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Sample records for fr17jn10p bulk solid

  1. 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

  2. 75 FR 64585 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Science.gov (United States)

    2010-10-19

    ... nonsubstantive changes, however, to correct grammar, internal paragraph references, and a temperature conversion... means the English version of the ``International Maritime Solid Bulk Cargoes Code'' published by...

  3. Evidence for Bulk Ripplocations in Layered Solids

    Science.gov (United States)

    Gruber, Jacob; Lang, Andrew C.; Griggs, Justin; Taheri, Mitra L.; Tucker, Garritt J.; Barsoum, Michel W.

    2016-09-01

    Plastically anisotropic/layered solids are ubiquitous in nature and understanding how they deform is crucial in geology, nuclear engineering, microelectronics, among other fields. Recently, a new defect termed a ripplocation–best described as an atomic scale ripple–was proposed to explain deformation in two-dimensional solids. Herein, we leverage atomistic simulations of graphite to extend the ripplocation idea to bulk layered solids, and confirm that it is essentially a buckling phenomenon. In contrast to dislocations, bulk ripplocations have no Burgers vector and no polarity. In graphite, ripplocations are attracted to other ripplocations, both within the same, and on adjacent layers, the latter resulting in kink boundaries. Furthermore, we present transmission electron microscopy evidence consistent with the existence of bulk ripplocations in Ti3SiC2. Ripplocations are a topological imperative, as they allow atomic layers to glide relative to each other without breaking the in-plane bonds. A more complete understanding of their mechanics and behavior is critically important, and could profoundly influence our current understanding of how graphite, layered silicates, the MAX phases, and many other plastically anisotropic/layered solids, deform and accommodate strain.

  4. 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

  5. Tailoring Magnetic Properties in Bulk Nanostructured Solids

    Science.gov (United States)

    Morales, Jason Rolando

    Important magnetic properties and behaviors such as coercivity, remanence, susceptibility, energy product, and exchange coupling can be tailored by controlling the grain size, composition, and density of bulk magnetic materials. At nanometric length scales the grain size plays an increasingly important role since magnetic domain behavior and grain boundary concentration determine bulk magnetic behavior. This has spurred a significant amount of work devoted to developing magnetic materials with nanometric features (thickness, grain/crystallite size, inclusions or shells) in 0D (powder), 1D (wires), and 2D (thin films) materials. Large 3D nanocrystalline materials are more suitable for many applications such as permanent magnets, magneto-optical Faraday isolators etc. Yet there are relatively few successful demonstrations of 3D magnetic materials with nanoscale influenced properties available in the literature. Making dense 3D bulk materials with magnetic nanocrystalline microstructures is a challenge because many traditional densification techniques (HIP, pressureless sintering, etc.) move the microstructure out of the "nano" regime during densification. This dissertation shows that the Current Activated Pressure Assisted Densification (CAPAD) method, also known as spark plasma sintering, can be used to create dense, bulk, magnetic, nanocrystalline solids with varied compositions suited to fit many applications. The results of my research will first show important implications for the use of CAPAD for the production of exchange-coupled nanocomposite magnets. Decreases in grain size were shown to have a significant role in increasing the magnitude of exchange bias. Second, preferentially ordered bulk magnetic materials were produced with highly anisotropic material properties. The ordered microstructure resulted in changing magnetic property magnitudes (ex. change in coercivity by almost 10x) depending on the relative orientation (0° vs. 90°) of an externally

  6. Solidex 84 - modern technology in bulk solids handling

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Proceedings from Conference on solids handling. Sections which are of interest include coal and ash handling, and flow problems and explosion hazards in bulk handling plant. 14 papers have been abstracted separately.

  7. 75 FR 34573 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

    Science.gov (United States)

    2010-06-17

    ... Bulk MSDS Material Safety Data Sheet NCB National Cargo Bureau NEPA National Environmental Policy Act... material safety data sheet (MSDS) address some portions of proposed Sec. 148.60. We agree with the comment... in the form of an MSDS. e. One comment observed that, as proposed in the 1994 NPRM, Sec. 148.60(d...

  8. Proceedings of the technical program, powder and bulk solids handling and processing

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    A total of 56 papers were presented under the following headings: solids storage and silos; pneumatic conveying; particle size enlargement; particle separation; particle characterization; mechanical handling of bulk solids; bulk solids process control; hazards and safety aspects; fluidization and fluid particle technology; coal handling and storage; and bulk solids processing. 8 papers have been abstracted separately.

  9. Solid-State Explosive Reaction for Nanoporous Bulk Thermoelectric Materials.

    Science.gov (United States)

    Zhao, Kunpeng; Duan, Haozhi; Raghavendra, Nunna; Qiu, Pengfei; Zeng, Yi; Zhang, Wenqing; Yang, Jihui; Shi, Xun; Chen, Lidong

    2017-09-29

    High-performance thermoelectric materials require ultralow lattice thermal conductivity typically through either shortening the phonon mean free path or reducing the specific heat. Beyond these two approaches, a new unique, simple, yet ultrafast solid-state explosive reaction is proposed to fabricate nanoporous bulk thermoelectric materials with well-controlled pore sizes and distributions to suppress thermal conductivity. By investigating a wide variety of functional materials, general criteria for solid-state explosive reactions are built upon both thermodynamics and kinetics, and then successfully used to tailor material's microstructures and porosity. A drastic decrease in lattice thermal conductivity down below the minimum value of the fully densified materials and enhancement in thermoelectric figure of merit are achieved in porous bulk materials. This work demonstrates that controlling materials' porosity is a very effective strategy and is easy to be combined with other approaches for optimizing thermoelectric performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. 49 CFR 173.242 - Bulk packagings for certain medium hazard liquids and solids, including solids with dual hazards.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bulk packagings for certain medium hazard liquids and solids, including solids with dual hazards. 173.242 Section 173.242 Transportation Other... medium hazard liquids and solids, including solids with dual hazards. When § 172.101 of this subchapter...

  11. Proceedings of the technical program: powder and bulk solids handling and processing

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    Papers are presented on the topic of powder and bulk solids handling under the following subject headings: computer applications; particle characterization; fluidization and fluid-particle technology; belt conveyors; pneumatic conveying; solids storage; particle size enlargement; flow metering and process monitoring and control; mechanical handling; solids processing; mixing and handling; separation technologies; solids feeding systems; particle rheology and solids systems flow; system safety considerations; size reduction. Relevant papers have been abstracted separately.

  12. Strong surface effect on direct bulk flexoelectric response in solids

    Energy Technology Data Exchange (ETDEWEB)

    Yurkov, A. S. [Ioffe Physical-Technical Institute, 26 Politekhnicheskaya, 194021 St. Petersburg (Russian Federation); Tagantsev, A. K. [Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne (Switzerland); Ioffe Physical-Technical Institute, 26 Politekhnicheskaya, 194021 St. Petersburg (Russian Federation)

    2016-01-11

    In the framework of a continuum theory, it is shown that the direct bulk flexoelectric response of a finite sample essentially depends on the surface polarization energy, even in the thermodynamic limit where the body size tends to infinity. It is found that a modification of the surface energy can lead to a change in the polarization response by a factor of two. The origin of the effect is an electric field produced by surface dipoles induced by the strain gradient. The unexpected sensitivity of the polarization response to the surface energy in the thermodynamic limit is conditioned by the fact that the moments of the surface dipoles may scale as the body size.

  13. The Role of Bulk Additions in Solid Lubricant Compacts

    Science.gov (United States)

    1987-04-01

    Solid Lubricants," Labe Ina*- Luis 7 (1967). 5. R. Do Hubbell and B. D. McConnell* "Vear Behavior of Polybonsi-idPsolt Bonded Solld-lilS Lubeioants-S J...0. Grim and Luis J. Matienso, "X-Ray Photoelectron Spectroscopy of Inorganic and Organometallic Ccpounds of Molybdenum," Inors. Cheo., 14, 1014-1018...A. Rincon and L. Arizuendi, "Extreme Pressure Lubricating Properties of Inorganic Oxidus," Wear, 60, 393-399 (1980). 211 86. American Standard for

  14. Correspondence between Experiment and Theory of Bulk Electrocrystallisation at Solid Electrodes in Aqueous Electrolyte

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    A theory of bulk-metal electrocrystallisation at solid-metal surfaces in aqueous electrolytes is presented. The electrochemical processes in the vicinity of the electrode surface are dynamic interactions between charged and uncharged species. Redox processes in the classical sense constitute only...

  15. Direct determination of bulk etching rate for LR-115-II solid state nuclear track detectors

    Indian Academy of Sciences (India)

    T A Salama; U Seddik; T M Heggazy; A Ahmed Morsy

    2006-09-01

    The thickness of the removed layer of the LR-115-II solid state nuclear track detector during etching is measured directly with a rather precise instrument. Dependence of bulk etching rate on temperature of the etching solution is investigated. It has been found that the bulk etching rate is 3.2 m/h at 60°C in 2.5 N NaOH of water solution. It is also found that the track density in detectors exposed to soil samples increases linearly with the removed layer.

  16. Experiment and mechanism of vibration liquefaction and compacting of saturated bulk solid

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The paper studies the probability of industrial application of vibration liquefaction of bulk solid from the opposite point of view, and proposing turning its harmful effects into benefits. Utilizing a new device of vibration liquefaction and by compacting saturated bulk solid, a set of additional device for experiment was designed. These experiments examined the problems related to vibration liquefaction of fine-ores and tailings on the basis of DSA-1 type direct shear apparatus, including models of straight tubes, curved tubes and a sandbox. The changing properties of tailings under vibration and the mechanism of vibration liquefaction and compacting of tailings were studied, and future application of the technique to mines has been put forward.

  17. [Recycle of contaminated scrap metal]: Task 1.3.2, Bulk solids feed system. Topical report, October 1993-- January 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    A critical requirement in DOE`s efforts to recycle, reuse, and dispose of materials from its decontamination and decommissioning activities is the design of a robust system to process a wide variety of bulk solid feeds. The capability to process bulk solids will increase the range of materials and broaden the application of Catalytic Extraction Processing (CEP). The term bulk solids refers to materials that are more economically fed into the top of a molten metal bath than by submerged injection through a tuyere. Molten Metal Technology, Inc. (MMT) has characterized CEP`s ability to process bulk solid feed materials and has achieved significant growth in the size of bulk solid particles compatible with Catalytic Extraction Processing. Parametric experimental studies using various feed materials representative of the components of various DOE waste streams have validated design models which establish the reactor operating range as a function of feed material, mass flow rate, and particle size. MMT is investigating the use of a slurry system for bulk solid addition as it is the most efficient means for injecting soils, sludges, and similar physical forms into a catalytic processing unit. MMT is continuing to evaluate condensed phase product removal systems and alternative energy addition sources to enhance the operating efficiency of bulk solids CEP units. A condensed phase product removal system capable of on-demand product removal has been successfully demonstrated. MMT is also investigating the use of a plasma arc torch to provide supplemental heating during bulk solids processing. This comprehensive approach to bulk solids processing is expected to further improve overall process efficiency prior to the deployment of CEP for the recycle, reuse, and disposal of materials from DOE decontamination and decommissioning Activities.

  18. Effects of bulk and interfacial anharmonicity on thermal conductance at solid/solid interfaces

    Science.gov (United States)

    Le, Nam Q.; Polanco, Carlos A.; Rastgarkafshgarkolaei, Rouzbeh; Zhang, Jingjie; Ghosh, Avik W.; Norris, Pamela M.

    2017-06-01

    We present the results of classical molecular dynamics simulations to assess the relative contributions to interfacial thermal conductance from inelastic phonon processes at the interface and in the adjacent bulk materials. The simulated system is the prototypical interface between argon and "heavy argon" crystals, which enables comparison with many past computational studies. We run simulations interchanging the Lennard-Jones potential with its harmonic approximation to test the effect of anharmonicity on conductance. The results confirm that the presence of anharmonicity is correlated with increasing thermal conductance with temperature, which supports conclusions from prior experimental and theoretical work. However, in the model Ar/heavy-Ar system, anharmonic effects at the interface itself contribute a surprisingly small part of the total thermal conductance. The larger fraction of the thermal conductance at high temperatures arises from anharmonic effects away from the interface. These observations are supported by comparisons of the spectral energy density, which suggest that bulk anharmonic processes increase the interfacial conductance by thermalizing energy from modes with low transmission to modes with high transmission.

  19. THE RELATIONSHIP OF TOTAL DISSOLVED SOLIDS MEASUREMENTS TO BULK ELECTRICAL CONDUCTIVITY IN AN AQUIFER CONTAMINATED WITH HYDROCARBON

    Science.gov (United States)

    A recent conceptual model links high bulk electrical conductivities at hydrocarbon impacted sites to higher total dissolved solids (TDS) resulting from enhanced mineral weathering due to acids produced during biodegradation. In this study, we investigated the vertical distributio...

  20. Manufacturing Solid Dosage Forms from Bulk Liquids Using the Fluid-bed Drying Technology.

    Science.gov (United States)

    Qi, Jianping; Lu, Y I; Wu, Wei

    2015-01-01

    Solid dosage forms are better than liquid dosage forms in many ways, such as improved physical and chemical stability, ease of storage and transportation, improved handling properties, and patient compliance. Therefore, it is required to transform dosage forms of liquid origins into solid dosage forms. The functional approaches are to absorb the liquids by solid excipients or through drying. The conventional drying technologies for this purpose include drying by heating, vacuum-, freeze- and spray-drying, etc. Among these drying technologies, fluidbed drying emerges as a new technology that possesses unique advantages. Fluid-bed drying or coating is highly efficient in solvent removal, can be performed at relatively low temperatures, and is a one-step process to manufacture formulations in pellet forms. In this article, the status of the art of manufacturing solid dosage forms from bulk liquids by fluid-bed drying technology was reviewed emphasizing on its application in solid dispersion, inclusion complexes, self-microemulsifying systems, and various nanoscale drug delivery systems.

  1. Surface and bulk crystallization of amorphous solid water films: Confirmation of "top-down" crystallization

    Science.gov (United States)

    Yuan, Chunqing; Smith, R. Scott; Kay, Bruce D.

    2016-10-01

    The crystallization kinetics of nanoscale amorphous solid water (ASW) films are investigated using temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). TPD measurements are used to probe surface crystallization and RAIRS measurements are used to probe bulk crystallization. Isothermal TPD results show that surface crystallization is independent of the film thickness (from 100 to 1000 ML). Conversely, the RAIRS measurements show that the bulk crystallization time increases linearly with increasing film thickness. These results suggest that nucleation and crystallization begin at the ASW/vacuum interface and then the crystallization growth front propagates linearly into the bulk. This mechanism was confirmed by selective placement of an isotopic layer (5% D2O in H2O) at various positions in an ASW (H2O) film. In this case, the closer the isotopic layer was to the vacuum interface, the earlier the isotopic layer crystallized. These experiments provide direct evidence to confirm that ASW crystallization in vacuum proceeds by a "top-down" crystallization mechanism.

  2. Surface and bulk crystallization of amorphous solid water films: Confirmation of “top-down” crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Chunqing; Smith, R. Scott; Kay, Bruce D.

    2016-10-01

    The crystallization kinetics of nanoscale amorphous solid water (ASW) films are investigated using temperature-programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS). TPD measurements are used to probe surface crystallization and RAIRS measurements are used to probe bulk crystallization. Isothermal TPD results show that surface crystallization is independent of the film thickness (from 100 to 1000 ML). Conversely, the RAIRS measurements show that the bulk crystallization time increases linearly with increasing film thickness. These results suggest that nucleation and crystallization begin at the ASW/vacuum interface and then the crystallization growth front propagates linearly into the bulk. This mechanism was confirmed by selective placement of an isotopic layer (5% D2O in H2O) at various positions in an ASW (H2O) film. In this case, the closer the isotopic layer was to the vacuum interface, the earlier the isotopic layer crystallized. These experiments provide direct evidence to confirm that ASW crystallization in vacuum proceeds by a “top-down” crystallization mechanism.

  3. Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass -- Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    J. Richard Hess; Christopher T. Wright; Kevin L. Kenney; Erin M. Searcy

    2009-04-01

    This report, Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass, prepared by Idaho National Laboratory (INL), acknowledges the need and provides supportive designs for an evolutionary progression from present day conventional bale-based supply systems to a uniform-format, bulk solid supply system that transitions incrementally as the industry launches and matures. These designs couple to and build from current state of technology and address science and engineering constraints that have been identified by rigorous sensitivity analyses as having the greatest impact on feedstock supply system efficiencies and costs.

  4. Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass -- Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    J. Richard Hess; Christopher T. Wright; Kevin L. Kenney; Erin M. Searcy

    2009-04-01

    This report, Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass, prepared by Idaho National Laboratory (INL), acknowledges the need and provides supportive designs for an evolutionary progression from present day conventional bale-based supply systems to a uniform-format, bulk solid supply system that transitions incrementally as the industry launches and matures. These designs couple to and build from current state of technology and address science and engineering constraints that have been identified by rigorous sensitivity analyses as having the greatest impact on feedstock supply system efficiencies and costs.

  5. Effect of initial bulk density on high-solids anaerobic digestion of MSW: General mechanism.

    Science.gov (United States)

    Caicedo, Luis M; Wang, Hongtao; Lu, Wenjing; De Clercq, Djavan; Liu, Yanjun; Xu, Sai; Ni, Zhe

    2017-06-01

    Initial bulk density (IBD) is an important variable in anaerobic digestion since it defines and optimizes the treatment capacity of a system. This study reveals the mechanism on how IBD might affect anaerobic digestion of waste. Four different IBD values: D1 (500-700kgm(-3)), D2 (900-1000kgm(-3)), D3 (1100-1200kgm(-3)) and D4 (1200-1400kgm(-3)) were set and tested over a period of 90days in simulated landfill reactors. The main variables affected by the IBD are the methane generation, saturation degree, extraction of organic matter, and the total population of methanogens. The study identified that IBD >1000kgm(-3) may have significant effect on methane generation, either prolonging the lag time or completely inhibiting the process. This study provides a new understanding of the anaerobic digestion process in saturated high-solids systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Thermoelectric properties of bulk MoSi2 synthesized by solid state microwave heating

    Science.gov (United States)

    Lan, Yu; Xie, Mianyu; Ouyang, Ting; Yue, Song

    2016-07-01

    In this research, single phase α-MoSi2 was prepared by solid state hybrid microwave heating within 90 min at relatively low temperature 1273 K. Such precursor powders were then ball milled and sintered by microwave heating at different temperatures. The thermoelectric (TE) properties of MoSi2 bulks were investigated in the temperature range of 300-673 K. When the sintering temperature increases from 973 K to 1273 K, the electrical resistivity decreases significantly and the Seebeck coefficients increase obviously, leading to the maximum TE powder factor of 6.2 × 10-6Wm-1K-2 at 673 K. These results demonstrate the feasibility of high efficient and economical synthesis of MoSi2 by microwave heating technique, with the final products having comparable TE performance in comparison to those from typical methods with long duration and energy-extensive consumption.

  7. Investigation of preparation methods on surface/bulk structural relaxation and glass fragility of amorphous solid dispersions.

    Science.gov (United States)

    Ke, Peng; Hasegawa, Susumu; Al-Obaidi, Hisham; Buckton, Graham

    2012-01-17

    The objective of this study was to investigate the effect of preparation methods on the surface/bulk molecular mobility and glass fragility of solid dispersions. Solid dispersions containing indomethacin and PVP K30 were chosen as the model system. An inverse gas chromatography method was used to determine the surface structural relaxation of the solid dispersions and these data were compared to those for bulk relaxation obtained by DSC. The values of τ(β) for the surface relaxation were 4.6, 7.1 and 1.8h for melt quenched, ball milled and spray dried solid dispersions respectively, compared to 15.6, 7.9 and 9.8h of the bulk. In all systems, the surface had higher molecular mobility than the bulk. The glass fragility of the solid dispersions was also influenced by the preparation methods with the most fragile system showing the best stability. The zero mobility temperature (T(0)) was used to correlate with the physical stability of the solid dispersions. Despite having similar T(g) (65°C), the T(0) of the melt quenched, ball milled and spray dried samples were 21.6, -4.2 and 16.7°C respectively which correlated well with their physical stability results. Therefore, T(0) appears to be a better indicator than T(g) for predicting stability of amorphous materials.

  8. Molecular simulation of fluid mixtures in bulk and at solid-liquid interfaces

    Science.gov (United States)

    Kern, Jesse L.

    The properties of a diverse range of mixture systems at interfaces are investigated using a variety of computational techniques. Molecular simulation is used to examine the thermodynamic, structural, and transport properties of heterogeneous systems of theoretical and practical importance. The study of binary hard-sphere mixtures at a hard wall demonstrates the high accuracy of recently developed classical-density functionals. The study of aluminum--gallium solid--liquid heterogeneous interfaces predicts a significant amount of prefreezing of the liquid by adopting the structure of the solid surface. The study of ethylene-expanded methanol within model silica mesopores shows the effect of confinement and surface functionalzation on the mixture composition and transport inside of the pores. From our molecular-dynamics study of binary hard-sphere fluid mixtures at a hard wall, we obtained high-precision calculations of the wall-fluid interfacial free energies, gamma. We have considered mixtures of varying diameter ratio, alpha = 0.7,0.8,0.9; mole fraction, x 1 = 0.25,0.50,0.75; and packing fraction, eta compressive stress on the Ga atoms. Bulk methanol--ethylene mixtures under vapor-liquid equilibrium conditions have been characterized using Monte Carlo and molecular dynamics. The simulated vapor-liquid coexistence curves for the pure-component and binary mixtures agree well with experiment, as do the mixture volumetric expansion results. Using chemical potentials obtained from the bulk simulations, the filling of a number of model silica mesopores with ethylene and methanol is simulated. We report the compositions of the confined fluid mixtures over a range of pressures and for three degrees of nominal pore hydrophobicity.

  9. A study of influence of gravity on bulk behavior of particulate solid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper examines the influence of gravity on the bulk responses of a granular solid. The loading scenarios in this study include confined compression, rod penetration into a granular medium and discharging through an orifice. Similar loading and flow conditions are likely to be encountered in the stress and deformation regimes that regoliths are subjected to in extraterrestrial exploration activities including in situ resource utilisation processes. Both spherical and non-spherical particles were studied using the discrete element method (DEM). Whilst DEM is increasingly used to model granular solids, careful validations of the simulation outcomes are rather rare. Thus in addition to exploring the effect of gravity, this paper also compares DEM simulations with experiments under terrestrial condition to verify whether DEM can produce satisfactory predictions.The terrestrial experiments were conducted with great care and simulated closely using DEM. The key mechanical and geometrical properties for the particles were measured in laboratory tests for use in the DEM simulations. A series of DEM computations were then performed under reduced gravity to simulate these experiments under extraterrestrial environment. It was found that gravity has no noticeable effect on the force transmission in the confined compression case; the loading gradient in the rod penetration is linearly proportional to the gravity; the mass flow rate in silo discharge is proportional to square root of the gravity and the angle of repose increases with reducing gravity. These findings are in agreement with expectation and existing scientific evidence.

  10. Solid, shape recovered 'Bulk' nitinol: Part II-Mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Saigal, Anil, E-mail: anil.saigal@tufts.edu [Department of Mechanical Engineering, Tufts University, Medford, MA 02155 (United States); Fonte, Matthew [Department of Mechanical Engineering, Tufts University, Medford, MA 02155 (United States)

    2011-06-25

    Highlights: {yields} Evaluate use of solid bulk Nitinol as a potential material for hip replacements. {yields} At 400 MPa, Nitinol has an endurance limit greater than 10 million cycles. {yields} Below 445 MPa [1 1 1] textured specimens last longer than [1 1 0] textured specimens. {yields} Above 445 MPa, it switches and both fail relatively quickly around 400,000 cycles. {yields} Impact toughness - Charpy: 4 ft-lbs {+-} 3%, CT: 20-31 MPa{radical}m. - Abstract: The use of Nitinol for medical purposes was first reported in the late 1960s. Today Nitinol is commonly used for the manufacture of stents, which are primarily used in peripheral and coronary bypass graft interventions. The application of NiTi in orthopedics is an exciting prospect but one that has yet to be realized. Nitinol's unique mechanical behavior is derived from the coordinated atomic movements manifesting in phase transformations from cubic austenite to monoclinic martensite. These phase transformations are solid-to-solid phase transformations that occur without diffusion or plasticity, potentially making them reversible. They involve changes in the crystalline structure that can be induced by changes in either temperature or stress. In addition to phase transformations, Nitinol's mechanical strength is strongly dependent on the alloy composition and the method in which the material is processed, i.e. rolled, drawn, extruded, or forged. The mechanical work, combined with the intermediate heat treatment steps, contribute to modify microstructure, transformation temperatures and mechanical properties. These manufacturing processing steps lead to texturing (crystallographic alignment) of the material. Alignment of the atomic planes from texture in the polycrystalline material have a marked influence on the mechanical properties by either limiting or promoting phase transformations and shape recovery strains. This paper focuses on the fatigue and fracture properties of Nitinol.

  11. Testing a simple method for computing directly the bulk modulus by NPT simulation: The case of polydisperse hard sphere solids

    Science.gov (United States)

    Li, Da; Xu, Hong

    2015-10-01

    The bulk modulus of hard sphere solids has been computed directly by constant pressure Monte-Carlo simulations, using the histogram of the volume fluctuations. In considering first the one-component system, we show that the method is accurate in a large range of pressures, including high-pressure regime. The method is then applied to a polydisperse solid with relatively low polydispersity index. For illustrative purpose, we took a three-component mixture with symmetric size-distribution, and we studied the solid phase (fcc crystal) of this system. Our results show that the equation of state is very sensitive to the polydispersity. Furthermore, in the high-pressure region, where no (accurate) analytical fit for the equation of state exists, our simulations are able to predict the bulk modulus of such systems.

  12. Proceedings of the technical program. Powder and bulk solids handling and processing

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    Papers are presented under the following session headings: powder system properties; computer applications, system instrumentation and control; fluidization and fluid-particle technology; solids feeders; filtration, separation and dust control; solids mixing and blending; powder production and processing; solids handling, discharge and flow improvement; safety considerations in solids handling and processing; solids drying; size reduction I; pneumatic conveying I; fractals and particle morphology; containers and storage systems; size reduction II; particle characterization; coal technology; belt conveyors; and pneumatic conveying II.

  13. Bulk and surface acoustic waves in solid-fluid Fibonacci layered materials.

    Science.gov (United States)

    Quotane, I; El Boudouti, E H; Djafari-Rouhani, B; El Hassouani, Y; Velasco, V R

    2015-08-01

    We study theoretically the propagation and localization of acoustic waves in quasi-periodic structures made of solid and fluid layers arranged according to a Fibonacci sequence. We consider two types of structures: either a given Fibonacci sequence or a periodic repetition of a given sequence called Fibonacci superlattice. Various properties of these systems such as: the scaling law and the self-similarity of the transmission spectra or the power law behavior of the measure of the energy spectrum have been highlighted for waves of sagittal polarization in normal and oblique incidence. In addition to the allowed modes which propagate along the system, we study surface modes induced by the surface of the Fibonacci superlattice. In comparison with solid-solid layered structures, the solid-fluid systems exhibit transmission zeros which can break the self-similarity behavior in the transmission spectra for a given sequence or induce additional gaps other than Bragg gaps in a periodic structure.

  14. Thermally activated reaction–diffusion-controlled chemical bulk reactions of gases and solids

    Directory of Open Access Journals (Sweden)

    S. Möller

    2015-01-01

    Full Text Available The chemical kinetics of the reaction of thin films with reactive gases is investigated. The removal of thin films using thermally activated solid–gas to gas reactions is a method to in-situ control deposition inventory in vacuum and plasma vessels. Significant scatter of experimental deposit removal rates at apparently similar conditions was observed in the past, highlighting the need for understanding the underlying processes. A model based on the presence of reactive gas in the films bulk and chemical kinetics is presented. The model describes the diffusion of reactive gas into the film and its chemical interaction with film constituents in the bulk using a stationary reaction–diffusion equation. This yields the reactive gas concentration and reaction rates. Diffusion and reaction rate limitations are depicted in parameter studies. Comparison with literature data on tokamak co-deposit removal results in good agreement of removal rates as a function of pressure, film thickness and temperature.

  15. Anaerobic treatment of wastewater with high suspended solids from a bulk drug industry using fixed film reactor (AFFR).

    Science.gov (United States)

    Gangagni Rao, A; Venkata Naidu, G; Krishna Prasad, K; Chandrasekhar Rao, N; Venkata Mohan, S; Jetty, Annapurna; Sarma, P N

    2005-01-01

    Studies were carried out on the treatment of wastewater from a bulk drug industry using an anaerobic fixed film reactor (AFFR) designed and fabricated in the laboratory. The chemical oxygen demand (COD) and total dissolved solids (TDS) of the wastewater were found to be very high with low biochemical oxygen demand (BOD) to COD ratio and high total suspended solid (TSS) concentration. Acclimatization of seed consortia and startup of the reactor was carried out by directly using the wastewater, which resulted in reducing the period of startup to 30 days. The reactor was studied at different organic loading rates (OLR) and it was found that the optimum OLR was 10 kg COD/m(3)/day. The wastewater under investigation, which had a considerable quantity of SS, was treated anaerobically without any pretreatment. COD and BOD of the reactor outlet wastewater were monitored and at steady state and optimum OLR 60-70% of COD and 80-90% of BOD were removed. The reactor was subjected to organic shock loads at two different OLR and the reaction could withstand the shocks and performance could be restored to normalcy at that OLR. The results obtained indicated that AFFR could be used efficiently for the treatment of wastewater from a bulk drug industry having high COD, TDS and TSS.

  16. Effect of adding bulking materials over the composting process of municipal solid biowastes

    Directory of Open Access Journals (Sweden)

    Ricardo Oviedo-Ocaña

    2015-12-01

    Full Text Available Biowastes (BW, the main raw materials for the composting installations in developing countries, are characterized for containing uncooked food wastes (FW, high moisture content, low porosity, acidic pH, and low C/N ratios which affects the overall composting process (CP. In this study, we evaluated the effect of adding sugarcane bagasse (SCB and star grass (SG (Cynodon plectostachyus (K. Schum. Pilg. as bulking materials (BM over the quality of the substrate, progress of the process, and quality of the obtained product. In this sense, two pilot-scale experiments were performed. The first one contained a substrate formed by 78% BW and 22% SCB (pile A. The second experiment contained a substrate formed by 66% BW and 34% SG (pile B. For each experiment, control treatments (piles A' and B' respectively were performed by using 100% BW without BM. The results showed that in both cases the adding of BM improved substrate quality (pH, moisture, and total organic C content [TOC], speeding up the starting step (2-3 d and reducing the duration of the thermophilic phase of CP (3 d. However, the physico-chemical properties of both BM increased cooling and maturation phases duration (between 15 and 20 d. Obtained products quality was improved in terms of higher TOC, cation-exchange capacity, bulk density, and higher water holding capacity. Application of obtained products A and B could improve some soil properties like major nutrient, water retention, and increasing the organic matter.

  17. Connecting point defect parameters with bulk properties to describe diffusion in solids

    Science.gov (United States)

    Chroneos, A.

    2016-12-01

    Diffusion is a fundamental process that can have an impact on numerous technological applications, such as nanoelectronics, nuclear materials, fuel cells, and batteries, whereas its understanding is important across scientific fields including materials science and geophysics. In numerous systems, it is difficult to experimentally determine the diffusion properties over a range of temperatures and pressures. This gap can be bridged by the use of thermodynamic models that link point defect parameters to bulk properties, which are more easily accessible. The present review offers a discussion on the applicability of the cBΩ model, which assumes that the defect Gibbs energy is proportional to the isothermal bulk modulus and the mean volume per atom. This thermodynamic model was first introduced 40 years ago; however, consequent advances in computational modelling and experimental techniques have regenerated the interest of the community in using it to calculate diffusion properties, particularly under extreme conditions. This work examines recent characteristic examples, in which the model has been employed in semiconductor and nuclear materials. Finally, there is a discussion on future directions and systems that will possibly be the focus of studies in the decades to come.

  18. Femtosecond laser surface ablation of transparent solids: understanding the bulk filamentation damage

    Science.gov (United States)

    Kudryashov, Sergey I.; Joglekar, A.; Mourou, G.; Ionin, A. A.; Zvorykin, V. D.; Hunt, A. J.

    2007-06-01

    Direct SEM examination reveals a complex nanoscale structure of deep narrow central channels within shallow wide external craters produced by single-shot high-intensity femtosecond laser radiation on Corning 0211 glass and sapphire surfaces. These internal narrow channels are not expected from ordinary surface melt spallation and expulsion processes characteristic of the external surface nanocraters, but exhibit nearly the same appearance threshold. Surprisingly, the nanochannel radiuses rapidly saturate versus incident laser intensity indicating bulk rather than surface character of laser energy deposition, in contrast to the external craters extending versus laser intensity in a regular manner. These facts may be explained by channeling of electromagnetic radiation by near-surface ablative filamentary propagation of intense femtosecond laser pulses in the highly electronically excited dielectrics, by spherical aberrations in the surface layer, or deep drilling of the samples by short-wavelength Bremsstrahlung radiation of relatively hot surface electron-hole or electron-ion plasma. The double structure of ablated surface nano-features is consistent with similar structures observed for bulk damage features fabricated by femtosecond laser pulses at supercritical laser powers, but much lower laser intensities.

  19. Tunable Quantum Dot Solids: Impact of Interparticle Interactions on Bulk Properties

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, Michael B. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Fan, Hongyou [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Brener, Igal [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Liu, Sheng [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Luk, Ting S. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Li, Binsong [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    QD-solids comprising self-assembled semiconductor nanocrystals such as CdSe are currently under investigation for use in a wide array of applications including light emitting diodes, solar cells, field effect transistors, photodetectors, and biosensors. The goal of this LDRD project was develop a fundamental understanding of the relationship between nanoparticle interactions and the different regimes of charge and energy transport in semiconductor quantum dot (QD) solids. Interparticle spacing was tuned through the application of hydrostatic pressure in a diamond anvil cell, and the impact on interparticle interactions was probed using x-ray scattering and a variety of static and transient optical spectroscopies. During the course of this LDRD, we discovered a new, previously unknown, route to synthesize semiconductor quantum wires using high pressure sintering of self-assembled quantum dot crystals. We believe that this new, pressure driven synthesis approach holds great potential as a new tool for nanomaterials synthesis and engineering.

  20. Time Evolution of Reflective Thermal Lenses and Measurement of Thermal Diffusivity in Bulk Solids

    Science.gov (United States)

    Doiron, Serge; Haché, Alain

    2004-07-01

    A simple method for optically measuring the thermal diffusivity of solids is demonstrated. The thermal displacement created on a substrate by a focused laser beam is determined from the divergence that it induces in a weak probe beam. The dynamics of the surface lens and the amplitude of the probe beam's divergence are then used to determine the thermal diffusivity of the substrate. Several materials that span a wide range of thermal properties are studied.

  1. Simple Rules for Solid-state Design: From Bulk to Interface

    Science.gov (United States)

    Butler, Keith; Walsh, Aron; Jackson, Adam; Davies, Dan; Oba, Fumiyasu; Kumagai, Yu; Walsh Materials Design Team; JSPS Collaboration

    High-throughput screening enterprises such as Materials Project and the OQMD are well suited to the application of density functional theory for assessing the merits of known bulk materials. The blind exploration of the new combinations and permutations of the periodic table is a daunting task, to paraphrase Samuel Beckett we feel lost before the confusion of innumerable prospects. Centuries of research have provided us with myriad rules for assessing the feasibility of a given stoichiometry and the likelihood of particular crystal arrangements. We explore the ways in which chemical knowledge and state-of-the-art computational physics can be combined to accelerate materials design. We present the SMACT (Semiconducting Materials by Analogy and Chemical Theory) package, which combines these rules with searching of chemical space to predict plausible and heretofore unknown compounds. I will then provide some illustrative examples of materials' design focusing on several important issues: (i) designing new photovoltaic materials, (ii) the role of surfaces and polymorphism in controlling electronic properties, and (iii) the design of porous materials.

  2. Integrated Solid/Nanoporous Copper/Oxide Hybrid Bulk Electrodes for High-performance Lithium-Ion Batteries

    Science.gov (United States)

    Hou, Chao; Lang, Xing-You; Han, Gao-Feng; Li, Ying-Qi; Zhao, Lei; Wen, Zi; Zhu, Yong-Fu; Zhao, Ming; Li, Jian-Chen; Lian, Jian-She; Jiang, Qing

    2013-01-01

    Nanoarchitectured electroactive materials can boost rates of Li insertion/extraction, showing genuine potential to increase power output of Li-ion batteries. However, electrodes assembled with low-dimensional nanostructured transition metal oxides by conventional approach suffer from dramatic reductions in energy capacities owing to sluggish ion and electron transport kinetics. Here we report that flexible bulk electrodes, made of three-dimensional bicontinuous nanoporous Cu/MnO2 hybrid and seamlessly integrated with Cu solid current collector, substantially optimizes Li storage behavior of the constituent MnO2. As a result of the unique integration of solid/nanoporous hybrid architecture that simultaneously enhances the electron transport of MnO2, facilitates fast ion diffusion and accommodates large volume changes on Li insertion/extraction of MnO2, the supported MnO2 exhibits a stable capacity of as high as ~1100 mA h g−1 for 1000 cycles, and ultrahigh charge/discharge rates. It makes the environmentally friendly and low-cost electrode as a promising anode for high-performance Li-ion battery applications. PMID:24096928

  3. Solid state synthesis and characterization of bulk β-FeSe superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Onar, K. [İnönü Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, 44280 Malatya (Turkey); Yakinci, M.E. [İnönü Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, 44280 Malatya (Turkey); İnönü Üniversitesi, Mühendislik Fakültesi, Biyomedikal Mühendisliği Bölümü, 44280 Malatya (Turkey)

    2015-01-25

    Highlights: • The upper critical field H{sub c2}(0) was determined to be 23.2 T. • At the zero field coherence length value was calculated to be 3.33 nm. • Calculated μ{sub 0}H{sub c2}(0)/k{sub B}T{sub c} rate was found to be 3.17 T/K. • Obtained results were suggested unconventional nature of superconductivity. - Abstract: Polycrystalline FeSe{sub 0.88} was synthesized by solid-state reaction method in sealed quartz tube at different heat heating cycles. The identification and characterization of FeSe{sub 0.88} samples were determined by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The electrical transport, magnetic and thermal transport properties of the obtained samples were also investigated. The results showed that the sensitivity of resistivity and magnetic susceptibility depends on heating cycles while the structural formation of samples does not. The upper critical field H{sub c2}(0) has been determined with the magnetic field parallel to the sample surface and yielding a maximum value of 23.2 T. At the zero field coherence length, ξ, value was calculated to be 3.33 nm. Calculated μ{sub 0}H{sub c2}(0)/k{sub B}T{sub c} rate indicated comparably higher value (3.17 T/K) than the Pauli limit (1.84 T/K) and obtained results were suggested unconventional nature of superconductivity in our samples.

  4. Determination of the main solid-state form of albendazole in bulk drug, employing Raman spectroscopy coupled to multivariate analysis.

    Science.gov (United States)

    Calvo, Natalia L; Arias, Juan M; Altabef, Aída Ben; Maggio, Rubén M; Kaufman, Teodoro S

    2016-09-10

    Albendazole (ALB) is a broad-spectrum anthelmintic, which exhibits two solid-state forms (Forms I and II). The Form I is the metastable crystal at room temperature, while Form II is the stable one. Because the drug has poor aqueous solubility and Form II is less soluble than Form I, it is desirable to have a method to assess the solid-state form of the drug employed for manufacturing purposes. Therefore, a Partial Least Squares (PLS) model was developed for the determination of Form I of ALB in its mixtures with Form II. For model development, both solid-state forms of ALB were prepared and characterized by microscopic (optical and with normal and polarized light), thermal (DSC) and spectroscopic (ATR-FTIR, Raman) techniques. Mixtures of solids in different ratios were prepared by weighing and mechanical mixing of the components. Their Raman spectra were acquired, and subjected to peak smoothing, normalization, standard normal variate correction and de-trending, before performing the PLS calculations. The optimal spectral region (1396-1280cm(-1)) and number of latent variables (LV=3) were obtained employing a moving window of variable size strategy. The method was internally validated by means of the leave one out procedure, providing satisfactory statistics (r(2)=0.9729 and RMSD=5.6%) and figures of merit (LOD=9.4% and MDDC=1.4). Furthermore, the method's performance was also evaluated by analysis of two validation sets. Validation set I was used for assessment of linearity and range and Validation set II, to demonstrate accuracy and precision (Recovery=101.4% and RSD=2.8%). Additionally, a third set of spiked commercial samples was evaluated, exhibiting excellent recoveries (94.2±6.4%). The results suggest that the combination of Raman spectroscopy with multivariate analysis could be applied to the assessment of the main crystal form and its quantitation in samples of ALB bulk drug, in the routine quality control laboratory. Copyright © 2016 Elsevier B.V. All

  5. Pyrosequencing reveals bacterial communities in unchlorinated drinking water distribution system: an integral study of bulk water, suspended solids, loose deposits, and pipe wall biofilm.

    Science.gov (United States)

    Liu, G; Bakker, G L; Li, S; Vreeburg, J H G; Verberk, J Q J C; Medema, G J; Liu, W T; Van Dijk, J C

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  6. Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

    KAUST Repository

    Liu, G.

    2014-05-20

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

  7. Temperature and volumetric water content petrophysical relationships in municipal solid waste for the interpretation of bulk electrical resistivity data

    Science.gov (United States)

    Pilawski, Tamara; Dumont, Gaël; Nguyen, Frédéric

    2015-04-01

    Landfills pose major environmental issues including long-term methane emissions, and local pollution of soil and aquifers but can also be seen as potential energy resources and mining opportunities. Water content in landfills determine whether solid fractions can be separated and recycled, and controls the existence and efficiency of natural or enhanced biodegradation. Geophysical techniques, such as electrical and electromagnetic methods have proven successful in the detection and qualitative investigation of sanitary landfills. However, their interpretation in terms of quantitative water content estimates makes it more challenging due to the influence of parameters such as temperature, compaction, waste composition or pore fluid. To improve the confidence given to bulk electrical resistivity data and to their interpretation, we established temperature and volumetric water content petrophysical relationships that we tested on field and laboratory electrical resistivity measurements. We carried out two laboratory experiments on leachates and waste samples from a landfill located in Mont-Saint-Guibert, Belgium. We determined a first relationship between temperature and electrical resistivity with pure and diluted leachates by progressively increasing the temperature from 5°C to 65°C, and then cooling down to 5°C. The second relationship was obtained by measuring electrical resistivity on waste samples of different volumetric water contents. First, we used the correlations obtained from the experiments to compare electrical resistivity measurements performed in a landfill borehole and on reworked waste samples excavated at different depths. Electrical resistivities were measured every 20cm with an electromagnetic logging device (EM39) while a temperature profile was acquired with optic fibres. Waste samples were excavated every 2m in the same borehole. We filled experimental columns with these samples and measured electrical resistivities at laboratory temperature

  8. Addressing the Interface Issues in All-Solid-State Bulk-Type Lithium Ion Battery via an All-Composite Approach.

    Science.gov (United States)

    Chen, Ru-Jun; Zhang, Yi-Bo; Liu, Ting; Xu, Bing-Qing; Lin, Yuan-Hua; Nan, Ce-Wen; Shen, Yang

    2017-03-22

    All-solid-state bulk-type lithium ion batteries (LIBs) are considered ultimate solutions to the safety issues associated with conventional LIBs using flammable liquid electrolyte. The development of bulk-type all-solid-state LIBs has been hindered by the low loading of active cathode materials, hence low specific surface capacity, and by the high interface resistance, which results in low rate and cyclic performance. In this contribution, we propose and demonstrate a synergistic all-composite approach to fabricating flexible all-solid-state LIBs. PEO-based composite cathode layers (filled with LiFePO4 particles) of ∼300 μm in thickness and composite electrolyte layers (filled with Al-LLZTO particles) are stacked layer-by-layer with lithium foils as negative layer and hot-pressed into a monolithic all-solid-state LIB. The flexible LIB delivers a high specific discharge capacity of 155 mAh/g, which corresponds to an ultrahigh surface capacity of 10.8 mAh/cm(2), exhibits excellent capacity retention up to at least 10 cycles and could work properly under harsh operating conditions such as bending or being sectioned into pieces. The all-composite approach is favorable for improving both mesoscopic and microscopic interfaces inside the all-solid-state LIB and may provide a new toolbox for design and fabrication of all-solid-state LIBs.

  9. Nonlinear Acoustics of Bounded Solid-Reflection and Refraction of Second-Order Bulk Waves(Ⅱ)——SV- or SH- Wave Incidence

    Institute of Scientific and Technical Information of China (English)

    钱祖文

    1994-01-01

    In the case of SV- or SH-wave oblique incidence,the reflection and refraction of the second-order bulk waves resulting from a plane boundary between two solid media are investigated and the mathematical expressions of them are given.It is shown that an SH-wave incidence is absolutely necessary to an overall knowledge of the relationship between the TOEs for isotropic solid.The importance of both contributions of the nonaccumulation waves and the effects of the boundary surface are indicated by numerical computation.

  10. Superconducting and mechanical properties of the bulk Bi(pb)SCCO system prepared via solid state and ammonium nitrate precipitation methods

    Science.gov (United States)

    Safran, S.; Kılıçarslan, E.; Ozturk, H.; Alp, M.; Akdogan, M.; Asikuzun, E.; Ozturk, O.; Kılıç, A.

    2015-09-01

    We have investigated the effect of preparation method on superconducting and mechanical properties of Bi(Pb)-2223 bulk samples using Bi1.85Pb0.35Sr2Ca2Cu3O10±y stoichiometry. Solid-state reaction and ammonium nitrate precipitation methods have been used for fabrication of the bulk samples. In addition, the effect of annealing time on BSCCO samples have been studied. Structural, electrical, magnetic and microhardness analyses of samples are performed by the X-ray powder diffraction (XRD), the Scanning Electron Microscopy (SEM), DC resistivity, AC susceptibility and Vickers microhardness test. The critical transition temperature, phase purity, surface morphology and crystallinity of the prepared bulk samples are compared with each other. Elasticity (E), brittleness (Bi), fracture toughness (KIC) and yield strength (Y) values are also determined according to annealing time, applied load and production parameters of materials.

  11. Prediction and improvement of the solid particles transfer rate for the bulk handing system design of offshore drilling vessels

    Directory of Open Access Journals (Sweden)

    Mincheol Ryu

    2015-11-01

    Full Text Available Numerous experiments with a scaled pilot facility were carried out to compare the relative bulk transfer performance of three special devices for applications to drilling systems. The pipe diameter for bulk transportation was 3 in., which corresponds to around half of the actual system dimensions. Two different pressures, 3 and 4 bar, were considered to check the relative performance under different pressure conditions at a bulk storage tank. And to make a practical estimation method of the bulk transfer rate at the early design stages of the bulk handling system, a series of experiments were conducted for real scaled bulk handing systems of two drilling vessels. The pressure drops at each pipe element as well as the bulk transfer rates were measured under different operating conditions. Using the measured results, the friction factor for each pipe element was calculated and a procedure for transfer rate estimation was developed. Compared to the measured transfer rate results for other drilling vessels, the estimated transfer rates were within a maximum 15% error bound.

  12. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy.

    Science.gov (United States)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-01

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  13. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    Science.gov (United States)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-01

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  14. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons, E-mail: baiker@chem.ethz.ch [Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Hönggerberg, HCI, CH-8093 Zürich (Switzerland)

    2014-08-15

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  15. Rungs 1 to 4 of DFT Jacob's ladder: Extensive test on the lattice constant, bulk modulus, and cohesive energy of solids

    Science.gov (United States)

    Tran, Fabien; Stelzl, Julia; Blaha, Peter

    2016-05-01

    A large panel of old and recently proposed exchange-correlation functionals belonging to rungs 1 to 4 of Jacob's ladder of density functional theory are tested (with and without a dispersion correction term) for the calculation of the lattice constant, bulk modulus, and cohesive energy of solids. Particular attention will be paid to the functionals MGGA_MS2 [J. Sun et al., J. Chem. Phys. 138, 044113 (2013)], mBEEF [J. Wellendorff et al., J. Chem. Phys. 140, 144107 (2014)], and SCAN [J. Sun et al., Phys. Rev. Lett. 115, 036402 (2015)] which are meta-generalized gradient approximations (meta-GGA) and are developed with the goal to be universally good. Another goal is also to determine for which semilocal functionals and groups of solids it is beneficial (or not necessary) to use the Hartree-Fock exchange or a dispersion correction term. It is concluded that for strongly bound solids, functionals of the GGA, i.e., rung 2 of Jacob's ladder, are as accurate as the more sophisticated functionals of the higher rungs, while it is necessary to use dispersion corrected functionals in order to expect at least meaningful results for weakly bound solids. If results for finite systems are also considered, then the meta-GGA functionals are overall clearly superior to the GGA functionals.

  16. Estimation of particle velocity in moving beds based on a flow model for bulk solids. Ryudo model ni motozuita idoso no ryushi sokudo no suisan

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, H. (Muroran Inst. of Tech., Hokkaido (Japan)); Honda, Y. (Snow Brand Milk Products Co. Ltd., Sapporo (Japan))

    1992-11-10

    Based on a particle flow model (stress-shear strain velocity relational expression) which takes account of the bulk volume expansion effect during shearing deformation of particles, a new estimation method for particle velocity distribution and stress distribution is proposed. The method is applied to a crossflow moving bed and to a moving bed for comparison with the experimental values to examine its validity. The method is further extended to predict the velocity profile and stress profile of moving beds in a vertical tube (countercurrent and concurrent) accompanying gas flow. It is indicated that the bulk volume expansion effect differs according to dimensions. The velocity distribution and the stress distribution of flows in a vertical tube are greatly influenced by the nature of the flow, i.e. whether it is a counterflow or a concurrent flow, and the frictional force of solids on a wall surface increases markedly in a concurrent flow, which induces considerable lag of particle velocity. The parameter which is contained in the model and indicates the bulk volume expansion effect is a function of the particle velocity, and it is almost unaffected by the flow rate of gas moving. 7 refs., 10 figs.

  17. Superconducting and mechanical properties of the bulk Bi(pb)SCCO system prepared via solid state and ammonium nitrate precipitation methods

    Energy Technology Data Exchange (ETDEWEB)

    Safran, S., E-mail: safran@science.ankara.edu.tr [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Kılıçarslan, E.; Ozturk, H. [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Alp, M. [Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Akdogan, M. [Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey); Abant İzzet Baysal University, Department of Physics, Bolu (Turkey); Asikuzun, E.; Ozturk, O. [Kastamonu University, Department of Physics, Kastamonu (Turkey); Kastamonu University, Research and Application Center, Kastamonu (Turkey); Kılıç, A. [Ankara University, Faculty of Science, Department of Physics, Tandoğan, Ankara 06100 (Turkey); Center of Excellence for Superconductivity Research, 50 Year Campus, Golbaşı, Ankara (Turkey)

    2015-09-01

    We have investigated the effect of preparation method on superconducting and mechanical properties of Bi(Pb)-2223 bulk samples using Bi{sub 1.85}Pb{sub 0.35}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10±y} stoichiometry. Solid-state reaction and ammonium nitrate precipitation methods have been used for fabrication of the bulk samples. In addition, the effect of annealing time on BSCCO samples have been studied. Structural, electrical, magnetic and microhardness analyses of samples are performed by the X-ray powder diffraction (XRD), the Scanning Electron Microscopy (SEM), DC resistivity, AC susceptibility and Vickers microhardness test. The critical transition temperature, phase purity, surface morphology and crystallinity of the prepared bulk samples are compared with each other. Elasticity (E), brittleness (B{sub i}), fracture toughness (K{sub IC}) and yield strength (Y) values are also determined according to annealing time, applied load and production parameters of materials.

