holds important information regarding galaxy formation and evolution. We describe a new statistical technique to link galaxies to their dark matter haloes, or light to mass, using the clustering properties of galaxies as function of their luminosity. The galaxy-dark matter connection thus established, and parameterized through the conditional luminosity function, indicates the presence of two characteristic scales in galaxy fo...

  16. Bulk viscous cosmology: statefinder and entropy

    CERN Document Server

    He, X

    2006-01-01

    The statefinder diagnostic pair is adopted to differentiate viscous cosmology models and it is found that the trajectories of these viscous cosmology models on the statefinder pair $s-r$ plane are quite different from those of the corresponding non-viscous cases. Particularly for the quiessence model, the singular properties of state parameter $w=-1$ are obviously demonstrated on the statefinder diagnostic pair planes. We then discuss the entropy of the viscous / dissipative cosmology system which may be more practical to describe the present cosmic observations as the perfect fluid is just a global approximation to the complicated cosmic media in current universe evolution. When the bulk viscosity takes the form of $\\zeta=\\zeta_{1}\\dot{a}/a$($\\zeta_{1}$ is constant), the relationship between the entropy $S$ and the redshift $z$ is explicitly given out. We find that the entropy of the viscous cosmology is always increasing and consistent with the thermodynamics arrow of time for the universe evolution. With t...

  17. Mirror matter

    OpenAIRE

    Ignatiev, A. Yu.; Volkas, R. R.

    2003-01-01

    One of the deepest unsolved puzzles of subatomic physics is why Nature prefers the left particles to the right ones. Mirror matter is an attempt to understand this mystery by assuming the existence of a "parallel''world where this preference is exactly opposite. Thus in the Universe consisting of the ordinary and the mirror matter the symmetry between the left and right is completely restored. Mirror matter is constrained to interact with us only very weakly. Still, its existence can be infer...

  18. Bulk-boundary interaction and the second law in Hořava-Lifshitz cosmology

    Science.gov (United States)

    Cruz, Miguel; Lepe, Samuel; Peña, Francisco

    2015-12-01

    By defining Q as a function which realizes the energy transference between the bulk and the boundary of spacetime, as we interpret it here in the framework of the flat case of Hořava-Lifshitz cosmology, we discuss the validity of the second law of thermodynamics in light of the sign changes of Q (changes in the direction of energy transference) and its consequences through the cosmic evolution, in particular, whether the thermal equilibrium between the bulk and the boundary is reached or not. Additionally, we discuss possible phase transitions experienced by the bulk and the boundary (seen as sign changes in their heat capacities) through the cosmic evolution. The energy density in the bulk is modeled under a holographic perspective. As far as we know, currently there is not observational data on the bulk-boundary interaction.

  19. Bulk-Boundary interaction and the second law in Ho\\v{r}ava-Lifshitz cosmology

    CERN Document Server

    Cruz, Miguel; Peña, Francisco

    2015-01-01

    By defining $Q$ as a function which realizes the energy transference between the bulk and the boundary of spacetime, as we interprete it here in the framework of Ho\\v{r}ava-Lifshitz (HL) cosmology, flat case, we discuss the validity of the second law of thermodynamics in the light of the sign changes of $Q$ (changes in the direction of energy transference) and its consequences through the cosmic evolution, in particular, whether the thermal equilibrium between bulk and boundary is reached or not. Additionally, we discuss possible phase transitions experienced by the bulk and the boundary (seen as sign changes in their heat capacities) through the cosmic evolution. The energy density in the bulk is modeled under an holographic perspective. As far as we know, currently there is not observational data on bulk-boundary interaction.

  20. Gravitational collapse due to dark matter and dark energy in the brane world scenario

    OpenAIRE

    Nath, Soma; Chakraborty, Subenoy; Debnath, Ujjal

    2005-01-01

    Gravitational collapse of FRW brane world embedded in a conformaly flat bulk is considered for matter cloud consists of dark matter and dark energy with equation of state $p=\\epsilon \\rho$ $(\\epsilon

  1. Cosmological perturbations in a mimetic matter model

    Science.gov (United States)

    Matsumoto, Jiro; Odintsov, Sergei D.; Sushkov, Sergey V.

    2015-03-01

    We investigate the cosmological evolution of a mimetic matter model with arbitrary scalar potential. The cosmological reconstruction—which is the method for constructing a model for an arbitrary evolution of the scale factor—is explicitly performed for different choices of potential. The cases where the mimetic matter model shows the evolution as cold dark matter (CDM), the w CDM model, dark matter and dark energy with a dynamical O m (z ) [where O m (z )≡[(H (z )/H0)2-1 ]/[(1 +z )3-1 ] ], and phantom dark energy with a phantom-nonphantom crossing are presented in detail. The cosmological perturbations for such evolutions are studied in the mimetic matter model. For instance, the evolution behavior of the matter density contrast (which is different than the usual one, i.e., δ ¨+2 H δ ˙-κ2ρ δ /2 =0 ) is investigated. The possibility of a peculiar evolution of δ in the model under consideration is shown. Special attention is paid to the behavior of the matter density contrast near the future singularity, where the decay of perturbations may occur much earlier than the singularity.

  2. Dark matters

    Science.gov (United States)

    Steigman, Gary

    The observational evidence for dark matter in the universe is reviewed. Constraints on the baryon density from primordial nucleosynthesis are presented and compared to the dynamical estimates of the mass on various scales. Baryons can account for the observed luminous mass as well as some, perhaps most, of the 'observed' dark mass. However if, as inflation/naturalness suggest, the total density of the universe is equal to the critical density, then nonbaryonic dark matter is required. The assets and liabilities of, as well as the candidates for, hot and cold dark matter are outlined. At present, there is no completely satisfactory candidate for nonbaryonic dark matter.

  3. Bulk charges in eleven dimensions

    Science.gov (United States)

    Hawking, S. W.; Taylor-Robinson, M. M.

    1998-07-01

    Eleven dimensional supergravity has electric type currents arising from the Chern-Simon and anomaly terms in the action. However the bulk charge integrates to zero for asymptotically flat solutions with topological trivial spatial sections. We show that by relaxing the boundary conditions to generalisations of the ALE and ALF boundary conditions in four dimensions one can obtain static solutions with a bulk charge. Solutions involving anomaly terms preserve between 1/16 and 1/4 of the supersymmetries but Chern-Simons fluxes generally break all of the remaining supersymmetry. One can introduce membranes with the same sign of charge into these backgrounds. This raises the possibility that these generalized membranes might decay quantum mechanically to leave just a bulk distribution of charge. Alternatively and more probably, a bulk distribution of charge can decay into a collection of singly charged membranes. Dimensional reductions of these solutions lead to novel representations of extreme black holes in four dimensions with up to four charges. We discuss how the eleven-dimensional Kaluza-Klein monopole wrapped around a space with non-zero first Pontryagin class picks up an electric charge proportional to the Pontryagin number.

  4. Bulk viscosity and deflationary universes

    CERN Document Server

    Lima, J A S; Waga, I

    2007-01-01

    We analyze the conditions that make possible the description of entropy generation in the new inflationary model by means of a nearequilibrium process. We show that there are situations in which the bulk viscosity cannot describe particle production during the coherent field oscillations phase.

  5. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja;

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...

  6. Bulk correlation functions in 2D quantum gravity

    CERN Document Server

    Kostov, I K

    2005-01-01

    We compute bulk 3- and 4-point tachyon correlators in the 2d Liouville gravity with non-rational matter central charge c<1, following and comparing two approaches. The continuous CFT approach exploits the action on the tachyons of the ground ring generators deformed by Liouville and matter ``screening charges''. A by-product general formula for the matter 3-point OPE structure constants is derived. We also consider a ``diagonal'' CFT of 2D quantum gravity, in which the degenerate fields are restricted to the diagonal of the semi-infinite Kac table. The discrete formulation of the theory is a generalization of the ADE string theories, in which the target space is the semi-infinite chain of points.

  7. Asymmetric condensed dark matter

    Science.gov (United States)

    Aguirre, Anthony; Diez-Tejedor, Alberto

    2016-04-01

    We explore the viability of a boson dark matter candidate with an asymmetry between the number densities of particles and antiparticles. A simple thermal field theory analysis confirms that, under certain general conditions, this component would develop a Bose-Einstein condensate in the early universe that, for appropriate model parameters, could survive the ensuing cosmological evolution until now. The condensation of a dark matter component in equilibrium with the thermal plasma is a relativistic process, hence the amount of matter dictated by the charge asymmetry is complemented by a hot relic density frozen out at the time of decoupling. Contrary to the case of ordinary WIMPs, dark matter particles in a condensate must be lighter than a few tens of eV so that the density from thermal relics is not too large. Big-Bang nucleosynthesis constrains the temperature of decoupling to the scale of the QCD phase transition or above. This requires large dark matter-to-photon ratios and very weak interactions with standard model particles.

  8. Polymerisationseigenschaften von Bulk-Fill Kompositen

    OpenAIRE

    Maier, Eva

    2015-01-01

    Hintergrund und Ziele: Untersuchung der Polymerisationseigenschaften von Bulk-Fill Kompositen bzgl. Konversionsrate (degree of conversion = DC), Vickers-Härte (HV), Polymerisationsschrumpfungsstress (PSS) und Polymerisationsvolumenschrumpfung (PVS) im Vergleich zu konventionellen Kompositen. Material und Methode: Untersucht wurden die Bulk-Fill Komposite Filtek Bulk Fill Flowable (FBF, 3M ESPE, Seefeld), Surefil Smart Dentin Replacement (SDR, Dentsply, Konstanz), Tetric EvoCeram Bulk Fill...

  9. In search of dark matter

    CERN Document Server

    Freeman, Kenneth C

    2006-01-01

    The dark matter problem is one of the most fundamental and profoundly difficult to solve problems in the history of science. Not knowing what makes up most of the known universe goes to the heart of our understanding of the Universe and our place in it. In Search of Dark Matter is the story of the emergence of the dark matter problem, from the initial erroneous ‘discovery’ of dark matter by Jan Oort to contemporary explanations for the nature of dark matter and its role in the origin and evolution of the Universe. Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.

  10. Coulombic Fluids Bulk and Interfaces

    CERN Document Server

    Freyland, Werner

    2011-01-01

    Ionic liquids have attracted considerable interest in recent years. In this book the bulk and interfacial physico-chemical characteristics of various fluid systems dominated by Coulomb interactions are treated which includes molten salts, ionic liquids as well as metal-molten salt mixtures and expanded fluid metals. Of particular interest is the comparison of the different systems. Topics in the bulk phase concern the microscopic structure, the phase behaviour and critical phenomena, and the metal-nonmetal transition. Interfacial phenomena include wetting transitions, electrowetting, surface freezing, and the electrified ionic liquid/ electrode interface. With regard to the latter 2D and 3D electrochemical phase formation of metals and semi-conductors on the nanometer scale is described for a number of selected examples. The basic concepts and various experimental methods are introduced making the book suitable for both graduate students and researchers interested in Coulombic fluids.

  11. Time evolution of a warped cosmic string

    Science.gov (United States)

    Slagter, Reinoud Jan

    2014-06-01

    The time evolution of a self-gravitating U(1) cosmic string on a warped five-dimensional (5D) axially symmetric spacetime is numerically investigated. Although cosmic strings are theoretically predicted in four-dimensional (4D) general relativistic models, there is still no observational evidence of their existence. From recent observations of the cosmic microwave background (CMB), it is concluded that these cosmic strings cannot provide a satisfactory explanation for the bulk of density perturbations. They even could not survive inflation. It is conjectured that only in a 5D warped braneworld model there will be observable imprint of these so-called cosmic superstrings on the induced effective 4D brane metric for values of the symmetry breaking scale larger than the grand unified theory (GUT) values. The warp factor makes these strings consistent with the predicted mass per unit length on the brane. However, in a time-dependent setting, it seems that there is a wavelike energy-momentum transfer to infinity on the brane, a high-energy braneworld behavior. This in contrast to earlier results in approximation models. Evidence of this information from the bulk geometry could be found in the gravitational cosmic background radiation via gravitational wave energy-momentum affecting the brane evolution. Fluctuations of the brane when there is a U(1) gauge field present, are comparable with the proposed brane tension fluctuations, or branons, whose relic abundance can be a dark matter candidate. We briefly made a connection with the critical behavior at the threshold of black hole formation found by Choptuik several decades ago in self-gravitating time-dependent scalar field models. The critical distinction between dispersion of the scalar waves and singular behavior fade away when a time-dependent warp factor is present.

  12. Dark Matter

    CERN Document Server

    Einasto, Jaan

    2009-01-01

    A review of the development of the concept of dark matter is given. I begin the review with the description of the discovery of the mass paradox in our Galaxy and in clusters of galaxies. In mid 1970s the amount of observational data was sufficient to suggest the presence of a massive and invisible population around galaxies and in clusters of galaxies. The nature of the dark population was not clear at that time, but the hypotheses of stellar as well as of gaseous nature of the new population had serious difficulties. These difficulties disappeared when non-baryonic nature of dark matter was suggested in early 1980s. In addition to the presence of Dark Matter, recent observations suggest the presence of Dark Energy, which together with Dark Matter and ordinary baryonic matter makes the total matter/energy density of the Universe equal to the critical cosmological density. There are various hypothesis as for the nature of the dark matter particles, and generally some form of weakly interactive massive particl...

  13. Bulk density and water tensions in the soil on corn root production

    OpenAIRE

    João A. S. Nunes; Edna M. Bonfim-Silva; Tonny J. A. da Silva

    2016-01-01

    ABSTRACT Inadequate management of soil and water can cause changes in soil physical characteristics, resulting in lower root development. Thus the objective of the present study was to evaluate the dry matter production of corn roots under combinations of levels of bulk density and water tension in the soil. The experiment was conducted in a greenhouse in a randomized block design, based on a modified central composite design of a 52 fractional factorial scheme, of combinations of bulk densit...

  14. Using measurements of the cosmic bulk flow to constrain $f(R)$ Gravity

    OpenAIRE

    Seiler, Jacob; Parkinson, David

    2016-01-01

    As an alternative explanation for the cosmic acceleration, $f(R)$ theories of gravity can predict an almost identical expansion history to standard $\\Lambda$CDM, yet make very different predictions for the growth of cosmological structures. Measurements of the cosmic bulk flow provides a method for determining the strength of gravity over the history of structure formation. We use the modified gravity N-body code ECOSMOG to simulate dark matter particles and make predictions for the bulk flow...

  15. Intergalactic medium heating by dark matter

    NARCIS (Netherlands)

    Ripamonti, E.; Mapelli, M.; Ferrara, A.

    2006-01-01

    Abstract: We derive the evolution of the energy deposition in the intergalactic medium (IGM) by dark matter (DM) decays/annihilations for both sterile neutrinos and light dark matter (LDM) particles. At z > 200 sterile neutrinos transfer a fraction f_abs~0.5 of their rest mass energy into the IGM; a

  16. Intergalactic medium heating by dark matter

    NARCIS (Netherlands)

    Ripamonti, E.; Mapelli, M.; Ferrara, A.

    2007-01-01

    We derive the evolution of the energy deposition in the intergalactic medium (IGM) by dark matter (DM) decays/annihilations for both sterile neutrinos and light dark matter (LDM) particles. At z > 200 sterile neutrinos transfer a fraction f(abs) similar to 0.5 of their rest mass energy into the IGM;

  17. Behavior of luminous matter in the head-on encounter of two ultralight BEC dark matter halos

    OpenAIRE

    Guzman, F. S.; Gonzalez, J. A.; Cruz, J. P.

    2016-01-01

    Within the context of ultralight BEC dark matter, we analyze the head-on encounters of two structures. These structures are made of a BEC component, which is a ground state equilibrium solution of the Gross-Pitaevskii-Poisson system, together with a component of luminous matter. The evolution of the Condensate dark matter is carried out by solving the time dependent GPP equations, whereas the luminous matter is modeled with particles interacting gravitationally on top of the BEC dark matter h...

  18. Behavior of luminous matter in the head-on encounter of two ultralight BEC dark matter halos

    CERN Document Server

    Guzman, F S; Cruz, J P

    2016-01-01

    Within the context of ultralight BEC dark matter, we analyze the head-on encounters of two structures. These structures are made of a BEC component, which is a ground state equilibrium solution of the Gross-Pitaevskii-Poisson system, together with a component of luminous matter. The evolution of the Condensate dark matter is carried out by solving the time dependent GPP equations, whereas the luminous matter is modeled with particles interacting gravitationally on top of the BEC dark matter halos. We track the evolution of frontal encounters for various values of the collision velocity and analyze the regime of high velocity regime showing solitonic behavior of the BEC halos and that of slow velocities producing a single final structure. We measure the relative velocity of the dark matter with respect to the luminous matter after the encounters in the solitonic case and track the evolution of luminous matter in the case of merger.

  19. Behavior of luminous matter in the head-on encounter of two ultralight BEC dark matter halos

    Science.gov (United States)

    Guzmán, F. S.; González, J. A.; Cruz-Pérez, J. P.

    2016-05-01

    Within the context of ultralight Bose-Einstein condensate (BEC) dark matter, we analyze the head-on encounters of two structures. These structures are made of a BEC component, which is a ground-state equilibrium solution of the Gross-Pitaevskii-Poisson (GPP) system, together with a component of luminous matter. The evolution of the condensate dark matter is carried out by solving the time-dependent GPP equations, whereas the luminous matter is modeled with particles interacting gravitationally on top of the BEC dark matter halos. We track the evolution of frontal encounters for various values of the collision velocity and analyze the high-velocity regime showing solitonic behavior of the BEC halos and that of slow velocities producing a single final structure. We measure the relative velocity of the dark matter with respect to the luminous matter after the encounters in the solitonic case and track the evolution of luminous matter in the case of merger.

  20. Antimatter Matters

    CERN Multimedia

    CERN

    2016-01-01

    This video is a teaser-introduction to the Antimatter Matters exhibtion at the Royal Society's Summer Science exhibition July 4-10 2016. The exhibition is jointly organised and hosted by UK members of the ALPHA and LHCb collaborations.

  1. Annihilating Asymmetric Dark Matter

    CERN Document Server

    Bell, Nicole F; Shoemaker, Ian M

    2014-01-01

    The relic abundance of particle and antiparticle dark matter (DM) need not be vastly different in thermal asymmetric dark matter (ADM) models. By considering the effect of a primordial asymmetry on the thermal Boltzmann evolution of coupled DM and anti-DM, we derive the requisite annihilation cross section. This is used in conjunction with CMB and Fermi-LAT gamma-ray data to impose a limit on the number density of anti-DM particles surviving thermal freeze-out. When the extended gamma-ray emission from the Galactic Center is reanalyzed in a thermal ADM framework, we find that annihilation into $\\tau$ leptons prefer anti-DM number densities 1-4$\\%$ that of DM while the $b$-quark channel prefers 50-100$\\%$.

  2. Résines et asphaltènes : évolution en fonction des types de matière organique et de leur enfouissement Resins and Asphaltenes: Evolution As a Function of Organic-Matter Type and Burial

    Directory of Open Access Journals (Sweden)

    Castex H.

    2006-11-01

    several basins. It was shown that: (a Resins have higher mean carbon and hydrogen values as well as a lower C/H ratio than asphaltenes. Resins thus have a more aliphatic and or more alicyclic structure. On the other hand, asphaltenes contain more sulfur, oxygen end nitrogen. (b Sulfur and oxygen are not parameters enabling basins to be differentiated. (c Different types of organic matter are revealed by an H/C, O/C diagram. Their chemical evolution with burial is characterized by a decrease in hydrogen, oxygen and sulfur contents. Proton nuclear magnetic resonance (NMR and infrared spectroscopy (IRS were used to follow the structural evolution of resins and asphaltenes coming from different types of organic matter (algal, marine and terrestrial buried at increasing depths. NMR can be used to compute several structural parameters such as FA aromaticity and the degree of sigma substitution of the aromatic system. The FA factor seems to increase with burial and according to the type of organic matter, while sigma seems to decrease. These data were completed by infrared spectroscopy. The surface areas of the bands corresponding to the following functions were computed: (a OH in the 3700-2700 cm-1 range; (b carbonyl C-O around 1700 cm-1; (c aliphatic C-H at 2900, 2455 and 1380 cm-1; (d aromatic C-H at 1610 cm-1. Variations in the intensity of bands: (a decrease of aliphatic C-H and of C-O functions; (b increase of aromatic C-H and C-C are related to both the type of organic matter and its catagenesis.

  3. Bulk metallic glass tube casting

    International Nuclear Information System (INIS)

    Research highlights: → Tubular specimens of Zr55Cu30Al10Ni5 cast in custom arc-melting furnace. → Tilt casting supplemented by suction casting. → Bulk metallic glass formed only with optimized processing parameters. → Fully amorphous tubes with 1.8 mm wall thickness and 25 mm diameter. - Abstract: Tubular bulk metallic glass specimens were produced, using a custom-built combined arc-melting tilt-casting furnace. Zr55Cu30Al10Ni5 tubes with outer diameter of 25 mm and 0.8-3 mm wall thicknesses were cast, with both tilt and suction casting to ensure mold filling. Tilt casting was found to fill one side of the tube mold first, with the rest of the tube circumference filled subsequently by suction casting. Optimized casting parameters were required to fully fill the mold and ensure glass formation. Too small melt mass and too low arc power filled the mold only partially. However, too large melt mass and higher arc power which lead to the best mold filling also lead to partial crystallization. Variations in processing parameters were explored, until a glassy ring with 1.8 mm thickness was produced. Different sections of the as-cast ring were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and instrumented indentation to ensure amorphous microstructure. Atomic force microscopy (AFM) was used to compare the surface qualities of the first- and last-filled sections. These measurements confirmed the glassy structure of the cast ring, and that, the tilt cast tube section consistently showed better surface quality than the suction cast section. Optimized casting parameters are required to fully realize the potential of directly manufacturing complex shapes out of high-purity bulk metallic glasses by tilt casting.

  4. Bulk Moisture and Salinity Sensor

    Science.gov (United States)

    Nurge, Mark; Monje, Oscar; Prenger, Jessica; Catechis, John

    2013-01-01

    Measurement and feedback control of nutrient solutions in plant root zones is critical to the development of healthy plants in both terrestrial and reduced-gravity environments. In addition to the water content, the amount of fertilizer in the nutrient solution is important to plant health. This typically requires a separate set of sensors to accomplish. A combination bulk moisture and salinity sensor has been designed, built, and tested with different nutrient solutions in several substrates. The substrates include glass beads, a clay-like substrate, and a nutrient-enriched substrate with the presence of plant roots. By measuring two key parameters, the sensor is able to monitor both the volumetric water content and salinity of the nutrient solution in bulk media. Many commercially available moisture sensors are point sensors, making localized measurements over a small volume at the point of insertion. Consequently, they are more prone to suffer from interferences with air bubbles, contact area of media, and root growth. This makes it difficult to get an accurate representation of true moisture content and distribution in the bulk media. Additionally, a network of point sensors is required, increasing the cabling, data acquisition, and calibration requirements. measure the dielectric properties of a material in the annular space of the vessel. Because the pore water in the media often has high salinity, a method to measure the media moisture content and salinity simultaneously was devised. Characterization of the frequency response for capacitance and conductance across the electrodes was completed for 2-mm glass bead media, 1- to 2-mm Turface (a clay like media), and 1- to 2-mm fertilized Turface with the presence of root mass. These measurements were then used to find empirical relationships among capacitance (C), the dissipation factor (D), the volumetric water content, and the pore water salinity.

  5. Gold based bulk metallic glass

    OpenAIRE

    Schroers, Jan; Lohwongwatana, Boonrat; Johnson, William L.; Peker, Atakan

    2005-01-01

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5 mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644 K, a glass transition temperature of 401 K, and a supercooled liquid region of 58 K. The Vickers hardness of the alloys in this system...

  6. Iron - based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Babilas

    2010-07-01

    Full Text Available Purpose: The paper presents a structure characterization, thermal and soft magnetic properties analysis of Fe-based bulk amorphous materials in as-cast state and after crystallization process. In addition, the paper gives some brief review about achieving, formation and structure of bulk metallic glasses as a special group of amorphous materials.Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA and differential scanning calorimetry (DSC. The magnetic properties contained initial and maximum magnetic permeability, coercive force and magnetic after-effects measurements were determined by the Maxwell-Wien bridge and VSM methods.Findings: The X-ray diffraction and transmission electron microscopy investigations revealed that the studied as-cast bulk metallic glasses in form of ribbons and rods were amorphous. Two stage crystallization process was observed for studied bulk amorphous alloy. The differences of crystallization temperature between ribbons and rods with chosen thickness are probably caused by different amorphous structures as a result of the different cooling rates in casting process. The SEM images showed that studied fractures could be classified as mixed fractures with indicated two zones contained “river” and “smooth” areas. The changing of chosen soft magnetic properties (μr, Bs, Hc obtained for samples with different thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The annealing process in temperature range from 373 to 773 K causes structural relaxation of tested amorphous materials, which leads to changes in their physical properties. The qualitative

  7. Bulk viscosity coefficients due to phonons in superfluid neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, Cristina; Tolos, Laura [Institut de Ciències del Espai (IEEC/CSIC), Facultat de Ciències, Campus Universitat Autònoma de Barcelona, Torre C5, E-08193 Bellaterra (Spain); Tarrús, Jaume, E-mail: cmanuel@ieec.uab.es, E-mail: tarrus@ecm.ub.edu, E-mail: tolos@ice.csic.es [Departament d' Estructura i Constituents de la Matèria, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona (Spain)

    2013-07-01

    We calculate the three bulk viscosity coefficients as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon collisional processes, written as a function of the equation of state of the system. The solution of the dynamical evolution of the phonon number density allows us to calculate the bulk viscosity coefficients as function of the phonon collisional rate and the phonon dispersion law, which depends on the neutron pairing gap. Our method of computation is rather general, and could be used for different superfluid systems, provided they share the same underlying symmetries. We find that the behavior with temperature of the bulk viscosity coefficients is dominated by the contributions coming from the collinear regime of the 2↔3 phonon processes. For typical star radial pulsation frequencies of ω ∼ 10{sup 4}s{sup −1}, we obtain that the bulk viscosity coefficients at densities n∼>4n{sub 0} are within 10% from its static value for T∼<10{sup 9} K and for the case of strong neutron superfluidity in the core with a maximum value of the {sup 3}P{sub 2} gap above 1 MeV, while, otherwise, the static solution is not a valid approximation to the bulk viscosity coefficients. Compared to previous results from Urca and modified Urca reactions, we conclude that at T ∼ 10{sup 9}K phonon collisions give the leading contribution to the bulk viscosities in the core of the neutron stars, except for n ∼ 2n{sub 0} when the opening of the Urca processes takes place.

  8. Dynamic coupling of bulk chemistry, trace elements and mantle flow

    Science.gov (United States)

    Davies, J. H.; Heck, H. V.; Nowacki, A.; Wookey, J. M.; Elliott, T.; Porcelli, D.

    2015-12-01

    Fully dynamical models that not only track the evolution of chemical heterogeneities through the mantle, but also incorporate the effect of chemical heterogeneities on the dynamics of mantle convection are now emerging. Since in general analytical solutions to these complex problems are lacking, careful testing and investigations of the effect and usefulness of these models is needed. We extend our existing numerical mantle convection code that can track fluid flow in 3D spherical geometry and tracks both bulk chemical components (basal fraction) and different trace elements. The chemical components fractionate upon melting when and where the solidus is crossed. Now, the chemical information will effect the flow of the fluid in the following ways: The bulk composition will link to density and the (radioactive) trace element abundance to heat production. Results will be reported of the effect of different density structures; either starting with a primordial dense layer at the base of the mantle, having all density variation originate from melting (basalt production), or a combination between these two end-member scenarios. In particular we will focus on the connection between large scale bulk chemical structures in the (deep) mantle and the evolution of the distribution of noble gasses (He and Ar). The distribution of noble gasses depend upon 1) assumptions on the initial distributions in the mantle, 2) the mantle flow, 3) radioactive production and, 4) outgassing to the atmosphere upon melting close to the surface.

  9. Brane World Dynamics and Adiabatic Matter creation

    CERN Document Server

    Gopakumar, P

    2006-01-01

    We have treated the adiabatic matter creation process in various three-brane models by applying thermodynamics of open systems. The matter creation rate is found to affect the evolution of scale factor and energy density of the universe. We find modification at early stages of cosmic dynamics. In GB and RS brane worlds, by chosing appropriate parameters we obtain standard scenario, while the warped DGP model has different Friedmann equations. During later stages, since the matter creation is negligible the evolution reduces to FRW expansion, in RS and GB models.

  10. The evolution of organic matter in space

    NARCIS (Netherlands)

    Ehrenfreund, Pascale; Spaans, Marco; Holm, Nils G.

    2011-01-01

    Carbon, and molecules made from it, have already been observed in the early Universe. During cosmic time, many galaxies undergo intense periods of star formation, during which heavy elements like carbon, oxygen, nitrogen, silicon and iron are produced. Also, many complex molecules, from carbon monox

  11. Two-brane system in a vacuum bulk with a single equation of state

    CERN Document Server

    Perez, Juan L; Urena-Lopez, L Arturo; 10.1063/1.4748545

    2012-01-01

    We study the cosmology of a two-brane model in a five-dimensional spacetime, where the extra spatial coordinate is compactifed on an orbifold. Additionally, we consider the existence on each brane of matter fields that evolve in time. Solving the Einstein equations in a vacuum bulk, we can show how the matter fields in both branes are connected and they do not evolve independently

  12. Static Response of Neutron Matter

    Science.gov (United States)

    Buraczynski, Mateusz; Gezerlis, Alexandros

    2016-04-01

    We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully nonperturbative microscopic quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems.

  13. Static Response of Neutron Matter

    CERN Document Server

    Buraczynski, Mateusz

    2015-01-01

    We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully non-perturbative microscopic Quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems.

  14. Static Response of Neutron Matter.

    Science.gov (United States)

    Buraczynski, Mateusz; Gezerlis, Alexandros

    2016-04-15

    We generalize the problem of strongly interacting neutron matter by adding a periodic external modulation. This allows us to study from first principles a neutron system that is extended and inhomogeneous, with connections to the physics of both neutron-star crusts and neutron-rich nuclei. We carry out fully nonperturbative microscopic quantum Monte Carlo calculations of the energy of neutron matter at different densities, as well as different strengths and periodicities of the external potential. In order to remove systematic errors, we examine finite-size effects and the impact of the wave function ansatz. We also make contact with energy-density functional theories of nuclei and disentangle isovector gradient contributions from bulk properties. Finally, we calculate the static density-density linear response function of neutron matter and compare it with the response of other physical systems. PMID:27127963

  15. On the capture of dark matter by neutron stars

    OpenAIRE

    Güver, Tolga; Erkoca, Arif Emre; Reno, Mary Hall; Sarcevic, Ina

    2012-01-01

    We calculate the number of dark matter particles that a neutron star accumulates over its lifetime as it rotates around the center of a galaxy, when the dark matter particle is a self-interacting boson but does not self-annihilate. We take into account dark matter interactions with baryonic matter and the time evolution of the dark matter sphere as it collapses within the neutron star. We show that dark matter self-interactions play an important role in the rapid accumulation of dark matter i...

  16. Cosmological Perturbations in Brane World - Brane view v.s. Bulk view -

    CERN Document Server

    Soda, J; Soda, Jiro; Koyama, Kazuya

    2003-01-01

    First, we will study the cosmological perturbations from the brane point of view. It turns out that two types of the extra data are necessary to know the evolution of the system. To fix these data, the analysis of the bulk is needed. So, we have solved equations of motion for the bulk gravity and determined the extra data. We would like to stress that, both analysis take complementary roles to achieve this goal.

  17. Local and bulk melting of Cu at grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shengnian [Los Alamos National Laboratory; Han, Li - Bo [USTC; An, Qi [USTC/CALTECH; Fu, Rong - Shan [USTC; Zheng, Lianqing [FSU

    2008-01-01

    We investigate gain boundary (GB) melting using molecular dynamics simulations on face-centered-cubic Cu bicrystals with symmetric {l_angle}110{r_angle} tilt grain boundaries. Two representative types of GBs are explored: {Sigma} = 11/(113)/50.48{sup o} (low GB energy) and {Sigma} = 27/(552)/148.41{sup o} (high GB energy). The temperature and temporal evolutions of the Cu bicrystals under stepped heating are characterized in terms of order parameters and diffusion coefficients, as ell as the nucleation and growth of melt. Within the GB region, continuous local melting precedes discontinuous bulk melting, while continuous solid state disordering may precede local melting. Premelting may occur for local melting but not for bulk melting. For {Sigma} = 11/(113)/50.48{sup o}, premelting of the GB region is negligible, and local melting occurs near the thermodynamic melting temperature. The GB region as a whole is superheated by about 13% before its bulk melting. In the case of {Sigma} = 27/(552)/148.41, considerable premelting is observed for local melting, while the bulk melting occurs with negligible superheating. The exact melting behavior of a general GB depends on the GB energy, but is likely bracketed within these two cases.

  18. Bulk viscosity from the Polyakov-Nambu-Jona-Lasinio model

    International Nuclear Information System (INIS)

    The insufficiency of ideal fluid dynamics to reproduce certain expected results threw light on the necessity of dissipative effects. The viscosity coefficients give an estimate of the hydrodynamical evolution of fluid dissipative processes. Not only do they provide information about the deviation of the system from ideal hydrodynamics, they also give us a picture of the fluid dynamics and critical phenomena. In this work we concentrate on the effects of bulk viscosity. Bulk viscosity bears essential significance like in the context of violation of scale invariance. Now, the smallness of sound velocity being directly related to the former, it becomes obvious that bulk viscosity will show a peak-like nature in the critical region. Bulk viscosity manifests itself by an addition of the diagonal term πδij to the stress tensor Tij in the local rest frame. In this work we take resort to the Kubo formalism which relates viscosity coefficients to the correlation functions of the energy-momentum (E-M) tensor

  19. Chemical evolution of galaxies

    International Nuclear Information System (INIS)

    Initial conditions are probably set by results of Big Bang nucleosynthesis (BBNS) without intervening complications affecting the composition of visible matter so that extrapolation of observed abundances to BBNS products seems fairly secure. Primordial helium and deuterium abundances deduced in this way place upper and lower limits on baryonic density implying that both baryonic and non-baryonic dark matter exist and predicting no more than 3 neutrino flavours as recently confirmed in accelerator experiments. The validity of simple galactic chemical evolution models assumed in extrapolating back to the Big Bang is examined in the light of the frequency distribution of iron or oxygen abundances in the Galactic halo, bulge and disk. (orig.)

  20. String Evolution with Friction

    OpenAIRE

    Martins, C.J.A.P.(Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, Porto, 4150-762, Portugal); Shellard, E. P. S.

    1995-01-01

    We study the effects of friction on the scaling evolution of string networks in condensed matter and cosmological contexts. We derive a generalized `one-scale' model with the string correlation length $L$ and velocity $v$ as dynamical variables. In non-relativistic systems, we obtain a well-known $L\\propto t^{1/2}$ law, showing that loop production is important. For electroweak cosmic strings, we show transient damped epoch scaling with $L\\propto t^{5/4}$ (or, in the matter era, $L\\propto t^{...

  1. Final Report (2010-2015) for the Topical Collaboration on Quantitative Jet and Electromagnetic Tomography (JET) of Extreme Phases of Matter in Heavy-ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Gyulassy, Miklos [Columbia Univ., New York, NY (United States); Romatschke, Paul [Univ. of Colorado, Boulder, CO (United States); Bass, Steffen [Duke Univ., Durham, NC (United States); Muller, Berndt [Duke Univ., Durham, NC (United States); Strickland, Michael [Kent State Univ., Kent, OH (United States); Wang, Xin -Nian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vogt, Ramona [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vitev, Ivan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gale, Charles [McGill Univ., Montreal, QC (Canada); Jeon, Sangyong [McGill Univ., Montreal, QC (Canada); Heinz, Ulrich [The Ohio State Univ., Columbus, OH (United States); Molnar, Denes [Purdue Univ., West Lafayette, IN (United States); Fries, Rainer [Texas A & M Univ., College Station, TX (United States); Ko, Che -Ming [Texas A & M Univ., College Station, TX (United States); Majumder, Abhijit [Wayne State Univ., Detroit, MI (United States)

    2015-08-31

    During the 5-year funding period (2010-2015), the JET Collaboration carried out a comprehensive research program with coordinated efforts involving all PI members and external associated members according to the plan and milestones outlined in the approved JET proposal. We identified important issues in the study of parton energy loss and made significant progress toward NLO calculations; advanced event-by-event hydrodynamic simulations of bulk matter evolution; developed Monte Carlo tools that combine different parton energy loss approaches, hydrodynamic models and parton recombination model for jet hadronization; and carried out the first comprehensive phenomenological study to extract the jet transport parameter.

  2. Final Report (2010-2015) for the Topical Collaboration on Quantitative Jet and Electromagnetic Tomography (JET) of Extreme Phases of Matter in Heavy-ion Collisions

    International Nuclear Information System (INIS)

    During the 5-year funding period (2010-2015), the JET Collaboration carried out a comprehensive research program with coordinated efforts involving all PI members and external associated members according to the plan and milestones outlined in the approved JET proposal. We identified important issues in the study of parton energy loss and made significant progress toward NLO calculations; advanced event-by-event hydrodynamic simulations of bulk matter evolution; developed Monte Carlo tools that combine different parton energy loss approaches, hydrodynamic models and parton recombination model for jet hadronization; and carried out the first comprehensive phenomenological study to extract the jet transport parameter.