  18. 49 CFR 173.211 - Non-bulk packagings for solid hazardous materials in Packing Group I.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group I. 173.211 Section 173.211 Transportation Other Regulations Relating to... materials in Packing Group I. (a) When § 172.101 of this subchapter specifies that a solid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I...

  19. 49 CFR 173.213 - Non-bulk packagings for solid hazardous materials in Packing Group III.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group III. 173.213 Section 173.213 Transportation Other Regulations Relating to... materials in Packing Group III. (a) When § 172.101 of this subchapter specifies that a solid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I, II or...

  20. 49 CFR 173.212 - Non-bulk packagings for solid hazardous materials in Packing Group II.

    Science.gov (United States)

    2010-10-01

    ... in Packing Group II. 173.212 Section 173.212 Transportation Other Regulations Relating to... materials in Packing Group II. (a) When § 172.101 of this subchapter specifies that a solid hazardous... of part 173, to the requirements of part 178 of this subchapter at the Packing Group I or...

  1. Simulation study of a chaotic cavity transducer based virtual phased array used for focusing in the bulk of a solid material.

    Science.gov (United States)

    Delrue, Steven; Van Den Abeele, Koen; Matar, Olivier Bou

    2016-04-01

    In acoustic and ultrasonic non-destructive testing techniques, it is sometimes beneficial to concentrate sound energy at a chosen location in space and at a specific instance in time, for example to improve the signal-to-noise ratio or activate the nonlinearity of damage features. Time Reversal (TR) techniques, taking advantage of the reversible character of the wave equation, are particularly suited to focus ultrasonic waves in time and space. The characteristics of the energy focusing in solid media using principles of time reversed acoustics are highly influenced by the nature and dimensions of the medium, the number of transducers and the length of the received signals. Usually, a large number of transducers enclosing the domain of interest is needed to improve the quality of the focusing. However, in the case of highly reverberant media, the number of transducers can be reduced to only one (single-channel TR). For focusing in a non-reverberant medium, which is impossible when using only one source, an adaptation of the single-channel reciprocal TR procedure has been recently suggested by means of a Chaotic Cavity Transducer (CCT), a single element transducer glued on a cavity of chaotic shape. In this paper, a CCT is used to focus elastic energy, at different times, in different points along a predefined line on the upper surface of a thick solid sample. Doing so, all focusing points can act as a virtual phased array transducer, allowing to focus in any point along the depth direction of the sample. This is impossible using conventional reciprocal TR, as you need to have access to all points in the bulk of the material for detecting signals to be used in the TR process. To asses and provide a better understanding of this concept, a numerical study has been developed, allowing to verify the basic concepts of the virtual phased array and to illustrate multi-component time reversal focusing in the bulk of a solid material.

  2. Development of high-power and high-energy 2 µm bulk solid-state lasers and amplifiers

    CSIR Research Space (South Africa)

    Koen, W

    2016-04-01

    Full Text Available with the proliferation of both neodymium solid-state lasers as well as diode lasers. Mid-infrared laser sources in the 2-5 µm region, however, lagged behind in both power and availability. Even though they were demonstrated soon after the first laser was developed... for aircraft from anti-aircraft missiles. Mid-infrared lasers may also be used as target designators and for range finding. Free space communication is also possible, provided the laser wavelength coincides with an atmospheric transmission window, as shown...

  3. Anhydrous ringwoodites in the mantle transition zone: Their bulk modulus, solid solution behavior, compositional variation, and sound velocity feature

    Directory of Open Access Journals (Sweden)

    Xi Liu

    2016-06-01

    Full Text Available The isothermal bulk moduli of anhydrous Mg2SiO4-ringwoodite (Rw and Fe2SiO4-Rw, and other 4–2 oxide spinels at ambient P-T condition have been evaluated, and empirically fitted to a model as KT0 = 270.8(300 + 0.343(59*V0 + 23.04(269*EN-total, where KT0 is the isothermal bulk modulus in GPa, V0 the unit-cell volume in Å3 and EN-total the electronegativity total of all cations in the chemical formula. This model well reproduces all data used in its calibration, and may be used to predict the KT0 of other 4–2 oxide spinels. Combined with the generally linear volume–composition relationship of the Rw solid solutions along the join Mg2SiO4–Fe2SiO4, this model leads to a much smaller composition effect on the KT0: KT0 = 185.0(1 + 7.0(1*XFe, where XFe is the atomic ratio Fe/(Fe + Mg. Furthermore, a bulk composition-independent compositional variation with P has been disclosed for the Rw at the P-T conditions of the lower part of the mantle transition zone (MTZ: XFe = 0.222(41 – 0.0053(19*P, with P in GPa. The nearly ideal mixing behavior, much smaller composition effect on the bulk modulus, and significant compositional variation of the Rw in the lower part of the MTZ substantially increase the gradients of the Vs-P and Vp-P profiles to generally match those constrained by the seismic reference models PREM and AK135. If there is any global low-T anomaly at the depth of 660 km, its required magnitude is most likely not larger than 200 K.

  4. Solid state synthesis and characterization of bulk FeTe0.5Se0.5 superconductors

    Science.gov (United States)

    Onar, K.; Yakinci, M. E.

    2016-01-01

    FeTe0.5Se0.5 polycrystalline superconductor samples were synthesized by solid- state reaction method at different heating temperatures. The morphological and structural characterization of FeTe0 5Se0.5 samples were carried out by X-rays Diffraction, Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopy. The electrical, magnetic and thermal transport properties were investigated up to 8 T by using physical property measurement system. The results reveal that the sensitivity of electrical and magnetic properties strongly depends on the heat treatment cycles. The upper critical field, Hc2(0), was determined with the magnetic field parallel to the sample surface. It gives a maximum value of 36.3 T. The lower critical field, Hc1(T), was obtained as 210, 140 and 70 Oe at 5, 8 and 12 K, respectively. The coherence length, ξ, at the zero field, was calculated to be 1.94 nm and suggested a transparent intergrain boundaries peculiarity. The μ0Hc2(0)/kBTc rate shows higher value (3.36 T/K) than the Pauli limit (1.84 T/K) which suggests unconventional nature of superconductivity for the polycrystalline FeTe0.5Se0.5 superconducting samples.

  5. Strong work-hardening behavior induced by the solid solution strengthening of dendrites in TiZr-based bulk metallic glass matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Ma, D.Q. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Jiao, W.T. [College of Education, Hebei Normal University of Science and Technology, Qinhuangdao 066004 (China); Zhang, Y.F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Hebei Vocational and Technical College of Building Materials, Qinhuangdao 066004 (China); Wang, B.A.; Li, J.; Zhang, X.Y. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Ma, M.Z., E-mail: mz550509@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, R.P. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-03-05

    Highlights: • Hardness of dendrite of TiZr-based BMGMCs increases. • Strong work-hardening behavior is obtained after solid solution strengthening. • Lattice distortions of dendrite suffering from rapid cooling are detected. - Abstract: A series of TiZr-based bulk metallic glass matrix composites (BMGMCs) with distinguished mechanical properties are successfully fabricated by adding different volume fractions of Ta (Ti{sub 38.8}Zr{sub 28.8}Cu{sub 6.2}Be{sub 16.2}Nb{sub 10} as the basic composition, denoted as Ta{sub 0.0}–Ta{sub 8.0}). Along with the growth of precipitated phase, typical dendritic morphology is fully developed in the TiZr-based BMGMCs of Ta{sub 8.0}. Energy-dispersive spectrometry analysis of the dendrites and glass matrix indicates that the metallic elements of Nb and Ta should preferentially form solid solution into dendrites. The chaotic structure of high-temperature precipitate phase is trapped down by the rapid cooling of the copper-mould. The detected lattice distortions in the dendrites are attributed to the strong solid solution strengthening of the metallic elements of Ti, Zr, Nb, and Ta. These lattice distortions increase the resistance of the dislocation motion and pin the dislocations, thus the strength and hardness of dendrite increase. Dendrites create a strong barrier for the shear band propagation and generate multiple shear bands after solid solution strengthening, thereby providing the TiZr-based BMGMCs with greatly improved capacity to sustain plastic deformation and resistance to brittle fracture. Thus, the TiZr-based BMGMCs possess distinguished work-hardening capability. Among these TiZr-based BMGMCs, the sample Ta{sub 0.5} possesses the largest plastic strain (ε{sub p}) at 20.3% and ultimate strength (σ{sub max}) of 2613 MPa during compressive loading. In addition, the sample of Ta{sub 0.5} exhibits work-hardening up to an ultrahigh tensile strength of 1680 MPa during the tensile process, and then progressively

  6. Bulk Nanostructured Materials

    Science.gov (United States)

    Koch, C. C.; Langdon, T. G.; Lavernia, E. J.

    2017-09-01

    This paper will address three topics of importance to bulk nanostructured materials. Bulk nanostructured materials are defined as bulk solids with nanoscale or partly nanoscale microstructures. This category of nanostructured materials has historical roots going back many decades but has relatively recent focus due to new discoveries of unique properties of some nanoscale materials. Bulk nanostructured materials are prepared by a variety of severe plastic deformation methods, and these will be reviewed. Powder processing to prepare bulk nanostructured materials requires that the powders be consolidated by typical combinations of pressure and temperature, the latter leading to coarsening of the microstructure. The thermal stability of nanostructured materials will also be discussed. An example of bringing nanostructured materials to applications as structural materials will be described in terms of the cryomilling of powders and their consolidation.

  7. Unravelling Li-Ion Transport from Picoseconds to Seconds: Bulk versus Interfaces in an Argyrodite Li6PS5Cl-Li2S All-Solid-State Li-Ion Battery.

    Science.gov (United States)

    Yu, Chuang; Ganapathy, Swapna; de Klerk, Niek J J; Roslon, Irek; van Eck, Ernst R H; Kentgens, Arno P M; Wagemaker, Marnix

    2016-09-01

    One of the main challenges of all-solid-state Li-ion batteries is the restricted power density due to the poor Li-ion transport between the electrodes via the electrolyte. However, to establish what diffusional process is the bottleneck for Li-ion transport requires the ability to distinguish the various processes. The present work investigates the Li-ion diffusion in argyrodite Li6PS5Cl, a promising electrolyte based on its high Li-ion conductivity, using a combination of (7)Li NMR experiments and DFT based molecular dynamics simulations. This allows us to distinguish the local Li-ion mobility from the long-range Li-ion motional process, quantifying both and giving a coherent and consistent picture of the bulk diffusion in Li6PS5Cl. NMR exchange experiments are used to unambiguously characterize Li-ion transport over the solid electrolyte-electrode interface for the electrolyte-electrode combination Li6PS5Cl-Li2S, giving unprecedented and direct quantitative insight into the impact of the interface on Li-ion charge transport in all-solid-state batteries. The limited Li-ion transport over the Li6PS5Cl-Li2S interface, orders of magnitude smaller compared with that in the bulk Li6PS5Cl, appears to be the bottleneck for the performance of the Li6PS5Cl-Li2S battery, quantifying one of the major challenges toward improved performance of all-solid-state batteries.

  8. Impact of Bulk Aggregation on the Electronic Structure of Streptocyanines: Implications for the Solid-State Nonlinear Optical Properties and All-Optical Switching Applications

    KAUST Repository

    Gieseking, Rebecca L.

    2014-10-16

    Polymethine dyes in dilute solutions show many of the electronic and optical properties required for all-optical switching applications. However, in the form of thin films, their aggregation and interactions with counterions do generally strongly limit their utility. Here, we present a theoretical approach combining molecular-dynamics simulations and quantum-chemical calculations to describe the bulk molecular packing of streptocyanines (taken as representative of simple polymethines) with counterions of different hardness (Cl and BPh4 ) and understand the impact on the optical properties. The accuracy of the force field we use is verified by reproducing experimental crystal parameters as well as the configurations of polymethine/counterion complexes obtained from electronic-structure calculations. The aggregation characteristics can be understood in terms of both polymethinecounterion and polymethinepolymethine interactions. The counterions are found to localize near one end of the streptocyanine backbones, and the streptocyanines form a broad range of aggregates with significant electronic couplings between neighboring molecules. As a consequence, the linear and nonlinear optical properties are substantially modified in the bulk. By providing an understanding of the relationship between the molecular interactions and the bulk optical properties, our results point to a clear strategy for designing polymethine and counterion molecular structures and optimizing the materials properties for all-optical switching applications.

  9. Electrochemical and structural evaluation for bulk-type all-solid-state batteries using Li4GeS4-Li3PS4 electrolyte coating on LiCoO2 particles

    Science.gov (United States)

    Ito, Yusuke; Otoyama, Misae; Hayashi, Akitoshi; Ohtomo, Takamasa; Tatsumisago, Masahiro

    2017-08-01

    Bulk-type all-solid-state batteries, which use composite electrodes with a powder mixture of active materials and solid electrolytes, are anticipated for large-scale power sources. However, conventional powder mixing protocols are insufficient to maintain ion-conductive pathways within composite electrodes. Herein, sulfide electrolyte coatings have attracted attention as a promising means to overcome this difficulty. We assessed the effects of sulfide electrolyte coatings for active materials on the electrochemical properties and structural changes in all-solid-state cells. A favorable electrode-electrolyte interface was formed by coating significantly small amounts (ca. 3 wt%) of Li4GeS4-Li3PS4 solid electrolyte (SE) onto LiCoO2 particles via vapor phase process. The all-solid-state cell (In/Li2S-P2S5/SE-coated LiCoO2) was charged and discharged with a larger capacity than that using non-SE-coated LiCoO2 particles, indicating that the SE-coating is effective in forming a favorable ion-conductive pathway to LiCoO2 particles. Improvement of the cell performance after heat treatment was considered to derive not only from the enhancement of ionic conductivity in the SE-coating layer, but also from the reduction of voids in the composite electrode. Less ionic resistance and denser environment are beneficial for the Li-ion supply to the deepest part in the composite electrode, which results in more homogeneous electrochemical reaction in all-solid-state cells.

  10. Fabrication and characterization of oriented Nd2NiO4 bulk and cathode for low-temperature operating solid oxide fuel cell

    Science.gov (United States)

    Murata, Atsufumi; Uchikoshi, Tetsuo; Matsuda, Motohide

    2015-10-01

    Textured Nd2NiO4 (NNO) bulks were fabricated by slip casting in a 5 T magnetic field generated by a superconducting magnet. The easy-magnetization axis of NNO was determined by X-ray diffraction (XRD) measurements performed on the surfaces parallel and perpendicular to the applied magnetic field direction of the sintered bulk NNO ceramics. The anisotropic electric conductivity and thermal expansion coefficient of the textured NNO were characterized by the conventional DC four-terminal method and dilatometry, respectively. A higher electric conductivity and lower thermal expansion in the direction perpendicular to the c-axis were confirmed. Based on the obtained experimental data, fabrication of the a-b plane perpendicular-oriented NNO cathode layer on a Gd-doped ceria (GDC) electrolyte was finally attempted in a 0.9 T magnetic field generated by neodymium magnets. The effect of the rotation of the magnetic field in the horizontal plane on the orientation condition of the NNO layer was also investigated. The rotation of the magnetic field could produce the random orientation of the c-axis while retaining the a-b plane orientation against the electrolyte. Based on the performance tests of single cells equipped with different oriented NNO cathodes, the ideal situation of the NNO cathode layer leading to good performance is proposed.

  11. Coarse-grained simulations for flow of complex soft matter fluids in the bulk and in the presence of solid interfaces

    Science.gov (United States)

    Ahuja, V. R.; van der Gucht, J.; Briels, W. J.

    2016-11-01

    We present a coarse-grained particle-based simulation technique for modeling flow of complex soft matter fluids such as polymer solutions in the presence of solid interfaces. In our coarse-grained description of the system, we track the motion of polymer molecules using their centers-of-mass as our coarse-grain co-ordinates and also keep track of another set of variables that describe the background flow field. The coarse-grain motion is thus influenced not only by the interactions based on appropriate potentials used to model the particular polymer system of interest and the random kicks associated with thermal fluctuations, but also by the motion of the background fluid. In order to couple the motion of the coarse-grain co-ordinates with the background fluid motion, we use a Galilean invariant, first order Brownian dynamics algorithm developed by Padding and Briels [J. Chem. Phys. 141, 244108 (2014)], which on the one hand draws inspiration from smoothed particle hydrodynamics in a way that the motion of the background fluid is efficiently calculated based on a discretization of the Navier-Stokes equation at the positions of the coarse-grain coordinates where it is actually needed, but also differs from it because of the inclusion of thermal fluctuations by having momentum-conserving pairwise stochastic updates. In this paper, we make a few modifications to this algorithm and introduce a new parameter, viz., a friction coefficient associated with the background fluid, and analyze the relationship of the model parameters with the dynamic properties of the system. We also test this algorithm for flow in the presence of solid interfaces to show that appropriate boundary conditions can be imposed at solid-fluid interfaces by using artificial particles embedded in the solid walls which offer friction to the real fluid particles in the vicinity of the wall. We have tested our method using a model system of a star polymer solution at the overlap concentration.

  12. Coarse-grained simulations for flow of complex soft matter fluids in the bulk and in the presence of solid interfaces.

    Science.gov (United States)

    Ahuja, V R; van der Gucht, J; Briels, W J

    2016-11-21

    We present a coarse-grained particle-based simulation technique for modeling flow of complex soft matter fluids such as polymer solutions in the presence of solid interfaces. In our coarse-grained description of the system, we track the motion of polymer molecules using their centers-of-mass as our coarse-grain co-ordinates and also keep track of another set of variables that describe the background flow field. The coarse-grain motion is thus influenced not only by the interactions based on appropriate potentials used to model the particular polymer system of interest and the random kicks associated with thermal fluctuations, but also by the motion of the background fluid. In order to couple the motion of the coarse-grain co-ordinates with the background fluid motion, we use a Galilean invariant, first order Brownian dynamics algorithm developed by Padding and Briels [J. Chem. Phys. 141, 244108 (2014)], which on the one hand draws inspiration from smoothed particle hydrodynamics in a way that the motion of the background fluid is efficiently calculated based on a discretization of the Navier-Stokes equation at the positions of the coarse-grain coordinates where it is actually needed, but also differs from it because of the inclusion of thermal fluctuations by having momentum-conserving pairwise stochastic updates. In this paper, we make a few modifications to this algorithm and introduce a new parameter, viz., a friction coefficient associated with the background fluid, and analyze the relationship of the model parameters with the dynamic properties of the system. We also test this algorithm for flow in the presence of solid interfaces to show that appropriate boundary conditions can be imposed at solid-fluid interfaces by using artificial particles embedded in the solid walls which offer friction to the real fluid particles in the vicinity of the wall. We have tested our method using a model system of a star polymer solution at the overlap concentration.

  13. Bulk Stable Isotope Analysis of Carbon from Solids and Liquids using an Elemental Analyzer Coupled to a Wavelength-Scanned Cavity Ring-Down Spectrophotometer

    Science.gov (United States)

    Saad, N.; Rella, C.; van Pelt, A.

    2009-04-01

    We report here on the novel employment of a small footprint Wavelength-Scanned Cavity Ring-Down Spectrometer (WS-CRDS) interfaced to an elemental analyzer for the measurement of the bulk isotopic carbon signature in plants and food products. The current system provides an inexpensive alternative with unparalleled ease-of-use as compared to standard methods using the more complex analytical instrumentation of isotope ratio mass spectrometry. A precision of carbon isotopic ratio measurements of less than 1 permil was achieved in minutes of measurement time. Such precision readily distinguishes the isotopic carbon signatures of a variety of environmental and agricultural products from different origins, providing information about food authenticity and climate changes effect on plant physiology.

  14. Bulk-Type All-Solid-State Lithium-Ion Batteries: Remarkable Performances of a Carbon Nanofiber-Supported MgH2 Composite Electrode.

    Science.gov (United States)

    Zeng, Liang; Ichikawa, Takayuki; Kawahito, Koji; Miyaoka, Hiroki; Kojima, Yoshitsugu

    2017-01-25

    Magnesium hydride, MgH2, a recently developed compound for lithium-ion batteries, is considered to be a promising conversion-type negative electrode material due to its high theoretical lithium storage capacity of over 2000 mA h g(-1), suitable working potential, and relatively small volume expansion. Nevertheless, it suffers from unsatisfactory cyclability, poor reversibility, and slow kinetics in conventional nonaqueous electrolyte systems, which greatly limit the practical application of MgH2. In this work, a vapor-grown carbon nanofiber was used to enhance the electrical conductivity of MgH2 using LiBH4 as the solid-state electrolyte. It shows that a reversible capacity of over 1200 mA h g(-1) with an average voltage of 0.5 V (vs Li/Li(+)) can be obtained after 50 cycles at a current density of 1000 mA g(-1). In addition, the capacity of MgH2 retains over 1100 mA h g(-1) at a high current density of 8000 mA g(-1), which indicates the possibility of using MgH2 as a negative electrode material for high power and high capacity lithium-ion batteries in future practical applications. Moreover, the widely studied sulfide-based solid electrolyte was also used to assemble battery cells with MgH2 electrode in the same system, and the electrochemical performance was as good as that using LiBH4 electrolyte.

  15. Human Factor Considered Safety Management of Maritime Transportation of Solid Bulk Concentrate%基于“人”的因素的海上运输易流态精选矿的安全管理

    Institute of Scientific and Technical Information of China (English)

    缪克银

    2012-01-01

    从介绍易流态精选矿的特性出发,深层次分析运输精选矿的风险致因,指出“人”的因素是所有事故原因中的主因,并具体提出保障易流态精选矿运输安全的管理措施.%Starting with an introduction of the property of solid bulk concentrate, we analyzed in—depth the causes of risks in its maritime transportation, pointed out that "human was the main factor in almost all the accidents discussed and finally proposed its safety management measures.

  16. Early diagenesis of mangrove leaves in a tropical estuary: Bulk chemical characterization using solid-state 13C NMR and elemental analyses

    Science.gov (United States)

    Benner, R.; Hatcher, P.G.; Hedges, J.I.

    1990-01-01

    Changes in the chemical composition of mangrove (Rhizophora mangle) leaves during decomposition in tropical estuarine waters were characterized using solid-state 13C nuclear magnetic resonance (NMR) and elemental (CHNO) analysis. Carbohydrates were the most abundant components of the leaves accounting for about 50 wt% of senescent tissues. Tannins were estimated to account for about 20 wt% of leaf tissues, and lipid components, cutin, and possibly other aliphatic biopolymers in leaf cuticles accounted for about 15 wt%. Carbohydrates were generally less resistant to decomposition than the other constituents and decreased in relative concentration during decomposition. Tannins were of intermediate resistance to decomposition and remained in fairly constant proportion during decomposition. Paraffinic components were very resistant to decomposition and increased in relative concentration as decomposition progressed. Lignin was a minor component of all leaf tissues. Standard methods for the colorimetric determination of tannins (Folin-Dennis reagent) and the gravimetric determination of lignin (Klason lignin) were highly inaccurate when applied to mangrove leaves. The N content of the leaves was particularly dynamic with values ranging from 1.27 wt% in green leaves to 0.65 wt% in senescent yellow leaves attached to trees. During decomposition in the water the N content initially decreased to 0.51 wt% due to leaching, but values steadily increased thereafter to 1.07 wt% in the most degraded leaf samples. The absolute mass of N in the leaves increased during decomposition indicating that N immobilization was occurring as decomposition progressed. ?? 1990.

  17. Non-monotonic compositional dependence of isothermal bulk modulus of the (Mg1–xMnxCr2O4 spinel solid solutions, and its origin and implication

    Directory of Open Access Journals (Sweden)

    Xi Liu

    2016-12-01

    Full Text Available The compressibility of the spinel solid solutions, (Mg1−xMnxCr2O4 with x = 0.00 (0, 0.20 (0, 0.44 (2, 0.61 (2, 0.77 (2 and 1.00 (0, has been investigated by using a diamond-anvil cell coupled with synchrotron X-ray radiation up to ∼10 GPa (ambient T. The second-order Birch–Murnaghan equation of state was used to fit the PV data, yielding the following values for the isothermal bulk moduli (KT, 198.2 (36, 187.8 (87, 176.1 (32, 168.7 (52, 192.9 (61 and 199.2 (61 GPa, for the spinel solid solutions with x = 0.00 (0, 0.20 (0, 0.44 (2, 0.61 (2, 0.77 (2 and 1.00 (0, respectively (KT′ fixed as 4. The KT value of the MgCr2O4 spinel is in good agreement with existing experimental determinations and theoretical calculations. The correlation between the KT and x is not monotonic, with the KT values similar at both ends of the binary MgCr2O4MnCr2O4, but decreasing towards the middle. This non-monotonic correlation can be described by two equations, KT = −49.2 (11x + 198.0 (4 (x ≤ ∼0.6 and KT = 92 (41x + 115 (30 (x ≥ ∼0.6, and can be explained by the evolution of the average bond lengths of the tetrahedra and octahedra of the spinel solid solutions. Additionally, the relationship between the thermal expansion coefficient and composition is correspondingly reinterpreted, the continuous deformation of the oxygen array is demonstrated, and the evolution of the component polyhedra is discussed for this series of spinel solid solutions. Our results suggest that the correlation between the KT and composition of a solid solution series may be complicated, and great care should be paid while estimating the KT of some intermediate compositions from the KT of the end-members.

  18. Amorphous LiCoO2sbnd Li2SO4 active materials: Potential positive electrodes for bulk-type all-oxide solid-state lithium batteries with high energy density

    Science.gov (United States)

    Nagao, Kenji; Hayashi, Akitoshi; Deguchi, Minako; Tsukasaki, Hirofumi; Mori, Shigeo; Tatsumisago, Masahiro

    2017-04-01

    Newly amorphous Li2-x/100Cox/100S1-x/100O4-x/50 (xLiCoO2·(100-x)Li2SO4 (mol%)) positive electrode active materials are synthesized using mechanochemical techniques. SEM observation indicates that average radii of the Li1.2Co0.8S0.2O2.4 (80LiCoO2·20Li2SO4 (mol%)) particles are about 3 μm. HR-TEM images indicate that the particles comprise nano-crystalline and amorphous phases. The crystalline phase is attributable to cubic LiCoO2 phase. These active materials exhibit a high electronic conductivity of around 10-5-10-1 S cm-1 and an ionic conductivity of around 10-7-10-6 S cm-1 at room temperature. Bulk-type all-oxide solid-state cells (Lisbnd In alloy/Li3BO3-based glass-ceramic electrolyte/amorphous Li2-x/100Cox/100S1-x/100O4-x/50) are fabricated by pressing at room temperature without high temperature sintering. Although the cell with the milled LiCoO2 shows no capacity, the cell using the Li1.2Co0.8S0.2O2.4 electrode with no conductive components (ca. 150 μm thickness) operates as a secondary battery at 100 °C, with an average discharge potential of 3.3 V (vs. Li+/Li) and discharge capacity of 163 mAh g-1. A positive electrode with large amounts of active materials is suitable for achieving high energy density in all-solid-state batteries. These newly synthesized amorphous Li2-x/100Cox/100S1-x/100O4-x/50 electrodes with ionic and electronic conductivities and good processability meet that demand.

  19. Solid Waste Treatment Technology

    Science.gov (United States)

    Hershaft, Alex

    1972-01-01

    Advances in research and commercial solid waste handling are offering many more processing choices. This survey discusses techniques of storage and removal, fragmentation and sorting, bulk reduction, conversion, reclamation, mining and mineral processing, and disposal. (BL)

  20. Gases, liquids and solids

    CERN Document Server

    Tabor, David

    1969-01-01

    It has been tradional to treat gases, liquids and solids as if they were completely unrelated material. However, this book shows that many of their bulk properties can been explained in terms of intermolecular forces.

  1. Polymer-fullerene bulk heterojunction solar cells

    NARCIS (Netherlands)

    Janssen, RAJ; Hummelen, JC; Saricifti, NS

    2005-01-01

    Nanostructured phase-separated blends, or bulk heterojunctions, of conjugated Polymers and fullerene derivatives form a very attractive approach to large-area, solid-state organic solar cells.The key feature of these cells is that they combine easy, processing from solution on a variety of substrate

  2. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  3. Application of the penetration theory for gas - Liquid mass transfer without liquid bulk : Differences with system with a bulk

    NARCIS (Netherlands)

    van Elk, E. P.; Knaap, M. C.; Versteeg, G. F.

    2007-01-01

    Frequently applied micro models for gas-liquid mass transfer all assume the presence of a liquid bulk. However, some systems are characterized by the absence of a liquid bulk, a very thin layer of liquid flows over a solid surface. An example of such a process is absorption in a column equipped with

  4. Eco Issues in Bulk Materials Handling Technologies in Ports

    Directory of Open Access Journals (Sweden)

    Nenad Zrnić

    2011-09-01

    Full Text Available This paper deals with eco issues in bulk materials handling in ports. Solid, free-flowing materials are said to be in bulk. Bulk materials handling is very difficult, because it incorporates all the features of liquids, gasses and mass solids. Energy efficiency, dust emissions in nearby environment, dust explosions, jamming, noise, handling of hazardous materials and protection of materials from contamination are issues that will be considered in this paper. Here are also presented possible solutions for some of these issues

  5. 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

  6. Auctioning Bulk Mobile Messages

    NARCIS (Netherlands)

    S. Meij (Simon); L-F. Pau (Louis-François); H.W.G.M. van Heck (Eric)

    2003-01-01

    textabstractThe search for enablers of continued growth of SMS traffic, as well as the take-off of the more diversified MMS message contents, open up for enterprises the potential of bulk use of mobile messaging , instead of essentially one-by-one use. In parallel, such enterprises or value added

  7. 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

  8. Radiative Bulk Viscosity

    CERN Document Server

    Chen, X

    2001-01-01

    Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for a classical gas of hard spheres, when the mean free paths or mean flight times of constituent particles are long, we find a nonvanishing bulk viscosity. Here we apply a method recently used to uncover this result for a classical rarefied gas to radiative transfer theory and derive an expression for the radiative stress tensor for a gray medium with absorption and Thomson scattering. We determine the transport coefficients through the calculation of the comoving entropy generation. When scattering dominates absorption, the bulk viscosity becomes much larger than either the shear viscosity or the thermal conductivity.

  9. Particles, contacts, bulk behavior

    NARCIS (Netherlands)

    Luding, Stefan; Tomas, J.

    2014-01-01

    Granular matter consists of discrete “particles”. These can be separate sand-grains, agglomerates (made of many primary particles), or solid materials like rock, composites, or metal-alloys—all with particulate inhomogeneous, possibly anisotropic micro-structure. Particles can be as small as

  10. U.S. Department of Energy, National Energy Technology Laboratory Solid-State Lighting Core Technologies Light Emitting Diodes on Semipolar Bulk GaN Substrate with IQE > 80% at 150 A/cm2 and 100 0C

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Arpan [Soraa, Inc., Fremont, CA (United States); David, Aurelien [Soraa, Inc., Fremont, CA (United States); Grundmann, Michael [Soraa, Inc., Fremont, CA (United States); Tyagi, Anurag [Soraa, Inc., Fremont, CA (United States); Craven, Michael [Soraa, Inc., Fremont, CA (United States); Hurni, Christophe [Soraa, Inc., Fremont, CA (United States); Cich, Michael [Soraa, Inc., Fremont, CA (United States)

    2015-03-31

    GaN is a crucial material for light-emitting diodes (LEDs) emitting in the violet-to-green range. Despite its good performance, it still suffers from significant technical limitations. In particular, the efficiency of GaN-based LEDs decreases at high current (“current droop”) and high temperature (“temperature droop”). This is problematic in some lighting applications, where a high-power operation is required. This program studied the use of particular substrates to improve the efficiency of GaN-based LEDs: bulk semipolar (SP) GaN substrates. These substrates possess a very high material quality, and physical properties which are distinctly different from legacy substrates currently used in the LED industry. The program focused on the development of accurate metrology to quantify the performance of GaN-based LEDs, and on improvement to LED quality and design on SP substrates. Through a thorough optimization process, we demonstrated violet LEDs with very high internal quantum efficiency, exceeding 85% at high temperature and high current. We also investigated longer-wavelength blue emitters, but found that the limited strain budget was a key limitation.

  11. Compositional ordering and stability in nanostructured, bulk thermoelectric alloys.

    Energy Technology Data Exchange (ETDEWEB)

    Hekmaty, Michelle A.; Faleev, S.; Medlin, Douglas L.; Leonard, F.; Lensch-Falk, J.; Sharma, Peter Anand; Sugar, J. D.

    2009-09-01

    Thermoelectric materials have many applications in the conversion of thermal energy to electrical power and in solid-state cooling. One route to improving thermoelectric energy conversion efficiency in bulk material is to embed nanoscale inclusions. This report summarize key results from a recently completed LDRD project exploring the science underpinning the formation and stability of nanostructures in bulk thermoelectric and the quantitative relationships between such structures and thermoelectric properties.

  12. Assessment of bioburden encapsulated in bulk materials

    Science.gov (United States)

    Schubert, Wayne W.; Newlin, Laura; Chung, Shirley Y.; Ellyin, Raymond

    2016-05-01

    The National Aeronautics and Space Administration (NASA) imposes bioburden limitations on all spacecraft destined for solar system bodies that might harbor evidence of extant or extinct life. The subset of microorganisms trapped within solid materials during manufacture and assembly is referred to as encapsulated bioburden. In the absence of spacecraft-specific data, NASA relies on specification values to estimate total spacecraft encapsulated bioburden, typically 30 endospores/cm3 or 300 viable cells/cm3 in non-electronic materials. Specification values for endospores have been established conservatively, and represent no less than an order of magnitude greater abundance than that derived from empirical assessments of actual spacecraft materials. The goal of this study was to generate data germane to determining whether revised bulk encapsulated material values (lower than those estimated by historical specifications) tailored specifically to the materials designated in modern-day spacecraft design could be used, on a case-by-case basis, to comply with planetary protection requirements. Organic materials having distinctly different chemical properties and configurations were selected. This required more than one experimental and analytical approach. Filtration was employed for liquid electrolytes, lubricants were suspended in an aqueous solution and solids (wire and epoxy sealant) were cryogenically milled. The final data characteristic for all bioburden estimates was microbial colony formation in rich agar growth medium. To assess survival potential, three non-spore-forming bacterial cell lines were systematically encapsulated in an epoxy matrix, liberated via cryogenic grinding, and cultured. Results suggest that bulk solid materials harbor significantly fewer encapsulated microorganisms than are estimated by specification values. Lithium-ion battery electrolyte reagents housed fewer than 1 CFU/cm3. Results also demonstrated that non-spore-forming microorganisms

  13. Comparing near-infrared conventional diffuse reflectance spectroscopy and hyperspectral imaging for determination of the bulk properties of solid samples by multivariate regression: determination of Mooney viscosity and plasticity indices of natural rubber.

    Science.gov (United States)

    Juliano da Silva, Carlos; Pasquini, Celio

    2015-01-21

    Conventional reflectance spectroscopy (NIRS) and hyperspectral imaging (HI) in the near-infrared region (1000-2500 nm) are evaluated and compared, using, as the case study, the determination of relevant properties related to the quality of natural rubber. Mooney viscosity (MV) and plasticity indices (PI) (PI0 - original plasticity, PI30 - plasticity after accelerated aging, and PRI - the plasticity retention index after accelerated aging) of rubber were determined using multivariate regression models. Two hundred and eighty six samples of rubber were measured using conventional and hyperspectral near-infrared imaging reflectance instruments in the range of 1000-2500 nm. The sample set was split into regression (n = 191) and external validation (n = 95) sub-sets. Three instruments were employed for data acquisition: a line scanning hyperspectral camera and two conventional FT-NIR spectrometers. Sample heterogeneity was evaluated using hyperspectral images obtained with a resolution of 150 × 150 μm and principal component analysis. The probed sample area (5 cm(2); 24,000 pixels) to achieve representativeness was found to be equivalent to the average of 6 spectra for a 1 cm diameter probing circular window of one FT-NIR instrument. The other spectrophotometer can probe the whole sample in only one measurement. The results show that the rubber properties can be determined with very similar accuracy and precision by Partial Least Square (PLS) regression models regardless of whether HI-NIR or conventional FT-NIR produce the spectral datasets. The best Root Mean Square Errors of Prediction (RMSEPs) of external validation for MV, PI0, PI30, and PRI were 4.3, 1.8, 3.4, and 5.3%, respectively. Though the quantitative results provided by the three instruments can be considered equivalent, the hyperspectral imaging instrument presents a number of advantages, being about 6 times faster than conventional bulk spectrometers, producing robust spectral data by ensuring sample

  14. Dissolution of bulk specimens of silicon nitride

    Science.gov (United States)

    Davis, W. F.; Merkle, E. J.

    1981-01-01

    An accurate chemical characterization of silicon nitride has become important in connection with current efforts to incorporate components of this material into advanced heat engines. However, there are problems concerning a chemical analysis of bulk silicon nitride. Current analytical methods require the pulverization of bulk specimens. A pulverization procedure making use of grinding media, on the other hand, will introduce contaminants. A description is given of a dissolution procedure which overcomes these difficulties. It has been found that up to at least 0.6 g solid pieces of various samples of hot pressed and reaction bonded silicon nitride can be decomposed in a mixture of 3 mL hydrofluoric acid and 1 mL nitric acid overnight at 150 C in a Parr bomb. High-purity silicon nitride is completely soluble in nitric acid after treatment in the bomb. Following decomposition, silicon and hydrofluoric acid are volatilized and insoluble fluorides are converted to a soluble form.

  15. Bulk sound velocity of porous materials at high pressures

    Institute of Scientific and Technical Information of China (English)

    耿华运; 吴强; 谭华; 蔡灵仓; 经福谦

    2002-01-01

    A correction of Walsh's method for bulk sound velocity calculation for shocked porous materials is accomplishedbased on the Wu-Jing thermodynamic equation of state. The corrected bulk velocities for solid and porous sampleswith low porosities are in good agreement with the corresponding experimental data published previously. On the basisof this corrected equation, the influence of thermoelectrons on the bulk velocity of shocked materials is discussed indetail at pressures of 50, 70 and 200 GPa. Some interesting phenomena are revealed, which seem to be the uniquefeatures of a dynamic-pressure-loading process and could not be found in static experiments.

  16. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

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

    2015-01-01

    the 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-viscosity bulk...

  17. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    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. 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 ...

  19. 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.

  20. Developing bulk exchange spring magnets

    Energy Technology Data Exchange (ETDEWEB)

    Mccall, Scott K.; Kuntz, Joshua D.

    2017-06-27

    A method of making a bulk exchange spring magnet by providing a magnetically soft material, providing a hard magnetic material, and producing a composite of said magnetically soft material and said hard magnetic material to make the bulk exchange spring magnet. The step of producing a composite of magnetically soft material and hard magnetic material is accomplished by electrophoretic deposition of the magnetically soft material and the hard magnetic material to make the bulk exchange spring magnet.

  1. 77 FR 12293 - PCBs Bulk Product v. Remediation Waste

    Science.gov (United States)

    2012-02-29

    ... AGENCY PCBs Bulk Product v. Remediation Waste AGENCY: Environmental Protection Agency (EPA). ACTION... remediation waste. The proposed reinterpretation is ] in response to questions EPA received about the... Resource Conservation and Recovery, Office of Solid Waste and Emergency Response, U.S. Environmental...

  2. Perovskite oxides: Oxygen electrocatalysis and bulk structure

    Science.gov (United States)

    Carbonio, R. E.; Fierro, C.; Tryk, D.; Scherson, D.; Yeager, Ernest

    1987-01-01

    Perovskite type oxides were considered for use as oxygen reduction and generation electrocatalysts in alkaline electrolytes. Perovskite stability and electrocatalytic activity are studied along with possible relationships of the latter with the bulk solid state properties. A series of compounds of the type LaFe(x)Ni1(-x)O3 was used as a model system to gain information on the possible relationships between surface catalytic activity and bulk structure. Hydrogen peroxide decomposition rate constants were measured for these compounds. Ex situ Mossbauer effect spectroscopy (MES), and magnetic susceptibility measurements were used to study the solid state properties. X ray photoelectron spectroscopy (XPS) was used to examine the surface. MES has indicated the presence of a paramagnetic to magnetically ordered phase transition for values of x between 0.4 and 0.5. A correlation was found between the values of the MES isomer shift and the catalytic activity for peroxide decomposition. Thus, the catalytic activity can be correlated to the d-electron density for the transition metal cations.

  3. Molecular imprinting of bulk, microporous silica

    Science.gov (United States)

    Katz, Alexander; Davis, Mark E.

    2000-01-01

    Molecular imprinting aims to create solid materials containing chemical functionalities that are spatially organized by covalent or non-covalent interactions with imprint (or template) molecules during the synthesis process. Subsequent removal of the imprint molecules leaves behind designed sites for the recognition of small molecules, making the material ideally suited for applications such as separations, chemical sensing and catalysis. Until now, the molecular imprinting of bulk polymers and polymer and silica surfaces has been reported, but the extension of these methods to a wider range of materials remains problematic. For example, the formation of substrate-specific cavities within bulk silica, while conceptually straightforward, has been difficult to accomplish experimentally. Here we describe the imprinting of bulk amorphous silicas with single aromatic rings carrying up to three 3-aminopropyltriethoxysilane side groups; this generates and occupies microporosity and attaches functional organic groups to the pore walls in a controlled fashion. The triethoxysilane part of the molecules' side groups is incorporated into the silica framework during sol-gel synthesis, and subsequent removal of the aromatic core creates a cavity with spatially organized aminopropyl groups covalently anchored to the pore walls. We find that the imprinted silicas act as shape-selective base catalysts. Our strategy can be extended to imprint other functional groups, which should give access to a wide range of functionalized materials.

  4. Materials for Bulk Acoustic Resonators and Filters

    Science.gov (United States)

    Loebl, Hans-Peter

    2003-03-01

    Highly selective solidly mounted bulk acoustic wave (BAW) band pass filters are suited for mobile and wireless systems in the GHz frequency range between 0.8 and 10 GHz. Electro-acoustic thin film BAW resonators are the building blocks these BAW filters. Piezoelectric materials used in these resonators include mainly AlN or ZnO which can be deposited by dedicated thin film sputter deposition techniques. Using these piezo-electric materials and using suited materials for the acoustic Bragg reflector, BAW resonators with high quality factors can be fabricated. The achievable filter bandwidth is approximately 4Alternatively, also ferroelectric thin films might be used to achieve higher coupling coefficient and thus filter bandwidth. BAW resonators and filters have been designed and fabricated on 6" Silicon and glass wafers. Results are presented for resonators and filters operating between 1.95 and 8 GHz. The talk will give an overview of the material aspects which are important for BAW devices. It will be shown that modeling of the resonator and filter response using 1D electro-acoustic simulation (1,2) which includes losses is essential to extract acoustic and electrical material parameters. (1) Solidly Mounted Bulk Acoustic Wave Filters for the Ghz Frequency Range, H.P. Loebl, C. Metzmacher , D.N.Peligrad , R. Mauczok , M. Klee , W. Brand , R.F. Milsom , P.Lok , F.van Straten , A. Tuinhout , J.W.Lobeek, IEEE 2002 Ultrasonics Symposium Munich, October 2002. (2) Combined Acoustic-Electromagnetic Simulation Of Thin-Film Bulk Acoustic Wave Filters, R.F. Milsom, H-P. Löbl, D.N. Peligrad, J-W. Lobeek, A. Tuinhout, R. H. ten Dolle IEEE 2002 Ultrasonics Symposium Munich, October 2002.

  5. Brane Couplings from Bulk Loops

    OpenAIRE

    Georgi, Howard; Grant, Aaron K.; Hailu, Girma

    2000-01-01

    We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

  6. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-09-15

    Contrary to other claims, we argue that bulk viscosity associated with the interactions of non- relativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk-viscosity effects of a weakly interacting mixture of relativistic and nonrelativistic particles.

  7. Growth and Characterization of Bulk GeSi Solid Solutions

    Science.gov (United States)

    Ritter, Timothy M.

    1999-01-01

    In this work we have grown and characterized several GeSi samples in order to investigate the effects that Silicon concentration, applied magnetic field, and liquid encapsulation have on crystalline quality. Characterization techniques include NDIC microscopy and microprobe spectroscopy. Two samples were grown with a Silicon concentration of approximately 3% and are compared to previous growths having a Silicon fraction of approximately 5%. Growth conditions for one of these samples was varied with the presence of an external applied magnetic field to investigate the possibility of magnetic field damping. A comparison between these two ingots, and with previously grown material, revealed no clear improvement in sample crystalline quality. Three additional samples were grown using a CaCl2 liquid encapsulation technique that produced GeSi material with improved structural quality over previous samples. Comparisons to prior non-encapsulation grown material, details of our methodology, and suggestions for further improvements are discussed.

  8. Solidex 86 - modern technology in bulk solids handling

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    A total of 30 papers were presented covering the following topics: coal and ash handling; dust control and explosion hazards; pneumatic conveying; mechanical conveying; storage and wear; and weighing technology and automated materials handling. 15 papers have been abstracted separately.

  9. Crucial Role of Quantum Entanglement in Bulk Properties of Solids

    CERN Document Server

    Brukner, C; Zeilinger, Anton; Brukner, Caslav; Vedral, Vlatko; Zeilinger, Anton

    2004-01-01

    We demonstrate that the magnetic susceptibility of strongly alternating antiferromagnetic spin-1/2 chains is an entanglement witness. Specifically, magnetic susceptibility of copper nitrate (CN) measured in 1963 (Berger et al., Phys. Rev. 132, 1057 (1963)) cannot be described without presence of entanglement. A detailed analysis of the spin correlations in CN as obtained from neutron scattering experiments (Xu et al., Phys. Rev. Lett. 84, 4465 (2000)) provides microscopic support for this interpretation. We present a quantitative analysis resulting in the critical temperature of 5K in both, completely independent, experiments below which entanglement exists.

  10. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-04-01

    Contrary to other claims, we argue that, bulk viscosity associated with the interactions of nonrelativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk viscosity effects of a weakly-interacting mixture of relativistic and nonrelativistic particles. 13 refs., 1 fig.

  11. A Batch Feeder for Inhomogeneous Bulk Materials

    Science.gov (United States)

    Vislov, I. S.; Kladiev, S. N.; Slobodyan, S. M.; Bogdan, A. M.

    2016-04-01

    The work includes the mechanical analysis of mechanical feeders and batchers that find application in various technological processes and industrial fields. Feeders are usually classified according to their design features into two groups: conveyor-type feeders and non-conveyor feeders. Batchers are used to batch solid bulk materials. Less frequently, they are used for liquids. In terms of a batching method, they are divided into volumetric and weighting batchers. Weighting batchers do not provide for sufficient batching accuracy. Automatic weighting batchers include a mass controlling sensor and systems for automatic material feed and automatic mass discharge control. In terms of operating principle, batchers are divided into gravitational batchers and batchers with forced feed of material using conveyors and pumps. Improved consumption of raw materials, decreased loss of materials, ease of use in automatic control systems of industrial facilities allows increasing the quality of technological processes and improve labor conditions. The batch feeder suggested by the authors is a volumetric batcher that has no comparable counterparts among conveyor-type feeders and allows solving the problem of targeted feeding of bulk material batches increasing reliability and hermeticity of the device.

  12. Determination of thermal properties of composting bulking materials.

    Science.gov (United States)

    Ahn, H K; Sauer, T J; Richard, T L; Glanville, T D

    2009-09-01

    Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric heat capacity of 12 compost bulking materials were determined in this study. Thermal properties were determined at varying bulk densities (1, 1.3, 1.7, 2.5, and 5 times uncompacted bulk density), particle sizes (ground and bulk), and water contents (0, 20, 50, 80% of water holding capacity and saturated condition). For the water content at 80% of water holding capacity, saw dust, soil compost blend, beef manure, and turkey litter showed the highest thermal conductivity (K) and volumetric heat capacity (C) (K: 0.12-0.81 W/m degrees C and C: 1.36-4.08 MJ/m(3) degrees C). Silage showed medium values at the same water content (K: 0.09-0.47 W/m degrees C and C: 0.93-3.09 MJ/m(3) degrees C). Wheat straw, oat straw, soybean straw, cornstalks, alfalfa hay, and wood shavings produced the lowest K and C values (K: 0.03-0.30 W/m degrees C and C: 0.26-3.45 MJ/m(3) degrees C). Thermal conductivity and volumetric heat capacity showed a linear relationship with moisture content and bulk density, while thermal diffusivity showed a nonlinear relationship. Since the water, air, and solid materials have their own specific thermal property values, thermal properties of compost bulking materials vary with the rate of those three components by changing water content, bulk density, and particle size. The degree of saturation was used to represent the interaction between volumes of water, air, and solids under the various combinations of moisture content, bulk density, and particle size. The first order regression models developed in this paper represent the relationship between degree of saturation and volumetric heat capacity (r=0.95-0.99) and thermal conductivity (r=0.84-0.99) well. Improved

  13. 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.

  14. Unpaired Majorana Modes in Josephson-Junction Arrays with Gapless Bulk Excitations

    Science.gov (United States)

    Pino, M.; Tsvelik, A. M.; Ioffe, L. B.

    2015-11-01

    The search for Majorana bound states in solid-state physics has been limited to materials that display a gap in their bulk spectrum. We show that such unpaired states appear in certain quasi-one-dimensional Josephson-junction arrays with gapless bulk excitations. The bulk modes mediate a coupling between Majorana bound states via the Ruderman-Kittel-Yosida-Kasuya mechanism. As a consequence, the lowest energy doublet acquires a finite energy difference. For a realistic set of parameters this energy splitting remains much smaller than the energy of the bulk eigenstates even for short chains of length L ˜10 .

  15. Bulk nano-crystalline alloys

    OpenAIRE

    T.-S. Chin; Lin, C. Y.; Lee, M.C.; R.T. Huang; S. M. Huang

    2009-01-01

    Bulk metallic glasses (BMGs) Fe–B–Y–Nb–Cu, 2 mm in diameter, were successfully annealed to become bulk nano-crystalline alloys (BNCAs) with α-Fe crystallite 11–13 nm in size. A ‘crystallization-and-stop’ model was proposed to explain this behavior. Following this model, alloy-design criteria were elucidated and confirmed successful on another Fe-based BMG Fe–B–Si–Nb–Cu, 1 mm in diameter, with crystallite sizes 10–40 nm. It was concluded that BNCAs can be designed in general by the proposed cr...

  16. 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...

  17. 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.

  18. The Universe With Bulk Viscosity

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Exact solutions for a model with variable G, A and bulk viscosity areobtained. Inflationary solutions with constant (de Sitter-type) and variable energydensity are found. An expanding anisotropic universe is found to isotropize duringits expansion but a static universe cannot isotropize. The gravitational constant isfound to increase with time and the cosmological constant decreases with time asAo∝t-2.