  3. Neutron stars, supernova and phases of dense quark matter

    International Nuclear Information System (INIS)

    We present a brief discussion on the possible role of quark matter in 'neutron' stars. Observable aspects of neutron star structure and early evolution of the newly born neutron star are discussed in this context. The phase structure of dense quark matter and its impact on the equation of state and transport properties of dense matter are highlighted

  4. Relic abundance of mass-varying cold dark matter particles

    OpenAIRE

    Rosenfeld, R.

    2005-01-01

    In models of coupled dark energy and dark matter the mass of the dark matter particle depends on the cosmological evolution of the dark energy field. In this note we exemplify in a simple model the effects of this mass variation on the relic abundance of cold dark matter.

  5. Open Heavy Flavor in QCD Matter and in Nuclear Collisions

    CERN Document Server

    Prino, Francesco

    2016-01-01

    We review the experimental and theoretical status of open heavy-flavor (HF) production in high-energy nuclear collisions at RHIC and LHC. We first overview the theoretical concepts and pertinent calculations of HF transport in QCD matter, including perturbative and non-perturbative approaches in the quark-gluon plasma, effective models in hadronic matter, as well as implementations of heavy-quark (HQ) hadronization. This is followed by a brief discussion of bulk evolution models for heavy-ion collisions and initial conditions for the HQ distributions which are needed to calculate HF spectra in comparison to observables. We then turn to a discussion of experimental data that have been collected to date at RHIC and LHC, specifically for the nuclear suppression factor and elliptic flow of semileptonic HF decays, D mesons, non-prompt $J/\\psi$ from B-meson decays, and b-jets. Model comparisons to HF data are conducted with regards to extracting the magnitude, temperature and momentum-dependence of HF transport coe...

  6. Open heavy flavor in QCD matter and in nuclear collisions

    Science.gov (United States)

    Prino, Francesco; Rapp, Ralf

    2016-09-01

    We review the experimental and theoretical status of open heavy-flavor (HF) production in high-energy nuclear collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). We first overview the theoretical concepts and pertinent calculations of HF transport in strong-interaction matter, including perturbative and non-perturbative approaches in quark–gluon plasma, effective models in hadronic matter, as well as implementations of heavy-quark (HQ) hadronization. This is followed by a brief discussion of bulk evolution models for heavy-ion collisions and initial conditions for the HQ distributions which are needed to calculate HF spectra in comparison to observables. We then turn to a discussion of experimental data that have been collected to date at RHIC and the LHC, specifically for the nuclear modification factor and elliptic flow of leptons from semileptonic HF decays, D mesons, non-prompt J/\\psi from B-meson decays, and b-jets. Model comparisons to HF data are conducted with regards to extracting the magnitude, temperature and momentum dependence of HF transport coefficients from experiment.

  7. Handling of bulk solids theory and practice

    CERN Document Server

    Shamlou, P A

    1990-01-01

    Handling of Bulk Solids provides a comprehensive discussion of the field of solids flow and handling in the process industries. Presentation of the subject follows classical lines of separate discussions for each topic, so each chapter is self-contained and can be read on its own. Topics discussed include bulk solids flow and handling properties; pressure profiles in bulk solids storage vessels; the design of storage silos for reliable discharge of bulk materials; gravity flow of particulate materials from storage vessels; pneumatic transportation of bulk solids; and the hazards of solid-mater

  8. Prediction of Filamentous Sludge Bulking using a State-based Gaussian Processes Regression Model

    Science.gov (United States)

    Liu, Yiqi; Guo, Jianhua; Wang, Qilin; Huang, Daoping

    2016-01-01

    Activated sludge process has been widely adopted to remove pollutants in wastewater treatment plants (WWTPs). However, stable operation of activated sludge process is often compromised by the occurrence of filamentous bulking. The aim of this study is to build a proper model for timely diagnosis and prediction of filamentous sludge bulking in an activated sludge process. This study developed a state-based Gaussian Process Regression (GPR) model to monitor the filamentous sludge bulking related parameter, sludge volume index (SVI), in such a way that the evolution of SVI can be predicted over multi-step ahead. This methodology was validated with SVI data collected from one full-scale WWTP. Online diagnosis and prediction of filamentous bulking sludge with real-time SVI prediction was tested through a simulation study. The results showed that the proposed methodology was capable of predicting future SVIs with good accuracy, thus providing sufficient time for predicting and controlling filamentous sludge bulking. PMID:27498888

  9. Prediction of Filamentous Sludge Bulking using a State-based Gaussian Processes Regression Model.

    Science.gov (United States)

    Liu, Yiqi; Guo, Jianhua; Wang, Qilin; Huang, Daoping

    2016-01-01

    Activated sludge process has been widely adopted to remove pollutants in wastewater treatment plants (WWTPs). However, stable operation of activated sludge process is often compromised by the occurrence of filamentous bulking. The aim of this study is to build a proper model for timely diagnosis and prediction of filamentous sludge bulking in an activated sludge process. This study developed a state-based Gaussian Process Regression (GPR) model to monitor the filamentous sludge bulking related parameter, sludge volume index (SVI), in such a way that the evolution of SVI can be predicted over multi-step ahead. This methodology was validated with SVI data collected from one full-scale WWTP. Online diagnosis and prediction of filamentous bulking sludge with real-time SVI prediction was tested through a simulation study. The results showed that the proposed methodology was capable of predicting future SVIs with good accuracy, thus providing sufficient time for predicting and controlling filamentous sludge bulking. PMID:27498888

  10. Gold based bulk metallic glass

    Science.gov (United States)

    Schroers, Jan; Lohwongwatana, Boonrat; Johnson, William L.; Peker, Atakan

    2005-08-01

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644K, a glass transition temperature of 401K, and a supercooled liquid region of 58K. The Vickers hardness of the alloys in this system is ˜350Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry.

  11. Gold based bulk metallic glass

    International Nuclear Information System (INIS)

    Gold-based bulk metallic glass alloys based on Au-Cu-Si are introduced. The alloys exhibit a gold content comparable to 18-karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5 mm in the best glassformer. Au49Ag5.5Pd2.3Cu26.9Si16.3 has a liquidus temperature of 644 K, a glass transition temperature of 401 K, and a supercooled liquid region of 58 K. The Vickers hardness of the alloys in this system is ∼350 Hv, twice that of conventional 18-karat crystalline gold alloys. This combination of properties makes the alloys attractive for many applications including electronic, medical, dental, surface coating, and jewelry

  12. Bulk analysis using nuclear techniques

    International Nuclear Information System (INIS)

    Bulk analysis techniques developed for the mining industry are reviewed. Using penetrating neutron and #betta#-radiations, measurements are obtained directly from a large volume of sample (3-30 kg) #betta#-techniques were used to determine the grade of iron ore and to detect shale on conveyor belts. Thermal neutron irradiation was developed for the simultaneous determination of iron and aluminium in iron ore on a conveyor belt. Thermal-neutron activation analysis includes the determination of alumina in bauxite, and manganese and alumina in manganese ore. Fast neutron activation analysis is used to determine silicon in iron ores, and alumina and silica in bauxite. Fast and thermal neutron activation has been used to determine the soil in shredded sugar cane. (U.K.)

  13. Isotopic signatures by bulk analyses

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has developed a series of measurement techniques for identification of nuclear signatures by analyzing bulk samples. Two specific applications for isotopic fingerprinting to identify the origin of anthropogenic radioactivity in bulk samples are presented. The first example is the analyses of environmental samples collected in the US Arctic to determine the impact of dumping of radionuclides in this polar region. Analyses of sediment and biota samples indicate that for the areas sampled the anthropogenic radionuclide content of sediments was predominantly the result of the deposition of global fallout. The anthropogenic radionuclide concentrations in fish, birds and mammals were very low. It can be surmised that marine food chains are presently not significantly affected. The second example is isotopic fingerprinting of water and sediment samples from the Rocky Flats Facility (RFP). The largest source of anthropogenic radioactivity presently affecting surface-waters at RFP is the sediments that are currently residing in the holding ponds. One gram of sediment from a holding pond contains approximately 50 times more plutonium than 1 liter of water from the pond. Essentially 100% of the uranium in Ponds A-1 and A-2 originated as depleted uranium. The largest source of radioactivity in the terminal Ponds A-4, B-5 and C-2 was naturally occurring uranium and its decay product radium. The uranium concentrations in the waters collected from the terminal ponds contained 0.05% or less of the interim standard calculated derived concentration guide for uranium in waters available to the public. All of the radioactivity observed in soil, sediment and water samples collected at RFP was naturally occurring, the result of processes at RFP or the result of global fallout. No extraneous anthropogenic alpha, beta or gamma activities were detected. The plutonium concentrations in Pond C-2 appear to vary seasonally

  14. Non-gated laser-induced breakdown spectroscopy in bulk water by position-selective detection

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Ye; Xue, Boyang; Song, Jiaojian; Lu, Yuan; Zheng, Ronger, E-mail: rzheng@ouc.edu.cn [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao 266100 (China)

    2015-09-14

    Temporal and spatial evolutions of the laser-induced plasma in bulk water are investigated using fast imaging and emission spectroscopic techniques. By tightly focusing a single-pulse nanosecond Nd: YAG laser beam into the bulk water, we generate a strongly expanded plasma with high reproducibility. Such a strong expanding plasma enables us to obtain well-resolved spectral lines by means of position-selective detection; hence, the time-gated detector becomes abdicable. The present results suggest not only a possible non-gated approach for underwater laser-induced breakdown spectroscopy but also give an insight into the plasma generation and expansion in bulk water.

  15. Guidelines for Measuring Bulk Density of Soil

    International Nuclear Information System (INIS)

    Bulk density is defined as the dry weight of soil per unit volume of undisturbed soil. • Bulk density can be used to give an indication of the porosity and structure of the soil influencing O2 and H2O movement in the soil. • Soils with a bulk density higher than 1.6 g/cm3 may restrict root development. • Bulk density is also a measurement of the degree of compaction of the soil. • Bulk density increases with compaction and tends to increase with soil depth. • Sandy soils tend to have higher bulk density (1.4-1.5 g/cm3) than clay soils (1.2-1/3g/cm3). The measurement of soil bulk density is carried out by collecting undisturbed soil samples through inserting metal rings (with a known volume) into the soil, and determining the weight of the collected soil after drying

  16. Quantum matter

    International Nuclear Information System (INIS)

    The following topics are dealt with: Artificial atoms and molecules, tailored from solids, fractional flux quanta, molecular magnets, controlled interaction in quantum gases, the theory of quantum correlations in mott matter, cold gases, and mesoscopic systems, Bose-Einstein condensates on the chip, on the route to the quantum computer, a quantum computer in diamond. (HSI)

  17. Dark Matter Searches at ATLAS

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The astrophysical evidence of dark matter provides some of the most compelling clues to the nature of physics beyond the Standard Model. From these clues, ATLAS has developed a broad and systematic search program for dark matter production in LHC collisions. These searches are now entering their prime, with the LHC now colliding protons at the increased 13 TeV centre-of-mass energy and set to deliver much larger datasets than ever before. The results of these searches on the first 13 TeV data, their interpretation, and the design and possible evolution of the search program will be presented.

  18. The theory of evolution

    Directory of Open Access Journals (Sweden)

    Oleg Bazaluk

    2015-06-01

    Full Text Available The book The Theory of Evolution: from the Space Vacuum to Neural Ensembles and Moving Forward, an edition of 100 copies, was published in Russian language, in December 2014 in Kiev. Its Russian version is here: http://en.bazaluk.com/journals.html. Introduction, Chapter 10 and Conclusion published in English for the first time. Since 2004 author have been researching in the field of theory of Evolution, Big History. The book was written on the base of analysis of more than 2000 primary sources of this research topic. The volume is 90,000 words (with Reference. The book is for a wide range of professionals, from students to professors and researchers working in the fields of: philosophical anthropology, philosophy, Big History, cosmology, biology, neuroscience and etc. In the book, the author defines the evolution as continuous and nonlinear complication of the structure of matter, the types of interaction and environments; analyzes existing in modern science and philosophy approaches to the research of the process of evolution, degree of development of the factors and causes of evolution. Unifying interdisciplinary researches of evolution in cosmology, biology, neuroscience and philosophy, the author presents his vision of the model of «Evolving Matter», which allows us to consider not only the laws of transition of space vacuum in neural ensembles but also to see our Universe as a complication, heterogeneous organization. Interdisciplinary amount of information on the theory of evolution is systematized and a new method of world perception is proposed in the book.

  19. Disposal Of Waste Matter

    International Nuclear Information System (INIS)

    This book deals with disposal of waste matter management of soiled waste matter in city with introduction, definition of waste matter, meaning of management of waste matter, management system of waste matter, current condition in the country, collect and transportation of waste matter disposal liquid waste matter, industrial waste matter like plastic, waste gas sludge, pulp and sulfuric acid, recycling technology of waste matter such as recycling system of Black clawson, Monroe and Rome.

  20. Boundary conditions for star matter and other periodic fermionic systems

    OpenAIRE

    Gulminelli, F.; Furuta, T.; Juillet, O.; Leclercq, C

    2011-01-01

    International audience Bulk fermionic matter, as it can be notably found in supernova matter and neutrons stars, is subject to correlations of infinite range due to the antisymmetrisation of the N-body wave function, which cannot be explicitly accounted for in a practical simulation. This problem is usually addressed in condensed matter physics by means of the so-called Twist Averaged Boundary Condition method. A different ansatz based on the localized Wannier representation has been propo...

  1. Dark Matter from QCD-balls

    CERN Document Server

    Zhitnitsky, A R

    2003-01-01

    We discuss a novel cold dark matter candidate which is formed from the ordinary quarks during the QCD phase transition when the axion domain wall undergoes an unchecked collapse due to the tension in the wall. If a large number of quarks is trapped inside the bulk of a closed axion domain wall, the collapse stops due to the internal Fermi pressure. In this case the system in the bulk, may reach the critical density when it undergoes a phase transition to a color superconducting phase with the ground state being the quark condensate, similar to BCS theory. If this happens, the new state of matter representing the diquark condensate with a large baryon number B > 10^{20} becomes a stable soliton-like configuration. Consequently, it may serve as a novel cold dark matter candidate. We also discuss a possibility that baryogenesis happens exactly at the same instant during the QCD phase transition.

  2. 'Nonbaryonic' dark matter as baryonic colour superconductor

    International Nuclear Information System (INIS)

    We discuss a novel cold dark matter candidate which is formed from the ordinary quarks during the QCD phase transition when the axion domain wall undergoes an unchecked collapse due to the tension in the wall. If a large number of quarks is trapped inside the bulk of a closed axion domain wall, the collapse stops due to the internal Fermi pressure. In this case the system in the bulk, may reach the critical density when it undergoes a phase transition to a colour superconducting phase with the ground state being the quark condensate, similar to BCS theory. If this happens, the new state of matter representing the diquark condensate with a large baryon number B ∼ 1032 becomes a stable soliton-like configuration. Consequently, it may serve as a novel cold dark matter candidate

  3. Couplings between holographic dark energy and dark matter

    OpenAIRE

    Ma, Yin-Zhe; Gong, Yan; Chen, Xuelei

    2009-01-01

    We consider the interaction between dark matter and dark energy in the framework of holographic dark energy, and propose a natural and physically plausible form of interaction, in which the interacting term is proportional to the product of the powers of the dark matter and dark energy densities. We investigate the cosmic evolution in such models. The impact of the coupling on the dark matter and dark energy components may be asymmetric. While the dark energy decouples from the dark matter at...

  4. Testing Alternative Theories of Dark Matter with the CMB

    OpenAIRE

    Li, Baojiu; Barrow, John D.; Mota, David F.; Zhao, HongSheng

    2008-01-01

    We propose a method to study and constrain modified gravity theories for dark matter using CMB temperature anisotropies and polarization. We assume that the theories considered here have already passed the matter power-spectrum test of large-scale structure. With this requirement met, we show that a modified gravity theory can be specified by parametrizing the time evolution of its dark-matter density contrast, which is completely controlled by the dark matter stress history. We calculate how...

  5. Cavitation instability in bulk metallic glasses

    Directory of Open Access Journals (Sweden)

    Dai L.H.

    2015-01-01

    Full Text Available Recent experiments have shown that fracture surfaces of bulk metallic glasses (BMGs usually exhibit an intriguing nanoscale corrugation like fractographic feature mediated by nanoscale void formation. We attribute the onset of this nanoscale corrugation to TTZs (tension transformation zones mediated cavitation. In our recent study, the spall experiments of Zr-based BMG using a single-stage light gas gun were performed. To uncover the mechanisms of the spallation damage nucleation and evolution, the samples were designed to be subjected to dynamic tensile loadings of identical amplitude but with different durations by making use of the multi-stress pulse and the double-flyer techniques. It is clearly revealed that the macroscopic spall fracture in BMGs originates from the nucleation, growth and coalescence of micro-voids. Then, a microvoid nucleation model of BMGs based on free volume theory is proposed, which indicates that the nucleation of microvoids at the early stage of spallation in BMGs is resulted from diffusion and coalescence of free volume. Furthermore, a theoretical model of void growth in BMGs undergoing remote dynamic hydrostatic tension is developed. The critical condition of cavitation instability is obtained. It is found that dynamic void growth in BMGs can be well controlled by a dimensionless inertial number characterizing the competition between intrinsic and extrinsic time scales. To unveil the atomic-level mechanism of cavitation, a systematic molecular dynamics (MD simulation of spallation behaviour of a binary metallic glass with different impact velocities was performed. It is found that micro-void nucleation is determined TTZs while the growth is controlled by shear transformation zones (STZs at atomic scale.

  6. Cavitation instability in bulk metallic glasses

    Science.gov (United States)

    Dai, L. H.; Huang, X.; Ling, Z.

    2015-09-01

    Recent experiments have shown that fracture surfaces of bulk metallic glasses (BMGs) usually exhibit an intriguing nanoscale corrugation like fractographic feature mediated by nanoscale void formation. We attribute the onset of this nanoscale corrugation to TTZs (tension transformation zones) mediated cavitation. In our recent study, the spall experiments of Zr-based BMG using a single-stage light gas gun were performed. To uncover the mechanisms of the spallation damage nucleation and evolution, the samples were designed to be subjected to dynamic tensile loadings of identical amplitude but with different durations by making use of the multi-stress pulse and the double-flyer techniques. It is clearly revealed that the macroscopic spall fracture in BMGs originates from the nucleation, growth and coalescence of micro-voids. Then, a microvoid nucleation model of BMGs based on free volume theory is proposed, which indicates that the nucleation of microvoids at the early stage of spallation in BMGs is resulted from diffusion and coalescence of free volume. Furthermore, a theoretical model of void growth in BMGs undergoing remote dynamic hydrostatic tension is developed. The critical condition of cavitation instability is obtained. It is found that dynamic void growth in BMGs can be well controlled by a dimensionless inertial number characterizing the competition between intrinsic and extrinsic time scales. To unveil the atomic-level mechanism of cavitation, a systematic molecular dynamics (MD) simulation of spallation behaviour of a binary metallic glass with different impact velocities was performed. It is found that micro-void nucleation is determined TTZs while the growth is controlled by shear transformation zones (STZs) at atomic scale.

  7. Hard-body models of bulk liquid crystals.

    Science.gov (United States)

    Mederos, Luis; Velasco, Enrique; Martínez-Ratón, Yuri

    2014-11-19

    Hard models for particle interactions have played a crucial role in the understanding of the structure of condensed matter. In particular, they help to explain the formation of oriented phases in liquids made of anisotropic molecules or colloidal particles and continue to be of great interest in the formulation of theories for liquids in bulk, near interfaces and in biophysical environments. Hard models of anisotropic particles give rise to complex phase diagrams, including uniaxial and biaxial nematic phases, discotic phases and spatially ordered phases such as smectic, columnar or crystal. Also, their mixtures exhibit additional interesting behaviours where demixing competes with orientational order. Here we review the different models of hard particles used in the theory of bulk anisotropic liquids, leaving aside interfacial properties and discuss the associated theoretical approaches and computer simulations, focusing on applications in equilibrium situations. The latter include one-component bulk fluids, mixtures and polydisperse fluids, both in two and three dimensions, and emphasis is put on liquid-crystal phase transitions and complex phase behaviour in general. PMID:25335432

  8. Bulk and shear viscosities of hot and dense hadron gas

    International Nuclear Information System (INIS)

    We estimate the bulk and the shear viscosity at finite temperature and baryon densities of hadronic matter within a hadron resonance gas model which includes a Hagedorn spectrum. The parameters of the Hagedorn spectrum are adjusted to fit recent lattice QCD simulations at finite chemical potential. For the estimation of the bulk viscosity we use low energy theorems of QCD for the energy momentum tensor correlators. For the shear viscosity coefficient, we estimate the same using molecular kinetic theory to relate the shear viscosity coefficient to average momentum of the hadrons in the hot and dense hadron gas. The bulk viscosity to entropy ratio increases with chemical potential and is related to the reduction of velocity of sound at nonzero chemical potential. The shear viscosity to entropy ratio on the other hand, shows a nontrivial behavior with the ratio decreasing with chemical potential for small temperatures but increasing with chemical potential at high temperatures and is related to decrease of entropy density with chemical potential at high temperature due to finite volume of the hadrons

  9. Dark matter.

    Science.gov (United States)

    Peebles, P James E

    2015-10-01

    The evidence for the dark matter (DM) of the hot big bang cosmology is about as good as it gets in natural science. The exploration of its nature is now led by direct and indirect detection experiments, to be complemented by advances in the full range of cosmological tests, including judicious consideration of the rich phenomenology of galaxies. The results may confirm ideas about DM already under discussion. If we are lucky, we also will be surprised once again. PMID:24794526

  10. Relative entropy equals bulk relative entropy

    CERN Document Server

    Jafferis, Daniel L; Maldacena, Juan; Suh, S Josephine

    2015-01-01

    We consider the gravity dual of the modular Hamiltonian associated to a general subregion of a boundary theory. We use it to argue that the relative entropy of nearby states is given by the relative entropy in the bulk, to leading order in the bulk gravitational coupling. We also argue that the boundary modular flow is dual to the bulk modular flow in the entanglement wedge, with implications for entanglement wedge reconstruction.

  11. Coupling brane fields to bulk supergravity

    International Nuclear Information System (INIS)

    In this note we present a simple, general prescription for coupling brane localized fields to bulk supergravity. We illustrate the procedure by considering 6D N=2 bulk supergravity on a 2D orbifold, with brane fields localized at the fixed points. The resulting action enjoys the full 6D N=2 symmetries in the bulk, and those of 4D N=1 supergravity at the brane positions. (orig.)

  12. Coupling brane fields to bulk supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Parameswaran, Susha L. [Uppsala Univ. (Sweden). Theoretical Physics; Schmidt, Jonas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-12-15

    In this note we present a simple, general prescription for coupling brane localized fields to bulk supergravity. We illustrate the procedure by considering 6D N=2 bulk supergravity on a 2D orbifold, with brane fields localized at the fixed points. The resulting action enjoys the full 6D N=2 symmetries in the bulk, and those of 4D N=1 supergravity at the brane positions. (orig.)

  13. Galaxy formation and chemical evolution

    OpenAIRE

    2014-01-01

    The manner the galaxy accretes matter along with the star formation rates at different epochs, influence the evolution of the stable isotopic inventories of the galaxy. A detailed analysis is presented here to study the dependence of the galactic chemical evolution on the accretion scenario of the galaxy along with the star formation rate during the early accretionary phase of the galactic thick disk and thin disk. Our results indicate that a rapid early accretion of the galaxy during the for...

  14. Bulk scalar field in DGP braneworld cosmology

    CERN Document Server

    Ansari, Rizwan ul Haq

    2007-01-01

    We investigated the effects of bulk scalar field in the braneworld cosmological scenario. The Friedmann equations and acceleration condition in presence of the bulk scalar field for a zero tension brane and cosmological constant are studied. In DGP model the effective Einstein equation on the brane is obtained with bulk scalar field. The rescaled bulk scalar field on the brane in the DGP model behaves as an effective four dimensional field, thus standard type cosmology is recovered. In present study of the DGP model, the late-time accelerating phase of the universe can be explained .

  15. First-principles investigation of diffusion behaviours of H isotopes: From W(110) surface into bulk and in bulk W

    International Nuclear Information System (INIS)

    The diffusion behaviours of hydrogen (H), deuterium (D), and tritium (T) from W(110) surface into bulk and in bulk W are investigated using first-principles calculations combined with simplified models. The diffusion energy barrier is shown to be 1.87 eV from W(110) surface to the subsurface, along with a much reduced barrier of 0.06 eV for the reverse diffusion process. After H enters into the bulk, its diffusion energy barrier with quantum correction is 0.19 eV. In terms of the diffusion theory presented by Wert and Zener, the diffusion pre-exponential factor of H is calculated to be 1.57×10−7 m2·s−1, and it is quantitatively in agreement with the experimental value of 4.1×10−7 m2·s−1. Subsequently, according to mass dependence (√1/m) of H isotope effect, the diffusion pre-exponential factors of D and T are estimated to be 1.11×10−7 m2·s−1 and 0.91×10−7 m2·s−1, respectively. (condensed matter: structural, mechanical, and thermal properties)

  16. Bulk viscosity for pion and nucleon thermal fluctuation in the hadron resonance gas model

    CERN Document Server

    Ghosh, Sabyasachi; Mohanty, Bedangdas

    2016-01-01

    We have calculated microscopically bulk viscosity of hadronic matter, where equilibrium thermodynamics for all hadrons in medium are described by Hadron Resonance Gas (HRG) model. Considering pions and nucleons as abundant medium constituents, we have calculated their thermal widths, which inversely control the strength of bulk viscosities for respective components and represent their in-medium scattering probabilities with other mesonic and baryonic resonances, present in the medium. Our calculations show that bulk viscosity increases with both temperature and baryon chemical potential, whereas viscosity to entropy density ratio decreases with temperature and with baryon chemical potential, the ratio increases first and then decreases. The decreasing nature of the ratio with temperature is observed in most of the earlier investigations with few exceptions. We find that the temperature dependence of bulk viscosity crucially depends on the structure of the relaxation time. Along the chemical freeze-out line in...

  17. Inflationary Attractor from Tachyonic Matter

    CERN Document Server

    Guo, Z K; Cai, R G; Zhang, Y Z; Guo, Zong-Kuan; Piao, Yun-Song; Cai, Rong-Gen; Zhang, Yuan-Zhong

    2003-01-01

    We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behaviour of the tachyonic inflation using the Hamilton-Jacobi formalism. We else obtain analytical approximations to the trajectories of the tachyon field in different regions. The numerical calculation shows that an initial non-vanishing momentum does not prevent the onset of inflation. The slow-rolling solution is an attractor.

  18. Inflationary attractor from tachyonic matter

    Science.gov (United States)

    Guo, Zong-Kuan; Piao, Yun-Song; Cai, Rong-Gen; Zhang, Yuan-Zhong

    2003-08-01

    We study the complete evolution of a flat and homogeneous universe dominated by tachyonic matter. We demonstrate the attractor behavior of tachyonic inflation using the Hamilton-Jacobi formalism. We also obtain analytical approximations for the trajectories of the tachyon field in different regions. The numerical calculation shows that an initial nonvanishing momentum does not prevent the onset of inflation. The slow-rolling solution is an attractor.

  19. Organic matter in the universe

    CERN Document Server

    Kwok, Sun

    2012-01-01

    Authored by an experienced writer and a well-known researcher of stellar evolution, interstellar matter and spectroscopy, this unique treatise on the formation and observation of organic compounds in space includes a spectroscopy refresher, as well as links to geological findings and finishes with the outlook for future astronomical facilities and solar system exploration missions. A whole section on laboratory simulations includes the Miller-Urey experiment and the ultraviolet photolysis of ices.

  20. Predicted bulk composition of petroleum generated by Lower Cretaceous Wealden black shales, Lower Saxony Basin, Germany

    Science.gov (United States)

    Ziegs, Volker; Mahlstedt, Nicolaj; Bruns, Benjamin; Horsfield, Brian

    2015-09-01

    The Berriasian Wealden Shale provides the favourable situation of possessing immature to overmature source rock intervals due to differential subsidence within the Lower Saxony Basin. Hydrocarbon generation kinetics and petroleum physical properties have been investigated on four immature Wealden Shale samples situated in different depth intervals and following the PhaseKinetics approach of di Primio and Horsfield (AAPG Bull 90(7):1031-1058, 2006). Kinetic parameters and phase prediction were applied to a thermally calibrated 1D model of the geodynamic evolution at the location of an overmature well. The immature source rocks of all depth intervals comprise kerogen type I being derived from the lacustrine algae Botryococcus braunii. Bulk kinetics of the lower three depth intervals (sample 2-4) can be described by one single activation energy E a, typical for homogeneous, lacustrine organic matter (OM), whereas sample 1 from the uppermost interval shows a slightly broader E a distribution which hints to a more heterogeneous, less stable OM, but still of lacustrine origin. Predicted physical properties of the generated petroleum fluids are characteristic of variably waxy, black oil possessing GOR's below 100 Sm3/Sm3 and saturations pressures below 150 bar. Petroleum fluids from the more heterogeneous OM-containing sample 1 can always be described by slightly higher values. Based on the occurrence of paraffinic, free hydrocarbons in the uppermost horizon of the overmature well and gas/condensate in the lower 3 depth intervals, two scenarios have been discussed. From the first and least realistic scenario assuming no expulsion from the source rock, it can be deduced that phase separation in the course of uplift can only have occurred in the uppermost interval containing the slightly less stable OM but not in the lower intervals being composed of a more stable OM. Therefore and taking secondary cracking into account, all depth intervals should contain gas

  1. Bulk Laser Material Modification: Towards a Kerfless Laser Wafering Process

    Science.gov (United States)

    LeBeau, James

    Due to the ever increasing relevance of finer machining control as well as necessary reduction in material waste by large area semiconductor device manufacturers, a novel bulk laser machining method was investigated. Because the cost of silicon and sapphire substrates are limiting to the reduction in cost of devices in both the light emitting diode (LED) and solar industries, and the present substrate wafering process results in >50% waste, the need for an improved ingot wafering technique exists. The focus of this work is the design and understanding of a novel semiconductor wafering technique that utilizes the nonlinear absorption properties of band-gapped materials to achieve bulk (subsurface) morphological changes in matter using highly focused laser light. A method and tool was designed and developed to form controlled damage regions in the bulk of a crystalline sapphire wafer leaving the surfaces unaltered. The controllability of the subsurface damage geometry was investigated, and the effect of numerical aperture of the focusing optic, energy per pulse, wavelength, and number of pulses was characterized for a nanosecond pulse length variable wavelength Nd:YAG OPO laser. A novel model was developed to describe the geometry of laser induced morphological changes in the bulk of semiconducting materials for nanosecond pulse lengths. The beam propagation aspect of the model was based on ray-optics, and the full Keldysh multiphoton photoionization theory in conjuncture with Thornber's and Drude's models for impact ionization were used to describe high fluence laser light absorption and carrier generation ultimately resulting in permanent material modification though strong electron-plasma absorption and plasma melting. Although the electron-plasma description of laser damage formation is usually reserved for extremely short laser pulses (precision stage control.

  2. Deformation-strengthening during rolling Cu60Zr20Ti20 bulk metallic glass

    DEFF Research Database (Denmark)

    Cao, Q.P.; Li, J.F.; Hu, Yuyan;

    2007-01-01

    Mechanical strength evolutions during rolling the Cu60Zr20Ti20 bulk metallic glass (BMG) at room temperature (RT) and cryogenic temperature (CT) have been investigated by measuring the microhardness. The hardness slightly increases during the initial rolling stage as a result of the gradually...

  3. Plasma modes and collision frequency - from bulk to cluster

    International Nuclear Information System (INIS)

    Complete text of publication follows. Diagnostics of Coulomb systems in bulk as well as in clusters via transport and optical properties is investigated. Deduction of plasma parameters from line shapes and photoabsorption spectroscopy is discussed. Perturbative calculations as well as molecular dynamics (MD) simulations are applied in order to understand experiments, in particular, on shock-wave or laser induced warm dense matter. Systems of reduced dimensionality are considered with respect to the transition from bulk to cluster. While bulk plasmons cannot be excited via light waves, the more complex structure of longitudinal and transverse collective excitation modes in clusters should be observable via optical investigations. Within a generalized linear response theory, optical properties in bulk are described consistently including collision effects relevant in correlated systems. Going beyond RPA for the dielectric function, the concept of the dynamical collision frequency, which is related to auto correlation functions, is applied. Collisions prove to be of relevance in strongly coupled plasmas. Exemplary, results for line shifts and broadening in bulk systems are presented, in the optical as well as in the X-ray regime. Plasma frequency and collision frequency are well defined quantities in bulk systems. We are interested in their generalization for finite systems, and the application to laser excited clusters. For the evaluation of equilibrium auto-correlation functions at arbitrary coupling strength we apply MD simulation techniques for classical systems. A restricted MD simulations scheme for finite systems has been developed and the spatially resolved momentum auto-correlation spectrum is interpreted in terms of collective electron excitation modes in. Resonance frequencies are calculated and interpreted as rigid oscillation of all electrons and plane wave oscillations as well as so-called breathing modes. Damping rates are discussed. The energy of

  4. Bulk Flows and End of the Dark Ages with the SKA

    CERN Document Server

    Maio, Umberto; Koopmans, Leon V E

    2015-01-01

    The early Universe is a precious probe of the birth of primordial objects, first star formation events and consequent production of photons and heavy elements. Higher-order corrections to the cosmological linear perturbation theory predicts the formation of coherent supersonic gaseous streaming motions at decoupling time. These bulk flows impact the gas cooling process and determine a cascade effect on the whole baryon evolution. By analytical estimates and N-body hydrodynamical chemistry numerical simulations including atomic and molecular evolution, gas cooling, star formation, feedback effects and metal spreading for individual species from different stellar populations according to the proper yields and lifetimes, we discuss the role of these primordial bulk flows at the end of the dark ages and their detectable impacts during the first Gyr in view of the upcoming SKA mission. Early bulk flows can inhibit molecular gas cooling capabilities, suppressing star formation, metal spreading and the abundance of ...

  5. Evaluation quantitative des produits formés lors de l'évolution géochimique de la matière organique Quantitative Evaluation of Products Formed During the Geochemical Evolution of Organic Matter

    Directory of Open Access Journals (Sweden)

    Pelet R.

    2006-11-01

    Full Text Available L'évaluation quantitative des produits mobiles formés lors de l'évolution géochimique de la matière organique est nécessaire parce qu'on ne peut jamais retrouver ces produits en place dans. la roche où ils ont pris naissance. Ils ont, en effet, pu migrer durant l'histoire géologique, et de toute manière une fraction, importante et non connue, se perd lors de la prise des échantillons puis de leur conservation avant analyse. La connaissance de l'analyse d'un état E et d'un état plus évolué E' ne suffit pas pour reconstituer les quantités de produits formés. La pyrolyse type Rock-Eval sur kérogènes, avec détermination du carbone résiduel, permet par contre, à partir d'une hypothèse raisonnable, de calculer les hydrocarbures produits. L'analyse élémentaire permet d'y ajouter CO2, H2O, H2S et N2 (considérés comme seuls produits à côté des hydrocarbures. Une analyse chromatographique sommaire supplémentaire permet d'estimer la composition globale des hydrocarbures. Dans le cas des roches, on propose des techniques de correction de l'effet de matrice pratiquement utilisables et qui permettent de retrouver les résultats précédents, au prix d'une incertitude accrue. The mobile products formed during the geochemical evolution of organic matter must be quantitatively evaluated because these products can never be found in place in the rock where they were formed. Indeed, they may have migrated during geological history, and in any case a large and unknown fraction gets lost when samples are taken and then stored before being analysed. Knowing the elemental analysis of a state E and of a more evolved state E' does not suffice for recreating the amounts of products formed. On the other hand Rock-Eval type pyrolysis of kerogens, including the determination of the residual carbon, can be used to compute the hydrocarbons produced, on the basis of a reasonable hypothesis. Elemental analysis then enables the evaluation of CO2, H2O

  6. Temperature Dependent Nuclear Matter Approach

    International Nuclear Information System (INIS)

    Full text: The nuclear matter approach provides an effective interaction in the presence of a sea of nucleons. Especially it accounts for the Pauli principle which forbids scattering processes into the occupied states of the nucleonic see. It is well suited to describe the bulk properties of nuclei as well as optical potentials beyond 40 MeV incident energy. Difficulties in the description of nucleon-nucleus reactions beyond 70 MeV may indicate the importance of excited doorway states for reaction processes and therefore the optical potentials. In this contribution we consider the g-matrix approach for excited nuclear matter. The g-matrix is evaluated via the Bethe-Goldstone equation with an exact Pauli operator accounting for excitations with arbitrary occupation distributions. The features of the g-matrix with regard to changes in excitation are discussed. (author)

  7. 27 CFR 20.191 - Bulk articles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bulk articles. 20.191... Users of Specially Denatured Spirits Operations by Users § 20.191 Bulk articles. Users who convey articles in containers exceeding one gallon may provide the recipient with a photocopy of subpart G of...

  8. Bulk equations of motion from CFT correlators

    CERN Document Server

    Kabat, Daniel

    2015-01-01

    To O(1/N) we derive, purely from CFT data, the bulk equations of motion for interacting scalar fields and for scalars coupled to gauge fields and gravity. We first uplift CFT operators to mimic local AdS fields by imposing bulk microcausality. This requires adding an infinite tower of smeared higher-dimension double-trace operators to the CFT definition of a bulk field, with coefficients that we explicitly compute. By summing the contribution of the higher-dimension operators we derive the equations of motion satisfied by these uplifted CFT operators and show that we precisely recover the expected bulk equations of motion. We exhibit the freedom in the CFT construction which corresponds to bulk field redefinitions.