  19. Solid-solid phase transitions via melting in metals

    Science.gov (United States)

    Pogatscher, S.; Leutenegger, D.; Schawe, J. E. K.; Uggowitzer, P. J.; Löffler, J. F.

    2016-04-01

    Observing solid-solid phase transitions in-situ with sufficient temporal and spatial resolution is a great challenge, and is often only possible via computer simulations or in model systems. Recently, a study of polymeric colloidal particles, where the particles mimic atoms, revealed an intermediate liquid state in the transition from one solid to another. While not yet observed there, this finding suggests that such phenomena may also occur in metals and alloys. Here we present experimental evidence for a solid-solid transition via the formation of a metastable liquid in a `real' atomic system. We observe this transition in a bulk glass-forming metallic system in-situ using fast differential scanning calorimetry. We investigate the corresponding transformation kinetics and discuss the underlying thermodynamics. The mechanism is likely to be a feature of many metallic glasses and metals in general, and may provide further insight into phase transition theory.

  20. Storage and flow of solids. Bulletin No. 123; Vol. 53, No. 26, November 1964

    Energy Technology Data Exchange (ETDEWEB)

    Jenike, A.W.

    1976-11-01

    Information is presented on: the concepts of flowability of bulk solids and of channels and the flow-no flow postulate; equipment and procedures for testing the flow of bulk solids; and bulk flow equipment design. This information should be sufficient to enable the engineer to design storage plants and flow channels for unobstructed bulk flow. Only an outline of the theory of flow is included. (LCL)

  1. Cosmic bulk viscosity through backreaction

    CERN Document Server

    Barbosa, Rodrigo M; Zimdahl, Winfried; Piattella, Oliver F

    2015-01-01

    We consider an effective viscous pressure as the result of a backreaction of inhomogeneities within Buchert's formalism. The use of an effective metric with a time-dependent curvature radius allows us to calculate the luminosity distance of the backreaction model. This quantity is different from its counterpart for a "conventional" spatially flat bulk viscous fluid universe. Both expressions are tested against the SNIa data of the Union2.1 sample with only marginally different results.

  2. Bulk Superconductors in Mobile Application

    Science.gov (United States)

    Werfel, F. N.; Delor, U. Floegel-; Rothfeld, R.; Riedel, T.; Wippich, D.; Goebel, B.; Schirrmeister, P.

    We investigate and review concepts of multi - seeded REBCO bulk superconductors in mobile application. ATZ's compact HTS bulk magnets can trap routinely 1 T@77 K. Except of magnetization, flux creep and hysteresis, industrial - like properties as compactness, power density, and robustness are of major device interest if mobility and light-weight construction is in focus. For mobile application in levitated trains or demonstrator magnets we examine the performance of on-board cryogenics either by LN2 or cryo-cooler application. The mechanical, electric and thermodynamical requirements of compact vacuum cryostats for Maglev train operation were studied systematically. More than 30 units are manufactured and tested. The attractive load to weight ratio is more than 10 and favours group module device constructions up to 5 t load on permanent magnet (PM) track. A transportable and compact YBCO bulk magnet cooled with in-situ 4 Watt Stirling cryo-cooler for 50 - 80 K operation is investigated. Low cooling power and effective HTS cold mass drives the system construction to a minimum - thermal loss and light-weight design.

  3. Elastic properties of Pd40Cu30Ni10P20 bulk glass in supercooled liquid region

    DEFF Research Database (Denmark)

    Nishiyama, N.; Inoue, A.; Jiang, Jianzhong

    2001-01-01

    In situ ultrasonic measurements for the Pd40Cu30Ni10P20 bulk glass in three states: Glassy solid, supercooled liquid, and crystalline, have been performed. It is found that velocities of both longitudinal and transverse waves and elastic moduli (shear modulus, bulk modulus, Young's modulus, and L...

  4. Solid propellants.

    Science.gov (United States)

    Marsh, H. E., Jr.; Hutchison, J. J.

    1972-01-01

    The basic principles underlying propulsion by rocket motor are examined together with the configuration of a solid propellant motor. Solid propellants and their preparation are discussed, giving attention to homogeneous propellants, composite propellants, energetic considerations in choosing a solid propellant, the processing of composite propellants, and some examples of new developments. The performance of solid propellants is investigated, taking into account characteristics velocity, the specific impulse, and performance calculations. Aspects of propellant development considered include nonperformance requirements for solid propellants, the approach to development, propellant mechanical properties, and future trends.

  5. 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.

  6. Toughness of Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Shantanu V. Madge

    2015-07-01

    Full Text Available Bulk metallic glasses (BMGs have desirable properties like high strength and low modulus, but their toughness can show much variation, depending on the kind of test as well as alloy chemistry. This article reviews the type of toughness tests commonly performed and the factors influencing the data obtained. It appears that even the less-tough metallic glasses are tougher than oxide glasses. The current theories describing the links between toughness and material parameters, including elastic constants and alloy chemistry (ordering in the glass, are discussed. Based on the current literature, a few important issues for further work are identified.

  7. Photoelectron spectroscopy bulk and surface electronic structures

    CERN Document Server

    Suga, Shigemasa

    2014-01-01

    Photoelectron spectroscopy is now becoming more and more required to investigate electronic structures of various solid materials in the bulk, on surfaces as well as at buried interfaces. The energy resolution was much improved in the last decade down to 1 meV in the low photon energy region. Now this technique is available from a few eV up to 10 keV by use of lasers, electron cyclotron resonance lamps in addition to synchrotron radiation and X-ray tubes. High resolution angle resolved photoelectron spectroscopy (ARPES) is now widely applied to band mapping of materials. It attracts a wide attention from both fundamental science and material engineering. Studies of the dynamics of excited states are feasible by time of flight spectroscopy with fully utilizing the pulse structures of synchrotron radiation as well as lasers including the free electron lasers (FEL). Spin resolved studies also made dramatic progress by using higher efficiency spin detectors and two dimensional spin detectors. Polarization depend...

  8. Detection of Berry's phase in a Bulk Rashba semiconductor.

    Science.gov (United States)

    Murakawa, H; Bahramy, M S; Tokunaga, M; Kohama, Y; Bell, C; Kaneko, Y; Nagaosa, N; Hwang, H Y; Tokura, Y

    2013-12-20

    The motion of electrons in a solid has a profound effect on its topological properties and may result in a nonzero Berry's phase, a geometric quantum phase encoded in the system's electronic wave function. Despite its ubiquity, there are few experimental observations of Berry's phase of bulk states. Here, we report detection of a nontrivial π Berry's phase in the bulk Rashba semiconductor BiTeI via analysis of the Shubnikov-de Haas (SdH) effect. The extremely large Rashba splitting in this material enables the separation of SdH oscillations, stemming from the spin-split inner and outer Fermi surfaces. For both Fermi surfaces, we observe a systematic π-phase shift in SdH oscillations, consistent with the theoretically predicted nontrivial π Berry's phase in Rashba systems.

  9. Solid state physics at ISOLDE

    CERN Document Server

    Deicher, M; Wichert, T

    2003-01-01

    Radioactive atoms have been used in solid state physics and in materials science for decades. Besides their classical applications as tracers for diffusion studies, nuclear techniques such as Mossbauer spectroscopy, perturbed gamma gamma angular correlation, beta -NMR, and emission channeling make use of nuclear properties (via hyperfine interactions or emitted alpha or beta particles) to gain microscopic information on structural and dynamical properties of solids. During the last decade, the availability of many different radioactive isotopes as clean ion beams at ISOL facilities like ISOLDE/CERN has triggered a new era involving methods sensitive to the optical and electronic properties of solids, especially in the field of semiconductor physics. This overview will browse through ongoing solid state physics experiments with radioactive ion beams at ISOLDE. A wide variety of problems is under study, involving bulk properties, surfaces and interfaces in many different systems like semiconductors, superconduc...

  10. Solid lubricants

    Science.gov (United States)

    Sliney, Harold E.

    1993-01-01

    The state of knowledge of solid lubricants is reviewed. The results of research on solid lubricants from the 1940's to the present are presented from a historical perspective. Emphasis is placed largely, but not exclusively, on work performed at NASA Lewis Research Center with a natural focus on aerospace applications. However, because of the generic nature of the research, the information presented in this review is applicable to most areas where solid lubricant technology is useful.

  11. New fermions in the bulk

    CERN Document Server

    de Brito, K P S

    2016-01-01

    Spinor fields on 5-dimensional Lorentzian manifolds are classified, according to the geometric Fierz identities that involve their bilinear covariants. Based upon this classification that generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are, hence, found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density, through the truncated exterior bundle. In order to accomplish a realisation of these new spinors, a Killing vector field is constructed on the horizon of 5-dimensional Kerr black holes. This Killing vector field is shown to reach the time-like Killing vector field at the spatial infinity, through a current 1-form density, constructed with the derived new spinor fields. The current density is, moreover, expressed as the f\\"unfbein components, assuming a condensed for...

  12. New fermions in the bulk

    Science.gov (United States)

    de Brito, K. P. S.; da Rocha, Roldão

    2016-10-01

    The spinor fields on 5-dimensional Lorentzian manifolds are classified according to the geometric Fierz identities, which involve their bilinear covariants. Based upon this classification, which generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are hence found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density through the truncated exterior bundle. In order to accomplish the realisation of these new spinors, a Killing vector field is constructed on the horizon of a 5-dimensional Kerr black hole. This Killing vector field is shown to reach the time-like Killing vector field at spatial infinity through a current 1-form density, constructed with the new derived spinor fields. The current density is, moreover, expressed as the fünfbein component, assuming a condensed form.

  13. Nanofluidics, from bulk to interfaces.

    Science.gov (United States)

    Bocquet, Lydéric; Charlaix, Elisabeth

    2010-03-01

    Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest for scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at nanometer scales. Why is the nanometer scale specific? What fluid properties are probed at nanometric scales? In other words, why does 'nanofluidics' deserve its own brand name? In this critical review, we will explore the vast manifold of length scales emerging for fluid behavior at the nanoscale, as well as the associated mechanisms and corresponding applications. We will in particular explore the interplay between bulk and interface phenomena. The limit of validity of the continuum approaches will be discussed, as well as the numerous surface induced effects occurring at these scales, from hydrodynamic slippage to the various electro-kinetic phenomena originating from the couplings between hydrodynamics and electrostatics. An enlightening analogy between ion transport in nanochannels and transport in doped semi-conductors will be discussed (156 references).

  14. Solid Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Supported by a generous quantity of full-color illustrations and interesting sidebars, Solid Matter introduces the basic characteristics and properties of solid matter. It briefly describes the cosmic connection of the elements, leading readers through several key events in human pre-history that resulted in more advanced uses of matter in the solid state. Chapters include:. -Solid Matter: An Initial Perspective. -Physical Behavior of Matter. -The Gravity of Matter. -Fundamentals of Materials Science. -Rocks and Minerals. -Metals. -Building Materials. -Carbon Earth's Most Versatile Element. -S

  15. Extreme Water: Characterizing Exoplanets with Excess Bulk Water Interiors

    Science.gov (United States)

    Sasselov, Dimitar

    2015-12-01

    A number of planets with radii of 1 - 2.5 Earth radius have measured mean densities that allow more than 20% of their bulk interior to be composed of water. How do planets with solid-state water mantles modulate the fluxes of gases reaching the surface? What should we expect about the composition of their evolved atmospheres? I review theoretical models of the interiors and near-surface layers that constrain the fluxes of major gases (in and out) and resulting atmospheric compositions. The results have implications for observational characterization of rocky versus water planets, when the density alone is not enough, as well as the search for biosignatures and habitability.

  16. Carrier Bulk-Lifetime Measurements

    Directory of Open Access Journals (Sweden)

    M. Solcansky

    2012-01-01

    Full Text Available For the measurement of the minority carrier bulk-lifetime the characterization method MW-PCD is used, where the result of measurement is the effective carrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surface passivation. This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Various solutions are tested on silicon wafers for their consequent comparison. The main purpose is to find optimal solution, which suits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibility of a perfect cleaning of a passivating solution remains from a silicon surface, so that the parameters of a measured silicon wafer will not worsen and there will not be any contamination of the other wafers series in the production after a repetitive return of the measured wafer into the production process. The cleaning process itself is also a subject of a development.

  17. 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.)

  18. 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.

  19. Packaged bulk micromachined triglyceride biosensor

    Science.gov (United States)

    Mohanasundaram, S. V.; Mercy, S.; Harikrishna, P. V.; Rani, Kailash; Bhattacharya, Enakshi; Chadha, Anju

    2010-02-01

    Estimation of triglyceride concentration is important for the health and food industries. Use of solid state biosensors like Electrolyte Insulator Semiconductor Capacitors (EISCAP) ensures ease in operation with good accuracy and sensitivity when compared to conventional sensors. In this paper we report on packaging of miniaturized EISCAP sensors on silicon. The packaging involves glass to silicon bonding using adhesive. Since this kind of packaging is done at room temperature, it cannot damage the thin dielectric layers on the silicon wafer unlike the high temperature anodic bonding technique and can be used for sensors with immobilized enzyme without denaturing the enzyme. The packaging also involves a teflon capping arrangement which helps in easy handling of the bio-analyte solutions. The capping solves two problems. Firstly, it helps in the immobilization process where it ensures the enzyme immobilization happens only on one pit and secondly it helps with easy transport of the bio-analyte into the sensor pit for measurements.

  20. 33 CFR 127.313 - Bulk storage.

    Science.gov (United States)

    2010-07-01

    ...) WATERFRONT FACILITIES WATERFRONT FACILITIES HANDLING LIQUEFIED NATURAL GAS AND LIQUEFIED HAZARDOUS GAS Waterfront Facilities Handling Liquefied Natural Gas Operations § 127.313 Bulk storage. (a) The...

  1. Applications of bulk high-temperature superconductors

    Science.gov (United States)

    Hull, J. R.

    The development of high-temperature superconductors (HTS's) can be broadly generalized into thin-film electronics, wire applications, and bulk applications. We consider bulk HTS's to include sintered or crystallized forms that do not take the geometry of filaments or tapes, and we discuss major applications for these materials. For the most part applications may be realized with the HTS's cooled to 77 K, and the properties of the bulk HTS's are often already sufficient for commercial use. A non-exhaustive list of applications for bulk HTS's includes trapped field magnets, hysteresis motors, magnetic shielding, current leads, and magnetic bearings. These applications are briefly discussed in this paper.

  2. Hyperon bulk viscosity in strong magnetic fields

    CERN Document Server

    Sinha, Monika

    2008-01-01

    We study bulk viscosity in neutron star matter including $\\Lambda$ hyperons in the presence of quantizing magnetic fields. Relaxation time and bulk viscosity due to both the non-leptonic weak process involving $\\Lambda$ hyperons and the direct Urca (dUrca) process are calculated here. In the presence of a strong magnetic field, bulk viscosity coefficients are enhanced when protons, electrons and muons are populated in their respective zeroth Landau levels compared with the field free cases. The enhancement of bulk viscosity coefficient is larger for the dUrca case.

  3. Solid consistency

    Science.gov (United States)

    Bordin, Lorenzo; Creminelli, Paolo; Mirbabayi, Mehrdad; Noreña, Jorge

    2017-03-01

    We argue that isotropic scalar fluctuations in solid inflation are adiabatic in the super-horizon limit. During the solid phase this adiabatic mode has peculiar features: constant energy-density slices and comoving slices do not coincide, and their curvatures, parameterized respectively by ζ and Script R, both evolve in time. The existence of this adiabatic mode implies that Maldacena's squeezed limit consistency relation holds after angular average over the long mode. The correlation functions of a long-wavelength spherical scalar mode with several short scalar or tensor modes is fixed by the scaling behavior of the correlators of short modes, independently of the solid inflation action or dynamics of reheating.

  4. 40 CFR 264.314 - Special requirements for bulk and containerized liquids.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE.... (a) The placement of bulk or non-containerized liquid hazardous waste or hazardous waste containing...) The placement of any liquid which is not a hazardous waste in a landfill is prohibited unless the...

  5. Perovskite-type oxides - Oxygen electrocatalysis and bulk structure

    Science.gov (United States)

    Carbonio, R. E.; Fierro, C.; Tryk, D.; Scherson, D.; Yeager, E.

    1988-01-01

    Perovskite type oxides were considered for use as oxygen reduction and generation electrocatalysts in alkaline electrolytes. Perovskite stability and electrocatalytic activity are studied along with possible relationships of the latter with the bulk solid state properties. A series of compounds of the type LaFe(x)Ni1(-x)O3 was used as a model system to gain information on the possible relationships between surface catalytic activity and bulk structure. Hydrogen peroxide decomposition rate constants were measured for these compounds. Ex situ Mossbauer effect spectroscopy (MES), and magnetic susceptibility measurements were used to study the solid state properties. X ray photoelectron spectroscopy (XPS) was used to examine the surface. MES has indicated the presence of a paramagnetic to magnetically ordered phase transition for values of x between 0.4 and 0.5. A correlation was found between the values of the MES isomer shift and the catalytic activity for peroxide decomposition. Thus, the catalytic activity can be correlated to the d-electron density for the transition metal cations.

  6. Structure and physical properties of silicon clusters and of vacancy clusters in bulk silicon

    CERN Document Server

    Sieck, A

    2000-01-01

    different from the solid. The calculated stabilities and positron-lifetimes of vacancy clusters in bulk silicon indicate the positron-lifetimes of about 435 ps detected in irradiated silicon to be related to clusters of 9 or 10 vacancies. The vacancies in these clusters form neighboring hexa-rings and, therefore, minimize the number of dangling bonds. In this thesis the growth-pattern of free silicon clusters and vacancy clusters in bulk silicon is investigated. The aim is to describe and to better understand the cluster to bulk transition. Silicon structures in between clusters and solids feature new interesting physical properties. The structure and physical properties of silicon clusters can be revealed by a combination of theory and experiment, only. Low-energy clusters are determined with different optimization techniques and a density-functional based tight-binding method. Additionally, infrared and Raman spectra, and polarizabilities calculated within self-consistent field density-functional theory are...

  7. A comparison of observables for solid-solid phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, Laura B [Los Alamos National Laboratory; Henson, Bryan F [Los Alamos National Laboratory; Romero, Jerry J [Los Alamos National Laboratory

    2009-01-01

    The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries. Bulk generation of SHG is allowed by symmetry only in noncentrosymmetric crystallographic space groups. For the organic energetic nitramine octahydro-1,3 ,5,7 -tetranitro-1,3 ,5,7 -tatrazocine (HMX), the beta phase is centro symmetric (space group P2{sub 1}/c) and the delta phase iS noncentrosymmetric (space group P6{sub 1}22) making SHG an extremely sensitive, essentially zero background probe of the phase change progress. We have used SHG as a tool to follow the progress of the transformation from beta to delta phase during the solid-solid transformation. However, kinetic models of the transformation derived using different observables from several other groups have differed, showing later onset for the phase change and faster progression to completion. In this work, we have intercompared several techniques to understand these differences. The three techniques discussed are second harmonic generation, Raman spectroscopy, and differential scanning calorimetry (DSC). The progress of the beta to delta phase transition in HMX observed with each of these different probes will be discussed and advantages and disadvantages of each technique described. This paper compares several different observables for use in measuring the kinetics of solid-solid phase transitions. Relative advantages and disadvantages for each technique are described and a direct comparison of results is made for the beta to delta polymorphic phase transition of the energetic nitramine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tatrazocine.

  8. 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...

  9. Minor alloying behavior in bulk metallic glasses and high-entropy alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effect of minor alloying on several bulk metallic glasses and high-entropy al-loys was studied. It was found that minor Nb addition can optimize the interface structure between the W fiber and the Zr-based bulk metallic glass in the compos-ites,and improve the mechanical properties. Minor Y addition can destabilize the crystalline phases by inducing lattice distortion as a result to improve the glass-forming ability,and the lattice distortion energy is closely related to the effi-ciency of space filling of the competing crystalline phases. A long-period ordered structure can precipitate in the Mg-based bulk metallic glass by yttrium alloying. For the high-entropy alloys,solid solution can be formed by alloying,and its me-chanical properties can be comparable to most of the bulk metallic glasses.

  10. 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.

  11. Bulk equations of motion from CFT correlators

    Energy Technology Data Exchange (ETDEWEB)

    Kabat, Daniel [Department of Physics and Astronomy,Lehman College, City University of New York, Bronx NY 10468 (United States); Lifschytz, Gilad [Department of Physics and Astronomy,Lehman College, City University of New York, Bronx NY 10468 (United States); Physics Department,City College, City University of New York, New York NY 10031 (United States); Department of Mathematics and Physics,University of Haifa at Oranim, Kiryat Tivon 36006 (Israel)

    2015-09-10

    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.

  12. Bulk Vitrification Castable Refractory Block Protection Study

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.; Bagaasen, Larry M.; Beck, Andrew E.; Brouns, Thomas M.; Caldwell, Dustin D.; Elliott, Michael L.; Matyas, Josef; Minister, Kevin BC; Schweiger, Michael J.; Strachan, Denis M.; Tinsley, Bronnie P.; Hollenberg, Glenn W.

    2005-05-01

    Bulk vitrification (BV) was selected for a pilot-scale test and demonstration facility for supplemental treatment to accelerate the cleanup of low-activity waste (LAW) at the Hanford U.S. DOE Site. During engineering-scale (ES) tests, a small fraction of radioactive Tc (and Re, its nonradioactive surrogate) were transferred out of the LAW glass feed and molten LAW glass, and deposited on the surface and within the pores of the castable refractory block (CRB). Laboratory experiments were undertaken to understand the mechanisms of the transport Tc/Re into the CRB during vitrification and to evaluate various means of CRB protection against the deposition of leachable Tc/Re. The tests used Re as a chemical surrogate for Tc. The tests with the baseline CRB showed that the molten LAW penetrates into CRB pores before it converts to glass, leaving deposits of sulfates and chlorides when the nitrate components decompose. Na2O from the LAW reacts with the CRB to create a durable glass phase that may contain Tc/Re. Limited data from a single CRB sample taken from an ES experiment indicate that, while a fraction of Tc/Re is present in the CRB in a readily leachable form, most of the Tc/Re deposited in the refractory is retained in the form of a durable glass phase. In addition, the molten salts from the LAW, mainly sulfates, chlorides, and nitrates, begin to evaporate from BV feeds at temperatures below 800 C and condense on solid surfaces at temperatures below 530 C. Three approaches aimed at reducing or preventing the deposition of soluble Tc/Re within the CRB were proposed: metal lining, sealing the CRB surface with a glaze, and lining the CRB with ceramic tiles. Metal liners were deemed unsuitable because evaluations showed that they can cause unacceptable distortions of the electric field in the BV system. Sodium silicate and a low-alkali borosilicate glaze were selected for testing. The glazes slowed down molten salt condensate penetration, but did little to reduce the

  13. Holographic representation of local bulk operators

    CERN Document Server

    Hamilton, A; Lifschytz, G; Lowe, D A; Hamilton, Alex; Kabat, Daniel; Lifschytz, Gilad; Lowe, David A.

    2006-01-01

    The Lorentzian AdS/CFT correspondence implies a map between local operators in supergravity and non-local operators in the CFT. By explicit computation we construct CFT operators which are dual to local bulk fields in the semiclassical limit. The computation is done for general dimension in global, Poincare and Rindler coordinates. We find that the CFT operators can be taken to have compact support in a region of the complexified boundary whose size is set by the bulk radial position. We show that at finite N the number of independent commuting operators localized within a bulk volume saturates the holographic bound.

  14. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  15. Measuring Bulk Flows in Large Scale Surveys

    CERN Document Server

    Feldman, H A; Feldman, Hume A.; Watkins, Richard

    1993-01-01

    We follow a formalism presented by Kaiser to calculate the variance of bulk flows in large scale surveys. We apply the formalism to a mock survey of Abell clusters \\'a la Lauer \\& Postman and find the variance in the expected bulk velocities in a universe with CDM, MDM and IRAS--QDOT power spectra. We calculate the velocity variance as a function of the 1--D velocity dispersion of the clusters and the size of the survey.

  16. The Bulk Multicore Architecture for Improved Programmability

    Science.gov (United States)

    2009-12-01

    algorithm, forcing the same order of chunk commits as in the recording step. This design, which we call PicoLog , typically incurs a performance cost... PicoLog . Data-race detection at production- run speed. The Bulk Multicore can support an efficient data-race detec- tor based on the “happens-before...Bulk Multicore (a), with a possible OrderOnly execution log (b) and PicoLog execution log (c). contributed articles DECEMBER 2009 | VOL. 52

  17. Prospects for Detecting a Cosmic Bulk Flow

    Science.gov (United States)

    Rose, Benjamin; Garnavich, Peter M.; Mathews, Grant James

    2015-01-01

    The ΛCDM model is based upon a homogeneous, isotropic space-time leading to uniform expansion with random peculiar velocities caused by local gravitation perturbations. The Cosmic Microwave Background (CMB) radiation evidences a significant dipole moment in the frame of the Local Group. This motion is usually explained with the Local Group's motion relative to the background Hubble expansion. An alternative explanation, however, is that the dipole moment is the result of horizon-scale curvature remaining from the birth of space-time, possibly a result of quantum entanglement with another universe. This would appear as a single velocity (a bulk flow) added to all points in space. These two explanations differ observationally on cosmic distance scales (z > 0.1). There have been many differing attempts to detect a bulk flow, many with no detectable bulk flow but some with a bulk flow velocity as large as 1000 km/s. Here we report on a technique based upon minimizing the scatter around the expected cosine distribution of the Hubble redshift residuals with respect to angular distance on the sky. That is, the algorithm searches for a directional dependence of Hubble residuals. We find results consistent with most other bulk flow detections at z Type Ia Supernovae to be ~0.01, whereas the current error (~0.2.) is more than an order of magnitude too large for the detection of bulk flow beyond z~0.05.

  18. Occupational vitiligo due to unsuspected presence of phenolic antioxidant byproducts in commercial bulk rubber

    Energy Technology Data Exchange (ETDEWEB)

    O' Malley, M.A.; Mathias, C.G.; Priddy, M.; Molina, D.; Grote, A.A.; Halperin, W.E.

    1988-06-01

    We investigated the occurrence of cutaneous depigmentation (vitiligo) among employees of a company that manufactured hydraulic pumps. The interiors of these pumps were injection-molded with rubber. We identified a small but significant cluster of vitiligo cases among a group of employees who frequently handled the rubber used in this injection molding process. Although none of the additives specified in the rubber formulations was a phenolic or catecholic derivative, known to be potential causes of chemically induced vitiligo, gas chromatographic analysis identified a para-substituted phenol (2,4-di-tert-butylphenol, DTBP) in solid samples of the most frequently used rubber. Surface wipe analysis confirmed that workers could be exposed to DTBP from simple handling of the rubber. We subsequently established that the solid bulk rubber used as the base in these stock rubber formulations contained both DTBP and smaller quantities of p-tert-butylphenol. Both had formed as unsuspected byproducts during chemical synthesis of two antioxidants added to the solid bulk rubber by a major rubber supplier. We conclude that the unsuspected presence of potential chemical depigmenting agents in solid bulk rubber, from which industrial rubber products are formulated, may contribute to the occurrence of occupational vitiligo, and that a simple review of ingredients in rubber formulations is inadequate to detect their presence.

  19. On the early and developed stages of surface condensation: competition mechanism between interfacial and condensate bulk thermal resistances

    Science.gov (United States)

    Sun, Jie; Wang, Hua Sheng

    2016-10-01

    We use molecular dynamics simulation to investigate the early and developed stages of surface condensation. We find that the liquid-vapor and solid-liquid interfacial thermal resistances depend on the properties of solid and fluid, which are time-independent, while the condensate bulk thermal resistance depends on the condensate thickness, which is time-dependent. There exists intrinsic competition between the interfacial and condensate bulk thermal resistances in timeline and the resultant total thermal resistance determines the condensation intensity for a given vapor-solid temperature difference. We reveal the competition mechanism that the interfacial thermal resistance dominates at the onset of condensation and holds afterwards while the condensate bulk thermal resistance gradually takes over with condensate thickness growing. The weaker the solid-liquid bonding, the later the takeover occurs. This competition mechanism suggests that only when the condensate bulk thermal resistance is reduced after it takes over the domination can the condensation be effectively intensified. We propose a unified theoretical model for the thermal resistance analysis by making dropwise condensation equivalent to filmwise condensation. We further find that near a critical point (contact angle being ca. 153°) the bulk thermal resistance has the least opportunity to take over the domination while away from it the probability increases.

  20. Opportunities for shear energy scaling in bulk acoustic wave resonators.

    Science.gov (United States)

    Jose, Sumy; Hueting, Raymond J E

    2014-10-01

    An important energy loss contribution in bulk acoustic wave resonators is formed by so-called shear waves, which are transversal waves that propagate vertically through the devices with a horizontal motion. In this work, we report for the first time scaling of the shear-confined spots, i.e., spots containing a high concentration of shear wave displacement, controlled by the frame region width at the edge of the resonator. We also demonstrate a novel methodology to arrive at an optimum frame region width for spurious mode suppression and shear wave confinement. This methodology makes use of dispersion curves obtained from finite-element method (FEM) eigenfrequency simulations for arriving at an optimum frame region width. The frame region optimization is demonstrated for solidly mounted resonators employing several shear wave optimized reflector stacks. Finally, the FEM simulation results are compared with measurements for resonators with Ta2O5/ SiO2 stacks showing suppression of the spurious modes.

  1. Phase diagram of a bulk 1d lattice Coulomb gas

    Science.gov (United States)

    Démery, V.; Monsarrat, R.; Dean, D. S.; Podgornik, R.

    2016-01-01

    The exact solution, via transfer matrix, of the simple one-dimensional lattice Coulomb gas (1d LCG) model can reproduce peculiar features of ionic liquid capacitors, such as overscreening, layering, and camel- and bell-shaped capacitance curves. Using the same transfer matrix method, we now compute the bulk properties of the 1d LCG in the constant voltage ensemble. We unveil a phase diagram with rich structure exhibiting low-density disordered and high-density ordered phases, separated by a first-order phase transition at low temperature; the solid state at full packing can be ordered or not, depending on the temperature. This phase diagram, which is strikingly similar to its three-dimensional counterpart, also sheds light on the behaviour of the confined system.

  2. Microstructural characterization of bulk MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wiederhold, Alex; Koblischka, Michael; Hartmann, Uwe [Institute of Experimental Physics, Saarland University, P. O. Box 151150, D-66123 Saarbruecken (Germany); Inoue, Kazuo; Muralidhar, Miryala; Murakami, Masato [Department of Material Science and Engeneering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Berger, Kevin; Douine, Bruno [GREEN, Universite de Lorraine, Vandoeuvre-les-Nancy (France); Hauet, Thomas [Institute Jean Lamour, Universite de Lorraine, Vandoeuvre-les-Nancy (France); Noudem, Jacques [CRISMAT-CNRS, Cherbourg (France)

    2015-07-01

    A series of disk-shaped bulk MgB{sub 2} superconductors (sample diameter up to 4 cm) was prepared in order to improve the performance for superconducting super-magnets. Several samples were fabricated using a solid state reaction in pure Ar atmosphere from 750 to 950 C to obtain the highest critical current density (j{sub c}) as well as large trapped field values. Magnetization and transport measurements revealed that at the low reaction temperatures flux pinning at grain boundaries is dominant, which is decreasing on increasing temperature. At the highest reaction temperature, j{sub c} was found to increase again indicating a change of the pinning mechanism. In order to clarify this behavior the samples were characterized in detail by means of transmission electron microscopy (TEM) and transmission electron backscatter diffraction (t-EBSD).

  3. 46 CFR 148.04-19 - Tankage, garbage or rough ammoniate, solid.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Tankage, garbage or rough ammoniate, solid. 148.04-19... CARRIAGE OF SOLID HAZARDOUS MATERIALS IN BULK Special Additional Requirements for Certain Material § 148.04-19 Tankage, garbage or rough ammoniate, solid. (a) The material must contain at least 7...

  4. Soy protein isolate molecular level contributions to bulk adhesive properties

    Science.gov (United States)

    Shera, Jeanne Norton

    Increasing environmental awareness and the recognized health hazards of formaldehyde-based resins has prompted a strong demand for environmentally-responsible adhesives for wood composites. Soy protein-based adhesives have been shown to be commercially viable with 90-day shelf stability and composite physical properties comparable to those of commercial formaldehyde-based particleboards. The main research focus is to isolate and characterize the molecular level features in soy protein isolate responsible for providing mechanical properties, storage stability, and water resistance during adhesive formulation, processing, and wood composite fabrication. Commercial composite board will be reviewed to enhance our understanding of the individual components and processes required for particleboard production. The levels of protein structure will be defined and an overview of current bio-based technology will be presented. In the process, the logic for utilizing soy protein as a sole binder in the adhesive will be reinforced. Variables such as adhesive components, pH, divalent ions, blend aging, protein molecular weight, formulation solids content, and soy protein functionalization will relate the bulk properties of soy protein adhesives to the molecular configuration of the soybean protein. This work has demonstrated that when intermolecular beta-sheet interactions and protein long-range order is disrupted, viscosity and mechanical properties decrease. Storage stability can be maintained through the stabilization of intermolecular beta-sheet interactions. When molecular weight is reduced through enzymatic digestion, long-range order is disrupted and viscosity and mechanical properties decrease accordingly. Processibility and physical properties must be balanced to increase solids while maintaining low viscosity, desirable mechanical properties, and adequate storage stability. The structure of the soybean protein must be related to the particleboard bulk mechanical

  5. 5 MJ flywheel based on bulk HTS magnetic suspension

    Science.gov (United States)

    Poltavets, V.; Kovalev, K.; Ilyasov, R.; Glazunov, A.; Maevsky, V.; Verzbitsky, L.; Akhmadyshev, V.; Shikov, A.

    2014-05-01

    Nowadays the flywheel energy storage systems (FES) are developed intensively as uninterruptible power supply (UPS) devices for on-land and transport (especially airborne) applications worldwide. This work is devoted to the FES with magnetic suspension on the base of bulk HTS YBCO elements and permanent magnets. The developed FES is intended to be used as UPS in Russian atomic industry in case of an emergency. For the successful design of the FES the following questions should be solved: design of the motor/generator, design of the rotor (flywheel), design of the bearing system, design of the control system and system of power load matching, design of the cooling system. The developed small-scale FES with the stored energy 0.5 MJ was used to solve these basic questions. The elaborated FES consists of the synchronous electric machine with permanent magnets, the solid flywheel with axial magnetic suspension on the base of YBCO bulks and permanent magnets, the system of control and power load matching, and the system of liquid nitrogen cooling. The results of theoretical modeling of different schematics of magnetic suspension and experimental investigations of the constructed FES are presented. The design of the future full-scale FES with the stored energy ~5 MJ and output power up to 100 kW is described. The test results of the flywheel rotor and HTS magnetic suspension of 5 MJ FES are presented. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry"

  6. Melt processing of bulk high Tc superconductors and their application

    Science.gov (United States)

    Murakami, M.; Oyama, T.; Fujimoto, H.; Gotoh, S.; Yamaguchi, K.

    1991-03-01

    The authors report a melt-powder-melt-growth (MPMG) process which results in high Jc for bulk Y-Ba-Cu-O superconductors. The Y-Ba-Cu-O pellets or powders are melt quenched. The quenched plates are crushed into powder and mixed well. The powder is then compacted into desired shapes, remelted, and slowly cooled in a thermal gradient. When the starting composition is changed from the 1:2:3 stoichiometry toward the Y2BaCuO5(211) rich region, the 211 inclusions can be dispersed in the YBa2Cu3O(x) matrix, which contributes to increases in both flux pinning force and fracture toughness. A Jc value exceeding 3 x 108 A/sq m has been achieved at 77 K and 1 T. Another attractive feature of the MPMG process is that other components such as fine Ag powders can be added during solid-state mixing. Fine dispersion of Ag particles can effectively reduce the amount of cracking. MPMG-processed Y-Ba-Cu-O with Ag doping can levitate a mass of 3-kg at 1-mm height using a repulsive force against a 0.4-T magnet. A noncontacting rotation device such as a magnetic bearing can be made utilizing bulk high-Jc materials. A superconducting permanent magnet is also a promising candidate for future application. MPMG-processed Y-Ba-Cu-O can generate 0.25 T at 77 K.

  7. 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.

  8. Into the Bulk: A Covariant Approach

    CERN Document Server

    Engelhardt, Netta

    2016-01-01

    I propose a general, covariant way of defining when one region is "deeper in the bulk" than another. This definition is formulated outside of an event horizon (or in the absence thereof) in generic geometries; it may be applied to both points and surfaces, and may be used to compare the depth of bulk points or surfaces relative to a particular boundary subregion or relative to the entire boundary. Using the recently proposed "lightcone cut" formalism, the comparative depth between two bulk points can be determined from the singularity structure of Lorentzian correlators in the dual field theory. I prove that, by this definition, causal wedges of progressively larger regions probe monotonically deeper in the bulk. The definition furthermore matches expectations in pure AdS and in static AdS black holes with isotropic spatial slices, where a well-defined holographic coordinate exists. In terms of holographic RG flow, this new definition of bulk depth makes contact with coarse-graining over both large distances ...

  9. Crystallization of High Bulk Density Nitroguanidine

    Science.gov (United States)

    2011-06-01

    microscope after obtaining solid crystals , which were filtered and washed using acetone. For measuring dissolved NQ concentration in the RC-1, a Mettler...known volume of clear supernatant solution was dried on a hot plate at 100°C and the weight of solid crystals was measured from which the solubility

  10. 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.

  11. A stereoscopic look into the bulk

    Science.gov (United States)

    Czech, Bartlomiej; Lamprou, Lampros; McCandlish, Samuel; Mosk, Benjamin; Sully, James

    2016-07-01

    We present the foundation for a holographic dictionary with depth perception. The dictionary consists of natural CFT operators whose duals are simple, diffeomorphisminvariant bulk operators. The CFT operators of interest are the "OPE blocks," contributions to the OPE from a single conformal family. In holographic theories, we show that the OPE blocks are dual at leading order in 1 /N to integrals of effective bulk fields along geodesics or homogeneous minimal surfaces in anti-de Sitter space. One widely studied example of an OPE block is the modular Hamiltonian, which is dual to the fluctuation in the area of a minimal surface. Thus, our operators pave the way for generalizing the Ryu-Takayanagi relation to other bulk fields.

  12. Bulk amorphous Mg-based alloys

    DEFF Research Database (Denmark)

    Pryds, Nini

    2004-01-01

    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...

  13. 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.

  14. Bulk fields from the boundary OPE

    CERN Document Server

    Guica, Monica

    2016-01-01

    Previous work has established an equality between the geodesic integral of a free bulk field in AdS and the contribution of the conformal descendants of its dual CFT primary operator to the OPE of two other operators inserted at the endpoints of the geodesic. Working in the context of AdS$_3$/CFT$_2$, we extend this relation to include all $1/N$ corrections to the bulk field obtained by dressing it with i) a $U(1)$ current and ii) the CFT stress tensor, and argue it equals the contribution of the Ka\\v{c}-Moody/the Virasoro block to the respective boundary OPE. This equality holds for a particular framing of the bulk field to the boundary that involves a split Wilson line.

  15. Multiphase composites with extremal bulk modulus

    DEFF Research Database (Denmark)

    Gibiansky, L. V.; Sigmund, Ole

    2000-01-01

    This paper is devoted to the analytical and numerical study of isotropic elastic composites made of three or more isotropic phases. The ranges of their effective bulk and shear moduli are restricted by the Hashin-Shtrikman-Walpole (HSW) bounds. For two-phase composites, these bounds are attainable......, that is, there exist composites with extreme bulk and shear moduli. For multiphase composites, they may or may not be attainable depending on phase moduli and volume fractions. Sufficient conditions of attainability of the bounds and various previously known and new types of optimal composites...... are described. Most of our new results are related to the two-dimensional problem. A numerical topology optimization procedure that solves the inverse homogenization problem is adopted and used to look for two-dimensional three-phase composites with a maximal effective bulk modulus. For the combination...

  16. 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...

  17. A Diphoton Resonance from Bulk RS

    CERN Document Server

    Csaki, Csaba

    2016-01-01

    Recent LHC data hints at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to Higges and to any other Standard Model particles are so far too low to be detected. 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. We argue that if the state is a scalar, some form of sequestering is likely to be necessary to naturally explain the suppressed scalar-Higgs interactions. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from 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.

  18. Spherically symmetric brane spacetime with bulk gravity

    Science.gov (United States)

    Chakraborty, Sumanta; SenGupta, Soumitra

    2015-01-01

    Introducing term in the five-dimensional bulk action we derive effective Einstein's equation on the brane using Gauss-Codazzi equation. This effective equation is then solved for different conditions on dark radiation and dark pressure to obtain various spherically symmetric solutions. Some of these static spherically symmetric solutions correspond to black hole solutions, with parameters induced from the bulk. Specially, the dark pressure and dark radiation terms (electric part of Weyl curvature) affect the brane spherically symmetric solutions significantly. We have solved for one parameter group of conformal motions where the dark radiation and dark pressure terms are exactly obtained exploiting the corresponding Lie symmetry. Various thermodynamic features of these spherically symmetric space-times are studied, showing existence of second order phase transition. This phenomenon has its origin in the higher curvature term with gravity in the bulk.

  19. Bulk Vitrification Performance Enhancement: Refractory Lining Protection Against Molten Salt Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.; Bagaasen, Larry M.; Schweiger, Michael J.; Evans, Michael B.; Smith, Benjamin T.; Arrigoni, Benjamin M.; Kim, Dong-Sang; Rodriguez, Carmen P.; Yokuda, Satoru T.; Matyas, Josef; Buchmiller, William C.; Gallegos, Autumn B.; Fluegel, Alexander

    2007-08-06

    Bulk vitrification (BV) is a process that heats a feed material that consists of glass-forming solids and dried low-activity waste (LAW) in a disposable refractory-lined metal box using electrical power supplied through carbon electrodes. The feed is heated to the point that the LAW decomposes and combines with the solids to generate a vitreous waste form. This study supports the BV design and operations by exploring various methods aimed at reducing the quantities of soluble Tc in the castable refractory block portion of the refractory lining, which limits the effectiveness of the final waste form.

  20. Monitoring hydrate formation and dissociation in sandstone and bulk with magnetic resonance imaging.

    Science.gov (United States)

    Baldwin, B A; Moradi-Araghi, A; Stevens, J C

    2003-11-01

    Magnetic resonance imaging (MRI) has been shown to be a very effective tool for monitoring the formation and dissociation of hydrates because of the large intensity contrast between the images of the liquid components and the solid hydrate. Tetrahydrofuran/water hydrate was used because the two liquid components are miscible and form hydrate at ambient pressure. These properties made this feasibility study proceed much faster than using methane/water, which requires high pressure to form the hydrate. The formation and dissociation was monitored first in a THF/water-saturated Berea sandstone plug and second in the bulk. In both cases it appeared that nucleation was needed to begin the formation process, i.e., the presence of surfaces in the sandstone and shaking of the bulk solution. Dissociation appeared to be dominated by the rate of thermal energy transfer. The dissociation temperature of hydrate formed in the sandstone plug was not significantly different from the dissociation temperature in bulk.

  1. Making bulk-conductive glass microchannel plates

    Science.gov (United States)

    Yi, Jay J. L.; Niu, Lihong

    2008-02-01

    The fabrication of microchannel plate (MCP) with bulk-conductive characteristics has been studied. Semiconducting clad glass and leachable core glass were used for drawing fibers and making MCP. Co-axial single fiber was drawn from a platinum double-crucible in an automatic fiberizing system, and the fibers were stacked and redrawn into multifiber by a special gripping mechanism. The multifibers were stacked again and the boule was made and sliced into discs. New MCPs were made after chemically leaching process without the traditional hydrogen firing. It was shown that bulk-conductive glass MCP can operate at higher voltage with lower noise.

  2. "Work-Hardenable" ductile bulk metallic glass.

    Science.gov (United States)

    Das, Jayanta; Tang, Mei Bo; Kim, Ki Buem; Theissmann, Ralf; Baier, Falko; Wang, Wei Hua; Eckert, Jürgen

    2005-05-27

    Usually, monolithic bulk metallic glasses undergo inhomogeneous plastic deformation and exhibit poor ductility (< 1%) at room temperature. We present a new class of bulk metallic glass, which exhibits high strength of up to 2265 MPa together with extensive "work hardening" and large ductility of 18%. Significant increase in the flow stress was observed during deformation. The "work-hardening" capability and ductility of this class of metallic glass is attributed to a unique structure correlated with atomic-scale inhomogeneity, leading to an inherent capability of extensive shear band formation, interactions, and multiplication of shear bands.

  3. 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.

  4. Towards a Reconstruction of General Bulk Metrics

    CERN Document Server

    Engelhardt, Netta

    2016-01-01

    We prove that the metric of a general holographic spacetime can be reconstructed (up to an overall conformal factor) from distinguished spatial slices - "light-cone cuts" - of the conformal boundary. Our prescription is covariant and applies to bulk points in causal contact with the boundary. Furthermore, we describe a procedure for determining the light-cone cuts corresponding to bulk points in the causal wedge of the boundary in terms of the divergences of correlators in the dual field theory. Possible extensions for determining the conformal factor and including the cuts of points outside of the causal wedge are discussed. We also comment on implications for subregion/subregion duality.

  5. Titania doping effect on superconducting properties of MgB2 bulk samples

    Science.gov (United States)

    Serrano, G.; Bridoux, G.; Serquis, A.

    2009-05-01

    In this work we study the microstructural and superconducting properties of doped and undoped bulk MgB2 samples prepared by solid-state reaction, with 0 and 2.5 %at. nominal TiO2 nanotubes contents, annealed at different temperatures in the 750-900°C range. We discuss the Tc, Jc and Hc2 performance and their correlation with the different synthesis parameters.

  6. Titania doping effect on superconducting properties of MgB{sub 2} bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, G; Serquis, A [Institute Balseiro - Centra Atomico Bariloche and CONICET, (8400) S. C. de Bariloche, Rio Negro (Argentina); Bridoux, G, E-mail: serranog@ib.cnea.gov.a [Institute Balseiro - Centra Atomico Bariloche, (8400) S. C. de Bariloche, Rio Negro (Argentina)

    2009-05-01

    In this work we study the microstructural and superconducting properties of doped and undoped bulk MgB{sub 2} samples prepared by solid-state reaction, with 0 and 2.5 %at. nominal TiO{sub 2} nanotubes contents, annealed at different temperatures in the 750-900 deg. C range. We discuss the T{sub c}, J{sub c} and H{sub c2} performance and their correlation with the different synthesis parameters.

  7. Sludge Bulking Prediction Using Principle Component Regression and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Inchio Lou

    2012-01-01

    Full Text Available Sludge bulking is the most common solids settling problem in wastewater treatment plants, which is caused by the excessive growth of filamentous bacteria extending outside the flocs, resulting in decreasing the wastewater treatment efficiency and deteriorating the water quality in the effluent. Previous studies using molecular techniques have been widely used from the microbiological aspects, while the mechanisms have not yet been completely understood to form the deterministic cause-effect relationship. In this study, system identification techniques based on the analysis of the inputs and outputs of the activated sludge system are applied to the data-driven modeling. Principle component regression (PCR and artificial neural network (ANN were identified using the data from Chongqing wastewater treatment plant (CQWWTP, including temperature, pH, biochemical oxygen demand (BOD, chemical oxygen demand (COD, suspended solids (SSs, ammonia (NH4+, total nitrogen (TN, total phosphorus (TP, and mixed liquor suspended solids (MLSSs. The models were subsequently used to predict the sludge volume index (SVI, the indicator of the bulking occurrence. Comparison of the results obtained by both models is also presented. The results showed that ANN has better prediction power (R2=0.9 than PCR (R2=0.7 and thus provides a useful guide for practical sludge bulking control.

  8. Failure by fracture in bulk metal forming

    DEFF Research Database (Denmark)

    Silva, C.M.A.; Alves, Luis M.; Nielsen, Chris Valentin

    2015-01-01

    This paper revisits formability in bulk metal forming in the light of fundamental concepts of plasticity,ductile damage and crack opening modes. It proposes a new test to appraise the accuracy, reliability and validity of fracture loci associated with crack opening by tension and out-of-plane she...

  9. 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.

  10. Forming of bulk metallic glass microcomponents

    DEFF Research Database (Denmark)

    Wert, John A.; Thomsen, Christian; Jensen, Rune Debel

    2009-01-01

    The present article considers forward extrusion, closed-die forging and backward extrusion processes for fabrication of individual microcomponents from two bulk metallic glass (BMG) compositions: Mg60Cu30Y10 and Zr44Cu40Ag8Al8. Two types of tooling were used in the present work: relatively massive...

  11. Bulk viscosity effects on ultrasonic thermoacoustic instability

    Science.gov (United States)

    Lin, Jeffrey; Scalo, Carlo; Hesselink, Lambertus

    2016-11-01

    We have carried out unstructured fully-compressible Navier-Stokes simulations of a minimal-unit traveling-wave ultrasonic thermoacoustic device in looped configuration. The model comprises a thermoacoustic stack with 85% porosity and a tapered area change to suppress the fundamental standing-wave mode. A bulk viscosity model, which accounts for vibrational and rotational molecular relaxation effects, is derived and implemented via direct modification of the viscous stress tensor, τij ≡ 2 μSij +λ/2 μ ∂uk/∂xk δij , where the bulk viscosity is defined by μb ≡ λ +2/3 μ . The effective bulk viscosity coefficient accurately captures acoustic absorption from low to high ultrasonic frequencies and matches experimental wave attenuation rates across five decades. Using pressure-based similitude, the model was downscaled from total length L = 2 . 58 m to 0 . 0258 m, corresponding to the frequency range f = 242 - 24200 Hz, revealing the effects of bulk viscosity and direct modification of the thermodynamic pressure. Simulations are carried out to limit cycle and exhibit growth rates consistent with linear stability analyses, based on Rott's theory.

  12. Longitudinal bulk a coustic mass sensor

    DEFF Research Database (Denmark)

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

    2009-01-01

    Design, fabrication and characterization, in terms of mass sensitivity, is presented for a polycrystalline silicon longitudinal bulk acoustic cantilever. The device is operated in air at 51 MHz, resulting in a mass sensitivity of 100 HZ/fg (1 fg = 10{su−15 g). The initial characterization...

  13. Winterization strategies for bulk storage of pickles

    Science.gov (United States)

    Cucumbers are commercially fermented and stored in bulk in outdoor open top fiberglass tanks. During winter, snow and ice accumulates around and on top of tanks influencing heat transfer in an unpredictable manner, often compromising the fruit quality. This study evaluates the performance of inexpen...

  14. A Stereoscopic Look into the Bulk

    CERN Document Server

    Czech, Bartlomiej; McCandlish, Samuel; Mosk, Benjamin; Sully, James

    2016-01-01

    We present the foundation for a holographic dictionary with depth perception. The dictionary consists of natural CFT operators whose duals are simple, diffeomorphism-invariant bulk operators. The CFT operators of interest are the "OPE blocks," contributions to the OPE from a single conformal family. In holographic theories, we show that the OPE blocks are dual at leading order in 1/N to integrals of effective bulk fields along geodesics or homogeneous minimal surfaces in anti-de Sitter space. One widely studied example of an OPE block is the modular Hamiltonian, which is dual to the fluctuation in the area of a minimal surface. Thus, our operators pave the way for generalizing the Ryu-Takayanagi relation to other bulk fields. Although the OPE blocks are non-local operators in the CFT, they admit a simple geometric description as fields in kinematic space--the space of pairs of CFT points. We develop the tools for constructing local bulk operators in terms of these non-local objects. The OPE blocks also allow ...