  9. Interacting dark energy collapse with matter components separation

    Energy Technology Data Exchange (ETDEWEB)

    Delliou, M. Le [Departamento de Física Matemática, Instituto de Física, Universidade de São Paulo, CP 66.318 — 05314-970, São Paulo, SP (Brazil); Barreiro, T., E-mail: delliou@cii.fc.ul.pt, E-mail: tmbarreiro@ulusofona.pt [Departamento de Matemática da FFMCC, Universidade Lusófona de Humanidades e Tecnologias, Campo Grande, 376 — 1749-024 Lisboa (Portugal)

    2013-02-01

    We use the spherical collapse model of structure formation to investigate the separation in the collapse of uncoupled matter (essentially baryons) and coupled dark matter in an interacting dark energy scenario. Following the usual assumption of a single radius of collapse for all species, we show that we only need to evolve the uncoupled matter sector to obtain the evolution for all matter components. This gives us more information on the collapse with a simplified set of evolution equations compared with the usual approaches. We then apply these results to four quintessence potentials and show how we can discriminate between different quintessence models.

  10. Quantum Information from Graviton-Matter Gas

    Directory of Open Access Journals (Sweden)

    Lukasz-Andrzej Glinka

    2007-09-01

    Full Text Available We present basics of conceptually new-type way for explaining of the origin, evolution and current physical properties of our Universe from the graviton-matter gas viewpoint. Quantization method for the Friedmann-Lemaitre Universe based on the canonical Hamilton equations of motion is proposed and quantum information theory way to physics of the Universe is showed. The current contribution from the graviton-matter gas temperature in quintessence approximation is discussed.

  11. On physical scales of dark matter halos

    International Nuclear Information System (INIS)

    It is common practice to describe formal size and mass scales of dark matter halos as spherical overdensities with respect to an evolving density threshold. Here, we critically investigate the evolutionary effects of several such commonly used definitions and compare them to the halo evolution within fixed physical scales as well as to the evolution of other intrinsic physical properties of dark matter halos. It is shown that, in general, the traditional way of characterizing sizes and masses of halos dramatically overpredicts the degree of evolution in the last 10 Gyr, especially for low-mass halos. This pseudo-evolution leads to the illusion of growth even though there are no major changes within fixed physical scales. Such formal size definitions also serve as proxies for the virialized region of a halo in the literature. In general, those spherical overdensity scales do not coincide with the virialized region. A physically more precise nomenclature would be to simply characterize them by their very definition instead of calling such formal size and mass definitions 'virial'. In general, we find a discrepancy between the evolution of the underlying physical structure of dark matter halos seen in cosmological structure formation simulations and pseudo-evolving formal virial quantities. We question the importance of the role of formal virial quantities currently ubiquitously used in descriptions, models, and relations that involve properties of dark matter structures. Concepts and relations based on pseudo-evolving formal virial quantities do not properly reflect the actual evolution of dark matter halos and lead to an inaccurate picture of the physical evolution of our universe.

  12. Natural implementation of neutralino dark matter

    International Nuclear Information System (INIS)

    The prediction of neutralino dark matter is generally regarded as one of the successes of the Minimal Supersymmetric Standard Model (MSSM). However the successful regions of parameter space allowed by WMAP and collider constraints are quite restricted. We discuss fine-tuning with respect to both dark matter and Electroweak Symmetry Breaking (EWSB) and explore regions of MSSM parameter space with non-universal gaugino and third family scalar masses in which neutralino dark matter may be implemented naturally. In particular allowing non-universal gauginos opens up the bulk region that allows Bino annihilation via t-channel slepton exchange, leading to 'supernatural dark matter' corresponding to no fine-tuning at all with respect to dark matter. By contrast we find that the recently proposed 'well tempered neutralino' regions involve substantial fine-tuning of MSSM parameters in order to satisfy the dark matter constraints, although the fine tuning may be ameliorated if several annihilation channels act simultaneously. Although we have identified regions of 'supernatural dark matter' in which there is no fine tuning to achieve successful dark matter, the usual MSSM fine tuning to achieve EWSB always remains

  13. Influence of an AGN complex photon field on the jet bulk Lorentz factor through Compton rocket effect

    CERN Document Server

    Vuillaume, Thomas; Henri, Gilles

    2014-01-01

    AGNs jets are known to display relativistic motion on parsec scales but the accelerating mechanism as well as the exact bulk Lorentz factor of the flow are still a matter of discussion. Under certain assumptions, a plasma can be accelerated to relativistic speeds through the Compton rocket effect. Here, we study this effect and the resulting bulk Lorentz factor in the complex environment of an AGN including various external sources. This is the proceedings to the IAU Symposium 313.

  14. Stable isotope composition of bulk and secondary carbonates from the Quaternary loess-paleosol sequence in Sutto, Hungary

    DEFF Research Database (Denmark)

    Koeniger, Paul; Barta, Gabriella; Thiel, Christine;

    2014-01-01

    Stable carbon and oxygen isotope composition of pedogenic carbonates were studied from the Quaternary loess-paleosol sequence of Sutto in Hungary to investigate genetic processes in a paleoenvironmental context and to distinguish subtypes. Bulk carbonate samples taken at 2 cm vertical resolution,...... matter or vegetation. Secondary carbonates are more reliable than bulk samples because of their direct connection to the host strata. (C) 2012 Elsevier Ltd and INQUA. All rights reserved....

  15. Bulk scalar field in brane-worlds with induced gravity inspired by the L(R) term

    Energy Technology Data Exchange (ETDEWEB)

    Heydari-Fard, M. [Department of Physics, The University of Qom, Qom 37185-359 (Iran, Islamic Republic of); Sepangi, H.R., E-mail: heydarifard@qom.ac.ir, E-mail: hr-sepangi@sbu.ac.ir [Department of Physics, Shahid Beheshti University, Evin, Tehran 19839 (Iran, Islamic Republic of)

    2009-01-15

    We obtain the effective field equations in a brane-world scenario within the framework of a DGP model where the action on the brane is an arbitrary function of the Ricci scalar, L(R), and the bulk action includes a scalar field in the matter Lagrangian. We obtain the Friedmann equations and acceleration conditions in the presence of the bulk scalar field for the R{sup n} term in four-dimensional gravity.

  16. The Cryogenic Dark Matter Search and Background Rejection with Event Position Information

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gen-sheng

    2005-01-01

    Evidence from observational cosmology and astrophysics indicates that about one third of the universe is matter, but that the known baryonic matter only contributes to the universe at 4%. A large fraction of the universe is cold and non-baryonic matter, which has important role in the universe structure formation and its evolution. The leading candidate for the non-baryonic dark matter is Weakly Interacting Massive Particles (WIMPs), which naturally occurs in the supersymmetry theory in particle physics. The Cryogenic Dark Matter Search (CDMS) experiment is searching for evidence of a WIMP interaction off an atomic nucleus in crystals of Ge and Si by measuring simultaneously the phonon energy and ionization energy of the interaction in the CDMS detectors. The WIMP interaction energy is from a few keV to tens of keV with a rate less than 0.1 events/kg/day. To reach the goal of WIMP detection, the CDMS experiment has been conducted in the Soudan mine with an active muon veto and multistage passive background shields. The CDMS detectors have a low energy threshold and background rejection capabilities based on ionization yield. However, betas from contamination and other radioactive sources produce surface interactions, which have low ionization yield, comparable to that of bulk nuclear interactions. The low-ionization surface electron recoils must be removed in the WIMP search data analysis. An emphasis of this thesis is on developing the method of the surface-interaction rejection using location information of the interactions, phonon energy distributions and phonon timing parameters. The result of the CDMS Soudan run118 92.3 live day WIMP search data analysis is presented, and represents the most sensitive search yet performed.

  17. Thermodynamics of cosmological matter creation.

    Science.gov (United States)

    Prigogine, I; Geheniau, J; Gunzig, E; Nardone, P

    1988-10-01

    A type of cosmological history that includes large-scale entropy production is proposed. These cosmologies are based on reinterpretation of the matter-energy stress tensor in Einstein's equations. This modifies the usual adiabatic energy conservation laws, thereby including irreversible matter creation. This creation corresponds to an irreversible energy flow from the gravitational field to the created matter constituents. This point of view results from consideration of the thermodynamics of open systems in the framework of cosmology. It is shown that the second law of thermodynamics requires that space-time transforms into matter, while the inverse transformation is forbidden. It appears that the usual initial singularity associated with the big bang is structurally unstable with respect to irreversible matter creation. The corresponding cosmological history therefore starts from an instability of the vacuum rather than from a singularity. This is exemplified in the framework of a simple phenomenological model that leads to a three-stage cosmology: the first drives the cosmological system from the initial instability to a de Sitter regime, and the last connects with the usual matter-radiation Robertson-Walker universe. Matter as well as entropy creation occurs during the first two stages, while the third involves the traditional cosmological evolution. A remarkable fact is that the de Sitter stage appears to be an attractor independent of the initial fluctuation. This is also the case for all the physical predictions involving the present Robertson-Walker universe. Most results obtained previously, in the framework of quantum field theory, can now be obtained on a macroscopic basis. It is shown that this description leads quite naturally to the introduction of primeval black holes as the intermediate stage between the Minkowski vacuum and the present matter-radiation universe. The instability at the origin of the universe is the result of fluctuations of the

  18. Asymmetric WIMP dark matter

    OpenAIRE

    Graesser, Michael L.; Shoemaker, Ian M.; Vecchi, Luca

    2011-01-01

    In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymmetric WIMP framewo...

  19. Dark matter candidates

    International Nuclear Information System (INIS)

    One of the simplest, yet most profound, questions we can ask about the Universe is, how much stuff is in it, and further what is that stuff composed of? Needless to say, the answer to this question has very important implications for the evolution of the Universe, determining both the ultimate fate and the course of structure formation. Remarkably, at this late date in the history of the Universe we still do not have a definitive answer to this simplest of questions---although we have some very intriguing clues. It is known with certainty that most of the material in the Universe is dark, and we have the strong suspicion that the dominant component of material in the Cosmos is not baryons, but rather is exotic relic elementary particles left over from the earliest, very hot epoch of the Universe. If true, the Dark Matter question is a most fundamental one facing both particle physics and cosmology. The leading particle dark matter candidates are: the axion, the neutralino, and a light neutrino species. All three candidates are accessible to experimental tests, and experiments are now in progress. In addition, there are several dark horse, long shot, candidates, including the superheavy magnetic monopole and soliton stars. 13 refs

  20. Maxwell Matters

    CERN Document Server

    Eisenberg, Bob

    2016-01-01

    Charges are everywhere because most atoms are charged. Chemical bonds are formed by electrons with their charge. Charges move and interact according to Maxwell's equations in space and in atoms where the equations of electrodynamics are embedded in Schroedinger's equation as the potential. Maxwell's equations are universal, valid inside atoms and between stars from times much shorter than those of atomic motion (0.1 femtoseconds) to years (32 mega-seconds). Maxwell's equations enforce the conservation of current. Analysis shows that the electric field can take on whatever value is needed to ensure conservation of current. The properties of matter rearrange themselves to satisfy Maxwell's equations and conservation of current. Conservation of current is as universal as Maxwell's equations themselves. Yet equations of electrodynamics find little place in the literature of material physics, chemistry, or biochemistry. Kinetic models of chemistry and Markov treatments of atomic motion are ordinary differential eq...

  1. Bulk Viscosity in Holographic Lifshitz Hydrodynamics

    CERN Document Server

    Hoyos, Carlos; Oz, Yaron

    2013-01-01

    We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical exponent and the hyperscaling violation exponent.

  2. Bulk viscosity in holographic Lifshitz hydrodynamics

    OpenAIRE

    Carlos Hoyos; Bom Soo Kim; Yaron Oz

    2014-01-01

    We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical ...

  3. Bulk viscosity in holographic Lifshitz hydrodynamics

    International Nuclear Information System (INIS)

    We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical exponent and the hyperscaling violation exponent

  4. Bulk viscosity of hot and dense hadrons

    International Nuclear Information System (INIS)

    The bulk viscosity of hot and dense hadrons has been estimated within the framework of hadronic resonance gas model. We observe that the bulk viscosity to entropy ratio increases faster with temperature for higher μB. The magnitude of ζ is more at high μB. This results will have crucial importance for fire-ball produced at low energy nuclear collisions (FAIR, NICA). We note that the bulk to shear viscosity ratio remains above the bound set by AdS/CFT

  5. Dark matter superfluid and DBI dark energy

    CERN Document Server

    Cai, Rong-Gen

    2016-01-01

    It was shown recently that, without jeopardizing the success of the $\\Lambda$CDM model on cosmic scales, the MOdified Newtonian Dynamics (MOND) can be derived as an emergent phenomenon when axion-like dark matter particles condense into superfluid on galactic scales. We propose in this letter a Dirac-Born-Infeld (DBI) dark energy conformally coupled to local matter components to solve both galactic and cosmic coincidences that the MOND critical acceleration coincides with present Hubble scale and the matter energy density coincides with dark energy density today. The cosmological evolution of DBI dark energy behaves as a freezing Chaplygin gas and approaches to a cosmological constant in the asymptotic future.

  6. Mind and matter.

    Science.gov (United States)

    Freris, Leon

    2013-11-01

    In the View Point article of Reference 1, the editor of CIB was kind enough to let me express my views on the topic of Darwinian evolution. Since then and mainly through contacts generated by that article, I felt that there was more to be said on this topic. The editor was kind enough to allow me to air my views again.   I have no qualifications in biology or philosophy, so the readers of CIB may find that some of the material on evolution in this article is well-known territory to them, but for me it was a part of the unfolding story that informed my understanding and led me to some conclusions. My thesis is that the explanations based on the present materialist/reductionist views on how experiential qualities developed out of inert matter are unconvincing and that an alternative viewpoint offers a more parsimonious and logically coherent account. The article presents my rearrangement of material contained or taken from references 2, 4, 5, and 6 linked by my own commentary. For a better-argued and ultimately more convincing exposition of the views in this article the interested reader should study the references. PMID:24505505

  7. Entanglement Entropy Evolution under Double-trace Deformation

    OpenAIRE

    Song, Yushu

    2016-01-01

    In this paper, we study the bulk entanglement entropy evolution in conical BTZ black bole background using the heat kernel method. This is motivated by exploring the new examples where quantum corrections of entanglement entropy give the leading contribution. We find that in the large black hole limit the bulk entanglement entropy decreases under the double-trace deformation which is consistent with the holographic $c$ theorem and in the small black hole limit the bulk entanglement entropy in...

  8. Bulk and surface sensitivities of surface plasmon waveguides

    International Nuclear Information System (INIS)

    The potential of surface plasmon waveguides for bulk and surface (bio)chemical sensing was assessed theoretically, anticipating their use in an integrated optics sensor such as a Mach-Zehnder interferometer (MZI). The performance of a generic MZI implemented with attenuating waveguides was assessed initially, revealing that attenuating waveguides constrain the sensing length to an optimal length equal to the propagation length of the mode used. The MZI sensitivities for bulk and surface sensing were found to be proportional to the ratio of the waveguide sensitivity to its normalized attenuation: H=(∂neff/∂nc)/keff for bulk sensing and G=(∂neff/∂a)/keff for surface sensing. Maximizing H or G maximizes the corresponding MZI sensitivity and minimizes its detection limit, leading to preferred waveguide designs and operating wavelengths. The propagation constant, the sensitivities, and the H and G parameters were then determined for the surface plasmon in the single interface, the sb mode in the metal-insulator-metal (MIM) waveguide and the sb mode in three variants of the insulator-metal-insulator (IMI) waveguide, as a function of dimensions, for wavelengths spanning 600≤λ0≤1600 nm, assuming Au and H2O as the materials and adlayers representative of biochemical matter. The principal findings are: (i) the surface sensitivity in the thin MIM can be 100x larger than in the single interface, whereas that in the thin IMI is up to 5x smaller; (ii) the bulk sensitivity in the thin MIM can be 3x larger than in the single interface, whereas that in the IMI is slightly smaller; (iii) G in the thin MIM can be 3x larger than in the single interface, whereas G in the IMI is about 10x larger; and (iv) H in the thin MIM can be 10x smaller than in the single interface, whereas H in the thin IMI is about 10x larger. The IMI and the MIM both offer an improvement in sensitivity and detection limit for surface sensing over the single interface in an integrated MZI (or

  9. Hot and flowing, asymmetric nuclear matter

    International Nuclear Information System (INIS)

    We develop a consistent treatment for hot and flowing asymmetric nuclear matter. Using the mean-field theory, predictions of the σ- ω Walecka model at finite temperature are compared with the corresponding results of the Zimanyi-Moszlowski and the non-linear models. The statistical theory of grand-canonical potentials is incorporated to the formalism. We also describe the behavior, at finite temperature, of the asymmetric and flowing nuclear matter. As an application, we describe bulk properties of neutron and protoneutron stars by considering the Tolman-Oppenheimer-Volkoff equations. (author)

  10. Overview and highlights of bulk correlations at STAR

    Science.gov (United States)

    McDonald, Daniel

    2015-08-01

    The first phase of the Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider (RHIC) was completed during the years 2010, 2011 and 2014, with Au+Au collisions at center-of-mass energies () of 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV. The BES has three distinct goals: search for the turning off of the signatures of the Quark Gluon Plasma (QGP), search for the first-order phase transition, and search for the critical point of nuclear matter. We report several interesting results on each of these fronts. In addition, we report the first bulk correlation results from U+U collisions at STAR from a three week exploratory run in 2012.

  11. Thermal Fluctuations of Dark Matter in Bouncing Cosmology

    CERN Document Server

    Li, Changhong

    2015-01-01

    We investigate the statistical nature of the dark matter particles produced in bouncing cosmology, including its total energy and the evolution of its sub-horizon and super-horizon thermal fluctuations. We find that the super-horizon modes of the dark matter thermal perturbations are developing during the generic bouncing universe scenario--in contrast to the case that no significant super-horizon thermal perturbations of dark matter appear in the inflation scenario such as WIMP(-less) miracles. By explicitly deriving and solving the equation of motion of super-horizon mode, we fully determine the evolution of thermal perturbation of dark matter in a generic bouncing background. And we also prove that the evolution of super-horizon modes is stable and will not ruin out the background evolution till the Planck scale.

  12. Sirius Matters

    CERN Document Server

    Brosch, Noah

    2008-01-01

    Since very early times Sirius was a point of attraction in the night sky. It served to synchronize calendars in antiquity and was the subject of many myths and legends, including some modern ones. It was perceived as a red star for more than 400 years, but such reports were relegated to the Mediterranean region. Astronomically, Sirius is a very bright star. This, and its present close distance to us, argues in favor of it being the target of detailed studies of stellar structure and evolution. Its binary nature, with a companion that is one of the more massive white dwarfs, is an additional reason for such studies. This book collects the published information on Sirius in an attempt to derive a coherent picture of how this system came to look as it does.