  15. Fluctuating brane in a dilatonic bulk

    CERN Document Server

    Brax, P; Rodríguez-Martinez, M; Brax, Philippe; Langlois, David; Rodriguez-Martinez, Maria

    2003-01-01

    We consider a cosmological brane moving in a static five-dimensional bulk spacetime endowed with a scalar field whose potential is exponential. After studying various cosmological behaviours for the homogeneous background, we investigate the fluctuations of the brane that leave spacetime unaffected. A single mode embodies these fluctuations and obeys a wave equation which we study for bouncing and ever-expanding branes.

  16. Meteoroid Bulk Density and Ceplecha Types

    Science.gov (United States)

    Blaauw, R. C.; Moser, D. E.; Moorhead, A. V.

    2017-01-01

    The determination of asteroid bulk density is an important aspect of Near Earth Object (NEO) characterization. A fraction of meteoroids originate from asteroids (including some NEOs), thus in lieu of mutual perturbations, satellites, or expensive spacecraft missions, a study of meteoroid bulk densities can potentially provide useful insights into the densities of NEOs and PHOs (Potentially Hazardous Objects). Meteoroid bulk density is still inherently difficult to measure, and is most often determined by modeling the ablation of the meteoroid. One approach towards determining a meteoroid density distribution entails using a more easily measured proxy for the densities, then calibrating the proxy with known densities from meteorite falls, ablation modelling, and other sources. An obvious proxy choice is the Ceplecha type, KB (Ceplecha, 1958), which is thought to indicate the strength of a meteoroid and often correlated to different bulk densities in literature. KB is calculated using the air density at the beginning height of the meteor, the initial velocity, and the zenith angle of the radiant; quantities more readily determined than meteoroid bulk density itself. Numerical values of K(sub B) are sorted into groups (A, B, C, etc.), which have been matched to meteorite falls or meteor showers with known composition such as the porous Draconids. An extensive survey was conducted to establish the strength of the relationship between bulk density and K(sub B), specifically looking at those that additionally determined K(sub B) for the meteors. In examining the modeling of high-resolution meteor data from Kikwaya et al. (2011), the correlation between K(sub B) and bulk density was not as strong as hoped. However, a distinct split by dynamical type was seen with Jovian Tisserand parameter (T(sub J)), with meteoroids from Halley Type comets (T(sub J) densities than those originating from Jupiter Family comets and asteroids (T(sub J) > 2). Therefore, this work indicates

  17. Integration of bulk piezoelectric materials into microsystems

    Science.gov (United States)

    Aktakka, Ethem Erkan

    Bulk piezoelectric ceramics, compared to deposited piezoelectric thin-films, provide greater electromechanical coupling and charge capacity, which are highly desirable in many MEMS applications. In this thesis, a technology platform is developed for wafer-level integration of bulk piezoelectric substrates on silicon, with a final film thickness of 5-100microm. The characterized processes include reliable low-temperature (200°C) AuIn diffusion bonding and parylene bonding of bulk-PZT on silicon, wafer-level lapping of bulk-PZT with high-uniformity (+/-0.5microm), and low-damage micro-machining of PZT films via dicing-saw patterning, laser ablation, and wet-etching. Preservation of ferroelectric and piezoelectric properties is confirmed with hysteresis and piezo-response measurements. The introduced technology offers higher material quality and unique advantages in fabrication flexibility over existing piezoelectric film deposition methods. In order to confirm the preserved bulk properties in the final film, diaphragm and cantilever beam actuators operating in the transverse-mode are designed, fabricated and tested. The diaphragm structure and electrode shapes/sizes are optimized for maximum deflection through finite-element simulations. During tests of fabricated devices, greater than 12microm PP displacement is obtained by actuation of a 1mm2 diaphragm at 111kHz with management IC, which incorporates a supply-independent bias circuitry, an active diode for low-dropout rectification, a bias-flip system for higher efficiency, and a trickle battery charger. The overall system does not require a pre-charged battery, and has power consumption of sleep-mode (simulated). Under lg vibration at 155Hz, a 70mF ultra-capacitor is charged from OV to 1.85V in 50 minutes.

  18. 46 CFR 148.04-23 - Unslaked lime in bulk.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Unslaked lime in bulk. 148.04-23 Section 148.04-23... HAZARDOUS MATERIALS IN BULK Special Additional Requirements for Certain Material § 148.04-23 Unslaked lime in bulk. (a) Unslaked lime in bulk must be transported in unmanned, all steel, double-hulled...

  19. CHARACTERIZATION OF BULK SOIL HUMIN AND ITS ALKALINE-SOLUBLE AND ALKALINE-INSOLUBLE FRACTIONS

    Directory of Open Access Journals (Sweden)

    Cuilan Li

    2015-02-01

    Full Text Available 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 better understanding of the structure and properties of humin. However, the structural relationship between bulk humin and its alkaline-soluble (AS and alkaline-insoluble (AIS fractions is still unknown. In this study, we isolated bulk humin from two soils of Northeast China by exhaustive extraction (25 to 28 times with 0.1 mol L-1 NaOH + 0.1 mol L-1 Na4P2O7, followed by the traditional treatment with 10 % HF-HCl. The isolated bulk humin was then fractionated into AS-humin and AIS-humin by exhaustive extraction (12 to 15 times with 0.1 mol L-1 NaOH. Elemental analysis and solid-state 13C cross-polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR spectroscopy were used to characterize and compare the chemical structures of bulk humin and its corresponding fractions. The results showed that, regardless of soil types, bulk humin was the most aliphatic and most hydrophobic, AS-humin was the least aliphatic, and AIS-humin was the least alkylated among the three humic components. The results showed that bulk humin and its corresponding AS-humin and AIS-humin fractions are structurally differed from one another, implying that the functions of these humic components in the soil environment differed.

  20. An approach to predict free surface fracture in bulk forming

    Science.gov (United States)

    Ragab, A. R.

    2006-04-01

    This work presents a unified approach to predict surface strains at failure in bulk forming processes. The approach does not deal with a specific process but rather with prescribed strain and stress paths. The material to be processed is assumed to possess an initial void volume fraction that grows and colaesces with straining, ending by fracture. The predictions are based on a formulation for voided solids according to the Gurson-Tvergaard yield function adapted to include orthotropic anisotropy. The incident of fracture is characterized by shear band formation within the ligaments of the matrix material among spheroidal voids as described by McClintock. The results are represented by a straight line plot of tensile limit strain versus the compressive strain for different loading paths. These limit curves are shown to be dependent on the initial void fraction, hardening, and anisotropy of the matrix matrial. Alloys with lower initial void fractions as well as those of higher hardening show better workability. The model is applied to predict bulk formability curves for steels AISI 1040 and 1045, Aluminum AI 7075-T6, and copper, based on the proper selection of micromechanical parameters for these alloys. The validity of the model is ensured through fairly favorable comparison with experimentally determined limit curves. The current failure conditions are suitable to predict the experimental dual slope fracture line that may exist for some alloys such as cold-drawn steel AISI 1045 and aluminum 2024-T6 by considering two mechanisms of failure: internal necking in the ligament material between voids, followed by transition to shear band formation.

  1. Bulk locality and boundary creating operators

    Science.gov (United States)

    Nakayama, Yu; Ooguri, Hirosi

    2015-10-01

    We formulate a minimum requirement for CFT operators to be localized in the dual AdS. In any spacetime dimensions, we show that a general solution to the requirement is a linear superposition of operators creating spherical boundaries in CFT, with the dilatation by the imaginary unit from their centers. This generalizes the recent proposal by Miyaji et al. for bulk local operators in the three dimensional AdS. We show that Ishibashi states for the global conformal symmetry in any dimensions and with the imaginary di-latation obey free field equations in AdS and that incorporating bulk interactions require their superpositions. We also comment on the recent proposals by Kabat et al., and by H. Verlinde.

  2. Bulk Locality and Boundary Creating Operators

    CERN Document Server

    Nakayama, Yu

    2015-01-01

    We formulate a minimum requirement for CFT operators to be localized in the dual AdS. In any spacetime dimensions, we show that a general solution to the requirement is a linear superposition of operators creating spherical boundaries in CFT, with the dilatation by the imaginary unit from their centers. This generalizes the recent proposal by Miyaji et al. for bulk local operators in the three dimensional AdS. We show that Ishibashi states for the global conformal symmetry in any dimensions and with the imaginary dilatation obey free field equations in AdS and that incorporating bulk interactions require their superpositions. We also comment on the recent proposals by Kabat et al., and by H. Verlinde.

  3. Bulk locality and boundary creating operators

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yu [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125 (United States); Ooguri, Hirosi [Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, California 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan)

    2015-10-19

    We formulate a minimum requirement for CFT operators to be localized in the dual AdS. In any spacetime dimensions, we show that a general solution to the requirement is a linear superposition of operators creating spherical boundaries in CFT, with the dilatation by the imaginary unit from their centers. This generalizes the recent proposal by Miyaji et al. for bulk local operators in the three dimensional AdS. We show that Ishibashi states for the global conformal symmetry in any dimensions and with the imaginary dilatation obey free field equations in AdS and that incorporating bulk interactions require their superpositions. We also comment on the recent proposals by Kabat et al., and by H. Verlinde.

  4. Bulk and shear viscosity in Hagedorn fluid

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, A.; Wahba, M. [Egyptian Center for Theoretical Physics (ECTP), MTI University, Faculty of Engineering, Cairo (Egypt)

    2010-11-15

    Assuming that the Hagedorn fluid composed of known particles and resonances with masses m <2 GeV obeys the first-order theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium of hadron resonances are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the in-medium thermal effects on bulk and shear viscosity and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equilibrium thermodynamics and the cosmological models, which require thermo- and hydro-dynamics equations of state. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  5. Bulk and Shear Viscosity in Hagedorn Fluid

    CERN Document Server

    Tawfik, A

    2010-01-01

    Assuming that the Hagedorn fluid composed of known particles and resonances with masses $m<2\\,$GeV obeys the {\\it first-order} theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the {\\it in-medium} thermal effects on bulk and shear viscosities and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equlibrium thermodynamics and the cosmological models, which require thermo and hydrodynamics equations of state.

  6. Portable design rules for bulk CMOS

    Science.gov (United States)

    Griswold, T. W.

    1982-01-01

    It is pointed out that for the past several years, one school of IC designers has used a simplified set of nMOS geometric design rules (GDR) which is 'portable', in that it can be used by many different nMOS manufacturers. The present investigation is concerned with a preliminary set of design rules for bulk CMOS which has been verified for simple test structures. The GDR are defined in terms of Caltech Intermediate Form (CIF), which is a geometry-description language that defines simple geometrical objects in layers. The layers are abstractions of physical mask layers. The design rules do not presume the existence of any particular design methodology. Attention is given to p-well and n-well CMOS processes, bulk CMOS and CMOS-SOS, CMOS geometric rules, and a description of the advantages of CMOS technology.

  7. Fully antisymmetrised dynamics for bulk fermion systems

    CERN Document Server

    Vantournhout, Klaas

    2011-01-01

    The neutron star's crust and mantel are typical examples of non-uniform bulk systems with spacial localisations. When modelling such systems at low temperatures, as is the case in the crust, one has to work with antisymmetrised many-body states to get the correct fermion behaviour. Fermionic molecular dynamics, which works with an antisymmetrised product of localised wave packets, should be an appropriate choice. Implementing periodic boundary conditions into the fermionic molecular dynamics formalism would allow the study of the neutron star's crust as a bulk quantum system. Unfortunately, the antisymmetrisation is a non-local entanglement which reaches far out of the periodically repeated unit cell. In this proceeding, we give a brief overview how periodic boundary conditions and fermionic molecular dynamics can be combined without truncating the long-range many-body correlation induced by the antisymmetry of the many-body state.

  8. Large bulk Micromegas detectors for TPC applications

    CERN Document Server

    Anvar, S; Boyer, M; Beucher, J; Calvet, D; Colas, P; De La Broise, X; Delagnes, E; Delbart, A; Druillole, F; Emery, S; Giganti, C; Giomataris, I; Mazzucato, E; Monmarthe, E; Nizery, F; Pierre, F; Ritou, J L; Sarrat, A; Zito, M; Catanesi, M G; Radicioni, E; De Oliveira, R; Blondel, A; Di Marco, M; Ferrere, D; Perrin, E; Ravonel, M; Jover, G; Lux, T; Rodriguez, A Y; Sanchez, F; Cervera, A; Hansen, C; Monfregola, L

    2009-01-01

    A large volume TPC will be used in the near future in a variety of experiments including T2K. The bulk Micromegas detector for this TPC is built using a novel production technique particularly suited for compact, thin and robust low mass detectors. The capability to pave a large surface with a simple mounting solution and small dead space is of particular interest for these applications. We have built several large bulk Micromegas detectors () and we have tested one in the former HARP field cage with a magnetic field. Prototypes cards of the T2K front end electronics, based on the AFTER ASIC chip, have been used in this TPC test for the first time. Cosmic ray data have been acquired in a variety of experimental conditions. Good detector performances, space point resolution and energy loss measurement have been achieved.

  9. Bulk micromegas detectors for large TPC applications

    CERN Document Server

    Bouchez, J; Cavata, Ch; Colas, P; De La Broise, X; Delbart, A; Giganon, Arnaud; Giomataris, Ioanis; Graffin, P; Mols, J Ph; Pierre, F; Ritou, J L; Sarrat, A; Virique, E; Zito, M; Radicioni, E; De Oliveira, R; Dumarchez, J; Abgrall, N; Bene, P; Blondel, A; Cervera-Villanueva, Anselmo; Ferrère, D; Maschiocchi, F; Perrin, E; Richeux, J P; Schroeter, R; Jover, G; Lux,; Rodriguez, A Y; Sánchez, F

    2007-01-01

    A large volume TPC will be used in the near future in a variety of experiments including T2K. The bulk Micromegas detector for this TPC is built using a novel production technique particularly suited for compact and robust low mass detectors. The capability to pave a large surface with a simple mounting solution and small dead space between modules is of particular interest for these applications. We have built several large bulk Micromegas detectors and we have tested them in the former HARP field cage setup with a magnetic field. Cosmic ray data have been acquired in a variety of experimental conditions. Good detector performances and space point resolution have been achieved.

  10. Effective pure states for bulk quantum computation

    Energy Technology Data Exchange (ETDEWEB)

    Knill, E.; Chuang, I.; Laflamme, R.

    1997-11-01

    In bulk quantum computation one can manipulate a large number of indistinguishable quantum computers by parallel unitary operations and measure expectation values of certain observables with limited sensitivity. The initial state of each computer in the ensemble is known but not pure. Methods for obtaining effective pure input states by a series of manipulations have been described by Gershenfeld and Chuang (logical labeling) and Corey et al. (spatial averaging) for the case of quantum computation with nuclear magnetic resonance. We give a different technique called temporal averaging. This method is based on classical randomization, requires no ancilla qubits and can be implemented in nuclear magnetic resonance without using gradient fields. We introduce several temporal averaging algorithms suitable for both high temperature and low temperature bulk quantum computing and analyze the signal to noise behavior of each.

  11. Modeling direct interband tunneling. I. Bulk semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Andrew, E-mail: pandrew@ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Chui, Chi On [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2014-08-07

    Interband tunneling is frequently studied using the semiclassical Kane model, despite uncertainty about its validity. Revisiting the physical basis of this formula, we find that it neglects coupling to other bands and underestimates transverse tunneling. As a result, significant errors can arise at low and high fields for small and large gap materials, respectively. We derive a simple multiband tunneling model to correct these defects analytically without arbitrary parameters. Through extensive comparison with band structure and quantum transport calculations for bulk InGaAs, InAs, and InSb, we probe the accuracy of the Kane and multiband formulas and establish the superiority of the latter. We also show that the nonlocal average electric field should be used when applying either of these models to nonuniform potentials. Our findings are important for efficient analysis and simulation of bulk semiconductor devices involving tunneling.

  12. Towards a reconstruction of general bulk metrics

    Science.gov (United States)

    Engelhardt, Netta; Horowitz, Gary T.

    2017-01-01

    We prove that the metric of a general holographic spacetime can be reconstructed (up to an overall conformal factor) from distinguished spatial slices—‘light-cone cuts’—of the conformal boundary. Our prescription is covariant and applies to bulk points in causal contact with the boundary. Furthermore, we describe a procedure for determining the light-cone cuts corresponding to bulk points in the causal wedge of the boundary in terms of the divergences of correlators in the dual field theory. Possible extensions for determining the conformal factor and including the cuts of points outside of the causal wedge are discussed. We also comment on implications for subregion/subregion duality.

  13. Metal reduction at bulk chemical filtration

    Science.gov (United States)

    Umeda, Toru; Daikoku, Shusaku; Tsuzuki, Shuichi; Murakami, Tetsuya

    2017-03-01

    OK73 thinner and cyclohexanone, both of which were spiked with metals were passed through Nylon 6,6 filter, varying flow rate, which include the conditions of both point-of-use and bulk filtrations. The influent and effluent metal concentrations were measured using ICP-MS for metal removal efficiency of the filtration. As a result, removal efficiency for some metals descended depending on the flow rate, while others maintained. Slower flow rate is recommended to maintain low metal concentration in bulk filtration based on the result. Metals in cyclohexanone were reduced at higher efficiency than in OK73 thinner, agrees with a metal removal model of hydrophilic adsorbent in organic solvent, evidenced in our previous paper. Further, metal reduction on 300 mm φ Si wafer after coating organic solvents with Nylon 6,6 filtration was evidenced with TREX analysis.

  14. Multilayer Integrated Film Bulk Acoustic Resonators

    CERN Document Server

    Zhang, Yafei

    2013-01-01

    Multilayer Integrated Film Bulk Acoustic Resonators mainly introduces the theory, design, fabrication technology and application of a recently developed new type of device, multilayer integrated film bulk acoustic resonators, at the micro and nano scale involving microelectronic devices, integrated circuits, optical devices, sensors and actuators, acoustic resonators, micro-nano manufacturing, multilayer integration, device theory and design principles, etc. These devices can work at very high frequencies by using the newly developed theory, design, and fabrication technology of nano and micro devices. Readers in fields of IC, electronic devices, sensors, materials, and films etc. will benefit from this book by learning the detailed fundamentals and potential applications of these advanced devices. Prof. Yafei Zhang is the director of the Ministry of Education’s Key Laboratory for Thin Films and Microfabrication Technology, PRC; Dr. Da Chen was a PhD student in Prof. Yafei Zhang’s research group.

  15. Microfabricated bulk wave acoustic bandgap device

    Science.gov (United States)

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol

    2010-06-08

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  16. Crystalline-to-plastic phase transitions in molecularly thin n-dotriacontane films adsorbed on solid surfaces

    DEFF Research Database (Denmark)

    Cisternas, Edgardo; Corrales, T. P.; del Campo, V.;

    2009-01-01

    Crystalline-to-rotator phase transitions have been widely studied in bulk hydrocarbons, in particular in normal alkanes. But few studies of these transitions deal with molecularly thin films of pure n-alkanes on solid substrates. In this work, we were able to grow dotriacontane (n-C32H66) films...... identify with a solid-solid phase transition. At higher coverages, we observed additional steps in the ellipsometric signal that we identify with a solid-solid phase transition in multilayer islands (similar to 333 K) and with the transition to the rotator phase in bulk crystallites (similar to 337 K...

  17. Raman characterization of bulk ferromagnetic nanostructured graphite

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, Helena, E-mail: hpardo@fq.edu.uy [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay); Divine Khan, Ngwashi [Mantfort University, Leicester (United Kingdom); Faccio, Ricardo [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay); Araujo-Moreira, F.M. [Grupo de Materiais e Dispositivos-CMDMC, Departamento de Fisica e Engenharia Fisica, UFSCar, Caixa Postal 676, 13565-905, Sao Carlos SP (Brazil); Fernandez-Werner, Luciana [Centro NanoMat, Polo Tecnologico de Pando, Facultad de Quimica, Universidad de la Republica, Cno. Aparicio Saravia s/n, 91000, Pando, Canelones (Uruguay); Crystallography, Solid State and Materials Laboratory (Cryssmat-Lab), DETEMA, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, P.O. Box 1157, Montevideo (Uruguay)

    2012-08-15

    Raman spectroscopy was used to characterize bulk ferromagnetic graphite samples prepared by controlled oxidation of commercial pristine graphite powder. The G:D band intensity ratio, the shape and position of the 2D band and the presence of a band around 2950 cm{sup -1} showed a high degree of disorder in the modified graphite sample, with a significant presence of exposed edges of graphitic planes as well as a high degree of attached hydrogen atoms.

  18. On bulk viscosity and moduli decay

    OpenAIRE

    M. Laine

    2010-01-01

    This pedagogically intended lecture, one of four under the header "Basics of thermal QCD", reviews an interesting relationship, originally pointed out by Bodeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, furthermore, as a platform on whic...

  19. Depleted bulk heterojunction colloidal quantum dot photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Barkhouse, D.A.R. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); IBM Thomas J. Watson Research Center, Kitchawan Road, Yorktown Heights, NY, 10598 (United States); Debnath, Ratan; Kramer, Illan J.; Zhitomirsky, David; Levina, Larissa; Sargent, Edward H. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Pattantyus-Abraham, Andras G. [Department of Electrical and Computer Engineering, University of Toronto, 10 King' s College Road, Toronto, Ontario M5S 3G4 (Canada); Quantum Solar Power Corporation, 1055 W. Hastings, Ste. 300, Vancouver, BC, V6E 2E9 (Canada); Etgar, Lioz; Graetzel, Michael [Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, School of Basic Sciences, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland)

    2011-07-26

    The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Depleted Bulk Heterojunction Colloidal Quantum Dot Photovoltaics

    KAUST Repository

    Barkhouse, D. Aaron R.

    2011-05-26

    The first solution-processed depleted bulk heterojunction colloidal quantum dot solar cells are presented. The architecture allows for high absorption with full depletion, thereby breaking the photon absorption/carrier extraction compromise inherent in planar devices. A record power conversion of 5.5% under simulated AM 1.5 illumination conditions is reported. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Effects of bulk viscosity on cosmological evolution

    CERN Document Server

    Pimentel, L O; Pimentel, L O; Diaz-Rivera, L M

    1994-01-01

    Abstract:The effect of bulk viscisity on the evolution of the homogeneous and isotropic cosmological models is considered. Solutions are found, with a barotropic equation of state, and a viscosity coefficient that is proportional to a power of the energy density of the universe. For flat space, power law expansions, related to extended inflation are found as well as exponential solutions, related to old inflation; also a solution with expansion that is an exponential of an exponential of the time is found.

  2. Modeling of Microimprinting of Bulk Metallic Glasses

    Institute of Scientific and Technical Information of China (English)

    Ming CHENG; John A. Wert

    2006-01-01

    A finite element analysis (FEA) model has been developed to analyze microimprinting of bulk metallic glasses (BMG) near the glass transition temperature (Tg). The results reveal an approximately universal imprinting response for BMG, independent of surface feature length scale. The scale-independent nature of BMG imprinting derives from the flow characteristics of BMG in the temperature range above Tg. It also shows that the lubrication condition has a mild influence on BMG imprinting in the temperature range above Tg.

  3. 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.

  4. Pseudo-Riemannian Universe from Euclidean bulk

    CERN Document Server

    Vasilić, Milovan

    2015-01-01

    I develop the idea that our world is a brane-like object embedded in Euclidean bulk. In its ground state, the brane constituent matter is assumed to be homogeneous and isotropic, and of negligible influence on the bulk geometry. No action functional is initially specified. Instead, the brane dynamics is derived from the universally valid stress-energy conservation equations. The present work studies the cosmology of a $3$-sphere in the $5$-dimensional Euclidean bulk. It is shown that the conventional equation of state $p=\\alpha\\rho$ is universal in the sector of small energy densities, and so is the resulting brane dynamics. The inequality $\\alpha<0$ is found to be a necessary condition for the existence of a stable ground state of the Universe. It is demonstrated that the generic braneworld physics rules out the Big Bang cosmology, and in that matter, any cosmology of finite lifetime. I also demonstrate that stable brane vibrations satisfy Klein-Gordon-like equation with an effective metric of Minkowski s...

  5. Bulk Higgs with a heavy diphoton signal

    Science.gov (United States)

    Frank, Mariana; Pourtolami, Nima; Toharia, Manuel

    2017-02-01

    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. Inspired by the puzzling excess of diphoton events at 750 GeV reported in the early LHC Run II data (since then understood as a statistical excess), we consider here the general question as to whether the simplest extra-dimensional extension of the Standard Model Higgs sector, i.e., a five-dimensional bulk Higgs doublet, can lead to an intermediate mass resonance (between 500 GeV and 1.5 TeV) of which the first signature would be the presence of diphoton events. This surprising phenomenology can happen if the resonance is the lightest C P -odd state coming from the Higgs sector. No new matter content is required, the only new ingredient being the presence of (positive) brane localized kinetic terms associated to the five-dimensional bulk Higgs (which reduce the mass of the C P -odd states). Production and decay of this resonance can naturally give rise to observable diphoton signals, keeping dijet production under control, with very low ZZ and WW signals and with a highly reduced top pair production in an important region of parameter space. We use the 750 GeV excess as an example case scenario.

  6. Bulk Rashba Semiconductors and Related Quantum Phenomena.

    Science.gov (United States)

    Bahramy, Mohammad Saeed; Ogawa, Naoki

    2017-03-29

    Bithmuth tellurohalides BiTeX (X = Cl, Br and I) are model examples of bulk Rashba semiconductors, exhibiting a giant Rashba-type spin splitting among their both valence and conduction bands. Extensive spectroscopic and transport experiments combined with the state-of-the-art first-principles calculations have revealed many unique quantum phenomena emerging from the bulk Rashba effect in these systems. The novel features such as the exotic inter- and intra-band optical transitions, enhanced magneto-optical response, divergent orbital dia-/para-magnetic susceptibility and helical spin textures with a nontrivial Berry's phase in the momentum space are among the salient discoveries, all arising from this effect. Also, it is theoretically proposed and indications have been experimentally reported that bulk Rashba semiconductors such as BiTeI have the capability of becoming a topological insulator under the application of a hydrostatic pressure. Here, we overview these studies and show that BiTeX are an ideal platform to explore the next aspects of quantum matter, which could ultimately be utilized to create spintronic devices with novel functionalities.

  7. Cosmological Implications of QGP Bulk Viscosity

    CERN Document Server

    Anand, Sampurn; Bhatt, Jitesh R

    2016-01-01

    Recent studies of the hot QCD matter indicate that the bulk viscosity ($\\zeta$) of quark-gluon plasma (QGP) rises sharply near the critical point of the QCD phase transition. In this work, we show that such a sharp rise of the bulk viscosity will lead to an effective negative pressure near the critical temperature, $T_{c}$ which in turn drives the Universe to inflate. This inflation has a natural graceful exist when the viscous effect evanesce. We estimate that, depending upon the peak value of $\\zeta$, universe expands by a factor of $10$ to $80$ times in a very short span ($\\Delta t\\sim 10^{-8}$ seconds). Another important outcome of the bulk viscosity dominated dynamics is the cavitation of QGP around $T \\sim 1.5T_{c}$. This would lead to the phenomenon of formation of cavitation bubbles within the QGP phase. The above scenario is independent of the order of QCD phase transition. We delineate some of the important cosmological consequences of the inflation and the cavitation.

  8. Statics of deformable solids

    CERN Document Server

    Bisplinghoff, Raymond L; Pian, Theodore HH

    2014-01-01

    Profusely illustrated exposition of fundamentals of solid mechanics and principles of mechanics, statics, and simple statically indeterminate systems. Covers strain and stress in three-dimensional solids, elementary elasticity, energy principles in solid continuum, and more. 1965 edition.

  9. Perspectives on a Solid State NMR Quantum Computer

    OpenAIRE

    Fel'dman, Edward B.; Lacelle, Serge

    2001-01-01

    A quantum information processing device, based on bulk solid state NMR of the quasi-one dimensional material hydroxyapatite, is proposed following the magnetic resonance force microscopy work of Yamamoto et al (quant-ph/0009122). In a macroscopic sample of hydroxyapatite, our solid state NMR model yields a limit of 10^8 qubits imposed by physics, while development of current technological considerations should allow an upper bound in the range of hundreds to thousands of qubits.

  10. Exactly isochoric deformations of soft solids

    Science.gov (United States)

    Biggins, John S.; Wei, Z.; Mahadevan, L.

    2014-12-01

    Many materials of contemporary interest, such as gels, biological tissues and elastomers, are easily deformed but essentially incompressible. Traditional linear theory of elasticity implements incompressibility only to first order and thus permits some volume changes, which become problematically large even at very small strains. Using a mixed coordinate transformation originally due to Gauss, we enforce the constraint of isochoric deformations exactly to develop a linear theory with perfect volume conservation that remains valid until strains become geometrically large. We demonstrate the utility of this approach by calculating the response of an infinite soft isochoric solid to a point force that leads to a nonlinear generalization of the Kelvin solution. Our approach naturally generalizes to a range of problems involving deformations of soft solids and interfaces in two-dimensional and axisymmetric geometries, which we exemplify by determining the solution to a distributed load that mimics muscular contraction within the bulk of a soft solid.

  11. Hubble Parameter in Bulk Viscous Cosmology

    CERN Document Server

    Tawfik, A; Wahba, M

    2009-01-01

    We discuss influences of bulk viscosity on the Early Universe, which is modeled by Friedmann-Robertson-Walker metric and Einstein field equations. We assume that the matter filling the isotropic and homogeneous background is relativistic viscous characterized by ultra-relativistic equations of state deduced from recent lattice QCD simulations. We obtain a set of complicated differential equations, for which we suggest approximate solutions for Hubble parameter $H$. We find that finite viscosity in Eckart and Israel-Stewart fluids would significantly modify our picture about the Early Universe.

  12. Fabrication of Porous Bulk Metallic Glass

    Institute of Scientific and Technical Information of China (English)

    Keqiang QIU; Yinglei REN

    2005-01-01

    An open-cell porous bulk metallic glass (BMG)with a diameter of at least 6 mm was fabricated by using an U-turn quartz tube and infiltration casting aroundsoluble NaCl placeholders. The pore formation and glassy structure were examined by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the pores or cells are connected to each other and the specimenis composed of a mostly glassy phase.This paper provides a suitable method for fabrication of porous BMG and BMG with larger size in diameter.

  13. Bulk metamaterials: Design, fabrication and characterization

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Alabastri, Alessandro

    2009-01-01

    Bulk metamaterials claim a lot of attention worldwide. We report about our activity and advances in design, fabrication and characterization of metal-dielectric composites with three-dimensional lattices. The nomenclature of designs exhibiting negative index behaviour in the near infrared includes...... the generic family of so-called nested structures. Such designs allow keeping the cubic symmetry of the unit cell along with the electric and magnetic responses showed by different parts in separate. For extraction of effective parameters we employ homemade wave propagation retrieving method free from...

  14. Calculated Bulk Properties of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.

    1978-01-01

    Self-consistent relativistic calculations of the electronic properties for seven actinides (Ac-Am) have been performed using the linear muffin-tin orbitals method within the atomic-sphere approximation. Exchange and correlation were included in the local spin-density scheme. The theory explains...... the variation of the atomic volume and the bulk modulus through the 5f series in terms of an increasing 5f binding up to plutonium followed by a sudden localisation (through complete spin polarisation) in americium...

  15. Diffusion and bulk flow in phloem loading

    DEFF Research Database (Denmark)

    Dölger, Julia; Rademaker, Hanna; Liesche, Johannes

    2014-01-01

    loading mechanism, active symplasmic loading, also called the polymer trap mechanism, where sucrose is transformed into heavier sugars, such as raffinose and stachyose, in the intermediary-type companion cells bordering the sieve elements in the minor veins of the phloem. Keeping the heavier sugars from......%-20% to the sucrose flux into the intermediary cells, while the main part is transported by diffusion. On the other hand, the subsequent sugar translocation into the sieve elements would very likely be carried predominantly by bulk water flow through the plasmodesmata. Thus, in contrast to apoplasmic loaders, all...

  16. New Class of Plastic Bulk Metallic Glass

    Science.gov (United States)

    Chen, L. Y.; Fu, Z. D.; Zhang, G. Q.; Hao, X. P.; Jiang, Q. K.; Wang, X. D.; Cao, Q. P.; Franz, H.; Liu, Y. G.; Xie, H. S.; Zhang, S. L.; Wang, B. Y.; Zeng, Y. W.; Jiang, J. Z.

    2008-02-01

    An intrinsic plastic Cu45Zr46Al7Ti2 bulk metallic glass (BMG) with high strength and superior compressive plastic strain of up to 32.5% was successfully fabricated by copper mold casting. The superior compressive plastic strain was attributed to a large amount of randomly distributed free volume induced by Ti minor alloying, which results in extensive shear band formation, branching, interaction and self-healing of minor cracks. The mechanism of plasticity presented here suggests that the creation of a large amount of free volume in BMGs by minor alloying or other methods might be a promising new way to enhance the plasticity of BMGs.

  17. Calculated Bulk Properties of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.

    1978-01-01

    Self-consistent relativistic calculations of the electronic properties for seven actinides (Ac-Am) have been performed using the linear muffin-tin orbitals method within the atomic-sphere approximation. Exchange and correlation were included in the local spin-density scheme. The theory explains t...... the variation of the atomic volume and the bulk modulus through the 5f series in terms of an increasing 5f binding up to plutonium followed by a sudden localisation (through complete spin polarisation) in americium...

  18. Improving the bulk data transfer experience

    Energy Technology Data Exchange (ETDEWEB)

    Guok, Chin; Guok, Chin; Lee, Jason R.; Berket, Karlo

    2008-05-07

    Scientific computations and collaborations increasingly rely on the network to provide high-speed data transfer, dissemination of results, access to instruments, support for computational steering, etc. The Energy Sciences Network is establishing a science data network to provide user driven bandwidth allocation. In a shared network environment, some reservations may not be granted due to the lack of available bandwidth on any single path. In many cases, the available bandwidth across multiple paths would be sufficient to grant the reservation. In this paper we investigate how to utilize the available bandwidth across multiple paths in the case of bulk data transfer.

  19. Binary Cu-Zr Bulk Metallic Glasses

    Institute of Scientific and Technical Information of China (English)

    TANG Mei-Bo; ZHAO De-Qian; PAN Ming-Xiang; WANG Wei-Hua

    2004-01-01

    @@ We report that bulk metallic glasses (BMGs) can be produced up to 2 mm by a copper mould casting in Cux Zr1-x binary alloy with a wide glass forming composition range (45 < x < 60 at.%). We find that the formation mechanism for the binary Cu-Zr binary BMG-forming alloy is obviously different from that of the intensively studied multicomponent BMGs. Our results demonstrate that the criteria for the multicomponent alloys with composition near deep eutectic and strong liquid behaviour are no longer the major concern for designing BMGs.

  20. Pinch-off of rods by bulk diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Aagesen, L.K.; Johnson, A.E.; Fife, J.L. [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208-3108 (United States); Voorhees, P.W., E-mail: p-voorhees@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208-3108 (United States); Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208-3108 (United States); Miksis, M.J. [Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208-3108 (United States); Poulsen, S.O.; Lauridsen, E.M. [Riso National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, DK-4000 Roskilde (Denmark); Marone, F. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Stampanoni, M. [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Institute for Biomedical Engineering, University and ETH Zuerich, 8092 Zuerich (Switzerland)

    2011-07-15

    The morphology of a rod embedded in a matrix undergoing pinching by interfacial-energy-driven bulk diffusion is determined near the point of pinching. We find a self-similar solution that gives a unique temporal power law and interfacial shape prior to pinching and self-similar solutions after pinching. The theory is compared to experiments that employ in situ four-dimensional X-ray tomographic microscopy for rods of liquid or solid pinching by solute diffusion in the high-diffusivity liquid phase. The excellent agreement between experiment and theory confirms that the interfacial morphology near the singularity is universal both before and after pinching; the shape holds regardless of the material system and initial condition. This also implies that the predictions of the time-dependence of the process can be used to determine the time to pinching for a wide variety of physical systems, and thus provide estimates of the time required for capillarity-driven break-up of microstructures from the detachment of secondary dendrite arms to polymer blends.

  1. Usage of pumice as bulking agent in sewage sludge composting.

    Science.gov (United States)

    Wu, Chuandong; Li, Weiguang; Wang, Ke; Li, Yunbei

    2015-08-01

    In this study, the impacts of reused and sucrose-decorated pumice as bulking agents on the composting of sewage sludge were evaluated in the lab-scale reactor. The variations of temperature, pH, NH3 and CO2 emission rate, moisture content (MC), volatile solid, dissolved organic carbon, C/N and the water absorption characteristics of pumice were detected during the 25days composting. The MC of pumice achieved 65.23% of the 24h water absorptivity within the first 2h at the mass ratio of 0.6:1 (pumice:sewage sludge). Reused pumice increased 23.68% of CO2 production and reduced 21.25% of NH3 emission. The sucrose-decorated pumice reduced 43.37% of nitrogen loss. These results suggested that adding pumice and sucrose-decorated pumice in sludge composting matrix could not only adjust the MC of materials, but also improve the degradation of organic matters and reduce nitrogen loss. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Production, Properties and Applications of Bulk Amorphous Alloys

    Institute of Scientific and Technical Information of China (English)

    Tao Zhang; Akihisa Inoue

    2000-01-01

    A review is given of recent work concerned with the production method, the characteristic properties(1) Bulk amorphous system; (2) Mechanical and magnetic properties of bulkamorphous alloys; (3)application of bulk amorphous alloys.

  3. Constructing local bulk observables in interacting AdS/CFT

    CERN Document Server

    Kabat, Daniel; Lowe, David A

    2011-01-01

    Local operators in the bulk of AdS can be represented as smeared operators in the dual CFT. We show how to construct these bulk observables by requiring that the bulk operators commute at spacelike separation. This extends our previous work by taking interactions into account. Large-N factorization plays a key role in the construction. We show diagrammatically how this procedure is related to bulk Feynman diagrams.

  4. Experimenting with Different Bulking Agents in an Aerobic Food Waste Composter

    Science.gov (United States)

    Chann, S.

    2016-12-01

    With one third of Hong Kong's solid wastage being food scraps, reducing food waste has become crucial. The ISF Academy, a Hong Kong private school, had an A900 Rocket Food Composter installed in 2013, hoping to reduce its carbon footprint. The 27 metric tons of food wastage produced annually by the school is put through an aerobic process and the wastage is converted into humus. The composter has a capacity of 1750 litres of food and it produces humus every 14 days. The base of the humus consists of a bulking agent and food waste (2:1). A bulking agent is a carbon based material used to absorb moisture and odors, add structure and air and eliminate bugs from humus. This study contains comparative data on a few of the listed bulking agents: Hemp, Kenaf, rapeseed oil straw, miscanthus and shredded cardboard. The aim of this study is to determine an alternative reliable, affordable and suitable bulking agent to wood shavings: the current agent used. The humus produced must pass regulations for "general agricultural use" as it is used for experiential learning and gardening with primary school students. Over 500 children are participating in the school's plantation project, producing legumes for the school cafeteria. ISF pioneers and sets an example for other Hong Kong schools, showing that a composting and plantation scheme, not only proves to have environmental benefits but also educational uses.

  5. Boundary Engineering for the Thermoelectric Performance of Bulk Alloys Based on Bismuth Telluride.

    Science.gov (United States)

    Mun, Hyeona; Choi, Soon-Mok; Lee, Kyu Hyoung; Kim, Sung Wng

    2015-07-20

    Thermoelectrics, which transports heat for refrigeration or converts heat into electricity directly, is a key technology for renewable energy harvesting and solid-state refrigeration. Despite its importance, the widespread use of thermoelectric devices is constrained because of the low efficiency of thermoelectric bulk alloys. However, boundary engineering has been demonstrated as one of the most effective ways to enhance the thermoelectric performance of conventional thermoelectric materials such as Bi2 Te3 , PbTe, and SiGe alloys because their thermal and electronic transport properties can be manipulated separately by this approach. We review our recent progress on the enhancement of the thermoelectric figure of merit through boundary engineering together with the processing technologies for boundary engineering developed most recently using Bi2 Te3 -based bulk alloys. A brief discussion of the principles and current status of boundary-engineered bulk alloys for the enhancement of the thermoelectric figure of merit is presented. We focus mainly on (1) the reduction of the thermal conductivity by grain boundary engineering and (2) the reduction of thermal conductivity without deterioration of the electrical conductivity by phase boundary engineering. We also discuss the next potential approach using two boundary engineering strategies for a breakthrough in the area of bulk thermoelectric alloys.

  6. Formation of solid Kr nanoclusters in MgO

    NARCIS (Netherlands)

    van Huis, MA; van Veen, A; Schut, H; Kooi, BJ; De Hosson, JTM

    2003-01-01

    The phenomenon of positron confinement enables us to investigate the electronic structure of nanoclusters embedded in host matrices. Solid Kr nanoclusters are a very interesting subject of investigation because of the very low predicted value of the positron affinity of bulk Kr. In this work,

  7. Boundary-bulk relation in topological orders

    Directory of Open Access Journals (Sweden)

    Liang Kong

    2017-09-01

    Full Text Available In this paper, we study the relation between an anomaly-free n+1D topological order, which are often called n+1D topological order in physics literature, and its nD gapped boundary phases. We argue that the n+1D bulk anomaly-free topological order for a given nD gapped boundary phase is unique. This uniqueness defines the notion of the “bulk” for a given gapped boundary phase. In this paper, we show that the n+1D “bulk” phase is given by the “center” of the nD boundary phase. In other words, the geometric notion of the “bulk” corresponds precisely to the algebraic notion of the “center”. We achieve this by first introducing the notion of a morphism between two (potentially anomalous topological orders of the same dimension, then proving that the notion of the “bulk” satisfies the same universal property as that of the “center” of an algebra in mathematics, i.e. “bulk = center”. The entire argument does not require us to know the precise mathematical description of a (potentially anomalous topological order. This result leads to concrete physical predictions.

  8. Enhancing bulk superconductivity by engineering granular materials

    Science.gov (United States)

    Mayoh, James; García García, Antonio

    2014-03-01

    The quest for higher critical temperatures is one of the main driving forces in the field of superconductivity. Recent theoretical and experimental results indicate that quantum size effects in isolated nano-grains can boost superconductivity with respect to the bulk limit. Here we explore the optimal range of parameters that lead to an enhancement of the critical temperature in a large three dimensional array of these superconducting nano-grains by combining mean-field, semiclassical and percolation techniques. We identify a broad range of parameters for which the array critical temperature, TcArray, can be up to a few times greater than the non-granular bulk limit, Tc 0. This prediction, valid only for conventional superconductors, takes into account an experimentally realistic distribution of grain sizes in the array, charging effects, dissipation by quasiparticles and limitations related to the proliferation of thermal fluctuations for sufficiently small grains. For small resistances we find the transition is percolation driven. Whereas at larger resistances the transition occurs above the percolation threshold due to phase fluctuations. JM acknowledes support from an EPSRC Ph.D studentship, AMG acknowledges support from EPSRC, grant No. EP/I004637/1, FCT, grant PTDC/FIS/111348/2009 and a Marie Curie International Reintegration Grant PIRG07-GA-2010-268172.

  9. Bulk nanocrystalline Al prepared by cryomilling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Bulk nanocrystalline Al was fabricated by mechanically milling at cryogenic temperature (cryomilling) and then by hot pressing in vacuum. By using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), the microstructure evolution of the material during cryomilling and consolidation was investigated. With increasing the milling time, the grain size decreased sharply and reduced to 42 nm when cryomilled for 12 h. The grains had grown up, and the columnar grain was formed under the hot pressing and extrusion compared with the cryomilled powders. The grain size of as-extruded specimen was approximately 300-500 nm. The reason of high thermal stability of this bulk was attributed primarily to the Zener pinning from the grain boundary of the AlN arising from cryomilling and the solute drag of the impurity. Tensile tests show that the strength of nanocrystalline Al is enhanced with decreasing grain size. The ultimate tensile strength and tensile elongation were 173 MPa and 17.5%, respectively. It appears that the measured high strength in the cryomilled Al is related to a grain-size effect, dispersion strengthening, and dislocation strengthening.

  10. Substantial bulk photovoltaic effect enhancement via nanolayering.

    Science.gov (United States)

    Wang, Fenggong; Young, Steve M; Zheng, Fan; Grinberg, Ilya; Rappe, Andrew M

    2016-01-21

    Spontaneous polarization and inversion symmetry breaking in ferroelectric materials lead to their use as photovoltaic devices. However, further advancement of their applications are hindered by the paucity of ways of reducing bandgaps and enhancing photocurrent. By unravelling the correlation between ferroelectric materials' responses to solar irradiation and their local structure and electric polarization landscapes, here we show from first principles that substantial bulk photovoltaic effect enhancement can be achieved by nanolayering PbTiO3 with nickel ions and oxygen vacancies ((PbNiO2)x(PbTiO3)(1-x)). The enhancement of the total photocurrent for different spacings between the Ni-containing layers can be as high as 43 times due to a smaller bandgap and photocurrent direction alignment for all absorption energies. This is due to the electrostatic effect that arises from nanolayering. This opens up the possibility for control of the bulk photovoltaic effect in ferroelectric materials by nanoscale engineering of their structure and composition.

  11. 19 CFR 151.24 - Unlading facilities for bulk sugar.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Unlading facilities for bulk sugar. 151.24 Section... OF THE TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Sugars, Sirups, and Molasses § 151.24 Unlading facilities for bulk sugar. When dutiable sugar is to be imported in bulk, a full...

  12. 30 CFR 56.6802 - Bulk delivery vehicles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bulk delivery vehicles. 56.6802 Section 56.6802... § 56.6802 Bulk delivery vehicles. No welding or cutting shall be performed on a bulk delivery vehicle until the vehicle has been washed down and all explosive material has been removed. Before welding...

  13. 30 CFR 57.6802 - Bulk delivery vehicles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bulk delivery vehicles. 57.6802 Section 57.6802...-Surface and Underground § 57.6802 Bulk delivery vehicles. No welding or cutting shall be performed on a bulk delivery vehicle until the vehicle has been washed down and all explosive material has...

  14. Solid lubricants and surfaces

    CERN Document Server

    Braithwaite, E R

    1964-01-01

    Solid Lubricants and Surfaces deals with the theory and use of solid lubricants, particularly in colloidal form. Portions of this book are devoted to graphite and molybdenum disulfides, which are widely used solid lubricants in colloidal form. An extensive literature on the laboratory examination of hundreds of solids as potential lubricants is also provided in this text. Other topics discussed include the metals and solid lubricants; techniques for examining surfaces; other solid lubricants; metal shaping; and industrial uses of solid-lubricant dispersions. This publication is beneficial to e

  15. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    NARCIS (Netherlands)

    Zielinska, K.

    2014-01-01

    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid

  16. Solid phase microextraction speciation analysis of triclosan in aqueous mediacontaining sorbing nanoparticles

    NARCIS (Netherlands)

    Zielinska, K.

    2014-01-01

    Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid phas

  17. The influence of fibrous bed bulk density on the bed properties

    Directory of Open Access Journals (Sweden)

    Šećerov-Sokolović Radmila M.

    2003-01-01

    Full Text Available The mean properties of seven different fibrous materials and the properties of their different bed bulk densities were investigated. The morphology of the surface, size and geometry were measured by optical microscopy. The bed porosity was measured by the weighing method. The experimental bed permeability, in a high range of bulk density, was calculated from the values of the sanitary water pressure drop at a constant temperature of 15°C, since the data followed Darcy's law. The Reynolds number for a fibrous bed was calculated using a relation from the literature. The Reynolds number was less than 1 for all ranges of fluid velocity. Three empirical relations for fibrous bed permeability were used and compared with the experimental data. It was determined that the empirical data depended on the fiber diameter and fraction of solid in the bed. The relative error linearly increased with increasing fiber diameter.

  18. Nucleation site and mechanism leading to growth of bulk-quantity Mn3O4 nanorods

    Science.gov (United States)

    Chen, Z. W.; Lai, J. K. L.; Shek, C. H.

    2005-05-01

    We report a simple and effective method for the generation of bulk-quantity nanorods of manganese oxide, Mn3O4, under surroundings of a suitable surfactant and alkaline solution. It is found that the Mn3O4 nanorod is smooth, straight, and that the geometrical shape is structurally perfect, which is produced with lengths from several hundreds nanometers to a few micrometers, and diameters range from 10nmto30nm. We amazedly found that the dripping speed of the NaOH solution plays an important role in formation of bulk-quantity Mn3O4 nanorods. The difference of dripping speed of the NaOH solution leads to a large difference of Mn3O4 morphologies, which is observed in the transmission electron microscopy images. The growth of the Mn3O4 nanorods is suggested first to follow a self-catalyzed solution-liquid-solid mechanism.

  19. Surface and Bulk Effects in Photochemical Reactions and Photomechanical Effects in Dynamic Molecular Crystals.

    Science.gov (United States)

    Nath, Naba K; Runčevski, Tomče; Lai, Chia-Yun; Chiesa, Matteo; Dinnebier, Robert E; Naumov, Panče

    2015-11-04

    The increasing number of reports on photomechanical effects in molecular crystals necessitates systematic studies to understand the intrinsic and external effectors that determine and have predictive power of their type and magnitude. Differential light absorption and product gradient between the surface and the bulk of the crystal are often invoked to qualitatively explain the mechanical response of crystals to light; however, the details on how this difference in photochemical response accounts for macroscopic effects such as surface modification, deformation, or disintegration of crystals are yet to be established. Using both bulk- and surface-sensitive analytical techniques, a rare instance of benzylidenefuranone crystals is studied here, and it is capable of several distinct types of photomechanical response including surface striation and delamination, photosalient effect (ballistic disintegration and motion), and photoinduced bending by dimerization. The results provide a holistic view on these effects and set the stage for the development of overarching theoretical models to describe the photomechanics in the ordered solid state.

  20. Inorganic-Organic Hybrid 18-Molybdodiphosphate Nanoparticles Bulk-modified Carbon Paste Electrode and Its Electrocatalysis

    Institute of Scientific and Technical Information of China (English)

    WANG,Xiu-Li(王秀丽); KANG,Zhen-Hui(康振辉); WANG,En-Bo(王恩波); HU,Chang-Wen(胡长文)

    2002-01-01

    A kind of inorganic- organic hybrid 18-molybdodiphosphate nanoparticles ([(C4H9)4N]6P2Mo18O62 @4H2O) was firstly used as a bulk-modifier to fabricate a three-dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square-wave voltammetry. The hybrid 18-molybdodiphosphate nanoparticles bulk-modified CPE (MNP-CPE) displayed a high electrocatalytic activity towards the reduction of nitrite,bromate and hydrogen peroxide. The remarkable advantages of the MNP-CPE over the traditional polyoxometalates-modified electrodes are their excellent reproducibility of surface-renewal and high stability owing to the insolubility of the hybrid 18-molybdodiphosphate nanoparticles.