  13. Technical specifications for the bulk shielding reactor

    International Nuclear Information System (INIS)

    This report provides information concerning the technical specifications for the Bulk Shielding Reactor. Areas covered include: safety limits and limiting safety settings; limiting conditions for operation; surveillance requirements; design features; administrative controls; and monitoring of airborne effluents. 10 refs

  14. The bulk radio expansion of Cassiopeia A

    International Nuclear Information System (INIS)

    Comparison, in the visibility plane, or radio observations of Cassiopeia A made at 151 MHz over a 2.3 yr interval indicates that the bulk of the radio emitting material has not been decelerated strongly

  15. PHONON ECHOES IN BULK AND POWDERED MATERIALS

    OpenAIRE

    Kajimura, K.

    1981-01-01

    Experimental and theoretical studies of phonon echoes in bulk and powdered materials are reviewed. Phonon echoes have been observed in many materials such as bulk piezoelectric crystals, paramagnets, glasses, doped semiconductors, and piezoelectric, magnetic, and metallic powders, etc. The echoes arise from a time reversal of the phase, like spin echoes, of a primary pulsed acoustic excitation due to a second acoustic or rf pulse. The phase reversal occurs through the nonlinear interactions o...

  16. An intrinsic mobility ceiling of Si bulk

    OpenAIRE

    Garcia-Castello, Nuria; Prades, Joan Daniel; Cirera, Albert

    2011-01-01

    We compute by Density Functional Theory-Non Equilibrium Green Functions Formalism (DFT-NEGFF) the conductance of bulk Si along different crystallographic directions. We find a ceiling value for the intrinsic mobility of bulk silicon of $8.4\\cdot10^6 cm^2/V\\cdot s$. We suggest that this result is related to the lowest effective mass of the $$ direction.

  17. Effect of bulking agents on maturity and gaseous emissions during kitchen waste composting.

    Science.gov (United States)

    Yang, Fan; Li, Guo Xue; Yang, Qing Yuan; Luo, Wen Hai

    2013-10-01

    This study investigated the effect of bulking agents on the maturity and gaseous emissions of composting kitchen waste. Three different bulking agents (cornstalks, sawdust, and spent mushroom substrate) were used to compost kitchen waste under aerobic conditions in 60-L reactors for a 28-d period. A control treatment was also studied using kitchen waste without a bulking agent. During the experiment, maturity indexes such as temperature, pH value, C/N ratio, and germination index were determined, and continuous measurements of leachate and gaseous emissions (CH₄, N₂O, and NH₃) were taken. The results showed that all of the composts with bulking agents reached the required maturity standard, and the addition of spent mushroom substrate gave the highest maturity (C/N ratio decreased from 23 to 16 and germination index increased from 53% to 111%). The bulking agents also reduced leachate production and CH₄ and N₂O emissions, but had little impact on NH3 emissions. Composting with sawdust as a bulking agent was found to emit less total greenhouse gas (33 kg CO₂-eqt(-1) dry matter) than the other treatments. PMID:24001663

  18. Effectiveness of three bulking agents for food waste composting

    International Nuclear Information System (INIS)

    Rather than landfilling, composting the organic fraction of municipal solid wastes recycles the waste as a safe and nutrient enriched soil amendment, reduces emissions of greenhouse gases and generates less leachate. The objective of this project was to investigate the composting effectiveness of three bulking agents, namely chopped wheat (Triticum) straw, chopped mature hay consisting of 80% timothy (milium) and 20% clover (triphullum) and pine (pinus) wood shavings. These bulking agents were each mixed in duplicates at three different ratios with food waste (FW) and composted for 10 days using prototype in-vessel composters to observe their temperature and pH trends. Then, each mixture was matured in vertical barrels for 56 days to measure their mass loss and final nutrient content and to visually evaluate their level of decomposition. Chopped wheat straw (CWS) and chopped hay (CH) were the only two formulas that reached thermophilic temperatures during the 10 days of active composting when mixed with FW at a wet mass ratio of 8.9 and 8.6:1 (FW:CWS and FW:CH), respectively. After 56 days of maturation, these two formulas were well decomposed with no or very few recognizable substrate particles, and offered a final TN exceeding the original. Wood shavings (WS) produced the least decomposed compost at maturation, with wood particles still visible in the final product, and with a TN lower than the initial. Nevertheless, all bulking agents produced compost with an organic matter, TN, TP and TK content suitable for use as soil amendment

  19. Osmotic pressure of matter and vacuum energy

    CERN Document Server

    Volovik, G E

    2009-01-01

    The walls of the box which contains matter represent a membrane that allows the relativistic quantum vacuum to pass but not matter. That is why the pressure of matter in the box may be considered as the analog of the osmotic pressure. However, we demonstrate that the osmotic pressure of matter is modified due to interaction of matter with vacuum. This interaction induces the nonzero negative vacuum pressure inside the box, as a result the measured osmotic pressure becomes smaller than the matter pressure. As distinct from the Casimir effect, this induced vacuum pressure is the bulk effect and does not depend on the size of the box. This effect dominates in the thermodynamic limit of the infinite volume of the box. Analog of this effect has been observed in the dilute solution of 3He in liquid 4He, where the superfluid 4He plays the role of the non-relativistic quantum vacuum, and 3He atoms play the role of matter.

  20. Meteorite zircon constraints on the bulk Lu−Hf isotope composition and early differentiation of the Earth

    OpenAIRE

    Iizuka, Tsuyoshi; Yamaguchi, Takao; Hibiya, Yuki; Amelin, Yuri

    2015-01-01

    The radioactive decay of lutetium-176 to hafnium-176 has been used to study Earth’s crust−mantle differentiation that is the primary agent of the chemical and thermal evolution of the silicate Earth. Yet the data interpretation requires a well-defined hafnium isotope growth curve of the bulk Earth, which is notoriously difficult to reconstruct from the variable bulk compositions of undifferentiated chondrite meteorites. Here we use lutetium–hafnium systematics of meteorite zircon crystals to ...

  1. Mind Over Matter: Methamphetamine

    Science.gov (United States)

    ... Over Matter Teaching Guide and Series / Methamphetamine Print Mind Over Matter: Methamphetamine (Meth) Order Free Publication in: ... someday you'll make the next major breakthrough. Mind Over Matter is produced by the National Institute ...

  2. Mind Over Matter: Cocaine

    Science.gov (United States)

    ... Over Matter Teaching Guide and Series / Cocaine Print Mind Over Matter: Cocaine Order Free Publication in: English ... how drugs affect the brain and nervous system. Mind Over Matter is produced by the National Institute ...

  3. Baryonic matter and beyond

    CERN Document Server

    Fukushima, Kenji

    2014-01-01

    We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

  4. Galaxy formation and evolution

    CERN Document Server

    Mo, Houjun; White, Simon

    2010-01-01

    The rapidly expanding field of galaxy formation lies at the interface between astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual chapters explore the evolution of the Universe as a whole and its particle and radiation content; linear and nonlinear growth of cosmic structure; processes affecting the gaseous and dark matter components of galaxies and their stellar populations; the formation of spiral and elliptical galaxies; central supermassive black holes and the activity associated with them; galaxy interactions; and the intergalactic medium. Emphasizing both observational and theoretical aspects, this book provides a coherent introduction for astronomers, cosmologists, and astroparticle physicists to the broad range of science underlying the formation and evolution of galaxies.

  5. Evolution of mycorrhiza systems

    Science.gov (United States)

    Cairney, J. W. G.

    Most terrestrial plants live in mutualistic symbiosis with root-infecting mycorrhizal fungi. Fossil records and molecular clock dating suggest that all extant land plants have arisen from an ancestral arbuscular mycorrhizal condition. Arbuscular mycorrhizas evolved concurrently with the first colonisation of land by plants some 450-500 million years ago and persist in most extant plant taxa. Ectomycorrhizas (about 200million years ago) and ericoid mycorrhizas (about 100million years ago) evolved subsequently as the organic matter content of some ancient soils increased and sclerophyllous vegetation arose as a response to nutrient-poor soils respectively. Mycorrhizal associations appear to be the result of relatively diffuse coevolutionary processes. While early events in the evolution of mycorrhizal symbioses may have involved reciprocal genetic changes in ancestral plants and free-living fungi, available evidence points largely to ongoing parallel evolution of the partners in response to environmental change.

  6. Fermion Portal Dark Matter

    OpenAIRE

    Bai, Yang; Berger, Joshua(SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA)

    2013-01-01

    We study a class of simplified dark matter models in which one dark matter particle couples with a mediator and a Standard Model fermion. In such models, collider and direct detection searches probe complimentary regions of parameter space. For Majorana dark matter, direct detection covers the region near mediator-dark matter degeneracy, while colliders probe regions with a large dark matter and mediator mass splitting. For Dirac and complex dark matter, direct detection is effective for the ...

  7. Black Holes as Dark Matter Annihilation Boosters

    OpenAIRE

    Mattia FornasaINFN Padova, IAP; Gianfranco Bertone(IAP)

    2007-01-01

    We review the consequences of the growth and evolution of Black Holes on the distribution of stars and Dark Matter (DM) around them. We focus in particular on Supermassive and Intermediate Mass Black Holes, and discuss under what circumstances they can lead to significant overdensities in the surrounding distribution of DM, thus effectively acting as DM annihilation boosters.

  8. Organic matter and soil moisture content and double cropping with organic matter sourceplants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2005-05-01

    Full Text Available Double cropping of coffee with organic matter source plants is thought to increase organic matter content of soil. This study examined the effect of double cropping of coffee and organic matter source plants on soil organic matter content and yield of coffee plants. Arabica coffee trees in Andungsari Experimental Station (Bondowoso district, 1400 m asl. and climate type C; and Robusta coffee trees in Sumberasin Experimental Station (Malang district, 550 m asl. and climate type C, were used as experimental sites of this study which lasted for five years. Organic matter source plants consisted of some species that can be routinedly pruned and surface applied to coffee soil, and other creeping species that not being pruned, however the organic matter source derived from their fallen leaves. Application of farm manure and control (neither organic matter source plants nor farm yard manure were used as comparison treatments. Results indicate that Ramayana (Cassia spectabilis had vigorus growth resulting in greater biomass production compared to lamtoro (Leucaena leucocephala, mogania (Moghania macrophylla and even kaliandra (Calyandra calothyrsus which produced greater biomass among organic matter source plants grown in Arabica coffee farming. Double cropping of coffee with organic matter source plants did not affect soil organic matter content of Arabica and Robusta coffee farmings, though farm yard manure application increased soil organic matter content and soil bulk density, especially of Robusta coffee farm. Soil moisture content examined in dry season was not affected by double cropping. In contrary, Robusta coffee farm applied with farm yard manure had higher soil moisture content. At Arabica coffee farm, double cropping did not influence green coffee yield, on the other hand Ramayana reduced green coffee yield of Robusta coffee while farm yard manure increased the yield.Keywords : Coffeea arabica, Coffeea canephora, organic matter, soil

  9. B¯→Xsγ with a warped bulk Higgs

    Directory of Open Access Journals (Sweden)

    P. Moch

    2016-01-01

    Full Text Available We study the decay B¯→Xsγ in Randall–Sundrum models with an IR-localised bulk Higgs. The two models under consideration are a minimal model and a model with a custodial protection mechanism. We include the effects of tree- and one-loop diagrams involving 5D gluon and Higgs exchanges as well as QCD corrections arising from the evolution from the Kaluza–Klein scale to the typical scale of the decay. We find the RS corrections to the branching fraction can be sizeable for large Yukawas and moderate KK scales T; for small Yukawas the RS contribution is small enough to be invisible in current experimental data.

  10. Higgs quartic coupling and neutrino sector evolution in 2UED models

    CERN Document Server

    Abdalgabar, Ammar; Deandrea, Aldo; Tarhini, Ahmad

    2013-01-01

    Two compact universal extra dimensional models are an interesting class of models for different theoretical and phenomenological issues, such as the justification of having three standard model fermion families, suppression of proton decay rate, dark matter parity from relics of the 6-dimensional Lorentz symmetry, origin of masses and mixings in the standard model. However, these theories are merely effective ones, with typically a reduced range of validity in their energy scale. We explore two limiting cases of the three standard model generations all propagating in the bulk or all localised to a brane, from the point of view of renormalisation group equation evolutions for the Higgs sector and for the neutrino sector of these models. The recent experimental results of the Higgs boson from the LHC allow, in some scenarios, stronger constraints on the cut-off scale to be placed, from the requirement of the stability of the Higgs potential.

  11. Higgs quartic coupling and neutrino sector evolution in 2UED models

    KAUST Repository

    Abdalgabar, A.

    2014-05-20

    Two compact universal extra-dimensional models are an interesting class of models for different theoretical and phenomenological issues, such as the justification of having three standard model fermion families, suppression of proton decay rate, dark matter parity from relics of the six-dimensional Lorentz symmetry, origin of masses and mixings in the standard model. However, these theories are merely effective ones, with typically a reduced range of validity in their energy scale. We explore two limiting cases of the three standard model generations all propagating in the bulk or all localised to a brane, from the point of view of renormalisation group equation evolutions for the Higgs sector and for the neutrino sector of these models. The recent experimental results of the Higgs boson from the LHC allow, in some scenarios, stronger constraints on the cutoff scale to be placed, from the requirement of the stability of the Higgs potential. 2014 The Author(s).

  12. CHARACTERIZATION OF BULK SOIL HUMIN AND ITS ALKALINE-SOLUBLE AND ALKALINE-INSOLUBLE FRACTIONS

    OpenAIRE

    Cuilan Li; Shuqing Gao; Qiang Gao,; Lichun Wang; Jinjing Zhang

    2015-01-01

    Humic substances are the major components of soil organic matter. Among the three humic substance components (humic acid, fulvic acid, and humin), humin is the most insoluble in aqueous solution at any pH value and, in turn, the least understood. Humin has poor solubility mainly because it is tightly bonded to inorganic soil colloids. By breaking the linkage between humin and inorganic soil colloids using inorganic or organic solvents, bulk humin can be partially soluble in alkali, enabling a...

  13. Magneto-transmission as a probe of Dirac fermions in bulk graphite

    Czech Academy of Sciences Publication Activity Database

    Orlita, Milan; Faugeras, C.; Martinez, G.; Maude, D. K.; Sadowski, M.L.; Schneider, J.M.; Potemski, M.

    2008-01-01

    Roč. 20, č. 45 (2008), 454223/1-454223/4. ISSN 0953-8984 R&D Projects: GA AV ČR KAN400100652 Grant ostatní: EC(XE) RITA-CT-2003-505474; ANR(FR) ANR-06- NANO -019 Institutional research plan: CEZ:AV0Z10100521 Keywords : bulk graphite * Dirac fermions * magnetic field Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.900, year: 2008

  14. Cosmological constraints on the matter equation of state

    International Nuclear Information System (INIS)

    We investigate the impact of a nonstandard time evolution of the dark matter component on current cosmological bounds from cosmic microwave background (CMB) anisotropies. We found that a less than 0.1% variation in the effective dark matter equation of state wdm can drastically change current CMB bounds on the matter density, the Hubble parameter and the age of the Universe. A flat universe without dark energy could provide an excellent fit to current CMB data, providing that wdm∼-10-2.

  15. First order phase transition of expanding matter and its fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Chikazumi, Shinpei [Tsukuba Univ., Institute of Physics, Tsukuba, Ibaraki (Japan); Iwamoto, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-09-01

    Using an expanding matter model with a Lennard-Jones potential, the instability of the expanding system is investigated. The pressure, the temperature, and the density fluctuations are calculated as functions of density during the time evolution of the expanding matter, which are compared to the coexistence curve calculated by the Gibbs ensemble. The expanding matter undergoes the first order phase transition in the limit of the quasistatic expansion. The resultant fragment mass distributions are also investigated. (author)

  16. Dark Energy Scaling from Dark Matter to Acceleration

    OpenAIRE

    Bielefeld, Jannis; Caldwell, Robert R.; Linder, Eric V.

    2014-01-01

    The dark sector of the Universe need not be completely separable into distinct dark matter and dark energy components. We consider a model of early dark energy in which the dark energy mimics a dark matter component in both evolution and perturbations at early times. Barotropic aether dark energy scales as a fixed fraction, possibly greater than one, of the dark matter density and has vanishing sound speed at early times before undergoing a transition. This gives signatures not only in cosmic...

  17. Sedimentation stacking diagram of binary colloidal mixtures and bulk phases in the plane of chemical potentials

    Science.gov (United States)

    de las Heras, Daniel; Schmidt, Matthias

    2015-05-01

    We give a full account of a recently proposed theory that explicitly relates the bulk phase diagram of a binary colloidal mixture to its phase stacking phenomenology under gravity (de las Heras and Schmidt 2013 Soft Matter 9 8636). As we demonstrate, the full set of possible phase stacking sequences in sedimentation-diffusion equilibrium originates from straight lines (sedimentation paths) in the chemical potential representation of the bulk phase diagram. From the analysis of various standard topologies of bulk phase diagrams, we conclude that the corresponding sedimentation stacking diagrams can be very rich, even more so when finite sample height is taken into account. We apply the theory to obtain the stacking diagram of a mixture of nonadsorbing polymers and colloids. We also present a catalog of generic phase diagrams in the plane of chemical potentials in order to facilitate the practical application of our concept, which also generalizes to multi-component mixtures.

  18. Matter in Strong Magnetic Fields

    CERN Document Server

    Lai, D

    2001-01-01

    The properties of matter are significantly modified by strong magnetic fields, $B>>2.35\\times 10^9$ Gauss ($1 G =10^{-4} Tesla$), as are typically found on the surfaces of neutron stars. In such strong magnetic fields, the Coulomb force on an electron acts as a small perturbation compared to the magnetic force. The strong field condition can also be mimicked in laboratory semiconductors. Because of the strong magnetic confinement of electrons perpendicular to the field, atoms attain a much greater binding energy compared to the zero-field case, and various other bound states become possible, including molecular chains and three-dimensional condensed matter. This article reviews the electronic structure of atoms, molecules and bulk matter, as well as the thermodynamic properties of dense plasma, in strong magnetic fields, with $10^9G << B < 10^{16}G$. The focus is on the basic physical pictures and approximate scaling relations, although various theoretical approaches and numerical results are also di...

  19. Processing of bulk Bi-2223 high-temperature superconductor

    Directory of Open Access Journals (Sweden)

    Alexander Polasek

    2005-12-01

    Full Text Available The Bi2Sr2Ca2Cu3 O10+x (Bi-2223 is one of the main high temperature superconductors for applications. One of these applications is the Superconductor Fault Current Limiter (SCFCL, which is a very promising high temperature superconducting device. SCFCL's can be improved by using bulk superconductors with high critical currents, which requires a sufficiently dense and textured material. In the present work, a process for improving the microstructure of Bi-2223 bulk samples is investigated. Pressed precursor blocks are processed by sintering with a further partial melting step, in order to enhance the Bi-2223 grain texture and to healing cracks induced by pressing. In order to improve the microstructure, the precursor is mixed with silver powder before pressing. Samples with and without silver powder have been studied, with the aim of investigating the influence of silver on the microstructure evolution. The phase contents and the microstructure obtained have been analyzed through XRD and SEM/EDS. The electromagnetic characterization has been performed by Magnetic Susceptibility Analysis. We present and discuss the process and the properties of the superconducting blocks. High fractions of textured Bi-2223 grains have been obtained.