  1. Evidence of the hydrogen release mechanism in bulk MgH2

    Science.gov (United States)

    Nogita, Kazuhiro; Tran, Xuan Q.; Yamamoto, Tomokazu; Tanaka, Eishi; McDonald, Stuart D.; Gourlay, Christopher M.; Yasuda, Kazuhiro; Matsumura, Syo

    2015-02-01

    Hydrogen has the potential to power much of the modern world with only water as a by-product, but storing hydrogen safely and efficiently in solid form such as magnesium hydride remains a major obstacle. A significant challenge has been the difficulty of proving the hydriding/dehydriding mechanisms and, therefore, the mechanisms have long been the subject of debate. Here we use in situ ultra-high voltage transmission electron microscopy (TEM) to directly verify the mechanisms of the hydride decomposition of bulk MgH2 in Mg-Ni alloys. We find that the hydrogen release mechanism from bulk (2 μm) MgH2 particles is based on the growth of multiple pre-existing Mg crystallites within the MgH2 matrix, present due to the difficulty of fully transforming all Mg during a hydrogenation cycle whereas, in thin samples analogous to nano-powders, dehydriding occurs by a `shrinking core' mechanism.

  2. Thermoelectric properties of Mg2X (X = Si, Ge) based bulk and quantum well systems

    Science.gov (United States)

    Yelgel, Övgü Ceyda

    2017-01-01

    Mg2X (X = Si, Ge) compounds are promising thermoelectric materials for middle temperature applications due to good thermoelectric properties, nontoxicity, and abundantly available constituent elements. So far, these materials used in applications have all been in bulk form. Herein we report a full theory of thermoelectric transport properties of 3D bulk and 2D quantum well systems. The main aim of this present work is to show the effect of quantum confinement on the enhancement of the thermoelectric figure of merit theoretically. Results are given for n-type Mg2 Si0.5 Ge0.5 solid solutions and n-type Mg2Si/Mg2Ge/Mg2Si quantum well systems where the values of well widths are taken as 10 nm, 15 nm, and 20 nm, respectively. The n-type doping is made by using Sb- and La-elements as dopants. Experimental results for solid solutions are included to provide demonstration of proof of principle for the theoretical model applied for 3D bulk structures. The maximum thermoelectric figure of merits of Lax Mg2 -x Si0.49 Ge0.5 Sb0.01 solid solutions are obtained to be 0.64 and 0.56 at 800 K for x = 0 and x = 0.01 sample, respectively. While, at the same temperature, due to the relatively low phonon thermal conductivity the state-of-the-art ZT values of 2.41 and 2.26 have been attained in the Mg2Si/Mg2Ge/Mg2Si quantum well samples with 0.01 wt. % Sb-doped and 0.01 wt. % Sb- and 0.01 wt. % La-doped, respectively.

  3. Technical issues of a high-Tc superconducting bulk magnet

    Science.gov (United States)

    Fujimoto, Hiroyuki

    2000-06-01

    Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.

  4. A route to transparent bulk metals

    KAUST Repository

    Schwingenschlögl, Udo

    2012-07-23

    Hypothetical compounds based on a sapphire host are investigated with respect to their structural as well as electronic features. The results are obtained by electronic structure calculations within density functional theory and the generalized gradient approximation. A quarter of the Al atoms in Al 2O 3 is replaced by a 4d transition metal M ion, with d 0 to d 9 electronic configuration. We perform structure optimizations for all the compounds and analyze the electronic states. Due to the sizeable band gap of the Al 2O 3 host, we can identify promising candidates for transparent bulk metals. We explain the mechanisms leading to this combination of materials properties. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Combustion of bulk titanium in oxygen

    Science.gov (United States)

    Clark, A. F.; Moulder, J. C.; Runyan, C. C.

    1975-01-01

    The combustion of bulk titanium in one atmosphere oxygen is studied using laser ignition and several analytical techniques. These were high-speed color cinematography, time and space resolved spectra in the visible region, metallography (including SEM) of specimens quenched in argon gas, X-ray and chemical product analyses, and a new optical technique, the Hilbert transform method. The cinematographic application of this technique for visualizing phase objects in the combustion zone is described. The results indicate an initial vapor phase reaction immediately adjacent to the molten surface but as the oxygen uptake progresses the evaporation approaches the point of congruency and a much reduced evaporation rate. This and the accumulation of the various soluble oxides soon drive the reaction zone below the surface where gas formation causes boiling and ejection of particles. The buildup of rutile cuts off the oxygen supply and the reaction ceases.

  6. DEPLOYMENT OF THE BULK TRITIUM SHIPPING PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, P.

    2013-10-10

    A new Bulk Tritium Shipping Package (BTSP) was designed by the Savannah River National Laboratory to be a replacement for a package that has been used to ship tritium in a variety of content configurations and forms since the early 1970s. The BTSP was certified by the National Nuclear Safety Administration in 2011 for shipments of up to 150 grams of Tritium. Thirty packages were procured and are being delivered to various DOE sites for operational use. This paper summarizes the design features of the BTSP, as well as associated engineered material improvements. Fabrication challenges encountered during production are discussed as well as fielding requirements. Current approved tritium content forms (gas and tritium hydrides), are reviewed, as well as, a new content, tritium contaminated water on molecular sieves. Issues associated with gas generation will also be discussed.

  7. Tuneable film bulk acoustic wave resonators

    CERN Document Server

    Gevorgian, Spartak Sh; Vorobiev, Andrei K

    2013-01-01

    To handle many standards and ever increasing bandwidth requirements, large number of filters and switches are used in transceivers of modern wireless communications systems. It makes the cost, performance, form factor, and power consumption of these systems, including cellular phones, critical issues. At present, the fixed frequency filter banks based on Film Bulk Acoustic Resonators (FBAR) are regarded as one of the most promising technologies to address performance -form factor-cost issues. Even though the FBARs improve the overall performances the complexity of these systems remains high.  Attempts are being made to exclude some of the filters by bringing the digital signal processing (including channel selection) as close to the antennas as possible. However handling the increased interference levels is unrealistic for low-cost battery operated radios. Replacing fixed frequency filter banks by one tuneable filter is the most desired and widely considered scenario. As an example, development of the softwa...

  8. Criticality in Bulk Metallic Glass Constituent Elements

    Science.gov (United States)

    Mota, Rodrigo Miguel Ojeda; Graedel, T. E.; Pekarskaya, Evgenia; Schroers, Jan

    2017-07-01

    Bulk metallic glasses (BMGs), which readily form amorphous phases during solidification, are increasingly being used in first applications of watch components, electronic casings, and sporting goods. The compositions of BMGs typically include four to six elements. Various political and geological factors have recently led to supply disruptions for several metals, including some present in BMG compositions. In this work, we assess the "criticality" of 22 technologically interesting BMG compositions, compare the results with those for three common engineering alloy groups, and derive recommendations for BMG composition choices from a criticality perspective. The criticality of BMGs is found to be generally much higher compared with those for the established engineering alloys. Therefore, criticality concerns should also be considered in the choice between existing and developing novel BMGs.

  9. Organoboron polymers for photovoltaic bulk heterojunctions.

    Science.gov (United States)

    Cataldo, Sebastiano; Fabiano, Simone; Ferrante, Francesco; Previti, Francesco; Patanè, Salvatore; Pignataro, Bruno

    2010-07-15

    We report on the application of three-coordinate organoboron polymers, inherently strong electron acceptors, in flexible photovoltaic (PV) cells. Poly[(1,4-divinylenephenylene)(2,4,6-triisopropylphenylborane)] (PDB) has been blended with poly(3-hexylthiophene-2,5-diyl) (P3HT) to form a thin film bulk heterojunction (BHJ) on PET/ITO substrates. Morphology may be modulated to give a high percentage of domains (10-20 nm in size) allowing exciton separation. The photoelectric properties of the BHJs in devices with aluminium back electrodes were imaged by light beam induced current (LBIC) and light beam induced voltage (LBIV) techniques. Open circuit voltages, short circuit currents and overall external quantum efficiencies obtained are among the highest reported for all-polymer PV cells.

  10. New optical technique for bulk magnetostriction measurement

    CERN Document Server

    Samata, H; Uchida, T; Abe, S

    2000-01-01

    A new optical technique was applied to the measurement of magnetostriction in bulk samples. This technique utilizes an optical fiber bundle, AC-modulated light and lock-in detection. Deformation of the sample is determined from the ratio of the incident and reflected light intensities. Noise due to the instability of the light source is eliminated by obtaining the ratio of the incident and reflected light intensities, and the noise caused in the detector circuit can be reduced by lock-in detection. The performance of this method was characterized with a series of measurements using a gold film and crystal disks of pure iron and nickel. This technique offers a resolution of 0.5 nm and is sensitive enough to measure magnetostriction as small as 5x10 sup - sup 7 in 1 mm thick samples.

  11. Transformation of bulk alloys to oxide nanowires

    Science.gov (United States)

    Lei, Danni; Benson, Jim; Magasinski, Alexandre; Berdichevsky, Gene; Yushin, Gleb

    2017-01-01

    One dimensional (1D) nanostructures offer prospects for enhancing the electrical, thermal, and mechanical properties of a broad range of functional materials and composites, but their synthesis methods are typically elaborate and expensive. We demonstrate a direct transformation of bulk materials into nanowires under ambient conditions without the use of catalysts or any external stimuli. The nanowires form via minimization of strain energy at the boundary of a chemical reaction front. We show the transformation of multimicrometer-sized particles of aluminum or magnesium alloys into alkoxide nanowires of tunable dimensions, which are converted into oxide nanowires upon heating in air. Fabricated separators based on aluminum oxide nanowires enhanced the safety and rate capabilities of lithium-ion batteries. The reported approach allows ultralow-cost scalable synthesis of 1D materials and membranes.

  12. On bulk viscosity and moduli decay

    CERN Document Server

    Laine, M

    2010-01-01

    This pedagogically intended lecture, one of four under the header "Basics of thermal QCD", reviews an interesting relationship, originally pointed out by Bodeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, futhermore, as a platform on which a number of generic thermal field theory concepts are illustrated. The other three lectures (on the QCD equation of state and the rates of elastic as well as inelastic processes experienced by heavy quarks) are recapitulated in brief encyclopedic form.

  13. Bulk semiconducting scintillator device for radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Stowe, Ashley C.; Burger, Arnold; Groza, Michael

    2016-08-30

    A bulk semiconducting scintillator device, including: a Li-containing semiconductor compound of general composition Li-III-VI.sub.2, wherein III is a Group III element and VI is a Group VI element; wherein the Li-containing semiconductor compound is used in one or more of a first mode and a second mode, wherein: in the first mode, the Li-containing semiconductor compound is coupled to an electrical circuit under bias operable for measuring electron-hole pairs in the Li-containing semiconductor compound in the presence of neutrons and the Li-containing semiconductor compound is also coupled to current detection electronics operable for detecting a corresponding current in the Li-containing semiconductor compound; and, in the second mode, the Li-containing semiconductor compound is coupled to a photodetector operable for detecting photons generated in the Li-containing semiconductor compound in the presence of the neutrons.

  14. Bulk disk resonator based ultrasensitive mass sensor

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Davis, Zachary James

    2009-01-01

    In the framework of developing an innovative label-free sensor for multiarrayed biodetection applications, we present a novel bulk resonator based mass sensor. The sensor is a polysilicon disk which shows a Q-factor of 6400 in air at 68.8 MHz, resulting in mass resolutions down in the femtogram...... range. The sensor has been characterized in terms of sensitivity both for distributed mass detection, performing six consecutive depositions of e-beam evaporated Au, and localized mass detection, depositing approximately 7.5 pg of Pt/Ga/C three times consecutively with a Focused Ion Beam system....... The sensor has an extremely high distributed mass to frequency shift sensitivity of 60104 Hzcm2/¿g and shows a localized mass to frequency sensitivity up to 4405 Hz/pg with a localized mass resolution down to 15 fg. The device has been fabricated with a new microfabrication process that uses only two...

  15. Universe Models with Negative Bulk Viscosity

    CERN Document Server

    Brevik, Iver

    2013-01-01

    The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting ensemble of ultracold atoms is investigated experimentally and found to correspond to a negative-temperature system since the entropy decreases with increasing energy at the high end of the energy spectrum. As the authors suggest, it would be of interest to investigate whether a suitable generalization of standard cosmological theory could be helpful, in order to elucidate the observed accelerated expansion of the universe usually explained in terms of a positive tensile stress (negative pressure). In the present note we take up this basic idea and investigate a generalization of the standard viscous cosmological theory, not by admitting negative temperatures but instead by letting the bulk viscosity take negative values. Evidently, such an approach breaks standard thermodynamics,...

  16. Bulk heterojunction solar cells of three polythienothiophenes

    Directory of Open Access Journals (Sweden)

    Elif Alturk Parlak

    2015-06-01

    Full Text Available Semiconducting conjugated copolymers poly(3-phenyl-2-(thiophen-2-ylthieno[3,2-b]thiophene (PTTPh, poly(3-(4-methoxyphenyl-2-(thiophen-2-ylthieno[3,2-b]thiophene (PTTPh-OMe and poly(3-(4-N,N-dimethylaminophenyl-2-(thiophen-2-ylthieno[3,2-b]thiophene (PTTPh-N(CH 3 2, which were synthesized previously through Suzuki coupling method, were fabricated for solar cell applications. The devices had a structure of glass/ITO/PEDOT:PSS/polymer:PC61BM/Al. Bulk heterojunction photovoltaic cells were prepared as blends of PTTPh, PTTPh-OMe, PTTPh-N(CH 3 2 and PC61BM in a 1:1 ratio, which delivered power conversion efficiencies of 0.43%, 0.039% and 0.027%, respectively, without addition of additives or device optimization.

  17. Vortices in superconducting bulk, films and SQUIDs

    Indian Academy of Sciences (India)

    Ernst Helmut Brandt

    2006-01-01

    The properties of the ideal periodic vortex lattice in bulk superconductors and in films of any thickness can be calculated from Ginzburg-Landau theory by an iteration method using Fourier series. The London theory yields general analytic expressions for the magnetic field and energy of arbitrary arrangements of straight or curved vortex lines. The elasticity of the vortex lattice is highly nonlocal. The magnetic response of superconductors of realistic shapes like thin and thick strips and disks or thin rectangular plates or films, containing pinned vortices, can be computed within continuum theory by solving an integral equation. A useful example is a thin square with a central hole and a radial slit, used as superconducting quantum interference device (SQUID).

  18. Charm mass effects in bulk channel correlations

    CERN Document Server

    Burnier, Y

    2013-01-01

    The bulk viscosity of thermalized QCD matter at temperatures above a few hundred MeV could be significantly influenced by charm quarks because their contribution arises four perturbative orders before purely gluonic effects. In an attempt to clarify the challenges of a lattice study, we determine the relevant imaginary-time correlator (of massive scalar densities) up to NLO in perturbation theory, and compare with existing data. We find discrepancies much larger than in the vector channel; this may hint, apart from the importance of taking a continuum limit, to larger non-perturbative effects in the scalar channel. We also recall how a transport peak related to the scalar density spectral function encodes non-perturbative information concerning the charm quark chemical equilibration rate close to equilibrium.

  19. Holographic bulk viscosity: GPR vs EO

    CERN Document Server

    Buchel, Alex; Kiritsis, Elias

    2011-01-01

    Recently Eling and Oz (EO) proposed a formula for the holographic bulk viscosity, in arXiv:1103.1657, derived from the null horizon focusing equation. This formula seems different from that obtained earlier by Gubser, Pufu and Rocha (GPR) in arXiv:0806.0407 calculated from the IR limit of the two-point function of the trace of the stress tensor. The two were shown to agree only for some simple scaling cases. We point out that the two formulae agree in two non-trivial holographic theories describing RG flows. The first is the strongly coupled N=2* gauge theory plasma. The second is the semi-phenomenological model of Improved Holographic QCD.

  20. Organic hybrid planar-nanocrystalline bulk heterojunctions

    Science.gov (United States)

    Forrest, Stephen R.; Yang, Fan

    2011-03-01

    A photosensitive optoelectronic device having an improved hybrid planar bulk heterojunction includes a plurality of photoconductive materials disposed between the anode and the cathode. The photoconductive materials include a first continuous layer of donor material and a second continuous layer of acceptor material. A first network of donor material or materials extends from the first continuous layer toward the second continuous layer, providing continuous pathways for conduction of holes to the first continuous layer. A second network of acceptor material or materials extends from the second continuous layer toward the first continuous layer, providing continuous pathways for conduction of electrons to the second continuous layer. The first network and the second network are interlaced with each other. At least one other photoconductive material is interspersed between the interlaced networks. This other photoconductive material or materials has an absorption spectra different from the donor and acceptor materials.

  1. Holographic dictionary and defects in the bulk

    Science.gov (United States)

    Khramtsov, Mikhail

    2016-10-01

    We study the holographic dual of the AdS3 spacetime with a conical defect. We calculate the boundary two-point correlator using the holographic Gubser-Klebanov-Polyakov/Witten dictionary for a scalar field in the bulk. We consider the general case, when the conical defect breaks conformal symmetry at the boundary. The results are compared with previous studies based on the geodesic approximation. They are in good agreement for short correlators, and main discrepancy comes in the region of long correlations. It is shown that in the case when the spacetime is the AdS3/ℤN orbifold, both methods give the same result which also produces the result expected from the orbifold CFT.

  2. Anisotropy of transport in bulk Rashba metals

    Science.gov (United States)

    Brosco, Valentina; Grimaldi, Claudio

    2017-05-01

    The recent experimental discovery of three-dimensional (3D) materials hosting a strong Rashba spin-orbit coupling calls for the theoretical investigation of their transport properties. Here we study the zero-temperature dc conductivity of a 3D Rashba metal in the presence of static diluted impurities. We show that, at variance with the two-dimensional case, in 3D systems, spin-orbit coupling affects dc charge transport in all density regimes. We find in particular that the effect of spin-orbit interaction strongly depends on the direction of the current, and we show that this yields strongly anisotropic transport characteristics. In the dominant spin-orbit coupling regime where only the lowest band is occupied, the conductivity anisotropy is governed entirely by the anomalous component of the renormalized current. We propose that measurements of the conductivity anisotropy in bulk Rashba metals may give a direct experimental assessment of the spin-orbit strength.

  3. 49 CFR 173.241 - Bulk packagings for certain low hazard liquid and solid materials.

    Science.gov (United States)

    2010-10-01

    ... table. (a) Rail cars: Class DOT 103, 104, 105, 109, 111, 112, 114, 115, or 120 tank car tanks; Class 106 or 110 multi-unit tank car tanks and AAR Class 203W, 206W, and 211W tank car tanks. (b) Cargo tanks... 312, MC 330, MC 331, DOT 406, DOT 407, and DOT 412 cargo tank motor vehicles; and...

  4. Correspondence between Experiment and Theory of Bulk Electrocrystallisation at Solid Electrodes in Aqueous Electrolyte

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    overpotentials in cyclic voltammetry (dc). The lack of complete reversibility in nernstian systems is a key topic of the present model, and the description also involves a prediction of the properties observed in non-reversible systems. These considerations lead to a novel concept for reversibility that is based...... position relative to the electrode, the rate of reduction and oxidation may increase thus leading to current densities that exceed the magnitude of conventional diffusion current densities observed in cyclic voltammetry. This result was accomplished by including in the description a depletion layer devoid...

  5. Correspondence between Experiment and Theory of Bulk Electrocrystallisation at Solid Electrodes in Aqueous Electrolyte

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2009-01-01

    A model of electrodeposition and electrodissolution at electrode surfaces in aqueous solution is presented. The description is based on the assumption that redox reaction of water is the more important process controlling the electrode kinetics. Chronoamperometric measurements and experiments...... of cyclic voltammetry indicate that the current fundamentally is proportional to inverse time. It was proposed that redox-active species different from water never touch the surface but they predominantly interact with surface-active hydrogen or oxygen formed at the surface by redox processes of water...

  6. PD-related stresses in the bulk dielectric and their evaluation

    DEFF Research Database (Denmark)

    Pedersen, Aage; Crichton - Fratrådt, George C; McAllister, Iain Wilson

    1993-01-01

    The application of electromagnetic field theory to the subject of partial discharges shows that discharging in a void generates large field distortions within the bulk dielectric in the proximity of the void. Such inherent over-stressing of a dielectric could be the effect which triggers the onset...... of electrical treeing and other damaging processes, and which subsequently precipitates the breakdown of the insulation. If there were a train of partial discharge events per power frequency cycle, then, during each half period, these events would lead to cumulative stress levels within the solid dielectric...

  7. Accurate bulk density determination of irregularly shaped translucent and opaque aerogels

    Science.gov (United States)

    Petkov, M. P.; Jones, S. M.

    2016-05-01

    We present a volumetric method for accurate determination of bulk density of aerogels, calculated from extrapolated weight of the dry pure solid and volume estimates based on the Archimedes' principle of volume displacement, using packed 100 μm-sized monodispersed glass spheres as a "quasi-fluid" media. Hard particle packing theory is invoked to demonstrate the reproducibility of the apparent density of the quasi-fluid. Accuracy rivaling that of the refractive index method is demonstrated for both translucent and opaque aerogels with different absorptive properties, as well as for aerogels with regular and irregular shapes.

  8. Inner Structure of Boiling Nucleus and Interfacial Energy Between Nucleus and Bulk Liquid

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Dong; TIAN Yong; PENG Xiao-Feng; WANG Bu-Xuan

    2004-01-01

    @@ A model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent on the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provide solid theoretical evidence to clarify the definition of nucleation rate and understand the nucleation phenomenon with insight into the physical nature.

  9. Crystallization and thermophysical properties of Cu46Zr47Al6Co1 bulk metallic glass

    Directory of Open Access Journals (Sweden)

    Kang Wu

    2013-11-01

    Full Text Available Phase evolution of two-step crystallization and the subsequent B2-phase transformation was presented in Cu46Zr47Al6Co1 bulk metallic glass (BMG during heating process. Thermophysical properties, i.e. the thermal diffusivity and the specific heat capacity, of the BMG in amorphous solid state and supercooled liquid state as well as its crystalline counterparts were measured from room temperature to 1070 K. The thermal conductivity was also calculated through combination of the data of the thermal diffusivity and the specific heat capacity. The possible influence of the crystallization on the thermophysical properties was discussed.

  10. Electrochemical and Numerical Studies of Surface, Grain-Boundary and Bulk Copper Diffusion Into Gold

    Science.gov (United States)

    Miller, Eric Todd

    Surface, grain-boundary, and bulk chemical diffusivities of copper into gold were measured by chronoamperometry -potentiometry applied to Cu|CuCl |Au solid state galvanic cells at 300-400^circC. The cells were constructed using a novel vapor deposition technique which is described. The automated data acquisition techniques utilizing unique hardware and custom designed software are also presented. Chronoamperometry and a two electrode limited potential cyclic voltammetry technique were comparatively used to determine cell capacitance and resistance. Both gave similar RC values at lower temperatures but diverged from each other at higher temperatures. Electron hole conductivity of CuCl could not be determined from intercept values in the chronoamperometry Cottrell analysis. The partial molar enthalpy and entropy of mixing copper into gold were determined from Emf vs temperature vs composition measurements of Cu|CuCl |Au-Cu alloy cells. The results support the regular solution model of mixing with interaction energy parameter {bf{cal Q}} = 10kJ. Diffusion coefficients were calculated from the chronoamperometry-potentiometry time/flux/concentration data in two ways: via the Cottrell equation, for an average diffusion coefficient; and via a simplex and finite difference program for the simultaneous determination of surface, grain-boundary, and bulk diffusion coefficients. This program was run on a MASPAR MP-2 massively parallel computer. The surface and grain-boundary diffusivities were numerically determinable in single and polycrystalline cathodes at short diffusion times. Bulk diffusivity was determinable at short and long diffusion times and agreed with previous data. Surface diffusivity was two orders of magnitude larger than the bulk with lower activation energy. Grain -boundary diffusivity was one order of magnitude larger than the bulk with similar activation energy. The Cottrell equation was only valid at very long diffusion times due to the transient interface

  11. Solid state physics

    CERN Document Server

    Burns, Gerald

    2013-01-01

    Solid State Physics, International Edition covers the fundamentals and the advanced concepts of solid state physics. The book is comprised of 18 chapters that tackle a specific aspect of solid state physics. Chapters 1 to 3 discuss the symmetry aspects of crystalline solids, while Chapter 4 covers the application of X-rays in solid state science. Chapter 5 deals with the anisotropic character of crystals. Chapters 6 to 8 talk about the five common types of bonding in solids, while Chapters 9 and 10 cover the free electron theory and band theory. Chapters 11 and 12 discuss the effects of moveme

  12. Theoretical solid state physics

    CERN Document Server

    Haug, Albert

    2013-01-01

    Theoretical Solid State Physics, Volume 1 focuses on the study of solid state physics. The volume first takes a look at the basic concepts and structures of solid state physics, including potential energies of solids, concept and classification of solids, and crystal structure. The book then explains single-electron approximation wherein the methods for calculating energy bands; electron in the field of crystal atoms; laws of motion of the electrons in solids; and electron statistics are discussed. The text describes general forms of solutions and relationships, including collective electron i

  13. Gaseous emissions from management of solid waste: a systematic review.

    Science.gov (United States)

    Pardo, Guillermo; Moral, Raúl; Aguilera, Eduardo; Del Prado, Agustín

    2015-03-01

    The establishment of sustainable soil waste management practices implies minimizing their environmental losses associated with climate change (greenhouse gases: GHGs) and ecosystems acidification (ammonia: NH3 ). Although a number of management strategies for solid waste management have been investigated to quantify nitrogen (N) and carbon (C) losses in relation to varied environmental and operational conditions, their overall effect is still uncertain. In this context, we have analyzed the current scientific information through a systematic review. We quantified the response of GHG emissions, NH3 emissions, and total N losses to different solid waste management strategies (conventional solid storage, turned composting, forced aerated composting, covering, compaction, addition/substitution of bulking agents and the use of additives). Our study is based on a meta-analysis of 50 research articles involving 304 observations. Our results indicated that improving the structure of the pile (waste or manure heap) via addition or substitution of certain bulking agents significantly reduced nitrous oxide (N2 O) and methane (CH4 ) emissions by 53% and 71%, respectively. Turned composting systems, unlike forced aerated composted systems, showed potential for reducing GHGs (N2 O: 50% and CH4 : 71%). Bulking agents and both composting systems involved a certain degree of pollution swapping as they significantly promoted NH3 emissions by 35%, 54%, and 121% for bulking agents, turned and forced aerated composting, respectively. Strategies based on the restriction of O2 supply, such as covering or compaction, did not show significant effects on reducing GHGs but substantially decreased NH3 emissions by 61% and 54% for covering and compaction, respectively. The use of specific additives significantly reduced NH3 losses by 69%. Our meta-analysis suggested that there is enough evidence to refine future Intergovernmental Panel on Climate Change (IPCC) methodologies from solid waste

  14. Topological Surface States in Dense Solid Hydrogen.

    Science.gov (United States)

    Naumov, Ivan I; Hemley, Russell J

    2016-11-11

    Metallization of dense hydrogen and associated possible high-temperature superconductivity represents one of the key problems of physics. Recent theoretical studies indicate that before becoming a good metal, compressed solid hydrogen passes through a semimetallic stage. We show that such semimetallic phases predicted to be the most stable at multimegabar (∼300  GPa) pressures are not conventional semimetals: they exhibit topological metallic surface states inside the bulk "direct" gap in the two-dimensional surface Brillouin zone; that is, metallic surfaces may appear even when the bulk of the material remains insulating. Examples include hydrogen in the Cmca-12 and Cmca-4 structures; Pbcn hydrogen also has metallic surface states but they are of a nontopological nature. The results provide predictions for future measurements, including probes of possible surface superconductivity in dense hydrogen.

  15. Cell wall elasticity: I. A critique of the bulk elastic modulus approach and an analysis using polymer elastic principles

    Science.gov (United States)

    Wu, H. I.; Spence, R. D.; Sharpe, P. J.; Goeschl, J. D.

    1985-01-01

    The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The bulk modulus describes stress/strain relations of solid, homogeneous bodies undergoing small deformations, whereas the plant cell is best described as a thin-shelled, fluid-filled structure with a polymer base. Because cell walls possess a polymer structure, an alternative method of mechanical analysis is presented using polymer elasticity principles. This initial study presents the groundwork of polymer mechanics as would be applied to cell walls and discusses how the matrix and microfibrillar network induce nonlinear stress/strain relationships in the cell wall in response to turgor pressure. In subsequent studies, these concepts will be expanded to include anisotropic expansion as regulated by the microfibrillar network.

  16. Numerical investigation of crystal growth process of bulk Si and nitrides - a review

    Energy Technology Data Exchange (ETDEWEB)

    Kakimoto, K.; Liu, L.; Miyazawa, H.; Nakano, S.; Kashiwagi, D.; Chen, X.J.; Kangawa, Y. [Research Institute for Applied Mechanics, Kyushu University, Kasuga (Japan)

    2007-12-15

    Heat and mass transfer during crystal growth of bulk Si and nitrides by using numerical analysis was studied. A three-dimensional analysis was carried out to investigate temperature distribution and solid-liquid interface shape of silicon for large-scale integrated circuits and photovoltaic silicon. The analysis enables prediction of the solid-liquid interface shape of silicon crystals. The result shows that the interface shape became bevel like structure in the case without crystal rotation. We also carried out analysis of nitrogen transfer in gallium melt during crystal growth of gallium nitride using liquid-phase epitaxy. The result shows that the growth rate at the center was smaller than that at the center. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Performance and applications of quench melt-growth bulk magnets

    Science.gov (United States)

    Nariki, S.; Teshima, H.; Morita, M.

    2016-03-01

    This paper describes the progress in quench melt-growth (QMG) bulk magnets, developed by the Nippon Steel & Sumitomo Metal Corporation, which consist of single crystalline RE123 phase and finely dispersed RE211 particles. QMG bulks can trap high magnetic fields. The field-trapping ability of QMG bulks is largely increased with an improvement in its J c and size, promising the realization of various applications such as flywheel energy-storage systems, ship motors, NMR/MRI spectrometers, wind-power generators and so on. Intensive research has revealed that the optimal RE element is different depending on application requirements. Gd-QMG bulk is the most promising material for several high-field engineering applications. The trapped magnetic field of Gd-QMG bulk 60 mm in diameter at 77 K is twice as large as that of Y-QMG bulk with a similar size due to its excellent J c properties. The large Gd-based QMG bulks up to 150 mm in diameter are fabricated by incorporating the RE compositional gradient method. Compact NMR/MRI spectrometers are one of the promising applications of bulk superconductors. Eu-QMG bulks are suitable for NMR magnets. NMR applications require extremely homogeneous magnetic fields. In the Eu-system, the small paramagnetic moment of a Eu ion compared to a Gd ion improves the field homogeneity in the bulk. For the application of current leads, Dy-based QMG is available by utilizing a low thermal conductivity.

  18. Locality, bulk equations of motion and the conformal bootstrap

    Energy Technology Data Exchange (ETDEWEB)

    Kabat, Daniel [Department of Physics and Astronomy, Lehman College, City University of New York,250 Bedford Park Blvd. W, Bronx NY 10468 (United States); Lifschytz, Gilad [Department of Mathematics, Faculty of Natural Science, University of Haifa,199 Aba Khoushy Ave., Haifa 31905 (Israel)

    2016-10-18

    We develop an approach to construct local bulk operators in a CFT to order 1/N{sup 2}. Since 4-point functions are not fixed by conformal invariance we use the OPE to categorize possible forms for a bulk operator. Using previous results on 3-point functions we construct a local bulk operator in each OPE channel. We then impose the condition that the bulk operators constructed in different channels agree, and hence give rise to a well-defined bulk operator. We refer to this condition as the “bulk bootstrap.” We argue and explicitly show in some examples that the bulk bootstrap leads to some of the same results as the regular conformal bootstrap. In fact the bulk bootstrap provides an easier way to determine some CFT data, since it does not require knowing the form of the conformal blocks. This analysis clarifies previous results on the relation between bulk locality and the bootstrap for theories with a 1/N expansion, and it identifies a simple and direct way in which OPE coefficients and anomalous dimensions determine the bulk equations of motion to order 1/N{sup 2}.

  19. What Are Solid Fats?

    Science.gov (United States)

    ... fatty acids. Most solid fats are high in saturated fats and/or trans fats and have less monounsaturated ... Animal products containing solid fats also contain cholesterol. Saturated fats and trans fats tend to raise "bad" (LDL) ...

  20. Solid-state NMR of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Mirau, P

    2001-07-01

    Nuclear magnetic resonance (NMR) spectroscopy has emerged as one of the most important methods for the solid-state characterisation of polymers. The popularity of NMR is due to the fact that many molecular level features can be measured from the NMR spectra, including the polymer chain conformation, the morphology and the dynamics. The spectral features and relaxation times are affected by local interactions, so they provide information about the structure of polymers on a length scale (2-200 A) that is difficult to measure by other methods. In favourable cases, the NMR experiments provide a molecular-level explanation for the transitions observed by differential scanning calorimetry (DSC) and other methods, and the NMR properties can often be related to the bulk properties. Solid-state NMR has long been of interest in polymer science, and the first solid-state NMR studies of polymers were reported approximately a year after the discovery of nuclear resonance in bulk matter. It was reported in this initial study that the proton line width for natural rubber at room temperature is more like that of a mobile liquid than of a solid, but that the resonance broadens near the glass transition temperature (T{sub g}). This was recognised as being related to a change in chain dynamics above and below the T{sub g}. NMR methods developed rapidly after these initial observations, first for polymers in solution and, more recently, for polymers in the solid-state. Solid-state NMR studies of polymers were developed more slowly than their solution-state counterparts because solid-state NMR requires more specialised equipment. Solid-state NMR is now such an important tool that most modern spectrometers are capable of performing these studies. The interest in the NMR of solid polymers is due in part to the fact that most polymers are used in the solid state, and in many cases the NMR properties can be directly related to the macroscopic properties. Polymers have restricted mobility

  1. Tetraphenylborate Solids Stability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-06-25

    Tetraphenylborate solids are a potentially large source of benzene in the slurries produced in the In-Tank Precipitation (ITP) process. The stability of the solids is an important consideration in the safety analysis of the process and we desire an understanding of the factors that influence the rate of conversion of the solids to benzene. This report discusses current testing of the stability of tetraphenylborate solids.

  2. Laser cooling of solids

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

    2008-01-01

    We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

  3. 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.

  4. A CFT Perspective on Gravitational Dressing and Bulk Locality

    CERN Document Server

    Lewkowycz, Aitor; Verlinde, Herman

    2016-01-01

    We revisit the construction of local bulk operators in AdS/CFT with special focus on gravitational dressing and its consequences for bulk locality. Specializing to 2+1-dimensions, we investigate these issues via the proposed identification between bulk operators and cross-cap boundary states. We obtain explicit expressions for correlation functions of bulk fields with boundary stress tensor insertions, and find that they are free of non-local branch cuts but do have non-local poles. We recover the HKLL recipe for restoring bulk locality for interacting fields as the outcome of a natural CFT crossing condition. We show that, in a suitable gauge, the cross-cap states solve the bulk wave equation for general background geometries, and satisfy a conformal Ward identity analogous to a soft graviton theorem, Virasoro symmetry, the large N conformal bootstrap and the uniformization theorem all play a key role in our derivations.

  5. Bulk Glassy Alloys: Historical Development and Current Research

    Directory of Open Access Journals (Sweden)

    Akihisa Inoue

    2015-06-01

    Full Text Available This paper reviews the development of current research in bulk glassy alloys by focusing on the trigger point for the synthesis of the first bulk glassy alloys by the conventional mold casting method. This review covers the background, discovery, characteristics, and applications of bulk glassy alloys, as well as recent topics regarding them. Applications of bulk glassy alloys have been expanding, particularly for Fe-based bulk glassy alloys, due to their unique properties, high glass-forming ability, and low cost. In the near future, the engineering importance of bulk glassy alloys is expected to increase steadily, and continuous interest in these novel metallic materials for basic science research is anticipated.

  6. 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.

  7. Finsler geometric perspective on the bulk flow in the universe

    CERN Document Server

    Cahng, Zhe; Wang, Sai

    2013-01-01

    Astronomical observations showed that there exists a bulk flow with peculiar velocities in the universe, which contradicts with the (\\Lambda)CDM model. The bulk flow reveals that the observational universe is anisotropic at large scales. In this paper, we propose a "wind" scenario to the bulk flow. Under the influence of the "wind", the spacetime metric could become a Finsler structure. By resolving the null geodesic equation, we obtain the modified luminosity distance, which has a dipolar form at the leading order. Thus, the "wind" describes well the bulk flow. In addition, we perform a least-(\\chi^2) fit to the data of type Ia supernovae (SNe Ia) in the Union2.1 compilation. The peculiar velocity of the bulk flow has an upper limit (v_{bulk}\\lesssim 4000 \\rm{km/s}), which is compatible with all the existing observational values.

  8. Material Profile Influences in Bulk-Heterojunctions

    Energy Technology Data Exchange (ETDEWEB)

    Roehling, John D.; Rochester, Christopher W.; Ro, Hyun W.; Wang, Peng; Majewski, Jaroslaw; Batenburg, Kees J.; Arslan, Ilke; Delongchamp, Dean M.; Moule, Adam J.

    2014-10-01

    he morphology in mixed bulk-heterojunction films are compared using three different quantitative measurement techniques. We compare the vertical composition changes using high-angle annular dark-field scanning transmission electron microscopy with electron tomography and neutron and x-ray reflectometry. The three measurement techniques yield qualita-tively comparable vertical concentration measurements. The presence of a metal cathode during thermal annealing is observed to alter the fullerene concentration throughout the thickness of the film for all measurements. However, the abso-lute vertical concentration of fullerene is quantitatively different for the three measurements. The origin of the quantitative measurement differences is discussed. The authors thank Luna Innovations, Inc. for donating the endohedral fullerenes used in this study and Plextronics for the P3HT. They are gratefully thank the National Science Foundation Energy for Sustainability Program, Award No. 0933435. This work benefited from the use of the Lujan Neutron Scattering Center at Los Alamos Neutron Science Center funded by the DOE Office of Basic Energy Sciences and Los Alamos National Laboratory under DOE Contract DE-AC52-06NA25396. This research was also supported in part by Laboratory Directed Research & Development program at PNNL. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy under contract DE-AC05-76RL01830.

  9. Failure Prediction in Bulk Metal Forming Process

    Directory of Open Access Journals (Sweden)

    Ameen Topa

    2014-01-01

    Full Text Available An important concern in metal forming is whether the desired deformation can be accomplished without defects in the final product. Various ductile fracture criteria have been developed and experimentally verified for a limited number of cases of metal forming processes. These criteria are highly dependent on the geometry of the workpiece and cannot be utilized for complicated shapes without experimental verification. However, experimental work is a resource hungry process. This paper proposes the ability of finite element analysis (FEA software such as LS-DYNA to pinpoint the crack-like flaws in bulk metal forming products. Two different approaches named as arbitrary Lagrangian-Eulerian (ALE and smooth particle hydrodynamics (SPH formulations were adopted. The results of the simulations agree well with the experimental work and a comparison between the two formulations has been carried out. Both approximation methods successfully predicted the flow of workpiece material (plastic deformation. However ALE method was able to pinpoint the location of the flaws.

  10. On methods of estimating cosmological bulk flows

    CERN Document Server

    Nusser, Adi

    2015-01-01

    We explore similarities and differences between several estimators of the cosmological bulk flow, $\\bf B$, from the observed radial peculiar velocities of galaxies. A distinction is made between two theoretical definitions of $\\bf B$ as a dipole moment of the velocity field weighted by a radial window function. One definition involves the three dimensional (3D) peculiar velocity, while the other is based on its radial component alone. Different methods attempt at inferring $\\bf B$ for either of these definitions which coincide only for a constant velocity field. We focus on the Wiener Filtering (WF, Hoffman et al. 2015) and the Constrained Minimum Variance (CMV,Feldman et al. 2010) methodologies. Both methodologies require a prior expressed in terms of the radial velocity correlation function. Hoffman et al. compute $\\bf B$ in Top-Hat windows from a WF realization of the 3D peculiar velocity field. Feldman et al. infer $\\bf B$ directly from the observed velocities for the second definition of $\\bf B$. The WF ...

  11. Fault current limiter using bulk oxides superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Belmont, O.; Ferracci, P.; Porcar, L.; Barbut, J.M. [Schneider Electric, Grenoble (France). Usine A3; Tixador, P.; Noudem, J.G.; Bourgault, D.; Tournier, R

    1998-08-01

    We study the limitation possibilities of bulk Bi high T{sub c} materials. For this we test these materials with AC or DC currents above their critical currents. We study particularly the evolution of the voltage with time or with current. The material, the value of the current and the time duration play important parts. For sintered Bi samples the voltage depends only on the current even for values much larger than the critical current. With textured samples the V(I) curves shows an hysteretic behaviour due to a warming up. The textured materials are more interesting than sintered ones in terms of required volume for the current limitation. In both cases the superconductors are in a dissipative state but not in the normal state. This state is nevertheless reached if the dissipated energy inside the sample is sufficient. We have tried to apply a magnetic field on the samples in order to trigger a more effective limitation. The voltage increases but with a limited effect for currents much higher (3-4 times) than the critical zero field current. We think that the dissipative state is due mainly to the grain boundaries which become resistive above the critical current. (orig.) 11 refs.

  12. Studies of bulk heterojunction solar cells

    Science.gov (United States)

    Cossel, Raquel; McIntyre, Max; Tzolov, Marian

    We are studying bulk heterojunction solar cells that were fabricated using a mixture of PCPDTBT and PCBM­C60. The impedance data of the cells in dark responded like a simple RC circuit. The value of the dielectric constant derived from these results is consistent with the values reported in the literature for these materials. We are showing that the parallel resistance in the equivalent circuit of linear lump elements can be interpreted using the DC current­voltage measurements. The impedance spectra under light illumination indicated the existence of additional polarization. This extra feature can be described by a model that includes a series RC circuit in parallel with the equivalent circuit for a device in dark. The physical interpretation of the additional polarization is based on photo­generated charges getting trapped in wells, which have a characteristic relaxation time corresponding to the observed break frequency in the impedance spectra. We have studied the influence of the anode and cathode interface on this phenomena, either by using different interface materials, or by depositing the metal electrode while the substate is heated.

  13. Recent developments of film bulk acoustic resonators

    Science.gov (United States)

    Gao, Junning; Liu, Guorong; Li, Jie; Li, Guoqiang

    2016-06-01

    Film bulk acoustic wave resonator (FBAR) experienced skyrocketing development in the past 15 years, owing to the explosive development of mobile communication. It stands out in acoustic filters mainly because of high quality factor, which enables low insertion loss and sharp roll off. Except for the massive application in wireless communication, FBARs are also promising sensors because of the high sensitivity and readily integration ability to miniaturize circuits. On the ground of summarizing FBAR’s application in wireless communication as filters and in sensors including electronic nose, bio field, and pressure sensing, this paper review the main challenges of each application faced. The number of filters installed in the mobile phone has being grown explosively, which leads to overcrowded bands and put harsh requirements on component size and power consumption control for each unit. Data flow and rate are becoming increasingly demanding as well. This paper discusses three promising technical strategies addressing these issues. Among which coupled resonator filter is given intense attention because it is able to vigorously reduce the filter size by stacking two or more resonators together, and it is a great technique to increase data flow and rate. Temperature compensation methods are discussed considering their vital influence on frequency stability. Finally, materials improvement and novel materials exploration for band width modulation, tunable band acquisition, and quality factor improvement are discussed. The authors appeal attention of the academic society to bring AlN epitaxial thin film into the FBAR fabrication and have proposed a configuration to implement this idea.

  14. 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...

  15. Determination of Bulk Dimensional Variation in Castings

    Energy Technology Data Exchange (ETDEWEB)

    Dr. James F. Cuttino Dr. Edward P. Morse

    2005-04-14

    The purpose of this work is to improve the efficiency of green sand foundries so that they may continue to compete as the most cost-effective method of fabrication while meeting tightening constraints on near-net shape manufacturing. In order to achieve this objective, the study is divided into two major components. The first component concentrated on identifying which processes control surface finish on the castings and which provide potential reductions in variations. The second component identified metrological methods that effectively discern between the geometry of bulk material versus surface finish in order to more accurately determine the quality of a part. The research resulted in the determination of an empirical relationship relating pouring parameters to dimensional variation, with an R2 value of greater than 0.79. A significant difference in variations obtained from vertical vs. horizontal molding machines was also noticed. When analyzed separately, however, the resulting empirical relationships for horizontal and vertical machines had reduced R2 values, probably due to the reduced data sets. Significant parameters when considering vertical and horizontal molding machines together included surface roughness, pattern type, iron type, pouring rate, copper content, amount of Western Bentonite, and permeability.

  16. Thermodynamic properties of bulk and confined water

    Energy Technology Data Exchange (ETDEWEB)

    Mallamace, Francesco, E-mail: francesco.mallamace@unime.it [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Mallamace, Domenico [Dipartimento di Scienze dell' Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Vasi, Sebastiano; Vasi, Cirino [IPCF-CNR, I-98166 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

    2014-11-14

    The thermodynamic response functions of water display anomalous behaviors. We study these anomalous behaviors in bulk and confined water. We use nuclear magnetic resonance (NMR) to examine the configurational specific heat and the transport parameters in both the thermal stable and the metastable supercooled phases. The data we obtain suggest that there is a behavior common to both phases: that the dynamics of water exhibit two singular temperatures belonging to the supercooled and the stable phase, respectively. One is the dynamic fragile-to-strong crossover temperature (T{sub L} ≃ 225 K). The second, T{sup *} ∼ 315 ± 5 K, is a special locus of the isothermal compressibility K{sub T}(T, P) and the thermal expansion coefficient α{sub P}(T, P) in the P–T plane. In the case of water confined inside a protein, we observe that these two temperatures mark, respectively, the onset of protein flexibility from its low temperature glass state (T{sub L}) and the onset of the unfolding process (T{sup *})

  17. Solid State Division

    Energy Technology Data Exchange (ETDEWEB)

    Green, P.H.; Watson, D.M. (eds.)

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)

  18. Bulk Extractor 1.4 User’s Manual

    Science.gov (United States)

    2013-08-01

    51 12 Related Reading 52 Appendices 54 A Output of bulk_extractor Help Command 54 v 1 Introduction 1.1 Overview of bulk_extractor bulk_extractor is a...10485760 Threads: 4 All data are read ; waiting for threads to finish... Time elapsed waiting for 1 thread to finish: (timeout in 60 min .) Time elapsed...anything but a[A-Z] = A to Z[A\\-Z]= A, Z, or hyphen (!)[A-Zaeiou] = capitalsor lowercase vowels [.+*?\\

  19. Locality, bulk equations of motion and the conformal bootstrap

    CERN Document Server

    Kabat, Daniel

    2016-01-01

    We develop an approach to construct local bulk operators in a CFT to order 1/N^2. Since 4-point functions are not fixed by conformal invariance we use the OPE to categorize possible forms for a bulk operator. Using previous results on 3-point functions we construct a local bulk operator in each OPE channel. We then impose the condition that the bulk operators constructed in different channels agree, and hence give rise to a well-defined bulk operator. We refer to this condition as the "bulk bootstrap." We argue and explicitly show in some examples that the bulk bootstrap leads to some of the same results as the regular conformal bootstrap. In fact the bulk bootstrap provides an easier way to determine some CFT data, since it does not require knowing the form of the conformal blocks. This analysis clarifies previous results on the relation between bulk locality and the bootstrap for theories with a 1/N expansion, and it identifies a simple and direct way in which OPE coefficients and anomalous dimensions deter...

  20. Preliminary study of superconducting bulk magnets for Maglev

    Science.gov (United States)

    Fujimoto, Hiroyuki; Kamijo, Hiroki

    Recent development shows that melt-processed YBaCuO (Y123) or Rare Earth (RE)123 superconductors have a high Jc at 77 K and high magnetic field, leading to high field application as a superconducting quasi-permanent bulk magnet with the liquid nitrogen refrigeration. One of the promising applications is a superconducting magnet for the magnetically levitated (Maglev) train. We discuss a superconducting bulk magnet for the Maglev train in the aspect of a preliminary design of the bulk magnet and also processing for (L)REBaCuO bulk superconductors and their characteristic superconducting properties.

  1. Bulk flow scaling for turbulent channel and pipe flows

    CERN Document Server

    Chen, Xi; She, Zhen-Su

    2016-01-01

    We report a theory deriving bulk flow scaling for canonical wall-bounded flows. The theory accounts for the symmetries of boundary geometry (flat plate channel versus circular pipe) by a variational calculation for a large-scale energy length, which characterizes its bulk flow scaling by a simple exponent, i.e. $m=4$ for channel and 5 for pipe. The predicted mean velocity shows excellent agreement with several dozen sets of quality empirical data for a wide range of the Reynolds number (Re), with a universal bulk flow constant $\\kappa\\approx0.45$. Predictions for dissipation and turbulent transport in the bulk flow are also given, awaiting data verification.

  2. Solid expellant plasma generator

    Science.gov (United States)

    Stone, Nobie H. (Inventor); Poe, Garrett D. (Inventor); Rood, Robert (Inventor)

    2010-01-01

    An improved solid expellant plasma generator has been developed. The plasma generator includes a support housing, an electrode rod located in the central portion of the housing, and a mass of solid expellant material that surrounds the electrode rod within the support housing. The electrode rod and the solid expellant material are made of separate materials that are selected so that the electrode and the solid expellant material decompose at the same rate when the plasma generator is ignited. This maintains a point of discharge of the plasma at the interface between the electrode and the solid expellant material.

  3. Solid state phenomena

    CERN Document Server

    Lawrance, R

    1972-01-01

    Solid State Phenomena explores the fundamentals of the structure and their influence on the properties of solids. This book is composed of five chapters that focus on the electrical and thermal conductivities of crystalline solids. Chapter 1 describes the nature of solids, particularly metals and crystalline materials. This chapter also presents a model to evaluate crystal structure, the forces between atom pairs, and the mechanism of plastic and elastic deformation. Chapter 2 demonstrates random vibrations of atoms in a solid using a one-dimensional array, while Chapter 3 examines the resista

  4. CHARACTERIZATION OF SOLID CONES

    Institute of Scientific and Technical Information of China (English)

    Qiu Jinghui

    2008-01-01

    The author gives a dual characterization of solid cones in locally convex spaces.From this the author obtains some criteria for judging convex cones to be solid in various inds of locally convex spaces. Using a general expression of the interior of a solid cone,the author obtains a number of necessary and sufficient conditions for convex cones to be solid in the framework of Banach spaces. In particular, the author gives a dual relationship between solid cones and generalized sharp cones. The related known results are improved and extended.

  5. Alternative method to determine the bulk etch rate of Lr-115 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Sajo B, L.; Barros, H.; Greaves, E. D. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Palacios, F. [Universidad de Oriente, Santiago de Cuba (Cuba)

    2010-02-15

    The measurements using the Lr-115 solid-state nuclear track detector depend critically on the removed thickness of the active layer during etching. In this work, Lr-115 detectors exposed to alpha particles were etched under no stirring in a 2.5 N NaOH solution at a temperature of 60{+-}1 C and different etching times (from 0.5 to 2.5 hours). The thickness of the removed layer was determined by a variant of the gravimetric method, so that the bulk etch rate could be deduced from mass change measurements of detectors. The bulk etch rate was found to be 3.63 {+-} 0.09 {mu}m.h{sup -}1, which agrees with most of the reported values. Comparisons of our results with the obtained by the optical density method are in correspondence. We propose here a fast, simple, and nondestructive method to determine the active-layer thickness of the Lr-115 solid-state nuclear track detector with good accuracy for routine measurements. (Author)

  6. Nanostructuring and Thermoelectric Properties of Bulk N-type Mg2Si

    Institute of Scientific and Technical Information of China (English)

    YANG Meijun; ZHANG Lianmeng; SHEN Qiang

    2009-01-01

    Preparation and thermoelectric properties of nanostructured n-type Mg_2Si bulk ma-terials were reported.Nanosized Mg_2Si powder was obtained by mechanical milling of the microsized Mg_2Si powder prepared by solid-state reaction.The bulk materials with 30 nm and 5μm were prepared by spark plasma sintering of the nanosized and microsized Mg_2Si powder,respectively.Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase deter-minately with the grain size decrease from 5μm to 30 nm.On the other hand,the electrical and thermal conductivity decrease with the decrease of grain size.Accordingly,decreasing their grain size in-creases their thermoelectric-figure-of-merit.A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg_2Si sample at 823 K,which is 38%higher than that of mi-crosized Mg_2Si bulk materials and higher than results of other literatures.It could be expected that the properties of the nanocomposites could be further improved by doping optimization.

  7. Magnetic characterization of Ag-addet bulk MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Wiederhold, Alex; Koblischka, Michael; Hartmann, Uwe [Institute of Experimental Physics, Saarland University, P. O. Box 151150, D-66123 Saarbruecken (Germany); Inoue, Kazuo; Muralidhar, Miryala; Murakami, Masato [Department of Material Science and Engeneering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Hauet, Thomas [Institute Jean Lamour, Universite de Lorraine, Vandoeuvre-les-Nancy (France)

    2015-07-01

    An earlier studies, it was found that bulk sintered MgB{sub 2} samples contained numerous voids which hinder the current flow. Therefore, a series of bulk MgB{sub 2} superconductors with Ag contents of 0-10 wt% was prepared in order to improve the critical current densities and the mechanical performance. Several samples were fabricated using a solid state reaction in pure Ar atmosphere at the optimal reaction temperature of 775 C. Thorough microstructural observations obtained from scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicate that metallic Ag particles are embedded in the void regions.Furthermore, nanometer-sized AgMg{sub 3} particles are also present within the MgB{sub 2} matrix, leading to improved flux pinning. Small samples cut from the bulks were characterized by transport measurements (R(T,B) and I/V characteristics) in magnetic fields up to 8 T and by magnetization loops measured using a SQUID magnetometer.

  8. Bulk Properties of Transition Metals: A Challenge for the Design of Universal Density Functionals.

    Science.gov (United States)

    Janthon, Patanachai; Luo, Sijie Andy; Kozlov, Sergey M; Viñes, Francesc; Limtrakul, Jumras; Truhlar, Donald G; Illas, Francesc

    2014-09-09

    Systematic evaluation of the accuracy of exchange-correlation functionals is essential to guide scientists in their choice of an optimal method for a given problem when using density functional theory. In this work, accuracy of one Generalized Gradient Approximation (GGA) functional, three meta-GGA functionals, one Nonseparable Gradient Approximation (NGA) functional, one meta-NGA, and three hybrid GGA functionals was evaluated for calculations of the closest interatomic distances, cohesive energies, and bulk moduli of all 3d, 4d, and 5d bulk transition metals that have face centered cubic (fcc), hexagonal closed packed (hcp), or body centered cubic (bcc) structures (a total of 27 cases). Our results show that including the extra elements of kinetic energy density and Hartree-Fock exchange energy density into gradient approximation density functionals does not usually improve them. Nevertheless, the accuracies of the Tao-Perdew-Staroverov-Scuseria (TPSS) and M06-L meta-GGAs and the MN12-L meta-NGA approach the accuracy of the Perdew-Burke-Ernzerhof (PBE) GGA, so usage of these functionals may be advisable for systems containing both solid-state transition metals and molecular species. The N12 NGA functional is also shown to be almost as accurate as PBE for bulk transition metals, and thus it could be a good choice for studies of catalysis given its proven good performance for molecular species.

  9. Bulk Disposal of Unserviceable Toxic Cresylic Acid Waste Using Polymerisation Technique

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Rai

    2011-09-01

    Full Text Available A bulk amount of unserviceable toxic cresylic acid waste has been disposed off in a safe and environmentally benign manner. A process to immobilize this waste into non-toxic solid cresol formaldehyde polymer has been developed. Initial study was performed for 1.0 Kg batch size for optimizing the process parameters and conditions, and on the basis of this data, process was scaled-up for bulk disposal (100 Kg / batch. The effect of ratio of reactants, type of catalyst [H2SO4, NaOH and Ca(OH2], catalyst concentration, reaction temperature and reaction time have been studied in a batch process. Maximum immobilization in the 1.0 Kg batch studies was obtained when cresylic acid and formaldehyde were taken in a molar ratio 1 : 1.5 using NaOH as a catalyst. For bulk polymerization, a ratio of 1.0 : 1.2 (cresylic acid : formaldehyde with NaOH {0.7 % (wt. / wt. of total charge} was found optimum. The final polymerized product has been buried as per standard procedure in two brick lined pits and finally, the site has been declared as free from the toxic waste.Defence Science Journal, 2011, 61(5, pp.505-511, DOI:http://dx.doi.org/10.14429/dsj.61.515

  10. Solid State Physics Principles and Modern Applications

    CERN Document Server

    Quinn, John J

    2009-01-01

    Intended for a two semester advanced undergraduate or graduate course in Solid State Physics, this treatment offers modern coverage of the theory and related experiments, including the group theoretical approach to band structures, Moessbauer recoil free fraction, semi-classical electron theory, magnetoconductivity, electron self-energy and Landau theory of Fermi liquid, and both quantum and fractional quantum Hall effects. Integrated throughout are developments from the newest semiconductor devices, e.g. space charge layers, quantum wells and superlattices. The first half includes all material usually covered in the introductory course, but in greater depth than most introductory textbooks. The second half includes most of the important developments in solid-state researches of the past half century, addressing e.g. optical and electronic properties such as collective bulk and surface modes and spectral function of a quasiparticle, which is a basic concept for understanding LEED intensities, X ray fine struc...

  11. Optimization of processing conditions towards high trapped fields in MgB{sub 2} bulks

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, M., E-mail: miryala1@shibaura-it.ac.jp [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Inoue, K. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Koblischka, M.R. [Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken (Germany); Tomita, M. [Railway Technical Research Institute, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan); Murakami, M. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan)

    2014-09-01

    Highlights: • Bulk MgB{sub 2} samples were prepared via solid state reaction at various sintering temperatures. • The J{sub c} value at 10 K and 0 T was 2.60 × 10{sup 5} A/cm{sup 2}. • A pinning force analysis for the samples sintered at 775 °C revealed a non-scaling behavior. • The trapped field results showed that processing temperature is the key to improving TF values. - Abstract: The present investigation focuses on the effects of various sintering temperatures on the critical current densities and the trapped field values of disk-shaped bulk MgB{sub 2} superconductors fabricated with a simple solid state reaction. The samples were prepared by varying the sintering temperature from 750 to 950 °C in pure Ar atmosphere. Scanning electron microscopy (SEM) and X-ray diffraction analyses showed that single phase and homogenous MgB{sub 2} bulks are produced in using sintering temperatures in the range of 750–825 °C. The samples sintered at 775 °C showed the highest critical current density (J{sub c}) values of 250 kA/cm{sup 2} at 10 K and 181 kA/cm{sup 2} at 20 K in self field. We also measured the trapped field values at 20 K for bulk MgB{sub 2} samples 20 mm in diameter and 7 mm in thickness, sintered at temperatures in the range of 700–950 °C with the same sintering duration of 3 h. Almost all the samples exhibited the trapped field values higher than 1 T, which shows the high potential of sintered MgB{sub 2} bulk materials as trapped field magnets. The highest value of 1.51 T at 20 K was achieved in the MgB{sub 2} sample sintered at 775 °C, reflecting its high pinning performance and homogeneous microstructure.

  12. Solids fluidizer-injector

    Science.gov (United States)

    Bulicz, T.R.

    1990-04-17

    An apparatus and process are described for fluidizing solid particles by causing rotary motion of the solid particles in a fluidizing chamber by a plurality of rotating projections extending from a rotatable cylinder end wall interacting with a plurality of fixed projections extending from an opposite fixed end wall and passing the solid particles through a radial feed orifice open to the solids fluidizing chamber on one side and a solid particle utilization device on the other side. The apparatus and process are particularly suited for obtaining intermittent feeding with continual solids supply to the fluidizing chamber. The apparatus and process are suitable for injecting solid particles, such as coal, to an internal combustion engine. 3 figs.

  13. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio

    2011-01-01

    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  14. 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.

  15. Silicon bulk micromachined hybrid dimensional artifact.

    Energy Technology Data Exchange (ETDEWEB)

    Claudet, Andre A.; Tran, Hy D.; Bauer, Todd Marks; Shilling, Katherine Meghan; Oliver, Andrew David

    2010-03-01

    A mesoscale dimensional artifact based on silicon bulk micromachining fabrication has been developed and manufactured with the intention of evaluating the artifact both on a high precision coordinate measuring machine (CMM) and video-probe based measuring systems. This hybrid artifact has features that can be located by both a touch probe and a video probe system with a k=2 uncertainty of 0.4 {micro}m, more than twice as good as a glass reference artifact. We also present evidence that this uncertainty could be lowered to as little as 50 nm (k=2). While video-probe based systems are commonly used to inspect mesoscale mechanical components, a video-probe system's certified accuracy is generally much worse than its repeatability. To solve this problem, an artifact has been developed which can be calibrated using a commercially available high-accuracy tactile system and then be used to calibrate typical production vision-based measurement systems. This allows for error mapping to a higher degree of accuracy than is possible with a glass reference artifact. Details of the designed features and manufacturing process of the hybrid dimensional artifact are given and a comparison of the designed features to the measured features of the manufactured artifact is presented and discussed. Measurement results from vision and touch probe systems are compared and evaluated to determine the capability of the manufactured artifact to serve as a calibration tool for video-probe systems. An uncertainty analysis for calibration of the artifact using a CMM is presented.

  16. Bulk forming of industrial micro components in conventional metals and bulk metallic glasses

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Paldan, Nikolas Aulin; Eriksen, Rasmus Solmer;

    2007-01-01

    For production of micro components in large numbers, forging is an interesting and challenging process. The conventional metals like silver, steel and aluminum often require multi-step processes, but high productivity and increased strength justify the investment. As an alternative, bulk metallic...... glasses will at elevated temperatures behave like a highly viscous liquid, which can easily form even complicated geometries in 1 step. The strengths and limitations of forming the 2 materials are analyzed for a micro 3D component in a silver alloy and an Mg-Cu-Y BMG. ©2007 American Institute of Physics...

  17. 27 CFR 24.301 - Bulk still wine record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bulk still wine record. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.301 Bulk still wine record. A proprietor who produces or receives still wine in bond, (including wine intended for use as distilling material or vinegar...

  18. 7 CFR 58.211 - Packaging room for bulk products.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Packaging room for bulk products. 58.211 Section 58... Service 1 Rooms and Compartments § 58.211 Packaging room for bulk products. A separate room or area shall... dust within the packaging room and where needed, a dust collector shall be provided and...

  19. T-duality trivializes bulk-boundary correspondence

    CERN Document Server

    Mathai, Varghese

    2015-01-01

    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.

  20. Import and Export of Bulk Pharmaceuticals in 2006

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ According to customs statistics, the total import and export value of bulk pharmaceuticals (excluding chemical raw materials and bulk pesticides) in China was US$10.346 billion in 2006. The export value was US$7.482 billion - an increase of 22% over the 2005.

  1. Modelling and Forecasting in the Dry Bulk Shipping Market

    NARCIS (Netherlands)

    Chen, S.

    2011-01-01

    This dissertation proposes strategies not only for modelling price behavior in the dry bulk market, but also for modelling relationships between economic and technical variables of dry bulk ships, by using modern time series approaches, Monte Carlo simulation and other economic techniques. The time

  2. Advanced and new developments in bulk metal forming

    DEFF Research Database (Denmark)

    Bay, Niels; Wanheim, Tarras; Ravn, Bjarne Gottlieb;

    2000-01-01

    Increasing demands to manufacturing industry of faster, better and cheaper production has intensified the research and development of bulk metal forming. The present paper gives examples on European industrial research on secondary bulk metal forming processes. The R&D follows three lines of appr...

  3. Nucleation of bulk superconductivity close to critical magnetic fields

    DEFF Research Database (Denmark)

    Fournais, Søren; Kachmar, Ayman

    2011-01-01

    threshold value of the applied magnetic field for which bulk superconductivity contributes to the leading order of the energy. Furthermore, the energy of the bulk is related to that of the Abrikosov problem in a periodic lattice. A key ingredient of the proof is a novel L∞ -bound which is of independent...

  4. Density functional theory in the solid state.

    Science.gov (United States)

    Hasnip, Philip J; Refson, Keith; Probert, Matt I J; Yates, Jonathan R; Clark, Stewart J; Pickard, Chris J

    2014-03-13

    Density functional theory (DFT) has been used in many fields of the physical sciences, but none so successfully as in the solid state. From its origins in condensed matter physics, it has expanded into materials science, high-pressure physics and mineralogy, solid-state chemistry and more, powering entire computational subdisciplines. Modern DFT simulation codes can calculate a vast range of structural, chemical, optical, spectroscopic, elastic, vibrational and thermodynamic phenomena. The ability to predict structure-property relationships has revolutionized experimental fields, such as vibrational and solid-state NMR spectroscopy, where it is the primary method to analyse and interpret experimental spectra. In semiconductor physics, great progress has been made in the electronic structure of bulk and defect states despite the severe challenges presented by the description of excited states. Studies are no longer restricted to known crystallographic structures. DFT is increasingly used as an exploratory tool for materials discovery and computational experiments, culminating in ex nihilo crystal structure prediction, which addresses the long-standing difficult problem of how to predict crystal structure polymorphs from nothing but a specified chemical composition. We present an overview of the capabilities of solid-state DFT simulations in all of these topics, illustrated with recent examples using the CASTEP computer program.

  5. Stability of bulk metallic glass structure

    Energy Technology Data Exchange (ETDEWEB)

    Jain, H.; Williams, D.B.

    2003-06-18

    The fundamental origins of the stability of the (Pd-Ni){sub 80}P{sub 20} bulk metallic glasses (BMGs), a prototype for a whole class of BMG formers, were explored. While much of the properties of their BMGs have been characterized, their glass-stability have not been explained in terms of the atomic and electronic structure. The local structure around all three constituent atoms was obtained, in a complementary way, using extended X-ray absorption fine structure (EXAFS), to probe the nearest neighbor environment of the metals, and extended energy loss fine structure (EXELFS), to investigate the environment around P. The occupied electronic structure was investigated using X-ray photoelectron spectroscopy (XPS). The (Pd-Ni){sub 80}P{sub 20} BMGs receive their stability from cumulative, and interrelated, effects of both atomic and electronic origin. The stability of the (Pd-Ni){sub 80}P{sub 20} BMGs can be explained in terms of the stability of Pd{sub 60}Ni{sub 20}P{sub 20} and Pd{sub 30}Ni{sub 50}P{sub 20}, glasses at the end of BMG formation. The atomic structure in these alloys is very similar to those of the binary phosphide crystals near x=0 and x=80, which are trigonal prisms of Pd or Ni atoms surrounding P atoms. Such structures are known to exist in dense, randomly-packed systems. The structure of the best glass former in this series, Pd{sub 40}Ni{sub 40}P{sub 20} is further described by a weighted average of those of Pd{sub 30}Ni{sub 50}P{sub 20} and Pd{sub 60}Ni{sub 20}P{sub 20}. Bonding states present only in the ternary alloys were found and point to a further stabilization of the system through a negative heat of mixing between Pd and Ni atoms. The Nagel and Tauc criterion, correlating a decrease in the density of states at the Fermi level with an increase in the glass stability, was consistent with greater stability of the Pd{sub x}Ni{sub (80-x)}P{sub 20} glasses with respect to the binary alloys of P. A valence electron concentration of 1.8 e/a, which

  6. Improvements in discrimination of bulk and trace elements in long-wavelength double pulse LIBS

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, J.R., E-mail: freeman.justinr@gmail.com; Diwakar, P.K., E-mail: pdiwakar@purdue.edu; Harilal, S.S., E-mail: hari@pnnl.gov; Hassanein, A., E-mail: hassanein@purdue.edu

    2014-12-01

    In this work we study the effectiveness of long-wavelength heating in double pulse (DP) LIBS, quantitatively comparing figures of merit with those from traditional single pulse (SP) LIBS. The first laser pulse serves as the source of sample ablation, creating an aerosol-like plume that is subsequently reheated by the second laser pulse. At power densities used, the long-wavelength CO{sub 2} laser pulse does not ablate any of the solid sample in the atmospheric conditions investigated, meaning plasma emission and enhanced signal can be entirely attributed to the reheated plume rather than increased sample ablation. The signal discrimination was improved significantly using long-wavelength DP-LIBS. For bulk elemental analysis, DP-LIBS provided maximum enhancements of about 14 and 15 times for S/N and S/B, respectively, compared to SP-LIBS using the same quantity of ablated sample. For trace elemental analysis, maximum enhancements of about 7 and 4 times for S/N and S/B, respectively, were observed. These improvements are attributed to effective coupling between the second heating pulse and expanding plume and more efficient excitation of plume species than from the single pulse alone. Most significant improvements were observed in the case of low prepulse energy and minimal sample ablation. While bulk elemental analysis observed improvements for all prepulse energies studied, trace element discrimination only significantly improved for the lowest prepulse energy studied. - Highlights: • Enhancement by improved coupling and excitation efficiency, not increased ablated mass • S/N enhancements of 14 and 7 times for bulk and trace elements, respectively • S/B enhancements of 15 and 4 times for bulk and trace elements, respectively • Max enhancement observed for smaller quantities of ablated sample • Significant conclusions for delicate, mass-limited samples.

  7. Microthrix parvicella abundance associates with activated sludge settling velocity and rheology - Quantifying and modelling filamentous bulking.

    Science.gov (United States)

    Wágner, Dorottya S; Ramin, Elham; Szabo, Peter; Dechesne, Arnaud; Plósz, Benedek Gy

    2015-07-01

    The objective of this work is to identify relevant settling velocity and rheology model parameters and to assess the underlying filamentous microbial community characteristics that can influence the solids mixing and transport in secondary settling tanks. Parameter values for hindered, transient and compression settling velocity functions were estimated by carrying out biweekly batch settling tests using a novel column setup through a four-month long measurement campaign. To estimate viscosity model parameters, rheological experiments were carried out on the same sludge sample using a rotational viscometer. Quantitative fluorescence in-situ hybridisation (qFISH) analysis, targeting Microthrix parvicella and phylum Chloroflexi, was used. This study finds that M. parvicella - predominantly residing inside the microbial flocs in our samples - can significantly influence secondary settling through altering the hindered settling velocity and yield stress parameter. Strikingly, this is not the case for Chloroflexi, occurring in more than double the abundance of M. parvicella, and forming filaments primarily protruding from the flocs. The transient and compression settling parameters show a comparably high variability, and no significant association with filamentous abundance. A two-dimensional, axi-symmetrical computational fluid dynamics (CFD) model was used to assess calibration scenarios to model filamentous bulking. Our results suggest that model predictions can significantly benefit from explicitly accounting for filamentous bulking by calibrating the hindered settling velocity function. Furthermore, accounting for the transient and compression settling velocity in the computational domain is crucial to improve model accuracy when modelling filamentous bulking. However, the case-specific calibration of transient and compression settling parameters as well as yield stress is not necessary, and an average parameter set - obtained under bulking and good settling

  8. Bulk viscosity, interaction and the viability of phantom solutions

    CERN Document Server

    Leyva, Yoelsy

    2016-01-01

    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with $w<-1$. From the different cases that we study, the only possible scenario, with bulk viscosity and interac...

  9. Bulk viscosity of spin-one color superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Sa' d, Basil A.

    2009-08-27

    The bulk viscosity of several quark matter phases is calculated. It is found that the effect of color superconductivity is not trivial, it may suppress, or enhance the bulk viscosity depending on the critical temperature and the temperature at which the bulk viscosity is calculated. Also, is it found that the effect of neutrino-emitting Urca processes cannot be neglected in the consideration of the bulk viscosity of strange quark matter. The results for the bulk viscosity of strange quark matter are used to calculate the r-mode instability window of quark stars with several possible phases. It is shown that each possible phase has a different structure for the r-mode instability window. (orig.)

  10. 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.

  11. Bulk density - RTD results and status of the standardisation

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, T.; Hartmann, H. [Technologie- und Foerderzentrum fuer Nachwachsende Rohstoffe - TFZ, Straubing (Germany); Daugbjerg Jensen, P. [Royal Veterinary and Agricultural University, Vejle (Denmark). Danish Centre for Forest, Landscape and Planning - DFLRI; Temmerman, M.; Rabier, F. [CRA, Gembloux (Belgium). Department Genie Rural; Jirjis, R.; Burvall, J. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Department of Bioenergy; Hersener, J.L. [Ingenieurbuero HERSENER, Wiesendangen (Switzerland); Rathbauer, J. [Bundesanstalt fuer Landtechnik - BLT, Wieselburg (Austria)

    2004-07-01

    Bulk density is an important property for determining storage and transportation room demands and for volume based payment of biofuels. It is also used for calculation of the energy density. Furthermore, bulk density influences the readings from many physical principles for rapid moisture content determination (e. g. microwave reflection method, time domain reflectometric or capacitive sensors [6]). Although bulk density is mostly regarded as an easily determinable parameter, the applied national and international standard methods are highly inconsistent in practice [1, 4, 8]. The goal of the here presented research was therefore to provide a sound knowledge basis for bulk density determination, which shall be used in the ongoing process of European biofuel standardisation. In particular the research focus was to determine the - effect of container size and shape in respect of different biofuels, - effect of shock impact and the - effect of moisture content (as received) on measured bulk density (dry basis). (orig.)

  12. Carbon nanotubes grown on bulk materials and methods for fabrication

    Science.gov (United States)

    Menchhofer, Paul A.; Montgomery, Frederick C.; Baker, Frederick S.

    2011-11-08

    Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

  13. First principles study on the charge density and the bulk modulus of the transition metals and their carbides and nitrides

    Institute of Scientific and Technical Information of China (English)

    Li Cheng-Bin; Li Ming-Kai; Yin Dong; Liu Fu-Qing; Fan Xiang-Jun

    2005-01-01

    A first principles study of the electronic properties and bulk modulus (B0) of the fcc and bcc transition metals,transition metal carbides and nitrides is presented. The calculations were performed by plane-wave pseudopotential method in the framework of the density functional theory with local density approximation. The density of states and the valence charge densities of these solids are plotted. The results show that B0 does not vary monotonically when the number of the valence d electrons increases. B0 reaches a maximum and then decreases for each of the four sorts of solids. It is related to the occupation of the bonding and anti-bonding states in the solid. The value of the valence charge density at the midpoint between the two nearest metal atoms tends to be proportional to B0.

  14. End-Member Formulation of Solid Solutions and Reactive Transport

    Energy Technology Data Exchange (ETDEWEB)

    Lichtner, Peter C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    A model for incorporating solid solutions into reactive transport equations is presented based on an end-member representation. Reactive transport equations are solved directly for the composition and bulk concentration of the solid solution. Reactions of a solid solution with an aqueous solution are formulated in terms of an overall stoichiometric reaction corresponding to a time-varying composition and exchange reactions, equivalent to reaction end-members. Reaction rates are treated kinetically using a transition state rate law for the overall reaction and a pseudo-kinetic rate law for exchange reactions. The composition of the solid solution at the onset of precipitation is assumed to correspond to the least soluble composition, equivalent to the composition at equilibrium. The stoichiometric saturation determines if the solid solution is super-saturated with respect to the aqueous solution. The method is implemented for a simple prototype batch reactor using Mathematica for a binary solid solution. Finally, the sensitivity of the results on the kinetic rate constant for a binary solid solution is investigated for reaction of an initially stoichiometric solid phase with an undersaturated aqueous solution.

  15. Characterization of bulk ultrafine grained and nanocrystalline materials

    Science.gov (United States)

    Chauhan, Manish

    Thermal stability in bulk ultra fine grained (UFG) 5083 Al that exhibited initial grain size of 305 nm, and that was processed by gas atomization followed by cryomilling, consolidation and extrusion, and in bulk nanocrystalline (nc) Ni, initial grain size of 15 and 20 nm, prepared by electrodeposition was investigated. In both the materials, two grain growth regimes were identified: a low temperature region and a high temperature region. In the low temperature regime, relatively low activation energy was found: 25 +/- 5 kJ/mol for UFG 5083 Al and 11 +/- 3 kJ/mol for nc-Ni. It is suggested that this low activation energy represents the energy for the reordering of thermodynamically non-equilibrium grain boundaries in the UFG and nc-materials. In the high temperature regime the value of activation energy for UFG 5083 Al (124 +/- 5 kJ/mol) lies in between that for grain boundary diffusion and lattice diffusion of polycrystalline Al. For nc-Ni an approximate activation energy of 105 +/- 3 kJ/mol, which is close to the activation energy for grain boundary diffusion in polycrystalline Ni, was measured. The value of the grain growth exponent, n, for both the materials (deduced from the grain growth data) were higher than the value of 2 predicted from elementary grain growth theories. The discrepancy was attributed to the operation of strong pinning forces on boundaries during the annealing treatment. An examination of the microstructure suggests that the origin of the pinning forces is most likely related to the presence of impurities and dispersion-particles on the grain boundaries. Creep and ductility behavior of UFG 5083 Al were also studied in the temperature range of 523 K-648 K in the present investigation. The curve of ductility as a function of strain rate shows the presence of a maximum that shifts to higher strain rates with increasing temperature. An analysis of the experimental data indicates that the true stress exponent is about 2, and that the ductility

  16. 78 FR 72841 - List of Bulk Drug Substances That May Be Used in Pharmacy Compounding; Bulk Drug Substances That...

    Science.gov (United States)

    2013-12-04

    ... Used in Pharmacy Compounding; Bulk Drug Substances That May Be Used To Compound Drug Products in... Administration (FDA or Agency) is withdrawing the proposed rule to list bulk drug substances used in pharmacy... Pharmacopoeia chapter on pharmacy compounding; (II) if such a monograph does not exist, are drug substances that...

  17. Solid state video cameras

    CERN Document Server

    Cristol, Y

    2013-01-01

    Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.

  18. Solid propellant rocket motor

    Science.gov (United States)

    Dowler, W. L.; Shafer, J. I.; Behm, J. W.; Strand, L. D. (Inventor)

    1973-01-01

    The characteristics of a solid propellant rocket engine with a controlled rate of thrust buildup to a desired thrust level are discussed. The engine uses a regressive burning controlled flow solid propellant igniter and a progressive burning main solid propellant charge. The igniter is capable of operating in a vacuum and sustains the burning of the propellant below its normal combustion limit until the burning propellant surface and combustion chamber pressure have increased sufficiently to provide a stable chamber pressure.

  19. Understanding solid state physics

    CERN Document Server

    Holgate, Sharon Ann

    2009-01-01

    Where Sharon Ann Holgate has succeeded in this book is in packing it with examples of the application of solid state physics to technology. … All the basic elements of solid state physics are covered … . The range of materials is good, including as it does polymers and glasses as well as crystalline solids. In general, the style makes for easy reading. … Overall this book succeeds in showing the relevance of solid state physics to the modern world … .-Contemporary Physics, Vol. 52, No. 2, 2011I was indeed amused and inspired by the wonderful images throughout the book, carefully selected by th

  20. Fuel spill identification using solid-phase extraction and solid-phase microextraction. 1. Aviation turbine fuels.

    Science.gov (United States)

    Lavine, B K; Brzozowski, D M; Ritter, J; Moores, A J; Mayfield, H T

    2001-12-01

    The water-soluble fraction of aviation jet fuels is examined using solid-phase extraction and solid-phase microextraction. Gas chromatographic profiles of solid-phase extracts and solid-phase microextracts of the water-soluble fraction of kerosene- and nonkerosene-based jet fuels reveal that each jet fuel possesses a unique profile. Pattern recognition analysis reveals fingerprint patterns within the data characteristic of fuel type. By using a novel genetic algorithm (GA) that emulates human pattern recognition through machine learning, it is possible to identify features characteristic of the chromatographic profile of each fuel class. The pattern recognition GA identifies a set of features that optimize the separation of the fuel classes in a plot of the two largest principal components of the data. Because principal components maximize variance, the bulk of the information encoded by the selected features is primarily about the differences between the fuel classes.

  1. Improving Performance in Dense Wireless Spaces by Controlling Bulk Traffic

    Directory of Open Access Journals (Sweden)

    Marat Zhanikeev

    2017-01-01

    Full Text Available The growing number of wireless devices nowadays often results in congestion of wireless channels. In research, this topic is referred to as networking in dense wireless spaces. The literature on the topic shows that the biggest problem is the high number of concurrent sessions to a wireless access point. The obvious solution is to reduce the number of concurrent sessions. This paper proposes a simple method called Bulk-n-Pick which minimizes the number of prolonged concurrent sessions by separating bulk from sync traffic. Aiming at educational applications, under the proposed design, web applications would distribute the main bulk of content once at the beginning of a class and then rely on small messages for real time sync traffic during the class. For realistic performance analysis, this paper first performs real-life experiments with various counts of wireless devices, bulk sizes, and levels of sync intensity. Based on the experiments, this paper shows that the proposed Bulk-n-Pick method outperforms the traditional design even when only two concurrent bulk sessions are allowed. The experiment shows that up to 10 concurrent bulk sessions are feasible in practice. Based on these results, a method for online performance optimization is proposed and validated in a trace-based emulation.

  2. Modeling the Microstructure Curvature of Boron-Doped Silicon in Bulk Micromachined Accelerometer

    Directory of Open Access Journals (Sweden)

    Xiaoping He

    2013-01-01

    Full Text Available Microstructure curvature, or buckling, is observed in the micromachining of silicon sensors because of the doping of impurities for realizing certain electrical and mechanical processes. This behavior can be a key source of error in inertial sensors. Therefore, identifying the factors that influence the buckling value is important in designing MEMS devices. In this study, the curvature in the proof mass of an accelerometer is modeled as a multilayered solid model. Modeling is performed according to the characteristics of the solid diffusion mechanism in the bulk-dissolved wafer process (BDWP based on the self-stopped etch technique. Moreover, the proposed multilayered solid model is established as an equivalent composite structure formed by a group of thin layers that are glued together. Each layer has a different Young’s modulus value and each undergoes different volume shrinkage strain owing to boron doping in silicon. Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.

  3. Alternative technology of nanoparticles consolidation in the bulk material

    Directory of Open Access Journals (Sweden)

    VOLKOV Georgiy Michailovich

    2016-02-01

    Full Text Available Theoretical bases and technological principles of single-stages nanoparticles conso-lidation into bulk material were offered. The theory was implemented on the model system of carbon-carbon in the process of high-temperature pyrolysis of hydrocar-bons. The bulk carbon nanomaterial with unique technical properties was produced. That made it possible to create engineering products which technical characteristics are higher than the existing level in the world. The proposed theory can be adapted to other gas-phase, liquid phase and secondary crystallization processes to create bulk nanomaterials of another chemical composition with no less unique properties.

  4. Negative Effects of Sludge Bulking in Membrane Bio-Reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; HUANG Zhi; REN Nanqi; MENG Qingjuan

    2006-01-01

    Sludge bulking property of membrane bio-reactor was investigated in this study through contrast research. When the sludge bulking appeared, the removal efficiency of COD in membrane bio-reactor increased slightly through the function of filamentous bacteria. However, the negative effects of the higher net water-head differential pressures, the high block rate of membrane pore and the great quantity of filamentous bacteria at the external surface presented at the same time. Thus, plenty of methods should be performed to control sludge bulking once it happened in membrane bio-reactor.

  5. Bulk local states and crosscaps in holographic CFT

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yu [Department of Physics, Rikkyo University,Toshima, Tokyo 175-8501 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Ooguri, Hirosi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Center for Mathematical Sciences and Applications andCenter for the Fundamental Laws of Nature, Harvard University,Cambridge, MA 02138 (United States)

    2016-10-17

    In a weakly coupled gravity theory in the anti-de Sitter space, local states in the bulk are linear superpositions of Ishibashi states for a crosscap in the dual conformal field theory. The superposition structure can be constrained either by the microscopic causality in the bulk gravity or the bootstrap condition in the boundary conformal field theory. We show, contrary to some expectation, that these two conditions are not compatible to each other in the weak gravity regime. We also present an evidence to show that bulk local states in three dimensions are not organized by the Virasoro symmetry.

  6. Engineering nanostructural routes for enhancing thermoelectric performance: bulk to nanoscale

    Directory of Open Access Journals (Sweden)

    Rajeshkumar eMohanraman

    2015-11-01

    Full Text Available Thermoelectricity is a very important physical property, especially its significance in heat-electricity conversion. If thermoelectric devices can be effectively applied to the recovery of the renewable energies, such as waste heat and solar energy, the energy shortage and global warming issues may be greatly relieved. This review focusses recent developments on the thermoelectric performance of a low-dimensional material, bulk nanostructured materials, conventional bulk materials etc. Particular emphasis is given on, how the nanostructure in nanostructured composites, confinement effects in one-dimensional nanowires and doping effects in conventional bulk composites plays an important role in ZT enhancement.

  7. Optimization and Performance Analysis of Bulk-Driven Differential Amplifier

    Directory of Open Access Journals (Sweden)

    Antarpreet kaur

    2014-04-01

    Full Text Available In recent years, there has been an increasing demand for high-speed digital circuits at low power consumption. This paper presents a design of input stage of Operational Amplifier i.e cascode differential amplifier using a standard 65nm CMOS Technology.A comparison betweem gate-driven, bulk-driven and cascode bulk driven bulk-driven differential amplifier is described. The Results demonstrate that CMMR is 83.98 dB, 3-dB Bandwidth is 1.04 MHz. The circuit dissipate power of 28uWunder single supply of 1.0V.

  8. Control of bulking phenomena and foaming by respirometry; Control del fenomeno bulking y foaming por respirometria

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, E.

    2002-07-01

    The kinetic respirometry may represent an irreplaceable tool for the F/M control and toxicity detection in a waste water treatment plant control. The benefit of the respirometry lies on the fact that when using the genuine activated sludge from the own plant biological reactor, it reflects its current reality. On the other hand, the simplicity of the technique offers its possibility to be incorporated in different types of monitoring and control systems. In addition to a possible out of range dissolved oxygen and pH, the most common cause of the bulking and foaming phenomenon appearance may come from the F/M unbalance and toxicity. The type of respirometry we should make use lies on a kinetic system in where a serie of respiration rates can graphically represent the metabolization process of the organic matter. On this subject, we are utilizing a biological activity parameter figured out from the specific respiration rate Rsp determination. (Author)

  9. Solid electrolyte properties of LaF3

    NARCIS (Netherlands)

    Schoonman, J.; Oversluizen, G.; Wapenaar, K.E.D.

    1980-01-01

    The small-signal ac response of cells with LaF3 or the solid solutions La1-xBaxF3-x and ionically blocking electrodes has been measured in the frequency range 0.1-3 × 104Hz, and for temperatures from 220 to 650 K. The bulk electrolyte conductivity of LaF3 crystals is anisotropic up to 415 K. For pol

  10. Solid electrolyte properties of LaF3

    NARCIS (Netherlands)

    Schoonman, J.; Oversluizen, G.; Wapenaar, K.E.D.

    The small-signal ac response of cells with LaF3 or the solid solutions La1-xBaxF3-x and ionically blocking electrodes has been measured in the frequency range 0.1-3 × 104Hz, and for temperatures from 220 to 650 K. The bulk electrolyte conductivity of LaF3 crystals is anisotropic up to 415 K. For

  11. Prediction of changes in important physical parameters during composting of separated animal slurry solid fractions

    DEFF Research Database (Denmark)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    and their interacting physical relationships in the composting matrix. Here we monitored moisture content, bulk density, particle density and air-filled porosity (AFP) during composting of SSF collected from four commercially available solid-liquid separators. Composting was performed in laboratory-scale reactors...... composts showed different dynamics as described by the first-order kinetic equation. The estimated component particle density of 1441 kg m-3 for VS and 2625 kg m-3 for fixed solids can be used to improve estimates of AFP for SSF within the range tested. The linear relationship between wet bulk density...... and AFP reported by previous researchers held true for SSF....

  12. Applied mechanics of solids

    CERN Document Server

    Bower, Allan F

    2009-01-01

    Modern computer simulations make stress analysis easy. As they continue to replace classical mathematical methods of analysis, these software programs require users to have a solid understanding of the fundamental principles on which they are based. Develop Intuitive Ability to Identify and Avoid Physically Meaningless Predictions Applied Mechanics of Solids is a powerful tool for understanding how to take advantage of these revolutionary computer advances in the field of solid mechanics. Beginning with a description of the physical and mathematical laws that govern deformation in solids, the text presents modern constitutive equations, as well as analytical and computational methods of stress analysis and fracture mechanics. It also addresses the nonlinear theory of deformable rods, membranes, plates, and shells, and solutions to important boundary and initial value problems in solid mechanics. The author uses the step-by-step manner of a blackboard lecture to explain problem solving methods, often providing...

  13. Interface Engineering of Garnet Solid Electrolytes

    Science.gov (United States)

    Cheng, Lei

    Solid lithium ion conductors represent a promising class of materials for next generation high energy density batteries, with the potential for enabling use of high capacity Li metal anodes and providing opportunities for novel lithium-free cathode materials. However, highly resistive interfaces stymie their practical use. This urgent scientific challenge requires mechanistic understanding of ion transport at interfaces, as well as development of novel processes to achieve low interfacial resistances. The goal of this PhD dissertation was to generate fundamental understandings of garnet-structured Al substituted Li7La3Zr2O 12 (LLZO) electrolyte surfaces and interfaces with lithium metal electrodes. Specifically in this research, the topmost surface microstructure, local chemical environment, and surface chemistry were carefully studied. The ceramic processing of garnet is discussed and ways to control the sintering behavior and microstructures were explored and successfully demonstrated. Factors contributing to high interfacial resistance were systematically studied. The source of the high interfacial impedance has been traced to the presence of Li2CO 3 on pellet surfaces resulting from air exposure after processing. In addition, it was discovered that surface grain boundaries are surprisingly fast ion transport pathways and surface microstructure is critically important to lithium ion transport at interfaces. Complex homo- and heterostructured LLZO solid electrolytes with controllable surface and bulk microstructures were successfully fabricated, which allowed the comparison and separation of the contribution from the surface and the bulk. Engineered pellet surfaces allowed us to achieve the lowest interfacial resistance ever reported for this composition, resulting in significantly improved cycling behavior. Lastly, it was found that LLZO surfaces can be effectively stabilized under air exposure conditions, preventing Li2CO3 formation and maintaining low

  14. Experimental evidence of beam-foil plasma creation during ion-solid interaction

    Science.gov (United States)

    Sharma, Prashant; Nandi, Tapan

    2016-08-01

    Charge state evolution of the energetic projectile ions during the passage through thin carbon foils has been revisited using the X-ray spectroscopy technique. Contributions from the bulk and the solid surface in the charge changing processes have been segregated by measuring the charge state distribution of the projectile ions in the bulk of the target during the ion-solid interaction. Interestingly, the charge state distribution measured in the bulk exhibits Lorentzian profile in contrast to the well-known Gaussian structure observed using the electromagnetic methods and the theoretical predictions. The occurrence of such behavior is a direct consequence of the imbalance between charge changing processes, which has been seen in various cases of the laboratory plasma. It suggests that the ion-solid collisions constitute high-density, localized plasma in the bulk of the solid target, called the beam-foil plasma. This condensed beam-foil plasma is similar to the high-density solar and stellar plasma which may have practical implementations in various fields, in particular, plasma physics and nuclear astrophysics. The present work suggests further modification in the theoretical charge state distribution calculations by incorporating the plasma coupling effects during the ion-solid interactions. Moreover, the multi-electron capture from the target exit surface has been confirmed through comparison between experimentally measured and theoretically predicted values of the mean charge state of the projectile ions.

  15. Developing and Characterizing Bulk Metallic Glasses for Extreme Applications

    Science.gov (United States)

    Roberts, Scott Nolan

    Metallic glasses have typically been treated as a "one size fits all" type of material. Every alloy is considered to have high strength, high hardness, large elastic limits, corrosion resistance, etc. However, similar to traditional crystalline materials, properties are strongly dependent upon the constituent elements, how it was processed, and the conditions under which it will be used. An important distinction which can be made is between metallic glasses and their composites. Charpy impact toughness measurements are performed to determine the effect processing and microstructure have on bulk metallic glass matrix composites (BMGMCs). Samples are suction cast, machined from commercial plates, and semi-solidly forged (SSF). The SSF specimens have been found to have the highest impact toughness due to the coarsening of the dendrites, which occurs during the semi-solid processing stages. Ductile to brittle transition (DTBT) temperatures are measured for a BMGMC. While at room temperature the BMGMC is highly toughened compared to a fully glassy alloy, it undergoes a DTBT by 250 K. At this point, its impact toughness mirrors that of the constituent glassy matrix. In the following chapter, BMGMCs are shown to have the capability of being capacitively welded to form single, monolithic structures. Shear measurements are performed across welded samples, and, at sufficient weld energies, are found to retain the strength of the parent alloy. Cross-sections are inspected via SEM and no visible crystallization of the matrix occurs. Next, metallic glasses and BMGMCs are formed into sheets and eggbox structures are tested in hypervelocity impacts. Metallic glasses are ideal candidates for protection against micrometeorite orbital debris due to their high hardness and relatively low density. A flat single layer, flat BMG is compared to a BMGMC eggbox and the latter creates a more diffuse projectile cloud after penetration. A three tiered eggbox structure is also tested by firing

  16. Nondestructive Method for Bulk Chemical Characterization of Barred Olivine Chondrules

    Science.gov (United States)

    Montoya-Perez, M. A.; Cervantes-de la Cruz, K. E.; Ruvalcaba-Sil, J. L.

    2017-02-01

    This work develops a bulk chemical characterization of barred olivine chondrules based on the XRF analysis using a portable equipment at the National Research and Conservation Science Laboratory of Cultural Heritage (LANCIC-IF) in Mexico City.

  17. Bulk metallic glass for low noise fluxgate Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The team of Prime Photonics, Virginia Tech, and Utron Kinetics propose to demonstrate a method for fabrication of a bulk, amorphous, cobalt-rich material that...

  18. Bulk metallic glasses: A new class of engineering materials

    Indian Academy of Sciences (India)

    Joysurya Basu; S Ranganathan

    2003-06-01

    Bulk glass-forming alloys have emerged over the past fifteen years with attractive properties and technological promise. A number of alloy systems based on lanthanum, magnesium, zirconium, palladium, iron, cobalt and nickel have been discovered. Glass-forming ability depends on various factors like enthalpy of mixing, atomic size and multicomponent alloying. A number of processes is available to synthesise bulk metallic glasses. The crystallisation behaviour and mechanical properties of these alloys pose interesting scientific questions. Upon crystallisation many of these glasses transform to bulk nanocrystals and nanoquasicrystals. A detailed study of the structure and the crystallisation behaviour of glasses has enabled the elucidation of the possible atomic configuration in liquid alloys. Their crystallisation behaviour can be exploited to synthesise novel nanocomposite microstructures and their mechanical properties can be enhanced. A broad overview of the present status of the science and technology of bulk metallic glasses and their potential technological uses is presented.

  19. Bulk Viscosity Effects in Event-by-Event Relativistic Hydrodynamics

    CERN Document Server

    Noronha-Hostler, Jacquelyn; Noronha, Jorge; Andrade, Rone P G; Grassi, Frederique

    2013-01-01

    Bulk viscosity effects on the collective flow harmonics in heavy ion collisions are investigated, on an event by event basis, using a newly developed 2+1 Lagrangian hydrodynamic code named v-USPhydro which implements the Smoothed Particle Hydrodynamics (SPH) algorithm for viscous hydrodynamics. A new formula for the bulk viscous corrections present in the distribution function at freeze-out is derived starting from the Boltzmann equation for multi-hadron species. Bulk viscosity is shown to enhance the collective flow Fourier coefficients from $v_2(p_T)$ to $v_5(p_T)$ when $% p_{T}\\sim 1-3$ GeV even when the bulk viscosity to entropy density ratio, $% \\zeta/s$, is significantly smaller than $1/(4\\pi)$.

  20. Nondestructive Method for Bulk Chemical Characterization of Barred Olivine Chondrules

    Science.gov (United States)

    Montoya-Perez, M. A.; Cervantes-de la Cruz, K. E.; Ruvalcaba-Sil, J. L.

    2017-05-01

    This work develops a bulk chemical characterization of barred olivine chondrules based on the XRF analysis using a portable equipment at the National Research and Conservation Science Laboratory of Cultural Heritage (LANCIC-IF) in Mexico City.

  1. Efficiency of bulk-heterojunction organic solar cells.

    Science.gov (United States)

    Scharber, M C; Sariciftci, N S

    2013-12-01

    During the last years the performance of bulk heterojunction solar cells has been improved significantly. For a large-scale application of this technology further improvements are required. This article reviews the basic working principles and the state of the art device design of bulk heterojunction solar cells. The importance of high power conversion efficiencies for the commercial exploitation is outlined and different efficiency models for bulk heterojunction solar cells are discussed. Assuming state of the art materials and device architectures several models predict power conversion efficiencies in the range of 10-15%. A more general approach assuming device operation close to the Shockley-Queisser-limit leads to even higher efficiencies. Bulk heterojunction devices exhibiting only radiative recombination of charge carriers could be as efficient as ideal inorganic photovoltaic devices.

  2. Role of the antiferromagnetic bulk spins in exchange bias

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Ivan K. [Center for Advanced Nanoscience and Physics Department, University of California San Diego, La Jolla, CA 92093 (United States); Morales, Rafael, E-mail: rafael.morales@ehu.es [Department of Chemical-Physics & BCMaterials, University of the Basque Country UPV/EHU (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Batlle, Xavier [Departament Física Fonamental and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, c/ Martí i Franqués s/n, 08028 Barcelona, Catalonia (Spain); Nowak, Ulrich [Department of Physics, University of Konstanz, 78464 Konstanz (Germany); Güntherodt, Gernot [Physics Institute (IIA), RWTH Aachen University, Campus RWTH-Melaten, 52074 Aachen (Germany)

    2016-10-15

    This “Critical Focused Issue” presents a brief review of experiments and models which describe the origin of exchange bias in epitaxial or textured ferromagnetic/antiferromagnetic bilayers. Evidence is presented which clearly indicates that inner, uncompensated, pinned moments in the bulk of the antiferromagnet (AFM) play a very important role in setting the magnitude of the exchange bias. A critical evaluation of the extensive literature in the field indicates that it is useful to think of this bulk, pinned uncompensated moments as a new type of a ferromagnet which has a low total moment, an ordering temperature given by the AFM Néel temperature, with parallel aligned moments randomly distributed on the regular AFM lattice. - Highlights: • We address the role of bulk antiferromagnetic spins in the exchange bias phenomenon. • Significant experiments on how bulk AFM spins determine exchange bias are highlighted. • We explain the model that accounts for experimental results.

  3. Efficiency of bulk-heterojunction organic solar cells

    Science.gov (United States)

    Scharber, M.C.; Sariciftci, N.S.

    2013-01-01

    During the last years the performance of bulk heterojunction solar cells has been improved significantly. For a large-scale application of this technology further improvements are required. This article reviews the basic working principles and the state of the art device design of bulk heterojunction solar cells. The importance of high power conversion efficiencies for the commercial exploitation is outlined and different efficiency models for bulk heterojunction solar cells are discussed. Assuming state of the art materials and device architectures several models predict power conversion efficiencies in the range of 10–15%. A more general approach assuming device operation close to the Shockley–Queisser-limit leads to even higher efficiencies. Bulk heterojunction devices exhibiting only radiative recombination of charge carriers could be as efficient as ideal inorganic photovoltaic devices. PMID:24302787

  4. 27 CFR 19.588 - Construction of bulk conveyances.

    Science.gov (United States)

    2010-04-01

    ... compartment) shall be so arranged that it can be completely drained. (3) Each tank car or tank truck shall... device, for carrying required marks or brands shall be provided on each bulk conveyance. (6)...

  5. Bulk modification of PDMS microchips by an amphiphilic copolymer.

    Science.gov (United States)

    Xiao, Yan; Yu, Xiao-Dong; Xu, Jing-Juan; Chen, Hong-Yuan

    2007-09-01

    A simple and rapid bulk-modification method based on adding an amphiphilic copolymer during the fabrication process was employed to modify PDMS microchips. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was used as the additive substance. Compared to the native PDMS microchips, both the contact angle and the EOF of the bulk-modified PDMS microchips decreased. The effects of the additive loading and the pH on the EOF were investigated in detail. The bulk-modified PDMS microchips exhibited reproducible and stable EOF behavior. The application of the bulk-modified PDMS microchips was also studied and the results indicated that they could be successfully used to separate amino acids and to suppress protein adsorption.

  6. Advanced Manufacturing Technologies (AMT): Bulk Metallic Glass Element

    Data.gov (United States)

    National Aeronautics and Space Administration — The first major objective of the ‘Bulk Metallic Glasses (BMGs) for Space Applications’ project is to raise the technology readiness level dry lubricated,...

  7. LHC signatures of vector boson emission from brane to bulk

    CERN Document Server

    Kirpichnikov, D V

    2012-01-01

    In the framework of the RSII-n model with n compact and one infinite extra dimensions, we study the production of Z-bosons and photons, which escape into the bulk, in association with a jet in pp collisions at the LHC energies. This would show up as the process pp -> jet+bulk. We calculate the distributions in the jet transverse momentum and rapidity and compare them with the Standard Model background pp->jet +\

  8. China's bulk shipping industry overview

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z. [China National Chartering Corp., Sinochart (China)

    2002-07-01

    A set of 20 slides/overheads (file LiZhen.ppt) in Chinese and English outlines the talk under the headings: recent development in marine shipping governance; trends and characteristics of international trade of China's main bulk cargo; China's bulk cargo fleet; and the development of China National Chartering Corp, SINOCHART. Four pages of text in English reports the talk.

  9. Alternative technology of nanoparticles consolidation in the bulk material

    OpenAIRE

    VOLKOV Georgiy Michailovich

    2016-01-01

    Theoretical bases and technological principles of single-stages nanoparticles conso-lidation into bulk material were offered. The theory was implemented on the model system of carbon-carbon in the process of high-temperature pyrolysis of hydrocar-bons. The bulk carbon nanomaterial with unique technical properties was produced. That made it possible to create engineering products which technical characteristics are higher than the existing level in the world. The proposed theory can be ada...

  10. Ionic Liquids in Bulk and at an Interface

    OpenAIRE

    Tariq, Mohammad; Shimizu, Karina; Lopes, Jose N. Canongia; Saramago, Benilde; Rebelo, Luis Paulo N.