  20. Cementation of kerogen-rich marls by alkaline fluids released during weathering of thermally metamorphosed marly sediments. Part II: Organic matter evolution, magnetic susceptibility and metals (Ti, Cr, Fe) at the Khushaym Matruk natural analogue (Central Jordan)

    International Nuclear Information System (INIS)

    Spontaneous combustion, less than 1 Ma ago, affected a 60-m thick sediment pile of bio-micrite at the Khushaym Matruck site (Jordan). The present study shows that three retrograde alteration stages occurred: weathering, thermal stress and oxidative alkaline perturbation. μ-FT-i.r. spectra of isolated kerogens and oxygen index of whole rocks indicate that oxidation of organic matter occurred down to similar to 10 m beneath the metamorphosed zone at Khushaym Matruck. The occurrence of the oxidative weathering bacterially mediated, as suggested by the mass chromatograms of saturated hydrocarbons, can explain high Rock-Eval Tmax values and low petroliferous potential measured along the sedimentary pile. On the other hand, the thermal extent of combustion events was limited to the first 2 m from the contact. The mean reflectance of 0.20-0.24% and porosity of ca. 50% of the grey clayey bio-micrites indicate that organic matter was very immature and sediments were unconsolidated at the time of the combustion event. Using mineralogy, microscopic analyses of vegetable debris and magnetic susceptibility, a suite of characteristic points corresponding to the thermal imprint can be assessed: (i) x = 0 m, T similar to 1000 degrees C, (ii) x 1 m, T similar to 350 degrees C, (iii) x = 2 m, T similar to 150 degrees C and (iv) x ≥ ∼ 8 m, T similar to 30 degrees C. Paleo-circulation of meteoric groundwater in the 'cement-marbles' generated high-pH fluids that have circulated via fractures and through the matrix porosity of the underlying bio-micrites but have also induced alkaline hydrolysis and oxidative attack of the organic matter. The polysaccharide/lignin ratio derived from mu-FT-i.r. analyses shows that the delignification of vegetable debris and degradation of polysaccharides progressively decline in the indurated zone, which indicates a decrease in the pH of migrating solutions. The latter, also severely oxidized organic matter at 2. 10 and 3.05 m as revealed by the

  1. Module 13: Bulk Packaging Shipments by Highway

    International Nuclear Information System (INIS)

    The Hazardous Materials Modular Training Program provides participating United States Department of Energy (DOE) sites with a basic, yet comprehensive, hazardous materials transportation training program for use onsite. This program may be used to assist individual program entities to satisfy the general awareness, safety training, and function specific training requirements addressed in Code of Federal Regulation (CFR), Title 49, Part 172, Subpart H -- ''Training.'' Module 13 -- Bulk Packaging Shipments by Highway is a supplement to the Basic Hazardous Materials Workshop. Module 13 -- Bulk Packaging Shipments by Highway focuses on bulk shipments of hazardous materials by highway mode, which have additional or unique requirements beyond those addressed in the ten module core program. Attendance in this course of instruction should be limited to those individuals with work experience in transporting hazardous materials utilizing bulk packagings and who have completed the Basic Hazardous Materials Workshop or an equivalent. Participants will become familiar with the rules and regulations governing the transportation by highway of hazardous materials in bulk packagings and will demonstrate the application of these requirements through work projects and examination

  2. Development of superconductor bulk for superconductor bearing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong (and others)

    2008-08-15

    Current carrying capacity is one of the most important issues in the consideration of superconductor bulk materials for engineering applications. There are numerous applications of Y-Ba-Cu-O (YBCO) bulk superconductors e.g. magnetic levitation train, flywheel energy storage system, levitation transportation, lunar telescope, centrifugal device, magnetic shielding materials, bulk magnets etc. Accordingly, to obtain YBCO materials in the form of large, single crystals without weak-link problem is necessary. A top seeded melt growth (TSMG) process was used to fabricate single crystal YBCO bulk superconductors. The seeded and infiltration growth (IG) technique was also very promising method for the synthesis of large, single-grain YBCO bulk superconductors with good superconducting properties. 5 wt.% Ag doped Y211 green compacts were sintered at 900 .deg. C {approx} 1200 .deg.C and then a single crystal YBCO was fabricated by an infiltration method. A refinement and uniform distribution of the Y211 particles in the Y123 matrix were achieved by sintering the Ag-doped samples. This enhancement of the critical current density was ascribable to a fine dispersion of the Y211 particles, a low porosity and the presence of Ag particles. In addition, we have designed and manufactured large YBCO single domain with levitation force of 10-13 kg/cm{sup 2} using TSMG processing technique.

  3. Quark matter formation in dense stellar objects

    Indian Academy of Sciences (India)

    S C Phatak

    2001-08-01

    It is expected that at very large densities and/or temperatures a quark-hadron phase transition takes place. Lattice QCD calculations at zero baryon density indicate that the transition occurs at c∼ 150-170 MeV. The transition is likely to be second order or a cross over phenomenon. Although not much is known about the density at which the phase transition takes place at small temperatures, it is expected to occur around the nuclear densities of few times nuclear matter density. Also, there is a strong reason to believe that the quark matter formed after the phase transition is in colour superconducting phase. The matter densities in the interior of neutron stars being larger than the nuclear matter density, the neutron star cores may possibly consist of quark matter which may be formed during the collapse of supernova. Starting with the assumption that the quark matter, when formed consists of predominantly and quarks, we consider the evolution of quarks by weak interactions in the present work. The reaction rates and time required to reach the chemical equilibrium are computed here. Our calculations show that the chemical equilibrium is reached in about 10-7 seconds. Further more during the equilibration process enormous amont of energy is released and copious numbers of neutrinos are produced. Implications of these on the evolution of supernovae will be discussed.

  4. Gravity-mediated (or composite) Dark Matter confronts astrophysical data

    Science.gov (United States)

    Lee, Hyun Min; Park, Myeonghun; Sanz, Verónica

    2014-05-01

    We consider the astrophysical bounds on a new form of dark matter, the so called Gravity-mediated Dark Matter. In this scenario, dark matter communicates with us through a mediator sector composed of gravitational resonances, namely a new scalar (radion) and a massive spin-two resonance (massive graviton). We consider specific models motivated by natural electroweak symmetry breaking or weak-scale dark matter in the context of models in warped extra-dimensions and their composite duals. The main Dark Matter annihilation mechanism is due to the interactions of KK gravitons to gauge bosons that propagate in bulk. We impose the bounds on monochromatic or continuum photons from Fermi-LAT and HESS. We also explore scenarios in which the Fermi gamma-ray line could be a manifestation of Gravity-mediated Dark Matter.

  5. Gravity-mediated (or Composite) Dark Matter Confronts Astrophysical Data

    CERN Document Server

    Lee, Hyun Min; Sanz, Veronica

    2014-01-01

    We consider the astrophysical bounds on a new form of dark matter, the so called Gravity-mediated Dark Matter. In this scenario, dark matter communicates with us through a mediator sector composed of gravitational resonances, namely a new scalar (radion) and a massive spin-two resonance (massive graviton). We consider specific models motivated by natural electroweak symmetry breaking or weak-scale dark matter in the context of models in warped extra-dimensions and their composite duals. The main Dark Matter annihilation mechanism is due to the interactions of KK gravitons to gauge bosons that propagate in bulk. We impose the bounds on monochromatic or continuum photons from Fermi-LAT and HESS. We also explore scenarios in which the Fermi gamma-ray line could be a manifestation of Gravity-mediated Dark Matter.

  6. Fate of bulk and trace organics during a simulated aquifer recharge and recovery (ARR)-ozone hybrid process

    KAUST Repository

    Yoon, Min

    2013-11-01

    The attenuation of bulk organic matter and trace organic contaminants (TOrCs) was evaluated for various aquifer recharge and recovery (ARR)-ozone (O3) hybrid treatment process combinations using soil-batch reactor and bench-scale ozonation experiments as a proof of concept prior to pilot and/or field studies. In water reclamation and especially potable reuse, refractory bulk organic matter and TOrCs are of potential health concern in recycled waters. In this study, the role of biotransformation of bulk organic matter and TOrCs was investigated considering different simulated treatment combinations, including soil passage (ARR) alone, ARR after ozonation (O3-ARR), and ARR prior to ozonation (ARR-O3). During oxic (aerobic) ARR simulations, soluble microbial-like substances (e.g., higher molecular weight polysaccharides and proteins) were easily removed while (lower molecular weight) humic substances and aromatic organic matter were not efficiently removed. During ARR-ozone treatment simulations, removals of bulk organic matter and TOrCs were rapid and effective compared to ARR alone. A higher reduction of effluent-derived organic matter, including aromatic organic matter and humic substances, was observed in the ARR-O3 hybrid followed by the O3-ARR hybrid. An enhanced attenuation of recalcitrant TOrCs was observed while increasing the ozone dose slightly (O3: DOC=1). TOrC removal efficiency also increased during the post-ozone treatment combination (i.e., ARR-O3). In addition, the carcinogenic wastewater disinfection byproduct N-nitrosodimethylamine (NDMA) was eliminated below the method reporting limit (<5ngL-1) both during ARR treatment alone and the ARR-ozone hybrid. © 2013 Elsevier Ltd.

  7. Degradation of mangrove tissues by arboreal termites (Nasutitermes acajutlae) and their role in the mangrove C cycle (Puerto Rico): Chemical characterization and organic matter provenance using bulk δ13C, C/N, alkaline CuO oxidation-GC/MS, and solid-state 13C NMR

    Science.gov (United States)

    Vane, Christopher H.; Kim, Alexander W.; Moss-Hayes, Vicky; Snape, Colin E.; Diaz, Miguel Castro; Khan, Nicole S.; Engelhart, Simon E.; Horton, Benjamin P.

    2013-08-01

    Arboreal termites are wood decaying organisms that play an important role in the first stages of C cycling in mangrove systems. The chemical composition of Rhizophora mangle, Avicennia germinans, and Laguncularia racemosa leaf, stem, and pneumatophore tissues as well as associated sediments was compared to that of nests of the termite Nasutitermes acajutlae. Nests gave δ13C values of -26.1 to -27.2‰ (±0.1) and C/N of 43.3 (±2.0) to 98.6 (±16.2) which were similar to all stem and pneumatophores but distinct from mangrove leaves or sediments. Organic matter processed by termites yielded lignin phenol concentrations (Λ, lambda) that were 2-4 times higher than stem or pneumatophores and 10-20 times higher than that of leaves or sediments, suggesting that the nests were more resistant to biodegradation than the mangrove vegetation source. 13C NMR revealed that polysaccharide content of mangrove tissues (50-69% C) was higher than that of the nests (46-51% C). Conversely, lignin accounted for 16.2-19.6% C of nest material, a threefold increase relative to living mangrove tissues; a similar increase in aromatic methoxyl content was also observed in the nests. Lipids (aliphatic and paraffinic moieties) were also important but rather variable chemical components of all three mangrove species, representing between 13.5 and 28.3% of the C content. Termite nests contained 3.14 Mg C ha-1 which represents approximately 2% of above ground C storage in mangroves, a value that is likely to increase upon burial due to their refractory chemical composition.

  8. The Evolution and Development of the Universe

    CERN Document Server

    Vidal, Clément; Blin, Alex H; Chaline, Jean; Crane, Louis; Durt, Thomas; Ekstig, Borje; Fairlamb, Horace; Greben, Jan; Hengeveld, Rob; Heylighen, Francis; Akkerhuis, Gerard Jagers op; Longo, Giuseppe; Lori, Nicolas F; Noble, Denis; Nottale, Laurent; Salthe, Stanley; Stewart, John; Vaas, Ruediger; Van de Vijver, Gertrudis; van Straalen, Nico M

    2009-01-01

    This document is the Special Issue of the First International Conference on the Evolution and Development (EDU 2008). Please refer to the preface and introduction for more details on the contributions. Keywords: acceleration, artificial cosmogenesis, artificial life, Big Bang, Big History, biological evolution, biological universe, biology, causality, classical vacuum energy, complex systems, complexity, computational universe, conscious evolution, cosmological artificial selection, cosmological natural selection, cosmology, critique, cultural evolution, dark energy, dark matter, development of the universe, development, emergence, evolution of the universe evolution, exobiology, extinction, fine-tuning, fractal space-time, fractal, information, initial conditions, intentional evolution, linear expansion of the universe, log-periodic laws, macroevolution, materialism, meduso-anthropic principle, multiple worlds, natural sciences, Nature, ontology, order, origin of the universe, particle hierarchy, philosophy,...

  9. A diphoton resonance from bulk RS

    Science.gov (United States)

    Csáki, Csaba; Randall, Lisa

    2016-07-01

    Recent LHC data hinted at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to any other Standard Model particles would be too low to be detected so far. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from but close to the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.

  10. Micro benchtop optics by bulk silicon micromachining

    Science.gov (United States)

    Lee, Abraham P.; Pocha, Michael D.; McConaghy, Charles F.; Deri, Robert J.

    2000-01-01

    Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

  11. Bulk amorphous Mg-based alloys

    DEFF Research Database (Denmark)

    Pryds, Nini

    The present paper describes the preparation and properties of bulk amorphous quarternary Mg-based alloys and the influence of additional elements on the ability of the alloy to form bulk amorphous. The main goal is to find a Mg-based alloy system which shows both high strength to weight ratio and a...... low glass transition temperature. The alloys were prepared by using a relatively simple technique, i.e. rapid cooling of the melt in a copper wedge mould. The essential structural changes that are achieved by going from the amorphous to the crystalline state through the supercooled liquid state are...... discussed in this paper. On the basis of these measurements phase diagrams of the different systems were constructed. Finally, it is demonstrated that when pressing the bulk amorphous alloy onto a metallic dies at temperatures within the supercooled liquid region, the alloy faithfully replicates the surface...

  12. Orchestrating Bulk Data Movement in Grid Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vazhkudai, SS

    2005-01-25

    Data Grids provide a convenient environment for researchers to manage and access massively distributed bulk data by addressing several system and transfer challenges inherent to these environments. This work addresses issues involved in the efficient selection and access of replicated data in Grid environments in the context of the Globus Toolkit{trademark}, building middleware that (1) selects datasets in highly replicated environments, enabling efficient scheduling of data transfer requests; (2) predicts transfer times of bulk wide-area data transfers using extensive statistical analysis; and (3) co-allocates bulk data transfer requests, enabling parallel downloads from mirrored sites. These efforts have demonstrated a decentralized data scheduling architecture, a set of forecasting tools that predict bandwidth availability within 15% error and co-allocation architecture, and heuristics that expedites data downloads by up to 2 times.

  13. Bulk Comptonization by Turbulence in Accretion Disks

    CERN Document Server

    Kaufman, J

    2016-01-01

    Radiation pressure dominated accretion discs around compact objects may have turbulent velocities that greatly exceed the electron thermal velocities within the disc. Bulk Comptonization by the turbulence may therefore dominate over thermal Comptonization in determining the emergent spectrum. Bulk Comptonization by divergenceless turbulence is due to radiation viscous dissipation only. It can be treated as thermal Comptonization by solving the Kompaneets equation with an equivalent "wave" temperature, which is a weighted sum over the power present at each scale in the turbulent cascade. Bulk Comptonization by turbulence with non-zero divergence is due to both pressure work and radiation viscous dissipation. Pressure work has negligible effect on photon spectra in the limit of optically thin turbulence, and in this limit radiation viscous dissipation alone can be treated as thermal Comptonization with a temperature equivalent to the full turbulent power. In the limit of extremely optically thick turbulence, ra...

  14. Dark Matter and Galaxy Formation

    CERN Document Server

    Primack, Joel R

    2009-01-01

    The four lectures that I gave in the XIII Ciclo de Cursos Especiais at the National Observatory of Brazil in Rio in October 2008 were (1) a brief history of dark matter and structure formation in a LambdaCDM universe; (2) challenges to LambdaCDM on small scales: satellites, cusps, and disks; (3) data on galaxy evolution and clustering compared with simulations; and (4) semi-analytic models. These lectures, themselves summaries of much work by many people, are summarized here briefly.

  15. Dissolved Organic Matter Transformations: Implications for Catchment-Scale Processes

    Science.gov (United States)

    Robinson, A.; Hernes, P.; Montanez, I.; Eustis, B.

    2006-12-01

    Particulate and dissolved phase lignin parameters are used to understand sources and dynamics of terrigenous organic matter (OM) in freshwater and marine systems. Impacts of catchment properties, such as soil type and mineralogy, vegetation distribution and hydrologic conditions on terrestrial dissolved and particulate biomarker compositions have not been addressed. Our experimental approach deciphers relative contributions of these parameters on bulk DOM compositions. Carbon-normalized lignin yields (Λ8) are one means to assess contributions of lignin phenols to bulk organic carbon. Ratios of syringyl (S), vanillyl (V) and cinnamyl (C) lignin phenols distinguish angiosperm and gymnosperm woody and nonwoody tissues. Ratios of acids:aldehydes (ad:ac) within vanillyl groups indicate diagenetic alteration of OM. Interpretation of these ratios relies on the fundamental assumption that each lignin compound behaves similarly, despite differences in solubility and sorption. Fractionation due to leaching impacts C:V, ac:al and (Λ8). C:V ranges from 1/2 to 4 times original plant compositions, increasing proportions of DOM ascribed to nonwoody tissues. Shifts in C:V and S:V due to leaching, suggest that source ratios from plant materials may not be appropriate endmembers for dissolved phases. An ~2-fold increase in ac:al ratios between litters and leachates suggest that dissolved phases are more diagenetically altered than litters, although this is simply due to solubilization. Λ8 values, tracking lignin and bulk carbon solubility differences, indicate greater loss of bulk OM relative to lignin for most plant litters. During sorption of leachates to mineral soils, lignin compositional trends are more variable compared to leaching data. Sorption of angiosperm leachates resulted in significant enrichment of S phenols on soils, which would increase the inferred contribution of angiosperms obtained for mixtures. C:V fractionation during sorption decreased in 3 of 4 plant

  16. Dark matter and cosmic acceleration from Wesson's IMT

    Science.gov (United States)

    Israelit, Mark

    2009-12-01

    In the present work a procedure is build up, that allows obtaining dark matter (DM) and cosmic acceleration in our 4D universe embedded in a 5D manifold. Both, DM and the factor causing cosmic acceleration, as well ordinary matter are induced in the 4D space-time by a warped, but empty from matter, 5D bulk. The procedure is carried out in the framework of the Weyl-Dirac version (Israelit, Found Phys 35:1725, 2005; Israelit, Found Phys 35:1769, 2005) of Paul Wesson’s Induced Matter Theory (Wesson, Space-time matter, 1999) enriched by Rosen’s approach (Found Phys 12:213, 1982). Considering chaotically oriented Weyl vector fields, which exist in microscopic cells, we obtain cold dark matter (CDM) consisting of weylons, massive bosons having spin 1. Assuming homogeneity and isotropy at large scale we derive cosmological equations in which luminous matter, CDM and dark energy may be considered separately. Making in the given procedure use of present observational data one can develop a model of the Universe with conventional matter, DM and cosmic acceleration, induced by the 5D bulk.