    2015-01-01

    In the present chapter, we describe different types of investigation carried out by research groups based at CQE/IST/UTL and ITQB/UNL and their ramifications in terms of surface science. Most of the work is focused on the characterization of ionic liquids (ILs) (both by experimental and theoretical techniques) and on the different types of interaction that they can experience in the bulk or at an interface. Studies in the bulk include the analysis of the aggregation behavior (micelle formatio...

  11. Bulk flow of halos in $\\Lambda$CDM simulation

    CERN Document Server

    Li, Ming; Gao, Liang; Jing, Yipeng; Yang, Xiaohu; Chi, Xuebin; Feng, Longlong; Kang, Xi; Lin, Weipeng; Shang, Guihua; Wang, Long; Zhao, Donghai; Zhang, Pengjie

    2012-01-01

    Analysis of the Pangu N-body simulation validates that bulk flow of halos follows Maxwellian distribution of which variance is consistent with prediction of linear perturbation theory of structure formation. We propose that consistency between observed bulk velocity and theories shall be examined at the effective scale as radius of spherical top-hat window function yielding the same smoothed velocity variance in linear theory as the sample window does. Then we compared some recently estimated bulk flows from observational samples with prediction of the $\\Lambda$CDM model we used, some results deviate the expectation at level of $\\sim 3\\sigma$ but the tension is not as severe as previously claimed. We disclose that bulk flow is weakly correlated with dipole of internal mass distribution, alignment angle between mass dipole and bulk flow has broad distribution but is peaked at $\\sim 30-50^\\circ$, meanwhile bulk flow shows little dependence on mass of halos used for estimation. In the simulation of box size $1h^...

  12. Exploring the BTZ bulk with boundary conformal blocks

    CERN Document Server

    da Cunha, Bruno Carneiro

    2016-01-01

    We point out a simple relation between the bulk field at an arbitrary radial position and the boundary OPE, by placing some old work by Ferrara, Gatto, Grillo and Parisi in the AdS/CFT context. This gives us, in principle, a prescription for extracting the classical bulk field from the boundary conformal block, and also clarifies why the latter is computed by a geodesic Witten diagram. We apply this prescription to the BTZ black hole - viewed as a pure state created by the insertion of a heavy operator in the boundary CFT_2 - and use it to relate a classical field in the bulk to a heavy-light Virasoro conformal block in the boundary. In particular, we obtain a relation between the radial bulk position and the conformal ratios in the boundary CFT. We use this to show that the singular points of the radial bulk equation occur when the dual boundary operators approach each other and that the associated bulk monodromies map to monodromies of the (appropriately transformed) conformal block, thus providing a CFT in...

  13. Dirac Fermions without bulk backscattering in rhombohedral topological insulators

    Science.gov (United States)

    Mera Acosta, Carlos; Lima, Matheus; Seixas, Leandro; da Silva, Antônio; Fazzio, Adalberto

    2015-03-01

    The realization of a spintronic device using topological insulators is not trivial, because there are inherent difficulties in achieving the surface transport regime. The majority of 3D topological insulators materials (3DTI) despite of support helical metallic surface states on an insulating bulk, forming topological Dirac fermions protected by the time-reversal symmetry, exhibit electronic scattering channels due to the presence of residual continuous bulk states near the Dirac-point. From ab initio calculations, we studied the microscopic origin of the continuous bulk states in rhombohedral topological insulators materials with the space group D3d 5 (R 3 m) , showing that it is possible to understand the emergence of residual continuous bulk states near the Dirac-point into a six bands effective model, where the breaking of the R3 symmetry beyond the Γ point has an important role in the hybridization of the px, py and pz atomic orbitals. Within these model, the mechanisms known to eliminate the bulk scattering, for instance: the stacking faults (SF), electric field and alloy, generated the similar effect in the effective states of the 3DTI. Finally, we show how the surface electronic transport is modified by perturbations of bulk with SF. We would like to thank the financial support by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).

  14. Multifunctional solid/solid phononic crystal

    Science.gov (United States)

    Swinteck, N.; Vasseur, J. O.; Hladky-Hennion, A. C.; Croënne, C.; Bringuier, S.; Deymier, P. A.

    2012-07-01

    A two-dimensional, solid/solid phononic crystal (PC) comprised a square array of steel cylinders in epoxy is shown to perform a variety of spectral, wave vector, and phase-space functions. Over a range of operating frequencies, the PC's elastic band structure shows uniquely shaped equifrequency contours that are only accessible to excitations of longitudinal polarization. Under this condition, the PC is shown to behave as (1) an acoustic wave collimator, (2) a defect-less wave guide, (3) a directional source for elastic waves, (4) an acoustic beam splitter, (5) a phase-control device, and (6) a k-space multiplexer. Wave vector diagrams and finite-difference time-domain simulations are employed to authenticate the above mentioned capabilities.

  15. Quantum Hall effect in a bulk antiferromagnet EuMnBi2 with magnetically confined two-dimensional Dirac fermions.

    Science.gov (United States)

    Masuda, Hidetoshi; Sakai, Hideaki; Tokunaga, Masashi; Yamasaki, Yuichi; Miyake, Atsushi; Shiogai, Junichi; Nakamura, Shintaro; Awaji, Satoshi; Tsukazaki, Atsushi; Nakao, Hironori; Murakami, Youichi; Arima, Taka-hisa; Tokura, Yoshinori; Ishiwata, Shintaro

    2016-01-01

    For the innovation of spintronic technologies, Dirac materials, in which low-energy excitation is described as relativistic Dirac fermions, are one of the most promising systems because of the fascinating magnetotransport associated with extremely high mobility. To incorporate Dirac fermions into spintronic applications, their quantum transport phenomena are desired to be manipulated to a large extent by magnetic order in a solid. We report a bulk half-integer quantum Hall effect in a layered antiferromagnet EuMnBi2, in which field-controllable Eu magnetic order significantly suppresses the interlayer coupling between the Bi layers with Dirac fermions. In addition to the high mobility of more than 10,000 cm(2)/V s, Landau level splittings presumably due to the lifting of spin and valley degeneracy are noticeable even in a bulk magnet. These results will pave a route to the engineering of magnetically functionalized Dirac materials.

  16. Crystallization of Pd40CU30Ni10P20 bulk metallic glass with and without pressure

    DEFF Research Database (Denmark)

    Yang, B.; Jiang, Jianzhong; Zhuang, Yanxin;

    2007-01-01

    The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD). The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high......-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal Cu3Pd-like, rhombohedral, fcc-Ni2Pd2P, fcc-(Ni, Pd) solid solution, and body-centered tetragonal (bct) Ni3P-like phases. The onset...... crystallization temperature increases with pressure having a slope of I I K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure....

  17. A Combined FTIR and TPD Study on the Bulk and Surface Dehydroxylation and Decarbonation of Synthetic Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Boily, Jean F; Szanyi, Janos; Felmy, Andrew R

    2006-08-01

    The thermal dehydroxylation of a goethite–carbonate solid solution was studied with combined Fourier-transform infrared (FTIR) – Temperature programmed desorption (TPD) experiments. The TPD data revealed dehydroxylation peaks involving the intrinsic dehydroxylation of goethite at 560 K and a low temperature peak at 485 K which was shown to be associated to the release of non-stoichiometric water from the goethite bulk and surface. The FTIR and the TPD data of goethite in the absence of adsorbed carbonate species revealed the presence of adventitious carbonate mostly sequestered in the goethite bulk. The release of carbonate was however not only related to the dehydration of goethite but also from the crystallization of hematite at temperatures exceeding 600 K. The relative abundance of surface hydroxyls was shown to change systematically upon goethite dehydroxylation with a preferential stripping of singlycoordinated AOH sites followed by a dramatic change in the dominance of the different surface hydroxyls upon the formation of hematite.

  18. Low-Dimensional Solids

    CERN Document Server

    Bruce, Duncan W; O'Hare, Dermot

    2010-01-01

    With physical properties that often may not be described by the transposition of physical laws from 3D space across to 2D or even 1D space, low-dimensional solids exhibit a high degree of anisotropy in the spatial distribution of their chemical bonds. This means that they can demonstrate new phenomena such as charge-density waves and can display nanoparticulate (0D), fibrous (1D) and lamellar (2D) morphologies. Low-Dimensional Solids presents some of the most recent research into the synthesis and properties of these solids and covers: Metal Oxide Nanoparticles; Inorganic Nanotubes and Nanowir

  19. Applications in solid mechanics

    DEFF Research Database (Denmark)

    Ølgaard, Kristian Breum; Wells, Garth N.

    2012-01-01

    Problems in solid mechanics constitute perhaps the largest field of application of finite element methods. The vast majority of solid mechanics problems involve the standard momentum balance equation, posed in a Lagrangian setting, with different models distinguished by the choice of nonlinear...... or linearized kinematics, and the constitutive model for determining the stress. For some common models, the constitutive relationships are rather complex. This chapter addresses a number of canonical solid mechanics models in the context of automated modeling, and focuses on some pertinent issues that arise...

  20. Solid propellant motor

    Science.gov (United States)

    Shafer, J. I.; Marsh, H. E., Jr. (Inventor)

    1978-01-01

    A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

  1. The solid state maser

    CERN Document Server

    Orton, J W; Walling, J C; Ter Haar, D

    1970-01-01

    The Solid State Maser presents readings related to solid state maser amplifier from the first tentative theoretical proposals that appeared in the early 1950s to the successful realization of practical devices and their application to satellite communications and radio astronomy almost exactly 10 years later. The book discusses a historical account of the early developments (including that of the ammonia maser) of solid state maser; the properties of paramagnetic ions in crystals; the development of practical low noise amplifiers; and the characteristics of maser devices designed for communica

  2. Laser cooling of solids

    OpenAIRE

    Nemova, Galina

    2009-01-01

    Parallel to advances in laser cooling of atoms and ions in dilute gas phase, which has progressed immensely, resulting in physics Nobel prizes in 1997 and 2001, major progress has recently been made in laser cooling of solids. I compare the physical nature of the laser cooling of atoms and ions with that of the laser cooling of solids. I point out all advantages of this new and very promising area of laser physics. Laser cooling of solids (optical refrigeration) at the present time can be lar...

  3. Acoustic tests of Lorentz symmetry using Bulk Acoustic Wave quartz oscillators

    CERN Document Server

    Goryachev, M; Haslinger, Ph; Mizrachi, E; Anderegg, L; Müller, H; Hohensee, M; Tobar, M E

    2016-01-01

    A new method of probing Lorentz invariance in the neutron sector is described. The method is baed on stable quartz bulk acoustic wave oscillators compared on a rotating table. Due to Lorentz-invariance violation, the resonance frequencies of acoustic wave resonators depend on the direction in space via a corresponding dependence of masses of the constituent elements of solids. This dependence is measured via observation of oscillator phase noise built around such devices. The first such experiment now shows sensitivity to violation down to the limit $\\tilde{c}^n_Q=(-1.8\\pm2.2)\\times 10^{-14}$ GeV. Methods to improve the sensitivity are described together with some other applications of the technology in tests of fundamental physics.

  4. Reentrant spin glass ordering in an Fe-based bulk metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Qiang; Shen, Jun, E-mail: junshen@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 201804 (China)

    2015-02-07

    We report the results of the complex susceptibility, temperature, and field dependence of DC magnetization and the nonequilibrium dynamics of a bulk metallic glass Fe{sub 40}Co{sub 8}Cr{sub 15}Mo{sub 14}C{sub 15}B{sub 6}Er{sub 2}. Solid indication of the coexistence of reentrant spin glass (SG) and ferromagnetic orderings is determined from both DC magnetization and AC susceptibility under different DC fields. Dynamics scaling of AC susceptibility indicates critical slowing down to a reentrant SG state with a static transition temperature T{sub s} = ∼17.8 K and a dynamic exponent zv = ∼7.3. The SG nature is further corroborated from chaos and memory effects, magnetic hysteresis, and aging behavior. We discuss the results in terms of the competition among random magnetic anisotropy and exchange interactions and compare them with simulation predictions.

  5. Bulk and surface properties of ZnTe-ZnS system semiconductors

    Science.gov (United States)

    Kirovskaya, I. A.; Mironova, E. V.; Kosarev, B. A.; Nor, P. E.; Bukashkina, T. L.

    2016-10-01

    Physicochemical studies of a new ZnTe-ZnS semiconductor system are conducted. It is found that at certain ratios of binary components, substitutional solid solutions with a cubic sphalerite structure are formed in this system. Interrelated laws governing changes in the bulk (crystal chemical, structural) and surface (acid-base) properties with varying system composition are identified. It is assumed they can be attributed to the nature of the active (acid-base) sites. The presented data, observed patterns, and an interpretation of them are used not only to confirm earlier proposed mechanisms of atomic-molecular interaction on diamond-like semiconductors, but to search for promising materials for use in highly sensitive selective sensors for environmental and medical purposes as well.

  6. Advanced finite element analysis of die wear in sheet-bulk metal forming processes

    Science.gov (United States)

    Behrens, Bernd-Arno; Bouguecha, Anas; Vucetic, Milan; Chugreev, Alexander; Rosenbusch, Daniel

    2016-10-01

    The novel sheet-bulk metal forming (SBMF) technology allows the production of solid metal components with various functional design features out of flat sheet specimens. However, due to the high working pressures arising during the forming process the efficiency of SBMF is tightly related to the tool service life, which is mainly limited by die wear. In the forming processes involving high contact pressures (e.g. SBMF) the influence of contact normal stresses on the die wear can be overestimated. In order to provide a realistic estimation of the die wear, the shear friction stress must be considered. The presented paper introduces a die wear model that intends the tangential component of contact stress and its implementation in the commercial FE code.

  7. Magnetism in Mn and Co doped ZnO bulk samples

    Institute of Scientific and Technical Information of China (English)

    WANG YongQiang; YUAN SongLiu; SONG YunXing; LIU Li; TIAN ZhaoMing; LI Pai; ZHOU YuanMing; LI YunLong; YIN ShiYan

    2007-01-01

    Bulk samples with nominal composition Zn0.95Co0.05O and Zn0.92Co0.05Mn0.03O were fabricated by a solid-state reaction method at 600℃. X-ray diffraction experiment showed that the peaks of secondary phase Co3O4 with a cubic structure were visible in both samples, besides the main peaks of wurtzite structure as ZnO. Magnetization measurement indicated that doping Co alone can induce ferromagnetism in ZnO itself, while the introduction of Mn significantly enhances ferromagnetism. However,both samples showed different magnetic behavior at temperatures below 50 K. It was also noted that ferromagnetic coupling interaction was weakened due to the presence of antiferromagnetic Co3O4.

  8. Large difference between the magnetic properties of Ba and Ti co-doped BiFeO3 bulk materials and their corresponding nanoparticles prepared by ultrasonication

    Science.gov (United States)

    Ahmmad, Bashir; Kanomata, Kensaku; Koike, Kunihiro; Kubota, Shigeru; Kato, Hiroaki; Hirose, Fumihiko; Billah, Areef; Jalil, M. A.; Basith, M. A.

    2016-07-01

    The ceramic pellets of the nominal compositions Bi0.7Ba0.3Fe1-x Ti x O3 (x  =  0.00-0.20) were prepared initially by standard solid state reaction technique. The pellets were then ground into micrometer-sized powders and mixed with isopropanol in an ultrasonic bath to prepare nanoparticles. The x-ray diffraction patterns demonstrate the presence of a significant number of impurity phases in bulk powder materials. Interestingly, these secondary phases were completely removed due to the sonication of these bulk powder materials for 60 minutes. The field and temperature dependent magnetization measurements exhibited significant difference between the magnetic properties of the bulk materials and their corresponding nanoparticles. We anticipate that the large difference in the magnetic behavior may be associated with the presence and absence of secondary impurity phases in the bulk materials and their corresponding nanoparticles, respectively. The leakage current density of the bulk materials was also found to suppress in the ultrasonically prepared nanoparticles compared to that of bulk counterparts.

  9. Superconducting Properties and Microstructure in MgB2 Bulks, Wires and Tapes

    Institute of Scientific and Technical Information of China (English)

    冯勇; 阎果; 赵勇; 吴晓京; 周廉; 张平祥

    2003-01-01

    We prepared a series of MgB2 bulk samples under different temperatures, holding time and increasing rates in temperature by the solid state reaction. The thermodynamic behavior and phase formation in the Mg-B system were studied by using DTA,XRD and SEM. The results indicate that the formation of the MgB2 phase is very fast and the high increasing rate in temperature is necessary to obtain high quality MgB2. In addition, the effects of the Zr-doping in Mg1-xZrxB2 bulk samples fabricated by the solid state reaction at ambient pressure on phase compositions, microstructure and flux pinning behavior were investigated by using XRD, SQUID magnetometer, SEM and TEM. Critical current density Jc can be significantly enhanced by the Zr-doping and the best data are achieved in Mg0.9Zr0.1B2. For this sample, Jc values are remarkably improved to 1.83×106 A/cm2 in self-field and 5.51×105 A/cm2 in 1 T at 20 K. Also, high quality MgB2/Ta/Cu wires and tapes with and without Ti-doping, MgB2/Fe wires and 18 filament MgB2/NbZr/Cu tapes were fabricated by the powder-in-tube (PIT) method at ambient pressure. The phase compositions, microstructure features and flux pinning properties were studied. The results suggest that Fe is thebest metal for these sheaths. MgB2/Fe wires exhibit very high Jc at high temperatures and high fields. Jc values reach as high as 1.43×105 A/cm2 (4.2 K, 4 T) and 3.72×104 A/cm2 (15 K, 4 T).

  10. Weak ferromagnetic component on the bulk ZnFe{sub 2}O{sub 4} compound

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, C.B.R. [Departamento de Física, Campus prof. Aluísio de Campos, UFS, 49100-000 São Cristóvão, SE (Brazil); Mendonça, E.C. [Departamento de Física, Campus prof. Alberto Carvalho, UFS, 49500-000 Itabaiana, SE (Brazil); Silva, L.S. [Departamento de Física, Campus prof. Aluísio de Campos, UFS, 49100-000 São Cristóvão, SE (Brazil); Folly, W.S.D.; Meneses, C.T. [Departamento de Física, Campus prof. Alberto Carvalho, UFS, 49500-000 Itabaiana, SE (Brazil); Duque, J.G.S., E-mail: gerivaldoduque@gmail.com [Departamento de Física, Campus prof. Alberto Carvalho, UFS, 49500-000 Itabaiana, SE (Brazil)

    2014-01-15

    Magnetization data on the bulk ZnFe{sub 2}O{sub 4} antiferromagnetic compound (T{sub N}≈10 K) obtained via solid state reaction at different synthesis temperatures show one weak ferromagnetic component at room temperature. We have related it with the cationic disorder effect present on spinel structure of our bulk samples which comes from the magnetic interaction between iron ions sit on both octahedral and tetrahedral sites. The magnetization measurements show to all samples a clear peak around 10 K consistent with the antiferromagnetic phase transition. On the other hand, after extracted the paramagnetic component, the hysteresis loops measured at room temperature display one weak ferromagnetic component. Once the T-dependence of magnetization does not fit to a Curie–Weiss law to temperatures well above the magnetic transition we have used a combination of the Curie–Weiss law (paramagnetic spins) and a typical temperature dependence of M{sub 0}, M{sub 0}(T)=M{sub 0}(0)[1−(T/T{sub C}){sup 2}]{sup 0.5} (ordered ferromagnetic spins). We note an increase of the M{sub 0}(0) as function of the synthesis temperature. This reinforce our supposition of a cationic disorder effect driving the system to present two kinds of magnetic interactions between iron ions on A and B sites. - Highlights: • Study of the cationic disorder at bulk ZnFe{sub 2}O{sub 4} compound. • Structural and magnetization characterization. • The observation of two magnetic phases.

  11. Photocatalysis with chromium-doped TiO2: Bulk and surface doping

    KAUST Repository

    Ould-Chikh, Samy

    2014-04-15

    The photocatalytic properties of TiO2 modified by chromium are usually found to depend strongly on the preparation method. To clarify this problem, two series of chromium-doped titania with a chromium content of up to 1.56 wt % have been prepared under hydrothermal conditions: the first series (Cr:TiO2) is intended to dope the bulk of TiO2, whereas the second series (Cr/TiO2) is intended to load the surface of TiO2 with Cr. The catalytic properties have been compared in the photocatalytic oxidation of formic acid. Characterization data provides evidence that in the Cr/TiO2 catalysts chromium is located on the surface of TiO2 as amorphous CrOOH clusters. In contrast, in the Cr:TiO 2 series, chromium is mostly dissolved in the titania lattice, although a minor part is still present on the surface. Photocatalytic tests show that both series of chromium-doped titania demonstrate visible-light-driven photo-oxidation activity. Surface-doped Cr/TiO2 solids appear to be more efficient photocatalysts than the bulk-doped Cr:TiO2 counterparts. It\\'s classified! The photocatalytic properties of TiO2 modified by chromium depend strongly on the preparation method. To clarify this problem, two types of modified titania are discussed: one with CrIII doped in the bulk and one with CrOOH clusters on the TiO2 surface (see picture). Both series show visible-light-driven photo-oxidation activity. However, surface modification appears to be a more efficient strategy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Optimizing vermistabilization of waste activated sludge using vermicompost as bulking material.

    Science.gov (United States)

    Hait, Subrata; Tare, Vinod

    2011-03-01

    An integrated composting-vermicomposting system has been developed for stabilization of waste activated sludge (WAS) using matured vermicompost as bulking material and Eisenia fetida as earthworm species. Composting was considered as the main processing unit and vermicomposting as polishing unit. The integrated system was optimized by successive recycling and mixing of bulking material with WAS during composting and examining the effects of environmental condition (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) on vermicomposting. The composting stage resulted in sufficient enrichment of bulking material with organic matter after 20 cycles of recycling and mixing with WAS and produced materials acceptable for vermicomposting. Vermicomposting of composted material caused significant reduction in pH, volatile solids (VS), specific oxygen uptake rate (SOUR), total carbon (TC), total organic carbon (TOC), C/N ratio and pathogens and a substantial increase in electrical conductivity (EC), total nitrogen (TN) and total phosphorous (TP). The environmental conditions (i.e. temperature: 10-30°C and relative humidity: 50 and 90%) and stocking density (0-5 kg/m(2)) have profound effects on vermicomposting. Temperature of 20°C with high humidity is the best suited environmental condition for vermicomposting employing E. fetida. The favorable stocking density range for vermiculture is 0.5-2.0 kg/m(2) (optimum: 0.5 kg/m(2)) and for vermicomposting is 2.0-4.0 kg/m(2) (optimum: 3.0 kg/m(2)), respectively. The integrated composting-vermicomposting system potentially stabilizes and converts the hazardous WAS into quality organic manure for agronomic applications without any adverse effects.

  13. Preparation and investigation of bulk and thin film samples of strontium ferrite

    Directory of Open Access Journals (Sweden)

    A Poorbafrani

    2008-07-01

    Full Text Available   In this article, bulk and thin film samples of strontium ferrite have been studied. Due to the high electrical resistivity in strontium ferrite, energy loss due to eddy currents reduces and because of this, it can be used in high frequency magnetic circuits. On the other hand, strontium ferrite has attracted much attention as a permanent magnet. At first, we study the preparation process of bulk samples of strontium ferrite by a solid state reaction technique. In preparation of samples, to optimize the magnetic properties, we have used the stoichiometry factor (n = Fe2O3 / SrO of 5.25. In addition, we have used additives such as CaO and SiO2 to control grain growth. The samples have been prepared in two series: Isotropic and Anisotropic. For preparation of anisotropic samples, the magnetic field of 1T has been used for orientation of the grains during the press. Then, X-ray diffraction, Scanning Electron Microscopy (SEM, EDAX analysis and Magnetometer, was used for analyzing and comparing of structural and magnetic properties of isotropic and anisotropic samples. The results indicate that, due to the applied magnetic field, the structural and Magnetic properties of anisotropic samples improved efficiently because of the orientation of the grains during the press. In the next stage, we used bulk samples to prepare strontium ferrite thin films by Pulsed Laser Deposition technique (PLD. The Si (111 substrate has been used to prepare the thin films. Then we have studied the microstructure of thin films by X-ray diffraction, SEM and EDAX analysis. These studies on different samples show that for the preparation of crystalline phase of strontium ferrite thin films, the substrate temperature must be higher than 800˚C. The optimum conditions for preparation of strontium, ferrite thin films have been achieved on the substrate temperature of 840˚C and oxygen pressure of 75 mtorr.

  14. High critical current densities in bulk MgB{sub 2} fabricated using amorphous boron

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, Miryala; Kenta, Nozaki; Murakami, Masato [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, Tokyo 135-8548 (Japan); Koblischka, Michael R. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, 66041 Saarbruecken (Germany)

    2015-10-15

    We prepared bulk MgB{sub 2} from high-purity commercial powders of Mg metal (99.9% purity) and amorphous B (99% purity) powders using a single-step solid state reaction at 775 C for varying sintering duration from 1 to 10 h in pure argon atmosphere. X-ray diffraction analysis showed that all the samples were single phase MgB{sub 2}. The magnetization measurements confirmed a sharp superconducting transition with T{sub c,onset} at around 38.2-38.8 K. The critical current density (J{sub c}) values for the MgB{sub 2} samples produced at 1 h sintering time is the highest one in all processed materials here. Scanning electron microscopy analyses indicated that the sintering time has a crucial influence on the grain size. As a result, the highest J{sub c} value of 270 kA cm{sup -2} at 20 K and self-field was achieved in the sample produced at 775 C for 1 h. Our results clearly demonstrate that the optimization of the sintering conditions is essential to improve the bulk MgB{sub 2} performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Giant Rashba-type spin splitting in bulk BiTeI.

    Science.gov (United States)

    Ishizaka, K; Bahramy, M S; Murakawa, H; Sakano, M; Shimojima, T; Sonobe, T; Koizumi, K; Shin, S; Miyahara, H; Kimura, A; Miyamoto, K; Okuda, T; Namatame, H; Taniguchi, M; Arita, R; Nagaosa, N; Kobayashi, K; Murakami, Y; Kumai, R; Kaneko, Y; Onose, Y; Tokura, Y

    2011-06-19

    There has been increasing interest in phenomena emerging from relativistic electrons in a solid, which have a potential impact on spintronics and magnetoelectrics. One example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of spin-orbit interaction under broken inversion symmetry. A high-energy-scale Rashba spin splitting is highly desirable for enhancing the coupling between electron spins and electricity relevant for spintronic functions. Here we describe the finding of a huge spin-orbit interaction effect in a polar semiconductor composed of heavy elements, BiTeI, where the bulk carriers are ruled by large Rashba-like spin splitting. The band splitting and its spin polarization obtained by spin- and angle-resolved photoemission spectroscopy are well in accord with relativistic first-principles calculations, confirming that the spin splitting is indeed derived from bulk atomic configurations. Together with the feasibility of carrier-doping control, the giant-Rashba semiconductor BiTeI possesses excellent potential for application to various spin-dependent electronic functions.

  16. Molecular dynamics simulations of zinc oxide solubility: From bulk down to nanoparticles.

    Science.gov (United States)

    Escorihuela, Laura; Fernández, Alberto; Rallo, Robert; Martorell, Benjamí

    2017-07-20

    The solubility of metal oxides is one of the key descriptors for the evaluation of their potential toxic effects, both in the bulk form and in nanoparticulated aggregates. Current work presents a new methodology for the in silico assessment of the solubility of metal oxides, which is demonstrated using a well-studied system, ZnO. The calculation of the solubility is based on statistical thermodynamics tools combined with Density Functional Tight Binding theory for the evaluation of the free energy exchange during the dissolution process. Models of small ZnO clusters are used for describing the final dissolved material, since the complete ionic dissolution of ZnO is hindered by the formation of O(2-) anions in solution, which are highly unstable. Results show very good agreement between the computed solubility values and experimental data for ZnO bulk, up to 0.5 mg L(-1) and equivalents of 50 μg L(-1) for the free Zn(2+) cation in solution. However, the reference model for solid nanoparticles formed by free space nanoparticles can only give a limited quantitative solubility evaluation for ZnO nanoparticles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Bulk and surface properties of magnesium peroxide MgO2

    Science.gov (United States)

    Esch, Tobit R.; Bredow, Thomas

    2016-12-01

    Magnesium peroxide has been identified in Mg/air batteries as an intermediate in the oxygen reduction reaction (ORR) [1]. It is assumed that MgO2 is involved in the solid-electrolyte interphase on the cathode surface. Therefore its structure and stability play a crucial role in the performance of Mg/air batteries. In this work we present a theoretical study of the bulk and low-index surface properties of MgO2. All methods give a good account of the experimental lattice parameters for MgO2 and MgO bulk. The reaction energies, enthalpies and free energies for MgO2 formation from MgO are compared among the different DFT methods and with the local MP2 method. A pronounced dependence from the applied functional is found. At variance with a previous theoretical study but in agreement with recent experiments we find that the MgO2 formation reaction is endothermic (HSE06-D3BJ: ΔH = 51.9 kJ/mol). The stability of low-index surfaces MgO2 (001) (Es = 0.96 J/m2) and (011) (Es = 1.98 J/m2) is calculated and compared to the surface energy of MgO (001). The formation energy of neutral oxygen vacancies in the topmost layer of the MgO2 (001) surface is calculated and compared with defect formation energies for MgO (001).

  18. On the adsorption properties of magnetic fluids: Impact of bulk structure

    Science.gov (United States)

    Kubovcikova, Martina; Gapon, Igor V.; Zavisova, Vlasta; Koneracka, Martina; Petrenko, Viktor I.; Soltwedel, Olaf; Almasy, László; Avdeev, Mikhail V.; Kopcansky, Peter

    2017-04-01

    Adsorption of nanoparticles from magnetic fluids (MFs) on solid surface (crystalline silicon) was studied by neutron reflectometry (NR) and related to the bulk structural organization of MFs concluded from small-angle neutron scattering (SANS). The initial aqueous MF with nanomagnetite (co-precipitation reaction) stabilized by sodium oleate and MF modified by a biocompatible polymer, poly(ethylene glycol) (PEG), were considered. Regarding the bulk structure it was confirmed in the SANS experiment that comparatively small and compact (size 30 nm) aggregates of nanoparticle in the initial sample transfer to large and developed (size>130 nm, fractal dimension 2.7) associates in the PEG modified MF. This reorganization in the aggregates correlates with the changes in the neutron reflectivity that showed that a single adsorption layer of individual nanoparticles on the oxidized silicon surface for the initial MF disappears after the PEG modification. It is concluded that all particles in the modified fluid are in the aggregates that are not adsorbed by silicon.

  19. Photocatalysis with chromium-doped TiO2: bulk and surface doping.

    Science.gov (United States)

    Ould-Chikh, Samy; Proux, Olivier; Afanasiev, Pavel; Khrouz, Lhoussain; Hedhili, Mohamed N; Anjum, Dalaver H; Harb, Moussab; Geantet, Christophe; Basset, Jean-Marie; Puzenat, Eric

    2014-05-01

    The photocatalytic properties of TiO2 modified by chromium are usually found to depend strongly on the preparation method. To clarify this problem, two series of chromium-doped titania with a chromium content of up to 1.56 wt % have been prepared under hydrothermal conditions: the first series (Cr:TiO2) is intended to dope the bulk of TiO2, whereas the second series (Cr/TiO2) is intended to load the surface of TiO2 with Cr. The catalytic properties have been compared in the photocatalytic oxidation of formic acid. Characterization data provides evidence that in the Cr/TiO2 catalysts chromium is located on the surface of TiO2 as amorphous CrOOH clusters. In contrast, in the Cr:TiO2 series, chromium is mostly dissolved in the titania lattice, although a minor part is still present on the surface. Photocatalytic tests show that both series of chromium-doped titania demonstrate visible-light-driven photo-oxidation activity. Surface-doped Cr/TiO2 solids appear to be more efficient photocatalysts than the bulk-doped Cr:TiO2 counterparts.

  20. Solids Accumulation Scouting Studies

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  1. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  2. Solid Waste Management Districts

    Data.gov (United States)

    Vermont Center for Geographic Information — The Solid waste management districts layer is part of a dataset that contains administrative boundaries for Vermont's Agency of Natural Resources. This dataset...

  3. Solid model design simplification

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.L.; Rivera, J.J.; Webb, A.J.; Hensinger, D.M.

    1997-12-01

    This paper documents an investigation of approaches to improving the quality of Pro/Engineer-created solid model data for use by downstream applications. The investigation identified a number of sources of problems caused by deficiencies in Pro/Engineer`s geometric engine, and developed prototype software capable of detecting many of these problems and guiding users towards simplified, useable models. The prototype software was tested using Sandia production solid models, and provided significant leverage in attacking the simplification problem.

  4. Organic Molecular Solids

    CERN Document Server

    Schwoerer, Marcus

    2007-01-01

    This is the first comprehensive textbook on the physical aspects of organic solids. All phenomena which are necessary in order to understand modern technical applications are being dealt with in a way which makes the concepts of the topics accessible for students. The chapters - from the basics, production and characterization of organic solids and layers to organic semiconductors, superconductors and opto-electronical applications - have been arranged in a logical and well thought-out order.

  5. Solid State Research

    Science.gov (United States)

    1993-01-31

    intermediate-field Meissner region, and high-field Bean model . The solid line is a fit of RsM = a + b(f,T)Hrf 2 to the results in the Meissner region...model the results: low-field weak links, intermediate-field Meissner region, and high-field Bean model The solid line is a fit of R1 M-- a + b (f T) Hff

  6. Aluminium geochemistry in the bulk and rhizospheric soil of the species colonising an abandoned copper mine in Galicia (NW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Esperanza; Fernandez-Sanjurjo, Maria; Otero, Xose Luis [Univ. de Santiago de Compostela, Lugo (Spain). Escuela Politecnica Superior; Macias, Felipe [Univ. de Santiago de Compostela (Spain). Facultad de Biologia

    2010-10-15

    Aluminium partitioning in the solid fraction and aluminium in solution in the bulk and rhizospheric soil of different plant species colonising an abandoned Cu mine slope (Calluna vulgaris, Erica cinerea and Salix atrocinerea) and mine dump (C. vulgaris and E. cinerea) were investigated. The aim of the study was to determine the changes that the species induce in the Al forms in the rhizosphere in order to adapt to heterogeneous substrates. Materials and methods: Al was extracted from the solid phase with different solutions: ammonium oxalate (Alo), sodium pyrophosphate (Alp), copper chloride (Alcu), lanthanum chloride (Alla) and ammonium chloride (AlNH{sub 4}). The following Al fractions were obtained: inorganic non-crystalline Al (Alop = Alo-Alp), highly stable organoaluminium complexes (Alpcu = Alp-Alcu), organoaluminium complexes of intermediate stability (Alcula = Alcu-Alla) and labile organoaluminium complexes (Alla). The concentration of Al present in the aqueous phase was also determined. Results and discussion: The pH of the soil in the mine slope was close to 7, and the roots of Ericaceae caused strong acidification so that the pH of the rhizospheric soil was low (3.6-4.7). In contrast, the pH of the bulk and the rhizospheric soil of S. atrocinerea remained close to 7. In the mine dump (pH 3.7), the changes in the pH of the Ericaceae rhizosphere in relation to the bulk soil were not as marked as in the mine slope. Alop predominated in the solid phase (more than 70% of the Alo), and Alpcu predominated in the organoaluminium complexes (more than 55%), followed by Alcula (13% and 47%) and Alla (3% and 21%). The concentration of Al in solution was significantly related to the concentrations of AlNH4 (r = 0.43), Alla (r = 0.50) and Alcula (r = 0.45). Conclusions: Ericaceae species grew in dump and slope materials because they modified the pH of the rhizospheric soil, while S. atrocinerea only grew in areas where the soil conditions were close to neutral. The

  7. Lyophilization -Solid Waste Treatment

    Science.gov (United States)

    Litwiller, Eric; Flynn, Michael; Fisher, John; Reinhard, Martin

    2004-01-01

    This paper discusses the development of a solid waste treatment system that has been designed for a Mars transit exploration mission. The technology described is an energy-efficient lyophilization technique that is designed to recover water from spacecraft solid wastes. Candidate wastes include feces, concentrated brines from water processors, and other solid wastes that contain free water. The system is designed to operate as a stand-alone process or to be integrated into the International Space Station Waste Collection System. In the lyophilization process, water in an aqueous waste is frozen and then sublimed, separating the waste into a dried solid material and liquid water. The sublimed water is then condensed in a solid ice phase and then melted to generate a liquid product. In the subject system the waste solids are contained within a 0.2 micron bio-guard bag and after drying are removed from the system and stored in a secondary container. This technology is ideally suited to applications such as the Mars Reference Mission, where water recovery rates approaching 100% are desirable but production of CO2 is not. The system is designed to minimize power consumption through the use of thermoelectric heat pumps. The results of preliminary testing of a prototype system and testing of the final configuration are provided. A mathematical model of the system is also described.

  8. Solid Mathematical Marbling.

    Science.gov (United States)

    Lu, Shufang; Jin, Xiaogang; Jaffer, Aubrey; Gao, Fei; Mao, Xiaoyang

    2016-05-25

    Years of research have been devoted to computer-generated two-dimensional marbling. However, three-dimensional marbling has yet to be explored. In this paper, we present mathematical marbling of three-dimensional solids which supports a compact random-access vector representation. Our solid marbling textures are created by composing closed-form 3D pattern tool functions. These tool functions are an injection function and five deformation functions. The injection function is used to generate basic patterns, and the deformation functions are responsible for transforming the basic pattern into complex marbling effects. The resulting representation is feature preserving and resolution-independent. Our approach can render high-quality images preserving both the sharp features and the smooth color variations of a solid texture. When implemented on the GPU, our representation enables efficient color evaluation during the real-time solid marbling texture mapping. The color of a point in the volume space is computed by the 3D pattern tool functions from its coordinates. Our method consumes very little memory because only the mathematical functions and their corresponding parameters are stored. In addition, we develop an intuitive user interface and a genetic algorithm to facilitate the solid marbling texture authoring process. We demonstrate the effectiveness of our approach through various solid marbling textures and 3D objects carved from them.

  9. Evaluation and remediation of bulk soap dispensers for biofilm.

    Science.gov (United States)

    Lorenz, Lindsey A; Ramsay, Bradley D; Goeres, Darla M; Fields, Matthew W; Zapka, Carrie A; Macinga, David R

    2012-01-01

    Recent studies evaluating bulk soap in public restroom soap dispensers have demonstrated up to 25% of open refillable bulk-soap dispensers were contaminated with ~ 6 log(10)(CFU ml(-1)) heterotrophic bacteria. In this study, plastic counter-mounted, plastic wall-mounted and stainless steel wall-mounted dispensers were analyzed for suspended and biofilm bacteria using total cell and viable plate counts. Independent of dispenser type or construction material, the bulk soap was contaminated with 4-7 log(10)(CFU ml(-1)) bacteria, while 4-6 log(10)(CFU cm(-2)) biofilm bacteria were isolated from the inside surfaces of the dispensers (n = 6). Dispenser remediation studies, including a 10 min soak with 5000 mg l(-1) sodium hypochlorite, were then conducted to determine the efficacy of cleaning and disinfectant procedures against established biofilms. The testing showed that contamination of the bulk soap returned to pre-test levels within 7-14 days. These results demonstrate biofilm is present in contaminated bulk-soap dispensers and remediation studies to clean and sanitize the dispensers are temporary.

  10. Bulk viscosity, interaction and the viability of phantom solutions

    Energy Technology Data Exchange (ETDEWEB)

    Leyva, Yoelsy; Sepulveda, Mirko [Universidad de Tarapaca, Departamento de Fisica, Facultad de Ciencias, Arica (Chile)

    2017-06-15

    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) Universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with w < -1. From the different cases that we study, the only possible scenario, with bulk viscosity and interaction term, belongs to the quintessence region. In the latter case, we find bounds on the interaction parameter compatible with latest observational data. (orig.)

  11. Running with rugby balls: bulk renormalization of codimension-2 branes

    Science.gov (United States)

    Williams, M.; Burgess, C. P.; van Nierop, L.; Salvio, A.

    2013-01-01

    We compute how one-loop bulk effects renormalize both bulk and brane effective interactions for geometries sourced by codimension-two branes. We do so by explicitly integrating out spin-zero, -half and -one particles in 6-dimensional Einstein-Maxwell-Scalar theories compactified to 4 dimensions on a flux-stabilized 2D geometry. (Our methods apply equally well for D dimensions compactified to D - 2 dimensions, although our explicit formulae do not capture all divergences when D > 6.) The renormalization of bulk interactions are independent of the boundary conditions assumed at the brane locations, and reproduce standard heat-kernel calculations. Boundary conditions at any particular brane do affect how bulk loops renormalize this brane's effective action, but not the renormalization of other distant branes. Although we explicitly compute our loops using a rugby ball geometry, because we follow only UV effects our results apply more generally to any geometry containing codimension-two sources with conical singularities. Our results have a variety of uses, including calculating the UV sensitivity of one-loop vacuum energy seen by observers localized on the brane. We show how these one-loop effects combine in a surprising way with bulk back-reaction to give the complete low-energy effective cosmological constant, and comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

  12. Universal properties of bulk viscosity near the QCD phase transition

    CERN Document Server

    Karsch, F; Tuchin, K

    2008-01-01

    We extract the bulk viscosity of hot quark-gluon matter in the presence of light quarks from the recent lattice data on the QCD equation of state. For that purpose we extend the sum rule analysis by including the contribution of light quarks. We also discuss the universal properties of bulk viscosity in the vicinity of a second order phase transition, as it might occur in the chiral limit of QCD at fixed strange quark mass and most likely does occur in two-flavor QCD. We point out that a chiral transition in the O(4) universality class at zero baryon density as well as the transition at the chiral critical point which belongs to the Z(2) universality class both lead to the critical behavior of bulk viscosity. In particular, the latter universality class implies the divergence of the bulk viscosity, which may be used as a signature of the critical point. We discuss the physical picture behind the dramatic increase of bulk viscosity seen in our analysis, and devise possible experimental tests of related phenome...

  13. Depth of cure of bulk-fill flowable composite resins.

    Science.gov (United States)

    Pedalino, Inaam; Hartup, Grant R; Vandewalle, Kraig S

    2015-01-01

    In recent years, manufacturers have introduced flowable composite resins that reportedly can be placed in increments of 4 mm or greater. The purpose of this study was to evaluate the depth of cure of bulk-fill flowable composite resins (SureFil SDR Flow, Grandio Flow, and Venus Bulk Fill) and a conventional flowable composite resin (Revolution Formula 2). Depth of cure was measured in terms of bottom-maximum Knoop hardness number (KHN) ratios and the International Organization for Standardization (ISO) 4049 scrape technique. Shades A2 and A3 of SureFil SDR Flow, Grandio Flow, and Revolution Formula 2 were tested. Venus Bulk Fill was tested in its only available shade (universal). Specimens in thicknesses of 2, 3, 4, 5, and 6 mm were polymerized for 20 or 40 seconds, and a hardness tester was used to determine the hardness ratios for each shade at each thickness. For the scraping technique, after specimens were exposed to the curing light, unpolymerized composite resin was removed with a plastic instrument, the polymerized composite was measured, and the length was divided by 2 per ISO guidelines. According to the KHN ratios and the scrape test, Venus Bulk Fill predictably exceeded the manufacturer's claim of a 4-mm depth of cure at both 20 and 40 seconds of curing time. The overall results for depth of cure showed that Venus Bulk Fill ≥ SureFil SDR Flow ≥ Grandio Flow ≥ Revolution Formula 2.

  14. Color of bulk-fill composite resin restorative materials.

    Science.gov (United States)

    Barutcigil, Çağatay; Barutcigil, Kubilay; Özarslan, Mehmet Mustafa; Dündar, Ayşe; Yilmaz, Burak

    2017-09-28

    To evaluate the color stability of novel bulk-fill composite resins. Color measurements of a nanohybrid composite resin (Z550) and 3 bulk-fill composite resins (BLK, AFX, XTF; n = 45) were performed before polymerization. After polymerization, color measurements were repeated and specimens were immersed in distilled water or red wine, or coffee. Color change [CIEDE2000 (ΔE00 )] was calculated after 24 h, 1 and 3 weeks. Data were analyzed with Kruskal-Wallis, Mann-Whitney U and Wilcoxon tests (α = 0.05). Color changes observed after polymerization were significant for all groups. Color changes observed in distilled water for Z550 and AFX were significant. Color changes after stored in red wine and coffee were significant for all groups. Bulk-fill composite resin color change increased over time for all groups in red wine and coffee (P composite resin and bulk-fill composite resins. AFX had the highest color change in distilled water. The color of tested bulk-fill composite resins significantly changed after immersion in beverages and over time. Color change observed with the nanohybrid composite resin after 1 week was stable. Clinicians should keep in mind that tested composite resins may change color when exposed to water and significantly change color immediately after they are polymerized. In addition, the color change continues over time should the patient is a coffee and/or red wine consumer. © 2017 Wiley Periodicals, Inc.

  15. Developments in the processing of bulk (RE)BCO superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Babu, N. Hari, E-mail: mtsthbn@brunel.ac.u [Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University, West London UB8 3PH (United Kingdom); Shi, Y.-H.; Pathak, S.K.; Dennis, A.R.; Cardwell, D.A. [Bulk Superconductivity Group, Engineering Department, University of Cambridge, Cambridge CB2 1PZ (United Kingdom)

    2011-03-15

    Research highlights: {yields} (RE)-Ba-Cu-O bulk superconductors containing nano-scale inclusions are fabricated. {yields} Generic seed crystal development enabled batch process for Gd-Ba-Cu-O. {yields} Multi-grains with strongly coupled grain boundaries are fabricated. {yields} We propose recycling concept for bulk superconductors. - Abstract: The development of a practical processing method for the fabrication of high performance large, single grain bulk superconductors is essential for their cost-effective application in a variety of high field engineering devices. We discuss recent developments in the processing of these materials that enable high performance bulk superconductors to be fabricated in a practical way. These include the introduction of nano-scale second phase inclusions to the superconducting phase matrix, the development of a generic seed crystal, the development of practical, batch processing routes for the fabrication of light rare earth superconductors, the processing of complex shaped geometries via controlled multi-seeding and recycling of scrap bulk samples into high performance, single grains.

  16. Large-scale HTS bulks for magnetic application

    Science.gov (United States)

    Werfel, Frank N.; Floegel-Delor, Uta; Riedel, Thomas; Goebel, Bernd; Rothfeld, Rolf; Schirrmeister, Peter; Wippich, Dieter

    2013-01-01

    ATZ Company has constructed about 130 HTS magnet systems using high-Tc bulk magnets. A key feature in scaling-up is the fabrication of YBCO melts textured multi-seeded large bulks with three to eight seeds. Except of levitation, magnetization, trapped field and hysteresis, we review system engineering parameters of HTS magnetic linear and rotational bearings like compactness, cryogenics, power density, efficiency and robust construction. We examine mobile compact YBCO bulk magnet platforms cooled with LN2 and Stirling cryo-cooler for demonstrator use. Compact cryostats for Maglev train operation contain 24 pieces of 3-seed bulks and can levitate 2500-3000 N at 10 mm above a permanent magnet (PM) track. The effective magnetic distance of the thermally insulated bulks is 2 mm only; the stored 2.5 l LN2 allows more than 24 h operation without refilling. 34 HTS Maglev vacuum cryostats are manufactured tested and operate in Germany, China and Brazil. The magnetic levitation load to weight ratio is more than 15, and by group assembling the HTS cryostats under vehicles up to 5 t total loads levitated above a magnetic track is achieved.

  17. Critical soil bulk density for soybean growth in Oxisols

    Science.gov (United States)

    Keisuke Sato, Michel; Veras de Lima, Herdjania; Oliveira, Pedro Daniel de; Rodrigues, Sueli

    2015-10-01

    The aim of this study was to evaluate the critical soil bulk density from the soil penetration resistance measurements for soybean root growth in Brazilian Amazon Oxisols. The experiment was carried out in a greenhouse using disturbed soil samples collected from the northwest of Para characterized by different texture. The treatments consisted of a range of soil bulk densities for each soil textural class. Three pots were used for soybean growth of and two for the soil penetration resistance curve. From the fitted model, the critical soil bulk density was determined considering the penetration resistance values of 2 and 3 MPa. After sixty days, plants were cut and root length, dry mass of root, and dry mass of shoots were determined. At higher bulk densities, the increase in soil water content decreased the penetration resistance, allowing unrestricted growth of soybean roots. Regardless of soil texture, the penetration resistance of 2 and 3 MPa had a slight effect on root growth in soil moisture at field capacity and a reduction of 50% in the soybean root growth was achieved at critical soil bulk density of 1.82, 1.75, 1.51, and 1.45 Mg m-3 for the sandy loam, sandy clay loam, clayey, and very clayey soil.

  18. Dark goo: Bulk viscosity as an alternative to dark energy

    CERN Document Server

    Gagnon, Jean-Sebastien

    2011-01-01

    We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective" pressure containing the bulk viscosity. For a sufficiently large bulk viscosity, the effective pressure becomes negative and could mimic a dark energy equation of state. Our microscopic model includes self-interacting spin-zero particles (for which the bulk viscosity is known) that are added to the usual energy content of the universe. We study both background equations and linear perturbations in this model. We show that a dark energy behavior is obtained for reasonable values of the two parameters of the model (i.e. the mass and coupling of the spin-zero particles) and that linear perturbations are well-behaved. There is no apparent fine tuning involved. We also discuss the conditions under which hydrodynamics holds, in particular that the spin-zero particles must be in local eq...

  19. Thermoplastic Micro-Forming of Bulk Metallic Glasses: A Review

    Science.gov (United States)

    Li, Ning; Chen, Wen; Liu, Lin

    2016-04-01

    Bulk metallic glasses are a fascinating class of metallic alloys with an isotropic amorphous structure that is rapidly quenched from liquid melts. The absence of a crystalline micro-structure endows them with a portfolio of properties such as high strength, high elasticity, and excellent corrosion resistance. Whereas the limited plasticity and hence poor workability at ambient temperature impede the structural application of bulk metallic glasses, the unique superplasticity within the supercooled liquid region opens an alternative window of so-called thermoplastic forming, which allows precise and versatile net-shaping of complex geometries on length scales ranging from nanometers to centimeters that were previously unachievable with conventional crystalline metal processing. Thermoplastic forming not only breaks through the bottleneck of the manufacture of bulk metallic glasses at ambient temperature but also offers an alluring prospect in micro-engineering applications. This paper comprehensively reviews some pivotal aspects of bulk metallic glasses during thermoplastic micro-forming, including an in-depth understanding of the crystallization kinetics of bulk metallic glasses and the thermoplastic processing time window, the thermoplastic forming map that clarifies the relationship between the flow characteristics and the formability, the interfacial friction in micro-forming and novel forming methods to improve the formability, and the potential applications of the hot-embossed micro-patterns/components.

  20. STUDY ON BIODEGRADATION TECHNOLOGY APPLICATION IN BULK IN THE REMEDIATION OF SOILS CONTAMINATED WITH POLYCYCLIC AROMATIC HYDROCARBONS

    Directory of Open Access Journals (Sweden)

    Irina Ramona PECINGINĂ

    2015-05-01

    Full Text Available Biodecontaminare methods are based on biodegradation in the subsurface presence of microorganisms capable of degrading most of carbonaceous organic pollutants and much of inorganic pollutants. Biodegradation in bulk meet that principle biological decontamination several ways. These methods are intended solely for solids, and is often used for on-site remediation of soils contaminated with organic products. Station bioremediation ensure reducing the harmfulness of residues from oil exploitation activities considered hazardous, using a bioremediation process. Bioremediation process will lead to reduction of oil content and thus reducing the hazard of waste.