  17. LHC - In search of matter

    International Nuclear Information System (INIS)

    After an overview of the evolution of knowledge in particle physics during the last hundred years, with notably the difference between matter particles or elementary fermions (leptons and quarks) and interaction particles (bosons), the author outlines the importance of the Higgs boson. He recalls the creation and the evolution of the CERN, the greatest research laboratory in the world, and the construction of the LHC (Large Hadron Collider), the different experiments which have been performed with this large equipment. The author briefly describes its operation, characteristics and performance. He also describes its complementary devices (Alice, Atlas, CMS, and LHCb), each of them being dedicated to a precise purpose. Then he gives an overview of the obtained results and notably evokes some of them which concerned different fields, for example the main tools of the Internet

  18. Dark matter searches with asteroseismology

    Directory of Open Access Journals (Sweden)

    Casanellas Jordi

    2015-01-01

    Full Text Available High-precision asteroseismic data provides an excellent opportunity to test theories of stellar evolution and new physics, such as the properties of the dark matter (DM of the Universe. Here we will show that some models of DM lead to changes in the classical scenario of stellar evolution. The accumulation of DM in the core of low-mass stars reduces their central temperatures and inhibits the formation of small convective cores in 1.1-1.3 Ms stars.We review the asteroseismic constraints that have been set to the characteristics of the DM particles, obtained comparing the oscillations of the star α Cen B with modified stellar models. To conclude, we discuss the prospects to use CoRoT and Kepler data on main-sequence stars and red giants to further constrain the nature of DM.

  19. Dark matter searches with asteroseismology

    CERN Document Server

    Casanellas, Jordi

    2015-01-01

    High-precision asteroseismic data provides an excellent opportunity to test theories of stellar evolution and new physics, such as the properties of the dark matter (DM) of the Universe. Here we will show that some models of DM lead to changes in the classical scenario of stellar evolution. The accumulation of DM in the core of low-mass stars reduces their central temperatures and inhibits the formation of small convective cores in 1.1-1.3 Ms stars. We review the asteroseismic constraints that have been set to the characteristics of the DM particles, obtained comparing the oscillations of the star Alpha Cen B with modified stellar models. To conclude, we discuss the prospects to use CoRoT and Kepler data on main-sequence stars and red giants to further constrain the nature of DM.

  20. Synthesis of Bulk Superconducting Magnesium Diboride

    Directory of Open Access Journals (Sweden)

    Margie Olbinado

    2002-06-01

    Full Text Available Bulk polycrystalline superconducting magnesium diboride, MgB2, samples were successfully prepared via a one-step sintering program at 750°C, in pre Argon with a pressure of 1atm. Both electrical resistivity and magnetic susceptibility measurements confirmed the superconductivity of the material at 39K, with a transition width of 5K. The polycrystalline nature, granular morphology, and composition of the sintered bulk material were confirmed using X-ray diffractometry (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray analysis (EDX.

  1. Remedial investigations for quarry bulk wastes

    International Nuclear Information System (INIS)

    The US Department of Energy proposes, as a separate operable unit of the Weldon Spring Site Remedial Action Project, to remove contaminated bulk wastes from the Weldon Spring quarry and transport them approximately four miles to the chemical plant portion of the raffinate pits and chemical plant area. The wastes will be held in temporary storage prior to the record of decision for the overall remedial action. The decision on the ultimate disposal of these bulk wastes will be included as part of the decision for management of the waste materials resulting from remedial action activities at the raffinate pits and chemical plant area. 86 refs., 71 figs., 83 tabs

  2. Radiation-hardened bulk CMOS technology

    International Nuclear Information System (INIS)

    The evolutionary development of a radiation-hardened bulk CMOS technology is reviewed. The metal gate hardened CMOS status is summarized, including both radiation and reliability data. The development of a radiation-hardened bulk silicon gate process which was successfully implemented to a commercial microprocessor family and applied to a new, radiation-hardened, LSI standard cell family is also discussed. The cell family is reviewed and preliminary characterization data is presented. Finally, a brief comparison of the various radiation-hardened technologies with regard to performance, reliability, and availability is made

  3. Bulk Entropy in Loop Quantum Gravity

    OpenAIRE

    Livine, Etera R; Terno, Daniel R.

    2007-01-01

    In the framework of loop quantum gravity (LQG), having quantum black holes in mind, we generalize the previous boundary state counting (gr-qc/0508085) to a full bulk state counting. After a suitable gauge fixing we are able to compute the bulk entropy of a bounded region (the "black hole") with fixed boundary. This allows us to study the relationship between the entropy and the boundary area in details and we identify a holographic regime of LQG where the leading order of the entropy scales w...

  4. Bulk Entropy in Loop Quantum Gravity

    CERN Document Server

    Livine, Etera R

    2007-01-01

    In the framework of loop quantum gravity (LQG), having quantum black holes in mind, we generalize the previous boundary state counting (gr-qc/0508085) to a full bulk state counting. After a suitable gauge fixing we are able to compute the bulk entropy of a bounded region (the "black hole") with fixed boundary. This allows us to study the relationship between the entropy and the boundary area in details and we identify a holographic regime of LQG where the leading order of the entropy scales with the area. We show that in this regime we can fine tune the factor between entropy and area without changing the Immirzi parameter.

  5. The Relations Between Soil Water Retention Characteristics, Particle Size Distributions, Bulk Densities and Calcium Carbonate Contents for Danish Soils

    DEFF Research Database (Denmark)

    Jensen, Niels H.; Balstrøm, Thomas; Breuning-Madsen, Henrik

    2005-01-01

    A database containing about 800 soil profiles located in a 7-km grid covering Denmark has been used to develop a set of regression equations of soil water content at pressure heads –1, -10, -100 and –1500 kPa versus particle size distribution, organic matter, CaCO3 and bulk density. One purpose was...... to elaborate equations based of soil parameters available in the Danish Soil Classification's texture database on particle size distribution and organic matter. It was also tested if inclusion of bulk density or CaCO3 content (in CaCO3-containing samples) as predictors or grouping in surface and...... pedotransfer functions developed in HYPRES (Hydraulic Properties of European Soils). Introducing bulk density as a predictor improved the equation for pressure head –1 kPa but not for lower ones. The grouping of data sets in surface and subsurface horizons or in textural classes did not improve the equations...

  6. Evolution of primordial magnetic fields in mean-field approximation

    Science.gov (United States)

    Campanelli, Leonardo

    2014-01-01

    We study the evolution of phase-transition-generated cosmic magnetic fields coupled to the primeval cosmic plasma in the turbulent and viscous free-streaming regimes. The evolution laws for the magnetic energy density and the correlation length, both in the helical and the non-helical cases, are found by solving the autoinduction and Navier-Stokes equations in the mean-field approximation. Analytical results are derived in Minkowski spacetime and then extended to the case of a Friedmann universe with zero spatial curvature, both in the radiation- and the matter-dominated era. The three possible viscous free-streaming phases are characterized by a drag term in the Navier-Stokes equation which depends on the free-streaming properties of neutrinos, photons, or hydrogen atoms, respectively. In the case of non-helical magnetic fields, the magnetic intensity and the magnetic correlation length evolve asymptotically with the temperature, , as and . Here, , , and are, respectively, the temperature, the number of magnetic domains per horizon length, and the bulk velocity at the onset of the particular regime. The coefficients , , , , , and , depend on the index of the assumed initial power-law magnetic spectrum, , and on the particular regime, with the order-one constants and depending also on the cutoff adopted for the initial magnetic spectrum. In the helical case, the quasi-conservation of the magnetic helicity implies, apart from logarithmic corrections and a factor proportional to the initial fractional helicity, power-like evolution laws equal to those in the non-helical case, but with equal to zero.

  7. Stellar evolution

    CERN Document Server

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

  8. Linking structure to fragility in bulk metallic glass-forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shuai, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287 (United States); Stolpe, Moritz, E-mail: shuai.wei@asu.edu, E-mail: m.stolpe@mx.uni-saarland.de; Gross, Oliver; Gallino, Isabella; Hembree, William; Busch, Ralf [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Evenson, Zach [Department of Materials Science and Engineering, Saarland University, Campus C63, 66123 Saarbrücken (Germany); Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln (Germany); Bednarcik, Jozef [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Kruzic, Jamie J. [Material Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, Oregon 97331 (United States)

    2015-05-04

    Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near T{sub g}. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure.

  9. Linking structure to fragility in bulk metallic glass-forming liquids

    International Nuclear Information System (INIS)

    Using in-situ synchrotron X-ray scattering, we show that the structural evolution of various bulk metallic glass-forming liquids can be quantitatively connected to their viscosity behavior in the supercooled liquid near Tg. The structural signature of fragility is identified as the temperature dependence of local dilatation on distinct key atomic length scales. A more fragile behavior results from a more pronounced thermally induced dilatation of the structure on a length scale of about 3 to 4 atomic diameters, coupled with shallower temperature dependence of structural changes in the nearest neighbor environment. These findings shed light on the structural origin of viscous slowdown during undercooling of bulk metallic glass-forming liquids and demonstrate the promise of predicting the properties of bulk metallic glasses from the atomic scale structure

  10. Dark Matter From Spacetime Nonlocality

    CERN Document Server

    Saravani, Mehdi

    2015-01-01

    We propose that dark matter is not yet another new particle in nature, but that it is a remnant of quantum gravitational effects on known fields. We arrive at this possibility in an indirect and surprising manner: by considering retarded, nonlocal, and Lorentzian evolution for quantum fields. This is inspired by recent developments in causal set theory, where such an evolution shows up as the continuum limit of scalar field propagation on a background causal set. Concretely, we study the quantum theory of a massless scalar field whose evolution is given not by the the d'Alembertian $\\Box$, but by an operator $\\tilde \\Box$ which is Lorentz invariant, reduces to $\\Box$ at low energies, and defines an explicitly retarded evolution: $(\\tilde \\Box \\phi)(x)$ only depends on $\\phi(y)$, with $y$ is in the causal past of $x$. This modification results in the existence of a continuum of massive particles, in addition to the usual massless ones, in the free theory. When interactions are introduced, these massive or off-...

  11. Dark Matter: Early Considerations

    OpenAIRE

    Einasto, J.

    2004-01-01

    A review of the study of dark matter is given, starting with earliest studies and finishing with the establishment of the standard Cold Dark Matter paradigm in mid 1980-s. Particular attention is given to the collision of the classical and new paradigms concerning the matter content of the Universe. Also the amount of baryonic matter, dark matter and dark energy is discussed using modern estimates.

  12. Hollow nuclear matter

    OpenAIRE

    Yong, Gao-Chan

    2015-01-01

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

  13. Hollow nuclear matter

    CERN Document Server

    Yong, Gao-Chan

    2016-01-01

    It is generally considered that an atomic nucleus is always compact. Based on the isospin-dependent Boltzmann nuclear transport model, here I show that large block nuclear matter or excited nuclear matter may both be hollow. And the size of inner bubble in these matter is affected by the charge number of nuclear matter. Existence of hollow nuclear matter may have many implications in nuclear or atomic physics or astrophysics as well as some practical applications.

  14. Front Matter.

    Science.gov (United States)

    2016-01-01

    There's never been a more exciting time to be involved with health informatics. In the last few decades, health informaticians have established the knowledge base and practical expertise to facilitate the development of ever-more capable technical systems, increasing connectivity, expanding access and greater mobility of e-health and information management systems. We have seen the evolution from simple computer based records to systems that allow intra-organisational, national, even international communication and information exchange. We have also seen progress in e-health and most recently m-health, facilitating access to information and advice almost anytime, anywhere. The health informatics community is now building on this strong foundation, taking a central role in the digital transformation of the healthcare sector. The Australian National Health Informatics Conference (HIC), Australia's premier health informatics event, is a key avenue for facilitating this transformation. This Conference, organised by the Health Informatics Society of Australia (HISA), with the support of the Australasian College of Health Informatics (ACHI), provides the ideal professional and social environment for clinicians, researchers, health IT professionals, industry and consumers to integrate, educate and share their knowledge to drive innovative thinking, to enhance services and allow greater consumer involvement. This is emphasised in the primary theme of the 2016 Conference: Digital Health Innovation for Consumers, Clinicians, Connectivity, Community. The papers in this volume reflect this theme, highlighting the cutting edge research evidence, technology updates and innovations that are seeing the digital transformation of the healthcare sector. The papers are indicative of the wide spectrum of work encompassing major theoretical concepts, examples of key applications of new technologies and important new developments in the field of health informatics. They emphasise the

  15. Morphological Evolution of Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Martel, H. [Department of Astronomy, University of Texas, Austin, Texas 78712 (United States); Premadi, P.; Matzner, R. [Center for Relativity, University of Texas, Austin, Texas 78712 (United States); Premadi, P.; Matzner, R. [Department of Physics, University of Texas, Austin, Texas 78712 (United States)

    1998-04-01

    We simulate the growth of large-scale structure for three different cosmological models, an Einstein{endash}de Sitter model (density parameter {Omega}{sub 0} = 1), an open model ({Omega}{sub 0} = 0.2), and a flat model with nonzero cosmological constant ({Omega}{sub 0} = 0.2, cosmological constant {lambda}{sub 0} = 0.8), using a cosmological {ital N}-body code (particle-particle/particle-mesh) with 64{sup 3} dark matter particles in a comoving cubic volume of present comoving size 128 Mpc. The calculations start at {ital z} = 24 and end at {ital z} = 0. We use the results of these simulations to generate distributions of galaxies at the present ({ital z} = 0), as follows: Using a Monte Carlo method based on the present distribution of dark matter, we located {approximately}40,000 galaxies in the computational volume. We then ascribe to each galaxy a morphological type based on the local number density of galaxies in order to reproduce the observed morphology-density relation. The resulting galaxy distributions are similar to the observed ones, with most ellipticals concentrated in the densest regions, and most spirals concentrated in low-density regions. By {open_quotes}tying{close_quotes} each galaxy to its nearest dark matter particle, we can trace the trajectory of that galaxy back in time by simply looking at the location of that dark matter particle at earlier time slices provided by the {ital N}-body code. This enables us to reconstruct the distribution of galaxies at high redshift and the trajectory of each galaxy from its formation epoch to the present. We use these galaxy distributions to investigate the problem of morphological evolution. Our goal is to determine whether the morphological type of galaxies is determined primarily by the initial conditions in which these galaxies form or by evolutionary processes (such as mergers or tidal stripping) occurring after the galaxies have formed and eventually altering their morphology, or a combination of both

  16. Schumpeter's Evolution

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    This draft of a book on Schumpeter is distributed for commenting. It is a stylised intellectual biography that focus on the emergence and extension of the Schumpeterian vision and analysis of economic and social evolution. The draft provides novel interpretations of Schumpeter's six major books. He...... reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model of...... economic evolution and added evolutionary contributions to other social sciences. History, which was published by his widow, was based on his evolutionary theory of the history of economic analysis. This sequential analysis of Schumpeter's six books demonstrates the progress he within his research...

  17. THE OPTIMIZATION OF PLUSH YARNS BULKING PROCESS

    Directory of Open Access Journals (Sweden)

    VINEREANU Adam

    2014-05-01

    Full Text Available This paper presents the experiments that were conducted on the installation of continuous bulking and thermofixing “SUPERBA” type TVP-2S for optimization of the plush yarns bulking process. There were considered plush yarns Nm 6.5/2, made of the fibrous blend of 50% indigenous wool sort 41 and 50% PES. In the first stage, it performs a thermal treatment with a turboprevaporizer at a temperature lower than thermofixing temperature, at atmospheric pressure, such that the plush yarns - deposed in a freely state on a belt conveyor - are uniformly bulking and contracting. It was followed the mathematical modeling procedure, working with a factorial program, rotatable central composite type, and two independent variables. After analyzing the parameters that have a direct influence on the bulking degree, there were selected the pre-vaporization temperature (coded x1,oC and the velocity of belt inside pre-vaporizer (coded x 2, m/min. As for the dependent variable, it was chosen the plush yarn diameter (coded y, mm. There were found the coordinates of the optimal point, and then this pair of values was verified in practice. These coordinates are: x1optim= 90oC and x 2optim= 6.5 m/min. The conclusion is that the goal was accomplished: it was obtained a good cover degree f or double-plush carpets by reducing the number of tufts per unit surface.

  18. Determining the bulk strength of strata

    International Nuclear Information System (INIS)

    The bulk rock strength of strata is determined by logging a bore-hole with an instrument to obtain a neutron-neutron log of the hole and determining in conjunction with the lithology of the strata the strength by applying an inverse relation formula. (author)

  19. Realistic anomaly mediation with bulk gauge fields

    International Nuclear Information System (INIS)

    We present a simple general framework for realistic models of supersymmetry breaking driven by anomaly mediation. We consider a 5-dimensional 'brane universe' where the visible and hidden sectors are localized on different branes, and the standard model gauge bosons propagate in the bulk. In this framework there can be charged scalar messengers that have contact interactions with the hidden sector, either localized in the hidden sector or in the bulk. These scalars obtain soft masses that feed into visible sector scalar masses at two loop order via bulk gauge interactions. This contribution is automatically flavor-blind, and can be naturally positive. If the messengers are in the bulk this contribution is automatically the same order of magnitude as the anomaly mediated contribution, independent of the brane spacing. If the messengers are localized to a brane the two effects are of the same order for relatively small brane spacings. The gaugino masses and A terms are determined completely by anomaly mediation. In order for anomaly mediation to dominate over radion mediation the radion must be is stabilized in a manner that preserves supersymmetry, with supergravity effects included. We show that this occurs in simple models. We also show that the mu problem can be solved by the vacuum expectation value of a singlet in this framework. (author)

  20. Crevice chemistry estimation from bulk water chemistry

    International Nuclear Information System (INIS)

    Since the first PWR plant in Japan started commercial operation in 1970, 22 plants are running in Japan as of the end of 1994. The main purpose of secondary water chemistry control is to minimize the corrosion possibility of the secondary system equipment, especially steam generators (SG). To achieve this objective, much effort has been concentrated on improving secondary water chemistry control. As a result of this effort, the recent secondary water chemistry in Japanese plants is well maintained in every stage of operation. However, to ensure and improve the reliability of SG, it is necessary to control crevice environments, which are located at tube/tube support plate intersections and under the sludge pile on the tube sheet. According to recent crevice monitoring examination results, the concentration behavior impurities in SG bulk water at the crevice is different for each species, and SG bulk water and crevice chemical compositions are not always equal. From these results, to control the crevice chemistry, improving bulk water chemistry control methods and a new type of molar ratio control index is needed. This paper introduces a brief summary of a recent crevice chemistry evaluation technique and bulk water chemistry control method, which is employed for crevice chemistry control, based on crevice monitoring examination results