  1. Solid/liquid interfacial free energies in binary systems

    Science.gov (United States)

    Nason, D.; Tiller, W. A.

    1973-01-01

    Description of a semiquantitative technique for predicting the segregation characteristics of smooth interfaces between binary solid and liquid solutions in terms of readily available thermodynamic parameters of the bulk solutions. A lattice-liquid interfacial model and a pair-bonded regular solution model are employed in the treatment with an accommodation for liquid interfacial entropy. The method is used to calculate the interfacial segregation and the free energy of segregation for solid-liquid interfaces between binary solutions for the (111) boundary of fcc crystals. The zone of compositional transition across the interface is shown to be on the order of a few atomic layers in width, being moderately narrower for ideal solutions. The free energy of the segregated interface depends primarily upon the solid composition and the heats of fusion of the component atoms, the composition difference of the solutions, and the difference of the heats of mixing of the solutions.

  2. Roles of Bulk and Surface Chemistry in the Oxygen Exchange Kinetics and Related Properties of Mixed Conducting Perovskite Oxide Electrodes

    Directory of Open Access Journals (Sweden)

    Nicola H. Perry

    2016-10-01

    Full Text Available Mixed conducting perovskite oxides and related structures serving as electrodes for electrochemical oxygen incorporation and evolution in solid oxide fuel and electrolysis cells, respectively, play a significant role in determining the cell efficiency and lifetime. Desired improvements in catalytic activity for rapid surface oxygen exchange, fast bulk transport (electronic and ionic, and thermo-chemo-mechanical stability of oxygen electrodes will require increased understanding of the impact of both bulk and surface chemistry on these properties. This review highlights selected work at the International Institute for Carbon-Neutral Energy Research (I2CNER, Kyushu University, set in the context of work in the broader community, aiming to characterize and understand relationships between bulk and surface composition and oxygen electrode performance. Insights into aspects of bulk point defect chemistry, electronic structure, crystal structure, and cation choice that impact carrier concentrations and mobilities, surface exchange kinetics, and chemical expansion coefficients are emerging. At the same time, an understanding of the relationship between bulk and surface chemistry is being developed that may assist design of electrodes with more robust surface chemistries, e.g., impurity tolerance or limited surface segregation. Ion scattering techniques (e.g., secondary ion mass spectrometry, SIMS, or low energy ion scattering spectroscopy, LEIS with high surface sensitivity and increasing lateral resolution are proving useful for measuring surface exchange kinetics, diffusivity, and corresponding outer monolayer chemistry of electrodes exposed to typical operating conditions. Beyond consideration of chemical composition, the use of strain and/or a high density of active interfaces also show promise for enhancing performance.

  3. Quantum-Confined and Enhanced Optical Absorption of Colloidal PbS Quantum Dots at Wavelengths with Expected Bulk Behavior.

    Science.gov (United States)

    Debellis, Doriana; Gigli, Giuseppe; Ten Brinck, Stephanie; Infante, Ivan; Giansante, Carlo

    2017-02-08

    Nowadays it is well-accepted to attribute bulk-like optical absorption properties to colloidal PbS quantum dots (QDs) at wavelengths above 400 nm. This assumption permits to describe PbS QD light absorption by using bulk optical constants and to determine QD concentration in colloidal solutions from simple spectrophotometric measurements. Here we demonstrate that PbS QDs experience the quantum confinement regime across the entire near UV-vis-NIR spectral range, therefore also between 350 and 400 nm already proposed to be sufficiently far above the band gap to suppress quantum confinement. This effect is particularly relevant for small PbS QDs (with diameter of ≤4 nm) leading to absorption coefficients that largely differ from bulk values (up to ∼40% less). As a result of the broadband quantum confinement and of the high surface-to-volume ratio peculiar of nanocrystals, suitable surface chemical modification of PbS QDs is exploited to achieve a marked, size-dependent enhancement of the absorption coefficients compared to bulk values (up to ∼250%). We provide empirical relations to determine the absorption coefficients at 400 nm of as-synthesized and ligand-exchanged PbS QDs, accounting for the broadband quantum confinement and suggesting a heuristic approach to qualitatively predict the ligand effects on the optical absorption properties of PbS QDs. Our findings go beyond formalisms derived from Maxwell Garnett effective medium theory to describe QD optical properties and permit to spectrophotometrically calculate the concentration of PbS QD solutions avoiding underestimation due to deviations from the bulk. In perspective, we envisage the use of extended π-conjugated ligands bearing electronically active substituents to enhance light-harvesting in QD solids and suggest the inadequacy of the representation of ligands at the QD surface as mere electric dipoles.

  4. Simulation of radiation dose distribution and thermal analysis for the bulk shielding of an optimized molten salt reactor

    Institute of Scientific and Technical Information of China (English)

    张志宏; 夏晓彬; 蔡军; 王建华; 李长园; 葛良全; 张庆贤

    2015-01-01

    The Chinese Academy of Science has launched a thorium-based molten-salt reactor (TMSR) research project with a mission to research and develop a fission energy system of the fourth generation. The TMSR project intends to construct a liquid fuel molten-salt reactor (TMSR-LF), which uses fluoride salt as both the fuel and coolant, and a solid fuel molten-salt reactor (TMSR-SF), which uses fluoride salt as coolant and TRISO fuel. An optimized 2 MWth TMSR-LF has been designed to solve major technological challenges in the Th-U fuel cycle. Preliminary conceptual shielding design has also been performed to develop bulk shielding. In this study, the radiation dose and temperature distribution of the shielding bulk due to the core were simulated and analyzed by performing Monte Carlo simulations and computational fluid dynamics (CFD) analysis. The MCNP calculated dose rate and neutron and gamma spectra indicate that the total dose rate due to the core at the external surface of the concrete wall was 1.91 µSv/h in the radial direction, 1.16 µSv/h above and 1.33 µSv/h below the bulk shielding. All the radiation dose rates due to the core were below the design criteria. Thermal analysis results show that the temperature at the outermost surface of the bulk shielding was 333.86 K, which was below the required limit value. The results indicate that the designed bulk shielding satisfies the radiation shielding requirements for the 2 MWth TMSR-LF.

  5. Magnetic characterisation of large grain, bulk Y-Ba-Cu-O superconductor-soft ferromagnetic alloy hybrid structures

    Science.gov (United States)

    Philippe, M. P.; Fagnard, J.-F.; Kirsch, S.; Xu, Z.; Dennis, A. R.; Shi, Y.-H.; Cardwell, D. A.; Vanderheyden, B.; Vanderbemden, P.

    2014-07-01

    Large grain, bulk Y-Ba-Cu-O (YBCO) high temperature superconductors (HTS) have significant potential for use in a variety of practical applications that incorporate powerful quasi-permanent magnets. In the present work, we investigate how the trapped field of such magnets can be improved by combining bulk YBCO with a soft FeNi, ferromagnetic alloy. This involves machining the alloy into components of various shapes, such as cylinders and rings, which are attached subsequently to the top surface of a solid, bulk HTS cylinder. The effect of these modifications on the magnetic hysteresis curve and trapped field of the bulk superconductor at 77 K are then studied using pick-up coil and Hall probe measurements. The experimental data are compared to finite element modelling of the magnetic flux distribution using Campbell’s algorithm. Initially we establish the validity of the technique involving pick-up coils wrapped around the bulk superconductor to obtain its magnetic hysteresis curve in a non-destructive way and highlight the difference between the measured signal and the true magnetization of the sample. We then consider the properties of hybrid ferromagnet/superconductor (F/S) structures. Hall probe measurements, together with the results of the model, establish that flux lines curve outwards through the ferromagnet, which acts, effectively, like a magnetic short circuit. Magnetic hysteresis curves show that the effects of the superconductor and the ferromagnet simply add when the ferromagnet is saturated fully by the applied field. The trapped field of the hybrid structure is always larger than that of the superconductor alone below this saturation level, and especially when the applied field is removed. The results of the study show further that the beneficial effects on the trapped field are enhanced when the ferromagnet covers the entire surface of the superconductor for different ferromagnetic components of various shapes and fixed volume.

  6. EBSD analysis of MgB2 bulk superconductors

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  7. Theoretical expectations for bulk flows in large scale surveys

    CERN Document Server

    Feldman, H A; Hume A Feldman; Richard Watkins

    1993-01-01

    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 consider the power spectrum calculated from the IRAS-QDOT survey, as well as spectra from hot + cold and standard cold dark matter models. We find that sparse sampling and clustering can lead to an unexpectedly large bulk flow, even in a very deep survey. Our results suggest that the expected bulk motion is inconsistent with that reported by Lauer and Postman at the 90-94% confidence level.

  8. 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.

  9. Confined linear carbon chains as a route to bulk carbyne

    Science.gov (United States)

    Shi, Lei; Rohringer, Philip; Suenaga, Kazu; Niimi, Yoshiko; Kotakoski, Jani; Meyer, Jannik C.; Peterlik, Herwig; Wanko, Marius; Cahangirov, Seymur; Rubio, Angel; Lapin, Zachary J.; Novotny, Lukas; Ayala, Paola; Pichler, Thomas

    2016-06-01

    Strong chemical activity and extreme instability in ambient conditions characterize carbyne, an infinite sp1 hybridized carbon chain. As a result, much less has been explored about carbyne as compared to other carbon allotropes such as fullerenes, nanotubes and graphene. Although end-capping groups can be used to stabilize carbon chains, length limitations are still a barrier for production, and even more so for application. We report a method for the bulk production of long acetylenic linear carbon chains protected by thin double-walled carbon nanotubes. The synthesis of very long arrangements is confirmed by a combination of transmission electron microscopy, X-ray diffraction and (near-field) resonance Raman spectroscopy. Our results establish a route for the bulk production of exceptionally long and stable chains composed of more than 6,000 carbon atoms, representing an elegant forerunner towards the final goal of carbyne’s bulk production.

  10. Spherically symmetric brane spacetime with bulk f(R) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Sumanta [IUCAA, Ganeshkhind, Pune University Campus, Post Bag 4, Pune (India); SenGupta, Soumitra [Indian Association for the Cultivation of Science, Department of Theoretical Physics, Kolkata (India)

    2015-01-01

    Introducing f(R) term in the five-dimensional bulk action we derive effective Einstein's equation on the brane using Gauss-Codazzi equation. This effective equation is then solved for different conditions on dark radiation and dark pressure to obtain various spherically symmetric solutions. Some of these static spherically symmetric solutions correspond to black hole solutions, with parameters induced from the bulk. Specially, the dark pressure and dark radiation terms (electric part of Weyl curvature) affect the brane spherically symmetric solutions significantly. We have solved for one parameter group of conformal motions where the dark radiation and dark pressure terms are exactly obtained exploiting the corresponding Lie symmetry. Various thermodynamic features of these spherically symmetric space-times are studied, showing existence of second order phase transition. This phenomenon has its origin in the higher curvature term with f(R) gravity in the bulk. (orig.)

  11. Bulk Locality from Entanglement in Gauge/Gravity Duality

    CERN Document Server

    Lin, Jennifer

    2015-01-01

    Gauge/gravity duality posits an equivalence between certain strongly coupled quantum field theories and theories of gravity with negative cosmological constant in a higher number of spacetime dimensions. The map between the degrees of freedom on the two sides is non-local and incompletely understood. I describe recent work towards characterizing this map using entanglement in the QFT, where near the dual AdS boundary, the classical energy density at a point in the bulk is stored in the relative entropies of boundary subregions whose homologous minimal surfaces pass through the bulk point. I also derive bulk classical energy conditions near the AdS boundary from entanglement inequalities in the CFT. This is based on the paper [1] with Matilde Marcolli, Hirosi Ooguri and Bogdan Stoica. More generally, in recent years, there has appeared some evidence that quantum entanglement is responsible for the emergence of spacetime. I review and comment on the state of these developments.

  12. Composite superconducting bulks for efficient heat dissipation during pulse magnetization

    Science.gov (United States)

    Baskys, A.; Patel, A.; Hopkins, S.; Kenfaui, D.; Chaud, X.; Zhang, M.; Glowacki, B. A.

    2014-05-01

    Pulsed field magnetization is the most practical method of magnetizing a (RE)BCO bulk, however large heat generation limits the trapped field to significantly less than possible using field cooling. Modelling has been used to show that effective heat removal from the bulk interior, using embedded metallic structures, can enhance trapped field by increasing thermal stability. The reported results are for experimental pulsed magnetization of a thin walled YBCO sample with 55 vertical holes embedded with high thermal conductivity wires. A specially designed copper coldhead was used to increase the trapped field and flux of the perforated YBCO by about 12% at 35 K using a multi-pulse magnetization. Moreover, by filling the perforations with copper, the central trapped field was enhanced by 15% after a single-pulse at 35 K. 3D FEM computer model of a perforated YBCO bulk was also developed showing localised heating effects around the perforations during pulse magnetisation.

  13. Bulk fabrication and properties of solar grade silicon microwires

    Directory of Open Access Journals (Sweden)

    F. A. Martinsen

    2014-11-01

    Full Text Available We demonstrate a substrate-free novel route for fabrication of solar grade silicon microwires for photovoltaic applications. The microwires are fabricated from low purity starting material via a bulk molten-core fibre drawing method. In-situ segregation of impurities during the directional solidification of the fibres yields solar grade silicon cores (microwires where the concentration of electrically detrimental transition metals has been reduced between one and two orders of magnitude. The microwires show bulk minority carrier diffusion lengths measuring ∼40 μm, and mobilities comparable to those of single-crystal silicon. Microwires passivated with amorphous silicon yield diffusion lengths comparable to those in the bulk.

  14. Phantom dark energy as an effect of bulk viscosity

    CERN Document Server

    Velten, Hermano; Meng, Xinhe

    2013-01-01

    In a homogeneous and isotropic universe bulk viscosity is the unique viscous effect capable to modify the background dynamics. Effects like shear viscosity or heat conduction can only change the evolution of the perturbations. The existence of a bulk viscous pressure in a fluid, which in order to obey to the second law of thermodynamics is negative, reduces its effective pressure. We discuss in this study the degeneracy in bulk viscous cosmologies and address the possibility that phantom dark energy cosmology could be caused by the existence of non-equilibrium pressure in any cosmic component. We establish the conditions under which either matter or radiation viscous cosmologies can be mapped into the phantom dark energy scenario with constraints from multiple observational data-sets

  15. Preparation of bulk superhard B-C-N nanocomposite compact

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yusheng (Los Alamos, NM); He, Duanwei (Sichuan, CN)

    2011-05-10

    Bulk, superhard, B--C--N nanocomposite compacts were prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture at a pressure in a range of from about 15 GPa to about 25 GPa, and sintering the pressurized encapsulated ball-milled mixture at a temperature in a range of from about 1800-2500 K. The product bulk, superhard, nanocomposite compacts were well sintered compacts with nanocrystalline grains of at least one high-pressure phase of B--C--N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compacts had a measured Vicker's hardness in a range of from about 41 GPa to about 68 GPa.

  16. 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.

  17. Retrieving HapMap Data via Bulk Download.

    Science.gov (United States)

    Smith, Albert Vernon

    2008-07-01

    INTRODUCTIONThe primary goal of the International Haplotype Map Project has been to develop a haplotype map of the human genome that describes the common patterns of genetic variation, in order to accelerate the search for the genetic causes of human disease. Within the project, ~3.9 million distinct single-nucleotide polymorphisms (SNPs) have been genotyped in 270 individuals from four worldwide populations. The project data are available for unrestricted public use at the HapMap Web site. This site, which is the primary portal to genotype data produced by the project, offers bulk downloads of the data set, as well as interactive data browsing and analysis tools that are not available elsewhere. Bulk downloads of chromosome- or genome-wide data provide text dumps of the entire HapMap data set. Although complete, such downloads do not provide any filtering or selection services. This protocol describes the retrieval of HapMap data via bulk download.

  18. Structure-Property Relationships of Solids in Pharmaceutical Processing

    Science.gov (United States)

    Chattoraj, Sayantan

    Pharmaceutical development and manufacturing of solid dosage forms is witnessing a seismic shift in the recent years. In contrast to the earlier days when drug development was empirical, now there is a significant emphasis on a more scientific and structured development process, primarily driven by the Quality-by-Design (QbD) initiatives of US Food and Drug Administration (US-FDA). Central to such an approach is the enhanced understanding of solid materials using the concept of Materials Science Tetrahedron (MST) that probes the interplay between four elements, viz., the structure, properties, processing, and performance of materials. In this thesis work, we have investigated the relationships between the structure and those properties of pharmaceutical solids that influence their processing behavior. In all cases, we have used material-sparing approaches to facilitate property assessment using very small sample size of materials, which is a pre-requisite in the early stages of drug development when the availability of materials, drugs in particular, is limited. The influence of solid structure, either at the molecular or bulk powder levels, on crystal plasticity and powder compaction, powder flow, and solid-state amorphization during milling, has been investigated in this study. Through such a systematic evaluation, we have captured the involvement of structure-property correlations within a wide spectrum of relevant processing behaviors of pharmaceutical solids. Such a holistic analysis will be beneficial for addressing both regulatory and scientific issues in drug development.

  19. Ion conduction in crystalline superionic solids and its applications

    Science.gov (United States)

    Chandra, Angesh

    2014-06-01

    Superionic solids an area of multidisciplinary research activity, incorporates to study the physical, chemical and technological aspects of rapid ion movements within the bulk of the special class of ionic materials. It is an emerging area of materials science, as these solids show tremendous technological scopes to develop wide variety of solid state electrochemical devices such as batteries, fuel cells, supercapacitors, sensors, electrochromic displays (ECDs), memories, etc. These devices have wide range of applicabilities viz. power sources for IC microchips to transport vehicles, novel sensors for controlling atmospheric pollution, new kind of memories for computers, smart windows/display panels, etc. The field grew with a rapid pace since then, especially with regards to designing new materials as well as to explore their device potentialities. Amongst the known superionic solids, fast Ag+ ion conducting crystalline solid electrolytes are attracted special attention due to their relatively higher room temperature conductivity as well as ease of materials handling/synthesis. Ion conduction in these electrolytes is very much interesting part of today. In the present review article, the ion conducting phenomenon and some device applications of crystalline/polycrystalline superionic solid electrolytes have been reviewed in brief. Synthesis and characterization tools have also been discussed in the present review article.

  20. Liquid alkali metals - Equation of state and reduced-pressure, bulk-modulus, sound-velocity, and specific-heat functions

    Science.gov (United States)

    Schlosser, Herbert; Ferrante, John

    1989-01-01

    The previous work of Schlosser and Ferrante (1988) on universality in solids is extended to the study of liquid metals. As in the case of solids, to a good approximation, in the absence of phase transitions, plots of the logarithm of the reduced-pressure function H, of the reduced-isothermal-bulk-modulus function b, and of the reduced-sound-velocity function v are all linear in 1-X. Finally, it is demonstrated that ln(Cp/C/v) is also linear in 1-X, where X = (V/V/0/)exp 1/3), and V(0) is the volume at zero pressure.

  1. Rare-gas liquids - Equation of state and reduced-pressure, reduced-bulk-modulus, and reduced-sound-velocity functions

    Science.gov (United States)

    Schlosser, Herbert

    1990-01-01

    This paper is concerned with verification of the applicability of the Vinet et al. (1987) universal equation of state to the liquid phase of the rare-gas elements under pressure. As previously observed in solids and liquids metals, to a good approximation, in the absence of phase transitions, plots of the logarithms of the reduced pressure function, of the reduced sound velocity, and of the reduced bulk modulus, are all linear functions of 1 - X over the entire experimental pressure range. The results obtained on the rare-gas liquids are comparable in accuracy to those obtained in previous work on solids and liquid metals.

  2. Size Dependence of a Temperature-Induced Solid-Solid Phase Transition in Copper(I) Sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Rivest, Jessy B; Fong, Lam-Kiu; Jain, Prashant K; Toney, Michael F; Alivisatos, A Paul

    2011-07-24

    Determination of the phase diagrams for the nanocrystalline forms of materials is crucial for our understanding of nanostructures and the design of functional materials using nanoscale building blocks. The ability to study such transformations in nanomaterials with controlled shape offers further insight into transition mechanisms and the influence of particular facets. Here we present an investigation of the size-dependent, temperature-induced solid-solid phase transition in copper sulfide nanorods from low- to high-chalcocite. We find the transition temperature to be substantially reduced, with the high chalcocite phase appearing in the smallest nanocrystals at temperatures so low that they are typical of photovoltaic operation. Size dependence in phase trans- formations suggests the possibility of accessing morphologies that are not found in bulk solids at ambient conditions. These other- wise-inaccessible crystal phases could enable higher-performing materials in a range of applications, including sensing, switching, lighting, and photovoltaics.

  3. The preliminary studies on preparation and characterization of bulk nanoporous zinc as a laser target candidate to generate soft x-ray

    Directory of Open Access Journals (Sweden)

    Mohd Lutfi Ahmad Shahar

    2012-12-01

    Full Text Available Bulk nanoporous metal has become a reliable source to replace liquid as source to generate EUV lithography which have debris problem to tackle. A solid yet low density porous material promised a low melting point and low plasma density. The plasma density of bulk nanoporous Sn and SnO2 profile plays a key role in the generation of 13.5 nm light for an extreme ultraviolet lithography (EUVL source from laser produced plasma (LPP. The success of this preparation method might solve problems related to EUV lithography, or even soft Xray (XUV lithography. In this paper, we present the preliminary result of preparing such ideal low density target in form of bulk metal porous.

  4. It's harder to splash on soft solids

    Science.gov (United States)

    Howison, Sam; Howland, Christopher; Antkowiak, Arnaud; Castrejon-Pita, Rafael; Oliver, James; Style, Robert; Castrejon-Pita, Alfonso

    2016-11-01

    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. By imaging ethanol drops impacting silicone gels of different stiffnesses we show that substrate stiffness also affects the splashing thresh- old. Splashing is reduced or even eliminated: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that this is due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Young's moduli prevention. Soft substrates also serve as a useful system for testing splash-formation theories and sheet-ejection mechanisms, as they allow the characteristics of ejection sheets to be controlled independently of the bulk impact dynamics of droplets. EPSRC (CJH), John Fell Oxford University Press (OUP) Research Fund (AACP and RWS), The Royal Society (AAC-P).

  5. Localized diffusive motion on two different time scales in solid alkane nanoparticles

    DEFF Research Database (Denmark)

    Wang, S. K.; Mamontov, E.; Bai, M.

    2010-01-01

    High-energy-resolution quasielastic neutron scattering on three complementary spectrometers has been used to investigate molecular diffusive motion in solid nano- to bulk-sized particles of the alkane n-C32H66. The crystalline-to-plastic and plastic-to-fluid phase transition temperatures are obse...

  6. Properties of Bulk Sintered Silver As a Function of Porosity

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL; Wang, Hsin [ORNL; Ferber, Mattison K [ORNL; Liang, Zhenxian [ORNL

    2012-06-01

    This report summarizes a study where various properties of bulk-sintered silver were investigated over a range of porosity. This work was conducted within the National Transportation Research Center's Power Device Packaging project that is part of the DOE Vehicle Technologies Advanced Power Electronics and Electric Motors Program. Sintered silver, as an interconnect material in power electronics, inherently has porosity in its produced structure because of the way it is made. Therefore, interest existed in this study to examine if that porosity affected electrical properties, thermal properties, and mechanical properties because any dependencies could affect the intended function (e.g., thermal transfer, mechanical stress relief, etc.) or reliability of that interconnect layer and alter how its performance is modeled. Disks of bulk-sintered silver were fabricated using different starting silver pastes and different sintering conditions to promote different amounts of porosity. Test coupons were harvested out of the disks to measure electrical resistivity and electrical conductivity, thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and yield stress. The authors fully recognize that the microstructure of processed bulk silver coupons may indeed not be identical to the microstructure produced in thin (20-50 microns) layers of sintered silver. However, measuring these same properties with such a thin actual structure is very difficult, requires very specialized specimen preparation and unique testing instrumentation, is expensive, and has experimental shortfalls of its own, so the authors concluded that the herein measured responses using processed bulk sintered silver coupons would be sufficient to determine acceptable values of those properties. Almost all the investigated properties of bulk sintered silver changed with porosity content within a range of 3-38% porosity. Electrical resistivity, electrical conductivity

  7. Large-scale HTS bulks for magnetic application

    Energy Technology Data Exchange (ETDEWEB)

    Werfel, Frank N., E-mail: werfel@t-online.de [Adelwitz Technologiezentrum GmbH (ATZ), Rittergut Adelwitz 16, 04886 Arzberg-Adelwitz (Germany); Floegel-Delor, Uta; Riedel, Thomas; Goebel, Bernd; Rothfeld, Rolf; Schirrmeister, Peter; Wippich, Dieter [Adelwitz Technologiezentrum GmbH (ATZ), Rittergut Adelwitz 16, 04886 Arzberg-Adelwitz (Germany)

    2013-01-15

    Highlights: ► ATZ Company has constructed about 130 HTS magnet systems. ► Multi-seeded YBCO bulks joint the way for large-scale application. ► Levitation platforms demonstrate “superconductivity” to a great public audience (100 years anniversary). ► HTS magnetic bearings show forces up to 1 t. ► Modular HTS maglev vacuum cryostats are tested for train demonstrators in Brazil, China and Germany. -- Abstract: ATZ Company has constructed about 130 HTS magnet systems using high-Tc bulk magnets. A key feature in scaling-up is the fabrication of YBCO melts textured multi-seeded large bulks with three to eight seeds. Except of levitation, magnetization, trapped field and hysteresis, we review system engineering parameters of HTS magnetic linear and rotational bearings like compactness, cryogenics, power density, efficiency and robust construction. We examine mobile compact YBCO bulk magnet platforms cooled with LN{sub 2} and Stirling cryo-cooler for demonstrator use. Compact cryostats for Maglev train operation contain 24 pieces of 3-seed bulks and can levitate 2500–3000 N at 10 mm above a permanent magnet (PM) track. The effective magnetic distance of the thermally insulated bulks is 2 mm only; the stored 2.5 l LN{sub 2} allows more than 24 h operation without refilling. 34 HTS Maglev vacuum cryostats are manufactured tested and operate in Germany, China and Brazil. The magnetic levitation load to weight ratio is more than 15, and by group assembling the HTS cryostats under vehicles up to 5 t total loads levitated above a magnetic track is achieved.

  8. Analysis of physical demands during bulk bag closing and sealing.

    Science.gov (United States)

    Nasarwanji, Mahiyar F; Reardon, Leanna M; Heberger, John R; Dempsey, Patrick G

    2016-05-01

    Several tools are sold and recommended for closing and sealing flexible intermediate bulk containers (bulk bags) which are used to transport product that has been mined and processed. However, there is limited information on the risks, physical demands, or the benefits of using one tool over another. The purpose of this study was to evaluate the physical demands involved with two closing methods and several sealing tools in order to provide recommendations for selecting tools to reduce exposure to risk factors for work-related musculoskeletal disorders. In this study, twelve participants completed bag closing and sealing tasks using two different closing methods and eight sealing tools on two types of bulk bags. Physical demands and performance were evaluated using muscle activity, perceived exertion, subjective ratings of use, and time. Results indicate that using the "flowering" method to close bags required on average 32% less muscle activity, 30% less perceived exertion, 42% less time, and was preferred by participants compared to using the "snaking" method. For sealing, there was no single method significantly better across all measures; however, using a pneumatic cable tie gun consistently had the lowest muscle activity and perceived exertion ratings. The pneumatic cable tie gun did require approximately 33% more time to seal the bag compared to methods without a tool, but the amount of time to seal the bag was comparable to using other tools. Further, sealing a spout bulk bag required on average 13% less muscle activity, 18% less perceived exertion, 35% less time, and was preferred by participants compared to sealing a duffle bulk bag. The current results suggest that closing the spout bag using the flowering method and sealing the bag using the pneumatic cable tie gun that is installed with a tool balancer is ergonomically advantageous. Our findings can help organizations select methods and tools that pose the lowest physical demands when closing and

  9. ENERGETICS OF SOLID/SOLID AND LIQUID/SOLID INTERFACES

    Energy Technology Data Exchange (ETDEWEB)

    DR. PAUL WYNBLATT

    2004-10-13

    The main thrust of this research was to develop better understanding of the interfacial energetics of crystalline particles of one phase confined (or embedded) in matrices of another phase. Much of the work that motivated this research had been performed on Pb particles embedded in Al. Furthermore, significant contributions to that body of knowledge had emerged from collaborative work between Dr. U. Dahmen of the National Center for Electron Microscopy at LBNL and Prof. E. Johnson of the Neils Bohr Institute of the University of Copenhagen. Thus, the work performed under this Grant benefited from significant input into the design of the research from Dr. Dahmen and Prof. Johnson, who were officially listed as collaborators on the grant. Beyond interest in interfacial energies, there were several intriguing observations on Pb particles embedded in Al for which understanding was lacking. These included observations of large melting point elevation, or superheating, of embedded Pb particles. The melting temperature of these particles was found to increase with decreasing particle size, and to rise several tens of degrees above the bulk melting temperature for nano-scale particles. Since nucleation phenomena play an important role in melting and freezing, it was clear that the difficulties of interpreting superheating during melting could not readily be addressed without knowledge of the interfacial energies that enter into the formalism used to predict nucleation effects. The approaches taken in the studies included computer simulations, experimental studies and analytical modeling. Although about half of the work focused on Pb particles embedded in Al, other systems and issues were also addressed.

  10. Quantum Electronic Solids

    Science.gov (United States)

    2013-03-07

    Schuller, UCSD MURI Supersearch New Superconductors Discovered  Service to Others Phase Spread Alloys Bulk Synthesis • High-Pressure • High...DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution 13 Questions: Stress, Performance, Fabrication • Back gate (gold-palladium alloy ), PEN...substrate • Hafnium -oxide gate dielectric • CVD graphene transferred over gates 20 μm Source Gate Drain Drain x y Graphene Yields High

  11. Bulk single crystal growth of SiGe by PMCZ method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Weilian; NIU Xinhuan; CHEN Hongjian; ZHANG Jianxin; SUN Junsheng; ZHANG Enhuai

    2003-01-01

    A new type of magnetic device was used to replace the conventional electro-magnetic field for CZSi (doped with Ge) growth. The device was composed of three permanent magnetic rings and called PMCZ device. The lines of magnetic force are horizontally distributed at radial 360°. Using the ring permanent magnetic field, thermal convection in melt and centrifugal pumping flows due to crystal rotation could be strongly suppressed so that the fluctuations of temperature and micro-growth rate at solid/liquid interface could be restrained effectively. In the PMCZ condition, the growing environment of SiGe bulk single crystal was similar to the crystal growth in space under the condition of micro-gravity. The motion of impurities (Ge, oxygen, etc.) had been controlled by diffusion near the solid/liquid interface. Oxygen concentraion became lower and the distribution of composition became more homogeneous along longitudinal direction and across a radial section in the grown SiGe crystal. The mechanism of PMCZ superior to MCZ was also discussed.

  12. Correlation between structural, electrical and magnetic properties of GdMnO{sub 3} bulk ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Samantaray, S. [Institute of Materials Science, Planetarium Building, Bhubaneswar 751013, Odisha (India); Mishra, D.K. [Department of Physics, Institute of Technical Education and Research, S ‘O’ A University, Bhubaneswar 751030, Odisha (India); Pradhan, S.K. [Institute of Materials Science, Planetarium Building, Bhubaneswar 751013, Odisha (India); Mishra, P.; Sekhar, B.R. [Institue of Physics, Sachivalaya Marg, Bhubaneswar, Odisha (India); Behera, Debdhyan [Advanced Materials Technology Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar 751013, Odisha (India); Rout, P.P.; Das, S.K. [Institute of Materials Science, Planetarium Building, Bhubaneswar 751013, Odisha (India); Sahu, D.R. [School of Physics, University of the Witwatersrand, Johannesburg (South Africa); Roul, B.K., E-mail: ims@iopb.res.in [Institute of Materials Science, Planetarium Building, Bhubaneswar 751013, Odisha (India)

    2013-08-15

    This paper reports the effect of sintering temperature on ferroelectric properties of GdMnO{sub 3} (GMO) bulk ceramics at room temperature prepared by the conventional solid state reaction route following slow step sintering schedule. Ferroelectric hysteresis loop as well as sharp dielectric anomaly in pure (99.999%) GMO sintered ceramics has been clearly observed. Samples sintered at 1350 °C become orthorhombic with Pbnm space group and showed frequency independent sharp dielectric anomalies at 373 K and a square type of novel ferroelectric hysteresis loop was observed at room temperature. Interestingly, dielectric anomalies and ferroelectric behavior were observed to be dependent upon sintering temperature of GdMnO{sub 3}. Room temperature dielectric constant (ε{sub r}) value at different frequencies is observed to be abnormally high. The magnetic field and temperature dependent magnetization show antiferromagnetic behavior at 40 K for both 1350 °C and 1700 °C sintered GMO. Present findings showed the possibility of application of GdMnO{sub 3} at room temperature as multifunctional materials. - Highlights: • Preparation of single-phasic polycrystalline GdMnO{sub 3} sample by the solid state sintering route. • Observation of square type P–E hysteresis loop with higher saturation and remnant polarization. • Observation of antiferromagnetic behavior at 40 K in polycrystalline GdMnO{sub 3}. • Possibility of room temperature application of GdMnO{sub 3} as multifunctional material.

  13. Bianchi Type Ⅲ String Cosmological Model with Bulk Viscosity

    Institute of Scientific and Technical Information of China (English)

    WANGXing-Xiang

    2004-01-01

    The Bianchi type Ⅲ cosmological model for a cloud string with bulk viscosity are presented. To obtain a determinate model, an equation of state ρ=kλ and a relation between metric potentials B = Cn are assumed. The physical and geometric aspects of the model are also discussed. The model describes a shearing non-rotating continuously expanding universe with a big-bang start, and the relation between the coefficient of bulk viscosity and the energy density is ζ∝ρ1/2.

  14. Bianchi Type Ⅲ String Cosmological Model with Bulk Viscosity

    Institute of Scientific and Technical Information of China (English)

    WANG Xing-Xiang

    2004-01-01

    The Bianchi type Ⅲ cosmological model for a cloud string with bulk viscosity are presented. To obtaina determinate model, an equation of state p = κλ and a relation between metric potentials B = Cn are assumed. Thephysical and geometric aspects of the model are also discussed. The model describes a shearing non-rotating continuouslyexpanding universe with a big-bang start, and the relation between the coefficient of bulk viscosity and the energy densityis ζ∝1 p1/2.

  15. Enhancement of the Bulk Photovoltaic Effect in Topological Insulators

    Science.gov (United States)

    Tan, Liang Z.; Rappe, Andrew M.

    2016-06-01

    We investigate the shift current bulk photovoltaic response of materials close to a band inversion topological phase transition. We find that the bulk photocurrent reverses direction across the band inversion transition, and that its magnitude is enhanced in the vicinity of the phase transition. These results are demonstrated with first principles density functional theory calculations of BiTeI and CsPbI3 under hydrostatic pressure, and explained with an analytical model, suggesting that this phenomenon remains robust across disparate material systems.

  16. Investigations of waste heat recovery from bulk milk cooler

    OpenAIRE

    S.N. Sapali; S.M. Pise; A.T. Pise; D.V. Ghewade

    2014-01-01

    Bulk milk coolers are used to chill the milk from its harvest temperature of 35–4 °C to arrest the bacterial growth and maintain the quality of harvested milk. Milk chilling practices are energy intensive with low coefficient of performance (COP) of about 3.0. Increased energy cost concern encouraged an investigation of heat recovery from bulk milk cooler as one conservation alternative for reducing water heating cost in dairy industry. Heat dissipated to atmosphere through condenser is recov...

  17. Bulk Restoration for SDN-Based Transport Network

    Directory of Open Access Journals (Sweden)

    Yang Zhao

    2016-01-01

    Full Text Available We propose a bulk restoration scheme for software defined networking- (SDN- based transport network. To enhance the network survivability and improve the throughput, we allow disrupted flows to be recovered synchronously in dynamic order. In addition backup paths are scheduled globally by applying the principles of load balance. We model the bulk restoration problem using a mixed integer linear programming (MILP formulation. Then, a heuristic algorithm is devised. The proposed algorithm is verified by simulation and the results are analyzed comparing with sequential restoration schemes.

  18. Bulk saturable absorption in topological insulator thin films

    Science.gov (United States)

    Gopal, Radha Krishna; Ambast, Deepak K. S.; Singh, Sourabh; Sarkar, Jit; Pal, Bipul; Mitra, Chiranjib

    2017-07-01

    We present nonlinear optical absorption properties of pulsed laser deposited thin films of topological insulator (TI), Bi2Se3 on a quartz substrate, using an open aperture z-scan technique. We observed saturable absorption with a low saturation intensity in as deposited thin films. Past results from the literature are inconclusive in establishing whether the saturable absorption in TI is coming from surface states or the bulk. Specifically designed experiments with magnetically doped TI samples allow us to attribute the saturable absorption characteristic of TI to the bulk states. Detailed experimental procedures and possible explanation of observed results have been discussed.

  19. Reversible ultrafast melting in bulk CdSe

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenzhi [School of Electronic Engineering, Heilongjiang University, Harbin 150080 (China); Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); He, Feng; Wang, Yaguo, E-mail: yaguo.wang@austin.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); The Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-02-07

    In this work, transient reflectivity changes in bulk CdSe have been measured with two-color femtosecond pump-probe spectroscopy under a wide range of pump fluences. Three regions of reflectivity change with pump fluences have been consistently revealed for excited carrier density, coherent phonon amplitude, and lattice temperature. For laser fluences from 13 to 19.3 mJ/cm{sup 2}, ultrafast melting happens in first several picoseconds. This melting process is purely thermal and reversible. A complete phase transformation in bulk CdSe may be reached when the absorbed laser energy is localized long enough, as observed in nanocrystalline CdSe.

  20. 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.

  1. BRST Hamiltonian for Bulk-Quantized Gauge Theory

    CERN Document Server

    Rutenburg, A

    2003-01-01

    By treating the bulk-quantized Yang-Mills theory as a constrained system we obtain a consistent gauge-fixed BRST hamiltonian in the minimal sector. This provides an independent derivation of the 5-d lagrangian bulk action. The ground state is independent of the (anti)ghosts and is interpreted as the solution of the Fokker-Planck equation, thus establishing a direct connection to the Fokker-Planck hamiltonian. The vacuum state correlators are shown to be in agreement with correlators in lagrangian 5-d formulation. It is verified that the complete propagators remain parabolic in one-loop dimensional regularization.

  2. Thermal rectification in non-linear structures with bulk losses

    Science.gov (United States)

    Schmidt, Martin; Kottos, Tsampikos

    2013-03-01

    A mechanism for thermal rectification based on the interplay between non-uniform bulk losses with nonlinearity is presented. We theoretically analyze the phenomenon using an anharmonic array of coupled oscillators coupled to the left and right with two Langevin reservoirs. A third probe thermostat (with temperature TB) is placed in an asymmetric position in the bulk of the lattice thus breaking the translational symmetry and leading to rectification of heat flow. We note that for TB = 0 this Langevin term is equivalent to a simple friction. We find that an increase of the friction strength can increase both the asymmetry and heat flux. Visiting Student from Germany

  3. Cosmology with bulk viscosity and the gravitino problem

    CERN Document Server

    Buoninfante, L

    2016-01-01

    The gravitino problem is revisited in the framework of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. Dissipative effects (or bulk viscosity effects) arise owing to the different cooling rates of the fluid components. We show that the effects of the bulk viscosity allow to avoid the late abundance of gravitinos. In particular, we found that for a particular choice of the parameters characterizing the cosmological model, the gravitino abundance turns out to be independent on the reheating temperature.

  4. Advanced and new developments in bulk metal forming

    DEFF Research Database (Denmark)

    Bay, Niels; Wanheim, Tarras; Ravn, Bjarne Gottlieb

    2000-01-01

    Increasing demands to manufacturing industry of faster, better and cheaper production has intensified the research and development of bulk metal forming. The present paper gives examples on European industrial research on secondary bulk metal forming processes. The R&D follows three lines...... of approach, 1. the classical process development, 2. development of physical as well as numerical modelling techniques and 3. the thematic approach, where integrated analysis of the interactions between workpiece, tool and press are now possible with objectives like prediction of workpiece defects...

  5. Enhancement of the Bulk Photovoltaic Effect in Topological Insulators.

    Science.gov (United States)

    Tan, Liang Z; Rappe, Andrew M

    2016-06-10

    We investigate the shift current bulk photovoltaic response of materials close to a band inversion topological phase transition. We find that the bulk photocurrent reverses direction across the band inversion transition, and that its magnitude is enhanced in the vicinity of the phase transition. These results are demonstrated with first principles density functional theory calculations of BiTeI and CsPbI_{3} under hydrostatic pressure, and explained with an analytical model, suggesting that this phenomenon remains robust across disparate material systems.

  6. An analytical protocol for the determination of total mercury concentrations in solid peat samples

    DEFF Research Database (Denmark)

    Roos-Barraclough, F; Givelet, N; Martinez-Cortizas, A

    2002-01-01

    and Pseudevernia furfuracea) are particularly efficient Hg retainers. The disproportionally high Hg concentrations in these species can cause considerable variation in Hg concentrations within a peat slice. The variation of water content (1.6% throughout 17-cm core, 0.97% in a 10 x 10 cm slice), bulk density (40...... AMA 254, capable of determining mercury concentrations in solid samples. Finally, an analytical protocol for the determination of Hg concentrations in solid peat samples is proposed. This method allows correction for variation in factors such as vegetation type, bulk density, water content and Hg...... concentration in individual peat slices. Several subsamples from each peat slice are air dried, combined and measured for Hg using the AMA254, using a program of 30 s (drying), 125 s (decomposition) and 45 s (waiting). Bulk density and water content measurements are performed on every slice using separate...

  7. Strong Evidence of Plasma-like Behavior for Ion-Solid Collisions

    CERN Document Server

    Sharma, Prashant

    2015-01-01

    Charge state distributions of various projectile ions passing through thin carbon foils have been studied in the energy range of 0.7-3.0 MeV/u using x-ray spectroscopy. This technique is found to be appropriate to segregate the charge state distribution in the bulk from that of the surface by measuring the charge changing phenomena right at the interaction zone i.e. at t=0. This observation has been confirmed by different theoretical approaches. Surprisingly, it is found that the charge state distribution measured in the bulk, exhibits Lorentzian profile which is an important characteristic of any plasma. The occurrence of such behaviour suggests that ion-solid collisions constitute tenuous plasma in the bulk of the solid target. Thus, this work is expected to have practical implications in various fields, in particular, plasma physics and astrophysics.

  8. Influence of liquid surface segregation on the pitting corrosion behavior of semi-solid metal high pressure die cast alloy F357

    CSIR Research Space (South Africa)

    Moller, H

    2009-01-01

    Full Text Available Semi-solid metal processing results in liquid segregation at the surface of the components. The pitting behaviour of this surface layer of semi-solid metal processed alloy F357 was compared with the centre (or bulk) of cast plates in 3.5% Na...

  9. Solid electrolytic fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Masayasu; Yamauchi, Yasuhiro; Kamisaka, Mitsuo; Notomi, Kei.

    1989-04-21

    Concerning a solid electrolytic fuel cell with a gas permeable substrate pipe, a fuel electrode installed on this substrate pipe and an air electrode which is laminated on this fuel electrode with the electrolyte in between, the existing fuel cell of this kind uses crystals of CaMnO3, etc. for the material of the air electrode, but its electric resistance is big and in order to avert this, it is necessary to make the film thickness of the air electrode big. However, in such a case, the entry of the air into its inside worsens and the cell performance cannot develop satisfactorily. In view of the above, in order to obtain a high performance solid electrolytic fuel cell which can improve electric conductivity without damaging diffusion rate of the air, this invention proposes with regard to the aforementioned solid electrolytic fuel cell to install a heat resistant and conductive member inside the above air electrode. 6 figs.

  10. Nanoscale Phase Immiscibility in High-ZT Bulk Lead Telluride Thermoelectric Materials

    Science.gov (United States)

    Girard, Steven Neal

    Renewable energy initiatives have increased interest in thermoelectric materials as an option for inexpensive and environmentally friendly waste heat-to-power generation. Unfortunately, low efficiencies have limited their wide-scale utilization. This work describes the synthesis and characterization of bulk nanostructured thermoelectric materials wherein natural phase immiscibility is manipulated to selectively generate nanoscale inclusions of a second phase that improve their efficiency through reductions in lattice thermal conductivity. The PbTe-PbS system exhibits natural phase separation by nucleation and growth or spinodal decomposition phase transformations depending on composition and temperature treatment. Through rapid quenching, nearly ideal solid solution alloys of PbTe-PbS are observed by powder X-ray diffraction. However, characterization by solid-state NMR and IR reflectivity show that solid solutions are obtained for rapidly quenched samples within the nucleation and growth region of the phase diagram, but samples within the spinodal decomposition region exhibit very slight phase immiscibility. We report the temperatures of phase separation using high temperature powder X-ray diffraction. Microscopy reveals that phase separation in PbTe-PbS naturally produces nanoinclusions. A decrease in lattice thermal conductivity is observed as a result of the solid solution-to-nanostructured phase transformation in this materials system, increasing thermoelectric figure of merit. Sn addition to PbTe-PbS produces a pseudobinary system of PbTe-PbSnS 2. This materials system produces microscale lamellae that effectively reduce lattice thermal conductivity. Unfortunately, the PbSnS2 inclusions also scatter electrons, reducing electrical conductivity and producing only a minimal increase in thermoelectric figure of merit. We additionally investigate PbSnS2 as prepared through Bridgman crystal growth. PbTe-PbS doped with Na appears to increase the kinetic rate of

  11. Solid phases of tenoxicam.

    Science.gov (United States)

    Cantera, Rodrigo G; Leza, María G; Bachiller, Carmen M

    2002-10-01

    In this report we describe the preparation and characterization of four polymorphic forms of tenoxicam; they are, three 1:1 stoichiometric solvates with acetonitrile, dioxane, and N,N-dimethylformamide, and an amorphous phase obtained by recrystallization in various solvents. Polymorph IV and solvates with dioxane and N,N-dimethylformamide are reported for the first time in this paper. In addition, three solvates were crystallized in acetone, ethyl acetate, and isopropyl alcohol. These solid forms were characterized by X-ray powder diffraction, differential scanning calorimetry, infrared spectroscopy, thermogravimetry, optical microscopy, and elemental analysis. Solid-state properties, intrinsic dissolution rate, and dissolution kinetics from formulated tablets are also provided.

  12. Photochemistry on solid surfaces

    CERN Document Server

    Matsuura, T

    1989-01-01

    The latest developments in photochemistry on solid surfaces, i.e. photochemistry in heterogeneous systems, including liquid crystallines, are brought together for the first time in a single volume. Distinguished photochemists from various fields have contributed to the book which covers a number of important applications: molecular photo-devices for super-memory, photochemical vapor deposition to produce thin-layered electronic semiconducting materials, sensitive optical media, the control of photochemical reactions pathways, etc. Photochemistry on solid surfaces is now a major field and this

  13. Optical properties of solids

    CERN Document Server

    Wooten, Frederick

    1972-01-01

    Optical Properties of Solids covers the important concepts of intrinsic optical properties and photoelectric emission. The book starts by providing an introduction to the fundamental optical spectra of solids. The text then discusses Maxwell's equations and the dielectric function; absorption and dispersion; and the theory of free-electron metals. The quantum mechanical theory of direct and indirect transitions between bands; the applications of dispersion relations; and the derivation of an expression for the dielectric function in the self-consistent field approximation are also encompassed.

  14. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  15. Solid state theory

    CERN Document Server

    Harrison, Walter A

    2011-01-01

    ""A well-written text . . . should find a wide readership, especially among graduate students."" - Dr. J. I. Pankove, RCA.The field of solid state theory, including crystallography, semi-conductor physics, and various applications in chemistry and electrical engineering, is highly relevant to many areas of modern science and industry. Professor Harrison's well-known text offers an excellent one-year graduate course in this active and important area of research. While presenting a broad overview of the fundamental concepts and methods of solid state physics, including the basic quantum theory o

  16. Hybrid elastic solids

    KAUST Repository

    Lai, Yun

    2011-06-26

    Metamaterials can exhibit electromagnetic and elastic characteristics beyond those found in nature. In this work, we present a design of elastic metamaterial that exhibits multiple resonances in its building blocks. Band structure calculations show two negative dispersion bands, of which one supports only compressional waves and thereby blurs the distinction between a fluid and a solid over a finite frequency regime, whereas the other displays super anisotropy-in which compressional waves and shear waves can propagate only along different directions. Such unusual characteristics, well explained by the effective medium theory, have no comparable analogue in conventional solids and may lead to novel applications. © 2011 Macmillan Publishers Limited. All rights reserved.

  17. Proton tunneling in solids

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, J.

    1998-10-01

    The tunneling rate of the proton and its isotopes between interstitial sites in solids is studied theoretically. The phonons and/or the electrons in the solid have two effects on the tunneling phenomenon. First, they suppress the transfer integral between two neighbouring states. Second, they give rise to a finite lifetime of the proton state. Usually the second effect is large and the tunneling probability per unit time (tunneling rate) can be defined. In some cases, however, a coherent tunneling is expected and actually observed. (author)

  18. Local Solid Shape

    Directory of Open Access Journals (Sweden)

    Jan Koenderink

    2015-10-01

    Full Text Available Local solid shape applies to the surface curvature of small surface patches—essentially regions of approximately constant curvatures—of volumetric objects that are smooth volumetric regions in Euclidean 3-space. This should be distinguished from local shape in pictorial space. The difference is categorical. Although local solid shape has naturally been explored in haptics, results in vision are not forthcoming. We describe a simple experiment in which observers judge shape quality and magnitude of cinematographic presentations. Without prior training, observers readily use continuous shape index and Casorati curvature scales with reasonable resolution.

  19. Solid State Research

    Science.gov (United States)

    2010-08-26

    width at half-maximum measured at 4 K of GalnAsSb layers grown on GaSb substrates. Solid circles this work; open squares from [9]; open triangle from...Rowe N. R. Newbury A. Sanchez-Rubio C. A. Primmerman Bermuda Grass Smut Spores WhitET 0 12 3 4 5 6 Ratio (PMT1 / PMT2) Figure 1-4...measured at 4 K of GalnAsSb layers grown on GaSb sub- strates. Solid circles this work; open squares from [9]; open triangle from [10]. [9],[10

  20. Reactions at Solid Surfaces

    CERN Document Server

    Ertl, Gerhard

    2009-01-01

    Expanding on the ideas first presented in Gerhard Ertl's acclaimed Baker Lectures at Cornell University, Reactions at Solid Surfaces comprises an authoritative, self-contained, book-length introduction to surface reactions for both professional chemists and students alike. Outlining our present understanding of the fundamental processes underlying reactions at solid surfaces, the book provides the reader with a complete view of how chemistry works at surfaces, and how to understand and probe the dynamics of surface reactions. Comparing traditional surface probes with more modern ones, and brin